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