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 #include <sys/ktrace.h> 83 84 #include <net/vnet.h> 85 86 #include <security/audit/audit.h> 87 88 #include <vm/uma.h> 89 #include <vm/vm.h> 90 91 #include <ddb/ddb.h> 92 93 static MALLOC_DEFINE(M_FILEDESC, "filedesc", "Open file descriptor table"); 94 static MALLOC_DEFINE(M_PWD, "pwd", "Descriptor table vnodes"); 95 static MALLOC_DEFINE(M_PWDDESC, "pwddesc", "Pwd descriptors"); 96 static MALLOC_DEFINE(M_FILEDESC_TO_LEADER, "filedesc_to_leader", 97 "file desc to leader structures"); 98 static MALLOC_DEFINE(M_SIGIO, "sigio", "sigio structures"); 99 MALLOC_DEFINE(M_FILECAPS, "filecaps", "descriptor capabilities"); 100 101 MALLOC_DECLARE(M_FADVISE); 102 103 static __read_mostly uma_zone_t file_zone; 104 static __read_mostly uma_zone_t filedesc0_zone; 105 __read_mostly uma_zone_t pwd_zone; 106 VFS_SMR_DECLARE; 107 108 static int closefp(struct filedesc *fdp, int fd, struct file *fp, 109 struct thread *td, bool holdleaders, bool audit); 110 static int fd_first_free(struct filedesc *fdp, int low, int size); 111 static void fdgrowtable(struct filedesc *fdp, int nfd); 112 static void fdgrowtable_exp(struct filedesc *fdp, int nfd); 113 static void fdunused(struct filedesc *fdp, int fd); 114 static void fdused(struct filedesc *fdp, int fd); 115 static int getmaxfd(struct thread *td); 116 static u_long *filecaps_copy_prep(const struct filecaps *src); 117 static void filecaps_copy_finish(const struct filecaps *src, 118 struct filecaps *dst, u_long *ioctls); 119 static u_long *filecaps_free_prep(struct filecaps *fcaps); 120 static void filecaps_free_finish(u_long *ioctls); 121 122 static struct pwd *pwd_alloc(void); 123 124 /* 125 * Each process has: 126 * 127 * - An array of open file descriptors (fd_ofiles) 128 * - An array of file flags (fd_ofileflags) 129 * - A bitmap recording which descriptors are in use (fd_map) 130 * 131 * A process starts out with NDFILE descriptors. The value of NDFILE has 132 * been selected based the historical limit of 20 open files, and an 133 * assumption that the majority of processes, especially short-lived 134 * processes like shells, will never need more. 135 * 136 * If this initial allocation is exhausted, a larger descriptor table and 137 * map are allocated dynamically, and the pointers in the process's struct 138 * filedesc are updated to point to those. This is repeated every time 139 * the process runs out of file descriptors (provided it hasn't hit its 140 * resource limit). 141 * 142 * Since threads may hold references to individual descriptor table 143 * entries, the tables are never freed. Instead, they are placed on a 144 * linked list and freed only when the struct filedesc is released. 145 */ 146 #define NDFILE 20 147 #define NDSLOTSIZE sizeof(NDSLOTTYPE) 148 #define NDENTRIES (NDSLOTSIZE * __CHAR_BIT) 149 #define NDSLOT(x) ((x) / NDENTRIES) 150 #define NDBIT(x) ((NDSLOTTYPE)1 << ((x) % NDENTRIES)) 151 #define NDSLOTS(x) (((x) + NDENTRIES - 1) / NDENTRIES) 152 153 /* 154 * SLIST entry used to keep track of ofiles which must be reclaimed when 155 * the process exits. 156 */ 157 struct freetable { 158 struct fdescenttbl *ft_table; 159 SLIST_ENTRY(freetable) ft_next; 160 }; 161 162 /* 163 * Initial allocation: a filedesc structure + the head of SLIST used to 164 * keep track of old ofiles + enough space for NDFILE descriptors. 165 */ 166 167 struct fdescenttbl0 { 168 int fdt_nfiles; 169 struct filedescent fdt_ofiles[NDFILE]; 170 }; 171 172 struct filedesc0 { 173 struct filedesc fd_fd; 174 SLIST_HEAD(, freetable) fd_free; 175 struct fdescenttbl0 fd_dfiles; 176 NDSLOTTYPE fd_dmap[NDSLOTS(NDFILE)]; 177 }; 178 179 /* 180 * Descriptor management. 181 */ 182 static int __exclusive_cache_line openfiles; /* actual number of open files */ 183 struct mtx sigio_lock; /* mtx to protect pointers to sigio */ 184 void __read_mostly (*mq_fdclose)(struct thread *td, int fd, struct file *fp); 185 186 /* 187 * If low >= size, just return low. Otherwise find the first zero bit in the 188 * given bitmap, starting at low and not exceeding size - 1. Return size if 189 * not found. 190 */ 191 static int 192 fd_first_free(struct filedesc *fdp, int low, int size) 193 { 194 NDSLOTTYPE *map = fdp->fd_map; 195 NDSLOTTYPE mask; 196 int off, maxoff; 197 198 if (low >= size) 199 return (low); 200 201 off = NDSLOT(low); 202 if (low % NDENTRIES) { 203 mask = ~(~(NDSLOTTYPE)0 >> (NDENTRIES - (low % NDENTRIES))); 204 if ((mask &= ~map[off]) != 0UL) 205 return (off * NDENTRIES + ffsl(mask) - 1); 206 ++off; 207 } 208 for (maxoff = NDSLOTS(size); off < maxoff; ++off) 209 if (map[off] != ~0UL) 210 return (off * NDENTRIES + ffsl(~map[off]) - 1); 211 return (size); 212 } 213 214 /* 215 * Find the last used fd. 216 * 217 * Call this variant if fdp can't be modified by anyone else (e.g, during exec). 218 * Otherwise use fdlastfile. 219 */ 220 int 221 fdlastfile_single(struct filedesc *fdp) 222 { 223 NDSLOTTYPE *map = fdp->fd_map; 224 int off, minoff; 225 226 off = NDSLOT(fdp->fd_nfiles - 1); 227 for (minoff = NDSLOT(0); off >= minoff; --off) 228 if (map[off] != 0) 229 return (off * NDENTRIES + flsl(map[off]) - 1); 230 return (-1); 231 } 232 233 int 234 fdlastfile(struct filedesc *fdp) 235 { 236 237 FILEDESC_LOCK_ASSERT(fdp); 238 return (fdlastfile_single(fdp)); 239 } 240 241 static int 242 fdisused(struct filedesc *fdp, int fd) 243 { 244 245 KASSERT(fd >= 0 && fd < fdp->fd_nfiles, 246 ("file descriptor %d out of range (0, %d)", fd, fdp->fd_nfiles)); 247 248 return ((fdp->fd_map[NDSLOT(fd)] & NDBIT(fd)) != 0); 249 } 250 251 /* 252 * Mark a file descriptor as used. 253 */ 254 static void 255 fdused_init(struct filedesc *fdp, int fd) 256 { 257 258 KASSERT(!fdisused(fdp, fd), ("fd=%d is already used", fd)); 259 260 fdp->fd_map[NDSLOT(fd)] |= NDBIT(fd); 261 } 262 263 static void 264 fdused(struct filedesc *fdp, int fd) 265 { 266 267 FILEDESC_XLOCK_ASSERT(fdp); 268 269 fdused_init(fdp, fd); 270 if (fd == fdp->fd_freefile) 271 fdp->fd_freefile++; 272 } 273 274 /* 275 * Mark a file descriptor as unused. 276 */ 277 static void 278 fdunused(struct filedesc *fdp, int fd) 279 { 280 281 FILEDESC_XLOCK_ASSERT(fdp); 282 283 KASSERT(fdisused(fdp, fd), ("fd=%d is already unused", fd)); 284 KASSERT(fdp->fd_ofiles[fd].fde_file == NULL, 285 ("fd=%d is still in use", fd)); 286 287 fdp->fd_map[NDSLOT(fd)] &= ~NDBIT(fd); 288 if (fd < fdp->fd_freefile) 289 fdp->fd_freefile = fd; 290 } 291 292 /* 293 * Free a file descriptor. 294 * 295 * Avoid some work if fdp is about to be destroyed. 296 */ 297 static inline void 298 fdefree_last(struct filedescent *fde) 299 { 300 301 filecaps_free(&fde->fde_caps); 302 } 303 304 static inline void 305 fdfree(struct filedesc *fdp, int fd) 306 { 307 struct filedescent *fde; 308 309 FILEDESC_XLOCK_ASSERT(fdp); 310 fde = &fdp->fd_ofiles[fd]; 311 #ifdef CAPABILITIES 312 seqc_write_begin(&fde->fde_seqc); 313 #endif 314 fde->fde_file = NULL; 315 #ifdef CAPABILITIES 316 seqc_write_end(&fde->fde_seqc); 317 #endif 318 fdefree_last(fde); 319 fdunused(fdp, fd); 320 } 321 322 /* 323 * System calls on descriptors. 324 */ 325 #ifndef _SYS_SYSPROTO_H_ 326 struct getdtablesize_args { 327 int dummy; 328 }; 329 #endif 330 /* ARGSUSED */ 331 int 332 sys_getdtablesize(struct thread *td, struct getdtablesize_args *uap) 333 { 334 #ifdef RACCT 335 uint64_t lim; 336 #endif 337 338 td->td_retval[0] = getmaxfd(td); 339 #ifdef RACCT 340 PROC_LOCK(td->td_proc); 341 lim = racct_get_limit(td->td_proc, RACCT_NOFILE); 342 PROC_UNLOCK(td->td_proc); 343 if (lim < td->td_retval[0]) 344 td->td_retval[0] = lim; 345 #endif 346 return (0); 347 } 348 349 /* 350 * Duplicate a file descriptor to a particular value. 351 * 352 * Note: keep in mind that a potential race condition exists when closing 353 * descriptors from a shared descriptor table (via rfork). 354 */ 355 #ifndef _SYS_SYSPROTO_H_ 356 struct dup2_args { 357 u_int from; 358 u_int to; 359 }; 360 #endif 361 /* ARGSUSED */ 362 int 363 sys_dup2(struct thread *td, struct dup2_args *uap) 364 { 365 366 return (kern_dup(td, FDDUP_FIXED, 0, (int)uap->from, (int)uap->to)); 367 } 368 369 /* 370 * Duplicate a file descriptor. 371 */ 372 #ifndef _SYS_SYSPROTO_H_ 373 struct dup_args { 374 u_int fd; 375 }; 376 #endif 377 /* ARGSUSED */ 378 int 379 sys_dup(struct thread *td, struct dup_args *uap) 380 { 381 382 return (kern_dup(td, FDDUP_NORMAL, 0, (int)uap->fd, 0)); 383 } 384 385 /* 386 * The file control system call. 387 */ 388 #ifndef _SYS_SYSPROTO_H_ 389 struct fcntl_args { 390 int fd; 391 int cmd; 392 long arg; 393 }; 394 #endif 395 /* ARGSUSED */ 396 int 397 sys_fcntl(struct thread *td, struct fcntl_args *uap) 398 { 399 400 return (kern_fcntl_freebsd(td, uap->fd, uap->cmd, uap->arg)); 401 } 402 403 int 404 kern_fcntl_freebsd(struct thread *td, int fd, int cmd, long arg) 405 { 406 struct flock fl; 407 struct __oflock ofl; 408 intptr_t arg1; 409 int error, newcmd; 410 411 error = 0; 412 newcmd = cmd; 413 switch (cmd) { 414 case F_OGETLK: 415 case F_OSETLK: 416 case F_OSETLKW: 417 /* 418 * Convert old flock structure to new. 419 */ 420 error = copyin((void *)(intptr_t)arg, &ofl, sizeof(ofl)); 421 fl.l_start = ofl.l_start; 422 fl.l_len = ofl.l_len; 423 fl.l_pid = ofl.l_pid; 424 fl.l_type = ofl.l_type; 425 fl.l_whence = ofl.l_whence; 426 fl.l_sysid = 0; 427 428 switch (cmd) { 429 case F_OGETLK: 430 newcmd = F_GETLK; 431 break; 432 case F_OSETLK: 433 newcmd = F_SETLK; 434 break; 435 case F_OSETLKW: 436 newcmd = F_SETLKW; 437 break; 438 } 439 arg1 = (intptr_t)&fl; 440 break; 441 case F_GETLK: 442 case F_SETLK: 443 case F_SETLKW: 444 case F_SETLK_REMOTE: 445 error = copyin((void *)(intptr_t)arg, &fl, sizeof(fl)); 446 arg1 = (intptr_t)&fl; 447 break; 448 default: 449 arg1 = arg; 450 break; 451 } 452 if (error) 453 return (error); 454 error = kern_fcntl(td, fd, newcmd, arg1); 455 if (error) 456 return (error); 457 if (cmd == F_OGETLK) { 458 ofl.l_start = fl.l_start; 459 ofl.l_len = fl.l_len; 460 ofl.l_pid = fl.l_pid; 461 ofl.l_type = fl.l_type; 462 ofl.l_whence = fl.l_whence; 463 error = copyout(&ofl, (void *)(intptr_t)arg, sizeof(ofl)); 464 } else if (cmd == F_GETLK) { 465 error = copyout(&fl, (void *)(intptr_t)arg, sizeof(fl)); 466 } 467 return (error); 468 } 469 470 int 471 kern_fcntl(struct thread *td, int fd, int cmd, intptr_t arg) 472 { 473 struct filedesc *fdp; 474 struct flock *flp; 475 struct file *fp, *fp2; 476 struct filedescent *fde; 477 struct proc *p; 478 struct vnode *vp; 479 struct mount *mp; 480 int error, flg, seals, tmp; 481 uint64_t bsize; 482 off_t foffset; 483 484 error = 0; 485 flg = F_POSIX; 486 p = td->td_proc; 487 fdp = p->p_fd; 488 489 AUDIT_ARG_FD(cmd); 490 AUDIT_ARG_CMD(cmd); 491 switch (cmd) { 492 case F_DUPFD: 493 tmp = arg; 494 error = kern_dup(td, FDDUP_FCNTL, 0, fd, tmp); 495 break; 496 497 case F_DUPFD_CLOEXEC: 498 tmp = arg; 499 error = kern_dup(td, FDDUP_FCNTL, FDDUP_FLAG_CLOEXEC, fd, tmp); 500 break; 501 502 case F_DUP2FD: 503 tmp = arg; 504 error = kern_dup(td, FDDUP_FIXED, 0, fd, tmp); 505 break; 506 507 case F_DUP2FD_CLOEXEC: 508 tmp = arg; 509 error = kern_dup(td, FDDUP_FIXED, FDDUP_FLAG_CLOEXEC, fd, tmp); 510 break; 511 512 case F_GETFD: 513 error = EBADF; 514 FILEDESC_SLOCK(fdp); 515 fde = fdeget_locked(fdp, fd); 516 if (fde != NULL) { 517 td->td_retval[0] = 518 (fde->fde_flags & UF_EXCLOSE) ? FD_CLOEXEC : 0; 519 error = 0; 520 } 521 FILEDESC_SUNLOCK(fdp); 522 break; 523 524 case F_SETFD: 525 error = EBADF; 526 FILEDESC_XLOCK(fdp); 527 fde = fdeget_locked(fdp, fd); 528 if (fde != NULL) { 529 fde->fde_flags = (fde->fde_flags & ~UF_EXCLOSE) | 530 (arg & FD_CLOEXEC ? UF_EXCLOSE : 0); 531 error = 0; 532 } 533 FILEDESC_XUNLOCK(fdp); 534 break; 535 536 case F_GETFL: 537 error = fget_fcntl(td, fd, &cap_fcntl_rights, F_GETFL, &fp); 538 if (error != 0) 539 break; 540 td->td_retval[0] = OFLAGS(fp->f_flag); 541 fdrop(fp, td); 542 break; 543 544 case F_SETFL: 545 error = fget_fcntl(td, fd, &cap_fcntl_rights, F_SETFL, &fp); 546 if (error != 0) 547 break; 548 if (fp->f_ops == &path_fileops) { 549 fdrop(fp, td); 550 error = EBADF; 551 break; 552 } 553 do { 554 tmp = flg = fp->f_flag; 555 tmp &= ~FCNTLFLAGS; 556 tmp |= FFLAGS(arg & ~O_ACCMODE) & FCNTLFLAGS; 557 } while (atomic_cmpset_int(&fp->f_flag, flg, tmp) == 0); 558 tmp = fp->f_flag & FNONBLOCK; 559 error = fo_ioctl(fp, FIONBIO, &tmp, td->td_ucred, td); 560 if (error != 0) { 561 fdrop(fp, td); 562 break; 563 } 564 tmp = fp->f_flag & FASYNC; 565 error = fo_ioctl(fp, FIOASYNC, &tmp, td->td_ucred, td); 566 if (error == 0) { 567 fdrop(fp, td); 568 break; 569 } 570 atomic_clear_int(&fp->f_flag, FNONBLOCK); 571 tmp = 0; 572 (void)fo_ioctl(fp, FIONBIO, &tmp, td->td_ucred, td); 573 fdrop(fp, td); 574 break; 575 576 case F_GETOWN: 577 error = fget_fcntl(td, fd, &cap_fcntl_rights, F_GETOWN, &fp); 578 if (error != 0) 579 break; 580 error = fo_ioctl(fp, FIOGETOWN, &tmp, td->td_ucred, td); 581 if (error == 0) 582 td->td_retval[0] = tmp; 583 fdrop(fp, td); 584 break; 585 586 case F_SETOWN: 587 error = fget_fcntl(td, fd, &cap_fcntl_rights, F_SETOWN, &fp); 588 if (error != 0) 589 break; 590 tmp = arg; 591 error = fo_ioctl(fp, FIOSETOWN, &tmp, td->td_ucred, td); 592 fdrop(fp, td); 593 break; 594 595 case F_SETLK_REMOTE: 596 error = priv_check(td, PRIV_NFS_LOCKD); 597 if (error != 0) 598 return (error); 599 flg = F_REMOTE; 600 goto do_setlk; 601 602 case F_SETLKW: 603 flg |= F_WAIT; 604 /* FALLTHROUGH F_SETLK */ 605 606 case F_SETLK: 607 do_setlk: 608 flp = (struct flock *)arg; 609 if ((flg & F_REMOTE) != 0 && flp->l_sysid == 0) { 610 error = EINVAL; 611 break; 612 } 613 614 error = fget_unlocked(fdp, fd, &cap_flock_rights, &fp); 615 if (error != 0) 616 break; 617 if (fp->f_type != DTYPE_VNODE || fp->f_ops == &path_fileops) { 618 error = EBADF; 619 fdrop(fp, td); 620 break; 621 } 622 623 if (flp->l_whence == SEEK_CUR) { 624 foffset = foffset_get(fp); 625 if (foffset < 0 || 626 (flp->l_start > 0 && 627 foffset > OFF_MAX - flp->l_start)) { 628 error = EOVERFLOW; 629 fdrop(fp, td); 630 break; 631 } 632 flp->l_start += foffset; 633 } 634 635 vp = fp->f_vnode; 636 switch (flp->l_type) { 637 case F_RDLCK: 638 if ((fp->f_flag & FREAD) == 0) { 639 error = EBADF; 640 break; 641 } 642 if ((p->p_leader->p_flag & P_ADVLOCK) == 0) { 643 PROC_LOCK(p->p_leader); 644 p->p_leader->p_flag |= P_ADVLOCK; 645 PROC_UNLOCK(p->p_leader); 646 } 647 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_SETLK, 648 flp, flg); 649 break; 650 case F_WRLCK: 651 if ((fp->f_flag & FWRITE) == 0) { 652 error = EBADF; 653 break; 654 } 655 if ((p->p_leader->p_flag & P_ADVLOCK) == 0) { 656 PROC_LOCK(p->p_leader); 657 p->p_leader->p_flag |= P_ADVLOCK; 658 PROC_UNLOCK(p->p_leader); 659 } 660 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_SETLK, 661 flp, flg); 662 break; 663 case F_UNLCK: 664 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_UNLCK, 665 flp, flg); 666 break; 667 case F_UNLCKSYS: 668 if (flg != F_REMOTE) { 669 error = EINVAL; 670 break; 671 } 672 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, 673 F_UNLCKSYS, flp, flg); 674 break; 675 default: 676 error = EINVAL; 677 break; 678 } 679 if (error != 0 || flp->l_type == F_UNLCK || 680 flp->l_type == F_UNLCKSYS) { 681 fdrop(fp, td); 682 break; 683 } 684 685 /* 686 * Check for a race with close. 687 * 688 * The vnode is now advisory locked (or unlocked, but this case 689 * is not really important) as the caller requested. 690 * We had to drop the filedesc lock, so we need to recheck if 691 * the descriptor is still valid, because if it was closed 692 * in the meantime we need to remove advisory lock from the 693 * vnode - close on any descriptor leading to an advisory 694 * locked vnode, removes that lock. 695 * We will return 0 on purpose in that case, as the result of 696 * successful advisory lock might have been externally visible 697 * already. This is fine - effectively we pretend to the caller 698 * that the closing thread was a bit slower and that the 699 * advisory lock succeeded before the close. 700 */ 701 error = fget_unlocked(fdp, fd, &cap_no_rights, &fp2); 702 if (error != 0) { 703 fdrop(fp, td); 704 break; 705 } 706 if (fp != fp2) { 707 flp->l_whence = SEEK_SET; 708 flp->l_start = 0; 709 flp->l_len = 0; 710 flp->l_type = F_UNLCK; 711 (void) VOP_ADVLOCK(vp, (caddr_t)p->p_leader, 712 F_UNLCK, flp, F_POSIX); 713 } 714 fdrop(fp, td); 715 fdrop(fp2, td); 716 break; 717 718 case F_GETLK: 719 error = fget_unlocked(fdp, fd, &cap_flock_rights, &fp); 720 if (error != 0) 721 break; 722 if (fp->f_type != DTYPE_VNODE || fp->f_ops == &path_fileops) { 723 error = EBADF; 724 fdrop(fp, td); 725 break; 726 } 727 flp = (struct flock *)arg; 728 if (flp->l_type != F_RDLCK && flp->l_type != F_WRLCK && 729 flp->l_type != F_UNLCK) { 730 error = EINVAL; 731 fdrop(fp, td); 732 break; 733 } 734 if (flp->l_whence == SEEK_CUR) { 735 foffset = foffset_get(fp); 736 if ((flp->l_start > 0 && 737 foffset > OFF_MAX - flp->l_start) || 738 (flp->l_start < 0 && 739 foffset < OFF_MIN - flp->l_start)) { 740 error = EOVERFLOW; 741 fdrop(fp, td); 742 break; 743 } 744 flp->l_start += foffset; 745 } 746 vp = fp->f_vnode; 747 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_GETLK, flp, 748 F_POSIX); 749 fdrop(fp, td); 750 break; 751 752 case F_ADD_SEALS: 753 error = fget_unlocked(fdp, fd, &cap_no_rights, &fp); 754 if (error != 0) 755 break; 756 error = fo_add_seals(fp, arg); 757 fdrop(fp, td); 758 break; 759 760 case F_GET_SEALS: 761 error = fget_unlocked(fdp, fd, &cap_no_rights, &fp); 762 if (error != 0) 763 break; 764 if (fo_get_seals(fp, &seals) == 0) 765 td->td_retval[0] = seals; 766 else 767 error = EINVAL; 768 fdrop(fp, td); 769 break; 770 771 case F_RDAHEAD: 772 arg = arg ? 128 * 1024: 0; 773 /* FALLTHROUGH */ 774 case F_READAHEAD: 775 error = fget_unlocked(fdp, fd, &cap_no_rights, &fp); 776 if (error != 0) 777 break; 778 if (fp->f_type != DTYPE_VNODE || fp->f_ops == &path_fileops) { 779 fdrop(fp, td); 780 error = EBADF; 781 break; 782 } 783 vp = fp->f_vnode; 784 if (vp->v_type != VREG) { 785 fdrop(fp, td); 786 error = ENOTTY; 787 break; 788 } 789 790 /* 791 * Exclusive lock synchronizes against f_seqcount reads and 792 * writes in sequential_heuristic(). 793 */ 794 error = vn_lock(vp, LK_EXCLUSIVE); 795 if (error != 0) { 796 fdrop(fp, td); 797 break; 798 } 799 if (arg >= 0) { 800 bsize = fp->f_vnode->v_mount->mnt_stat.f_iosize; 801 arg = MIN(arg, INT_MAX - bsize + 1); 802 fp->f_seqcount[UIO_READ] = MIN(IO_SEQMAX, 803 (arg + bsize - 1) / bsize); 804 atomic_set_int(&fp->f_flag, FRDAHEAD); 805 } else { 806 atomic_clear_int(&fp->f_flag, FRDAHEAD); 807 } 808 VOP_UNLOCK(vp); 809 fdrop(fp, td); 810 break; 811 812 case F_ISUNIONSTACK: 813 /* 814 * Check if the vnode is part of a union stack (either the 815 * "union" flag from mount(2) or unionfs). 816 * 817 * Prior to introduction of this op libc's readdir would call 818 * fstatfs(2), in effect unnecessarily copying kilobytes of 819 * data just to check fs name and a mount flag. 820 * 821 * Fixing the code to handle everything in the kernel instead 822 * is a non-trivial endeavor and has low priority, thus this 823 * horrible kludge facilitates the current behavior in a much 824 * cheaper manner until someone(tm) sorts this out. 825 */ 826 error = fget_unlocked(fdp, fd, &cap_no_rights, &fp); 827 if (error != 0) 828 break; 829 if (fp->f_type != DTYPE_VNODE) { 830 fdrop(fp, td); 831 error = EBADF; 832 break; 833 } 834 vp = fp->f_vnode; 835 /* 836 * Since we don't prevent dooming the vnode even non-null mp 837 * found can become immediately stale. This is tolerable since 838 * mount points are type-stable (providing safe memory access) 839 * and any vfs op on this vnode going forward will return an 840 * error (meaning return value in this case is meaningless). 841 */ 842 mp = atomic_load_ptr(&vp->v_mount); 843 if (__predict_false(mp == NULL)) { 844 fdrop(fp, td); 845 error = EBADF; 846 break; 847 } 848 td->td_retval[0] = 0; 849 if (mp->mnt_kern_flag & MNTK_UNIONFS || 850 mp->mnt_flag & MNT_UNION) 851 td->td_retval[0] = 1; 852 fdrop(fp, td); 853 break; 854 855 default: 856 error = EINVAL; 857 break; 858 } 859 return (error); 860 } 861 862 static int 863 getmaxfd(struct thread *td) 864 { 865 866 return (min((int)lim_cur(td, RLIMIT_NOFILE), maxfilesperproc)); 867 } 868 869 /* 870 * Common code for dup, dup2, fcntl(F_DUPFD) and fcntl(F_DUP2FD). 871 */ 872 int 873 kern_dup(struct thread *td, u_int mode, int flags, int old, int new) 874 { 875 struct filedesc *fdp; 876 struct filedescent *oldfde, *newfde; 877 struct proc *p; 878 struct file *delfp, *oldfp; 879 u_long *oioctls, *nioctls; 880 int error, maxfd; 881 882 p = td->td_proc; 883 fdp = p->p_fd; 884 oioctls = NULL; 885 886 MPASS((flags & ~(FDDUP_FLAG_CLOEXEC)) == 0); 887 MPASS(mode < FDDUP_LASTMODE); 888 889 AUDIT_ARG_FD(old); 890 /* XXXRW: if (flags & FDDUP_FIXED) AUDIT_ARG_FD2(new); */ 891 892 /* 893 * Verify we have a valid descriptor to dup from and possibly to 894 * dup to. Unlike dup() and dup2(), fcntl()'s F_DUPFD should 895 * return EINVAL when the new descriptor is out of bounds. 896 */ 897 if (old < 0) 898 return (EBADF); 899 if (new < 0) 900 return (mode == FDDUP_FCNTL ? EINVAL : EBADF); 901 maxfd = getmaxfd(td); 902 if (new >= maxfd) 903 return (mode == FDDUP_FCNTL ? EINVAL : EBADF); 904 905 error = EBADF; 906 FILEDESC_XLOCK(fdp); 907 if (fget_locked(fdp, old) == NULL) 908 goto unlock; 909 if ((mode == FDDUP_FIXED || mode == FDDUP_MUSTREPLACE) && old == new) { 910 td->td_retval[0] = new; 911 if (flags & FDDUP_FLAG_CLOEXEC) 912 fdp->fd_ofiles[new].fde_flags |= UF_EXCLOSE; 913 error = 0; 914 goto unlock; 915 } 916 917 oldfde = &fdp->fd_ofiles[old]; 918 oldfp = oldfde->fde_file; 919 if (!fhold(oldfp)) 920 goto unlock; 921 922 /* 923 * If the caller specified a file descriptor, make sure the file 924 * table is large enough to hold it, and grab it. Otherwise, just 925 * allocate a new descriptor the usual way. 926 */ 927 switch (mode) { 928 case FDDUP_NORMAL: 929 case FDDUP_FCNTL: 930 if ((error = fdalloc(td, new, &new)) != 0) { 931 fdrop(oldfp, td); 932 goto unlock; 933 } 934 break; 935 case FDDUP_MUSTREPLACE: 936 /* Target file descriptor must exist. */ 937 if (fget_locked(fdp, new) == NULL) { 938 fdrop(oldfp, td); 939 goto unlock; 940 } 941 break; 942 case FDDUP_FIXED: 943 if (new >= fdp->fd_nfiles) { 944 /* 945 * The resource limits are here instead of e.g. 946 * fdalloc(), because the file descriptor table may be 947 * shared between processes, so we can't really use 948 * racct_add()/racct_sub(). Instead of counting the 949 * number of actually allocated descriptors, just put 950 * the limit on the size of the file descriptor table. 951 */ 952 #ifdef RACCT 953 if (RACCT_ENABLED()) { 954 error = racct_set_unlocked(p, RACCT_NOFILE, new + 1); 955 if (error != 0) { 956 error = EMFILE; 957 fdrop(oldfp, td); 958 goto unlock; 959 } 960 } 961 #endif 962 fdgrowtable_exp(fdp, new + 1); 963 } 964 if (!fdisused(fdp, new)) 965 fdused(fdp, new); 966 break; 967 default: 968 KASSERT(0, ("%s unsupported mode %d", __func__, mode)); 969 } 970 971 KASSERT(old != new, ("new fd is same as old")); 972 973 /* Refetch oldfde because the table may have grown and old one freed. */ 974 oldfde = &fdp->fd_ofiles[old]; 975 KASSERT(oldfp == oldfde->fde_file, 976 ("fdt_ofiles shift from growth observed at fd %d", 977 old)); 978 979 newfde = &fdp->fd_ofiles[new]; 980 delfp = newfde->fde_file; 981 982 nioctls = filecaps_copy_prep(&oldfde->fde_caps); 983 984 /* 985 * Duplicate the source descriptor. 986 */ 987 #ifdef CAPABILITIES 988 seqc_write_begin(&newfde->fde_seqc); 989 #endif 990 oioctls = filecaps_free_prep(&newfde->fde_caps); 991 memcpy(newfde, oldfde, fde_change_size); 992 filecaps_copy_finish(&oldfde->fde_caps, &newfde->fde_caps, 993 nioctls); 994 if ((flags & FDDUP_FLAG_CLOEXEC) != 0) 995 newfde->fde_flags = oldfde->fde_flags | UF_EXCLOSE; 996 else 997 newfde->fde_flags = oldfde->fde_flags & ~UF_EXCLOSE; 998 #ifdef CAPABILITIES 999 seqc_write_end(&newfde->fde_seqc); 1000 #endif 1001 td->td_retval[0] = new; 1002 1003 error = 0; 1004 1005 if (delfp != NULL) { 1006 (void) closefp(fdp, new, delfp, td, true, false); 1007 FILEDESC_UNLOCK_ASSERT(fdp); 1008 } else { 1009 unlock: 1010 FILEDESC_XUNLOCK(fdp); 1011 } 1012 1013 filecaps_free_finish(oioctls); 1014 return (error); 1015 } 1016 1017 static void 1018 sigiofree(struct sigio *sigio) 1019 { 1020 crfree(sigio->sio_ucred); 1021 free(sigio, M_SIGIO); 1022 } 1023 1024 static struct sigio * 1025 funsetown_locked(struct sigio *sigio) 1026 { 1027 struct proc *p; 1028 struct pgrp *pg; 1029 1030 SIGIO_ASSERT_LOCKED(); 1031 1032 if (sigio == NULL) 1033 return (NULL); 1034 *sigio->sio_myref = NULL; 1035 if (sigio->sio_pgid < 0) { 1036 pg = sigio->sio_pgrp; 1037 PGRP_LOCK(pg); 1038 SLIST_REMOVE(&pg->pg_sigiolst, sigio, sigio, sio_pgsigio); 1039 PGRP_UNLOCK(pg); 1040 } else { 1041 p = sigio->sio_proc; 1042 PROC_LOCK(p); 1043 SLIST_REMOVE(&p->p_sigiolst, sigio, sigio, sio_pgsigio); 1044 PROC_UNLOCK(p); 1045 } 1046 return (sigio); 1047 } 1048 1049 /* 1050 * If sigio is on the list associated with a process or process group, 1051 * disable signalling from the device, remove sigio from the list and 1052 * free sigio. 1053 */ 1054 void 1055 funsetown(struct sigio **sigiop) 1056 { 1057 struct sigio *sigio; 1058 1059 /* Racy check, consumers must provide synchronization. */ 1060 if (*sigiop == NULL) 1061 return; 1062 1063 SIGIO_LOCK(); 1064 sigio = funsetown_locked(*sigiop); 1065 SIGIO_UNLOCK(); 1066 if (sigio != NULL) 1067 sigiofree(sigio); 1068 } 1069 1070 /* 1071 * Free a list of sigio structures. The caller must ensure that new sigio 1072 * structures cannot be added after this point. For process groups this is 1073 * guaranteed using the proctree lock; for processes, the P_WEXIT flag serves 1074 * as an interlock. 1075 */ 1076 void 1077 funsetownlst(struct sigiolst *sigiolst) 1078 { 1079 struct proc *p; 1080 struct pgrp *pg; 1081 struct sigio *sigio, *tmp; 1082 1083 /* Racy check. */ 1084 sigio = SLIST_FIRST(sigiolst); 1085 if (sigio == NULL) 1086 return; 1087 1088 p = NULL; 1089 pg = NULL; 1090 1091 SIGIO_LOCK(); 1092 sigio = SLIST_FIRST(sigiolst); 1093 if (sigio == NULL) { 1094 SIGIO_UNLOCK(); 1095 return; 1096 } 1097 1098 /* 1099 * Every entry of the list should belong to a single proc or pgrp. 1100 */ 1101 if (sigio->sio_pgid < 0) { 1102 pg = sigio->sio_pgrp; 1103 sx_assert(&proctree_lock, SX_XLOCKED); 1104 PGRP_LOCK(pg); 1105 } else /* if (sigio->sio_pgid > 0) */ { 1106 p = sigio->sio_proc; 1107 PROC_LOCK(p); 1108 KASSERT((p->p_flag & P_WEXIT) != 0, 1109 ("%s: process %p is not exiting", __func__, p)); 1110 } 1111 1112 SLIST_FOREACH(sigio, sigiolst, sio_pgsigio) { 1113 *sigio->sio_myref = NULL; 1114 if (pg != NULL) { 1115 KASSERT(sigio->sio_pgid < 0, 1116 ("Proc sigio in pgrp sigio list")); 1117 KASSERT(sigio->sio_pgrp == pg, 1118 ("Bogus pgrp in sigio list")); 1119 } else /* if (p != NULL) */ { 1120 KASSERT(sigio->sio_pgid > 0, 1121 ("Pgrp sigio in proc sigio list")); 1122 KASSERT(sigio->sio_proc == p, 1123 ("Bogus proc in sigio list")); 1124 } 1125 } 1126 1127 if (pg != NULL) 1128 PGRP_UNLOCK(pg); 1129 else 1130 PROC_UNLOCK(p); 1131 SIGIO_UNLOCK(); 1132 1133 SLIST_FOREACH_SAFE(sigio, sigiolst, sio_pgsigio, tmp) 1134 sigiofree(sigio); 1135 } 1136 1137 /* 1138 * This is common code for FIOSETOWN ioctl called by fcntl(fd, F_SETOWN, arg). 1139 * 1140 * After permission checking, add a sigio structure to the sigio list for 1141 * the process or process group. 1142 */ 1143 int 1144 fsetown(pid_t pgid, struct sigio **sigiop) 1145 { 1146 struct proc *proc; 1147 struct pgrp *pgrp; 1148 struct sigio *osigio, *sigio; 1149 int ret; 1150 1151 if (pgid == 0) { 1152 funsetown(sigiop); 1153 return (0); 1154 } 1155 1156 sigio = malloc(sizeof(struct sigio), M_SIGIO, M_WAITOK); 1157 sigio->sio_pgid = pgid; 1158 sigio->sio_ucred = crhold(curthread->td_ucred); 1159 sigio->sio_myref = sigiop; 1160 1161 osigio = NULL; 1162 ret = 0; 1163 if (pgid > 0) { 1164 ret = pget(pgid, PGET_NOTWEXIT | PGET_NOTID | PGET_HOLD, &proc); 1165 SIGIO_LOCK(); 1166 if (ret == 0) { 1167 osigio = funsetown_locked(*sigiop); 1168 1169 PROC_LOCK(proc); 1170 _PRELE(proc); 1171 if ((proc->p_flag & P_WEXIT) != 0) { 1172 ret = ESRCH; 1173 } else if (proc->p_session != 1174 curthread->td_proc->p_session) { 1175 /* 1176 * Policy - Don't allow a process to FSETOWN a 1177 * process in another session. 1178 * 1179 * Remove this test to allow maximum flexibility 1180 * or restrict FSETOWN to the current process or 1181 * process group for maximum safety. 1182 */ 1183 ret = EPERM; 1184 } else { 1185 sigio->sio_proc = proc; 1186 SLIST_INSERT_HEAD(&proc->p_sigiolst, sigio, 1187 sio_pgsigio); 1188 } 1189 PROC_UNLOCK(proc); 1190 } 1191 } else /* if (pgid < 0) */ { 1192 sx_slock(&proctree_lock); 1193 SIGIO_LOCK(); 1194 pgrp = pgfind(-pgid); 1195 if (pgrp == NULL) { 1196 ret = ESRCH; 1197 } else { 1198 osigio = funsetown_locked(*sigiop); 1199 1200 if (pgrp->pg_session != curthread->td_proc->p_session) { 1201 /* 1202 * Policy - Don't allow a process to FSETOWN a 1203 * process in another session. 1204 * 1205 * Remove this test to allow maximum flexibility 1206 * or restrict FSETOWN to the current process or 1207 * process group for maximum safety. 1208 */ 1209 ret = EPERM; 1210 } else { 1211 sigio->sio_pgrp = pgrp; 1212 SLIST_INSERT_HEAD(&pgrp->pg_sigiolst, sigio, 1213 sio_pgsigio); 1214 } 1215 PGRP_UNLOCK(pgrp); 1216 } 1217 sx_sunlock(&proctree_lock); 1218 } 1219 if (ret == 0) 1220 *sigiop = sigio; 1221 SIGIO_UNLOCK(); 1222 if (osigio != NULL) 1223 sigiofree(osigio); 1224 return (ret); 1225 } 1226 1227 /* 1228 * This is common code for FIOGETOWN ioctl called by fcntl(fd, F_GETOWN, arg). 1229 */ 1230 pid_t 1231 fgetown(struct sigio **sigiop) 1232 { 1233 pid_t pgid; 1234 1235 SIGIO_LOCK(); 1236 pgid = (*sigiop != NULL) ? (*sigiop)->sio_pgid : 0; 1237 SIGIO_UNLOCK(); 1238 return (pgid); 1239 } 1240 1241 static int 1242 closefp_impl(struct filedesc *fdp, int fd, struct file *fp, struct thread *td, 1243 bool audit) 1244 { 1245 int error; 1246 1247 FILEDESC_XLOCK_ASSERT(fdp); 1248 1249 /* 1250 * We now hold the fp reference that used to be owned by the 1251 * descriptor array. We have to unlock the FILEDESC *AFTER* 1252 * knote_fdclose to prevent a race of the fd getting opened, a knote 1253 * added, and deleteing a knote for the new fd. 1254 */ 1255 if (__predict_false(!TAILQ_EMPTY(&fdp->fd_kqlist))) 1256 knote_fdclose(td, fd); 1257 1258 /* 1259 * We need to notify mqueue if the object is of type mqueue. 1260 */ 1261 if (__predict_false(fp->f_type == DTYPE_MQUEUE)) 1262 mq_fdclose(td, fd, fp); 1263 FILEDESC_XUNLOCK(fdp); 1264 1265 #ifdef AUDIT 1266 if (AUDITING_TD(td) && audit) 1267 audit_sysclose(td, fd, fp); 1268 #endif 1269 error = closef(fp, td); 1270 1271 /* 1272 * All paths leading up to closefp() will have already removed or 1273 * replaced the fd in the filedesc table, so a restart would not 1274 * operate on the same file. 1275 */ 1276 if (error == ERESTART) 1277 error = EINTR; 1278 1279 return (error); 1280 } 1281 1282 static int 1283 closefp_hl(struct filedesc *fdp, int fd, struct file *fp, struct thread *td, 1284 bool holdleaders, bool audit) 1285 { 1286 int error; 1287 1288 FILEDESC_XLOCK_ASSERT(fdp); 1289 1290 if (holdleaders) { 1291 if (td->td_proc->p_fdtol != NULL) { 1292 /* 1293 * Ask fdfree() to sleep to ensure that all relevant 1294 * process leaders can be traversed in closef(). 1295 */ 1296 fdp->fd_holdleaderscount++; 1297 } else { 1298 holdleaders = false; 1299 } 1300 } 1301 1302 error = closefp_impl(fdp, fd, fp, td, audit); 1303 if (holdleaders) { 1304 FILEDESC_XLOCK(fdp); 1305 fdp->fd_holdleaderscount--; 1306 if (fdp->fd_holdleaderscount == 0 && 1307 fdp->fd_holdleaderswakeup != 0) { 1308 fdp->fd_holdleaderswakeup = 0; 1309 wakeup(&fdp->fd_holdleaderscount); 1310 } 1311 FILEDESC_XUNLOCK(fdp); 1312 } 1313 return (error); 1314 } 1315 1316 static int 1317 closefp(struct filedesc *fdp, int fd, struct file *fp, struct thread *td, 1318 bool holdleaders, bool audit) 1319 { 1320 1321 FILEDESC_XLOCK_ASSERT(fdp); 1322 1323 if (__predict_false(td->td_proc->p_fdtol != NULL)) { 1324 return (closefp_hl(fdp, fd, fp, td, holdleaders, audit)); 1325 } else { 1326 return (closefp_impl(fdp, fd, fp, td, audit)); 1327 } 1328 } 1329 1330 /* 1331 * Close a file descriptor. 1332 */ 1333 #ifndef _SYS_SYSPROTO_H_ 1334 struct close_args { 1335 int fd; 1336 }; 1337 #endif 1338 /* ARGSUSED */ 1339 int 1340 sys_close(struct thread *td, struct close_args *uap) 1341 { 1342 1343 return (kern_close(td, uap->fd)); 1344 } 1345 1346 int 1347 kern_close(struct thread *td, int fd) 1348 { 1349 struct filedesc *fdp; 1350 struct file *fp; 1351 1352 fdp = td->td_proc->p_fd; 1353 1354 FILEDESC_XLOCK(fdp); 1355 if ((fp = fget_locked(fdp, fd)) == NULL) { 1356 FILEDESC_XUNLOCK(fdp); 1357 return (EBADF); 1358 } 1359 fdfree(fdp, fd); 1360 1361 /* closefp() drops the FILEDESC lock for us. */ 1362 return (closefp(fdp, fd, fp, td, true, true)); 1363 } 1364 1365 int 1366 kern_close_range(struct thread *td, u_int lowfd, u_int highfd) 1367 { 1368 struct filedesc *fdp; 1369 const struct fdescenttbl *fdt; 1370 struct file *fp; 1371 int fd; 1372 1373 /* 1374 * Check this prior to clamping; closefrom(3) with only fd 0, 1, and 2 1375 * open should not be a usage error. From a close_range() perspective, 1376 * close_range(3, ~0U, 0) in the same scenario should also likely not 1377 * be a usage error as all fd above 3 are in-fact already closed. 1378 */ 1379 if (highfd < lowfd) { 1380 return (EINVAL); 1381 } 1382 1383 fdp = td->td_proc->p_fd; 1384 FILEDESC_XLOCK(fdp); 1385 fdt = atomic_load_ptr(&fdp->fd_files); 1386 highfd = MIN(highfd, fdt->fdt_nfiles - 1); 1387 fd = lowfd; 1388 if (__predict_false(fd > highfd)) { 1389 goto out_locked; 1390 } 1391 for (;;) { 1392 fp = fdt->fdt_ofiles[fd].fde_file; 1393 if (fp == NULL) { 1394 if (fd == highfd) 1395 goto out_locked; 1396 } else { 1397 fdfree(fdp, fd); 1398 (void) closefp(fdp, fd, fp, td, true, true); 1399 if (fd == highfd) 1400 goto out_unlocked; 1401 FILEDESC_XLOCK(fdp); 1402 fdt = atomic_load_ptr(&fdp->fd_files); 1403 } 1404 fd++; 1405 } 1406 out_locked: 1407 FILEDESC_XUNLOCK(fdp); 1408 out_unlocked: 1409 return (0); 1410 } 1411 1412 #ifndef _SYS_SYSPROTO_H_ 1413 struct close_range_args { 1414 u_int lowfd; 1415 u_int highfd; 1416 int flags; 1417 }; 1418 #endif 1419 int 1420 sys_close_range(struct thread *td, struct close_range_args *uap) 1421 { 1422 1423 AUDIT_ARG_FD(uap->lowfd); 1424 AUDIT_ARG_CMD(uap->highfd); 1425 AUDIT_ARG_FFLAGS(uap->flags); 1426 1427 /* No flags currently defined */ 1428 if (uap->flags != 0) 1429 return (EINVAL); 1430 return (kern_close_range(td, uap->lowfd, uap->highfd)); 1431 } 1432 1433 #ifdef COMPAT_FREEBSD12 1434 /* 1435 * Close open file descriptors. 1436 */ 1437 #ifndef _SYS_SYSPROTO_H_ 1438 struct freebsd12_closefrom_args { 1439 int lowfd; 1440 }; 1441 #endif 1442 /* ARGSUSED */ 1443 int 1444 freebsd12_closefrom(struct thread *td, struct freebsd12_closefrom_args *uap) 1445 { 1446 u_int lowfd; 1447 1448 AUDIT_ARG_FD(uap->lowfd); 1449 1450 /* 1451 * Treat negative starting file descriptor values identical to 1452 * closefrom(0) which closes all files. 1453 */ 1454 lowfd = MAX(0, uap->lowfd); 1455 return (kern_close_range(td, lowfd, ~0U)); 1456 } 1457 #endif /* COMPAT_FREEBSD12 */ 1458 1459 #if defined(COMPAT_43) 1460 /* 1461 * Return status information about a file descriptor. 1462 */ 1463 #ifndef _SYS_SYSPROTO_H_ 1464 struct ofstat_args { 1465 int fd; 1466 struct ostat *sb; 1467 }; 1468 #endif 1469 /* ARGSUSED */ 1470 int 1471 ofstat(struct thread *td, struct ofstat_args *uap) 1472 { 1473 struct ostat oub; 1474 struct stat ub; 1475 int error; 1476 1477 error = kern_fstat(td, uap->fd, &ub); 1478 if (error == 0) { 1479 cvtstat(&ub, &oub); 1480 error = copyout(&oub, uap->sb, sizeof(oub)); 1481 } 1482 return (error); 1483 } 1484 #endif /* COMPAT_43 */ 1485 1486 #if defined(COMPAT_FREEBSD11) 1487 int 1488 freebsd11_fstat(struct thread *td, struct freebsd11_fstat_args *uap) 1489 { 1490 struct stat sb; 1491 struct freebsd11_stat osb; 1492 int error; 1493 1494 error = kern_fstat(td, uap->fd, &sb); 1495 if (error != 0) 1496 return (error); 1497 error = freebsd11_cvtstat(&sb, &osb); 1498 if (error == 0) 1499 error = copyout(&osb, uap->sb, sizeof(osb)); 1500 return (error); 1501 } 1502 #endif /* COMPAT_FREEBSD11 */ 1503 1504 /* 1505 * Return status information about a file descriptor. 1506 */ 1507 #ifndef _SYS_SYSPROTO_H_ 1508 struct fstat_args { 1509 int fd; 1510 struct stat *sb; 1511 }; 1512 #endif 1513 /* ARGSUSED */ 1514 int 1515 sys_fstat(struct thread *td, struct fstat_args *uap) 1516 { 1517 struct stat ub; 1518 int error; 1519 1520 error = kern_fstat(td, uap->fd, &ub); 1521 if (error == 0) 1522 error = copyout(&ub, uap->sb, sizeof(ub)); 1523 return (error); 1524 } 1525 1526 int 1527 kern_fstat(struct thread *td, int fd, struct stat *sbp) 1528 { 1529 struct file *fp; 1530 int error; 1531 1532 AUDIT_ARG_FD(fd); 1533 1534 error = fget(td, fd, &cap_fstat_rights, &fp); 1535 if (__predict_false(error != 0)) 1536 return (error); 1537 1538 AUDIT_ARG_FILE(td->td_proc, fp); 1539 1540 error = fo_stat(fp, sbp, td->td_ucred, td); 1541 fdrop(fp, td); 1542 #ifdef __STAT_TIME_T_EXT 1543 sbp->st_atim_ext = 0; 1544 sbp->st_mtim_ext = 0; 1545 sbp->st_ctim_ext = 0; 1546 sbp->st_btim_ext = 0; 1547 #endif 1548 #ifdef KTRACE 1549 if (KTRPOINT(td, KTR_STRUCT)) 1550 ktrstat_error(sbp, error); 1551 #endif 1552 return (error); 1553 } 1554 1555 #if defined(COMPAT_FREEBSD11) 1556 /* 1557 * Return status information about a file descriptor. 1558 */ 1559 #ifndef _SYS_SYSPROTO_H_ 1560 struct freebsd11_nfstat_args { 1561 int fd; 1562 struct nstat *sb; 1563 }; 1564 #endif 1565 /* ARGSUSED */ 1566 int 1567 freebsd11_nfstat(struct thread *td, struct freebsd11_nfstat_args *uap) 1568 { 1569 struct nstat nub; 1570 struct stat ub; 1571 int error; 1572 1573 error = kern_fstat(td, uap->fd, &ub); 1574 if (error == 0) { 1575 freebsd11_cvtnstat(&ub, &nub); 1576 error = copyout(&nub, uap->sb, sizeof(nub)); 1577 } 1578 return (error); 1579 } 1580 #endif /* COMPAT_FREEBSD11 */ 1581 1582 /* 1583 * Return pathconf information about a file descriptor. 1584 */ 1585 #ifndef _SYS_SYSPROTO_H_ 1586 struct fpathconf_args { 1587 int fd; 1588 int name; 1589 }; 1590 #endif 1591 /* ARGSUSED */ 1592 int 1593 sys_fpathconf(struct thread *td, struct fpathconf_args *uap) 1594 { 1595 long value; 1596 int error; 1597 1598 error = kern_fpathconf(td, uap->fd, uap->name, &value); 1599 if (error == 0) 1600 td->td_retval[0] = value; 1601 return (error); 1602 } 1603 1604 int 1605 kern_fpathconf(struct thread *td, int fd, int name, long *valuep) 1606 { 1607 struct file *fp; 1608 struct vnode *vp; 1609 int error; 1610 1611 error = fget(td, fd, &cap_fpathconf_rights, &fp); 1612 if (error != 0) 1613 return (error); 1614 1615 if (name == _PC_ASYNC_IO) { 1616 *valuep = _POSIX_ASYNCHRONOUS_IO; 1617 goto out; 1618 } 1619 vp = fp->f_vnode; 1620 if (vp != NULL) { 1621 vn_lock(vp, LK_SHARED | LK_RETRY); 1622 error = VOP_PATHCONF(vp, name, valuep); 1623 VOP_UNLOCK(vp); 1624 } else if (fp->f_type == DTYPE_PIPE || fp->f_type == DTYPE_SOCKET) { 1625 if (name != _PC_PIPE_BUF) { 1626 error = EINVAL; 1627 } else { 1628 *valuep = PIPE_BUF; 1629 error = 0; 1630 } 1631 } else { 1632 error = EOPNOTSUPP; 1633 } 1634 out: 1635 fdrop(fp, td); 1636 return (error); 1637 } 1638 1639 /* 1640 * Copy filecaps structure allocating memory for ioctls array if needed. 1641 * 1642 * The last parameter indicates whether the fdtable is locked. If it is not and 1643 * ioctls are encountered, copying fails and the caller must lock the table. 1644 * 1645 * Note that if the table was not locked, the caller has to check the relevant 1646 * sequence counter to determine whether the operation was successful. 1647 */ 1648 bool 1649 filecaps_copy(const struct filecaps *src, struct filecaps *dst, bool locked) 1650 { 1651 size_t size; 1652 1653 if (src->fc_ioctls != NULL && !locked) 1654 return (false); 1655 memcpy(dst, src, sizeof(*src)); 1656 if (src->fc_ioctls == NULL) 1657 return (true); 1658 1659 KASSERT(src->fc_nioctls > 0, 1660 ("fc_ioctls != NULL, but fc_nioctls=%hd", src->fc_nioctls)); 1661 1662 size = sizeof(src->fc_ioctls[0]) * src->fc_nioctls; 1663 dst->fc_ioctls = malloc(size, M_FILECAPS, M_WAITOK); 1664 memcpy(dst->fc_ioctls, src->fc_ioctls, size); 1665 return (true); 1666 } 1667 1668 static u_long * 1669 filecaps_copy_prep(const struct filecaps *src) 1670 { 1671 u_long *ioctls; 1672 size_t size; 1673 1674 if (__predict_true(src->fc_ioctls == NULL)) 1675 return (NULL); 1676 1677 KASSERT(src->fc_nioctls > 0, 1678 ("fc_ioctls != NULL, but fc_nioctls=%hd", src->fc_nioctls)); 1679 1680 size = sizeof(src->fc_ioctls[0]) * src->fc_nioctls; 1681 ioctls = malloc(size, M_FILECAPS, M_WAITOK); 1682 return (ioctls); 1683 } 1684 1685 static void 1686 filecaps_copy_finish(const struct filecaps *src, struct filecaps *dst, 1687 u_long *ioctls) 1688 { 1689 size_t size; 1690 1691 *dst = *src; 1692 if (__predict_true(src->fc_ioctls == NULL)) { 1693 MPASS(ioctls == NULL); 1694 return; 1695 } 1696 1697 size = sizeof(src->fc_ioctls[0]) * src->fc_nioctls; 1698 dst->fc_ioctls = ioctls; 1699 bcopy(src->fc_ioctls, dst->fc_ioctls, size); 1700 } 1701 1702 /* 1703 * Move filecaps structure to the new place and clear the old place. 1704 */ 1705 void 1706 filecaps_move(struct filecaps *src, struct filecaps *dst) 1707 { 1708 1709 *dst = *src; 1710 bzero(src, sizeof(*src)); 1711 } 1712 1713 /* 1714 * Fill the given filecaps structure with full rights. 1715 */ 1716 static void 1717 filecaps_fill(struct filecaps *fcaps) 1718 { 1719 1720 CAP_ALL(&fcaps->fc_rights); 1721 fcaps->fc_ioctls = NULL; 1722 fcaps->fc_nioctls = -1; 1723 fcaps->fc_fcntls = CAP_FCNTL_ALL; 1724 } 1725 1726 /* 1727 * Free memory allocated within filecaps structure. 1728 */ 1729 void 1730 filecaps_free(struct filecaps *fcaps) 1731 { 1732 1733 free(fcaps->fc_ioctls, M_FILECAPS); 1734 bzero(fcaps, sizeof(*fcaps)); 1735 } 1736 1737 static u_long * 1738 filecaps_free_prep(struct filecaps *fcaps) 1739 { 1740 u_long *ioctls; 1741 1742 ioctls = fcaps->fc_ioctls; 1743 bzero(fcaps, sizeof(*fcaps)); 1744 return (ioctls); 1745 } 1746 1747 static void 1748 filecaps_free_finish(u_long *ioctls) 1749 { 1750 1751 free(ioctls, M_FILECAPS); 1752 } 1753 1754 /* 1755 * Validate the given filecaps structure. 1756 */ 1757 static void 1758 filecaps_validate(const struct filecaps *fcaps, const char *func) 1759 { 1760 1761 KASSERT(cap_rights_is_valid(&fcaps->fc_rights), 1762 ("%s: invalid rights", func)); 1763 KASSERT((fcaps->fc_fcntls & ~CAP_FCNTL_ALL) == 0, 1764 ("%s: invalid fcntls", func)); 1765 KASSERT(fcaps->fc_fcntls == 0 || 1766 cap_rights_is_set(&fcaps->fc_rights, CAP_FCNTL), 1767 ("%s: fcntls without CAP_FCNTL", func)); 1768 KASSERT(fcaps->fc_ioctls != NULL ? fcaps->fc_nioctls > 0 : 1769 (fcaps->fc_nioctls == -1 || fcaps->fc_nioctls == 0), 1770 ("%s: invalid ioctls", func)); 1771 KASSERT(fcaps->fc_nioctls == 0 || 1772 cap_rights_is_set(&fcaps->fc_rights, CAP_IOCTL), 1773 ("%s: ioctls without CAP_IOCTL", func)); 1774 } 1775 1776 static void 1777 fdgrowtable_exp(struct filedesc *fdp, int nfd) 1778 { 1779 int nfd1; 1780 1781 FILEDESC_XLOCK_ASSERT(fdp); 1782 1783 nfd1 = fdp->fd_nfiles * 2; 1784 if (nfd1 < nfd) 1785 nfd1 = nfd; 1786 fdgrowtable(fdp, nfd1); 1787 } 1788 1789 /* 1790 * Grow the file table to accommodate (at least) nfd descriptors. 1791 */ 1792 static void 1793 fdgrowtable(struct filedesc *fdp, int nfd) 1794 { 1795 struct filedesc0 *fdp0; 1796 struct freetable *ft; 1797 struct fdescenttbl *ntable; 1798 struct fdescenttbl *otable; 1799 int nnfiles, onfiles; 1800 NDSLOTTYPE *nmap, *omap; 1801 1802 KASSERT(fdp->fd_nfiles > 0, ("zero-length file table")); 1803 1804 /* save old values */ 1805 onfiles = fdp->fd_nfiles; 1806 otable = fdp->fd_files; 1807 omap = fdp->fd_map; 1808 1809 /* compute the size of the new table */ 1810 nnfiles = NDSLOTS(nfd) * NDENTRIES; /* round up */ 1811 if (nnfiles <= onfiles) 1812 /* the table is already large enough */ 1813 return; 1814 1815 /* 1816 * Allocate a new table. We need enough space for the number of 1817 * entries, file entries themselves and the struct freetable we will use 1818 * when we decommission the table and place it on the freelist. 1819 * We place the struct freetable in the middle so we don't have 1820 * to worry about padding. 1821 */ 1822 ntable = malloc(offsetof(struct fdescenttbl, fdt_ofiles) + 1823 nnfiles * sizeof(ntable->fdt_ofiles[0]) + 1824 sizeof(struct freetable), 1825 M_FILEDESC, M_ZERO | M_WAITOK); 1826 /* copy the old data */ 1827 ntable->fdt_nfiles = nnfiles; 1828 memcpy(ntable->fdt_ofiles, otable->fdt_ofiles, 1829 onfiles * sizeof(ntable->fdt_ofiles[0])); 1830 1831 /* 1832 * Allocate a new map only if the old is not large enough. It will 1833 * grow at a slower rate than the table as it can map more 1834 * entries than the table can hold. 1835 */ 1836 if (NDSLOTS(nnfiles) > NDSLOTS(onfiles)) { 1837 nmap = malloc(NDSLOTS(nnfiles) * NDSLOTSIZE, M_FILEDESC, 1838 M_ZERO | M_WAITOK); 1839 /* copy over the old data and update the pointer */ 1840 memcpy(nmap, omap, NDSLOTS(onfiles) * sizeof(*omap)); 1841 fdp->fd_map = nmap; 1842 } 1843 1844 /* 1845 * Make sure that ntable is correctly initialized before we replace 1846 * fd_files poiner. Otherwise fget_unlocked() may see inconsistent 1847 * data. 1848 */ 1849 atomic_store_rel_ptr((volatile void *)&fdp->fd_files, (uintptr_t)ntable); 1850 1851 /* 1852 * Free the old file table when not shared by other threads or processes. 1853 * The old file table is considered to be shared when either are true: 1854 * - The process has more than one thread. 1855 * - The file descriptor table has been shared via fdshare(). 1856 * 1857 * When shared, the old file table will be placed on a freelist 1858 * which will be processed when the struct filedesc is released. 1859 * 1860 * Note that if onfiles == NDFILE, we're dealing with the original 1861 * static allocation contained within (struct filedesc0 *)fdp, 1862 * which must not be freed. 1863 */ 1864 if (onfiles > NDFILE) { 1865 /* 1866 * Note we may be called here from fdinit while allocating a 1867 * table for a new process in which case ->p_fd points 1868 * elsewhere. 1869 */ 1870 if (curproc->p_fd != fdp || FILEDESC_IS_ONLY_USER(fdp)) { 1871 free(otable, M_FILEDESC); 1872 } else { 1873 ft = (struct freetable *)&otable->fdt_ofiles[onfiles]; 1874 fdp0 = (struct filedesc0 *)fdp; 1875 ft->ft_table = otable; 1876 SLIST_INSERT_HEAD(&fdp0->fd_free, ft, ft_next); 1877 } 1878 } 1879 /* 1880 * The map does not have the same possibility of threads still 1881 * holding references to it. So always free it as long as it 1882 * does not reference the original static allocation. 1883 */ 1884 if (NDSLOTS(onfiles) > NDSLOTS(NDFILE)) 1885 free(omap, M_FILEDESC); 1886 } 1887 1888 /* 1889 * Allocate a file descriptor for the process. 1890 */ 1891 int 1892 fdalloc(struct thread *td, int minfd, int *result) 1893 { 1894 struct proc *p = td->td_proc; 1895 struct filedesc *fdp = p->p_fd; 1896 int fd, maxfd, allocfd; 1897 #ifdef RACCT 1898 int error; 1899 #endif 1900 1901 FILEDESC_XLOCK_ASSERT(fdp); 1902 1903 if (fdp->fd_freefile > minfd) 1904 minfd = fdp->fd_freefile; 1905 1906 maxfd = getmaxfd(td); 1907 1908 /* 1909 * Search the bitmap for a free descriptor starting at minfd. 1910 * If none is found, grow the file table. 1911 */ 1912 fd = fd_first_free(fdp, minfd, fdp->fd_nfiles); 1913 if (__predict_false(fd >= maxfd)) 1914 return (EMFILE); 1915 if (__predict_false(fd >= fdp->fd_nfiles)) { 1916 allocfd = min(fd * 2, maxfd); 1917 #ifdef RACCT 1918 if (RACCT_ENABLED()) { 1919 error = racct_set_unlocked(p, RACCT_NOFILE, allocfd); 1920 if (error != 0) 1921 return (EMFILE); 1922 } 1923 #endif 1924 /* 1925 * fd is already equal to first free descriptor >= minfd, so 1926 * we only need to grow the table and we are done. 1927 */ 1928 fdgrowtable_exp(fdp, allocfd); 1929 } 1930 1931 /* 1932 * Perform some sanity checks, then mark the file descriptor as 1933 * used and return it to the caller. 1934 */ 1935 KASSERT(fd >= 0 && fd < min(maxfd, fdp->fd_nfiles), 1936 ("invalid descriptor %d", fd)); 1937 KASSERT(!fdisused(fdp, fd), 1938 ("fd_first_free() returned non-free descriptor")); 1939 KASSERT(fdp->fd_ofiles[fd].fde_file == NULL, 1940 ("file descriptor isn't free")); 1941 fdused(fdp, fd); 1942 *result = fd; 1943 return (0); 1944 } 1945 1946 /* 1947 * Allocate n file descriptors for the process. 1948 */ 1949 int 1950 fdallocn(struct thread *td, int minfd, int *fds, int n) 1951 { 1952 struct proc *p = td->td_proc; 1953 struct filedesc *fdp = p->p_fd; 1954 int i; 1955 1956 FILEDESC_XLOCK_ASSERT(fdp); 1957 1958 for (i = 0; i < n; i++) 1959 if (fdalloc(td, 0, &fds[i]) != 0) 1960 break; 1961 1962 if (i < n) { 1963 for (i--; i >= 0; i--) 1964 fdunused(fdp, fds[i]); 1965 return (EMFILE); 1966 } 1967 1968 return (0); 1969 } 1970 1971 /* 1972 * Create a new open file structure and allocate a file descriptor for the 1973 * process that refers to it. We add one reference to the file for the 1974 * descriptor table and one reference for resultfp. This is to prevent us 1975 * being preempted and the entry in the descriptor table closed after we 1976 * release the FILEDESC lock. 1977 */ 1978 int 1979 falloc_caps(struct thread *td, struct file **resultfp, int *resultfd, int flags, 1980 struct filecaps *fcaps) 1981 { 1982 struct file *fp; 1983 int error, fd; 1984 1985 MPASS(resultfp != NULL); 1986 MPASS(resultfd != NULL); 1987 1988 error = _falloc_noinstall(td, &fp, 2); 1989 if (__predict_false(error != 0)) { 1990 return (error); 1991 } 1992 1993 error = finstall_refed(td, fp, &fd, flags, fcaps); 1994 if (__predict_false(error != 0)) { 1995 falloc_abort(td, fp); 1996 return (error); 1997 } 1998 1999 *resultfp = fp; 2000 *resultfd = fd; 2001 2002 return (0); 2003 } 2004 2005 /* 2006 * Create a new open file structure without allocating a file descriptor. 2007 */ 2008 int 2009 _falloc_noinstall(struct thread *td, struct file **resultfp, u_int n) 2010 { 2011 struct file *fp; 2012 int maxuserfiles = maxfiles - (maxfiles / 20); 2013 int openfiles_new; 2014 static struct timeval lastfail; 2015 static int curfail; 2016 2017 KASSERT(resultfp != NULL, ("%s: resultfp == NULL", __func__)); 2018 MPASS(n > 0); 2019 2020 openfiles_new = atomic_fetchadd_int(&openfiles, 1) + 1; 2021 if ((openfiles_new >= maxuserfiles && 2022 priv_check(td, PRIV_MAXFILES) != 0) || 2023 openfiles_new >= maxfiles) { 2024 atomic_subtract_int(&openfiles, 1); 2025 if (ppsratecheck(&lastfail, &curfail, 1)) { 2026 printf("kern.maxfiles limit exceeded by uid %i, (%s) " 2027 "please see tuning(7).\n", td->td_ucred->cr_ruid, td->td_proc->p_comm); 2028 } 2029 return (ENFILE); 2030 } 2031 fp = uma_zalloc(file_zone, M_WAITOK); 2032 bzero(fp, sizeof(*fp)); 2033 refcount_init(&fp->f_count, n); 2034 fp->f_cred = crhold(td->td_ucred); 2035 fp->f_ops = &badfileops; 2036 *resultfp = fp; 2037 return (0); 2038 } 2039 2040 void 2041 falloc_abort(struct thread *td, struct file *fp) 2042 { 2043 2044 /* 2045 * For assertion purposes. 2046 */ 2047 refcount_init(&fp->f_count, 0); 2048 _fdrop(fp, td); 2049 } 2050 2051 /* 2052 * Install a file in a file descriptor table. 2053 */ 2054 void 2055 _finstall(struct filedesc *fdp, struct file *fp, int fd, int flags, 2056 struct filecaps *fcaps) 2057 { 2058 struct filedescent *fde; 2059 2060 MPASS(fp != NULL); 2061 if (fcaps != NULL) 2062 filecaps_validate(fcaps, __func__); 2063 FILEDESC_XLOCK_ASSERT(fdp); 2064 2065 fde = &fdp->fd_ofiles[fd]; 2066 #ifdef CAPABILITIES 2067 seqc_write_begin(&fde->fde_seqc); 2068 #endif 2069 fde->fde_file = fp; 2070 fde->fde_flags = (flags & O_CLOEXEC) != 0 ? UF_EXCLOSE : 0; 2071 if (fcaps != NULL) 2072 filecaps_move(fcaps, &fde->fde_caps); 2073 else 2074 filecaps_fill(&fde->fde_caps); 2075 #ifdef CAPABILITIES 2076 seqc_write_end(&fde->fde_seqc); 2077 #endif 2078 } 2079 2080 int 2081 finstall_refed(struct thread *td, struct file *fp, int *fd, int flags, 2082 struct filecaps *fcaps) 2083 { 2084 struct filedesc *fdp = td->td_proc->p_fd; 2085 int error; 2086 2087 MPASS(fd != NULL); 2088 2089 FILEDESC_XLOCK(fdp); 2090 error = fdalloc(td, 0, fd); 2091 if (__predict_true(error == 0)) { 2092 _finstall(fdp, fp, *fd, flags, fcaps); 2093 } 2094 FILEDESC_XUNLOCK(fdp); 2095 return (error); 2096 } 2097 2098 int 2099 finstall(struct thread *td, struct file *fp, int *fd, int flags, 2100 struct filecaps *fcaps) 2101 { 2102 int error; 2103 2104 MPASS(fd != NULL); 2105 2106 if (!fhold(fp)) 2107 return (EBADF); 2108 error = finstall_refed(td, fp, fd, flags, fcaps); 2109 if (__predict_false(error != 0)) { 2110 fdrop(fp, td); 2111 } 2112 return (error); 2113 } 2114 2115 /* 2116 * Build a new filedesc structure from another. 2117 * 2118 * If fdp is not NULL, return with it shared locked. 2119 */ 2120 struct filedesc * 2121 fdinit(struct filedesc *fdp, bool prepfiles, int *lastfile) 2122 { 2123 struct filedesc0 *newfdp0; 2124 struct filedesc *newfdp; 2125 2126 if (prepfiles) 2127 MPASS(lastfile != NULL); 2128 else 2129 MPASS(lastfile == NULL); 2130 2131 newfdp0 = uma_zalloc(filedesc0_zone, M_WAITOK | M_ZERO); 2132 newfdp = &newfdp0->fd_fd; 2133 2134 /* Create the file descriptor table. */ 2135 FILEDESC_LOCK_INIT(newfdp); 2136 refcount_init(&newfdp->fd_refcnt, 1); 2137 refcount_init(&newfdp->fd_holdcnt, 1); 2138 newfdp->fd_map = newfdp0->fd_dmap; 2139 newfdp->fd_files = (struct fdescenttbl *)&newfdp0->fd_dfiles; 2140 newfdp->fd_files->fdt_nfiles = NDFILE; 2141 2142 if (fdp == NULL) 2143 return (newfdp); 2144 2145 FILEDESC_SLOCK(fdp); 2146 if (!prepfiles) { 2147 FILEDESC_SUNLOCK(fdp); 2148 return (newfdp); 2149 } 2150 2151 for (;;) { 2152 *lastfile = fdlastfile(fdp); 2153 if (*lastfile < newfdp->fd_nfiles) 2154 break; 2155 FILEDESC_SUNLOCK(fdp); 2156 fdgrowtable(newfdp, *lastfile + 1); 2157 FILEDESC_SLOCK(fdp); 2158 } 2159 2160 return (newfdp); 2161 } 2162 2163 /* 2164 * Build a pwddesc structure from another. 2165 * Copy the current, root, and jail root vnode references. 2166 * 2167 * If pdp is not NULL, return with it shared locked. 2168 */ 2169 struct pwddesc * 2170 pdinit(struct pwddesc *pdp, bool keeplock) 2171 { 2172 struct pwddesc *newpdp; 2173 struct pwd *newpwd; 2174 2175 newpdp = malloc(sizeof(*newpdp), M_PWDDESC, M_WAITOK | M_ZERO); 2176 2177 PWDDESC_LOCK_INIT(newpdp); 2178 refcount_init(&newpdp->pd_refcount, 1); 2179 newpdp->pd_cmask = CMASK; 2180 2181 if (pdp == NULL) { 2182 newpwd = pwd_alloc(); 2183 smr_serialized_store(&newpdp->pd_pwd, newpwd, true); 2184 return (newpdp); 2185 } 2186 2187 PWDDESC_XLOCK(pdp); 2188 newpwd = pwd_hold_pwddesc(pdp); 2189 smr_serialized_store(&newpdp->pd_pwd, newpwd, true); 2190 if (!keeplock) 2191 PWDDESC_XUNLOCK(pdp); 2192 return (newpdp); 2193 } 2194 2195 /* 2196 * Hold either filedesc or pwddesc of the passed process. 2197 * 2198 * The process lock is used to synchronize against the target exiting and 2199 * freeing the data. 2200 * 2201 * Clearing can be ilustrated in 3 steps: 2202 * 1. set the pointer to NULL. Either routine can race against it, hence 2203 * atomic_load_ptr. 2204 * 2. observe the process lock as not taken. Until then fdhold/pdhold can 2205 * race to either still see the pointer or find NULL. It is still safe to 2206 * grab a reference as clearing is stalled. 2207 * 3. after the lock is observed as not taken, any fdhold/pdhold calls are 2208 * guaranteed to see NULL, making it safe to finish clearing 2209 */ 2210 static struct filedesc * 2211 fdhold(struct proc *p) 2212 { 2213 struct filedesc *fdp; 2214 2215 PROC_LOCK_ASSERT(p, MA_OWNED); 2216 fdp = atomic_load_ptr(&p->p_fd); 2217 if (fdp != NULL) 2218 refcount_acquire(&fdp->fd_holdcnt); 2219 return (fdp); 2220 } 2221 2222 static struct pwddesc * 2223 pdhold(struct proc *p) 2224 { 2225 struct pwddesc *pdp; 2226 2227 PROC_LOCK_ASSERT(p, MA_OWNED); 2228 pdp = atomic_load_ptr(&p->p_pd); 2229 if (pdp != NULL) 2230 refcount_acquire(&pdp->pd_refcount); 2231 return (pdp); 2232 } 2233 2234 static void 2235 fddrop(struct filedesc *fdp) 2236 { 2237 2238 if (refcount_load(&fdp->fd_holdcnt) > 1) { 2239 if (refcount_release(&fdp->fd_holdcnt) == 0) 2240 return; 2241 } 2242 2243 FILEDESC_LOCK_DESTROY(fdp); 2244 uma_zfree(filedesc0_zone, fdp); 2245 } 2246 2247 static void 2248 pddrop(struct pwddesc *pdp) 2249 { 2250 struct pwd *pwd; 2251 2252 if (refcount_release_if_not_last(&pdp->pd_refcount)) 2253 return; 2254 2255 PWDDESC_XLOCK(pdp); 2256 if (refcount_release(&pdp->pd_refcount) == 0) { 2257 PWDDESC_XUNLOCK(pdp); 2258 return; 2259 } 2260 pwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); 2261 pwd_set(pdp, NULL); 2262 PWDDESC_XUNLOCK(pdp); 2263 pwd_drop(pwd); 2264 2265 PWDDESC_LOCK_DESTROY(pdp); 2266 free(pdp, M_PWDDESC); 2267 } 2268 2269 /* 2270 * Share a filedesc structure. 2271 */ 2272 struct filedesc * 2273 fdshare(struct filedesc *fdp) 2274 { 2275 2276 refcount_acquire(&fdp->fd_refcnt); 2277 return (fdp); 2278 } 2279 2280 /* 2281 * Share a pwddesc structure. 2282 */ 2283 struct pwddesc * 2284 pdshare(struct pwddesc *pdp) 2285 { 2286 refcount_acquire(&pdp->pd_refcount); 2287 return (pdp); 2288 } 2289 2290 /* 2291 * Unshare a filedesc structure, if necessary by making a copy 2292 */ 2293 void 2294 fdunshare(struct thread *td) 2295 { 2296 struct filedesc *tmp; 2297 struct proc *p = td->td_proc; 2298 2299 if (refcount_load(&p->p_fd->fd_refcnt) == 1) 2300 return; 2301 2302 tmp = fdcopy(p->p_fd); 2303 fdescfree(td); 2304 p->p_fd = tmp; 2305 } 2306 2307 /* 2308 * Unshare a pwddesc structure. 2309 */ 2310 void 2311 pdunshare(struct thread *td) 2312 { 2313 struct pwddesc *pdp; 2314 struct proc *p; 2315 2316 p = td->td_proc; 2317 /* Not shared. */ 2318 if (p->p_pd->pd_refcount == 1) 2319 return; 2320 2321 pdp = pdcopy(p->p_pd); 2322 pdescfree(td); 2323 p->p_pd = pdp; 2324 } 2325 2326 void 2327 fdinstall_remapped(struct thread *td, struct filedesc *fdp) 2328 { 2329 2330 fdescfree(td); 2331 td->td_proc->p_fd = fdp; 2332 } 2333 2334 /* 2335 * Copy a filedesc structure. A NULL pointer in returns a NULL reference, 2336 * this is to ease callers, not catch errors. 2337 */ 2338 struct filedesc * 2339 fdcopy(struct filedesc *fdp) 2340 { 2341 struct filedesc *newfdp; 2342 struct filedescent *nfde, *ofde; 2343 int i, lastfile; 2344 2345 MPASS(fdp != NULL); 2346 2347 newfdp = fdinit(fdp, true, &lastfile); 2348 /* copy all passable descriptors (i.e. not kqueue) */ 2349 newfdp->fd_freefile = -1; 2350 for (i = 0; i <= lastfile; ++i) { 2351 ofde = &fdp->fd_ofiles[i]; 2352 if (ofde->fde_file == NULL || 2353 (ofde->fde_file->f_ops->fo_flags & DFLAG_PASSABLE) == 0 || 2354 !fhold(ofde->fde_file)) { 2355 if (newfdp->fd_freefile == -1) 2356 newfdp->fd_freefile = i; 2357 continue; 2358 } 2359 nfde = &newfdp->fd_ofiles[i]; 2360 *nfde = *ofde; 2361 filecaps_copy(&ofde->fde_caps, &nfde->fde_caps, true); 2362 fdused_init(newfdp, i); 2363 } 2364 if (newfdp->fd_freefile == -1) 2365 newfdp->fd_freefile = i; 2366 FILEDESC_SUNLOCK(fdp); 2367 return (newfdp); 2368 } 2369 2370 /* 2371 * Copy a pwddesc structure. 2372 */ 2373 struct pwddesc * 2374 pdcopy(struct pwddesc *pdp) 2375 { 2376 struct pwddesc *newpdp; 2377 2378 MPASS(pdp != NULL); 2379 2380 newpdp = pdinit(pdp, true); 2381 newpdp->pd_cmask = pdp->pd_cmask; 2382 PWDDESC_XUNLOCK(pdp); 2383 return (newpdp); 2384 } 2385 2386 /* 2387 * Copies a filedesc structure, while remapping all file descriptors 2388 * stored inside using a translation table. 2389 * 2390 * File descriptors are copied over to the new file descriptor table, 2391 * regardless of whether the close-on-exec flag is set. 2392 */ 2393 int 2394 fdcopy_remapped(struct filedesc *fdp, const int *fds, size_t nfds, 2395 struct filedesc **ret) 2396 { 2397 struct filedesc *newfdp; 2398 struct filedescent *nfde, *ofde; 2399 int error, i, lastfile; 2400 2401 MPASS(fdp != NULL); 2402 2403 newfdp = fdinit(fdp, true, &lastfile); 2404 if (nfds > lastfile + 1) { 2405 /* New table cannot be larger than the old one. */ 2406 error = E2BIG; 2407 goto bad; 2408 } 2409 /* Copy all passable descriptors (i.e. not kqueue). */ 2410 newfdp->fd_freefile = nfds; 2411 for (i = 0; i < nfds; ++i) { 2412 if (fds[i] < 0 || fds[i] > lastfile) { 2413 /* File descriptor out of bounds. */ 2414 error = EBADF; 2415 goto bad; 2416 } 2417 ofde = &fdp->fd_ofiles[fds[i]]; 2418 if (ofde->fde_file == NULL) { 2419 /* Unused file descriptor. */ 2420 error = EBADF; 2421 goto bad; 2422 } 2423 if ((ofde->fde_file->f_ops->fo_flags & DFLAG_PASSABLE) == 0) { 2424 /* File descriptor cannot be passed. */ 2425 error = EINVAL; 2426 goto bad; 2427 } 2428 if (!fhold(ofde->fde_file)) { 2429 error = EBADF; 2430 goto bad; 2431 } 2432 nfde = &newfdp->fd_ofiles[i]; 2433 *nfde = *ofde; 2434 filecaps_copy(&ofde->fde_caps, &nfde->fde_caps, true); 2435 fdused_init(newfdp, i); 2436 } 2437 FILEDESC_SUNLOCK(fdp); 2438 *ret = newfdp; 2439 return (0); 2440 bad: 2441 FILEDESC_SUNLOCK(fdp); 2442 fdescfree_remapped(newfdp); 2443 return (error); 2444 } 2445 2446 /* 2447 * Clear POSIX style locks. This is only used when fdp looses a reference (i.e. 2448 * one of processes using it exits) and the table used to be shared. 2449 */ 2450 static void 2451 fdclearlocks(struct thread *td) 2452 { 2453 struct filedesc *fdp; 2454 struct filedesc_to_leader *fdtol; 2455 struct flock lf; 2456 struct file *fp; 2457 struct proc *p; 2458 struct vnode *vp; 2459 int i, lastfile; 2460 2461 p = td->td_proc; 2462 fdp = p->p_fd; 2463 fdtol = p->p_fdtol; 2464 MPASS(fdtol != NULL); 2465 2466 FILEDESC_XLOCK(fdp); 2467 KASSERT(fdtol->fdl_refcount > 0, 2468 ("filedesc_to_refcount botch: fdl_refcount=%d", 2469 fdtol->fdl_refcount)); 2470 if (fdtol->fdl_refcount == 1 && 2471 (p->p_leader->p_flag & P_ADVLOCK) != 0) { 2472 lastfile = fdlastfile(fdp); 2473 for (i = 0; i <= lastfile; i++) { 2474 fp = fdp->fd_ofiles[i].fde_file; 2475 if (fp == NULL || fp->f_type != DTYPE_VNODE || 2476 !fhold(fp)) 2477 continue; 2478 FILEDESC_XUNLOCK(fdp); 2479 lf.l_whence = SEEK_SET; 2480 lf.l_start = 0; 2481 lf.l_len = 0; 2482 lf.l_type = F_UNLCK; 2483 vp = fp->f_vnode; 2484 (void) VOP_ADVLOCK(vp, 2485 (caddr_t)p->p_leader, F_UNLCK, 2486 &lf, F_POSIX); 2487 FILEDESC_XLOCK(fdp); 2488 fdrop(fp, td); 2489 } 2490 } 2491 retry: 2492 if (fdtol->fdl_refcount == 1) { 2493 if (fdp->fd_holdleaderscount > 0 && 2494 (p->p_leader->p_flag & P_ADVLOCK) != 0) { 2495 /* 2496 * close() or kern_dup() has cleared a reference 2497 * in a shared file descriptor table. 2498 */ 2499 fdp->fd_holdleaderswakeup = 1; 2500 sx_sleep(&fdp->fd_holdleaderscount, 2501 FILEDESC_LOCK(fdp), PLOCK, "fdlhold", 0); 2502 goto retry; 2503 } 2504 if (fdtol->fdl_holdcount > 0) { 2505 /* 2506 * Ensure that fdtol->fdl_leader remains 2507 * valid in closef(). 2508 */ 2509 fdtol->fdl_wakeup = 1; 2510 sx_sleep(fdtol, FILEDESC_LOCK(fdp), PLOCK, 2511 "fdlhold", 0); 2512 goto retry; 2513 } 2514 } 2515 fdtol->fdl_refcount--; 2516 if (fdtol->fdl_refcount == 0 && 2517 fdtol->fdl_holdcount == 0) { 2518 fdtol->fdl_next->fdl_prev = fdtol->fdl_prev; 2519 fdtol->fdl_prev->fdl_next = fdtol->fdl_next; 2520 } else 2521 fdtol = NULL; 2522 p->p_fdtol = NULL; 2523 FILEDESC_XUNLOCK(fdp); 2524 if (fdtol != NULL) 2525 free(fdtol, M_FILEDESC_TO_LEADER); 2526 } 2527 2528 /* 2529 * Release a filedesc structure. 2530 */ 2531 static void 2532 fdescfree_fds(struct thread *td, struct filedesc *fdp, bool needclose) 2533 { 2534 struct filedesc0 *fdp0; 2535 struct freetable *ft, *tft; 2536 struct filedescent *fde; 2537 struct file *fp; 2538 int i, lastfile; 2539 2540 KASSERT(refcount_load(&fdp->fd_refcnt) == 0, 2541 ("%s: fd table %p carries references", __func__, fdp)); 2542 2543 /* 2544 * Serialize with threads iterating over the table, if any. 2545 */ 2546 if (refcount_load(&fdp->fd_holdcnt) > 1) { 2547 FILEDESC_XLOCK(fdp); 2548 FILEDESC_XUNLOCK(fdp); 2549 } 2550 2551 lastfile = fdlastfile_single(fdp); 2552 for (i = 0; i <= lastfile; i++) { 2553 fde = &fdp->fd_ofiles[i]; 2554 fp = fde->fde_file; 2555 if (fp != NULL) { 2556 fdefree_last(fde); 2557 if (needclose) 2558 (void) closef(fp, td); 2559 else 2560 fdrop(fp, td); 2561 } 2562 } 2563 2564 if (NDSLOTS(fdp->fd_nfiles) > NDSLOTS(NDFILE)) 2565 free(fdp->fd_map, M_FILEDESC); 2566 if (fdp->fd_nfiles > NDFILE) 2567 free(fdp->fd_files, M_FILEDESC); 2568 2569 fdp0 = (struct filedesc0 *)fdp; 2570 SLIST_FOREACH_SAFE(ft, &fdp0->fd_free, ft_next, tft) 2571 free(ft->ft_table, M_FILEDESC); 2572 2573 fddrop(fdp); 2574 } 2575 2576 void 2577 fdescfree(struct thread *td) 2578 { 2579 struct proc *p; 2580 struct filedesc *fdp; 2581 2582 p = td->td_proc; 2583 fdp = p->p_fd; 2584 MPASS(fdp != NULL); 2585 2586 #ifdef RACCT 2587 if (RACCT_ENABLED()) 2588 racct_set_unlocked(p, RACCT_NOFILE, 0); 2589 #endif 2590 2591 if (p->p_fdtol != NULL) 2592 fdclearlocks(td); 2593 2594 /* 2595 * Check fdhold for an explanation. 2596 */ 2597 atomic_store_ptr(&p->p_fd, NULL); 2598 atomic_thread_fence_seq_cst(); 2599 PROC_WAIT_UNLOCKED(p); 2600 2601 if (refcount_release(&fdp->fd_refcnt) == 0) 2602 return; 2603 2604 fdescfree_fds(td, fdp, 1); 2605 } 2606 2607 void 2608 pdescfree(struct thread *td) 2609 { 2610 struct proc *p; 2611 struct pwddesc *pdp; 2612 2613 p = td->td_proc; 2614 pdp = p->p_pd; 2615 MPASS(pdp != NULL); 2616 2617 /* 2618 * Check pdhold for an explanation. 2619 */ 2620 atomic_store_ptr(&p->p_pd, NULL); 2621 atomic_thread_fence_seq_cst(); 2622 PROC_WAIT_UNLOCKED(p); 2623 2624 pddrop(pdp); 2625 } 2626 2627 void 2628 fdescfree_remapped(struct filedesc *fdp) 2629 { 2630 #ifdef INVARIANTS 2631 /* fdescfree_fds() asserts that fd_refcnt == 0. */ 2632 if (!refcount_release(&fdp->fd_refcnt)) 2633 panic("%s: fd table %p has extra references", __func__, fdp); 2634 #endif 2635 fdescfree_fds(curthread, fdp, 0); 2636 } 2637 2638 /* 2639 * For setugid programs, we don't want to people to use that setugidness 2640 * to generate error messages which write to a file which otherwise would 2641 * otherwise be off-limits to the process. We check for filesystems where 2642 * the vnode can change out from under us after execve (like [lin]procfs). 2643 * 2644 * Since fdsetugidsafety calls this only for fd 0, 1 and 2, this check is 2645 * sufficient. We also don't check for setugidness since we know we are. 2646 */ 2647 static bool 2648 is_unsafe(struct file *fp) 2649 { 2650 struct vnode *vp; 2651 2652 if (fp->f_type != DTYPE_VNODE) 2653 return (false); 2654 2655 vp = fp->f_vnode; 2656 return ((vp->v_vflag & VV_PROCDEP) != 0); 2657 } 2658 2659 /* 2660 * Make this setguid thing safe, if at all possible. 2661 */ 2662 void 2663 fdsetugidsafety(struct thread *td) 2664 { 2665 struct filedesc *fdp; 2666 struct file *fp; 2667 int i; 2668 2669 fdp = td->td_proc->p_fd; 2670 KASSERT(refcount_load(&fdp->fd_refcnt) == 1, 2671 ("the fdtable should not be shared")); 2672 MPASS(fdp->fd_nfiles >= 3); 2673 for (i = 0; i <= 2; i++) { 2674 fp = fdp->fd_ofiles[i].fde_file; 2675 if (fp != NULL && is_unsafe(fp)) { 2676 FILEDESC_XLOCK(fdp); 2677 knote_fdclose(td, i); 2678 /* 2679 * NULL-out descriptor prior to close to avoid 2680 * a race while close blocks. 2681 */ 2682 fdfree(fdp, i); 2683 FILEDESC_XUNLOCK(fdp); 2684 (void) closef(fp, td); 2685 } 2686 } 2687 } 2688 2689 /* 2690 * If a specific file object occupies a specific file descriptor, close the 2691 * file descriptor entry and drop a reference on the file object. This is a 2692 * convenience function to handle a subsequent error in a function that calls 2693 * falloc() that handles the race that another thread might have closed the 2694 * file descriptor out from under the thread creating the file object. 2695 */ 2696 void 2697 fdclose(struct thread *td, struct file *fp, int idx) 2698 { 2699 struct filedesc *fdp = td->td_proc->p_fd; 2700 2701 FILEDESC_XLOCK(fdp); 2702 if (fdp->fd_ofiles[idx].fde_file == fp) { 2703 fdfree(fdp, idx); 2704 FILEDESC_XUNLOCK(fdp); 2705 fdrop(fp, td); 2706 } else 2707 FILEDESC_XUNLOCK(fdp); 2708 } 2709 2710 /* 2711 * Close any files on exec? 2712 */ 2713 void 2714 fdcloseexec(struct thread *td) 2715 { 2716 struct filedesc *fdp; 2717 struct filedescent *fde; 2718 struct file *fp; 2719 int i, lastfile; 2720 2721 fdp = td->td_proc->p_fd; 2722 KASSERT(refcount_load(&fdp->fd_refcnt) == 1, 2723 ("the fdtable should not be shared")); 2724 lastfile = fdlastfile_single(fdp); 2725 for (i = 0; i <= lastfile; i++) { 2726 fde = &fdp->fd_ofiles[i]; 2727 fp = fde->fde_file; 2728 if (fp != NULL && (fp->f_type == DTYPE_MQUEUE || 2729 (fde->fde_flags & UF_EXCLOSE))) { 2730 FILEDESC_XLOCK(fdp); 2731 fdfree(fdp, i); 2732 (void) closefp(fdp, i, fp, td, false, false); 2733 FILEDESC_UNLOCK_ASSERT(fdp); 2734 } 2735 } 2736 } 2737 2738 /* 2739 * It is unsafe for set[ug]id processes to be started with file 2740 * descriptors 0..2 closed, as these descriptors are given implicit 2741 * significance in the Standard C library. fdcheckstd() will create a 2742 * descriptor referencing /dev/null for each of stdin, stdout, and 2743 * stderr that is not already open. 2744 */ 2745 int 2746 fdcheckstd(struct thread *td) 2747 { 2748 struct filedesc *fdp; 2749 register_t save; 2750 int i, error, devnull; 2751 2752 fdp = td->td_proc->p_fd; 2753 KASSERT(refcount_load(&fdp->fd_refcnt) == 1, 2754 ("the fdtable should not be shared")); 2755 MPASS(fdp->fd_nfiles >= 3); 2756 devnull = -1; 2757 for (i = 0; i <= 2; i++) { 2758 if (fdp->fd_ofiles[i].fde_file != NULL) 2759 continue; 2760 2761 save = td->td_retval[0]; 2762 if (devnull != -1) { 2763 error = kern_dup(td, FDDUP_FIXED, 0, devnull, i); 2764 } else { 2765 error = kern_openat(td, AT_FDCWD, "/dev/null", 2766 UIO_SYSSPACE, O_RDWR, 0); 2767 if (error == 0) { 2768 devnull = td->td_retval[0]; 2769 KASSERT(devnull == i, ("we didn't get our fd")); 2770 } 2771 } 2772 td->td_retval[0] = save; 2773 if (error != 0) 2774 return (error); 2775 } 2776 return (0); 2777 } 2778 2779 /* 2780 * Internal form of close. Decrement reference count on file structure. 2781 * Note: td may be NULL when closing a file that was being passed in a 2782 * message. 2783 */ 2784 int 2785 closef(struct file *fp, struct thread *td) 2786 { 2787 struct vnode *vp; 2788 struct flock lf; 2789 struct filedesc_to_leader *fdtol; 2790 struct filedesc *fdp; 2791 2792 MPASS(td != NULL); 2793 2794 /* 2795 * POSIX record locking dictates that any close releases ALL 2796 * locks owned by this process. This is handled by setting 2797 * a flag in the unlock to free ONLY locks obeying POSIX 2798 * semantics, and not to free BSD-style file locks. 2799 * If the descriptor was in a message, POSIX-style locks 2800 * aren't passed with the descriptor, and the thread pointer 2801 * will be NULL. Callers should be careful only to pass a 2802 * NULL thread pointer when there really is no owning 2803 * context that might have locks, or the locks will be 2804 * leaked. 2805 */ 2806 if (fp->f_type == DTYPE_VNODE) { 2807 vp = fp->f_vnode; 2808 if ((td->td_proc->p_leader->p_flag & P_ADVLOCK) != 0) { 2809 lf.l_whence = SEEK_SET; 2810 lf.l_start = 0; 2811 lf.l_len = 0; 2812 lf.l_type = F_UNLCK; 2813 (void) VOP_ADVLOCK(vp, (caddr_t)td->td_proc->p_leader, 2814 F_UNLCK, &lf, F_POSIX); 2815 } 2816 fdtol = td->td_proc->p_fdtol; 2817 if (fdtol != NULL) { 2818 /* 2819 * Handle special case where file descriptor table is 2820 * shared between multiple process leaders. 2821 */ 2822 fdp = td->td_proc->p_fd; 2823 FILEDESC_XLOCK(fdp); 2824 for (fdtol = fdtol->fdl_next; 2825 fdtol != td->td_proc->p_fdtol; 2826 fdtol = fdtol->fdl_next) { 2827 if ((fdtol->fdl_leader->p_flag & 2828 P_ADVLOCK) == 0) 2829 continue; 2830 fdtol->fdl_holdcount++; 2831 FILEDESC_XUNLOCK(fdp); 2832 lf.l_whence = SEEK_SET; 2833 lf.l_start = 0; 2834 lf.l_len = 0; 2835 lf.l_type = F_UNLCK; 2836 vp = fp->f_vnode; 2837 (void) VOP_ADVLOCK(vp, 2838 (caddr_t)fdtol->fdl_leader, F_UNLCK, &lf, 2839 F_POSIX); 2840 FILEDESC_XLOCK(fdp); 2841 fdtol->fdl_holdcount--; 2842 if (fdtol->fdl_holdcount == 0 && 2843 fdtol->fdl_wakeup != 0) { 2844 fdtol->fdl_wakeup = 0; 2845 wakeup(fdtol); 2846 } 2847 } 2848 FILEDESC_XUNLOCK(fdp); 2849 } 2850 } 2851 return (fdrop_close(fp, td)); 2852 } 2853 2854 /* 2855 * Hack for file descriptor passing code. 2856 */ 2857 void 2858 closef_nothread(struct file *fp) 2859 { 2860 2861 fdrop(fp, NULL); 2862 } 2863 2864 /* 2865 * Initialize the file pointer with the specified properties. 2866 * 2867 * The ops are set with release semantics to be certain that the flags, type, 2868 * and data are visible when ops is. This is to prevent ops methods from being 2869 * called with bad data. 2870 */ 2871 void 2872 finit(struct file *fp, u_int flag, short type, void *data, struct fileops *ops) 2873 { 2874 fp->f_data = data; 2875 fp->f_flag = flag; 2876 fp->f_type = type; 2877 atomic_store_rel_ptr((volatile uintptr_t *)&fp->f_ops, (uintptr_t)ops); 2878 } 2879 2880 void 2881 finit_vnode(struct file *fp, u_int flag, void *data, struct fileops *ops) 2882 { 2883 fp->f_seqcount[UIO_READ] = 1; 2884 fp->f_seqcount[UIO_WRITE] = 1; 2885 finit(fp, (flag & FMASK) | (fp->f_flag & FHASLOCK), DTYPE_VNODE, 2886 data, ops); 2887 } 2888 2889 int 2890 fget_cap_locked(struct filedesc *fdp, int fd, cap_rights_t *needrightsp, 2891 struct file **fpp, struct filecaps *havecapsp) 2892 { 2893 struct filedescent *fde; 2894 int error; 2895 2896 FILEDESC_LOCK_ASSERT(fdp); 2897 2898 fde = fdeget_locked(fdp, fd); 2899 if (fde == NULL) { 2900 error = EBADF; 2901 goto out; 2902 } 2903 2904 #ifdef CAPABILITIES 2905 error = cap_check(cap_rights_fde_inline(fde), needrightsp); 2906 if (error != 0) 2907 goto out; 2908 #endif 2909 2910 if (havecapsp != NULL) 2911 filecaps_copy(&fde->fde_caps, havecapsp, true); 2912 2913 *fpp = fde->fde_file; 2914 2915 error = 0; 2916 out: 2917 return (error); 2918 } 2919 2920 int 2921 fget_cap(struct thread *td, int fd, cap_rights_t *needrightsp, 2922 struct file **fpp, struct filecaps *havecapsp) 2923 { 2924 struct filedesc *fdp = td->td_proc->p_fd; 2925 int error; 2926 #ifndef CAPABILITIES 2927 error = fget_unlocked(fdp, fd, needrightsp, fpp); 2928 if (havecapsp != NULL && error == 0) 2929 filecaps_fill(havecapsp); 2930 #else 2931 struct file *fp; 2932 seqc_t seq; 2933 2934 *fpp = NULL; 2935 for (;;) { 2936 error = fget_unlocked_seq(fdp, fd, needrightsp, &fp, &seq); 2937 if (error != 0) 2938 return (error); 2939 2940 if (havecapsp != NULL) { 2941 if (!filecaps_copy(&fdp->fd_ofiles[fd].fde_caps, 2942 havecapsp, false)) { 2943 fdrop(fp, td); 2944 goto get_locked; 2945 } 2946 } 2947 2948 if (!fd_modified(fdp, fd, seq)) 2949 break; 2950 fdrop(fp, td); 2951 } 2952 2953 *fpp = fp; 2954 return (0); 2955 2956 get_locked: 2957 FILEDESC_SLOCK(fdp); 2958 error = fget_cap_locked(fdp, fd, needrightsp, fpp, havecapsp); 2959 if (error == 0 && !fhold(*fpp)) 2960 error = EBADF; 2961 FILEDESC_SUNLOCK(fdp); 2962 #endif 2963 return (error); 2964 } 2965 2966 #ifdef CAPABILITIES 2967 int 2968 fgetvp_lookup_smr(int fd, struct nameidata *ndp, struct vnode **vpp, bool *fsearch) 2969 { 2970 const struct filedescent *fde; 2971 const struct fdescenttbl *fdt; 2972 struct filedesc *fdp; 2973 struct file *fp; 2974 struct vnode *vp; 2975 const cap_rights_t *haverights; 2976 cap_rights_t rights; 2977 seqc_t seq; 2978 2979 VFS_SMR_ASSERT_ENTERED(); 2980 2981 rights = *ndp->ni_rightsneeded; 2982 cap_rights_set_one(&rights, CAP_LOOKUP); 2983 2984 fdp = curproc->p_fd; 2985 fdt = fdp->fd_files; 2986 if (__predict_false((u_int)fd >= fdt->fdt_nfiles)) 2987 return (EBADF); 2988 seq = seqc_read_notmodify(fd_seqc(fdt, fd)); 2989 fde = &fdt->fdt_ofiles[fd]; 2990 haverights = cap_rights_fde_inline(fde); 2991 fp = fde->fde_file; 2992 if (__predict_false(fp == NULL)) 2993 return (EAGAIN); 2994 if (__predict_false(cap_check_inline_transient(haverights, &rights))) 2995 return (EAGAIN); 2996 *fsearch = ((fp->f_flag & FSEARCH) != 0); 2997 vp = fp->f_vnode; 2998 if (__predict_false(vp == NULL || vp->v_type != VDIR)) { 2999 return (EAGAIN); 3000 } 3001 if (!filecaps_copy(&fde->fde_caps, &ndp->ni_filecaps, false)) { 3002 return (EAGAIN); 3003 } 3004 /* 3005 * Use an acquire barrier to force re-reading of fdt so it is 3006 * refreshed for verification. 3007 */ 3008 atomic_thread_fence_acq(); 3009 fdt = fdp->fd_files; 3010 if (__predict_false(!seqc_consistent_nomb(fd_seqc(fdt, fd), seq))) 3011 return (EAGAIN); 3012 /* 3013 * If file descriptor doesn't have all rights, 3014 * all lookups relative to it must also be 3015 * strictly relative. 3016 * 3017 * Not yet supported by fast path. 3018 */ 3019 CAP_ALL(&rights); 3020 if (!cap_rights_contains(&ndp->ni_filecaps.fc_rights, &rights) || 3021 ndp->ni_filecaps.fc_fcntls != CAP_FCNTL_ALL || 3022 ndp->ni_filecaps.fc_nioctls != -1) { 3023 #ifdef notyet 3024 ndp->ni_lcf |= NI_LCF_STRICTRELATIVE; 3025 #else 3026 return (EAGAIN); 3027 #endif 3028 } 3029 *vpp = vp; 3030 return (0); 3031 } 3032 #else 3033 int 3034 fgetvp_lookup_smr(int fd, struct nameidata *ndp, struct vnode **vpp, bool *fsearch) 3035 { 3036 const struct fdescenttbl *fdt; 3037 struct filedesc *fdp; 3038 struct file *fp; 3039 struct vnode *vp; 3040 3041 VFS_SMR_ASSERT_ENTERED(); 3042 3043 fdp = curproc->p_fd; 3044 fdt = fdp->fd_files; 3045 if (__predict_false((u_int)fd >= fdt->fdt_nfiles)) 3046 return (EBADF); 3047 fp = fdt->fdt_ofiles[fd].fde_file; 3048 if (__predict_false(fp == NULL)) 3049 return (EAGAIN); 3050 *fsearch = ((fp->f_flag & FSEARCH) != 0); 3051 vp = fp->f_vnode; 3052 if (__predict_false(vp == NULL || vp->v_type != VDIR)) { 3053 return (EAGAIN); 3054 } 3055 /* 3056 * Use an acquire barrier to force re-reading of fdt so it is 3057 * refreshed for verification. 3058 */ 3059 atomic_thread_fence_acq(); 3060 fdt = fdp->fd_files; 3061 if (__predict_false(fp != fdt->fdt_ofiles[fd].fde_file)) 3062 return (EAGAIN); 3063 filecaps_fill(&ndp->ni_filecaps); 3064 *vpp = vp; 3065 return (0); 3066 } 3067 #endif 3068 3069 int 3070 fget_unlocked_seq(struct filedesc *fdp, int fd, cap_rights_t *needrightsp, 3071 struct file **fpp, seqc_t *seqp) 3072 { 3073 #ifdef CAPABILITIES 3074 const struct filedescent *fde; 3075 #endif 3076 const struct fdescenttbl *fdt; 3077 struct file *fp; 3078 #ifdef CAPABILITIES 3079 seqc_t seq; 3080 cap_rights_t haverights; 3081 int error; 3082 #endif 3083 3084 fdt = fdp->fd_files; 3085 if (__predict_false((u_int)fd >= fdt->fdt_nfiles)) 3086 return (EBADF); 3087 /* 3088 * Fetch the descriptor locklessly. We avoid fdrop() races by 3089 * never raising a refcount above 0. To accomplish this we have 3090 * to use a cmpset loop rather than an atomic_add. The descriptor 3091 * must be re-verified once we acquire a reference to be certain 3092 * that the identity is still correct and we did not lose a race 3093 * due to preemption. 3094 */ 3095 for (;;) { 3096 #ifdef CAPABILITIES 3097 seq = seqc_read_notmodify(fd_seqc(fdt, fd)); 3098 fde = &fdt->fdt_ofiles[fd]; 3099 haverights = *cap_rights_fde_inline(fde); 3100 fp = fde->fde_file; 3101 if (!seqc_consistent(fd_seqc(fdt, fd), seq)) 3102 continue; 3103 #else 3104 fp = fdt->fdt_ofiles[fd].fde_file; 3105 #endif 3106 if (fp == NULL) 3107 return (EBADF); 3108 #ifdef CAPABILITIES 3109 error = cap_check_inline(&haverights, needrightsp); 3110 if (error != 0) 3111 return (error); 3112 #endif 3113 if (__predict_false(!refcount_acquire_if_not_zero(&fp->f_count))) { 3114 /* 3115 * Force a reload. Other thread could reallocate the 3116 * table before this fd was closed, so it is possible 3117 * that there is a stale fp pointer in cached version. 3118 */ 3119 fdt = atomic_load_ptr(&fdp->fd_files); 3120 continue; 3121 } 3122 /* 3123 * Use an acquire barrier to force re-reading of fdt so it is 3124 * refreshed for verification. 3125 */ 3126 atomic_thread_fence_acq(); 3127 fdt = fdp->fd_files; 3128 #ifdef CAPABILITIES 3129 if (seqc_consistent_nomb(fd_seqc(fdt, fd), seq)) 3130 #else 3131 if (fp == fdt->fdt_ofiles[fd].fde_file) 3132 #endif 3133 break; 3134 fdrop(fp, curthread); 3135 } 3136 *fpp = fp; 3137 if (seqp != NULL) { 3138 #ifdef CAPABILITIES 3139 *seqp = seq; 3140 #endif 3141 } 3142 return (0); 3143 } 3144 3145 /* 3146 * See the comments in fget_unlocked_seq for an explanation of how this works. 3147 * 3148 * This is a simplified variant which bails out to the aforementioned routine 3149 * if anything goes wrong. In practice this only happens when userspace is 3150 * racing with itself. 3151 */ 3152 int 3153 fget_unlocked(struct filedesc *fdp, int fd, cap_rights_t *needrightsp, 3154 struct file **fpp) 3155 { 3156 #ifdef CAPABILITIES 3157 const struct filedescent *fde; 3158 #endif 3159 const struct fdescenttbl *fdt; 3160 struct file *fp; 3161 #ifdef CAPABILITIES 3162 seqc_t seq; 3163 const cap_rights_t *haverights; 3164 #endif 3165 3166 fdt = fdp->fd_files; 3167 if (__predict_false((u_int)fd >= fdt->fdt_nfiles)) 3168 return (EBADF); 3169 #ifdef CAPABILITIES 3170 seq = seqc_read_notmodify(fd_seqc(fdt, fd)); 3171 fde = &fdt->fdt_ofiles[fd]; 3172 haverights = cap_rights_fde_inline(fde); 3173 fp = fde->fde_file; 3174 #else 3175 fp = fdt->fdt_ofiles[fd].fde_file; 3176 #endif 3177 if (__predict_false(fp == NULL)) 3178 goto out_fallback; 3179 #ifdef CAPABILITIES 3180 if (__predict_false(cap_check_inline_transient(haverights, needrightsp))) 3181 goto out_fallback; 3182 #endif 3183 if (__predict_false(!refcount_acquire_if_not_zero(&fp->f_count))) 3184 goto out_fallback; 3185 3186 /* 3187 * Use an acquire barrier to force re-reading of fdt so it is 3188 * refreshed for verification. 3189 */ 3190 atomic_thread_fence_acq(); 3191 fdt = fdp->fd_files; 3192 #ifdef CAPABILITIES 3193 if (__predict_false(!seqc_consistent_nomb(fd_seqc(fdt, fd), seq))) 3194 #else 3195 if (__predict_false(fp != fdt->fdt_ofiles[fd].fde_file)) 3196 #endif 3197 goto out_fdrop; 3198 *fpp = fp; 3199 return (0); 3200 out_fdrop: 3201 fdrop(fp, curthread); 3202 out_fallback: 3203 return (fget_unlocked_seq(fdp, fd, needrightsp, fpp, NULL)); 3204 } 3205 3206 /* 3207 * Translate fd -> file when the caller guarantees the file descriptor table 3208 * can't be changed by others. 3209 * 3210 * Note this does not mean the file object itself is only visible to the caller, 3211 * merely that it wont disappear without having to be referenced. 3212 * 3213 * Must be paired with fput_only_user. 3214 */ 3215 #ifdef CAPABILITIES 3216 int 3217 fget_only_user(struct filedesc *fdp, int fd, cap_rights_t *needrightsp, 3218 struct file **fpp) 3219 { 3220 const struct filedescent *fde; 3221 const struct fdescenttbl *fdt; 3222 const cap_rights_t *haverights; 3223 struct file *fp; 3224 int error; 3225 3226 MPASS(FILEDESC_IS_ONLY_USER(fdp)); 3227 3228 if (__predict_false(fd >= fdp->fd_nfiles)) 3229 return (EBADF); 3230 3231 fdt = fdp->fd_files; 3232 fde = &fdt->fdt_ofiles[fd]; 3233 fp = fde->fde_file; 3234 if (__predict_false(fp == NULL)) 3235 return (EBADF); 3236 MPASS(refcount_load(&fp->f_count) > 0); 3237 haverights = cap_rights_fde_inline(fde); 3238 error = cap_check_inline(haverights, needrightsp); 3239 if (__predict_false(error != 0)) 3240 return (error); 3241 *fpp = fp; 3242 return (0); 3243 } 3244 #else 3245 int 3246 fget_only_user(struct filedesc *fdp, int fd, cap_rights_t *needrightsp, 3247 struct file **fpp) 3248 { 3249 struct file *fp; 3250 3251 MPASS(FILEDESC_IS_ONLY_USER(fdp)); 3252 3253 if (__predict_false(fd >= fdp->fd_nfiles)) 3254 return (EBADF); 3255 3256 fp = fdp->fd_ofiles[fd].fde_file; 3257 if (__predict_false(fp == NULL)) 3258 return (EBADF); 3259 3260 MPASS(refcount_load(&fp->f_count) > 0); 3261 *fpp = fp; 3262 return (0); 3263 } 3264 #endif 3265 3266 /* 3267 * Extract the file pointer associated with the specified descriptor for the 3268 * current user process. 3269 * 3270 * If the descriptor doesn't exist or doesn't match 'flags', EBADF is 3271 * returned. 3272 * 3273 * File's rights will be checked against the capability rights mask. 3274 * 3275 * If an error occurred the non-zero error is returned and *fpp is set to 3276 * NULL. Otherwise *fpp is held and set and zero is returned. Caller is 3277 * responsible for fdrop(). 3278 */ 3279 static __inline int 3280 _fget(struct thread *td, int fd, struct file **fpp, int flags, 3281 cap_rights_t *needrightsp) 3282 { 3283 struct filedesc *fdp; 3284 struct file *fp; 3285 int error; 3286 3287 *fpp = NULL; 3288 fdp = td->td_proc->p_fd; 3289 error = fget_unlocked(fdp, fd, needrightsp, &fp); 3290 if (__predict_false(error != 0)) 3291 return (error); 3292 if (__predict_false(fp->f_ops == &badfileops)) { 3293 fdrop(fp, td); 3294 return (EBADF); 3295 } 3296 3297 /* 3298 * FREAD and FWRITE failure return EBADF as per POSIX. 3299 */ 3300 error = 0; 3301 switch (flags) { 3302 case FREAD: 3303 case FWRITE: 3304 if ((fp->f_flag & flags) == 0) 3305 error = EBADF; 3306 break; 3307 case FEXEC: 3308 if ((fp->f_flag & (FREAD | FEXEC)) == 0 || 3309 ((fp->f_flag & FWRITE) != 0)) 3310 error = EBADF; 3311 break; 3312 case 0: 3313 break; 3314 default: 3315 KASSERT(0, ("wrong flags")); 3316 } 3317 3318 if (error != 0) { 3319 fdrop(fp, td); 3320 return (error); 3321 } 3322 3323 *fpp = fp; 3324 return (0); 3325 } 3326 3327 int 3328 fget(struct thread *td, int fd, cap_rights_t *rightsp, struct file **fpp) 3329 { 3330 3331 return (_fget(td, fd, fpp, 0, rightsp)); 3332 } 3333 3334 int 3335 fget_mmap(struct thread *td, int fd, cap_rights_t *rightsp, vm_prot_t *maxprotp, 3336 struct file **fpp) 3337 { 3338 int error; 3339 #ifndef CAPABILITIES 3340 error = _fget(td, fd, fpp, 0, rightsp); 3341 if (maxprotp != NULL) 3342 *maxprotp = VM_PROT_ALL; 3343 return (error); 3344 #else 3345 cap_rights_t fdrights; 3346 struct filedesc *fdp; 3347 struct file *fp; 3348 seqc_t seq; 3349 3350 *fpp = NULL; 3351 fdp = td->td_proc->p_fd; 3352 MPASS(cap_rights_is_set(rightsp, CAP_MMAP)); 3353 for (;;) { 3354 error = fget_unlocked_seq(fdp, fd, rightsp, &fp, &seq); 3355 if (__predict_false(error != 0)) 3356 return (error); 3357 if (__predict_false(fp->f_ops == &badfileops)) { 3358 fdrop(fp, td); 3359 return (EBADF); 3360 } 3361 if (maxprotp != NULL) 3362 fdrights = *cap_rights(fdp, fd); 3363 if (!fd_modified(fdp, fd, seq)) 3364 break; 3365 fdrop(fp, td); 3366 } 3367 3368 /* 3369 * If requested, convert capability rights to access flags. 3370 */ 3371 if (maxprotp != NULL) 3372 *maxprotp = cap_rights_to_vmprot(&fdrights); 3373 *fpp = fp; 3374 return (0); 3375 #endif 3376 } 3377 3378 int 3379 fget_read(struct thread *td, int fd, cap_rights_t *rightsp, struct file **fpp) 3380 { 3381 3382 return (_fget(td, fd, fpp, FREAD, rightsp)); 3383 } 3384 3385 int 3386 fget_write(struct thread *td, int fd, cap_rights_t *rightsp, struct file **fpp) 3387 { 3388 3389 return (_fget(td, fd, fpp, FWRITE, rightsp)); 3390 } 3391 3392 int 3393 fget_fcntl(struct thread *td, int fd, cap_rights_t *rightsp, int needfcntl, 3394 struct file **fpp) 3395 { 3396 struct filedesc *fdp = td->td_proc->p_fd; 3397 #ifndef CAPABILITIES 3398 return (fget_unlocked(fdp, fd, rightsp, fpp)); 3399 #else 3400 struct file *fp; 3401 int error; 3402 seqc_t seq; 3403 3404 *fpp = NULL; 3405 MPASS(cap_rights_is_set(rightsp, CAP_FCNTL)); 3406 for (;;) { 3407 error = fget_unlocked_seq(fdp, fd, rightsp, &fp, &seq); 3408 if (error != 0) 3409 return (error); 3410 error = cap_fcntl_check(fdp, fd, needfcntl); 3411 if (!fd_modified(fdp, fd, seq)) 3412 break; 3413 fdrop(fp, td); 3414 } 3415 if (error != 0) { 3416 fdrop(fp, td); 3417 return (error); 3418 } 3419 *fpp = fp; 3420 return (0); 3421 #endif 3422 } 3423 3424 /* 3425 * Like fget() but loads the underlying vnode, or returns an error if the 3426 * descriptor does not represent a vnode. Note that pipes use vnodes but 3427 * never have VM objects. The returned vnode will be vref()'d. 3428 * 3429 * XXX: what about the unused flags ? 3430 */ 3431 static __inline int 3432 _fgetvp(struct thread *td, int fd, int flags, cap_rights_t *needrightsp, 3433 struct vnode **vpp) 3434 { 3435 struct file *fp; 3436 int error; 3437 3438 *vpp = NULL; 3439 error = _fget(td, fd, &fp, flags, needrightsp); 3440 if (error != 0) 3441 return (error); 3442 if (fp->f_vnode == NULL) { 3443 error = EINVAL; 3444 } else { 3445 *vpp = fp->f_vnode; 3446 vref(*vpp); 3447 } 3448 fdrop(fp, td); 3449 3450 return (error); 3451 } 3452 3453 int 3454 fgetvp(struct thread *td, int fd, cap_rights_t *rightsp, struct vnode **vpp) 3455 { 3456 3457 return (_fgetvp(td, fd, 0, rightsp, vpp)); 3458 } 3459 3460 int 3461 fgetvp_rights(struct thread *td, int fd, cap_rights_t *needrightsp, 3462 struct filecaps *havecaps, struct vnode **vpp) 3463 { 3464 struct filecaps caps; 3465 struct file *fp; 3466 int error; 3467 3468 error = fget_cap(td, fd, needrightsp, &fp, &caps); 3469 if (error != 0) 3470 return (error); 3471 if (fp->f_ops == &badfileops) { 3472 error = EBADF; 3473 goto out; 3474 } 3475 if (fp->f_vnode == NULL) { 3476 error = EINVAL; 3477 goto out; 3478 } 3479 3480 *havecaps = caps; 3481 *vpp = fp->f_vnode; 3482 vref(*vpp); 3483 fdrop(fp, td); 3484 3485 return (0); 3486 out: 3487 filecaps_free(&caps); 3488 fdrop(fp, td); 3489 return (error); 3490 } 3491 3492 int 3493 fgetvp_read(struct thread *td, int fd, cap_rights_t *rightsp, struct vnode **vpp) 3494 { 3495 3496 return (_fgetvp(td, fd, FREAD, rightsp, vpp)); 3497 } 3498 3499 int 3500 fgetvp_exec(struct thread *td, int fd, cap_rights_t *rightsp, struct vnode **vpp) 3501 { 3502 3503 return (_fgetvp(td, fd, FEXEC, rightsp, vpp)); 3504 } 3505 3506 #ifdef notyet 3507 int 3508 fgetvp_write(struct thread *td, int fd, cap_rights_t *rightsp, 3509 struct vnode **vpp) 3510 { 3511 3512 return (_fgetvp(td, fd, FWRITE, rightsp, vpp)); 3513 } 3514 #endif 3515 3516 /* 3517 * Handle the last reference to a file being closed. 3518 * 3519 * Without the noinline attribute clang keeps inlining the func thorough this 3520 * file when fdrop is used. 3521 */ 3522 int __noinline 3523 _fdrop(struct file *fp, struct thread *td) 3524 { 3525 int error; 3526 #ifdef INVARIANTS 3527 int count; 3528 3529 count = refcount_load(&fp->f_count); 3530 if (count != 0) 3531 panic("fdrop: fp %p count %d", fp, count); 3532 #endif 3533 error = fo_close(fp, td); 3534 atomic_subtract_int(&openfiles, 1); 3535 crfree(fp->f_cred); 3536 free(fp->f_advice, M_FADVISE); 3537 uma_zfree(file_zone, fp); 3538 3539 return (error); 3540 } 3541 3542 /* 3543 * Apply an advisory lock on a file descriptor. 3544 * 3545 * Just attempt to get a record lock of the requested type on the entire file 3546 * (l_whence = SEEK_SET, l_start = 0, l_len = 0). 3547 */ 3548 #ifndef _SYS_SYSPROTO_H_ 3549 struct flock_args { 3550 int fd; 3551 int how; 3552 }; 3553 #endif 3554 /* ARGSUSED */ 3555 int 3556 sys_flock(struct thread *td, struct flock_args *uap) 3557 { 3558 struct file *fp; 3559 struct vnode *vp; 3560 struct flock lf; 3561 int error; 3562 3563 error = fget(td, uap->fd, &cap_flock_rights, &fp); 3564 if (error != 0) 3565 return (error); 3566 if (fp->f_type != DTYPE_VNODE || fp->f_ops == &path_fileops) { 3567 fdrop(fp, td); 3568 return (EOPNOTSUPP); 3569 } 3570 3571 vp = fp->f_vnode; 3572 lf.l_whence = SEEK_SET; 3573 lf.l_start = 0; 3574 lf.l_len = 0; 3575 if (uap->how & LOCK_UN) { 3576 lf.l_type = F_UNLCK; 3577 atomic_clear_int(&fp->f_flag, FHASLOCK); 3578 error = VOP_ADVLOCK(vp, (caddr_t)fp, F_UNLCK, &lf, F_FLOCK); 3579 goto done2; 3580 } 3581 if (uap->how & LOCK_EX) 3582 lf.l_type = F_WRLCK; 3583 else if (uap->how & LOCK_SH) 3584 lf.l_type = F_RDLCK; 3585 else { 3586 error = EBADF; 3587 goto done2; 3588 } 3589 atomic_set_int(&fp->f_flag, FHASLOCK); 3590 error = VOP_ADVLOCK(vp, (caddr_t)fp, F_SETLK, &lf, 3591 (uap->how & LOCK_NB) ? F_FLOCK : F_FLOCK | F_WAIT); 3592 done2: 3593 fdrop(fp, td); 3594 return (error); 3595 } 3596 /* 3597 * Duplicate the specified descriptor to a free descriptor. 3598 */ 3599 int 3600 dupfdopen(struct thread *td, struct filedesc *fdp, int dfd, int mode, 3601 int openerror, int *indxp) 3602 { 3603 struct filedescent *newfde, *oldfde; 3604 struct file *fp; 3605 u_long *ioctls; 3606 int error, indx; 3607 3608 KASSERT(openerror == ENODEV || openerror == ENXIO, 3609 ("unexpected error %d in %s", openerror, __func__)); 3610 3611 /* 3612 * If the to-be-dup'd fd number is greater than the allowed number 3613 * of file descriptors, or the fd to be dup'd has already been 3614 * closed, then reject. 3615 */ 3616 FILEDESC_XLOCK(fdp); 3617 if ((fp = fget_locked(fdp, dfd)) == NULL) { 3618 FILEDESC_XUNLOCK(fdp); 3619 return (EBADF); 3620 } 3621 3622 error = fdalloc(td, 0, &indx); 3623 if (error != 0) { 3624 FILEDESC_XUNLOCK(fdp); 3625 return (error); 3626 } 3627 3628 /* 3629 * There are two cases of interest here. 3630 * 3631 * For ENODEV simply dup (dfd) to file descriptor (indx) and return. 3632 * 3633 * For ENXIO steal away the file structure from (dfd) and store it in 3634 * (indx). (dfd) is effectively closed by this operation. 3635 */ 3636 switch (openerror) { 3637 case ENODEV: 3638 /* 3639 * Check that the mode the file is being opened for is a 3640 * subset of the mode of the existing descriptor. 3641 */ 3642 if (((mode & (FREAD|FWRITE)) | fp->f_flag) != fp->f_flag) { 3643 fdunused(fdp, indx); 3644 FILEDESC_XUNLOCK(fdp); 3645 return (EACCES); 3646 } 3647 if (!fhold(fp)) { 3648 fdunused(fdp, indx); 3649 FILEDESC_XUNLOCK(fdp); 3650 return (EBADF); 3651 } 3652 newfde = &fdp->fd_ofiles[indx]; 3653 oldfde = &fdp->fd_ofiles[dfd]; 3654 ioctls = filecaps_copy_prep(&oldfde->fde_caps); 3655 #ifdef CAPABILITIES 3656 seqc_write_begin(&newfde->fde_seqc); 3657 #endif 3658 memcpy(newfde, oldfde, fde_change_size); 3659 filecaps_copy_finish(&oldfde->fde_caps, &newfde->fde_caps, 3660 ioctls); 3661 #ifdef CAPABILITIES 3662 seqc_write_end(&newfde->fde_seqc); 3663 #endif 3664 break; 3665 case ENXIO: 3666 /* 3667 * Steal away the file pointer from dfd and stuff it into indx. 3668 */ 3669 newfde = &fdp->fd_ofiles[indx]; 3670 oldfde = &fdp->fd_ofiles[dfd]; 3671 #ifdef CAPABILITIES 3672 seqc_write_begin(&newfde->fde_seqc); 3673 #endif 3674 memcpy(newfde, oldfde, fde_change_size); 3675 oldfde->fde_file = NULL; 3676 fdunused(fdp, dfd); 3677 #ifdef CAPABILITIES 3678 seqc_write_end(&newfde->fde_seqc); 3679 #endif 3680 break; 3681 } 3682 FILEDESC_XUNLOCK(fdp); 3683 *indxp = indx; 3684 return (0); 3685 } 3686 3687 /* 3688 * This sysctl determines if we will allow a process to chroot(2) if it 3689 * has a directory open: 3690 * 0: disallowed for all processes. 3691 * 1: allowed for processes that were not already chroot(2)'ed. 3692 * 2: allowed for all processes. 3693 */ 3694 3695 static int chroot_allow_open_directories = 1; 3696 3697 SYSCTL_INT(_kern, OID_AUTO, chroot_allow_open_directories, CTLFLAG_RW, 3698 &chroot_allow_open_directories, 0, 3699 "Allow a process to chroot(2) if it has a directory open"); 3700 3701 /* 3702 * Helper function for raised chroot(2) security function: Refuse if 3703 * any filedescriptors are open directories. 3704 */ 3705 static int 3706 chroot_refuse_vdir_fds(struct filedesc *fdp) 3707 { 3708 struct vnode *vp; 3709 struct file *fp; 3710 int fd, lastfile; 3711 3712 FILEDESC_LOCK_ASSERT(fdp); 3713 3714 lastfile = fdlastfile(fdp); 3715 for (fd = 0; fd <= lastfile; fd++) { 3716 fp = fget_locked(fdp, fd); 3717 if (fp == NULL) 3718 continue; 3719 if (fp->f_type == DTYPE_VNODE) { 3720 vp = fp->f_vnode; 3721 if (vp->v_type == VDIR) 3722 return (EPERM); 3723 } 3724 } 3725 return (0); 3726 } 3727 3728 static void 3729 pwd_fill(struct pwd *oldpwd, struct pwd *newpwd) 3730 { 3731 3732 if (newpwd->pwd_cdir == NULL && oldpwd->pwd_cdir != NULL) { 3733 vrefact(oldpwd->pwd_cdir); 3734 newpwd->pwd_cdir = oldpwd->pwd_cdir; 3735 } 3736 3737 if (newpwd->pwd_rdir == NULL && oldpwd->pwd_rdir != NULL) { 3738 vrefact(oldpwd->pwd_rdir); 3739 newpwd->pwd_rdir = oldpwd->pwd_rdir; 3740 } 3741 3742 if (newpwd->pwd_jdir == NULL && oldpwd->pwd_jdir != NULL) { 3743 vrefact(oldpwd->pwd_jdir); 3744 newpwd->pwd_jdir = oldpwd->pwd_jdir; 3745 } 3746 } 3747 3748 struct pwd * 3749 pwd_hold_pwddesc(struct pwddesc *pdp) 3750 { 3751 struct pwd *pwd; 3752 3753 PWDDESC_ASSERT_XLOCKED(pdp); 3754 pwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); 3755 if (pwd != NULL) 3756 refcount_acquire(&pwd->pwd_refcount); 3757 return (pwd); 3758 } 3759 3760 bool 3761 pwd_hold_smr(struct pwd *pwd) 3762 { 3763 3764 MPASS(pwd != NULL); 3765 if (__predict_true(refcount_acquire_if_not_zero(&pwd->pwd_refcount))) { 3766 return (true); 3767 } 3768 return (false); 3769 } 3770 3771 struct pwd * 3772 pwd_hold(struct thread *td) 3773 { 3774 struct pwddesc *pdp; 3775 struct pwd *pwd; 3776 3777 pdp = td->td_proc->p_pd; 3778 3779 vfs_smr_enter(); 3780 pwd = vfs_smr_entered_load(&pdp->pd_pwd); 3781 if (pwd_hold_smr(pwd)) { 3782 vfs_smr_exit(); 3783 return (pwd); 3784 } 3785 vfs_smr_exit(); 3786 PWDDESC_XLOCK(pdp); 3787 pwd = pwd_hold_pwddesc(pdp); 3788 MPASS(pwd != NULL); 3789 PWDDESC_XUNLOCK(pdp); 3790 return (pwd); 3791 } 3792 3793 static struct pwd * 3794 pwd_alloc(void) 3795 { 3796 struct pwd *pwd; 3797 3798 pwd = uma_zalloc_smr(pwd_zone, M_WAITOK); 3799 bzero(pwd, sizeof(*pwd)); 3800 refcount_init(&pwd->pwd_refcount, 1); 3801 return (pwd); 3802 } 3803 3804 void 3805 pwd_drop(struct pwd *pwd) 3806 { 3807 3808 if (!refcount_release(&pwd->pwd_refcount)) 3809 return; 3810 3811 if (pwd->pwd_cdir != NULL) 3812 vrele(pwd->pwd_cdir); 3813 if (pwd->pwd_rdir != NULL) 3814 vrele(pwd->pwd_rdir); 3815 if (pwd->pwd_jdir != NULL) 3816 vrele(pwd->pwd_jdir); 3817 uma_zfree_smr(pwd_zone, pwd); 3818 } 3819 3820 /* 3821 * The caller is responsible for invoking priv_check() and 3822 * mac_vnode_check_chroot() to authorize this operation. 3823 */ 3824 int 3825 pwd_chroot(struct thread *td, struct vnode *vp) 3826 { 3827 struct pwddesc *pdp; 3828 struct filedesc *fdp; 3829 struct pwd *newpwd, *oldpwd; 3830 int error; 3831 3832 fdp = td->td_proc->p_fd; 3833 pdp = td->td_proc->p_pd; 3834 newpwd = pwd_alloc(); 3835 FILEDESC_SLOCK(fdp); 3836 PWDDESC_XLOCK(pdp); 3837 oldpwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); 3838 if (chroot_allow_open_directories == 0 || 3839 (chroot_allow_open_directories == 1 && 3840 oldpwd->pwd_rdir != rootvnode)) { 3841 error = chroot_refuse_vdir_fds(fdp); 3842 FILEDESC_SUNLOCK(fdp); 3843 if (error != 0) { 3844 PWDDESC_XUNLOCK(pdp); 3845 pwd_drop(newpwd); 3846 return (error); 3847 } 3848 } else { 3849 FILEDESC_SUNLOCK(fdp); 3850 } 3851 3852 vrefact(vp); 3853 newpwd->pwd_rdir = vp; 3854 if (oldpwd->pwd_jdir == NULL) { 3855 vrefact(vp); 3856 newpwd->pwd_jdir = vp; 3857 } 3858 pwd_fill(oldpwd, newpwd); 3859 pwd_set(pdp, newpwd); 3860 PWDDESC_XUNLOCK(pdp); 3861 pwd_drop(oldpwd); 3862 return (0); 3863 } 3864 3865 void 3866 pwd_chdir(struct thread *td, struct vnode *vp) 3867 { 3868 struct pwddesc *pdp; 3869 struct pwd *newpwd, *oldpwd; 3870 3871 VNPASS(vp->v_usecount > 0, vp); 3872 3873 newpwd = pwd_alloc(); 3874 pdp = td->td_proc->p_pd; 3875 PWDDESC_XLOCK(pdp); 3876 oldpwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); 3877 newpwd->pwd_cdir = vp; 3878 pwd_fill(oldpwd, newpwd); 3879 pwd_set(pdp, newpwd); 3880 PWDDESC_XUNLOCK(pdp); 3881 pwd_drop(oldpwd); 3882 } 3883 3884 /* 3885 * jail_attach(2) changes both root and working directories. 3886 */ 3887 int 3888 pwd_chroot_chdir(struct thread *td, struct vnode *vp) 3889 { 3890 struct pwddesc *pdp; 3891 struct filedesc *fdp; 3892 struct pwd *newpwd, *oldpwd; 3893 int error; 3894 3895 fdp = td->td_proc->p_fd; 3896 pdp = td->td_proc->p_pd; 3897 newpwd = pwd_alloc(); 3898 FILEDESC_SLOCK(fdp); 3899 PWDDESC_XLOCK(pdp); 3900 oldpwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); 3901 error = chroot_refuse_vdir_fds(fdp); 3902 FILEDESC_SUNLOCK(fdp); 3903 if (error != 0) { 3904 PWDDESC_XUNLOCK(pdp); 3905 pwd_drop(newpwd); 3906 return (error); 3907 } 3908 3909 vrefact(vp); 3910 newpwd->pwd_rdir = vp; 3911 vrefact(vp); 3912 newpwd->pwd_cdir = vp; 3913 if (oldpwd->pwd_jdir == NULL) { 3914 vrefact(vp); 3915 newpwd->pwd_jdir = vp; 3916 } 3917 pwd_fill(oldpwd, newpwd); 3918 pwd_set(pdp, newpwd); 3919 PWDDESC_XUNLOCK(pdp); 3920 pwd_drop(oldpwd); 3921 return (0); 3922 } 3923 3924 void 3925 pwd_ensure_dirs(void) 3926 { 3927 struct pwddesc *pdp; 3928 struct pwd *oldpwd, *newpwd; 3929 3930 pdp = curproc->p_pd; 3931 PWDDESC_XLOCK(pdp); 3932 oldpwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); 3933 if (oldpwd->pwd_cdir != NULL && oldpwd->pwd_rdir != NULL) { 3934 PWDDESC_XUNLOCK(pdp); 3935 return; 3936 } 3937 PWDDESC_XUNLOCK(pdp); 3938 3939 newpwd = pwd_alloc(); 3940 PWDDESC_XLOCK(pdp); 3941 oldpwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); 3942 pwd_fill(oldpwd, newpwd); 3943 if (newpwd->pwd_cdir == NULL) { 3944 vrefact(rootvnode); 3945 newpwd->pwd_cdir = rootvnode; 3946 } 3947 if (newpwd->pwd_rdir == NULL) { 3948 vrefact(rootvnode); 3949 newpwd->pwd_rdir = rootvnode; 3950 } 3951 pwd_set(pdp, newpwd); 3952 PWDDESC_XUNLOCK(pdp); 3953 pwd_drop(oldpwd); 3954 } 3955 3956 void 3957 pwd_set_rootvnode(void) 3958 { 3959 struct pwddesc *pdp; 3960 struct pwd *oldpwd, *newpwd; 3961 3962 pdp = curproc->p_pd; 3963 3964 newpwd = pwd_alloc(); 3965 PWDDESC_XLOCK(pdp); 3966 oldpwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); 3967 vrefact(rootvnode); 3968 newpwd->pwd_cdir = rootvnode; 3969 vrefact(rootvnode); 3970 newpwd->pwd_rdir = rootvnode; 3971 pwd_fill(oldpwd, newpwd); 3972 pwd_set(pdp, newpwd); 3973 PWDDESC_XUNLOCK(pdp); 3974 pwd_drop(oldpwd); 3975 } 3976 3977 /* 3978 * Scan all active processes and prisons to see if any of them have a current 3979 * or root directory of `olddp'. If so, replace them with the new mount point. 3980 */ 3981 void 3982 mountcheckdirs(struct vnode *olddp, struct vnode *newdp) 3983 { 3984 struct pwddesc *pdp; 3985 struct pwd *newpwd, *oldpwd; 3986 struct prison *pr; 3987 struct proc *p; 3988 int nrele; 3989 3990 if (vrefcnt(olddp) == 1) 3991 return; 3992 nrele = 0; 3993 newpwd = pwd_alloc(); 3994 sx_slock(&allproc_lock); 3995 FOREACH_PROC_IN_SYSTEM(p) { 3996 PROC_LOCK(p); 3997 pdp = pdhold(p); 3998 PROC_UNLOCK(p); 3999 if (pdp == NULL) 4000 continue; 4001 PWDDESC_XLOCK(pdp); 4002 oldpwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); 4003 if (oldpwd == NULL || 4004 (oldpwd->pwd_cdir != olddp && 4005 oldpwd->pwd_rdir != olddp && 4006 oldpwd->pwd_jdir != olddp)) { 4007 PWDDESC_XUNLOCK(pdp); 4008 pddrop(pdp); 4009 continue; 4010 } 4011 if (oldpwd->pwd_cdir == olddp) { 4012 vrefact(newdp); 4013 newpwd->pwd_cdir = newdp; 4014 } 4015 if (oldpwd->pwd_rdir == olddp) { 4016 vrefact(newdp); 4017 newpwd->pwd_rdir = newdp; 4018 } 4019 if (oldpwd->pwd_jdir == olddp) { 4020 vrefact(newdp); 4021 newpwd->pwd_jdir = newdp; 4022 } 4023 pwd_fill(oldpwd, newpwd); 4024 pwd_set(pdp, newpwd); 4025 PWDDESC_XUNLOCK(pdp); 4026 pwd_drop(oldpwd); 4027 pddrop(pdp); 4028 newpwd = pwd_alloc(); 4029 } 4030 sx_sunlock(&allproc_lock); 4031 pwd_drop(newpwd); 4032 if (rootvnode == olddp) { 4033 vrefact(newdp); 4034 rootvnode = newdp; 4035 nrele++; 4036 } 4037 mtx_lock(&prison0.pr_mtx); 4038 if (prison0.pr_root == olddp) { 4039 vrefact(newdp); 4040 prison0.pr_root = newdp; 4041 nrele++; 4042 } 4043 mtx_unlock(&prison0.pr_mtx); 4044 sx_slock(&allprison_lock); 4045 TAILQ_FOREACH(pr, &allprison, pr_list) { 4046 mtx_lock(&pr->pr_mtx); 4047 if (pr->pr_root == olddp) { 4048 vrefact(newdp); 4049 pr->pr_root = newdp; 4050 nrele++; 4051 } 4052 mtx_unlock(&pr->pr_mtx); 4053 } 4054 sx_sunlock(&allprison_lock); 4055 while (nrele--) 4056 vrele(olddp); 4057 } 4058 4059 struct filedesc_to_leader * 4060 filedesc_to_leader_alloc(struct filedesc_to_leader *old, struct filedesc *fdp, struct proc *leader) 4061 { 4062 struct filedesc_to_leader *fdtol; 4063 4064 fdtol = malloc(sizeof(struct filedesc_to_leader), 4065 M_FILEDESC_TO_LEADER, M_WAITOK); 4066 fdtol->fdl_refcount = 1; 4067 fdtol->fdl_holdcount = 0; 4068 fdtol->fdl_wakeup = 0; 4069 fdtol->fdl_leader = leader; 4070 if (old != NULL) { 4071 FILEDESC_XLOCK(fdp); 4072 fdtol->fdl_next = old->fdl_next; 4073 fdtol->fdl_prev = old; 4074 old->fdl_next = fdtol; 4075 fdtol->fdl_next->fdl_prev = fdtol; 4076 FILEDESC_XUNLOCK(fdp); 4077 } else { 4078 fdtol->fdl_next = fdtol; 4079 fdtol->fdl_prev = fdtol; 4080 } 4081 return (fdtol); 4082 } 4083 4084 static int 4085 sysctl_kern_proc_nfds(SYSCTL_HANDLER_ARGS) 4086 { 4087 NDSLOTTYPE *map; 4088 struct filedesc *fdp; 4089 u_int namelen; 4090 int count, off, minoff; 4091 4092 namelen = arg2; 4093 if (namelen != 1) 4094 return (EINVAL); 4095 4096 if (*(int *)arg1 != 0) 4097 return (EINVAL); 4098 4099 fdp = curproc->p_fd; 4100 count = 0; 4101 FILEDESC_SLOCK(fdp); 4102 map = fdp->fd_map; 4103 off = NDSLOT(fdp->fd_nfiles - 1); 4104 for (minoff = NDSLOT(0); off >= minoff; --off) 4105 count += bitcountl(map[off]); 4106 FILEDESC_SUNLOCK(fdp); 4107 4108 return (SYSCTL_OUT(req, &count, sizeof(count))); 4109 } 4110 4111 static SYSCTL_NODE(_kern_proc, KERN_PROC_NFDS, nfds, 4112 CTLFLAG_RD|CTLFLAG_CAPRD|CTLFLAG_MPSAFE, sysctl_kern_proc_nfds, 4113 "Number of open file descriptors"); 4114 4115 /* 4116 * Get file structures globally. 4117 */ 4118 static int 4119 sysctl_kern_file(SYSCTL_HANDLER_ARGS) 4120 { 4121 struct xfile xf; 4122 struct filedesc *fdp; 4123 struct file *fp; 4124 struct proc *p; 4125 int error, n, lastfile; 4126 4127 error = sysctl_wire_old_buffer(req, 0); 4128 if (error != 0) 4129 return (error); 4130 if (req->oldptr == NULL) { 4131 n = 0; 4132 sx_slock(&allproc_lock); 4133 FOREACH_PROC_IN_SYSTEM(p) { 4134 PROC_LOCK(p); 4135 if (p->p_state == PRS_NEW) { 4136 PROC_UNLOCK(p); 4137 continue; 4138 } 4139 fdp = fdhold(p); 4140 PROC_UNLOCK(p); 4141 if (fdp == NULL) 4142 continue; 4143 /* overestimates sparse tables. */ 4144 n += fdp->fd_nfiles; 4145 fddrop(fdp); 4146 } 4147 sx_sunlock(&allproc_lock); 4148 return (SYSCTL_OUT(req, 0, n * sizeof(xf))); 4149 } 4150 error = 0; 4151 bzero(&xf, sizeof(xf)); 4152 xf.xf_size = sizeof(xf); 4153 sx_slock(&allproc_lock); 4154 FOREACH_PROC_IN_SYSTEM(p) { 4155 PROC_LOCK(p); 4156 if (p->p_state == PRS_NEW) { 4157 PROC_UNLOCK(p); 4158 continue; 4159 } 4160 if (p_cansee(req->td, p) != 0) { 4161 PROC_UNLOCK(p); 4162 continue; 4163 } 4164 xf.xf_pid = p->p_pid; 4165 xf.xf_uid = p->p_ucred->cr_uid; 4166 fdp = fdhold(p); 4167 PROC_UNLOCK(p); 4168 if (fdp == NULL) 4169 continue; 4170 FILEDESC_SLOCK(fdp); 4171 lastfile = fdlastfile(fdp); 4172 for (n = 0; refcount_load(&fdp->fd_refcnt) > 0 && n <= lastfile; 4173 n++) { 4174 if ((fp = fdp->fd_ofiles[n].fde_file) == NULL) 4175 continue; 4176 xf.xf_fd = n; 4177 xf.xf_file = (uintptr_t)fp; 4178 xf.xf_data = (uintptr_t)fp->f_data; 4179 xf.xf_vnode = (uintptr_t)fp->f_vnode; 4180 xf.xf_type = (uintptr_t)fp->f_type; 4181 xf.xf_count = refcount_load(&fp->f_count); 4182 xf.xf_msgcount = 0; 4183 xf.xf_offset = foffset_get(fp); 4184 xf.xf_flag = fp->f_flag; 4185 error = SYSCTL_OUT(req, &xf, sizeof(xf)); 4186 if (error) 4187 break; 4188 } 4189 FILEDESC_SUNLOCK(fdp); 4190 fddrop(fdp); 4191 if (error) 4192 break; 4193 } 4194 sx_sunlock(&allproc_lock); 4195 return (error); 4196 } 4197 4198 SYSCTL_PROC(_kern, KERN_FILE, file, CTLTYPE_OPAQUE|CTLFLAG_RD|CTLFLAG_MPSAFE, 4199 0, 0, sysctl_kern_file, "S,xfile", "Entire file table"); 4200 4201 #ifdef KINFO_FILE_SIZE 4202 CTASSERT(sizeof(struct kinfo_file) == KINFO_FILE_SIZE); 4203 #endif 4204 4205 static int 4206 xlate_fflags(int fflags) 4207 { 4208 static const struct { 4209 int fflag; 4210 int kf_fflag; 4211 } fflags_table[] = { 4212 { FAPPEND, KF_FLAG_APPEND }, 4213 { FASYNC, KF_FLAG_ASYNC }, 4214 { FFSYNC, KF_FLAG_FSYNC }, 4215 { FHASLOCK, KF_FLAG_HASLOCK }, 4216 { FNONBLOCK, KF_FLAG_NONBLOCK }, 4217 { FREAD, KF_FLAG_READ }, 4218 { FWRITE, KF_FLAG_WRITE }, 4219 { O_CREAT, KF_FLAG_CREAT }, 4220 { O_DIRECT, KF_FLAG_DIRECT }, 4221 { O_EXCL, KF_FLAG_EXCL }, 4222 { O_EXEC, KF_FLAG_EXEC }, 4223 { O_EXLOCK, KF_FLAG_EXLOCK }, 4224 { O_NOFOLLOW, KF_FLAG_NOFOLLOW }, 4225 { O_SHLOCK, KF_FLAG_SHLOCK }, 4226 { O_TRUNC, KF_FLAG_TRUNC } 4227 }; 4228 unsigned int i; 4229 int kflags; 4230 4231 kflags = 0; 4232 for (i = 0; i < nitems(fflags_table); i++) 4233 if (fflags & fflags_table[i].fflag) 4234 kflags |= fflags_table[i].kf_fflag; 4235 return (kflags); 4236 } 4237 4238 /* Trim unused data from kf_path by truncating the structure size. */ 4239 void 4240 pack_kinfo(struct kinfo_file *kif) 4241 { 4242 4243 kif->kf_structsize = offsetof(struct kinfo_file, kf_path) + 4244 strlen(kif->kf_path) + 1; 4245 kif->kf_structsize = roundup(kif->kf_structsize, sizeof(uint64_t)); 4246 } 4247 4248 static void 4249 export_file_to_kinfo(struct file *fp, int fd, cap_rights_t *rightsp, 4250 struct kinfo_file *kif, struct filedesc *fdp, int flags) 4251 { 4252 int error; 4253 4254 bzero(kif, sizeof(*kif)); 4255 4256 /* Set a default type to allow for empty fill_kinfo() methods. */ 4257 kif->kf_type = KF_TYPE_UNKNOWN; 4258 kif->kf_flags = xlate_fflags(fp->f_flag); 4259 if (rightsp != NULL) 4260 kif->kf_cap_rights = *rightsp; 4261 else 4262 cap_rights_init_zero(&kif->kf_cap_rights); 4263 kif->kf_fd = fd; 4264 kif->kf_ref_count = refcount_load(&fp->f_count); 4265 kif->kf_offset = foffset_get(fp); 4266 4267 /* 4268 * This may drop the filedesc lock, so the 'fp' cannot be 4269 * accessed after this call. 4270 */ 4271 error = fo_fill_kinfo(fp, kif, fdp); 4272 if (error == 0) 4273 kif->kf_status |= KF_ATTR_VALID; 4274 if ((flags & KERN_FILEDESC_PACK_KINFO) != 0) 4275 pack_kinfo(kif); 4276 else 4277 kif->kf_structsize = roundup2(sizeof(*kif), sizeof(uint64_t)); 4278 } 4279 4280 static void 4281 export_vnode_to_kinfo(struct vnode *vp, int fd, int fflags, 4282 struct kinfo_file *kif, int flags) 4283 { 4284 int error; 4285 4286 bzero(kif, sizeof(*kif)); 4287 4288 kif->kf_type = KF_TYPE_VNODE; 4289 error = vn_fill_kinfo_vnode(vp, kif); 4290 if (error == 0) 4291 kif->kf_status |= KF_ATTR_VALID; 4292 kif->kf_flags = xlate_fflags(fflags); 4293 cap_rights_init_zero(&kif->kf_cap_rights); 4294 kif->kf_fd = fd; 4295 kif->kf_ref_count = -1; 4296 kif->kf_offset = -1; 4297 if ((flags & KERN_FILEDESC_PACK_KINFO) != 0) 4298 pack_kinfo(kif); 4299 else 4300 kif->kf_structsize = roundup2(sizeof(*kif), sizeof(uint64_t)); 4301 vrele(vp); 4302 } 4303 4304 struct export_fd_buf { 4305 struct filedesc *fdp; 4306 struct pwddesc *pdp; 4307 struct sbuf *sb; 4308 ssize_t remainder; 4309 struct kinfo_file kif; 4310 int flags; 4311 }; 4312 4313 static int 4314 export_kinfo_to_sb(struct export_fd_buf *efbuf) 4315 { 4316 struct kinfo_file *kif; 4317 4318 kif = &efbuf->kif; 4319 if (efbuf->remainder != -1) { 4320 if (efbuf->remainder < kif->kf_structsize) { 4321 /* Terminate export. */ 4322 efbuf->remainder = 0; 4323 return (0); 4324 } 4325 efbuf->remainder -= kif->kf_structsize; 4326 } 4327 return (sbuf_bcat(efbuf->sb, kif, kif->kf_structsize) == 0 ? 0 : ENOMEM); 4328 } 4329 4330 static int 4331 export_file_to_sb(struct file *fp, int fd, cap_rights_t *rightsp, 4332 struct export_fd_buf *efbuf) 4333 { 4334 int error; 4335 4336 if (efbuf->remainder == 0) 4337 return (0); 4338 export_file_to_kinfo(fp, fd, rightsp, &efbuf->kif, efbuf->fdp, 4339 efbuf->flags); 4340 FILEDESC_SUNLOCK(efbuf->fdp); 4341 error = export_kinfo_to_sb(efbuf); 4342 FILEDESC_SLOCK(efbuf->fdp); 4343 return (error); 4344 } 4345 4346 static int 4347 export_vnode_to_sb(struct vnode *vp, int fd, int fflags, 4348 struct export_fd_buf *efbuf) 4349 { 4350 int error; 4351 4352 if (efbuf->remainder == 0) 4353 return (0); 4354 if (efbuf->pdp != NULL) 4355 PWDDESC_XUNLOCK(efbuf->pdp); 4356 export_vnode_to_kinfo(vp, fd, fflags, &efbuf->kif, efbuf->flags); 4357 error = export_kinfo_to_sb(efbuf); 4358 if (efbuf->pdp != NULL) 4359 PWDDESC_XLOCK(efbuf->pdp); 4360 return (error); 4361 } 4362 4363 /* 4364 * Store a process file descriptor information to sbuf. 4365 * 4366 * Takes a locked proc as argument, and returns with the proc unlocked. 4367 */ 4368 int 4369 kern_proc_filedesc_out(struct proc *p, struct sbuf *sb, ssize_t maxlen, 4370 int flags) 4371 { 4372 struct file *fp; 4373 struct filedesc *fdp; 4374 struct pwddesc *pdp; 4375 struct export_fd_buf *efbuf; 4376 struct vnode *cttyvp, *textvp, *tracevp; 4377 struct pwd *pwd; 4378 int error, i, lastfile; 4379 cap_rights_t rights; 4380 4381 PROC_LOCK_ASSERT(p, MA_OWNED); 4382 4383 /* ktrace vnode */ 4384 tracevp = ktr_get_tracevp(p, true); 4385 /* text vnode */ 4386 textvp = p->p_textvp; 4387 if (textvp != NULL) 4388 vrefact(textvp); 4389 /* Controlling tty. */ 4390 cttyvp = NULL; 4391 if (p->p_pgrp != NULL && p->p_pgrp->pg_session != NULL) { 4392 cttyvp = p->p_pgrp->pg_session->s_ttyvp; 4393 if (cttyvp != NULL) 4394 vrefact(cttyvp); 4395 } 4396 fdp = fdhold(p); 4397 pdp = pdhold(p); 4398 PROC_UNLOCK(p); 4399 efbuf = malloc(sizeof(*efbuf), M_TEMP, M_WAITOK); 4400 efbuf->fdp = NULL; 4401 efbuf->pdp = NULL; 4402 efbuf->sb = sb; 4403 efbuf->remainder = maxlen; 4404 efbuf->flags = flags; 4405 if (tracevp != NULL) 4406 export_vnode_to_sb(tracevp, KF_FD_TYPE_TRACE, FREAD | FWRITE, 4407 efbuf); 4408 if (textvp != NULL) 4409 export_vnode_to_sb(textvp, KF_FD_TYPE_TEXT, FREAD, efbuf); 4410 if (cttyvp != NULL) 4411 export_vnode_to_sb(cttyvp, KF_FD_TYPE_CTTY, FREAD | FWRITE, 4412 efbuf); 4413 error = 0; 4414 if (pdp == NULL || fdp == NULL) 4415 goto fail; 4416 efbuf->fdp = fdp; 4417 efbuf->pdp = pdp; 4418 PWDDESC_XLOCK(pdp); 4419 pwd = pwd_hold_pwddesc(pdp); 4420 if (pwd != NULL) { 4421 /* working directory */ 4422 if (pwd->pwd_cdir != NULL) { 4423 vrefact(pwd->pwd_cdir); 4424 export_vnode_to_sb(pwd->pwd_cdir, KF_FD_TYPE_CWD, 4425 FREAD, efbuf); 4426 } 4427 /* root directory */ 4428 if (pwd->pwd_rdir != NULL) { 4429 vrefact(pwd->pwd_rdir); 4430 export_vnode_to_sb(pwd->pwd_rdir, KF_FD_TYPE_ROOT, 4431 FREAD, efbuf); 4432 } 4433 /* jail directory */ 4434 if (pwd->pwd_jdir != NULL) { 4435 vrefact(pwd->pwd_jdir); 4436 export_vnode_to_sb(pwd->pwd_jdir, KF_FD_TYPE_JAIL, 4437 FREAD, efbuf); 4438 } 4439 } 4440 PWDDESC_XUNLOCK(pdp); 4441 if (pwd != NULL) 4442 pwd_drop(pwd); 4443 FILEDESC_SLOCK(fdp); 4444 lastfile = fdlastfile(fdp); 4445 for (i = 0; refcount_load(&fdp->fd_refcnt) > 0 && i <= lastfile; i++) { 4446 if ((fp = fdp->fd_ofiles[i].fde_file) == NULL) 4447 continue; 4448 #ifdef CAPABILITIES 4449 rights = *cap_rights(fdp, i); 4450 #else /* !CAPABILITIES */ 4451 rights = cap_no_rights; 4452 #endif 4453 /* 4454 * Create sysctl entry. It is OK to drop the filedesc 4455 * lock inside of export_file_to_sb() as we will 4456 * re-validate and re-evaluate its properties when the 4457 * loop continues. 4458 */ 4459 error = export_file_to_sb(fp, i, &rights, efbuf); 4460 if (error != 0 || efbuf->remainder == 0) 4461 break; 4462 } 4463 FILEDESC_SUNLOCK(fdp); 4464 fail: 4465 if (fdp != NULL) 4466 fddrop(fdp); 4467 if (pdp != NULL) 4468 pddrop(pdp); 4469 free(efbuf, M_TEMP); 4470 return (error); 4471 } 4472 4473 #define FILEDESC_SBUF_SIZE (sizeof(struct kinfo_file) * 5) 4474 4475 /* 4476 * Get per-process file descriptors for use by procstat(1), et al. 4477 */ 4478 static int 4479 sysctl_kern_proc_filedesc(SYSCTL_HANDLER_ARGS) 4480 { 4481 struct sbuf sb; 4482 struct proc *p; 4483 ssize_t maxlen; 4484 u_int namelen; 4485 int error, error2, *name; 4486 4487 namelen = arg2; 4488 if (namelen != 1) 4489 return (EINVAL); 4490 4491 name = (int *)arg1; 4492 4493 sbuf_new_for_sysctl(&sb, NULL, FILEDESC_SBUF_SIZE, req); 4494 sbuf_clear_flags(&sb, SBUF_INCLUDENUL); 4495 error = pget((pid_t)name[0], PGET_CANDEBUG | PGET_NOTWEXIT, &p); 4496 if (error != 0) { 4497 sbuf_delete(&sb); 4498 return (error); 4499 } 4500 maxlen = req->oldptr != NULL ? req->oldlen : -1; 4501 error = kern_proc_filedesc_out(p, &sb, maxlen, 4502 KERN_FILEDESC_PACK_KINFO); 4503 error2 = sbuf_finish(&sb); 4504 sbuf_delete(&sb); 4505 return (error != 0 ? error : error2); 4506 } 4507 4508 #ifdef COMPAT_FREEBSD7 4509 #ifdef KINFO_OFILE_SIZE 4510 CTASSERT(sizeof(struct kinfo_ofile) == KINFO_OFILE_SIZE); 4511 #endif 4512 4513 static void 4514 kinfo_to_okinfo(struct kinfo_file *kif, struct kinfo_ofile *okif) 4515 { 4516 4517 okif->kf_structsize = sizeof(*okif); 4518 okif->kf_type = kif->kf_type; 4519 okif->kf_fd = kif->kf_fd; 4520 okif->kf_ref_count = kif->kf_ref_count; 4521 okif->kf_flags = kif->kf_flags & (KF_FLAG_READ | KF_FLAG_WRITE | 4522 KF_FLAG_APPEND | KF_FLAG_ASYNC | KF_FLAG_FSYNC | KF_FLAG_NONBLOCK | 4523 KF_FLAG_DIRECT | KF_FLAG_HASLOCK); 4524 okif->kf_offset = kif->kf_offset; 4525 if (kif->kf_type == KF_TYPE_VNODE) 4526 okif->kf_vnode_type = kif->kf_un.kf_file.kf_file_type; 4527 else 4528 okif->kf_vnode_type = KF_VTYPE_VNON; 4529 strlcpy(okif->kf_path, kif->kf_path, sizeof(okif->kf_path)); 4530 if (kif->kf_type == KF_TYPE_SOCKET) { 4531 okif->kf_sock_domain = kif->kf_un.kf_sock.kf_sock_domain0; 4532 okif->kf_sock_type = kif->kf_un.kf_sock.kf_sock_type0; 4533 okif->kf_sock_protocol = kif->kf_un.kf_sock.kf_sock_protocol0; 4534 okif->kf_sa_local = kif->kf_un.kf_sock.kf_sa_local; 4535 okif->kf_sa_peer = kif->kf_un.kf_sock.kf_sa_peer; 4536 } else { 4537 okif->kf_sa_local.ss_family = AF_UNSPEC; 4538 okif->kf_sa_peer.ss_family = AF_UNSPEC; 4539 } 4540 } 4541 4542 static int 4543 export_vnode_for_osysctl(struct vnode *vp, int type, struct kinfo_file *kif, 4544 struct kinfo_ofile *okif, struct pwddesc *pdp, struct sysctl_req *req) 4545 { 4546 int error; 4547 4548 vrefact(vp); 4549 PWDDESC_XUNLOCK(pdp); 4550 export_vnode_to_kinfo(vp, type, 0, kif, KERN_FILEDESC_PACK_KINFO); 4551 kinfo_to_okinfo(kif, okif); 4552 error = SYSCTL_OUT(req, okif, sizeof(*okif)); 4553 PWDDESC_XLOCK(pdp); 4554 return (error); 4555 } 4556 4557 /* 4558 * Get per-process file descriptors for use by procstat(1), et al. 4559 */ 4560 static int 4561 sysctl_kern_proc_ofiledesc(SYSCTL_HANDLER_ARGS) 4562 { 4563 struct kinfo_ofile *okif; 4564 struct kinfo_file *kif; 4565 struct filedesc *fdp; 4566 struct pwddesc *pdp; 4567 struct pwd *pwd; 4568 u_int namelen; 4569 int error, i, lastfile, *name; 4570 struct file *fp; 4571 struct proc *p; 4572 4573 namelen = arg2; 4574 if (namelen != 1) 4575 return (EINVAL); 4576 4577 name = (int *)arg1; 4578 error = pget((pid_t)name[0], PGET_CANDEBUG | PGET_NOTWEXIT, &p); 4579 if (error != 0) 4580 return (error); 4581 fdp = fdhold(p); 4582 if (fdp != NULL) 4583 pdp = pdhold(p); 4584 PROC_UNLOCK(p); 4585 if (fdp == NULL || pdp == NULL) { 4586 if (fdp != NULL) 4587 fddrop(fdp); 4588 return (ENOENT); 4589 } 4590 kif = malloc(sizeof(*kif), M_TEMP, M_WAITOK); 4591 okif = malloc(sizeof(*okif), M_TEMP, M_WAITOK); 4592 PWDDESC_XLOCK(pdp); 4593 pwd = pwd_hold_pwddesc(pdp); 4594 if (pwd != NULL) { 4595 if (pwd->pwd_cdir != NULL) 4596 export_vnode_for_osysctl(pwd->pwd_cdir, KF_FD_TYPE_CWD, kif, 4597 okif, pdp, req); 4598 if (pwd->pwd_rdir != NULL) 4599 export_vnode_for_osysctl(pwd->pwd_rdir, KF_FD_TYPE_ROOT, kif, 4600 okif, pdp, req); 4601 if (pwd->pwd_jdir != NULL) 4602 export_vnode_for_osysctl(pwd->pwd_jdir, KF_FD_TYPE_JAIL, kif, 4603 okif, pdp, req); 4604 } 4605 PWDDESC_XUNLOCK(pdp); 4606 if (pwd != NULL) 4607 pwd_drop(pwd); 4608 FILEDESC_SLOCK(fdp); 4609 lastfile = fdlastfile(fdp); 4610 for (i = 0; refcount_load(&fdp->fd_refcnt) > 0 && i <= lastfile; i++) { 4611 if ((fp = fdp->fd_ofiles[i].fde_file) == NULL) 4612 continue; 4613 export_file_to_kinfo(fp, i, NULL, kif, fdp, 4614 KERN_FILEDESC_PACK_KINFO); 4615 FILEDESC_SUNLOCK(fdp); 4616 kinfo_to_okinfo(kif, okif); 4617 error = SYSCTL_OUT(req, okif, sizeof(*okif)); 4618 FILEDESC_SLOCK(fdp); 4619 if (error) 4620 break; 4621 } 4622 FILEDESC_SUNLOCK(fdp); 4623 fddrop(fdp); 4624 pddrop(pdp); 4625 free(kif, M_TEMP); 4626 free(okif, M_TEMP); 4627 return (0); 4628 } 4629 4630 static SYSCTL_NODE(_kern_proc, KERN_PROC_OFILEDESC, ofiledesc, 4631 CTLFLAG_RD|CTLFLAG_MPSAFE, sysctl_kern_proc_ofiledesc, 4632 "Process ofiledesc entries"); 4633 #endif /* COMPAT_FREEBSD7 */ 4634 4635 int 4636 vntype_to_kinfo(int vtype) 4637 { 4638 struct { 4639 int vtype; 4640 int kf_vtype; 4641 } vtypes_table[] = { 4642 { VBAD, KF_VTYPE_VBAD }, 4643 { VBLK, KF_VTYPE_VBLK }, 4644 { VCHR, KF_VTYPE_VCHR }, 4645 { VDIR, KF_VTYPE_VDIR }, 4646 { VFIFO, KF_VTYPE_VFIFO }, 4647 { VLNK, KF_VTYPE_VLNK }, 4648 { VNON, KF_VTYPE_VNON }, 4649 { VREG, KF_VTYPE_VREG }, 4650 { VSOCK, KF_VTYPE_VSOCK } 4651 }; 4652 unsigned int i; 4653 4654 /* 4655 * Perform vtype translation. 4656 */ 4657 for (i = 0; i < nitems(vtypes_table); i++) 4658 if (vtypes_table[i].vtype == vtype) 4659 return (vtypes_table[i].kf_vtype); 4660 4661 return (KF_VTYPE_UNKNOWN); 4662 } 4663 4664 static SYSCTL_NODE(_kern_proc, KERN_PROC_FILEDESC, filedesc, 4665 CTLFLAG_RD|CTLFLAG_MPSAFE, sysctl_kern_proc_filedesc, 4666 "Process filedesc entries"); 4667 4668 /* 4669 * Store a process current working directory information to sbuf. 4670 * 4671 * Takes a locked proc as argument, and returns with the proc unlocked. 4672 */ 4673 int 4674 kern_proc_cwd_out(struct proc *p, struct sbuf *sb, ssize_t maxlen) 4675 { 4676 struct pwddesc *pdp; 4677 struct pwd *pwd; 4678 struct export_fd_buf *efbuf; 4679 struct vnode *cdir; 4680 int error; 4681 4682 PROC_LOCK_ASSERT(p, MA_OWNED); 4683 4684 pdp = pdhold(p); 4685 PROC_UNLOCK(p); 4686 if (pdp == NULL) 4687 return (EINVAL); 4688 4689 efbuf = malloc(sizeof(*efbuf), M_TEMP, M_WAITOK); 4690 efbuf->pdp = pdp; 4691 efbuf->sb = sb; 4692 efbuf->remainder = maxlen; 4693 4694 PWDDESC_XLOCK(pdp); 4695 pwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); 4696 cdir = pwd->pwd_cdir; 4697 if (cdir == NULL) { 4698 error = EINVAL; 4699 } else { 4700 vrefact(cdir); 4701 error = export_vnode_to_sb(cdir, KF_FD_TYPE_CWD, FREAD, efbuf); 4702 } 4703 PWDDESC_XUNLOCK(pdp); 4704 pddrop(pdp); 4705 free(efbuf, M_TEMP); 4706 return (error); 4707 } 4708 4709 /* 4710 * Get per-process current working directory. 4711 */ 4712 static int 4713 sysctl_kern_proc_cwd(SYSCTL_HANDLER_ARGS) 4714 { 4715 struct sbuf sb; 4716 struct proc *p; 4717 ssize_t maxlen; 4718 u_int namelen; 4719 int error, error2, *name; 4720 4721 namelen = arg2; 4722 if (namelen != 1) 4723 return (EINVAL); 4724 4725 name = (int *)arg1; 4726 4727 sbuf_new_for_sysctl(&sb, NULL, sizeof(struct kinfo_file), req); 4728 sbuf_clear_flags(&sb, SBUF_INCLUDENUL); 4729 error = pget((pid_t)name[0], PGET_CANDEBUG | PGET_NOTWEXIT, &p); 4730 if (error != 0) { 4731 sbuf_delete(&sb); 4732 return (error); 4733 } 4734 maxlen = req->oldptr != NULL ? req->oldlen : -1; 4735 error = kern_proc_cwd_out(p, &sb, maxlen); 4736 error2 = sbuf_finish(&sb); 4737 sbuf_delete(&sb); 4738 return (error != 0 ? error : error2); 4739 } 4740 4741 static SYSCTL_NODE(_kern_proc, KERN_PROC_CWD, cwd, CTLFLAG_RD|CTLFLAG_MPSAFE, 4742 sysctl_kern_proc_cwd, "Process current working directory"); 4743 4744 #ifdef DDB 4745 /* 4746 * For the purposes of debugging, generate a human-readable string for the 4747 * file type. 4748 */ 4749 static const char * 4750 file_type_to_name(short type) 4751 { 4752 4753 switch (type) { 4754 case 0: 4755 return ("zero"); 4756 case DTYPE_VNODE: 4757 return ("vnode"); 4758 case DTYPE_SOCKET: 4759 return ("socket"); 4760 case DTYPE_PIPE: 4761 return ("pipe"); 4762 case DTYPE_FIFO: 4763 return ("fifo"); 4764 case DTYPE_KQUEUE: 4765 return ("kqueue"); 4766 case DTYPE_CRYPTO: 4767 return ("crypto"); 4768 case DTYPE_MQUEUE: 4769 return ("mqueue"); 4770 case DTYPE_SHM: 4771 return ("shm"); 4772 case DTYPE_SEM: 4773 return ("ksem"); 4774 case DTYPE_PTS: 4775 return ("pts"); 4776 case DTYPE_DEV: 4777 return ("dev"); 4778 case DTYPE_PROCDESC: 4779 return ("proc"); 4780 case DTYPE_EVENTFD: 4781 return ("eventfd"); 4782 case DTYPE_LINUXTFD: 4783 return ("ltimer"); 4784 default: 4785 return ("unkn"); 4786 } 4787 } 4788 4789 /* 4790 * For the purposes of debugging, identify a process (if any, perhaps one of 4791 * many) that references the passed file in its file descriptor array. Return 4792 * NULL if none. 4793 */ 4794 static struct proc * 4795 file_to_first_proc(struct file *fp) 4796 { 4797 struct filedesc *fdp; 4798 struct proc *p; 4799 int n; 4800 4801 FOREACH_PROC_IN_SYSTEM(p) { 4802 if (p->p_state == PRS_NEW) 4803 continue; 4804 fdp = p->p_fd; 4805 if (fdp == NULL) 4806 continue; 4807 for (n = 0; n < fdp->fd_nfiles; n++) { 4808 if (fp == fdp->fd_ofiles[n].fde_file) 4809 return (p); 4810 } 4811 } 4812 return (NULL); 4813 } 4814 4815 static void 4816 db_print_file(struct file *fp, int header) 4817 { 4818 #define XPTRWIDTH ((int)howmany(sizeof(void *) * NBBY, 4)) 4819 struct proc *p; 4820 4821 if (header) 4822 db_printf("%*s %6s %*s %8s %4s %5s %6s %*s %5s %s\n", 4823 XPTRWIDTH, "File", "Type", XPTRWIDTH, "Data", "Flag", 4824 "GCFl", "Count", "MCount", XPTRWIDTH, "Vnode", "FPID", 4825 "FCmd"); 4826 p = file_to_first_proc(fp); 4827 db_printf("%*p %6s %*p %08x %04x %5d %6d %*p %5d %s\n", XPTRWIDTH, 4828 fp, file_type_to_name(fp->f_type), XPTRWIDTH, fp->f_data, 4829 fp->f_flag, 0, refcount_load(&fp->f_count), 0, XPTRWIDTH, fp->f_vnode, 4830 p != NULL ? p->p_pid : -1, p != NULL ? p->p_comm : "-"); 4831 4832 #undef XPTRWIDTH 4833 } 4834 4835 DB_SHOW_COMMAND(file, db_show_file) 4836 { 4837 struct file *fp; 4838 4839 if (!have_addr) { 4840 db_printf("usage: show file <addr>\n"); 4841 return; 4842 } 4843 fp = (struct file *)addr; 4844 db_print_file(fp, 1); 4845 } 4846 4847 DB_SHOW_COMMAND(files, db_show_files) 4848 { 4849 struct filedesc *fdp; 4850 struct file *fp; 4851 struct proc *p; 4852 int header; 4853 int n; 4854 4855 header = 1; 4856 FOREACH_PROC_IN_SYSTEM(p) { 4857 if (p->p_state == PRS_NEW) 4858 continue; 4859 if ((fdp = p->p_fd) == NULL) 4860 continue; 4861 for (n = 0; n < fdp->fd_nfiles; ++n) { 4862 if ((fp = fdp->fd_ofiles[n].fde_file) == NULL) 4863 continue; 4864 db_print_file(fp, header); 4865 header = 0; 4866 } 4867 } 4868 } 4869 #endif 4870 4871 SYSCTL_INT(_kern, KERN_MAXFILESPERPROC, maxfilesperproc, CTLFLAG_RW, 4872 &maxfilesperproc, 0, "Maximum files allowed open per process"); 4873 4874 SYSCTL_INT(_kern, KERN_MAXFILES, maxfiles, CTLFLAG_RW, 4875 &maxfiles, 0, "Maximum number of files"); 4876 4877 SYSCTL_INT(_kern, OID_AUTO, openfiles, CTLFLAG_RD, 4878 &openfiles, 0, "System-wide number of open files"); 4879 4880 /* ARGSUSED*/ 4881 static void 4882 filelistinit(void *dummy) 4883 { 4884 4885 file_zone = uma_zcreate("Files", sizeof(struct file), NULL, NULL, 4886 NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE); 4887 filedesc0_zone = uma_zcreate("filedesc0", sizeof(struct filedesc0), 4888 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0); 4889 pwd_zone = uma_zcreate("PWD", sizeof(struct pwd), NULL, NULL, 4890 NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_SMR); 4891 /* 4892 * XXXMJG this is a temporary hack due to boot ordering issues against 4893 * the vnode zone. 4894 */ 4895 vfs_smr = uma_zone_get_smr(pwd_zone); 4896 mtx_init(&sigio_lock, "sigio lock", NULL, MTX_DEF); 4897 } 4898 SYSINIT(select, SI_SUB_LOCK, SI_ORDER_FIRST, filelistinit, NULL); 4899 4900 /*-------------------------------------------------------------------*/ 4901 4902 static int 4903 badfo_readwrite(struct file *fp, struct uio *uio, struct ucred *active_cred, 4904 int flags, struct thread *td) 4905 { 4906 4907 return (EBADF); 4908 } 4909 4910 static int 4911 badfo_truncate(struct file *fp, off_t length, struct ucred *active_cred, 4912 struct thread *td) 4913 { 4914 4915 return (EINVAL); 4916 } 4917 4918 static int 4919 badfo_ioctl(struct file *fp, u_long com, void *data, struct ucred *active_cred, 4920 struct thread *td) 4921 { 4922 4923 return (EBADF); 4924 } 4925 4926 static int 4927 badfo_poll(struct file *fp, int events, struct ucred *active_cred, 4928 struct thread *td) 4929 { 4930 4931 return (0); 4932 } 4933 4934 static int 4935 badfo_kqfilter(struct file *fp, struct knote *kn) 4936 { 4937 4938 return (EBADF); 4939 } 4940 4941 static int 4942 badfo_stat(struct file *fp, struct stat *sb, struct ucred *active_cred, 4943 struct thread *td) 4944 { 4945 4946 return (EBADF); 4947 } 4948 4949 static int 4950 badfo_close(struct file *fp, struct thread *td) 4951 { 4952 4953 return (0); 4954 } 4955 4956 static int 4957 badfo_chmod(struct file *fp, mode_t mode, struct ucred *active_cred, 4958 struct thread *td) 4959 { 4960 4961 return (EBADF); 4962 } 4963 4964 static int 4965 badfo_chown(struct file *fp, uid_t uid, gid_t gid, struct ucred *active_cred, 4966 struct thread *td) 4967 { 4968 4969 return (EBADF); 4970 } 4971 4972 static int 4973 badfo_sendfile(struct file *fp, int sockfd, struct uio *hdr_uio, 4974 struct uio *trl_uio, off_t offset, size_t nbytes, off_t *sent, int flags, 4975 struct thread *td) 4976 { 4977 4978 return (EBADF); 4979 } 4980 4981 static int 4982 badfo_fill_kinfo(struct file *fp, struct kinfo_file *kif, struct filedesc *fdp) 4983 { 4984 4985 return (0); 4986 } 4987 4988 struct fileops badfileops = { 4989 .fo_read = badfo_readwrite, 4990 .fo_write = badfo_readwrite, 4991 .fo_truncate = badfo_truncate, 4992 .fo_ioctl = badfo_ioctl, 4993 .fo_poll = badfo_poll, 4994 .fo_kqfilter = badfo_kqfilter, 4995 .fo_stat = badfo_stat, 4996 .fo_close = badfo_close, 4997 .fo_chmod = badfo_chmod, 4998 .fo_chown = badfo_chown, 4999 .fo_sendfile = badfo_sendfile, 5000 .fo_fill_kinfo = badfo_fill_kinfo, 5001 }; 5002 5003 static int 5004 path_poll(struct file *fp, int events, struct ucred *active_cred, 5005 struct thread *td) 5006 { 5007 return (POLLNVAL); 5008 } 5009 5010 static int 5011 path_close(struct file *fp, struct thread *td) 5012 { 5013 MPASS(fp->f_type == DTYPE_VNODE); 5014 fp->f_ops = &badfileops; 5015 vdrop(fp->f_vnode); 5016 return (0); 5017 } 5018 5019 struct fileops path_fileops = { 5020 .fo_read = badfo_readwrite, 5021 .fo_write = badfo_readwrite, 5022 .fo_truncate = badfo_truncate, 5023 .fo_ioctl = badfo_ioctl, 5024 .fo_poll = path_poll, 5025 .fo_kqfilter = vn_kqfilter_opath, 5026 .fo_stat = vn_statfile, 5027 .fo_close = path_close, 5028 .fo_chmod = badfo_chmod, 5029 .fo_chown = badfo_chown, 5030 .fo_sendfile = badfo_sendfile, 5031 .fo_fill_kinfo = vn_fill_kinfo, 5032 .fo_flags = DFLAG_PASSABLE, 5033 }; 5034 5035 int 5036 invfo_rdwr(struct file *fp, struct uio *uio, struct ucred *active_cred, 5037 int flags, struct thread *td) 5038 { 5039 5040 return (EOPNOTSUPP); 5041 } 5042 5043 int 5044 invfo_truncate(struct file *fp, off_t length, struct ucred *active_cred, 5045 struct thread *td) 5046 { 5047 5048 return (EINVAL); 5049 } 5050 5051 int 5052 invfo_ioctl(struct file *fp, u_long com, void *data, 5053 struct ucred *active_cred, struct thread *td) 5054 { 5055 5056 return (ENOTTY); 5057 } 5058 5059 int 5060 invfo_poll(struct file *fp, int events, struct ucred *active_cred, 5061 struct thread *td) 5062 { 5063 5064 return (poll_no_poll(events)); 5065 } 5066 5067 int 5068 invfo_kqfilter(struct file *fp, struct knote *kn) 5069 { 5070 5071 return (EINVAL); 5072 } 5073 5074 int 5075 invfo_chmod(struct file *fp, mode_t mode, struct ucred *active_cred, 5076 struct thread *td) 5077 { 5078 5079 return (EINVAL); 5080 } 5081 5082 int 5083 invfo_chown(struct file *fp, uid_t uid, gid_t gid, struct ucred *active_cred, 5084 struct thread *td) 5085 { 5086 5087 return (EINVAL); 5088 } 5089 5090 int 5091 invfo_sendfile(struct file *fp, int sockfd, struct uio *hdr_uio, 5092 struct uio *trl_uio, off_t offset, size_t nbytes, off_t *sent, int flags, 5093 struct thread *td) 5094 { 5095 5096 return (EINVAL); 5097 } 5098 5099 /*-------------------------------------------------------------------*/ 5100 5101 /* 5102 * File Descriptor pseudo-device driver (/dev/fd/). 5103 * 5104 * Opening minor device N dup()s the file (if any) connected to file 5105 * descriptor N belonging to the calling process. Note that this driver 5106 * consists of only the ``open()'' routine, because all subsequent 5107 * references to this file will be direct to the other driver. 5108 * 5109 * XXX: we could give this one a cloning event handler if necessary. 5110 */ 5111 5112 /* ARGSUSED */ 5113 static int 5114 fdopen(struct cdev *dev, int mode, int type, struct thread *td) 5115 { 5116 5117 /* 5118 * XXX Kludge: set curthread->td_dupfd to contain the value of the 5119 * the file descriptor being sought for duplication. The error 5120 * return ensures that the vnode for this device will be released 5121 * by vn_open. Open will detect this special error and take the 5122 * actions in dupfdopen below. Other callers of vn_open or VOP_OPEN 5123 * will simply report the error. 5124 */ 5125 td->td_dupfd = dev2unit(dev); 5126 return (ENODEV); 5127 } 5128 5129 static struct cdevsw fildesc_cdevsw = { 5130 .d_version = D_VERSION, 5131 .d_open = fdopen, 5132 .d_name = "FD", 5133 }; 5134 5135 static void 5136 fildesc_drvinit(void *unused) 5137 { 5138 struct cdev *dev; 5139 5140 dev = make_dev_credf(MAKEDEV_ETERNAL, &fildesc_cdevsw, 0, NULL, 5141 UID_ROOT, GID_WHEEL, 0666, "fd/0"); 5142 make_dev_alias(dev, "stdin"); 5143 dev = make_dev_credf(MAKEDEV_ETERNAL, &fildesc_cdevsw, 1, NULL, 5144 UID_ROOT, GID_WHEEL, 0666, "fd/1"); 5145 make_dev_alias(dev, "stdout"); 5146 dev = make_dev_credf(MAKEDEV_ETERNAL, &fildesc_cdevsw, 2, NULL, 5147 UID_ROOT, GID_WHEEL, 0666, "fd/2"); 5148 make_dev_alias(dev, "stderr"); 5149 } 5150 5151 SYSINIT(fildescdev, SI_SUB_DRIVERS, SI_ORDER_MIDDLE, fildesc_drvinit, NULL); 5152