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/poll.h> 65 #include <sys/priv.h> 66 #include <sys/proc.h> 67 #include <sys/protosw.h> 68 #include <sys/racct.h> 69 #include <sys/resourcevar.h> 70 #include <sys/sbuf.h> 71 #include <sys/signalvar.h> 72 #include <sys/kdb.h> 73 #include <sys/smr.h> 74 #include <sys/stat.h> 75 #include <sys/sx.h> 76 #include <sys/syscallsubr.h> 77 #include <sys/sysctl.h> 78 #include <sys/sysproto.h> 79 #include <sys/unistd.h> 80 #include <sys/user.h> 81 #include <sys/vnode.h> 82 #ifdef KTRACE 83 #include <sys/ktrace.h> 84 #endif 85 86 #include <net/vnet.h> 87 88 #include <security/audit/audit.h> 89 90 #include <vm/uma.h> 91 #include <vm/vm.h> 92 93 #include <ddb/ddb.h> 94 95 static MALLOC_DEFINE(M_FILEDESC, "filedesc", "Open file descriptor table"); 96 static MALLOC_DEFINE(M_PWD, "pwd", "Descriptor table vnodes"); 97 static MALLOC_DEFINE(M_PWDDESC, "pwddesc", "Pwd descriptors"); 98 static MALLOC_DEFINE(M_FILEDESC_TO_LEADER, "filedesc_to_leader", 99 "file desc to leader structures"); 100 static MALLOC_DEFINE(M_SIGIO, "sigio", "sigio structures"); 101 MALLOC_DEFINE(M_FILECAPS, "filecaps", "descriptor capabilities"); 102 103 MALLOC_DECLARE(M_FADVISE); 104 105 static __read_mostly uma_zone_t file_zone; 106 static __read_mostly uma_zone_t filedesc0_zone; 107 __read_mostly uma_zone_t pwd_zone; 108 VFS_SMR_DECLARE; 109 110 static int closefp(struct filedesc *fdp, int fd, struct file *fp, 111 struct thread *td, bool holdleaders, bool audit); 112 static int fd_first_free(struct filedesc *fdp, int low, int size); 113 static void fdgrowtable(struct filedesc *fdp, int nfd); 114 static void fdgrowtable_exp(struct filedesc *fdp, int nfd); 115 static void fdunused(struct filedesc *fdp, int fd); 116 static void fdused(struct filedesc *fdp, int fd); 117 static int getmaxfd(struct thread *td); 118 static u_long *filecaps_copy_prep(const struct filecaps *src); 119 static void filecaps_copy_finish(const struct filecaps *src, 120 struct filecaps *dst, u_long *ioctls); 121 static u_long *filecaps_free_prep(struct filecaps *fcaps); 122 static void filecaps_free_finish(u_long *ioctls); 123 124 static struct pwd *pwd_alloc(void); 125 126 /* 127 * Each process has: 128 * 129 * - An array of open file descriptors (fd_ofiles) 130 * - An array of file flags (fd_ofileflags) 131 * - A bitmap recording which descriptors are in use (fd_map) 132 * 133 * A process starts out with NDFILE descriptors. The value of NDFILE has 134 * been selected based the historical limit of 20 open files, and an 135 * assumption that the majority of processes, especially short-lived 136 * processes like shells, will never need more. 137 * 138 * If this initial allocation is exhausted, a larger descriptor table and 139 * map are allocated dynamically, and the pointers in the process's struct 140 * filedesc are updated to point to those. This is repeated every time 141 * the process runs out of file descriptors (provided it hasn't hit its 142 * resource limit). 143 * 144 * Since threads may hold references to individual descriptor table 145 * entries, the tables are never freed. Instead, they are placed on a 146 * linked list and freed only when the struct filedesc is released. 147 */ 148 #define NDFILE 20 149 #define NDSLOTSIZE sizeof(NDSLOTTYPE) 150 #define NDENTRIES (NDSLOTSIZE * __CHAR_BIT) 151 #define NDSLOT(x) ((x) / NDENTRIES) 152 #define NDBIT(x) ((NDSLOTTYPE)1 << ((x) % NDENTRIES)) 153 #define NDSLOTS(x) (((x) + NDENTRIES - 1) / NDENTRIES) 154 155 /* 156 * SLIST entry used to keep track of ofiles which must be reclaimed when 157 * the process exits. 158 */ 159 struct freetable { 160 struct fdescenttbl *ft_table; 161 SLIST_ENTRY(freetable) ft_next; 162 }; 163 164 /* 165 * Initial allocation: a filedesc structure + the head of SLIST used to 166 * keep track of old ofiles + enough space for NDFILE descriptors. 167 */ 168 169 struct fdescenttbl0 { 170 int fdt_nfiles; 171 struct filedescent fdt_ofiles[NDFILE]; 172 }; 173 174 struct filedesc0 { 175 struct filedesc fd_fd; 176 SLIST_HEAD(, freetable) fd_free; 177 struct fdescenttbl0 fd_dfiles; 178 NDSLOTTYPE fd_dmap[NDSLOTS(NDFILE)]; 179 }; 180 181 /* 182 * Descriptor management. 183 */ 184 static int __exclusive_cache_line openfiles; /* actual number of open files */ 185 struct mtx sigio_lock; /* mtx to protect pointers to sigio */ 186 void __read_mostly (*mq_fdclose)(struct thread *td, int fd, struct file *fp); 187 188 /* 189 * If low >= size, just return low. Otherwise find the first zero bit in the 190 * given bitmap, starting at low and not exceeding size - 1. Return size if 191 * not found. 192 */ 193 static int 194 fd_first_free(struct filedesc *fdp, int low, int size) 195 { 196 NDSLOTTYPE *map = fdp->fd_map; 197 NDSLOTTYPE mask; 198 int off, maxoff; 199 200 if (low >= size) 201 return (low); 202 203 off = NDSLOT(low); 204 if (low % NDENTRIES) { 205 mask = ~(~(NDSLOTTYPE)0 >> (NDENTRIES - (low % NDENTRIES))); 206 if ((mask &= ~map[off]) != 0UL) 207 return (off * NDENTRIES + ffsl(mask) - 1); 208 ++off; 209 } 210 for (maxoff = NDSLOTS(size); off < maxoff; ++off) 211 if (map[off] != ~0UL) 212 return (off * NDENTRIES + ffsl(~map[off]) - 1); 213 return (size); 214 } 215 216 /* 217 * Find the last used fd. 218 * 219 * Call this variant if fdp can't be modified by anyone else (e.g, during exec). 220 * Otherwise use fdlastfile. 221 */ 222 int 223 fdlastfile_single(struct filedesc *fdp) 224 { 225 NDSLOTTYPE *map = fdp->fd_map; 226 int off, minoff; 227 228 off = NDSLOT(fdp->fd_nfiles - 1); 229 for (minoff = NDSLOT(0); off >= minoff; --off) 230 if (map[off] != 0) 231 return (off * NDENTRIES + flsl(map[off]) - 1); 232 return (-1); 233 } 234 235 int 236 fdlastfile(struct filedesc *fdp) 237 { 238 239 FILEDESC_LOCK_ASSERT(fdp); 240 return (fdlastfile_single(fdp)); 241 } 242 243 static int 244 fdisused(struct filedesc *fdp, int fd) 245 { 246 247 KASSERT(fd >= 0 && fd < fdp->fd_nfiles, 248 ("file descriptor %d out of range (0, %d)", fd, fdp->fd_nfiles)); 249 250 return ((fdp->fd_map[NDSLOT(fd)] & NDBIT(fd)) != 0); 251 } 252 253 /* 254 * Mark a file descriptor as used. 255 */ 256 static void 257 fdused_init(struct filedesc *fdp, int fd) 258 { 259 260 KASSERT(!fdisused(fdp, fd), ("fd=%d is already used", fd)); 261 262 fdp->fd_map[NDSLOT(fd)] |= NDBIT(fd); 263 } 264 265 static void 266 fdused(struct filedesc *fdp, int fd) 267 { 268 269 FILEDESC_XLOCK_ASSERT(fdp); 270 271 fdused_init(fdp, fd); 272 if (fd == fdp->fd_freefile) 273 fdp->fd_freefile++; 274 } 275 276 /* 277 * Mark a file descriptor as unused. 278 */ 279 static void 280 fdunused(struct filedesc *fdp, int fd) 281 { 282 283 FILEDESC_XLOCK_ASSERT(fdp); 284 285 KASSERT(fdisused(fdp, fd), ("fd=%d is already unused", fd)); 286 KASSERT(fdp->fd_ofiles[fd].fde_file == NULL, 287 ("fd=%d is still in use", fd)); 288 289 fdp->fd_map[NDSLOT(fd)] &= ~NDBIT(fd); 290 if (fd < fdp->fd_freefile) 291 fdp->fd_freefile = fd; 292 } 293 294 /* 295 * Free a file descriptor. 296 * 297 * Avoid some work if fdp is about to be destroyed. 298 */ 299 static inline void 300 fdefree_last(struct filedescent *fde) 301 { 302 303 filecaps_free(&fde->fde_caps); 304 } 305 306 static inline void 307 fdfree(struct filedesc *fdp, int fd) 308 { 309 struct filedescent *fde; 310 311 FILEDESC_XLOCK_ASSERT(fdp); 312 fde = &fdp->fd_ofiles[fd]; 313 #ifdef CAPABILITIES 314 seqc_write_begin(&fde->fde_seqc); 315 #endif 316 fde->fde_file = NULL; 317 #ifdef CAPABILITIES 318 seqc_write_end(&fde->fde_seqc); 319 #endif 320 fdefree_last(fde); 321 fdunused(fdp, fd); 322 } 323 324 /* 325 * System calls on descriptors. 326 */ 327 #ifndef _SYS_SYSPROTO_H_ 328 struct getdtablesize_args { 329 int dummy; 330 }; 331 #endif 332 /* ARGSUSED */ 333 int 334 sys_getdtablesize(struct thread *td, struct getdtablesize_args *uap) 335 { 336 #ifdef RACCT 337 uint64_t lim; 338 #endif 339 340 td->td_retval[0] = getmaxfd(td); 341 #ifdef RACCT 342 PROC_LOCK(td->td_proc); 343 lim = racct_get_limit(td->td_proc, RACCT_NOFILE); 344 PROC_UNLOCK(td->td_proc); 345 if (lim < td->td_retval[0]) 346 td->td_retval[0] = lim; 347 #endif 348 return (0); 349 } 350 351 /* 352 * Duplicate a file descriptor to a particular value. 353 * 354 * Note: keep in mind that a potential race condition exists when closing 355 * descriptors from a shared descriptor table (via rfork). 356 */ 357 #ifndef _SYS_SYSPROTO_H_ 358 struct dup2_args { 359 u_int from; 360 u_int to; 361 }; 362 #endif 363 /* ARGSUSED */ 364 int 365 sys_dup2(struct thread *td, struct dup2_args *uap) 366 { 367 368 return (kern_dup(td, FDDUP_FIXED, 0, (int)uap->from, (int)uap->to)); 369 } 370 371 /* 372 * Duplicate a file descriptor. 373 */ 374 #ifndef _SYS_SYSPROTO_H_ 375 struct dup_args { 376 u_int fd; 377 }; 378 #endif 379 /* ARGSUSED */ 380 int 381 sys_dup(struct thread *td, struct dup_args *uap) 382 { 383 384 return (kern_dup(td, FDDUP_NORMAL, 0, (int)uap->fd, 0)); 385 } 386 387 /* 388 * The file control system call. 389 */ 390 #ifndef _SYS_SYSPROTO_H_ 391 struct fcntl_args { 392 int fd; 393 int cmd; 394 long arg; 395 }; 396 #endif 397 /* ARGSUSED */ 398 int 399 sys_fcntl(struct thread *td, struct fcntl_args *uap) 400 { 401 402 return (kern_fcntl_freebsd(td, uap->fd, uap->cmd, uap->arg)); 403 } 404 405 int 406 kern_fcntl_freebsd(struct thread *td, int fd, int cmd, long arg) 407 { 408 struct flock fl; 409 struct __oflock ofl; 410 intptr_t arg1; 411 int error, newcmd; 412 413 error = 0; 414 newcmd = cmd; 415 switch (cmd) { 416 case F_OGETLK: 417 case F_OSETLK: 418 case F_OSETLKW: 419 /* 420 * Convert old flock structure to new. 421 */ 422 error = copyin((void *)(intptr_t)arg, &ofl, sizeof(ofl)); 423 fl.l_start = ofl.l_start; 424 fl.l_len = ofl.l_len; 425 fl.l_pid = ofl.l_pid; 426 fl.l_type = ofl.l_type; 427 fl.l_whence = ofl.l_whence; 428 fl.l_sysid = 0; 429 430 switch (cmd) { 431 case F_OGETLK: 432 newcmd = F_GETLK; 433 break; 434 case F_OSETLK: 435 newcmd = F_SETLK; 436 break; 437 case F_OSETLKW: 438 newcmd = F_SETLKW; 439 break; 440 } 441 arg1 = (intptr_t)&fl; 442 break; 443 case F_GETLK: 444 case F_SETLK: 445 case F_SETLKW: 446 case F_SETLK_REMOTE: 447 error = copyin((void *)(intptr_t)arg, &fl, sizeof(fl)); 448 arg1 = (intptr_t)&fl; 449 break; 450 default: 451 arg1 = arg; 452 break; 453 } 454 if (error) 455 return (error); 456 error = kern_fcntl(td, fd, newcmd, arg1); 457 if (error) 458 return (error); 459 if (cmd == F_OGETLK) { 460 ofl.l_start = fl.l_start; 461 ofl.l_len = fl.l_len; 462 ofl.l_pid = fl.l_pid; 463 ofl.l_type = fl.l_type; 464 ofl.l_whence = fl.l_whence; 465 error = copyout(&ofl, (void *)(intptr_t)arg, sizeof(ofl)); 466 } else if (cmd == F_GETLK) { 467 error = copyout(&fl, (void *)(intptr_t)arg, sizeof(fl)); 468 } 469 return (error); 470 } 471 472 int 473 kern_fcntl(struct thread *td, int fd, int cmd, intptr_t arg) 474 { 475 struct filedesc *fdp; 476 struct flock *flp; 477 struct file *fp, *fp2; 478 struct filedescent *fde; 479 struct proc *p; 480 struct vnode *vp; 481 struct mount *mp; 482 int error, flg, seals, tmp; 483 uint64_t bsize; 484 off_t foffset; 485 486 error = 0; 487 flg = F_POSIX; 488 p = td->td_proc; 489 fdp = p->p_fd; 490 491 AUDIT_ARG_FD(cmd); 492 AUDIT_ARG_CMD(cmd); 493 switch (cmd) { 494 case F_DUPFD: 495 tmp = arg; 496 error = kern_dup(td, FDDUP_FCNTL, 0, fd, tmp); 497 break; 498 499 case F_DUPFD_CLOEXEC: 500 tmp = arg; 501 error = kern_dup(td, FDDUP_FCNTL, FDDUP_FLAG_CLOEXEC, fd, tmp); 502 break; 503 504 case F_DUP2FD: 505 tmp = arg; 506 error = kern_dup(td, FDDUP_FIXED, 0, fd, tmp); 507 break; 508 509 case F_DUP2FD_CLOEXEC: 510 tmp = arg; 511 error = kern_dup(td, FDDUP_FIXED, FDDUP_FLAG_CLOEXEC, fd, tmp); 512 break; 513 514 case F_GETFD: 515 error = EBADF; 516 FILEDESC_SLOCK(fdp); 517 fde = fdeget_locked(fdp, fd); 518 if (fde != NULL) { 519 td->td_retval[0] = 520 (fde->fde_flags & UF_EXCLOSE) ? FD_CLOEXEC : 0; 521 error = 0; 522 } 523 FILEDESC_SUNLOCK(fdp); 524 break; 525 526 case F_SETFD: 527 error = EBADF; 528 FILEDESC_XLOCK(fdp); 529 fde = fdeget_locked(fdp, fd); 530 if (fde != NULL) { 531 fde->fde_flags = (fde->fde_flags & ~UF_EXCLOSE) | 532 (arg & FD_CLOEXEC ? UF_EXCLOSE : 0); 533 error = 0; 534 } 535 FILEDESC_XUNLOCK(fdp); 536 break; 537 538 case F_GETFL: 539 error = fget_fcntl(td, fd, &cap_fcntl_rights, F_GETFL, &fp); 540 if (error != 0) 541 break; 542 td->td_retval[0] = OFLAGS(fp->f_flag); 543 fdrop(fp, td); 544 break; 545 546 case F_SETFL: 547 error = fget_fcntl(td, fd, &cap_fcntl_rights, F_SETFL, &fp); 548 if (error != 0) 549 break; 550 if (fp->f_ops == &path_fileops) { 551 fdrop(fp, td); 552 error = EBADF; 553 break; 554 } 555 do { 556 tmp = flg = fp->f_flag; 557 tmp &= ~FCNTLFLAGS; 558 tmp |= FFLAGS(arg & ~O_ACCMODE) & FCNTLFLAGS; 559 } while (atomic_cmpset_int(&fp->f_flag, flg, tmp) == 0); 560 tmp = fp->f_flag & FNONBLOCK; 561 error = fo_ioctl(fp, FIONBIO, &tmp, td->td_ucred, td); 562 if (error != 0) { 563 fdrop(fp, td); 564 break; 565 } 566 tmp = fp->f_flag & FASYNC; 567 error = fo_ioctl(fp, FIOASYNC, &tmp, td->td_ucred, td); 568 if (error == 0) { 569 fdrop(fp, td); 570 break; 571 } 572 atomic_clear_int(&fp->f_flag, FNONBLOCK); 573 tmp = 0; 574 (void)fo_ioctl(fp, FIONBIO, &tmp, td->td_ucred, td); 575 fdrop(fp, td); 576 break; 577 578 case F_GETOWN: 579 error = fget_fcntl(td, fd, &cap_fcntl_rights, F_GETOWN, &fp); 580 if (error != 0) 581 break; 582 error = fo_ioctl(fp, FIOGETOWN, &tmp, td->td_ucred, td); 583 if (error == 0) 584 td->td_retval[0] = tmp; 585 fdrop(fp, td); 586 break; 587 588 case F_SETOWN: 589 error = fget_fcntl(td, fd, &cap_fcntl_rights, F_SETOWN, &fp); 590 if (error != 0) 591 break; 592 tmp = arg; 593 error = fo_ioctl(fp, FIOSETOWN, &tmp, td->td_ucred, td); 594 fdrop(fp, td); 595 break; 596 597 case F_SETLK_REMOTE: 598 error = priv_check(td, PRIV_NFS_LOCKD); 599 if (error != 0) 600 return (error); 601 flg = F_REMOTE; 602 goto do_setlk; 603 604 case F_SETLKW: 605 flg |= F_WAIT; 606 /* FALLTHROUGH F_SETLK */ 607 608 case F_SETLK: 609 do_setlk: 610 flp = (struct flock *)arg; 611 if ((flg & F_REMOTE) != 0 && flp->l_sysid == 0) { 612 error = EINVAL; 613 break; 614 } 615 616 error = fget_unlocked(fdp, fd, &cap_flock_rights, &fp); 617 if (error != 0) 618 break; 619 if (fp->f_type != DTYPE_VNODE || fp->f_ops == &path_fileops) { 620 error = EBADF; 621 fdrop(fp, td); 622 break; 623 } 624 625 if (flp->l_whence == SEEK_CUR) { 626 foffset = foffset_get(fp); 627 if (foffset < 0 || 628 (flp->l_start > 0 && 629 foffset > OFF_MAX - flp->l_start)) { 630 error = EOVERFLOW; 631 fdrop(fp, td); 632 break; 633 } 634 flp->l_start += foffset; 635 } 636 637 vp = fp->f_vnode; 638 switch (flp->l_type) { 639 case F_RDLCK: 640 if ((fp->f_flag & FREAD) == 0) { 641 error = EBADF; 642 break; 643 } 644 if ((p->p_leader->p_flag & P_ADVLOCK) == 0) { 645 PROC_LOCK(p->p_leader); 646 p->p_leader->p_flag |= P_ADVLOCK; 647 PROC_UNLOCK(p->p_leader); 648 } 649 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_SETLK, 650 flp, flg); 651 break; 652 case F_WRLCK: 653 if ((fp->f_flag & FWRITE) == 0) { 654 error = EBADF; 655 break; 656 } 657 if ((p->p_leader->p_flag & P_ADVLOCK) == 0) { 658 PROC_LOCK(p->p_leader); 659 p->p_leader->p_flag |= P_ADVLOCK; 660 PROC_UNLOCK(p->p_leader); 661 } 662 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_SETLK, 663 flp, flg); 664 break; 665 case F_UNLCK: 666 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_UNLCK, 667 flp, flg); 668 break; 669 case F_UNLCKSYS: 670 if (flg != F_REMOTE) { 671 error = EINVAL; 672 break; 673 } 674 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, 675 F_UNLCKSYS, flp, flg); 676 break; 677 default: 678 error = EINVAL; 679 break; 680 } 681 if (error != 0 || flp->l_type == F_UNLCK || 682 flp->l_type == F_UNLCKSYS) { 683 fdrop(fp, td); 684 break; 685 } 686 687 /* 688 * Check for a race with close. 689 * 690 * The vnode is now advisory locked (or unlocked, but this case 691 * is not really important) as the caller requested. 692 * We had to drop the filedesc lock, so we need to recheck if 693 * the descriptor is still valid, because if it was closed 694 * in the meantime we need to remove advisory lock from the 695 * vnode - close on any descriptor leading to an advisory 696 * locked vnode, removes that lock. 697 * We will return 0 on purpose in that case, as the result of 698 * successful advisory lock might have been externally visible 699 * already. This is fine - effectively we pretend to the caller 700 * that the closing thread was a bit slower and that the 701 * advisory lock succeeded before the close. 702 */ 703 error = fget_unlocked(fdp, fd, &cap_no_rights, &fp2); 704 if (error != 0) { 705 fdrop(fp, td); 706 break; 707 } 708 if (fp != fp2) { 709 flp->l_whence = SEEK_SET; 710 flp->l_start = 0; 711 flp->l_len = 0; 712 flp->l_type = F_UNLCK; 713 (void) VOP_ADVLOCK(vp, (caddr_t)p->p_leader, 714 F_UNLCK, flp, F_POSIX); 715 } 716 fdrop(fp, td); 717 fdrop(fp2, td); 718 break; 719 720 case F_GETLK: 721 error = fget_unlocked(fdp, fd, &cap_flock_rights, &fp); 722 if (error != 0) 723 break; 724 if (fp->f_type != DTYPE_VNODE || fp->f_ops == &path_fileops) { 725 error = EBADF; 726 fdrop(fp, td); 727 break; 728 } 729 flp = (struct flock *)arg; 730 if (flp->l_type != F_RDLCK && flp->l_type != F_WRLCK && 731 flp->l_type != F_UNLCK) { 732 error = EINVAL; 733 fdrop(fp, td); 734 break; 735 } 736 if (flp->l_whence == SEEK_CUR) { 737 foffset = foffset_get(fp); 738 if ((flp->l_start > 0 && 739 foffset > OFF_MAX - flp->l_start) || 740 (flp->l_start < 0 && 741 foffset < OFF_MIN - flp->l_start)) { 742 error = EOVERFLOW; 743 fdrop(fp, td); 744 break; 745 } 746 flp->l_start += foffset; 747 } 748 vp = fp->f_vnode; 749 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_GETLK, flp, 750 F_POSIX); 751 fdrop(fp, td); 752 break; 753 754 case F_ADD_SEALS: 755 error = fget_unlocked(fdp, fd, &cap_no_rights, &fp); 756 if (error != 0) 757 break; 758 error = fo_add_seals(fp, arg); 759 fdrop(fp, td); 760 break; 761 762 case F_GET_SEALS: 763 error = fget_unlocked(fdp, fd, &cap_no_rights, &fp); 764 if (error != 0) 765 break; 766 if (fo_get_seals(fp, &seals) == 0) 767 td->td_retval[0] = seals; 768 else 769 error = EINVAL; 770 fdrop(fp, td); 771 break; 772 773 case F_RDAHEAD: 774 arg = arg ? 128 * 1024: 0; 775 /* FALLTHROUGH */ 776 case F_READAHEAD: 777 error = fget_unlocked(fdp, fd, &cap_no_rights, &fp); 778 if (error != 0) 779 break; 780 if (fp->f_type != DTYPE_VNODE || fp->f_ops == &path_fileops) { 781 fdrop(fp, td); 782 error = EBADF; 783 break; 784 } 785 vp = fp->f_vnode; 786 if (vp->v_type != VREG) { 787 fdrop(fp, td); 788 error = ENOTTY; 789 break; 790 } 791 792 /* 793 * Exclusive lock synchronizes against f_seqcount reads and 794 * writes in sequential_heuristic(). 795 */ 796 error = vn_lock(vp, LK_EXCLUSIVE); 797 if (error != 0) { 798 fdrop(fp, td); 799 break; 800 } 801 if (arg >= 0) { 802 bsize = fp->f_vnode->v_mount->mnt_stat.f_iosize; 803 arg = MIN(arg, INT_MAX - bsize + 1); 804 fp->f_seqcount[UIO_READ] = MIN(IO_SEQMAX, 805 (arg + bsize - 1) / bsize); 806 atomic_set_int(&fp->f_flag, FRDAHEAD); 807 } else { 808 atomic_clear_int(&fp->f_flag, FRDAHEAD); 809 } 810 VOP_UNLOCK(vp); 811 fdrop(fp, td); 812 break; 813 814 case F_ISUNIONSTACK: 815 /* 816 * Check if the vnode is part of a union stack (either the 817 * "union" flag from mount(2) or unionfs). 818 * 819 * Prior to introduction of this op libc's readdir would call 820 * fstatfs(2), in effect unnecessarily copying kilobytes of 821 * data just to check fs name and a mount flag. 822 * 823 * Fixing the code to handle everything in the kernel instead 824 * is a non-trivial endeavor and has low priority, thus this 825 * horrible kludge facilitates the current behavior in a much 826 * cheaper manner until someone(tm) sorts this out. 827 */ 828 error = fget_unlocked(fdp, fd, &cap_no_rights, &fp); 829 if (error != 0) 830 break; 831 if (fp->f_type != DTYPE_VNODE) { 832 fdrop(fp, td); 833 error = EBADF; 834 break; 835 } 836 vp = fp->f_vnode; 837 /* 838 * Since we don't prevent dooming the vnode even non-null mp 839 * found can become immediately stale. This is tolerable since 840 * mount points are type-stable (providing safe memory access) 841 * and any vfs op on this vnode going forward will return an 842 * error (meaning return value in this case is meaningless). 843 */ 844 mp = atomic_load_ptr(&vp->v_mount); 845 if (__predict_false(mp == NULL)) { 846 fdrop(fp, td); 847 error = EBADF; 848 break; 849 } 850 td->td_retval[0] = 0; 851 if (mp->mnt_kern_flag & MNTK_UNIONFS || 852 mp->mnt_flag & MNT_UNION) 853 td->td_retval[0] = 1; 854 fdrop(fp, td); 855 break; 856 857 default: 858 error = EINVAL; 859 break; 860 } 861 return (error); 862 } 863 864 static int 865 getmaxfd(struct thread *td) 866 { 867 868 return (min((int)lim_cur(td, RLIMIT_NOFILE), maxfilesperproc)); 869 } 870 871 /* 872 * Common code for dup, dup2, fcntl(F_DUPFD) and fcntl(F_DUP2FD). 873 */ 874 int 875 kern_dup(struct thread *td, u_int mode, int flags, int old, int new) 876 { 877 struct filedesc *fdp; 878 struct filedescent *oldfde, *newfde; 879 struct proc *p; 880 struct file *delfp, *oldfp; 881 u_long *oioctls, *nioctls; 882 int error, maxfd; 883 884 p = td->td_proc; 885 fdp = p->p_fd; 886 oioctls = NULL; 887 888 MPASS((flags & ~(FDDUP_FLAG_CLOEXEC)) == 0); 889 MPASS(mode < FDDUP_LASTMODE); 890 891 AUDIT_ARG_FD(old); 892 /* XXXRW: if (flags & FDDUP_FIXED) AUDIT_ARG_FD2(new); */ 893 894 /* 895 * Verify we have a valid descriptor to dup from and possibly to 896 * dup to. Unlike dup() and dup2(), fcntl()'s F_DUPFD should 897 * return EINVAL when the new descriptor is out of bounds. 898 */ 899 if (old < 0) 900 return (EBADF); 901 if (new < 0) 902 return (mode == FDDUP_FCNTL ? EINVAL : EBADF); 903 maxfd = getmaxfd(td); 904 if (new >= maxfd) 905 return (mode == FDDUP_FCNTL ? EINVAL : EBADF); 906 907 error = EBADF; 908 FILEDESC_XLOCK(fdp); 909 if (fget_locked(fdp, old) == NULL) 910 goto unlock; 911 if ((mode == FDDUP_FIXED || mode == FDDUP_MUSTREPLACE) && old == new) { 912 td->td_retval[0] = new; 913 if (flags & FDDUP_FLAG_CLOEXEC) 914 fdp->fd_ofiles[new].fde_flags |= UF_EXCLOSE; 915 error = 0; 916 goto unlock; 917 } 918 919 oldfde = &fdp->fd_ofiles[old]; 920 oldfp = oldfde->fde_file; 921 if (!fhold(oldfp)) 922 goto unlock; 923 924 /* 925 * If the caller specified a file descriptor, make sure the file 926 * table is large enough to hold it, and grab it. Otherwise, just 927 * allocate a new descriptor the usual way. 928 */ 929 switch (mode) { 930 case FDDUP_NORMAL: 931 case FDDUP_FCNTL: 932 if ((error = fdalloc(td, new, &new)) != 0) { 933 fdrop(oldfp, td); 934 goto unlock; 935 } 936 break; 937 case FDDUP_MUSTREPLACE: 938 /* Target file descriptor must exist. */ 939 if (fget_locked(fdp, new) == NULL) { 940 fdrop(oldfp, td); 941 goto unlock; 942 } 943 break; 944 case FDDUP_FIXED: 945 if (new >= fdp->fd_nfiles) { 946 /* 947 * The resource limits are here instead of e.g. 948 * fdalloc(), because the file descriptor table may be 949 * shared between processes, so we can't really use 950 * racct_add()/racct_sub(). Instead of counting the 951 * number of actually allocated descriptors, just put 952 * the limit on the size of the file descriptor table. 953 */ 954 #ifdef RACCT 955 if (RACCT_ENABLED()) { 956 error = racct_set_unlocked(p, RACCT_NOFILE, new + 1); 957 if (error != 0) { 958 error = EMFILE; 959 fdrop(oldfp, td); 960 goto unlock; 961 } 962 } 963 #endif 964 fdgrowtable_exp(fdp, new + 1); 965 } 966 if (!fdisused(fdp, new)) 967 fdused(fdp, new); 968 break; 969 default: 970 KASSERT(0, ("%s unsupported mode %d", __func__, mode)); 971 } 972 973 KASSERT(old != new, ("new fd is same as old")); 974 975 /* Refetch oldfde because the table may have grown and old one freed. */ 976 oldfde = &fdp->fd_ofiles[old]; 977 KASSERT(oldfp == oldfde->fde_file, 978 ("fdt_ofiles shift from growth observed at fd %d", 979 old)); 980 981 newfde = &fdp->fd_ofiles[new]; 982 delfp = newfde->fde_file; 983 984 nioctls = filecaps_copy_prep(&oldfde->fde_caps); 985 986 /* 987 * Duplicate the source descriptor. 988 */ 989 #ifdef CAPABILITIES 990 seqc_write_begin(&newfde->fde_seqc); 991 #endif 992 oioctls = filecaps_free_prep(&newfde->fde_caps); 993 memcpy(newfde, oldfde, fde_change_size); 994 filecaps_copy_finish(&oldfde->fde_caps, &newfde->fde_caps, 995 nioctls); 996 if ((flags & FDDUP_FLAG_CLOEXEC) != 0) 997 newfde->fde_flags = oldfde->fde_flags | UF_EXCLOSE; 998 else 999 newfde->fde_flags = oldfde->fde_flags & ~UF_EXCLOSE; 1000 #ifdef CAPABILITIES 1001 seqc_write_end(&newfde->fde_seqc); 1002 #endif 1003 td->td_retval[0] = new; 1004 1005 error = 0; 1006 1007 if (delfp != NULL) { 1008 (void) closefp(fdp, new, delfp, td, true, false); 1009 FILEDESC_UNLOCK_ASSERT(fdp); 1010 } else { 1011 unlock: 1012 FILEDESC_XUNLOCK(fdp); 1013 } 1014 1015 filecaps_free_finish(oioctls); 1016 return (error); 1017 } 1018 1019 static void 1020 sigiofree(struct sigio *sigio) 1021 { 1022 crfree(sigio->sio_ucred); 1023 free(sigio, M_SIGIO); 1024 } 1025 1026 static struct sigio * 1027 funsetown_locked(struct sigio *sigio) 1028 { 1029 struct proc *p; 1030 struct pgrp *pg; 1031 1032 SIGIO_ASSERT_LOCKED(); 1033 1034 if (sigio == NULL) 1035 return (NULL); 1036 *(sigio->sio_myref) = NULL; 1037 if (sigio->sio_pgid < 0) { 1038 pg = sigio->sio_pgrp; 1039 PGRP_LOCK(pg); 1040 SLIST_REMOVE(&sigio->sio_pgrp->pg_sigiolst, sigio, 1041 sigio, sio_pgsigio); 1042 PGRP_UNLOCK(pg); 1043 } else { 1044 p = sigio->sio_proc; 1045 PROC_LOCK(p); 1046 SLIST_REMOVE(&sigio->sio_proc->p_sigiolst, sigio, 1047 sigio, sio_pgsigio); 1048 PROC_UNLOCK(p); 1049 } 1050 return (sigio); 1051 } 1052 1053 /* 1054 * If sigio is on the list associated with a process or process group, 1055 * disable signalling from the device, remove sigio from the list and 1056 * free sigio. 1057 */ 1058 void 1059 funsetown(struct sigio **sigiop) 1060 { 1061 struct sigio *sigio; 1062 1063 /* Racy check, consumers must provide synchronization. */ 1064 if (*sigiop == NULL) 1065 return; 1066 1067 SIGIO_LOCK(); 1068 sigio = funsetown_locked(*sigiop); 1069 SIGIO_UNLOCK(); 1070 if (sigio != NULL) 1071 sigiofree(sigio); 1072 } 1073 1074 /* 1075 * Free a list of sigio structures. The caller must ensure that new sigio 1076 * structures cannot be added after this point. For process groups this is 1077 * guaranteed using the proctree lock; for processes, the P_WEXIT flag serves 1078 * as an interlock. 1079 */ 1080 void 1081 funsetownlst(struct sigiolst *sigiolst) 1082 { 1083 struct proc *p; 1084 struct pgrp *pg; 1085 struct sigio *sigio, *tmp; 1086 1087 /* Racy check. */ 1088 sigio = SLIST_FIRST(sigiolst); 1089 if (sigio == NULL) 1090 return; 1091 1092 p = NULL; 1093 pg = NULL; 1094 1095 SIGIO_LOCK(); 1096 sigio = SLIST_FIRST(sigiolst); 1097 if (sigio == NULL) { 1098 SIGIO_UNLOCK(); 1099 return; 1100 } 1101 1102 /* 1103 * Every entry of the list should belong to a single proc or pgrp. 1104 */ 1105 if (sigio->sio_pgid < 0) { 1106 pg = sigio->sio_pgrp; 1107 sx_assert(&proctree_lock, SX_XLOCKED); 1108 PGRP_LOCK(pg); 1109 } else /* if (sigio->sio_pgid > 0) */ { 1110 p = sigio->sio_proc; 1111 PROC_LOCK(p); 1112 KASSERT((p->p_flag & P_WEXIT) != 0, 1113 ("%s: process %p is not exiting", __func__, p)); 1114 } 1115 1116 SLIST_FOREACH(sigio, sigiolst, sio_pgsigio) { 1117 *sigio->sio_myref = NULL; 1118 if (pg != NULL) { 1119 KASSERT(sigio->sio_pgid < 0, 1120 ("Proc sigio in pgrp sigio list")); 1121 KASSERT(sigio->sio_pgrp == pg, 1122 ("Bogus pgrp in sigio list")); 1123 } else /* if (p != NULL) */ { 1124 KASSERT(sigio->sio_pgid > 0, 1125 ("Pgrp sigio in proc sigio list")); 1126 KASSERT(sigio->sio_proc == p, 1127 ("Bogus proc in sigio list")); 1128 } 1129 } 1130 1131 if (pg != NULL) 1132 PGRP_UNLOCK(pg); 1133 else 1134 PROC_UNLOCK(p); 1135 SIGIO_UNLOCK(); 1136 1137 SLIST_FOREACH_SAFE(sigio, sigiolst, sio_pgsigio, tmp) 1138 sigiofree(sigio); 1139 } 1140 1141 /* 1142 * This is common code for FIOSETOWN ioctl called by fcntl(fd, F_SETOWN, arg). 1143 * 1144 * After permission checking, add a sigio structure to the sigio list for 1145 * the process or process group. 1146 */ 1147 int 1148 fsetown(pid_t pgid, struct sigio **sigiop) 1149 { 1150 struct proc *proc; 1151 struct pgrp *pgrp; 1152 struct sigio *osigio, *sigio; 1153 int ret; 1154 1155 if (pgid == 0) { 1156 funsetown(sigiop); 1157 return (0); 1158 } 1159 1160 ret = 0; 1161 1162 sigio = malloc(sizeof(struct sigio), M_SIGIO, M_WAITOK); 1163 sigio->sio_pgid = pgid; 1164 sigio->sio_ucred = crhold(curthread->td_ucred); 1165 sigio->sio_myref = sigiop; 1166 1167 sx_slock(&proctree_lock); 1168 SIGIO_LOCK(); 1169 osigio = funsetown_locked(*sigiop); 1170 if (pgid > 0) { 1171 proc = pfind(pgid); 1172 if (proc == NULL) { 1173 ret = ESRCH; 1174 goto fail; 1175 } 1176 1177 /* 1178 * Policy - Don't allow a process to FSETOWN a process 1179 * in another session. 1180 * 1181 * Remove this test to allow maximum flexibility or 1182 * restrict FSETOWN to the current process or process 1183 * group for maximum safety. 1184 */ 1185 if (proc->p_session != curthread->td_proc->p_session) { 1186 PROC_UNLOCK(proc); 1187 ret = EPERM; 1188 goto fail; 1189 } 1190 1191 sigio->sio_proc = proc; 1192 SLIST_INSERT_HEAD(&proc->p_sigiolst, sigio, sio_pgsigio); 1193 PROC_UNLOCK(proc); 1194 } else /* if (pgid < 0) */ { 1195 pgrp = pgfind(-pgid); 1196 if (pgrp == NULL) { 1197 ret = ESRCH; 1198 goto fail; 1199 } 1200 1201 /* 1202 * Policy - Don't allow a process to FSETOWN a process 1203 * in another session. 1204 * 1205 * Remove this test to allow maximum flexibility or 1206 * restrict FSETOWN to the current process or process 1207 * group for maximum safety. 1208 */ 1209 if (pgrp->pg_session != curthread->td_proc->p_session) { 1210 PGRP_UNLOCK(pgrp); 1211 ret = EPERM; 1212 goto fail; 1213 } 1214 1215 SLIST_INSERT_HEAD(&pgrp->pg_sigiolst, sigio, sio_pgsigio); 1216 sigio->sio_pgrp = pgrp; 1217 PGRP_UNLOCK(pgrp); 1218 } 1219 sx_sunlock(&proctree_lock); 1220 *sigiop = sigio; 1221 SIGIO_UNLOCK(); 1222 if (osigio != NULL) 1223 sigiofree(osigio); 1224 return (0); 1225 1226 fail: 1227 SIGIO_UNLOCK(); 1228 sx_sunlock(&proctree_lock); 1229 sigiofree(sigio); 1230 if (osigio != NULL) 1231 sigiofree(osigio); 1232 return (ret); 1233 } 1234 1235 /* 1236 * This is common code for FIOGETOWN ioctl called by fcntl(fd, F_GETOWN, arg). 1237 */ 1238 pid_t 1239 fgetown(struct sigio **sigiop) 1240 { 1241 pid_t pgid; 1242 1243 SIGIO_LOCK(); 1244 pgid = (*sigiop != NULL) ? (*sigiop)->sio_pgid : 0; 1245 SIGIO_UNLOCK(); 1246 return (pgid); 1247 } 1248 1249 static int 1250 closefp_impl(struct filedesc *fdp, int fd, struct file *fp, struct thread *td, 1251 bool audit) 1252 { 1253 int error; 1254 1255 FILEDESC_XLOCK_ASSERT(fdp); 1256 1257 /* 1258 * We now hold the fp reference that used to be owned by the 1259 * descriptor array. We have to unlock the FILEDESC *AFTER* 1260 * knote_fdclose to prevent a race of the fd getting opened, a knote 1261 * added, and deleteing a knote for the new fd. 1262 */ 1263 if (__predict_false(!TAILQ_EMPTY(&fdp->fd_kqlist))) 1264 knote_fdclose(td, fd); 1265 1266 /* 1267 * We need to notify mqueue if the object is of type mqueue. 1268 */ 1269 if (__predict_false(fp->f_type == DTYPE_MQUEUE)) 1270 mq_fdclose(td, fd, fp); 1271 FILEDESC_XUNLOCK(fdp); 1272 1273 #ifdef AUDIT 1274 if (AUDITING_TD(td) && audit) 1275 audit_sysclose(td, fd, fp); 1276 #endif 1277 error = closef(fp, td); 1278 1279 /* 1280 * All paths leading up to closefp() will have already removed or 1281 * replaced the fd in the filedesc table, so a restart would not 1282 * operate on the same file. 1283 */ 1284 if (error == ERESTART) 1285 error = EINTR; 1286 1287 return (error); 1288 } 1289 1290 static int 1291 closefp_hl(struct filedesc *fdp, int fd, struct file *fp, struct thread *td, 1292 bool holdleaders, bool audit) 1293 { 1294 int error; 1295 1296 FILEDESC_XLOCK_ASSERT(fdp); 1297 1298 if (holdleaders) { 1299 if (td->td_proc->p_fdtol != NULL) { 1300 /* 1301 * Ask fdfree() to sleep to ensure that all relevant 1302 * process leaders can be traversed in closef(). 1303 */ 1304 fdp->fd_holdleaderscount++; 1305 } else { 1306 holdleaders = false; 1307 } 1308 } 1309 1310 error = closefp_impl(fdp, fd, fp, td, audit); 1311 if (holdleaders) { 1312 FILEDESC_XLOCK(fdp); 1313 fdp->fd_holdleaderscount--; 1314 if (fdp->fd_holdleaderscount == 0 && 1315 fdp->fd_holdleaderswakeup != 0) { 1316 fdp->fd_holdleaderswakeup = 0; 1317 wakeup(&fdp->fd_holdleaderscount); 1318 } 1319 FILEDESC_XUNLOCK(fdp); 1320 } 1321 return (error); 1322 } 1323 1324 static int 1325 closefp(struct filedesc *fdp, int fd, struct file *fp, struct thread *td, 1326 bool holdleaders, bool audit) 1327 { 1328 1329 FILEDESC_XLOCK_ASSERT(fdp); 1330 1331 if (__predict_false(td->td_proc->p_fdtol != NULL)) { 1332 return (closefp_hl(fdp, fd, fp, td, holdleaders, audit)); 1333 } else { 1334 return (closefp_impl(fdp, fd, fp, td, audit)); 1335 } 1336 } 1337 1338 /* 1339 * Close a file descriptor. 1340 */ 1341 #ifndef _SYS_SYSPROTO_H_ 1342 struct close_args { 1343 int fd; 1344 }; 1345 #endif 1346 /* ARGSUSED */ 1347 int 1348 sys_close(struct thread *td, struct close_args *uap) 1349 { 1350 1351 return (kern_close(td, uap->fd)); 1352 } 1353 1354 int 1355 kern_close(struct thread *td, int fd) 1356 { 1357 struct filedesc *fdp; 1358 struct file *fp; 1359 1360 fdp = td->td_proc->p_fd; 1361 1362 FILEDESC_XLOCK(fdp); 1363 if ((fp = fget_locked(fdp, fd)) == NULL) { 1364 FILEDESC_XUNLOCK(fdp); 1365 return (EBADF); 1366 } 1367 fdfree(fdp, fd); 1368 1369 /* closefp() drops the FILEDESC lock for us. */ 1370 return (closefp(fdp, fd, fp, td, true, true)); 1371 } 1372 1373 int 1374 kern_close_range(struct thread *td, u_int lowfd, u_int highfd) 1375 { 1376 struct filedesc *fdp; 1377 const struct fdescenttbl *fdt; 1378 struct file *fp; 1379 int fd; 1380 1381 /* 1382 * Check this prior to clamping; closefrom(3) with only fd 0, 1, and 2 1383 * open should not be a usage error. From a close_range() perspective, 1384 * close_range(3, ~0U, 0) in the same scenario should also likely not 1385 * be a usage error as all fd above 3 are in-fact already closed. 1386 */ 1387 if (highfd < lowfd) { 1388 return (EINVAL); 1389 } 1390 1391 fdp = td->td_proc->p_fd; 1392 FILEDESC_XLOCK(fdp); 1393 fdt = atomic_load_ptr(&fdp->fd_files); 1394 highfd = MIN(highfd, fdt->fdt_nfiles - 1); 1395 fd = lowfd; 1396 if (__predict_false(fd > highfd)) { 1397 goto out_locked; 1398 } 1399 for (;;) { 1400 fp = fdt->fdt_ofiles[fd].fde_file; 1401 if (fp == NULL) { 1402 if (fd == highfd) 1403 goto out_locked; 1404 } else { 1405 fdfree(fdp, fd); 1406 (void) closefp(fdp, fd, fp, td, true, true); 1407 if (fd == highfd) 1408 goto out_unlocked; 1409 FILEDESC_XLOCK(fdp); 1410 fdt = atomic_load_ptr(&fdp->fd_files); 1411 } 1412 fd++; 1413 } 1414 out_locked: 1415 FILEDESC_XUNLOCK(fdp); 1416 out_unlocked: 1417 return (0); 1418 } 1419 1420 #ifndef _SYS_SYSPROTO_H_ 1421 struct close_range_args { 1422 u_int lowfd; 1423 u_int highfd; 1424 int flags; 1425 }; 1426 #endif 1427 int 1428 sys_close_range(struct thread *td, struct close_range_args *uap) 1429 { 1430 1431 AUDIT_ARG_FD(uap->lowfd); 1432 AUDIT_ARG_CMD(uap->highfd); 1433 AUDIT_ARG_FFLAGS(uap->flags); 1434 1435 /* No flags currently defined */ 1436 if (uap->flags != 0) 1437 return (EINVAL); 1438 return (kern_close_range(td, uap->lowfd, uap->highfd)); 1439 } 1440 1441 #ifdef COMPAT_FREEBSD12 1442 /* 1443 * Close open file descriptors. 1444 */ 1445 #ifndef _SYS_SYSPROTO_H_ 1446 struct freebsd12_closefrom_args { 1447 int lowfd; 1448 }; 1449 #endif 1450 /* ARGSUSED */ 1451 int 1452 freebsd12_closefrom(struct thread *td, struct freebsd12_closefrom_args *uap) 1453 { 1454 u_int lowfd; 1455 1456 AUDIT_ARG_FD(uap->lowfd); 1457 1458 /* 1459 * Treat negative starting file descriptor values identical to 1460 * closefrom(0) which closes all files. 1461 */ 1462 lowfd = MAX(0, uap->lowfd); 1463 return (kern_close_range(td, lowfd, ~0U)); 1464 } 1465 #endif /* COMPAT_FREEBSD12 */ 1466 1467 #if defined(COMPAT_43) 1468 /* 1469 * Return status information about a file descriptor. 1470 */ 1471 #ifndef _SYS_SYSPROTO_H_ 1472 struct ofstat_args { 1473 int fd; 1474 struct ostat *sb; 1475 }; 1476 #endif 1477 /* ARGSUSED */ 1478 int 1479 ofstat(struct thread *td, struct ofstat_args *uap) 1480 { 1481 struct ostat oub; 1482 struct stat ub; 1483 int error; 1484 1485 error = kern_fstat(td, uap->fd, &ub); 1486 if (error == 0) { 1487 cvtstat(&ub, &oub); 1488 error = copyout(&oub, uap->sb, sizeof(oub)); 1489 } 1490 return (error); 1491 } 1492 #endif /* COMPAT_43 */ 1493 1494 #if defined(COMPAT_FREEBSD11) 1495 int 1496 freebsd11_fstat(struct thread *td, struct freebsd11_fstat_args *uap) 1497 { 1498 struct stat sb; 1499 struct freebsd11_stat osb; 1500 int error; 1501 1502 error = kern_fstat(td, uap->fd, &sb); 1503 if (error != 0) 1504 return (error); 1505 error = freebsd11_cvtstat(&sb, &osb); 1506 if (error == 0) 1507 error = copyout(&osb, uap->sb, sizeof(osb)); 1508 return (error); 1509 } 1510 #endif /* COMPAT_FREEBSD11 */ 1511 1512 /* 1513 * Return status information about a file descriptor. 1514 */ 1515 #ifndef _SYS_SYSPROTO_H_ 1516 struct fstat_args { 1517 int fd; 1518 struct stat *sb; 1519 }; 1520 #endif 1521 /* ARGSUSED */ 1522 int 1523 sys_fstat(struct thread *td, struct fstat_args *uap) 1524 { 1525 struct stat ub; 1526 int error; 1527 1528 error = kern_fstat(td, uap->fd, &ub); 1529 if (error == 0) 1530 error = copyout(&ub, uap->sb, sizeof(ub)); 1531 return (error); 1532 } 1533 1534 int 1535 kern_fstat(struct thread *td, int fd, struct stat *sbp) 1536 { 1537 struct file *fp; 1538 int error; 1539 1540 AUDIT_ARG_FD(fd); 1541 1542 error = fget(td, fd, &cap_fstat_rights, &fp); 1543 if (__predict_false(error != 0)) 1544 return (error); 1545 1546 AUDIT_ARG_FILE(td->td_proc, fp); 1547 1548 error = fo_stat(fp, sbp, td->td_ucred, td); 1549 fdrop(fp, td); 1550 #ifdef __STAT_TIME_T_EXT 1551 sbp->st_atim_ext = 0; 1552 sbp->st_mtim_ext = 0; 1553 sbp->st_ctim_ext = 0; 1554 sbp->st_btim_ext = 0; 1555 #endif 1556 #ifdef KTRACE 1557 if (KTRPOINT(td, KTR_STRUCT)) 1558 ktrstat_error(sbp, error); 1559 #endif 1560 return (error); 1561 } 1562 1563 #if defined(COMPAT_FREEBSD11) 1564 /* 1565 * Return status information about a file descriptor. 1566 */ 1567 #ifndef _SYS_SYSPROTO_H_ 1568 struct freebsd11_nfstat_args { 1569 int fd; 1570 struct nstat *sb; 1571 }; 1572 #endif 1573 /* ARGSUSED */ 1574 int 1575 freebsd11_nfstat(struct thread *td, struct freebsd11_nfstat_args *uap) 1576 { 1577 struct nstat nub; 1578 struct stat ub; 1579 int error; 1580 1581 error = kern_fstat(td, uap->fd, &ub); 1582 if (error == 0) { 1583 freebsd11_cvtnstat(&ub, &nub); 1584 error = copyout(&nub, uap->sb, sizeof(nub)); 1585 } 1586 return (error); 1587 } 1588 #endif /* COMPAT_FREEBSD11 */ 1589 1590 /* 1591 * Return pathconf information about a file descriptor. 1592 */ 1593 #ifndef _SYS_SYSPROTO_H_ 1594 struct fpathconf_args { 1595 int fd; 1596 int name; 1597 }; 1598 #endif 1599 /* ARGSUSED */ 1600 int 1601 sys_fpathconf(struct thread *td, struct fpathconf_args *uap) 1602 { 1603 long value; 1604 int error; 1605 1606 error = kern_fpathconf(td, uap->fd, uap->name, &value); 1607 if (error == 0) 1608 td->td_retval[0] = value; 1609 return (error); 1610 } 1611 1612 int 1613 kern_fpathconf(struct thread *td, int fd, int name, long *valuep) 1614 { 1615 struct file *fp; 1616 struct vnode *vp; 1617 int error; 1618 1619 error = fget(td, fd, &cap_fpathconf_rights, &fp); 1620 if (error != 0) 1621 return (error); 1622 1623 if (name == _PC_ASYNC_IO) { 1624 *valuep = _POSIX_ASYNCHRONOUS_IO; 1625 goto out; 1626 } 1627 vp = fp->f_vnode; 1628 if (vp != NULL) { 1629 vn_lock(vp, LK_SHARED | LK_RETRY); 1630 error = VOP_PATHCONF(vp, name, valuep); 1631 VOP_UNLOCK(vp); 1632 } else if (fp->f_type == DTYPE_PIPE || fp->f_type == DTYPE_SOCKET) { 1633 if (name != _PC_PIPE_BUF) { 1634 error = EINVAL; 1635 } else { 1636 *valuep = PIPE_BUF; 1637 error = 0; 1638 } 1639 } else { 1640 error = EOPNOTSUPP; 1641 } 1642 out: 1643 fdrop(fp, td); 1644 return (error); 1645 } 1646 1647 /* 1648 * Copy filecaps structure allocating memory for ioctls array if needed. 1649 * 1650 * The last parameter indicates whether the fdtable is locked. If it is not and 1651 * ioctls are encountered, copying fails and the caller must lock the table. 1652 * 1653 * Note that if the table was not locked, the caller has to check the relevant 1654 * sequence counter to determine whether the operation was successful. 1655 */ 1656 bool 1657 filecaps_copy(const struct filecaps *src, struct filecaps *dst, bool locked) 1658 { 1659 size_t size; 1660 1661 if (src->fc_ioctls != NULL && !locked) 1662 return (false); 1663 memcpy(dst, src, sizeof(*src)); 1664 if (src->fc_ioctls == NULL) 1665 return (true); 1666 1667 KASSERT(src->fc_nioctls > 0, 1668 ("fc_ioctls != NULL, but fc_nioctls=%hd", src->fc_nioctls)); 1669 1670 size = sizeof(src->fc_ioctls[0]) * src->fc_nioctls; 1671 dst->fc_ioctls = malloc(size, M_FILECAPS, M_WAITOK); 1672 memcpy(dst->fc_ioctls, src->fc_ioctls, size); 1673 return (true); 1674 } 1675 1676 static u_long * 1677 filecaps_copy_prep(const struct filecaps *src) 1678 { 1679 u_long *ioctls; 1680 size_t size; 1681 1682 if (__predict_true(src->fc_ioctls == NULL)) 1683 return (NULL); 1684 1685 KASSERT(src->fc_nioctls > 0, 1686 ("fc_ioctls != NULL, but fc_nioctls=%hd", src->fc_nioctls)); 1687 1688 size = sizeof(src->fc_ioctls[0]) * src->fc_nioctls; 1689 ioctls = malloc(size, M_FILECAPS, M_WAITOK); 1690 return (ioctls); 1691 } 1692 1693 static void 1694 filecaps_copy_finish(const struct filecaps *src, struct filecaps *dst, 1695 u_long *ioctls) 1696 { 1697 size_t size; 1698 1699 *dst = *src; 1700 if (__predict_true(src->fc_ioctls == NULL)) { 1701 MPASS(ioctls == NULL); 1702 return; 1703 } 1704 1705 size = sizeof(src->fc_ioctls[0]) * src->fc_nioctls; 1706 dst->fc_ioctls = ioctls; 1707 bcopy(src->fc_ioctls, dst->fc_ioctls, size); 1708 } 1709 1710 /* 1711 * Move filecaps structure to the new place and clear the old place. 1712 */ 1713 void 1714 filecaps_move(struct filecaps *src, struct filecaps *dst) 1715 { 1716 1717 *dst = *src; 1718 bzero(src, sizeof(*src)); 1719 } 1720 1721 /* 1722 * Fill the given filecaps structure with full rights. 1723 */ 1724 static void 1725 filecaps_fill(struct filecaps *fcaps) 1726 { 1727 1728 CAP_ALL(&fcaps->fc_rights); 1729 fcaps->fc_ioctls = NULL; 1730 fcaps->fc_nioctls = -1; 1731 fcaps->fc_fcntls = CAP_FCNTL_ALL; 1732 } 1733 1734 /* 1735 * Free memory allocated within filecaps structure. 1736 */ 1737 void 1738 filecaps_free(struct filecaps *fcaps) 1739 { 1740 1741 free(fcaps->fc_ioctls, M_FILECAPS); 1742 bzero(fcaps, sizeof(*fcaps)); 1743 } 1744 1745 static u_long * 1746 filecaps_free_prep(struct filecaps *fcaps) 1747 { 1748 u_long *ioctls; 1749 1750 ioctls = fcaps->fc_ioctls; 1751 bzero(fcaps, sizeof(*fcaps)); 1752 return (ioctls); 1753 } 1754 1755 static void 1756 filecaps_free_finish(u_long *ioctls) 1757 { 1758 1759 free(ioctls, M_FILECAPS); 1760 } 1761 1762 /* 1763 * Validate the given filecaps structure. 1764 */ 1765 static void 1766 filecaps_validate(const struct filecaps *fcaps, const char *func) 1767 { 1768 1769 KASSERT(cap_rights_is_valid(&fcaps->fc_rights), 1770 ("%s: invalid rights", func)); 1771 KASSERT((fcaps->fc_fcntls & ~CAP_FCNTL_ALL) == 0, 1772 ("%s: invalid fcntls", func)); 1773 KASSERT(fcaps->fc_fcntls == 0 || 1774 cap_rights_is_set(&fcaps->fc_rights, CAP_FCNTL), 1775 ("%s: fcntls without CAP_FCNTL", func)); 1776 KASSERT(fcaps->fc_ioctls != NULL ? fcaps->fc_nioctls > 0 : 1777 (fcaps->fc_nioctls == -1 || fcaps->fc_nioctls == 0), 1778 ("%s: invalid ioctls", func)); 1779 KASSERT(fcaps->fc_nioctls == 0 || 1780 cap_rights_is_set(&fcaps->fc_rights, CAP_IOCTL), 1781 ("%s: ioctls without CAP_IOCTL", func)); 1782 } 1783 1784 static void 1785 fdgrowtable_exp(struct filedesc *fdp, int nfd) 1786 { 1787 int nfd1; 1788 1789 FILEDESC_XLOCK_ASSERT(fdp); 1790 1791 nfd1 = fdp->fd_nfiles * 2; 1792 if (nfd1 < nfd) 1793 nfd1 = nfd; 1794 fdgrowtable(fdp, nfd1); 1795 } 1796 1797 /* 1798 * Grow the file table to accommodate (at least) nfd descriptors. 1799 */ 1800 static void 1801 fdgrowtable(struct filedesc *fdp, int nfd) 1802 { 1803 struct filedesc0 *fdp0; 1804 struct freetable *ft; 1805 struct fdescenttbl *ntable; 1806 struct fdescenttbl *otable; 1807 int nnfiles, onfiles; 1808 NDSLOTTYPE *nmap, *omap; 1809 1810 KASSERT(fdp->fd_nfiles > 0, ("zero-length file table")); 1811 1812 /* save old values */ 1813 onfiles = fdp->fd_nfiles; 1814 otable = fdp->fd_files; 1815 omap = fdp->fd_map; 1816 1817 /* compute the size of the new table */ 1818 nnfiles = NDSLOTS(nfd) * NDENTRIES; /* round up */ 1819 if (nnfiles <= onfiles) 1820 /* the table is already large enough */ 1821 return; 1822 1823 /* 1824 * Allocate a new table. We need enough space for the number of 1825 * entries, file entries themselves and the struct freetable we will use 1826 * when we decommission the table and place it on the freelist. 1827 * We place the struct freetable in the middle so we don't have 1828 * to worry about padding. 1829 */ 1830 ntable = malloc(offsetof(struct fdescenttbl, fdt_ofiles) + 1831 nnfiles * sizeof(ntable->fdt_ofiles[0]) + 1832 sizeof(struct freetable), 1833 M_FILEDESC, M_ZERO | M_WAITOK); 1834 /* copy the old data */ 1835 ntable->fdt_nfiles = nnfiles; 1836 memcpy(ntable->fdt_ofiles, otable->fdt_ofiles, 1837 onfiles * sizeof(ntable->fdt_ofiles[0])); 1838 1839 /* 1840 * Allocate a new map only if the old is not large enough. It will 1841 * grow at a slower rate than the table as it can map more 1842 * entries than the table can hold. 1843 */ 1844 if (NDSLOTS(nnfiles) > NDSLOTS(onfiles)) { 1845 nmap = malloc(NDSLOTS(nnfiles) * NDSLOTSIZE, M_FILEDESC, 1846 M_ZERO | M_WAITOK); 1847 /* copy over the old data and update the pointer */ 1848 memcpy(nmap, omap, NDSLOTS(onfiles) * sizeof(*omap)); 1849 fdp->fd_map = nmap; 1850 } 1851 1852 /* 1853 * Make sure that ntable is correctly initialized before we replace 1854 * fd_files poiner. Otherwise fget_unlocked() may see inconsistent 1855 * data. 1856 */ 1857 atomic_store_rel_ptr((volatile void *)&fdp->fd_files, (uintptr_t)ntable); 1858 1859 /* 1860 * Free the old file table when not shared by other threads or processes. 1861 * The old file table is considered to be shared when either are true: 1862 * - The process has more than one thread. 1863 * - The file descriptor table has been shared via fdshare(). 1864 * 1865 * When shared, the old file table will be placed on a freelist 1866 * which will be processed when the struct filedesc is released. 1867 * 1868 * Note that if onfiles == NDFILE, we're dealing with the original 1869 * static allocation contained within (struct filedesc0 *)fdp, 1870 * which must not be freed. 1871 */ 1872 if (onfiles > NDFILE) { 1873 /* 1874 * Note we may be called here from fdinit while allocating a 1875 * table for a new process in which case ->p_fd points 1876 * elsewhere. 1877 */ 1878 if (curproc->p_fd != fdp || FILEDESC_IS_ONLY_USER(fdp)) { 1879 free(otable, M_FILEDESC); 1880 } else { 1881 ft = (struct freetable *)&otable->fdt_ofiles[onfiles]; 1882 fdp0 = (struct filedesc0 *)fdp; 1883 ft->ft_table = otable; 1884 SLIST_INSERT_HEAD(&fdp0->fd_free, ft, ft_next); 1885 } 1886 } 1887 /* 1888 * The map does not have the same possibility of threads still 1889 * holding references to it. So always free it as long as it 1890 * does not reference the original static allocation. 1891 */ 1892 if (NDSLOTS(onfiles) > NDSLOTS(NDFILE)) 1893 free(omap, M_FILEDESC); 1894 } 1895 1896 /* 1897 * Allocate a file descriptor for the process. 1898 */ 1899 int 1900 fdalloc(struct thread *td, int minfd, int *result) 1901 { 1902 struct proc *p = td->td_proc; 1903 struct filedesc *fdp = p->p_fd; 1904 int fd, maxfd, allocfd; 1905 #ifdef RACCT 1906 int error; 1907 #endif 1908 1909 FILEDESC_XLOCK_ASSERT(fdp); 1910 1911 if (fdp->fd_freefile > minfd) 1912 minfd = fdp->fd_freefile; 1913 1914 maxfd = getmaxfd(td); 1915 1916 /* 1917 * Search the bitmap for a free descriptor starting at minfd. 1918 * If none is found, grow the file table. 1919 */ 1920 fd = fd_first_free(fdp, minfd, fdp->fd_nfiles); 1921 if (__predict_false(fd >= maxfd)) 1922 return (EMFILE); 1923 if (__predict_false(fd >= fdp->fd_nfiles)) { 1924 allocfd = min(fd * 2, maxfd); 1925 #ifdef RACCT 1926 if (RACCT_ENABLED()) { 1927 error = racct_set_unlocked(p, RACCT_NOFILE, allocfd); 1928 if (error != 0) 1929 return (EMFILE); 1930 } 1931 #endif 1932 /* 1933 * fd is already equal to first free descriptor >= minfd, so 1934 * we only need to grow the table and we are done. 1935 */ 1936 fdgrowtable_exp(fdp, allocfd); 1937 } 1938 1939 /* 1940 * Perform some sanity checks, then mark the file descriptor as 1941 * used and return it to the caller. 1942 */ 1943 KASSERT(fd >= 0 && fd < min(maxfd, fdp->fd_nfiles), 1944 ("invalid descriptor %d", fd)); 1945 KASSERT(!fdisused(fdp, fd), 1946 ("fd_first_free() returned non-free descriptor")); 1947 KASSERT(fdp->fd_ofiles[fd].fde_file == NULL, 1948 ("file descriptor isn't free")); 1949 fdused(fdp, fd); 1950 *result = fd; 1951 return (0); 1952 } 1953 1954 /* 1955 * Allocate n file descriptors for the process. 1956 */ 1957 int 1958 fdallocn(struct thread *td, int minfd, int *fds, int n) 1959 { 1960 struct proc *p = td->td_proc; 1961 struct filedesc *fdp = p->p_fd; 1962 int i; 1963 1964 FILEDESC_XLOCK_ASSERT(fdp); 1965 1966 for (i = 0; i < n; i++) 1967 if (fdalloc(td, 0, &fds[i]) != 0) 1968 break; 1969 1970 if (i < n) { 1971 for (i--; i >= 0; i--) 1972 fdunused(fdp, fds[i]); 1973 return (EMFILE); 1974 } 1975 1976 return (0); 1977 } 1978 1979 /* 1980 * Create a new open file structure and allocate a file descriptor for the 1981 * process that refers to it. We add one reference to the file for the 1982 * descriptor table and one reference for resultfp. This is to prevent us 1983 * being preempted and the entry in the descriptor table closed after we 1984 * release the FILEDESC lock. 1985 */ 1986 int 1987 falloc_caps(struct thread *td, struct file **resultfp, int *resultfd, int flags, 1988 struct filecaps *fcaps) 1989 { 1990 struct file *fp; 1991 int error, fd; 1992 1993 MPASS(resultfp != NULL); 1994 MPASS(resultfd != NULL); 1995 1996 error = _falloc_noinstall(td, &fp, 2); 1997 if (__predict_false(error != 0)) { 1998 return (error); 1999 } 2000 2001 error = finstall_refed(td, fp, &fd, flags, fcaps); 2002 if (__predict_false(error != 0)) { 2003 falloc_abort(td, fp); 2004 return (error); 2005 } 2006 2007 *resultfp = fp; 2008 *resultfd = fd; 2009 2010 return (0); 2011 } 2012 2013 /* 2014 * Create a new open file structure without allocating a file descriptor. 2015 */ 2016 int 2017 _falloc_noinstall(struct thread *td, struct file **resultfp, u_int n) 2018 { 2019 struct file *fp; 2020 int maxuserfiles = maxfiles - (maxfiles / 20); 2021 int openfiles_new; 2022 static struct timeval lastfail; 2023 static int curfail; 2024 2025 KASSERT(resultfp != NULL, ("%s: resultfp == NULL", __func__)); 2026 MPASS(n > 0); 2027 2028 openfiles_new = atomic_fetchadd_int(&openfiles, 1) + 1; 2029 if ((openfiles_new >= maxuserfiles && 2030 priv_check(td, PRIV_MAXFILES) != 0) || 2031 openfiles_new >= maxfiles) { 2032 atomic_subtract_int(&openfiles, 1); 2033 if (ppsratecheck(&lastfail, &curfail, 1)) { 2034 printf("kern.maxfiles limit exceeded by uid %i, (%s) " 2035 "please see tuning(7).\n", td->td_ucred->cr_ruid, td->td_proc->p_comm); 2036 } 2037 return (ENFILE); 2038 } 2039 fp = uma_zalloc(file_zone, M_WAITOK); 2040 bzero(fp, sizeof(*fp)); 2041 refcount_init(&fp->f_count, n); 2042 fp->f_cred = crhold(td->td_ucred); 2043 fp->f_ops = &badfileops; 2044 *resultfp = fp; 2045 return (0); 2046 } 2047 2048 void 2049 falloc_abort(struct thread *td, struct file *fp) 2050 { 2051 2052 /* 2053 * For assertion purposes. 2054 */ 2055 refcount_init(&fp->f_count, 0); 2056 _fdrop(fp, td); 2057 } 2058 2059 /* 2060 * Install a file in a file descriptor table. 2061 */ 2062 void 2063 _finstall(struct filedesc *fdp, struct file *fp, int fd, int flags, 2064 struct filecaps *fcaps) 2065 { 2066 struct filedescent *fde; 2067 2068 MPASS(fp != NULL); 2069 if (fcaps != NULL) 2070 filecaps_validate(fcaps, __func__); 2071 FILEDESC_XLOCK_ASSERT(fdp); 2072 2073 fde = &fdp->fd_ofiles[fd]; 2074 #ifdef CAPABILITIES 2075 seqc_write_begin(&fde->fde_seqc); 2076 #endif 2077 fde->fde_file = fp; 2078 fde->fde_flags = (flags & O_CLOEXEC) != 0 ? UF_EXCLOSE : 0; 2079 if (fcaps != NULL) 2080 filecaps_move(fcaps, &fde->fde_caps); 2081 else 2082 filecaps_fill(&fde->fde_caps); 2083 #ifdef CAPABILITIES 2084 seqc_write_end(&fde->fde_seqc); 2085 #endif 2086 } 2087 2088 int 2089 finstall_refed(struct thread *td, struct file *fp, int *fd, int flags, 2090 struct filecaps *fcaps) 2091 { 2092 struct filedesc *fdp = td->td_proc->p_fd; 2093 int error; 2094 2095 MPASS(fd != NULL); 2096 2097 FILEDESC_XLOCK(fdp); 2098 error = fdalloc(td, 0, fd); 2099 if (__predict_true(error == 0)) { 2100 _finstall(fdp, fp, *fd, flags, fcaps); 2101 } 2102 FILEDESC_XUNLOCK(fdp); 2103 return (error); 2104 } 2105 2106 int 2107 finstall(struct thread *td, struct file *fp, int *fd, int flags, 2108 struct filecaps *fcaps) 2109 { 2110 int error; 2111 2112 MPASS(fd != NULL); 2113 2114 if (!fhold(fp)) 2115 return (EBADF); 2116 error = finstall_refed(td, fp, fd, flags, fcaps); 2117 if (__predict_false(error != 0)) { 2118 fdrop(fp, td); 2119 } 2120 return (error); 2121 } 2122 2123 /* 2124 * Build a new filedesc structure from another. 2125 * 2126 * If fdp is not NULL, return with it shared locked. 2127 */ 2128 struct filedesc * 2129 fdinit(struct filedesc *fdp, bool prepfiles, int *lastfile) 2130 { 2131 struct filedesc0 *newfdp0; 2132 struct filedesc *newfdp; 2133 2134 if (prepfiles) 2135 MPASS(lastfile != NULL); 2136 else 2137 MPASS(lastfile == NULL); 2138 2139 newfdp0 = uma_zalloc(filedesc0_zone, M_WAITOK | M_ZERO); 2140 newfdp = &newfdp0->fd_fd; 2141 2142 /* Create the file descriptor table. */ 2143 FILEDESC_LOCK_INIT(newfdp); 2144 refcount_init(&newfdp->fd_refcnt, 1); 2145 refcount_init(&newfdp->fd_holdcnt, 1); 2146 newfdp->fd_map = newfdp0->fd_dmap; 2147 newfdp->fd_files = (struct fdescenttbl *)&newfdp0->fd_dfiles; 2148 newfdp->fd_files->fdt_nfiles = NDFILE; 2149 2150 if (fdp == NULL) 2151 return (newfdp); 2152 2153 FILEDESC_SLOCK(fdp); 2154 if (!prepfiles) { 2155 FILEDESC_SUNLOCK(fdp); 2156 return (newfdp); 2157 } 2158 2159 for (;;) { 2160 *lastfile = fdlastfile(fdp); 2161 if (*lastfile < newfdp->fd_nfiles) 2162 break; 2163 FILEDESC_SUNLOCK(fdp); 2164 fdgrowtable(newfdp, *lastfile + 1); 2165 FILEDESC_SLOCK(fdp); 2166 } 2167 2168 return (newfdp); 2169 } 2170 2171 /* 2172 * Build a pwddesc structure from another. 2173 * Copy the current, root, and jail root vnode references. 2174 * 2175 * If pdp is not NULL, return with it shared locked. 2176 */ 2177 struct pwddesc * 2178 pdinit(struct pwddesc *pdp, bool keeplock) 2179 { 2180 struct pwddesc *newpdp; 2181 struct pwd *newpwd; 2182 2183 newpdp = malloc(sizeof(*newpdp), M_PWDDESC, M_WAITOK | M_ZERO); 2184 2185 PWDDESC_LOCK_INIT(newpdp); 2186 refcount_init(&newpdp->pd_refcount, 1); 2187 newpdp->pd_cmask = CMASK; 2188 2189 if (pdp == NULL) { 2190 newpwd = pwd_alloc(); 2191 smr_serialized_store(&newpdp->pd_pwd, newpwd, true); 2192 return (newpdp); 2193 } 2194 2195 PWDDESC_XLOCK(pdp); 2196 newpwd = pwd_hold_pwddesc(pdp); 2197 smr_serialized_store(&newpdp->pd_pwd, newpwd, true); 2198 if (!keeplock) 2199 PWDDESC_XUNLOCK(pdp); 2200 return (newpdp); 2201 } 2202 2203 static struct filedesc * 2204 fdhold(struct proc *p) 2205 { 2206 struct filedesc *fdp; 2207 2208 PROC_LOCK_ASSERT(p, MA_OWNED); 2209 fdp = p->p_fd; 2210 if (fdp != NULL) 2211 refcount_acquire(&fdp->fd_holdcnt); 2212 return (fdp); 2213 } 2214 2215 static struct pwddesc * 2216 pdhold(struct proc *p) 2217 { 2218 struct pwddesc *pdp; 2219 2220 PROC_LOCK_ASSERT(p, MA_OWNED); 2221 pdp = p->p_pd; 2222 if (pdp != NULL) 2223 refcount_acquire(&pdp->pd_refcount); 2224 return (pdp); 2225 } 2226 2227 static void 2228 fddrop(struct filedesc *fdp) 2229 { 2230 2231 if (refcount_load(&fdp->fd_holdcnt) > 1) { 2232 if (refcount_release(&fdp->fd_holdcnt) == 0) 2233 return; 2234 } 2235 2236 FILEDESC_LOCK_DESTROY(fdp); 2237 uma_zfree(filedesc0_zone, fdp); 2238 } 2239 2240 static void 2241 pddrop(struct pwddesc *pdp) 2242 { 2243 struct pwd *pwd; 2244 2245 if (refcount_release_if_not_last(&pdp->pd_refcount)) 2246 return; 2247 2248 PWDDESC_XLOCK(pdp); 2249 if (refcount_release(&pdp->pd_refcount) == 0) { 2250 PWDDESC_XUNLOCK(pdp); 2251 return; 2252 } 2253 pwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); 2254 pwd_set(pdp, NULL); 2255 PWDDESC_XUNLOCK(pdp); 2256 pwd_drop(pwd); 2257 2258 PWDDESC_LOCK_DESTROY(pdp); 2259 free(pdp, M_PWDDESC); 2260 } 2261 2262 /* 2263 * Share a filedesc structure. 2264 */ 2265 struct filedesc * 2266 fdshare(struct filedesc *fdp) 2267 { 2268 2269 refcount_acquire(&fdp->fd_refcnt); 2270 return (fdp); 2271 } 2272 2273 /* 2274 * Share a pwddesc structure. 2275 */ 2276 struct pwddesc * 2277 pdshare(struct pwddesc *pdp) 2278 { 2279 refcount_acquire(&pdp->pd_refcount); 2280 return (pdp); 2281 } 2282 2283 /* 2284 * Unshare a filedesc structure, if necessary by making a copy 2285 */ 2286 void 2287 fdunshare(struct thread *td) 2288 { 2289 struct filedesc *tmp; 2290 struct proc *p = td->td_proc; 2291 2292 if (refcount_load(&p->p_fd->fd_refcnt) == 1) 2293 return; 2294 2295 tmp = fdcopy(p->p_fd); 2296 fdescfree(td); 2297 p->p_fd = tmp; 2298 } 2299 2300 /* 2301 * Unshare a pwddesc structure. 2302 */ 2303 void 2304 pdunshare(struct thread *td) 2305 { 2306 struct pwddesc *pdp; 2307 struct proc *p; 2308 2309 p = td->td_proc; 2310 /* Not shared. */ 2311 if (p->p_pd->pd_refcount == 1) 2312 return; 2313 2314 pdp = pdcopy(p->p_pd); 2315 pdescfree(td); 2316 p->p_pd = pdp; 2317 } 2318 2319 void 2320 fdinstall_remapped(struct thread *td, struct filedesc *fdp) 2321 { 2322 2323 fdescfree(td); 2324 td->td_proc->p_fd = fdp; 2325 } 2326 2327 /* 2328 * Copy a filedesc structure. A NULL pointer in returns a NULL reference, 2329 * this is to ease callers, not catch errors. 2330 */ 2331 struct filedesc * 2332 fdcopy(struct filedesc *fdp) 2333 { 2334 struct filedesc *newfdp; 2335 struct filedescent *nfde, *ofde; 2336 int i, lastfile; 2337 2338 MPASS(fdp != NULL); 2339 2340 newfdp = fdinit(fdp, true, &lastfile); 2341 /* copy all passable descriptors (i.e. not kqueue) */ 2342 newfdp->fd_freefile = -1; 2343 for (i = 0; i <= lastfile; ++i) { 2344 ofde = &fdp->fd_ofiles[i]; 2345 if (ofde->fde_file == NULL || 2346 (ofde->fde_file->f_ops->fo_flags & DFLAG_PASSABLE) == 0 || 2347 !fhold(ofde->fde_file)) { 2348 if (newfdp->fd_freefile == -1) 2349 newfdp->fd_freefile = i; 2350 continue; 2351 } 2352 nfde = &newfdp->fd_ofiles[i]; 2353 *nfde = *ofde; 2354 filecaps_copy(&ofde->fde_caps, &nfde->fde_caps, true); 2355 fdused_init(newfdp, i); 2356 } 2357 if (newfdp->fd_freefile == -1) 2358 newfdp->fd_freefile = i; 2359 FILEDESC_SUNLOCK(fdp); 2360 return (newfdp); 2361 } 2362 2363 /* 2364 * Copy a pwddesc structure. 2365 */ 2366 struct pwddesc * 2367 pdcopy(struct pwddesc *pdp) 2368 { 2369 struct pwddesc *newpdp; 2370 2371 MPASS(pdp != NULL); 2372 2373 newpdp = pdinit(pdp, true); 2374 newpdp->pd_cmask = pdp->pd_cmask; 2375 PWDDESC_XUNLOCK(pdp); 2376 return (newpdp); 2377 } 2378 2379 /* 2380 * Copies a filedesc structure, while remapping all file descriptors 2381 * stored inside using a translation table. 2382 * 2383 * File descriptors are copied over to the new file descriptor table, 2384 * regardless of whether the close-on-exec flag is set. 2385 */ 2386 int 2387 fdcopy_remapped(struct filedesc *fdp, const int *fds, size_t nfds, 2388 struct filedesc **ret) 2389 { 2390 struct filedesc *newfdp; 2391 struct filedescent *nfde, *ofde; 2392 int error, i, lastfile; 2393 2394 MPASS(fdp != NULL); 2395 2396 newfdp = fdinit(fdp, true, &lastfile); 2397 if (nfds > lastfile + 1) { 2398 /* New table cannot be larger than the old one. */ 2399 error = E2BIG; 2400 goto bad; 2401 } 2402 /* Copy all passable descriptors (i.e. not kqueue). */ 2403 newfdp->fd_freefile = nfds; 2404 for (i = 0; i < nfds; ++i) { 2405 if (fds[i] < 0 || fds[i] > lastfile) { 2406 /* File descriptor out of bounds. */ 2407 error = EBADF; 2408 goto bad; 2409 } 2410 ofde = &fdp->fd_ofiles[fds[i]]; 2411 if (ofde->fde_file == NULL) { 2412 /* Unused file descriptor. */ 2413 error = EBADF; 2414 goto bad; 2415 } 2416 if ((ofde->fde_file->f_ops->fo_flags & DFLAG_PASSABLE) == 0) { 2417 /* File descriptor cannot be passed. */ 2418 error = EINVAL; 2419 goto bad; 2420 } 2421 if (!fhold(ofde->fde_file)) { 2422 error = EBADF; 2423 goto bad; 2424 } 2425 nfde = &newfdp->fd_ofiles[i]; 2426 *nfde = *ofde; 2427 filecaps_copy(&ofde->fde_caps, &nfde->fde_caps, true); 2428 fdused_init(newfdp, i); 2429 } 2430 FILEDESC_SUNLOCK(fdp); 2431 *ret = newfdp; 2432 return (0); 2433 bad: 2434 FILEDESC_SUNLOCK(fdp); 2435 fdescfree_remapped(newfdp); 2436 return (error); 2437 } 2438 2439 /* 2440 * Clear POSIX style locks. This is only used when fdp looses a reference (i.e. 2441 * one of processes using it exits) and the table used to be shared. 2442 */ 2443 static void 2444 fdclearlocks(struct thread *td) 2445 { 2446 struct filedesc *fdp; 2447 struct filedesc_to_leader *fdtol; 2448 struct flock lf; 2449 struct file *fp; 2450 struct proc *p; 2451 struct vnode *vp; 2452 int i, lastfile; 2453 2454 p = td->td_proc; 2455 fdp = p->p_fd; 2456 fdtol = p->p_fdtol; 2457 MPASS(fdtol != NULL); 2458 2459 FILEDESC_XLOCK(fdp); 2460 KASSERT(fdtol->fdl_refcount > 0, 2461 ("filedesc_to_refcount botch: fdl_refcount=%d", 2462 fdtol->fdl_refcount)); 2463 if (fdtol->fdl_refcount == 1 && 2464 (p->p_leader->p_flag & P_ADVLOCK) != 0) { 2465 lastfile = fdlastfile(fdp); 2466 for (i = 0; i <= lastfile; i++) { 2467 fp = fdp->fd_ofiles[i].fde_file; 2468 if (fp == NULL || fp->f_type != DTYPE_VNODE || 2469 !fhold(fp)) 2470 continue; 2471 FILEDESC_XUNLOCK(fdp); 2472 lf.l_whence = SEEK_SET; 2473 lf.l_start = 0; 2474 lf.l_len = 0; 2475 lf.l_type = F_UNLCK; 2476 vp = fp->f_vnode; 2477 (void) VOP_ADVLOCK(vp, 2478 (caddr_t)p->p_leader, F_UNLCK, 2479 &lf, F_POSIX); 2480 FILEDESC_XLOCK(fdp); 2481 fdrop(fp, td); 2482 } 2483 } 2484 retry: 2485 if (fdtol->fdl_refcount == 1) { 2486 if (fdp->fd_holdleaderscount > 0 && 2487 (p->p_leader->p_flag & P_ADVLOCK) != 0) { 2488 /* 2489 * close() or kern_dup() has cleared a reference 2490 * in a shared file descriptor table. 2491 */ 2492 fdp->fd_holdleaderswakeup = 1; 2493 sx_sleep(&fdp->fd_holdleaderscount, 2494 FILEDESC_LOCK(fdp), PLOCK, "fdlhold", 0); 2495 goto retry; 2496 } 2497 if (fdtol->fdl_holdcount > 0) { 2498 /* 2499 * Ensure that fdtol->fdl_leader remains 2500 * valid in closef(). 2501 */ 2502 fdtol->fdl_wakeup = 1; 2503 sx_sleep(fdtol, FILEDESC_LOCK(fdp), PLOCK, 2504 "fdlhold", 0); 2505 goto retry; 2506 } 2507 } 2508 fdtol->fdl_refcount--; 2509 if (fdtol->fdl_refcount == 0 && 2510 fdtol->fdl_holdcount == 0) { 2511 fdtol->fdl_next->fdl_prev = fdtol->fdl_prev; 2512 fdtol->fdl_prev->fdl_next = fdtol->fdl_next; 2513 } else 2514 fdtol = NULL; 2515 p->p_fdtol = NULL; 2516 FILEDESC_XUNLOCK(fdp); 2517 if (fdtol != NULL) 2518 free(fdtol, M_FILEDESC_TO_LEADER); 2519 } 2520 2521 /* 2522 * Release a filedesc structure. 2523 */ 2524 static void 2525 fdescfree_fds(struct thread *td, struct filedesc *fdp, bool needclose) 2526 { 2527 struct filedesc0 *fdp0; 2528 struct freetable *ft, *tft; 2529 struct filedescent *fde; 2530 struct file *fp; 2531 int i, lastfile; 2532 2533 KASSERT(refcount_load(&fdp->fd_refcnt) == 0, 2534 ("%s: fd table %p carries references", __func__, fdp)); 2535 2536 /* 2537 * Serialize with threads iterating over the table, if any. 2538 */ 2539 if (refcount_load(&fdp->fd_holdcnt) > 1) { 2540 FILEDESC_XLOCK(fdp); 2541 FILEDESC_XUNLOCK(fdp); 2542 } 2543 2544 lastfile = fdlastfile_single(fdp); 2545 for (i = 0; i <= lastfile; i++) { 2546 fde = &fdp->fd_ofiles[i]; 2547 fp = fde->fde_file; 2548 if (fp != NULL) { 2549 fdefree_last(fde); 2550 if (needclose) 2551 (void) closef(fp, td); 2552 else 2553 fdrop(fp, td); 2554 } 2555 } 2556 2557 if (NDSLOTS(fdp->fd_nfiles) > NDSLOTS(NDFILE)) 2558 free(fdp->fd_map, M_FILEDESC); 2559 if (fdp->fd_nfiles > NDFILE) 2560 free(fdp->fd_files, M_FILEDESC); 2561 2562 fdp0 = (struct filedesc0 *)fdp; 2563 SLIST_FOREACH_SAFE(ft, &fdp0->fd_free, ft_next, tft) 2564 free(ft->ft_table, M_FILEDESC); 2565 2566 fddrop(fdp); 2567 } 2568 2569 void 2570 fdescfree(struct thread *td) 2571 { 2572 struct proc *p; 2573 struct filedesc *fdp; 2574 2575 p = td->td_proc; 2576 fdp = p->p_fd; 2577 MPASS(fdp != NULL); 2578 2579 #ifdef RACCT 2580 if (RACCT_ENABLED()) 2581 racct_set_unlocked(p, RACCT_NOFILE, 0); 2582 #endif 2583 2584 if (p->p_fdtol != NULL) 2585 fdclearlocks(td); 2586 2587 PROC_LOCK(p); 2588 p->p_fd = NULL; 2589 PROC_UNLOCK(p); 2590 2591 if (refcount_release(&fdp->fd_refcnt) == 0) 2592 return; 2593 2594 fdescfree_fds(td, fdp, 1); 2595 } 2596 2597 void 2598 pdescfree(struct thread *td) 2599 { 2600 struct proc *p; 2601 struct pwddesc *pdp; 2602 2603 p = td->td_proc; 2604 pdp = p->p_pd; 2605 MPASS(pdp != NULL); 2606 2607 PROC_LOCK(p); 2608 p->p_pd = NULL; 2609 PROC_UNLOCK(p); 2610 2611 pddrop(pdp); 2612 } 2613 2614 void 2615 fdescfree_remapped(struct filedesc *fdp) 2616 { 2617 #ifdef INVARIANTS 2618 /* fdescfree_fds() asserts that fd_refcnt == 0. */ 2619 if (!refcount_release(&fdp->fd_refcnt)) 2620 panic("%s: fd table %p has extra references", __func__, fdp); 2621 #endif 2622 fdescfree_fds(curthread, fdp, 0); 2623 } 2624 2625 /* 2626 * For setugid programs, we don't want to people to use that setugidness 2627 * to generate error messages which write to a file which otherwise would 2628 * otherwise be off-limits to the process. We check for filesystems where 2629 * the vnode can change out from under us after execve (like [lin]procfs). 2630 * 2631 * Since fdsetugidsafety calls this only for fd 0, 1 and 2, this check is 2632 * sufficient. We also don't check for setugidness since we know we are. 2633 */ 2634 static bool 2635 is_unsafe(struct file *fp) 2636 { 2637 struct vnode *vp; 2638 2639 if (fp->f_type != DTYPE_VNODE) 2640 return (false); 2641 2642 vp = fp->f_vnode; 2643 return ((vp->v_vflag & VV_PROCDEP) != 0); 2644 } 2645 2646 /* 2647 * Make this setguid thing safe, if at all possible. 2648 */ 2649 void 2650 fdsetugidsafety(struct thread *td) 2651 { 2652 struct filedesc *fdp; 2653 struct file *fp; 2654 int i; 2655 2656 fdp = td->td_proc->p_fd; 2657 KASSERT(refcount_load(&fdp->fd_refcnt) == 1, 2658 ("the fdtable should not be shared")); 2659 MPASS(fdp->fd_nfiles >= 3); 2660 for (i = 0; i <= 2; i++) { 2661 fp = fdp->fd_ofiles[i].fde_file; 2662 if (fp != NULL && is_unsafe(fp)) { 2663 FILEDESC_XLOCK(fdp); 2664 knote_fdclose(td, i); 2665 /* 2666 * NULL-out descriptor prior to close to avoid 2667 * a race while close blocks. 2668 */ 2669 fdfree(fdp, i); 2670 FILEDESC_XUNLOCK(fdp); 2671 (void) closef(fp, td); 2672 } 2673 } 2674 } 2675 2676 /* 2677 * If a specific file object occupies a specific file descriptor, close the 2678 * file descriptor entry and drop a reference on the file object. This is a 2679 * convenience function to handle a subsequent error in a function that calls 2680 * falloc() that handles the race that another thread might have closed the 2681 * file descriptor out from under the thread creating the file object. 2682 */ 2683 void 2684 fdclose(struct thread *td, struct file *fp, int idx) 2685 { 2686 struct filedesc *fdp = td->td_proc->p_fd; 2687 2688 FILEDESC_XLOCK(fdp); 2689 if (fdp->fd_ofiles[idx].fde_file == fp) { 2690 fdfree(fdp, idx); 2691 FILEDESC_XUNLOCK(fdp); 2692 fdrop(fp, td); 2693 } else 2694 FILEDESC_XUNLOCK(fdp); 2695 } 2696 2697 /* 2698 * Close any files on exec? 2699 */ 2700 void 2701 fdcloseexec(struct thread *td) 2702 { 2703 struct filedesc *fdp; 2704 struct filedescent *fde; 2705 struct file *fp; 2706 int i, lastfile; 2707 2708 fdp = td->td_proc->p_fd; 2709 KASSERT(refcount_load(&fdp->fd_refcnt) == 1, 2710 ("the fdtable should not be shared")); 2711 lastfile = fdlastfile_single(fdp); 2712 for (i = 0; i <= lastfile; i++) { 2713 fde = &fdp->fd_ofiles[i]; 2714 fp = fde->fde_file; 2715 if (fp != NULL && (fp->f_type == DTYPE_MQUEUE || 2716 (fde->fde_flags & UF_EXCLOSE))) { 2717 FILEDESC_XLOCK(fdp); 2718 fdfree(fdp, i); 2719 (void) closefp(fdp, i, fp, td, false, false); 2720 FILEDESC_UNLOCK_ASSERT(fdp); 2721 } 2722 } 2723 } 2724 2725 /* 2726 * It is unsafe for set[ug]id processes to be started with file 2727 * descriptors 0..2 closed, as these descriptors are given implicit 2728 * significance in the Standard C library. fdcheckstd() will create a 2729 * descriptor referencing /dev/null for each of stdin, stdout, and 2730 * stderr that is not already open. 2731 */ 2732 int 2733 fdcheckstd(struct thread *td) 2734 { 2735 struct filedesc *fdp; 2736 register_t save; 2737 int i, error, devnull; 2738 2739 fdp = td->td_proc->p_fd; 2740 KASSERT(refcount_load(&fdp->fd_refcnt) == 1, 2741 ("the fdtable should not be shared")); 2742 MPASS(fdp->fd_nfiles >= 3); 2743 devnull = -1; 2744 for (i = 0; i <= 2; i++) { 2745 if (fdp->fd_ofiles[i].fde_file != NULL) 2746 continue; 2747 2748 save = td->td_retval[0]; 2749 if (devnull != -1) { 2750 error = kern_dup(td, FDDUP_FIXED, 0, devnull, i); 2751 } else { 2752 error = kern_openat(td, AT_FDCWD, "/dev/null", 2753 UIO_SYSSPACE, O_RDWR, 0); 2754 if (error == 0) { 2755 devnull = td->td_retval[0]; 2756 KASSERT(devnull == i, ("we didn't get our fd")); 2757 } 2758 } 2759 td->td_retval[0] = save; 2760 if (error != 0) 2761 return (error); 2762 } 2763 return (0); 2764 } 2765 2766 /* 2767 * Internal form of close. Decrement reference count on file structure. 2768 * Note: td may be NULL when closing a file that was being passed in a 2769 * message. 2770 */ 2771 int 2772 closef(struct file *fp, struct thread *td) 2773 { 2774 struct vnode *vp; 2775 struct flock lf; 2776 struct filedesc_to_leader *fdtol; 2777 struct filedesc *fdp; 2778 2779 MPASS(td != NULL); 2780 2781 /* 2782 * POSIX record locking dictates that any close releases ALL 2783 * locks owned by this process. This is handled by setting 2784 * a flag in the unlock to free ONLY locks obeying POSIX 2785 * semantics, and not to free BSD-style file locks. 2786 * If the descriptor was in a message, POSIX-style locks 2787 * aren't passed with the descriptor, and the thread pointer 2788 * will be NULL. Callers should be careful only to pass a 2789 * NULL thread pointer when there really is no owning 2790 * context that might have locks, or the locks will be 2791 * leaked. 2792 */ 2793 if (fp->f_type == DTYPE_VNODE) { 2794 vp = fp->f_vnode; 2795 if ((td->td_proc->p_leader->p_flag & P_ADVLOCK) != 0) { 2796 lf.l_whence = SEEK_SET; 2797 lf.l_start = 0; 2798 lf.l_len = 0; 2799 lf.l_type = F_UNLCK; 2800 (void) VOP_ADVLOCK(vp, (caddr_t)td->td_proc->p_leader, 2801 F_UNLCK, &lf, F_POSIX); 2802 } 2803 fdtol = td->td_proc->p_fdtol; 2804 if (fdtol != NULL) { 2805 /* 2806 * Handle special case where file descriptor table is 2807 * shared between multiple process leaders. 2808 */ 2809 fdp = td->td_proc->p_fd; 2810 FILEDESC_XLOCK(fdp); 2811 for (fdtol = fdtol->fdl_next; 2812 fdtol != td->td_proc->p_fdtol; 2813 fdtol = fdtol->fdl_next) { 2814 if ((fdtol->fdl_leader->p_flag & 2815 P_ADVLOCK) == 0) 2816 continue; 2817 fdtol->fdl_holdcount++; 2818 FILEDESC_XUNLOCK(fdp); 2819 lf.l_whence = SEEK_SET; 2820 lf.l_start = 0; 2821 lf.l_len = 0; 2822 lf.l_type = F_UNLCK; 2823 vp = fp->f_vnode; 2824 (void) VOP_ADVLOCK(vp, 2825 (caddr_t)fdtol->fdl_leader, F_UNLCK, &lf, 2826 F_POSIX); 2827 FILEDESC_XLOCK(fdp); 2828 fdtol->fdl_holdcount--; 2829 if (fdtol->fdl_holdcount == 0 && 2830 fdtol->fdl_wakeup != 0) { 2831 fdtol->fdl_wakeup = 0; 2832 wakeup(fdtol); 2833 } 2834 } 2835 FILEDESC_XUNLOCK(fdp); 2836 } 2837 } 2838 return (fdrop_close(fp, td)); 2839 } 2840 2841 /* 2842 * Hack for file descriptor passing code. 2843 */ 2844 void 2845 closef_nothread(struct file *fp) 2846 { 2847 2848 fdrop(fp, NULL); 2849 } 2850 2851 /* 2852 * Initialize the file pointer with the specified properties. 2853 * 2854 * The ops are set with release semantics to be certain that the flags, type, 2855 * and data are visible when ops is. This is to prevent ops methods from being 2856 * called with bad data. 2857 */ 2858 void 2859 finit(struct file *fp, u_int flag, short type, void *data, struct fileops *ops) 2860 { 2861 fp->f_data = data; 2862 fp->f_flag = flag; 2863 fp->f_type = type; 2864 atomic_store_rel_ptr((volatile uintptr_t *)&fp->f_ops, (uintptr_t)ops); 2865 } 2866 2867 void 2868 finit_vnode(struct file *fp, u_int flag, void *data, struct fileops *ops) 2869 { 2870 fp->f_seqcount[UIO_READ] = 1; 2871 fp->f_seqcount[UIO_WRITE] = 1; 2872 finit(fp, (flag & FMASK) | (fp->f_flag & FHASLOCK), DTYPE_VNODE, 2873 data, ops); 2874 } 2875 2876 int 2877 fget_cap_locked(struct filedesc *fdp, int fd, cap_rights_t *needrightsp, 2878 struct file **fpp, struct filecaps *havecapsp) 2879 { 2880 struct filedescent *fde; 2881 int error; 2882 2883 FILEDESC_LOCK_ASSERT(fdp); 2884 2885 fde = fdeget_locked(fdp, fd); 2886 if (fde == NULL) { 2887 error = EBADF; 2888 goto out; 2889 } 2890 2891 #ifdef CAPABILITIES 2892 error = cap_check(cap_rights_fde_inline(fde), needrightsp); 2893 if (error != 0) 2894 goto out; 2895 #endif 2896 2897 if (havecapsp != NULL) 2898 filecaps_copy(&fde->fde_caps, havecapsp, true); 2899 2900 *fpp = fde->fde_file; 2901 2902 error = 0; 2903 out: 2904 return (error); 2905 } 2906 2907 int 2908 fget_cap(struct thread *td, int fd, cap_rights_t *needrightsp, 2909 struct file **fpp, struct filecaps *havecapsp) 2910 { 2911 struct filedesc *fdp = td->td_proc->p_fd; 2912 int error; 2913 #ifndef CAPABILITIES 2914 error = fget_unlocked(fdp, fd, needrightsp, fpp); 2915 if (havecapsp != NULL && error == 0) 2916 filecaps_fill(havecapsp); 2917 #else 2918 struct file *fp; 2919 seqc_t seq; 2920 2921 *fpp = NULL; 2922 for (;;) { 2923 error = fget_unlocked_seq(fdp, fd, needrightsp, &fp, &seq); 2924 if (error != 0) 2925 return (error); 2926 2927 if (havecapsp != NULL) { 2928 if (!filecaps_copy(&fdp->fd_ofiles[fd].fde_caps, 2929 havecapsp, false)) { 2930 fdrop(fp, td); 2931 goto get_locked; 2932 } 2933 } 2934 2935 if (!fd_modified(fdp, fd, seq)) 2936 break; 2937 fdrop(fp, td); 2938 } 2939 2940 *fpp = fp; 2941 return (0); 2942 2943 get_locked: 2944 FILEDESC_SLOCK(fdp); 2945 error = fget_cap_locked(fdp, fd, needrightsp, fpp, havecapsp); 2946 if (error == 0 && !fhold(*fpp)) 2947 error = EBADF; 2948 FILEDESC_SUNLOCK(fdp); 2949 #endif 2950 return (error); 2951 } 2952 2953 #ifdef CAPABILITIES 2954 int 2955 fgetvp_lookup_smr(int fd, struct nameidata *ndp, struct vnode **vpp, bool *fsearch) 2956 { 2957 const struct filedescent *fde; 2958 const struct fdescenttbl *fdt; 2959 struct filedesc *fdp; 2960 struct file *fp; 2961 struct vnode *vp; 2962 const cap_rights_t *haverights; 2963 cap_rights_t rights; 2964 seqc_t seq; 2965 2966 VFS_SMR_ASSERT_ENTERED(); 2967 2968 rights = *ndp->ni_rightsneeded; 2969 cap_rights_set_one(&rights, CAP_LOOKUP); 2970 2971 fdp = curproc->p_fd; 2972 fdt = fdp->fd_files; 2973 if (__predict_false((u_int)fd >= fdt->fdt_nfiles)) 2974 return (EBADF); 2975 seq = seqc_read_notmodify(fd_seqc(fdt, fd)); 2976 fde = &fdt->fdt_ofiles[fd]; 2977 haverights = cap_rights_fde_inline(fde); 2978 fp = fde->fde_file; 2979 if (__predict_false(fp == NULL)) 2980 return (EAGAIN); 2981 if (__predict_false(cap_check_inline_transient(haverights, &rights))) 2982 return (EAGAIN); 2983 *fsearch = ((fp->f_flag & FSEARCH) != 0); 2984 vp = fp->f_vnode; 2985 if (__predict_false(vp == NULL || vp->v_type != VDIR)) { 2986 return (EAGAIN); 2987 } 2988 if (!filecaps_copy(&fde->fde_caps, &ndp->ni_filecaps, false)) { 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(!seqc_consistent_nomb(fd_seqc(fdt, fd), seq))) 2998 return (EAGAIN); 2999 /* 3000 * If file descriptor doesn't have all rights, 3001 * all lookups relative to it must also be 3002 * strictly relative. 3003 * 3004 * Not yet supported by fast path. 3005 */ 3006 CAP_ALL(&rights); 3007 if (!cap_rights_contains(&ndp->ni_filecaps.fc_rights, &rights) || 3008 ndp->ni_filecaps.fc_fcntls != CAP_FCNTL_ALL || 3009 ndp->ni_filecaps.fc_nioctls != -1) { 3010 #ifdef notyet 3011 ndp->ni_lcf |= NI_LCF_STRICTRELATIVE; 3012 #else 3013 return (EAGAIN); 3014 #endif 3015 } 3016 *vpp = vp; 3017 return (0); 3018 } 3019 #else 3020 int 3021 fgetvp_lookup_smr(int fd, struct nameidata *ndp, struct vnode **vpp, bool *fsearch) 3022 { 3023 const struct fdescenttbl *fdt; 3024 struct filedesc *fdp; 3025 struct file *fp; 3026 struct vnode *vp; 3027 3028 VFS_SMR_ASSERT_ENTERED(); 3029 3030 fdp = curproc->p_fd; 3031 fdt = fdp->fd_files; 3032 if (__predict_false((u_int)fd >= fdt->fdt_nfiles)) 3033 return (EBADF); 3034 fp = fdt->fdt_ofiles[fd].fde_file; 3035 if (__predict_false(fp == NULL)) 3036 return (EAGAIN); 3037 *fsearch = ((fp->f_flag & FSEARCH) != 0); 3038 vp = fp->f_vnode; 3039 if (__predict_false(vp == NULL || vp->v_type != VDIR)) { 3040 return (EAGAIN); 3041 } 3042 /* 3043 * Use an acquire barrier to force re-reading of fdt so it is 3044 * refreshed for verification. 3045 */ 3046 atomic_thread_fence_acq(); 3047 fdt = fdp->fd_files; 3048 if (__predict_false(fp != fdt->fdt_ofiles[fd].fde_file)) 3049 return (EAGAIN); 3050 filecaps_fill(&ndp->ni_filecaps); 3051 *vpp = vp; 3052 return (0); 3053 } 3054 #endif 3055 3056 int 3057 fget_unlocked_seq(struct filedesc *fdp, int fd, cap_rights_t *needrightsp, 3058 struct file **fpp, seqc_t *seqp) 3059 { 3060 #ifdef CAPABILITIES 3061 const struct filedescent *fde; 3062 #endif 3063 const struct fdescenttbl *fdt; 3064 struct file *fp; 3065 #ifdef CAPABILITIES 3066 seqc_t seq; 3067 cap_rights_t haverights; 3068 int error; 3069 #endif 3070 3071 fdt = fdp->fd_files; 3072 if (__predict_false((u_int)fd >= fdt->fdt_nfiles)) 3073 return (EBADF); 3074 /* 3075 * Fetch the descriptor locklessly. We avoid fdrop() races by 3076 * never raising a refcount above 0. To accomplish this we have 3077 * to use a cmpset loop rather than an atomic_add. The descriptor 3078 * must be re-verified once we acquire a reference to be certain 3079 * that the identity is still correct and we did not lose a race 3080 * due to preemption. 3081 */ 3082 for (;;) { 3083 #ifdef CAPABILITIES 3084 seq = seqc_read_notmodify(fd_seqc(fdt, fd)); 3085 fde = &fdt->fdt_ofiles[fd]; 3086 haverights = *cap_rights_fde_inline(fde); 3087 fp = fde->fde_file; 3088 if (!seqc_consistent(fd_seqc(fdt, fd), seq)) 3089 continue; 3090 #else 3091 fp = fdt->fdt_ofiles[fd].fde_file; 3092 #endif 3093 if (fp == NULL) 3094 return (EBADF); 3095 #ifdef CAPABILITIES 3096 error = cap_check_inline(&haverights, needrightsp); 3097 if (error != 0) 3098 return (error); 3099 #endif 3100 if (__predict_false(!refcount_acquire_if_not_zero(&fp->f_count))) { 3101 /* 3102 * Force a reload. Other thread could reallocate the 3103 * table before this fd was closed, so it is possible 3104 * that there is a stale fp pointer in cached version. 3105 */ 3106 fdt = atomic_load_ptr(&fdp->fd_files); 3107 continue; 3108 } 3109 /* 3110 * Use an acquire barrier to force re-reading of fdt so it is 3111 * refreshed for verification. 3112 */ 3113 atomic_thread_fence_acq(); 3114 fdt = fdp->fd_files; 3115 #ifdef CAPABILITIES 3116 if (seqc_consistent_nomb(fd_seqc(fdt, fd), seq)) 3117 #else 3118 if (fp == fdt->fdt_ofiles[fd].fde_file) 3119 #endif 3120 break; 3121 fdrop(fp, curthread); 3122 } 3123 *fpp = fp; 3124 if (seqp != NULL) { 3125 #ifdef CAPABILITIES 3126 *seqp = seq; 3127 #endif 3128 } 3129 return (0); 3130 } 3131 3132 /* 3133 * See the comments in fget_unlocked_seq for an explanation of how this works. 3134 * 3135 * This is a simplified variant which bails out to the aforementioned routine 3136 * if anything goes wrong. In practice this only happens when userspace is 3137 * racing with itself. 3138 */ 3139 int 3140 fget_unlocked(struct filedesc *fdp, int fd, cap_rights_t *needrightsp, 3141 struct file **fpp) 3142 { 3143 #ifdef CAPABILITIES 3144 const struct filedescent *fde; 3145 #endif 3146 const struct fdescenttbl *fdt; 3147 struct file *fp; 3148 #ifdef CAPABILITIES 3149 seqc_t seq; 3150 const cap_rights_t *haverights; 3151 #endif 3152 3153 fdt = fdp->fd_files; 3154 if (__predict_false((u_int)fd >= fdt->fdt_nfiles)) 3155 return (EBADF); 3156 #ifdef CAPABILITIES 3157 seq = seqc_read_notmodify(fd_seqc(fdt, fd)); 3158 fde = &fdt->fdt_ofiles[fd]; 3159 haverights = cap_rights_fde_inline(fde); 3160 fp = fde->fde_file; 3161 #else 3162 fp = fdt->fdt_ofiles[fd].fde_file; 3163 #endif 3164 if (__predict_false(fp == NULL)) 3165 goto out_fallback; 3166 #ifdef CAPABILITIES 3167 if (__predict_false(cap_check_inline_transient(haverights, needrightsp))) 3168 goto out_fallback; 3169 #endif 3170 if (__predict_false(!refcount_acquire_if_not_zero(&fp->f_count))) 3171 goto out_fallback; 3172 3173 /* 3174 * Use an acquire barrier to force re-reading of fdt so it is 3175 * refreshed for verification. 3176 */ 3177 atomic_thread_fence_acq(); 3178 fdt = fdp->fd_files; 3179 #ifdef CAPABILITIES 3180 if (__predict_false(!seqc_consistent_nomb(fd_seqc(fdt, fd), seq))) 3181 #else 3182 if (__predict_false(fp != fdt->fdt_ofiles[fd].fde_file)) 3183 #endif 3184 goto out_fdrop; 3185 *fpp = fp; 3186 return (0); 3187 out_fdrop: 3188 fdrop(fp, curthread); 3189 out_fallback: 3190 return (fget_unlocked_seq(fdp, fd, needrightsp, fpp, NULL)); 3191 } 3192 3193 /* 3194 * Translate fd -> file when the caller guarantees the file descriptor table 3195 * can't be changed by others. 3196 * 3197 * Note this does not mean the file object itself is only visible to the caller, 3198 * merely that it wont disappear without having to be referenced. 3199 * 3200 * Must be paired with fput_only_user. 3201 */ 3202 #ifdef CAPABILITIES 3203 int 3204 fget_only_user(struct filedesc *fdp, int fd, cap_rights_t *needrightsp, 3205 struct file **fpp) 3206 { 3207 const struct filedescent *fde; 3208 const struct fdescenttbl *fdt; 3209 const cap_rights_t *haverights; 3210 struct file *fp; 3211 int error; 3212 3213 MPASS(FILEDESC_IS_ONLY_USER(fdp)); 3214 3215 if (__predict_false(fd >= fdp->fd_nfiles)) 3216 return (EBADF); 3217 3218 fdt = fdp->fd_files; 3219 fde = &fdt->fdt_ofiles[fd]; 3220 fp = fde->fde_file; 3221 if (__predict_false(fp == NULL)) 3222 return (EBADF); 3223 MPASS(refcount_load(&fp->f_count) > 0); 3224 haverights = cap_rights_fde_inline(fde); 3225 error = cap_check_inline(haverights, needrightsp); 3226 if (__predict_false(error != 0)) 3227 return (error); 3228 *fpp = fp; 3229 return (0); 3230 } 3231 #else 3232 int 3233 fget_only_user(struct filedesc *fdp, int fd, cap_rights_t *needrightsp, 3234 struct file **fpp) 3235 { 3236 struct file *fp; 3237 3238 MPASS(FILEDESC_IS_ONLY_USER(fdp)); 3239 3240 if (__predict_false(fd >= fdp->fd_nfiles)) 3241 return (EBADF); 3242 3243 fp = fdp->fd_ofiles[fd].fde_file; 3244 if (__predict_false(fp == NULL)) 3245 return (EBADF); 3246 3247 MPASS(refcount_load(&fp->f_count) > 0); 3248 *fpp = fp; 3249 return (0); 3250 } 3251 #endif 3252 3253 /* 3254 * Extract the file pointer associated with the specified descriptor for the 3255 * current user process. 3256 * 3257 * If the descriptor doesn't exist or doesn't match 'flags', EBADF is 3258 * returned. 3259 * 3260 * File's rights will be checked against the capability rights mask. 3261 * 3262 * If an error occurred the non-zero error is returned and *fpp is set to 3263 * NULL. Otherwise *fpp is held and set and zero is returned. Caller is 3264 * responsible for fdrop(). 3265 */ 3266 static __inline int 3267 _fget(struct thread *td, int fd, struct file **fpp, int flags, 3268 cap_rights_t *needrightsp) 3269 { 3270 struct filedesc *fdp; 3271 struct file *fp; 3272 int error; 3273 3274 *fpp = NULL; 3275 fdp = td->td_proc->p_fd; 3276 error = fget_unlocked(fdp, fd, needrightsp, &fp); 3277 if (__predict_false(error != 0)) 3278 return (error); 3279 if (__predict_false(fp->f_ops == &badfileops)) { 3280 fdrop(fp, td); 3281 return (EBADF); 3282 } 3283 3284 /* 3285 * FREAD and FWRITE failure return EBADF as per POSIX. 3286 */ 3287 error = 0; 3288 switch (flags) { 3289 case FREAD: 3290 case FWRITE: 3291 if ((fp->f_flag & flags) == 0) 3292 error = EBADF; 3293 break; 3294 case FEXEC: 3295 if ((fp->f_flag & (FREAD | FEXEC)) == 0 || 3296 ((fp->f_flag & FWRITE) != 0)) 3297 error = EBADF; 3298 break; 3299 case 0: 3300 break; 3301 default: 3302 KASSERT(0, ("wrong flags")); 3303 } 3304 3305 if (error != 0) { 3306 fdrop(fp, td); 3307 return (error); 3308 } 3309 3310 *fpp = fp; 3311 return (0); 3312 } 3313 3314 int 3315 fget(struct thread *td, int fd, cap_rights_t *rightsp, struct file **fpp) 3316 { 3317 3318 return (_fget(td, fd, fpp, 0, rightsp)); 3319 } 3320 3321 int 3322 fget_mmap(struct thread *td, int fd, cap_rights_t *rightsp, vm_prot_t *maxprotp, 3323 struct file **fpp) 3324 { 3325 int error; 3326 #ifndef CAPABILITIES 3327 error = _fget(td, fd, fpp, 0, rightsp); 3328 if (maxprotp != NULL) 3329 *maxprotp = VM_PROT_ALL; 3330 return (error); 3331 #else 3332 cap_rights_t fdrights; 3333 struct filedesc *fdp; 3334 struct file *fp; 3335 seqc_t seq; 3336 3337 *fpp = NULL; 3338 fdp = td->td_proc->p_fd; 3339 MPASS(cap_rights_is_set(rightsp, CAP_MMAP)); 3340 for (;;) { 3341 error = fget_unlocked_seq(fdp, fd, rightsp, &fp, &seq); 3342 if (__predict_false(error != 0)) 3343 return (error); 3344 if (__predict_false(fp->f_ops == &badfileops)) { 3345 fdrop(fp, td); 3346 return (EBADF); 3347 } 3348 if (maxprotp != NULL) 3349 fdrights = *cap_rights(fdp, fd); 3350 if (!fd_modified(fdp, fd, seq)) 3351 break; 3352 fdrop(fp, td); 3353 } 3354 3355 /* 3356 * If requested, convert capability rights to access flags. 3357 */ 3358 if (maxprotp != NULL) 3359 *maxprotp = cap_rights_to_vmprot(&fdrights); 3360 *fpp = fp; 3361 return (0); 3362 #endif 3363 } 3364 3365 int 3366 fget_read(struct thread *td, int fd, cap_rights_t *rightsp, struct file **fpp) 3367 { 3368 3369 return (_fget(td, fd, fpp, FREAD, rightsp)); 3370 } 3371 3372 int 3373 fget_write(struct thread *td, int fd, cap_rights_t *rightsp, struct file **fpp) 3374 { 3375 3376 return (_fget(td, fd, fpp, FWRITE, rightsp)); 3377 } 3378 3379 int 3380 fget_fcntl(struct thread *td, int fd, cap_rights_t *rightsp, int needfcntl, 3381 struct file **fpp) 3382 { 3383 struct filedesc *fdp = td->td_proc->p_fd; 3384 #ifndef CAPABILITIES 3385 return (fget_unlocked(fdp, fd, rightsp, fpp)); 3386 #else 3387 struct file *fp; 3388 int error; 3389 seqc_t seq; 3390 3391 *fpp = NULL; 3392 MPASS(cap_rights_is_set(rightsp, CAP_FCNTL)); 3393 for (;;) { 3394 error = fget_unlocked_seq(fdp, fd, rightsp, &fp, &seq); 3395 if (error != 0) 3396 return (error); 3397 error = cap_fcntl_check(fdp, fd, needfcntl); 3398 if (!fd_modified(fdp, fd, seq)) 3399 break; 3400 fdrop(fp, td); 3401 } 3402 if (error != 0) { 3403 fdrop(fp, td); 3404 return (error); 3405 } 3406 *fpp = fp; 3407 return (0); 3408 #endif 3409 } 3410 3411 /* 3412 * Like fget() but loads the underlying vnode, or returns an error if the 3413 * descriptor does not represent a vnode. Note that pipes use vnodes but 3414 * never have VM objects. The returned vnode will be vref()'d. 3415 * 3416 * XXX: what about the unused flags ? 3417 */ 3418 static __inline int 3419 _fgetvp(struct thread *td, int fd, int flags, cap_rights_t *needrightsp, 3420 struct vnode **vpp) 3421 { 3422 struct file *fp; 3423 int error; 3424 3425 *vpp = NULL; 3426 error = _fget(td, fd, &fp, flags, needrightsp); 3427 if (error != 0) 3428 return (error); 3429 if (fp->f_vnode == NULL) { 3430 error = EINVAL; 3431 } else { 3432 *vpp = fp->f_vnode; 3433 vref(*vpp); 3434 } 3435 fdrop(fp, td); 3436 3437 return (error); 3438 } 3439 3440 int 3441 fgetvp(struct thread *td, int fd, cap_rights_t *rightsp, struct vnode **vpp) 3442 { 3443 3444 return (_fgetvp(td, fd, 0, rightsp, vpp)); 3445 } 3446 3447 int 3448 fgetvp_rights(struct thread *td, int fd, cap_rights_t *needrightsp, 3449 struct filecaps *havecaps, struct vnode **vpp) 3450 { 3451 struct filecaps caps; 3452 struct file *fp; 3453 int error; 3454 3455 error = fget_cap(td, fd, needrightsp, &fp, &caps); 3456 if (error != 0) 3457 return (error); 3458 if (fp->f_ops == &badfileops) { 3459 error = EBADF; 3460 goto out; 3461 } 3462 if (fp->f_vnode == NULL) { 3463 error = EINVAL; 3464 goto out; 3465 } 3466 3467 *havecaps = caps; 3468 *vpp = fp->f_vnode; 3469 vref(*vpp); 3470 fdrop(fp, td); 3471 3472 return (0); 3473 out: 3474 filecaps_free(&caps); 3475 fdrop(fp, td); 3476 return (error); 3477 } 3478 3479 int 3480 fgetvp_read(struct thread *td, int fd, cap_rights_t *rightsp, struct vnode **vpp) 3481 { 3482 3483 return (_fgetvp(td, fd, FREAD, rightsp, vpp)); 3484 } 3485 3486 int 3487 fgetvp_exec(struct thread *td, int fd, cap_rights_t *rightsp, struct vnode **vpp) 3488 { 3489 3490 return (_fgetvp(td, fd, FEXEC, rightsp, vpp)); 3491 } 3492 3493 #ifdef notyet 3494 int 3495 fgetvp_write(struct thread *td, int fd, cap_rights_t *rightsp, 3496 struct vnode **vpp) 3497 { 3498 3499 return (_fgetvp(td, fd, FWRITE, rightsp, vpp)); 3500 } 3501 #endif 3502 3503 /* 3504 * Handle the last reference to a file being closed. 3505 * 3506 * Without the noinline attribute clang keeps inlining the func thorough this 3507 * file when fdrop is used. 3508 */ 3509 int __noinline 3510 _fdrop(struct file *fp, struct thread *td) 3511 { 3512 int error; 3513 #ifdef INVARIANTS 3514 int count; 3515 3516 count = refcount_load(&fp->f_count); 3517 if (count != 0) 3518 panic("fdrop: fp %p count %d", fp, count); 3519 #endif 3520 error = fo_close(fp, td); 3521 atomic_subtract_int(&openfiles, 1); 3522 crfree(fp->f_cred); 3523 free(fp->f_advice, M_FADVISE); 3524 uma_zfree(file_zone, fp); 3525 3526 return (error); 3527 } 3528 3529 /* 3530 * Apply an advisory lock on a file descriptor. 3531 * 3532 * Just attempt to get a record lock of the requested type on the entire file 3533 * (l_whence = SEEK_SET, l_start = 0, l_len = 0). 3534 */ 3535 #ifndef _SYS_SYSPROTO_H_ 3536 struct flock_args { 3537 int fd; 3538 int how; 3539 }; 3540 #endif 3541 /* ARGSUSED */ 3542 int 3543 sys_flock(struct thread *td, struct flock_args *uap) 3544 { 3545 struct file *fp; 3546 struct vnode *vp; 3547 struct flock lf; 3548 int error; 3549 3550 error = fget(td, uap->fd, &cap_flock_rights, &fp); 3551 if (error != 0) 3552 return (error); 3553 if (fp->f_type != DTYPE_VNODE || fp->f_ops == &path_fileops) { 3554 fdrop(fp, td); 3555 return (EOPNOTSUPP); 3556 } 3557 3558 vp = fp->f_vnode; 3559 lf.l_whence = SEEK_SET; 3560 lf.l_start = 0; 3561 lf.l_len = 0; 3562 if (uap->how & LOCK_UN) { 3563 lf.l_type = F_UNLCK; 3564 atomic_clear_int(&fp->f_flag, FHASLOCK); 3565 error = VOP_ADVLOCK(vp, (caddr_t)fp, F_UNLCK, &lf, F_FLOCK); 3566 goto done2; 3567 } 3568 if (uap->how & LOCK_EX) 3569 lf.l_type = F_WRLCK; 3570 else if (uap->how & LOCK_SH) 3571 lf.l_type = F_RDLCK; 3572 else { 3573 error = EBADF; 3574 goto done2; 3575 } 3576 atomic_set_int(&fp->f_flag, FHASLOCK); 3577 error = VOP_ADVLOCK(vp, (caddr_t)fp, F_SETLK, &lf, 3578 (uap->how & LOCK_NB) ? F_FLOCK : F_FLOCK | F_WAIT); 3579 done2: 3580 fdrop(fp, td); 3581 return (error); 3582 } 3583 /* 3584 * Duplicate the specified descriptor to a free descriptor. 3585 */ 3586 int 3587 dupfdopen(struct thread *td, struct filedesc *fdp, int dfd, int mode, 3588 int openerror, int *indxp) 3589 { 3590 struct filedescent *newfde, *oldfde; 3591 struct file *fp; 3592 u_long *ioctls; 3593 int error, indx; 3594 3595 KASSERT(openerror == ENODEV || openerror == ENXIO, 3596 ("unexpected error %d in %s", openerror, __func__)); 3597 3598 /* 3599 * If the to-be-dup'd fd number is greater than the allowed number 3600 * of file descriptors, or the fd to be dup'd has already been 3601 * closed, then reject. 3602 */ 3603 FILEDESC_XLOCK(fdp); 3604 if ((fp = fget_locked(fdp, dfd)) == NULL) { 3605 FILEDESC_XUNLOCK(fdp); 3606 return (EBADF); 3607 } 3608 3609 error = fdalloc(td, 0, &indx); 3610 if (error != 0) { 3611 FILEDESC_XUNLOCK(fdp); 3612 return (error); 3613 } 3614 3615 /* 3616 * There are two cases of interest here. 3617 * 3618 * For ENODEV simply dup (dfd) to file descriptor (indx) and return. 3619 * 3620 * For ENXIO steal away the file structure from (dfd) and store it in 3621 * (indx). (dfd) is effectively closed by this operation. 3622 */ 3623 switch (openerror) { 3624 case ENODEV: 3625 /* 3626 * Check that the mode the file is being opened for is a 3627 * subset of the mode of the existing descriptor. 3628 */ 3629 if (((mode & (FREAD|FWRITE)) | fp->f_flag) != fp->f_flag) { 3630 fdunused(fdp, indx); 3631 FILEDESC_XUNLOCK(fdp); 3632 return (EACCES); 3633 } 3634 if (!fhold(fp)) { 3635 fdunused(fdp, indx); 3636 FILEDESC_XUNLOCK(fdp); 3637 return (EBADF); 3638 } 3639 newfde = &fdp->fd_ofiles[indx]; 3640 oldfde = &fdp->fd_ofiles[dfd]; 3641 ioctls = filecaps_copy_prep(&oldfde->fde_caps); 3642 #ifdef CAPABILITIES 3643 seqc_write_begin(&newfde->fde_seqc); 3644 #endif 3645 memcpy(newfde, oldfde, fde_change_size); 3646 filecaps_copy_finish(&oldfde->fde_caps, &newfde->fde_caps, 3647 ioctls); 3648 #ifdef CAPABILITIES 3649 seqc_write_end(&newfde->fde_seqc); 3650 #endif 3651 break; 3652 case ENXIO: 3653 /* 3654 * Steal away the file pointer from dfd and stuff it into indx. 3655 */ 3656 newfde = &fdp->fd_ofiles[indx]; 3657 oldfde = &fdp->fd_ofiles[dfd]; 3658 #ifdef CAPABILITIES 3659 seqc_write_begin(&newfde->fde_seqc); 3660 #endif 3661 memcpy(newfde, oldfde, fde_change_size); 3662 oldfde->fde_file = NULL; 3663 fdunused(fdp, dfd); 3664 #ifdef CAPABILITIES 3665 seqc_write_end(&newfde->fde_seqc); 3666 #endif 3667 break; 3668 } 3669 FILEDESC_XUNLOCK(fdp); 3670 *indxp = indx; 3671 return (0); 3672 } 3673 3674 /* 3675 * This sysctl determines if we will allow a process to chroot(2) if it 3676 * has a directory open: 3677 * 0: disallowed for all processes. 3678 * 1: allowed for processes that were not already chroot(2)'ed. 3679 * 2: allowed for all processes. 3680 */ 3681 3682 static int chroot_allow_open_directories = 1; 3683 3684 SYSCTL_INT(_kern, OID_AUTO, chroot_allow_open_directories, CTLFLAG_RW, 3685 &chroot_allow_open_directories, 0, 3686 "Allow a process to chroot(2) if it has a directory open"); 3687 3688 /* 3689 * Helper function for raised chroot(2) security function: Refuse if 3690 * any filedescriptors are open directories. 3691 */ 3692 static int 3693 chroot_refuse_vdir_fds(struct filedesc *fdp) 3694 { 3695 struct vnode *vp; 3696 struct file *fp; 3697 int fd, lastfile; 3698 3699 FILEDESC_LOCK_ASSERT(fdp); 3700 3701 lastfile = fdlastfile(fdp); 3702 for (fd = 0; fd <= lastfile; fd++) { 3703 fp = fget_locked(fdp, fd); 3704 if (fp == NULL) 3705 continue; 3706 if (fp->f_type == DTYPE_VNODE) { 3707 vp = fp->f_vnode; 3708 if (vp->v_type == VDIR) 3709 return (EPERM); 3710 } 3711 } 3712 return (0); 3713 } 3714 3715 static void 3716 pwd_fill(struct pwd *oldpwd, struct pwd *newpwd) 3717 { 3718 3719 if (newpwd->pwd_cdir == NULL && oldpwd->pwd_cdir != NULL) { 3720 vrefact(oldpwd->pwd_cdir); 3721 newpwd->pwd_cdir = oldpwd->pwd_cdir; 3722 } 3723 3724 if (newpwd->pwd_rdir == NULL && oldpwd->pwd_rdir != NULL) { 3725 vrefact(oldpwd->pwd_rdir); 3726 newpwd->pwd_rdir = oldpwd->pwd_rdir; 3727 } 3728 3729 if (newpwd->pwd_jdir == NULL && oldpwd->pwd_jdir != NULL) { 3730 vrefact(oldpwd->pwd_jdir); 3731 newpwd->pwd_jdir = oldpwd->pwd_jdir; 3732 } 3733 } 3734 3735 struct pwd * 3736 pwd_hold_pwddesc(struct pwddesc *pdp) 3737 { 3738 struct pwd *pwd; 3739 3740 PWDDESC_ASSERT_XLOCKED(pdp); 3741 pwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); 3742 if (pwd != NULL) 3743 refcount_acquire(&pwd->pwd_refcount); 3744 return (pwd); 3745 } 3746 3747 bool 3748 pwd_hold_smr(struct pwd *pwd) 3749 { 3750 3751 MPASS(pwd != NULL); 3752 if (__predict_true(refcount_acquire_if_not_zero(&pwd->pwd_refcount))) { 3753 return (true); 3754 } 3755 return (false); 3756 } 3757 3758 struct pwd * 3759 pwd_hold(struct thread *td) 3760 { 3761 struct pwddesc *pdp; 3762 struct pwd *pwd; 3763 3764 pdp = td->td_proc->p_pd; 3765 3766 vfs_smr_enter(); 3767 pwd = vfs_smr_entered_load(&pdp->pd_pwd); 3768 if (pwd_hold_smr(pwd)) { 3769 vfs_smr_exit(); 3770 return (pwd); 3771 } 3772 vfs_smr_exit(); 3773 PWDDESC_XLOCK(pdp); 3774 pwd = pwd_hold_pwddesc(pdp); 3775 MPASS(pwd != NULL); 3776 PWDDESC_XUNLOCK(pdp); 3777 return (pwd); 3778 } 3779 3780 static struct pwd * 3781 pwd_alloc(void) 3782 { 3783 struct pwd *pwd; 3784 3785 pwd = uma_zalloc_smr(pwd_zone, M_WAITOK); 3786 bzero(pwd, sizeof(*pwd)); 3787 refcount_init(&pwd->pwd_refcount, 1); 3788 return (pwd); 3789 } 3790 3791 void 3792 pwd_drop(struct pwd *pwd) 3793 { 3794 3795 if (!refcount_release(&pwd->pwd_refcount)) 3796 return; 3797 3798 if (pwd->pwd_cdir != NULL) 3799 vrele(pwd->pwd_cdir); 3800 if (pwd->pwd_rdir != NULL) 3801 vrele(pwd->pwd_rdir); 3802 if (pwd->pwd_jdir != NULL) 3803 vrele(pwd->pwd_jdir); 3804 uma_zfree_smr(pwd_zone, pwd); 3805 } 3806 3807 /* 3808 * The caller is responsible for invoking priv_check() and 3809 * mac_vnode_check_chroot() to authorize this operation. 3810 */ 3811 int 3812 pwd_chroot(struct thread *td, struct vnode *vp) 3813 { 3814 struct pwddesc *pdp; 3815 struct filedesc *fdp; 3816 struct pwd *newpwd, *oldpwd; 3817 int error; 3818 3819 fdp = td->td_proc->p_fd; 3820 pdp = td->td_proc->p_pd; 3821 newpwd = pwd_alloc(); 3822 FILEDESC_SLOCK(fdp); 3823 PWDDESC_XLOCK(pdp); 3824 oldpwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); 3825 if (chroot_allow_open_directories == 0 || 3826 (chroot_allow_open_directories == 1 && 3827 oldpwd->pwd_rdir != rootvnode)) { 3828 error = chroot_refuse_vdir_fds(fdp); 3829 FILEDESC_SUNLOCK(fdp); 3830 if (error != 0) { 3831 PWDDESC_XUNLOCK(pdp); 3832 pwd_drop(newpwd); 3833 return (error); 3834 } 3835 } else { 3836 FILEDESC_SUNLOCK(fdp); 3837 } 3838 3839 vrefact(vp); 3840 newpwd->pwd_rdir = vp; 3841 if (oldpwd->pwd_jdir == NULL) { 3842 vrefact(vp); 3843 newpwd->pwd_jdir = vp; 3844 } 3845 pwd_fill(oldpwd, newpwd); 3846 pwd_set(pdp, newpwd); 3847 PWDDESC_XUNLOCK(pdp); 3848 pwd_drop(oldpwd); 3849 return (0); 3850 } 3851 3852 void 3853 pwd_chdir(struct thread *td, struct vnode *vp) 3854 { 3855 struct pwddesc *pdp; 3856 struct pwd *newpwd, *oldpwd; 3857 3858 VNPASS(vp->v_usecount > 0, vp); 3859 3860 newpwd = pwd_alloc(); 3861 pdp = td->td_proc->p_pd; 3862 PWDDESC_XLOCK(pdp); 3863 oldpwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); 3864 newpwd->pwd_cdir = vp; 3865 pwd_fill(oldpwd, newpwd); 3866 pwd_set(pdp, newpwd); 3867 PWDDESC_XUNLOCK(pdp); 3868 pwd_drop(oldpwd); 3869 } 3870 3871 /* 3872 * jail_attach(2) changes both root and working directories. 3873 */ 3874 int 3875 pwd_chroot_chdir(struct thread *td, struct vnode *vp) 3876 { 3877 struct pwddesc *pdp; 3878 struct filedesc *fdp; 3879 struct pwd *newpwd, *oldpwd; 3880 int error; 3881 3882 fdp = td->td_proc->p_fd; 3883 pdp = td->td_proc->p_pd; 3884 newpwd = pwd_alloc(); 3885 FILEDESC_SLOCK(fdp); 3886 PWDDESC_XLOCK(pdp); 3887 oldpwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); 3888 error = chroot_refuse_vdir_fds(fdp); 3889 FILEDESC_SUNLOCK(fdp); 3890 if (error != 0) { 3891 PWDDESC_XUNLOCK(pdp); 3892 pwd_drop(newpwd); 3893 return (error); 3894 } 3895 3896 vrefact(vp); 3897 newpwd->pwd_rdir = vp; 3898 vrefact(vp); 3899 newpwd->pwd_cdir = vp; 3900 if (oldpwd->pwd_jdir == NULL) { 3901 vrefact(vp); 3902 newpwd->pwd_jdir = vp; 3903 } 3904 pwd_fill(oldpwd, newpwd); 3905 pwd_set(pdp, newpwd); 3906 PWDDESC_XUNLOCK(pdp); 3907 pwd_drop(oldpwd); 3908 return (0); 3909 } 3910 3911 void 3912 pwd_ensure_dirs(void) 3913 { 3914 struct pwddesc *pdp; 3915 struct pwd *oldpwd, *newpwd; 3916 3917 pdp = curproc->p_pd; 3918 PWDDESC_XLOCK(pdp); 3919 oldpwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); 3920 if (oldpwd->pwd_cdir != NULL && oldpwd->pwd_rdir != NULL) { 3921 PWDDESC_XUNLOCK(pdp); 3922 return; 3923 } 3924 PWDDESC_XUNLOCK(pdp); 3925 3926 newpwd = pwd_alloc(); 3927 PWDDESC_XLOCK(pdp); 3928 oldpwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); 3929 pwd_fill(oldpwd, newpwd); 3930 if (newpwd->pwd_cdir == NULL) { 3931 vrefact(rootvnode); 3932 newpwd->pwd_cdir = rootvnode; 3933 } 3934 if (newpwd->pwd_rdir == NULL) { 3935 vrefact(rootvnode); 3936 newpwd->pwd_rdir = rootvnode; 3937 } 3938 pwd_set(pdp, newpwd); 3939 PWDDESC_XUNLOCK(pdp); 3940 pwd_drop(oldpwd); 3941 } 3942 3943 void 3944 pwd_set_rootvnode(void) 3945 { 3946 struct pwddesc *pdp; 3947 struct pwd *oldpwd, *newpwd; 3948 3949 pdp = curproc->p_pd; 3950 3951 newpwd = pwd_alloc(); 3952 PWDDESC_XLOCK(pdp); 3953 oldpwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); 3954 vrefact(rootvnode); 3955 newpwd->pwd_cdir = rootvnode; 3956 vrefact(rootvnode); 3957 newpwd->pwd_rdir = rootvnode; 3958 pwd_fill(oldpwd, newpwd); 3959 pwd_set(pdp, newpwd); 3960 PWDDESC_XUNLOCK(pdp); 3961 pwd_drop(oldpwd); 3962 } 3963 3964 /* 3965 * Scan all active processes and prisons to see if any of them have a current 3966 * or root directory of `olddp'. If so, replace them with the new mount point. 3967 */ 3968 void 3969 mountcheckdirs(struct vnode *olddp, struct vnode *newdp) 3970 { 3971 struct pwddesc *pdp; 3972 struct pwd *newpwd, *oldpwd; 3973 struct prison *pr; 3974 struct proc *p; 3975 int nrele; 3976 3977 if (vrefcnt(olddp) == 1) 3978 return; 3979 nrele = 0; 3980 newpwd = pwd_alloc(); 3981 sx_slock(&allproc_lock); 3982 FOREACH_PROC_IN_SYSTEM(p) { 3983 PROC_LOCK(p); 3984 pdp = pdhold(p); 3985 PROC_UNLOCK(p); 3986 if (pdp == NULL) 3987 continue; 3988 PWDDESC_XLOCK(pdp); 3989 oldpwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); 3990 if (oldpwd == NULL || 3991 (oldpwd->pwd_cdir != olddp && 3992 oldpwd->pwd_rdir != olddp && 3993 oldpwd->pwd_jdir != olddp)) { 3994 PWDDESC_XUNLOCK(pdp); 3995 pddrop(pdp); 3996 continue; 3997 } 3998 if (oldpwd->pwd_cdir == olddp) { 3999 vrefact(newdp); 4000 newpwd->pwd_cdir = newdp; 4001 } 4002 if (oldpwd->pwd_rdir == olddp) { 4003 vrefact(newdp); 4004 newpwd->pwd_rdir = newdp; 4005 } 4006 if (oldpwd->pwd_jdir == olddp) { 4007 vrefact(newdp); 4008 newpwd->pwd_jdir = newdp; 4009 } 4010 pwd_fill(oldpwd, newpwd); 4011 pwd_set(pdp, newpwd); 4012 PWDDESC_XUNLOCK(pdp); 4013 pwd_drop(oldpwd); 4014 pddrop(pdp); 4015 newpwd = pwd_alloc(); 4016 } 4017 sx_sunlock(&allproc_lock); 4018 pwd_drop(newpwd); 4019 if (rootvnode == olddp) { 4020 vrefact(newdp); 4021 rootvnode = newdp; 4022 nrele++; 4023 } 4024 mtx_lock(&prison0.pr_mtx); 4025 if (prison0.pr_root == olddp) { 4026 vrefact(newdp); 4027 prison0.pr_root = newdp; 4028 nrele++; 4029 } 4030 mtx_unlock(&prison0.pr_mtx); 4031 sx_slock(&allprison_lock); 4032 TAILQ_FOREACH(pr, &allprison, pr_list) { 4033 mtx_lock(&pr->pr_mtx); 4034 if (pr->pr_root == olddp) { 4035 vrefact(newdp); 4036 pr->pr_root = newdp; 4037 nrele++; 4038 } 4039 mtx_unlock(&pr->pr_mtx); 4040 } 4041 sx_sunlock(&allprison_lock); 4042 while (nrele--) 4043 vrele(olddp); 4044 } 4045 4046 struct filedesc_to_leader * 4047 filedesc_to_leader_alloc(struct filedesc_to_leader *old, struct filedesc *fdp, struct proc *leader) 4048 { 4049 struct filedesc_to_leader *fdtol; 4050 4051 fdtol = malloc(sizeof(struct filedesc_to_leader), 4052 M_FILEDESC_TO_LEADER, M_WAITOK); 4053 fdtol->fdl_refcount = 1; 4054 fdtol->fdl_holdcount = 0; 4055 fdtol->fdl_wakeup = 0; 4056 fdtol->fdl_leader = leader; 4057 if (old != NULL) { 4058 FILEDESC_XLOCK(fdp); 4059 fdtol->fdl_next = old->fdl_next; 4060 fdtol->fdl_prev = old; 4061 old->fdl_next = fdtol; 4062 fdtol->fdl_next->fdl_prev = fdtol; 4063 FILEDESC_XUNLOCK(fdp); 4064 } else { 4065 fdtol->fdl_next = fdtol; 4066 fdtol->fdl_prev = fdtol; 4067 } 4068 return (fdtol); 4069 } 4070 4071 static int 4072 sysctl_kern_proc_nfds(SYSCTL_HANDLER_ARGS) 4073 { 4074 NDSLOTTYPE *map; 4075 struct filedesc *fdp; 4076 int count, off, minoff; 4077 4078 if (*(int *)arg1 != 0) 4079 return (EINVAL); 4080 4081 fdp = curproc->p_fd; 4082 count = 0; 4083 FILEDESC_SLOCK(fdp); 4084 map = fdp->fd_map; 4085 off = NDSLOT(fdp->fd_nfiles - 1); 4086 for (minoff = NDSLOT(0); off >= minoff; --off) 4087 count += bitcountl(map[off]); 4088 FILEDESC_SUNLOCK(fdp); 4089 4090 return (SYSCTL_OUT(req, &count, sizeof(count))); 4091 } 4092 4093 static SYSCTL_NODE(_kern_proc, KERN_PROC_NFDS, nfds, 4094 CTLFLAG_RD|CTLFLAG_CAPRD|CTLFLAG_MPSAFE, sysctl_kern_proc_nfds, 4095 "Number of open file descriptors"); 4096 4097 /* 4098 * Get file structures globally. 4099 */ 4100 static int 4101 sysctl_kern_file(SYSCTL_HANDLER_ARGS) 4102 { 4103 struct xfile xf; 4104 struct filedesc *fdp; 4105 struct file *fp; 4106 struct proc *p; 4107 int error, n, lastfile; 4108 4109 error = sysctl_wire_old_buffer(req, 0); 4110 if (error != 0) 4111 return (error); 4112 if (req->oldptr == NULL) { 4113 n = 0; 4114 sx_slock(&allproc_lock); 4115 FOREACH_PROC_IN_SYSTEM(p) { 4116 PROC_LOCK(p); 4117 if (p->p_state == PRS_NEW) { 4118 PROC_UNLOCK(p); 4119 continue; 4120 } 4121 fdp = fdhold(p); 4122 PROC_UNLOCK(p); 4123 if (fdp == NULL) 4124 continue; 4125 /* overestimates sparse tables. */ 4126 n += fdp->fd_nfiles; 4127 fddrop(fdp); 4128 } 4129 sx_sunlock(&allproc_lock); 4130 return (SYSCTL_OUT(req, 0, n * sizeof(xf))); 4131 } 4132 error = 0; 4133 bzero(&xf, sizeof(xf)); 4134 xf.xf_size = sizeof(xf); 4135 sx_slock(&allproc_lock); 4136 FOREACH_PROC_IN_SYSTEM(p) { 4137 PROC_LOCK(p); 4138 if (p->p_state == PRS_NEW) { 4139 PROC_UNLOCK(p); 4140 continue; 4141 } 4142 if (p_cansee(req->td, p) != 0) { 4143 PROC_UNLOCK(p); 4144 continue; 4145 } 4146 xf.xf_pid = p->p_pid; 4147 xf.xf_uid = p->p_ucred->cr_uid; 4148 fdp = fdhold(p); 4149 PROC_UNLOCK(p); 4150 if (fdp == NULL) 4151 continue; 4152 FILEDESC_SLOCK(fdp); 4153 lastfile = fdlastfile(fdp); 4154 for (n = 0; refcount_load(&fdp->fd_refcnt) > 0 && n <= lastfile; 4155 n++) { 4156 if ((fp = fdp->fd_ofiles[n].fde_file) == NULL) 4157 continue; 4158 xf.xf_fd = n; 4159 xf.xf_file = (uintptr_t)fp; 4160 xf.xf_data = (uintptr_t)fp->f_data; 4161 xf.xf_vnode = (uintptr_t)fp->f_vnode; 4162 xf.xf_type = (uintptr_t)fp->f_type; 4163 xf.xf_count = refcount_load(&fp->f_count); 4164 xf.xf_msgcount = 0; 4165 xf.xf_offset = foffset_get(fp); 4166 xf.xf_flag = fp->f_flag; 4167 error = SYSCTL_OUT(req, &xf, sizeof(xf)); 4168 if (error) 4169 break; 4170 } 4171 FILEDESC_SUNLOCK(fdp); 4172 fddrop(fdp); 4173 if (error) 4174 break; 4175 } 4176 sx_sunlock(&allproc_lock); 4177 return (error); 4178 } 4179 4180 SYSCTL_PROC(_kern, KERN_FILE, file, CTLTYPE_OPAQUE|CTLFLAG_RD|CTLFLAG_MPSAFE, 4181 0, 0, sysctl_kern_file, "S,xfile", "Entire file table"); 4182 4183 #ifdef KINFO_FILE_SIZE 4184 CTASSERT(sizeof(struct kinfo_file) == KINFO_FILE_SIZE); 4185 #endif 4186 4187 static int 4188 xlate_fflags(int fflags) 4189 { 4190 static const struct { 4191 int fflag; 4192 int kf_fflag; 4193 } fflags_table[] = { 4194 { FAPPEND, KF_FLAG_APPEND }, 4195 { FASYNC, KF_FLAG_ASYNC }, 4196 { FFSYNC, KF_FLAG_FSYNC }, 4197 { FHASLOCK, KF_FLAG_HASLOCK }, 4198 { FNONBLOCK, KF_FLAG_NONBLOCK }, 4199 { FREAD, KF_FLAG_READ }, 4200 { FWRITE, KF_FLAG_WRITE }, 4201 { O_CREAT, KF_FLAG_CREAT }, 4202 { O_DIRECT, KF_FLAG_DIRECT }, 4203 { O_EXCL, KF_FLAG_EXCL }, 4204 { O_EXEC, KF_FLAG_EXEC }, 4205 { O_EXLOCK, KF_FLAG_EXLOCK }, 4206 { O_NOFOLLOW, KF_FLAG_NOFOLLOW }, 4207 { O_SHLOCK, KF_FLAG_SHLOCK }, 4208 { O_TRUNC, KF_FLAG_TRUNC } 4209 }; 4210 unsigned int i; 4211 int kflags; 4212 4213 kflags = 0; 4214 for (i = 0; i < nitems(fflags_table); i++) 4215 if (fflags & fflags_table[i].fflag) 4216 kflags |= fflags_table[i].kf_fflag; 4217 return (kflags); 4218 } 4219 4220 /* Trim unused data from kf_path by truncating the structure size. */ 4221 void 4222 pack_kinfo(struct kinfo_file *kif) 4223 { 4224 4225 kif->kf_structsize = offsetof(struct kinfo_file, kf_path) + 4226 strlen(kif->kf_path) + 1; 4227 kif->kf_structsize = roundup(kif->kf_structsize, sizeof(uint64_t)); 4228 } 4229 4230 static void 4231 export_file_to_kinfo(struct file *fp, int fd, cap_rights_t *rightsp, 4232 struct kinfo_file *kif, struct filedesc *fdp, int flags) 4233 { 4234 int error; 4235 4236 bzero(kif, sizeof(*kif)); 4237 4238 /* Set a default type to allow for empty fill_kinfo() methods. */ 4239 kif->kf_type = KF_TYPE_UNKNOWN; 4240 kif->kf_flags = xlate_fflags(fp->f_flag); 4241 if (rightsp != NULL) 4242 kif->kf_cap_rights = *rightsp; 4243 else 4244 cap_rights_init_zero(&kif->kf_cap_rights); 4245 kif->kf_fd = fd; 4246 kif->kf_ref_count = refcount_load(&fp->f_count); 4247 kif->kf_offset = foffset_get(fp); 4248 4249 /* 4250 * This may drop the filedesc lock, so the 'fp' cannot be 4251 * accessed after this call. 4252 */ 4253 error = fo_fill_kinfo(fp, kif, fdp); 4254 if (error == 0) 4255 kif->kf_status |= KF_ATTR_VALID; 4256 if ((flags & KERN_FILEDESC_PACK_KINFO) != 0) 4257 pack_kinfo(kif); 4258 else 4259 kif->kf_structsize = roundup2(sizeof(*kif), sizeof(uint64_t)); 4260 } 4261 4262 static void 4263 export_vnode_to_kinfo(struct vnode *vp, int fd, int fflags, 4264 struct kinfo_file *kif, int flags) 4265 { 4266 int error; 4267 4268 bzero(kif, sizeof(*kif)); 4269 4270 kif->kf_type = KF_TYPE_VNODE; 4271 error = vn_fill_kinfo_vnode(vp, kif); 4272 if (error == 0) 4273 kif->kf_status |= KF_ATTR_VALID; 4274 kif->kf_flags = xlate_fflags(fflags); 4275 cap_rights_init_zero(&kif->kf_cap_rights); 4276 kif->kf_fd = fd; 4277 kif->kf_ref_count = -1; 4278 kif->kf_offset = -1; 4279 if ((flags & KERN_FILEDESC_PACK_KINFO) != 0) 4280 pack_kinfo(kif); 4281 else 4282 kif->kf_structsize = roundup2(sizeof(*kif), sizeof(uint64_t)); 4283 vrele(vp); 4284 } 4285 4286 struct export_fd_buf { 4287 struct filedesc *fdp; 4288 struct pwddesc *pdp; 4289 struct sbuf *sb; 4290 ssize_t remainder; 4291 struct kinfo_file kif; 4292 int flags; 4293 }; 4294 4295 static int 4296 export_kinfo_to_sb(struct export_fd_buf *efbuf) 4297 { 4298 struct kinfo_file *kif; 4299 4300 kif = &efbuf->kif; 4301 if (efbuf->remainder != -1) { 4302 if (efbuf->remainder < kif->kf_structsize) { 4303 /* Terminate export. */ 4304 efbuf->remainder = 0; 4305 return (0); 4306 } 4307 efbuf->remainder -= kif->kf_structsize; 4308 } 4309 return (sbuf_bcat(efbuf->sb, kif, kif->kf_structsize) == 0 ? 0 : ENOMEM); 4310 } 4311 4312 static int 4313 export_file_to_sb(struct file *fp, int fd, cap_rights_t *rightsp, 4314 struct export_fd_buf *efbuf) 4315 { 4316 int error; 4317 4318 if (efbuf->remainder == 0) 4319 return (0); 4320 export_file_to_kinfo(fp, fd, rightsp, &efbuf->kif, efbuf->fdp, 4321 efbuf->flags); 4322 FILEDESC_SUNLOCK(efbuf->fdp); 4323 error = export_kinfo_to_sb(efbuf); 4324 FILEDESC_SLOCK(efbuf->fdp); 4325 return (error); 4326 } 4327 4328 static int 4329 export_vnode_to_sb(struct vnode *vp, int fd, int fflags, 4330 struct export_fd_buf *efbuf) 4331 { 4332 int error; 4333 4334 if (efbuf->remainder == 0) 4335 return (0); 4336 if (efbuf->pdp != NULL) 4337 PWDDESC_XUNLOCK(efbuf->pdp); 4338 export_vnode_to_kinfo(vp, fd, fflags, &efbuf->kif, efbuf->flags); 4339 error = export_kinfo_to_sb(efbuf); 4340 if (efbuf->pdp != NULL) 4341 PWDDESC_XLOCK(efbuf->pdp); 4342 return (error); 4343 } 4344 4345 /* 4346 * Store a process file descriptor information to sbuf. 4347 * 4348 * Takes a locked proc as argument, and returns with the proc unlocked. 4349 */ 4350 int 4351 kern_proc_filedesc_out(struct proc *p, struct sbuf *sb, ssize_t maxlen, 4352 int flags) 4353 { 4354 struct file *fp; 4355 struct filedesc *fdp; 4356 struct pwddesc *pdp; 4357 struct export_fd_buf *efbuf; 4358 struct vnode *cttyvp, *textvp, *tracevp; 4359 struct pwd *pwd; 4360 int error, i, lastfile; 4361 cap_rights_t rights; 4362 4363 PROC_LOCK_ASSERT(p, MA_OWNED); 4364 4365 /* ktrace vnode */ 4366 tracevp = p->p_tracevp; 4367 if (tracevp != NULL) 4368 vrefact(tracevp); 4369 /* text vnode */ 4370 textvp = p->p_textvp; 4371 if (textvp != NULL) 4372 vrefact(textvp); 4373 /* Controlling tty. */ 4374 cttyvp = NULL; 4375 if (p->p_pgrp != NULL && p->p_pgrp->pg_session != NULL) { 4376 cttyvp = p->p_pgrp->pg_session->s_ttyvp; 4377 if (cttyvp != NULL) 4378 vrefact(cttyvp); 4379 } 4380 fdp = fdhold(p); 4381 pdp = pdhold(p); 4382 PROC_UNLOCK(p); 4383 efbuf = malloc(sizeof(*efbuf), M_TEMP, M_WAITOK); 4384 efbuf->fdp = NULL; 4385 efbuf->pdp = NULL; 4386 efbuf->sb = sb; 4387 efbuf->remainder = maxlen; 4388 efbuf->flags = flags; 4389 if (tracevp != NULL) 4390 export_vnode_to_sb(tracevp, KF_FD_TYPE_TRACE, FREAD | FWRITE, 4391 efbuf); 4392 if (textvp != NULL) 4393 export_vnode_to_sb(textvp, KF_FD_TYPE_TEXT, FREAD, efbuf); 4394 if (cttyvp != NULL) 4395 export_vnode_to_sb(cttyvp, KF_FD_TYPE_CTTY, FREAD | FWRITE, 4396 efbuf); 4397 error = 0; 4398 if (pdp == NULL || fdp == NULL) 4399 goto fail; 4400 efbuf->fdp = fdp; 4401 efbuf->pdp = pdp; 4402 PWDDESC_XLOCK(pdp); 4403 pwd = pwd_hold_pwddesc(pdp); 4404 if (pwd != NULL) { 4405 /* working directory */ 4406 if (pwd->pwd_cdir != NULL) { 4407 vrefact(pwd->pwd_cdir); 4408 export_vnode_to_sb(pwd->pwd_cdir, KF_FD_TYPE_CWD, FREAD, efbuf); 4409 } 4410 /* root directory */ 4411 if (pwd->pwd_rdir != NULL) { 4412 vrefact(pwd->pwd_rdir); 4413 export_vnode_to_sb(pwd->pwd_rdir, KF_FD_TYPE_ROOT, FREAD, efbuf); 4414 } 4415 /* jail directory */ 4416 if (pwd->pwd_jdir != NULL) { 4417 vrefact(pwd->pwd_jdir); 4418 export_vnode_to_sb(pwd->pwd_jdir, KF_FD_TYPE_JAIL, FREAD, efbuf); 4419 } 4420 } 4421 PWDDESC_XUNLOCK(pdp); 4422 if (pwd != NULL) 4423 pwd_drop(pwd); 4424 FILEDESC_SLOCK(fdp); 4425 lastfile = fdlastfile(fdp); 4426 for (i = 0; refcount_load(&fdp->fd_refcnt) > 0 && i <= lastfile; i++) { 4427 if ((fp = fdp->fd_ofiles[i].fde_file) == NULL) 4428 continue; 4429 #ifdef CAPABILITIES 4430 rights = *cap_rights(fdp, i); 4431 #else /* !CAPABILITIES */ 4432 rights = cap_no_rights; 4433 #endif 4434 /* 4435 * Create sysctl entry. It is OK to drop the filedesc 4436 * lock inside of export_file_to_sb() as we will 4437 * re-validate and re-evaluate its properties when the 4438 * loop continues. 4439 */ 4440 error = export_file_to_sb(fp, i, &rights, efbuf); 4441 if (error != 0 || efbuf->remainder == 0) 4442 break; 4443 } 4444 FILEDESC_SUNLOCK(fdp); 4445 fail: 4446 if (fdp != NULL) 4447 fddrop(fdp); 4448 if (pdp != NULL) 4449 pddrop(pdp); 4450 free(efbuf, M_TEMP); 4451 return (error); 4452 } 4453 4454 #define FILEDESC_SBUF_SIZE (sizeof(struct kinfo_file) * 5) 4455 4456 /* 4457 * Get per-process file descriptors for use by procstat(1), et al. 4458 */ 4459 static int 4460 sysctl_kern_proc_filedesc(SYSCTL_HANDLER_ARGS) 4461 { 4462 struct sbuf sb; 4463 struct proc *p; 4464 ssize_t maxlen; 4465 int error, error2, *name; 4466 4467 name = (int *)arg1; 4468 4469 sbuf_new_for_sysctl(&sb, NULL, FILEDESC_SBUF_SIZE, req); 4470 sbuf_clear_flags(&sb, SBUF_INCLUDENUL); 4471 error = pget((pid_t)name[0], PGET_CANDEBUG | PGET_NOTWEXIT, &p); 4472 if (error != 0) { 4473 sbuf_delete(&sb); 4474 return (error); 4475 } 4476 maxlen = req->oldptr != NULL ? req->oldlen : -1; 4477 error = kern_proc_filedesc_out(p, &sb, maxlen, 4478 KERN_FILEDESC_PACK_KINFO); 4479 error2 = sbuf_finish(&sb); 4480 sbuf_delete(&sb); 4481 return (error != 0 ? error : error2); 4482 } 4483 4484 #ifdef COMPAT_FREEBSD7 4485 #ifdef KINFO_OFILE_SIZE 4486 CTASSERT(sizeof(struct kinfo_ofile) == KINFO_OFILE_SIZE); 4487 #endif 4488 4489 static void 4490 kinfo_to_okinfo(struct kinfo_file *kif, struct kinfo_ofile *okif) 4491 { 4492 4493 okif->kf_structsize = sizeof(*okif); 4494 okif->kf_type = kif->kf_type; 4495 okif->kf_fd = kif->kf_fd; 4496 okif->kf_ref_count = kif->kf_ref_count; 4497 okif->kf_flags = kif->kf_flags & (KF_FLAG_READ | KF_FLAG_WRITE | 4498 KF_FLAG_APPEND | KF_FLAG_ASYNC | KF_FLAG_FSYNC | KF_FLAG_NONBLOCK | 4499 KF_FLAG_DIRECT | KF_FLAG_HASLOCK); 4500 okif->kf_offset = kif->kf_offset; 4501 if (kif->kf_type == KF_TYPE_VNODE) 4502 okif->kf_vnode_type = kif->kf_un.kf_file.kf_file_type; 4503 else 4504 okif->kf_vnode_type = KF_VTYPE_VNON; 4505 strlcpy(okif->kf_path, kif->kf_path, sizeof(okif->kf_path)); 4506 if (kif->kf_type == KF_TYPE_SOCKET) { 4507 okif->kf_sock_domain = kif->kf_un.kf_sock.kf_sock_domain0; 4508 okif->kf_sock_type = kif->kf_un.kf_sock.kf_sock_type0; 4509 okif->kf_sock_protocol = kif->kf_un.kf_sock.kf_sock_protocol0; 4510 okif->kf_sa_local = kif->kf_un.kf_sock.kf_sa_local; 4511 okif->kf_sa_peer = kif->kf_un.kf_sock.kf_sa_peer; 4512 } else { 4513 okif->kf_sa_local.ss_family = AF_UNSPEC; 4514 okif->kf_sa_peer.ss_family = AF_UNSPEC; 4515 } 4516 } 4517 4518 static int 4519 export_vnode_for_osysctl(struct vnode *vp, int type, struct kinfo_file *kif, 4520 struct kinfo_ofile *okif, struct pwddesc *pdp, struct sysctl_req *req) 4521 { 4522 int error; 4523 4524 vrefact(vp); 4525 PWDDESC_XUNLOCK(pdp); 4526 export_vnode_to_kinfo(vp, type, 0, kif, KERN_FILEDESC_PACK_KINFO); 4527 kinfo_to_okinfo(kif, okif); 4528 error = SYSCTL_OUT(req, okif, sizeof(*okif)); 4529 PWDDESC_XLOCK(pdp); 4530 return (error); 4531 } 4532 4533 /* 4534 * Get per-process file descriptors for use by procstat(1), et al. 4535 */ 4536 static int 4537 sysctl_kern_proc_ofiledesc(SYSCTL_HANDLER_ARGS) 4538 { 4539 struct kinfo_ofile *okif; 4540 struct kinfo_file *kif; 4541 struct filedesc *fdp; 4542 struct pwddesc *pdp; 4543 struct pwd *pwd; 4544 int error, i, lastfile, *name; 4545 struct file *fp; 4546 struct proc *p; 4547 4548 name = (int *)arg1; 4549 error = pget((pid_t)name[0], PGET_CANDEBUG | PGET_NOTWEXIT, &p); 4550 if (error != 0) 4551 return (error); 4552 fdp = fdhold(p); 4553 if (fdp != NULL) 4554 pdp = pdhold(p); 4555 PROC_UNLOCK(p); 4556 if (fdp == NULL || pdp == NULL) { 4557 if (fdp != NULL) 4558 fddrop(fdp); 4559 return (ENOENT); 4560 } 4561 kif = malloc(sizeof(*kif), M_TEMP, M_WAITOK); 4562 okif = malloc(sizeof(*okif), M_TEMP, M_WAITOK); 4563 PWDDESC_XLOCK(pdp); 4564 pwd = pwd_hold_pwddesc(pdp); 4565 if (pwd != NULL) { 4566 if (pwd->pwd_cdir != NULL) 4567 export_vnode_for_osysctl(pwd->pwd_cdir, KF_FD_TYPE_CWD, kif, 4568 okif, pdp, req); 4569 if (pwd->pwd_rdir != NULL) 4570 export_vnode_for_osysctl(pwd->pwd_rdir, KF_FD_TYPE_ROOT, kif, 4571 okif, pdp, req); 4572 if (pwd->pwd_jdir != NULL) 4573 export_vnode_for_osysctl(pwd->pwd_jdir, KF_FD_TYPE_JAIL, kif, 4574 okif, pdp, req); 4575 } 4576 PWDDESC_XUNLOCK(pdp); 4577 if (pwd != NULL) 4578 pwd_drop(pwd); 4579 FILEDESC_SLOCK(fdp); 4580 lastfile = fdlastfile(fdp); 4581 for (i = 0; refcount_load(&fdp->fd_refcnt) > 0 && i <= lastfile; i++) { 4582 if ((fp = fdp->fd_ofiles[i].fde_file) == NULL) 4583 continue; 4584 export_file_to_kinfo(fp, i, NULL, kif, fdp, 4585 KERN_FILEDESC_PACK_KINFO); 4586 FILEDESC_SUNLOCK(fdp); 4587 kinfo_to_okinfo(kif, okif); 4588 error = SYSCTL_OUT(req, okif, sizeof(*okif)); 4589 FILEDESC_SLOCK(fdp); 4590 if (error) 4591 break; 4592 } 4593 FILEDESC_SUNLOCK(fdp); 4594 fddrop(fdp); 4595 pddrop(pdp); 4596 free(kif, M_TEMP); 4597 free(okif, M_TEMP); 4598 return (0); 4599 } 4600 4601 static SYSCTL_NODE(_kern_proc, KERN_PROC_OFILEDESC, ofiledesc, 4602 CTLFLAG_RD|CTLFLAG_MPSAFE, sysctl_kern_proc_ofiledesc, 4603 "Process ofiledesc entries"); 4604 #endif /* COMPAT_FREEBSD7 */ 4605 4606 int 4607 vntype_to_kinfo(int vtype) 4608 { 4609 struct { 4610 int vtype; 4611 int kf_vtype; 4612 } vtypes_table[] = { 4613 { VBAD, KF_VTYPE_VBAD }, 4614 { VBLK, KF_VTYPE_VBLK }, 4615 { VCHR, KF_VTYPE_VCHR }, 4616 { VDIR, KF_VTYPE_VDIR }, 4617 { VFIFO, KF_VTYPE_VFIFO }, 4618 { VLNK, KF_VTYPE_VLNK }, 4619 { VNON, KF_VTYPE_VNON }, 4620 { VREG, KF_VTYPE_VREG }, 4621 { VSOCK, KF_VTYPE_VSOCK } 4622 }; 4623 unsigned int i; 4624 4625 /* 4626 * Perform vtype translation. 4627 */ 4628 for (i = 0; i < nitems(vtypes_table); i++) 4629 if (vtypes_table[i].vtype == vtype) 4630 return (vtypes_table[i].kf_vtype); 4631 4632 return (KF_VTYPE_UNKNOWN); 4633 } 4634 4635 static SYSCTL_NODE(_kern_proc, KERN_PROC_FILEDESC, filedesc, 4636 CTLFLAG_RD|CTLFLAG_MPSAFE, sysctl_kern_proc_filedesc, 4637 "Process filedesc entries"); 4638 4639 /* 4640 * Store a process current working directory information to sbuf. 4641 * 4642 * Takes a locked proc as argument, and returns with the proc unlocked. 4643 */ 4644 int 4645 kern_proc_cwd_out(struct proc *p, struct sbuf *sb, ssize_t maxlen) 4646 { 4647 struct pwddesc *pdp; 4648 struct pwd *pwd; 4649 struct export_fd_buf *efbuf; 4650 struct vnode *cdir; 4651 int error; 4652 4653 PROC_LOCK_ASSERT(p, MA_OWNED); 4654 4655 pdp = pdhold(p); 4656 PROC_UNLOCK(p); 4657 if (pdp == NULL) 4658 return (EINVAL); 4659 4660 efbuf = malloc(sizeof(*efbuf), M_TEMP, M_WAITOK); 4661 efbuf->pdp = pdp; 4662 efbuf->sb = sb; 4663 efbuf->remainder = maxlen; 4664 4665 PWDDESC_XLOCK(pdp); 4666 pwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); 4667 cdir = pwd->pwd_cdir; 4668 if (cdir == NULL) { 4669 error = EINVAL; 4670 } else { 4671 vrefact(cdir); 4672 error = export_vnode_to_sb(cdir, KF_FD_TYPE_CWD, FREAD, efbuf); 4673 } 4674 PWDDESC_XUNLOCK(pdp); 4675 pddrop(pdp); 4676 free(efbuf, M_TEMP); 4677 return (error); 4678 } 4679 4680 /* 4681 * Get per-process current working directory. 4682 */ 4683 static int 4684 sysctl_kern_proc_cwd(SYSCTL_HANDLER_ARGS) 4685 { 4686 struct sbuf sb; 4687 struct proc *p; 4688 ssize_t maxlen; 4689 int error, error2, *name; 4690 4691 name = (int *)arg1; 4692 4693 sbuf_new_for_sysctl(&sb, NULL, sizeof(struct kinfo_file), req); 4694 sbuf_clear_flags(&sb, SBUF_INCLUDENUL); 4695 error = pget((pid_t)name[0], PGET_CANDEBUG | PGET_NOTWEXIT, &p); 4696 if (error != 0) { 4697 sbuf_delete(&sb); 4698 return (error); 4699 } 4700 maxlen = req->oldptr != NULL ? req->oldlen : -1; 4701 error = kern_proc_cwd_out(p, &sb, maxlen); 4702 error2 = sbuf_finish(&sb); 4703 sbuf_delete(&sb); 4704 return (error != 0 ? error : error2); 4705 } 4706 4707 static SYSCTL_NODE(_kern_proc, KERN_PROC_CWD, cwd, CTLFLAG_RD|CTLFLAG_MPSAFE, 4708 sysctl_kern_proc_cwd, "Process current working directory"); 4709 4710 #ifdef DDB 4711 /* 4712 * For the purposes of debugging, generate a human-readable string for the 4713 * file type. 4714 */ 4715 static const char * 4716 file_type_to_name(short type) 4717 { 4718 4719 switch (type) { 4720 case 0: 4721 return ("zero"); 4722 case DTYPE_VNODE: 4723 return ("vnode"); 4724 case DTYPE_SOCKET: 4725 return ("socket"); 4726 case DTYPE_PIPE: 4727 return ("pipe"); 4728 case DTYPE_FIFO: 4729 return ("fifo"); 4730 case DTYPE_KQUEUE: 4731 return ("kqueue"); 4732 case DTYPE_CRYPTO: 4733 return ("crypto"); 4734 case DTYPE_MQUEUE: 4735 return ("mqueue"); 4736 case DTYPE_SHM: 4737 return ("shm"); 4738 case DTYPE_SEM: 4739 return ("ksem"); 4740 case DTYPE_PTS: 4741 return ("pts"); 4742 case DTYPE_DEV: 4743 return ("dev"); 4744 case DTYPE_PROCDESC: 4745 return ("proc"); 4746 case DTYPE_EVENTFD: 4747 return ("eventfd"); 4748 case DTYPE_LINUXTFD: 4749 return ("ltimer"); 4750 default: 4751 return ("unkn"); 4752 } 4753 } 4754 4755 /* 4756 * For the purposes of debugging, identify a process (if any, perhaps one of 4757 * many) that references the passed file in its file descriptor array. Return 4758 * NULL if none. 4759 */ 4760 static struct proc * 4761 file_to_first_proc(struct file *fp) 4762 { 4763 struct filedesc *fdp; 4764 struct proc *p; 4765 int n; 4766 4767 FOREACH_PROC_IN_SYSTEM(p) { 4768 if (p->p_state == PRS_NEW) 4769 continue; 4770 fdp = p->p_fd; 4771 if (fdp == NULL) 4772 continue; 4773 for (n = 0; n < fdp->fd_nfiles; n++) { 4774 if (fp == fdp->fd_ofiles[n].fde_file) 4775 return (p); 4776 } 4777 } 4778 return (NULL); 4779 } 4780 4781 static void 4782 db_print_file(struct file *fp, int header) 4783 { 4784 #define XPTRWIDTH ((int)howmany(sizeof(void *) * NBBY, 4)) 4785 struct proc *p; 4786 4787 if (header) 4788 db_printf("%*s %6s %*s %8s %4s %5s %6s %*s %5s %s\n", 4789 XPTRWIDTH, "File", "Type", XPTRWIDTH, "Data", "Flag", 4790 "GCFl", "Count", "MCount", XPTRWIDTH, "Vnode", "FPID", 4791 "FCmd"); 4792 p = file_to_first_proc(fp); 4793 db_printf("%*p %6s %*p %08x %04x %5d %6d %*p %5d %s\n", XPTRWIDTH, 4794 fp, file_type_to_name(fp->f_type), XPTRWIDTH, fp->f_data, 4795 fp->f_flag, 0, refcount_load(&fp->f_count), 0, XPTRWIDTH, fp->f_vnode, 4796 p != NULL ? p->p_pid : -1, p != NULL ? p->p_comm : "-"); 4797 4798 #undef XPTRWIDTH 4799 } 4800 4801 DB_SHOW_COMMAND(file, db_show_file) 4802 { 4803 struct file *fp; 4804 4805 if (!have_addr) { 4806 db_printf("usage: show file <addr>\n"); 4807 return; 4808 } 4809 fp = (struct file *)addr; 4810 db_print_file(fp, 1); 4811 } 4812 4813 DB_SHOW_COMMAND(files, db_show_files) 4814 { 4815 struct filedesc *fdp; 4816 struct file *fp; 4817 struct proc *p; 4818 int header; 4819 int n; 4820 4821 header = 1; 4822 FOREACH_PROC_IN_SYSTEM(p) { 4823 if (p->p_state == PRS_NEW) 4824 continue; 4825 if ((fdp = p->p_fd) == NULL) 4826 continue; 4827 for (n = 0; n < fdp->fd_nfiles; ++n) { 4828 if ((fp = fdp->fd_ofiles[n].fde_file) == NULL) 4829 continue; 4830 db_print_file(fp, header); 4831 header = 0; 4832 } 4833 } 4834 } 4835 #endif 4836 4837 SYSCTL_INT(_kern, KERN_MAXFILESPERPROC, maxfilesperproc, CTLFLAG_RW, 4838 &maxfilesperproc, 0, "Maximum files allowed open per process"); 4839 4840 SYSCTL_INT(_kern, KERN_MAXFILES, maxfiles, CTLFLAG_RW, 4841 &maxfiles, 0, "Maximum number of files"); 4842 4843 SYSCTL_INT(_kern, OID_AUTO, openfiles, CTLFLAG_RD, 4844 &openfiles, 0, "System-wide number of open files"); 4845 4846 /* ARGSUSED*/ 4847 static void 4848 filelistinit(void *dummy) 4849 { 4850 4851 file_zone = uma_zcreate("Files", sizeof(struct file), NULL, NULL, 4852 NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE); 4853 filedesc0_zone = uma_zcreate("filedesc0", sizeof(struct filedesc0), 4854 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0); 4855 pwd_zone = uma_zcreate("PWD", sizeof(struct pwd), NULL, NULL, 4856 NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_SMR); 4857 /* 4858 * XXXMJG this is a temporary hack due to boot ordering issues against 4859 * the vnode zone. 4860 */ 4861 vfs_smr = uma_zone_get_smr(pwd_zone); 4862 mtx_init(&sigio_lock, "sigio lock", NULL, MTX_DEF); 4863 } 4864 SYSINIT(select, SI_SUB_LOCK, SI_ORDER_FIRST, filelistinit, NULL); 4865 4866 /*-------------------------------------------------------------------*/ 4867 4868 static int 4869 badfo_readwrite(struct file *fp, struct uio *uio, struct ucred *active_cred, 4870 int flags, struct thread *td) 4871 { 4872 4873 return (EBADF); 4874 } 4875 4876 static int 4877 badfo_truncate(struct file *fp, off_t length, struct ucred *active_cred, 4878 struct thread *td) 4879 { 4880 4881 return (EINVAL); 4882 } 4883 4884 static int 4885 badfo_ioctl(struct file *fp, u_long com, void *data, struct ucred *active_cred, 4886 struct thread *td) 4887 { 4888 4889 return (EBADF); 4890 } 4891 4892 static int 4893 badfo_poll(struct file *fp, int events, struct ucred *active_cred, 4894 struct thread *td) 4895 { 4896 4897 return (0); 4898 } 4899 4900 static int 4901 badfo_kqfilter(struct file *fp, struct knote *kn) 4902 { 4903 4904 return (EBADF); 4905 } 4906 4907 static int 4908 badfo_stat(struct file *fp, struct stat *sb, struct ucred *active_cred, 4909 struct thread *td) 4910 { 4911 4912 return (EBADF); 4913 } 4914 4915 static int 4916 badfo_close(struct file *fp, struct thread *td) 4917 { 4918 4919 return (0); 4920 } 4921 4922 static int 4923 badfo_chmod(struct file *fp, mode_t mode, struct ucred *active_cred, 4924 struct thread *td) 4925 { 4926 4927 return (EBADF); 4928 } 4929 4930 static int 4931 badfo_chown(struct file *fp, uid_t uid, gid_t gid, struct ucred *active_cred, 4932 struct thread *td) 4933 { 4934 4935 return (EBADF); 4936 } 4937 4938 static int 4939 badfo_sendfile(struct file *fp, int sockfd, struct uio *hdr_uio, 4940 struct uio *trl_uio, off_t offset, size_t nbytes, off_t *sent, int flags, 4941 struct thread *td) 4942 { 4943 4944 return (EBADF); 4945 } 4946 4947 static int 4948 badfo_fill_kinfo(struct file *fp, struct kinfo_file *kif, struct filedesc *fdp) 4949 { 4950 4951 return (0); 4952 } 4953 4954 struct fileops badfileops = { 4955 .fo_read = badfo_readwrite, 4956 .fo_write = badfo_readwrite, 4957 .fo_truncate = badfo_truncate, 4958 .fo_ioctl = badfo_ioctl, 4959 .fo_poll = badfo_poll, 4960 .fo_kqfilter = badfo_kqfilter, 4961 .fo_stat = badfo_stat, 4962 .fo_close = badfo_close, 4963 .fo_chmod = badfo_chmod, 4964 .fo_chown = badfo_chown, 4965 .fo_sendfile = badfo_sendfile, 4966 .fo_fill_kinfo = badfo_fill_kinfo, 4967 }; 4968 4969 static int 4970 path_poll(struct file *fp, int events, struct ucred *active_cred, 4971 struct thread *td) 4972 { 4973 return (POLLNVAL); 4974 } 4975 4976 static int 4977 path_close(struct file *fp, struct thread *td) 4978 { 4979 MPASS(fp->f_type == DTYPE_VNODE); 4980 fp->f_ops = &badfileops; 4981 vdrop(fp->f_vnode); 4982 return (0); 4983 } 4984 4985 struct fileops path_fileops = { 4986 .fo_read = badfo_readwrite, 4987 .fo_write = badfo_readwrite, 4988 .fo_truncate = badfo_truncate, 4989 .fo_ioctl = badfo_ioctl, 4990 .fo_poll = path_poll, 4991 .fo_kqfilter = vn_kqfilter_opath, 4992 .fo_stat = vn_statfile, 4993 .fo_close = path_close, 4994 .fo_chmod = badfo_chmod, 4995 .fo_chown = badfo_chown, 4996 .fo_sendfile = badfo_sendfile, 4997 .fo_fill_kinfo = vn_fill_kinfo, 4998 .fo_flags = DFLAG_PASSABLE, 4999 }; 5000 5001 int 5002 invfo_rdwr(struct file *fp, struct uio *uio, struct ucred *active_cred, 5003 int flags, struct thread *td) 5004 { 5005 5006 return (EOPNOTSUPP); 5007 } 5008 5009 int 5010 invfo_truncate(struct file *fp, off_t length, struct ucred *active_cred, 5011 struct thread *td) 5012 { 5013 5014 return (EINVAL); 5015 } 5016 5017 int 5018 invfo_ioctl(struct file *fp, u_long com, void *data, 5019 struct ucred *active_cred, struct thread *td) 5020 { 5021 5022 return (ENOTTY); 5023 } 5024 5025 int 5026 invfo_poll(struct file *fp, int events, struct ucred *active_cred, 5027 struct thread *td) 5028 { 5029 5030 return (poll_no_poll(events)); 5031 } 5032 5033 int 5034 invfo_kqfilter(struct file *fp, struct knote *kn) 5035 { 5036 5037 return (EINVAL); 5038 } 5039 5040 int 5041 invfo_chmod(struct file *fp, mode_t mode, struct ucred *active_cred, 5042 struct thread *td) 5043 { 5044 5045 return (EINVAL); 5046 } 5047 5048 int 5049 invfo_chown(struct file *fp, uid_t uid, gid_t gid, struct ucred *active_cred, 5050 struct thread *td) 5051 { 5052 5053 return (EINVAL); 5054 } 5055 5056 int 5057 invfo_sendfile(struct file *fp, int sockfd, struct uio *hdr_uio, 5058 struct uio *trl_uio, off_t offset, size_t nbytes, off_t *sent, int flags, 5059 struct thread *td) 5060 { 5061 5062 return (EINVAL); 5063 } 5064 5065 /*-------------------------------------------------------------------*/ 5066 5067 /* 5068 * File Descriptor pseudo-device driver (/dev/fd/). 5069 * 5070 * Opening minor device N dup()s the file (if any) connected to file 5071 * descriptor N belonging to the calling process. Note that this driver 5072 * consists of only the ``open()'' routine, because all subsequent 5073 * references to this file will be direct to the other driver. 5074 * 5075 * XXX: we could give this one a cloning event handler if necessary. 5076 */ 5077 5078 /* ARGSUSED */ 5079 static int 5080 fdopen(struct cdev *dev, int mode, int type, struct thread *td) 5081 { 5082 5083 /* 5084 * XXX Kludge: set curthread->td_dupfd to contain the value of the 5085 * the file descriptor being sought for duplication. The error 5086 * return ensures that the vnode for this device will be released 5087 * by vn_open. Open will detect this special error and take the 5088 * actions in dupfdopen below. Other callers of vn_open or VOP_OPEN 5089 * will simply report the error. 5090 */ 5091 td->td_dupfd = dev2unit(dev); 5092 return (ENODEV); 5093 } 5094 5095 static struct cdevsw fildesc_cdevsw = { 5096 .d_version = D_VERSION, 5097 .d_open = fdopen, 5098 .d_name = "FD", 5099 }; 5100 5101 static void 5102 fildesc_drvinit(void *unused) 5103 { 5104 struct cdev *dev; 5105 5106 dev = make_dev_credf(MAKEDEV_ETERNAL, &fildesc_cdevsw, 0, NULL, 5107 UID_ROOT, GID_WHEEL, 0666, "fd/0"); 5108 make_dev_alias(dev, "stdin"); 5109 dev = make_dev_credf(MAKEDEV_ETERNAL, &fildesc_cdevsw, 1, NULL, 5110 UID_ROOT, GID_WHEEL, 0666, "fd/1"); 5111 make_dev_alias(dev, "stdout"); 5112 dev = make_dev_credf(MAKEDEV_ETERNAL, &fildesc_cdevsw, 2, NULL, 5113 UID_ROOT, GID_WHEEL, 0666, "fd/2"); 5114 make_dev_alias(dev, "stderr"); 5115 } 5116 5117 SYSINIT(fildescdev, SI_SUB_DRIVERS, SI_ORDER_MIDDLE, fildesc_drvinit, NULL); 5118