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 37 #include "opt_capsicum.h" 38 #include "opt_ddb.h" 39 #include "opt_ktrace.h" 40 41 #define EXTERR_CATEGORY EXTERR_CAT_FILEDESC 42 #include <sys/systm.h> 43 #include <sys/capsicum.h> 44 #include <sys/conf.h> 45 #include <sys/exterrvar.h> 46 #include <sys/fcntl.h> 47 #include <sys/file.h> 48 #include <sys/filedesc.h> 49 #include <sys/filio.h> 50 #include <sys/jail.h> 51 #include <sys/kernel.h> 52 #include <sys/limits.h> 53 #include <sys/lock.h> 54 #include <sys/malloc.h> 55 #include <sys/mount.h> 56 #include <sys/mutex.h> 57 #include <sys/namei.h> 58 #include <sys/selinfo.h> 59 #include <sys/poll.h> 60 #include <sys/priv.h> 61 #include <sys/proc.h> 62 #include <sys/protosw.h> 63 #include <sys/racct.h> 64 #include <sys/resourcevar.h> 65 #include <sys/sbuf.h> 66 #include <sys/signalvar.h> 67 #include <sys/kdb.h> 68 #include <sys/smr.h> 69 #include <sys/stat.h> 70 #include <sys/sx.h> 71 #include <sys/syscallsubr.h> 72 #include <sys/sysctl.h> 73 #include <sys/sysproto.h> 74 #include <sys/unistd.h> 75 #include <sys/user.h> 76 #include <sys/vnode.h> 77 #include <sys/ktrace.h> 78 79 #include <net/vnet.h> 80 81 #include <security/audit/audit.h> 82 83 #include <vm/uma.h> 84 #include <vm/vm.h> 85 86 #include <ddb/ddb.h> 87 88 static MALLOC_DEFINE(M_FILEDESC, "filedesc", "Open file descriptor table"); 89 static MALLOC_DEFINE(M_PWD, "pwd", "Descriptor table vnodes"); 90 static MALLOC_DEFINE(M_PWDDESC, "pwddesc", "Pwd descriptors"); 91 static MALLOC_DEFINE(M_FILEDESC_TO_LEADER, "filedesc_to_leader", 92 "file desc to leader structures"); 93 static MALLOC_DEFINE(M_SIGIO, "sigio", "sigio structures"); 94 MALLOC_DEFINE(M_FILECAPS, "filecaps", "descriptor capabilities"); 95 96 MALLOC_DECLARE(M_FADVISE); 97 98 static __read_mostly uma_zone_t file_zone; 99 static __read_mostly uma_zone_t filedesc0_zone; 100 __read_mostly uma_zone_t pwd_zone; 101 VFS_SMR_DECLARE; 102 103 static int closefp(struct filedesc *fdp, int fd, struct file *fp, 104 struct thread *td, bool holdleaders, bool audit); 105 static void export_file_to_kinfo(struct file *fp, int fd, 106 cap_rights_t *rightsp, struct kinfo_file *kif, 107 struct filedesc *fdp, int flags); 108 static int fd_first_free(struct filedesc *fdp, int low, int size); 109 static void fdgrowtable(struct filedesc *fdp, int nfd); 110 static void fdgrowtable_exp(struct filedesc *fdp, int nfd); 111 static void fdunused(struct filedesc *fdp, int fd); 112 static void fdused(struct filedesc *fdp, int fd); 113 static int fget_unlocked_seq(struct thread *td, int fd, 114 const cap_rights_t *needrightsp, uint8_t *flagsp, 115 struct file **fpp, seqc_t *seqp); 116 static int getmaxfd(struct thread *td); 117 static u_long *filecaps_copy_prep(const struct filecaps *src); 118 static void filecaps_copy_finish(const struct filecaps *src, 119 struct filecaps *dst, u_long *ioctls); 120 static u_long *filecaps_free_prep(struct filecaps *fcaps); 121 static void filecaps_free_finish(u_long *ioctls); 122 123 static struct pwd *pwd_alloc(void); 124 125 /* 126 * Each process has: 127 * 128 * - An array of open file descriptors (fd_ofiles) 129 * - An array of file flags (fd_ofileflags) 130 * - A bitmap recording which descriptors are in use (fd_map) 131 * 132 * A process starts out with NDFILE descriptors. The value of NDFILE has 133 * been selected based the historical limit of 20 open files, and an 134 * assumption that the majority of processes, especially short-lived 135 * processes like shells, will never need more. 136 * 137 * If this initial allocation is exhausted, a larger descriptor table and 138 * map are allocated dynamically, and the pointers in the process's struct 139 * filedesc are updated to point to those. This is repeated every time 140 * the process runs out of file descriptors (provided it hasn't hit its 141 * resource limit). 142 * 143 * Since threads may hold references to individual descriptor table 144 * entries, the tables are never freed. Instead, they are placed on a 145 * linked list and freed only when the struct filedesc is released. 146 */ 147 #define NDFILE 20 148 #define NDSLOTSIZE sizeof(NDSLOTTYPE) 149 #define NDENTRIES (NDSLOTSIZE * __CHAR_BIT) 150 #define NDSLOT(x) ((x) / NDENTRIES) 151 #define NDBIT(x) ((NDSLOTTYPE)1 << ((x) % NDENTRIES)) 152 #define NDSLOTS(x) (((x) + NDENTRIES - 1) / NDENTRIES) 153 154 #define FILEDESC_FOREACH_FDE(fdp, _iterator, _fde) \ 155 struct filedesc *_fdp = (fdp); \ 156 int _lastfile = fdlastfile_single(_fdp); \ 157 for (_iterator = 0; _iterator <= _lastfile; _iterator++) \ 158 if ((_fde = &_fdp->fd_ofiles[_iterator])->fde_file != NULL) 159 160 #define FILEDESC_FOREACH_FP(fdp, _iterator, _fp) \ 161 struct filedesc *_fdp = (fdp); \ 162 int _lastfile = fdlastfile_single(_fdp); \ 163 for (_iterator = 0; _iterator <= _lastfile; _iterator++) \ 164 if ((_fp = _fdp->fd_ofiles[_iterator].fde_file) != NULL) 165 166 /* 167 * SLIST entry used to keep track of ofiles which must be reclaimed when 168 * the process exits. 169 */ 170 struct freetable { 171 struct fdescenttbl *ft_table; 172 SLIST_ENTRY(freetable) ft_next; 173 }; 174 175 /* 176 * Initial allocation: a filedesc structure + the head of SLIST used to 177 * keep track of old ofiles + enough space for NDFILE descriptors. 178 */ 179 180 struct fdescenttbl0 { 181 int fdt_nfiles; 182 struct filedescent fdt_ofiles[NDFILE]; 183 }; 184 185 struct filedesc0 { 186 struct filedesc fd_fd; 187 SLIST_HEAD(, freetable) fd_free; 188 struct fdescenttbl0 fd_dfiles; 189 NDSLOTTYPE fd_dmap[NDSLOTS(NDFILE)]; 190 }; 191 192 /* 193 * Descriptor management. 194 */ 195 static int __exclusive_cache_line openfiles; /* actual number of open files */ 196 struct mtx sigio_lock; /* mtx to protect pointers to sigio */ 197 void __read_mostly (*mq_fdclose)(struct thread *td, int fd, struct file *fp); 198 199 /* 200 * If low >= size, just return low. Otherwise find the first zero bit in the 201 * given bitmap, starting at low and not exceeding size - 1. Return size if 202 * not found. 203 */ 204 static int 205 fd_first_free(struct filedesc *fdp, int low, int size) 206 { 207 NDSLOTTYPE *map = fdp->fd_map; 208 NDSLOTTYPE mask; 209 int off, maxoff; 210 211 if (low >= size) 212 return (low); 213 214 off = NDSLOT(low); 215 if (low % NDENTRIES) { 216 mask = ~(~(NDSLOTTYPE)0 >> (NDENTRIES - (low % NDENTRIES))); 217 if ((mask &= ~map[off]) != 0UL) 218 return (off * NDENTRIES + ffsl(mask) - 1); 219 ++off; 220 } 221 for (maxoff = NDSLOTS(size); off < maxoff; ++off) 222 if (map[off] != ~0UL) 223 return (off * NDENTRIES + ffsl(~map[off]) - 1); 224 return (size); 225 } 226 227 /* 228 * Find the last used fd. 229 * 230 * Call this variant if fdp can't be modified by anyone else (e.g, during exec). 231 * Otherwise use fdlastfile. 232 */ 233 int 234 fdlastfile_single(struct filedesc *fdp) 235 { 236 NDSLOTTYPE *map = fdp->fd_map; 237 int off, minoff; 238 239 off = NDSLOT(fdp->fd_nfiles - 1); 240 for (minoff = NDSLOT(0); off >= minoff; --off) 241 if (map[off] != 0) 242 return (off * NDENTRIES + flsl(map[off]) - 1); 243 return (-1); 244 } 245 246 int 247 fdlastfile(struct filedesc *fdp) 248 { 249 250 FILEDESC_LOCK_ASSERT(fdp); 251 return (fdlastfile_single(fdp)); 252 } 253 254 static int 255 fdisused(struct filedesc *fdp, int fd) 256 { 257 258 KASSERT(fd >= 0 && fd < fdp->fd_nfiles, 259 ("file descriptor %d out of range (0, %d)", fd, fdp->fd_nfiles)); 260 261 return ((fdp->fd_map[NDSLOT(fd)] & NDBIT(fd)) != 0); 262 } 263 264 /* 265 * Mark a file descriptor as used. 266 */ 267 static void 268 fdused_init(struct filedesc *fdp, int fd) 269 { 270 271 KASSERT(!fdisused(fdp, fd), ("fd=%d is already used", fd)); 272 273 fdp->fd_map[NDSLOT(fd)] |= NDBIT(fd); 274 } 275 276 static void 277 fdused(struct filedesc *fdp, int fd) 278 { 279 280 FILEDESC_XLOCK_ASSERT(fdp); 281 282 fdused_init(fdp, fd); 283 if (fd == fdp->fd_freefile) 284 fdp->fd_freefile++; 285 } 286 287 /* 288 * Mark a file descriptor as unused. 289 */ 290 static void 291 fdunused(struct filedesc *fdp, int fd) 292 { 293 294 FILEDESC_XLOCK_ASSERT(fdp); 295 296 KASSERT(fdisused(fdp, fd), ("fd=%d is already unused", fd)); 297 KASSERT(fdp->fd_ofiles[fd].fde_file == NULL, 298 ("fd=%d is still in use", fd)); 299 300 fdp->fd_map[NDSLOT(fd)] &= ~NDBIT(fd); 301 if (fd < fdp->fd_freefile) 302 fdp->fd_freefile = fd; 303 } 304 305 /* 306 * Free a file descriptor. 307 * 308 * Avoid some work if fdp is about to be destroyed. 309 */ 310 static inline void 311 fdefree_last(struct filedescent *fde) 312 { 313 314 filecaps_free(&fde->fde_caps); 315 } 316 317 static inline void 318 fdfree(struct filedesc *fdp, int fd) 319 { 320 struct filedescent *fde; 321 322 FILEDESC_XLOCK_ASSERT(fdp); 323 fde = &fdp->fd_ofiles[fd]; 324 #ifdef CAPABILITIES 325 seqc_write_begin(&fde->fde_seqc); 326 #endif 327 fde->fde_file = NULL; 328 #ifdef CAPABILITIES 329 seqc_write_end(&fde->fde_seqc); 330 #endif 331 fdefree_last(fde); 332 fdunused(fdp, fd); 333 } 334 335 /* 336 * System calls on descriptors. 337 */ 338 #ifndef _SYS_SYSPROTO_H_ 339 struct getdtablesize_args { 340 int dummy; 341 }; 342 #endif 343 /* ARGSUSED */ 344 int 345 sys_getdtablesize(struct thread *td, struct getdtablesize_args *uap) 346 { 347 #ifdef RACCT 348 uint64_t lim; 349 #endif 350 351 td->td_retval[0] = getmaxfd(td); 352 #ifdef RACCT 353 PROC_LOCK(td->td_proc); 354 lim = racct_get_limit(td->td_proc, RACCT_NOFILE); 355 PROC_UNLOCK(td->td_proc); 356 if (lim < td->td_retval[0]) 357 td->td_retval[0] = lim; 358 #endif 359 return (0); 360 } 361 362 /* 363 * Duplicate a file descriptor to a particular value. 364 * 365 * Note: keep in mind that a potential race condition exists when closing 366 * descriptors from a shared descriptor table (via rfork). 367 */ 368 #ifndef _SYS_SYSPROTO_H_ 369 struct dup2_args { 370 u_int from; 371 u_int to; 372 }; 373 #endif 374 /* ARGSUSED */ 375 int 376 sys_dup2(struct thread *td, struct dup2_args *uap) 377 { 378 379 return (kern_dup(td, FDDUP_FIXED, 0, (int)uap->from, (int)uap->to)); 380 } 381 382 /* 383 * Duplicate a file descriptor. 384 */ 385 #ifndef _SYS_SYSPROTO_H_ 386 struct dup_args { 387 u_int fd; 388 }; 389 #endif 390 /* ARGSUSED */ 391 int 392 sys_dup(struct thread *td, struct dup_args *uap) 393 { 394 395 return (kern_dup(td, FDDUP_NORMAL, 0, (int)uap->fd, 0)); 396 } 397 398 /* 399 * The file control system call. 400 */ 401 #ifndef _SYS_SYSPROTO_H_ 402 struct fcntl_args { 403 int fd; 404 int cmd; 405 long arg; 406 }; 407 #endif 408 /* ARGSUSED */ 409 int 410 sys_fcntl(struct thread *td, struct fcntl_args *uap) 411 { 412 413 return (kern_fcntl_freebsd(td, uap->fd, uap->cmd, uap->arg)); 414 } 415 416 int 417 kern_fcntl_freebsd(struct thread *td, int fd, int cmd, intptr_t arg) 418 { 419 struct flock fl; 420 struct __oflock ofl; 421 intptr_t arg1; 422 int error, newcmd; 423 424 error = 0; 425 newcmd = cmd; 426 switch (cmd) { 427 case F_OGETLK: 428 case F_OSETLK: 429 case F_OSETLKW: 430 /* 431 * Convert old flock structure to new. 432 */ 433 error = copyin((void *)arg, &ofl, sizeof(ofl)); 434 fl.l_start = ofl.l_start; 435 fl.l_len = ofl.l_len; 436 fl.l_pid = ofl.l_pid; 437 fl.l_type = ofl.l_type; 438 fl.l_whence = ofl.l_whence; 439 fl.l_sysid = 0; 440 441 switch (cmd) { 442 case F_OGETLK: 443 newcmd = F_GETLK; 444 break; 445 case F_OSETLK: 446 newcmd = F_SETLK; 447 break; 448 case F_OSETLKW: 449 newcmd = F_SETLKW; 450 break; 451 } 452 arg1 = (intptr_t)&fl; 453 break; 454 case F_GETLK: 455 case F_SETLK: 456 case F_SETLKW: 457 case F_SETLK_REMOTE: 458 error = copyin((void *)arg, &fl, sizeof(fl)); 459 arg1 = (intptr_t)&fl; 460 break; 461 default: 462 arg1 = arg; 463 break; 464 } 465 if (error) 466 return (error); 467 error = kern_fcntl(td, fd, newcmd, arg1); 468 if (error) 469 return (error); 470 if (cmd == F_OGETLK) { 471 ofl.l_start = fl.l_start; 472 ofl.l_len = fl.l_len; 473 ofl.l_pid = fl.l_pid; 474 ofl.l_type = fl.l_type; 475 ofl.l_whence = fl.l_whence; 476 error = copyout(&ofl, (void *)arg, sizeof(ofl)); 477 } else if (cmd == F_GETLK) { 478 error = copyout(&fl, (void *)arg, sizeof(fl)); 479 } 480 return (error); 481 } 482 483 struct flags_trans_elem { 484 u_int f; 485 u_int t; 486 }; 487 488 static u_int 489 flags_trans(const struct flags_trans_elem *ftes, int nitems, u_int from_flags) 490 { 491 u_int res; 492 int i; 493 494 res = 0; 495 for (i = 0; i < nitems; i++) { 496 if ((from_flags & ftes[i].f) != 0) 497 res |= ftes[i].t; 498 } 499 return (res); 500 } 501 502 static uint8_t 503 fd_to_fde_flags(int fd_flags) 504 { 505 static const struct flags_trans_elem fd_to_fde_flags_s[] = { 506 { .f = FD_CLOEXEC, .t = UF_EXCLOSE }, 507 { .f = FD_CLOFORK, .t = UF_FOCLOSE }, 508 { .f = FD_RESOLVE_BENEATH, .t = UF_RESOLVE_BENEATH }, 509 }; 510 511 return (flags_trans(fd_to_fde_flags_s, nitems(fd_to_fde_flags_s), 512 fd_flags)); 513 } 514 515 static int 516 fde_to_fd_flags(uint8_t fde_flags) 517 { 518 static const struct flags_trans_elem fde_to_fd_flags_s[] = { 519 { .f = UF_EXCLOSE, .t = FD_CLOEXEC }, 520 { .f = UF_FOCLOSE, .t = FD_CLOFORK }, 521 { .f = UF_RESOLVE_BENEATH, .t = FD_RESOLVE_BENEATH }, 522 }; 523 524 return (flags_trans(fde_to_fd_flags_s, nitems(fde_to_fd_flags_s), 525 fde_flags)); 526 } 527 528 static uint8_t 529 fddup_to_fde_flags(int fddup_flags) 530 { 531 static const struct flags_trans_elem fddup_to_fde_flags_s[] = { 532 { .f = FDDUP_FLAG_CLOEXEC, .t = UF_EXCLOSE }, 533 { .f = FDDUP_FLAG_CLOFORK, .t = UF_FOCLOSE }, 534 }; 535 536 return (flags_trans(fddup_to_fde_flags_s, nitems(fddup_to_fde_flags_s), 537 fddup_flags)); 538 } 539 540 static uint8_t 541 close_range_to_fde_flags(int close_range_flags) 542 { 543 static const struct flags_trans_elem close_range_to_fde_flags_s[] = { 544 { .f = CLOSE_RANGE_CLOEXEC, .t = UF_EXCLOSE }, 545 { .f = CLOSE_RANGE_CLOFORK, .t = UF_FOCLOSE }, 546 }; 547 548 return (flags_trans(close_range_to_fde_flags_s, 549 nitems(close_range_to_fde_flags_s), close_range_flags)); 550 } 551 552 static uint8_t 553 open_to_fde_flags(int open_flags, bool sticky_orb) 554 { 555 static const struct flags_trans_elem open_to_fde_flags_s[] = { 556 { .f = O_CLOEXEC, .t = UF_EXCLOSE }, 557 { .f = O_CLOFORK, .t = UF_FOCLOSE }, 558 { .f = O_RESOLVE_BENEATH, .t = UF_RESOLVE_BENEATH }, 559 }; 560 #if defined(__clang__) && __clang_major__ >= 19 561 _Static_assert(open_to_fde_flags_s[nitems(open_to_fde_flags_s) - 1].f == 562 O_RESOLVE_BENEATH, "O_RESOLVE_BENEATH must be last, for sticky_orb"); 563 #endif 564 565 return (flags_trans(open_to_fde_flags_s, nitems(open_to_fde_flags_s) - 566 (sticky_orb ? 0 : 1), open_flags)); 567 } 568 569 int 570 kern_fcntl(struct thread *td, int fd, int cmd, intptr_t arg) 571 { 572 struct filedesc *fdp; 573 struct flock *flp; 574 struct file *fp, *fp2; 575 struct filedescent *fde; 576 struct proc *p; 577 struct vnode *vp; 578 struct mount *mp; 579 struct kinfo_file *kif; 580 int error, flg, kif_sz, seals, tmp, got_set, got_cleared; 581 uint64_t bsize; 582 off_t foffset; 583 int flags; 584 585 error = 0; 586 flg = F_POSIX; 587 p = td->td_proc; 588 fdp = p->p_fd; 589 590 AUDIT_ARG_FD(cmd); 591 AUDIT_ARG_CMD(cmd); 592 switch (cmd) { 593 case F_DUPFD: 594 tmp = arg; 595 error = kern_dup(td, FDDUP_FCNTL, 0, fd, tmp); 596 break; 597 598 case F_DUPFD_CLOEXEC: 599 tmp = arg; 600 error = kern_dup(td, FDDUP_FCNTL, FDDUP_FLAG_CLOEXEC, fd, tmp); 601 break; 602 603 case F_DUPFD_CLOFORK: 604 tmp = arg; 605 error = kern_dup(td, FDDUP_FCNTL, FDDUP_FLAG_CLOFORK, fd, tmp); 606 break; 607 608 case F_DUP2FD: 609 tmp = arg; 610 error = kern_dup(td, FDDUP_FIXED, 0, fd, tmp); 611 break; 612 613 case F_DUP2FD_CLOEXEC: 614 tmp = arg; 615 error = kern_dup(td, FDDUP_FIXED, FDDUP_FLAG_CLOEXEC, fd, tmp); 616 break; 617 618 case F_GETFD: 619 error = EBADF; 620 FILEDESC_SLOCK(fdp); 621 fde = fdeget_noref(fdp, fd); 622 if (fde != NULL) { 623 td->td_retval[0] = fde_to_fd_flags(fde->fde_flags); 624 error = 0; 625 } 626 FILEDESC_SUNLOCK(fdp); 627 break; 628 629 case F_SETFD: 630 error = EBADF; 631 FILEDESC_XLOCK(fdp); 632 fde = fdeget_noref(fdp, fd); 633 if (fde != NULL) { 634 /* 635 * UF_RESOLVE_BENEATH is sticky and cannot be cleared. 636 */ 637 fde->fde_flags = (fde->fde_flags & 638 ~(UF_EXCLOSE | UF_FOCLOSE)) | fd_to_fde_flags(arg); 639 error = 0; 640 } 641 FILEDESC_XUNLOCK(fdp); 642 break; 643 644 case F_GETFL: 645 error = fget_fcntl(td, fd, &cap_fcntl_rights, F_GETFL, &fp); 646 if (error != 0) 647 break; 648 td->td_retval[0] = OFLAGS(fp->f_flag); 649 fdrop(fp, td); 650 break; 651 652 case F_SETFL: 653 error = fget_fcntl(td, fd, &cap_fcntl_rights, F_SETFL, &fp); 654 if (error != 0) 655 break; 656 if (fp->f_ops == &path_fileops) { 657 fdrop(fp, td); 658 error = EBADF; 659 break; 660 } 661 do { 662 tmp = flg = fp->f_flag; 663 tmp &= ~FCNTLFLAGS; 664 tmp |= FFLAGS(arg & ~O_ACCMODE) & FCNTLFLAGS; 665 } while (atomic_cmpset_int(&fp->f_flag, flg, tmp) == 0); 666 got_set = tmp & ~flg; 667 got_cleared = flg & ~tmp; 668 if (((got_set | got_cleared) & FNONBLOCK) != 0) { 669 tmp = fp->f_flag & FNONBLOCK; 670 error = fo_ioctl(fp, FIONBIO, &tmp, td->td_ucred, td); 671 if (error != 0) 672 goto revert_flags; 673 } 674 if (((got_set | got_cleared) & FASYNC) != 0) { 675 tmp = fp->f_flag & FASYNC; 676 error = fo_ioctl(fp, FIOASYNC, &tmp, td->td_ucred, td); 677 if (error != 0) 678 goto revert_nonblock; 679 } 680 fdrop(fp, td); 681 break; 682 revert_nonblock: 683 if (((got_set | got_cleared) & FNONBLOCK) != 0) { 684 tmp = ~fp->f_flag & FNONBLOCK; 685 (void)fo_ioctl(fp, FIONBIO, &tmp, td->td_ucred, td); 686 } 687 revert_flags: 688 do { 689 tmp = flg = fp->f_flag; 690 tmp &= ~FCNTLFLAGS; 691 tmp |= got_cleared; 692 tmp &= ~got_set; 693 } while (atomic_cmpset_int(&fp->f_flag, flg, tmp) == 0); 694 fdrop(fp, td); 695 break; 696 697 case F_GETOWN: 698 error = fget_fcntl(td, fd, &cap_fcntl_rights, F_GETOWN, &fp); 699 if (error != 0) 700 break; 701 error = fo_ioctl(fp, FIOGETOWN, &tmp, td->td_ucred, td); 702 if (error == 0) 703 td->td_retval[0] = tmp; 704 fdrop(fp, td); 705 break; 706 707 case F_SETOWN: 708 error = fget_fcntl(td, fd, &cap_fcntl_rights, F_SETOWN, &fp); 709 if (error != 0) 710 break; 711 tmp = arg; 712 error = fo_ioctl(fp, FIOSETOWN, &tmp, td->td_ucred, td); 713 fdrop(fp, td); 714 break; 715 716 case F_SETLK_REMOTE: 717 error = priv_check(td, PRIV_NFS_LOCKD); 718 if (error != 0) 719 return (error); 720 flg = F_REMOTE; 721 goto do_setlk; 722 723 case F_SETLKW: 724 flg |= F_WAIT; 725 /* FALLTHROUGH F_SETLK */ 726 727 case F_SETLK: 728 do_setlk: 729 flp = (struct flock *)arg; 730 if ((flg & F_REMOTE) != 0 && flp->l_sysid == 0) { 731 error = EINVAL; 732 break; 733 } 734 735 error = fget_unlocked(td, fd, &cap_flock_rights, &fp); 736 if (error != 0) 737 break; 738 if (fp->f_type != DTYPE_VNODE || fp->f_ops == &path_fileops) { 739 error = EBADF; 740 fdrop(fp, td); 741 break; 742 } 743 744 if (flp->l_whence == SEEK_CUR) { 745 foffset = foffset_get(fp); 746 if (foffset < 0 || 747 (flp->l_start > 0 && 748 foffset > OFF_MAX - flp->l_start)) { 749 error = EOVERFLOW; 750 fdrop(fp, td); 751 break; 752 } 753 flp->l_start += foffset; 754 } 755 756 vp = fp->f_vnode; 757 switch (flp->l_type) { 758 case F_RDLCK: 759 if ((fp->f_flag & FREAD) == 0) { 760 error = EBADF; 761 break; 762 } 763 if ((p->p_leader->p_flag & P_ADVLOCK) == 0) { 764 PROC_LOCK(p->p_leader); 765 p->p_leader->p_flag |= P_ADVLOCK; 766 PROC_UNLOCK(p->p_leader); 767 } 768 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_SETLK, 769 flp, flg); 770 break; 771 case F_WRLCK: 772 if ((fp->f_flag & FWRITE) == 0) { 773 error = EBADF; 774 break; 775 } 776 if ((p->p_leader->p_flag & P_ADVLOCK) == 0) { 777 PROC_LOCK(p->p_leader); 778 p->p_leader->p_flag |= P_ADVLOCK; 779 PROC_UNLOCK(p->p_leader); 780 } 781 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_SETLK, 782 flp, flg); 783 break; 784 case F_UNLCK: 785 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_UNLCK, 786 flp, flg); 787 break; 788 case F_UNLCKSYS: 789 if (flg != F_REMOTE) { 790 error = EINVAL; 791 break; 792 } 793 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, 794 F_UNLCKSYS, flp, flg); 795 break; 796 default: 797 error = EINVAL; 798 break; 799 } 800 if (error != 0 || flp->l_type == F_UNLCK || 801 flp->l_type == F_UNLCKSYS) { 802 fdrop(fp, td); 803 break; 804 } 805 806 /* 807 * Check for a race with close. 808 * 809 * The vnode is now advisory locked (or unlocked, but this case 810 * is not really important) as the caller requested. 811 * We had to drop the filedesc lock, so we need to recheck if 812 * the descriptor is still valid, because if it was closed 813 * in the meantime we need to remove advisory lock from the 814 * vnode - close on any descriptor leading to an advisory 815 * locked vnode, removes that lock. 816 * We will return 0 on purpose in that case, as the result of 817 * successful advisory lock might have been externally visible 818 * already. This is fine - effectively we pretend to the caller 819 * that the closing thread was a bit slower and that the 820 * advisory lock succeeded before the close. 821 */ 822 error = fget_unlocked(td, fd, &cap_no_rights, &fp2); 823 if (error != 0) { 824 fdrop(fp, td); 825 break; 826 } 827 if (fp != fp2) { 828 flp->l_whence = SEEK_SET; 829 flp->l_start = 0; 830 flp->l_len = 0; 831 flp->l_type = F_UNLCK; 832 (void) VOP_ADVLOCK(vp, (caddr_t)p->p_leader, 833 F_UNLCK, flp, F_POSIX); 834 } 835 fdrop(fp, td); 836 fdrop(fp2, td); 837 break; 838 839 case F_GETLK: 840 error = fget_unlocked(td, fd, &cap_flock_rights, &fp); 841 if (error != 0) 842 break; 843 if (fp->f_type != DTYPE_VNODE || fp->f_ops == &path_fileops) { 844 error = EBADF; 845 fdrop(fp, td); 846 break; 847 } 848 flp = (struct flock *)arg; 849 if (flp->l_type != F_RDLCK && flp->l_type != F_WRLCK && 850 flp->l_type != F_UNLCK) { 851 error = EINVAL; 852 fdrop(fp, td); 853 break; 854 } 855 if (flp->l_whence == SEEK_CUR) { 856 foffset = foffset_get(fp); 857 if ((flp->l_start > 0 && 858 foffset > OFF_MAX - flp->l_start) || 859 (flp->l_start < 0 && 860 foffset < OFF_MIN - flp->l_start)) { 861 error = EOVERFLOW; 862 fdrop(fp, td); 863 break; 864 } 865 flp->l_start += foffset; 866 } 867 vp = fp->f_vnode; 868 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_GETLK, flp, 869 F_POSIX); 870 fdrop(fp, td); 871 break; 872 873 case F_ADD_SEALS: 874 error = fget_unlocked(td, fd, &cap_no_rights, &fp); 875 if (error != 0) 876 break; 877 error = fo_add_seals(fp, arg); 878 fdrop(fp, td); 879 break; 880 881 case F_GET_SEALS: 882 error = fget_unlocked(td, fd, &cap_no_rights, &fp); 883 if (error != 0) 884 break; 885 if (fo_get_seals(fp, &seals) == 0) 886 td->td_retval[0] = seals; 887 else 888 error = EINVAL; 889 fdrop(fp, td); 890 break; 891 892 case F_RDAHEAD: 893 arg = arg ? 128 * 1024: 0; 894 /* FALLTHROUGH */ 895 case F_READAHEAD: 896 error = fget_unlocked(td, fd, &cap_no_rights, &fp); 897 if (error != 0) 898 break; 899 if (fp->f_type != DTYPE_VNODE || fp->f_ops == &path_fileops) { 900 fdrop(fp, td); 901 error = EBADF; 902 break; 903 } 904 vp = fp->f_vnode; 905 if (vp->v_type != VREG) { 906 fdrop(fp, td); 907 error = ENOTTY; 908 break; 909 } 910 911 /* 912 * Exclusive lock synchronizes against f_seqcount reads and 913 * writes in sequential_heuristic(). 914 */ 915 error = vn_lock(vp, LK_EXCLUSIVE); 916 if (error != 0) { 917 fdrop(fp, td); 918 break; 919 } 920 if (arg >= 0) { 921 bsize = fp->f_vnode->v_mount->mnt_stat.f_iosize; 922 arg = MIN(arg, INT_MAX - bsize + 1); 923 fp->f_seqcount[UIO_READ] = MIN(IO_SEQMAX, 924 (arg + bsize - 1) / bsize); 925 atomic_set_int(&fp->f_flag, FRDAHEAD); 926 } else { 927 atomic_clear_int(&fp->f_flag, FRDAHEAD); 928 } 929 VOP_UNLOCK(vp); 930 fdrop(fp, td); 931 break; 932 933 case F_ISUNIONSTACK: 934 /* 935 * Check if the vnode is part of a union stack (either the 936 * "union" flag from mount(2) or unionfs). 937 * 938 * Prior to introduction of this op libc's readdir would call 939 * fstatfs(2), in effect unnecessarily copying kilobytes of 940 * data just to check fs name and a mount flag. 941 * 942 * Fixing the code to handle everything in the kernel instead 943 * is a non-trivial endeavor and has low priority, thus this 944 * horrible kludge facilitates the current behavior in a much 945 * cheaper manner until someone(tm) sorts this out. 946 */ 947 error = fget_unlocked(td, fd, &cap_no_rights, &fp); 948 if (error != 0) 949 break; 950 if (fp->f_type != DTYPE_VNODE) { 951 fdrop(fp, td); 952 error = EBADF; 953 break; 954 } 955 vp = fp->f_vnode; 956 /* 957 * Since we don't prevent dooming the vnode even non-null mp 958 * found can become immediately stale. This is tolerable since 959 * mount points are type-stable (providing safe memory access) 960 * and any vfs op on this vnode going forward will return an 961 * error (meaning return value in this case is meaningless). 962 */ 963 mp = atomic_load_ptr(&vp->v_mount); 964 if (__predict_false(mp == NULL)) { 965 fdrop(fp, td); 966 error = EBADF; 967 break; 968 } 969 td->td_retval[0] = 0; 970 if (mp->mnt_kern_flag & MNTK_UNIONFS || 971 mp->mnt_flag & MNT_UNION) 972 td->td_retval[0] = 1; 973 fdrop(fp, td); 974 break; 975 976 case F_KINFO: 977 #ifdef CAPABILITY_MODE 978 if (CAP_TRACING(td)) 979 ktrcapfail(CAPFAIL_SYSCALL, &cmd); 980 if (IN_CAPABILITY_MODE(td)) { 981 error = ECAPMODE; 982 break; 983 } 984 #endif 985 error = copyin((void *)arg, &kif_sz, sizeof(kif_sz)); 986 if (error != 0) 987 break; 988 if (kif_sz != sizeof(*kif)) { 989 error = EINVAL; 990 break; 991 } 992 kif = malloc(sizeof(*kif), M_TEMP, M_WAITOK | M_ZERO); 993 FILEDESC_SLOCK(fdp); 994 error = fget_cap_noref(fdp, fd, &cap_fcntl_rights, &fp, NULL); 995 if (error == 0 && fhold(fp)) { 996 export_file_to_kinfo(fp, fd, NULL, kif, fdp, 0); 997 FILEDESC_SUNLOCK(fdp); 998 fdrop(fp, td); 999 if ((kif->kf_status & KF_ATTR_VALID) != 0) { 1000 kif->kf_structsize = sizeof(*kif); 1001 error = copyout(kif, (void *)arg, sizeof(*kif)); 1002 } else { 1003 error = EBADF; 1004 } 1005 } else { 1006 FILEDESC_SUNLOCK(fdp); 1007 if (error == 0) 1008 error = EBADF; 1009 } 1010 free(kif, M_TEMP); 1011 break; 1012 1013 default: 1014 if ((cmd & ((1u << F_DUP3FD_SHIFT) - 1)) != F_DUP3FD) 1015 return (EXTERROR(EINVAL, "invalid fcntl cmd")); 1016 /* Handle F_DUP3FD */ 1017 flags = (cmd >> F_DUP3FD_SHIFT); 1018 if ((flags & ~(FD_CLOEXEC | FD_CLOFORK)) != 0) 1019 return (EXTERROR(EINVAL, "invalid flags for F_DUP3FD")); 1020 tmp = arg; 1021 error = kern_dup(td, FDDUP_FIXED, 1022 ((flags & FD_CLOEXEC) != 0 ? FDDUP_FLAG_CLOEXEC : 0) | 1023 ((flags & FD_CLOFORK) != 0 ? FDDUP_FLAG_CLOFORK : 0), 1024 fd, tmp); 1025 break; 1026 } 1027 return (error); 1028 } 1029 1030 static int 1031 getmaxfd(struct thread *td) 1032 { 1033 1034 return (min((int)lim_cur(td, RLIMIT_NOFILE), maxfilesperproc)); 1035 } 1036 1037 /* 1038 * Common code for dup, dup2, fcntl(F_DUPFD) and fcntl(F_DUP2FD). 1039 */ 1040 int 1041 kern_dup(struct thread *td, u_int mode, int flags, int old, int new) 1042 { 1043 struct filedesc *fdp; 1044 struct filedescent *oldfde, *newfde; 1045 struct proc *p; 1046 struct file *delfp, *oldfp; 1047 u_long *oioctls, *nioctls; 1048 int error, maxfd; 1049 1050 p = td->td_proc; 1051 fdp = p->p_fd; 1052 oioctls = NULL; 1053 1054 MPASS((flags & ~(FDDUP_FLAG_CLOEXEC | FDDUP_FLAG_CLOFORK)) == 0); 1055 MPASS(mode < FDDUP_LASTMODE); 1056 1057 AUDIT_ARG_FD(old); 1058 /* XXXRW: if (flags & FDDUP_FIXED) AUDIT_ARG_FD2(new); */ 1059 1060 /* 1061 * Verify we have a valid descriptor to dup from and possibly to 1062 * dup to. Unlike dup() and dup2(), fcntl()'s F_DUPFD should 1063 * return EINVAL when the new descriptor is out of bounds. 1064 */ 1065 if (old < 0) 1066 return (EBADF); 1067 if (new < 0) 1068 return (mode == FDDUP_FCNTL ? EINVAL : EBADF); 1069 maxfd = getmaxfd(td); 1070 if (new >= maxfd) 1071 return (mode == FDDUP_FCNTL ? EINVAL : EBADF); 1072 1073 error = EBADF; 1074 FILEDESC_XLOCK(fdp); 1075 if (fget_noref(fdp, old) == NULL) 1076 goto unlock; 1077 if (mode == FDDUP_FIXED && old == new) { 1078 td->td_retval[0] = new; 1079 fdp->fd_ofiles[new].fde_flags |= fddup_to_fde_flags(flags); 1080 error = 0; 1081 goto unlock; 1082 } 1083 1084 oldfde = &fdp->fd_ofiles[old]; 1085 oldfp = oldfde->fde_file; 1086 if (!fhold(oldfp)) 1087 goto unlock; 1088 1089 /* 1090 * If the caller specified a file descriptor, make sure the file 1091 * table is large enough to hold it, and grab it. Otherwise, just 1092 * allocate a new descriptor the usual way. 1093 */ 1094 switch (mode) { 1095 case FDDUP_NORMAL: 1096 case FDDUP_FCNTL: 1097 if ((error = fdalloc(td, new, &new)) != 0) { 1098 fdrop(oldfp, td); 1099 goto unlock; 1100 } 1101 break; 1102 case FDDUP_FIXED: 1103 if (new >= fdp->fd_nfiles) { 1104 /* 1105 * The resource limits are here instead of e.g. 1106 * fdalloc(), because the file descriptor table may be 1107 * shared between processes, so we can't really use 1108 * racct_add()/racct_sub(). Instead of counting the 1109 * number of actually allocated descriptors, just put 1110 * the limit on the size of the file descriptor table. 1111 */ 1112 #ifdef RACCT 1113 if (RACCT_ENABLED()) { 1114 error = racct_set_unlocked(p, RACCT_NOFILE, new + 1); 1115 if (error != 0) { 1116 error = EMFILE; 1117 fdrop(oldfp, td); 1118 goto unlock; 1119 } 1120 } 1121 #endif 1122 fdgrowtable_exp(fdp, new + 1); 1123 } 1124 if (!fdisused(fdp, new)) 1125 fdused(fdp, new); 1126 break; 1127 default: 1128 KASSERT(0, ("%s unsupported mode %d", __func__, mode)); 1129 } 1130 1131 KASSERT(old != new, ("new fd is same as old")); 1132 1133 /* Refetch oldfde because the table may have grown and old one freed. */ 1134 oldfde = &fdp->fd_ofiles[old]; 1135 KASSERT(oldfp == oldfde->fde_file, 1136 ("fdt_ofiles shift from growth observed at fd %d", 1137 old)); 1138 1139 newfde = &fdp->fd_ofiles[new]; 1140 delfp = newfde->fde_file; 1141 1142 nioctls = filecaps_copy_prep(&oldfde->fde_caps); 1143 1144 /* 1145 * Duplicate the source descriptor. 1146 */ 1147 #ifdef CAPABILITIES 1148 seqc_write_begin(&newfde->fde_seqc); 1149 #endif 1150 oioctls = filecaps_free_prep(&newfde->fde_caps); 1151 fde_copy(oldfde, newfde); 1152 filecaps_copy_finish(&oldfde->fde_caps, &newfde->fde_caps, 1153 nioctls); 1154 newfde->fde_flags = (oldfde->fde_flags & ~(UF_EXCLOSE | UF_FOCLOSE)) | 1155 fddup_to_fde_flags(flags); 1156 #ifdef CAPABILITIES 1157 seqc_write_end(&newfde->fde_seqc); 1158 #endif 1159 td->td_retval[0] = new; 1160 1161 error = 0; 1162 1163 if (delfp != NULL) { 1164 (void) closefp(fdp, new, delfp, td, true, false); 1165 FILEDESC_UNLOCK_ASSERT(fdp); 1166 } else { 1167 unlock: 1168 FILEDESC_XUNLOCK(fdp); 1169 } 1170 1171 filecaps_free_finish(oioctls); 1172 return (error); 1173 } 1174 1175 static void 1176 sigiofree(struct sigio *sigio) 1177 { 1178 crfree(sigio->sio_ucred); 1179 free(sigio, M_SIGIO); 1180 } 1181 1182 static struct sigio * 1183 funsetown_locked(struct sigio *sigio) 1184 { 1185 struct proc *p; 1186 struct pgrp *pg; 1187 1188 SIGIO_ASSERT_LOCKED(); 1189 1190 if (sigio == NULL) 1191 return (NULL); 1192 *sigio->sio_myref = NULL; 1193 if (sigio->sio_pgid < 0) { 1194 pg = sigio->sio_pgrp; 1195 PGRP_LOCK(pg); 1196 SLIST_REMOVE(&pg->pg_sigiolst, sigio, sigio, sio_pgsigio); 1197 PGRP_UNLOCK(pg); 1198 } else { 1199 p = sigio->sio_proc; 1200 PROC_LOCK(p); 1201 SLIST_REMOVE(&p->p_sigiolst, sigio, sigio, sio_pgsigio); 1202 PROC_UNLOCK(p); 1203 } 1204 return (sigio); 1205 } 1206 1207 /* 1208 * If sigio is on the list associated with a process or process group, 1209 * disable signalling from the device, remove sigio from the list and 1210 * free sigio. 1211 */ 1212 void 1213 funsetown(struct sigio **sigiop) 1214 { 1215 struct sigio *sigio; 1216 1217 /* Racy check, consumers must provide synchronization. */ 1218 if (*sigiop == NULL) 1219 return; 1220 1221 SIGIO_LOCK(); 1222 sigio = funsetown_locked(*sigiop); 1223 SIGIO_UNLOCK(); 1224 if (sigio != NULL) 1225 sigiofree(sigio); 1226 } 1227 1228 /* 1229 * Free a list of sigio structures. The caller must ensure that new sigio 1230 * structures cannot be added after this point. For process groups this is 1231 * guaranteed using the proctree lock; for processes, the P_WEXIT flag serves 1232 * as an interlock. 1233 */ 1234 void 1235 funsetownlst(struct sigiolst *sigiolst) 1236 { 1237 struct proc *p; 1238 struct pgrp *pg; 1239 struct sigio *sigio, *tmp; 1240 1241 /* Racy check. */ 1242 sigio = SLIST_FIRST(sigiolst); 1243 if (sigio == NULL) 1244 return; 1245 1246 p = NULL; 1247 pg = NULL; 1248 1249 SIGIO_LOCK(); 1250 sigio = SLIST_FIRST(sigiolst); 1251 if (sigio == NULL) { 1252 SIGIO_UNLOCK(); 1253 return; 1254 } 1255 1256 /* 1257 * Every entry of the list should belong to a single proc or pgrp. 1258 */ 1259 if (sigio->sio_pgid < 0) { 1260 pg = sigio->sio_pgrp; 1261 sx_assert(&proctree_lock, SX_XLOCKED); 1262 PGRP_LOCK(pg); 1263 } else /* if (sigio->sio_pgid > 0) */ { 1264 p = sigio->sio_proc; 1265 PROC_LOCK(p); 1266 KASSERT((p->p_flag & P_WEXIT) != 0, 1267 ("%s: process %p is not exiting", __func__, p)); 1268 } 1269 1270 SLIST_FOREACH(sigio, sigiolst, sio_pgsigio) { 1271 *sigio->sio_myref = NULL; 1272 if (pg != NULL) { 1273 KASSERT(sigio->sio_pgid < 0, 1274 ("Proc sigio in pgrp sigio list")); 1275 KASSERT(sigio->sio_pgrp == pg, 1276 ("Bogus pgrp in sigio list")); 1277 } else /* if (p != NULL) */ { 1278 KASSERT(sigio->sio_pgid > 0, 1279 ("Pgrp sigio in proc sigio list")); 1280 KASSERT(sigio->sio_proc == p, 1281 ("Bogus proc in sigio list")); 1282 } 1283 } 1284 1285 if (pg != NULL) 1286 PGRP_UNLOCK(pg); 1287 else 1288 PROC_UNLOCK(p); 1289 SIGIO_UNLOCK(); 1290 1291 SLIST_FOREACH_SAFE(sigio, sigiolst, sio_pgsigio, tmp) 1292 sigiofree(sigio); 1293 } 1294 1295 /* 1296 * This is common code for FIOSETOWN ioctl called by fcntl(fd, F_SETOWN, arg). 1297 * 1298 * After permission checking, add a sigio structure to the sigio list for 1299 * the process or process group. 1300 */ 1301 int 1302 fsetown(pid_t pgid, struct sigio **sigiop) 1303 { 1304 struct proc *proc; 1305 struct pgrp *pgrp; 1306 struct sigio *osigio, *sigio; 1307 int ret; 1308 1309 if (pgid == 0) { 1310 funsetown(sigiop); 1311 return (0); 1312 } 1313 1314 sigio = malloc(sizeof(struct sigio), M_SIGIO, M_WAITOK); 1315 sigio->sio_pgid = pgid; 1316 sigio->sio_ucred = crhold(curthread->td_ucred); 1317 sigio->sio_myref = sigiop; 1318 1319 ret = 0; 1320 if (pgid > 0) { 1321 ret = pget(pgid, PGET_NOTWEXIT | PGET_NOTID | PGET_HOLD, &proc); 1322 SIGIO_LOCK(); 1323 osigio = funsetown_locked(*sigiop); 1324 if (ret == 0) { 1325 PROC_LOCK(proc); 1326 _PRELE(proc); 1327 if ((proc->p_flag & P_WEXIT) != 0) { 1328 ret = ESRCH; 1329 } else if (proc->p_session != 1330 curthread->td_proc->p_session) { 1331 /* 1332 * Policy - Don't allow a process to FSETOWN a 1333 * process in another session. 1334 * 1335 * Remove this test to allow maximum flexibility 1336 * or restrict FSETOWN to the current process or 1337 * process group for maximum safety. 1338 */ 1339 ret = EPERM; 1340 } else { 1341 sigio->sio_proc = proc; 1342 SLIST_INSERT_HEAD(&proc->p_sigiolst, sigio, 1343 sio_pgsigio); 1344 } 1345 PROC_UNLOCK(proc); 1346 } 1347 } else /* if (pgid < 0) */ { 1348 sx_slock(&proctree_lock); 1349 SIGIO_LOCK(); 1350 osigio = funsetown_locked(*sigiop); 1351 pgrp = pgfind(-pgid); 1352 if (pgrp == NULL) { 1353 ret = ESRCH; 1354 } else { 1355 if (pgrp->pg_session != curthread->td_proc->p_session) { 1356 /* 1357 * Policy - Don't allow a process to FSETOWN a 1358 * process in another session. 1359 * 1360 * Remove this test to allow maximum flexibility 1361 * or restrict FSETOWN to the current process or 1362 * process group for maximum safety. 1363 */ 1364 ret = EPERM; 1365 } else { 1366 sigio->sio_pgrp = pgrp; 1367 SLIST_INSERT_HEAD(&pgrp->pg_sigiolst, sigio, 1368 sio_pgsigio); 1369 } 1370 PGRP_UNLOCK(pgrp); 1371 } 1372 sx_sunlock(&proctree_lock); 1373 } 1374 if (ret == 0) 1375 *sigiop = sigio; 1376 SIGIO_UNLOCK(); 1377 if (osigio != NULL) 1378 sigiofree(osigio); 1379 return (ret); 1380 } 1381 1382 /* 1383 * This is common code for FIOGETOWN ioctl called by fcntl(fd, F_GETOWN, arg). 1384 */ 1385 pid_t 1386 fgetown(struct sigio **sigiop) 1387 { 1388 pid_t pgid; 1389 1390 SIGIO_LOCK(); 1391 pgid = (*sigiop != NULL) ? (*sigiop)->sio_pgid : 0; 1392 SIGIO_UNLOCK(); 1393 return (pgid); 1394 } 1395 1396 static int 1397 closefp_impl(struct filedesc *fdp, int fd, struct file *fp, struct thread *td, 1398 bool audit) 1399 { 1400 int error; 1401 1402 FILEDESC_XLOCK_ASSERT(fdp); 1403 1404 /* 1405 * We now hold the fp reference that used to be owned by the 1406 * descriptor array. We have to unlock the FILEDESC *AFTER* 1407 * knote_fdclose to prevent a race of the fd getting opened, a knote 1408 * added, and deleteing a knote for the new fd. 1409 */ 1410 if (__predict_false(!TAILQ_EMPTY(&fdp->fd_kqlist))) 1411 knote_fdclose(td, fd); 1412 1413 /* 1414 * We need to notify mqueue if the object is of type mqueue. 1415 */ 1416 if (__predict_false(fp->f_type == DTYPE_MQUEUE)) 1417 mq_fdclose(td, fd, fp); 1418 FILEDESC_XUNLOCK(fdp); 1419 1420 #ifdef AUDIT 1421 if (AUDITING_TD(td) && audit) 1422 audit_sysclose(td, fd, fp); 1423 #endif 1424 error = closef(fp, td); 1425 1426 /* 1427 * All paths leading up to closefp() will have already removed or 1428 * replaced the fd in the filedesc table, so a restart would not 1429 * operate on the same file. 1430 */ 1431 if (error == ERESTART) 1432 error = EINTR; 1433 1434 return (error); 1435 } 1436 1437 static int 1438 closefp_hl(struct filedesc *fdp, int fd, struct file *fp, struct thread *td, 1439 bool holdleaders, bool audit) 1440 { 1441 int error; 1442 1443 FILEDESC_XLOCK_ASSERT(fdp); 1444 1445 if (holdleaders) { 1446 if (td->td_proc->p_fdtol != NULL) { 1447 /* 1448 * Ask fdfree() to sleep to ensure that all relevant 1449 * process leaders can be traversed in closef(). 1450 */ 1451 fdp->fd_holdleaderscount++; 1452 } else { 1453 holdleaders = false; 1454 } 1455 } 1456 1457 error = closefp_impl(fdp, fd, fp, td, audit); 1458 if (holdleaders) { 1459 FILEDESC_XLOCK(fdp); 1460 fdp->fd_holdleaderscount--; 1461 if (fdp->fd_holdleaderscount == 0 && 1462 fdp->fd_holdleaderswakeup != 0) { 1463 fdp->fd_holdleaderswakeup = 0; 1464 wakeup(&fdp->fd_holdleaderscount); 1465 } 1466 FILEDESC_XUNLOCK(fdp); 1467 } 1468 return (error); 1469 } 1470 1471 static int 1472 closefp(struct filedesc *fdp, int fd, struct file *fp, struct thread *td, 1473 bool holdleaders, bool audit) 1474 { 1475 1476 FILEDESC_XLOCK_ASSERT(fdp); 1477 1478 if (__predict_false(td->td_proc->p_fdtol != NULL)) { 1479 return (closefp_hl(fdp, fd, fp, td, holdleaders, audit)); 1480 } else { 1481 return (closefp_impl(fdp, fd, fp, td, audit)); 1482 } 1483 } 1484 1485 /* 1486 * Close a file descriptor. 1487 */ 1488 #ifndef _SYS_SYSPROTO_H_ 1489 struct close_args { 1490 int fd; 1491 }; 1492 #endif 1493 /* ARGSUSED */ 1494 int 1495 sys_close(struct thread *td, struct close_args *uap) 1496 { 1497 1498 return (kern_close(td, uap->fd)); 1499 } 1500 1501 int 1502 kern_close(struct thread *td, int fd) 1503 { 1504 struct filedesc *fdp; 1505 struct file *fp; 1506 1507 fdp = td->td_proc->p_fd; 1508 1509 FILEDESC_XLOCK(fdp); 1510 if ((fp = fget_noref(fdp, fd)) == NULL) { 1511 FILEDESC_XUNLOCK(fdp); 1512 return (EBADF); 1513 } 1514 fdfree(fdp, fd); 1515 1516 /* closefp() drops the FILEDESC lock for us. */ 1517 return (closefp(fdp, fd, fp, td, true, true)); 1518 } 1519 1520 static int 1521 close_range_flags(struct thread *td, u_int lowfd, u_int highfd, int flags) 1522 { 1523 struct filedesc *fdp; 1524 struct fdescenttbl *fdt; 1525 struct filedescent *fde; 1526 int fd, fde_flags; 1527 1528 fde_flags = close_range_to_fde_flags(flags); 1529 fdp = td->td_proc->p_fd; 1530 FILEDESC_XLOCK(fdp); 1531 fdt = atomic_load_ptr(&fdp->fd_files); 1532 highfd = MIN(highfd, fdt->fdt_nfiles - 1); 1533 fd = lowfd; 1534 if (__predict_false(fd > highfd)) { 1535 goto out_locked; 1536 } 1537 for (; fd <= highfd; fd++) { 1538 fde = &fdt->fdt_ofiles[fd]; 1539 if (fde->fde_file != NULL) 1540 fde->fde_flags |= fde_flags; 1541 } 1542 out_locked: 1543 FILEDESC_XUNLOCK(fdp); 1544 return (0); 1545 } 1546 1547 static int 1548 close_range_impl(struct thread *td, u_int lowfd, u_int highfd) 1549 { 1550 struct filedesc *fdp; 1551 const struct fdescenttbl *fdt; 1552 struct file *fp; 1553 int fd; 1554 1555 fdp = td->td_proc->p_fd; 1556 FILEDESC_XLOCK(fdp); 1557 fdt = atomic_load_ptr(&fdp->fd_files); 1558 highfd = MIN(highfd, fdt->fdt_nfiles - 1); 1559 fd = lowfd; 1560 if (__predict_false(fd > highfd)) { 1561 goto out_locked; 1562 } 1563 for (;;) { 1564 fp = fdt->fdt_ofiles[fd].fde_file; 1565 if (fp == NULL) { 1566 if (fd == highfd) 1567 goto out_locked; 1568 } else { 1569 fdfree(fdp, fd); 1570 (void) closefp(fdp, fd, fp, td, true, true); 1571 if (fd == highfd) 1572 goto out_unlocked; 1573 FILEDESC_XLOCK(fdp); 1574 fdt = atomic_load_ptr(&fdp->fd_files); 1575 } 1576 fd++; 1577 } 1578 out_locked: 1579 FILEDESC_XUNLOCK(fdp); 1580 out_unlocked: 1581 return (0); 1582 } 1583 1584 int 1585 kern_close_range(struct thread *td, int flags, u_int lowfd, u_int highfd) 1586 { 1587 1588 /* 1589 * Check this prior to clamping; closefrom(3) with only fd 0, 1, and 2 1590 * open should not be a usage error. From a close_range() perspective, 1591 * close_range(3, ~0U, 0) in the same scenario should also likely not 1592 * be a usage error as all fd above 3 are in-fact already closed. 1593 */ 1594 if (highfd < lowfd) { 1595 return (EINVAL); 1596 } 1597 1598 if ((flags & (CLOSE_RANGE_CLOEXEC | CLOSE_RANGE_CLOFORK)) != 0) 1599 return (close_range_flags(td, lowfd, highfd, flags)); 1600 1601 return (close_range_impl(td, lowfd, highfd)); 1602 } 1603 1604 #ifndef _SYS_SYSPROTO_H_ 1605 struct close_range_args { 1606 u_int lowfd; 1607 u_int highfd; 1608 int flags; 1609 }; 1610 #endif 1611 int 1612 sys_close_range(struct thread *td, struct close_range_args *uap) 1613 { 1614 1615 AUDIT_ARG_FD(uap->lowfd); 1616 AUDIT_ARG_CMD(uap->highfd); 1617 AUDIT_ARG_FFLAGS(uap->flags); 1618 1619 if ((uap->flags & ~(CLOSE_RANGE_CLOEXEC | CLOSE_RANGE_CLOFORK)) != 0) 1620 return (EINVAL); 1621 return (kern_close_range(td, uap->flags, uap->lowfd, uap->highfd)); 1622 } 1623 1624 #ifdef COMPAT_FREEBSD12 1625 /* 1626 * Close open file descriptors. 1627 */ 1628 #ifndef _SYS_SYSPROTO_H_ 1629 struct freebsd12_closefrom_args { 1630 int lowfd; 1631 }; 1632 #endif 1633 /* ARGSUSED */ 1634 int 1635 freebsd12_closefrom(struct thread *td, struct freebsd12_closefrom_args *uap) 1636 { 1637 u_int lowfd; 1638 1639 AUDIT_ARG_FD(uap->lowfd); 1640 1641 /* 1642 * Treat negative starting file descriptor values identical to 1643 * closefrom(0) which closes all files. 1644 */ 1645 lowfd = MAX(0, uap->lowfd); 1646 return (kern_close_range(td, 0, lowfd, ~0U)); 1647 } 1648 #endif /* COMPAT_FREEBSD12 */ 1649 1650 #if defined(COMPAT_43) 1651 /* 1652 * Return status information about a file descriptor. 1653 */ 1654 #ifndef _SYS_SYSPROTO_H_ 1655 struct ofstat_args { 1656 int fd; 1657 struct ostat *sb; 1658 }; 1659 #endif 1660 /* ARGSUSED */ 1661 int 1662 ofstat(struct thread *td, struct ofstat_args *uap) 1663 { 1664 struct ostat oub; 1665 struct stat ub; 1666 int error; 1667 1668 error = kern_fstat(td, uap->fd, &ub); 1669 if (error == 0) { 1670 cvtstat(&ub, &oub); 1671 error = copyout(&oub, uap->sb, sizeof(oub)); 1672 } 1673 return (error); 1674 } 1675 #endif /* COMPAT_43 */ 1676 1677 #if defined(COMPAT_FREEBSD11) 1678 int 1679 freebsd11_fstat(struct thread *td, struct freebsd11_fstat_args *uap) 1680 { 1681 struct stat sb; 1682 struct freebsd11_stat osb; 1683 int error; 1684 1685 error = kern_fstat(td, uap->fd, &sb); 1686 if (error != 0) 1687 return (error); 1688 error = freebsd11_cvtstat(&sb, &osb); 1689 if (error == 0) 1690 error = copyout(&osb, uap->sb, sizeof(osb)); 1691 return (error); 1692 } 1693 #endif /* COMPAT_FREEBSD11 */ 1694 1695 /* 1696 * Return status information about a file descriptor. 1697 */ 1698 #ifndef _SYS_SYSPROTO_H_ 1699 struct fstat_args { 1700 int fd; 1701 struct stat *sb; 1702 }; 1703 #endif 1704 /* ARGSUSED */ 1705 int 1706 sys_fstat(struct thread *td, struct fstat_args *uap) 1707 { 1708 struct stat ub; 1709 int error; 1710 1711 error = kern_fstat(td, uap->fd, &ub); 1712 if (error == 0) 1713 error = copyout(&ub, uap->sb, sizeof(ub)); 1714 return (error); 1715 } 1716 1717 int 1718 kern_fstat(struct thread *td, int fd, struct stat *sbp) 1719 { 1720 struct file *fp; 1721 int error; 1722 1723 AUDIT_ARG_FD(fd); 1724 1725 error = fget(td, fd, &cap_fstat_rights, &fp); 1726 if (__predict_false(error != 0)) 1727 return (error); 1728 1729 AUDIT_ARG_FILE(td->td_proc, fp); 1730 1731 sbp->st_filerev = 0; 1732 sbp->st_bsdflags = 0; 1733 error = fo_stat(fp, sbp, td->td_ucred); 1734 fdrop(fp, td); 1735 #ifdef __STAT_TIME_T_EXT 1736 sbp->st_atim_ext = 0; 1737 sbp->st_mtim_ext = 0; 1738 sbp->st_ctim_ext = 0; 1739 sbp->st_btim_ext = 0; 1740 #endif 1741 #ifdef KTRACE 1742 if (KTRPOINT(td, KTR_STRUCT)) 1743 ktrstat_error(sbp, error); 1744 #endif 1745 return (error); 1746 } 1747 1748 #if defined(COMPAT_FREEBSD11) 1749 /* 1750 * Return status information about a file descriptor. 1751 */ 1752 #ifndef _SYS_SYSPROTO_H_ 1753 struct freebsd11_nfstat_args { 1754 int fd; 1755 struct nstat *sb; 1756 }; 1757 #endif 1758 /* ARGSUSED */ 1759 int 1760 freebsd11_nfstat(struct thread *td, struct freebsd11_nfstat_args *uap) 1761 { 1762 struct nstat nub; 1763 struct stat ub; 1764 int error; 1765 1766 error = kern_fstat(td, uap->fd, &ub); 1767 if (error != 0) 1768 return (error); 1769 error = freebsd11_cvtnstat(&ub, &nub); 1770 if (error != 0) 1771 error = copyout(&nub, uap->sb, sizeof(nub)); 1772 return (error); 1773 } 1774 #endif /* COMPAT_FREEBSD11 */ 1775 1776 /* 1777 * Return pathconf information about a file descriptor. 1778 */ 1779 #ifndef _SYS_SYSPROTO_H_ 1780 struct fpathconf_args { 1781 int fd; 1782 int name; 1783 }; 1784 #endif 1785 /* ARGSUSED */ 1786 int 1787 sys_fpathconf(struct thread *td, struct fpathconf_args *uap) 1788 { 1789 long value; 1790 int error; 1791 1792 error = kern_fpathconf(td, uap->fd, uap->name, &value); 1793 if (error == 0) 1794 td->td_retval[0] = value; 1795 return (error); 1796 } 1797 1798 int 1799 kern_fpathconf(struct thread *td, int fd, int name, long *valuep) 1800 { 1801 struct file *fp; 1802 struct vnode *vp; 1803 int error; 1804 1805 error = fget(td, fd, &cap_fpathconf_rights, &fp); 1806 if (error != 0) 1807 return (error); 1808 1809 if (name == _PC_ASYNC_IO) { 1810 *valuep = _POSIX_ASYNCHRONOUS_IO; 1811 goto out; 1812 } 1813 vp = fp->f_vnode; 1814 if (vp != NULL) { 1815 vn_lock(vp, LK_SHARED | LK_RETRY); 1816 error = VOP_PATHCONF(vp, name, valuep); 1817 VOP_UNLOCK(vp); 1818 } else if (fp->f_type == DTYPE_PIPE || fp->f_type == DTYPE_SOCKET) { 1819 if (name != _PC_PIPE_BUF) { 1820 error = EINVAL; 1821 } else { 1822 *valuep = PIPE_BUF; 1823 error = 0; 1824 } 1825 } else { 1826 error = EOPNOTSUPP; 1827 } 1828 out: 1829 fdrop(fp, td); 1830 return (error); 1831 } 1832 1833 /* 1834 * Copy filecaps structure allocating memory for ioctls array if needed. 1835 * 1836 * The last parameter indicates whether the fdtable is locked. If it is not and 1837 * ioctls are encountered, copying fails and the caller must lock the table. 1838 * 1839 * Note that if the table was not locked, the caller has to check the relevant 1840 * sequence counter to determine whether the operation was successful. 1841 */ 1842 bool 1843 filecaps_copy(const struct filecaps *src, struct filecaps *dst, bool locked) 1844 { 1845 size_t size; 1846 1847 if (src->fc_ioctls != NULL && !locked) 1848 return (false); 1849 memcpy(dst, src, sizeof(*src)); 1850 if (src->fc_ioctls == NULL) 1851 return (true); 1852 1853 KASSERT(src->fc_nioctls > 0, 1854 ("fc_ioctls != NULL, but fc_nioctls=%hd", src->fc_nioctls)); 1855 1856 size = sizeof(src->fc_ioctls[0]) * src->fc_nioctls; 1857 dst->fc_ioctls = malloc(size, M_FILECAPS, M_WAITOK); 1858 memcpy(dst->fc_ioctls, src->fc_ioctls, size); 1859 return (true); 1860 } 1861 1862 static u_long * 1863 filecaps_copy_prep(const struct filecaps *src) 1864 { 1865 u_long *ioctls; 1866 size_t size; 1867 1868 if (__predict_true(src->fc_ioctls == NULL)) 1869 return (NULL); 1870 1871 KASSERT(src->fc_nioctls > 0, 1872 ("fc_ioctls != NULL, but fc_nioctls=%hd", src->fc_nioctls)); 1873 1874 size = sizeof(src->fc_ioctls[0]) * src->fc_nioctls; 1875 ioctls = malloc(size, M_FILECAPS, M_WAITOK); 1876 return (ioctls); 1877 } 1878 1879 static void 1880 filecaps_copy_finish(const struct filecaps *src, struct filecaps *dst, 1881 u_long *ioctls) 1882 { 1883 size_t size; 1884 1885 *dst = *src; 1886 if (__predict_true(src->fc_ioctls == NULL)) { 1887 MPASS(ioctls == NULL); 1888 return; 1889 } 1890 1891 size = sizeof(src->fc_ioctls[0]) * src->fc_nioctls; 1892 dst->fc_ioctls = ioctls; 1893 bcopy(src->fc_ioctls, dst->fc_ioctls, size); 1894 } 1895 1896 /* 1897 * Move filecaps structure to the new place and clear the old place. 1898 */ 1899 void 1900 filecaps_move(struct filecaps *src, struct filecaps *dst) 1901 { 1902 1903 *dst = *src; 1904 bzero(src, sizeof(*src)); 1905 } 1906 1907 /* 1908 * Fill the given filecaps structure with full rights. 1909 */ 1910 static void 1911 filecaps_fill(struct filecaps *fcaps) 1912 { 1913 1914 CAP_ALL(&fcaps->fc_rights); 1915 fcaps->fc_ioctls = NULL; 1916 fcaps->fc_nioctls = -1; 1917 fcaps->fc_fcntls = CAP_FCNTL_ALL; 1918 } 1919 1920 /* 1921 * Free memory allocated within filecaps structure. 1922 */ 1923 static void 1924 filecaps_free_ioctl(struct filecaps *fcaps) 1925 { 1926 1927 free(fcaps->fc_ioctls, M_FILECAPS); 1928 fcaps->fc_ioctls = NULL; 1929 } 1930 1931 void 1932 filecaps_free(struct filecaps *fcaps) 1933 { 1934 1935 filecaps_free_ioctl(fcaps); 1936 bzero(fcaps, sizeof(*fcaps)); 1937 } 1938 1939 static u_long * 1940 filecaps_free_prep(struct filecaps *fcaps) 1941 { 1942 u_long *ioctls; 1943 1944 ioctls = fcaps->fc_ioctls; 1945 bzero(fcaps, sizeof(*fcaps)); 1946 return (ioctls); 1947 } 1948 1949 static void 1950 filecaps_free_finish(u_long *ioctls) 1951 { 1952 1953 free(ioctls, M_FILECAPS); 1954 } 1955 1956 /* 1957 * Validate the given filecaps structure. 1958 */ 1959 static void 1960 filecaps_validate(const struct filecaps *fcaps, const char *func) 1961 { 1962 1963 KASSERT(cap_rights_is_valid(&fcaps->fc_rights), 1964 ("%s: invalid rights", func)); 1965 KASSERT((fcaps->fc_fcntls & ~CAP_FCNTL_ALL) == 0, 1966 ("%s: invalid fcntls", func)); 1967 KASSERT(fcaps->fc_fcntls == 0 || 1968 cap_rights_is_set(&fcaps->fc_rights, CAP_FCNTL), 1969 ("%s: fcntls without CAP_FCNTL", func)); 1970 /* 1971 * open calls without WANTIOCTLCAPS free caps but leave the counter 1972 */ 1973 #if 0 1974 KASSERT(fcaps->fc_ioctls != NULL ? fcaps->fc_nioctls > 0 : 1975 (fcaps->fc_nioctls == -1 || fcaps->fc_nioctls == 0), 1976 ("%s: invalid ioctls", func)); 1977 #endif 1978 KASSERT(fcaps->fc_nioctls == 0 || 1979 cap_rights_is_set(&fcaps->fc_rights, CAP_IOCTL), 1980 ("%s: ioctls without CAP_IOCTL", func)); 1981 } 1982 1983 static void 1984 fdgrowtable_exp(struct filedesc *fdp, int nfd) 1985 { 1986 int nfd1; 1987 1988 FILEDESC_XLOCK_ASSERT(fdp); 1989 1990 nfd1 = fdp->fd_nfiles * 2; 1991 if (nfd1 < nfd) 1992 nfd1 = nfd; 1993 fdgrowtable(fdp, nfd1); 1994 } 1995 1996 /* 1997 * Grow the file table to accommodate (at least) nfd descriptors. 1998 */ 1999 static void 2000 fdgrowtable(struct filedesc *fdp, int nfd) 2001 { 2002 struct filedesc0 *fdp0; 2003 struct freetable *ft; 2004 struct fdescenttbl *ntable; 2005 struct fdescenttbl *otable; 2006 int nnfiles, onfiles; 2007 NDSLOTTYPE *nmap, *omap; 2008 2009 KASSERT(fdp->fd_nfiles > 0, ("zero-length file table")); 2010 2011 /* save old values */ 2012 onfiles = fdp->fd_nfiles; 2013 otable = fdp->fd_files; 2014 omap = fdp->fd_map; 2015 2016 /* compute the size of the new table */ 2017 nnfiles = NDSLOTS(nfd) * NDENTRIES; /* round up */ 2018 if (nnfiles <= onfiles) 2019 /* the table is already large enough */ 2020 return; 2021 2022 /* 2023 * Allocate a new table. We need enough space for the number of 2024 * entries, file entries themselves and the struct freetable we will use 2025 * when we decommission the table and place it on the freelist. 2026 * We place the struct freetable in the middle so we don't have 2027 * to worry about padding. 2028 */ 2029 ntable = malloc(offsetof(struct fdescenttbl, fdt_ofiles) + 2030 nnfiles * sizeof(ntable->fdt_ofiles[0]) + 2031 sizeof(struct freetable), 2032 M_FILEDESC, M_ZERO | M_WAITOK); 2033 /* copy the old data */ 2034 ntable->fdt_nfiles = nnfiles; 2035 memcpy(ntable->fdt_ofiles, otable->fdt_ofiles, 2036 onfiles * sizeof(ntable->fdt_ofiles[0])); 2037 2038 /* 2039 * Allocate a new map only if the old is not large enough. It will 2040 * grow at a slower rate than the table as it can map more 2041 * entries than the table can hold. 2042 */ 2043 if (NDSLOTS(nnfiles) > NDSLOTS(onfiles)) { 2044 nmap = malloc(NDSLOTS(nnfiles) * NDSLOTSIZE, M_FILEDESC, 2045 M_ZERO | M_WAITOK); 2046 /* copy over the old data and update the pointer */ 2047 memcpy(nmap, omap, NDSLOTS(onfiles) * sizeof(*omap)); 2048 fdp->fd_map = nmap; 2049 } 2050 2051 /* 2052 * Make sure that ntable is correctly initialized before we replace 2053 * fd_files poiner. Otherwise fget_unlocked() may see inconsistent 2054 * data. 2055 */ 2056 atomic_store_rel_ptr((volatile void *)&fdp->fd_files, (uintptr_t)ntable); 2057 2058 /* 2059 * Free the old file table when not shared by other threads or processes. 2060 * The old file table is considered to be shared when either are true: 2061 * - The process has more than one thread. 2062 * - The file descriptor table has been shared via fdshare(). 2063 * 2064 * When shared, the old file table will be placed on a freelist 2065 * which will be processed when the struct filedesc is released. 2066 * 2067 * Note that if onfiles == NDFILE, we're dealing with the original 2068 * static allocation contained within (struct filedesc0 *)fdp, 2069 * which must not be freed. 2070 */ 2071 if (onfiles > NDFILE) { 2072 /* 2073 * Note we may be called here from fdinit while allocating a 2074 * table for a new process in which case ->p_fd points 2075 * elsewhere. 2076 */ 2077 if (curproc->p_fd != fdp || FILEDESC_IS_ONLY_USER(fdp)) { 2078 free(otable, M_FILEDESC); 2079 } else { 2080 ft = (struct freetable *)&otable->fdt_ofiles[onfiles]; 2081 fdp0 = (struct filedesc0 *)fdp; 2082 ft->ft_table = otable; 2083 SLIST_INSERT_HEAD(&fdp0->fd_free, ft, ft_next); 2084 } 2085 } 2086 /* 2087 * The map does not have the same possibility of threads still 2088 * holding references to it. So always free it as long as it 2089 * does not reference the original static allocation. 2090 */ 2091 if (NDSLOTS(onfiles) > NDSLOTS(NDFILE)) 2092 free(omap, M_FILEDESC); 2093 } 2094 2095 /* 2096 * Allocate a file descriptor for the process. 2097 */ 2098 int 2099 fdalloc(struct thread *td, int minfd, int *result) 2100 { 2101 struct proc *p = td->td_proc; 2102 struct filedesc *fdp = p->p_fd; 2103 int fd, maxfd, allocfd; 2104 #ifdef RACCT 2105 int error; 2106 #endif 2107 2108 FILEDESC_XLOCK_ASSERT(fdp); 2109 2110 if (fdp->fd_freefile > minfd) 2111 minfd = fdp->fd_freefile; 2112 2113 maxfd = getmaxfd(td); 2114 2115 /* 2116 * Search the bitmap for a free descriptor starting at minfd. 2117 * If none is found, grow the file table. 2118 */ 2119 fd = fd_first_free(fdp, minfd, fdp->fd_nfiles); 2120 if (__predict_false(fd >= maxfd)) 2121 return (EMFILE); 2122 if (__predict_false(fd >= fdp->fd_nfiles)) { 2123 allocfd = min(fd * 2, maxfd); 2124 #ifdef RACCT 2125 if (RACCT_ENABLED()) { 2126 error = racct_set_unlocked(p, RACCT_NOFILE, allocfd); 2127 if (error != 0) 2128 return (EMFILE); 2129 } 2130 #endif 2131 /* 2132 * fd is already equal to first free descriptor >= minfd, so 2133 * we only need to grow the table and we are done. 2134 */ 2135 fdgrowtable_exp(fdp, allocfd); 2136 } 2137 2138 /* 2139 * Perform some sanity checks, then mark the file descriptor as 2140 * used and return it to the caller. 2141 */ 2142 KASSERT(fd >= 0 && fd < min(maxfd, fdp->fd_nfiles), 2143 ("invalid descriptor %d", fd)); 2144 KASSERT(!fdisused(fdp, fd), 2145 ("fd_first_free() returned non-free descriptor")); 2146 KASSERT(fdp->fd_ofiles[fd].fde_file == NULL, 2147 ("file descriptor isn't free")); 2148 fdused(fdp, fd); 2149 *result = fd; 2150 return (0); 2151 } 2152 2153 /* 2154 * Allocate n file descriptors for the process. 2155 */ 2156 int 2157 fdallocn(struct thread *td, int minfd, int *fds, int n) 2158 { 2159 struct proc *p = td->td_proc; 2160 struct filedesc *fdp = p->p_fd; 2161 int i; 2162 2163 FILEDESC_XLOCK_ASSERT(fdp); 2164 2165 for (i = 0; i < n; i++) 2166 if (fdalloc(td, 0, &fds[i]) != 0) 2167 break; 2168 2169 if (i < n) { 2170 for (i--; i >= 0; i--) 2171 fdunused(fdp, fds[i]); 2172 return (EMFILE); 2173 } 2174 2175 return (0); 2176 } 2177 2178 /* 2179 * Create a new open file structure and allocate a file descriptor for the 2180 * process that refers to it. We add one reference to the file for the 2181 * descriptor table and one reference for resultfp. This is to prevent us 2182 * being preempted and the entry in the descriptor table closed after we 2183 * release the FILEDESC lock. 2184 */ 2185 int 2186 falloc_caps(struct thread *td, struct file **resultfp, int *resultfd, int flags, 2187 struct filecaps *fcaps) 2188 { 2189 struct file *fp; 2190 int error, fd; 2191 2192 MPASS(resultfp != NULL); 2193 MPASS(resultfd != NULL); 2194 2195 error = _falloc_noinstall(td, &fp, 2); 2196 if (__predict_false(error != 0)) { 2197 return (error); 2198 } 2199 2200 error = finstall_refed(td, fp, &fd, flags, fcaps); 2201 if (__predict_false(error != 0)) { 2202 falloc_abort(td, fp); 2203 return (error); 2204 } 2205 2206 *resultfp = fp; 2207 *resultfd = fd; 2208 2209 return (0); 2210 } 2211 2212 /* 2213 * Create a new open file structure without allocating a file descriptor. 2214 */ 2215 int 2216 _falloc_noinstall(struct thread *td, struct file **resultfp, u_int n) 2217 { 2218 struct file *fp; 2219 int maxuserfiles = maxfiles - (maxfiles / 20); 2220 int openfiles_new; 2221 static struct timeval lastfail; 2222 static int curfail; 2223 2224 KASSERT(resultfp != NULL, ("%s: resultfp == NULL", __func__)); 2225 MPASS(n > 0); 2226 2227 openfiles_new = atomic_fetchadd_int(&openfiles, 1) + 1; 2228 if ((openfiles_new >= maxuserfiles && 2229 priv_check(td, PRIV_MAXFILES) != 0) || 2230 openfiles_new >= maxfiles) { 2231 atomic_subtract_int(&openfiles, 1); 2232 if (ppsratecheck(&lastfail, &curfail, 1)) { 2233 printf("kern.maxfiles limit exceeded by uid %i, (%s) " 2234 "please see tuning(7).\n", td->td_ucred->cr_ruid, td->td_proc->p_comm); 2235 } 2236 return (ENFILE); 2237 } 2238 fp = uma_zalloc(file_zone, M_WAITOK); 2239 bzero(fp, sizeof(*fp)); 2240 refcount_init(&fp->f_count, n); 2241 fp->f_cred = crhold(td->td_ucred); 2242 fp->f_ops = &badfileops; 2243 *resultfp = fp; 2244 return (0); 2245 } 2246 2247 void 2248 falloc_abort(struct thread *td, struct file *fp) 2249 { 2250 2251 /* 2252 * For assertion purposes. 2253 */ 2254 refcount_init(&fp->f_count, 0); 2255 _fdrop(fp, td); 2256 } 2257 2258 /* 2259 * Install a file in a file descriptor table. 2260 */ 2261 void 2262 _finstall(struct filedesc *fdp, struct file *fp, int fd, int flags, 2263 struct filecaps *fcaps) 2264 { 2265 struct filedescent *fde; 2266 2267 MPASS(fp != NULL); 2268 if (fcaps != NULL) 2269 filecaps_validate(fcaps, __func__); 2270 FILEDESC_XLOCK_ASSERT(fdp); 2271 2272 fde = &fdp->fd_ofiles[fd]; 2273 #ifdef CAPABILITIES 2274 seqc_write_begin(&fde->fde_seqc); 2275 #endif 2276 fde->fde_file = fp; 2277 fde->fde_flags = open_to_fde_flags(flags, true); 2278 if (fcaps != NULL) 2279 filecaps_move(fcaps, &fde->fde_caps); 2280 else 2281 filecaps_fill(&fde->fde_caps); 2282 #ifdef CAPABILITIES 2283 seqc_write_end(&fde->fde_seqc); 2284 #endif 2285 } 2286 2287 int 2288 finstall_refed(struct thread *td, struct file *fp, int *fd, int flags, 2289 struct filecaps *fcaps) 2290 { 2291 struct filedesc *fdp = td->td_proc->p_fd; 2292 int error; 2293 2294 MPASS(fd != NULL); 2295 2296 FILEDESC_XLOCK(fdp); 2297 error = fdalloc(td, 0, fd); 2298 if (__predict_true(error == 0)) { 2299 _finstall(fdp, fp, *fd, flags, fcaps); 2300 } 2301 FILEDESC_XUNLOCK(fdp); 2302 return (error); 2303 } 2304 2305 int 2306 finstall(struct thread *td, struct file *fp, int *fd, int flags, 2307 struct filecaps *fcaps) 2308 { 2309 int error; 2310 2311 MPASS(fd != NULL); 2312 2313 if (!fhold(fp)) 2314 return (EBADF); 2315 error = finstall_refed(td, fp, fd, flags, fcaps); 2316 if (__predict_false(error != 0)) { 2317 fdrop(fp, td); 2318 } 2319 return (error); 2320 } 2321 2322 /* 2323 * Build a new filedesc structure from another. 2324 * 2325 * If fdp is not NULL, return with it shared locked. 2326 */ 2327 struct filedesc * 2328 fdinit(void) 2329 { 2330 struct filedesc0 *newfdp0; 2331 struct filedesc *newfdp; 2332 2333 newfdp0 = uma_zalloc(filedesc0_zone, M_WAITOK | M_ZERO); 2334 newfdp = &newfdp0->fd_fd; 2335 2336 /* Create the file descriptor table. */ 2337 FILEDESC_LOCK_INIT(newfdp); 2338 refcount_init(&newfdp->fd_refcnt, 1); 2339 refcount_init(&newfdp->fd_holdcnt, 1); 2340 newfdp->fd_map = newfdp0->fd_dmap; 2341 newfdp->fd_files = (struct fdescenttbl *)&newfdp0->fd_dfiles; 2342 newfdp->fd_files->fdt_nfiles = NDFILE; 2343 2344 return (newfdp); 2345 } 2346 2347 /* 2348 * Build a pwddesc structure from another. 2349 * Copy the current, root, and jail root vnode references. 2350 * 2351 * If pdp is not NULL and keeplock is true, return with it (exclusively) locked. 2352 */ 2353 struct pwddesc * 2354 pdinit(struct pwddesc *pdp, bool keeplock) 2355 { 2356 struct pwddesc *newpdp; 2357 struct pwd *newpwd; 2358 2359 newpdp = malloc(sizeof(*newpdp), M_PWDDESC, M_WAITOK | M_ZERO); 2360 2361 PWDDESC_LOCK_INIT(newpdp); 2362 refcount_init(&newpdp->pd_refcount, 1); 2363 newpdp->pd_cmask = CMASK; 2364 2365 if (pdp == NULL) { 2366 newpwd = pwd_alloc(); 2367 smr_serialized_store(&newpdp->pd_pwd, newpwd, true); 2368 return (newpdp); 2369 } 2370 2371 PWDDESC_XLOCK(pdp); 2372 newpwd = pwd_hold_pwddesc(pdp); 2373 smr_serialized_store(&newpdp->pd_pwd, newpwd, true); 2374 if (!keeplock) 2375 PWDDESC_XUNLOCK(pdp); 2376 return (newpdp); 2377 } 2378 2379 /* 2380 * Hold either filedesc or pwddesc of the passed process. 2381 * 2382 * The process lock is used to synchronize against the target exiting and 2383 * freeing the data. 2384 * 2385 * Clearing can be ilustrated in 3 steps: 2386 * 1. set the pointer to NULL. Either routine can race against it, hence 2387 * atomic_load_ptr. 2388 * 2. observe the process lock as not taken. Until then fdhold/pdhold can 2389 * race to either still see the pointer or find NULL. It is still safe to 2390 * grab a reference as clearing is stalled. 2391 * 3. after the lock is observed as not taken, any fdhold/pdhold calls are 2392 * guaranteed to see NULL, making it safe to finish clearing 2393 */ 2394 static struct filedesc * 2395 fdhold(struct proc *p) 2396 { 2397 struct filedesc *fdp; 2398 2399 PROC_LOCK_ASSERT(p, MA_OWNED); 2400 fdp = atomic_load_ptr(&p->p_fd); 2401 if (fdp != NULL) 2402 refcount_acquire(&fdp->fd_holdcnt); 2403 return (fdp); 2404 } 2405 2406 static struct pwddesc * 2407 pdhold(struct proc *p) 2408 { 2409 struct pwddesc *pdp; 2410 2411 PROC_LOCK_ASSERT(p, MA_OWNED); 2412 pdp = atomic_load_ptr(&p->p_pd); 2413 if (pdp != NULL) 2414 refcount_acquire(&pdp->pd_refcount); 2415 return (pdp); 2416 } 2417 2418 static void 2419 fddrop(struct filedesc *fdp) 2420 { 2421 2422 if (refcount_load(&fdp->fd_holdcnt) > 1) { 2423 if (refcount_release(&fdp->fd_holdcnt) == 0) 2424 return; 2425 } 2426 2427 FILEDESC_LOCK_DESTROY(fdp); 2428 uma_zfree(filedesc0_zone, fdp); 2429 } 2430 2431 static void 2432 pddrop(struct pwddesc *pdp) 2433 { 2434 struct pwd *pwd; 2435 2436 if (refcount_release_if_not_last(&pdp->pd_refcount)) 2437 return; 2438 2439 PWDDESC_XLOCK(pdp); 2440 if (refcount_release(&pdp->pd_refcount) == 0) { 2441 PWDDESC_XUNLOCK(pdp); 2442 return; 2443 } 2444 pwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); 2445 pwd_set(pdp, NULL); 2446 PWDDESC_XUNLOCK(pdp); 2447 pwd_drop(pwd); 2448 2449 PWDDESC_LOCK_DESTROY(pdp); 2450 free(pdp, M_PWDDESC); 2451 } 2452 2453 /* 2454 * Share a filedesc structure. 2455 */ 2456 struct filedesc * 2457 fdshare(struct filedesc *fdp) 2458 { 2459 2460 refcount_acquire(&fdp->fd_refcnt); 2461 return (fdp); 2462 } 2463 2464 /* 2465 * Share a pwddesc structure. 2466 */ 2467 struct pwddesc * 2468 pdshare(struct pwddesc *pdp) 2469 { 2470 refcount_acquire(&pdp->pd_refcount); 2471 return (pdp); 2472 } 2473 2474 /* 2475 * Unshare a filedesc structure, if necessary by making a copy 2476 */ 2477 void 2478 fdunshare(struct thread *td) 2479 { 2480 struct filedesc *tmp; 2481 struct proc *p = td->td_proc; 2482 2483 if (refcount_load(&p->p_fd->fd_refcnt) == 1) 2484 return; 2485 2486 tmp = fdcopy(p->p_fd); 2487 fdescfree(td); 2488 p->p_fd = tmp; 2489 } 2490 2491 /* 2492 * Unshare a pwddesc structure. 2493 */ 2494 void 2495 pdunshare(struct thread *td) 2496 { 2497 struct pwddesc *pdp; 2498 struct proc *p; 2499 2500 p = td->td_proc; 2501 /* Not shared. */ 2502 if (refcount_load(&p->p_pd->pd_refcount) == 1) 2503 return; 2504 2505 pdp = pdcopy(p->p_pd); 2506 pdescfree(td); 2507 p->p_pd = pdp; 2508 } 2509 2510 /* 2511 * Copy a filedesc structure. A NULL pointer in returns a NULL reference, 2512 * this is to ease callers, not catch errors. 2513 */ 2514 struct filedesc * 2515 fdcopy(struct filedesc *fdp) 2516 { 2517 struct filedesc *newfdp; 2518 struct filedescent *nfde, *ofde; 2519 int i, lastfile; 2520 2521 MPASS(fdp != NULL); 2522 2523 newfdp = fdinit(); 2524 FILEDESC_SLOCK(fdp); 2525 for (;;) { 2526 lastfile = fdlastfile(fdp); 2527 if (lastfile < newfdp->fd_nfiles) 2528 break; 2529 FILEDESC_SUNLOCK(fdp); 2530 fdgrowtable(newfdp, lastfile + 1); 2531 FILEDESC_SLOCK(fdp); 2532 } 2533 /* copy all passable descriptors (i.e. not kqueue) */ 2534 newfdp->fd_freefile = fdp->fd_freefile; 2535 FILEDESC_FOREACH_FDE(fdp, i, ofde) { 2536 if ((ofde->fde_file->f_ops->fo_flags & DFLAG_PASSABLE) == 0 || 2537 (ofde->fde_flags & UF_FOCLOSE) != 0 || 2538 !fhold(ofde->fde_file)) { 2539 if (newfdp->fd_freefile == fdp->fd_freefile) 2540 newfdp->fd_freefile = i; 2541 continue; 2542 } 2543 nfde = &newfdp->fd_ofiles[i]; 2544 *nfde = *ofde; 2545 filecaps_copy(&ofde->fde_caps, &nfde->fde_caps, true); 2546 fdused_init(newfdp, i); 2547 } 2548 MPASS(newfdp->fd_freefile != -1); 2549 FILEDESC_SUNLOCK(fdp); 2550 return (newfdp); 2551 } 2552 2553 /* 2554 * Copy a pwddesc structure. 2555 */ 2556 struct pwddesc * 2557 pdcopy(struct pwddesc *pdp) 2558 { 2559 struct pwddesc *newpdp; 2560 2561 MPASS(pdp != NULL); 2562 2563 newpdp = pdinit(pdp, true); 2564 newpdp->pd_cmask = pdp->pd_cmask; 2565 PWDDESC_XUNLOCK(pdp); 2566 return (newpdp); 2567 } 2568 2569 /* 2570 * Clear POSIX style locks. This is only used when fdp looses a reference (i.e. 2571 * one of processes using it exits) and the table used to be shared. 2572 */ 2573 static void 2574 fdclearlocks(struct thread *td) 2575 { 2576 struct filedesc *fdp; 2577 struct filedesc_to_leader *fdtol; 2578 struct flock lf; 2579 struct file *fp; 2580 struct proc *p; 2581 struct vnode *vp; 2582 int i; 2583 2584 p = td->td_proc; 2585 fdp = p->p_fd; 2586 fdtol = p->p_fdtol; 2587 MPASS(fdtol != NULL); 2588 2589 FILEDESC_XLOCK(fdp); 2590 KASSERT(fdtol->fdl_refcount > 0, 2591 ("filedesc_to_refcount botch: fdl_refcount=%d", 2592 fdtol->fdl_refcount)); 2593 if (fdtol->fdl_refcount == 1 && 2594 (p->p_leader->p_flag & P_ADVLOCK) != 0) { 2595 FILEDESC_FOREACH_FP(fdp, i, fp) { 2596 if (fp->f_type != DTYPE_VNODE || 2597 !fhold(fp)) 2598 continue; 2599 FILEDESC_XUNLOCK(fdp); 2600 lf.l_whence = SEEK_SET; 2601 lf.l_start = 0; 2602 lf.l_len = 0; 2603 lf.l_type = F_UNLCK; 2604 vp = fp->f_vnode; 2605 (void) VOP_ADVLOCK(vp, 2606 (caddr_t)p->p_leader, F_UNLCK, 2607 &lf, F_POSIX); 2608 FILEDESC_XLOCK(fdp); 2609 fdrop(fp, td); 2610 } 2611 } 2612 retry: 2613 if (fdtol->fdl_refcount == 1) { 2614 if (fdp->fd_holdleaderscount > 0 && 2615 (p->p_leader->p_flag & P_ADVLOCK) != 0) { 2616 /* 2617 * close() or kern_dup() has cleared a reference 2618 * in a shared file descriptor table. 2619 */ 2620 fdp->fd_holdleaderswakeup = 1; 2621 sx_sleep(&fdp->fd_holdleaderscount, 2622 FILEDESC_LOCK(fdp), PLOCK, "fdlhold", 0); 2623 goto retry; 2624 } 2625 if (fdtol->fdl_holdcount > 0) { 2626 /* 2627 * Ensure that fdtol->fdl_leader remains 2628 * valid in closef(). 2629 */ 2630 fdtol->fdl_wakeup = 1; 2631 sx_sleep(fdtol, FILEDESC_LOCK(fdp), PLOCK, 2632 "fdlhold", 0); 2633 goto retry; 2634 } 2635 } 2636 fdtol->fdl_refcount--; 2637 if (fdtol->fdl_refcount == 0 && 2638 fdtol->fdl_holdcount == 0) { 2639 fdtol->fdl_next->fdl_prev = fdtol->fdl_prev; 2640 fdtol->fdl_prev->fdl_next = fdtol->fdl_next; 2641 } else 2642 fdtol = NULL; 2643 p->p_fdtol = NULL; 2644 FILEDESC_XUNLOCK(fdp); 2645 if (fdtol != NULL) 2646 free(fdtol, M_FILEDESC_TO_LEADER); 2647 } 2648 2649 /* 2650 * Release a filedesc structure. 2651 */ 2652 static void 2653 fdescfree_fds(struct thread *td, struct filedesc *fdp) 2654 { 2655 struct filedesc0 *fdp0; 2656 struct freetable *ft, *tft; 2657 struct filedescent *fde; 2658 struct file *fp; 2659 int i; 2660 2661 KASSERT(refcount_load(&fdp->fd_refcnt) == 0, 2662 ("%s: fd table %p carries references", __func__, fdp)); 2663 2664 /* 2665 * Serialize with threads iterating over the table, if any. 2666 */ 2667 if (refcount_load(&fdp->fd_holdcnt) > 1) { 2668 FILEDESC_XLOCK(fdp); 2669 FILEDESC_XUNLOCK(fdp); 2670 } 2671 2672 FILEDESC_FOREACH_FDE(fdp, i, fde) { 2673 fp = fde->fde_file; 2674 fdefree_last(fde); 2675 (void) closef(fp, td); 2676 } 2677 2678 if (NDSLOTS(fdp->fd_nfiles) > NDSLOTS(NDFILE)) 2679 free(fdp->fd_map, M_FILEDESC); 2680 if (fdp->fd_nfiles > NDFILE) 2681 free(fdp->fd_files, M_FILEDESC); 2682 2683 fdp0 = (struct filedesc0 *)fdp; 2684 SLIST_FOREACH_SAFE(ft, &fdp0->fd_free, ft_next, tft) 2685 free(ft->ft_table, M_FILEDESC); 2686 2687 fddrop(fdp); 2688 } 2689 2690 void 2691 fdescfree(struct thread *td) 2692 { 2693 struct proc *p; 2694 struct filedesc *fdp; 2695 2696 p = td->td_proc; 2697 fdp = p->p_fd; 2698 MPASS(fdp != NULL); 2699 2700 #ifdef RACCT 2701 if (RACCT_ENABLED()) 2702 racct_set_unlocked(p, RACCT_NOFILE, 0); 2703 #endif 2704 2705 if (p->p_fdtol != NULL) 2706 fdclearlocks(td); 2707 2708 /* 2709 * Check fdhold for an explanation. 2710 */ 2711 atomic_store_ptr(&p->p_fd, NULL); 2712 atomic_thread_fence_seq_cst(); 2713 PROC_WAIT_UNLOCKED(p); 2714 2715 if (refcount_release(&fdp->fd_refcnt) == 0) 2716 return; 2717 2718 fdescfree_fds(td, fdp); 2719 } 2720 2721 void 2722 pdescfree(struct thread *td) 2723 { 2724 struct proc *p; 2725 struct pwddesc *pdp; 2726 2727 p = td->td_proc; 2728 pdp = p->p_pd; 2729 MPASS(pdp != NULL); 2730 2731 /* 2732 * Check pdhold for an explanation. 2733 */ 2734 atomic_store_ptr(&p->p_pd, NULL); 2735 atomic_thread_fence_seq_cst(); 2736 PROC_WAIT_UNLOCKED(p); 2737 2738 pddrop(pdp); 2739 } 2740 2741 /* 2742 * For setugid programs, we don't want to people to use that setugidness 2743 * to generate error messages which write to a file which otherwise would 2744 * otherwise be off-limits to the process. We check for filesystems where 2745 * the vnode can change out from under us after execve (like [lin]procfs). 2746 * 2747 * Since fdsetugidsafety calls this only for fd 0, 1 and 2, this check is 2748 * sufficient. We also don't check for setugidness since we know we are. 2749 */ 2750 static bool 2751 is_unsafe(struct file *fp) 2752 { 2753 struct vnode *vp; 2754 2755 if (fp->f_type != DTYPE_VNODE) 2756 return (false); 2757 2758 vp = fp->f_vnode; 2759 return ((vp->v_vflag & VV_PROCDEP) != 0); 2760 } 2761 2762 /* 2763 * Make this setguid thing safe, if at all possible. 2764 */ 2765 void 2766 fdsetugidsafety(struct thread *td) 2767 { 2768 struct filedesc *fdp; 2769 struct file *fp; 2770 int i; 2771 2772 fdp = td->td_proc->p_fd; 2773 KASSERT(refcount_load(&fdp->fd_refcnt) == 1, 2774 ("the fdtable should not be shared")); 2775 MPASS(fdp->fd_nfiles >= 3); 2776 for (i = 0; i <= 2; i++) { 2777 fp = fdp->fd_ofiles[i].fde_file; 2778 if (fp != NULL && is_unsafe(fp)) { 2779 FILEDESC_XLOCK(fdp); 2780 knote_fdclose(td, i); 2781 /* 2782 * NULL-out descriptor prior to close to avoid 2783 * a race while close blocks. 2784 */ 2785 fdfree(fdp, i); 2786 FILEDESC_XUNLOCK(fdp); 2787 (void) closef(fp, td); 2788 } 2789 } 2790 } 2791 2792 /* 2793 * If a specific file object occupies a specific file descriptor, close the 2794 * file descriptor entry and drop a reference on the file object. This is a 2795 * convenience function to handle a subsequent error in a function that calls 2796 * falloc() that handles the race that another thread might have closed the 2797 * file descriptor out from under the thread creating the file object. 2798 */ 2799 void 2800 fdclose(struct thread *td, struct file *fp, int idx) 2801 { 2802 struct filedesc *fdp = td->td_proc->p_fd; 2803 2804 FILEDESC_XLOCK(fdp); 2805 if (fdp->fd_ofiles[idx].fde_file == fp) { 2806 fdfree(fdp, idx); 2807 FILEDESC_XUNLOCK(fdp); 2808 fdrop(fp, td); 2809 } else 2810 FILEDESC_XUNLOCK(fdp); 2811 } 2812 2813 /* 2814 * Close any files on exec? 2815 */ 2816 void 2817 fdcloseexec(struct thread *td) 2818 { 2819 struct filedesc *fdp; 2820 struct filedescent *fde; 2821 struct file *fp; 2822 int i; 2823 2824 fdp = td->td_proc->p_fd; 2825 KASSERT(refcount_load(&fdp->fd_refcnt) == 1, 2826 ("the fdtable should not be shared")); 2827 FILEDESC_FOREACH_FDE(fdp, i, fde) { 2828 fp = fde->fde_file; 2829 if (fp->f_type == DTYPE_MQUEUE || 2830 (fde->fde_flags & UF_EXCLOSE)) { 2831 FILEDESC_XLOCK(fdp); 2832 fdfree(fdp, i); 2833 (void) closefp(fdp, i, fp, td, false, false); 2834 FILEDESC_UNLOCK_ASSERT(fdp); 2835 } else if (fde->fde_flags & UF_FOCLOSE) { 2836 /* 2837 * https://austingroupbugs.net/view.php?id=1851 2838 * FD_CLOFORK should not be preserved across exec 2839 */ 2840 fde->fde_flags &= ~UF_FOCLOSE; 2841 } 2842 } 2843 } 2844 2845 /* 2846 * It is unsafe for set[ug]id processes to be started with file 2847 * descriptors 0..2 closed, as these descriptors are given implicit 2848 * significance in the Standard C library. fdcheckstd() will create a 2849 * descriptor referencing /dev/null for each of stdin, stdout, and 2850 * stderr that is not already open. 2851 */ 2852 int 2853 fdcheckstd(struct thread *td) 2854 { 2855 struct filedesc *fdp; 2856 register_t save; 2857 int i, error, devnull; 2858 2859 fdp = td->td_proc->p_fd; 2860 KASSERT(refcount_load(&fdp->fd_refcnt) == 1, 2861 ("the fdtable should not be shared")); 2862 MPASS(fdp->fd_nfiles >= 3); 2863 devnull = -1; 2864 for (i = 0; i <= 2; i++) { 2865 if (fdp->fd_ofiles[i].fde_file != NULL) 2866 continue; 2867 2868 save = td->td_retval[0]; 2869 if (devnull != -1) { 2870 error = kern_dup(td, FDDUP_FIXED, 0, devnull, i); 2871 } else { 2872 error = kern_openat(td, AT_FDCWD, "/dev/null", 2873 UIO_SYSSPACE, O_RDWR, 0); 2874 if (error == 0) { 2875 devnull = td->td_retval[0]; 2876 KASSERT(devnull == i, ("we didn't get our fd")); 2877 } 2878 } 2879 td->td_retval[0] = save; 2880 if (error != 0) 2881 return (error); 2882 } 2883 return (0); 2884 } 2885 2886 /* 2887 * Internal form of close. Decrement reference count on file structure. 2888 * Note: td may be NULL when closing a file that was being passed in a 2889 * message. 2890 */ 2891 int 2892 closef(struct file *fp, struct thread *td) 2893 { 2894 struct vnode *vp; 2895 struct flock lf; 2896 struct filedesc_to_leader *fdtol; 2897 struct filedesc *fdp; 2898 2899 MPASS(td != NULL); 2900 2901 /* 2902 * POSIX record locking dictates that any close releases ALL 2903 * locks owned by this process. This is handled by setting 2904 * a flag in the unlock to free ONLY locks obeying POSIX 2905 * semantics, and not to free BSD-style file locks. 2906 * If the descriptor was in a message, POSIX-style locks 2907 * aren't passed with the descriptor, and the thread pointer 2908 * will be NULL. Callers should be careful only to pass a 2909 * NULL thread pointer when there really is no owning 2910 * context that might have locks, or the locks will be 2911 * leaked. 2912 */ 2913 if (fp->f_type == DTYPE_VNODE) { 2914 vp = fp->f_vnode; 2915 if ((td->td_proc->p_leader->p_flag & P_ADVLOCK) != 0) { 2916 lf.l_whence = SEEK_SET; 2917 lf.l_start = 0; 2918 lf.l_len = 0; 2919 lf.l_type = F_UNLCK; 2920 (void) VOP_ADVLOCK(vp, (caddr_t)td->td_proc->p_leader, 2921 F_UNLCK, &lf, F_POSIX); 2922 } 2923 fdtol = td->td_proc->p_fdtol; 2924 if (fdtol != NULL) { 2925 /* 2926 * Handle special case where file descriptor table is 2927 * shared between multiple process leaders. 2928 */ 2929 fdp = td->td_proc->p_fd; 2930 FILEDESC_XLOCK(fdp); 2931 for (fdtol = fdtol->fdl_next; 2932 fdtol != td->td_proc->p_fdtol; 2933 fdtol = fdtol->fdl_next) { 2934 if ((fdtol->fdl_leader->p_flag & 2935 P_ADVLOCK) == 0) 2936 continue; 2937 fdtol->fdl_holdcount++; 2938 FILEDESC_XUNLOCK(fdp); 2939 lf.l_whence = SEEK_SET; 2940 lf.l_start = 0; 2941 lf.l_len = 0; 2942 lf.l_type = F_UNLCK; 2943 vp = fp->f_vnode; 2944 (void) VOP_ADVLOCK(vp, 2945 (caddr_t)fdtol->fdl_leader, F_UNLCK, &lf, 2946 F_POSIX); 2947 FILEDESC_XLOCK(fdp); 2948 fdtol->fdl_holdcount--; 2949 if (fdtol->fdl_holdcount == 0 && 2950 fdtol->fdl_wakeup != 0) { 2951 fdtol->fdl_wakeup = 0; 2952 wakeup(fdtol); 2953 } 2954 } 2955 FILEDESC_XUNLOCK(fdp); 2956 } 2957 } 2958 return (fdrop_close(fp, td)); 2959 } 2960 2961 /* 2962 * Hack for file descriptor passing code. 2963 */ 2964 void 2965 closef_nothread(struct file *fp) 2966 { 2967 2968 fdrop(fp, NULL); 2969 } 2970 2971 /* 2972 * Initialize the file pointer with the specified properties. 2973 * 2974 * The ops are set with release semantics to be certain that the flags, type, 2975 * and data are visible when ops is. This is to prevent ops methods from being 2976 * called with bad data. 2977 */ 2978 void 2979 finit(struct file *fp, u_int flag, short type, void *data, 2980 const struct fileops *ops) 2981 { 2982 fp->f_data = data; 2983 fp->f_flag = flag; 2984 fp->f_type = type; 2985 atomic_store_rel_ptr((volatile uintptr_t *)&fp->f_ops, (uintptr_t)ops); 2986 } 2987 2988 void 2989 finit_vnode(struct file *fp, u_int flag, void *data, const struct fileops *ops) 2990 { 2991 fp->f_seqcount[UIO_READ] = 1; 2992 fp->f_seqcount[UIO_WRITE] = 1; 2993 finit(fp, (flag & FMASK) | (fp->f_flag & FHASLOCK), DTYPE_VNODE, 2994 data, ops); 2995 } 2996 2997 int 2998 fget_cap_noref(struct filedesc *fdp, int fd, const cap_rights_t *needrightsp, 2999 struct file **fpp, struct filecaps *havecapsp) 3000 { 3001 struct filedescent *fde; 3002 int error; 3003 3004 FILEDESC_LOCK_ASSERT(fdp); 3005 3006 *fpp = NULL; 3007 fde = fdeget_noref(fdp, fd); 3008 if (fde == NULL) { 3009 error = EBADF; 3010 goto out; 3011 } 3012 3013 #ifdef CAPABILITIES 3014 error = cap_check(cap_rights_fde_inline(fde), needrightsp); 3015 if (error != 0) 3016 goto out; 3017 #endif 3018 3019 if (havecapsp != NULL) 3020 filecaps_copy(&fde->fde_caps, havecapsp, true); 3021 3022 *fpp = fde->fde_file; 3023 3024 error = 0; 3025 out: 3026 return (error); 3027 } 3028 3029 #ifdef CAPABILITIES 3030 int 3031 fget_cap(struct thread *td, int fd, const cap_rights_t *needrightsp, 3032 uint8_t *flagsp, struct file **fpp, struct filecaps *havecapsp) 3033 { 3034 struct filedesc *fdp = td->td_proc->p_fd; 3035 int error; 3036 struct file *fp; 3037 seqc_t seq; 3038 3039 *fpp = NULL; 3040 for (;;) { 3041 error = fget_unlocked_seq(td, fd, needrightsp, flagsp, &fp, 3042 &seq); 3043 if (error != 0) 3044 return (error); 3045 3046 if (havecapsp != NULL) { 3047 if (!filecaps_copy(&fdp->fd_ofiles[fd].fde_caps, 3048 havecapsp, false)) { 3049 fdrop(fp, td); 3050 goto get_locked; 3051 } 3052 } 3053 3054 if (!fd_modified(fdp, fd, seq)) 3055 break; 3056 fdrop(fp, td); 3057 } 3058 3059 *fpp = fp; 3060 return (0); 3061 3062 get_locked: 3063 FILEDESC_SLOCK(fdp); 3064 error = fget_cap_noref(fdp, fd, needrightsp, fpp, havecapsp); 3065 if (error == 0 && !fhold(*fpp)) 3066 error = EBADF; 3067 FILEDESC_SUNLOCK(fdp); 3068 return (error); 3069 } 3070 #else 3071 int 3072 fget_cap(struct thread *td, int fd, const cap_rights_t *needrightsp, 3073 uint8_t *flagsp, struct file **fpp, struct filecaps *havecapsp) 3074 { 3075 int error; 3076 error = fget_unlocked_flags(td, fd, needrightsp, flagsp, fpp); 3077 if (havecapsp != NULL && error == 0) 3078 filecaps_fill(havecapsp); 3079 3080 return (error); 3081 } 3082 #endif 3083 3084 int 3085 fget_remote(struct thread *td, struct proc *p, int fd, struct file **fpp) 3086 { 3087 struct filedesc *fdp; 3088 struct file *fp; 3089 int error; 3090 3091 if (p == td->td_proc) /* curproc */ 3092 return (fget_unlocked(td, fd, &cap_no_rights, fpp)); 3093 3094 PROC_LOCK(p); 3095 fdp = fdhold(p); 3096 PROC_UNLOCK(p); 3097 if (fdp == NULL) 3098 return (ENOENT); 3099 FILEDESC_SLOCK(fdp); 3100 if (refcount_load(&fdp->fd_refcnt) != 0) { 3101 fp = fget_noref(fdp, fd); 3102 if (fp != NULL && fhold(fp)) { 3103 *fpp = fp; 3104 error = 0; 3105 } else { 3106 error = EBADF; 3107 } 3108 } else { 3109 error = ENOENT; 3110 } 3111 FILEDESC_SUNLOCK(fdp); 3112 fddrop(fdp); 3113 return (error); 3114 } 3115 3116 int 3117 fget_remote_foreach(struct thread *td, struct proc *p, 3118 int (*fn)(struct proc *, int, struct file *, void *), void *arg) 3119 { 3120 struct filedesc *fdp; 3121 struct fdescenttbl *fdt; 3122 struct file *fp; 3123 int error, error1, fd, highfd; 3124 3125 error = 0; 3126 PROC_LOCK(p); 3127 fdp = fdhold(p); 3128 PROC_UNLOCK(p); 3129 if (fdp == NULL) 3130 return (ENOENT); 3131 3132 FILEDESC_SLOCK(fdp); 3133 if (refcount_load(&fdp->fd_refcnt) != 0) { 3134 fdt = atomic_load_ptr(&fdp->fd_files); 3135 highfd = fdt->fdt_nfiles - 1; 3136 FILEDESC_SUNLOCK(fdp); 3137 } else { 3138 error = ENOENT; 3139 FILEDESC_SUNLOCK(fdp); 3140 goto out; 3141 } 3142 3143 for (fd = 0; fd <= highfd; fd++) { 3144 error1 = fget_remote(td, p, fd, &fp); 3145 if (error1 != 0) 3146 continue; 3147 error = fn(p, fd, fp, arg); 3148 fdrop(fp, td); 3149 if (error != 0) 3150 break; 3151 } 3152 out: 3153 fddrop(fdp); 3154 return (error); 3155 } 3156 3157 #ifdef CAPABILITIES 3158 int 3159 fgetvp_lookup_smr(struct nameidata *ndp, struct vnode **vpp, int *flagsp) 3160 { 3161 const struct filedescent *fde; 3162 const struct fdescenttbl *fdt; 3163 struct filedesc *fdp; 3164 struct file *fp; 3165 struct vnode *vp; 3166 const cap_rights_t *haverights; 3167 cap_rights_t rights; 3168 seqc_t seq; 3169 int fd, flags; 3170 3171 VFS_SMR_ASSERT_ENTERED(); 3172 3173 fd = ndp->ni_dirfd; 3174 rights = *ndp->ni_rightsneeded; 3175 cap_rights_set_one(&rights, CAP_LOOKUP); 3176 3177 fdp = curproc->p_fd; 3178 fdt = fdp->fd_files; 3179 if (__predict_false((u_int)fd >= fdt->fdt_nfiles)) 3180 return (EBADF); 3181 seq = seqc_read_notmodify(fd_seqc(fdt, fd)); 3182 fde = &fdt->fdt_ofiles[fd]; 3183 haverights = cap_rights_fde_inline(fde); 3184 fp = fde->fde_file; 3185 if (__predict_false(fp == NULL)) 3186 return (EAGAIN); 3187 if (__predict_false(cap_check_inline_transient(haverights, &rights))) 3188 return (EAGAIN); 3189 flags = fp->f_flag & FSEARCH; 3190 flags |= (fde->fde_flags & UF_RESOLVE_BENEATH) != 0 ? 3191 O_RESOLVE_BENEATH : 0; 3192 vp = fp->f_vnode; 3193 if (__predict_false(vp == NULL)) { 3194 return (EAGAIN); 3195 } 3196 if (!filecaps_copy(&fde->fde_caps, &ndp->ni_filecaps, false)) { 3197 return (EAGAIN); 3198 } 3199 /* 3200 * Use an acquire barrier to force re-reading of fdt so it is 3201 * refreshed for verification. 3202 */ 3203 atomic_thread_fence_acq(); 3204 fdt = fdp->fd_files; 3205 if (__predict_false(!seqc_consistent_no_fence(fd_seqc(fdt, fd), seq))) 3206 return (EAGAIN); 3207 /* 3208 * If file descriptor doesn't have all rights, 3209 * all lookups relative to it must also be 3210 * strictly relative. 3211 * 3212 * Not yet supported by fast path. 3213 */ 3214 CAP_ALL(&rights); 3215 if (!cap_rights_contains(&ndp->ni_filecaps.fc_rights, &rights) || 3216 ndp->ni_filecaps.fc_fcntls != CAP_FCNTL_ALL || 3217 ndp->ni_filecaps.fc_nioctls != -1) { 3218 #ifdef notyet 3219 ndp->ni_lcf |= NI_LCF_STRICTREL; 3220 #else 3221 return (EAGAIN); 3222 #endif 3223 } 3224 *vpp = vp; 3225 *flagsp = flags; 3226 return (0); 3227 } 3228 #else 3229 int 3230 fgetvp_lookup_smr(struct nameidata *ndp, struct vnode **vpp, int *flagsp) 3231 { 3232 const struct filedescent *fde; 3233 const struct fdescenttbl *fdt; 3234 struct filedesc *fdp; 3235 struct file *fp; 3236 struct vnode *vp; 3237 int fd, flags; 3238 3239 VFS_SMR_ASSERT_ENTERED(); 3240 3241 fd = ndp->ni_dirfd; 3242 fdp = curproc->p_fd; 3243 fdt = fdp->fd_files; 3244 if (__predict_false((u_int)fd >= fdt->fdt_nfiles)) 3245 return (EBADF); 3246 fde = &fdt->fdt_ofiles[fd]; 3247 fp = fde->fde_file; 3248 if (__predict_false(fp == NULL)) 3249 return (EAGAIN); 3250 flags = fp->f_flag & FSEARCH; 3251 flags |= (fde->fde_flags & UF_RESOLVE_BENEATH) != 0 ? 3252 O_RESOLVE_BENEATH : 0; 3253 vp = fp->f_vnode; 3254 if (__predict_false(vp == NULL || vp->v_type != VDIR)) { 3255 return (EAGAIN); 3256 } 3257 /* 3258 * Use an acquire barrier to force re-reading of fdt so it is 3259 * refreshed for verification. 3260 */ 3261 atomic_thread_fence_acq(); 3262 fdt = fdp->fd_files; 3263 if (__predict_false(fp != fdt->fdt_ofiles[fd].fde_file)) 3264 return (EAGAIN); 3265 filecaps_fill(&ndp->ni_filecaps); 3266 *vpp = vp; 3267 *flagsp = flags; 3268 return (0); 3269 } 3270 #endif 3271 3272 int 3273 fgetvp_lookup(struct nameidata *ndp, struct vnode **vpp) 3274 { 3275 struct thread *td; 3276 struct file *fp; 3277 struct vnode *vp; 3278 struct componentname *cnp; 3279 cap_rights_t rights; 3280 int error; 3281 uint8_t flags; 3282 3283 td = curthread; 3284 rights = *ndp->ni_rightsneeded; 3285 cap_rights_set_one(&rights, CAP_LOOKUP); 3286 cnp = &ndp->ni_cnd; 3287 3288 error = fget_cap(td, ndp->ni_dirfd, &rights, &flags, &fp, 3289 &ndp->ni_filecaps); 3290 if (__predict_false(error != 0)) 3291 return (error); 3292 if (__predict_false(fp->f_ops == &badfileops)) { 3293 error = EBADF; 3294 goto out_free; 3295 } 3296 vp = fp->f_vnode; 3297 if (__predict_false(vp == NULL)) { 3298 error = ENOTDIR; 3299 goto out_free; 3300 } 3301 vrefact(vp); 3302 /* 3303 * XXX does not check for VDIR, handled by namei_setup 3304 */ 3305 if ((fp->f_flag & FSEARCH) != 0) 3306 cnp->cn_flags |= NOEXECCHECK; 3307 if ((flags & UF_RESOLVE_BENEATH) != 0) { 3308 cnp->cn_flags |= RBENEATH; 3309 ndp->ni_resflags |= NIRES_BENEATH; 3310 } 3311 fdrop(fp, td); 3312 3313 #ifdef CAPABILITIES 3314 /* 3315 * If file descriptor doesn't have all rights, 3316 * all lookups relative to it must also be 3317 * strictly relative. 3318 */ 3319 CAP_ALL(&rights); 3320 if (!cap_rights_contains(&ndp->ni_filecaps.fc_rights, &rights) || 3321 ndp->ni_filecaps.fc_fcntls != CAP_FCNTL_ALL || 3322 ndp->ni_filecaps.fc_nioctls != -1) { 3323 ndp->ni_lcf |= NI_LCF_STRICTREL; 3324 ndp->ni_resflags |= NIRES_STRICTREL; 3325 } 3326 #endif 3327 3328 /* 3329 * TODO: avoid copying ioctl caps if it can be helped to begin with 3330 */ 3331 if ((cnp->cn_flags & WANTIOCTLCAPS) == 0) 3332 filecaps_free_ioctl(&ndp->ni_filecaps); 3333 3334 *vpp = vp; 3335 return (0); 3336 3337 out_free: 3338 filecaps_free(&ndp->ni_filecaps); 3339 fdrop(fp, td); 3340 return (error); 3341 } 3342 3343 /* 3344 * Fetch the descriptor locklessly. 3345 * 3346 * We avoid fdrop() races by never raising a refcount above 0. To accomplish 3347 * this we have to use a cmpset loop rather than an atomic_add. The descriptor 3348 * must be re-verified once we acquire a reference to be certain that the 3349 * identity is still correct and we did not lose a race due to preemption. 3350 * 3351 * Force a reload of fdt when looping. Another thread could reallocate 3352 * the table before this fd was closed, so it is possible that there is 3353 * a stale fp pointer in cached version. 3354 */ 3355 #ifdef CAPABILITIES 3356 static int 3357 fget_unlocked_seq(struct thread *td, int fd, const cap_rights_t *needrightsp, 3358 uint8_t *flagsp, struct file **fpp, seqc_t *seqp) 3359 { 3360 struct filedesc *fdp; 3361 const struct filedescent *fde; 3362 const struct fdescenttbl *fdt; 3363 struct file *fp; 3364 seqc_t seq; 3365 cap_rights_t haverights; 3366 int error; 3367 uint8_t flags; 3368 3369 fdp = td->td_proc->p_fd; 3370 fdt = fdp->fd_files; 3371 if (__predict_false((u_int)fd >= fdt->fdt_nfiles)) 3372 return (EBADF); 3373 3374 for (;;) { 3375 seq = seqc_read_notmodify(fd_seqc(fdt, fd)); 3376 fde = &fdt->fdt_ofiles[fd]; 3377 haverights = *cap_rights_fde_inline(fde); 3378 fp = fde->fde_file; 3379 flags = fde->fde_flags; 3380 if (__predict_false(fp == NULL)) { 3381 if (seqc_consistent(fd_seqc(fdt, fd), seq)) 3382 return (EBADF); 3383 fdt = atomic_load_ptr(&fdp->fd_files); 3384 continue; 3385 } 3386 error = cap_check_inline(&haverights, needrightsp); 3387 if (__predict_false(error != 0)) { 3388 if (seqc_consistent(fd_seqc(fdt, fd), seq)) 3389 return (error); 3390 fdt = atomic_load_ptr(&fdp->fd_files); 3391 continue; 3392 } 3393 if (__predict_false(!refcount_acquire_if_not_zero(&fp->f_count))) { 3394 fdt = atomic_load_ptr(&fdp->fd_files); 3395 continue; 3396 } 3397 /* 3398 * Use an acquire barrier to force re-reading of fdt so it is 3399 * refreshed for verification. 3400 */ 3401 atomic_thread_fence_acq(); 3402 fdt = fdp->fd_files; 3403 if (seqc_consistent_no_fence(fd_seqc(fdt, fd), seq)) 3404 break; 3405 fdrop(fp, td); 3406 } 3407 *fpp = fp; 3408 if (flagsp != NULL) 3409 *flagsp = flags; 3410 if (seqp != NULL) 3411 *seqp = seq; 3412 return (0); 3413 } 3414 #else 3415 static int 3416 fget_unlocked_seq(struct thread *td, int fd, const cap_rights_t *needrightsp, 3417 uint8_t *flagsp, struct file **fpp, seqc_t *seqp __unused) 3418 { 3419 struct filedesc *fdp; 3420 const struct fdescenttbl *fdt; 3421 struct file *fp; 3422 uint8_t flags; 3423 3424 fdp = td->td_proc->p_fd; 3425 fdt = fdp->fd_files; 3426 if (__predict_false((u_int)fd >= fdt->fdt_nfiles)) 3427 return (EBADF); 3428 3429 for (;;) { 3430 fp = fdt->fdt_ofiles[fd].fde_file; 3431 flags = fdt->fdt_ofiles[fd].fde_flags; 3432 if (__predict_false(fp == NULL)) 3433 return (EBADF); 3434 if (__predict_false(!refcount_acquire_if_not_zero(&fp->f_count))) { 3435 fdt = atomic_load_ptr(&fdp->fd_files); 3436 continue; 3437 } 3438 /* 3439 * Use an acquire barrier to force re-reading of fdt so it is 3440 * refreshed for verification. 3441 */ 3442 atomic_thread_fence_acq(); 3443 fdt = fdp->fd_files; 3444 if (__predict_true(fp == fdt->fdt_ofiles[fd].fde_file)) 3445 break; 3446 fdrop(fp, td); 3447 } 3448 if (flagsp != NULL) 3449 *flagsp = flags; 3450 *fpp = fp; 3451 return (0); 3452 } 3453 #endif 3454 3455 /* 3456 * See the comments in fget_unlocked_seq for an explanation of how this works. 3457 * 3458 * This is a simplified variant which bails out to the aforementioned routine 3459 * if anything goes wrong. In practice this only happens when userspace is 3460 * racing with itself. 3461 */ 3462 int 3463 fget_unlocked_flags(struct thread *td, int fd, const cap_rights_t *needrightsp, 3464 uint8_t *flagsp, struct file **fpp) 3465 { 3466 struct filedesc *fdp; 3467 #ifdef CAPABILITIES 3468 const struct filedescent *fde; 3469 #endif 3470 const struct fdescenttbl *fdt; 3471 struct file *fp; 3472 #ifdef CAPABILITIES 3473 seqc_t seq; 3474 const cap_rights_t *haverights; 3475 #endif 3476 uint8_t flags; 3477 3478 fdp = td->td_proc->p_fd; 3479 fdt = fdp->fd_files; 3480 if (__predict_false((u_int)fd >= fdt->fdt_nfiles)) { 3481 *fpp = NULL; 3482 return (EBADF); 3483 } 3484 #ifdef CAPABILITIES 3485 seq = seqc_read_notmodify(fd_seqc(fdt, fd)); 3486 fde = &fdt->fdt_ofiles[fd]; 3487 haverights = cap_rights_fde_inline(fde); 3488 fp = fde->fde_file; 3489 flags = fde->fde_flags; 3490 #else 3491 fp = fdt->fdt_ofiles[fd].fde_file; 3492 flags = fdt->fdt_ofiles[fd].fde_flags; 3493 #endif 3494 if (__predict_false(fp == NULL)) 3495 goto out_fallback; 3496 #ifdef CAPABILITIES 3497 if (__predict_false(cap_check_inline_transient(haverights, needrightsp))) 3498 goto out_fallback; 3499 #endif 3500 if (__predict_false(!refcount_acquire_if_not_zero(&fp->f_count))) 3501 goto out_fallback; 3502 3503 /* 3504 * Use an acquire barrier to force re-reading of fdt so it is 3505 * refreshed for verification. 3506 */ 3507 atomic_thread_fence_acq(); 3508 fdt = fdp->fd_files; 3509 #ifdef CAPABILITIES 3510 if (__predict_false(!seqc_consistent_no_fence(fd_seqc(fdt, fd), seq))) 3511 #else 3512 if (__predict_false(fp != fdt->fdt_ofiles[fd].fde_file)) 3513 #endif 3514 goto out_fdrop; 3515 *fpp = fp; 3516 if (flagsp != NULL) 3517 *flagsp = flags; 3518 return (0); 3519 out_fdrop: 3520 fdrop(fp, td); 3521 out_fallback: 3522 *fpp = NULL; 3523 return (fget_unlocked_seq(td, fd, needrightsp, flagsp, fpp, NULL)); 3524 } 3525 3526 int 3527 fget_unlocked(struct thread *td, int fd, const cap_rights_t *needrightsp, 3528 struct file **fpp) 3529 { 3530 return (fget_unlocked_flags(td, fd, needrightsp, NULL, fpp)); 3531 } 3532 3533 /* 3534 * Translate fd -> file when the caller guarantees the file descriptor table 3535 * can't be changed by others. 3536 * 3537 * Note this does not mean the file object itself is only visible to the caller, 3538 * merely that it wont disappear without having to be referenced. 3539 * 3540 * Must be paired with fput_only_user. 3541 */ 3542 #ifdef CAPABILITIES 3543 int 3544 fget_only_user(struct filedesc *fdp, int fd, const cap_rights_t *needrightsp, 3545 struct file **fpp) 3546 { 3547 const struct filedescent *fde; 3548 const struct fdescenttbl *fdt; 3549 const cap_rights_t *haverights; 3550 struct file *fp; 3551 int error; 3552 3553 MPASS(FILEDESC_IS_ONLY_USER(fdp)); 3554 3555 *fpp = NULL; 3556 if (__predict_false(fd >= fdp->fd_nfiles)) 3557 return (EBADF); 3558 3559 fdt = fdp->fd_files; 3560 fde = &fdt->fdt_ofiles[fd]; 3561 fp = fde->fde_file; 3562 if (__predict_false(fp == NULL)) 3563 return (EBADF); 3564 MPASS(refcount_load(&fp->f_count) > 0); 3565 haverights = cap_rights_fde_inline(fde); 3566 error = cap_check_inline(haverights, needrightsp); 3567 if (__predict_false(error != 0)) 3568 return (error); 3569 *fpp = fp; 3570 return (0); 3571 } 3572 #else 3573 int 3574 fget_only_user(struct filedesc *fdp, int fd, const cap_rights_t *needrightsp, 3575 struct file **fpp) 3576 { 3577 struct file *fp; 3578 3579 MPASS(FILEDESC_IS_ONLY_USER(fdp)); 3580 3581 *fpp = NULL; 3582 if (__predict_false(fd >= fdp->fd_nfiles)) 3583 return (EBADF); 3584 3585 fp = fdp->fd_ofiles[fd].fde_file; 3586 if (__predict_false(fp == NULL)) 3587 return (EBADF); 3588 3589 MPASS(refcount_load(&fp->f_count) > 0); 3590 *fpp = fp; 3591 return (0); 3592 } 3593 #endif 3594 3595 /* 3596 * Extract the file pointer associated with the specified descriptor for the 3597 * current user process. 3598 * 3599 * If the descriptor doesn't exist or doesn't match 'flags', EBADF is 3600 * returned. 3601 * 3602 * File's rights will be checked against the capability rights mask. 3603 * 3604 * If an error occurred the non-zero error is returned and *fpp is set to 3605 * NULL. Otherwise *fpp is held and set and zero is returned. Caller is 3606 * responsible for fdrop(). 3607 */ 3608 static __inline int 3609 _fget(struct thread *td, int fd, struct file **fpp, int flags, 3610 const cap_rights_t *needrightsp) 3611 { 3612 struct file *fp; 3613 int error; 3614 3615 *fpp = NULL; 3616 error = fget_unlocked(td, fd, needrightsp, &fp); 3617 if (__predict_false(error != 0)) 3618 return (error); 3619 if (__predict_false(fp->f_ops == &badfileops)) { 3620 fdrop(fp, td); 3621 return (EBADF); 3622 } 3623 3624 /* 3625 * FREAD and FWRITE failure return EBADF as per POSIX. 3626 */ 3627 error = 0; 3628 switch (flags) { 3629 case FREAD: 3630 case FWRITE: 3631 if ((fp->f_flag & flags) == 0) 3632 error = EBADF; 3633 break; 3634 case FEXEC: 3635 if (fp->f_ops != &path_fileops && 3636 ((fp->f_flag & (FREAD | FEXEC)) == 0 || 3637 (fp->f_flag & FWRITE) != 0)) 3638 error = EBADF; 3639 break; 3640 case 0: 3641 break; 3642 default: 3643 KASSERT(0, ("wrong flags")); 3644 } 3645 3646 if (error != 0) { 3647 fdrop(fp, td); 3648 return (error); 3649 } 3650 3651 *fpp = fp; 3652 return (0); 3653 } 3654 3655 int 3656 fget(struct thread *td, int fd, const cap_rights_t *rightsp, struct file **fpp) 3657 { 3658 3659 return (_fget(td, fd, fpp, 0, rightsp)); 3660 } 3661 3662 int 3663 fget_mmap(struct thread *td, int fd, const cap_rights_t *rightsp, 3664 vm_prot_t *maxprotp, struct file **fpp) 3665 { 3666 int error; 3667 #ifndef CAPABILITIES 3668 error = _fget(td, fd, fpp, 0, rightsp); 3669 if (maxprotp != NULL) 3670 *maxprotp = VM_PROT_ALL; 3671 return (error); 3672 #else 3673 cap_rights_t fdrights; 3674 struct filedesc *fdp; 3675 struct file *fp; 3676 seqc_t seq; 3677 3678 *fpp = NULL; 3679 fdp = td->td_proc->p_fd; 3680 MPASS(cap_rights_is_set(rightsp, CAP_MMAP)); 3681 for (;;) { 3682 error = fget_unlocked_seq(td, fd, rightsp, NULL, &fp, &seq); 3683 if (__predict_false(error != 0)) 3684 return (error); 3685 if (__predict_false(fp->f_ops == &badfileops)) { 3686 fdrop(fp, td); 3687 return (EBADF); 3688 } 3689 if (maxprotp != NULL) 3690 fdrights = *cap_rights(fdp, fd); 3691 if (!fd_modified(fdp, fd, seq)) 3692 break; 3693 fdrop(fp, td); 3694 } 3695 3696 /* 3697 * If requested, convert capability rights to access flags. 3698 */ 3699 if (maxprotp != NULL) 3700 *maxprotp = cap_rights_to_vmprot(&fdrights); 3701 *fpp = fp; 3702 return (0); 3703 #endif 3704 } 3705 3706 int 3707 fget_read(struct thread *td, int fd, const cap_rights_t *rightsp, 3708 struct file **fpp) 3709 { 3710 3711 return (_fget(td, fd, fpp, FREAD, rightsp)); 3712 } 3713 3714 int 3715 fget_write(struct thread *td, int fd, const cap_rights_t *rightsp, 3716 struct file **fpp) 3717 { 3718 3719 return (_fget(td, fd, fpp, FWRITE, rightsp)); 3720 } 3721 3722 int 3723 fget_fcntl(struct thread *td, int fd, const cap_rights_t *rightsp, 3724 int needfcntl, struct file **fpp) 3725 { 3726 #ifndef CAPABILITIES 3727 return (fget_unlocked(td, fd, rightsp, fpp)); 3728 #else 3729 struct filedesc *fdp = td->td_proc->p_fd; 3730 struct file *fp; 3731 int error; 3732 seqc_t seq; 3733 3734 *fpp = NULL; 3735 MPASS(cap_rights_is_set(rightsp, CAP_FCNTL)); 3736 for (;;) { 3737 error = fget_unlocked_seq(td, fd, rightsp, NULL, &fp, &seq); 3738 if (error != 0) 3739 return (error); 3740 error = cap_fcntl_check(fdp, fd, needfcntl); 3741 if (!fd_modified(fdp, fd, seq)) 3742 break; 3743 fdrop(fp, td); 3744 } 3745 if (error != 0) { 3746 fdrop(fp, td); 3747 return (error); 3748 } 3749 *fpp = fp; 3750 return (0); 3751 #endif 3752 } 3753 3754 /* 3755 * Like fget() but loads the underlying vnode, or returns an error if the 3756 * descriptor does not represent a vnode. Note that pipes use vnodes but 3757 * never have VM objects. The returned vnode will be vref()'d. 3758 * 3759 * XXX: what about the unused flags ? 3760 */ 3761 static __inline int 3762 _fgetvp(struct thread *td, int fd, int flags, const cap_rights_t *needrightsp, 3763 struct vnode **vpp) 3764 { 3765 struct file *fp; 3766 int error; 3767 3768 *vpp = NULL; 3769 error = _fget(td, fd, &fp, flags, needrightsp); 3770 if (error != 0) 3771 return (error); 3772 if (fp->f_vnode == NULL) { 3773 error = EINVAL; 3774 } else { 3775 *vpp = fp->f_vnode; 3776 vrefact(*vpp); 3777 } 3778 fdrop(fp, td); 3779 3780 return (error); 3781 } 3782 3783 int 3784 fgetvp(struct thread *td, int fd, const cap_rights_t *rightsp, 3785 struct vnode **vpp) 3786 { 3787 3788 return (_fgetvp(td, fd, 0, rightsp, vpp)); 3789 } 3790 3791 int 3792 fgetvp_rights(struct thread *td, int fd, const cap_rights_t *needrightsp, 3793 struct filecaps *havecaps, struct vnode **vpp) 3794 { 3795 struct filecaps caps; 3796 struct file *fp; 3797 int error; 3798 3799 error = fget_cap(td, fd, needrightsp, NULL, &fp, &caps); 3800 if (error != 0) 3801 return (error); 3802 if (fp->f_ops == &badfileops) { 3803 error = EBADF; 3804 goto out; 3805 } 3806 if (fp->f_vnode == NULL) { 3807 error = EINVAL; 3808 goto out; 3809 } 3810 3811 *havecaps = caps; 3812 *vpp = fp->f_vnode; 3813 vrefact(*vpp); 3814 fdrop(fp, td); 3815 3816 return (0); 3817 out: 3818 filecaps_free(&caps); 3819 fdrop(fp, td); 3820 return (error); 3821 } 3822 3823 int 3824 fgetvp_read(struct thread *td, int fd, const cap_rights_t *rightsp, 3825 struct vnode **vpp) 3826 { 3827 3828 return (_fgetvp(td, fd, FREAD, rightsp, vpp)); 3829 } 3830 3831 int 3832 fgetvp_exec(struct thread *td, int fd, const cap_rights_t *rightsp, 3833 struct vnode **vpp) 3834 { 3835 3836 return (_fgetvp(td, fd, FEXEC, rightsp, vpp)); 3837 } 3838 3839 #ifdef notyet 3840 int 3841 fgetvp_write(struct thread *td, int fd, const cap_rights_t *rightsp, 3842 struct vnode **vpp) 3843 { 3844 3845 return (_fgetvp(td, fd, FWRITE, rightsp, vpp)); 3846 } 3847 #endif 3848 3849 /* 3850 * Handle the last reference to a file being closed. 3851 * 3852 * Without the noinline attribute clang keeps inlining the func thorough this 3853 * file when fdrop is used. 3854 */ 3855 int __noinline 3856 _fdrop(struct file *fp, struct thread *td) 3857 { 3858 int error; 3859 3860 KASSERT(refcount_load(&fp->f_count) == 0, 3861 ("fdrop: fp %p count %d", fp, refcount_load(&fp->f_count))); 3862 3863 error = fo_close(fp, td); 3864 atomic_subtract_int(&openfiles, 1); 3865 crfree(fp->f_cred); 3866 free(fp->f_advice, M_FADVISE); 3867 uma_zfree(file_zone, fp); 3868 3869 return (error); 3870 } 3871 3872 /* 3873 * Apply an advisory lock on a file descriptor. 3874 * 3875 * Just attempt to get a record lock of the requested type on the entire file 3876 * (l_whence = SEEK_SET, l_start = 0, l_len = 0). 3877 */ 3878 #ifndef _SYS_SYSPROTO_H_ 3879 struct flock_args { 3880 int fd; 3881 int how; 3882 }; 3883 #endif 3884 /* ARGSUSED */ 3885 int 3886 sys_flock(struct thread *td, struct flock_args *uap) 3887 { 3888 struct file *fp; 3889 struct vnode *vp; 3890 struct flock lf; 3891 int error; 3892 3893 error = fget(td, uap->fd, &cap_flock_rights, &fp); 3894 if (error != 0) 3895 return (error); 3896 error = EOPNOTSUPP; 3897 if (fp->f_type != DTYPE_VNODE && fp->f_type != DTYPE_FIFO) { 3898 goto done; 3899 } 3900 if (fp->f_ops == &path_fileops) { 3901 goto done; 3902 } 3903 3904 error = 0; 3905 vp = fp->f_vnode; 3906 lf.l_whence = SEEK_SET; 3907 lf.l_start = 0; 3908 lf.l_len = 0; 3909 if (uap->how & LOCK_UN) { 3910 lf.l_type = F_UNLCK; 3911 atomic_clear_int(&fp->f_flag, FHASLOCK); 3912 error = VOP_ADVLOCK(vp, (caddr_t)fp, F_UNLCK, &lf, F_FLOCK); 3913 goto done; 3914 } 3915 if (uap->how & LOCK_EX) 3916 lf.l_type = F_WRLCK; 3917 else if (uap->how & LOCK_SH) 3918 lf.l_type = F_RDLCK; 3919 else { 3920 error = EBADF; 3921 goto done; 3922 } 3923 atomic_set_int(&fp->f_flag, FHASLOCK); 3924 error = VOP_ADVLOCK(vp, (caddr_t)fp, F_SETLK, &lf, 3925 (uap->how & LOCK_NB) ? F_FLOCK : F_FLOCK | F_WAIT); 3926 done: 3927 fdrop(fp, td); 3928 return (error); 3929 } 3930 /* 3931 * Duplicate the specified descriptor to a free descriptor. 3932 */ 3933 int 3934 dupfdopen(struct thread *td, struct filedesc *fdp, int dfd, int mode, 3935 int openerror, int *indxp) 3936 { 3937 struct filedescent *newfde, *oldfde; 3938 struct file *fp; 3939 u_long *ioctls; 3940 int error, indx; 3941 3942 KASSERT(openerror == ENODEV || openerror == ENXIO, 3943 ("unexpected error %d in %s", openerror, __func__)); 3944 3945 /* 3946 * If the to-be-dup'd fd number is greater than the allowed number 3947 * of file descriptors, or the fd to be dup'd has already been 3948 * closed, then reject. 3949 */ 3950 FILEDESC_XLOCK(fdp); 3951 if ((fp = fget_noref(fdp, dfd)) == NULL) { 3952 FILEDESC_XUNLOCK(fdp); 3953 return (EBADF); 3954 } 3955 3956 error = fdalloc(td, 0, &indx); 3957 if (error != 0) { 3958 FILEDESC_XUNLOCK(fdp); 3959 return (error); 3960 } 3961 3962 /* 3963 * There are two cases of interest here. 3964 * 3965 * For ENODEV simply dup (dfd) to file descriptor (indx) and return. 3966 * 3967 * For ENXIO steal away the file structure from (dfd) and store it in 3968 * (indx). (dfd) is effectively closed by this operation. 3969 */ 3970 switch (openerror) { 3971 case ENODEV: 3972 /* 3973 * Check that the mode the file is being opened for is a 3974 * subset of the mode of the existing descriptor. 3975 */ 3976 if (((mode & (FREAD|FWRITE)) | fp->f_flag) != fp->f_flag) { 3977 fdunused(fdp, indx); 3978 FILEDESC_XUNLOCK(fdp); 3979 return (EACCES); 3980 } 3981 if (!fhold(fp)) { 3982 fdunused(fdp, indx); 3983 FILEDESC_XUNLOCK(fdp); 3984 return (EBADF); 3985 } 3986 newfde = &fdp->fd_ofiles[indx]; 3987 oldfde = &fdp->fd_ofiles[dfd]; 3988 ioctls = filecaps_copy_prep(&oldfde->fde_caps); 3989 #ifdef CAPABILITIES 3990 seqc_write_begin(&newfde->fde_seqc); 3991 #endif 3992 fde_copy(oldfde, newfde); 3993 filecaps_copy_finish(&oldfde->fde_caps, &newfde->fde_caps, 3994 ioctls); 3995 #ifdef CAPABILITIES 3996 seqc_write_end(&newfde->fde_seqc); 3997 #endif 3998 break; 3999 case ENXIO: 4000 /* 4001 * Steal away the file pointer from dfd and stuff it into indx. 4002 */ 4003 newfde = &fdp->fd_ofiles[indx]; 4004 oldfde = &fdp->fd_ofiles[dfd]; 4005 #ifdef CAPABILITIES 4006 seqc_write_begin(&oldfde->fde_seqc); 4007 seqc_write_begin(&newfde->fde_seqc); 4008 #endif 4009 fde_copy(oldfde, newfde); 4010 oldfde->fde_file = NULL; 4011 fdunused(fdp, dfd); 4012 #ifdef CAPABILITIES 4013 seqc_write_end(&newfde->fde_seqc); 4014 seqc_write_end(&oldfde->fde_seqc); 4015 #endif 4016 break; 4017 } 4018 FILEDESC_XUNLOCK(fdp); 4019 *indxp = indx; 4020 return (0); 4021 } 4022 4023 /* 4024 * This sysctl determines if we will allow a process to chroot(2) if it 4025 * has a directory open: 4026 * 0: disallowed for all processes. 4027 * 1: allowed for processes that were not already chroot(2)'ed. 4028 * 2: allowed for all processes. 4029 */ 4030 4031 static int chroot_allow_open_directories = 1; 4032 4033 SYSCTL_INT(_kern, OID_AUTO, chroot_allow_open_directories, CTLFLAG_RW, 4034 &chroot_allow_open_directories, 0, 4035 "Allow a process to chroot(2) if it has a directory open"); 4036 4037 /* 4038 * Helper function for raised chroot(2) security function: Refuse if 4039 * any filedescriptors are open directories. 4040 */ 4041 static int 4042 chroot_refuse_vdir_fds(struct filedesc *fdp) 4043 { 4044 struct vnode *vp; 4045 struct file *fp; 4046 int i; 4047 4048 FILEDESC_LOCK_ASSERT(fdp); 4049 4050 FILEDESC_FOREACH_FP(fdp, i, fp) { 4051 if (fp->f_type == DTYPE_VNODE) { 4052 vp = fp->f_vnode; 4053 if (vp->v_type == VDIR) 4054 return (EPERM); 4055 } 4056 } 4057 return (0); 4058 } 4059 4060 static void 4061 pwd_fill(struct pwd *oldpwd, struct pwd *newpwd) 4062 { 4063 4064 if (newpwd->pwd_cdir == NULL && oldpwd->pwd_cdir != NULL) { 4065 vrefact(oldpwd->pwd_cdir); 4066 newpwd->pwd_cdir = oldpwd->pwd_cdir; 4067 } 4068 4069 if (newpwd->pwd_rdir == NULL && oldpwd->pwd_rdir != NULL) { 4070 vrefact(oldpwd->pwd_rdir); 4071 newpwd->pwd_rdir = oldpwd->pwd_rdir; 4072 } 4073 4074 if (newpwd->pwd_jdir == NULL && oldpwd->pwd_jdir != NULL) { 4075 vrefact(oldpwd->pwd_jdir); 4076 newpwd->pwd_jdir = oldpwd->pwd_jdir; 4077 } 4078 4079 if (newpwd->pwd_adir == NULL && oldpwd->pwd_adir != NULL) { 4080 vrefact(oldpwd->pwd_adir); 4081 newpwd->pwd_adir = oldpwd->pwd_adir; 4082 } 4083 } 4084 4085 struct pwd * 4086 pwd_hold_pwddesc(struct pwddesc *pdp) 4087 { 4088 struct pwd *pwd; 4089 4090 PWDDESC_ASSERT_XLOCKED(pdp); 4091 pwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); 4092 if (pwd != NULL) 4093 refcount_acquire(&pwd->pwd_refcount); 4094 return (pwd); 4095 } 4096 4097 bool 4098 pwd_hold_smr(struct pwd *pwd) 4099 { 4100 4101 MPASS(pwd != NULL); 4102 if (__predict_true(refcount_acquire_if_not_zero(&pwd->pwd_refcount))) { 4103 return (true); 4104 } 4105 return (false); 4106 } 4107 4108 struct pwd * 4109 pwd_hold(struct thread *td) 4110 { 4111 struct pwddesc *pdp; 4112 struct pwd *pwd; 4113 4114 pdp = td->td_proc->p_pd; 4115 4116 vfs_smr_enter(); 4117 pwd = vfs_smr_entered_load(&pdp->pd_pwd); 4118 if (pwd_hold_smr(pwd)) { 4119 vfs_smr_exit(); 4120 return (pwd); 4121 } 4122 vfs_smr_exit(); 4123 PWDDESC_XLOCK(pdp); 4124 pwd = pwd_hold_pwddesc(pdp); 4125 MPASS(pwd != NULL); 4126 PWDDESC_XUNLOCK(pdp); 4127 return (pwd); 4128 } 4129 4130 struct pwd * 4131 pwd_hold_proc(struct proc *p) 4132 { 4133 struct pwddesc *pdp; 4134 struct pwd *pwd; 4135 4136 PROC_ASSERT_HELD(p); 4137 PROC_LOCK(p); 4138 pdp = pdhold(p); 4139 MPASS(pdp != NULL); 4140 PROC_UNLOCK(p); 4141 4142 PWDDESC_XLOCK(pdp); 4143 pwd = pwd_hold_pwddesc(pdp); 4144 MPASS(pwd != NULL); 4145 PWDDESC_XUNLOCK(pdp); 4146 pddrop(pdp); 4147 return (pwd); 4148 } 4149 4150 static struct pwd * 4151 pwd_alloc(void) 4152 { 4153 struct pwd *pwd; 4154 4155 pwd = uma_zalloc_smr(pwd_zone, M_WAITOK); 4156 bzero(pwd, sizeof(*pwd)); 4157 refcount_init(&pwd->pwd_refcount, 1); 4158 return (pwd); 4159 } 4160 4161 void 4162 pwd_drop(struct pwd *pwd) 4163 { 4164 4165 if (!refcount_release(&pwd->pwd_refcount)) 4166 return; 4167 4168 if (pwd->pwd_cdir != NULL) 4169 vrele(pwd->pwd_cdir); 4170 if (pwd->pwd_rdir != NULL) 4171 vrele(pwd->pwd_rdir); 4172 if (pwd->pwd_jdir != NULL) 4173 vrele(pwd->pwd_jdir); 4174 if (pwd->pwd_adir != NULL) 4175 vrele(pwd->pwd_adir); 4176 uma_zfree_smr(pwd_zone, pwd); 4177 } 4178 4179 /* 4180 * The caller is responsible for invoking priv_check() and 4181 * mac_vnode_check_chroot() to authorize this operation. 4182 */ 4183 int 4184 pwd_chroot(struct thread *td, struct vnode *vp) 4185 { 4186 struct pwddesc *pdp; 4187 struct filedesc *fdp; 4188 struct pwd *newpwd, *oldpwd; 4189 int error; 4190 4191 fdp = td->td_proc->p_fd; 4192 pdp = td->td_proc->p_pd; 4193 newpwd = pwd_alloc(); 4194 FILEDESC_SLOCK(fdp); 4195 PWDDESC_XLOCK(pdp); 4196 oldpwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); 4197 if (chroot_allow_open_directories == 0 || 4198 (chroot_allow_open_directories == 1 && 4199 oldpwd->pwd_rdir != rootvnode)) { 4200 error = chroot_refuse_vdir_fds(fdp); 4201 FILEDESC_SUNLOCK(fdp); 4202 if (error != 0) { 4203 PWDDESC_XUNLOCK(pdp); 4204 pwd_drop(newpwd); 4205 return (error); 4206 } 4207 } else { 4208 FILEDESC_SUNLOCK(fdp); 4209 } 4210 4211 vrefact(vp); 4212 newpwd->pwd_rdir = vp; 4213 vrefact(vp); 4214 newpwd->pwd_adir = vp; 4215 if (oldpwd->pwd_jdir == NULL) { 4216 vrefact(vp); 4217 newpwd->pwd_jdir = vp; 4218 } 4219 pwd_fill(oldpwd, newpwd); 4220 pwd_set(pdp, newpwd); 4221 PWDDESC_XUNLOCK(pdp); 4222 pwd_drop(oldpwd); 4223 return (0); 4224 } 4225 4226 void 4227 pwd_chdir(struct thread *td, struct vnode *vp) 4228 { 4229 struct pwddesc *pdp; 4230 struct pwd *newpwd, *oldpwd; 4231 4232 VNPASS(vp->v_usecount > 0, vp); 4233 4234 newpwd = pwd_alloc(); 4235 pdp = td->td_proc->p_pd; 4236 PWDDESC_XLOCK(pdp); 4237 oldpwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); 4238 newpwd->pwd_cdir = vp; 4239 pwd_fill(oldpwd, newpwd); 4240 pwd_set(pdp, newpwd); 4241 PWDDESC_XUNLOCK(pdp); 4242 pwd_drop(oldpwd); 4243 } 4244 4245 /* 4246 * Process is transitioning to/from a non-native ABI. 4247 */ 4248 void 4249 pwd_altroot(struct thread *td, struct vnode *altroot_vp) 4250 { 4251 struct pwddesc *pdp; 4252 struct pwd *newpwd, *oldpwd; 4253 4254 newpwd = pwd_alloc(); 4255 pdp = td->td_proc->p_pd; 4256 PWDDESC_XLOCK(pdp); 4257 oldpwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); 4258 if (altroot_vp != NULL) { 4259 /* 4260 * Native process to a non-native ABI. 4261 */ 4262 4263 vrefact(altroot_vp); 4264 newpwd->pwd_adir = altroot_vp; 4265 } else { 4266 /* 4267 * Non-native process to the native ABI. 4268 */ 4269 4270 vrefact(oldpwd->pwd_rdir); 4271 newpwd->pwd_adir = oldpwd->pwd_rdir; 4272 } 4273 pwd_fill(oldpwd, newpwd); 4274 pwd_set(pdp, newpwd); 4275 PWDDESC_XUNLOCK(pdp); 4276 pwd_drop(oldpwd); 4277 } 4278 4279 /* 4280 * jail_attach(2) changes both root and working directories. 4281 */ 4282 int 4283 pwd_chroot_chdir(struct thread *td, struct vnode *vp) 4284 { 4285 struct pwddesc *pdp; 4286 struct filedesc *fdp; 4287 struct pwd *newpwd, *oldpwd; 4288 int error; 4289 4290 fdp = td->td_proc->p_fd; 4291 pdp = td->td_proc->p_pd; 4292 newpwd = pwd_alloc(); 4293 FILEDESC_SLOCK(fdp); 4294 PWDDESC_XLOCK(pdp); 4295 oldpwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); 4296 error = chroot_refuse_vdir_fds(fdp); 4297 FILEDESC_SUNLOCK(fdp); 4298 if (error != 0) { 4299 PWDDESC_XUNLOCK(pdp); 4300 pwd_drop(newpwd); 4301 return (error); 4302 } 4303 4304 vrefact(vp); 4305 newpwd->pwd_rdir = vp; 4306 vrefact(vp); 4307 newpwd->pwd_cdir = vp; 4308 if (oldpwd->pwd_jdir == NULL) { 4309 vrefact(vp); 4310 newpwd->pwd_jdir = vp; 4311 } 4312 vrefact(vp); 4313 newpwd->pwd_adir = vp; 4314 pwd_fill(oldpwd, newpwd); 4315 pwd_set(pdp, newpwd); 4316 PWDDESC_XUNLOCK(pdp); 4317 pwd_drop(oldpwd); 4318 return (0); 4319 } 4320 4321 void 4322 pwd_ensure_dirs(void) 4323 { 4324 struct pwddesc *pdp; 4325 struct pwd *oldpwd, *newpwd; 4326 4327 pdp = curproc->p_pd; 4328 PWDDESC_XLOCK(pdp); 4329 oldpwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); 4330 if (oldpwd->pwd_cdir != NULL && oldpwd->pwd_rdir != NULL && 4331 oldpwd->pwd_adir != NULL) { 4332 PWDDESC_XUNLOCK(pdp); 4333 return; 4334 } 4335 PWDDESC_XUNLOCK(pdp); 4336 4337 newpwd = pwd_alloc(); 4338 PWDDESC_XLOCK(pdp); 4339 oldpwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); 4340 pwd_fill(oldpwd, newpwd); 4341 if (newpwd->pwd_cdir == NULL) { 4342 vrefact(rootvnode); 4343 newpwd->pwd_cdir = rootvnode; 4344 } 4345 if (newpwd->pwd_rdir == NULL) { 4346 vrefact(rootvnode); 4347 newpwd->pwd_rdir = rootvnode; 4348 } 4349 if (newpwd->pwd_adir == NULL) { 4350 vrefact(rootvnode); 4351 newpwd->pwd_adir = rootvnode; 4352 } 4353 pwd_set(pdp, newpwd); 4354 PWDDESC_XUNLOCK(pdp); 4355 pwd_drop(oldpwd); 4356 } 4357 4358 void 4359 pwd_set_rootvnode(void) 4360 { 4361 struct pwddesc *pdp; 4362 struct pwd *oldpwd, *newpwd; 4363 4364 pdp = curproc->p_pd; 4365 4366 newpwd = pwd_alloc(); 4367 PWDDESC_XLOCK(pdp); 4368 oldpwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); 4369 vrefact(rootvnode); 4370 newpwd->pwd_cdir = rootvnode; 4371 vrefact(rootvnode); 4372 newpwd->pwd_rdir = rootvnode; 4373 vrefact(rootvnode); 4374 newpwd->pwd_adir = rootvnode; 4375 pwd_fill(oldpwd, newpwd); 4376 pwd_set(pdp, newpwd); 4377 PWDDESC_XUNLOCK(pdp); 4378 pwd_drop(oldpwd); 4379 } 4380 4381 /* 4382 * Scan all active processes and prisons to see if any of them have a current 4383 * or root directory of `olddp'. If so, replace them with the new mount point. 4384 */ 4385 void 4386 mountcheckdirs(struct vnode *olddp, struct vnode *newdp) 4387 { 4388 struct pwddesc *pdp; 4389 struct pwd *newpwd, *oldpwd; 4390 struct prison *pr; 4391 struct proc *p; 4392 int nrele; 4393 4394 if (vrefcnt(olddp) == 1) 4395 return; 4396 nrele = 0; 4397 newpwd = pwd_alloc(); 4398 sx_slock(&allproc_lock); 4399 FOREACH_PROC_IN_SYSTEM(p) { 4400 PROC_LOCK(p); 4401 pdp = pdhold(p); 4402 PROC_UNLOCK(p); 4403 if (pdp == NULL) 4404 continue; 4405 PWDDESC_XLOCK(pdp); 4406 oldpwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); 4407 if (oldpwd == NULL || 4408 (oldpwd->pwd_cdir != olddp && 4409 oldpwd->pwd_rdir != olddp && 4410 oldpwd->pwd_jdir != olddp && 4411 oldpwd->pwd_adir != olddp)) { 4412 PWDDESC_XUNLOCK(pdp); 4413 pddrop(pdp); 4414 continue; 4415 } 4416 if (oldpwd->pwd_cdir == olddp) { 4417 vrefact(newdp); 4418 newpwd->pwd_cdir = newdp; 4419 } 4420 if (oldpwd->pwd_rdir == olddp) { 4421 vrefact(newdp); 4422 newpwd->pwd_rdir = newdp; 4423 } 4424 if (oldpwd->pwd_jdir == olddp) { 4425 vrefact(newdp); 4426 newpwd->pwd_jdir = newdp; 4427 } 4428 if (oldpwd->pwd_adir == olddp) { 4429 vrefact(newdp); 4430 newpwd->pwd_adir = newdp; 4431 } 4432 pwd_fill(oldpwd, newpwd); 4433 pwd_set(pdp, newpwd); 4434 PWDDESC_XUNLOCK(pdp); 4435 pwd_drop(oldpwd); 4436 pddrop(pdp); 4437 newpwd = pwd_alloc(); 4438 } 4439 sx_sunlock(&allproc_lock); 4440 pwd_drop(newpwd); 4441 if (rootvnode == olddp) { 4442 vrefact(newdp); 4443 rootvnode = newdp; 4444 nrele++; 4445 } 4446 mtx_lock(&prison0.pr_mtx); 4447 if (prison0.pr_root == olddp) { 4448 vrefact(newdp); 4449 prison0.pr_root = newdp; 4450 nrele++; 4451 } 4452 mtx_unlock(&prison0.pr_mtx); 4453 sx_slock(&allprison_lock); 4454 TAILQ_FOREACH(pr, &allprison, pr_list) { 4455 mtx_lock(&pr->pr_mtx); 4456 if (pr->pr_root == olddp) { 4457 vrefact(newdp); 4458 pr->pr_root = newdp; 4459 nrele++; 4460 } 4461 mtx_unlock(&pr->pr_mtx); 4462 } 4463 sx_sunlock(&allprison_lock); 4464 while (nrele--) 4465 vrele(olddp); 4466 } 4467 4468 int 4469 descrip_check_write_mp(struct filedesc *fdp, struct mount *mp) 4470 { 4471 struct file *fp; 4472 struct vnode *vp; 4473 int error, i; 4474 4475 error = 0; 4476 FILEDESC_SLOCK(fdp); 4477 FILEDESC_FOREACH_FP(fdp, i, fp) { 4478 if (fp->f_type != DTYPE_VNODE || 4479 (atomic_load_int(&fp->f_flag) & FWRITE) == 0) 4480 continue; 4481 vp = fp->f_vnode; 4482 if (vp->v_mount == mp) { 4483 error = EDEADLK; 4484 break; 4485 } 4486 } 4487 FILEDESC_SUNLOCK(fdp); 4488 return (error); 4489 } 4490 4491 struct filedesc_to_leader * 4492 filedesc_to_leader_alloc(struct filedesc_to_leader *old, struct filedesc *fdp, 4493 struct proc *leader) 4494 { 4495 struct filedesc_to_leader *fdtol; 4496 4497 fdtol = malloc(sizeof(struct filedesc_to_leader), 4498 M_FILEDESC_TO_LEADER, M_WAITOK); 4499 fdtol->fdl_refcount = 1; 4500 fdtol->fdl_holdcount = 0; 4501 fdtol->fdl_wakeup = 0; 4502 fdtol->fdl_leader = leader; 4503 if (old != NULL) { 4504 FILEDESC_XLOCK(fdp); 4505 fdtol->fdl_next = old->fdl_next; 4506 fdtol->fdl_prev = old; 4507 old->fdl_next = fdtol; 4508 fdtol->fdl_next->fdl_prev = fdtol; 4509 FILEDESC_XUNLOCK(fdp); 4510 } else { 4511 fdtol->fdl_next = fdtol; 4512 fdtol->fdl_prev = fdtol; 4513 } 4514 return (fdtol); 4515 } 4516 4517 struct filedesc_to_leader * 4518 filedesc_to_leader_share(struct filedesc_to_leader *fdtol, struct filedesc *fdp) 4519 { 4520 FILEDESC_XLOCK(fdp); 4521 fdtol->fdl_refcount++; 4522 FILEDESC_XUNLOCK(fdp); 4523 return (fdtol); 4524 } 4525 4526 static int 4527 filedesc_nfiles(struct filedesc *fdp) 4528 { 4529 NDSLOTTYPE *map; 4530 int count, off, minoff; 4531 4532 if (fdp == NULL) 4533 return (0); 4534 count = 0; 4535 FILEDESC_SLOCK(fdp); 4536 map = fdp->fd_map; 4537 off = NDSLOT(fdp->fd_nfiles - 1); 4538 for (minoff = NDSLOT(0); off >= minoff; --off) 4539 count += bitcountl(map[off]); 4540 FILEDESC_SUNLOCK(fdp); 4541 return (count); 4542 } 4543 4544 int 4545 proc_nfiles(struct proc *p) 4546 { 4547 struct filedesc *fdp; 4548 int res; 4549 4550 PROC_LOCK(p); 4551 fdp = fdhold(p); 4552 PROC_UNLOCK(p); 4553 res = filedesc_nfiles(fdp); 4554 fddrop(fdp); 4555 return (res); 4556 } 4557 4558 static int 4559 sysctl_kern_proc_nfds(SYSCTL_HANDLER_ARGS) 4560 { 4561 u_int namelen; 4562 int count; 4563 4564 namelen = arg2; 4565 if (namelen != 1) 4566 return (EINVAL); 4567 4568 if (*(int *)arg1 != 0) 4569 return (EINVAL); 4570 4571 count = filedesc_nfiles(curproc->p_fd); 4572 return (SYSCTL_OUT(req, &count, sizeof(count))); 4573 } 4574 4575 static SYSCTL_NODE(_kern_proc, KERN_PROC_NFDS, nfds, 4576 CTLFLAG_RD|CTLFLAG_CAPRD|CTLFLAG_MPSAFE, sysctl_kern_proc_nfds, 4577 "Number of open file descriptors"); 4578 4579 /* 4580 * Get file structures globally. 4581 */ 4582 static int 4583 sysctl_kern_file(SYSCTL_HANDLER_ARGS) 4584 { 4585 struct xfile xf; 4586 struct filedesc *fdp; 4587 struct file *fp; 4588 struct proc *p; 4589 int error, n; 4590 4591 error = sysctl_wire_old_buffer(req, 0); 4592 if (error != 0) 4593 return (error); 4594 if (req->oldptr == NULL) { 4595 n = 0; 4596 sx_slock(&allproc_lock); 4597 FOREACH_PROC_IN_SYSTEM(p) { 4598 PROC_LOCK(p); 4599 if (p->p_state == PRS_NEW) { 4600 PROC_UNLOCK(p); 4601 continue; 4602 } 4603 fdp = fdhold(p); 4604 PROC_UNLOCK(p); 4605 if (fdp == NULL) 4606 continue; 4607 /* overestimates sparse tables. */ 4608 n += fdp->fd_nfiles; 4609 fddrop(fdp); 4610 } 4611 sx_sunlock(&allproc_lock); 4612 return (SYSCTL_OUT(req, 0, n * sizeof(xf))); 4613 } 4614 error = 0; 4615 bzero(&xf, sizeof(xf)); 4616 xf.xf_size = sizeof(xf); 4617 sx_slock(&allproc_lock); 4618 FOREACH_PROC_IN_SYSTEM(p) { 4619 PROC_LOCK(p); 4620 if (p->p_state == PRS_NEW) { 4621 PROC_UNLOCK(p); 4622 continue; 4623 } 4624 if (p_cansee(req->td, p) != 0) { 4625 PROC_UNLOCK(p); 4626 continue; 4627 } 4628 xf.xf_pid = p->p_pid; 4629 xf.xf_uid = p->p_ucred->cr_uid; 4630 fdp = fdhold(p); 4631 PROC_UNLOCK(p); 4632 if (fdp == NULL) 4633 continue; 4634 FILEDESC_SLOCK(fdp); 4635 if (refcount_load(&fdp->fd_refcnt) == 0) 4636 goto nextproc; 4637 FILEDESC_FOREACH_FP(fdp, n, fp) { 4638 xf.xf_fd = n; 4639 xf.xf_file = (uintptr_t)fp; 4640 xf.xf_data = (uintptr_t)fp->f_data; 4641 xf.xf_vnode = (uintptr_t)fp->f_vnode; 4642 xf.xf_type = (uintptr_t)fp->f_type; 4643 xf.xf_count = refcount_load(&fp->f_count); 4644 xf.xf_msgcount = 0; 4645 xf.xf_offset = foffset_get(fp); 4646 xf.xf_flag = fp->f_flag; 4647 error = SYSCTL_OUT(req, &xf, sizeof(xf)); 4648 4649 /* 4650 * There is no need to re-check the fdtable refcount 4651 * here since the filedesc lock is not dropped in the 4652 * loop body. 4653 */ 4654 if (error != 0) 4655 break; 4656 } 4657 nextproc: 4658 FILEDESC_SUNLOCK(fdp); 4659 fddrop(fdp); 4660 if (error) 4661 break; 4662 } 4663 sx_sunlock(&allproc_lock); 4664 return (error); 4665 } 4666 4667 SYSCTL_PROC(_kern, KERN_FILE, file, CTLTYPE_OPAQUE|CTLFLAG_RD|CTLFLAG_MPSAFE, 4668 0, 0, sysctl_kern_file, "S,xfile", "Entire file table"); 4669 4670 #ifdef KINFO_FILE_SIZE 4671 CTASSERT(sizeof(struct kinfo_file) == KINFO_FILE_SIZE); 4672 #endif 4673 4674 static int 4675 xlate_fflags(int fflags) 4676 { 4677 static const struct { 4678 int fflag; 4679 int kf_fflag; 4680 } fflags_table[] = { 4681 { FAPPEND, KF_FLAG_APPEND }, 4682 { FASYNC, KF_FLAG_ASYNC }, 4683 { FFSYNC, KF_FLAG_FSYNC }, 4684 { FHASLOCK, KF_FLAG_HASLOCK }, 4685 { FNONBLOCK, KF_FLAG_NONBLOCK }, 4686 { FREAD, KF_FLAG_READ }, 4687 { FWRITE, KF_FLAG_WRITE }, 4688 { O_CREAT, KF_FLAG_CREAT }, 4689 { O_DIRECT, KF_FLAG_DIRECT }, 4690 { O_EXCL, KF_FLAG_EXCL }, 4691 { O_EXEC, KF_FLAG_EXEC }, 4692 { O_EXLOCK, KF_FLAG_EXLOCK }, 4693 { O_NOFOLLOW, KF_FLAG_NOFOLLOW }, 4694 { O_SHLOCK, KF_FLAG_SHLOCK }, 4695 { O_TRUNC, KF_FLAG_TRUNC } 4696 }; 4697 unsigned int i; 4698 int kflags; 4699 4700 kflags = 0; 4701 for (i = 0; i < nitems(fflags_table); i++) 4702 if (fflags & fflags_table[i].fflag) 4703 kflags |= fflags_table[i].kf_fflag; 4704 return (kflags); 4705 } 4706 4707 /* Trim unused data from kf_path by truncating the structure size. */ 4708 void 4709 pack_kinfo(struct kinfo_file *kif) 4710 { 4711 4712 kif->kf_structsize = offsetof(struct kinfo_file, kf_path) + 4713 strlen(kif->kf_path) + 1; 4714 kif->kf_structsize = roundup(kif->kf_structsize, sizeof(uint64_t)); 4715 } 4716 4717 static void 4718 export_file_to_kinfo(struct file *fp, int fd, cap_rights_t *rightsp, 4719 struct kinfo_file *kif, struct filedesc *fdp, int flags) 4720 { 4721 int error; 4722 4723 bzero(kif, sizeof(*kif)); 4724 4725 /* Set a default type to allow for empty fill_kinfo() methods. */ 4726 kif->kf_type = KF_TYPE_UNKNOWN; 4727 kif->kf_flags = xlate_fflags(fp->f_flag); 4728 if (rightsp != NULL) 4729 kif->kf_cap_rights = *rightsp; 4730 else 4731 cap_rights_init_zero(&kif->kf_cap_rights); 4732 kif->kf_fd = fd; 4733 kif->kf_ref_count = refcount_load(&fp->f_count); 4734 kif->kf_offset = foffset_get(fp); 4735 4736 /* 4737 * This may drop the filedesc lock, so the 'fp' cannot be 4738 * accessed after this call. 4739 */ 4740 error = fo_fill_kinfo(fp, kif, fdp); 4741 if (error == 0) 4742 kif->kf_status |= KF_ATTR_VALID; 4743 if ((flags & KERN_FILEDESC_PACK_KINFO) != 0) 4744 pack_kinfo(kif); 4745 else 4746 kif->kf_structsize = roundup2(sizeof(*kif), sizeof(uint64_t)); 4747 } 4748 4749 static void 4750 export_vnode_to_kinfo(struct vnode *vp, int fd, int fflags, 4751 struct kinfo_file *kif, int flags) 4752 { 4753 int error; 4754 4755 bzero(kif, sizeof(*kif)); 4756 4757 kif->kf_type = KF_TYPE_VNODE; 4758 error = vn_fill_kinfo_vnode(vp, kif); 4759 if (error == 0) 4760 kif->kf_status |= KF_ATTR_VALID; 4761 kif->kf_flags = xlate_fflags(fflags); 4762 cap_rights_init_zero(&kif->kf_cap_rights); 4763 kif->kf_fd = fd; 4764 kif->kf_ref_count = -1; 4765 kif->kf_offset = -1; 4766 if ((flags & KERN_FILEDESC_PACK_KINFO) != 0) 4767 pack_kinfo(kif); 4768 else 4769 kif->kf_structsize = roundup2(sizeof(*kif), sizeof(uint64_t)); 4770 vrele(vp); 4771 } 4772 4773 struct export_fd_buf { 4774 struct filedesc *fdp; 4775 struct pwddesc *pdp; 4776 struct sbuf *sb; 4777 ssize_t remainder; 4778 struct kinfo_file kif; 4779 int flags; 4780 }; 4781 4782 static int 4783 export_kinfo_to_sb(struct export_fd_buf *efbuf) 4784 { 4785 struct kinfo_file *kif; 4786 4787 kif = &efbuf->kif; 4788 if (efbuf->remainder != -1) { 4789 if (efbuf->remainder < kif->kf_structsize) 4790 return (ENOMEM); 4791 efbuf->remainder -= kif->kf_structsize; 4792 } 4793 if (sbuf_bcat(efbuf->sb, kif, kif->kf_structsize) != 0) 4794 return (sbuf_error(efbuf->sb)); 4795 return (0); 4796 } 4797 4798 static int 4799 export_file_to_sb(struct file *fp, int fd, cap_rights_t *rightsp, 4800 struct export_fd_buf *efbuf) 4801 { 4802 int error; 4803 4804 if (efbuf->remainder == 0) 4805 return (ENOMEM); 4806 export_file_to_kinfo(fp, fd, rightsp, &efbuf->kif, efbuf->fdp, 4807 efbuf->flags); 4808 FILEDESC_SUNLOCK(efbuf->fdp); 4809 error = export_kinfo_to_sb(efbuf); 4810 FILEDESC_SLOCK(efbuf->fdp); 4811 return (error); 4812 } 4813 4814 static int 4815 export_vnode_to_sb(struct vnode *vp, int fd, int fflags, 4816 struct export_fd_buf *efbuf) 4817 { 4818 int error; 4819 4820 if (efbuf->remainder == 0) 4821 return (ENOMEM); 4822 if (efbuf->pdp != NULL) 4823 PWDDESC_XUNLOCK(efbuf->pdp); 4824 export_vnode_to_kinfo(vp, fd, fflags, &efbuf->kif, efbuf->flags); 4825 error = export_kinfo_to_sb(efbuf); 4826 if (efbuf->pdp != NULL) 4827 PWDDESC_XLOCK(efbuf->pdp); 4828 return (error); 4829 } 4830 4831 /* 4832 * Store a process file descriptor information to sbuf. 4833 * 4834 * Takes a locked proc as argument, and returns with the proc unlocked. 4835 */ 4836 int 4837 kern_proc_filedesc_out(struct proc *p, struct sbuf *sb, ssize_t maxlen, 4838 int flags) 4839 { 4840 struct file *fp; 4841 struct filedesc *fdp; 4842 struct pwddesc *pdp; 4843 struct export_fd_buf *efbuf; 4844 struct vnode *cttyvp, *textvp, *tracevp; 4845 struct pwd *pwd; 4846 int error, i; 4847 cap_rights_t rights; 4848 4849 PROC_LOCK_ASSERT(p, MA_OWNED); 4850 4851 /* ktrace vnode */ 4852 tracevp = ktr_get_tracevp(p, true); 4853 /* text vnode */ 4854 textvp = p->p_textvp; 4855 if (textvp != NULL) 4856 vrefact(textvp); 4857 /* Controlling tty. */ 4858 cttyvp = NULL; 4859 if (p->p_pgrp != NULL && p->p_pgrp->pg_session != NULL) { 4860 cttyvp = p->p_pgrp->pg_session->s_ttyvp; 4861 if (cttyvp != NULL) 4862 vrefact(cttyvp); 4863 } 4864 fdp = fdhold(p); 4865 pdp = pdhold(p); 4866 PROC_UNLOCK(p); 4867 4868 efbuf = malloc(sizeof(*efbuf), M_TEMP, M_WAITOK); 4869 efbuf->fdp = NULL; 4870 efbuf->pdp = NULL; 4871 efbuf->sb = sb; 4872 efbuf->remainder = maxlen; 4873 efbuf->flags = flags; 4874 4875 error = 0; 4876 if (tracevp != NULL) 4877 error = export_vnode_to_sb(tracevp, KF_FD_TYPE_TRACE, 4878 FREAD | FWRITE, efbuf); 4879 if (error == 0 && textvp != NULL) 4880 error = export_vnode_to_sb(textvp, KF_FD_TYPE_TEXT, FREAD, 4881 efbuf); 4882 if (error == 0 && cttyvp != NULL) 4883 error = export_vnode_to_sb(cttyvp, KF_FD_TYPE_CTTY, 4884 FREAD | FWRITE, efbuf); 4885 if (error != 0 || pdp == NULL || fdp == NULL) 4886 goto fail; 4887 efbuf->fdp = fdp; 4888 efbuf->pdp = pdp; 4889 PWDDESC_XLOCK(pdp); 4890 pwd = pwd_hold_pwddesc(pdp); 4891 if (pwd != NULL) { 4892 /* working directory */ 4893 if (pwd->pwd_cdir != NULL) { 4894 vrefact(pwd->pwd_cdir); 4895 error = export_vnode_to_sb(pwd->pwd_cdir, 4896 KF_FD_TYPE_CWD, FREAD, efbuf); 4897 } 4898 /* root directory */ 4899 if (error == 0 && pwd->pwd_rdir != NULL) { 4900 vrefact(pwd->pwd_rdir); 4901 error = export_vnode_to_sb(pwd->pwd_rdir, 4902 KF_FD_TYPE_ROOT, FREAD, efbuf); 4903 } 4904 /* jail directory */ 4905 if (error == 0 && pwd->pwd_jdir != NULL) { 4906 vrefact(pwd->pwd_jdir); 4907 error = export_vnode_to_sb(pwd->pwd_jdir, 4908 KF_FD_TYPE_JAIL, FREAD, efbuf); 4909 } 4910 } 4911 PWDDESC_XUNLOCK(pdp); 4912 if (error != 0) 4913 goto fail; 4914 if (pwd != NULL) 4915 pwd_drop(pwd); 4916 FILEDESC_SLOCK(fdp); 4917 if (refcount_load(&fdp->fd_refcnt) == 0) 4918 goto skip; 4919 FILEDESC_FOREACH_FP(fdp, i, fp) { 4920 #ifdef CAPABILITIES 4921 rights = *cap_rights(fdp, i); 4922 #else /* !CAPABILITIES */ 4923 rights = cap_no_rights; 4924 #endif 4925 /* 4926 * Create sysctl entry. It is OK to drop the filedesc 4927 * lock inside of export_file_to_sb() as we will 4928 * re-validate and re-evaluate its properties when the 4929 * loop continues. 4930 */ 4931 error = export_file_to_sb(fp, i, &rights, efbuf); 4932 if (error != 0 || refcount_load(&fdp->fd_refcnt) == 0) 4933 break; 4934 } 4935 skip: 4936 FILEDESC_SUNLOCK(fdp); 4937 fail: 4938 if (fdp != NULL) 4939 fddrop(fdp); 4940 if (pdp != NULL) 4941 pddrop(pdp); 4942 free(efbuf, M_TEMP); 4943 return (error); 4944 } 4945 4946 #define FILEDESC_SBUF_SIZE (sizeof(struct kinfo_file) * 5) 4947 4948 /* 4949 * Get per-process file descriptors for use by procstat(1), et al. 4950 */ 4951 static int 4952 sysctl_kern_proc_filedesc(SYSCTL_HANDLER_ARGS) 4953 { 4954 struct sbuf sb; 4955 struct proc *p; 4956 ssize_t maxlen; 4957 u_int namelen; 4958 int error, error2, *name; 4959 4960 namelen = arg2; 4961 if (namelen != 1) 4962 return (EINVAL); 4963 4964 name = (int *)arg1; 4965 4966 sbuf_new_for_sysctl(&sb, NULL, FILEDESC_SBUF_SIZE, req); 4967 sbuf_clear_flags(&sb, SBUF_INCLUDENUL); 4968 error = pget((pid_t)name[0], PGET_CANDEBUG | PGET_NOTWEXIT, &p); 4969 if (error != 0) { 4970 sbuf_delete(&sb); 4971 return (error); 4972 } 4973 maxlen = req->oldptr != NULL ? req->oldlen : -1; 4974 error = kern_proc_filedesc_out(p, &sb, maxlen, 4975 KERN_FILEDESC_PACK_KINFO); 4976 error2 = sbuf_finish(&sb); 4977 sbuf_delete(&sb); 4978 return (error != 0 ? error : error2); 4979 } 4980 4981 #ifdef COMPAT_FREEBSD7 4982 #ifdef KINFO_OFILE_SIZE 4983 CTASSERT(sizeof(struct kinfo_ofile) == KINFO_OFILE_SIZE); 4984 #endif 4985 4986 static void 4987 kinfo_to_okinfo(struct kinfo_file *kif, struct kinfo_ofile *okif) 4988 { 4989 4990 okif->kf_structsize = sizeof(*okif); 4991 okif->kf_type = kif->kf_type; 4992 okif->kf_fd = kif->kf_fd; 4993 okif->kf_ref_count = kif->kf_ref_count; 4994 okif->kf_flags = kif->kf_flags & (KF_FLAG_READ | KF_FLAG_WRITE | 4995 KF_FLAG_APPEND | KF_FLAG_ASYNC | KF_FLAG_FSYNC | KF_FLAG_NONBLOCK | 4996 KF_FLAG_DIRECT | KF_FLAG_HASLOCK); 4997 okif->kf_offset = kif->kf_offset; 4998 if (kif->kf_type == KF_TYPE_VNODE) 4999 okif->kf_vnode_type = kif->kf_un.kf_file.kf_file_type; 5000 else 5001 okif->kf_vnode_type = KF_VTYPE_VNON; 5002 strlcpy(okif->kf_path, kif->kf_path, sizeof(okif->kf_path)); 5003 if (kif->kf_type == KF_TYPE_SOCKET) { 5004 okif->kf_sock_domain = kif->kf_un.kf_sock.kf_sock_domain0; 5005 okif->kf_sock_type = kif->kf_un.kf_sock.kf_sock_type0; 5006 okif->kf_sock_protocol = kif->kf_un.kf_sock.kf_sock_protocol0; 5007 okif->kf_sa_local = kif->kf_un.kf_sock.kf_sa_local; 5008 okif->kf_sa_peer = kif->kf_un.kf_sock.kf_sa_peer; 5009 } else { 5010 okif->kf_sa_local.ss_family = AF_UNSPEC; 5011 okif->kf_sa_peer.ss_family = AF_UNSPEC; 5012 } 5013 } 5014 5015 static int 5016 export_vnode_for_osysctl(struct vnode *vp, int type, struct kinfo_file *kif, 5017 struct kinfo_ofile *okif, struct pwddesc *pdp, struct sysctl_req *req) 5018 { 5019 int error; 5020 5021 vrefact(vp); 5022 PWDDESC_XUNLOCK(pdp); 5023 export_vnode_to_kinfo(vp, type, 0, kif, KERN_FILEDESC_PACK_KINFO); 5024 kinfo_to_okinfo(kif, okif); 5025 error = SYSCTL_OUT(req, okif, sizeof(*okif)); 5026 PWDDESC_XLOCK(pdp); 5027 return (error); 5028 } 5029 5030 /* 5031 * Get per-process file descriptors for use by procstat(1), et al. 5032 */ 5033 static int 5034 sysctl_kern_proc_ofiledesc(SYSCTL_HANDLER_ARGS) 5035 { 5036 struct kinfo_ofile *okif; 5037 struct kinfo_file *kif; 5038 struct filedesc *fdp; 5039 struct pwddesc *pdp; 5040 struct pwd *pwd; 5041 u_int namelen; 5042 int error, i, *name; 5043 struct file *fp; 5044 struct proc *p; 5045 5046 namelen = arg2; 5047 if (namelen != 1) 5048 return (EINVAL); 5049 5050 name = (int *)arg1; 5051 error = pget((pid_t)name[0], PGET_CANDEBUG | PGET_NOTWEXIT, &p); 5052 if (error != 0) 5053 return (error); 5054 fdp = fdhold(p); 5055 if (fdp != NULL) 5056 pdp = pdhold(p); 5057 PROC_UNLOCK(p); 5058 if (fdp == NULL || pdp == NULL) { 5059 if (fdp != NULL) 5060 fddrop(fdp); 5061 return (ENOENT); 5062 } 5063 kif = malloc(sizeof(*kif), M_TEMP, M_WAITOK); 5064 okif = malloc(sizeof(*okif), M_TEMP, M_WAITOK); 5065 PWDDESC_XLOCK(pdp); 5066 pwd = pwd_hold_pwddesc(pdp); 5067 if (pwd != NULL) { 5068 if (pwd->pwd_cdir != NULL) 5069 export_vnode_for_osysctl(pwd->pwd_cdir, KF_FD_TYPE_CWD, kif, 5070 okif, pdp, req); 5071 if (pwd->pwd_rdir != NULL) 5072 export_vnode_for_osysctl(pwd->pwd_rdir, KF_FD_TYPE_ROOT, kif, 5073 okif, pdp, req); 5074 if (pwd->pwd_jdir != NULL) 5075 export_vnode_for_osysctl(pwd->pwd_jdir, KF_FD_TYPE_JAIL, kif, 5076 okif, pdp, req); 5077 } 5078 PWDDESC_XUNLOCK(pdp); 5079 if (pwd != NULL) 5080 pwd_drop(pwd); 5081 FILEDESC_SLOCK(fdp); 5082 if (refcount_load(&fdp->fd_refcnt) == 0) 5083 goto skip; 5084 FILEDESC_FOREACH_FP(fdp, i, fp) { 5085 export_file_to_kinfo(fp, i, NULL, kif, fdp, 5086 KERN_FILEDESC_PACK_KINFO); 5087 FILEDESC_SUNLOCK(fdp); 5088 kinfo_to_okinfo(kif, okif); 5089 error = SYSCTL_OUT(req, okif, sizeof(*okif)); 5090 FILEDESC_SLOCK(fdp); 5091 if (error != 0 || refcount_load(&fdp->fd_refcnt) == 0) 5092 break; 5093 } 5094 skip: 5095 FILEDESC_SUNLOCK(fdp); 5096 fddrop(fdp); 5097 pddrop(pdp); 5098 free(kif, M_TEMP); 5099 free(okif, M_TEMP); 5100 return (0); 5101 } 5102 5103 static SYSCTL_NODE(_kern_proc, KERN_PROC_OFILEDESC, ofiledesc, 5104 CTLFLAG_RD|CTLFLAG_MPSAFE, sysctl_kern_proc_ofiledesc, 5105 "Process ofiledesc entries"); 5106 #endif /* COMPAT_FREEBSD7 */ 5107 5108 int 5109 vntype_to_kinfo(int vtype) 5110 { 5111 struct { 5112 int vtype; 5113 int kf_vtype; 5114 } vtypes_table[] = { 5115 { VBAD, KF_VTYPE_VBAD }, 5116 { VBLK, KF_VTYPE_VBLK }, 5117 { VCHR, KF_VTYPE_VCHR }, 5118 { VDIR, KF_VTYPE_VDIR }, 5119 { VFIFO, KF_VTYPE_VFIFO }, 5120 { VLNK, KF_VTYPE_VLNK }, 5121 { VNON, KF_VTYPE_VNON }, 5122 { VREG, KF_VTYPE_VREG }, 5123 { VSOCK, KF_VTYPE_VSOCK } 5124 }; 5125 unsigned int i; 5126 5127 /* 5128 * Perform vtype translation. 5129 */ 5130 for (i = 0; i < nitems(vtypes_table); i++) 5131 if (vtypes_table[i].vtype == vtype) 5132 return (vtypes_table[i].kf_vtype); 5133 5134 return (KF_VTYPE_UNKNOWN); 5135 } 5136 5137 static SYSCTL_NODE(_kern_proc, KERN_PROC_FILEDESC, filedesc, 5138 CTLFLAG_RD|CTLFLAG_MPSAFE, sysctl_kern_proc_filedesc, 5139 "Process filedesc entries"); 5140 5141 /* 5142 * Store a process current working directory information to sbuf. 5143 * 5144 * Takes a locked proc as argument, and returns with the proc unlocked. 5145 */ 5146 int 5147 kern_proc_cwd_out(struct proc *p, struct sbuf *sb, ssize_t maxlen) 5148 { 5149 struct pwddesc *pdp; 5150 struct pwd *pwd; 5151 struct export_fd_buf *efbuf; 5152 struct vnode *cdir; 5153 int error; 5154 5155 PROC_LOCK_ASSERT(p, MA_OWNED); 5156 5157 pdp = pdhold(p); 5158 PROC_UNLOCK(p); 5159 if (pdp == NULL) 5160 return (EINVAL); 5161 5162 efbuf = malloc(sizeof(*efbuf), M_TEMP, M_WAITOK); 5163 efbuf->fdp = NULL; 5164 efbuf->pdp = pdp; 5165 efbuf->sb = sb; 5166 efbuf->remainder = maxlen; 5167 efbuf->flags = 0; 5168 5169 PWDDESC_XLOCK(pdp); 5170 pwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); 5171 cdir = pwd->pwd_cdir; 5172 if (cdir == NULL) { 5173 error = EINVAL; 5174 } else { 5175 vrefact(cdir); 5176 error = export_vnode_to_sb(cdir, KF_FD_TYPE_CWD, FREAD, efbuf); 5177 } 5178 PWDDESC_XUNLOCK(pdp); 5179 pddrop(pdp); 5180 free(efbuf, M_TEMP); 5181 return (error); 5182 } 5183 5184 /* 5185 * Get per-process current working directory. 5186 */ 5187 static int 5188 sysctl_kern_proc_cwd(SYSCTL_HANDLER_ARGS) 5189 { 5190 struct sbuf sb; 5191 struct proc *p; 5192 ssize_t maxlen; 5193 u_int namelen; 5194 int error, error2, *name; 5195 5196 namelen = arg2; 5197 if (namelen != 1) 5198 return (EINVAL); 5199 5200 name = (int *)arg1; 5201 5202 sbuf_new_for_sysctl(&sb, NULL, sizeof(struct kinfo_file), req); 5203 sbuf_clear_flags(&sb, SBUF_INCLUDENUL); 5204 error = pget((pid_t)name[0], PGET_CANDEBUG | PGET_NOTWEXIT, &p); 5205 if (error != 0) { 5206 sbuf_delete(&sb); 5207 return (error); 5208 } 5209 maxlen = req->oldptr != NULL ? req->oldlen : -1; 5210 error = kern_proc_cwd_out(p, &sb, maxlen); 5211 error2 = sbuf_finish(&sb); 5212 sbuf_delete(&sb); 5213 return (error != 0 ? error : error2); 5214 } 5215 5216 static SYSCTL_NODE(_kern_proc, KERN_PROC_CWD, cwd, CTLFLAG_RD|CTLFLAG_MPSAFE, 5217 sysctl_kern_proc_cwd, "Process current working directory"); 5218 5219 #ifdef DDB 5220 /* 5221 * For the purposes of debugging, generate a human-readable string for the 5222 * file type. 5223 */ 5224 static const char * 5225 file_type_to_name(short type) 5226 { 5227 5228 switch (type) { 5229 case 0: 5230 return ("zero"); 5231 case DTYPE_VNODE: 5232 return ("vnode"); 5233 case DTYPE_SOCKET: 5234 return ("socket"); 5235 case DTYPE_PIPE: 5236 return ("pipe"); 5237 case DTYPE_FIFO: 5238 return ("fifo"); 5239 case DTYPE_KQUEUE: 5240 return ("kqueue"); 5241 case DTYPE_CRYPTO: 5242 return ("crypto"); 5243 case DTYPE_MQUEUE: 5244 return ("mqueue"); 5245 case DTYPE_SHM: 5246 return ("shm"); 5247 case DTYPE_SEM: 5248 return ("ksem"); 5249 case DTYPE_PTS: 5250 return ("pts"); 5251 case DTYPE_DEV: 5252 return ("dev"); 5253 case DTYPE_PROCDESC: 5254 return ("proc"); 5255 case DTYPE_EVENTFD: 5256 return ("eventfd"); 5257 case DTYPE_TIMERFD: 5258 return ("timerfd"); 5259 case DTYPE_JAILDESC: 5260 return ("jail"); 5261 default: 5262 return ("unkn"); 5263 } 5264 } 5265 5266 /* 5267 * For the purposes of debugging, identify a process (if any, perhaps one of 5268 * many) that references the passed file in its file descriptor array. Return 5269 * NULL if none. 5270 */ 5271 static struct proc * 5272 file_to_first_proc(struct file *fp) 5273 { 5274 struct filedesc *fdp; 5275 struct proc *p; 5276 int n; 5277 5278 FOREACH_PROC_IN_SYSTEM(p) { 5279 if (p->p_state == PRS_NEW) 5280 continue; 5281 fdp = p->p_fd; 5282 if (fdp == NULL) 5283 continue; 5284 for (n = 0; n < fdp->fd_nfiles; n++) { 5285 if (fp == fdp->fd_ofiles[n].fde_file) 5286 return (p); 5287 } 5288 } 5289 return (NULL); 5290 } 5291 5292 static void 5293 db_print_file(struct file *fp, int header) 5294 { 5295 #define XPTRWIDTH ((int)howmany(sizeof(void *) * NBBY, 4)) 5296 struct proc *p; 5297 5298 if (header) 5299 db_printf("%*s %6s %*s %8s %4s %5s %6s %*s %5s %s\n", 5300 XPTRWIDTH, "File", "Type", XPTRWIDTH, "Data", "Flag", 5301 "GCFl", "Count", "MCount", XPTRWIDTH, "Vnode", "FPID", 5302 "FCmd"); 5303 p = file_to_first_proc(fp); 5304 db_printf("%*p %6s %*p %08x %04x %5d %6d %*p %5d %s\n", XPTRWIDTH, 5305 fp, file_type_to_name(fp->f_type), XPTRWIDTH, fp->f_data, 5306 fp->f_flag, 0, refcount_load(&fp->f_count), 0, XPTRWIDTH, fp->f_vnode, 5307 p != NULL ? p->p_pid : -1, p != NULL ? p->p_comm : "-"); 5308 5309 #undef XPTRWIDTH 5310 } 5311 5312 DB_SHOW_COMMAND(file, db_show_file) 5313 { 5314 struct file *fp; 5315 5316 if (!have_addr) { 5317 db_printf("usage: show file <addr>\n"); 5318 return; 5319 } 5320 fp = (struct file *)addr; 5321 db_print_file(fp, 1); 5322 } 5323 5324 DB_SHOW_COMMAND_FLAGS(files, db_show_files, DB_CMD_MEMSAFE) 5325 { 5326 struct filedesc *fdp; 5327 struct file *fp; 5328 struct proc *p; 5329 int header; 5330 int n; 5331 5332 header = 1; 5333 FOREACH_PROC_IN_SYSTEM(p) { 5334 if (p->p_state == PRS_NEW) 5335 continue; 5336 if ((fdp = p->p_fd) == NULL) 5337 continue; 5338 for (n = 0; n < fdp->fd_nfiles; ++n) { 5339 if ((fp = fdp->fd_ofiles[n].fde_file) == NULL) 5340 continue; 5341 db_print_file(fp, header); 5342 header = 0; 5343 } 5344 } 5345 } 5346 #endif 5347 5348 SYSCTL_INT(_kern, KERN_MAXFILESPERPROC, maxfilesperproc, 5349 CTLFLAG_RWTUN | CTLFLAG_NOFETCH, 5350 &maxfilesperproc, 0, "Maximum files allowed open per process"); 5351 5352 SYSCTL_INT(_kern, KERN_MAXFILES, maxfiles, CTLFLAG_RWTUN | CTLFLAG_NOFETCH, 5353 &maxfiles, 0, "Maximum number of files"); 5354 5355 SYSCTL_INT(_kern, OID_AUTO, openfiles, CTLFLAG_RD, 5356 &openfiles, 0, "System-wide number of open files"); 5357 5358 /* ARGSUSED*/ 5359 static void 5360 filelistinit(void *dummy) 5361 { 5362 5363 file_zone = uma_zcreate("Files", sizeof(struct file), NULL, NULL, 5364 NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE); 5365 filedesc0_zone = uma_zcreate("filedesc0", sizeof(struct filedesc0), 5366 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0); 5367 pwd_zone = uma_zcreate("PWD", sizeof(struct pwd), NULL, NULL, 5368 NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_SMR); 5369 /* 5370 * XXXMJG this is a temporary hack due to boot ordering issues against 5371 * the vnode zone. 5372 */ 5373 vfs_smr = uma_zone_get_smr(pwd_zone); 5374 mtx_init(&sigio_lock, "sigio lock", NULL, MTX_DEF); 5375 } 5376 SYSINIT(select, SI_SUB_LOCK, SI_ORDER_FIRST, filelistinit, NULL); 5377 5378 /*-------------------------------------------------------------------*/ 5379 5380 static int 5381 badfo_readwrite(struct file *fp, struct uio *uio, struct ucred *active_cred, 5382 int flags, struct thread *td) 5383 { 5384 5385 return (EBADF); 5386 } 5387 5388 static int 5389 badfo_truncate(struct file *fp, off_t length, struct ucred *active_cred, 5390 struct thread *td) 5391 { 5392 5393 return (EINVAL); 5394 } 5395 5396 static int 5397 badfo_ioctl(struct file *fp, u_long com, void *data, struct ucred *active_cred, 5398 struct thread *td) 5399 { 5400 5401 return (EBADF); 5402 } 5403 5404 static int 5405 badfo_poll(struct file *fp, int events, struct ucred *active_cred, 5406 struct thread *td) 5407 { 5408 5409 return (0); 5410 } 5411 5412 static int 5413 badfo_kqfilter(struct file *fp, struct knote *kn) 5414 { 5415 5416 return (EBADF); 5417 } 5418 5419 static int 5420 badfo_stat(struct file *fp, struct stat *sb, struct ucred *active_cred) 5421 { 5422 5423 return (EBADF); 5424 } 5425 5426 static int 5427 badfo_close(struct file *fp, struct thread *td) 5428 { 5429 5430 return (0); 5431 } 5432 5433 static int 5434 badfo_chmod(struct file *fp, mode_t mode, struct ucred *active_cred, 5435 struct thread *td) 5436 { 5437 5438 return (EBADF); 5439 } 5440 5441 static int 5442 badfo_chown(struct file *fp, uid_t uid, gid_t gid, struct ucred *active_cred, 5443 struct thread *td) 5444 { 5445 5446 return (EBADF); 5447 } 5448 5449 static int 5450 badfo_sendfile(struct file *fp, int sockfd, struct uio *hdr_uio, 5451 struct uio *trl_uio, off_t offset, size_t nbytes, off_t *sent, int flags, 5452 struct thread *td) 5453 { 5454 5455 return (EBADF); 5456 } 5457 5458 static int 5459 badfo_fill_kinfo(struct file *fp, struct kinfo_file *kif, struct filedesc *fdp) 5460 { 5461 5462 return (0); 5463 } 5464 5465 const struct fileops badfileops = { 5466 .fo_read = badfo_readwrite, 5467 .fo_write = badfo_readwrite, 5468 .fo_truncate = badfo_truncate, 5469 .fo_ioctl = badfo_ioctl, 5470 .fo_poll = badfo_poll, 5471 .fo_kqfilter = badfo_kqfilter, 5472 .fo_stat = badfo_stat, 5473 .fo_close = badfo_close, 5474 .fo_chmod = badfo_chmod, 5475 .fo_chown = badfo_chown, 5476 .fo_sendfile = badfo_sendfile, 5477 .fo_fill_kinfo = badfo_fill_kinfo, 5478 }; 5479 5480 static int 5481 path_poll(struct file *fp, int events, struct ucred *active_cred, 5482 struct thread *td) 5483 { 5484 return (POLLNVAL); 5485 } 5486 5487 static int 5488 path_close(struct file *fp, struct thread *td) 5489 { 5490 MPASS(fp->f_type == DTYPE_VNODE); 5491 fp->f_ops = &badfileops; 5492 vrele(fp->f_vnode); 5493 return (0); 5494 } 5495 5496 const struct fileops path_fileops = { 5497 .fo_read = badfo_readwrite, 5498 .fo_write = badfo_readwrite, 5499 .fo_truncate = badfo_truncate, 5500 .fo_ioctl = badfo_ioctl, 5501 .fo_poll = path_poll, 5502 .fo_kqfilter = vn_kqfilter_opath, 5503 .fo_stat = vn_statfile, 5504 .fo_close = path_close, 5505 .fo_chmod = badfo_chmod, 5506 .fo_chown = badfo_chown, 5507 .fo_sendfile = badfo_sendfile, 5508 .fo_fill_kinfo = vn_fill_kinfo, 5509 .fo_cmp = vn_cmp, 5510 .fo_flags = DFLAG_PASSABLE, 5511 }; 5512 5513 int 5514 invfo_rdwr(struct file *fp, struct uio *uio, struct ucred *active_cred, 5515 int flags, struct thread *td) 5516 { 5517 5518 return (EOPNOTSUPP); 5519 } 5520 5521 int 5522 invfo_truncate(struct file *fp, off_t length, struct ucred *active_cred, 5523 struct thread *td) 5524 { 5525 5526 return (EINVAL); 5527 } 5528 5529 int 5530 invfo_ioctl(struct file *fp, u_long com, void *data, 5531 struct ucred *active_cred, struct thread *td) 5532 { 5533 5534 return (ENOTTY); 5535 } 5536 5537 int 5538 invfo_poll(struct file *fp, int events, struct ucred *active_cred, 5539 struct thread *td) 5540 { 5541 5542 return (poll_no_poll(events)); 5543 } 5544 5545 int 5546 invfo_kqfilter(struct file *fp, struct knote *kn) 5547 { 5548 5549 return (EINVAL); 5550 } 5551 5552 int 5553 invfo_chmod(struct file *fp, mode_t mode, struct ucred *active_cred, 5554 struct thread *td) 5555 { 5556 5557 return (EINVAL); 5558 } 5559 5560 int 5561 invfo_chown(struct file *fp, uid_t uid, gid_t gid, struct ucred *active_cred, 5562 struct thread *td) 5563 { 5564 5565 return (EINVAL); 5566 } 5567 5568 int 5569 invfo_sendfile(struct file *fp, int sockfd, struct uio *hdr_uio, 5570 struct uio *trl_uio, off_t offset, size_t nbytes, off_t *sent, int flags, 5571 struct thread *td) 5572 { 5573 5574 return (EINVAL); 5575 } 5576 5577 /*-------------------------------------------------------------------*/ 5578 5579 /* 5580 * File Descriptor pseudo-device driver (/dev/fd/). 5581 * 5582 * Opening minor device N dup()s the file (if any) connected to file 5583 * descriptor N belonging to the calling process. Note that this driver 5584 * consists of only the ``open()'' routine, because all subsequent 5585 * references to this file will be direct to the other driver. 5586 * 5587 * XXX: we could give this one a cloning event handler if necessary. 5588 */ 5589 5590 /* ARGSUSED */ 5591 static int 5592 fdopen(struct cdev *dev, int mode, int type, struct thread *td) 5593 { 5594 5595 /* 5596 * XXX Kludge: set curthread->td_dupfd to contain the value of the 5597 * the file descriptor being sought for duplication. The error 5598 * return ensures that the vnode for this device will be released 5599 * by vn_open. Open will detect this special error and take the 5600 * actions in dupfdopen below. Other callers of vn_open or VOP_OPEN 5601 * will simply report the error. 5602 */ 5603 td->td_dupfd = dev2unit(dev); 5604 return (ENODEV); 5605 } 5606 5607 static struct cdevsw fildesc_cdevsw = { 5608 .d_version = D_VERSION, 5609 .d_open = fdopen, 5610 .d_name = "FD", 5611 }; 5612 5613 static void 5614 fildesc_drvinit(void *unused) 5615 { 5616 struct cdev *dev; 5617 5618 dev = make_dev_credf(MAKEDEV_ETERNAL, &fildesc_cdevsw, 0, NULL, 5619 UID_ROOT, GID_WHEEL, 0666, "fd/0"); 5620 make_dev_alias(dev, "stdin"); 5621 dev = make_dev_credf(MAKEDEV_ETERNAL, &fildesc_cdevsw, 1, NULL, 5622 UID_ROOT, GID_WHEEL, 0666, "fd/1"); 5623 make_dev_alias(dev, "stdout"); 5624 dev = make_dev_credf(MAKEDEV_ETERNAL, &fildesc_cdevsw, 2, NULL, 5625 UID_ROOT, GID_WHEEL, 0666, "fd/2"); 5626 make_dev_alias(dev, "stderr"); 5627 } 5628 5629 SYSINIT(fildescdev, SI_SUB_DRIVERS, SI_ORDER_MIDDLE, fildesc_drvinit, NULL); 5630