1 /*- 2 * SPDX-License-Identifier: BSD-3-Clause 3 * 4 * Copyright (c) 1982, 1986, 1989, 1991, 1993 5 * The Regents of the University of California. All rights reserved. 6 * (c) UNIX System Laboratories, Inc. 7 * All or some portions of this file are derived from material licensed 8 * to the University of California by American Telephone and Telegraph 9 * Co. or Unix System Laboratories, Inc. and are reproduced herein with 10 * the permission of UNIX System Laboratories, Inc. 11 * 12 * Redistribution and use in source and binary forms, with or without 13 * modification, are permitted provided that the following conditions 14 * are met: 15 * 1. Redistributions of source code must retain the above copyright 16 * notice, this list of conditions and the following disclaimer. 17 * 2. Redistributions in binary form must reproduce the above copyright 18 * notice, this list of conditions and the following disclaimer in the 19 * documentation and/or other materials provided with the distribution. 20 * 3. Neither the name of the University nor the names of its contributors 21 * may be used to endorse or promote products derived from this software 22 * without specific prior written permission. 23 * 24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34 * SUCH DAMAGE. 35 * 36 * @(#)kern_descrip.c 8.6 (Berkeley) 4/19/94 37 */ 38 39 #include <sys/cdefs.h> 40 __FBSDID("$FreeBSD$"); 41 42 #include "opt_capsicum.h" 43 #include "opt_ddb.h" 44 #include "opt_ktrace.h" 45 46 #include <sys/param.h> 47 #include <sys/systm.h> 48 49 #include <sys/capsicum.h> 50 #include <sys/conf.h> 51 #include <sys/fcntl.h> 52 #include <sys/file.h> 53 #include <sys/filedesc.h> 54 #include <sys/filio.h> 55 #include <sys/jail.h> 56 #include <sys/kernel.h> 57 #include <sys/limits.h> 58 #include <sys/lock.h> 59 #include <sys/malloc.h> 60 #include <sys/mount.h> 61 #include <sys/mutex.h> 62 #include <sys/namei.h> 63 #include <sys/selinfo.h> 64 #include <sys/priv.h> 65 #include <sys/proc.h> 66 #include <sys/protosw.h> 67 #include <sys/racct.h> 68 #include <sys/resourcevar.h> 69 #include <sys/sbuf.h> 70 #include <sys/signalvar.h> 71 #include <sys/kdb.h> 72 #include <sys/smr.h> 73 #include <sys/stat.h> 74 #include <sys/sx.h> 75 #include <sys/syscallsubr.h> 76 #include <sys/sysctl.h> 77 #include <sys/sysproto.h> 78 #include <sys/unistd.h> 79 #include <sys/user.h> 80 #include <sys/vnode.h> 81 #ifdef KTRACE 82 #include <sys/ktrace.h> 83 #endif 84 85 #include <net/vnet.h> 86 87 #include <security/audit/audit.h> 88 89 #include <vm/uma.h> 90 #include <vm/vm.h> 91 92 #include <ddb/ddb.h> 93 94 static MALLOC_DEFINE(M_FILEDESC, "filedesc", "Open file descriptor table"); 95 static MALLOC_DEFINE(M_PWD, "pwd", "Descriptor table vnodes"); 96 static MALLOC_DEFINE(M_PWDDESC, "pwddesc", "Pwd descriptors"); 97 static MALLOC_DEFINE(M_FILEDESC_TO_LEADER, "filedesc_to_leader", 98 "file desc to leader structures"); 99 static MALLOC_DEFINE(M_SIGIO, "sigio", "sigio structures"); 100 MALLOC_DEFINE(M_FILECAPS, "filecaps", "descriptor capabilities"); 101 102 MALLOC_DECLARE(M_FADVISE); 103 104 static __read_mostly uma_zone_t file_zone; 105 static __read_mostly uma_zone_t filedesc0_zone; 106 __read_mostly uma_zone_t pwd_zone; 107 VFS_SMR_DECLARE; 108 109 static int closefp(struct filedesc *fdp, int fd, struct file *fp, 110 struct thread *td, bool holdleaders, bool audit); 111 static int fd_first_free(struct filedesc *fdp, int low, int size); 112 static void fdgrowtable(struct filedesc *fdp, int nfd); 113 static void fdgrowtable_exp(struct filedesc *fdp, int nfd); 114 static void fdunused(struct filedesc *fdp, int fd); 115 static void fdused(struct filedesc *fdp, int fd); 116 static int getmaxfd(struct thread *td); 117 static u_long *filecaps_copy_prep(const struct filecaps *src); 118 static void filecaps_copy_finish(const struct filecaps *src, 119 struct filecaps *dst, u_long *ioctls); 120 static u_long *filecaps_free_prep(struct filecaps *fcaps); 121 static void filecaps_free_finish(u_long *ioctls); 122 123 static struct pwd *pwd_alloc(void); 124 125 /* 126 * Each process has: 127 * 128 * - An array of open file descriptors (fd_ofiles) 129 * - An array of file flags (fd_ofileflags) 130 * - A bitmap recording which descriptors are in use (fd_map) 131 * 132 * A process starts out with NDFILE descriptors. The value of NDFILE has 133 * been selected based the historical limit of 20 open files, and an 134 * assumption that the majority of processes, especially short-lived 135 * processes like shells, will never need more. 136 * 137 * If this initial allocation is exhausted, a larger descriptor table and 138 * map are allocated dynamically, and the pointers in the process's struct 139 * filedesc are updated to point to those. This is repeated every time 140 * the process runs out of file descriptors (provided it hasn't hit its 141 * resource limit). 142 * 143 * Since threads may hold references to individual descriptor table 144 * entries, the tables are never freed. Instead, they are placed on a 145 * linked list and freed only when the struct filedesc is released. 146 */ 147 #define NDFILE 20 148 #define NDSLOTSIZE sizeof(NDSLOTTYPE) 149 #define NDENTRIES (NDSLOTSIZE * __CHAR_BIT) 150 #define NDSLOT(x) ((x) / NDENTRIES) 151 #define NDBIT(x) ((NDSLOTTYPE)1 << ((x) % NDENTRIES)) 152 #define NDSLOTS(x) (((x) + NDENTRIES - 1) / NDENTRIES) 153 154 /* 155 * SLIST entry used to keep track of ofiles which must be reclaimed when 156 * the process exits. 157 */ 158 struct freetable { 159 struct fdescenttbl *ft_table; 160 SLIST_ENTRY(freetable) ft_next; 161 }; 162 163 /* 164 * Initial allocation: a filedesc structure + the head of SLIST used to 165 * keep track of old ofiles + enough space for NDFILE descriptors. 166 */ 167 168 struct fdescenttbl0 { 169 int fdt_nfiles; 170 struct filedescent fdt_ofiles[NDFILE]; 171 }; 172 173 struct filedesc0 { 174 struct filedesc fd_fd; 175 SLIST_HEAD(, freetable) fd_free; 176 struct fdescenttbl0 fd_dfiles; 177 NDSLOTTYPE fd_dmap[NDSLOTS(NDFILE)]; 178 }; 179 180 /* 181 * Descriptor management. 182 */ 183 static int __exclusive_cache_line openfiles; /* actual number of open files */ 184 struct mtx sigio_lock; /* mtx to protect pointers to sigio */ 185 void __read_mostly (*mq_fdclose)(struct thread *td, int fd, struct file *fp); 186 187 /* 188 * If low >= size, just return low. Otherwise find the first zero bit in the 189 * given bitmap, starting at low and not exceeding size - 1. Return size if 190 * not found. 191 */ 192 static int 193 fd_first_free(struct filedesc *fdp, int low, int size) 194 { 195 NDSLOTTYPE *map = fdp->fd_map; 196 NDSLOTTYPE mask; 197 int off, maxoff; 198 199 if (low >= size) 200 return (low); 201 202 off = NDSLOT(low); 203 if (low % NDENTRIES) { 204 mask = ~(~(NDSLOTTYPE)0 >> (NDENTRIES - (low % NDENTRIES))); 205 if ((mask &= ~map[off]) != 0UL) 206 return (off * NDENTRIES + ffsl(mask) - 1); 207 ++off; 208 } 209 for (maxoff = NDSLOTS(size); off < maxoff; ++off) 210 if (map[off] != ~0UL) 211 return (off * NDENTRIES + ffsl(~map[off]) - 1); 212 return (size); 213 } 214 215 /* 216 * Find the last used fd. 217 * 218 * Call this variant if fdp can't be modified by anyone else (e.g, during exec). 219 * Otherwise use fdlastfile. 220 */ 221 int 222 fdlastfile_single(struct filedesc *fdp) 223 { 224 NDSLOTTYPE *map = fdp->fd_map; 225 int off, minoff; 226 227 off = NDSLOT(fdp->fd_nfiles - 1); 228 for (minoff = NDSLOT(0); off >= minoff; --off) 229 if (map[off] != 0) 230 return (off * NDENTRIES + flsl(map[off]) - 1); 231 return (-1); 232 } 233 234 int 235 fdlastfile(struct filedesc *fdp) 236 { 237 238 FILEDESC_LOCK_ASSERT(fdp); 239 return (fdlastfile_single(fdp)); 240 } 241 242 static int 243 fdisused(struct filedesc *fdp, int fd) 244 { 245 246 KASSERT(fd >= 0 && fd < fdp->fd_nfiles, 247 ("file descriptor %d out of range (0, %d)", fd, fdp->fd_nfiles)); 248 249 return ((fdp->fd_map[NDSLOT(fd)] & NDBIT(fd)) != 0); 250 } 251 252 /* 253 * Mark a file descriptor as used. 254 */ 255 static void 256 fdused_init(struct filedesc *fdp, int fd) 257 { 258 259 KASSERT(!fdisused(fdp, fd), ("fd=%d is already used", fd)); 260 261 fdp->fd_map[NDSLOT(fd)] |= NDBIT(fd); 262 } 263 264 static void 265 fdused(struct filedesc *fdp, int fd) 266 { 267 268 FILEDESC_XLOCK_ASSERT(fdp); 269 270 fdused_init(fdp, fd); 271 if (fd == fdp->fd_freefile) 272 fdp->fd_freefile++; 273 } 274 275 /* 276 * Mark a file descriptor as unused. 277 */ 278 static void 279 fdunused(struct filedesc *fdp, int fd) 280 { 281 282 FILEDESC_XLOCK_ASSERT(fdp); 283 284 KASSERT(fdisused(fdp, fd), ("fd=%d is already unused", fd)); 285 KASSERT(fdp->fd_ofiles[fd].fde_file == NULL, 286 ("fd=%d is still in use", fd)); 287 288 fdp->fd_map[NDSLOT(fd)] &= ~NDBIT(fd); 289 if (fd < fdp->fd_freefile) 290 fdp->fd_freefile = fd; 291 } 292 293 /* 294 * Free a file descriptor. 295 * 296 * Avoid some work if fdp is about to be destroyed. 297 */ 298 static inline void 299 fdefree_last(struct filedescent *fde) 300 { 301 302 filecaps_free(&fde->fde_caps); 303 } 304 305 static inline void 306 fdfree(struct filedesc *fdp, int fd) 307 { 308 struct filedescent *fde; 309 310 FILEDESC_XLOCK_ASSERT(fdp); 311 fde = &fdp->fd_ofiles[fd]; 312 #ifdef CAPABILITIES 313 seqc_write_begin(&fde->fde_seqc); 314 #endif 315 fde->fde_file = NULL; 316 #ifdef CAPABILITIES 317 seqc_write_end(&fde->fde_seqc); 318 #endif 319 fdefree_last(fde); 320 fdunused(fdp, fd); 321 } 322 323 /* 324 * System calls on descriptors. 325 */ 326 #ifndef _SYS_SYSPROTO_H_ 327 struct getdtablesize_args { 328 int dummy; 329 }; 330 #endif 331 /* ARGSUSED */ 332 int 333 sys_getdtablesize(struct thread *td, struct getdtablesize_args *uap) 334 { 335 #ifdef RACCT 336 uint64_t lim; 337 #endif 338 339 td->td_retval[0] = getmaxfd(td); 340 #ifdef RACCT 341 PROC_LOCK(td->td_proc); 342 lim = racct_get_limit(td->td_proc, RACCT_NOFILE); 343 PROC_UNLOCK(td->td_proc); 344 if (lim < td->td_retval[0]) 345 td->td_retval[0] = lim; 346 #endif 347 return (0); 348 } 349 350 /* 351 * Duplicate a file descriptor to a particular value. 352 * 353 * Note: keep in mind that a potential race condition exists when closing 354 * descriptors from a shared descriptor table (via rfork). 355 */ 356 #ifndef _SYS_SYSPROTO_H_ 357 struct dup2_args { 358 u_int from; 359 u_int to; 360 }; 361 #endif 362 /* ARGSUSED */ 363 int 364 sys_dup2(struct thread *td, struct dup2_args *uap) 365 { 366 367 return (kern_dup(td, FDDUP_FIXED, 0, (int)uap->from, (int)uap->to)); 368 } 369 370 /* 371 * Duplicate a file descriptor. 372 */ 373 #ifndef _SYS_SYSPROTO_H_ 374 struct dup_args { 375 u_int fd; 376 }; 377 #endif 378 /* ARGSUSED */ 379 int 380 sys_dup(struct thread *td, struct dup_args *uap) 381 { 382 383 return (kern_dup(td, FDDUP_NORMAL, 0, (int)uap->fd, 0)); 384 } 385 386 /* 387 * The file control system call. 388 */ 389 #ifndef _SYS_SYSPROTO_H_ 390 struct fcntl_args { 391 int fd; 392 int cmd; 393 long arg; 394 }; 395 #endif 396 /* ARGSUSED */ 397 int 398 sys_fcntl(struct thread *td, struct fcntl_args *uap) 399 { 400 401 return (kern_fcntl_freebsd(td, uap->fd, uap->cmd, uap->arg)); 402 } 403 404 int 405 kern_fcntl_freebsd(struct thread *td, int fd, int cmd, long arg) 406 { 407 struct flock fl; 408 struct __oflock ofl; 409 intptr_t arg1; 410 int error, newcmd; 411 412 error = 0; 413 newcmd = cmd; 414 switch (cmd) { 415 case F_OGETLK: 416 case F_OSETLK: 417 case F_OSETLKW: 418 /* 419 * Convert old flock structure to new. 420 */ 421 error = copyin((void *)(intptr_t)arg, &ofl, sizeof(ofl)); 422 fl.l_start = ofl.l_start; 423 fl.l_len = ofl.l_len; 424 fl.l_pid = ofl.l_pid; 425 fl.l_type = ofl.l_type; 426 fl.l_whence = ofl.l_whence; 427 fl.l_sysid = 0; 428 429 switch (cmd) { 430 case F_OGETLK: 431 newcmd = F_GETLK; 432 break; 433 case F_OSETLK: 434 newcmd = F_SETLK; 435 break; 436 case F_OSETLKW: 437 newcmd = F_SETLKW; 438 break; 439 } 440 arg1 = (intptr_t)&fl; 441 break; 442 case F_GETLK: 443 case F_SETLK: 444 case F_SETLKW: 445 case F_SETLK_REMOTE: 446 error = copyin((void *)(intptr_t)arg, &fl, sizeof(fl)); 447 arg1 = (intptr_t)&fl; 448 break; 449 default: 450 arg1 = arg; 451 break; 452 } 453 if (error) 454 return (error); 455 error = kern_fcntl(td, fd, newcmd, arg1); 456 if (error) 457 return (error); 458 if (cmd == F_OGETLK) { 459 ofl.l_start = fl.l_start; 460 ofl.l_len = fl.l_len; 461 ofl.l_pid = fl.l_pid; 462 ofl.l_type = fl.l_type; 463 ofl.l_whence = fl.l_whence; 464 error = copyout(&ofl, (void *)(intptr_t)arg, sizeof(ofl)); 465 } else if (cmd == F_GETLK) { 466 error = copyout(&fl, (void *)(intptr_t)arg, sizeof(fl)); 467 } 468 return (error); 469 } 470 471 int 472 kern_fcntl(struct thread *td, int fd, int cmd, intptr_t arg) 473 { 474 struct filedesc *fdp; 475 struct flock *flp; 476 struct file *fp, *fp2; 477 struct filedescent *fde; 478 struct proc *p; 479 struct vnode *vp; 480 struct mount *mp; 481 int error, flg, seals, tmp; 482 uint64_t bsize; 483 off_t foffset; 484 485 error = 0; 486 flg = F_POSIX; 487 p = td->td_proc; 488 fdp = p->p_fd; 489 490 AUDIT_ARG_FD(cmd); 491 AUDIT_ARG_CMD(cmd); 492 switch (cmd) { 493 case F_DUPFD: 494 tmp = arg; 495 error = kern_dup(td, FDDUP_FCNTL, 0, fd, tmp); 496 break; 497 498 case F_DUPFD_CLOEXEC: 499 tmp = arg; 500 error = kern_dup(td, FDDUP_FCNTL, FDDUP_FLAG_CLOEXEC, fd, tmp); 501 break; 502 503 case F_DUP2FD: 504 tmp = arg; 505 error = kern_dup(td, FDDUP_FIXED, 0, fd, tmp); 506 break; 507 508 case F_DUP2FD_CLOEXEC: 509 tmp = arg; 510 error = kern_dup(td, FDDUP_FIXED, FDDUP_FLAG_CLOEXEC, fd, tmp); 511 break; 512 513 case F_GETFD: 514 error = EBADF; 515 FILEDESC_SLOCK(fdp); 516 fde = fdeget_locked(fdp, fd); 517 if (fde != NULL) { 518 td->td_retval[0] = 519 (fde->fde_flags & UF_EXCLOSE) ? FD_CLOEXEC : 0; 520 error = 0; 521 } 522 FILEDESC_SUNLOCK(fdp); 523 break; 524 525 case F_SETFD: 526 error = EBADF; 527 FILEDESC_XLOCK(fdp); 528 fde = fdeget_locked(fdp, fd); 529 if (fde != NULL) { 530 fde->fde_flags = (fde->fde_flags & ~UF_EXCLOSE) | 531 (arg & FD_CLOEXEC ? UF_EXCLOSE : 0); 532 error = 0; 533 } 534 FILEDESC_XUNLOCK(fdp); 535 break; 536 537 case F_GETFL: 538 error = fget_fcntl(td, fd, &cap_fcntl_rights, F_GETFL, &fp); 539 if (error != 0) 540 break; 541 td->td_retval[0] = OFLAGS(fp->f_flag); 542 fdrop(fp, td); 543 break; 544 545 case F_SETFL: 546 error = fget_fcntl(td, fd, &cap_fcntl_rights, F_SETFL, &fp); 547 if (error != 0) 548 break; 549 do { 550 tmp = flg = fp->f_flag; 551 tmp &= ~FCNTLFLAGS; 552 tmp |= FFLAGS(arg & ~O_ACCMODE) & FCNTLFLAGS; 553 } while(atomic_cmpset_int(&fp->f_flag, flg, tmp) == 0); 554 tmp = fp->f_flag & FNONBLOCK; 555 error = fo_ioctl(fp, FIONBIO, &tmp, td->td_ucred, td); 556 if (error != 0) { 557 fdrop(fp, td); 558 break; 559 } 560 tmp = fp->f_flag & FASYNC; 561 error = fo_ioctl(fp, FIOASYNC, &tmp, td->td_ucred, td); 562 if (error == 0) { 563 fdrop(fp, td); 564 break; 565 } 566 atomic_clear_int(&fp->f_flag, FNONBLOCK); 567 tmp = 0; 568 (void)fo_ioctl(fp, FIONBIO, &tmp, td->td_ucred, td); 569 fdrop(fp, td); 570 break; 571 572 case F_GETOWN: 573 error = fget_fcntl(td, fd, &cap_fcntl_rights, F_GETOWN, &fp); 574 if (error != 0) 575 break; 576 error = fo_ioctl(fp, FIOGETOWN, &tmp, td->td_ucred, td); 577 if (error == 0) 578 td->td_retval[0] = tmp; 579 fdrop(fp, td); 580 break; 581 582 case F_SETOWN: 583 error = fget_fcntl(td, fd, &cap_fcntl_rights, F_SETOWN, &fp); 584 if (error != 0) 585 break; 586 tmp = arg; 587 error = fo_ioctl(fp, FIOSETOWN, &tmp, td->td_ucred, td); 588 fdrop(fp, td); 589 break; 590 591 case F_SETLK_REMOTE: 592 error = priv_check(td, PRIV_NFS_LOCKD); 593 if (error != 0) 594 return (error); 595 flg = F_REMOTE; 596 goto do_setlk; 597 598 case F_SETLKW: 599 flg |= F_WAIT; 600 /* FALLTHROUGH F_SETLK */ 601 602 case F_SETLK: 603 do_setlk: 604 flp = (struct flock *)arg; 605 if ((flg & F_REMOTE) != 0 && flp->l_sysid == 0) { 606 error = EINVAL; 607 break; 608 } 609 610 error = fget_unlocked(fdp, fd, &cap_flock_rights, &fp); 611 if (error != 0) 612 break; 613 if (fp->f_type != DTYPE_VNODE) { 614 error = EBADF; 615 fdrop(fp, td); 616 break; 617 } 618 619 if (flp->l_whence == SEEK_CUR) { 620 foffset = foffset_get(fp); 621 if (foffset < 0 || 622 (flp->l_start > 0 && 623 foffset > OFF_MAX - flp->l_start)) { 624 error = EOVERFLOW; 625 fdrop(fp, td); 626 break; 627 } 628 flp->l_start += foffset; 629 } 630 631 vp = fp->f_vnode; 632 switch (flp->l_type) { 633 case F_RDLCK: 634 if ((fp->f_flag & FREAD) == 0) { 635 error = EBADF; 636 break; 637 } 638 if ((p->p_leader->p_flag & P_ADVLOCK) == 0) { 639 PROC_LOCK(p->p_leader); 640 p->p_leader->p_flag |= P_ADVLOCK; 641 PROC_UNLOCK(p->p_leader); 642 } 643 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_SETLK, 644 flp, flg); 645 break; 646 case F_WRLCK: 647 if ((fp->f_flag & FWRITE) == 0) { 648 error = EBADF; 649 break; 650 } 651 if ((p->p_leader->p_flag & P_ADVLOCK) == 0) { 652 PROC_LOCK(p->p_leader); 653 p->p_leader->p_flag |= P_ADVLOCK; 654 PROC_UNLOCK(p->p_leader); 655 } 656 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_SETLK, 657 flp, flg); 658 break; 659 case F_UNLCK: 660 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_UNLCK, 661 flp, flg); 662 break; 663 case F_UNLCKSYS: 664 if (flg != F_REMOTE) { 665 error = EINVAL; 666 break; 667 } 668 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, 669 F_UNLCKSYS, flp, flg); 670 break; 671 default: 672 error = EINVAL; 673 break; 674 } 675 if (error != 0 || flp->l_type == F_UNLCK || 676 flp->l_type == F_UNLCKSYS) { 677 fdrop(fp, td); 678 break; 679 } 680 681 /* 682 * Check for a race with close. 683 * 684 * The vnode is now advisory locked (or unlocked, but this case 685 * is not really important) as the caller requested. 686 * We had to drop the filedesc lock, so we need to recheck if 687 * the descriptor is still valid, because if it was closed 688 * in the meantime we need to remove advisory lock from the 689 * vnode - close on any descriptor leading to an advisory 690 * locked vnode, removes that lock. 691 * We will return 0 on purpose in that case, as the result of 692 * successful advisory lock might have been externally visible 693 * already. This is fine - effectively we pretend to the caller 694 * that the closing thread was a bit slower and that the 695 * advisory lock succeeded before the close. 696 */ 697 error = fget_unlocked(fdp, fd, &cap_no_rights, &fp2); 698 if (error != 0) { 699 fdrop(fp, td); 700 break; 701 } 702 if (fp != fp2) { 703 flp->l_whence = SEEK_SET; 704 flp->l_start = 0; 705 flp->l_len = 0; 706 flp->l_type = F_UNLCK; 707 (void) VOP_ADVLOCK(vp, (caddr_t)p->p_leader, 708 F_UNLCK, flp, F_POSIX); 709 } 710 fdrop(fp, td); 711 fdrop(fp2, td); 712 break; 713 714 case F_GETLK: 715 error = fget_unlocked(fdp, fd, &cap_flock_rights, &fp); 716 if (error != 0) 717 break; 718 if (fp->f_type != DTYPE_VNODE) { 719 error = EBADF; 720 fdrop(fp, td); 721 break; 722 } 723 flp = (struct flock *)arg; 724 if (flp->l_type != F_RDLCK && flp->l_type != F_WRLCK && 725 flp->l_type != F_UNLCK) { 726 error = EINVAL; 727 fdrop(fp, td); 728 break; 729 } 730 if (flp->l_whence == SEEK_CUR) { 731 foffset = foffset_get(fp); 732 if ((flp->l_start > 0 && 733 foffset > OFF_MAX - flp->l_start) || 734 (flp->l_start < 0 && 735 foffset < OFF_MIN - flp->l_start)) { 736 error = EOVERFLOW; 737 fdrop(fp, td); 738 break; 739 } 740 flp->l_start += foffset; 741 } 742 vp = fp->f_vnode; 743 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_GETLK, flp, 744 F_POSIX); 745 fdrop(fp, td); 746 break; 747 748 case F_ADD_SEALS: 749 error = fget_unlocked(fdp, fd, &cap_no_rights, &fp); 750 if (error != 0) 751 break; 752 error = fo_add_seals(fp, arg); 753 fdrop(fp, td); 754 break; 755 756 case F_GET_SEALS: 757 error = fget_unlocked(fdp, fd, &cap_no_rights, &fp); 758 if (error != 0) 759 break; 760 if (fo_get_seals(fp, &seals) == 0) 761 td->td_retval[0] = seals; 762 else 763 error = EINVAL; 764 fdrop(fp, td); 765 break; 766 767 case F_RDAHEAD: 768 arg = arg ? 128 * 1024: 0; 769 /* FALLTHROUGH */ 770 case F_READAHEAD: 771 error = fget_unlocked(fdp, fd, &cap_no_rights, &fp); 772 if (error != 0) 773 break; 774 if (fp->f_type != DTYPE_VNODE) { 775 fdrop(fp, td); 776 error = EBADF; 777 break; 778 } 779 vp = fp->f_vnode; 780 if (vp->v_type != VREG) { 781 fdrop(fp, td); 782 error = ENOTTY; 783 break; 784 } 785 786 /* 787 * Exclusive lock synchronizes against f_seqcount reads and 788 * writes in sequential_heuristic(). 789 */ 790 error = vn_lock(vp, LK_EXCLUSIVE); 791 if (error != 0) { 792 fdrop(fp, td); 793 break; 794 } 795 if (arg >= 0) { 796 bsize = fp->f_vnode->v_mount->mnt_stat.f_iosize; 797 arg = MIN(arg, INT_MAX - bsize + 1); 798 fp->f_seqcount[UIO_READ] = MIN(IO_SEQMAX, 799 (arg + bsize - 1) / bsize); 800 atomic_set_int(&fp->f_flag, FRDAHEAD); 801 } else { 802 atomic_clear_int(&fp->f_flag, FRDAHEAD); 803 } 804 VOP_UNLOCK(vp); 805 fdrop(fp, td); 806 break; 807 808 case F_ISUNIONSTACK: 809 /* 810 * Check if the vnode is part of a union stack (either the 811 * "union" flag from mount(2) or unionfs). 812 * 813 * Prior to introduction of this op libc's readdir would call 814 * fstatfs(2), in effect unnecessarily copying kilobytes of 815 * data just to check fs name and a mount flag. 816 * 817 * Fixing the code to handle everything in the kernel instead 818 * is a non-trivial endeavor and has low priority, thus this 819 * horrible kludge facilitates the current behavior in a much 820 * cheaper manner until someone(tm) sorts this out. 821 */ 822 error = fget_unlocked(fdp, fd, &cap_no_rights, &fp); 823 if (error != 0) 824 break; 825 if (fp->f_type != DTYPE_VNODE) { 826 fdrop(fp, td); 827 error = EBADF; 828 break; 829 } 830 vp = fp->f_vnode; 831 /* 832 * Since we don't prevent dooming the vnode even non-null mp 833 * found can become immediately stale. This is tolerable since 834 * mount points are type-stable (providing safe memory access) 835 * and any vfs op on this vnode going forward will return an 836 * error (meaning return value in this case is meaningless). 837 */ 838 mp = atomic_load_ptr(&vp->v_mount); 839 if (__predict_false(mp == NULL)) { 840 fdrop(fp, td); 841 error = EBADF; 842 break; 843 } 844 td->td_retval[0] = 0; 845 if (mp->mnt_kern_flag & MNTK_UNIONFS || 846 mp->mnt_flag & MNT_UNION) 847 td->td_retval[0] = 1; 848 fdrop(fp, td); 849 break; 850 851 default: 852 error = EINVAL; 853 break; 854 } 855 return (error); 856 } 857 858 static int 859 getmaxfd(struct thread *td) 860 { 861 862 return (min((int)lim_cur(td, RLIMIT_NOFILE), maxfilesperproc)); 863 } 864 865 /* 866 * Common code for dup, dup2, fcntl(F_DUPFD) and fcntl(F_DUP2FD). 867 */ 868 int 869 kern_dup(struct thread *td, u_int mode, int flags, int old, int new) 870 { 871 struct filedesc *fdp; 872 struct filedescent *oldfde, *newfde; 873 struct proc *p; 874 struct file *delfp, *oldfp; 875 u_long *oioctls, *nioctls; 876 int error, maxfd; 877 878 p = td->td_proc; 879 fdp = p->p_fd; 880 oioctls = NULL; 881 882 MPASS((flags & ~(FDDUP_FLAG_CLOEXEC)) == 0); 883 MPASS(mode < FDDUP_LASTMODE); 884 885 AUDIT_ARG_FD(old); 886 /* XXXRW: if (flags & FDDUP_FIXED) AUDIT_ARG_FD2(new); */ 887 888 /* 889 * Verify we have a valid descriptor to dup from and possibly to 890 * dup to. Unlike dup() and dup2(), fcntl()'s F_DUPFD should 891 * return EINVAL when the new descriptor is out of bounds. 892 */ 893 if (old < 0) 894 return (EBADF); 895 if (new < 0) 896 return (mode == FDDUP_FCNTL ? EINVAL : EBADF); 897 maxfd = getmaxfd(td); 898 if (new >= maxfd) 899 return (mode == FDDUP_FCNTL ? EINVAL : EBADF); 900 901 error = EBADF; 902 FILEDESC_XLOCK(fdp); 903 if (fget_locked(fdp, old) == NULL) 904 goto unlock; 905 if ((mode == FDDUP_FIXED || mode == FDDUP_MUSTREPLACE) && old == new) { 906 td->td_retval[0] = new; 907 if (flags & FDDUP_FLAG_CLOEXEC) 908 fdp->fd_ofiles[new].fde_flags |= UF_EXCLOSE; 909 error = 0; 910 goto unlock; 911 } 912 913 oldfde = &fdp->fd_ofiles[old]; 914 oldfp = oldfde->fde_file; 915 if (!fhold(oldfp)) 916 goto unlock; 917 918 /* 919 * If the caller specified a file descriptor, make sure the file 920 * table is large enough to hold it, and grab it. Otherwise, just 921 * allocate a new descriptor the usual way. 922 */ 923 switch (mode) { 924 case FDDUP_NORMAL: 925 case FDDUP_FCNTL: 926 if ((error = fdalloc(td, new, &new)) != 0) { 927 fdrop(oldfp, td); 928 goto unlock; 929 } 930 break; 931 case FDDUP_MUSTREPLACE: 932 /* Target file descriptor must exist. */ 933 if (fget_locked(fdp, new) == NULL) { 934 fdrop(oldfp, td); 935 goto unlock; 936 } 937 break; 938 case FDDUP_FIXED: 939 if (new >= fdp->fd_nfiles) { 940 /* 941 * The resource limits are here instead of e.g. 942 * fdalloc(), because the file descriptor table may be 943 * shared between processes, so we can't really use 944 * racct_add()/racct_sub(). Instead of counting the 945 * number of actually allocated descriptors, just put 946 * the limit on the size of the file descriptor table. 947 */ 948 #ifdef RACCT 949 if (RACCT_ENABLED()) { 950 error = racct_set_unlocked(p, RACCT_NOFILE, new + 1); 951 if (error != 0) { 952 error = EMFILE; 953 fdrop(oldfp, td); 954 goto unlock; 955 } 956 } 957 #endif 958 fdgrowtable_exp(fdp, new + 1); 959 } 960 if (!fdisused(fdp, new)) 961 fdused(fdp, new); 962 break; 963 default: 964 KASSERT(0, ("%s unsupported mode %d", __func__, mode)); 965 } 966 967 KASSERT(old != new, ("new fd is same as old")); 968 969 /* Refetch oldfde because the table may have grown and old one freed. */ 970 oldfde = &fdp->fd_ofiles[old]; 971 KASSERT(oldfp == oldfde->fde_file, 972 ("fdt_ofiles shift from growth observed at fd %d", 973 old)); 974 975 newfde = &fdp->fd_ofiles[new]; 976 delfp = newfde->fde_file; 977 978 nioctls = filecaps_copy_prep(&oldfde->fde_caps); 979 980 /* 981 * Duplicate the source descriptor. 982 */ 983 #ifdef CAPABILITIES 984 seqc_write_begin(&newfde->fde_seqc); 985 #endif 986 oioctls = filecaps_free_prep(&newfde->fde_caps); 987 memcpy(newfde, oldfde, fde_change_size); 988 filecaps_copy_finish(&oldfde->fde_caps, &newfde->fde_caps, 989 nioctls); 990 if ((flags & FDDUP_FLAG_CLOEXEC) != 0) 991 newfde->fde_flags = oldfde->fde_flags | UF_EXCLOSE; 992 else 993 newfde->fde_flags = oldfde->fde_flags & ~UF_EXCLOSE; 994 #ifdef CAPABILITIES 995 seqc_write_end(&newfde->fde_seqc); 996 #endif 997 td->td_retval[0] = new; 998 999 error = 0; 1000 1001 if (delfp != NULL) { 1002 (void) closefp(fdp, new, delfp, td, true, false); 1003 FILEDESC_UNLOCK_ASSERT(fdp); 1004 } else { 1005 unlock: 1006 FILEDESC_XUNLOCK(fdp); 1007 } 1008 1009 filecaps_free_finish(oioctls); 1010 return (error); 1011 } 1012 1013 static void 1014 sigiofree(struct sigio *sigio) 1015 { 1016 crfree(sigio->sio_ucred); 1017 free(sigio, M_SIGIO); 1018 } 1019 1020 static struct sigio * 1021 funsetown_locked(struct sigio *sigio) 1022 { 1023 struct proc *p; 1024 struct pgrp *pg; 1025 1026 SIGIO_ASSERT_LOCKED(); 1027 1028 if (sigio == NULL) 1029 return (NULL); 1030 *(sigio->sio_myref) = NULL; 1031 if (sigio->sio_pgid < 0) { 1032 pg = sigio->sio_pgrp; 1033 PGRP_LOCK(pg); 1034 SLIST_REMOVE(&sigio->sio_pgrp->pg_sigiolst, sigio, 1035 sigio, sio_pgsigio); 1036 PGRP_UNLOCK(pg); 1037 } else { 1038 p = sigio->sio_proc; 1039 PROC_LOCK(p); 1040 SLIST_REMOVE(&sigio->sio_proc->p_sigiolst, sigio, 1041 sigio, sio_pgsigio); 1042 PROC_UNLOCK(p); 1043 } 1044 return (sigio); 1045 } 1046 1047 /* 1048 * If sigio is on the list associated with a process or process group, 1049 * disable signalling from the device, remove sigio from the list and 1050 * free sigio. 1051 */ 1052 void 1053 funsetown(struct sigio **sigiop) 1054 { 1055 struct sigio *sigio; 1056 1057 /* Racy check, consumers must provide synchronization. */ 1058 if (*sigiop == NULL) 1059 return; 1060 1061 SIGIO_LOCK(); 1062 sigio = funsetown_locked(*sigiop); 1063 SIGIO_UNLOCK(); 1064 if (sigio != NULL) 1065 sigiofree(sigio); 1066 } 1067 1068 /* 1069 * Free a list of sigio structures. The caller must ensure that new sigio 1070 * structures cannot be added after this point. For process groups this is 1071 * guaranteed using the proctree lock; for processes, the P_WEXIT flag serves 1072 * as an interlock. 1073 */ 1074 void 1075 funsetownlst(struct sigiolst *sigiolst) 1076 { 1077 struct proc *p; 1078 struct pgrp *pg; 1079 struct sigio *sigio, *tmp; 1080 1081 /* Racy check. */ 1082 sigio = SLIST_FIRST(sigiolst); 1083 if (sigio == NULL) 1084 return; 1085 1086 p = NULL; 1087 pg = NULL; 1088 1089 SIGIO_LOCK(); 1090 sigio = SLIST_FIRST(sigiolst); 1091 if (sigio == NULL) { 1092 SIGIO_UNLOCK(); 1093 return; 1094 } 1095 1096 /* 1097 * Every entry of the list should belong to a single proc or pgrp. 1098 */ 1099 if (sigio->sio_pgid < 0) { 1100 pg = sigio->sio_pgrp; 1101 sx_assert(&proctree_lock, SX_XLOCKED); 1102 PGRP_LOCK(pg); 1103 } else /* if (sigio->sio_pgid > 0) */ { 1104 p = sigio->sio_proc; 1105 PROC_LOCK(p); 1106 KASSERT((p->p_flag & P_WEXIT) != 0, 1107 ("%s: process %p is not exiting", __func__, p)); 1108 } 1109 1110 SLIST_FOREACH(sigio, sigiolst, sio_pgsigio) { 1111 *sigio->sio_myref = NULL; 1112 if (pg != NULL) { 1113 KASSERT(sigio->sio_pgid < 0, 1114 ("Proc sigio in pgrp sigio list")); 1115 KASSERT(sigio->sio_pgrp == pg, 1116 ("Bogus pgrp in sigio list")); 1117 } else /* if (p != NULL) */ { 1118 KASSERT(sigio->sio_pgid > 0, 1119 ("Pgrp sigio in proc sigio list")); 1120 KASSERT(sigio->sio_proc == p, 1121 ("Bogus proc in sigio list")); 1122 } 1123 } 1124 1125 if (pg != NULL) 1126 PGRP_UNLOCK(pg); 1127 else 1128 PROC_UNLOCK(p); 1129 SIGIO_UNLOCK(); 1130 1131 SLIST_FOREACH_SAFE(sigio, sigiolst, sio_pgsigio, tmp) 1132 sigiofree(sigio); 1133 } 1134 1135 /* 1136 * This is common code for FIOSETOWN ioctl called by fcntl(fd, F_SETOWN, arg). 1137 * 1138 * After permission checking, add a sigio structure to the sigio list for 1139 * the process or process group. 1140 */ 1141 int 1142 fsetown(pid_t pgid, struct sigio **sigiop) 1143 { 1144 struct proc *proc; 1145 struct pgrp *pgrp; 1146 struct sigio *osigio, *sigio; 1147 int ret; 1148 1149 if (pgid == 0) { 1150 funsetown(sigiop); 1151 return (0); 1152 } 1153 1154 ret = 0; 1155 1156 sigio = malloc(sizeof(struct sigio), M_SIGIO, M_WAITOK); 1157 sigio->sio_pgid = pgid; 1158 sigio->sio_ucred = crhold(curthread->td_ucred); 1159 sigio->sio_myref = sigiop; 1160 1161 sx_slock(&proctree_lock); 1162 SIGIO_LOCK(); 1163 osigio = funsetown_locked(*sigiop); 1164 if (pgid > 0) { 1165 proc = pfind(pgid); 1166 if (proc == NULL) { 1167 ret = ESRCH; 1168 goto fail; 1169 } 1170 1171 /* 1172 * Policy - Don't allow a process to FSETOWN a process 1173 * in another session. 1174 * 1175 * Remove this test to allow maximum flexibility or 1176 * restrict FSETOWN to the current process or process 1177 * group for maximum safety. 1178 */ 1179 if (proc->p_session != curthread->td_proc->p_session) { 1180 PROC_UNLOCK(proc); 1181 ret = EPERM; 1182 goto fail; 1183 } 1184 1185 sigio->sio_proc = proc; 1186 SLIST_INSERT_HEAD(&proc->p_sigiolst, sigio, sio_pgsigio); 1187 PROC_UNLOCK(proc); 1188 } else /* if (pgid < 0) */ { 1189 pgrp = pgfind(-pgid); 1190 if (pgrp == NULL) { 1191 ret = ESRCH; 1192 goto fail; 1193 } 1194 1195 /* 1196 * Policy - Don't allow a process to FSETOWN a process 1197 * in another session. 1198 * 1199 * Remove this test to allow maximum flexibility or 1200 * restrict FSETOWN to the current process or process 1201 * group for maximum safety. 1202 */ 1203 if (pgrp->pg_session != curthread->td_proc->p_session) { 1204 PGRP_UNLOCK(pgrp); 1205 ret = EPERM; 1206 goto fail; 1207 } 1208 1209 SLIST_INSERT_HEAD(&pgrp->pg_sigiolst, sigio, sio_pgsigio); 1210 sigio->sio_pgrp = pgrp; 1211 PGRP_UNLOCK(pgrp); 1212 } 1213 sx_sunlock(&proctree_lock); 1214 *sigiop = sigio; 1215 SIGIO_UNLOCK(); 1216 if (osigio != NULL) 1217 sigiofree(osigio); 1218 return (0); 1219 1220 fail: 1221 SIGIO_UNLOCK(); 1222 sx_sunlock(&proctree_lock); 1223 sigiofree(sigio); 1224 if (osigio != NULL) 1225 sigiofree(osigio); 1226 return (ret); 1227 } 1228 1229 /* 1230 * This is common code for FIOGETOWN ioctl called by fcntl(fd, F_GETOWN, arg). 1231 */ 1232 pid_t 1233 fgetown(struct sigio **sigiop) 1234 { 1235 pid_t pgid; 1236 1237 SIGIO_LOCK(); 1238 pgid = (*sigiop != NULL) ? (*sigiop)->sio_pgid : 0; 1239 SIGIO_UNLOCK(); 1240 return (pgid); 1241 } 1242 1243 static int 1244 closefp_impl(struct filedesc *fdp, int fd, struct file *fp, struct thread *td, 1245 bool audit) 1246 { 1247 int error; 1248 1249 FILEDESC_XLOCK_ASSERT(fdp); 1250 1251 /* 1252 * We now hold the fp reference that used to be owned by the 1253 * descriptor array. We have to unlock the FILEDESC *AFTER* 1254 * knote_fdclose to prevent a race of the fd getting opened, a knote 1255 * added, and deleteing a knote for the new fd. 1256 */ 1257 if (__predict_false(!TAILQ_EMPTY(&fdp->fd_kqlist))) 1258 knote_fdclose(td, fd); 1259 1260 /* 1261 * We need to notify mqueue if the object is of type mqueue. 1262 */ 1263 if (__predict_false(fp->f_type == DTYPE_MQUEUE)) 1264 mq_fdclose(td, fd, fp); 1265 FILEDESC_XUNLOCK(fdp); 1266 1267 #ifdef AUDIT 1268 if (AUDITING_TD(td) && audit) 1269 audit_sysclose(td, fd, fp); 1270 #endif 1271 error = closef(fp, td); 1272 1273 /* 1274 * All paths leading up to closefp() will have already removed or 1275 * replaced the fd in the filedesc table, so a restart would not 1276 * operate on the same file. 1277 */ 1278 if (error == ERESTART) 1279 error = EINTR; 1280 1281 return (error); 1282 } 1283 1284 static int 1285 closefp_hl(struct filedesc *fdp, int fd, struct file *fp, struct thread *td, 1286 bool holdleaders, bool audit) 1287 { 1288 int error; 1289 1290 FILEDESC_XLOCK_ASSERT(fdp); 1291 1292 if (holdleaders) { 1293 if (td->td_proc->p_fdtol != NULL) { 1294 /* 1295 * Ask fdfree() to sleep to ensure that all relevant 1296 * process leaders can be traversed in closef(). 1297 */ 1298 fdp->fd_holdleaderscount++; 1299 } else { 1300 holdleaders = false; 1301 } 1302 } 1303 1304 error = closefp_impl(fdp, fd, fp, td, audit); 1305 if (holdleaders) { 1306 FILEDESC_XLOCK(fdp); 1307 fdp->fd_holdleaderscount--; 1308 if (fdp->fd_holdleaderscount == 0 && 1309 fdp->fd_holdleaderswakeup != 0) { 1310 fdp->fd_holdleaderswakeup = 0; 1311 wakeup(&fdp->fd_holdleaderscount); 1312 } 1313 FILEDESC_XUNLOCK(fdp); 1314 } 1315 return (error); 1316 } 1317 1318 static int 1319 closefp(struct filedesc *fdp, int fd, struct file *fp, struct thread *td, 1320 bool holdleaders, bool audit) 1321 { 1322 1323 FILEDESC_XLOCK_ASSERT(fdp); 1324 1325 if (__predict_false(td->td_proc->p_fdtol != NULL)) { 1326 return (closefp_hl(fdp, fd, fp, td, holdleaders, audit)); 1327 } else { 1328 return (closefp_impl(fdp, fd, fp, td, audit)); 1329 } 1330 } 1331 1332 /* 1333 * Close a file descriptor. 1334 */ 1335 #ifndef _SYS_SYSPROTO_H_ 1336 struct close_args { 1337 int fd; 1338 }; 1339 #endif 1340 /* ARGSUSED */ 1341 int 1342 sys_close(struct thread *td, struct close_args *uap) 1343 { 1344 1345 return (kern_close(td, uap->fd)); 1346 } 1347 1348 int 1349 kern_close(struct thread *td, int fd) 1350 { 1351 struct filedesc *fdp; 1352 struct file *fp; 1353 1354 fdp = td->td_proc->p_fd; 1355 1356 FILEDESC_XLOCK(fdp); 1357 if ((fp = fget_locked(fdp, fd)) == NULL) { 1358 FILEDESC_XUNLOCK(fdp); 1359 return (EBADF); 1360 } 1361 fdfree(fdp, fd); 1362 1363 /* closefp() drops the FILEDESC lock for us. */ 1364 return (closefp(fdp, fd, fp, td, true, true)); 1365 } 1366 1367 int 1368 kern_close_range(struct thread *td, u_int lowfd, u_int highfd) 1369 { 1370 struct filedesc *fdp; 1371 const struct fdescenttbl *fdt; 1372 struct file *fp; 1373 int fd; 1374 1375 /* 1376 * Check this prior to clamping; closefrom(3) with only fd 0, 1, and 2 1377 * open should not be a usage error. From a close_range() perspective, 1378 * close_range(3, ~0U, 0) in the same scenario should also likely not 1379 * be a usage error as all fd above 3 are in-fact already closed. 1380 */ 1381 if (highfd < lowfd) { 1382 return (EINVAL); 1383 } 1384 1385 fdp = td->td_proc->p_fd; 1386 FILEDESC_XLOCK(fdp); 1387 fdt = atomic_load_ptr(&fdp->fd_files); 1388 highfd = MIN(highfd, fdt->fdt_nfiles - 1); 1389 fd = lowfd; 1390 if (__predict_false(fd > highfd)) { 1391 goto out_locked; 1392 } 1393 for (;;) { 1394 fp = fdt->fdt_ofiles[fd].fde_file; 1395 if (fp == NULL) { 1396 if (fd == highfd) 1397 goto out_locked; 1398 } else { 1399 fdfree(fdp, fd); 1400 (void) closefp(fdp, fd, fp, td, true, true); 1401 if (fd == highfd) 1402 goto out_unlocked; 1403 FILEDESC_XLOCK(fdp); 1404 fdt = atomic_load_ptr(&fdp->fd_files); 1405 } 1406 fd++; 1407 } 1408 out_locked: 1409 FILEDESC_XUNLOCK(fdp); 1410 out_unlocked: 1411 return (0); 1412 } 1413 1414 #ifndef _SYS_SYSPROTO_H_ 1415 struct close_range_args { 1416 u_int lowfd; 1417 u_int highfd; 1418 int flags; 1419 }; 1420 #endif 1421 int 1422 sys_close_range(struct thread *td, struct close_range_args *uap) 1423 { 1424 1425 /* No flags currently defined */ 1426 if (uap->flags != 0) 1427 return (EINVAL); 1428 return (kern_close_range(td, uap->lowfd, uap->highfd)); 1429 } 1430 1431 #ifdef COMPAT_FREEBSD12 1432 /* 1433 * Close open file descriptors. 1434 */ 1435 #ifndef _SYS_SYSPROTO_H_ 1436 struct freebsd12_closefrom_args { 1437 int lowfd; 1438 }; 1439 #endif 1440 /* ARGSUSED */ 1441 int 1442 freebsd12_closefrom(struct thread *td, struct freebsd12_closefrom_args *uap) 1443 { 1444 u_int lowfd; 1445 1446 AUDIT_ARG_FD(uap->lowfd); 1447 1448 /* 1449 * Treat negative starting file descriptor values identical to 1450 * closefrom(0) which closes all files. 1451 */ 1452 lowfd = MAX(0, uap->lowfd); 1453 return (kern_close_range(td, lowfd, ~0U)); 1454 } 1455 #endif /* COMPAT_FREEBSD12 */ 1456 1457 #if defined(COMPAT_43) 1458 /* 1459 * Return status information about a file descriptor. 1460 */ 1461 #ifndef _SYS_SYSPROTO_H_ 1462 struct ofstat_args { 1463 int fd; 1464 struct ostat *sb; 1465 }; 1466 #endif 1467 /* ARGSUSED */ 1468 int 1469 ofstat(struct thread *td, struct ofstat_args *uap) 1470 { 1471 struct ostat oub; 1472 struct stat ub; 1473 int error; 1474 1475 error = kern_fstat(td, uap->fd, &ub); 1476 if (error == 0) { 1477 cvtstat(&ub, &oub); 1478 error = copyout(&oub, uap->sb, sizeof(oub)); 1479 } 1480 return (error); 1481 } 1482 #endif /* COMPAT_43 */ 1483 1484 #if defined(COMPAT_FREEBSD11) 1485 int 1486 freebsd11_fstat(struct thread *td, struct freebsd11_fstat_args *uap) 1487 { 1488 struct stat sb; 1489 struct freebsd11_stat osb; 1490 int error; 1491 1492 error = kern_fstat(td, uap->fd, &sb); 1493 if (error != 0) 1494 return (error); 1495 error = freebsd11_cvtstat(&sb, &osb); 1496 if (error == 0) 1497 error = copyout(&osb, uap->sb, sizeof(osb)); 1498 return (error); 1499 } 1500 #endif /* COMPAT_FREEBSD11 */ 1501 1502 /* 1503 * Return status information about a file descriptor. 1504 */ 1505 #ifndef _SYS_SYSPROTO_H_ 1506 struct fstat_args { 1507 int fd; 1508 struct stat *sb; 1509 }; 1510 #endif 1511 /* ARGSUSED */ 1512 int 1513 sys_fstat(struct thread *td, struct fstat_args *uap) 1514 { 1515 struct stat ub; 1516 int error; 1517 1518 error = kern_fstat(td, uap->fd, &ub); 1519 if (error == 0) 1520 error = copyout(&ub, uap->sb, sizeof(ub)); 1521 return (error); 1522 } 1523 1524 int 1525 kern_fstat(struct thread *td, int fd, struct stat *sbp) 1526 { 1527 struct file *fp; 1528 int error; 1529 1530 AUDIT_ARG_FD(fd); 1531 1532 error = fget(td, fd, &cap_fstat_rights, &fp); 1533 if (__predict_false(error != 0)) 1534 return (error); 1535 1536 AUDIT_ARG_FILE(td->td_proc, fp); 1537 1538 error = fo_stat(fp, sbp, td->td_ucred, td); 1539 fdrop(fp, td); 1540 #ifdef __STAT_TIME_T_EXT 1541 sbp->st_atim_ext = 0; 1542 sbp->st_mtim_ext = 0; 1543 sbp->st_ctim_ext = 0; 1544 sbp->st_btim_ext = 0; 1545 #endif 1546 #ifdef KTRACE 1547 if (KTRPOINT(td, KTR_STRUCT)) 1548 ktrstat_error(sbp, error); 1549 #endif 1550 return (error); 1551 } 1552 1553 #if defined(COMPAT_FREEBSD11) 1554 /* 1555 * Return status information about a file descriptor. 1556 */ 1557 #ifndef _SYS_SYSPROTO_H_ 1558 struct freebsd11_nfstat_args { 1559 int fd; 1560 struct nstat *sb; 1561 }; 1562 #endif 1563 /* ARGSUSED */ 1564 int 1565 freebsd11_nfstat(struct thread *td, struct freebsd11_nfstat_args *uap) 1566 { 1567 struct nstat nub; 1568 struct stat ub; 1569 int error; 1570 1571 error = kern_fstat(td, uap->fd, &ub); 1572 if (error == 0) { 1573 freebsd11_cvtnstat(&ub, &nub); 1574 error = copyout(&nub, uap->sb, sizeof(nub)); 1575 } 1576 return (error); 1577 } 1578 #endif /* COMPAT_FREEBSD11 */ 1579 1580 /* 1581 * Return pathconf information about a file descriptor. 1582 */ 1583 #ifndef _SYS_SYSPROTO_H_ 1584 struct fpathconf_args { 1585 int fd; 1586 int name; 1587 }; 1588 #endif 1589 /* ARGSUSED */ 1590 int 1591 sys_fpathconf(struct thread *td, struct fpathconf_args *uap) 1592 { 1593 long value; 1594 int error; 1595 1596 error = kern_fpathconf(td, uap->fd, uap->name, &value); 1597 if (error == 0) 1598 td->td_retval[0] = value; 1599 return (error); 1600 } 1601 1602 int 1603 kern_fpathconf(struct thread *td, int fd, int name, long *valuep) 1604 { 1605 struct file *fp; 1606 struct vnode *vp; 1607 int error; 1608 1609 error = fget(td, fd, &cap_fpathconf_rights, &fp); 1610 if (error != 0) 1611 return (error); 1612 1613 if (name == _PC_ASYNC_IO) { 1614 *valuep = _POSIX_ASYNCHRONOUS_IO; 1615 goto out; 1616 } 1617 vp = fp->f_vnode; 1618 if (vp != NULL) { 1619 vn_lock(vp, LK_SHARED | LK_RETRY); 1620 error = VOP_PATHCONF(vp, name, valuep); 1621 VOP_UNLOCK(vp); 1622 } else if (fp->f_type == DTYPE_PIPE || fp->f_type == DTYPE_SOCKET) { 1623 if (name != _PC_PIPE_BUF) { 1624 error = EINVAL; 1625 } else { 1626 *valuep = PIPE_BUF; 1627 error = 0; 1628 } 1629 } else { 1630 error = EOPNOTSUPP; 1631 } 1632 out: 1633 fdrop(fp, td); 1634 return (error); 1635 } 1636 1637 /* 1638 * Copy filecaps structure allocating memory for ioctls array if needed. 1639 * 1640 * The last parameter indicates whether the fdtable is locked. If it is not and 1641 * ioctls are encountered, copying fails and the caller must lock the table. 1642 * 1643 * Note that if the table was not locked, the caller has to check the relevant 1644 * sequence counter to determine whether the operation was successful. 1645 */ 1646 bool 1647 filecaps_copy(const struct filecaps *src, struct filecaps *dst, bool locked) 1648 { 1649 size_t size; 1650 1651 if (src->fc_ioctls != NULL && !locked) 1652 return (false); 1653 memcpy(dst, src, sizeof(*src)); 1654 if (src->fc_ioctls == NULL) 1655 return (true); 1656 1657 KASSERT(src->fc_nioctls > 0, 1658 ("fc_ioctls != NULL, but fc_nioctls=%hd", src->fc_nioctls)); 1659 1660 size = sizeof(src->fc_ioctls[0]) * src->fc_nioctls; 1661 dst->fc_ioctls = malloc(size, M_FILECAPS, M_WAITOK); 1662 memcpy(dst->fc_ioctls, src->fc_ioctls, size); 1663 return (true); 1664 } 1665 1666 static u_long * 1667 filecaps_copy_prep(const struct filecaps *src) 1668 { 1669 u_long *ioctls; 1670 size_t size; 1671 1672 if (__predict_true(src->fc_ioctls == NULL)) 1673 return (NULL); 1674 1675 KASSERT(src->fc_nioctls > 0, 1676 ("fc_ioctls != NULL, but fc_nioctls=%hd", src->fc_nioctls)); 1677 1678 size = sizeof(src->fc_ioctls[0]) * src->fc_nioctls; 1679 ioctls = malloc(size, M_FILECAPS, M_WAITOK); 1680 return (ioctls); 1681 } 1682 1683 static void 1684 filecaps_copy_finish(const struct filecaps *src, struct filecaps *dst, 1685 u_long *ioctls) 1686 { 1687 size_t size; 1688 1689 *dst = *src; 1690 if (__predict_true(src->fc_ioctls == NULL)) { 1691 MPASS(ioctls == NULL); 1692 return; 1693 } 1694 1695 size = sizeof(src->fc_ioctls[0]) * src->fc_nioctls; 1696 dst->fc_ioctls = ioctls; 1697 bcopy(src->fc_ioctls, dst->fc_ioctls, size); 1698 } 1699 1700 /* 1701 * Move filecaps structure to the new place and clear the old place. 1702 */ 1703 void 1704 filecaps_move(struct filecaps *src, struct filecaps *dst) 1705 { 1706 1707 *dst = *src; 1708 bzero(src, sizeof(*src)); 1709 } 1710 1711 /* 1712 * Fill the given filecaps structure with full rights. 1713 */ 1714 static void 1715 filecaps_fill(struct filecaps *fcaps) 1716 { 1717 1718 CAP_ALL(&fcaps->fc_rights); 1719 fcaps->fc_ioctls = NULL; 1720 fcaps->fc_nioctls = -1; 1721 fcaps->fc_fcntls = CAP_FCNTL_ALL; 1722 } 1723 1724 /* 1725 * Free memory allocated within filecaps structure. 1726 */ 1727 void 1728 filecaps_free(struct filecaps *fcaps) 1729 { 1730 1731 free(fcaps->fc_ioctls, M_FILECAPS); 1732 bzero(fcaps, sizeof(*fcaps)); 1733 } 1734 1735 static u_long * 1736 filecaps_free_prep(struct filecaps *fcaps) 1737 { 1738 u_long *ioctls; 1739 1740 ioctls = fcaps->fc_ioctls; 1741 bzero(fcaps, sizeof(*fcaps)); 1742 return (ioctls); 1743 } 1744 1745 static void 1746 filecaps_free_finish(u_long *ioctls) 1747 { 1748 1749 free(ioctls, M_FILECAPS); 1750 } 1751 1752 /* 1753 * Validate the given filecaps structure. 1754 */ 1755 static void 1756 filecaps_validate(const struct filecaps *fcaps, const char *func) 1757 { 1758 1759 KASSERT(cap_rights_is_valid(&fcaps->fc_rights), 1760 ("%s: invalid rights", func)); 1761 KASSERT((fcaps->fc_fcntls & ~CAP_FCNTL_ALL) == 0, 1762 ("%s: invalid fcntls", func)); 1763 KASSERT(fcaps->fc_fcntls == 0 || 1764 cap_rights_is_set(&fcaps->fc_rights, CAP_FCNTL), 1765 ("%s: fcntls without CAP_FCNTL", func)); 1766 KASSERT(fcaps->fc_ioctls != NULL ? fcaps->fc_nioctls > 0 : 1767 (fcaps->fc_nioctls == -1 || fcaps->fc_nioctls == 0), 1768 ("%s: invalid ioctls", func)); 1769 KASSERT(fcaps->fc_nioctls == 0 || 1770 cap_rights_is_set(&fcaps->fc_rights, CAP_IOCTL), 1771 ("%s: ioctls without CAP_IOCTL", func)); 1772 } 1773 1774 static void 1775 fdgrowtable_exp(struct filedesc *fdp, int nfd) 1776 { 1777 int nfd1; 1778 1779 FILEDESC_XLOCK_ASSERT(fdp); 1780 1781 nfd1 = fdp->fd_nfiles * 2; 1782 if (nfd1 < nfd) 1783 nfd1 = nfd; 1784 fdgrowtable(fdp, nfd1); 1785 } 1786 1787 /* 1788 * Grow the file table to accommodate (at least) nfd descriptors. 1789 */ 1790 static void 1791 fdgrowtable(struct filedesc *fdp, int nfd) 1792 { 1793 struct filedesc0 *fdp0; 1794 struct freetable *ft; 1795 struct fdescenttbl *ntable; 1796 struct fdescenttbl *otable; 1797 int nnfiles, onfiles; 1798 NDSLOTTYPE *nmap, *omap; 1799 1800 KASSERT(fdp->fd_nfiles > 0, ("zero-length file table")); 1801 1802 /* save old values */ 1803 onfiles = fdp->fd_nfiles; 1804 otable = fdp->fd_files; 1805 omap = fdp->fd_map; 1806 1807 /* compute the size of the new table */ 1808 nnfiles = NDSLOTS(nfd) * NDENTRIES; /* round up */ 1809 if (nnfiles <= onfiles) 1810 /* the table is already large enough */ 1811 return; 1812 1813 /* 1814 * Allocate a new table. We need enough space for the number of 1815 * entries, file entries themselves and the struct freetable we will use 1816 * when we decommission the table and place it on the freelist. 1817 * We place the struct freetable in the middle so we don't have 1818 * to worry about padding. 1819 */ 1820 ntable = malloc(offsetof(struct fdescenttbl, fdt_ofiles) + 1821 nnfiles * sizeof(ntable->fdt_ofiles[0]) + 1822 sizeof(struct freetable), 1823 M_FILEDESC, M_ZERO | M_WAITOK); 1824 /* copy the old data */ 1825 ntable->fdt_nfiles = nnfiles; 1826 memcpy(ntable->fdt_ofiles, otable->fdt_ofiles, 1827 onfiles * sizeof(ntable->fdt_ofiles[0])); 1828 1829 /* 1830 * Allocate a new map only if the old is not large enough. It will 1831 * grow at a slower rate than the table as it can map more 1832 * entries than the table can hold. 1833 */ 1834 if (NDSLOTS(nnfiles) > NDSLOTS(onfiles)) { 1835 nmap = malloc(NDSLOTS(nnfiles) * NDSLOTSIZE, M_FILEDESC, 1836 M_ZERO | M_WAITOK); 1837 /* copy over the old data and update the pointer */ 1838 memcpy(nmap, omap, NDSLOTS(onfiles) * sizeof(*omap)); 1839 fdp->fd_map = nmap; 1840 } 1841 1842 /* 1843 * Make sure that ntable is correctly initialized before we replace 1844 * fd_files poiner. Otherwise fget_unlocked() may see inconsistent 1845 * data. 1846 */ 1847 atomic_store_rel_ptr((volatile void *)&fdp->fd_files, (uintptr_t)ntable); 1848 1849 /* 1850 * Free the old file table when not shared by other threads or processes. 1851 * The old file table is considered to be shared when either are true: 1852 * - The process has more than one thread. 1853 * - The file descriptor table has been shared via fdshare(). 1854 * 1855 * When shared, the old file table will be placed on a freelist 1856 * which will be processed when the struct filedesc is released. 1857 * 1858 * Note that if onfiles == NDFILE, we're dealing with the original 1859 * static allocation contained within (struct filedesc0 *)fdp, 1860 * which must not be freed. 1861 */ 1862 if (onfiles > NDFILE) { 1863 if (curproc->p_numthreads == 1 && 1864 refcount_load(&fdp->fd_refcnt) == 1) 1865 free(otable, M_FILEDESC); 1866 else { 1867 ft = (struct freetable *)&otable->fdt_ofiles[onfiles]; 1868 fdp0 = (struct filedesc0 *)fdp; 1869 ft->ft_table = otable; 1870 SLIST_INSERT_HEAD(&fdp0->fd_free, ft, ft_next); 1871 } 1872 } 1873 /* 1874 * The map does not have the same possibility of threads still 1875 * holding references to it. So always free it as long as it 1876 * does not reference the original static allocation. 1877 */ 1878 if (NDSLOTS(onfiles) > NDSLOTS(NDFILE)) 1879 free(omap, M_FILEDESC); 1880 } 1881 1882 /* 1883 * Allocate a file descriptor for the process. 1884 */ 1885 int 1886 fdalloc(struct thread *td, int minfd, int *result) 1887 { 1888 struct proc *p = td->td_proc; 1889 struct filedesc *fdp = p->p_fd; 1890 int fd, maxfd, allocfd; 1891 #ifdef RACCT 1892 int error; 1893 #endif 1894 1895 FILEDESC_XLOCK_ASSERT(fdp); 1896 1897 if (fdp->fd_freefile > minfd) 1898 minfd = fdp->fd_freefile; 1899 1900 maxfd = getmaxfd(td); 1901 1902 /* 1903 * Search the bitmap for a free descriptor starting at minfd. 1904 * If none is found, grow the file table. 1905 */ 1906 fd = fd_first_free(fdp, minfd, fdp->fd_nfiles); 1907 if (__predict_false(fd >= maxfd)) 1908 return (EMFILE); 1909 if (__predict_false(fd >= fdp->fd_nfiles)) { 1910 allocfd = min(fd * 2, maxfd); 1911 #ifdef RACCT 1912 if (RACCT_ENABLED()) { 1913 error = racct_set_unlocked(p, RACCT_NOFILE, allocfd); 1914 if (error != 0) 1915 return (EMFILE); 1916 } 1917 #endif 1918 /* 1919 * fd is already equal to first free descriptor >= minfd, so 1920 * we only need to grow the table and we are done. 1921 */ 1922 fdgrowtable_exp(fdp, allocfd); 1923 } 1924 1925 /* 1926 * Perform some sanity checks, then mark the file descriptor as 1927 * used and return it to the caller. 1928 */ 1929 KASSERT(fd >= 0 && fd < min(maxfd, fdp->fd_nfiles), 1930 ("invalid descriptor %d", fd)); 1931 KASSERT(!fdisused(fdp, fd), 1932 ("fd_first_free() returned non-free descriptor")); 1933 KASSERT(fdp->fd_ofiles[fd].fde_file == NULL, 1934 ("file descriptor isn't free")); 1935 fdused(fdp, fd); 1936 *result = fd; 1937 return (0); 1938 } 1939 1940 /* 1941 * Allocate n file descriptors for the process. 1942 */ 1943 int 1944 fdallocn(struct thread *td, int minfd, int *fds, int n) 1945 { 1946 struct proc *p = td->td_proc; 1947 struct filedesc *fdp = p->p_fd; 1948 int i; 1949 1950 FILEDESC_XLOCK_ASSERT(fdp); 1951 1952 for (i = 0; i < n; i++) 1953 if (fdalloc(td, 0, &fds[i]) != 0) 1954 break; 1955 1956 if (i < n) { 1957 for (i--; i >= 0; i--) 1958 fdunused(fdp, fds[i]); 1959 return (EMFILE); 1960 } 1961 1962 return (0); 1963 } 1964 1965 /* 1966 * Create a new open file structure and allocate a file descriptor for the 1967 * process that refers to it. We add one reference to the file for the 1968 * descriptor table and one reference for resultfp. This is to prevent us 1969 * being preempted and the entry in the descriptor table closed after we 1970 * release the FILEDESC lock. 1971 */ 1972 int 1973 falloc_caps(struct thread *td, struct file **resultfp, int *resultfd, int flags, 1974 struct filecaps *fcaps) 1975 { 1976 struct file *fp; 1977 int error, fd; 1978 1979 MPASS(resultfp != NULL); 1980 MPASS(resultfd != NULL); 1981 1982 error = falloc_noinstall(td, &fp); 1983 if (error) 1984 return (error); /* no reference held on error */ 1985 1986 error = finstall(td, fp, &fd, flags, fcaps); 1987 if (error) { 1988 fdrop(fp, td); /* one reference (fp only) */ 1989 return (error); 1990 } 1991 1992 *resultfp = fp; 1993 *resultfd = fd; 1994 1995 return (0); 1996 } 1997 1998 /* 1999 * Create a new open file structure without allocating a file descriptor. 2000 */ 2001 int 2002 falloc_noinstall(struct thread *td, struct file **resultfp) 2003 { 2004 struct file *fp; 2005 int maxuserfiles = maxfiles - (maxfiles / 20); 2006 int openfiles_new; 2007 static struct timeval lastfail; 2008 static int curfail; 2009 2010 KASSERT(resultfp != NULL, ("%s: resultfp == NULL", __func__)); 2011 2012 openfiles_new = atomic_fetchadd_int(&openfiles, 1) + 1; 2013 if ((openfiles_new >= maxuserfiles && 2014 priv_check(td, PRIV_MAXFILES) != 0) || 2015 openfiles_new >= maxfiles) { 2016 atomic_subtract_int(&openfiles, 1); 2017 if (ppsratecheck(&lastfail, &curfail, 1)) { 2018 printf("kern.maxfiles limit exceeded by uid %i, (%s) " 2019 "please see tuning(7).\n", td->td_ucred->cr_ruid, td->td_proc->p_comm); 2020 } 2021 return (ENFILE); 2022 } 2023 fp = uma_zalloc(file_zone, M_WAITOK); 2024 bzero(fp, sizeof(*fp)); 2025 refcount_init(&fp->f_count, 1); 2026 fp->f_cred = crhold(td->td_ucred); 2027 fp->f_ops = &badfileops; 2028 *resultfp = fp; 2029 return (0); 2030 } 2031 2032 /* 2033 * Install a file in a file descriptor table. 2034 */ 2035 void 2036 _finstall(struct filedesc *fdp, struct file *fp, int fd, int flags, 2037 struct filecaps *fcaps) 2038 { 2039 struct filedescent *fde; 2040 2041 MPASS(fp != NULL); 2042 if (fcaps != NULL) 2043 filecaps_validate(fcaps, __func__); 2044 FILEDESC_XLOCK_ASSERT(fdp); 2045 2046 fde = &fdp->fd_ofiles[fd]; 2047 #ifdef CAPABILITIES 2048 seqc_write_begin(&fde->fde_seqc); 2049 #endif 2050 fde->fde_file = fp; 2051 fde->fde_flags = (flags & O_CLOEXEC) != 0 ? UF_EXCLOSE : 0; 2052 if (fcaps != NULL) 2053 filecaps_move(fcaps, &fde->fde_caps); 2054 else 2055 filecaps_fill(&fde->fde_caps); 2056 #ifdef CAPABILITIES 2057 seqc_write_end(&fde->fde_seqc); 2058 #endif 2059 } 2060 2061 int 2062 finstall(struct thread *td, struct file *fp, int *fd, int flags, 2063 struct filecaps *fcaps) 2064 { 2065 struct filedesc *fdp = td->td_proc->p_fd; 2066 int error; 2067 2068 MPASS(fd != NULL); 2069 2070 if (!fhold(fp)) 2071 return (EBADF); 2072 FILEDESC_XLOCK(fdp); 2073 error = fdalloc(td, 0, fd); 2074 if (__predict_false(error != 0)) { 2075 FILEDESC_XUNLOCK(fdp); 2076 fdrop(fp, td); 2077 return (error); 2078 } 2079 _finstall(fdp, fp, *fd, flags, fcaps); 2080 FILEDESC_XUNLOCK(fdp); 2081 return (0); 2082 } 2083 2084 /* 2085 * Build a new filedesc structure from another. 2086 * 2087 * If fdp is not NULL, return with it shared locked. 2088 */ 2089 struct filedesc * 2090 fdinit(struct filedesc *fdp, bool prepfiles, int *lastfile) 2091 { 2092 struct filedesc0 *newfdp0; 2093 struct filedesc *newfdp; 2094 2095 if (prepfiles) 2096 MPASS(lastfile != NULL); 2097 else 2098 MPASS(lastfile == NULL); 2099 2100 newfdp0 = uma_zalloc(filedesc0_zone, M_WAITOK | M_ZERO); 2101 newfdp = &newfdp0->fd_fd; 2102 2103 /* Create the file descriptor table. */ 2104 FILEDESC_LOCK_INIT(newfdp); 2105 refcount_init(&newfdp->fd_refcnt, 1); 2106 refcount_init(&newfdp->fd_holdcnt, 1); 2107 newfdp->fd_map = newfdp0->fd_dmap; 2108 newfdp->fd_files = (struct fdescenttbl *)&newfdp0->fd_dfiles; 2109 newfdp->fd_files->fdt_nfiles = NDFILE; 2110 2111 if (fdp == NULL) 2112 return (newfdp); 2113 2114 FILEDESC_SLOCK(fdp); 2115 if (!prepfiles) { 2116 FILEDESC_SUNLOCK(fdp); 2117 return (newfdp); 2118 } 2119 2120 for (;;) { 2121 *lastfile = fdlastfile(fdp); 2122 if (*lastfile < newfdp->fd_nfiles) 2123 break; 2124 FILEDESC_SUNLOCK(fdp); 2125 fdgrowtable(newfdp, *lastfile + 1); 2126 FILEDESC_SLOCK(fdp); 2127 } 2128 2129 return (newfdp); 2130 } 2131 2132 /* 2133 * Build a pwddesc structure from another. 2134 * Copy the current, root, and jail root vnode references. 2135 * 2136 * If pdp is not NULL, return with it shared locked. 2137 */ 2138 struct pwddesc * 2139 pdinit(struct pwddesc *pdp, bool keeplock) 2140 { 2141 struct pwddesc *newpdp; 2142 struct pwd *newpwd; 2143 2144 newpdp = malloc(sizeof(*newpdp), M_PWDDESC, M_WAITOK | M_ZERO); 2145 2146 PWDDESC_LOCK_INIT(newpdp); 2147 refcount_init(&newpdp->pd_refcount, 1); 2148 newpdp->pd_cmask = CMASK; 2149 2150 if (pdp == NULL) { 2151 newpwd = pwd_alloc(); 2152 smr_serialized_store(&newpdp->pd_pwd, newpwd, true); 2153 return (newpdp); 2154 } 2155 2156 PWDDESC_XLOCK(pdp); 2157 newpwd = pwd_hold_pwddesc(pdp); 2158 smr_serialized_store(&newpdp->pd_pwd, newpwd, true); 2159 if (!keeplock) 2160 PWDDESC_XUNLOCK(pdp); 2161 return (newpdp); 2162 } 2163 2164 static struct filedesc * 2165 fdhold(struct proc *p) 2166 { 2167 struct filedesc *fdp; 2168 2169 PROC_LOCK_ASSERT(p, MA_OWNED); 2170 fdp = p->p_fd; 2171 if (fdp != NULL) 2172 refcount_acquire(&fdp->fd_holdcnt); 2173 return (fdp); 2174 } 2175 2176 static struct pwddesc * 2177 pdhold(struct proc *p) 2178 { 2179 struct pwddesc *pdp; 2180 2181 PROC_LOCK_ASSERT(p, MA_OWNED); 2182 pdp = p->p_pd; 2183 if (pdp != NULL) 2184 refcount_acquire(&pdp->pd_refcount); 2185 return (pdp); 2186 } 2187 2188 static void 2189 fddrop(struct filedesc *fdp) 2190 { 2191 2192 if (refcount_load(&fdp->fd_holdcnt) > 1) { 2193 if (refcount_release(&fdp->fd_holdcnt) == 0) 2194 return; 2195 } 2196 2197 FILEDESC_LOCK_DESTROY(fdp); 2198 uma_zfree(filedesc0_zone, fdp); 2199 } 2200 2201 static void 2202 pddrop(struct pwddesc *pdp) 2203 { 2204 struct pwd *pwd; 2205 2206 if (refcount_release_if_not_last(&pdp->pd_refcount)) 2207 return; 2208 2209 PWDDESC_XLOCK(pdp); 2210 if (refcount_release(&pdp->pd_refcount) == 0) { 2211 PWDDESC_XUNLOCK(pdp); 2212 return; 2213 } 2214 pwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); 2215 pwd_set(pdp, NULL); 2216 PWDDESC_XUNLOCK(pdp); 2217 pwd_drop(pwd); 2218 2219 PWDDESC_LOCK_DESTROY(pdp); 2220 free(pdp, M_PWDDESC); 2221 } 2222 2223 /* 2224 * Share a filedesc structure. 2225 */ 2226 struct filedesc * 2227 fdshare(struct filedesc *fdp) 2228 { 2229 2230 refcount_acquire(&fdp->fd_refcnt); 2231 return (fdp); 2232 } 2233 2234 /* 2235 * Share a pwddesc structure. 2236 */ 2237 struct pwddesc * 2238 pdshare(struct pwddesc *pdp) 2239 { 2240 refcount_acquire(&pdp->pd_refcount); 2241 return (pdp); 2242 } 2243 2244 /* 2245 * Unshare a filedesc structure, if necessary by making a copy 2246 */ 2247 void 2248 fdunshare(struct thread *td) 2249 { 2250 struct filedesc *tmp; 2251 struct proc *p = td->td_proc; 2252 2253 if (refcount_load(&p->p_fd->fd_refcnt) == 1) 2254 return; 2255 2256 tmp = fdcopy(p->p_fd); 2257 fdescfree(td); 2258 p->p_fd = tmp; 2259 } 2260 2261 /* 2262 * Unshare a pwddesc structure. 2263 */ 2264 void 2265 pdunshare(struct thread *td) 2266 { 2267 struct pwddesc *pdp; 2268 struct proc *p; 2269 2270 p = td->td_proc; 2271 /* Not shared. */ 2272 if (p->p_pd->pd_refcount == 1) 2273 return; 2274 2275 pdp = pdcopy(p->p_pd); 2276 pdescfree(td); 2277 p->p_pd = pdp; 2278 } 2279 2280 void 2281 fdinstall_remapped(struct thread *td, struct filedesc *fdp) 2282 { 2283 2284 fdescfree(td); 2285 td->td_proc->p_fd = fdp; 2286 } 2287 2288 /* 2289 * Copy a filedesc structure. A NULL pointer in returns a NULL reference, 2290 * this is to ease callers, not catch errors. 2291 */ 2292 struct filedesc * 2293 fdcopy(struct filedesc *fdp) 2294 { 2295 struct filedesc *newfdp; 2296 struct filedescent *nfde, *ofde; 2297 int i, lastfile; 2298 2299 MPASS(fdp != NULL); 2300 2301 newfdp = fdinit(fdp, true, &lastfile); 2302 /* copy all passable descriptors (i.e. not kqueue) */ 2303 newfdp->fd_freefile = -1; 2304 for (i = 0; i <= lastfile; ++i) { 2305 ofde = &fdp->fd_ofiles[i]; 2306 if (ofde->fde_file == NULL || 2307 (ofde->fde_file->f_ops->fo_flags & DFLAG_PASSABLE) == 0 || 2308 !fhold(ofde->fde_file)) { 2309 if (newfdp->fd_freefile == -1) 2310 newfdp->fd_freefile = i; 2311 continue; 2312 } 2313 nfde = &newfdp->fd_ofiles[i]; 2314 *nfde = *ofde; 2315 filecaps_copy(&ofde->fde_caps, &nfde->fde_caps, true); 2316 fdused_init(newfdp, i); 2317 } 2318 if (newfdp->fd_freefile == -1) 2319 newfdp->fd_freefile = i; 2320 FILEDESC_SUNLOCK(fdp); 2321 return (newfdp); 2322 } 2323 2324 /* 2325 * Copy a pwddesc structure. 2326 */ 2327 struct pwddesc * 2328 pdcopy(struct pwddesc *pdp) 2329 { 2330 struct pwddesc *newpdp; 2331 2332 MPASS(pdp != NULL); 2333 2334 newpdp = pdinit(pdp, true); 2335 newpdp->pd_cmask = pdp->pd_cmask; 2336 PWDDESC_XUNLOCK(pdp); 2337 return (newpdp); 2338 } 2339 2340 /* 2341 * Copies a filedesc structure, while remapping all file descriptors 2342 * stored inside using a translation table. 2343 * 2344 * File descriptors are copied over to the new file descriptor table, 2345 * regardless of whether the close-on-exec flag is set. 2346 */ 2347 int 2348 fdcopy_remapped(struct filedesc *fdp, const int *fds, size_t nfds, 2349 struct filedesc **ret) 2350 { 2351 struct filedesc *newfdp; 2352 struct filedescent *nfde, *ofde; 2353 int error, i, lastfile; 2354 2355 MPASS(fdp != NULL); 2356 2357 newfdp = fdinit(fdp, true, &lastfile); 2358 if (nfds > lastfile + 1) { 2359 /* New table cannot be larger than the old one. */ 2360 error = E2BIG; 2361 goto bad; 2362 } 2363 /* Copy all passable descriptors (i.e. not kqueue). */ 2364 newfdp->fd_freefile = nfds; 2365 for (i = 0; i < nfds; ++i) { 2366 if (fds[i] < 0 || fds[i] > lastfile) { 2367 /* File descriptor out of bounds. */ 2368 error = EBADF; 2369 goto bad; 2370 } 2371 ofde = &fdp->fd_ofiles[fds[i]]; 2372 if (ofde->fde_file == NULL) { 2373 /* Unused file descriptor. */ 2374 error = EBADF; 2375 goto bad; 2376 } 2377 if ((ofde->fde_file->f_ops->fo_flags & DFLAG_PASSABLE) == 0) { 2378 /* File descriptor cannot be passed. */ 2379 error = EINVAL; 2380 goto bad; 2381 } 2382 if (!fhold(ofde->fde_file)) { 2383 error = EBADF; 2384 goto bad; 2385 } 2386 nfde = &newfdp->fd_ofiles[i]; 2387 *nfde = *ofde; 2388 filecaps_copy(&ofde->fde_caps, &nfde->fde_caps, true); 2389 fdused_init(newfdp, i); 2390 } 2391 FILEDESC_SUNLOCK(fdp); 2392 *ret = newfdp; 2393 return (0); 2394 bad: 2395 FILEDESC_SUNLOCK(fdp); 2396 fdescfree_remapped(newfdp); 2397 return (error); 2398 } 2399 2400 /* 2401 * Clear POSIX style locks. This is only used when fdp looses a reference (i.e. 2402 * one of processes using it exits) and the table used to be shared. 2403 */ 2404 static void 2405 fdclearlocks(struct thread *td) 2406 { 2407 struct filedesc *fdp; 2408 struct filedesc_to_leader *fdtol; 2409 struct flock lf; 2410 struct file *fp; 2411 struct proc *p; 2412 struct vnode *vp; 2413 int i, lastfile; 2414 2415 p = td->td_proc; 2416 fdp = p->p_fd; 2417 fdtol = p->p_fdtol; 2418 MPASS(fdtol != NULL); 2419 2420 FILEDESC_XLOCK(fdp); 2421 KASSERT(fdtol->fdl_refcount > 0, 2422 ("filedesc_to_refcount botch: fdl_refcount=%d", 2423 fdtol->fdl_refcount)); 2424 if (fdtol->fdl_refcount == 1 && 2425 (p->p_leader->p_flag & P_ADVLOCK) != 0) { 2426 lastfile = fdlastfile(fdp); 2427 for (i = 0; i <= lastfile; i++) { 2428 fp = fdp->fd_ofiles[i].fde_file; 2429 if (fp == NULL || fp->f_type != DTYPE_VNODE || 2430 !fhold(fp)) 2431 continue; 2432 FILEDESC_XUNLOCK(fdp); 2433 lf.l_whence = SEEK_SET; 2434 lf.l_start = 0; 2435 lf.l_len = 0; 2436 lf.l_type = F_UNLCK; 2437 vp = fp->f_vnode; 2438 (void) VOP_ADVLOCK(vp, 2439 (caddr_t)p->p_leader, F_UNLCK, 2440 &lf, F_POSIX); 2441 FILEDESC_XLOCK(fdp); 2442 fdrop(fp, td); 2443 } 2444 } 2445 retry: 2446 if (fdtol->fdl_refcount == 1) { 2447 if (fdp->fd_holdleaderscount > 0 && 2448 (p->p_leader->p_flag & P_ADVLOCK) != 0) { 2449 /* 2450 * close() or kern_dup() has cleared a reference 2451 * in a shared file descriptor table. 2452 */ 2453 fdp->fd_holdleaderswakeup = 1; 2454 sx_sleep(&fdp->fd_holdleaderscount, 2455 FILEDESC_LOCK(fdp), PLOCK, "fdlhold", 0); 2456 goto retry; 2457 } 2458 if (fdtol->fdl_holdcount > 0) { 2459 /* 2460 * Ensure that fdtol->fdl_leader remains 2461 * valid in closef(). 2462 */ 2463 fdtol->fdl_wakeup = 1; 2464 sx_sleep(fdtol, FILEDESC_LOCK(fdp), PLOCK, 2465 "fdlhold", 0); 2466 goto retry; 2467 } 2468 } 2469 fdtol->fdl_refcount--; 2470 if (fdtol->fdl_refcount == 0 && 2471 fdtol->fdl_holdcount == 0) { 2472 fdtol->fdl_next->fdl_prev = fdtol->fdl_prev; 2473 fdtol->fdl_prev->fdl_next = fdtol->fdl_next; 2474 } else 2475 fdtol = NULL; 2476 p->p_fdtol = NULL; 2477 FILEDESC_XUNLOCK(fdp); 2478 if (fdtol != NULL) 2479 free(fdtol, M_FILEDESC_TO_LEADER); 2480 } 2481 2482 /* 2483 * Release a filedesc structure. 2484 */ 2485 static void 2486 fdescfree_fds(struct thread *td, struct filedesc *fdp, bool needclose) 2487 { 2488 struct filedesc0 *fdp0; 2489 struct freetable *ft, *tft; 2490 struct filedescent *fde; 2491 struct file *fp; 2492 int i, lastfile; 2493 2494 KASSERT(refcount_load(&fdp->fd_refcnt) == 0, 2495 ("%s: fd table %p carries references", __func__, fdp)); 2496 2497 /* 2498 * Serialize with threads iterating over the table, if any. 2499 */ 2500 if (refcount_load(&fdp->fd_holdcnt) > 1) { 2501 FILEDESC_XLOCK(fdp); 2502 FILEDESC_XUNLOCK(fdp); 2503 } 2504 2505 lastfile = fdlastfile_single(fdp); 2506 for (i = 0; i <= lastfile; i++) { 2507 fde = &fdp->fd_ofiles[i]; 2508 fp = fde->fde_file; 2509 if (fp != NULL) { 2510 fdefree_last(fde); 2511 if (needclose) 2512 (void) closef(fp, td); 2513 else 2514 fdrop(fp, td); 2515 } 2516 } 2517 2518 if (NDSLOTS(fdp->fd_nfiles) > NDSLOTS(NDFILE)) 2519 free(fdp->fd_map, M_FILEDESC); 2520 if (fdp->fd_nfiles > NDFILE) 2521 free(fdp->fd_files, M_FILEDESC); 2522 2523 fdp0 = (struct filedesc0 *)fdp; 2524 SLIST_FOREACH_SAFE(ft, &fdp0->fd_free, ft_next, tft) 2525 free(ft->ft_table, M_FILEDESC); 2526 2527 fddrop(fdp); 2528 } 2529 2530 void 2531 fdescfree(struct thread *td) 2532 { 2533 struct proc *p; 2534 struct filedesc *fdp; 2535 2536 p = td->td_proc; 2537 fdp = p->p_fd; 2538 MPASS(fdp != NULL); 2539 2540 #ifdef RACCT 2541 if (RACCT_ENABLED()) 2542 racct_set_unlocked(p, RACCT_NOFILE, 0); 2543 #endif 2544 2545 if (p->p_fdtol != NULL) 2546 fdclearlocks(td); 2547 2548 PROC_LOCK(p); 2549 p->p_fd = NULL; 2550 PROC_UNLOCK(p); 2551 2552 if (refcount_release(&fdp->fd_refcnt) == 0) 2553 return; 2554 2555 fdescfree_fds(td, fdp, 1); 2556 } 2557 2558 void 2559 pdescfree(struct thread *td) 2560 { 2561 struct proc *p; 2562 struct pwddesc *pdp; 2563 2564 p = td->td_proc; 2565 pdp = p->p_pd; 2566 MPASS(pdp != NULL); 2567 2568 PROC_LOCK(p); 2569 p->p_pd = NULL; 2570 PROC_UNLOCK(p); 2571 2572 pddrop(pdp); 2573 } 2574 2575 void 2576 fdescfree_remapped(struct filedesc *fdp) 2577 { 2578 #ifdef INVARIANTS 2579 /* fdescfree_fds() asserts that fd_refcnt == 0. */ 2580 if (!refcount_release(&fdp->fd_refcnt)) 2581 panic("%s: fd table %p has extra references", __func__, fdp); 2582 #endif 2583 fdescfree_fds(curthread, fdp, 0); 2584 } 2585 2586 /* 2587 * For setugid programs, we don't want to people to use that setugidness 2588 * to generate error messages which write to a file which otherwise would 2589 * otherwise be off-limits to the process. We check for filesystems where 2590 * the vnode can change out from under us after execve (like [lin]procfs). 2591 * 2592 * Since fdsetugidsafety calls this only for fd 0, 1 and 2, this check is 2593 * sufficient. We also don't check for setugidness since we know we are. 2594 */ 2595 static bool 2596 is_unsafe(struct file *fp) 2597 { 2598 struct vnode *vp; 2599 2600 if (fp->f_type != DTYPE_VNODE) 2601 return (false); 2602 2603 vp = fp->f_vnode; 2604 return ((vp->v_vflag & VV_PROCDEP) != 0); 2605 } 2606 2607 /* 2608 * Make this setguid thing safe, if at all possible. 2609 */ 2610 void 2611 fdsetugidsafety(struct thread *td) 2612 { 2613 struct filedesc *fdp; 2614 struct file *fp; 2615 int i; 2616 2617 fdp = td->td_proc->p_fd; 2618 KASSERT(refcount_load(&fdp->fd_refcnt) == 1, 2619 ("the fdtable should not be shared")); 2620 MPASS(fdp->fd_nfiles >= 3); 2621 for (i = 0; i <= 2; i++) { 2622 fp = fdp->fd_ofiles[i].fde_file; 2623 if (fp != NULL && is_unsafe(fp)) { 2624 FILEDESC_XLOCK(fdp); 2625 knote_fdclose(td, i); 2626 /* 2627 * NULL-out descriptor prior to close to avoid 2628 * a race while close blocks. 2629 */ 2630 fdfree(fdp, i); 2631 FILEDESC_XUNLOCK(fdp); 2632 (void) closef(fp, td); 2633 } 2634 } 2635 } 2636 2637 /* 2638 * If a specific file object occupies a specific file descriptor, close the 2639 * file descriptor entry and drop a reference on the file object. This is a 2640 * convenience function to handle a subsequent error in a function that calls 2641 * falloc() that handles the race that another thread might have closed the 2642 * file descriptor out from under the thread creating the file object. 2643 */ 2644 void 2645 fdclose(struct thread *td, struct file *fp, int idx) 2646 { 2647 struct filedesc *fdp = td->td_proc->p_fd; 2648 2649 FILEDESC_XLOCK(fdp); 2650 if (fdp->fd_ofiles[idx].fde_file == fp) { 2651 fdfree(fdp, idx); 2652 FILEDESC_XUNLOCK(fdp); 2653 fdrop(fp, td); 2654 } else 2655 FILEDESC_XUNLOCK(fdp); 2656 } 2657 2658 /* 2659 * Close any files on exec? 2660 */ 2661 void 2662 fdcloseexec(struct thread *td) 2663 { 2664 struct filedesc *fdp; 2665 struct filedescent *fde; 2666 struct file *fp; 2667 int i, lastfile; 2668 2669 fdp = td->td_proc->p_fd; 2670 KASSERT(refcount_load(&fdp->fd_refcnt) == 1, 2671 ("the fdtable should not be shared")); 2672 lastfile = fdlastfile_single(fdp); 2673 for (i = 0; i <= lastfile; i++) { 2674 fde = &fdp->fd_ofiles[i]; 2675 fp = fde->fde_file; 2676 if (fp != NULL && (fp->f_type == DTYPE_MQUEUE || 2677 (fde->fde_flags & UF_EXCLOSE))) { 2678 FILEDESC_XLOCK(fdp); 2679 fdfree(fdp, i); 2680 (void) closefp(fdp, i, fp, td, false, false); 2681 FILEDESC_UNLOCK_ASSERT(fdp); 2682 } 2683 } 2684 } 2685 2686 /* 2687 * It is unsafe for set[ug]id processes to be started with file 2688 * descriptors 0..2 closed, as these descriptors are given implicit 2689 * significance in the Standard C library. fdcheckstd() will create a 2690 * descriptor referencing /dev/null for each of stdin, stdout, and 2691 * stderr that is not already open. 2692 */ 2693 int 2694 fdcheckstd(struct thread *td) 2695 { 2696 struct filedesc *fdp; 2697 register_t save; 2698 int i, error, devnull; 2699 2700 fdp = td->td_proc->p_fd; 2701 KASSERT(refcount_load(&fdp->fd_refcnt) == 1, 2702 ("the fdtable should not be shared")); 2703 MPASS(fdp->fd_nfiles >= 3); 2704 devnull = -1; 2705 for (i = 0; i <= 2; i++) { 2706 if (fdp->fd_ofiles[i].fde_file != NULL) 2707 continue; 2708 2709 save = td->td_retval[0]; 2710 if (devnull != -1) { 2711 error = kern_dup(td, FDDUP_FIXED, 0, devnull, i); 2712 } else { 2713 error = kern_openat(td, AT_FDCWD, "/dev/null", 2714 UIO_SYSSPACE, O_RDWR, 0); 2715 if (error == 0) { 2716 devnull = td->td_retval[0]; 2717 KASSERT(devnull == i, ("we didn't get our fd")); 2718 } 2719 } 2720 td->td_retval[0] = save; 2721 if (error != 0) 2722 return (error); 2723 } 2724 return (0); 2725 } 2726 2727 /* 2728 * Internal form of close. Decrement reference count on file structure. 2729 * Note: td may be NULL when closing a file that was being passed in a 2730 * message. 2731 */ 2732 int 2733 closef(struct file *fp, struct thread *td) 2734 { 2735 struct vnode *vp; 2736 struct flock lf; 2737 struct filedesc_to_leader *fdtol; 2738 struct filedesc *fdp; 2739 2740 /* 2741 * POSIX record locking dictates that any close releases ALL 2742 * locks owned by this process. This is handled by setting 2743 * a flag in the unlock to free ONLY locks obeying POSIX 2744 * semantics, and not to free BSD-style file locks. 2745 * If the descriptor was in a message, POSIX-style locks 2746 * aren't passed with the descriptor, and the thread pointer 2747 * will be NULL. Callers should be careful only to pass a 2748 * NULL thread pointer when there really is no owning 2749 * context that might have locks, or the locks will be 2750 * leaked. 2751 */ 2752 if (fp->f_type == DTYPE_VNODE && td != NULL) { 2753 vp = fp->f_vnode; 2754 if ((td->td_proc->p_leader->p_flag & P_ADVLOCK) != 0) { 2755 lf.l_whence = SEEK_SET; 2756 lf.l_start = 0; 2757 lf.l_len = 0; 2758 lf.l_type = F_UNLCK; 2759 (void) VOP_ADVLOCK(vp, (caddr_t)td->td_proc->p_leader, 2760 F_UNLCK, &lf, F_POSIX); 2761 } 2762 fdtol = td->td_proc->p_fdtol; 2763 if (fdtol != NULL) { 2764 /* 2765 * Handle special case where file descriptor table is 2766 * shared between multiple process leaders. 2767 */ 2768 fdp = td->td_proc->p_fd; 2769 FILEDESC_XLOCK(fdp); 2770 for (fdtol = fdtol->fdl_next; 2771 fdtol != td->td_proc->p_fdtol; 2772 fdtol = fdtol->fdl_next) { 2773 if ((fdtol->fdl_leader->p_flag & 2774 P_ADVLOCK) == 0) 2775 continue; 2776 fdtol->fdl_holdcount++; 2777 FILEDESC_XUNLOCK(fdp); 2778 lf.l_whence = SEEK_SET; 2779 lf.l_start = 0; 2780 lf.l_len = 0; 2781 lf.l_type = F_UNLCK; 2782 vp = fp->f_vnode; 2783 (void) VOP_ADVLOCK(vp, 2784 (caddr_t)fdtol->fdl_leader, F_UNLCK, &lf, 2785 F_POSIX); 2786 FILEDESC_XLOCK(fdp); 2787 fdtol->fdl_holdcount--; 2788 if (fdtol->fdl_holdcount == 0 && 2789 fdtol->fdl_wakeup != 0) { 2790 fdtol->fdl_wakeup = 0; 2791 wakeup(fdtol); 2792 } 2793 } 2794 FILEDESC_XUNLOCK(fdp); 2795 } 2796 } 2797 return (fdrop_close(fp, td)); 2798 } 2799 2800 /* 2801 * Initialize the file pointer with the specified properties. 2802 * 2803 * The ops are set with release semantics to be certain that the flags, type, 2804 * and data are visible when ops is. This is to prevent ops methods from being 2805 * called with bad data. 2806 */ 2807 void 2808 finit(struct file *fp, u_int flag, short type, void *data, struct fileops *ops) 2809 { 2810 fp->f_data = data; 2811 fp->f_flag = flag; 2812 fp->f_type = type; 2813 atomic_store_rel_ptr((volatile uintptr_t *)&fp->f_ops, (uintptr_t)ops); 2814 } 2815 2816 void 2817 finit_vnode(struct file *fp, u_int flag, void *data, struct fileops *ops) 2818 { 2819 fp->f_seqcount[UIO_READ] = 1; 2820 fp->f_seqcount[UIO_WRITE] = 1; 2821 finit(fp, (flag & FMASK) | (fp->f_flag & FHASLOCK), DTYPE_VNODE, 2822 data, ops); 2823 } 2824 2825 int 2826 fget_cap_locked(struct filedesc *fdp, int fd, cap_rights_t *needrightsp, 2827 struct file **fpp, struct filecaps *havecapsp) 2828 { 2829 struct filedescent *fde; 2830 int error; 2831 2832 FILEDESC_LOCK_ASSERT(fdp); 2833 2834 fde = fdeget_locked(fdp, fd); 2835 if (fde == NULL) { 2836 error = EBADF; 2837 goto out; 2838 } 2839 2840 #ifdef CAPABILITIES 2841 error = cap_check(cap_rights_fde_inline(fde), needrightsp); 2842 if (error != 0) 2843 goto out; 2844 #endif 2845 2846 if (havecapsp != NULL) 2847 filecaps_copy(&fde->fde_caps, havecapsp, true); 2848 2849 *fpp = fde->fde_file; 2850 2851 error = 0; 2852 out: 2853 return (error); 2854 } 2855 2856 int 2857 fget_cap(struct thread *td, int fd, cap_rights_t *needrightsp, 2858 struct file **fpp, struct filecaps *havecapsp) 2859 { 2860 struct filedesc *fdp = td->td_proc->p_fd; 2861 int error; 2862 #ifndef CAPABILITIES 2863 error = fget_unlocked(fdp, fd, needrightsp, fpp); 2864 if (havecapsp != NULL && error == 0) 2865 filecaps_fill(havecapsp); 2866 #else 2867 struct file *fp; 2868 seqc_t seq; 2869 2870 *fpp = NULL; 2871 for (;;) { 2872 error = fget_unlocked_seq(fdp, fd, needrightsp, &fp, &seq); 2873 if (error != 0) 2874 return (error); 2875 2876 if (havecapsp != NULL) { 2877 if (!filecaps_copy(&fdp->fd_ofiles[fd].fde_caps, 2878 havecapsp, false)) { 2879 fdrop(fp, td); 2880 goto get_locked; 2881 } 2882 } 2883 2884 if (!fd_modified(fdp, fd, seq)) 2885 break; 2886 fdrop(fp, td); 2887 } 2888 2889 *fpp = fp; 2890 return (0); 2891 2892 get_locked: 2893 FILEDESC_SLOCK(fdp); 2894 error = fget_cap_locked(fdp, fd, needrightsp, fpp, havecapsp); 2895 if (error == 0 && !fhold(*fpp)) 2896 error = EBADF; 2897 FILEDESC_SUNLOCK(fdp); 2898 #endif 2899 return (error); 2900 } 2901 2902 #ifdef CAPABILITIES 2903 int 2904 fgetvp_lookup_smr(int fd, struct nameidata *ndp, struct vnode **vpp, bool *fsearch) 2905 { 2906 const struct filedescent *fde; 2907 const struct fdescenttbl *fdt; 2908 struct filedesc *fdp; 2909 struct file *fp; 2910 struct vnode *vp; 2911 const cap_rights_t *haverights; 2912 cap_rights_t rights; 2913 seqc_t seq; 2914 2915 VFS_SMR_ASSERT_ENTERED(); 2916 2917 rights = *ndp->ni_rightsneeded; 2918 cap_rights_set_one(&rights, CAP_LOOKUP); 2919 2920 fdp = curproc->p_fd; 2921 fdt = fdp->fd_files; 2922 if (__predict_false((u_int)fd >= fdt->fdt_nfiles)) 2923 return (EBADF); 2924 seq = seqc_read_notmodify(fd_seqc(fdt, fd)); 2925 fde = &fdt->fdt_ofiles[fd]; 2926 haverights = cap_rights_fde_inline(fde); 2927 fp = fde->fde_file; 2928 if (__predict_false(fp == NULL)) 2929 return (EAGAIN); 2930 if (__predict_false(cap_check_inline_transient(haverights, &rights))) 2931 return (EAGAIN); 2932 *fsearch = ((fp->f_flag & FSEARCH) != 0); 2933 vp = fp->f_vnode; 2934 if (__predict_false(vp == NULL || vp->v_type != VDIR)) { 2935 return (EAGAIN); 2936 } 2937 if (!filecaps_copy(&fde->fde_caps, &ndp->ni_filecaps, false)) { 2938 return (EAGAIN); 2939 } 2940 /* 2941 * Use an acquire barrier to force re-reading of fdt so it is 2942 * refreshed for verification. 2943 */ 2944 atomic_thread_fence_acq(); 2945 fdt = fdp->fd_files; 2946 if (__predict_false(!seqc_consistent_nomb(fd_seqc(fdt, fd), seq))) 2947 return (EAGAIN); 2948 /* 2949 * If file descriptor doesn't have all rights, 2950 * all lookups relative to it must also be 2951 * strictly relative. 2952 * 2953 * Not yet supported by fast path. 2954 */ 2955 CAP_ALL(&rights); 2956 if (!cap_rights_contains(&ndp->ni_filecaps.fc_rights, &rights) || 2957 ndp->ni_filecaps.fc_fcntls != CAP_FCNTL_ALL || 2958 ndp->ni_filecaps.fc_nioctls != -1) { 2959 #ifdef notyet 2960 ndp->ni_lcf |= NI_LCF_STRICTRELATIVE; 2961 #else 2962 return (EAGAIN); 2963 #endif 2964 } 2965 *vpp = vp; 2966 return (0); 2967 } 2968 #else 2969 int 2970 fgetvp_lookup_smr(int fd, struct nameidata *ndp, struct vnode **vpp, bool *fsearch) 2971 { 2972 const struct fdescenttbl *fdt; 2973 struct filedesc *fdp; 2974 struct file *fp; 2975 struct vnode *vp; 2976 2977 VFS_SMR_ASSERT_ENTERED(); 2978 2979 fdp = curproc->p_fd; 2980 fdt = fdp->fd_files; 2981 if (__predict_false((u_int)fd >= fdt->fdt_nfiles)) 2982 return (EBADF); 2983 fp = fdt->fdt_ofiles[fd].fde_file; 2984 if (__predict_false(fp == NULL)) 2985 return (EAGAIN); 2986 *fsearch = ((fp->f_flag & FSEARCH) != 0); 2987 vp = fp->f_vnode; 2988 if (__predict_false(vp == NULL || vp->v_type != VDIR)) { 2989 return (EAGAIN); 2990 } 2991 /* 2992 * Use an acquire barrier to force re-reading of fdt so it is 2993 * refreshed for verification. 2994 */ 2995 atomic_thread_fence_acq(); 2996 fdt = fdp->fd_files; 2997 if (__predict_false(fp != fdt->fdt_ofiles[fd].fde_file)) 2998 return (EAGAIN); 2999 filecaps_fill(&ndp->ni_filecaps); 3000 *vpp = vp; 3001 return (0); 3002 } 3003 #endif 3004 3005 int 3006 fget_unlocked_seq(struct filedesc *fdp, int fd, cap_rights_t *needrightsp, 3007 struct file **fpp, seqc_t *seqp) 3008 { 3009 #ifdef CAPABILITIES 3010 const struct filedescent *fde; 3011 #endif 3012 const struct fdescenttbl *fdt; 3013 struct file *fp; 3014 #ifdef CAPABILITIES 3015 seqc_t seq; 3016 cap_rights_t haverights; 3017 int error; 3018 #endif 3019 3020 fdt = fdp->fd_files; 3021 if (__predict_false((u_int)fd >= fdt->fdt_nfiles)) 3022 return (EBADF); 3023 /* 3024 * Fetch the descriptor locklessly. We avoid fdrop() races by 3025 * never raising a refcount above 0. To accomplish this we have 3026 * to use a cmpset loop rather than an atomic_add. The descriptor 3027 * must be re-verified once we acquire a reference to be certain 3028 * that the identity is still correct and we did not lose a race 3029 * due to preemption. 3030 */ 3031 for (;;) { 3032 #ifdef CAPABILITIES 3033 seq = seqc_read_notmodify(fd_seqc(fdt, fd)); 3034 fde = &fdt->fdt_ofiles[fd]; 3035 haverights = *cap_rights_fde_inline(fde); 3036 fp = fde->fde_file; 3037 if (!seqc_consistent(fd_seqc(fdt, fd), seq)) 3038 continue; 3039 #else 3040 fp = fdt->fdt_ofiles[fd].fde_file; 3041 #endif 3042 if (fp == NULL) 3043 return (EBADF); 3044 #ifdef CAPABILITIES 3045 error = cap_check_inline(&haverights, needrightsp); 3046 if (error != 0) 3047 return (error); 3048 #endif 3049 if (__predict_false(!refcount_acquire_if_not_zero(&fp->f_count))) { 3050 /* 3051 * Force a reload. Other thread could reallocate the 3052 * table before this fd was closed, so it is possible 3053 * that there is a stale fp pointer in cached version. 3054 */ 3055 fdt = atomic_load_ptr(&fdp->fd_files); 3056 continue; 3057 } 3058 /* 3059 * Use an acquire barrier to force re-reading of fdt so it is 3060 * refreshed for verification. 3061 */ 3062 atomic_thread_fence_acq(); 3063 fdt = fdp->fd_files; 3064 #ifdef CAPABILITIES 3065 if (seqc_consistent_nomb(fd_seqc(fdt, fd), seq)) 3066 #else 3067 if (fp == fdt->fdt_ofiles[fd].fde_file) 3068 #endif 3069 break; 3070 fdrop(fp, curthread); 3071 } 3072 *fpp = fp; 3073 if (seqp != NULL) { 3074 #ifdef CAPABILITIES 3075 *seqp = seq; 3076 #endif 3077 } 3078 return (0); 3079 } 3080 3081 /* 3082 * See the comments in fget_unlocked_seq for an explanation of how this works. 3083 * 3084 * This is a simplified variant which bails out to the aforementioned routine 3085 * if anything goes wrong. In practice this only happens when userspace is 3086 * racing with itself. 3087 */ 3088 int 3089 fget_unlocked(struct filedesc *fdp, int fd, cap_rights_t *needrightsp, 3090 struct file **fpp) 3091 { 3092 #ifdef CAPABILITIES 3093 const struct filedescent *fde; 3094 #endif 3095 const struct fdescenttbl *fdt; 3096 struct file *fp; 3097 #ifdef CAPABILITIES 3098 seqc_t seq; 3099 const cap_rights_t *haverights; 3100 #endif 3101 3102 fdt = fdp->fd_files; 3103 if (__predict_false((u_int)fd >= fdt->fdt_nfiles)) 3104 return (EBADF); 3105 #ifdef CAPABILITIES 3106 seq = seqc_read_notmodify(fd_seqc(fdt, fd)); 3107 fde = &fdt->fdt_ofiles[fd]; 3108 haverights = cap_rights_fde_inline(fde); 3109 fp = fde->fde_file; 3110 #else 3111 fp = fdt->fdt_ofiles[fd].fde_file; 3112 #endif 3113 if (__predict_false(fp == NULL)) 3114 goto out_fallback; 3115 #ifdef CAPABILITIES 3116 if (__predict_false(cap_check_inline_transient(haverights, needrightsp))) 3117 goto out_fallback; 3118 #endif 3119 if (__predict_false(!refcount_acquire_if_not_zero(&fp->f_count))) 3120 goto out_fallback; 3121 3122 /* 3123 * Use an acquire barrier to force re-reading of fdt so it is 3124 * refreshed for verification. 3125 */ 3126 atomic_thread_fence_acq(); 3127 fdt = fdp->fd_files; 3128 #ifdef CAPABILITIES 3129 if (__predict_false(!seqc_consistent_nomb(fd_seqc(fdt, fd), seq))) 3130 #else 3131 if (__predict_false(fp != fdt->fdt_ofiles[fd].fde_file)) 3132 #endif 3133 goto out_fdrop; 3134 *fpp = fp; 3135 return (0); 3136 out_fdrop: 3137 fdrop(fp, curthread); 3138 out_fallback: 3139 return (fget_unlocked_seq(fdp, fd, needrightsp, fpp, NULL)); 3140 } 3141 3142 /* 3143 * Extract the file pointer associated with the specified descriptor for the 3144 * current user process. 3145 * 3146 * If the descriptor doesn't exist or doesn't match 'flags', EBADF is 3147 * returned. 3148 * 3149 * File's rights will be checked against the capability rights mask. 3150 * 3151 * If an error occurred the non-zero error is returned and *fpp is set to 3152 * NULL. Otherwise *fpp is held and set and zero is returned. Caller is 3153 * responsible for fdrop(). 3154 */ 3155 static __inline int 3156 _fget(struct thread *td, int fd, struct file **fpp, int flags, 3157 cap_rights_t *needrightsp) 3158 { 3159 struct filedesc *fdp; 3160 struct file *fp; 3161 int error; 3162 3163 *fpp = NULL; 3164 fdp = td->td_proc->p_fd; 3165 error = fget_unlocked(fdp, fd, needrightsp, &fp); 3166 if (__predict_false(error != 0)) 3167 return (error); 3168 if (__predict_false(fp->f_ops == &badfileops)) { 3169 fdrop(fp, td); 3170 return (EBADF); 3171 } 3172 3173 /* 3174 * FREAD and FWRITE failure return EBADF as per POSIX. 3175 */ 3176 error = 0; 3177 switch (flags) { 3178 case FREAD: 3179 case FWRITE: 3180 if ((fp->f_flag & flags) == 0) 3181 error = EBADF; 3182 break; 3183 case FEXEC: 3184 if ((fp->f_flag & (FREAD | FEXEC)) == 0 || 3185 ((fp->f_flag & FWRITE) != 0)) 3186 error = EBADF; 3187 break; 3188 case 0: 3189 break; 3190 default: 3191 KASSERT(0, ("wrong flags")); 3192 } 3193 3194 if (error != 0) { 3195 fdrop(fp, td); 3196 return (error); 3197 } 3198 3199 *fpp = fp; 3200 return (0); 3201 } 3202 3203 int 3204 fget(struct thread *td, int fd, cap_rights_t *rightsp, struct file **fpp) 3205 { 3206 3207 return (_fget(td, fd, fpp, 0, rightsp)); 3208 } 3209 3210 int 3211 fget_mmap(struct thread *td, int fd, cap_rights_t *rightsp, vm_prot_t *maxprotp, 3212 struct file **fpp) 3213 { 3214 int error; 3215 #ifndef CAPABILITIES 3216 error = _fget(td, fd, fpp, 0, rightsp); 3217 if (maxprotp != NULL) 3218 *maxprotp = VM_PROT_ALL; 3219 return (error); 3220 #else 3221 cap_rights_t fdrights; 3222 struct filedesc *fdp; 3223 struct file *fp; 3224 seqc_t seq; 3225 3226 *fpp = NULL; 3227 fdp = td->td_proc->p_fd; 3228 MPASS(cap_rights_is_set(rightsp, CAP_MMAP)); 3229 for (;;) { 3230 error = fget_unlocked_seq(fdp, fd, rightsp, &fp, &seq); 3231 if (__predict_false(error != 0)) 3232 return (error); 3233 if (__predict_false(fp->f_ops == &badfileops)) { 3234 fdrop(fp, td); 3235 return (EBADF); 3236 } 3237 if (maxprotp != NULL) 3238 fdrights = *cap_rights(fdp, fd); 3239 if (!fd_modified(fdp, fd, seq)) 3240 break; 3241 fdrop(fp, td); 3242 } 3243 3244 /* 3245 * If requested, convert capability rights to access flags. 3246 */ 3247 if (maxprotp != NULL) 3248 *maxprotp = cap_rights_to_vmprot(&fdrights); 3249 *fpp = fp; 3250 return (0); 3251 #endif 3252 } 3253 3254 int 3255 fget_read(struct thread *td, int fd, cap_rights_t *rightsp, struct file **fpp) 3256 { 3257 3258 return (_fget(td, fd, fpp, FREAD, rightsp)); 3259 } 3260 3261 int 3262 fget_write(struct thread *td, int fd, cap_rights_t *rightsp, struct file **fpp) 3263 { 3264 3265 return (_fget(td, fd, fpp, FWRITE, rightsp)); 3266 } 3267 3268 int 3269 fget_fcntl(struct thread *td, int fd, cap_rights_t *rightsp, int needfcntl, 3270 struct file **fpp) 3271 { 3272 struct filedesc *fdp = td->td_proc->p_fd; 3273 #ifndef CAPABILITIES 3274 return (fget_unlocked(fdp, fd, rightsp, fpp)); 3275 #else 3276 struct file *fp; 3277 int error; 3278 seqc_t seq; 3279 3280 *fpp = NULL; 3281 MPASS(cap_rights_is_set(rightsp, CAP_FCNTL)); 3282 for (;;) { 3283 error = fget_unlocked_seq(fdp, fd, rightsp, &fp, &seq); 3284 if (error != 0) 3285 return (error); 3286 error = cap_fcntl_check(fdp, fd, needfcntl); 3287 if (!fd_modified(fdp, fd, seq)) 3288 break; 3289 fdrop(fp, td); 3290 } 3291 if (error != 0) { 3292 fdrop(fp, td); 3293 return (error); 3294 } 3295 *fpp = fp; 3296 return (0); 3297 #endif 3298 } 3299 3300 /* 3301 * Like fget() but loads the underlying vnode, or returns an error if the 3302 * descriptor does not represent a vnode. Note that pipes use vnodes but 3303 * never have VM objects. The returned vnode will be vref()'d. 3304 * 3305 * XXX: what about the unused flags ? 3306 */ 3307 static __inline int 3308 _fgetvp(struct thread *td, int fd, int flags, cap_rights_t *needrightsp, 3309 struct vnode **vpp) 3310 { 3311 struct file *fp; 3312 int error; 3313 3314 *vpp = NULL; 3315 error = _fget(td, fd, &fp, flags, needrightsp); 3316 if (error != 0) 3317 return (error); 3318 if (fp->f_vnode == NULL) { 3319 error = EINVAL; 3320 } else { 3321 *vpp = fp->f_vnode; 3322 vrefact(*vpp); 3323 } 3324 fdrop(fp, td); 3325 3326 return (error); 3327 } 3328 3329 int 3330 fgetvp(struct thread *td, int fd, cap_rights_t *rightsp, struct vnode **vpp) 3331 { 3332 3333 return (_fgetvp(td, fd, 0, rightsp, vpp)); 3334 } 3335 3336 int 3337 fgetvp_rights(struct thread *td, int fd, cap_rights_t *needrightsp, 3338 struct filecaps *havecaps, struct vnode **vpp) 3339 { 3340 struct filecaps caps; 3341 struct file *fp; 3342 int error; 3343 3344 error = fget_cap(td, fd, needrightsp, &fp, &caps); 3345 if (error != 0) 3346 return (error); 3347 if (fp->f_ops == &badfileops) { 3348 error = EBADF; 3349 goto out; 3350 } 3351 if (fp->f_vnode == NULL) { 3352 error = EINVAL; 3353 goto out; 3354 } 3355 3356 *havecaps = caps; 3357 *vpp = fp->f_vnode; 3358 vrefact(*vpp); 3359 fdrop(fp, td); 3360 3361 return (0); 3362 out: 3363 filecaps_free(&caps); 3364 fdrop(fp, td); 3365 return (error); 3366 } 3367 3368 int 3369 fgetvp_read(struct thread *td, int fd, cap_rights_t *rightsp, struct vnode **vpp) 3370 { 3371 3372 return (_fgetvp(td, fd, FREAD, rightsp, vpp)); 3373 } 3374 3375 int 3376 fgetvp_exec(struct thread *td, int fd, cap_rights_t *rightsp, struct vnode **vpp) 3377 { 3378 3379 return (_fgetvp(td, fd, FEXEC, rightsp, vpp)); 3380 } 3381 3382 #ifdef notyet 3383 int 3384 fgetvp_write(struct thread *td, int fd, cap_rights_t *rightsp, 3385 struct vnode **vpp) 3386 { 3387 3388 return (_fgetvp(td, fd, FWRITE, rightsp, vpp)); 3389 } 3390 #endif 3391 3392 /* 3393 * Handle the last reference to a file being closed. 3394 * 3395 * Without the noinline attribute clang keeps inlining the func thorough this 3396 * file when fdrop is used. 3397 */ 3398 int __noinline 3399 _fdrop(struct file *fp, struct thread *td) 3400 { 3401 int error; 3402 #ifdef INVARIANTS 3403 int count; 3404 3405 count = refcount_load(&fp->f_count); 3406 if (count != 0) 3407 panic("fdrop: fp %p count %d", fp, count); 3408 #endif 3409 error = fo_close(fp, td); 3410 atomic_subtract_int(&openfiles, 1); 3411 crfree(fp->f_cred); 3412 free(fp->f_advice, M_FADVISE); 3413 uma_zfree(file_zone, fp); 3414 3415 return (error); 3416 } 3417 3418 /* 3419 * Apply an advisory lock on a file descriptor. 3420 * 3421 * Just attempt to get a record lock of the requested type on the entire file 3422 * (l_whence = SEEK_SET, l_start = 0, l_len = 0). 3423 */ 3424 #ifndef _SYS_SYSPROTO_H_ 3425 struct flock_args { 3426 int fd; 3427 int how; 3428 }; 3429 #endif 3430 /* ARGSUSED */ 3431 int 3432 sys_flock(struct thread *td, struct flock_args *uap) 3433 { 3434 struct file *fp; 3435 struct vnode *vp; 3436 struct flock lf; 3437 int error; 3438 3439 error = fget(td, uap->fd, &cap_flock_rights, &fp); 3440 if (error != 0) 3441 return (error); 3442 if (fp->f_type != DTYPE_VNODE) { 3443 fdrop(fp, td); 3444 return (EOPNOTSUPP); 3445 } 3446 3447 vp = fp->f_vnode; 3448 lf.l_whence = SEEK_SET; 3449 lf.l_start = 0; 3450 lf.l_len = 0; 3451 if (uap->how & LOCK_UN) { 3452 lf.l_type = F_UNLCK; 3453 atomic_clear_int(&fp->f_flag, FHASLOCK); 3454 error = VOP_ADVLOCK(vp, (caddr_t)fp, F_UNLCK, &lf, F_FLOCK); 3455 goto done2; 3456 } 3457 if (uap->how & LOCK_EX) 3458 lf.l_type = F_WRLCK; 3459 else if (uap->how & LOCK_SH) 3460 lf.l_type = F_RDLCK; 3461 else { 3462 error = EBADF; 3463 goto done2; 3464 } 3465 atomic_set_int(&fp->f_flag, FHASLOCK); 3466 error = VOP_ADVLOCK(vp, (caddr_t)fp, F_SETLK, &lf, 3467 (uap->how & LOCK_NB) ? F_FLOCK : F_FLOCK | F_WAIT); 3468 done2: 3469 fdrop(fp, td); 3470 return (error); 3471 } 3472 /* 3473 * Duplicate the specified descriptor to a free descriptor. 3474 */ 3475 int 3476 dupfdopen(struct thread *td, struct filedesc *fdp, int dfd, int mode, 3477 int openerror, int *indxp) 3478 { 3479 struct filedescent *newfde, *oldfde; 3480 struct file *fp; 3481 u_long *ioctls; 3482 int error, indx; 3483 3484 KASSERT(openerror == ENODEV || openerror == ENXIO, 3485 ("unexpected error %d in %s", openerror, __func__)); 3486 3487 /* 3488 * If the to-be-dup'd fd number is greater than the allowed number 3489 * of file descriptors, or the fd to be dup'd has already been 3490 * closed, then reject. 3491 */ 3492 FILEDESC_XLOCK(fdp); 3493 if ((fp = fget_locked(fdp, dfd)) == NULL) { 3494 FILEDESC_XUNLOCK(fdp); 3495 return (EBADF); 3496 } 3497 3498 error = fdalloc(td, 0, &indx); 3499 if (error != 0) { 3500 FILEDESC_XUNLOCK(fdp); 3501 return (error); 3502 } 3503 3504 /* 3505 * There are two cases of interest here. 3506 * 3507 * For ENODEV simply dup (dfd) to file descriptor (indx) and return. 3508 * 3509 * For ENXIO steal away the file structure from (dfd) and store it in 3510 * (indx). (dfd) is effectively closed by this operation. 3511 */ 3512 switch (openerror) { 3513 case ENODEV: 3514 /* 3515 * Check that the mode the file is being opened for is a 3516 * subset of the mode of the existing descriptor. 3517 */ 3518 if (((mode & (FREAD|FWRITE)) | fp->f_flag) != fp->f_flag) { 3519 fdunused(fdp, indx); 3520 FILEDESC_XUNLOCK(fdp); 3521 return (EACCES); 3522 } 3523 if (!fhold(fp)) { 3524 fdunused(fdp, indx); 3525 FILEDESC_XUNLOCK(fdp); 3526 return (EBADF); 3527 } 3528 newfde = &fdp->fd_ofiles[indx]; 3529 oldfde = &fdp->fd_ofiles[dfd]; 3530 ioctls = filecaps_copy_prep(&oldfde->fde_caps); 3531 #ifdef CAPABILITIES 3532 seqc_write_begin(&newfde->fde_seqc); 3533 #endif 3534 memcpy(newfde, oldfde, fde_change_size); 3535 filecaps_copy_finish(&oldfde->fde_caps, &newfde->fde_caps, 3536 ioctls); 3537 #ifdef CAPABILITIES 3538 seqc_write_end(&newfde->fde_seqc); 3539 #endif 3540 break; 3541 case ENXIO: 3542 /* 3543 * Steal away the file pointer from dfd and stuff it into indx. 3544 */ 3545 newfde = &fdp->fd_ofiles[indx]; 3546 oldfde = &fdp->fd_ofiles[dfd]; 3547 #ifdef CAPABILITIES 3548 seqc_write_begin(&newfde->fde_seqc); 3549 #endif 3550 memcpy(newfde, oldfde, fde_change_size); 3551 oldfde->fde_file = NULL; 3552 fdunused(fdp, dfd); 3553 #ifdef CAPABILITIES 3554 seqc_write_end(&newfde->fde_seqc); 3555 #endif 3556 break; 3557 } 3558 FILEDESC_XUNLOCK(fdp); 3559 *indxp = indx; 3560 return (0); 3561 } 3562 3563 /* 3564 * This sysctl determines if we will allow a process to chroot(2) if it 3565 * has a directory open: 3566 * 0: disallowed for all processes. 3567 * 1: allowed for processes that were not already chroot(2)'ed. 3568 * 2: allowed for all processes. 3569 */ 3570 3571 static int chroot_allow_open_directories = 1; 3572 3573 SYSCTL_INT(_kern, OID_AUTO, chroot_allow_open_directories, CTLFLAG_RW, 3574 &chroot_allow_open_directories, 0, 3575 "Allow a process to chroot(2) if it has a directory open"); 3576 3577 /* 3578 * Helper function for raised chroot(2) security function: Refuse if 3579 * any filedescriptors are open directories. 3580 */ 3581 static int 3582 chroot_refuse_vdir_fds(struct filedesc *fdp) 3583 { 3584 struct vnode *vp; 3585 struct file *fp; 3586 int fd, lastfile; 3587 3588 FILEDESC_LOCK_ASSERT(fdp); 3589 3590 lastfile = fdlastfile(fdp); 3591 for (fd = 0; fd <= lastfile; fd++) { 3592 fp = fget_locked(fdp, fd); 3593 if (fp == NULL) 3594 continue; 3595 if (fp->f_type == DTYPE_VNODE) { 3596 vp = fp->f_vnode; 3597 if (vp->v_type == VDIR) 3598 return (EPERM); 3599 } 3600 } 3601 return (0); 3602 } 3603 3604 static void 3605 pwd_fill(struct pwd *oldpwd, struct pwd *newpwd) 3606 { 3607 3608 if (newpwd->pwd_cdir == NULL && oldpwd->pwd_cdir != NULL) { 3609 vrefact(oldpwd->pwd_cdir); 3610 newpwd->pwd_cdir = oldpwd->pwd_cdir; 3611 } 3612 3613 if (newpwd->pwd_rdir == NULL && oldpwd->pwd_rdir != NULL) { 3614 vrefact(oldpwd->pwd_rdir); 3615 newpwd->pwd_rdir = oldpwd->pwd_rdir; 3616 } 3617 3618 if (newpwd->pwd_jdir == NULL && oldpwd->pwd_jdir != NULL) { 3619 vrefact(oldpwd->pwd_jdir); 3620 newpwd->pwd_jdir = oldpwd->pwd_jdir; 3621 } 3622 } 3623 3624 struct pwd * 3625 pwd_hold_pwddesc(struct pwddesc *pdp) 3626 { 3627 struct pwd *pwd; 3628 3629 PWDDESC_ASSERT_XLOCKED(pdp); 3630 pwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); 3631 if (pwd != NULL) 3632 refcount_acquire(&pwd->pwd_refcount); 3633 return (pwd); 3634 } 3635 3636 bool 3637 pwd_hold_smr(struct pwd *pwd) 3638 { 3639 3640 MPASS(pwd != NULL); 3641 if (__predict_true(refcount_acquire_if_not_zero(&pwd->pwd_refcount))) { 3642 return (true); 3643 } 3644 return (false); 3645 } 3646 3647 struct pwd * 3648 pwd_hold(struct thread *td) 3649 { 3650 struct pwddesc *pdp; 3651 struct pwd *pwd; 3652 3653 pdp = td->td_proc->p_pd; 3654 3655 vfs_smr_enter(); 3656 pwd = vfs_smr_entered_load(&pdp->pd_pwd); 3657 if (pwd_hold_smr(pwd)) { 3658 vfs_smr_exit(); 3659 return (pwd); 3660 } 3661 vfs_smr_exit(); 3662 PWDDESC_XLOCK(pdp); 3663 pwd = pwd_hold_pwddesc(pdp); 3664 MPASS(pwd != NULL); 3665 PWDDESC_XUNLOCK(pdp); 3666 return (pwd); 3667 } 3668 3669 static struct pwd * 3670 pwd_alloc(void) 3671 { 3672 struct pwd *pwd; 3673 3674 pwd = uma_zalloc_smr(pwd_zone, M_WAITOK); 3675 bzero(pwd, sizeof(*pwd)); 3676 refcount_init(&pwd->pwd_refcount, 1); 3677 return (pwd); 3678 } 3679 3680 void 3681 pwd_drop(struct pwd *pwd) 3682 { 3683 3684 if (!refcount_release(&pwd->pwd_refcount)) 3685 return; 3686 3687 if (pwd->pwd_cdir != NULL) 3688 vrele(pwd->pwd_cdir); 3689 if (pwd->pwd_rdir != NULL) 3690 vrele(pwd->pwd_rdir); 3691 if (pwd->pwd_jdir != NULL) 3692 vrele(pwd->pwd_jdir); 3693 uma_zfree_smr(pwd_zone, pwd); 3694 } 3695 3696 /* 3697 * Common routine for kern_chroot() and jail_attach(). The caller is 3698 * responsible for invoking priv_check() and mac_vnode_check_chroot() to 3699 * authorize this operation. 3700 */ 3701 int 3702 pwd_chroot(struct thread *td, struct vnode *vp) 3703 { 3704 struct pwddesc *pdp; 3705 struct filedesc *fdp; 3706 struct pwd *newpwd, *oldpwd; 3707 int error; 3708 3709 fdp = td->td_proc->p_fd; 3710 pdp = td->td_proc->p_pd; 3711 newpwd = pwd_alloc(); 3712 FILEDESC_SLOCK(fdp); 3713 PWDDESC_XLOCK(pdp); 3714 oldpwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); 3715 if (chroot_allow_open_directories == 0 || 3716 (chroot_allow_open_directories == 1 && 3717 oldpwd->pwd_rdir != rootvnode)) { 3718 error = chroot_refuse_vdir_fds(fdp); 3719 FILEDESC_SUNLOCK(fdp); 3720 if (error != 0) { 3721 PWDDESC_XUNLOCK(pdp); 3722 pwd_drop(newpwd); 3723 return (error); 3724 } 3725 } else { 3726 FILEDESC_SUNLOCK(fdp); 3727 } 3728 3729 vrefact(vp); 3730 newpwd->pwd_rdir = vp; 3731 if (oldpwd->pwd_jdir == NULL) { 3732 vrefact(vp); 3733 newpwd->pwd_jdir = vp; 3734 } 3735 pwd_fill(oldpwd, newpwd); 3736 pwd_set(pdp, newpwd); 3737 PWDDESC_XUNLOCK(pdp); 3738 pwd_drop(oldpwd); 3739 return (0); 3740 } 3741 3742 void 3743 pwd_chdir(struct thread *td, struct vnode *vp) 3744 { 3745 struct pwddesc *pdp; 3746 struct pwd *newpwd, *oldpwd; 3747 3748 VNPASS(vp->v_usecount > 0, vp); 3749 3750 newpwd = pwd_alloc(); 3751 pdp = td->td_proc->p_pd; 3752 PWDDESC_XLOCK(pdp); 3753 oldpwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); 3754 newpwd->pwd_cdir = vp; 3755 pwd_fill(oldpwd, newpwd); 3756 pwd_set(pdp, newpwd); 3757 PWDDESC_XUNLOCK(pdp); 3758 pwd_drop(oldpwd); 3759 } 3760 3761 void 3762 pwd_ensure_dirs(void) 3763 { 3764 struct pwddesc *pdp; 3765 struct pwd *oldpwd, *newpwd; 3766 3767 pdp = curproc->p_pd; 3768 PWDDESC_XLOCK(pdp); 3769 oldpwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); 3770 if (oldpwd->pwd_cdir != NULL && oldpwd->pwd_rdir != NULL) { 3771 PWDDESC_XUNLOCK(pdp); 3772 return; 3773 } 3774 PWDDESC_XUNLOCK(pdp); 3775 3776 newpwd = pwd_alloc(); 3777 PWDDESC_XLOCK(pdp); 3778 oldpwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); 3779 pwd_fill(oldpwd, newpwd); 3780 if (newpwd->pwd_cdir == NULL) { 3781 vrefact(rootvnode); 3782 newpwd->pwd_cdir = rootvnode; 3783 } 3784 if (newpwd->pwd_rdir == NULL) { 3785 vrefact(rootvnode); 3786 newpwd->pwd_rdir = rootvnode; 3787 } 3788 pwd_set(pdp, newpwd); 3789 PWDDESC_XUNLOCK(pdp); 3790 pwd_drop(oldpwd); 3791 } 3792 3793 void 3794 pwd_set_rootvnode(void) 3795 { 3796 struct pwddesc *pdp; 3797 struct pwd *oldpwd, *newpwd; 3798 3799 pdp = curproc->p_pd; 3800 3801 newpwd = pwd_alloc(); 3802 PWDDESC_XLOCK(pdp); 3803 oldpwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); 3804 vrefact(rootvnode); 3805 newpwd->pwd_cdir = rootvnode; 3806 vrefact(rootvnode); 3807 newpwd->pwd_rdir = rootvnode; 3808 pwd_fill(oldpwd, newpwd); 3809 pwd_set(pdp, newpwd); 3810 PWDDESC_XUNLOCK(pdp); 3811 pwd_drop(oldpwd); 3812 } 3813 3814 /* 3815 * Scan all active processes and prisons to see if any of them have a current 3816 * or root directory of `olddp'. If so, replace them with the new mount point. 3817 */ 3818 void 3819 mountcheckdirs(struct vnode *olddp, struct vnode *newdp) 3820 { 3821 struct pwddesc *pdp; 3822 struct pwd *newpwd, *oldpwd; 3823 struct prison *pr; 3824 struct proc *p; 3825 int nrele; 3826 3827 if (vrefcnt(olddp) == 1) 3828 return; 3829 nrele = 0; 3830 newpwd = pwd_alloc(); 3831 sx_slock(&allproc_lock); 3832 FOREACH_PROC_IN_SYSTEM(p) { 3833 PROC_LOCK(p); 3834 pdp = pdhold(p); 3835 PROC_UNLOCK(p); 3836 if (pdp == NULL) 3837 continue; 3838 PWDDESC_XLOCK(pdp); 3839 oldpwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); 3840 if (oldpwd == NULL || 3841 (oldpwd->pwd_cdir != olddp && 3842 oldpwd->pwd_rdir != olddp && 3843 oldpwd->pwd_jdir != olddp)) { 3844 PWDDESC_XUNLOCK(pdp); 3845 pddrop(pdp); 3846 continue; 3847 } 3848 if (oldpwd->pwd_cdir == olddp) { 3849 vrefact(newdp); 3850 newpwd->pwd_cdir = newdp; 3851 } 3852 if (oldpwd->pwd_rdir == olddp) { 3853 vrefact(newdp); 3854 newpwd->pwd_rdir = newdp; 3855 } 3856 if (oldpwd->pwd_jdir == olddp) { 3857 vrefact(newdp); 3858 newpwd->pwd_jdir = newdp; 3859 } 3860 pwd_fill(oldpwd, newpwd); 3861 pwd_set(pdp, newpwd); 3862 PWDDESC_XUNLOCK(pdp); 3863 pwd_drop(oldpwd); 3864 pddrop(pdp); 3865 newpwd = pwd_alloc(); 3866 } 3867 sx_sunlock(&allproc_lock); 3868 pwd_drop(newpwd); 3869 if (rootvnode == olddp) { 3870 vrefact(newdp); 3871 rootvnode = newdp; 3872 nrele++; 3873 } 3874 mtx_lock(&prison0.pr_mtx); 3875 if (prison0.pr_root == olddp) { 3876 vrefact(newdp); 3877 prison0.pr_root = newdp; 3878 nrele++; 3879 } 3880 mtx_unlock(&prison0.pr_mtx); 3881 sx_slock(&allprison_lock); 3882 TAILQ_FOREACH(pr, &allprison, pr_list) { 3883 mtx_lock(&pr->pr_mtx); 3884 if (pr->pr_root == olddp) { 3885 vrefact(newdp); 3886 pr->pr_root = newdp; 3887 nrele++; 3888 } 3889 mtx_unlock(&pr->pr_mtx); 3890 } 3891 sx_sunlock(&allprison_lock); 3892 while (nrele--) 3893 vrele(olddp); 3894 } 3895 3896 struct filedesc_to_leader * 3897 filedesc_to_leader_alloc(struct filedesc_to_leader *old, struct filedesc *fdp, struct proc *leader) 3898 { 3899 struct filedesc_to_leader *fdtol; 3900 3901 fdtol = malloc(sizeof(struct filedesc_to_leader), 3902 M_FILEDESC_TO_LEADER, M_WAITOK); 3903 fdtol->fdl_refcount = 1; 3904 fdtol->fdl_holdcount = 0; 3905 fdtol->fdl_wakeup = 0; 3906 fdtol->fdl_leader = leader; 3907 if (old != NULL) { 3908 FILEDESC_XLOCK(fdp); 3909 fdtol->fdl_next = old->fdl_next; 3910 fdtol->fdl_prev = old; 3911 old->fdl_next = fdtol; 3912 fdtol->fdl_next->fdl_prev = fdtol; 3913 FILEDESC_XUNLOCK(fdp); 3914 } else { 3915 fdtol->fdl_next = fdtol; 3916 fdtol->fdl_prev = fdtol; 3917 } 3918 return (fdtol); 3919 } 3920 3921 static int 3922 sysctl_kern_proc_nfds(SYSCTL_HANDLER_ARGS) 3923 { 3924 NDSLOTTYPE *map; 3925 struct filedesc *fdp; 3926 int count, off, minoff; 3927 3928 if (*(int *)arg1 != 0) 3929 return (EINVAL); 3930 3931 fdp = curproc->p_fd; 3932 count = 0; 3933 FILEDESC_SLOCK(fdp); 3934 map = fdp->fd_map; 3935 off = NDSLOT(fdp->fd_nfiles - 1); 3936 for (minoff = NDSLOT(0); off >= minoff; --off) 3937 count += bitcountl(map[off]); 3938 FILEDESC_SUNLOCK(fdp); 3939 3940 return (SYSCTL_OUT(req, &count, sizeof(count))); 3941 } 3942 3943 static SYSCTL_NODE(_kern_proc, KERN_PROC_NFDS, nfds, 3944 CTLFLAG_RD|CTLFLAG_CAPRD|CTLFLAG_MPSAFE, sysctl_kern_proc_nfds, 3945 "Number of open file descriptors"); 3946 3947 /* 3948 * Get file structures globally. 3949 */ 3950 static int 3951 sysctl_kern_file(SYSCTL_HANDLER_ARGS) 3952 { 3953 struct xfile xf; 3954 struct filedesc *fdp; 3955 struct file *fp; 3956 struct proc *p; 3957 int error, n, lastfile; 3958 3959 error = sysctl_wire_old_buffer(req, 0); 3960 if (error != 0) 3961 return (error); 3962 if (req->oldptr == NULL) { 3963 n = 0; 3964 sx_slock(&allproc_lock); 3965 FOREACH_PROC_IN_SYSTEM(p) { 3966 PROC_LOCK(p); 3967 if (p->p_state == PRS_NEW) { 3968 PROC_UNLOCK(p); 3969 continue; 3970 } 3971 fdp = fdhold(p); 3972 PROC_UNLOCK(p); 3973 if (fdp == NULL) 3974 continue; 3975 /* overestimates sparse tables. */ 3976 n += fdp->fd_nfiles; 3977 fddrop(fdp); 3978 } 3979 sx_sunlock(&allproc_lock); 3980 return (SYSCTL_OUT(req, 0, n * sizeof(xf))); 3981 } 3982 error = 0; 3983 bzero(&xf, sizeof(xf)); 3984 xf.xf_size = sizeof(xf); 3985 sx_slock(&allproc_lock); 3986 FOREACH_PROC_IN_SYSTEM(p) { 3987 PROC_LOCK(p); 3988 if (p->p_state == PRS_NEW) { 3989 PROC_UNLOCK(p); 3990 continue; 3991 } 3992 if (p_cansee(req->td, p) != 0) { 3993 PROC_UNLOCK(p); 3994 continue; 3995 } 3996 xf.xf_pid = p->p_pid; 3997 xf.xf_uid = p->p_ucred->cr_uid; 3998 fdp = fdhold(p); 3999 PROC_UNLOCK(p); 4000 if (fdp == NULL) 4001 continue; 4002 FILEDESC_SLOCK(fdp); 4003 lastfile = fdlastfile(fdp); 4004 for (n = 0; refcount_load(&fdp->fd_refcnt) > 0 && n <= lastfile; 4005 n++) { 4006 if ((fp = fdp->fd_ofiles[n].fde_file) == NULL) 4007 continue; 4008 xf.xf_fd = n; 4009 xf.xf_file = (uintptr_t)fp; 4010 xf.xf_data = (uintptr_t)fp->f_data; 4011 xf.xf_vnode = (uintptr_t)fp->f_vnode; 4012 xf.xf_type = (uintptr_t)fp->f_type; 4013 xf.xf_count = refcount_load(&fp->f_count); 4014 xf.xf_msgcount = 0; 4015 xf.xf_offset = foffset_get(fp); 4016 xf.xf_flag = fp->f_flag; 4017 error = SYSCTL_OUT(req, &xf, sizeof(xf)); 4018 if (error) 4019 break; 4020 } 4021 FILEDESC_SUNLOCK(fdp); 4022 fddrop(fdp); 4023 if (error) 4024 break; 4025 } 4026 sx_sunlock(&allproc_lock); 4027 return (error); 4028 } 4029 4030 SYSCTL_PROC(_kern, KERN_FILE, file, CTLTYPE_OPAQUE|CTLFLAG_RD|CTLFLAG_MPSAFE, 4031 0, 0, sysctl_kern_file, "S,xfile", "Entire file table"); 4032 4033 #ifdef KINFO_FILE_SIZE 4034 CTASSERT(sizeof(struct kinfo_file) == KINFO_FILE_SIZE); 4035 #endif 4036 4037 static int 4038 xlate_fflags(int fflags) 4039 { 4040 static const struct { 4041 int fflag; 4042 int kf_fflag; 4043 } fflags_table[] = { 4044 { FAPPEND, KF_FLAG_APPEND }, 4045 { FASYNC, KF_FLAG_ASYNC }, 4046 { FFSYNC, KF_FLAG_FSYNC }, 4047 { FHASLOCK, KF_FLAG_HASLOCK }, 4048 { FNONBLOCK, KF_FLAG_NONBLOCK }, 4049 { FREAD, KF_FLAG_READ }, 4050 { FWRITE, KF_FLAG_WRITE }, 4051 { O_CREAT, KF_FLAG_CREAT }, 4052 { O_DIRECT, KF_FLAG_DIRECT }, 4053 { O_EXCL, KF_FLAG_EXCL }, 4054 { O_EXEC, KF_FLAG_EXEC }, 4055 { O_EXLOCK, KF_FLAG_EXLOCK }, 4056 { O_NOFOLLOW, KF_FLAG_NOFOLLOW }, 4057 { O_SHLOCK, KF_FLAG_SHLOCK }, 4058 { O_TRUNC, KF_FLAG_TRUNC } 4059 }; 4060 unsigned int i; 4061 int kflags; 4062 4063 kflags = 0; 4064 for (i = 0; i < nitems(fflags_table); i++) 4065 if (fflags & fflags_table[i].fflag) 4066 kflags |= fflags_table[i].kf_fflag; 4067 return (kflags); 4068 } 4069 4070 /* Trim unused data from kf_path by truncating the structure size. */ 4071 void 4072 pack_kinfo(struct kinfo_file *kif) 4073 { 4074 4075 kif->kf_structsize = offsetof(struct kinfo_file, kf_path) + 4076 strlen(kif->kf_path) + 1; 4077 kif->kf_structsize = roundup(kif->kf_structsize, sizeof(uint64_t)); 4078 } 4079 4080 static void 4081 export_file_to_kinfo(struct file *fp, int fd, cap_rights_t *rightsp, 4082 struct kinfo_file *kif, struct filedesc *fdp, int flags) 4083 { 4084 int error; 4085 4086 bzero(kif, sizeof(*kif)); 4087 4088 /* Set a default type to allow for empty fill_kinfo() methods. */ 4089 kif->kf_type = KF_TYPE_UNKNOWN; 4090 kif->kf_flags = xlate_fflags(fp->f_flag); 4091 if (rightsp != NULL) 4092 kif->kf_cap_rights = *rightsp; 4093 else 4094 cap_rights_init_zero(&kif->kf_cap_rights); 4095 kif->kf_fd = fd; 4096 kif->kf_ref_count = refcount_load(&fp->f_count); 4097 kif->kf_offset = foffset_get(fp); 4098 4099 /* 4100 * This may drop the filedesc lock, so the 'fp' cannot be 4101 * accessed after this call. 4102 */ 4103 error = fo_fill_kinfo(fp, kif, fdp); 4104 if (error == 0) 4105 kif->kf_status |= KF_ATTR_VALID; 4106 if ((flags & KERN_FILEDESC_PACK_KINFO) != 0) 4107 pack_kinfo(kif); 4108 else 4109 kif->kf_structsize = roundup2(sizeof(*kif), sizeof(uint64_t)); 4110 } 4111 4112 static void 4113 export_vnode_to_kinfo(struct vnode *vp, int fd, int fflags, 4114 struct kinfo_file *kif, int flags) 4115 { 4116 int error; 4117 4118 bzero(kif, sizeof(*kif)); 4119 4120 kif->kf_type = KF_TYPE_VNODE; 4121 error = vn_fill_kinfo_vnode(vp, kif); 4122 if (error == 0) 4123 kif->kf_status |= KF_ATTR_VALID; 4124 kif->kf_flags = xlate_fflags(fflags); 4125 cap_rights_init_zero(&kif->kf_cap_rights); 4126 kif->kf_fd = fd; 4127 kif->kf_ref_count = -1; 4128 kif->kf_offset = -1; 4129 if ((flags & KERN_FILEDESC_PACK_KINFO) != 0) 4130 pack_kinfo(kif); 4131 else 4132 kif->kf_structsize = roundup2(sizeof(*kif), sizeof(uint64_t)); 4133 vrele(vp); 4134 } 4135 4136 struct export_fd_buf { 4137 struct filedesc *fdp; 4138 struct pwddesc *pdp; 4139 struct sbuf *sb; 4140 ssize_t remainder; 4141 struct kinfo_file kif; 4142 int flags; 4143 }; 4144 4145 static int 4146 export_kinfo_to_sb(struct export_fd_buf *efbuf) 4147 { 4148 struct kinfo_file *kif; 4149 4150 kif = &efbuf->kif; 4151 if (efbuf->remainder != -1) { 4152 if (efbuf->remainder < kif->kf_structsize) { 4153 /* Terminate export. */ 4154 efbuf->remainder = 0; 4155 return (0); 4156 } 4157 efbuf->remainder -= kif->kf_structsize; 4158 } 4159 return (sbuf_bcat(efbuf->sb, kif, kif->kf_structsize) == 0 ? 0 : ENOMEM); 4160 } 4161 4162 static int 4163 export_file_to_sb(struct file *fp, int fd, cap_rights_t *rightsp, 4164 struct export_fd_buf *efbuf) 4165 { 4166 int error; 4167 4168 if (efbuf->remainder == 0) 4169 return (0); 4170 export_file_to_kinfo(fp, fd, rightsp, &efbuf->kif, efbuf->fdp, 4171 efbuf->flags); 4172 FILEDESC_SUNLOCK(efbuf->fdp); 4173 error = export_kinfo_to_sb(efbuf); 4174 FILEDESC_SLOCK(efbuf->fdp); 4175 return (error); 4176 } 4177 4178 static int 4179 export_vnode_to_sb(struct vnode *vp, int fd, int fflags, 4180 struct export_fd_buf *efbuf) 4181 { 4182 int error; 4183 4184 if (efbuf->remainder == 0) 4185 return (0); 4186 if (efbuf->pdp != NULL) 4187 PWDDESC_XUNLOCK(efbuf->pdp); 4188 export_vnode_to_kinfo(vp, fd, fflags, &efbuf->kif, efbuf->flags); 4189 error = export_kinfo_to_sb(efbuf); 4190 if (efbuf->pdp != NULL) 4191 PWDDESC_XLOCK(efbuf->pdp); 4192 return (error); 4193 } 4194 4195 /* 4196 * Store a process file descriptor information to sbuf. 4197 * 4198 * Takes a locked proc as argument, and returns with the proc unlocked. 4199 */ 4200 int 4201 kern_proc_filedesc_out(struct proc *p, struct sbuf *sb, ssize_t maxlen, 4202 int flags) 4203 { 4204 struct file *fp; 4205 struct filedesc *fdp; 4206 struct pwddesc *pdp; 4207 struct export_fd_buf *efbuf; 4208 struct vnode *cttyvp, *textvp, *tracevp; 4209 struct pwd *pwd; 4210 int error, i, lastfile; 4211 cap_rights_t rights; 4212 4213 PROC_LOCK_ASSERT(p, MA_OWNED); 4214 4215 /* ktrace vnode */ 4216 tracevp = p->p_tracevp; 4217 if (tracevp != NULL) 4218 vrefact(tracevp); 4219 /* text vnode */ 4220 textvp = p->p_textvp; 4221 if (textvp != NULL) 4222 vrefact(textvp); 4223 /* Controlling tty. */ 4224 cttyvp = NULL; 4225 if (p->p_pgrp != NULL && p->p_pgrp->pg_session != NULL) { 4226 cttyvp = p->p_pgrp->pg_session->s_ttyvp; 4227 if (cttyvp != NULL) 4228 vrefact(cttyvp); 4229 } 4230 fdp = fdhold(p); 4231 pdp = pdhold(p); 4232 PROC_UNLOCK(p); 4233 efbuf = malloc(sizeof(*efbuf), M_TEMP, M_WAITOK); 4234 efbuf->fdp = NULL; 4235 efbuf->pdp = NULL; 4236 efbuf->sb = sb; 4237 efbuf->remainder = maxlen; 4238 efbuf->flags = flags; 4239 if (tracevp != NULL) 4240 export_vnode_to_sb(tracevp, KF_FD_TYPE_TRACE, FREAD | FWRITE, 4241 efbuf); 4242 if (textvp != NULL) 4243 export_vnode_to_sb(textvp, KF_FD_TYPE_TEXT, FREAD, efbuf); 4244 if (cttyvp != NULL) 4245 export_vnode_to_sb(cttyvp, KF_FD_TYPE_CTTY, FREAD | FWRITE, 4246 efbuf); 4247 error = 0; 4248 if (pdp == NULL || fdp == NULL) 4249 goto fail; 4250 efbuf->fdp = fdp; 4251 efbuf->pdp = pdp; 4252 PWDDESC_XLOCK(pdp); 4253 pwd = pwd_hold_pwddesc(pdp); 4254 if (pwd != NULL) { 4255 /* working directory */ 4256 if (pwd->pwd_cdir != NULL) { 4257 vrefact(pwd->pwd_cdir); 4258 export_vnode_to_sb(pwd->pwd_cdir, KF_FD_TYPE_CWD, FREAD, efbuf); 4259 } 4260 /* root directory */ 4261 if (pwd->pwd_rdir != NULL) { 4262 vrefact(pwd->pwd_rdir); 4263 export_vnode_to_sb(pwd->pwd_rdir, KF_FD_TYPE_ROOT, FREAD, efbuf); 4264 } 4265 /* jail directory */ 4266 if (pwd->pwd_jdir != NULL) { 4267 vrefact(pwd->pwd_jdir); 4268 export_vnode_to_sb(pwd->pwd_jdir, KF_FD_TYPE_JAIL, FREAD, efbuf); 4269 } 4270 } 4271 PWDDESC_XUNLOCK(pdp); 4272 if (pwd != NULL) 4273 pwd_drop(pwd); 4274 FILEDESC_SLOCK(fdp); 4275 lastfile = fdlastfile(fdp); 4276 for (i = 0; refcount_load(&fdp->fd_refcnt) > 0 && i <= lastfile; i++) { 4277 if ((fp = fdp->fd_ofiles[i].fde_file) == NULL) 4278 continue; 4279 #ifdef CAPABILITIES 4280 rights = *cap_rights(fdp, i); 4281 #else /* !CAPABILITIES */ 4282 rights = cap_no_rights; 4283 #endif 4284 /* 4285 * Create sysctl entry. It is OK to drop the filedesc 4286 * lock inside of export_file_to_sb() as we will 4287 * re-validate and re-evaluate its properties when the 4288 * loop continues. 4289 */ 4290 error = export_file_to_sb(fp, i, &rights, efbuf); 4291 if (error != 0 || efbuf->remainder == 0) 4292 break; 4293 } 4294 FILEDESC_SUNLOCK(fdp); 4295 fail: 4296 if (fdp != NULL) 4297 fddrop(fdp); 4298 if (pdp != NULL) 4299 pddrop(pdp); 4300 free(efbuf, M_TEMP); 4301 return (error); 4302 } 4303 4304 #define FILEDESC_SBUF_SIZE (sizeof(struct kinfo_file) * 5) 4305 4306 /* 4307 * Get per-process file descriptors for use by procstat(1), et al. 4308 */ 4309 static int 4310 sysctl_kern_proc_filedesc(SYSCTL_HANDLER_ARGS) 4311 { 4312 struct sbuf sb; 4313 struct proc *p; 4314 ssize_t maxlen; 4315 int error, error2, *name; 4316 4317 name = (int *)arg1; 4318 4319 sbuf_new_for_sysctl(&sb, NULL, FILEDESC_SBUF_SIZE, req); 4320 sbuf_clear_flags(&sb, SBUF_INCLUDENUL); 4321 error = pget((pid_t)name[0], PGET_CANDEBUG | PGET_NOTWEXIT, &p); 4322 if (error != 0) { 4323 sbuf_delete(&sb); 4324 return (error); 4325 } 4326 maxlen = req->oldptr != NULL ? req->oldlen : -1; 4327 error = kern_proc_filedesc_out(p, &sb, maxlen, 4328 KERN_FILEDESC_PACK_KINFO); 4329 error2 = sbuf_finish(&sb); 4330 sbuf_delete(&sb); 4331 return (error != 0 ? error : error2); 4332 } 4333 4334 #ifdef COMPAT_FREEBSD7 4335 #ifdef KINFO_OFILE_SIZE 4336 CTASSERT(sizeof(struct kinfo_ofile) == KINFO_OFILE_SIZE); 4337 #endif 4338 4339 static void 4340 kinfo_to_okinfo(struct kinfo_file *kif, struct kinfo_ofile *okif) 4341 { 4342 4343 okif->kf_structsize = sizeof(*okif); 4344 okif->kf_type = kif->kf_type; 4345 okif->kf_fd = kif->kf_fd; 4346 okif->kf_ref_count = kif->kf_ref_count; 4347 okif->kf_flags = kif->kf_flags & (KF_FLAG_READ | KF_FLAG_WRITE | 4348 KF_FLAG_APPEND | KF_FLAG_ASYNC | KF_FLAG_FSYNC | KF_FLAG_NONBLOCK | 4349 KF_FLAG_DIRECT | KF_FLAG_HASLOCK); 4350 okif->kf_offset = kif->kf_offset; 4351 if (kif->kf_type == KF_TYPE_VNODE) 4352 okif->kf_vnode_type = kif->kf_un.kf_file.kf_file_type; 4353 else 4354 okif->kf_vnode_type = KF_VTYPE_VNON; 4355 strlcpy(okif->kf_path, kif->kf_path, sizeof(okif->kf_path)); 4356 if (kif->kf_type == KF_TYPE_SOCKET) { 4357 okif->kf_sock_domain = kif->kf_un.kf_sock.kf_sock_domain0; 4358 okif->kf_sock_type = kif->kf_un.kf_sock.kf_sock_type0; 4359 okif->kf_sock_protocol = kif->kf_un.kf_sock.kf_sock_protocol0; 4360 okif->kf_sa_local = kif->kf_un.kf_sock.kf_sa_local; 4361 okif->kf_sa_peer = kif->kf_un.kf_sock.kf_sa_peer; 4362 } else { 4363 okif->kf_sa_local.ss_family = AF_UNSPEC; 4364 okif->kf_sa_peer.ss_family = AF_UNSPEC; 4365 } 4366 } 4367 4368 static int 4369 export_vnode_for_osysctl(struct vnode *vp, int type, struct kinfo_file *kif, 4370 struct kinfo_ofile *okif, struct pwddesc *pdp, struct sysctl_req *req) 4371 { 4372 int error; 4373 4374 vrefact(vp); 4375 PWDDESC_XUNLOCK(pdp); 4376 export_vnode_to_kinfo(vp, type, 0, kif, KERN_FILEDESC_PACK_KINFO); 4377 kinfo_to_okinfo(kif, okif); 4378 error = SYSCTL_OUT(req, okif, sizeof(*okif)); 4379 PWDDESC_XLOCK(pdp); 4380 return (error); 4381 } 4382 4383 /* 4384 * Get per-process file descriptors for use by procstat(1), et al. 4385 */ 4386 static int 4387 sysctl_kern_proc_ofiledesc(SYSCTL_HANDLER_ARGS) 4388 { 4389 struct kinfo_ofile *okif; 4390 struct kinfo_file *kif; 4391 struct filedesc *fdp; 4392 struct pwddesc *pdp; 4393 struct pwd *pwd; 4394 int error, i, lastfile, *name; 4395 struct file *fp; 4396 struct proc *p; 4397 4398 name = (int *)arg1; 4399 error = pget((pid_t)name[0], PGET_CANDEBUG | PGET_NOTWEXIT, &p); 4400 if (error != 0) 4401 return (error); 4402 fdp = fdhold(p); 4403 if (fdp != NULL) 4404 pdp = pdhold(p); 4405 PROC_UNLOCK(p); 4406 if (fdp == NULL || pdp == NULL) { 4407 if (fdp != NULL) 4408 fddrop(fdp); 4409 return (ENOENT); 4410 } 4411 kif = malloc(sizeof(*kif), M_TEMP, M_WAITOK); 4412 okif = malloc(sizeof(*okif), M_TEMP, M_WAITOK); 4413 PWDDESC_XLOCK(pdp); 4414 pwd = pwd_hold_pwddesc(pdp); 4415 if (pwd != NULL) { 4416 if (pwd->pwd_cdir != NULL) 4417 export_vnode_for_osysctl(pwd->pwd_cdir, KF_FD_TYPE_CWD, kif, 4418 okif, pdp, req); 4419 if (pwd->pwd_rdir != NULL) 4420 export_vnode_for_osysctl(pwd->pwd_rdir, KF_FD_TYPE_ROOT, kif, 4421 okif, pdp, req); 4422 if (pwd->pwd_jdir != NULL) 4423 export_vnode_for_osysctl(pwd->pwd_jdir, KF_FD_TYPE_JAIL, kif, 4424 okif, pdp, req); 4425 } 4426 PWDDESC_XUNLOCK(pdp); 4427 if (pwd != NULL) 4428 pwd_drop(pwd); 4429 FILEDESC_SLOCK(fdp); 4430 lastfile = fdlastfile(fdp); 4431 for (i = 0; refcount_load(&fdp->fd_refcnt) > 0 && i <= lastfile; i++) { 4432 if ((fp = fdp->fd_ofiles[i].fde_file) == NULL) 4433 continue; 4434 export_file_to_kinfo(fp, i, NULL, kif, fdp, 4435 KERN_FILEDESC_PACK_KINFO); 4436 FILEDESC_SUNLOCK(fdp); 4437 kinfo_to_okinfo(kif, okif); 4438 error = SYSCTL_OUT(req, okif, sizeof(*okif)); 4439 FILEDESC_SLOCK(fdp); 4440 if (error) 4441 break; 4442 } 4443 FILEDESC_SUNLOCK(fdp); 4444 fddrop(fdp); 4445 pddrop(pdp); 4446 free(kif, M_TEMP); 4447 free(okif, M_TEMP); 4448 return (0); 4449 } 4450 4451 static SYSCTL_NODE(_kern_proc, KERN_PROC_OFILEDESC, ofiledesc, 4452 CTLFLAG_RD|CTLFLAG_MPSAFE, sysctl_kern_proc_ofiledesc, 4453 "Process ofiledesc entries"); 4454 #endif /* COMPAT_FREEBSD7 */ 4455 4456 int 4457 vntype_to_kinfo(int vtype) 4458 { 4459 struct { 4460 int vtype; 4461 int kf_vtype; 4462 } vtypes_table[] = { 4463 { VBAD, KF_VTYPE_VBAD }, 4464 { VBLK, KF_VTYPE_VBLK }, 4465 { VCHR, KF_VTYPE_VCHR }, 4466 { VDIR, KF_VTYPE_VDIR }, 4467 { VFIFO, KF_VTYPE_VFIFO }, 4468 { VLNK, KF_VTYPE_VLNK }, 4469 { VNON, KF_VTYPE_VNON }, 4470 { VREG, KF_VTYPE_VREG }, 4471 { VSOCK, KF_VTYPE_VSOCK } 4472 }; 4473 unsigned int i; 4474 4475 /* 4476 * Perform vtype translation. 4477 */ 4478 for (i = 0; i < nitems(vtypes_table); i++) 4479 if (vtypes_table[i].vtype == vtype) 4480 return (vtypes_table[i].kf_vtype); 4481 4482 return (KF_VTYPE_UNKNOWN); 4483 } 4484 4485 static SYSCTL_NODE(_kern_proc, KERN_PROC_FILEDESC, filedesc, 4486 CTLFLAG_RD|CTLFLAG_MPSAFE, sysctl_kern_proc_filedesc, 4487 "Process filedesc entries"); 4488 4489 /* 4490 * Store a process current working directory information to sbuf. 4491 * 4492 * Takes a locked proc as argument, and returns with the proc unlocked. 4493 */ 4494 int 4495 kern_proc_cwd_out(struct proc *p, struct sbuf *sb, ssize_t maxlen) 4496 { 4497 struct pwddesc *pdp; 4498 struct pwd *pwd; 4499 struct export_fd_buf *efbuf; 4500 struct vnode *cdir; 4501 int error; 4502 4503 PROC_LOCK_ASSERT(p, MA_OWNED); 4504 4505 pdp = pdhold(p); 4506 PROC_UNLOCK(p); 4507 if (pdp == NULL) 4508 return (EINVAL); 4509 4510 efbuf = malloc(sizeof(*efbuf), M_TEMP, M_WAITOK); 4511 efbuf->pdp = pdp; 4512 efbuf->sb = sb; 4513 efbuf->remainder = maxlen; 4514 4515 PWDDESC_XLOCK(pdp); 4516 pwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); 4517 cdir = pwd->pwd_cdir; 4518 if (cdir == NULL) { 4519 error = EINVAL; 4520 } else { 4521 vrefact(cdir); 4522 error = export_vnode_to_sb(cdir, KF_FD_TYPE_CWD, FREAD, efbuf); 4523 } 4524 PWDDESC_XUNLOCK(pdp); 4525 pddrop(pdp); 4526 free(efbuf, M_TEMP); 4527 return (error); 4528 } 4529 4530 /* 4531 * Get per-process current working directory. 4532 */ 4533 static int 4534 sysctl_kern_proc_cwd(SYSCTL_HANDLER_ARGS) 4535 { 4536 struct sbuf sb; 4537 struct proc *p; 4538 ssize_t maxlen; 4539 int error, error2, *name; 4540 4541 name = (int *)arg1; 4542 4543 sbuf_new_for_sysctl(&sb, NULL, sizeof(struct kinfo_file), req); 4544 sbuf_clear_flags(&sb, SBUF_INCLUDENUL); 4545 error = pget((pid_t)name[0], PGET_CANDEBUG | PGET_NOTWEXIT, &p); 4546 if (error != 0) { 4547 sbuf_delete(&sb); 4548 return (error); 4549 } 4550 maxlen = req->oldptr != NULL ? req->oldlen : -1; 4551 error = kern_proc_cwd_out(p, &sb, maxlen); 4552 error2 = sbuf_finish(&sb); 4553 sbuf_delete(&sb); 4554 return (error != 0 ? error : error2); 4555 } 4556 4557 static SYSCTL_NODE(_kern_proc, KERN_PROC_CWD, cwd, CTLFLAG_RD|CTLFLAG_MPSAFE, 4558 sysctl_kern_proc_cwd, "Process current working directory"); 4559 4560 #ifdef DDB 4561 /* 4562 * For the purposes of debugging, generate a human-readable string for the 4563 * file type. 4564 */ 4565 static const char * 4566 file_type_to_name(short type) 4567 { 4568 4569 switch (type) { 4570 case 0: 4571 return ("zero"); 4572 case DTYPE_VNODE: 4573 return ("vnode"); 4574 case DTYPE_SOCKET: 4575 return ("socket"); 4576 case DTYPE_PIPE: 4577 return ("pipe"); 4578 case DTYPE_FIFO: 4579 return ("fifo"); 4580 case DTYPE_KQUEUE: 4581 return ("kqueue"); 4582 case DTYPE_CRYPTO: 4583 return ("crypto"); 4584 case DTYPE_MQUEUE: 4585 return ("mqueue"); 4586 case DTYPE_SHM: 4587 return ("shm"); 4588 case DTYPE_SEM: 4589 return ("ksem"); 4590 case DTYPE_PTS: 4591 return ("pts"); 4592 case DTYPE_DEV: 4593 return ("dev"); 4594 case DTYPE_PROCDESC: 4595 return ("proc"); 4596 case DTYPE_EVENTFD: 4597 return ("eventfd"); 4598 case DTYPE_LINUXTFD: 4599 return ("ltimer"); 4600 default: 4601 return ("unkn"); 4602 } 4603 } 4604 4605 /* 4606 * For the purposes of debugging, identify a process (if any, perhaps one of 4607 * many) that references the passed file in its file descriptor array. Return 4608 * NULL if none. 4609 */ 4610 static struct proc * 4611 file_to_first_proc(struct file *fp) 4612 { 4613 struct filedesc *fdp; 4614 struct proc *p; 4615 int n; 4616 4617 FOREACH_PROC_IN_SYSTEM(p) { 4618 if (p->p_state == PRS_NEW) 4619 continue; 4620 fdp = p->p_fd; 4621 if (fdp == NULL) 4622 continue; 4623 for (n = 0; n < fdp->fd_nfiles; n++) { 4624 if (fp == fdp->fd_ofiles[n].fde_file) 4625 return (p); 4626 } 4627 } 4628 return (NULL); 4629 } 4630 4631 static void 4632 db_print_file(struct file *fp, int header) 4633 { 4634 #define XPTRWIDTH ((int)howmany(sizeof(void *) * NBBY, 4)) 4635 struct proc *p; 4636 4637 if (header) 4638 db_printf("%*s %6s %*s %8s %4s %5s %6s %*s %5s %s\n", 4639 XPTRWIDTH, "File", "Type", XPTRWIDTH, "Data", "Flag", 4640 "GCFl", "Count", "MCount", XPTRWIDTH, "Vnode", "FPID", 4641 "FCmd"); 4642 p = file_to_first_proc(fp); 4643 db_printf("%*p %6s %*p %08x %04x %5d %6d %*p %5d %s\n", XPTRWIDTH, 4644 fp, file_type_to_name(fp->f_type), XPTRWIDTH, fp->f_data, 4645 fp->f_flag, 0, refcount_load(&fp->f_count), 0, XPTRWIDTH, fp->f_vnode, 4646 p != NULL ? p->p_pid : -1, p != NULL ? p->p_comm : "-"); 4647 4648 #undef XPTRWIDTH 4649 } 4650 4651 DB_SHOW_COMMAND(file, db_show_file) 4652 { 4653 struct file *fp; 4654 4655 if (!have_addr) { 4656 db_printf("usage: show file <addr>\n"); 4657 return; 4658 } 4659 fp = (struct file *)addr; 4660 db_print_file(fp, 1); 4661 } 4662 4663 DB_SHOW_COMMAND(files, db_show_files) 4664 { 4665 struct filedesc *fdp; 4666 struct file *fp; 4667 struct proc *p; 4668 int header; 4669 int n; 4670 4671 header = 1; 4672 FOREACH_PROC_IN_SYSTEM(p) { 4673 if (p->p_state == PRS_NEW) 4674 continue; 4675 if ((fdp = p->p_fd) == NULL) 4676 continue; 4677 for (n = 0; n < fdp->fd_nfiles; ++n) { 4678 if ((fp = fdp->fd_ofiles[n].fde_file) == NULL) 4679 continue; 4680 db_print_file(fp, header); 4681 header = 0; 4682 } 4683 } 4684 } 4685 #endif 4686 4687 SYSCTL_INT(_kern, KERN_MAXFILESPERPROC, maxfilesperproc, CTLFLAG_RW, 4688 &maxfilesperproc, 0, "Maximum files allowed open per process"); 4689 4690 SYSCTL_INT(_kern, KERN_MAXFILES, maxfiles, CTLFLAG_RW, 4691 &maxfiles, 0, "Maximum number of files"); 4692 4693 SYSCTL_INT(_kern, OID_AUTO, openfiles, CTLFLAG_RD, 4694 &openfiles, 0, "System-wide number of open files"); 4695 4696 /* ARGSUSED*/ 4697 static void 4698 filelistinit(void *dummy) 4699 { 4700 4701 file_zone = uma_zcreate("Files", sizeof(struct file), NULL, NULL, 4702 NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE); 4703 filedesc0_zone = uma_zcreate("filedesc0", sizeof(struct filedesc0), 4704 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0); 4705 pwd_zone = uma_zcreate("PWD", sizeof(struct pwd), NULL, NULL, 4706 NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_SMR); 4707 /* 4708 * XXXMJG this is a temporary hack due to boot ordering issues against 4709 * the vnode zone. 4710 */ 4711 vfs_smr = uma_zone_get_smr(pwd_zone); 4712 mtx_init(&sigio_lock, "sigio lock", NULL, MTX_DEF); 4713 } 4714 SYSINIT(select, SI_SUB_LOCK, SI_ORDER_FIRST, filelistinit, NULL); 4715 4716 /*-------------------------------------------------------------------*/ 4717 4718 static int 4719 badfo_readwrite(struct file *fp, struct uio *uio, struct ucred *active_cred, 4720 int flags, struct thread *td) 4721 { 4722 4723 return (EBADF); 4724 } 4725 4726 static int 4727 badfo_truncate(struct file *fp, off_t length, struct ucred *active_cred, 4728 struct thread *td) 4729 { 4730 4731 return (EINVAL); 4732 } 4733 4734 static int 4735 badfo_ioctl(struct file *fp, u_long com, void *data, struct ucred *active_cred, 4736 struct thread *td) 4737 { 4738 4739 return (EBADF); 4740 } 4741 4742 static int 4743 badfo_poll(struct file *fp, int events, struct ucred *active_cred, 4744 struct thread *td) 4745 { 4746 4747 return (0); 4748 } 4749 4750 static int 4751 badfo_kqfilter(struct file *fp, struct knote *kn) 4752 { 4753 4754 return (EBADF); 4755 } 4756 4757 static int 4758 badfo_stat(struct file *fp, struct stat *sb, struct ucred *active_cred, 4759 struct thread *td) 4760 { 4761 4762 return (EBADF); 4763 } 4764 4765 static int 4766 badfo_close(struct file *fp, struct thread *td) 4767 { 4768 4769 return (0); 4770 } 4771 4772 static int 4773 badfo_chmod(struct file *fp, mode_t mode, struct ucred *active_cred, 4774 struct thread *td) 4775 { 4776 4777 return (EBADF); 4778 } 4779 4780 static int 4781 badfo_chown(struct file *fp, uid_t uid, gid_t gid, struct ucred *active_cred, 4782 struct thread *td) 4783 { 4784 4785 return (EBADF); 4786 } 4787 4788 static int 4789 badfo_sendfile(struct file *fp, int sockfd, struct uio *hdr_uio, 4790 struct uio *trl_uio, off_t offset, size_t nbytes, off_t *sent, int flags, 4791 struct thread *td) 4792 { 4793 4794 return (EBADF); 4795 } 4796 4797 static int 4798 badfo_fill_kinfo(struct file *fp, struct kinfo_file *kif, struct filedesc *fdp) 4799 { 4800 4801 return (0); 4802 } 4803 4804 struct fileops badfileops = { 4805 .fo_read = badfo_readwrite, 4806 .fo_write = badfo_readwrite, 4807 .fo_truncate = badfo_truncate, 4808 .fo_ioctl = badfo_ioctl, 4809 .fo_poll = badfo_poll, 4810 .fo_kqfilter = badfo_kqfilter, 4811 .fo_stat = badfo_stat, 4812 .fo_close = badfo_close, 4813 .fo_chmod = badfo_chmod, 4814 .fo_chown = badfo_chown, 4815 .fo_sendfile = badfo_sendfile, 4816 .fo_fill_kinfo = badfo_fill_kinfo, 4817 }; 4818 4819 int 4820 invfo_rdwr(struct file *fp, struct uio *uio, struct ucred *active_cred, 4821 int flags, struct thread *td) 4822 { 4823 4824 return (EOPNOTSUPP); 4825 } 4826 4827 int 4828 invfo_truncate(struct file *fp, off_t length, struct ucred *active_cred, 4829 struct thread *td) 4830 { 4831 4832 return (EINVAL); 4833 } 4834 4835 int 4836 invfo_ioctl(struct file *fp, u_long com, void *data, 4837 struct ucred *active_cred, struct thread *td) 4838 { 4839 4840 return (ENOTTY); 4841 } 4842 4843 int 4844 invfo_poll(struct file *fp, int events, struct ucred *active_cred, 4845 struct thread *td) 4846 { 4847 4848 return (poll_no_poll(events)); 4849 } 4850 4851 int 4852 invfo_kqfilter(struct file *fp, struct knote *kn) 4853 { 4854 4855 return (EINVAL); 4856 } 4857 4858 int 4859 invfo_chmod(struct file *fp, mode_t mode, struct ucred *active_cred, 4860 struct thread *td) 4861 { 4862 4863 return (EINVAL); 4864 } 4865 4866 int 4867 invfo_chown(struct file *fp, uid_t uid, gid_t gid, struct ucred *active_cred, 4868 struct thread *td) 4869 { 4870 4871 return (EINVAL); 4872 } 4873 4874 int 4875 invfo_sendfile(struct file *fp, int sockfd, struct uio *hdr_uio, 4876 struct uio *trl_uio, off_t offset, size_t nbytes, off_t *sent, int flags, 4877 struct thread *td) 4878 { 4879 4880 return (EINVAL); 4881 } 4882 4883 /*-------------------------------------------------------------------*/ 4884 4885 /* 4886 * File Descriptor pseudo-device driver (/dev/fd/). 4887 * 4888 * Opening minor device N dup()s the file (if any) connected to file 4889 * descriptor N belonging to the calling process. Note that this driver 4890 * consists of only the ``open()'' routine, because all subsequent 4891 * references to this file will be direct to the other driver. 4892 * 4893 * XXX: we could give this one a cloning event handler if necessary. 4894 */ 4895 4896 /* ARGSUSED */ 4897 static int 4898 fdopen(struct cdev *dev, int mode, int type, struct thread *td) 4899 { 4900 4901 /* 4902 * XXX Kludge: set curthread->td_dupfd to contain the value of the 4903 * the file descriptor being sought for duplication. The error 4904 * return ensures that the vnode for this device will be released 4905 * by vn_open. Open will detect this special error and take the 4906 * actions in dupfdopen below. Other callers of vn_open or VOP_OPEN 4907 * will simply report the error. 4908 */ 4909 td->td_dupfd = dev2unit(dev); 4910 return (ENODEV); 4911 } 4912 4913 static struct cdevsw fildesc_cdevsw = { 4914 .d_version = D_VERSION, 4915 .d_open = fdopen, 4916 .d_name = "FD", 4917 }; 4918 4919 static void 4920 fildesc_drvinit(void *unused) 4921 { 4922 struct cdev *dev; 4923 4924 dev = make_dev_credf(MAKEDEV_ETERNAL, &fildesc_cdevsw, 0, NULL, 4925 UID_ROOT, GID_WHEEL, 0666, "fd/0"); 4926 make_dev_alias(dev, "stdin"); 4927 dev = make_dev_credf(MAKEDEV_ETERNAL, &fildesc_cdevsw, 1, NULL, 4928 UID_ROOT, GID_WHEEL, 0666, "fd/1"); 4929 make_dev_alias(dev, "stdout"); 4930 dev = make_dev_credf(MAKEDEV_ETERNAL, &fildesc_cdevsw, 2, NULL, 4931 UID_ROOT, GID_WHEEL, 0666, "fd/2"); 4932 make_dev_alias(dev, "stderr"); 4933 } 4934 4935 SYSINIT(fildescdev, SI_SUB_DRIVERS, SI_ORDER_MIDDLE, fildesc_drvinit, NULL); 4936