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 fsetfl_lock(fp); 662 do { 663 tmp = flg = fp->f_flag; 664 tmp &= ~FCNTLFLAGS; 665 tmp |= FFLAGS(arg & ~O_ACCMODE) & FCNTLFLAGS; 666 } while (atomic_cmpset_int(&fp->f_flag, flg, tmp) == 0); 667 got_set = tmp & ~flg; 668 got_cleared = flg & ~tmp; 669 if (((got_set | got_cleared) & FNONBLOCK) != 0) { 670 tmp = fp->f_flag & FNONBLOCK; 671 error = fo_ioctl(fp, FIONBIO, &tmp, td->td_ucred, td); 672 if (error != 0) 673 goto revert_flags; 674 } 675 if (((got_set | got_cleared) & FASYNC) != 0) { 676 tmp = fp->f_flag & FASYNC; 677 error = fo_ioctl(fp, FIOASYNC, &tmp, td->td_ucred, td); 678 if (error != 0) 679 goto revert_nonblock; 680 } 681 fsetfl_unlock(fp); 682 fdrop(fp, td); 683 break; 684 revert_nonblock: 685 if (((got_set | got_cleared) & FNONBLOCK) != 0) { 686 tmp = ~fp->f_flag & FNONBLOCK; 687 (void)fo_ioctl(fp, FIONBIO, &tmp, td->td_ucred, td); 688 } 689 revert_flags: 690 do { 691 tmp = flg = fp->f_flag; 692 tmp &= ~FCNTLFLAGS; 693 tmp |= got_cleared; 694 tmp &= ~got_set; 695 } while (atomic_cmpset_int(&fp->f_flag, flg, tmp) == 0); 696 fsetfl_unlock(fp); 697 fdrop(fp, td); 698 break; 699 700 case F_GETOWN: 701 error = fget_fcntl(td, fd, &cap_fcntl_rights, F_GETOWN, &fp); 702 if (error != 0) 703 break; 704 error = fo_ioctl(fp, FIOGETOWN, &tmp, td->td_ucred, td); 705 if (error == 0) 706 td->td_retval[0] = tmp; 707 fdrop(fp, td); 708 break; 709 710 case F_SETOWN: 711 error = fget_fcntl(td, fd, &cap_fcntl_rights, F_SETOWN, &fp); 712 if (error != 0) 713 break; 714 tmp = arg; 715 error = fo_ioctl(fp, FIOSETOWN, &tmp, td->td_ucred, td); 716 fdrop(fp, td); 717 break; 718 719 case F_SETLK_REMOTE: 720 error = priv_check(td, PRIV_NFS_LOCKD); 721 if (error != 0) 722 return (error); 723 flg = F_REMOTE; 724 goto do_setlk; 725 726 case F_SETLKW: 727 flg |= F_WAIT; 728 /* FALLTHROUGH F_SETLK */ 729 730 case F_SETLK: 731 do_setlk: 732 flp = (struct flock *)arg; 733 if ((flg & F_REMOTE) != 0 && flp->l_sysid == 0) { 734 error = EINVAL; 735 break; 736 } 737 738 error = fget_unlocked(td, fd, &cap_flock_rights, &fp); 739 if (error != 0) 740 break; 741 if (fp->f_type != DTYPE_VNODE || fp->f_ops == &path_fileops) { 742 error = EBADF; 743 fdrop(fp, td); 744 break; 745 } 746 747 if (flp->l_whence == SEEK_CUR) { 748 foffset = foffset_get(fp); 749 if (foffset < 0 || 750 (flp->l_start > 0 && 751 foffset > OFF_MAX - flp->l_start)) { 752 error = EOVERFLOW; 753 fdrop(fp, td); 754 break; 755 } 756 flp->l_start += foffset; 757 } 758 759 vp = fp->f_vnode; 760 switch (flp->l_type) { 761 case F_RDLCK: 762 if ((fp->f_flag & FREAD) == 0) { 763 error = EBADF; 764 break; 765 } 766 if ((p->p_leader->p_flag & P_ADVLOCK) == 0) { 767 PROC_LOCK(p->p_leader); 768 p->p_leader->p_flag |= P_ADVLOCK; 769 PROC_UNLOCK(p->p_leader); 770 } 771 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_SETLK, 772 flp, flg); 773 break; 774 case F_WRLCK: 775 if ((fp->f_flag & FWRITE) == 0) { 776 error = EBADF; 777 break; 778 } 779 if ((p->p_leader->p_flag & P_ADVLOCK) == 0) { 780 PROC_LOCK(p->p_leader); 781 p->p_leader->p_flag |= P_ADVLOCK; 782 PROC_UNLOCK(p->p_leader); 783 } 784 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_SETLK, 785 flp, flg); 786 break; 787 case F_UNLCK: 788 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_UNLCK, 789 flp, flg); 790 break; 791 case F_UNLCKSYS: 792 if (flg != F_REMOTE) { 793 error = EINVAL; 794 break; 795 } 796 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, 797 F_UNLCKSYS, flp, flg); 798 break; 799 default: 800 error = EINVAL; 801 break; 802 } 803 if (error != 0 || flp->l_type == F_UNLCK || 804 flp->l_type == F_UNLCKSYS) { 805 fdrop(fp, td); 806 break; 807 } 808 809 /* 810 * Check for a race with close. 811 * 812 * The vnode is now advisory locked (or unlocked, but this case 813 * is not really important) as the caller requested. 814 * We had to drop the filedesc lock, so we need to recheck if 815 * the descriptor is still valid, because if it was closed 816 * in the meantime we need to remove advisory lock from the 817 * vnode - close on any descriptor leading to an advisory 818 * locked vnode, removes that lock. 819 * We will return 0 on purpose in that case, as the result of 820 * successful advisory lock might have been externally visible 821 * already. This is fine - effectively we pretend to the caller 822 * that the closing thread was a bit slower and that the 823 * advisory lock succeeded before the close. 824 */ 825 error = fget_unlocked(td, fd, &cap_no_rights, &fp2); 826 if (error != 0) { 827 fdrop(fp, td); 828 break; 829 } 830 if (fp != fp2) { 831 flp->l_whence = SEEK_SET; 832 flp->l_start = 0; 833 flp->l_len = 0; 834 flp->l_type = F_UNLCK; 835 (void) VOP_ADVLOCK(vp, (caddr_t)p->p_leader, 836 F_UNLCK, flp, F_POSIX); 837 } 838 fdrop(fp, td); 839 fdrop(fp2, td); 840 break; 841 842 case F_GETLK: 843 error = fget_unlocked(td, fd, &cap_flock_rights, &fp); 844 if (error != 0) 845 break; 846 if (fp->f_type != DTYPE_VNODE || fp->f_ops == &path_fileops) { 847 error = EBADF; 848 fdrop(fp, td); 849 break; 850 } 851 flp = (struct flock *)arg; 852 if (flp->l_type != F_RDLCK && flp->l_type != F_WRLCK && 853 flp->l_type != F_UNLCK) { 854 error = EINVAL; 855 fdrop(fp, td); 856 break; 857 } 858 if (flp->l_whence == SEEK_CUR) { 859 foffset = foffset_get(fp); 860 if ((flp->l_start > 0 && 861 foffset > OFF_MAX - flp->l_start) || 862 (flp->l_start < 0 && 863 foffset < OFF_MIN - flp->l_start)) { 864 error = EOVERFLOW; 865 fdrop(fp, td); 866 break; 867 } 868 flp->l_start += foffset; 869 } 870 vp = fp->f_vnode; 871 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_GETLK, flp, 872 F_POSIX); 873 fdrop(fp, td); 874 break; 875 876 case F_ADD_SEALS: 877 error = fget_unlocked(td, fd, &cap_no_rights, &fp); 878 if (error != 0) 879 break; 880 error = fo_add_seals(fp, arg); 881 fdrop(fp, td); 882 break; 883 884 case F_GET_SEALS: 885 error = fget_unlocked(td, fd, &cap_no_rights, &fp); 886 if (error != 0) 887 break; 888 if (fo_get_seals(fp, &seals) == 0) 889 td->td_retval[0] = seals; 890 else 891 error = EINVAL; 892 fdrop(fp, td); 893 break; 894 895 case F_RDAHEAD: 896 arg = arg ? 128 * 1024: 0; 897 /* FALLTHROUGH */ 898 case F_READAHEAD: 899 error = fget_unlocked(td, fd, &cap_no_rights, &fp); 900 if (error != 0) 901 break; 902 if (fp->f_type != DTYPE_VNODE || fp->f_ops == &path_fileops) { 903 fdrop(fp, td); 904 error = EBADF; 905 break; 906 } 907 vp = fp->f_vnode; 908 if (vp->v_type != VREG) { 909 fdrop(fp, td); 910 error = ENOTTY; 911 break; 912 } 913 914 /* 915 * Exclusive lock synchronizes against f_seqcount reads and 916 * writes in sequential_heuristic(). 917 */ 918 error = vn_lock(vp, LK_EXCLUSIVE); 919 if (error != 0) { 920 fdrop(fp, td); 921 break; 922 } 923 if (arg >= 0) { 924 bsize = fp->f_vnode->v_mount->mnt_stat.f_iosize; 925 arg = MIN(arg, INT_MAX - bsize + 1); 926 fp->f_seqcount[UIO_READ] = MIN(IO_SEQMAX, 927 (arg + bsize - 1) / bsize); 928 atomic_set_int(&fp->f_flag, FRDAHEAD); 929 } else { 930 atomic_clear_int(&fp->f_flag, FRDAHEAD); 931 } 932 VOP_UNLOCK(vp); 933 fdrop(fp, td); 934 break; 935 936 case F_ISUNIONSTACK: 937 /* 938 * Check if the vnode is part of a union stack (either the 939 * "union" flag from mount(2) or unionfs). 940 * 941 * Prior to introduction of this op libc's readdir would call 942 * fstatfs(2), in effect unnecessarily copying kilobytes of 943 * data just to check fs name and a mount flag. 944 * 945 * Fixing the code to handle everything in the kernel instead 946 * is a non-trivial endeavor and has low priority, thus this 947 * horrible kludge facilitates the current behavior in a much 948 * cheaper manner until someone(tm) sorts this out. 949 */ 950 error = fget_unlocked(td, fd, &cap_no_rights, &fp); 951 if (error != 0) 952 break; 953 if (fp->f_type != DTYPE_VNODE) { 954 fdrop(fp, td); 955 error = EBADF; 956 break; 957 } 958 vp = fp->f_vnode; 959 /* 960 * Since we don't prevent dooming the vnode even non-null mp 961 * found can become immediately stale. This is tolerable since 962 * mount points are type-stable (providing safe memory access) 963 * and any vfs op on this vnode going forward will return an 964 * error (meaning return value in this case is meaningless). 965 */ 966 mp = atomic_load_ptr(&vp->v_mount); 967 if (__predict_false(mp == NULL)) { 968 fdrop(fp, td); 969 error = EBADF; 970 break; 971 } 972 td->td_retval[0] = 0; 973 if (mp->mnt_kern_flag & MNTK_UNIONFS || 974 mp->mnt_flag & MNT_UNION) 975 td->td_retval[0] = 1; 976 fdrop(fp, td); 977 break; 978 979 case F_KINFO: 980 #ifdef CAPABILITY_MODE 981 if (CAP_TRACING(td)) 982 ktrcapfail(CAPFAIL_SYSCALL, &cmd); 983 if (IN_CAPABILITY_MODE(td)) { 984 error = ECAPMODE; 985 break; 986 } 987 #endif 988 error = copyin((void *)arg, &kif_sz, sizeof(kif_sz)); 989 if (error != 0) 990 break; 991 if (kif_sz != sizeof(*kif)) { 992 error = EINVAL; 993 break; 994 } 995 kif = malloc(sizeof(*kif), M_TEMP, M_WAITOK | M_ZERO); 996 FILEDESC_SLOCK(fdp); 997 error = fget_cap_noref(fdp, fd, &cap_fcntl_rights, &fp, NULL); 998 if (error == 0 && fhold(fp)) { 999 export_file_to_kinfo(fp, fd, NULL, kif, fdp, 0); 1000 FILEDESC_SUNLOCK(fdp); 1001 fdrop(fp, td); 1002 if ((kif->kf_status & KF_ATTR_VALID) != 0) { 1003 kif->kf_structsize = sizeof(*kif); 1004 error = copyout(kif, (void *)arg, sizeof(*kif)); 1005 } else { 1006 error = EBADF; 1007 } 1008 } else { 1009 FILEDESC_SUNLOCK(fdp); 1010 if (error == 0) 1011 error = EBADF; 1012 } 1013 free(kif, M_TEMP); 1014 break; 1015 1016 default: 1017 if ((cmd & ((1u << F_DUP3FD_SHIFT) - 1)) != F_DUP3FD) 1018 return (EXTERROR(EINVAL, "invalid fcntl cmd")); 1019 /* Handle F_DUP3FD */ 1020 flags = (cmd >> F_DUP3FD_SHIFT); 1021 if ((flags & ~(FD_CLOEXEC | FD_CLOFORK)) != 0) 1022 return (EXTERROR(EINVAL, "invalid flags for F_DUP3FD")); 1023 tmp = arg; 1024 error = kern_dup(td, FDDUP_FIXED, 1025 ((flags & FD_CLOEXEC) != 0 ? FDDUP_FLAG_CLOEXEC : 0) | 1026 ((flags & FD_CLOFORK) != 0 ? FDDUP_FLAG_CLOFORK : 0), 1027 fd, tmp); 1028 break; 1029 } 1030 return (error); 1031 } 1032 1033 static int 1034 getmaxfd(struct thread *td) 1035 { 1036 1037 return (min((int)lim_cur(td, RLIMIT_NOFILE), maxfilesperproc)); 1038 } 1039 1040 /* 1041 * Common code for dup, dup2, fcntl(F_DUPFD) and fcntl(F_DUP2FD). 1042 */ 1043 int 1044 kern_dup(struct thread *td, u_int mode, int flags, int old, int new) 1045 { 1046 struct filedesc *fdp; 1047 struct filedescent *oldfde, *newfde; 1048 struct proc *p; 1049 struct file *delfp, *oldfp; 1050 u_long *oioctls, *nioctls; 1051 int error, maxfd; 1052 1053 p = td->td_proc; 1054 fdp = p->p_fd; 1055 oioctls = NULL; 1056 1057 MPASS((flags & ~(FDDUP_FLAG_CLOEXEC | FDDUP_FLAG_CLOFORK)) == 0); 1058 MPASS(mode < FDDUP_LASTMODE); 1059 1060 AUDIT_ARG_FD(old); 1061 /* XXXRW: if (flags & FDDUP_FIXED) AUDIT_ARG_FD2(new); */ 1062 1063 /* 1064 * Verify we have a valid descriptor to dup from and possibly to 1065 * dup to. Unlike dup() and dup2(), fcntl()'s F_DUPFD should 1066 * return EINVAL when the new descriptor is out of bounds. 1067 */ 1068 if (old < 0) 1069 return (EBADF); 1070 if (new < 0) 1071 return (mode == FDDUP_FCNTL ? EINVAL : EBADF); 1072 maxfd = getmaxfd(td); 1073 if (new >= maxfd) 1074 return (mode == FDDUP_FCNTL ? EINVAL : EBADF); 1075 1076 error = EBADF; 1077 FILEDESC_XLOCK(fdp); 1078 if (fget_noref(fdp, old) == NULL) 1079 goto unlock; 1080 if (mode == FDDUP_FIXED && old == new) { 1081 td->td_retval[0] = new; 1082 fdp->fd_ofiles[new].fde_flags |= fddup_to_fde_flags(flags); 1083 error = 0; 1084 goto unlock; 1085 } 1086 1087 oldfde = &fdp->fd_ofiles[old]; 1088 oldfp = oldfde->fde_file; 1089 if (!fhold(oldfp)) 1090 goto unlock; 1091 1092 /* 1093 * If the caller specified a file descriptor, make sure the file 1094 * table is large enough to hold it, and grab it. Otherwise, just 1095 * allocate a new descriptor the usual way. 1096 */ 1097 switch (mode) { 1098 case FDDUP_NORMAL: 1099 case FDDUP_FCNTL: 1100 if ((error = fdalloc(td, new, &new)) != 0) { 1101 fdrop(oldfp, td); 1102 goto unlock; 1103 } 1104 break; 1105 case FDDUP_FIXED: 1106 if (new >= fdp->fd_nfiles) { 1107 /* 1108 * The resource limits are here instead of e.g. 1109 * fdalloc(), because the file descriptor table may be 1110 * shared between processes, so we can't really use 1111 * racct_add()/racct_sub(). Instead of counting the 1112 * number of actually allocated descriptors, just put 1113 * the limit on the size of the file descriptor table. 1114 */ 1115 #ifdef RACCT 1116 if (RACCT_ENABLED()) { 1117 error = racct_set_unlocked(p, RACCT_NOFILE, new + 1); 1118 if (error != 0) { 1119 error = EMFILE; 1120 fdrop(oldfp, td); 1121 goto unlock; 1122 } 1123 } 1124 #endif 1125 fdgrowtable_exp(fdp, new + 1); 1126 } 1127 if (!fdisused(fdp, new)) 1128 fdused(fdp, new); 1129 break; 1130 default: 1131 KASSERT(0, ("%s unsupported mode %d", __func__, mode)); 1132 } 1133 1134 KASSERT(old != new, ("new fd is same as old")); 1135 1136 /* Refetch oldfde because the table may have grown and old one freed. */ 1137 oldfde = &fdp->fd_ofiles[old]; 1138 KASSERT(oldfp == oldfde->fde_file, 1139 ("fdt_ofiles shift from growth observed at fd %d", 1140 old)); 1141 1142 newfde = &fdp->fd_ofiles[new]; 1143 delfp = newfde->fde_file; 1144 1145 nioctls = filecaps_copy_prep(&oldfde->fde_caps); 1146 1147 /* 1148 * Duplicate the source descriptor. 1149 */ 1150 #ifdef CAPABILITIES 1151 seqc_write_begin(&newfde->fde_seqc); 1152 #endif 1153 oioctls = filecaps_free_prep(&newfde->fde_caps); 1154 fde_copy(oldfde, newfde); 1155 filecaps_copy_finish(&oldfde->fde_caps, &newfde->fde_caps, 1156 nioctls); 1157 newfde->fde_flags = (oldfde->fde_flags & ~(UF_EXCLOSE | UF_FOCLOSE)) | 1158 fddup_to_fde_flags(flags); 1159 #ifdef CAPABILITIES 1160 seqc_write_end(&newfde->fde_seqc); 1161 #endif 1162 td->td_retval[0] = new; 1163 1164 error = 0; 1165 1166 if (delfp != NULL) { 1167 (void) closefp(fdp, new, delfp, td, true, false); 1168 FILEDESC_UNLOCK_ASSERT(fdp); 1169 } else { 1170 unlock: 1171 FILEDESC_XUNLOCK(fdp); 1172 } 1173 1174 filecaps_free_finish(oioctls); 1175 return (error); 1176 } 1177 1178 static void 1179 sigiofree(struct sigio *sigio) 1180 { 1181 crfree(sigio->sio_ucred); 1182 free(sigio, M_SIGIO); 1183 } 1184 1185 static struct sigio * 1186 funsetown_locked(struct sigio *sigio) 1187 { 1188 struct proc *p; 1189 struct pgrp *pg; 1190 1191 SIGIO_ASSERT_LOCKED(); 1192 1193 if (sigio == NULL) 1194 return (NULL); 1195 *sigio->sio_myref = NULL; 1196 if (sigio->sio_pgid < 0) { 1197 pg = sigio->sio_pgrp; 1198 PGRP_LOCK(pg); 1199 SLIST_REMOVE(&pg->pg_sigiolst, sigio, sigio, sio_pgsigio); 1200 PGRP_UNLOCK(pg); 1201 } else { 1202 p = sigio->sio_proc; 1203 PROC_LOCK(p); 1204 SLIST_REMOVE(&p->p_sigiolst, sigio, sigio, sio_pgsigio); 1205 PROC_UNLOCK(p); 1206 } 1207 return (sigio); 1208 } 1209 1210 /* 1211 * If sigio is on the list associated with a process or process group, 1212 * disable signalling from the device, remove sigio from the list and 1213 * free sigio. 1214 */ 1215 void 1216 funsetown(struct sigio **sigiop) 1217 { 1218 struct sigio *sigio; 1219 1220 /* Racy check, consumers must provide synchronization. */ 1221 if (*sigiop == NULL) 1222 return; 1223 1224 SIGIO_LOCK(); 1225 sigio = funsetown_locked(*sigiop); 1226 SIGIO_UNLOCK(); 1227 if (sigio != NULL) 1228 sigiofree(sigio); 1229 } 1230 1231 /* 1232 * Free a list of sigio structures. The caller must ensure that new sigio 1233 * structures cannot be added after this point. For process groups this is 1234 * guaranteed using the proctree lock; for processes, the P_WEXIT flag serves 1235 * as an interlock. 1236 */ 1237 void 1238 funsetownlst(struct sigiolst *sigiolst) 1239 { 1240 struct proc *p; 1241 struct pgrp *pg; 1242 struct sigio *sigio, *tmp; 1243 1244 /* Racy check. */ 1245 sigio = SLIST_FIRST(sigiolst); 1246 if (sigio == NULL) 1247 return; 1248 1249 p = NULL; 1250 pg = NULL; 1251 1252 SIGIO_LOCK(); 1253 sigio = SLIST_FIRST(sigiolst); 1254 if (sigio == NULL) { 1255 SIGIO_UNLOCK(); 1256 return; 1257 } 1258 1259 /* 1260 * Every entry of the list should belong to a single proc or pgrp. 1261 */ 1262 if (sigio->sio_pgid < 0) { 1263 pg = sigio->sio_pgrp; 1264 sx_assert(&proctree_lock, SX_XLOCKED); 1265 PGRP_LOCK(pg); 1266 } else /* if (sigio->sio_pgid > 0) */ { 1267 p = sigio->sio_proc; 1268 PROC_LOCK(p); 1269 KASSERT((p->p_flag & P_WEXIT) != 0, 1270 ("%s: process %p is not exiting", __func__, p)); 1271 } 1272 1273 SLIST_FOREACH(sigio, sigiolst, sio_pgsigio) { 1274 *sigio->sio_myref = NULL; 1275 if (pg != NULL) { 1276 KASSERT(sigio->sio_pgid < 0, 1277 ("Proc sigio in pgrp sigio list")); 1278 KASSERT(sigio->sio_pgrp == pg, 1279 ("Bogus pgrp in sigio list")); 1280 } else /* if (p != NULL) */ { 1281 KASSERT(sigio->sio_pgid > 0, 1282 ("Pgrp sigio in proc sigio list")); 1283 KASSERT(sigio->sio_proc == p, 1284 ("Bogus proc in sigio list")); 1285 } 1286 } 1287 1288 if (pg != NULL) 1289 PGRP_UNLOCK(pg); 1290 else 1291 PROC_UNLOCK(p); 1292 SIGIO_UNLOCK(); 1293 1294 SLIST_FOREACH_SAFE(sigio, sigiolst, sio_pgsigio, tmp) 1295 sigiofree(sigio); 1296 } 1297 1298 /* 1299 * This is common code for FIOSETOWN ioctl called by fcntl(fd, F_SETOWN, arg). 1300 * 1301 * After permission checking, add a sigio structure to the sigio list for 1302 * the process or process group. 1303 */ 1304 int 1305 fsetown(pid_t pgid, struct sigio **sigiop) 1306 { 1307 struct proc *proc; 1308 struct pgrp *pgrp; 1309 struct sigio *osigio, *sigio; 1310 int ret; 1311 1312 if (pgid == 0) { 1313 funsetown(sigiop); 1314 return (0); 1315 } 1316 1317 sigio = malloc(sizeof(struct sigio), M_SIGIO, M_WAITOK); 1318 sigio->sio_pgid = pgid; 1319 sigio->sio_ucred = crhold(curthread->td_ucred); 1320 sigio->sio_myref = sigiop; 1321 1322 ret = 0; 1323 if (pgid > 0) { 1324 ret = pget(pgid, PGET_NOTWEXIT | PGET_NOTID | PGET_HOLD, &proc); 1325 SIGIO_LOCK(); 1326 osigio = funsetown_locked(*sigiop); 1327 if (ret == 0) { 1328 PROC_LOCK(proc); 1329 _PRELE(proc); 1330 if ((proc->p_flag & P_WEXIT) != 0) { 1331 ret = ESRCH; 1332 } else if (proc->p_session != 1333 curthread->td_proc->p_session) { 1334 /* 1335 * Policy - Don't allow a process to FSETOWN a 1336 * process in another session. 1337 * 1338 * Remove this test to allow maximum flexibility 1339 * or restrict FSETOWN to the current process or 1340 * process group for maximum safety. 1341 */ 1342 ret = EPERM; 1343 } else { 1344 sigio->sio_proc = proc; 1345 SLIST_INSERT_HEAD(&proc->p_sigiolst, sigio, 1346 sio_pgsigio); 1347 } 1348 PROC_UNLOCK(proc); 1349 } 1350 } else /* if (pgid < 0) */ { 1351 sx_slock(&proctree_lock); 1352 SIGIO_LOCK(); 1353 osigio = funsetown_locked(*sigiop); 1354 pgrp = pgfind(-pgid); 1355 if (pgrp == NULL) { 1356 ret = ESRCH; 1357 } else { 1358 if (pgrp->pg_session != curthread->td_proc->p_session) { 1359 /* 1360 * Policy - Don't allow a process to FSETOWN a 1361 * process in another session. 1362 * 1363 * Remove this test to allow maximum flexibility 1364 * or restrict FSETOWN to the current process or 1365 * process group for maximum safety. 1366 */ 1367 ret = EPERM; 1368 } else { 1369 sigio->sio_pgrp = pgrp; 1370 SLIST_INSERT_HEAD(&pgrp->pg_sigiolst, sigio, 1371 sio_pgsigio); 1372 } 1373 PGRP_UNLOCK(pgrp); 1374 } 1375 sx_sunlock(&proctree_lock); 1376 } 1377 if (ret == 0) 1378 *sigiop = sigio; 1379 SIGIO_UNLOCK(); 1380 if (osigio != NULL) 1381 sigiofree(osigio); 1382 return (ret); 1383 } 1384 1385 /* 1386 * This is common code for FIOGETOWN ioctl called by fcntl(fd, F_GETOWN, arg). 1387 */ 1388 pid_t 1389 fgetown(struct sigio **sigiop) 1390 { 1391 pid_t pgid; 1392 1393 SIGIO_LOCK(); 1394 pgid = (*sigiop != NULL) ? (*sigiop)->sio_pgid : 0; 1395 SIGIO_UNLOCK(); 1396 return (pgid); 1397 } 1398 1399 static int 1400 closefp_impl(struct filedesc *fdp, int fd, struct file *fp, struct thread *td, 1401 bool audit) 1402 { 1403 int error; 1404 1405 FILEDESC_XLOCK_ASSERT(fdp); 1406 1407 /* 1408 * We now hold the fp reference that used to be owned by the 1409 * descriptor array. We have to unlock the FILEDESC *AFTER* 1410 * knote_fdclose to prevent a race of the fd getting opened, a knote 1411 * added, and deleteing a knote for the new fd. 1412 */ 1413 if (__predict_false(!TAILQ_EMPTY(&fdp->fd_kqlist))) 1414 knote_fdclose(td, fd); 1415 1416 /* 1417 * We need to notify mqueue if the object is of type mqueue. 1418 */ 1419 if (__predict_false(fp->f_type == DTYPE_MQUEUE)) 1420 mq_fdclose(td, fd, fp); 1421 FILEDESC_XUNLOCK(fdp); 1422 1423 #ifdef AUDIT 1424 if (AUDITING_TD(td) && audit) 1425 audit_sysclose(td, fd, fp); 1426 #endif 1427 error = closef(fp, td); 1428 1429 /* 1430 * All paths leading up to closefp() will have already removed or 1431 * replaced the fd in the filedesc table, so a restart would not 1432 * operate on the same file. 1433 */ 1434 if (error == ERESTART) 1435 error = EINTR; 1436 1437 return (error); 1438 } 1439 1440 static int 1441 closefp_hl(struct filedesc *fdp, int fd, struct file *fp, struct thread *td, 1442 bool holdleaders, bool audit) 1443 { 1444 int error; 1445 1446 FILEDESC_XLOCK_ASSERT(fdp); 1447 1448 if (holdleaders) { 1449 if (td->td_proc->p_fdtol != NULL) { 1450 /* 1451 * Ask fdfree() to sleep to ensure that all relevant 1452 * process leaders can be traversed in closef(). 1453 */ 1454 fdp->fd_holdleaderscount++; 1455 } else { 1456 holdleaders = false; 1457 } 1458 } 1459 1460 error = closefp_impl(fdp, fd, fp, td, audit); 1461 if (holdleaders) { 1462 FILEDESC_XLOCK(fdp); 1463 fdp->fd_holdleaderscount--; 1464 if (fdp->fd_holdleaderscount == 0 && 1465 fdp->fd_holdleaderswakeup != 0) { 1466 fdp->fd_holdleaderswakeup = 0; 1467 wakeup(&fdp->fd_holdleaderscount); 1468 } 1469 FILEDESC_XUNLOCK(fdp); 1470 } 1471 return (error); 1472 } 1473 1474 static int 1475 closefp(struct filedesc *fdp, int fd, struct file *fp, struct thread *td, 1476 bool holdleaders, bool audit) 1477 { 1478 1479 FILEDESC_XLOCK_ASSERT(fdp); 1480 1481 if (__predict_false(td->td_proc->p_fdtol != NULL)) { 1482 return (closefp_hl(fdp, fd, fp, td, holdleaders, audit)); 1483 } else { 1484 return (closefp_impl(fdp, fd, fp, td, audit)); 1485 } 1486 } 1487 1488 /* 1489 * Close a file descriptor. 1490 */ 1491 #ifndef _SYS_SYSPROTO_H_ 1492 struct close_args { 1493 int fd; 1494 }; 1495 #endif 1496 /* ARGSUSED */ 1497 int 1498 sys_close(struct thread *td, struct close_args *uap) 1499 { 1500 1501 return (kern_close(td, uap->fd)); 1502 } 1503 1504 int 1505 kern_close(struct thread *td, int fd) 1506 { 1507 struct filedesc *fdp; 1508 struct file *fp; 1509 1510 fdp = td->td_proc->p_fd; 1511 1512 FILEDESC_XLOCK(fdp); 1513 if ((fp = fget_noref(fdp, fd)) == NULL) { 1514 FILEDESC_XUNLOCK(fdp); 1515 return (EBADF); 1516 } 1517 fdfree(fdp, fd); 1518 1519 /* closefp() drops the FILEDESC lock for us. */ 1520 return (closefp(fdp, fd, fp, td, true, true)); 1521 } 1522 1523 static int 1524 close_range_flags(struct thread *td, u_int lowfd, u_int highfd, int flags) 1525 { 1526 struct filedesc *fdp; 1527 struct fdescenttbl *fdt; 1528 struct filedescent *fde; 1529 int fd, fde_flags; 1530 1531 fde_flags = close_range_to_fde_flags(flags); 1532 fdp = td->td_proc->p_fd; 1533 FILEDESC_XLOCK(fdp); 1534 fdt = atomic_load_ptr(&fdp->fd_files); 1535 highfd = MIN(highfd, fdt->fdt_nfiles - 1); 1536 fd = lowfd; 1537 if (__predict_false(fd > highfd)) { 1538 goto out_locked; 1539 } 1540 for (; fd <= highfd; fd++) { 1541 fde = &fdt->fdt_ofiles[fd]; 1542 if (fde->fde_file != NULL) 1543 fde->fde_flags |= fde_flags; 1544 } 1545 out_locked: 1546 FILEDESC_XUNLOCK(fdp); 1547 return (0); 1548 } 1549 1550 static int 1551 close_range_impl(struct thread *td, u_int lowfd, u_int highfd) 1552 { 1553 struct filedesc *fdp; 1554 const struct fdescenttbl *fdt; 1555 struct file *fp; 1556 int fd; 1557 1558 fdp = td->td_proc->p_fd; 1559 FILEDESC_XLOCK(fdp); 1560 fdt = atomic_load_ptr(&fdp->fd_files); 1561 highfd = MIN(highfd, fdt->fdt_nfiles - 1); 1562 fd = lowfd; 1563 if (__predict_false(fd > highfd)) { 1564 goto out_locked; 1565 } 1566 for (;;) { 1567 fp = fdt->fdt_ofiles[fd].fde_file; 1568 if (fp == NULL) { 1569 if (fd == highfd) 1570 goto out_locked; 1571 } else { 1572 fdfree(fdp, fd); 1573 (void) closefp(fdp, fd, fp, td, true, true); 1574 if (fd == highfd) 1575 goto out_unlocked; 1576 FILEDESC_XLOCK(fdp); 1577 fdt = atomic_load_ptr(&fdp->fd_files); 1578 } 1579 fd++; 1580 } 1581 out_locked: 1582 FILEDESC_XUNLOCK(fdp); 1583 out_unlocked: 1584 return (0); 1585 } 1586 1587 int 1588 kern_close_range(struct thread *td, int flags, u_int lowfd, u_int highfd) 1589 { 1590 1591 /* 1592 * Check this prior to clamping; closefrom(3) with only fd 0, 1, and 2 1593 * open should not be a usage error. From a close_range() perspective, 1594 * close_range(3, ~0U, 0) in the same scenario should also likely not 1595 * be a usage error as all fd above 3 are in-fact already closed. 1596 */ 1597 if (highfd < lowfd) { 1598 return (EINVAL); 1599 } 1600 1601 if ((flags & (CLOSE_RANGE_CLOEXEC | CLOSE_RANGE_CLOFORK)) != 0) 1602 return (close_range_flags(td, lowfd, highfd, flags)); 1603 1604 return (close_range_impl(td, lowfd, highfd)); 1605 } 1606 1607 #ifndef _SYS_SYSPROTO_H_ 1608 struct close_range_args { 1609 u_int lowfd; 1610 u_int highfd; 1611 int flags; 1612 }; 1613 #endif 1614 int 1615 sys_close_range(struct thread *td, struct close_range_args *uap) 1616 { 1617 1618 AUDIT_ARG_FD(uap->lowfd); 1619 AUDIT_ARG_CMD(uap->highfd); 1620 AUDIT_ARG_FFLAGS(uap->flags); 1621 1622 if ((uap->flags & ~(CLOSE_RANGE_CLOEXEC | CLOSE_RANGE_CLOFORK)) != 0) 1623 return (EINVAL); 1624 return (kern_close_range(td, uap->flags, uap->lowfd, uap->highfd)); 1625 } 1626 1627 #ifdef COMPAT_FREEBSD12 1628 /* 1629 * Close open file descriptors. 1630 */ 1631 #ifndef _SYS_SYSPROTO_H_ 1632 struct freebsd12_closefrom_args { 1633 int lowfd; 1634 }; 1635 #endif 1636 /* ARGSUSED */ 1637 int 1638 freebsd12_closefrom(struct thread *td, struct freebsd12_closefrom_args *uap) 1639 { 1640 u_int lowfd; 1641 1642 AUDIT_ARG_FD(uap->lowfd); 1643 1644 /* 1645 * Treat negative starting file descriptor values identical to 1646 * closefrom(0) which closes all files. 1647 */ 1648 lowfd = MAX(0, uap->lowfd); 1649 return (kern_close_range(td, 0, lowfd, ~0U)); 1650 } 1651 #endif /* COMPAT_FREEBSD12 */ 1652 1653 #if defined(COMPAT_43) 1654 /* 1655 * Return status information about a file descriptor. 1656 */ 1657 #ifndef _SYS_SYSPROTO_H_ 1658 struct ofstat_args { 1659 int fd; 1660 struct ostat *sb; 1661 }; 1662 #endif 1663 /* ARGSUSED */ 1664 int 1665 ofstat(struct thread *td, struct ofstat_args *uap) 1666 { 1667 struct ostat oub; 1668 struct stat ub; 1669 int error; 1670 1671 error = kern_fstat(td, uap->fd, &ub); 1672 if (error == 0) { 1673 cvtstat(&ub, &oub); 1674 error = copyout(&oub, uap->sb, sizeof(oub)); 1675 } 1676 return (error); 1677 } 1678 #endif /* COMPAT_43 */ 1679 1680 #if defined(COMPAT_FREEBSD11) 1681 int 1682 freebsd11_fstat(struct thread *td, struct freebsd11_fstat_args *uap) 1683 { 1684 struct stat sb; 1685 struct freebsd11_stat osb; 1686 int error; 1687 1688 error = kern_fstat(td, uap->fd, &sb); 1689 if (error != 0) 1690 return (error); 1691 error = freebsd11_cvtstat(&sb, &osb); 1692 if (error == 0) 1693 error = copyout(&osb, uap->sb, sizeof(osb)); 1694 return (error); 1695 } 1696 #endif /* COMPAT_FREEBSD11 */ 1697 1698 /* 1699 * Return status information about a file descriptor. 1700 */ 1701 #ifndef _SYS_SYSPROTO_H_ 1702 struct fstat_args { 1703 int fd; 1704 struct stat *sb; 1705 }; 1706 #endif 1707 /* ARGSUSED */ 1708 int 1709 sys_fstat(struct thread *td, struct fstat_args *uap) 1710 { 1711 struct stat ub; 1712 int error; 1713 1714 error = kern_fstat(td, uap->fd, &ub); 1715 if (error == 0) 1716 error = copyout(&ub, uap->sb, sizeof(ub)); 1717 return (error); 1718 } 1719 1720 int 1721 kern_fstat(struct thread *td, int fd, struct stat *sbp) 1722 { 1723 struct file *fp; 1724 int error; 1725 1726 AUDIT_ARG_FD(fd); 1727 1728 error = fget(td, fd, &cap_fstat_rights, &fp); 1729 if (__predict_false(error != 0)) 1730 return (error); 1731 1732 AUDIT_ARG_FILE(td->td_proc, fp); 1733 1734 sbp->st_filerev = 0; 1735 sbp->st_bsdflags = 0; 1736 error = fo_stat(fp, sbp, td->td_ucred); 1737 fdrop(fp, td); 1738 #ifdef __STAT_TIME_T_EXT 1739 sbp->st_atim_ext = 0; 1740 sbp->st_mtim_ext = 0; 1741 sbp->st_ctim_ext = 0; 1742 sbp->st_btim_ext = 0; 1743 #endif 1744 #ifdef KTRACE 1745 if (KTRPOINT(td, KTR_STRUCT)) 1746 ktrstat_error(sbp, error); 1747 #endif 1748 return (error); 1749 } 1750 1751 #if defined(COMPAT_FREEBSD11) 1752 /* 1753 * Return status information about a file descriptor. 1754 */ 1755 #ifndef _SYS_SYSPROTO_H_ 1756 struct freebsd11_nfstat_args { 1757 int fd; 1758 struct nstat *sb; 1759 }; 1760 #endif 1761 /* ARGSUSED */ 1762 int 1763 freebsd11_nfstat(struct thread *td, struct freebsd11_nfstat_args *uap) 1764 { 1765 struct nstat nub; 1766 struct stat ub; 1767 int error; 1768 1769 error = kern_fstat(td, uap->fd, &ub); 1770 if (error != 0) 1771 return (error); 1772 error = freebsd11_cvtnstat(&ub, &nub); 1773 if (error != 0) 1774 error = copyout(&nub, uap->sb, sizeof(nub)); 1775 return (error); 1776 } 1777 #endif /* COMPAT_FREEBSD11 */ 1778 1779 /* 1780 * Return pathconf information about a file descriptor. 1781 */ 1782 #ifndef _SYS_SYSPROTO_H_ 1783 struct fpathconf_args { 1784 int fd; 1785 int name; 1786 }; 1787 #endif 1788 /* ARGSUSED */ 1789 int 1790 sys_fpathconf(struct thread *td, struct fpathconf_args *uap) 1791 { 1792 long value; 1793 int error; 1794 1795 error = kern_fpathconf(td, uap->fd, uap->name, &value); 1796 if (error == 0) 1797 td->td_retval[0] = value; 1798 return (error); 1799 } 1800 1801 int 1802 kern_fpathconf(struct thread *td, int fd, int name, long *valuep) 1803 { 1804 struct file *fp; 1805 struct vnode *vp; 1806 int error; 1807 1808 error = fget(td, fd, &cap_fpathconf_rights, &fp); 1809 if (error != 0) 1810 return (error); 1811 1812 if (name == _PC_ASYNC_IO) { 1813 *valuep = _POSIX_ASYNCHRONOUS_IO; 1814 goto out; 1815 } 1816 vp = fp->f_vnode; 1817 if (vp != NULL) { 1818 vn_lock(vp, LK_SHARED | LK_RETRY); 1819 error = VOP_PATHCONF(vp, name, valuep); 1820 VOP_UNLOCK(vp); 1821 } else if (fp->f_type == DTYPE_PIPE || fp->f_type == DTYPE_SOCKET) { 1822 if (name != _PC_PIPE_BUF) { 1823 error = EINVAL; 1824 } else { 1825 *valuep = PIPE_BUF; 1826 error = 0; 1827 } 1828 } else { 1829 error = EOPNOTSUPP; 1830 } 1831 out: 1832 fdrop(fp, td); 1833 return (error); 1834 } 1835 1836 /* 1837 * Copy filecaps structure allocating memory for ioctls array if needed. 1838 * 1839 * The last parameter indicates whether the fdtable is locked. If it is not and 1840 * ioctls are encountered, copying fails and the caller must lock the table. 1841 * 1842 * Note that if the table was not locked, the caller has to check the relevant 1843 * sequence counter to determine whether the operation was successful. 1844 */ 1845 bool 1846 filecaps_copy(const struct filecaps *src, struct filecaps *dst, bool locked) 1847 { 1848 size_t size; 1849 1850 if (src->fc_ioctls != NULL && !locked) 1851 return (false); 1852 memcpy(dst, src, sizeof(*src)); 1853 if (src->fc_ioctls == NULL) 1854 return (true); 1855 1856 KASSERT(src->fc_nioctls > 0, 1857 ("fc_ioctls != NULL, but fc_nioctls=%hd", src->fc_nioctls)); 1858 1859 size = sizeof(src->fc_ioctls[0]) * src->fc_nioctls; 1860 dst->fc_ioctls = malloc(size, M_FILECAPS, M_WAITOK); 1861 memcpy(dst->fc_ioctls, src->fc_ioctls, size); 1862 return (true); 1863 } 1864 1865 static u_long * 1866 filecaps_copy_prep(const struct filecaps *src) 1867 { 1868 u_long *ioctls; 1869 size_t size; 1870 1871 if (__predict_true(src->fc_ioctls == NULL)) 1872 return (NULL); 1873 1874 KASSERT(src->fc_nioctls > 0, 1875 ("fc_ioctls != NULL, but fc_nioctls=%hd", src->fc_nioctls)); 1876 1877 size = sizeof(src->fc_ioctls[0]) * src->fc_nioctls; 1878 ioctls = malloc(size, M_FILECAPS, M_WAITOK); 1879 return (ioctls); 1880 } 1881 1882 static void 1883 filecaps_copy_finish(const struct filecaps *src, struct filecaps *dst, 1884 u_long *ioctls) 1885 { 1886 size_t size; 1887 1888 *dst = *src; 1889 if (__predict_true(src->fc_ioctls == NULL)) { 1890 MPASS(ioctls == NULL); 1891 return; 1892 } 1893 1894 size = sizeof(src->fc_ioctls[0]) * src->fc_nioctls; 1895 dst->fc_ioctls = ioctls; 1896 bcopy(src->fc_ioctls, dst->fc_ioctls, size); 1897 } 1898 1899 /* 1900 * Move filecaps structure to the new place and clear the old place. 1901 */ 1902 void 1903 filecaps_move(struct filecaps *src, struct filecaps *dst) 1904 { 1905 1906 *dst = *src; 1907 bzero(src, sizeof(*src)); 1908 } 1909 1910 /* 1911 * Fill the given filecaps structure with full rights. 1912 */ 1913 static void 1914 filecaps_fill(struct filecaps *fcaps) 1915 { 1916 1917 CAP_ALL(&fcaps->fc_rights); 1918 fcaps->fc_ioctls = NULL; 1919 fcaps->fc_nioctls = -1; 1920 fcaps->fc_fcntls = CAP_FCNTL_ALL; 1921 } 1922 1923 /* 1924 * Free memory allocated within filecaps structure. 1925 */ 1926 static void 1927 filecaps_free_ioctl(struct filecaps *fcaps) 1928 { 1929 1930 free(fcaps->fc_ioctls, M_FILECAPS); 1931 fcaps->fc_ioctls = NULL; 1932 } 1933 1934 void 1935 filecaps_free(struct filecaps *fcaps) 1936 { 1937 1938 filecaps_free_ioctl(fcaps); 1939 bzero(fcaps, sizeof(*fcaps)); 1940 } 1941 1942 static u_long * 1943 filecaps_free_prep(struct filecaps *fcaps) 1944 { 1945 u_long *ioctls; 1946 1947 ioctls = fcaps->fc_ioctls; 1948 bzero(fcaps, sizeof(*fcaps)); 1949 return (ioctls); 1950 } 1951 1952 static void 1953 filecaps_free_finish(u_long *ioctls) 1954 { 1955 1956 free(ioctls, M_FILECAPS); 1957 } 1958 1959 /* 1960 * Validate the given filecaps structure. 1961 */ 1962 static void 1963 filecaps_validate(const struct filecaps *fcaps, const char *func) 1964 { 1965 1966 KASSERT(cap_rights_is_valid(&fcaps->fc_rights), 1967 ("%s: invalid rights", func)); 1968 KASSERT((fcaps->fc_fcntls & ~CAP_FCNTL_ALL) == 0, 1969 ("%s: invalid fcntls", func)); 1970 KASSERT(fcaps->fc_fcntls == 0 || 1971 cap_rights_is_set(&fcaps->fc_rights, CAP_FCNTL), 1972 ("%s: fcntls without CAP_FCNTL", func)); 1973 /* 1974 * open calls without WANTIOCTLCAPS free caps but leave the counter 1975 */ 1976 #if 0 1977 KASSERT(fcaps->fc_ioctls != NULL ? fcaps->fc_nioctls > 0 : 1978 (fcaps->fc_nioctls == -1 || fcaps->fc_nioctls == 0), 1979 ("%s: invalid ioctls", func)); 1980 #endif 1981 KASSERT(fcaps->fc_nioctls == 0 || 1982 cap_rights_is_set(&fcaps->fc_rights, CAP_IOCTL), 1983 ("%s: ioctls without CAP_IOCTL", func)); 1984 } 1985 1986 static void 1987 fdgrowtable_exp(struct filedesc *fdp, int nfd) 1988 { 1989 int nfd1; 1990 1991 FILEDESC_XLOCK_ASSERT(fdp); 1992 1993 nfd1 = fdp->fd_nfiles * 2; 1994 if (nfd1 < nfd) 1995 nfd1 = nfd; 1996 fdgrowtable(fdp, nfd1); 1997 } 1998 1999 /* 2000 * Grow the file table to accommodate (at least) nfd descriptors. 2001 */ 2002 static void 2003 fdgrowtable(struct filedesc *fdp, int nfd) 2004 { 2005 struct filedesc0 *fdp0; 2006 struct freetable *ft; 2007 struct fdescenttbl *ntable; 2008 struct fdescenttbl *otable; 2009 int nnfiles, onfiles; 2010 NDSLOTTYPE *nmap, *omap; 2011 2012 KASSERT(fdp->fd_nfiles > 0, ("zero-length file table")); 2013 2014 /* save old values */ 2015 onfiles = fdp->fd_nfiles; 2016 otable = fdp->fd_files; 2017 omap = fdp->fd_map; 2018 2019 /* compute the size of the new table */ 2020 nnfiles = NDSLOTS(nfd) * NDENTRIES; /* round up */ 2021 if (nnfiles <= onfiles) 2022 /* the table is already large enough */ 2023 return; 2024 2025 /* 2026 * Allocate a new table. We need enough space for the number of 2027 * entries, file entries themselves and the struct freetable we will use 2028 * when we decommission the table and place it on the freelist. 2029 * We place the struct freetable in the middle so we don't have 2030 * to worry about padding. 2031 */ 2032 ntable = malloc(offsetof(struct fdescenttbl, fdt_ofiles) + 2033 nnfiles * sizeof(ntable->fdt_ofiles[0]) + 2034 sizeof(struct freetable), 2035 M_FILEDESC, M_ZERO | M_WAITOK); 2036 /* copy the old data */ 2037 ntable->fdt_nfiles = nnfiles; 2038 memcpy(ntable->fdt_ofiles, otable->fdt_ofiles, 2039 onfiles * sizeof(ntable->fdt_ofiles[0])); 2040 2041 /* 2042 * Allocate a new map only if the old is not large enough. It will 2043 * grow at a slower rate than the table as it can map more 2044 * entries than the table can hold. 2045 */ 2046 if (NDSLOTS(nnfiles) > NDSLOTS(onfiles)) { 2047 nmap = malloc(NDSLOTS(nnfiles) * NDSLOTSIZE, M_FILEDESC, 2048 M_ZERO | M_WAITOK); 2049 /* copy over the old data and update the pointer */ 2050 memcpy(nmap, omap, NDSLOTS(onfiles) * sizeof(*omap)); 2051 fdp->fd_map = nmap; 2052 } 2053 2054 /* 2055 * Make sure that ntable is correctly initialized before we replace 2056 * fd_files poiner. Otherwise fget_unlocked() may see inconsistent 2057 * data. 2058 */ 2059 atomic_store_rel_ptr((volatile void *)&fdp->fd_files, (uintptr_t)ntable); 2060 2061 /* 2062 * Free the old file table when not shared by other threads or processes. 2063 * The old file table is considered to be shared when either are true: 2064 * - The process has more than one thread. 2065 * - The file descriptor table has been shared via fdshare(). 2066 * 2067 * When shared, the old file table will be placed on a freelist 2068 * which will be processed when the struct filedesc is released. 2069 * 2070 * Note that if onfiles == NDFILE, we're dealing with the original 2071 * static allocation contained within (struct filedesc0 *)fdp, 2072 * which must not be freed. 2073 */ 2074 if (onfiles > NDFILE) { 2075 /* 2076 * Note we may be called here from fdinit while allocating a 2077 * table for a new process in which case ->p_fd points 2078 * elsewhere. 2079 */ 2080 if (curproc->p_fd != fdp || FILEDESC_IS_ONLY_USER(fdp)) { 2081 free(otable, M_FILEDESC); 2082 } else { 2083 ft = (struct freetable *)&otable->fdt_ofiles[onfiles]; 2084 fdp0 = (struct filedesc0 *)fdp; 2085 ft->ft_table = otable; 2086 SLIST_INSERT_HEAD(&fdp0->fd_free, ft, ft_next); 2087 } 2088 } 2089 /* 2090 * The map does not have the same possibility of threads still 2091 * holding references to it. So always free it as long as it 2092 * does not reference the original static allocation. 2093 */ 2094 if (NDSLOTS(onfiles) > NDSLOTS(NDFILE)) 2095 free(omap, M_FILEDESC); 2096 } 2097 2098 /* 2099 * Allocate a file descriptor for the process. 2100 */ 2101 int 2102 fdalloc(struct thread *td, int minfd, int *result) 2103 { 2104 struct proc *p = td->td_proc; 2105 struct filedesc *fdp = p->p_fd; 2106 int fd, maxfd, allocfd; 2107 #ifdef RACCT 2108 int error; 2109 #endif 2110 2111 FILEDESC_XLOCK_ASSERT(fdp); 2112 2113 if (fdp->fd_freefile > minfd) 2114 minfd = fdp->fd_freefile; 2115 2116 maxfd = getmaxfd(td); 2117 2118 /* 2119 * Search the bitmap for a free descriptor starting at minfd. 2120 * If none is found, grow the file table. 2121 */ 2122 fd = fd_first_free(fdp, minfd, fdp->fd_nfiles); 2123 if (__predict_false(fd >= maxfd)) 2124 return (EMFILE); 2125 if (__predict_false(fd >= fdp->fd_nfiles)) { 2126 allocfd = min(fd * 2, maxfd); 2127 #ifdef RACCT 2128 if (RACCT_ENABLED()) { 2129 error = racct_set_unlocked(p, RACCT_NOFILE, allocfd); 2130 if (error != 0) 2131 return (EMFILE); 2132 } 2133 #endif 2134 /* 2135 * fd is already equal to first free descriptor >= minfd, so 2136 * we only need to grow the table and we are done. 2137 */ 2138 fdgrowtable_exp(fdp, allocfd); 2139 } 2140 2141 /* 2142 * Perform some sanity checks, then mark the file descriptor as 2143 * used and return it to the caller. 2144 */ 2145 KASSERT(fd >= 0 && fd < min(maxfd, fdp->fd_nfiles), 2146 ("invalid descriptor %d", fd)); 2147 KASSERT(!fdisused(fdp, fd), 2148 ("fd_first_free() returned non-free descriptor")); 2149 KASSERT(fdp->fd_ofiles[fd].fde_file == NULL, 2150 ("file descriptor isn't free")); 2151 fdused(fdp, fd); 2152 *result = fd; 2153 return (0); 2154 } 2155 2156 /* 2157 * Allocate n file descriptors for the process. 2158 */ 2159 int 2160 fdallocn(struct thread *td, int minfd, int *fds, int n) 2161 { 2162 struct proc *p = td->td_proc; 2163 struct filedesc *fdp = p->p_fd; 2164 int i; 2165 2166 FILEDESC_XLOCK_ASSERT(fdp); 2167 2168 for (i = 0; i < n; i++) 2169 if (fdalloc(td, 0, &fds[i]) != 0) 2170 break; 2171 2172 if (i < n) { 2173 for (i--; i >= 0; i--) 2174 fdunused(fdp, fds[i]); 2175 return (EMFILE); 2176 } 2177 2178 return (0); 2179 } 2180 2181 /* 2182 * Create a new open file structure and allocate a file descriptor for the 2183 * process that refers to it. We add one reference to the file for the 2184 * descriptor table and one reference for resultfp. This is to prevent us 2185 * being preempted and the entry in the descriptor table closed after we 2186 * release the FILEDESC lock. 2187 */ 2188 int 2189 falloc_caps(struct thread *td, struct file **resultfp, int *resultfd, int flags, 2190 struct filecaps *fcaps) 2191 { 2192 struct file *fp; 2193 int error, fd; 2194 2195 MPASS(resultfp != NULL); 2196 MPASS(resultfd != NULL); 2197 2198 error = _falloc_noinstall(td, &fp, 2); 2199 if (__predict_false(error != 0)) { 2200 return (error); 2201 } 2202 2203 error = finstall_refed(td, fp, &fd, flags, fcaps); 2204 if (__predict_false(error != 0)) { 2205 falloc_abort(td, fp); 2206 return (error); 2207 } 2208 2209 *resultfp = fp; 2210 *resultfd = fd; 2211 2212 return (0); 2213 } 2214 2215 /* 2216 * Create a new open file structure without allocating a file descriptor. 2217 */ 2218 int 2219 _falloc_noinstall(struct thread *td, struct file **resultfp, u_int n) 2220 { 2221 struct file *fp; 2222 int maxuserfiles = maxfiles - (maxfiles / 20); 2223 int openfiles_new; 2224 static struct timeval lastfail; 2225 static int curfail; 2226 2227 KASSERT(resultfp != NULL, ("%s: resultfp == NULL", __func__)); 2228 MPASS(n > 0); 2229 2230 openfiles_new = atomic_fetchadd_int(&openfiles, 1) + 1; 2231 if ((openfiles_new >= maxuserfiles && 2232 priv_check(td, PRIV_MAXFILES) != 0) || 2233 openfiles_new >= maxfiles) { 2234 atomic_subtract_int(&openfiles, 1); 2235 if (ppsratecheck(&lastfail, &curfail, 1)) { 2236 printf("kern.maxfiles limit exceeded by uid %i, (%s) " 2237 "please see tuning(7).\n", td->td_ucred->cr_ruid, td->td_proc->p_comm); 2238 } 2239 return (ENFILE); 2240 } 2241 fp = uma_zalloc(file_zone, M_WAITOK); 2242 bzero(fp, sizeof(*fp)); 2243 refcount_init(&fp->f_count, n); 2244 fp->f_cred = crhold(td->td_ucred); 2245 fp->f_ops = &badfileops; 2246 *resultfp = fp; 2247 return (0); 2248 } 2249 2250 void 2251 falloc_abort(struct thread *td, struct file *fp) 2252 { 2253 2254 /* 2255 * For assertion purposes. 2256 */ 2257 refcount_init(&fp->f_count, 0); 2258 _fdrop(fp, td); 2259 } 2260 2261 /* 2262 * Install a file in a file descriptor table. 2263 */ 2264 void 2265 _finstall(struct filedesc *fdp, struct file *fp, int fd, int flags, 2266 struct filecaps *fcaps) 2267 { 2268 struct filedescent *fde; 2269 2270 MPASS(fp != NULL); 2271 if (fcaps != NULL) 2272 filecaps_validate(fcaps, __func__); 2273 FILEDESC_XLOCK_ASSERT(fdp); 2274 2275 fde = &fdp->fd_ofiles[fd]; 2276 #ifdef CAPABILITIES 2277 seqc_write_begin(&fde->fde_seqc); 2278 #endif 2279 fde->fde_file = fp; 2280 fde->fde_flags = open_to_fde_flags(flags, true); 2281 if (fcaps != NULL) 2282 filecaps_move(fcaps, &fde->fde_caps); 2283 else 2284 filecaps_fill(&fde->fde_caps); 2285 #ifdef CAPABILITIES 2286 seqc_write_end(&fde->fde_seqc); 2287 #endif 2288 } 2289 2290 int 2291 finstall_refed(struct thread *td, struct file *fp, int *fd, int flags, 2292 struct filecaps *fcaps) 2293 { 2294 struct filedesc *fdp = td->td_proc->p_fd; 2295 int error; 2296 2297 MPASS(fd != NULL); 2298 2299 FILEDESC_XLOCK(fdp); 2300 error = fdalloc(td, 0, fd); 2301 if (__predict_true(error == 0)) { 2302 _finstall(fdp, fp, *fd, flags, fcaps); 2303 } 2304 FILEDESC_XUNLOCK(fdp); 2305 return (error); 2306 } 2307 2308 int 2309 finstall(struct thread *td, struct file *fp, int *fd, int flags, 2310 struct filecaps *fcaps) 2311 { 2312 int error; 2313 2314 MPASS(fd != NULL); 2315 2316 if (!fhold(fp)) 2317 return (EBADF); 2318 error = finstall_refed(td, fp, fd, flags, fcaps); 2319 if (__predict_false(error != 0)) { 2320 fdrop(fp, td); 2321 } 2322 return (error); 2323 } 2324 2325 /* 2326 * Build a new filedesc structure from another. 2327 * 2328 * If fdp is not NULL, return with it shared locked. 2329 */ 2330 struct filedesc * 2331 fdinit(void) 2332 { 2333 struct filedesc0 *newfdp0; 2334 struct filedesc *newfdp; 2335 2336 newfdp0 = uma_zalloc(filedesc0_zone, M_WAITOK | M_ZERO); 2337 newfdp = &newfdp0->fd_fd; 2338 2339 /* Create the file descriptor table. */ 2340 FILEDESC_LOCK_INIT(newfdp); 2341 refcount_init(&newfdp->fd_refcnt, 1); 2342 refcount_init(&newfdp->fd_holdcnt, 1); 2343 newfdp->fd_map = newfdp0->fd_dmap; 2344 newfdp->fd_files = (struct fdescenttbl *)&newfdp0->fd_dfiles; 2345 newfdp->fd_files->fdt_nfiles = NDFILE; 2346 2347 return (newfdp); 2348 } 2349 2350 /* 2351 * Build a pwddesc structure from another. 2352 * Copy the current, root, and jail root vnode references. 2353 * 2354 * If pdp is not NULL and keeplock is true, return with it (exclusively) locked. 2355 */ 2356 struct pwddesc * 2357 pdinit(struct pwddesc *pdp, bool keeplock) 2358 { 2359 struct pwddesc *newpdp; 2360 struct pwd *newpwd; 2361 2362 newpdp = malloc(sizeof(*newpdp), M_PWDDESC, M_WAITOK | M_ZERO); 2363 2364 PWDDESC_LOCK_INIT(newpdp); 2365 refcount_init(&newpdp->pd_refcount, 1); 2366 newpdp->pd_cmask = CMASK; 2367 2368 if (pdp == NULL) { 2369 newpwd = pwd_alloc(); 2370 smr_serialized_store(&newpdp->pd_pwd, newpwd, true); 2371 return (newpdp); 2372 } 2373 2374 PWDDESC_XLOCK(pdp); 2375 newpwd = pwd_hold_pwddesc(pdp); 2376 smr_serialized_store(&newpdp->pd_pwd, newpwd, true); 2377 if (!keeplock) 2378 PWDDESC_XUNLOCK(pdp); 2379 return (newpdp); 2380 } 2381 2382 /* 2383 * Hold either filedesc or pwddesc of the passed process. 2384 * 2385 * The process lock is used to synchronize against the target exiting and 2386 * freeing the data. 2387 * 2388 * Clearing can be ilustrated in 3 steps: 2389 * 1. set the pointer to NULL. Either routine can race against it, hence 2390 * atomic_load_ptr. 2391 * 2. observe the process lock as not taken. Until then fdhold/pdhold can 2392 * race to either still see the pointer or find NULL. It is still safe to 2393 * grab a reference as clearing is stalled. 2394 * 3. after the lock is observed as not taken, any fdhold/pdhold calls are 2395 * guaranteed to see NULL, making it safe to finish clearing 2396 */ 2397 static struct filedesc * 2398 fdhold(struct proc *p) 2399 { 2400 struct filedesc *fdp; 2401 2402 PROC_LOCK_ASSERT(p, MA_OWNED); 2403 fdp = atomic_load_ptr(&p->p_fd); 2404 if (fdp != NULL) 2405 refcount_acquire(&fdp->fd_holdcnt); 2406 return (fdp); 2407 } 2408 2409 static struct pwddesc * 2410 pdhold(struct proc *p) 2411 { 2412 struct pwddesc *pdp; 2413 2414 PROC_LOCK_ASSERT(p, MA_OWNED); 2415 pdp = atomic_load_ptr(&p->p_pd); 2416 if (pdp != NULL) 2417 refcount_acquire(&pdp->pd_refcount); 2418 return (pdp); 2419 } 2420 2421 static void 2422 fddrop(struct filedesc *fdp) 2423 { 2424 2425 if (refcount_load(&fdp->fd_holdcnt) > 1) { 2426 if (refcount_release(&fdp->fd_holdcnt) == 0) 2427 return; 2428 } 2429 2430 FILEDESC_LOCK_DESTROY(fdp); 2431 uma_zfree(filedesc0_zone, fdp); 2432 } 2433 2434 static void 2435 pddrop(struct pwddesc *pdp) 2436 { 2437 struct pwd *pwd; 2438 2439 if (refcount_release_if_not_last(&pdp->pd_refcount)) 2440 return; 2441 2442 PWDDESC_XLOCK(pdp); 2443 if (refcount_release(&pdp->pd_refcount) == 0) { 2444 PWDDESC_XUNLOCK(pdp); 2445 return; 2446 } 2447 pwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); 2448 pwd_set(pdp, NULL); 2449 PWDDESC_XUNLOCK(pdp); 2450 pwd_drop(pwd); 2451 2452 PWDDESC_LOCK_DESTROY(pdp); 2453 free(pdp, M_PWDDESC); 2454 } 2455 2456 /* 2457 * Share a filedesc structure. 2458 */ 2459 struct filedesc * 2460 fdshare(struct filedesc *fdp) 2461 { 2462 2463 refcount_acquire(&fdp->fd_refcnt); 2464 return (fdp); 2465 } 2466 2467 /* 2468 * Share a pwddesc structure. 2469 */ 2470 struct pwddesc * 2471 pdshare(struct pwddesc *pdp) 2472 { 2473 refcount_acquire(&pdp->pd_refcount); 2474 return (pdp); 2475 } 2476 2477 /* 2478 * Unshare a filedesc structure, if necessary by making a copy 2479 */ 2480 void 2481 fdunshare(struct thread *td) 2482 { 2483 struct filedesc *tmp; 2484 struct proc *p = td->td_proc; 2485 2486 if (refcount_load(&p->p_fd->fd_refcnt) == 1) 2487 return; 2488 2489 tmp = fdcopy(p->p_fd, p); 2490 fdescfree(td); 2491 p->p_fd = tmp; 2492 } 2493 2494 /* 2495 * Unshare a pwddesc structure. 2496 */ 2497 void 2498 pdunshare(struct thread *td) 2499 { 2500 struct pwddesc *pdp; 2501 struct proc *p; 2502 2503 p = td->td_proc; 2504 /* Not shared. */ 2505 if (refcount_load(&p->p_pd->pd_refcount) == 1) 2506 return; 2507 2508 pdp = pdcopy(p->p_pd); 2509 pdescfree(td); 2510 p->p_pd = pdp; 2511 } 2512 2513 /* 2514 * Copy a filedesc structure. A NULL pointer in returns a NULL reference, 2515 * this is to ease callers, not catch errors. 2516 */ 2517 struct filedesc * 2518 fdcopy(struct filedesc *fdp, struct proc *p1) 2519 { 2520 struct filedesc *newfdp; 2521 struct filedescent *nfde, *ofde; 2522 struct file *fp; 2523 int i, lastfile; 2524 bool fork_pass; 2525 2526 MPASS(fdp != NULL); 2527 2528 fork_pass = false; 2529 newfdp = fdinit(); 2530 FILEDESC_SLOCK(fdp); 2531 for (;;) { 2532 lastfile = fdlastfile(fdp); 2533 if (lastfile < newfdp->fd_nfiles) 2534 break; 2535 FILEDESC_SUNLOCK(fdp); 2536 fdgrowtable(newfdp, lastfile + 1); 2537 FILEDESC_SLOCK(fdp); 2538 } 2539 2540 /* 2541 * Copy all passable descriptors (i.e. not kqueue), and 2542 * prepare to handle copyable but not passable descriptors 2543 * (kqueues). 2544 * 2545 * The pass to handle copying is performed after all passable 2546 * files are installed into the new file descriptor's table, 2547 * since kqueues need all referenced file descriptors already 2548 * valid, including other kqueues. For the same reason the 2549 * copying is done in two passes by itself, first installing 2550 * not fully initialized ('empty') copyable files into the new 2551 * fd table, and then giving the subsystems a second chance to 2552 * really fill the copied file backing structure with the 2553 * content. 2554 */ 2555 newfdp->fd_freefile = fdp->fd_freefile; 2556 FILEDESC_FOREACH_FDE(fdp, i, ofde) { 2557 const struct fileops *ops; 2558 2559 ops = ofde->fde_file->f_ops; 2560 fp = NULL; 2561 if ((ops->fo_flags & DFLAG_FORK) != 0 && 2562 (ofde->fde_flags & UF_FOCLOSE) == 0) { 2563 if (ops->fo_fork(newfdp, ofde->fde_file, &fp, p1, 2564 curthread) != 0) 2565 continue; 2566 fork_pass = true; 2567 } else if ((ops->fo_flags & DFLAG_PASSABLE) == 0 || 2568 (ofde->fde_flags & UF_FOCLOSE) != 0 || 2569 !fhold(ofde->fde_file)) { 2570 if (newfdp->fd_freefile == fdp->fd_freefile) 2571 newfdp->fd_freefile = i; 2572 continue; 2573 } 2574 nfde = &newfdp->fd_ofiles[i]; 2575 *nfde = *ofde; 2576 if (fp != NULL) 2577 nfde->fde_file = fp; 2578 filecaps_copy(&ofde->fde_caps, &nfde->fde_caps, true); 2579 fdused_init(newfdp, i); 2580 } 2581 MPASS(newfdp->fd_freefile != -1); 2582 FILEDESC_SUNLOCK(fdp); 2583 2584 /* 2585 * Now handle copying kqueues, since all fds, including 2586 * kqueues, are in place. 2587 */ 2588 if (__predict_false(fork_pass)) { 2589 FILEDESC_FOREACH_FDE(newfdp, i, nfde) { 2590 const struct fileops *ops; 2591 2592 ops = nfde->fde_file->f_ops; 2593 if ((ops->fo_flags & DFLAG_FORK) == 0 || 2594 nfde->fde_file == NULL) 2595 continue; 2596 ops->fo_fork(newfdp, NULL, &nfde->fde_file, p1, 2597 curthread); 2598 } 2599 } 2600 return (newfdp); 2601 } 2602 2603 /* 2604 * Copy a pwddesc structure. 2605 */ 2606 struct pwddesc * 2607 pdcopy(struct pwddesc *pdp) 2608 { 2609 struct pwddesc *newpdp; 2610 2611 MPASS(pdp != NULL); 2612 2613 newpdp = pdinit(pdp, true); 2614 newpdp->pd_cmask = pdp->pd_cmask; 2615 PWDDESC_XUNLOCK(pdp); 2616 return (newpdp); 2617 } 2618 2619 /* 2620 * Clear POSIX style locks. This is only used when fdp looses a reference (i.e. 2621 * one of processes using it exits) and the table used to be shared. 2622 */ 2623 static void 2624 fdclearlocks(struct thread *td) 2625 { 2626 struct filedesc *fdp; 2627 struct filedesc_to_leader *fdtol; 2628 struct flock lf; 2629 struct file *fp; 2630 struct proc *p; 2631 struct vnode *vp; 2632 int i; 2633 2634 p = td->td_proc; 2635 fdp = p->p_fd; 2636 fdtol = p->p_fdtol; 2637 MPASS(fdtol != NULL); 2638 2639 FILEDESC_XLOCK(fdp); 2640 KASSERT(fdtol->fdl_refcount > 0, 2641 ("filedesc_to_refcount botch: fdl_refcount=%d", 2642 fdtol->fdl_refcount)); 2643 if (fdtol->fdl_refcount == 1 && 2644 (p->p_leader->p_flag & P_ADVLOCK) != 0) { 2645 FILEDESC_FOREACH_FP(fdp, i, fp) { 2646 if (fp->f_type != DTYPE_VNODE || 2647 !fhold(fp)) 2648 continue; 2649 FILEDESC_XUNLOCK(fdp); 2650 lf.l_whence = SEEK_SET; 2651 lf.l_start = 0; 2652 lf.l_len = 0; 2653 lf.l_type = F_UNLCK; 2654 vp = fp->f_vnode; 2655 (void) VOP_ADVLOCK(vp, 2656 (caddr_t)p->p_leader, F_UNLCK, 2657 &lf, F_POSIX); 2658 FILEDESC_XLOCK(fdp); 2659 fdrop(fp, td); 2660 } 2661 } 2662 retry: 2663 if (fdtol->fdl_refcount == 1) { 2664 if (fdp->fd_holdleaderscount > 0 && 2665 (p->p_leader->p_flag & P_ADVLOCK) != 0) { 2666 /* 2667 * close() or kern_dup() has cleared a reference 2668 * in a shared file descriptor table. 2669 */ 2670 fdp->fd_holdleaderswakeup = 1; 2671 sx_sleep(&fdp->fd_holdleaderscount, 2672 FILEDESC_LOCK(fdp), PLOCK, "fdlhold", 0); 2673 goto retry; 2674 } 2675 if (fdtol->fdl_holdcount > 0) { 2676 /* 2677 * Ensure that fdtol->fdl_leader remains 2678 * valid in closef(). 2679 */ 2680 fdtol->fdl_wakeup = 1; 2681 sx_sleep(fdtol, FILEDESC_LOCK(fdp), PLOCK, 2682 "fdlhold", 0); 2683 goto retry; 2684 } 2685 } 2686 fdtol->fdl_refcount--; 2687 if (fdtol->fdl_refcount == 0 && 2688 fdtol->fdl_holdcount == 0) { 2689 fdtol->fdl_next->fdl_prev = fdtol->fdl_prev; 2690 fdtol->fdl_prev->fdl_next = fdtol->fdl_next; 2691 } else 2692 fdtol = NULL; 2693 p->p_fdtol = NULL; 2694 FILEDESC_XUNLOCK(fdp); 2695 if (fdtol != NULL) 2696 free(fdtol, M_FILEDESC_TO_LEADER); 2697 } 2698 2699 /* 2700 * Release a filedesc structure. 2701 */ 2702 static void 2703 fdescfree_fds(struct thread *td, struct filedesc *fdp) 2704 { 2705 struct filedesc0 *fdp0; 2706 struct freetable *ft, *tft; 2707 struct filedescent *fde; 2708 struct file *fp; 2709 int i; 2710 2711 KASSERT(refcount_load(&fdp->fd_refcnt) == 0, 2712 ("%s: fd table %p carries references", __func__, fdp)); 2713 2714 /* 2715 * Serialize with threads iterating over the table, if any. 2716 */ 2717 if (refcount_load(&fdp->fd_holdcnt) > 1) { 2718 FILEDESC_XLOCK(fdp); 2719 FILEDESC_XUNLOCK(fdp); 2720 } 2721 2722 FILEDESC_FOREACH_FDE(fdp, i, fde) { 2723 fp = fde->fde_file; 2724 fdefree_last(fde); 2725 (void) closef(fp, td); 2726 } 2727 2728 if (NDSLOTS(fdp->fd_nfiles) > NDSLOTS(NDFILE)) 2729 free(fdp->fd_map, M_FILEDESC); 2730 if (fdp->fd_nfiles > NDFILE) 2731 free(fdp->fd_files, M_FILEDESC); 2732 2733 fdp0 = (struct filedesc0 *)fdp; 2734 SLIST_FOREACH_SAFE(ft, &fdp0->fd_free, ft_next, tft) 2735 free(ft->ft_table, M_FILEDESC); 2736 2737 fddrop(fdp); 2738 } 2739 2740 void 2741 fdescfree(struct thread *td) 2742 { 2743 struct proc *p; 2744 struct filedesc *fdp; 2745 2746 p = td->td_proc; 2747 fdp = p->p_fd; 2748 MPASS(fdp != NULL); 2749 2750 #ifdef RACCT 2751 if (RACCT_ENABLED()) 2752 racct_set_unlocked(p, RACCT_NOFILE, 0); 2753 #endif 2754 2755 if (p->p_fdtol != NULL) 2756 fdclearlocks(td); 2757 2758 /* 2759 * Check fdhold for an explanation. 2760 */ 2761 atomic_store_ptr(&p->p_fd, NULL); 2762 atomic_thread_fence_seq_cst(); 2763 PROC_WAIT_UNLOCKED(p); 2764 2765 if (refcount_release(&fdp->fd_refcnt) == 0) 2766 return; 2767 2768 fdescfree_fds(td, fdp); 2769 } 2770 2771 void 2772 pdescfree(struct thread *td) 2773 { 2774 struct proc *p; 2775 struct pwddesc *pdp; 2776 2777 p = td->td_proc; 2778 pdp = p->p_pd; 2779 MPASS(pdp != NULL); 2780 2781 /* 2782 * Check pdhold for an explanation. 2783 */ 2784 atomic_store_ptr(&p->p_pd, NULL); 2785 atomic_thread_fence_seq_cst(); 2786 PROC_WAIT_UNLOCKED(p); 2787 2788 pddrop(pdp); 2789 } 2790 2791 /* 2792 * For setugid programs, we don't want to people to use that setugidness 2793 * to generate error messages which write to a file which otherwise would 2794 * otherwise be off-limits to the process. We check for filesystems where 2795 * the vnode can change out from under us after execve (like [lin]procfs). 2796 * 2797 * Since fdsetugidsafety calls this only for fd 0, 1 and 2, this check is 2798 * sufficient. We also don't check for setugidness since we know we are. 2799 */ 2800 static bool 2801 is_unsafe(struct file *fp) 2802 { 2803 struct vnode *vp; 2804 2805 if (fp->f_type != DTYPE_VNODE) 2806 return (false); 2807 2808 vp = fp->f_vnode; 2809 return ((vp->v_vflag & VV_PROCDEP) != 0); 2810 } 2811 2812 /* 2813 * Make this setguid thing safe, if at all possible. 2814 */ 2815 void 2816 fdsetugidsafety(struct thread *td) 2817 { 2818 struct filedesc *fdp; 2819 struct file *fp; 2820 int i; 2821 2822 fdp = td->td_proc->p_fd; 2823 KASSERT(refcount_load(&fdp->fd_refcnt) == 1, 2824 ("the fdtable should not be shared")); 2825 MPASS(fdp->fd_nfiles >= 3); 2826 for (i = 0; i <= 2; i++) { 2827 fp = fdp->fd_ofiles[i].fde_file; 2828 if (fp != NULL && is_unsafe(fp)) { 2829 FILEDESC_XLOCK(fdp); 2830 knote_fdclose(td, i); 2831 /* 2832 * NULL-out descriptor prior to close to avoid 2833 * a race while close blocks. 2834 */ 2835 fdfree(fdp, i); 2836 FILEDESC_XUNLOCK(fdp); 2837 (void) closef(fp, td); 2838 } 2839 } 2840 } 2841 2842 /* 2843 * If a specific file object occupies a specific file descriptor, close the 2844 * file descriptor entry and drop a reference on the file object. This is a 2845 * convenience function to handle a subsequent error in a function that calls 2846 * falloc() that handles the race that another thread might have closed the 2847 * file descriptor out from under the thread creating the file object. 2848 */ 2849 void 2850 fdclose(struct thread *td, struct file *fp, int idx) 2851 { 2852 struct filedesc *fdp = td->td_proc->p_fd; 2853 2854 FILEDESC_XLOCK(fdp); 2855 if (fdp->fd_ofiles[idx].fde_file == fp) { 2856 fdfree(fdp, idx); 2857 FILEDESC_XUNLOCK(fdp); 2858 fdrop(fp, td); 2859 } else 2860 FILEDESC_XUNLOCK(fdp); 2861 } 2862 2863 /* 2864 * Close any files on exec? 2865 */ 2866 void 2867 fdcloseexec(struct thread *td) 2868 { 2869 struct filedesc *fdp; 2870 struct filedescent *fde; 2871 struct file *fp; 2872 int i; 2873 2874 fdp = td->td_proc->p_fd; 2875 KASSERT(refcount_load(&fdp->fd_refcnt) == 1, 2876 ("the fdtable should not be shared")); 2877 FILEDESC_FOREACH_FDE(fdp, i, fde) { 2878 fp = fde->fde_file; 2879 if (fp->f_type == DTYPE_MQUEUE || 2880 (fde->fde_flags & UF_EXCLOSE)) { 2881 FILEDESC_XLOCK(fdp); 2882 fdfree(fdp, i); 2883 (void) closefp(fdp, i, fp, td, false, false); 2884 FILEDESC_UNLOCK_ASSERT(fdp); 2885 } else if (fde->fde_flags & UF_FOCLOSE) { 2886 /* 2887 * https://austingroupbugs.net/view.php?id=1851 2888 * FD_CLOFORK should not be preserved across exec 2889 */ 2890 fde->fde_flags &= ~UF_FOCLOSE; 2891 } 2892 } 2893 } 2894 2895 /* 2896 * It is unsafe for set[ug]id processes to be started with file 2897 * descriptors 0..2 closed, as these descriptors are given implicit 2898 * significance in the Standard C library. fdcheckstd() will create a 2899 * descriptor referencing /dev/null for each of stdin, stdout, and 2900 * stderr that is not already open. 2901 */ 2902 int 2903 fdcheckstd(struct thread *td) 2904 { 2905 struct filedesc *fdp; 2906 register_t save; 2907 int i, error, devnull; 2908 2909 fdp = td->td_proc->p_fd; 2910 KASSERT(refcount_load(&fdp->fd_refcnt) == 1, 2911 ("the fdtable should not be shared")); 2912 MPASS(fdp->fd_nfiles >= 3); 2913 devnull = -1; 2914 for (i = 0; i <= 2; i++) { 2915 if (fdp->fd_ofiles[i].fde_file != NULL) 2916 continue; 2917 2918 save = td->td_retval[0]; 2919 if (devnull != -1) { 2920 error = kern_dup(td, FDDUP_FIXED, 0, devnull, i); 2921 } else { 2922 error = kern_openat(td, AT_FDCWD, "/dev/null", 2923 UIO_SYSSPACE, O_RDWR, 0); 2924 if (error == 0) { 2925 devnull = td->td_retval[0]; 2926 KASSERT(devnull == i, ("we didn't get our fd")); 2927 } 2928 } 2929 td->td_retval[0] = save; 2930 if (error != 0) 2931 return (error); 2932 } 2933 return (0); 2934 } 2935 2936 /* 2937 * Internal form of close. Decrement reference count on file structure. 2938 * Note: td may be NULL when closing a file that was being passed in a 2939 * message. 2940 */ 2941 int 2942 closef(struct file *fp, struct thread *td) 2943 { 2944 struct vnode *vp; 2945 struct flock lf; 2946 struct filedesc_to_leader *fdtol; 2947 struct filedesc *fdp; 2948 2949 MPASS(td != NULL); 2950 2951 /* 2952 * POSIX record locking dictates that any close releases ALL 2953 * locks owned by this process. This is handled by setting 2954 * a flag in the unlock to free ONLY locks obeying POSIX 2955 * semantics, and not to free BSD-style file locks. 2956 * If the descriptor was in a message, POSIX-style locks 2957 * aren't passed with the descriptor, and the thread pointer 2958 * will be NULL. Callers should be careful only to pass a 2959 * NULL thread pointer when there really is no owning 2960 * context that might have locks, or the locks will be 2961 * leaked. 2962 */ 2963 if (fp->f_type == DTYPE_VNODE) { 2964 vp = fp->f_vnode; 2965 if ((td->td_proc->p_leader->p_flag & P_ADVLOCK) != 0) { 2966 lf.l_whence = SEEK_SET; 2967 lf.l_start = 0; 2968 lf.l_len = 0; 2969 lf.l_type = F_UNLCK; 2970 (void) VOP_ADVLOCK(vp, (caddr_t)td->td_proc->p_leader, 2971 F_UNLCK, &lf, F_POSIX); 2972 } 2973 fdtol = td->td_proc->p_fdtol; 2974 if (fdtol != NULL) { 2975 /* 2976 * Handle special case where file descriptor table is 2977 * shared between multiple process leaders. 2978 */ 2979 fdp = td->td_proc->p_fd; 2980 FILEDESC_XLOCK(fdp); 2981 for (fdtol = fdtol->fdl_next; 2982 fdtol != td->td_proc->p_fdtol; 2983 fdtol = fdtol->fdl_next) { 2984 if ((fdtol->fdl_leader->p_flag & 2985 P_ADVLOCK) == 0) 2986 continue; 2987 fdtol->fdl_holdcount++; 2988 FILEDESC_XUNLOCK(fdp); 2989 lf.l_whence = SEEK_SET; 2990 lf.l_start = 0; 2991 lf.l_len = 0; 2992 lf.l_type = F_UNLCK; 2993 vp = fp->f_vnode; 2994 (void) VOP_ADVLOCK(vp, 2995 (caddr_t)fdtol->fdl_leader, F_UNLCK, &lf, 2996 F_POSIX); 2997 FILEDESC_XLOCK(fdp); 2998 fdtol->fdl_holdcount--; 2999 if (fdtol->fdl_holdcount == 0 && 3000 fdtol->fdl_wakeup != 0) { 3001 fdtol->fdl_wakeup = 0; 3002 wakeup(fdtol); 3003 } 3004 } 3005 FILEDESC_XUNLOCK(fdp); 3006 } 3007 } 3008 return (fdrop_close(fp, td)); 3009 } 3010 3011 /* 3012 * Hack for file descriptor passing code. 3013 */ 3014 void 3015 closef_nothread(struct file *fp) 3016 { 3017 3018 fdrop(fp, NULL); 3019 } 3020 3021 /* 3022 * Initialize the file pointer with the specified properties. 3023 * 3024 * The ops are set with release semantics to be certain that the flags, type, 3025 * and data are visible when ops is. This is to prevent ops methods from being 3026 * called with bad data. 3027 */ 3028 void 3029 finit(struct file *fp, u_int flag, short type, void *data, 3030 const struct fileops *ops) 3031 { 3032 fp->f_data = data; 3033 fp->f_flag = flag; 3034 fp->f_type = type; 3035 atomic_store_rel_ptr((volatile uintptr_t *)&fp->f_ops, (uintptr_t)ops); 3036 } 3037 3038 void 3039 finit_vnode(struct file *fp, u_int flag, void *data, const struct fileops *ops) 3040 { 3041 fp->f_seqcount[UIO_READ] = 1; 3042 fp->f_seqcount[UIO_WRITE] = 1; 3043 finit(fp, (flag & FMASK) | (fp->f_flag & FHASLOCK), DTYPE_VNODE, 3044 data, ops); 3045 } 3046 3047 int 3048 fget_cap_noref(struct filedesc *fdp, int fd, const cap_rights_t *needrightsp, 3049 struct file **fpp, struct filecaps *havecapsp) 3050 { 3051 struct filedescent *fde; 3052 int error; 3053 3054 FILEDESC_LOCK_ASSERT(fdp); 3055 3056 *fpp = NULL; 3057 fde = fdeget_noref(fdp, fd); 3058 if (fde == NULL) { 3059 error = EBADF; 3060 goto out; 3061 } 3062 3063 #ifdef CAPABILITIES 3064 error = cap_check(cap_rights_fde_inline(fde), needrightsp); 3065 if (error != 0) 3066 goto out; 3067 #endif 3068 3069 if (havecapsp != NULL) 3070 filecaps_copy(&fde->fde_caps, havecapsp, true); 3071 3072 *fpp = fde->fde_file; 3073 3074 error = 0; 3075 out: 3076 return (error); 3077 } 3078 3079 #ifdef CAPABILITIES 3080 int 3081 fget_cap(struct thread *td, int fd, const cap_rights_t *needrightsp, 3082 uint8_t *flagsp, struct file **fpp, struct filecaps *havecapsp) 3083 { 3084 struct filedesc *fdp = td->td_proc->p_fd; 3085 int error; 3086 struct file *fp; 3087 seqc_t seq; 3088 3089 *fpp = NULL; 3090 for (;;) { 3091 error = fget_unlocked_seq(td, fd, needrightsp, flagsp, &fp, 3092 &seq); 3093 if (error != 0) 3094 return (error); 3095 3096 if (havecapsp != NULL) { 3097 if (!filecaps_copy(&fdp->fd_ofiles[fd].fde_caps, 3098 havecapsp, false)) { 3099 fdrop(fp, td); 3100 goto get_locked; 3101 } 3102 } 3103 3104 if (!fd_modified(fdp, fd, seq)) 3105 break; 3106 fdrop(fp, td); 3107 } 3108 3109 *fpp = fp; 3110 return (0); 3111 3112 get_locked: 3113 FILEDESC_SLOCK(fdp); 3114 error = fget_cap_noref(fdp, fd, needrightsp, fpp, havecapsp); 3115 if (error == 0 && !fhold(*fpp)) 3116 error = EBADF; 3117 FILEDESC_SUNLOCK(fdp); 3118 return (error); 3119 } 3120 #else 3121 int 3122 fget_cap(struct thread *td, int fd, const cap_rights_t *needrightsp, 3123 uint8_t *flagsp, struct file **fpp, struct filecaps *havecapsp) 3124 { 3125 int error; 3126 error = fget_unlocked_flags(td, fd, needrightsp, flagsp, fpp); 3127 if (havecapsp != NULL && error == 0) 3128 filecaps_fill(havecapsp); 3129 3130 return (error); 3131 } 3132 #endif 3133 3134 int 3135 fget_remote(struct thread *td, struct proc *p, int fd, struct file **fpp) 3136 { 3137 struct filedesc *fdp; 3138 struct file *fp; 3139 int error; 3140 3141 if (p == td->td_proc) /* curproc */ 3142 return (fget_unlocked(td, fd, &cap_no_rights, fpp)); 3143 3144 PROC_LOCK(p); 3145 fdp = fdhold(p); 3146 PROC_UNLOCK(p); 3147 if (fdp == NULL) 3148 return (ENOENT); 3149 FILEDESC_SLOCK(fdp); 3150 if (refcount_load(&fdp->fd_refcnt) != 0) { 3151 fp = fget_noref(fdp, fd); 3152 if (fp != NULL && fhold(fp)) { 3153 *fpp = fp; 3154 error = 0; 3155 } else { 3156 error = EBADF; 3157 } 3158 } else { 3159 error = ENOENT; 3160 } 3161 FILEDESC_SUNLOCK(fdp); 3162 fddrop(fdp); 3163 return (error); 3164 } 3165 3166 int 3167 fget_remote_foreach(struct thread *td, struct proc *p, 3168 int (*fn)(struct proc *, int, struct file *, void *), void *arg) 3169 { 3170 struct filedesc *fdp; 3171 struct fdescenttbl *fdt; 3172 struct file *fp; 3173 int error, error1, fd, highfd; 3174 3175 error = 0; 3176 PROC_LOCK(p); 3177 fdp = fdhold(p); 3178 PROC_UNLOCK(p); 3179 if (fdp == NULL) 3180 return (ENOENT); 3181 3182 FILEDESC_SLOCK(fdp); 3183 if (refcount_load(&fdp->fd_refcnt) != 0) { 3184 fdt = atomic_load_ptr(&fdp->fd_files); 3185 highfd = fdt->fdt_nfiles - 1; 3186 FILEDESC_SUNLOCK(fdp); 3187 } else { 3188 error = ENOENT; 3189 FILEDESC_SUNLOCK(fdp); 3190 goto out; 3191 } 3192 3193 for (fd = 0; fd <= highfd; fd++) { 3194 error1 = fget_remote(td, p, fd, &fp); 3195 if (error1 != 0) 3196 continue; 3197 error = fn(p, fd, fp, arg); 3198 fdrop(fp, td); 3199 if (error != 0) 3200 break; 3201 } 3202 out: 3203 fddrop(fdp); 3204 return (error); 3205 } 3206 3207 #ifdef CAPABILITIES 3208 int 3209 fgetvp_lookup_smr(struct nameidata *ndp, struct vnode **vpp, int *flagsp) 3210 { 3211 const struct filedescent *fde; 3212 const struct fdescenttbl *fdt; 3213 struct filedesc *fdp; 3214 struct file *fp; 3215 struct vnode *vp; 3216 const cap_rights_t *haverights; 3217 cap_rights_t rights; 3218 seqc_t seq; 3219 int fd, flags; 3220 3221 VFS_SMR_ASSERT_ENTERED(); 3222 3223 fd = ndp->ni_dirfd; 3224 rights = *ndp->ni_rightsneeded; 3225 cap_rights_set_one(&rights, CAP_LOOKUP); 3226 3227 fdp = curproc->p_fd; 3228 fdt = fdp->fd_files; 3229 if (__predict_false((u_int)fd >= fdt->fdt_nfiles)) 3230 return (EBADF); 3231 seq = seqc_read_notmodify(fd_seqc(fdt, fd)); 3232 fde = &fdt->fdt_ofiles[fd]; 3233 haverights = cap_rights_fde_inline(fde); 3234 fp = fde->fde_file; 3235 if (__predict_false(fp == NULL)) 3236 return (EAGAIN); 3237 if (__predict_false(cap_check_inline_transient(haverights, &rights))) 3238 return (EAGAIN); 3239 flags = fp->f_flag & FSEARCH; 3240 flags |= (fde->fde_flags & UF_RESOLVE_BENEATH) != 0 ? 3241 O_RESOLVE_BENEATH : 0; 3242 vp = fp->f_vnode; 3243 if (__predict_false(vp == NULL)) { 3244 return (EAGAIN); 3245 } 3246 if (!filecaps_copy(&fde->fde_caps, &ndp->ni_filecaps, false)) { 3247 return (EAGAIN); 3248 } 3249 /* 3250 * Use an acquire barrier to force re-reading of fdt so it is 3251 * refreshed for verification. 3252 */ 3253 atomic_thread_fence_acq(); 3254 fdt = fdp->fd_files; 3255 if (__predict_false(!seqc_consistent_no_fence(fd_seqc(fdt, fd), seq))) 3256 return (EAGAIN); 3257 /* 3258 * If file descriptor doesn't have all rights, 3259 * all lookups relative to it must also be 3260 * strictly relative. 3261 * 3262 * Not yet supported by fast path. 3263 */ 3264 CAP_ALL(&rights); 3265 if (!cap_rights_contains(&ndp->ni_filecaps.fc_rights, &rights) || 3266 ndp->ni_filecaps.fc_fcntls != CAP_FCNTL_ALL || 3267 ndp->ni_filecaps.fc_nioctls != -1) { 3268 #ifdef notyet 3269 ndp->ni_lcf |= NI_LCF_STRICTREL; 3270 #else 3271 return (EAGAIN); 3272 #endif 3273 } 3274 *vpp = vp; 3275 *flagsp = flags; 3276 return (0); 3277 } 3278 #else 3279 int 3280 fgetvp_lookup_smr(struct nameidata *ndp, struct vnode **vpp, int *flagsp) 3281 { 3282 const struct filedescent *fde; 3283 const struct fdescenttbl *fdt; 3284 struct filedesc *fdp; 3285 struct file *fp; 3286 struct vnode *vp; 3287 int fd, flags; 3288 3289 VFS_SMR_ASSERT_ENTERED(); 3290 3291 fd = ndp->ni_dirfd; 3292 fdp = curproc->p_fd; 3293 fdt = fdp->fd_files; 3294 if (__predict_false((u_int)fd >= fdt->fdt_nfiles)) 3295 return (EBADF); 3296 fde = &fdt->fdt_ofiles[fd]; 3297 fp = fde->fde_file; 3298 if (__predict_false(fp == NULL)) 3299 return (EAGAIN); 3300 flags = fp->f_flag & FSEARCH; 3301 flags |= (fde->fde_flags & UF_RESOLVE_BENEATH) != 0 ? 3302 O_RESOLVE_BENEATH : 0; 3303 vp = fp->f_vnode; 3304 if (__predict_false(vp == NULL || vp->v_type != VDIR)) { 3305 return (EAGAIN); 3306 } 3307 /* 3308 * Use an acquire barrier to force re-reading of fdt so it is 3309 * refreshed for verification. 3310 */ 3311 atomic_thread_fence_acq(); 3312 fdt = fdp->fd_files; 3313 if (__predict_false(fp != fdt->fdt_ofiles[fd].fde_file)) 3314 return (EAGAIN); 3315 filecaps_fill(&ndp->ni_filecaps); 3316 *vpp = vp; 3317 *flagsp = flags; 3318 return (0); 3319 } 3320 #endif 3321 3322 int 3323 fgetvp_lookup(struct nameidata *ndp, struct vnode **vpp) 3324 { 3325 struct thread *td; 3326 struct file *fp; 3327 struct vnode *vp; 3328 struct componentname *cnp; 3329 cap_rights_t rights; 3330 int error; 3331 uint8_t flags; 3332 3333 td = curthread; 3334 rights = *ndp->ni_rightsneeded; 3335 cap_rights_set_one(&rights, CAP_LOOKUP); 3336 cnp = &ndp->ni_cnd; 3337 3338 error = fget_cap(td, ndp->ni_dirfd, &rights, &flags, &fp, 3339 &ndp->ni_filecaps); 3340 if (__predict_false(error != 0)) 3341 return (error); 3342 if (__predict_false(fp->f_ops == &badfileops)) { 3343 error = EBADF; 3344 goto out_free; 3345 } 3346 vp = fp->f_vnode; 3347 if (__predict_false(vp == NULL)) { 3348 error = ENOTDIR; 3349 goto out_free; 3350 } 3351 vrefact(vp); 3352 /* 3353 * XXX does not check for VDIR, handled by namei_setup 3354 */ 3355 if ((fp->f_flag & FSEARCH) != 0) 3356 cnp->cn_flags |= NOEXECCHECK; 3357 if ((flags & UF_RESOLVE_BENEATH) != 0) { 3358 cnp->cn_flags |= RBENEATH; 3359 ndp->ni_resflags |= NIRES_BENEATH; 3360 } 3361 fdrop(fp, td); 3362 3363 #ifdef CAPABILITIES 3364 /* 3365 * If file descriptor doesn't have all rights, 3366 * all lookups relative to it must also be 3367 * strictly relative. 3368 */ 3369 CAP_ALL(&rights); 3370 if (!cap_rights_contains(&ndp->ni_filecaps.fc_rights, &rights) || 3371 ndp->ni_filecaps.fc_fcntls != CAP_FCNTL_ALL || 3372 ndp->ni_filecaps.fc_nioctls != -1) { 3373 ndp->ni_lcf |= NI_LCF_STRICTREL; 3374 ndp->ni_resflags |= NIRES_STRICTREL; 3375 } 3376 #endif 3377 3378 /* 3379 * TODO: avoid copying ioctl caps if it can be helped to begin with 3380 */ 3381 if ((cnp->cn_flags & WANTIOCTLCAPS) == 0) 3382 filecaps_free_ioctl(&ndp->ni_filecaps); 3383 3384 *vpp = vp; 3385 return (0); 3386 3387 out_free: 3388 filecaps_free(&ndp->ni_filecaps); 3389 fdrop(fp, td); 3390 return (error); 3391 } 3392 3393 /* 3394 * Fetch the descriptor locklessly. 3395 * 3396 * We avoid fdrop() races by never raising a refcount above 0. To accomplish 3397 * this we have to use a cmpset loop rather than an atomic_add. The descriptor 3398 * must be re-verified once we acquire a reference to be certain that the 3399 * identity is still correct and we did not lose a race due to preemption. 3400 * 3401 * Force a reload of fdt when looping. Another thread could reallocate 3402 * the table before this fd was closed, so it is possible that there is 3403 * a stale fp pointer in cached version. 3404 */ 3405 #ifdef CAPABILITIES 3406 static int 3407 fget_unlocked_seq(struct thread *td, int fd, const cap_rights_t *needrightsp, 3408 uint8_t *flagsp, struct file **fpp, seqc_t *seqp) 3409 { 3410 struct filedesc *fdp; 3411 const struct filedescent *fde; 3412 const struct fdescenttbl *fdt; 3413 struct file *fp; 3414 seqc_t seq; 3415 cap_rights_t haverights; 3416 int error; 3417 uint8_t flags; 3418 3419 fdp = td->td_proc->p_fd; 3420 fdt = fdp->fd_files; 3421 if (__predict_false((u_int)fd >= fdt->fdt_nfiles)) 3422 return (EBADF); 3423 3424 for (;;) { 3425 seq = seqc_read_notmodify(fd_seqc(fdt, fd)); 3426 fde = &fdt->fdt_ofiles[fd]; 3427 haverights = *cap_rights_fde_inline(fde); 3428 fp = fde->fde_file; 3429 flags = fde->fde_flags; 3430 if (__predict_false(fp == NULL)) { 3431 if (seqc_consistent(fd_seqc(fdt, fd), seq)) 3432 return (EBADF); 3433 fdt = atomic_load_ptr(&fdp->fd_files); 3434 continue; 3435 } 3436 error = cap_check_inline(&haverights, needrightsp); 3437 if (__predict_false(error != 0)) { 3438 if (seqc_consistent(fd_seqc(fdt, fd), seq)) 3439 return (error); 3440 fdt = atomic_load_ptr(&fdp->fd_files); 3441 continue; 3442 } 3443 if (__predict_false(!refcount_acquire_if_not_zero(&fp->f_count))) { 3444 fdt = atomic_load_ptr(&fdp->fd_files); 3445 continue; 3446 } 3447 /* 3448 * Use an acquire barrier to force re-reading of fdt so it is 3449 * refreshed for verification. 3450 */ 3451 atomic_thread_fence_acq(); 3452 fdt = fdp->fd_files; 3453 if (seqc_consistent_no_fence(fd_seqc(fdt, fd), seq)) 3454 break; 3455 fdrop(fp, td); 3456 } 3457 *fpp = fp; 3458 if (flagsp != NULL) 3459 *flagsp = flags; 3460 if (seqp != NULL) 3461 *seqp = seq; 3462 return (0); 3463 } 3464 #else 3465 static int 3466 fget_unlocked_seq(struct thread *td, int fd, const cap_rights_t *needrightsp, 3467 uint8_t *flagsp, struct file **fpp, seqc_t *seqp __unused) 3468 { 3469 struct filedesc *fdp; 3470 const struct fdescenttbl *fdt; 3471 struct file *fp; 3472 uint8_t flags; 3473 3474 fdp = td->td_proc->p_fd; 3475 fdt = fdp->fd_files; 3476 if (__predict_false((u_int)fd >= fdt->fdt_nfiles)) 3477 return (EBADF); 3478 3479 for (;;) { 3480 fp = fdt->fdt_ofiles[fd].fde_file; 3481 flags = fdt->fdt_ofiles[fd].fde_flags; 3482 if (__predict_false(fp == NULL)) 3483 return (EBADF); 3484 if (__predict_false(!refcount_acquire_if_not_zero(&fp->f_count))) { 3485 fdt = atomic_load_ptr(&fdp->fd_files); 3486 continue; 3487 } 3488 /* 3489 * Use an acquire barrier to force re-reading of fdt so it is 3490 * refreshed for verification. 3491 */ 3492 atomic_thread_fence_acq(); 3493 fdt = fdp->fd_files; 3494 if (__predict_true(fp == fdt->fdt_ofiles[fd].fde_file)) 3495 break; 3496 fdrop(fp, td); 3497 } 3498 if (flagsp != NULL) 3499 *flagsp = flags; 3500 *fpp = fp; 3501 return (0); 3502 } 3503 #endif 3504 3505 /* 3506 * See the comments in fget_unlocked_seq for an explanation of how this works. 3507 * 3508 * This is a simplified variant which bails out to the aforementioned routine 3509 * if anything goes wrong. In practice this only happens when userspace is 3510 * racing with itself. 3511 */ 3512 int 3513 fget_unlocked_flags(struct thread *td, int fd, const cap_rights_t *needrightsp, 3514 uint8_t *flagsp, struct file **fpp) 3515 { 3516 struct filedesc *fdp; 3517 #ifdef CAPABILITIES 3518 const struct filedescent *fde; 3519 #endif 3520 const struct fdescenttbl *fdt; 3521 struct file *fp; 3522 #ifdef CAPABILITIES 3523 seqc_t seq; 3524 const cap_rights_t *haverights; 3525 #endif 3526 uint8_t flags; 3527 3528 fdp = td->td_proc->p_fd; 3529 fdt = fdp->fd_files; 3530 if (__predict_false((u_int)fd >= fdt->fdt_nfiles)) { 3531 *fpp = NULL; 3532 return (EBADF); 3533 } 3534 #ifdef CAPABILITIES 3535 seq = seqc_read_notmodify(fd_seqc(fdt, fd)); 3536 fde = &fdt->fdt_ofiles[fd]; 3537 haverights = cap_rights_fde_inline(fde); 3538 fp = fde->fde_file; 3539 flags = fde->fde_flags; 3540 #else 3541 fp = fdt->fdt_ofiles[fd].fde_file; 3542 flags = fdt->fdt_ofiles[fd].fde_flags; 3543 #endif 3544 if (__predict_false(fp == NULL)) 3545 goto out_fallback; 3546 #ifdef CAPABILITIES 3547 if (__predict_false(cap_check_inline_transient(haverights, needrightsp))) 3548 goto out_fallback; 3549 #endif 3550 if (__predict_false(!refcount_acquire_if_not_zero(&fp->f_count))) 3551 goto out_fallback; 3552 3553 /* 3554 * Use an acquire barrier to force re-reading of fdt so it is 3555 * refreshed for verification. 3556 */ 3557 atomic_thread_fence_acq(); 3558 fdt = fdp->fd_files; 3559 #ifdef CAPABILITIES 3560 if (__predict_false(!seqc_consistent_no_fence(fd_seqc(fdt, fd), seq))) 3561 #else 3562 if (__predict_false(fp != fdt->fdt_ofiles[fd].fde_file)) 3563 #endif 3564 goto out_fdrop; 3565 *fpp = fp; 3566 if (flagsp != NULL) 3567 *flagsp = flags; 3568 return (0); 3569 out_fdrop: 3570 fdrop(fp, td); 3571 out_fallback: 3572 *fpp = NULL; 3573 return (fget_unlocked_seq(td, fd, needrightsp, flagsp, fpp, NULL)); 3574 } 3575 3576 int 3577 fget_unlocked(struct thread *td, int fd, const cap_rights_t *needrightsp, 3578 struct file **fpp) 3579 { 3580 return (fget_unlocked_flags(td, fd, needrightsp, NULL, fpp)); 3581 } 3582 3583 /* 3584 * Translate fd -> file when the caller guarantees the file descriptor table 3585 * can't be changed by others. 3586 * 3587 * Note this does not mean the file object itself is only visible to the caller, 3588 * merely that it wont disappear without having to be referenced. 3589 * 3590 * Must be paired with fput_only_user. 3591 */ 3592 #ifdef CAPABILITIES 3593 int 3594 fget_only_user(struct filedesc *fdp, int fd, const cap_rights_t *needrightsp, 3595 struct file **fpp) 3596 { 3597 const struct filedescent *fde; 3598 const struct fdescenttbl *fdt; 3599 const cap_rights_t *haverights; 3600 struct file *fp; 3601 int error; 3602 3603 MPASS(FILEDESC_IS_ONLY_USER(fdp)); 3604 3605 *fpp = NULL; 3606 if (__predict_false(fd >= fdp->fd_nfiles)) 3607 return (EBADF); 3608 3609 fdt = fdp->fd_files; 3610 fde = &fdt->fdt_ofiles[fd]; 3611 fp = fde->fde_file; 3612 if (__predict_false(fp == NULL)) 3613 return (EBADF); 3614 MPASS(refcount_load(&fp->f_count) > 0); 3615 haverights = cap_rights_fde_inline(fde); 3616 error = cap_check_inline(haverights, needrightsp); 3617 if (__predict_false(error != 0)) 3618 return (error); 3619 *fpp = fp; 3620 return (0); 3621 } 3622 #else 3623 int 3624 fget_only_user(struct filedesc *fdp, int fd, const cap_rights_t *needrightsp, 3625 struct file **fpp) 3626 { 3627 struct file *fp; 3628 3629 MPASS(FILEDESC_IS_ONLY_USER(fdp)); 3630 3631 *fpp = NULL; 3632 if (__predict_false(fd >= fdp->fd_nfiles)) 3633 return (EBADF); 3634 3635 fp = fdp->fd_ofiles[fd].fde_file; 3636 if (__predict_false(fp == NULL)) 3637 return (EBADF); 3638 3639 MPASS(refcount_load(&fp->f_count) > 0); 3640 *fpp = fp; 3641 return (0); 3642 } 3643 #endif 3644 3645 /* 3646 * Extract the file pointer associated with the specified descriptor for the 3647 * current user process. 3648 * 3649 * If the descriptor doesn't exist or doesn't match 'flags', EBADF is 3650 * returned. 3651 * 3652 * File's rights will be checked against the capability rights mask. 3653 * 3654 * If an error occurred the non-zero error is returned and *fpp is set to 3655 * NULL. Otherwise *fpp is held and set and zero is returned. Caller is 3656 * responsible for fdrop(). 3657 */ 3658 static __inline int 3659 _fget(struct thread *td, int fd, struct file **fpp, int flags, 3660 const cap_rights_t *needrightsp) 3661 { 3662 struct file *fp; 3663 int error; 3664 3665 *fpp = NULL; 3666 error = fget_unlocked(td, fd, needrightsp, &fp); 3667 if (__predict_false(error != 0)) 3668 return (error); 3669 if (__predict_false(fp->f_ops == &badfileops)) { 3670 fdrop(fp, td); 3671 return (EBADF); 3672 } 3673 3674 /* 3675 * FREAD and FWRITE failure return EBADF as per POSIX. 3676 */ 3677 error = 0; 3678 switch (flags) { 3679 case FREAD: 3680 case FWRITE: 3681 if ((fp->f_flag & flags) == 0) 3682 error = EBADF; 3683 break; 3684 case FEXEC: 3685 if (fp->f_ops != &path_fileops && 3686 ((fp->f_flag & (FREAD | FEXEC)) == 0 || 3687 (fp->f_flag & FWRITE) != 0)) 3688 error = EBADF; 3689 break; 3690 case 0: 3691 break; 3692 default: 3693 KASSERT(0, ("wrong flags")); 3694 } 3695 3696 if (error != 0) { 3697 fdrop(fp, td); 3698 return (error); 3699 } 3700 3701 *fpp = fp; 3702 return (0); 3703 } 3704 3705 int 3706 fget(struct thread *td, int fd, const cap_rights_t *rightsp, struct file **fpp) 3707 { 3708 3709 return (_fget(td, fd, fpp, 0, rightsp)); 3710 } 3711 3712 int 3713 fget_mmap(struct thread *td, int fd, const cap_rights_t *rightsp, 3714 vm_prot_t *maxprotp, struct file **fpp) 3715 { 3716 int error; 3717 #ifndef CAPABILITIES 3718 error = _fget(td, fd, fpp, 0, rightsp); 3719 if (maxprotp != NULL) 3720 *maxprotp = VM_PROT_ALL; 3721 return (error); 3722 #else 3723 cap_rights_t fdrights; 3724 struct filedesc *fdp; 3725 struct file *fp; 3726 seqc_t seq; 3727 3728 *fpp = NULL; 3729 fdp = td->td_proc->p_fd; 3730 MPASS(cap_rights_is_set(rightsp, CAP_MMAP)); 3731 for (;;) { 3732 error = fget_unlocked_seq(td, fd, rightsp, NULL, &fp, &seq); 3733 if (__predict_false(error != 0)) 3734 return (error); 3735 if (__predict_false(fp->f_ops == &badfileops)) { 3736 fdrop(fp, td); 3737 return (EBADF); 3738 } 3739 if (maxprotp != NULL) 3740 fdrights = *cap_rights(fdp, fd); 3741 if (!fd_modified(fdp, fd, seq)) 3742 break; 3743 fdrop(fp, td); 3744 } 3745 3746 /* 3747 * If requested, convert capability rights to access flags. 3748 */ 3749 if (maxprotp != NULL) 3750 *maxprotp = cap_rights_to_vmprot(&fdrights); 3751 *fpp = fp; 3752 return (0); 3753 #endif 3754 } 3755 3756 int 3757 fget_read(struct thread *td, int fd, const cap_rights_t *rightsp, 3758 struct file **fpp) 3759 { 3760 3761 return (_fget(td, fd, fpp, FREAD, rightsp)); 3762 } 3763 3764 int 3765 fget_write(struct thread *td, int fd, const cap_rights_t *rightsp, 3766 struct file **fpp) 3767 { 3768 3769 return (_fget(td, fd, fpp, FWRITE, rightsp)); 3770 } 3771 3772 int 3773 fget_fcntl(struct thread *td, int fd, const cap_rights_t *rightsp, 3774 int needfcntl, struct file **fpp) 3775 { 3776 #ifndef CAPABILITIES 3777 return (fget_unlocked(td, fd, rightsp, fpp)); 3778 #else 3779 struct filedesc *fdp = td->td_proc->p_fd; 3780 struct file *fp; 3781 int error; 3782 seqc_t seq; 3783 3784 *fpp = NULL; 3785 MPASS(cap_rights_is_set(rightsp, CAP_FCNTL)); 3786 for (;;) { 3787 error = fget_unlocked_seq(td, fd, rightsp, NULL, &fp, &seq); 3788 if (error != 0) 3789 return (error); 3790 error = cap_fcntl_check(fdp, fd, needfcntl); 3791 if (!fd_modified(fdp, fd, seq)) 3792 break; 3793 fdrop(fp, td); 3794 } 3795 if (error != 0) { 3796 fdrop(fp, td); 3797 return (error); 3798 } 3799 *fpp = fp; 3800 return (0); 3801 #endif 3802 } 3803 3804 /* 3805 * Like fget() but loads the underlying vnode, or returns an error if the 3806 * descriptor does not represent a vnode. Note that pipes use vnodes but 3807 * never have VM objects. The returned vnode will be vref()'d. 3808 * 3809 * XXX: what about the unused flags ? 3810 */ 3811 static __inline int 3812 _fgetvp(struct thread *td, int fd, int flags, const cap_rights_t *needrightsp, 3813 struct vnode **vpp) 3814 { 3815 struct file *fp; 3816 int error; 3817 3818 *vpp = NULL; 3819 error = _fget(td, fd, &fp, flags, needrightsp); 3820 if (error != 0) 3821 return (error); 3822 if (fp->f_vnode == NULL) { 3823 error = EINVAL; 3824 } else { 3825 *vpp = fp->f_vnode; 3826 vrefact(*vpp); 3827 } 3828 fdrop(fp, td); 3829 3830 return (error); 3831 } 3832 3833 int 3834 fgetvp(struct thread *td, int fd, const cap_rights_t *rightsp, 3835 struct vnode **vpp) 3836 { 3837 3838 return (_fgetvp(td, fd, 0, rightsp, vpp)); 3839 } 3840 3841 int 3842 fgetvp_rights(struct thread *td, int fd, const cap_rights_t *needrightsp, 3843 struct filecaps *havecaps, struct vnode **vpp) 3844 { 3845 struct filecaps caps; 3846 struct file *fp; 3847 int error; 3848 3849 error = fget_cap(td, fd, needrightsp, NULL, &fp, &caps); 3850 if (error != 0) 3851 return (error); 3852 if (fp->f_ops == &badfileops) { 3853 error = EBADF; 3854 goto out; 3855 } 3856 if (fp->f_vnode == NULL) { 3857 error = EINVAL; 3858 goto out; 3859 } 3860 3861 *havecaps = caps; 3862 *vpp = fp->f_vnode; 3863 vrefact(*vpp); 3864 fdrop(fp, td); 3865 3866 return (0); 3867 out: 3868 filecaps_free(&caps); 3869 fdrop(fp, td); 3870 return (error); 3871 } 3872 3873 int 3874 fgetvp_read(struct thread *td, int fd, const cap_rights_t *rightsp, 3875 struct vnode **vpp) 3876 { 3877 3878 return (_fgetvp(td, fd, FREAD, rightsp, vpp)); 3879 } 3880 3881 int 3882 fgetvp_exec(struct thread *td, int fd, const cap_rights_t *rightsp, 3883 struct vnode **vpp) 3884 { 3885 3886 return (_fgetvp(td, fd, FEXEC, rightsp, vpp)); 3887 } 3888 3889 #ifdef notyet 3890 int 3891 fgetvp_write(struct thread *td, int fd, const cap_rights_t *rightsp, 3892 struct vnode **vpp) 3893 { 3894 3895 return (_fgetvp(td, fd, FWRITE, rightsp, vpp)); 3896 } 3897 #endif 3898 3899 /* 3900 * Handle the last reference to a file being closed. 3901 * 3902 * Without the noinline attribute clang keeps inlining the func thorough this 3903 * file when fdrop is used. 3904 */ 3905 int __noinline 3906 _fdrop(struct file *fp, struct thread *td) 3907 { 3908 int error; 3909 3910 KASSERT(refcount_load(&fp->f_count) == 0, 3911 ("fdrop: fp %p count %d", fp, refcount_load(&fp->f_count))); 3912 3913 error = fo_close(fp, td); 3914 atomic_subtract_int(&openfiles, 1); 3915 crfree(fp->f_cred); 3916 free(fp->f_advice, M_FADVISE); 3917 uma_zfree(file_zone, fp); 3918 3919 return (error); 3920 } 3921 3922 /* 3923 * Apply an advisory lock on a file descriptor. 3924 * 3925 * Just attempt to get a record lock of the requested type on the entire file 3926 * (l_whence = SEEK_SET, l_start = 0, l_len = 0). 3927 */ 3928 #ifndef _SYS_SYSPROTO_H_ 3929 struct flock_args { 3930 int fd; 3931 int how; 3932 }; 3933 #endif 3934 /* ARGSUSED */ 3935 int 3936 sys_flock(struct thread *td, struct flock_args *uap) 3937 { 3938 struct file *fp; 3939 struct vnode *vp; 3940 struct flock lf; 3941 int error; 3942 3943 error = fget(td, uap->fd, &cap_flock_rights, &fp); 3944 if (error != 0) 3945 return (error); 3946 error = EOPNOTSUPP; 3947 if (fp->f_type != DTYPE_VNODE && fp->f_type != DTYPE_FIFO) { 3948 goto done; 3949 } 3950 if (fp->f_ops == &path_fileops) { 3951 goto done; 3952 } 3953 3954 error = 0; 3955 vp = fp->f_vnode; 3956 lf.l_whence = SEEK_SET; 3957 lf.l_start = 0; 3958 lf.l_len = 0; 3959 if (uap->how & LOCK_UN) { 3960 lf.l_type = F_UNLCK; 3961 atomic_clear_int(&fp->f_flag, FHASLOCK); 3962 error = VOP_ADVLOCK(vp, (caddr_t)fp, F_UNLCK, &lf, F_FLOCK); 3963 goto done; 3964 } 3965 if (uap->how & LOCK_EX) 3966 lf.l_type = F_WRLCK; 3967 else if (uap->how & LOCK_SH) 3968 lf.l_type = F_RDLCK; 3969 else { 3970 error = EBADF; 3971 goto done; 3972 } 3973 atomic_set_int(&fp->f_flag, FHASLOCK); 3974 error = VOP_ADVLOCK(vp, (caddr_t)fp, F_SETLK, &lf, 3975 (uap->how & LOCK_NB) ? F_FLOCK : F_FLOCK | F_WAIT); 3976 done: 3977 fdrop(fp, td); 3978 return (error); 3979 } 3980 /* 3981 * Duplicate the specified descriptor to a free descriptor. 3982 */ 3983 int 3984 dupfdopen(struct thread *td, struct filedesc *fdp, int dfd, int mode, 3985 int openerror, int *indxp) 3986 { 3987 struct filedescent *newfde, *oldfde; 3988 struct file *fp; 3989 u_long *ioctls; 3990 int error, indx; 3991 3992 KASSERT(openerror == ENODEV || openerror == ENXIO, 3993 ("unexpected error %d in %s", openerror, __func__)); 3994 3995 /* 3996 * If the to-be-dup'd fd number is greater than the allowed number 3997 * of file descriptors, or the fd to be dup'd has already been 3998 * closed, then reject. 3999 */ 4000 FILEDESC_XLOCK(fdp); 4001 if ((fp = fget_noref(fdp, dfd)) == NULL) { 4002 FILEDESC_XUNLOCK(fdp); 4003 return (EBADF); 4004 } 4005 4006 error = fdalloc(td, 0, &indx); 4007 if (error != 0) { 4008 FILEDESC_XUNLOCK(fdp); 4009 return (error); 4010 } 4011 4012 /* 4013 * There are two cases of interest here. 4014 * 4015 * For ENODEV simply dup (dfd) to file descriptor (indx) and return. 4016 * 4017 * For ENXIO steal away the file structure from (dfd) and store it in 4018 * (indx). (dfd) is effectively closed by this operation. 4019 */ 4020 switch (openerror) { 4021 case ENODEV: 4022 /* 4023 * Check that the mode the file is being opened for is a 4024 * subset of the mode of the existing descriptor. 4025 */ 4026 if (((mode & (FREAD|FWRITE)) | fp->f_flag) != fp->f_flag) { 4027 fdunused(fdp, indx); 4028 FILEDESC_XUNLOCK(fdp); 4029 return (EACCES); 4030 } 4031 if (!fhold(fp)) { 4032 fdunused(fdp, indx); 4033 FILEDESC_XUNLOCK(fdp); 4034 return (EBADF); 4035 } 4036 newfde = &fdp->fd_ofiles[indx]; 4037 oldfde = &fdp->fd_ofiles[dfd]; 4038 ioctls = filecaps_copy_prep(&oldfde->fde_caps); 4039 #ifdef CAPABILITIES 4040 seqc_write_begin(&newfde->fde_seqc); 4041 #endif 4042 fde_copy(oldfde, newfde); 4043 filecaps_copy_finish(&oldfde->fde_caps, &newfde->fde_caps, 4044 ioctls); 4045 #ifdef CAPABILITIES 4046 seqc_write_end(&newfde->fde_seqc); 4047 #endif 4048 break; 4049 case ENXIO: 4050 /* 4051 * Steal away the file pointer from dfd and stuff it into indx. 4052 */ 4053 newfde = &fdp->fd_ofiles[indx]; 4054 oldfde = &fdp->fd_ofiles[dfd]; 4055 #ifdef CAPABILITIES 4056 seqc_write_begin(&oldfde->fde_seqc); 4057 seqc_write_begin(&newfde->fde_seqc); 4058 #endif 4059 fde_copy(oldfde, newfde); 4060 oldfde->fde_file = NULL; 4061 fdunused(fdp, dfd); 4062 #ifdef CAPABILITIES 4063 seqc_write_end(&newfde->fde_seqc); 4064 seqc_write_end(&oldfde->fde_seqc); 4065 #endif 4066 break; 4067 } 4068 FILEDESC_XUNLOCK(fdp); 4069 *indxp = indx; 4070 return (0); 4071 } 4072 4073 /* 4074 * This sysctl determines if we will allow a process to chroot(2) if it 4075 * has a directory open: 4076 * 0: disallowed for all processes. 4077 * 1: allowed for processes that were not already chroot(2)'ed. 4078 * 2: allowed for all processes. 4079 */ 4080 4081 static int chroot_allow_open_directories = 1; 4082 4083 SYSCTL_INT(_kern, OID_AUTO, chroot_allow_open_directories, CTLFLAG_RW, 4084 &chroot_allow_open_directories, 0, 4085 "Allow a process to chroot(2) if it has a directory open"); 4086 4087 /* 4088 * Helper function for raised chroot(2) security function: Refuse if 4089 * any filedescriptors are open directories. 4090 */ 4091 static int 4092 chroot_refuse_vdir_fds(struct filedesc *fdp) 4093 { 4094 struct vnode *vp; 4095 struct file *fp; 4096 int i; 4097 4098 FILEDESC_LOCK_ASSERT(fdp); 4099 4100 FILEDESC_FOREACH_FP(fdp, i, fp) { 4101 if (fp->f_type == DTYPE_VNODE) { 4102 vp = fp->f_vnode; 4103 if (vp->v_type == VDIR) 4104 return (EPERM); 4105 } 4106 } 4107 return (0); 4108 } 4109 4110 static void 4111 pwd_fill(struct pwd *oldpwd, struct pwd *newpwd) 4112 { 4113 4114 if (newpwd->pwd_cdir == NULL && oldpwd->pwd_cdir != NULL) { 4115 vrefact(oldpwd->pwd_cdir); 4116 newpwd->pwd_cdir = oldpwd->pwd_cdir; 4117 } 4118 4119 if (newpwd->pwd_rdir == NULL && oldpwd->pwd_rdir != NULL) { 4120 vrefact(oldpwd->pwd_rdir); 4121 newpwd->pwd_rdir = oldpwd->pwd_rdir; 4122 } 4123 4124 if (newpwd->pwd_jdir == NULL && oldpwd->pwd_jdir != NULL) { 4125 vrefact(oldpwd->pwd_jdir); 4126 newpwd->pwd_jdir = oldpwd->pwd_jdir; 4127 } 4128 4129 if (newpwd->pwd_adir == NULL && oldpwd->pwd_adir != NULL) { 4130 vrefact(oldpwd->pwd_adir); 4131 newpwd->pwd_adir = oldpwd->pwd_adir; 4132 } 4133 } 4134 4135 struct pwd * 4136 pwd_hold_pwddesc(struct pwddesc *pdp) 4137 { 4138 struct pwd *pwd; 4139 4140 PWDDESC_ASSERT_XLOCKED(pdp); 4141 pwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); 4142 if (pwd != NULL) 4143 refcount_acquire(&pwd->pwd_refcount); 4144 return (pwd); 4145 } 4146 4147 bool 4148 pwd_hold_smr(struct pwd *pwd) 4149 { 4150 4151 MPASS(pwd != NULL); 4152 if (__predict_true(refcount_acquire_if_not_zero(&pwd->pwd_refcount))) { 4153 return (true); 4154 } 4155 return (false); 4156 } 4157 4158 struct pwd * 4159 pwd_hold(struct thread *td) 4160 { 4161 struct pwddesc *pdp; 4162 struct pwd *pwd; 4163 4164 pdp = td->td_proc->p_pd; 4165 4166 vfs_smr_enter(); 4167 pwd = vfs_smr_entered_load(&pdp->pd_pwd); 4168 if (pwd_hold_smr(pwd)) { 4169 vfs_smr_exit(); 4170 return (pwd); 4171 } 4172 vfs_smr_exit(); 4173 PWDDESC_XLOCK(pdp); 4174 pwd = pwd_hold_pwddesc(pdp); 4175 MPASS(pwd != NULL); 4176 PWDDESC_XUNLOCK(pdp); 4177 return (pwd); 4178 } 4179 4180 struct pwd * 4181 pwd_hold_proc(struct proc *p) 4182 { 4183 struct pwddesc *pdp; 4184 struct pwd *pwd; 4185 4186 PROC_ASSERT_HELD(p); 4187 PROC_LOCK(p); 4188 pdp = pdhold(p); 4189 MPASS(pdp != NULL); 4190 PROC_UNLOCK(p); 4191 4192 PWDDESC_XLOCK(pdp); 4193 pwd = pwd_hold_pwddesc(pdp); 4194 MPASS(pwd != NULL); 4195 PWDDESC_XUNLOCK(pdp); 4196 pddrop(pdp); 4197 return (pwd); 4198 } 4199 4200 static struct pwd * 4201 pwd_alloc(void) 4202 { 4203 struct pwd *pwd; 4204 4205 pwd = uma_zalloc_smr(pwd_zone, M_WAITOK); 4206 bzero(pwd, sizeof(*pwd)); 4207 refcount_init(&pwd->pwd_refcount, 1); 4208 return (pwd); 4209 } 4210 4211 void 4212 pwd_drop(struct pwd *pwd) 4213 { 4214 4215 if (!refcount_release(&pwd->pwd_refcount)) 4216 return; 4217 4218 if (pwd->pwd_cdir != NULL) 4219 vrele(pwd->pwd_cdir); 4220 if (pwd->pwd_rdir != NULL) 4221 vrele(pwd->pwd_rdir); 4222 if (pwd->pwd_jdir != NULL) 4223 vrele(pwd->pwd_jdir); 4224 if (pwd->pwd_adir != NULL) 4225 vrele(pwd->pwd_adir); 4226 uma_zfree_smr(pwd_zone, pwd); 4227 } 4228 4229 /* 4230 * The caller is responsible for invoking priv_check() and 4231 * mac_vnode_check_chroot() to authorize this operation. 4232 */ 4233 int 4234 pwd_chroot(struct thread *td, struct vnode *vp) 4235 { 4236 struct pwddesc *pdp; 4237 struct filedesc *fdp; 4238 struct pwd *newpwd, *oldpwd; 4239 int error; 4240 4241 fdp = td->td_proc->p_fd; 4242 pdp = td->td_proc->p_pd; 4243 newpwd = pwd_alloc(); 4244 FILEDESC_SLOCK(fdp); 4245 PWDDESC_XLOCK(pdp); 4246 oldpwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); 4247 if (chroot_allow_open_directories == 0 || 4248 (chroot_allow_open_directories == 1 && 4249 oldpwd->pwd_rdir != rootvnode)) { 4250 error = chroot_refuse_vdir_fds(fdp); 4251 FILEDESC_SUNLOCK(fdp); 4252 if (error != 0) { 4253 PWDDESC_XUNLOCK(pdp); 4254 pwd_drop(newpwd); 4255 return (error); 4256 } 4257 } else { 4258 FILEDESC_SUNLOCK(fdp); 4259 } 4260 4261 vrefact(vp); 4262 newpwd->pwd_rdir = vp; 4263 vrefact(vp); 4264 newpwd->pwd_adir = vp; 4265 if (oldpwd->pwd_jdir == NULL) { 4266 vrefact(vp); 4267 newpwd->pwd_jdir = vp; 4268 } 4269 pwd_fill(oldpwd, newpwd); 4270 pwd_set(pdp, newpwd); 4271 PWDDESC_XUNLOCK(pdp); 4272 pwd_drop(oldpwd); 4273 return (0); 4274 } 4275 4276 void 4277 pwd_chdir(struct thread *td, struct vnode *vp) 4278 { 4279 struct pwddesc *pdp; 4280 struct pwd *newpwd, *oldpwd; 4281 4282 VNPASS(vp->v_usecount > 0, vp); 4283 4284 newpwd = pwd_alloc(); 4285 pdp = td->td_proc->p_pd; 4286 PWDDESC_XLOCK(pdp); 4287 oldpwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); 4288 newpwd->pwd_cdir = vp; 4289 pwd_fill(oldpwd, newpwd); 4290 pwd_set(pdp, newpwd); 4291 PWDDESC_XUNLOCK(pdp); 4292 pwd_drop(oldpwd); 4293 } 4294 4295 /* 4296 * Process is transitioning to/from a non-native ABI. 4297 */ 4298 void 4299 pwd_altroot(struct thread *td, struct vnode *altroot_vp) 4300 { 4301 struct pwddesc *pdp; 4302 struct pwd *newpwd, *oldpwd; 4303 4304 newpwd = pwd_alloc(); 4305 pdp = td->td_proc->p_pd; 4306 PWDDESC_XLOCK(pdp); 4307 oldpwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); 4308 if (altroot_vp != NULL) { 4309 /* 4310 * Native process to a non-native ABI. 4311 */ 4312 4313 vrefact(altroot_vp); 4314 newpwd->pwd_adir = altroot_vp; 4315 } else { 4316 /* 4317 * Non-native process to the native ABI. 4318 */ 4319 4320 vrefact(oldpwd->pwd_rdir); 4321 newpwd->pwd_adir = oldpwd->pwd_rdir; 4322 } 4323 pwd_fill(oldpwd, newpwd); 4324 pwd_set(pdp, newpwd); 4325 PWDDESC_XUNLOCK(pdp); 4326 pwd_drop(oldpwd); 4327 } 4328 4329 /* 4330 * jail_attach(2) changes both root and working directories. 4331 */ 4332 int 4333 pwd_chroot_chdir(struct thread *td, struct vnode *vp) 4334 { 4335 struct pwddesc *pdp; 4336 struct filedesc *fdp; 4337 struct pwd *newpwd, *oldpwd; 4338 int error; 4339 4340 fdp = td->td_proc->p_fd; 4341 pdp = td->td_proc->p_pd; 4342 newpwd = pwd_alloc(); 4343 FILEDESC_SLOCK(fdp); 4344 PWDDESC_XLOCK(pdp); 4345 oldpwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); 4346 error = chroot_refuse_vdir_fds(fdp); 4347 FILEDESC_SUNLOCK(fdp); 4348 if (error != 0) { 4349 PWDDESC_XUNLOCK(pdp); 4350 pwd_drop(newpwd); 4351 return (error); 4352 } 4353 4354 vrefact(vp); 4355 newpwd->pwd_rdir = vp; 4356 vrefact(vp); 4357 newpwd->pwd_cdir = vp; 4358 if (oldpwd->pwd_jdir == NULL) { 4359 vrefact(vp); 4360 newpwd->pwd_jdir = vp; 4361 } 4362 vrefact(vp); 4363 newpwd->pwd_adir = vp; 4364 pwd_fill(oldpwd, newpwd); 4365 pwd_set(pdp, newpwd); 4366 PWDDESC_XUNLOCK(pdp); 4367 pwd_drop(oldpwd); 4368 return (0); 4369 } 4370 4371 void 4372 pwd_ensure_dirs(void) 4373 { 4374 struct pwddesc *pdp; 4375 struct pwd *oldpwd, *newpwd; 4376 4377 pdp = curproc->p_pd; 4378 PWDDESC_XLOCK(pdp); 4379 oldpwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); 4380 if (oldpwd->pwd_cdir != NULL && oldpwd->pwd_rdir != NULL && 4381 oldpwd->pwd_adir != NULL) { 4382 PWDDESC_XUNLOCK(pdp); 4383 return; 4384 } 4385 PWDDESC_XUNLOCK(pdp); 4386 4387 newpwd = pwd_alloc(); 4388 PWDDESC_XLOCK(pdp); 4389 oldpwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); 4390 pwd_fill(oldpwd, newpwd); 4391 if (newpwd->pwd_cdir == NULL) { 4392 vrefact(rootvnode); 4393 newpwd->pwd_cdir = rootvnode; 4394 } 4395 if (newpwd->pwd_rdir == NULL) { 4396 vrefact(rootvnode); 4397 newpwd->pwd_rdir = rootvnode; 4398 } 4399 if (newpwd->pwd_adir == NULL) { 4400 vrefact(rootvnode); 4401 newpwd->pwd_adir = rootvnode; 4402 } 4403 pwd_set(pdp, newpwd); 4404 PWDDESC_XUNLOCK(pdp); 4405 pwd_drop(oldpwd); 4406 } 4407 4408 void 4409 pwd_set_rootvnode(void) 4410 { 4411 struct pwddesc *pdp; 4412 struct pwd *oldpwd, *newpwd; 4413 4414 pdp = curproc->p_pd; 4415 4416 newpwd = pwd_alloc(); 4417 PWDDESC_XLOCK(pdp); 4418 oldpwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); 4419 vrefact(rootvnode); 4420 newpwd->pwd_cdir = rootvnode; 4421 vrefact(rootvnode); 4422 newpwd->pwd_rdir = rootvnode; 4423 vrefact(rootvnode); 4424 newpwd->pwd_adir = rootvnode; 4425 pwd_fill(oldpwd, newpwd); 4426 pwd_set(pdp, newpwd); 4427 PWDDESC_XUNLOCK(pdp); 4428 pwd_drop(oldpwd); 4429 } 4430 4431 /* 4432 * Scan all active processes and prisons to see if any of them have a current 4433 * or root directory of `olddp'. If so, replace them with the new mount point. 4434 */ 4435 void 4436 mountcheckdirs(struct vnode *olddp, struct vnode *newdp) 4437 { 4438 struct pwddesc *pdp; 4439 struct pwd *newpwd, *oldpwd; 4440 struct prison *pr; 4441 struct proc *p; 4442 int nrele; 4443 4444 if (vrefcnt(olddp) == 1) 4445 return; 4446 nrele = 0; 4447 newpwd = pwd_alloc(); 4448 sx_slock(&allproc_lock); 4449 FOREACH_PROC_IN_SYSTEM(p) { 4450 PROC_LOCK(p); 4451 pdp = pdhold(p); 4452 PROC_UNLOCK(p); 4453 if (pdp == NULL) 4454 continue; 4455 PWDDESC_XLOCK(pdp); 4456 oldpwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); 4457 if (oldpwd == NULL || 4458 (oldpwd->pwd_cdir != olddp && 4459 oldpwd->pwd_rdir != olddp && 4460 oldpwd->pwd_jdir != olddp && 4461 oldpwd->pwd_adir != olddp)) { 4462 PWDDESC_XUNLOCK(pdp); 4463 pddrop(pdp); 4464 continue; 4465 } 4466 if (oldpwd->pwd_cdir == olddp) { 4467 vrefact(newdp); 4468 newpwd->pwd_cdir = newdp; 4469 } 4470 if (oldpwd->pwd_rdir == olddp) { 4471 vrefact(newdp); 4472 newpwd->pwd_rdir = newdp; 4473 } 4474 if (oldpwd->pwd_jdir == olddp) { 4475 vrefact(newdp); 4476 newpwd->pwd_jdir = newdp; 4477 } 4478 if (oldpwd->pwd_adir == olddp) { 4479 vrefact(newdp); 4480 newpwd->pwd_adir = newdp; 4481 } 4482 pwd_fill(oldpwd, newpwd); 4483 pwd_set(pdp, newpwd); 4484 PWDDESC_XUNLOCK(pdp); 4485 pwd_drop(oldpwd); 4486 pddrop(pdp); 4487 newpwd = pwd_alloc(); 4488 } 4489 sx_sunlock(&allproc_lock); 4490 pwd_drop(newpwd); 4491 if (rootvnode == olddp) { 4492 vrefact(newdp); 4493 rootvnode = newdp; 4494 nrele++; 4495 } 4496 mtx_lock(&prison0.pr_mtx); 4497 if (prison0.pr_root == olddp) { 4498 vrefact(newdp); 4499 prison0.pr_root = newdp; 4500 nrele++; 4501 } 4502 mtx_unlock(&prison0.pr_mtx); 4503 sx_slock(&allprison_lock); 4504 TAILQ_FOREACH(pr, &allprison, pr_list) { 4505 mtx_lock(&pr->pr_mtx); 4506 if (pr->pr_root == olddp) { 4507 vrefact(newdp); 4508 pr->pr_root = newdp; 4509 nrele++; 4510 } 4511 mtx_unlock(&pr->pr_mtx); 4512 } 4513 sx_sunlock(&allprison_lock); 4514 while (nrele--) 4515 vrele(olddp); 4516 } 4517 4518 int 4519 descrip_check_write_mp(struct filedesc *fdp, struct mount *mp) 4520 { 4521 struct file *fp; 4522 struct vnode *vp; 4523 int error, i; 4524 4525 error = 0; 4526 FILEDESC_SLOCK(fdp); 4527 FILEDESC_FOREACH_FP(fdp, i, fp) { 4528 if (fp->f_type != DTYPE_VNODE || 4529 (atomic_load_int(&fp->f_flag) & FWRITE) == 0) 4530 continue; 4531 vp = fp->f_vnode; 4532 if (vp->v_mount == mp) { 4533 error = EDEADLK; 4534 break; 4535 } 4536 } 4537 FILEDESC_SUNLOCK(fdp); 4538 return (error); 4539 } 4540 4541 struct filedesc_to_leader * 4542 filedesc_to_leader_alloc(struct filedesc_to_leader *old, struct filedesc *fdp, 4543 struct proc *leader) 4544 { 4545 struct filedesc_to_leader *fdtol; 4546 4547 fdtol = malloc(sizeof(struct filedesc_to_leader), 4548 M_FILEDESC_TO_LEADER, M_WAITOK); 4549 fdtol->fdl_refcount = 1; 4550 fdtol->fdl_holdcount = 0; 4551 fdtol->fdl_wakeup = 0; 4552 fdtol->fdl_leader = leader; 4553 if (old != NULL) { 4554 FILEDESC_XLOCK(fdp); 4555 fdtol->fdl_next = old->fdl_next; 4556 fdtol->fdl_prev = old; 4557 old->fdl_next = fdtol; 4558 fdtol->fdl_next->fdl_prev = fdtol; 4559 FILEDESC_XUNLOCK(fdp); 4560 } else { 4561 fdtol->fdl_next = fdtol; 4562 fdtol->fdl_prev = fdtol; 4563 } 4564 return (fdtol); 4565 } 4566 4567 struct filedesc_to_leader * 4568 filedesc_to_leader_share(struct filedesc_to_leader *fdtol, struct filedesc *fdp) 4569 { 4570 FILEDESC_XLOCK(fdp); 4571 fdtol->fdl_refcount++; 4572 FILEDESC_XUNLOCK(fdp); 4573 return (fdtol); 4574 } 4575 4576 static int 4577 filedesc_nfiles(struct filedesc *fdp) 4578 { 4579 NDSLOTTYPE *map; 4580 int count, off, minoff; 4581 4582 if (fdp == NULL) 4583 return (0); 4584 count = 0; 4585 FILEDESC_SLOCK(fdp); 4586 map = fdp->fd_map; 4587 off = NDSLOT(fdp->fd_nfiles - 1); 4588 for (minoff = NDSLOT(0); off >= minoff; --off) 4589 count += bitcountl(map[off]); 4590 FILEDESC_SUNLOCK(fdp); 4591 return (count); 4592 } 4593 4594 int 4595 proc_nfiles(struct proc *p) 4596 { 4597 struct filedesc *fdp; 4598 int res; 4599 4600 PROC_LOCK(p); 4601 fdp = fdhold(p); 4602 PROC_UNLOCK(p); 4603 res = filedesc_nfiles(fdp); 4604 fddrop(fdp); 4605 return (res); 4606 } 4607 4608 static int 4609 sysctl_kern_proc_nfds(SYSCTL_HANDLER_ARGS) 4610 { 4611 u_int namelen; 4612 int count; 4613 4614 namelen = arg2; 4615 if (namelen != 1) 4616 return (EINVAL); 4617 4618 if (*(int *)arg1 != 0) 4619 return (EINVAL); 4620 4621 count = filedesc_nfiles(curproc->p_fd); 4622 return (SYSCTL_OUT(req, &count, sizeof(count))); 4623 } 4624 4625 static SYSCTL_NODE(_kern_proc, KERN_PROC_NFDS, nfds, 4626 CTLFLAG_RD|CTLFLAG_CAPRD|CTLFLAG_MPSAFE, sysctl_kern_proc_nfds, 4627 "Number of open file descriptors"); 4628 4629 /* 4630 * Get file structures globally. 4631 */ 4632 static int 4633 sysctl_kern_file(SYSCTL_HANDLER_ARGS) 4634 { 4635 struct xfile xf; 4636 struct filedesc *fdp; 4637 struct file *fp; 4638 struct proc *p; 4639 int error, n; 4640 4641 error = sysctl_wire_old_buffer(req, 0); 4642 if (error != 0) 4643 return (error); 4644 if (req->oldptr == NULL) { 4645 n = 0; 4646 sx_slock(&allproc_lock); 4647 FOREACH_PROC_IN_SYSTEM(p) { 4648 PROC_LOCK(p); 4649 if (p->p_state == PRS_NEW) { 4650 PROC_UNLOCK(p); 4651 continue; 4652 } 4653 fdp = fdhold(p); 4654 PROC_UNLOCK(p); 4655 if (fdp == NULL) 4656 continue; 4657 /* overestimates sparse tables. */ 4658 n += fdp->fd_nfiles; 4659 fddrop(fdp); 4660 } 4661 sx_sunlock(&allproc_lock); 4662 return (SYSCTL_OUT(req, 0, n * sizeof(xf))); 4663 } 4664 error = 0; 4665 bzero(&xf, sizeof(xf)); 4666 xf.xf_size = sizeof(xf); 4667 sx_slock(&allproc_lock); 4668 FOREACH_PROC_IN_SYSTEM(p) { 4669 PROC_LOCK(p); 4670 if (p->p_state == PRS_NEW) { 4671 PROC_UNLOCK(p); 4672 continue; 4673 } 4674 if (p_cansee(req->td, p) != 0) { 4675 PROC_UNLOCK(p); 4676 continue; 4677 } 4678 xf.xf_pid = p->p_pid; 4679 xf.xf_uid = p->p_ucred->cr_uid; 4680 fdp = fdhold(p); 4681 PROC_UNLOCK(p); 4682 if (fdp == NULL) 4683 continue; 4684 FILEDESC_SLOCK(fdp); 4685 if (refcount_load(&fdp->fd_refcnt) == 0) 4686 goto nextproc; 4687 FILEDESC_FOREACH_FP(fdp, n, fp) { 4688 xf.xf_fd = n; 4689 xf.xf_file = (uintptr_t)fp; 4690 xf.xf_data = (uintptr_t)fp->f_data; 4691 xf.xf_vnode = (uintptr_t)fp->f_vnode; 4692 xf.xf_type = (uintptr_t)fp->f_type; 4693 xf.xf_count = refcount_load(&fp->f_count); 4694 xf.xf_msgcount = 0; 4695 xf.xf_offset = foffset_get(fp); 4696 xf.xf_flag = fp->f_flag; 4697 error = SYSCTL_OUT(req, &xf, sizeof(xf)); 4698 4699 /* 4700 * There is no need to re-check the fdtable refcount 4701 * here since the filedesc lock is not dropped in the 4702 * loop body. 4703 */ 4704 if (error != 0) 4705 break; 4706 } 4707 nextproc: 4708 FILEDESC_SUNLOCK(fdp); 4709 fddrop(fdp); 4710 if (error) 4711 break; 4712 } 4713 sx_sunlock(&allproc_lock); 4714 return (error); 4715 } 4716 4717 SYSCTL_PROC(_kern, KERN_FILE, file, CTLTYPE_OPAQUE|CTLFLAG_RD|CTLFLAG_MPSAFE, 4718 0, 0, sysctl_kern_file, "S,xfile", "Entire file table"); 4719 4720 #ifdef KINFO_FILE_SIZE 4721 CTASSERT(sizeof(struct kinfo_file) == KINFO_FILE_SIZE); 4722 #endif 4723 4724 static int 4725 xlate_fflags(int fflags) 4726 { 4727 static const struct { 4728 int fflag; 4729 int kf_fflag; 4730 } fflags_table[] = { 4731 { FAPPEND, KF_FLAG_APPEND }, 4732 { FASYNC, KF_FLAG_ASYNC }, 4733 { FFSYNC, KF_FLAG_FSYNC }, 4734 { FHASLOCK, KF_FLAG_HASLOCK }, 4735 { FNONBLOCK, KF_FLAG_NONBLOCK }, 4736 { FREAD, KF_FLAG_READ }, 4737 { FWRITE, KF_FLAG_WRITE }, 4738 { O_CREAT, KF_FLAG_CREAT }, 4739 { O_DIRECT, KF_FLAG_DIRECT }, 4740 { O_EXCL, KF_FLAG_EXCL }, 4741 { O_EXEC, KF_FLAG_EXEC }, 4742 { O_EXLOCK, KF_FLAG_EXLOCK }, 4743 { O_NOFOLLOW, KF_FLAG_NOFOLLOW }, 4744 { O_SHLOCK, KF_FLAG_SHLOCK }, 4745 { O_TRUNC, KF_FLAG_TRUNC } 4746 }; 4747 unsigned int i; 4748 int kflags; 4749 4750 kflags = 0; 4751 for (i = 0; i < nitems(fflags_table); i++) 4752 if (fflags & fflags_table[i].fflag) 4753 kflags |= fflags_table[i].kf_fflag; 4754 return (kflags); 4755 } 4756 4757 /* Trim unused data from kf_path by truncating the structure size. */ 4758 void 4759 pack_kinfo(struct kinfo_file *kif) 4760 { 4761 4762 kif->kf_structsize = offsetof(struct kinfo_file, kf_path) + 4763 strlen(kif->kf_path) + 1; 4764 kif->kf_structsize = roundup(kif->kf_structsize, sizeof(uint64_t)); 4765 } 4766 4767 static void 4768 export_file_to_kinfo(struct file *fp, int fd, cap_rights_t *rightsp, 4769 struct kinfo_file *kif, struct filedesc *fdp, int flags) 4770 { 4771 int error; 4772 4773 bzero(kif, sizeof(*kif)); 4774 4775 /* Set a default type to allow for empty fill_kinfo() methods. */ 4776 kif->kf_type = KF_TYPE_UNKNOWN; 4777 kif->kf_flags = xlate_fflags(fp->f_flag); 4778 if (rightsp != NULL) 4779 kif->kf_cap_rights = *rightsp; 4780 else 4781 cap_rights_init_zero(&kif->kf_cap_rights); 4782 kif->kf_fd = fd; 4783 kif->kf_ref_count = refcount_load(&fp->f_count); 4784 kif->kf_offset = foffset_get(fp); 4785 4786 /* 4787 * This may drop the filedesc lock, so the 'fp' cannot be 4788 * accessed after this call. 4789 */ 4790 error = fo_fill_kinfo(fp, kif, fdp); 4791 if (error == 0) 4792 kif->kf_status |= KF_ATTR_VALID; 4793 if ((flags & KERN_FILEDESC_PACK_KINFO) != 0) 4794 pack_kinfo(kif); 4795 else 4796 kif->kf_structsize = roundup2(sizeof(*kif), sizeof(uint64_t)); 4797 } 4798 4799 static void 4800 export_vnode_to_kinfo(struct vnode *vp, int fd, int fflags, 4801 struct kinfo_file *kif, int flags) 4802 { 4803 int error; 4804 4805 bzero(kif, sizeof(*kif)); 4806 4807 kif->kf_type = KF_TYPE_VNODE; 4808 error = vn_fill_kinfo_vnode(vp, kif); 4809 if (error == 0) 4810 kif->kf_status |= KF_ATTR_VALID; 4811 kif->kf_flags = xlate_fflags(fflags); 4812 cap_rights_init_zero(&kif->kf_cap_rights); 4813 kif->kf_fd = fd; 4814 kif->kf_ref_count = -1; 4815 kif->kf_offset = -1; 4816 if ((flags & KERN_FILEDESC_PACK_KINFO) != 0) 4817 pack_kinfo(kif); 4818 else 4819 kif->kf_structsize = roundup2(sizeof(*kif), sizeof(uint64_t)); 4820 vrele(vp); 4821 } 4822 4823 struct export_fd_buf { 4824 struct filedesc *fdp; 4825 struct pwddesc *pdp; 4826 struct sbuf *sb; 4827 ssize_t remainder; 4828 struct kinfo_file kif; 4829 int flags; 4830 }; 4831 4832 static int 4833 export_kinfo_to_sb(struct export_fd_buf *efbuf) 4834 { 4835 struct kinfo_file *kif; 4836 4837 kif = &efbuf->kif; 4838 if (efbuf->remainder != -1) { 4839 if (efbuf->remainder < kif->kf_structsize) 4840 return (ENOMEM); 4841 efbuf->remainder -= kif->kf_structsize; 4842 } 4843 if (sbuf_bcat(efbuf->sb, kif, kif->kf_structsize) != 0) 4844 return (sbuf_error(efbuf->sb)); 4845 return (0); 4846 } 4847 4848 static int 4849 export_file_to_sb(struct file *fp, int fd, cap_rights_t *rightsp, 4850 struct export_fd_buf *efbuf) 4851 { 4852 int error; 4853 4854 if (efbuf->remainder == 0) 4855 return (ENOMEM); 4856 export_file_to_kinfo(fp, fd, rightsp, &efbuf->kif, efbuf->fdp, 4857 efbuf->flags); 4858 FILEDESC_SUNLOCK(efbuf->fdp); 4859 error = export_kinfo_to_sb(efbuf); 4860 FILEDESC_SLOCK(efbuf->fdp); 4861 return (error); 4862 } 4863 4864 static int 4865 export_vnode_to_sb(struct vnode *vp, int fd, int fflags, 4866 struct export_fd_buf *efbuf) 4867 { 4868 int error; 4869 4870 if (efbuf->remainder == 0) 4871 return (ENOMEM); 4872 if (efbuf->pdp != NULL) 4873 PWDDESC_XUNLOCK(efbuf->pdp); 4874 export_vnode_to_kinfo(vp, fd, fflags, &efbuf->kif, efbuf->flags); 4875 error = export_kinfo_to_sb(efbuf); 4876 if (efbuf->pdp != NULL) 4877 PWDDESC_XLOCK(efbuf->pdp); 4878 return (error); 4879 } 4880 4881 /* 4882 * Store a process file descriptor information to sbuf. 4883 * 4884 * Takes a locked proc as argument, and returns with the proc unlocked. 4885 */ 4886 int 4887 kern_proc_filedesc_out(struct proc *p, struct sbuf *sb, ssize_t maxlen, 4888 int flags) 4889 { 4890 struct file *fp; 4891 struct filedesc *fdp; 4892 struct pwddesc *pdp; 4893 struct export_fd_buf *efbuf; 4894 struct vnode *cttyvp, *textvp, *tracevp; 4895 struct pwd *pwd; 4896 int error, i; 4897 cap_rights_t rights; 4898 4899 PROC_LOCK_ASSERT(p, MA_OWNED); 4900 4901 /* ktrace vnode */ 4902 tracevp = ktr_get_tracevp(p, true); 4903 /* text vnode */ 4904 textvp = p->p_textvp; 4905 if (textvp != NULL) 4906 vrefact(textvp); 4907 /* Controlling tty. */ 4908 cttyvp = NULL; 4909 if (p->p_pgrp != NULL && p->p_pgrp->pg_session != NULL) { 4910 cttyvp = p->p_pgrp->pg_session->s_ttyvp; 4911 if (cttyvp != NULL) 4912 vrefact(cttyvp); 4913 } 4914 fdp = fdhold(p); 4915 pdp = pdhold(p); 4916 PROC_UNLOCK(p); 4917 4918 efbuf = malloc(sizeof(*efbuf), M_TEMP, M_WAITOK); 4919 efbuf->fdp = NULL; 4920 efbuf->pdp = NULL; 4921 efbuf->sb = sb; 4922 efbuf->remainder = maxlen; 4923 efbuf->flags = flags; 4924 4925 error = 0; 4926 if (tracevp != NULL) 4927 error = export_vnode_to_sb(tracevp, KF_FD_TYPE_TRACE, 4928 FREAD | FWRITE, efbuf); 4929 if (error == 0 && textvp != NULL) 4930 error = export_vnode_to_sb(textvp, KF_FD_TYPE_TEXT, FREAD, 4931 efbuf); 4932 if (error == 0 && cttyvp != NULL) 4933 error = export_vnode_to_sb(cttyvp, KF_FD_TYPE_CTTY, 4934 FREAD | FWRITE, efbuf); 4935 if (error != 0 || pdp == NULL || fdp == NULL) 4936 goto fail; 4937 efbuf->fdp = fdp; 4938 efbuf->pdp = pdp; 4939 PWDDESC_XLOCK(pdp); 4940 pwd = pwd_hold_pwddesc(pdp); 4941 if (pwd != NULL) { 4942 /* working directory */ 4943 if (pwd->pwd_cdir != NULL) { 4944 vrefact(pwd->pwd_cdir); 4945 error = export_vnode_to_sb(pwd->pwd_cdir, 4946 KF_FD_TYPE_CWD, FREAD, efbuf); 4947 } 4948 /* root directory */ 4949 if (error == 0 && pwd->pwd_rdir != NULL) { 4950 vrefact(pwd->pwd_rdir); 4951 error = export_vnode_to_sb(pwd->pwd_rdir, 4952 KF_FD_TYPE_ROOT, FREAD, efbuf); 4953 } 4954 /* jail directory */ 4955 if (error == 0 && pwd->pwd_jdir != NULL) { 4956 vrefact(pwd->pwd_jdir); 4957 error = export_vnode_to_sb(pwd->pwd_jdir, 4958 KF_FD_TYPE_JAIL, FREAD, efbuf); 4959 } 4960 } 4961 PWDDESC_XUNLOCK(pdp); 4962 if (error != 0) 4963 goto fail; 4964 if (pwd != NULL) 4965 pwd_drop(pwd); 4966 FILEDESC_SLOCK(fdp); 4967 if (refcount_load(&fdp->fd_refcnt) == 0) 4968 goto skip; 4969 FILEDESC_FOREACH_FP(fdp, i, fp) { 4970 #ifdef CAPABILITIES 4971 rights = *cap_rights(fdp, i); 4972 #else /* !CAPABILITIES */ 4973 rights = cap_no_rights; 4974 #endif 4975 /* 4976 * Create sysctl entry. It is OK to drop the filedesc 4977 * lock inside of export_file_to_sb() as we will 4978 * re-validate and re-evaluate its properties when the 4979 * loop continues. 4980 */ 4981 error = export_file_to_sb(fp, i, &rights, efbuf); 4982 if (error != 0 || refcount_load(&fdp->fd_refcnt) == 0) 4983 break; 4984 } 4985 skip: 4986 FILEDESC_SUNLOCK(fdp); 4987 fail: 4988 if (fdp != NULL) 4989 fddrop(fdp); 4990 if (pdp != NULL) 4991 pddrop(pdp); 4992 free(efbuf, M_TEMP); 4993 return (error); 4994 } 4995 4996 #define FILEDESC_SBUF_SIZE (sizeof(struct kinfo_file) * 5) 4997 4998 /* 4999 * Get per-process file descriptors for use by procstat(1), et al. 5000 */ 5001 static int 5002 sysctl_kern_proc_filedesc(SYSCTL_HANDLER_ARGS) 5003 { 5004 struct sbuf sb; 5005 struct proc *p; 5006 ssize_t maxlen; 5007 u_int namelen; 5008 int error, error2, *name; 5009 5010 namelen = arg2; 5011 if (namelen != 1) 5012 return (EINVAL); 5013 5014 name = (int *)arg1; 5015 5016 sbuf_new_for_sysctl(&sb, NULL, FILEDESC_SBUF_SIZE, req); 5017 sbuf_clear_flags(&sb, SBUF_INCLUDENUL); 5018 error = pget((pid_t)name[0], PGET_CANDEBUG | PGET_NOTWEXIT, &p); 5019 if (error != 0) { 5020 sbuf_delete(&sb); 5021 return (error); 5022 } 5023 maxlen = req->oldptr != NULL ? req->oldlen : -1; 5024 error = kern_proc_filedesc_out(p, &sb, maxlen, 5025 KERN_FILEDESC_PACK_KINFO); 5026 error2 = sbuf_finish(&sb); 5027 sbuf_delete(&sb); 5028 return (error != 0 ? error : error2); 5029 } 5030 5031 #ifdef COMPAT_FREEBSD7 5032 #ifdef KINFO_OFILE_SIZE 5033 CTASSERT(sizeof(struct kinfo_ofile) == KINFO_OFILE_SIZE); 5034 #endif 5035 5036 static void 5037 kinfo_to_okinfo(struct kinfo_file *kif, struct kinfo_ofile *okif) 5038 { 5039 5040 okif->kf_structsize = sizeof(*okif); 5041 okif->kf_type = kif->kf_type; 5042 okif->kf_fd = kif->kf_fd; 5043 okif->kf_ref_count = kif->kf_ref_count; 5044 okif->kf_flags = kif->kf_flags & (KF_FLAG_READ | KF_FLAG_WRITE | 5045 KF_FLAG_APPEND | KF_FLAG_ASYNC | KF_FLAG_FSYNC | KF_FLAG_NONBLOCK | 5046 KF_FLAG_DIRECT | KF_FLAG_HASLOCK); 5047 okif->kf_offset = kif->kf_offset; 5048 if (kif->kf_type == KF_TYPE_VNODE) 5049 okif->kf_vnode_type = kif->kf_un.kf_file.kf_file_type; 5050 else 5051 okif->kf_vnode_type = KF_VTYPE_VNON; 5052 strlcpy(okif->kf_path, kif->kf_path, sizeof(okif->kf_path)); 5053 if (kif->kf_type == KF_TYPE_SOCKET) { 5054 okif->kf_sock_domain = kif->kf_un.kf_sock.kf_sock_domain0; 5055 okif->kf_sock_type = kif->kf_un.kf_sock.kf_sock_type0; 5056 okif->kf_sock_protocol = kif->kf_un.kf_sock.kf_sock_protocol0; 5057 okif->kf_sa_local = kif->kf_un.kf_sock.kf_sa_local; 5058 okif->kf_sa_peer = kif->kf_un.kf_sock.kf_sa_peer; 5059 } else { 5060 okif->kf_sa_local.ss_family = AF_UNSPEC; 5061 okif->kf_sa_peer.ss_family = AF_UNSPEC; 5062 } 5063 } 5064 5065 static int 5066 export_vnode_for_osysctl(struct vnode *vp, int type, struct kinfo_file *kif, 5067 struct kinfo_ofile *okif, struct pwddesc *pdp, struct sysctl_req *req) 5068 { 5069 int error; 5070 5071 vrefact(vp); 5072 PWDDESC_XUNLOCK(pdp); 5073 export_vnode_to_kinfo(vp, type, 0, kif, KERN_FILEDESC_PACK_KINFO); 5074 kinfo_to_okinfo(kif, okif); 5075 error = SYSCTL_OUT(req, okif, sizeof(*okif)); 5076 PWDDESC_XLOCK(pdp); 5077 return (error); 5078 } 5079 5080 /* 5081 * Get per-process file descriptors for use by procstat(1), et al. 5082 */ 5083 static int 5084 sysctl_kern_proc_ofiledesc(SYSCTL_HANDLER_ARGS) 5085 { 5086 struct kinfo_ofile *okif; 5087 struct kinfo_file *kif; 5088 struct filedesc *fdp; 5089 struct pwddesc *pdp; 5090 struct pwd *pwd; 5091 u_int namelen; 5092 int error, i, *name; 5093 struct file *fp; 5094 struct proc *p; 5095 5096 namelen = arg2; 5097 if (namelen != 1) 5098 return (EINVAL); 5099 5100 name = (int *)arg1; 5101 error = pget((pid_t)name[0], PGET_CANDEBUG | PGET_NOTWEXIT, &p); 5102 if (error != 0) 5103 return (error); 5104 fdp = fdhold(p); 5105 if (fdp != NULL) 5106 pdp = pdhold(p); 5107 PROC_UNLOCK(p); 5108 if (fdp == NULL || pdp == NULL) { 5109 if (fdp != NULL) 5110 fddrop(fdp); 5111 return (ENOENT); 5112 } 5113 kif = malloc(sizeof(*kif), M_TEMP, M_WAITOK); 5114 okif = malloc(sizeof(*okif), M_TEMP, M_WAITOK); 5115 PWDDESC_XLOCK(pdp); 5116 pwd = pwd_hold_pwddesc(pdp); 5117 if (pwd != NULL) { 5118 if (pwd->pwd_cdir != NULL) 5119 export_vnode_for_osysctl(pwd->pwd_cdir, KF_FD_TYPE_CWD, kif, 5120 okif, pdp, req); 5121 if (pwd->pwd_rdir != NULL) 5122 export_vnode_for_osysctl(pwd->pwd_rdir, KF_FD_TYPE_ROOT, kif, 5123 okif, pdp, req); 5124 if (pwd->pwd_jdir != NULL) 5125 export_vnode_for_osysctl(pwd->pwd_jdir, KF_FD_TYPE_JAIL, kif, 5126 okif, pdp, req); 5127 } 5128 PWDDESC_XUNLOCK(pdp); 5129 if (pwd != NULL) 5130 pwd_drop(pwd); 5131 FILEDESC_SLOCK(fdp); 5132 if (refcount_load(&fdp->fd_refcnt) == 0) 5133 goto skip; 5134 FILEDESC_FOREACH_FP(fdp, i, fp) { 5135 export_file_to_kinfo(fp, i, NULL, kif, fdp, 5136 KERN_FILEDESC_PACK_KINFO); 5137 FILEDESC_SUNLOCK(fdp); 5138 kinfo_to_okinfo(kif, okif); 5139 error = SYSCTL_OUT(req, okif, sizeof(*okif)); 5140 FILEDESC_SLOCK(fdp); 5141 if (error != 0 || refcount_load(&fdp->fd_refcnt) == 0) 5142 break; 5143 } 5144 skip: 5145 FILEDESC_SUNLOCK(fdp); 5146 fddrop(fdp); 5147 pddrop(pdp); 5148 free(kif, M_TEMP); 5149 free(okif, M_TEMP); 5150 return (0); 5151 } 5152 5153 static SYSCTL_NODE(_kern_proc, KERN_PROC_OFILEDESC, ofiledesc, 5154 CTLFLAG_RD|CTLFLAG_MPSAFE, sysctl_kern_proc_ofiledesc, 5155 "Process ofiledesc entries"); 5156 #endif /* COMPAT_FREEBSD7 */ 5157 5158 int 5159 vntype_to_kinfo(int vtype) 5160 { 5161 struct { 5162 int vtype; 5163 int kf_vtype; 5164 } vtypes_table[] = { 5165 { VBAD, KF_VTYPE_VBAD }, 5166 { VBLK, KF_VTYPE_VBLK }, 5167 { VCHR, KF_VTYPE_VCHR }, 5168 { VDIR, KF_VTYPE_VDIR }, 5169 { VFIFO, KF_VTYPE_VFIFO }, 5170 { VLNK, KF_VTYPE_VLNK }, 5171 { VNON, KF_VTYPE_VNON }, 5172 { VREG, KF_VTYPE_VREG }, 5173 { VSOCK, KF_VTYPE_VSOCK } 5174 }; 5175 unsigned int i; 5176 5177 /* 5178 * Perform vtype translation. 5179 */ 5180 for (i = 0; i < nitems(vtypes_table); i++) 5181 if (vtypes_table[i].vtype == vtype) 5182 return (vtypes_table[i].kf_vtype); 5183 5184 return (KF_VTYPE_UNKNOWN); 5185 } 5186 5187 static SYSCTL_NODE(_kern_proc, KERN_PROC_FILEDESC, filedesc, 5188 CTLFLAG_RD|CTLFLAG_MPSAFE, sysctl_kern_proc_filedesc, 5189 "Process filedesc entries"); 5190 5191 /* 5192 * Store a process current working directory information to sbuf. 5193 * 5194 * Takes a locked proc as argument, and returns with the proc unlocked. 5195 */ 5196 int 5197 kern_proc_cwd_out(struct proc *p, struct sbuf *sb, ssize_t maxlen) 5198 { 5199 struct pwddesc *pdp; 5200 struct pwd *pwd; 5201 struct export_fd_buf *efbuf; 5202 struct vnode *cdir; 5203 int error; 5204 5205 PROC_LOCK_ASSERT(p, MA_OWNED); 5206 5207 pdp = pdhold(p); 5208 PROC_UNLOCK(p); 5209 if (pdp == NULL) 5210 return (EINVAL); 5211 5212 efbuf = malloc(sizeof(*efbuf), M_TEMP, M_WAITOK); 5213 efbuf->fdp = NULL; 5214 efbuf->pdp = pdp; 5215 efbuf->sb = sb; 5216 efbuf->remainder = maxlen; 5217 efbuf->flags = 0; 5218 5219 PWDDESC_XLOCK(pdp); 5220 pwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); 5221 cdir = pwd->pwd_cdir; 5222 if (cdir == NULL) { 5223 error = EINVAL; 5224 } else { 5225 vrefact(cdir); 5226 error = export_vnode_to_sb(cdir, KF_FD_TYPE_CWD, FREAD, efbuf); 5227 } 5228 PWDDESC_XUNLOCK(pdp); 5229 pddrop(pdp); 5230 free(efbuf, M_TEMP); 5231 return (error); 5232 } 5233 5234 /* 5235 * Get per-process current working directory. 5236 */ 5237 static int 5238 sysctl_kern_proc_cwd(SYSCTL_HANDLER_ARGS) 5239 { 5240 struct sbuf sb; 5241 struct proc *p; 5242 ssize_t maxlen; 5243 u_int namelen; 5244 int error, error2, *name; 5245 5246 namelen = arg2; 5247 if (namelen != 1) 5248 return (EINVAL); 5249 5250 name = (int *)arg1; 5251 5252 sbuf_new_for_sysctl(&sb, NULL, sizeof(struct kinfo_file), req); 5253 sbuf_clear_flags(&sb, SBUF_INCLUDENUL); 5254 error = pget((pid_t)name[0], PGET_CANDEBUG | PGET_NOTWEXIT, &p); 5255 if (error != 0) { 5256 sbuf_delete(&sb); 5257 return (error); 5258 } 5259 maxlen = req->oldptr != NULL ? req->oldlen : -1; 5260 error = kern_proc_cwd_out(p, &sb, maxlen); 5261 error2 = sbuf_finish(&sb); 5262 sbuf_delete(&sb); 5263 return (error != 0 ? error : error2); 5264 } 5265 5266 static SYSCTL_NODE(_kern_proc, KERN_PROC_CWD, cwd, CTLFLAG_RD|CTLFLAG_MPSAFE, 5267 sysctl_kern_proc_cwd, "Process current working directory"); 5268 5269 #ifdef DDB 5270 /* 5271 * For the purposes of debugging, generate a human-readable string for the 5272 * file type. 5273 */ 5274 static const char * 5275 file_type_to_name(short type) 5276 { 5277 5278 switch (type) { 5279 case 0: 5280 return ("zero"); 5281 case DTYPE_VNODE: 5282 return ("vnode"); 5283 case DTYPE_SOCKET: 5284 return ("socket"); 5285 case DTYPE_PIPE: 5286 return ("pipe"); 5287 case DTYPE_FIFO: 5288 return ("fifo"); 5289 case DTYPE_KQUEUE: 5290 return ("kqueue"); 5291 case DTYPE_CRYPTO: 5292 return ("crypto"); 5293 case DTYPE_MQUEUE: 5294 return ("mqueue"); 5295 case DTYPE_SHM: 5296 return ("shm"); 5297 case DTYPE_SEM: 5298 return ("ksem"); 5299 case DTYPE_PTS: 5300 return ("pts"); 5301 case DTYPE_DEV: 5302 return ("dev"); 5303 case DTYPE_PROCDESC: 5304 return ("proc"); 5305 case DTYPE_EVENTFD: 5306 return ("eventfd"); 5307 case DTYPE_TIMERFD: 5308 return ("timerfd"); 5309 case DTYPE_JAILDESC: 5310 return ("jail"); 5311 default: 5312 return ("unkn"); 5313 } 5314 } 5315 5316 /* 5317 * For the purposes of debugging, identify a process (if any, perhaps one of 5318 * many) that references the passed file in its file descriptor array. Return 5319 * NULL if none. 5320 */ 5321 static struct proc * 5322 file_to_first_proc(struct file *fp) 5323 { 5324 struct filedesc *fdp; 5325 struct proc *p; 5326 int n; 5327 5328 FOREACH_PROC_IN_SYSTEM(p) { 5329 if (p->p_state == PRS_NEW) 5330 continue; 5331 fdp = p->p_fd; 5332 if (fdp == NULL) 5333 continue; 5334 for (n = 0; n < fdp->fd_nfiles; n++) { 5335 if (fp == fdp->fd_ofiles[n].fde_file) 5336 return (p); 5337 } 5338 } 5339 return (NULL); 5340 } 5341 5342 static void 5343 db_print_file(struct file *fp, int header) 5344 { 5345 #define XPTRWIDTH ((int)howmany(sizeof(void *) * NBBY, 4)) 5346 struct proc *p; 5347 5348 if (header) 5349 db_printf("%*s %6s %*s %8s %4s %5s %6s %*s %5s %s\n", 5350 XPTRWIDTH, "File", "Type", XPTRWIDTH, "Data", "Flag", 5351 "GCFl", "Count", "MCount", XPTRWIDTH, "Vnode", "FPID", 5352 "FCmd"); 5353 p = file_to_first_proc(fp); 5354 db_printf("%*p %6s %*p %08x %04x %5d %6d %*p %5d %s\n", XPTRWIDTH, 5355 fp, file_type_to_name(fp->f_type), XPTRWIDTH, fp->f_data, 5356 fp->f_flag, 0, refcount_load(&fp->f_count), 0, XPTRWIDTH, fp->f_vnode, 5357 p != NULL ? p->p_pid : -1, p != NULL ? p->p_comm : "-"); 5358 5359 #undef XPTRWIDTH 5360 } 5361 5362 DB_SHOW_COMMAND(file, db_show_file) 5363 { 5364 struct file *fp; 5365 5366 if (!have_addr) { 5367 db_printf("usage: show file <addr>\n"); 5368 return; 5369 } 5370 fp = (struct file *)addr; 5371 db_print_file(fp, 1); 5372 } 5373 5374 DB_SHOW_COMMAND_FLAGS(files, db_show_files, DB_CMD_MEMSAFE) 5375 { 5376 struct filedesc *fdp; 5377 struct file *fp; 5378 struct proc *p; 5379 int header; 5380 int n; 5381 5382 header = 1; 5383 FOREACH_PROC_IN_SYSTEM(p) { 5384 if (p->p_state == PRS_NEW) 5385 continue; 5386 if ((fdp = p->p_fd) == NULL) 5387 continue; 5388 for (n = 0; n < fdp->fd_nfiles; ++n) { 5389 if ((fp = fdp->fd_ofiles[n].fde_file) == NULL) 5390 continue; 5391 db_print_file(fp, header); 5392 header = 0; 5393 } 5394 } 5395 } 5396 #endif 5397 5398 SYSCTL_INT(_kern, KERN_MAXFILESPERPROC, maxfilesperproc, 5399 CTLFLAG_RWTUN | CTLFLAG_NOFETCH, 5400 &maxfilesperproc, 0, "Maximum files allowed open per process"); 5401 5402 SYSCTL_INT(_kern, KERN_MAXFILES, maxfiles, CTLFLAG_RWTUN | CTLFLAG_NOFETCH, 5403 &maxfiles, 0, "Maximum number of files"); 5404 5405 SYSCTL_INT(_kern, OID_AUTO, openfiles, CTLFLAG_RD, 5406 &openfiles, 0, "System-wide number of open files"); 5407 5408 /* ARGSUSED*/ 5409 static void 5410 filelistinit(void *dummy) 5411 { 5412 5413 file_zone = uma_zcreate("Files", sizeof(struct file), NULL, NULL, 5414 NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE); 5415 filedesc0_zone = uma_zcreate("filedesc0", sizeof(struct filedesc0), 5416 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0); 5417 pwd_zone = uma_zcreate("PWD", sizeof(struct pwd), NULL, NULL, 5418 NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_SMR); 5419 /* 5420 * XXXMJG this is a temporary hack due to boot ordering issues against 5421 * the vnode zone. 5422 */ 5423 vfs_smr = uma_zone_get_smr(pwd_zone); 5424 mtx_init(&sigio_lock, "sigio lock", NULL, MTX_DEF); 5425 } 5426 SYSINIT(select, SI_SUB_LOCK, SI_ORDER_FIRST, filelistinit, NULL); 5427 5428 /*-------------------------------------------------------------------*/ 5429 5430 static int 5431 badfo_readwrite(struct file *fp, struct uio *uio, struct ucred *active_cred, 5432 int flags, struct thread *td) 5433 { 5434 5435 return (EBADF); 5436 } 5437 5438 static int 5439 badfo_truncate(struct file *fp, off_t length, struct ucred *active_cred, 5440 struct thread *td) 5441 { 5442 5443 return (EINVAL); 5444 } 5445 5446 static int 5447 badfo_ioctl(struct file *fp, u_long com, void *data, struct ucred *active_cred, 5448 struct thread *td) 5449 { 5450 5451 return (EBADF); 5452 } 5453 5454 static int 5455 badfo_poll(struct file *fp, int events, struct ucred *active_cred, 5456 struct thread *td) 5457 { 5458 5459 return (0); 5460 } 5461 5462 static int 5463 badfo_kqfilter(struct file *fp, struct knote *kn) 5464 { 5465 5466 return (EBADF); 5467 } 5468 5469 static int 5470 badfo_stat(struct file *fp, struct stat *sb, struct ucred *active_cred) 5471 { 5472 5473 return (EBADF); 5474 } 5475 5476 static int 5477 badfo_close(struct file *fp, struct thread *td) 5478 { 5479 5480 return (0); 5481 } 5482 5483 static int 5484 badfo_chmod(struct file *fp, mode_t mode, struct ucred *active_cred, 5485 struct thread *td) 5486 { 5487 5488 return (EBADF); 5489 } 5490 5491 static int 5492 badfo_chown(struct file *fp, uid_t uid, gid_t gid, struct ucred *active_cred, 5493 struct thread *td) 5494 { 5495 5496 return (EBADF); 5497 } 5498 5499 static int 5500 badfo_sendfile(struct file *fp, int sockfd, struct uio *hdr_uio, 5501 struct uio *trl_uio, off_t offset, size_t nbytes, off_t *sent, int flags, 5502 struct thread *td) 5503 { 5504 5505 return (EBADF); 5506 } 5507 5508 static int 5509 badfo_fill_kinfo(struct file *fp, struct kinfo_file *kif, struct filedesc *fdp) 5510 { 5511 5512 return (0); 5513 } 5514 5515 const struct fileops badfileops = { 5516 .fo_read = badfo_readwrite, 5517 .fo_write = badfo_readwrite, 5518 .fo_truncate = badfo_truncate, 5519 .fo_ioctl = badfo_ioctl, 5520 .fo_poll = badfo_poll, 5521 .fo_kqfilter = badfo_kqfilter, 5522 .fo_stat = badfo_stat, 5523 .fo_close = badfo_close, 5524 .fo_chmod = badfo_chmod, 5525 .fo_chown = badfo_chown, 5526 .fo_sendfile = badfo_sendfile, 5527 .fo_fill_kinfo = badfo_fill_kinfo, 5528 }; 5529 5530 static int 5531 path_poll(struct file *fp, int events, struct ucred *active_cred, 5532 struct thread *td) 5533 { 5534 return (POLLNVAL); 5535 } 5536 5537 static int 5538 path_close(struct file *fp, struct thread *td) 5539 { 5540 MPASS(fp->f_type == DTYPE_VNODE); 5541 fp->f_ops = &badfileops; 5542 vrele(fp->f_vnode); 5543 return (0); 5544 } 5545 5546 const struct fileops path_fileops = { 5547 .fo_read = badfo_readwrite, 5548 .fo_write = badfo_readwrite, 5549 .fo_truncate = badfo_truncate, 5550 .fo_ioctl = badfo_ioctl, 5551 .fo_poll = path_poll, 5552 .fo_kqfilter = vn_kqfilter_opath, 5553 .fo_stat = vn_statfile, 5554 .fo_close = path_close, 5555 .fo_chmod = badfo_chmod, 5556 .fo_chown = badfo_chown, 5557 .fo_sendfile = badfo_sendfile, 5558 .fo_fill_kinfo = vn_fill_kinfo, 5559 .fo_cmp = vn_cmp, 5560 .fo_flags = DFLAG_PASSABLE, 5561 }; 5562 5563 int 5564 invfo_rdwr(struct file *fp, struct uio *uio, struct ucred *active_cred, 5565 int flags, struct thread *td) 5566 { 5567 5568 return (EOPNOTSUPP); 5569 } 5570 5571 int 5572 invfo_truncate(struct file *fp, off_t length, struct ucred *active_cred, 5573 struct thread *td) 5574 { 5575 5576 return (EINVAL); 5577 } 5578 5579 int 5580 invfo_ioctl(struct file *fp, u_long com, void *data, 5581 struct ucred *active_cred, struct thread *td) 5582 { 5583 5584 return (ENOTTY); 5585 } 5586 5587 int 5588 invfo_poll(struct file *fp, int events, struct ucred *active_cred, 5589 struct thread *td) 5590 { 5591 5592 return (poll_no_poll(events)); 5593 } 5594 5595 int 5596 invfo_kqfilter(struct file *fp, struct knote *kn) 5597 { 5598 5599 return (EINVAL); 5600 } 5601 5602 int 5603 invfo_chmod(struct file *fp, mode_t mode, struct ucred *active_cred, 5604 struct thread *td) 5605 { 5606 5607 return (EINVAL); 5608 } 5609 5610 int 5611 invfo_chown(struct file *fp, uid_t uid, gid_t gid, struct ucred *active_cred, 5612 struct thread *td) 5613 { 5614 5615 return (EINVAL); 5616 } 5617 5618 int 5619 invfo_sendfile(struct file *fp, int sockfd, struct uio *hdr_uio, 5620 struct uio *trl_uio, off_t offset, size_t nbytes, off_t *sent, int flags, 5621 struct thread *td) 5622 { 5623 5624 return (EINVAL); 5625 } 5626 5627 /*-------------------------------------------------------------------*/ 5628 5629 /* 5630 * File Descriptor pseudo-device driver (/dev/fd/). 5631 * 5632 * Opening minor device N dup()s the file (if any) connected to file 5633 * descriptor N belonging to the calling process. Note that this driver 5634 * consists of only the ``open()'' routine, because all subsequent 5635 * references to this file will be direct to the other driver. 5636 * 5637 * XXX: we could give this one a cloning event handler if necessary. 5638 */ 5639 5640 /* ARGSUSED */ 5641 static int 5642 fdopen(struct cdev *dev, int mode, int type, struct thread *td) 5643 { 5644 5645 /* 5646 * XXX Kludge: set curthread->td_dupfd to contain the value of the 5647 * the file descriptor being sought for duplication. The error 5648 * return ensures that the vnode for this device will be released 5649 * by vn_open. Open will detect this special error and take the 5650 * actions in dupfdopen below. Other callers of vn_open or VOP_OPEN 5651 * will simply report the error. 5652 */ 5653 td->td_dupfd = dev2unit(dev); 5654 return (ENODEV); 5655 } 5656 5657 static struct cdevsw fildesc_cdevsw = { 5658 .d_version = D_VERSION, 5659 .d_open = fdopen, 5660 .d_name = "FD", 5661 }; 5662 5663 static void 5664 fildesc_drvinit(void *unused) 5665 { 5666 struct cdev *dev; 5667 5668 dev = make_dev_credf(MAKEDEV_ETERNAL, &fildesc_cdevsw, 0, NULL, 5669 UID_ROOT, GID_WHEEL, 0666, "fd/0"); 5670 make_dev_alias(dev, "stdin"); 5671 dev = make_dev_credf(MAKEDEV_ETERNAL, &fildesc_cdevsw, 1, NULL, 5672 UID_ROOT, GID_WHEEL, 0666, "fd/1"); 5673 make_dev_alias(dev, "stdout"); 5674 dev = make_dev_credf(MAKEDEV_ETERNAL, &fildesc_cdevsw, 2, NULL, 5675 UID_ROOT, GID_WHEEL, 0666, "fd/2"); 5676 make_dev_alias(dev, "stderr"); 5677 } 5678 5679 SYSINIT(fildescdev, SI_SUB_DRIVERS, SI_ORDER_MIDDLE, fildesc_drvinit, NULL); 5680