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