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