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 * @(#)kern_descrip.c 8.6 (Berkeley) 4/19/94 37 */ 38 39 #include <sys/cdefs.h> 40 __FBSDID("$FreeBSD$"); 41 42 #include "opt_capsicum.h" 43 #include "opt_ddb.h" 44 #include "opt_ktrace.h" 45 46 #include <sys/param.h> 47 #include <sys/systm.h> 48 49 #include <sys/capsicum.h> 50 #include <sys/conf.h> 51 #include <sys/fcntl.h> 52 #include <sys/file.h> 53 #include <sys/filedesc.h> 54 #include <sys/filio.h> 55 #include <sys/jail.h> 56 #include <sys/kernel.h> 57 #include <sys/limits.h> 58 #include <sys/lock.h> 59 #include <sys/malloc.h> 60 #include <sys/mount.h> 61 #include <sys/mutex.h> 62 #include <sys/namei.h> 63 #include <sys/selinfo.h> 64 #include <sys/poll.h> 65 #include <sys/priv.h> 66 #include <sys/proc.h> 67 #include <sys/protosw.h> 68 #include <sys/racct.h> 69 #include <sys/resourcevar.h> 70 #include <sys/sbuf.h> 71 #include <sys/signalvar.h> 72 #include <sys/kdb.h> 73 #include <sys/smr.h> 74 #include <sys/stat.h> 75 #include <sys/sx.h> 76 #include <sys/syscallsubr.h> 77 #include <sys/sysctl.h> 78 #include <sys/sysproto.h> 79 #include <sys/unistd.h> 80 #include <sys/user.h> 81 #include <sys/vnode.h> 82 #include <sys/ktrace.h> 83 84 #include <net/vnet.h> 85 86 #include <security/audit/audit.h> 87 88 #include <vm/uma.h> 89 #include <vm/vm.h> 90 91 #include <ddb/ddb.h> 92 93 static MALLOC_DEFINE(M_FILEDESC, "filedesc", "Open file descriptor table"); 94 static MALLOC_DEFINE(M_PWD, "pwd", "Descriptor table vnodes"); 95 static MALLOC_DEFINE(M_PWDDESC, "pwddesc", "Pwd descriptors"); 96 static MALLOC_DEFINE(M_FILEDESC_TO_LEADER, "filedesc_to_leader", 97 "file desc to leader structures"); 98 static MALLOC_DEFINE(M_SIGIO, "sigio", "sigio structures"); 99 MALLOC_DEFINE(M_FILECAPS, "filecaps", "descriptor capabilities"); 100 101 MALLOC_DECLARE(M_FADVISE); 102 103 static __read_mostly uma_zone_t file_zone; 104 static __read_mostly uma_zone_t filedesc0_zone; 105 __read_mostly uma_zone_t pwd_zone; 106 VFS_SMR_DECLARE; 107 108 static int closefp(struct filedesc *fdp, int fd, struct file *fp, 109 struct thread *td, bool holdleaders, bool audit); 110 static void export_file_to_kinfo(struct file *fp, int fd, 111 cap_rights_t *rightsp, struct kinfo_file *kif, 112 struct filedesc *fdp, int flags); 113 static int fd_first_free(struct filedesc *fdp, int low, int size); 114 static void fdgrowtable(struct filedesc *fdp, int nfd); 115 static void fdgrowtable_exp(struct filedesc *fdp, int nfd); 116 static void fdunused(struct filedesc *fdp, int fd); 117 static void fdused(struct filedesc *fdp, int fd); 118 static int getmaxfd(struct thread *td); 119 static u_long *filecaps_copy_prep(const struct filecaps *src); 120 static void filecaps_copy_finish(const struct filecaps *src, 121 struct filecaps *dst, u_long *ioctls); 122 static u_long *filecaps_free_prep(struct filecaps *fcaps); 123 static void filecaps_free_finish(u_long *ioctls); 124 125 static struct pwd *pwd_alloc(void); 126 127 /* 128 * Each process has: 129 * 130 * - An array of open file descriptors (fd_ofiles) 131 * - An array of file flags (fd_ofileflags) 132 * - A bitmap recording which descriptors are in use (fd_map) 133 * 134 * A process starts out with NDFILE descriptors. The value of NDFILE has 135 * been selected based the historical limit of 20 open files, and an 136 * assumption that the majority of processes, especially short-lived 137 * processes like shells, will never need more. 138 * 139 * If this initial allocation is exhausted, a larger descriptor table and 140 * map are allocated dynamically, and the pointers in the process's struct 141 * filedesc are updated to point to those. This is repeated every time 142 * the process runs out of file descriptors (provided it hasn't hit its 143 * resource limit). 144 * 145 * Since threads may hold references to individual descriptor table 146 * entries, the tables are never freed. Instead, they are placed on a 147 * linked list and freed only when the struct filedesc is released. 148 */ 149 #define NDFILE 20 150 #define NDSLOTSIZE sizeof(NDSLOTTYPE) 151 #define NDENTRIES (NDSLOTSIZE * __CHAR_BIT) 152 #define NDSLOT(x) ((x) / NDENTRIES) 153 #define NDBIT(x) ((NDSLOTTYPE)1 << ((x) % NDENTRIES)) 154 #define NDSLOTS(x) (((x) + NDENTRIES - 1) / NDENTRIES) 155 156 /* 157 * SLIST entry used to keep track of ofiles which must be reclaimed when 158 * the process exits. 159 */ 160 struct freetable { 161 struct fdescenttbl *ft_table; 162 SLIST_ENTRY(freetable) ft_next; 163 }; 164 165 /* 166 * Initial allocation: a filedesc structure + the head of SLIST used to 167 * keep track of old ofiles + enough space for NDFILE descriptors. 168 */ 169 170 struct fdescenttbl0 { 171 int fdt_nfiles; 172 struct filedescent fdt_ofiles[NDFILE]; 173 }; 174 175 struct filedesc0 { 176 struct filedesc fd_fd; 177 SLIST_HEAD(, freetable) fd_free; 178 struct fdescenttbl0 fd_dfiles; 179 NDSLOTTYPE fd_dmap[NDSLOTS(NDFILE)]; 180 }; 181 182 /* 183 * Descriptor management. 184 */ 185 static int __exclusive_cache_line openfiles; /* actual number of open files */ 186 struct mtx sigio_lock; /* mtx to protect pointers to sigio */ 187 void __read_mostly (*mq_fdclose)(struct thread *td, int fd, struct file *fp); 188 189 /* 190 * If low >= size, just return low. Otherwise find the first zero bit in the 191 * given bitmap, starting at low and not exceeding size - 1. Return size if 192 * not found. 193 */ 194 static int 195 fd_first_free(struct filedesc *fdp, int low, int size) 196 { 197 NDSLOTTYPE *map = fdp->fd_map; 198 NDSLOTTYPE mask; 199 int off, maxoff; 200 201 if (low >= size) 202 return (low); 203 204 off = NDSLOT(low); 205 if (low % NDENTRIES) { 206 mask = ~(~(NDSLOTTYPE)0 >> (NDENTRIES - (low % NDENTRIES))); 207 if ((mask &= ~map[off]) != 0UL) 208 return (off * NDENTRIES + ffsl(mask) - 1); 209 ++off; 210 } 211 for (maxoff = NDSLOTS(size); off < maxoff; ++off) 212 if (map[off] != ~0UL) 213 return (off * NDENTRIES + ffsl(~map[off]) - 1); 214 return (size); 215 } 216 217 /* 218 * Find the last used fd. 219 * 220 * Call this variant if fdp can't be modified by anyone else (e.g, during exec). 221 * Otherwise use fdlastfile. 222 */ 223 int 224 fdlastfile_single(struct filedesc *fdp) 225 { 226 NDSLOTTYPE *map = fdp->fd_map; 227 int off, minoff; 228 229 off = NDSLOT(fdp->fd_nfiles - 1); 230 for (minoff = NDSLOT(0); off >= minoff; --off) 231 if (map[off] != 0) 232 return (off * NDENTRIES + flsl(map[off]) - 1); 233 return (-1); 234 } 235 236 int 237 fdlastfile(struct filedesc *fdp) 238 { 239 240 FILEDESC_LOCK_ASSERT(fdp); 241 return (fdlastfile_single(fdp)); 242 } 243 244 static int 245 fdisused(struct filedesc *fdp, int fd) 246 { 247 248 KASSERT(fd >= 0 && fd < fdp->fd_nfiles, 249 ("file descriptor %d out of range (0, %d)", fd, fdp->fd_nfiles)); 250 251 return ((fdp->fd_map[NDSLOT(fd)] & NDBIT(fd)) != 0); 252 } 253 254 /* 255 * Mark a file descriptor as used. 256 */ 257 static void 258 fdused_init(struct filedesc *fdp, int fd) 259 { 260 261 KASSERT(!fdisused(fdp, fd), ("fd=%d is already used", fd)); 262 263 fdp->fd_map[NDSLOT(fd)] |= NDBIT(fd); 264 } 265 266 static void 267 fdused(struct filedesc *fdp, int fd) 268 { 269 270 FILEDESC_XLOCK_ASSERT(fdp); 271 272 fdused_init(fdp, fd); 273 if (fd == fdp->fd_freefile) 274 fdp->fd_freefile++; 275 } 276 277 /* 278 * Mark a file descriptor as unused. 279 */ 280 static void 281 fdunused(struct filedesc *fdp, int fd) 282 { 283 284 FILEDESC_XLOCK_ASSERT(fdp); 285 286 KASSERT(fdisused(fdp, fd), ("fd=%d is already unused", fd)); 287 KASSERT(fdp->fd_ofiles[fd].fde_file == NULL, 288 ("fd=%d is still in use", fd)); 289 290 fdp->fd_map[NDSLOT(fd)] &= ~NDBIT(fd); 291 if (fd < fdp->fd_freefile) 292 fdp->fd_freefile = fd; 293 } 294 295 /* 296 * Free a file descriptor. 297 * 298 * Avoid some work if fdp is about to be destroyed. 299 */ 300 static inline void 301 fdefree_last(struct filedescent *fde) 302 { 303 304 filecaps_free(&fde->fde_caps); 305 } 306 307 static inline void 308 fdfree(struct filedesc *fdp, int fd) 309 { 310 struct filedescent *fde; 311 312 FILEDESC_XLOCK_ASSERT(fdp); 313 fde = &fdp->fd_ofiles[fd]; 314 #ifdef CAPABILITIES 315 seqc_write_begin(&fde->fde_seqc); 316 #endif 317 fde->fde_file = NULL; 318 #ifdef CAPABILITIES 319 seqc_write_end(&fde->fde_seqc); 320 #endif 321 fdefree_last(fde); 322 fdunused(fdp, fd); 323 } 324 325 /* 326 * System calls on descriptors. 327 */ 328 #ifndef _SYS_SYSPROTO_H_ 329 struct getdtablesize_args { 330 int dummy; 331 }; 332 #endif 333 /* ARGSUSED */ 334 int 335 sys_getdtablesize(struct thread *td, struct getdtablesize_args *uap) 336 { 337 #ifdef RACCT 338 uint64_t lim; 339 #endif 340 341 td->td_retval[0] = getmaxfd(td); 342 #ifdef RACCT 343 PROC_LOCK(td->td_proc); 344 lim = racct_get_limit(td->td_proc, RACCT_NOFILE); 345 PROC_UNLOCK(td->td_proc); 346 if (lim < td->td_retval[0]) 347 td->td_retval[0] = lim; 348 #endif 349 return (0); 350 } 351 352 /* 353 * Duplicate a file descriptor to a particular value. 354 * 355 * Note: keep in mind that a potential race condition exists when closing 356 * descriptors from a shared descriptor table (via rfork). 357 */ 358 #ifndef _SYS_SYSPROTO_H_ 359 struct dup2_args { 360 u_int from; 361 u_int to; 362 }; 363 #endif 364 /* ARGSUSED */ 365 int 366 sys_dup2(struct thread *td, struct dup2_args *uap) 367 { 368 369 return (kern_dup(td, FDDUP_FIXED, 0, (int)uap->from, (int)uap->to)); 370 } 371 372 /* 373 * Duplicate a file descriptor. 374 */ 375 #ifndef _SYS_SYSPROTO_H_ 376 struct dup_args { 377 u_int fd; 378 }; 379 #endif 380 /* ARGSUSED */ 381 int 382 sys_dup(struct thread *td, struct dup_args *uap) 383 { 384 385 return (kern_dup(td, FDDUP_NORMAL, 0, (int)uap->fd, 0)); 386 } 387 388 /* 389 * The file control system call. 390 */ 391 #ifndef _SYS_SYSPROTO_H_ 392 struct fcntl_args { 393 int fd; 394 int cmd; 395 long arg; 396 }; 397 #endif 398 /* ARGSUSED */ 399 int 400 sys_fcntl(struct thread *td, struct fcntl_args *uap) 401 { 402 403 return (kern_fcntl_freebsd(td, uap->fd, uap->cmd, uap->arg)); 404 } 405 406 int 407 kern_fcntl_freebsd(struct thread *td, int fd, int cmd, long arg) 408 { 409 struct flock fl; 410 struct __oflock ofl; 411 intptr_t arg1; 412 int error, newcmd; 413 414 error = 0; 415 newcmd = cmd; 416 switch (cmd) { 417 case F_OGETLK: 418 case F_OSETLK: 419 case F_OSETLKW: 420 /* 421 * Convert old flock structure to new. 422 */ 423 error = copyin((void *)(intptr_t)arg, &ofl, sizeof(ofl)); 424 fl.l_start = ofl.l_start; 425 fl.l_len = ofl.l_len; 426 fl.l_pid = ofl.l_pid; 427 fl.l_type = ofl.l_type; 428 fl.l_whence = ofl.l_whence; 429 fl.l_sysid = 0; 430 431 switch (cmd) { 432 case F_OGETLK: 433 newcmd = F_GETLK; 434 break; 435 case F_OSETLK: 436 newcmd = F_SETLK; 437 break; 438 case F_OSETLKW: 439 newcmd = F_SETLKW; 440 break; 441 } 442 arg1 = (intptr_t)&fl; 443 break; 444 case F_GETLK: 445 case F_SETLK: 446 case F_SETLKW: 447 case F_SETLK_REMOTE: 448 error = copyin((void *)(intptr_t)arg, &fl, sizeof(fl)); 449 arg1 = (intptr_t)&fl; 450 break; 451 default: 452 arg1 = arg; 453 break; 454 } 455 if (error) 456 return (error); 457 error = kern_fcntl(td, fd, newcmd, arg1); 458 if (error) 459 return (error); 460 if (cmd == F_OGETLK) { 461 ofl.l_start = fl.l_start; 462 ofl.l_len = fl.l_len; 463 ofl.l_pid = fl.l_pid; 464 ofl.l_type = fl.l_type; 465 ofl.l_whence = fl.l_whence; 466 error = copyout(&ofl, (void *)(intptr_t)arg, sizeof(ofl)); 467 } else if (cmd == F_GETLK) { 468 error = copyout(&fl, (void *)(intptr_t)arg, sizeof(fl)); 469 } 470 return (error); 471 } 472 473 int 474 kern_fcntl(struct thread *td, int fd, int cmd, intptr_t arg) 475 { 476 struct filedesc *fdp; 477 struct flock *flp; 478 struct file *fp, *fp2; 479 struct filedescent *fde; 480 struct proc *p; 481 struct vnode *vp; 482 struct mount *mp; 483 struct kinfo_file *kif; 484 int error, flg, kif_sz, seals, tmp; 485 uint64_t bsize; 486 off_t foffset; 487 488 error = 0; 489 flg = F_POSIX; 490 p = td->td_proc; 491 fdp = p->p_fd; 492 493 AUDIT_ARG_FD(cmd); 494 AUDIT_ARG_CMD(cmd); 495 switch (cmd) { 496 case F_DUPFD: 497 tmp = arg; 498 error = kern_dup(td, FDDUP_FCNTL, 0, fd, tmp); 499 break; 500 501 case F_DUPFD_CLOEXEC: 502 tmp = arg; 503 error = kern_dup(td, FDDUP_FCNTL, FDDUP_FLAG_CLOEXEC, fd, tmp); 504 break; 505 506 case F_DUP2FD: 507 tmp = arg; 508 error = kern_dup(td, FDDUP_FIXED, 0, fd, tmp); 509 break; 510 511 case F_DUP2FD_CLOEXEC: 512 tmp = arg; 513 error = kern_dup(td, FDDUP_FIXED, FDDUP_FLAG_CLOEXEC, fd, tmp); 514 break; 515 516 case F_GETFD: 517 error = EBADF; 518 FILEDESC_SLOCK(fdp); 519 fde = fdeget_locked(fdp, fd); 520 if (fde != NULL) { 521 td->td_retval[0] = 522 (fde->fde_flags & UF_EXCLOSE) ? FD_CLOEXEC : 0; 523 error = 0; 524 } 525 FILEDESC_SUNLOCK(fdp); 526 break; 527 528 case F_SETFD: 529 error = EBADF; 530 FILEDESC_XLOCK(fdp); 531 fde = fdeget_locked(fdp, fd); 532 if (fde != NULL) { 533 fde->fde_flags = (fde->fde_flags & ~UF_EXCLOSE) | 534 (arg & FD_CLOEXEC ? UF_EXCLOSE : 0); 535 error = 0; 536 } 537 FILEDESC_XUNLOCK(fdp); 538 break; 539 540 case F_GETFL: 541 error = fget_fcntl(td, fd, &cap_fcntl_rights, F_GETFL, &fp); 542 if (error != 0) 543 break; 544 td->td_retval[0] = OFLAGS(fp->f_flag); 545 fdrop(fp, td); 546 break; 547 548 case F_SETFL: 549 error = fget_fcntl(td, fd, &cap_fcntl_rights, F_SETFL, &fp); 550 if (error != 0) 551 break; 552 if (fp->f_ops == &path_fileops) { 553 fdrop(fp, td); 554 error = EBADF; 555 break; 556 } 557 do { 558 tmp = flg = fp->f_flag; 559 tmp &= ~FCNTLFLAGS; 560 tmp |= FFLAGS(arg & ~O_ACCMODE) & FCNTLFLAGS; 561 } while (atomic_cmpset_int(&fp->f_flag, flg, tmp) == 0); 562 tmp = fp->f_flag & FNONBLOCK; 563 error = fo_ioctl(fp, FIONBIO, &tmp, td->td_ucred, td); 564 if (error != 0) { 565 fdrop(fp, td); 566 break; 567 } 568 tmp = fp->f_flag & FASYNC; 569 error = fo_ioctl(fp, FIOASYNC, &tmp, td->td_ucred, td); 570 if (error == 0) { 571 fdrop(fp, td); 572 break; 573 } 574 atomic_clear_int(&fp->f_flag, FNONBLOCK); 575 tmp = 0; 576 (void)fo_ioctl(fp, FIONBIO, &tmp, td->td_ucred, td); 577 fdrop(fp, td); 578 break; 579 580 case F_GETOWN: 581 error = fget_fcntl(td, fd, &cap_fcntl_rights, F_GETOWN, &fp); 582 if (error != 0) 583 break; 584 error = fo_ioctl(fp, FIOGETOWN, &tmp, td->td_ucred, td); 585 if (error == 0) 586 td->td_retval[0] = tmp; 587 fdrop(fp, td); 588 break; 589 590 case F_SETOWN: 591 error = fget_fcntl(td, fd, &cap_fcntl_rights, F_SETOWN, &fp); 592 if (error != 0) 593 break; 594 tmp = arg; 595 error = fo_ioctl(fp, FIOSETOWN, &tmp, td->td_ucred, td); 596 fdrop(fp, td); 597 break; 598 599 case F_SETLK_REMOTE: 600 error = priv_check(td, PRIV_NFS_LOCKD); 601 if (error != 0) 602 return (error); 603 flg = F_REMOTE; 604 goto do_setlk; 605 606 case F_SETLKW: 607 flg |= F_WAIT; 608 /* FALLTHROUGH F_SETLK */ 609 610 case F_SETLK: 611 do_setlk: 612 flp = (struct flock *)arg; 613 if ((flg & F_REMOTE) != 0 && flp->l_sysid == 0) { 614 error = EINVAL; 615 break; 616 } 617 618 error = fget_unlocked(fdp, fd, &cap_flock_rights, &fp); 619 if (error != 0) 620 break; 621 if (fp->f_type != DTYPE_VNODE || fp->f_ops == &path_fileops) { 622 error = EBADF; 623 fdrop(fp, td); 624 break; 625 } 626 627 if (flp->l_whence == SEEK_CUR) { 628 foffset = foffset_get(fp); 629 if (foffset < 0 || 630 (flp->l_start > 0 && 631 foffset > OFF_MAX - flp->l_start)) { 632 error = EOVERFLOW; 633 fdrop(fp, td); 634 break; 635 } 636 flp->l_start += foffset; 637 } 638 639 vp = fp->f_vnode; 640 switch (flp->l_type) { 641 case F_RDLCK: 642 if ((fp->f_flag & FREAD) == 0) { 643 error = EBADF; 644 break; 645 } 646 if ((p->p_leader->p_flag & P_ADVLOCK) == 0) { 647 PROC_LOCK(p->p_leader); 648 p->p_leader->p_flag |= P_ADVLOCK; 649 PROC_UNLOCK(p->p_leader); 650 } 651 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_SETLK, 652 flp, flg); 653 break; 654 case F_WRLCK: 655 if ((fp->f_flag & FWRITE) == 0) { 656 error = EBADF; 657 break; 658 } 659 if ((p->p_leader->p_flag & P_ADVLOCK) == 0) { 660 PROC_LOCK(p->p_leader); 661 p->p_leader->p_flag |= P_ADVLOCK; 662 PROC_UNLOCK(p->p_leader); 663 } 664 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_SETLK, 665 flp, flg); 666 break; 667 case F_UNLCK: 668 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_UNLCK, 669 flp, flg); 670 break; 671 case F_UNLCKSYS: 672 if (flg != F_REMOTE) { 673 error = EINVAL; 674 break; 675 } 676 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, 677 F_UNLCKSYS, flp, flg); 678 break; 679 default: 680 error = EINVAL; 681 break; 682 } 683 if (error != 0 || flp->l_type == F_UNLCK || 684 flp->l_type == F_UNLCKSYS) { 685 fdrop(fp, td); 686 break; 687 } 688 689 /* 690 * Check for a race with close. 691 * 692 * The vnode is now advisory locked (or unlocked, but this case 693 * is not really important) as the caller requested. 694 * We had to drop the filedesc lock, so we need to recheck if 695 * the descriptor is still valid, because if it was closed 696 * in the meantime we need to remove advisory lock from the 697 * vnode - close on any descriptor leading to an advisory 698 * locked vnode, removes that lock. 699 * We will return 0 on purpose in that case, as the result of 700 * successful advisory lock might have been externally visible 701 * already. This is fine - effectively we pretend to the caller 702 * that the closing thread was a bit slower and that the 703 * advisory lock succeeded before the close. 704 */ 705 error = fget_unlocked(fdp, fd, &cap_no_rights, &fp2); 706 if (error != 0) { 707 fdrop(fp, td); 708 break; 709 } 710 if (fp != fp2) { 711 flp->l_whence = SEEK_SET; 712 flp->l_start = 0; 713 flp->l_len = 0; 714 flp->l_type = F_UNLCK; 715 (void) VOP_ADVLOCK(vp, (caddr_t)p->p_leader, 716 F_UNLCK, flp, F_POSIX); 717 } 718 fdrop(fp, td); 719 fdrop(fp2, td); 720 break; 721 722 case F_GETLK: 723 error = fget_unlocked(fdp, fd, &cap_flock_rights, &fp); 724 if (error != 0) 725 break; 726 if (fp->f_type != DTYPE_VNODE || fp->f_ops == &path_fileops) { 727 error = EBADF; 728 fdrop(fp, td); 729 break; 730 } 731 flp = (struct flock *)arg; 732 if (flp->l_type != F_RDLCK && flp->l_type != F_WRLCK && 733 flp->l_type != F_UNLCK) { 734 error = EINVAL; 735 fdrop(fp, td); 736 break; 737 } 738 if (flp->l_whence == SEEK_CUR) { 739 foffset = foffset_get(fp); 740 if ((flp->l_start > 0 && 741 foffset > OFF_MAX - flp->l_start) || 742 (flp->l_start < 0 && 743 foffset < OFF_MIN - flp->l_start)) { 744 error = EOVERFLOW; 745 fdrop(fp, td); 746 break; 747 } 748 flp->l_start += foffset; 749 } 750 vp = fp->f_vnode; 751 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_GETLK, flp, 752 F_POSIX); 753 fdrop(fp, td); 754 break; 755 756 case F_ADD_SEALS: 757 error = fget_unlocked(fdp, fd, &cap_no_rights, &fp); 758 if (error != 0) 759 break; 760 error = fo_add_seals(fp, arg); 761 fdrop(fp, td); 762 break; 763 764 case F_GET_SEALS: 765 error = fget_unlocked(fdp, fd, &cap_no_rights, &fp); 766 if (error != 0) 767 break; 768 if (fo_get_seals(fp, &seals) == 0) 769 td->td_retval[0] = seals; 770 else 771 error = EINVAL; 772 fdrop(fp, td); 773 break; 774 775 case F_RDAHEAD: 776 arg = arg ? 128 * 1024: 0; 777 /* FALLTHROUGH */ 778 case F_READAHEAD: 779 error = fget_unlocked(fdp, fd, &cap_no_rights, &fp); 780 if (error != 0) 781 break; 782 if (fp->f_type != DTYPE_VNODE || fp->f_ops == &path_fileops) { 783 fdrop(fp, td); 784 error = EBADF; 785 break; 786 } 787 vp = fp->f_vnode; 788 if (vp->v_type != VREG) { 789 fdrop(fp, td); 790 error = ENOTTY; 791 break; 792 } 793 794 /* 795 * Exclusive lock synchronizes against f_seqcount reads and 796 * writes in sequential_heuristic(). 797 */ 798 error = vn_lock(vp, LK_EXCLUSIVE); 799 if (error != 0) { 800 fdrop(fp, td); 801 break; 802 } 803 if (arg >= 0) { 804 bsize = fp->f_vnode->v_mount->mnt_stat.f_iosize; 805 arg = MIN(arg, INT_MAX - bsize + 1); 806 fp->f_seqcount[UIO_READ] = MIN(IO_SEQMAX, 807 (arg + bsize - 1) / bsize); 808 atomic_set_int(&fp->f_flag, FRDAHEAD); 809 } else { 810 atomic_clear_int(&fp->f_flag, FRDAHEAD); 811 } 812 VOP_UNLOCK(vp); 813 fdrop(fp, td); 814 break; 815 816 case F_ISUNIONSTACK: 817 /* 818 * Check if the vnode is part of a union stack (either the 819 * "union" flag from mount(2) or unionfs). 820 * 821 * Prior to introduction of this op libc's readdir would call 822 * fstatfs(2), in effect unnecessarily copying kilobytes of 823 * data just to check fs name and a mount flag. 824 * 825 * Fixing the code to handle everything in the kernel instead 826 * is a non-trivial endeavor and has low priority, thus this 827 * horrible kludge facilitates the current behavior in a much 828 * cheaper manner until someone(tm) sorts this out. 829 */ 830 error = fget_unlocked(fdp, fd, &cap_no_rights, &fp); 831 if (error != 0) 832 break; 833 if (fp->f_type != DTYPE_VNODE) { 834 fdrop(fp, td); 835 error = EBADF; 836 break; 837 } 838 vp = fp->f_vnode; 839 /* 840 * Since we don't prevent dooming the vnode even non-null mp 841 * found can become immediately stale. This is tolerable since 842 * mount points are type-stable (providing safe memory access) 843 * and any vfs op on this vnode going forward will return an 844 * error (meaning return value in this case is meaningless). 845 */ 846 mp = atomic_load_ptr(&vp->v_mount); 847 if (__predict_false(mp == NULL)) { 848 fdrop(fp, td); 849 error = EBADF; 850 break; 851 } 852 td->td_retval[0] = 0; 853 if (mp->mnt_kern_flag & MNTK_UNIONFS || 854 mp->mnt_flag & MNT_UNION) 855 td->td_retval[0] = 1; 856 fdrop(fp, td); 857 break; 858 859 case F_KINFO: 860 #ifdef CAPABILITY_MODE 861 if (IN_CAPABILITY_MODE(td)) { 862 error = ECAPMODE; 863 break; 864 } 865 #endif 866 error = copyin((void *)arg, &kif_sz, sizeof(kif_sz)); 867 if (error != 0) 868 break; 869 if (kif_sz != sizeof(*kif)) { 870 error = EINVAL; 871 break; 872 } 873 kif = malloc(sizeof(*kif), M_TEMP, M_WAITOK | M_ZERO); 874 FILEDESC_SLOCK(fdp); 875 error = fget_cap_locked(fdp, fd, &cap_fcntl_rights, &fp, NULL); 876 if (error == 0 && fhold(fp)) { 877 export_file_to_kinfo(fp, fd, NULL, kif, fdp, 0); 878 FILEDESC_SUNLOCK(fdp); 879 fdrop(fp, td); 880 if ((kif->kf_status & KF_ATTR_VALID) != 0) { 881 kif->kf_structsize = sizeof(*kif); 882 error = copyout(kif, (void *)arg, sizeof(*kif)); 883 } else { 884 error = EBADF; 885 } 886 } else { 887 FILEDESC_SUNLOCK(fdp); 888 if (error == 0) 889 error = EBADF; 890 } 891 free(kif, M_TEMP); 892 break; 893 894 default: 895 error = EINVAL; 896 break; 897 } 898 return (error); 899 } 900 901 static int 902 getmaxfd(struct thread *td) 903 { 904 905 return (min((int)lim_cur(td, RLIMIT_NOFILE), maxfilesperproc)); 906 } 907 908 /* 909 * Common code for dup, dup2, fcntl(F_DUPFD) and fcntl(F_DUP2FD). 910 */ 911 int 912 kern_dup(struct thread *td, u_int mode, int flags, int old, int new) 913 { 914 struct filedesc *fdp; 915 struct filedescent *oldfde, *newfde; 916 struct proc *p; 917 struct file *delfp, *oldfp; 918 u_long *oioctls, *nioctls; 919 int error, maxfd; 920 921 p = td->td_proc; 922 fdp = p->p_fd; 923 oioctls = NULL; 924 925 MPASS((flags & ~(FDDUP_FLAG_CLOEXEC)) == 0); 926 MPASS(mode < FDDUP_LASTMODE); 927 928 AUDIT_ARG_FD(old); 929 /* XXXRW: if (flags & FDDUP_FIXED) AUDIT_ARG_FD2(new); */ 930 931 /* 932 * Verify we have a valid descriptor to dup from and possibly to 933 * dup to. Unlike dup() and dup2(), fcntl()'s F_DUPFD should 934 * return EINVAL when the new descriptor is out of bounds. 935 */ 936 if (old < 0) 937 return (EBADF); 938 if (new < 0) 939 return (mode == FDDUP_FCNTL ? EINVAL : EBADF); 940 maxfd = getmaxfd(td); 941 if (new >= maxfd) 942 return (mode == FDDUP_FCNTL ? EINVAL : EBADF); 943 944 error = EBADF; 945 FILEDESC_XLOCK(fdp); 946 if (fget_locked(fdp, old) == NULL) 947 goto unlock; 948 if (mode == FDDUP_FIXED && old == new) { 949 td->td_retval[0] = new; 950 if (flags & FDDUP_FLAG_CLOEXEC) 951 fdp->fd_ofiles[new].fde_flags |= UF_EXCLOSE; 952 error = 0; 953 goto unlock; 954 } 955 956 oldfde = &fdp->fd_ofiles[old]; 957 oldfp = oldfde->fde_file; 958 if (!fhold(oldfp)) 959 goto unlock; 960 961 /* 962 * If the caller specified a file descriptor, make sure the file 963 * table is large enough to hold it, and grab it. Otherwise, just 964 * allocate a new descriptor the usual way. 965 */ 966 switch (mode) { 967 case FDDUP_NORMAL: 968 case FDDUP_FCNTL: 969 if ((error = fdalloc(td, new, &new)) != 0) { 970 fdrop(oldfp, td); 971 goto unlock; 972 } 973 break; 974 case FDDUP_FIXED: 975 if (new >= fdp->fd_nfiles) { 976 /* 977 * The resource limits are here instead of e.g. 978 * fdalloc(), because the file descriptor table may be 979 * shared between processes, so we can't really use 980 * racct_add()/racct_sub(). Instead of counting the 981 * number of actually allocated descriptors, just put 982 * the limit on the size of the file descriptor table. 983 */ 984 #ifdef RACCT 985 if (RACCT_ENABLED()) { 986 error = racct_set_unlocked(p, RACCT_NOFILE, new + 1); 987 if (error != 0) { 988 error = EMFILE; 989 fdrop(oldfp, td); 990 goto unlock; 991 } 992 } 993 #endif 994 fdgrowtable_exp(fdp, new + 1); 995 } 996 if (!fdisused(fdp, new)) 997 fdused(fdp, new); 998 break; 999 default: 1000 KASSERT(0, ("%s unsupported mode %d", __func__, mode)); 1001 } 1002 1003 KASSERT(old != new, ("new fd is same as old")); 1004 1005 /* Refetch oldfde because the table may have grown and old one freed. */ 1006 oldfde = &fdp->fd_ofiles[old]; 1007 KASSERT(oldfp == oldfde->fde_file, 1008 ("fdt_ofiles shift from growth observed at fd %d", 1009 old)); 1010 1011 newfde = &fdp->fd_ofiles[new]; 1012 delfp = newfde->fde_file; 1013 1014 nioctls = filecaps_copy_prep(&oldfde->fde_caps); 1015 1016 /* 1017 * Duplicate the source descriptor. 1018 */ 1019 #ifdef CAPABILITIES 1020 seqc_write_begin(&newfde->fde_seqc); 1021 #endif 1022 oioctls = filecaps_free_prep(&newfde->fde_caps); 1023 memcpy(newfde, oldfde, fde_change_size); 1024 filecaps_copy_finish(&oldfde->fde_caps, &newfde->fde_caps, 1025 nioctls); 1026 if ((flags & FDDUP_FLAG_CLOEXEC) != 0) 1027 newfde->fde_flags = oldfde->fde_flags | UF_EXCLOSE; 1028 else 1029 newfde->fde_flags = oldfde->fde_flags & ~UF_EXCLOSE; 1030 #ifdef CAPABILITIES 1031 seqc_write_end(&newfde->fde_seqc); 1032 #endif 1033 td->td_retval[0] = new; 1034 1035 error = 0; 1036 1037 if (delfp != NULL) { 1038 (void) closefp(fdp, new, delfp, td, true, false); 1039 FILEDESC_UNLOCK_ASSERT(fdp); 1040 } else { 1041 unlock: 1042 FILEDESC_XUNLOCK(fdp); 1043 } 1044 1045 filecaps_free_finish(oioctls); 1046 return (error); 1047 } 1048 1049 static void 1050 sigiofree(struct sigio *sigio) 1051 { 1052 crfree(sigio->sio_ucred); 1053 free(sigio, M_SIGIO); 1054 } 1055 1056 static struct sigio * 1057 funsetown_locked(struct sigio *sigio) 1058 { 1059 struct proc *p; 1060 struct pgrp *pg; 1061 1062 SIGIO_ASSERT_LOCKED(); 1063 1064 if (sigio == NULL) 1065 return (NULL); 1066 *sigio->sio_myref = NULL; 1067 if (sigio->sio_pgid < 0) { 1068 pg = sigio->sio_pgrp; 1069 PGRP_LOCK(pg); 1070 SLIST_REMOVE(&pg->pg_sigiolst, sigio, sigio, sio_pgsigio); 1071 PGRP_UNLOCK(pg); 1072 } else { 1073 p = sigio->sio_proc; 1074 PROC_LOCK(p); 1075 SLIST_REMOVE(&p->p_sigiolst, sigio, sigio, sio_pgsigio); 1076 PROC_UNLOCK(p); 1077 } 1078 return (sigio); 1079 } 1080 1081 /* 1082 * If sigio is on the list associated with a process or process group, 1083 * disable signalling from the device, remove sigio from the list and 1084 * free sigio. 1085 */ 1086 void 1087 funsetown(struct sigio **sigiop) 1088 { 1089 struct sigio *sigio; 1090 1091 /* Racy check, consumers must provide synchronization. */ 1092 if (*sigiop == NULL) 1093 return; 1094 1095 SIGIO_LOCK(); 1096 sigio = funsetown_locked(*sigiop); 1097 SIGIO_UNLOCK(); 1098 if (sigio != NULL) 1099 sigiofree(sigio); 1100 } 1101 1102 /* 1103 * Free a list of sigio structures. The caller must ensure that new sigio 1104 * structures cannot be added after this point. For process groups this is 1105 * guaranteed using the proctree lock; for processes, the P_WEXIT flag serves 1106 * as an interlock. 1107 */ 1108 void 1109 funsetownlst(struct sigiolst *sigiolst) 1110 { 1111 struct proc *p; 1112 struct pgrp *pg; 1113 struct sigio *sigio, *tmp; 1114 1115 /* Racy check. */ 1116 sigio = SLIST_FIRST(sigiolst); 1117 if (sigio == NULL) 1118 return; 1119 1120 p = NULL; 1121 pg = NULL; 1122 1123 SIGIO_LOCK(); 1124 sigio = SLIST_FIRST(sigiolst); 1125 if (sigio == NULL) { 1126 SIGIO_UNLOCK(); 1127 return; 1128 } 1129 1130 /* 1131 * Every entry of the list should belong to a single proc or pgrp. 1132 */ 1133 if (sigio->sio_pgid < 0) { 1134 pg = sigio->sio_pgrp; 1135 sx_assert(&proctree_lock, SX_XLOCKED); 1136 PGRP_LOCK(pg); 1137 } else /* if (sigio->sio_pgid > 0) */ { 1138 p = sigio->sio_proc; 1139 PROC_LOCK(p); 1140 KASSERT((p->p_flag & P_WEXIT) != 0, 1141 ("%s: process %p is not exiting", __func__, p)); 1142 } 1143 1144 SLIST_FOREACH(sigio, sigiolst, sio_pgsigio) { 1145 *sigio->sio_myref = NULL; 1146 if (pg != NULL) { 1147 KASSERT(sigio->sio_pgid < 0, 1148 ("Proc sigio in pgrp sigio list")); 1149 KASSERT(sigio->sio_pgrp == pg, 1150 ("Bogus pgrp in sigio list")); 1151 } else /* if (p != NULL) */ { 1152 KASSERT(sigio->sio_pgid > 0, 1153 ("Pgrp sigio in proc sigio list")); 1154 KASSERT(sigio->sio_proc == p, 1155 ("Bogus proc in sigio list")); 1156 } 1157 } 1158 1159 if (pg != NULL) 1160 PGRP_UNLOCK(pg); 1161 else 1162 PROC_UNLOCK(p); 1163 SIGIO_UNLOCK(); 1164 1165 SLIST_FOREACH_SAFE(sigio, sigiolst, sio_pgsigio, tmp) 1166 sigiofree(sigio); 1167 } 1168 1169 /* 1170 * This is common code for FIOSETOWN ioctl called by fcntl(fd, F_SETOWN, arg). 1171 * 1172 * After permission checking, add a sigio structure to the sigio list for 1173 * the process or process group. 1174 */ 1175 int 1176 fsetown(pid_t pgid, struct sigio **sigiop) 1177 { 1178 struct proc *proc; 1179 struct pgrp *pgrp; 1180 struct sigio *osigio, *sigio; 1181 int ret; 1182 1183 if (pgid == 0) { 1184 funsetown(sigiop); 1185 return (0); 1186 } 1187 1188 sigio = malloc(sizeof(struct sigio), M_SIGIO, M_WAITOK); 1189 sigio->sio_pgid = pgid; 1190 sigio->sio_ucred = crhold(curthread->td_ucred); 1191 sigio->sio_myref = sigiop; 1192 1193 ret = 0; 1194 if (pgid > 0) { 1195 ret = pget(pgid, PGET_NOTWEXIT | PGET_NOTID | PGET_HOLD, &proc); 1196 SIGIO_LOCK(); 1197 osigio = funsetown_locked(*sigiop); 1198 if (ret == 0) { 1199 PROC_LOCK(proc); 1200 _PRELE(proc); 1201 if ((proc->p_flag & P_WEXIT) != 0) { 1202 ret = ESRCH; 1203 } else if (proc->p_session != 1204 curthread->td_proc->p_session) { 1205 /* 1206 * Policy - Don't allow a process to FSETOWN a 1207 * process in another session. 1208 * 1209 * Remove this test to allow maximum flexibility 1210 * or restrict FSETOWN to the current process or 1211 * process group for maximum safety. 1212 */ 1213 ret = EPERM; 1214 } else { 1215 sigio->sio_proc = proc; 1216 SLIST_INSERT_HEAD(&proc->p_sigiolst, sigio, 1217 sio_pgsigio); 1218 } 1219 PROC_UNLOCK(proc); 1220 } 1221 } else /* if (pgid < 0) */ { 1222 sx_slock(&proctree_lock); 1223 SIGIO_LOCK(); 1224 osigio = funsetown_locked(*sigiop); 1225 pgrp = pgfind(-pgid); 1226 if (pgrp == NULL) { 1227 ret = ESRCH; 1228 } else { 1229 if (pgrp->pg_session != curthread->td_proc->p_session) { 1230 /* 1231 * Policy - Don't allow a process to FSETOWN a 1232 * process in another session. 1233 * 1234 * Remove this test to allow maximum flexibility 1235 * or restrict FSETOWN to the current process or 1236 * process group for maximum safety. 1237 */ 1238 ret = EPERM; 1239 } else { 1240 sigio->sio_pgrp = pgrp; 1241 SLIST_INSERT_HEAD(&pgrp->pg_sigiolst, sigio, 1242 sio_pgsigio); 1243 } 1244 PGRP_UNLOCK(pgrp); 1245 } 1246 sx_sunlock(&proctree_lock); 1247 } 1248 if (ret == 0) 1249 *sigiop = sigio; 1250 SIGIO_UNLOCK(); 1251 if (osigio != NULL) 1252 sigiofree(osigio); 1253 return (ret); 1254 } 1255 1256 /* 1257 * This is common code for FIOGETOWN ioctl called by fcntl(fd, F_GETOWN, arg). 1258 */ 1259 pid_t 1260 fgetown(struct sigio **sigiop) 1261 { 1262 pid_t pgid; 1263 1264 SIGIO_LOCK(); 1265 pgid = (*sigiop != NULL) ? (*sigiop)->sio_pgid : 0; 1266 SIGIO_UNLOCK(); 1267 return (pgid); 1268 } 1269 1270 static int 1271 closefp_impl(struct filedesc *fdp, int fd, struct file *fp, struct thread *td, 1272 bool audit) 1273 { 1274 int error; 1275 1276 FILEDESC_XLOCK_ASSERT(fdp); 1277 1278 /* 1279 * We now hold the fp reference that used to be owned by the 1280 * descriptor array. We have to unlock the FILEDESC *AFTER* 1281 * knote_fdclose to prevent a race of the fd getting opened, a knote 1282 * added, and deleteing a knote for the new fd. 1283 */ 1284 if (__predict_false(!TAILQ_EMPTY(&fdp->fd_kqlist))) 1285 knote_fdclose(td, fd); 1286 1287 /* 1288 * We need to notify mqueue if the object is of type mqueue. 1289 */ 1290 if (__predict_false(fp->f_type == DTYPE_MQUEUE)) 1291 mq_fdclose(td, fd, fp); 1292 FILEDESC_XUNLOCK(fdp); 1293 1294 #ifdef AUDIT 1295 if (AUDITING_TD(td) && audit) 1296 audit_sysclose(td, fd, fp); 1297 #endif 1298 error = closef(fp, td); 1299 1300 /* 1301 * All paths leading up to closefp() will have already removed or 1302 * replaced the fd in the filedesc table, so a restart would not 1303 * operate on the same file. 1304 */ 1305 if (error == ERESTART) 1306 error = EINTR; 1307 1308 return (error); 1309 } 1310 1311 static int 1312 closefp_hl(struct filedesc *fdp, int fd, struct file *fp, struct thread *td, 1313 bool holdleaders, bool audit) 1314 { 1315 int error; 1316 1317 FILEDESC_XLOCK_ASSERT(fdp); 1318 1319 if (holdleaders) { 1320 if (td->td_proc->p_fdtol != NULL) { 1321 /* 1322 * Ask fdfree() to sleep to ensure that all relevant 1323 * process leaders can be traversed in closef(). 1324 */ 1325 fdp->fd_holdleaderscount++; 1326 } else { 1327 holdleaders = false; 1328 } 1329 } 1330 1331 error = closefp_impl(fdp, fd, fp, td, audit); 1332 if (holdleaders) { 1333 FILEDESC_XLOCK(fdp); 1334 fdp->fd_holdleaderscount--; 1335 if (fdp->fd_holdleaderscount == 0 && 1336 fdp->fd_holdleaderswakeup != 0) { 1337 fdp->fd_holdleaderswakeup = 0; 1338 wakeup(&fdp->fd_holdleaderscount); 1339 } 1340 FILEDESC_XUNLOCK(fdp); 1341 } 1342 return (error); 1343 } 1344 1345 static int 1346 closefp(struct filedesc *fdp, int fd, struct file *fp, struct thread *td, 1347 bool holdleaders, bool audit) 1348 { 1349 1350 FILEDESC_XLOCK_ASSERT(fdp); 1351 1352 if (__predict_false(td->td_proc->p_fdtol != NULL)) { 1353 return (closefp_hl(fdp, fd, fp, td, holdleaders, audit)); 1354 } else { 1355 return (closefp_impl(fdp, fd, fp, td, audit)); 1356 } 1357 } 1358 1359 /* 1360 * Close a file descriptor. 1361 */ 1362 #ifndef _SYS_SYSPROTO_H_ 1363 struct close_args { 1364 int fd; 1365 }; 1366 #endif 1367 /* ARGSUSED */ 1368 int 1369 sys_close(struct thread *td, struct close_args *uap) 1370 { 1371 1372 return (kern_close(td, uap->fd)); 1373 } 1374 1375 int 1376 kern_close(struct thread *td, int fd) 1377 { 1378 struct filedesc *fdp; 1379 struct file *fp; 1380 1381 fdp = td->td_proc->p_fd; 1382 1383 FILEDESC_XLOCK(fdp); 1384 if ((fp = fget_locked(fdp, fd)) == NULL) { 1385 FILEDESC_XUNLOCK(fdp); 1386 return (EBADF); 1387 } 1388 fdfree(fdp, fd); 1389 1390 /* closefp() drops the FILEDESC lock for us. */ 1391 return (closefp(fdp, fd, fp, td, true, true)); 1392 } 1393 1394 int 1395 kern_close_range(struct thread *td, u_int lowfd, u_int highfd) 1396 { 1397 struct filedesc *fdp; 1398 const struct fdescenttbl *fdt; 1399 struct file *fp; 1400 int fd; 1401 1402 /* 1403 * Check this prior to clamping; closefrom(3) with only fd 0, 1, and 2 1404 * open should not be a usage error. From a close_range() perspective, 1405 * close_range(3, ~0U, 0) in the same scenario should also likely not 1406 * be a usage error as all fd above 3 are in-fact already closed. 1407 */ 1408 if (highfd < lowfd) { 1409 return (EINVAL); 1410 } 1411 1412 fdp = td->td_proc->p_fd; 1413 FILEDESC_XLOCK(fdp); 1414 fdt = atomic_load_ptr(&fdp->fd_files); 1415 highfd = MIN(highfd, fdt->fdt_nfiles - 1); 1416 fd = lowfd; 1417 if (__predict_false(fd > highfd)) { 1418 goto out_locked; 1419 } 1420 for (;;) { 1421 fp = fdt->fdt_ofiles[fd].fde_file; 1422 if (fp == NULL) { 1423 if (fd == highfd) 1424 goto out_locked; 1425 } else { 1426 fdfree(fdp, fd); 1427 (void) closefp(fdp, fd, fp, td, true, true); 1428 if (fd == highfd) 1429 goto out_unlocked; 1430 FILEDESC_XLOCK(fdp); 1431 fdt = atomic_load_ptr(&fdp->fd_files); 1432 } 1433 fd++; 1434 } 1435 out_locked: 1436 FILEDESC_XUNLOCK(fdp); 1437 out_unlocked: 1438 return (0); 1439 } 1440 1441 #ifndef _SYS_SYSPROTO_H_ 1442 struct close_range_args { 1443 u_int lowfd; 1444 u_int highfd; 1445 int flags; 1446 }; 1447 #endif 1448 int 1449 sys_close_range(struct thread *td, struct close_range_args *uap) 1450 { 1451 1452 AUDIT_ARG_FD(uap->lowfd); 1453 AUDIT_ARG_CMD(uap->highfd); 1454 AUDIT_ARG_FFLAGS(uap->flags); 1455 1456 /* No flags currently defined */ 1457 if (uap->flags != 0) 1458 return (EINVAL); 1459 return (kern_close_range(td, uap->lowfd, uap->highfd)); 1460 } 1461 1462 #ifdef COMPAT_FREEBSD12 1463 /* 1464 * Close open file descriptors. 1465 */ 1466 #ifndef _SYS_SYSPROTO_H_ 1467 struct freebsd12_closefrom_args { 1468 int lowfd; 1469 }; 1470 #endif 1471 /* ARGSUSED */ 1472 int 1473 freebsd12_closefrom(struct thread *td, struct freebsd12_closefrom_args *uap) 1474 { 1475 u_int lowfd; 1476 1477 AUDIT_ARG_FD(uap->lowfd); 1478 1479 /* 1480 * Treat negative starting file descriptor values identical to 1481 * closefrom(0) which closes all files. 1482 */ 1483 lowfd = MAX(0, uap->lowfd); 1484 return (kern_close_range(td, lowfd, ~0U)); 1485 } 1486 #endif /* COMPAT_FREEBSD12 */ 1487 1488 #if defined(COMPAT_43) 1489 /* 1490 * Return status information about a file descriptor. 1491 */ 1492 #ifndef _SYS_SYSPROTO_H_ 1493 struct ofstat_args { 1494 int fd; 1495 struct ostat *sb; 1496 }; 1497 #endif 1498 /* ARGSUSED */ 1499 int 1500 ofstat(struct thread *td, struct ofstat_args *uap) 1501 { 1502 struct ostat oub; 1503 struct stat ub; 1504 int error; 1505 1506 error = kern_fstat(td, uap->fd, &ub); 1507 if (error == 0) { 1508 cvtstat(&ub, &oub); 1509 error = copyout(&oub, uap->sb, sizeof(oub)); 1510 } 1511 return (error); 1512 } 1513 #endif /* COMPAT_43 */ 1514 1515 #if defined(COMPAT_FREEBSD11) 1516 int 1517 freebsd11_fstat(struct thread *td, struct freebsd11_fstat_args *uap) 1518 { 1519 struct stat sb; 1520 struct freebsd11_stat osb; 1521 int error; 1522 1523 error = kern_fstat(td, uap->fd, &sb); 1524 if (error != 0) 1525 return (error); 1526 error = freebsd11_cvtstat(&sb, &osb); 1527 if (error == 0) 1528 error = copyout(&osb, uap->sb, sizeof(osb)); 1529 return (error); 1530 } 1531 #endif /* COMPAT_FREEBSD11 */ 1532 1533 /* 1534 * Return status information about a file descriptor. 1535 */ 1536 #ifndef _SYS_SYSPROTO_H_ 1537 struct fstat_args { 1538 int fd; 1539 struct stat *sb; 1540 }; 1541 #endif 1542 /* ARGSUSED */ 1543 int 1544 sys_fstat(struct thread *td, struct fstat_args *uap) 1545 { 1546 struct stat ub; 1547 int error; 1548 1549 error = kern_fstat(td, uap->fd, &ub); 1550 if (error == 0) 1551 error = copyout(&ub, uap->sb, sizeof(ub)); 1552 return (error); 1553 } 1554 1555 int 1556 kern_fstat(struct thread *td, int fd, struct stat *sbp) 1557 { 1558 struct file *fp; 1559 int error; 1560 1561 AUDIT_ARG_FD(fd); 1562 1563 error = fget(td, fd, &cap_fstat_rights, &fp); 1564 if (__predict_false(error != 0)) 1565 return (error); 1566 1567 AUDIT_ARG_FILE(td->td_proc, fp); 1568 1569 error = fo_stat(fp, sbp, td->td_ucred); 1570 fdrop(fp, td); 1571 #ifdef __STAT_TIME_T_EXT 1572 sbp->st_atim_ext = 0; 1573 sbp->st_mtim_ext = 0; 1574 sbp->st_ctim_ext = 0; 1575 sbp->st_btim_ext = 0; 1576 #endif 1577 #ifdef KTRACE 1578 if (KTRPOINT(td, KTR_STRUCT)) 1579 ktrstat_error(sbp, error); 1580 #endif 1581 return (error); 1582 } 1583 1584 #if defined(COMPAT_FREEBSD11) 1585 /* 1586 * Return status information about a file descriptor. 1587 */ 1588 #ifndef _SYS_SYSPROTO_H_ 1589 struct freebsd11_nfstat_args { 1590 int fd; 1591 struct nstat *sb; 1592 }; 1593 #endif 1594 /* ARGSUSED */ 1595 int 1596 freebsd11_nfstat(struct thread *td, struct freebsd11_nfstat_args *uap) 1597 { 1598 struct nstat nub; 1599 struct stat ub; 1600 int error; 1601 1602 error = kern_fstat(td, uap->fd, &ub); 1603 if (error != 0) 1604 return (error); 1605 error = freebsd11_cvtnstat(&ub, &nub); 1606 if (error != 0) 1607 error = copyout(&nub, uap->sb, sizeof(nub)); 1608 return (error); 1609 } 1610 #endif /* COMPAT_FREEBSD11 */ 1611 1612 /* 1613 * Return pathconf information about a file descriptor. 1614 */ 1615 #ifndef _SYS_SYSPROTO_H_ 1616 struct fpathconf_args { 1617 int fd; 1618 int name; 1619 }; 1620 #endif 1621 /* ARGSUSED */ 1622 int 1623 sys_fpathconf(struct thread *td, struct fpathconf_args *uap) 1624 { 1625 long value; 1626 int error; 1627 1628 error = kern_fpathconf(td, uap->fd, uap->name, &value); 1629 if (error == 0) 1630 td->td_retval[0] = value; 1631 return (error); 1632 } 1633 1634 int 1635 kern_fpathconf(struct thread *td, int fd, int name, long *valuep) 1636 { 1637 struct file *fp; 1638 struct vnode *vp; 1639 int error; 1640 1641 error = fget(td, fd, &cap_fpathconf_rights, &fp); 1642 if (error != 0) 1643 return (error); 1644 1645 if (name == _PC_ASYNC_IO) { 1646 *valuep = _POSIX_ASYNCHRONOUS_IO; 1647 goto out; 1648 } 1649 vp = fp->f_vnode; 1650 if (vp != NULL) { 1651 vn_lock(vp, LK_SHARED | LK_RETRY); 1652 error = VOP_PATHCONF(vp, name, valuep); 1653 VOP_UNLOCK(vp); 1654 } else if (fp->f_type == DTYPE_PIPE || fp->f_type == DTYPE_SOCKET) { 1655 if (name != _PC_PIPE_BUF) { 1656 error = EINVAL; 1657 } else { 1658 *valuep = PIPE_BUF; 1659 error = 0; 1660 } 1661 } else { 1662 error = EOPNOTSUPP; 1663 } 1664 out: 1665 fdrop(fp, td); 1666 return (error); 1667 } 1668 1669 /* 1670 * Copy filecaps structure allocating memory for ioctls array if needed. 1671 * 1672 * The last parameter indicates whether the fdtable is locked. If it is not and 1673 * ioctls are encountered, copying fails and the caller must lock the table. 1674 * 1675 * Note that if the table was not locked, the caller has to check the relevant 1676 * sequence counter to determine whether the operation was successful. 1677 */ 1678 bool 1679 filecaps_copy(const struct filecaps *src, struct filecaps *dst, bool locked) 1680 { 1681 size_t size; 1682 1683 if (src->fc_ioctls != NULL && !locked) 1684 return (false); 1685 memcpy(dst, src, sizeof(*src)); 1686 if (src->fc_ioctls == NULL) 1687 return (true); 1688 1689 KASSERT(src->fc_nioctls > 0, 1690 ("fc_ioctls != NULL, but fc_nioctls=%hd", src->fc_nioctls)); 1691 1692 size = sizeof(src->fc_ioctls[0]) * src->fc_nioctls; 1693 dst->fc_ioctls = malloc(size, M_FILECAPS, M_WAITOK); 1694 memcpy(dst->fc_ioctls, src->fc_ioctls, size); 1695 return (true); 1696 } 1697 1698 static u_long * 1699 filecaps_copy_prep(const struct filecaps *src) 1700 { 1701 u_long *ioctls; 1702 size_t size; 1703 1704 if (__predict_true(src->fc_ioctls == NULL)) 1705 return (NULL); 1706 1707 KASSERT(src->fc_nioctls > 0, 1708 ("fc_ioctls != NULL, but fc_nioctls=%hd", src->fc_nioctls)); 1709 1710 size = sizeof(src->fc_ioctls[0]) * src->fc_nioctls; 1711 ioctls = malloc(size, M_FILECAPS, M_WAITOK); 1712 return (ioctls); 1713 } 1714 1715 static void 1716 filecaps_copy_finish(const struct filecaps *src, struct filecaps *dst, 1717 u_long *ioctls) 1718 { 1719 size_t size; 1720 1721 *dst = *src; 1722 if (__predict_true(src->fc_ioctls == NULL)) { 1723 MPASS(ioctls == NULL); 1724 return; 1725 } 1726 1727 size = sizeof(src->fc_ioctls[0]) * src->fc_nioctls; 1728 dst->fc_ioctls = ioctls; 1729 bcopy(src->fc_ioctls, dst->fc_ioctls, size); 1730 } 1731 1732 /* 1733 * Move filecaps structure to the new place and clear the old place. 1734 */ 1735 void 1736 filecaps_move(struct filecaps *src, struct filecaps *dst) 1737 { 1738 1739 *dst = *src; 1740 bzero(src, sizeof(*src)); 1741 } 1742 1743 /* 1744 * Fill the given filecaps structure with full rights. 1745 */ 1746 static void 1747 filecaps_fill(struct filecaps *fcaps) 1748 { 1749 1750 CAP_ALL(&fcaps->fc_rights); 1751 fcaps->fc_ioctls = NULL; 1752 fcaps->fc_nioctls = -1; 1753 fcaps->fc_fcntls = CAP_FCNTL_ALL; 1754 } 1755 1756 /* 1757 * Free memory allocated within filecaps structure. 1758 */ 1759 void 1760 filecaps_free(struct filecaps *fcaps) 1761 { 1762 1763 free(fcaps->fc_ioctls, M_FILECAPS); 1764 bzero(fcaps, sizeof(*fcaps)); 1765 } 1766 1767 static u_long * 1768 filecaps_free_prep(struct filecaps *fcaps) 1769 { 1770 u_long *ioctls; 1771 1772 ioctls = fcaps->fc_ioctls; 1773 bzero(fcaps, sizeof(*fcaps)); 1774 return (ioctls); 1775 } 1776 1777 static void 1778 filecaps_free_finish(u_long *ioctls) 1779 { 1780 1781 free(ioctls, M_FILECAPS); 1782 } 1783 1784 /* 1785 * Validate the given filecaps structure. 1786 */ 1787 static void 1788 filecaps_validate(const struct filecaps *fcaps, const char *func) 1789 { 1790 1791 KASSERT(cap_rights_is_valid(&fcaps->fc_rights), 1792 ("%s: invalid rights", func)); 1793 KASSERT((fcaps->fc_fcntls & ~CAP_FCNTL_ALL) == 0, 1794 ("%s: invalid fcntls", func)); 1795 KASSERT(fcaps->fc_fcntls == 0 || 1796 cap_rights_is_set(&fcaps->fc_rights, CAP_FCNTL), 1797 ("%s: fcntls without CAP_FCNTL", func)); 1798 KASSERT(fcaps->fc_ioctls != NULL ? fcaps->fc_nioctls > 0 : 1799 (fcaps->fc_nioctls == -1 || fcaps->fc_nioctls == 0), 1800 ("%s: invalid ioctls", func)); 1801 KASSERT(fcaps->fc_nioctls == 0 || 1802 cap_rights_is_set(&fcaps->fc_rights, CAP_IOCTL), 1803 ("%s: ioctls without CAP_IOCTL", func)); 1804 } 1805 1806 static void 1807 fdgrowtable_exp(struct filedesc *fdp, int nfd) 1808 { 1809 int nfd1; 1810 1811 FILEDESC_XLOCK_ASSERT(fdp); 1812 1813 nfd1 = fdp->fd_nfiles * 2; 1814 if (nfd1 < nfd) 1815 nfd1 = nfd; 1816 fdgrowtable(fdp, nfd1); 1817 } 1818 1819 /* 1820 * Grow the file table to accommodate (at least) nfd descriptors. 1821 */ 1822 static void 1823 fdgrowtable(struct filedesc *fdp, int nfd) 1824 { 1825 struct filedesc0 *fdp0; 1826 struct freetable *ft; 1827 struct fdescenttbl *ntable; 1828 struct fdescenttbl *otable; 1829 int nnfiles, onfiles; 1830 NDSLOTTYPE *nmap, *omap; 1831 1832 KASSERT(fdp->fd_nfiles > 0, ("zero-length file table")); 1833 1834 /* save old values */ 1835 onfiles = fdp->fd_nfiles; 1836 otable = fdp->fd_files; 1837 omap = fdp->fd_map; 1838 1839 /* compute the size of the new table */ 1840 nnfiles = NDSLOTS(nfd) * NDENTRIES; /* round up */ 1841 if (nnfiles <= onfiles) 1842 /* the table is already large enough */ 1843 return; 1844 1845 /* 1846 * Allocate a new table. We need enough space for the number of 1847 * entries, file entries themselves and the struct freetable we will use 1848 * when we decommission the table and place it on the freelist. 1849 * We place the struct freetable in the middle so we don't have 1850 * to worry about padding. 1851 */ 1852 ntable = malloc(offsetof(struct fdescenttbl, fdt_ofiles) + 1853 nnfiles * sizeof(ntable->fdt_ofiles[0]) + 1854 sizeof(struct freetable), 1855 M_FILEDESC, M_ZERO | M_WAITOK); 1856 /* copy the old data */ 1857 ntable->fdt_nfiles = nnfiles; 1858 memcpy(ntable->fdt_ofiles, otable->fdt_ofiles, 1859 onfiles * sizeof(ntable->fdt_ofiles[0])); 1860 1861 /* 1862 * Allocate a new map only if the old is not large enough. It will 1863 * grow at a slower rate than the table as it can map more 1864 * entries than the table can hold. 1865 */ 1866 if (NDSLOTS(nnfiles) > NDSLOTS(onfiles)) { 1867 nmap = malloc(NDSLOTS(nnfiles) * NDSLOTSIZE, M_FILEDESC, 1868 M_ZERO | M_WAITOK); 1869 /* copy over the old data and update the pointer */ 1870 memcpy(nmap, omap, NDSLOTS(onfiles) * sizeof(*omap)); 1871 fdp->fd_map = nmap; 1872 } 1873 1874 /* 1875 * Make sure that ntable is correctly initialized before we replace 1876 * fd_files poiner. Otherwise fget_unlocked() may see inconsistent 1877 * data. 1878 */ 1879 atomic_store_rel_ptr((volatile void *)&fdp->fd_files, (uintptr_t)ntable); 1880 1881 /* 1882 * Free the old file table when not shared by other threads or processes. 1883 * The old file table is considered to be shared when either are true: 1884 * - The process has more than one thread. 1885 * - The file descriptor table has been shared via fdshare(). 1886 * 1887 * When shared, the old file table will be placed on a freelist 1888 * which will be processed when the struct filedesc is released. 1889 * 1890 * Note that if onfiles == NDFILE, we're dealing with the original 1891 * static allocation contained within (struct filedesc0 *)fdp, 1892 * which must not be freed. 1893 */ 1894 if (onfiles > NDFILE) { 1895 /* 1896 * Note we may be called here from fdinit while allocating a 1897 * table for a new process in which case ->p_fd points 1898 * elsewhere. 1899 */ 1900 if (curproc->p_fd != fdp || FILEDESC_IS_ONLY_USER(fdp)) { 1901 free(otable, M_FILEDESC); 1902 } else { 1903 ft = (struct freetable *)&otable->fdt_ofiles[onfiles]; 1904 fdp0 = (struct filedesc0 *)fdp; 1905 ft->ft_table = otable; 1906 SLIST_INSERT_HEAD(&fdp0->fd_free, ft, ft_next); 1907 } 1908 } 1909 /* 1910 * The map does not have the same possibility of threads still 1911 * holding references to it. So always free it as long as it 1912 * does not reference the original static allocation. 1913 */ 1914 if (NDSLOTS(onfiles) > NDSLOTS(NDFILE)) 1915 free(omap, M_FILEDESC); 1916 } 1917 1918 /* 1919 * Allocate a file descriptor for the process. 1920 */ 1921 int 1922 fdalloc(struct thread *td, int minfd, int *result) 1923 { 1924 struct proc *p = td->td_proc; 1925 struct filedesc *fdp = p->p_fd; 1926 int fd, maxfd, allocfd; 1927 #ifdef RACCT 1928 int error; 1929 #endif 1930 1931 FILEDESC_XLOCK_ASSERT(fdp); 1932 1933 if (fdp->fd_freefile > minfd) 1934 minfd = fdp->fd_freefile; 1935 1936 maxfd = getmaxfd(td); 1937 1938 /* 1939 * Search the bitmap for a free descriptor starting at minfd. 1940 * If none is found, grow the file table. 1941 */ 1942 fd = fd_first_free(fdp, minfd, fdp->fd_nfiles); 1943 if (__predict_false(fd >= maxfd)) 1944 return (EMFILE); 1945 if (__predict_false(fd >= fdp->fd_nfiles)) { 1946 allocfd = min(fd * 2, maxfd); 1947 #ifdef RACCT 1948 if (RACCT_ENABLED()) { 1949 error = racct_set_unlocked(p, RACCT_NOFILE, allocfd); 1950 if (error != 0) 1951 return (EMFILE); 1952 } 1953 #endif 1954 /* 1955 * fd is already equal to first free descriptor >= minfd, so 1956 * we only need to grow the table and we are done. 1957 */ 1958 fdgrowtable_exp(fdp, allocfd); 1959 } 1960 1961 /* 1962 * Perform some sanity checks, then mark the file descriptor as 1963 * used and return it to the caller. 1964 */ 1965 KASSERT(fd >= 0 && fd < min(maxfd, fdp->fd_nfiles), 1966 ("invalid descriptor %d", fd)); 1967 KASSERT(!fdisused(fdp, fd), 1968 ("fd_first_free() returned non-free descriptor")); 1969 KASSERT(fdp->fd_ofiles[fd].fde_file == NULL, 1970 ("file descriptor isn't free")); 1971 fdused(fdp, fd); 1972 *result = fd; 1973 return (0); 1974 } 1975 1976 /* 1977 * Allocate n file descriptors for the process. 1978 */ 1979 int 1980 fdallocn(struct thread *td, int minfd, int *fds, int n) 1981 { 1982 struct proc *p = td->td_proc; 1983 struct filedesc *fdp = p->p_fd; 1984 int i; 1985 1986 FILEDESC_XLOCK_ASSERT(fdp); 1987 1988 for (i = 0; i < n; i++) 1989 if (fdalloc(td, 0, &fds[i]) != 0) 1990 break; 1991 1992 if (i < n) { 1993 for (i--; i >= 0; i--) 1994 fdunused(fdp, fds[i]); 1995 return (EMFILE); 1996 } 1997 1998 return (0); 1999 } 2000 2001 /* 2002 * Create a new open file structure and allocate a file descriptor for the 2003 * process that refers to it. We add one reference to the file for the 2004 * descriptor table and one reference for resultfp. This is to prevent us 2005 * being preempted and the entry in the descriptor table closed after we 2006 * release the FILEDESC lock. 2007 */ 2008 int 2009 falloc_caps(struct thread *td, struct file **resultfp, int *resultfd, int flags, 2010 struct filecaps *fcaps) 2011 { 2012 struct file *fp; 2013 int error, fd; 2014 2015 MPASS(resultfp != NULL); 2016 MPASS(resultfd != NULL); 2017 2018 error = _falloc_noinstall(td, &fp, 2); 2019 if (__predict_false(error != 0)) { 2020 return (error); 2021 } 2022 2023 error = finstall_refed(td, fp, &fd, flags, fcaps); 2024 if (__predict_false(error != 0)) { 2025 falloc_abort(td, fp); 2026 return (error); 2027 } 2028 2029 *resultfp = fp; 2030 *resultfd = fd; 2031 2032 return (0); 2033 } 2034 2035 /* 2036 * Create a new open file structure without allocating a file descriptor. 2037 */ 2038 int 2039 _falloc_noinstall(struct thread *td, struct file **resultfp, u_int n) 2040 { 2041 struct file *fp; 2042 int maxuserfiles = maxfiles - (maxfiles / 20); 2043 int openfiles_new; 2044 static struct timeval lastfail; 2045 static int curfail; 2046 2047 KASSERT(resultfp != NULL, ("%s: resultfp == NULL", __func__)); 2048 MPASS(n > 0); 2049 2050 openfiles_new = atomic_fetchadd_int(&openfiles, 1) + 1; 2051 if ((openfiles_new >= maxuserfiles && 2052 priv_check(td, PRIV_MAXFILES) != 0) || 2053 openfiles_new >= maxfiles) { 2054 atomic_subtract_int(&openfiles, 1); 2055 if (ppsratecheck(&lastfail, &curfail, 1)) { 2056 printf("kern.maxfiles limit exceeded by uid %i, (%s) " 2057 "please see tuning(7).\n", td->td_ucred->cr_ruid, td->td_proc->p_comm); 2058 } 2059 return (ENFILE); 2060 } 2061 fp = uma_zalloc(file_zone, M_WAITOK); 2062 bzero(fp, sizeof(*fp)); 2063 refcount_init(&fp->f_count, n); 2064 fp->f_cred = crhold(td->td_ucred); 2065 fp->f_ops = &badfileops; 2066 *resultfp = fp; 2067 return (0); 2068 } 2069 2070 void 2071 falloc_abort(struct thread *td, struct file *fp) 2072 { 2073 2074 /* 2075 * For assertion purposes. 2076 */ 2077 refcount_init(&fp->f_count, 0); 2078 _fdrop(fp, td); 2079 } 2080 2081 /* 2082 * Install a file in a file descriptor table. 2083 */ 2084 void 2085 _finstall(struct filedesc *fdp, struct file *fp, int fd, int flags, 2086 struct filecaps *fcaps) 2087 { 2088 struct filedescent *fde; 2089 2090 MPASS(fp != NULL); 2091 if (fcaps != NULL) 2092 filecaps_validate(fcaps, __func__); 2093 FILEDESC_XLOCK_ASSERT(fdp); 2094 2095 fde = &fdp->fd_ofiles[fd]; 2096 #ifdef CAPABILITIES 2097 seqc_write_begin(&fde->fde_seqc); 2098 #endif 2099 fde->fde_file = fp; 2100 fde->fde_flags = (flags & O_CLOEXEC) != 0 ? UF_EXCLOSE : 0; 2101 if (fcaps != NULL) 2102 filecaps_move(fcaps, &fde->fde_caps); 2103 else 2104 filecaps_fill(&fde->fde_caps); 2105 #ifdef CAPABILITIES 2106 seqc_write_end(&fde->fde_seqc); 2107 #endif 2108 } 2109 2110 int 2111 finstall_refed(struct thread *td, struct file *fp, int *fd, int flags, 2112 struct filecaps *fcaps) 2113 { 2114 struct filedesc *fdp = td->td_proc->p_fd; 2115 int error; 2116 2117 MPASS(fd != NULL); 2118 2119 FILEDESC_XLOCK(fdp); 2120 error = fdalloc(td, 0, fd); 2121 if (__predict_true(error == 0)) { 2122 _finstall(fdp, fp, *fd, flags, fcaps); 2123 } 2124 FILEDESC_XUNLOCK(fdp); 2125 return (error); 2126 } 2127 2128 int 2129 finstall(struct thread *td, struct file *fp, int *fd, int flags, 2130 struct filecaps *fcaps) 2131 { 2132 int error; 2133 2134 MPASS(fd != NULL); 2135 2136 if (!fhold(fp)) 2137 return (EBADF); 2138 error = finstall_refed(td, fp, fd, flags, fcaps); 2139 if (__predict_false(error != 0)) { 2140 fdrop(fp, td); 2141 } 2142 return (error); 2143 } 2144 2145 /* 2146 * Build a new filedesc structure from another. 2147 * 2148 * If fdp is not NULL, return with it shared locked. 2149 */ 2150 struct filedesc * 2151 fdinit(struct filedesc *fdp, bool prepfiles, int *lastfile) 2152 { 2153 struct filedesc0 *newfdp0; 2154 struct filedesc *newfdp; 2155 2156 if (prepfiles) 2157 MPASS(lastfile != NULL); 2158 else 2159 MPASS(lastfile == NULL); 2160 2161 newfdp0 = uma_zalloc(filedesc0_zone, M_WAITOK | M_ZERO); 2162 newfdp = &newfdp0->fd_fd; 2163 2164 /* Create the file descriptor table. */ 2165 FILEDESC_LOCK_INIT(newfdp); 2166 refcount_init(&newfdp->fd_refcnt, 1); 2167 refcount_init(&newfdp->fd_holdcnt, 1); 2168 newfdp->fd_map = newfdp0->fd_dmap; 2169 newfdp->fd_files = (struct fdescenttbl *)&newfdp0->fd_dfiles; 2170 newfdp->fd_files->fdt_nfiles = NDFILE; 2171 2172 if (fdp == NULL) 2173 return (newfdp); 2174 2175 FILEDESC_SLOCK(fdp); 2176 if (!prepfiles) { 2177 FILEDESC_SUNLOCK(fdp); 2178 return (newfdp); 2179 } 2180 2181 for (;;) { 2182 *lastfile = fdlastfile(fdp); 2183 if (*lastfile < newfdp->fd_nfiles) 2184 break; 2185 FILEDESC_SUNLOCK(fdp); 2186 fdgrowtable(newfdp, *lastfile + 1); 2187 FILEDESC_SLOCK(fdp); 2188 } 2189 2190 return (newfdp); 2191 } 2192 2193 /* 2194 * Build a pwddesc structure from another. 2195 * Copy the current, root, and jail root vnode references. 2196 * 2197 * If pdp is not NULL, return with it shared locked. 2198 */ 2199 struct pwddesc * 2200 pdinit(struct pwddesc *pdp, bool keeplock) 2201 { 2202 struct pwddesc *newpdp; 2203 struct pwd *newpwd; 2204 2205 newpdp = malloc(sizeof(*newpdp), M_PWDDESC, M_WAITOK | M_ZERO); 2206 2207 PWDDESC_LOCK_INIT(newpdp); 2208 refcount_init(&newpdp->pd_refcount, 1); 2209 newpdp->pd_cmask = CMASK; 2210 2211 if (pdp == NULL) { 2212 newpwd = pwd_alloc(); 2213 smr_serialized_store(&newpdp->pd_pwd, newpwd, true); 2214 return (newpdp); 2215 } 2216 2217 PWDDESC_XLOCK(pdp); 2218 newpwd = pwd_hold_pwddesc(pdp); 2219 smr_serialized_store(&newpdp->pd_pwd, newpwd, true); 2220 if (!keeplock) 2221 PWDDESC_XUNLOCK(pdp); 2222 return (newpdp); 2223 } 2224 2225 /* 2226 * Hold either filedesc or pwddesc of the passed process. 2227 * 2228 * The process lock is used to synchronize against the target exiting and 2229 * freeing the data. 2230 * 2231 * Clearing can be ilustrated in 3 steps: 2232 * 1. set the pointer to NULL. Either routine can race against it, hence 2233 * atomic_load_ptr. 2234 * 2. observe the process lock as not taken. Until then fdhold/pdhold can 2235 * race to either still see the pointer or find NULL. It is still safe to 2236 * grab a reference as clearing is stalled. 2237 * 3. after the lock is observed as not taken, any fdhold/pdhold calls are 2238 * guaranteed to see NULL, making it safe to finish clearing 2239 */ 2240 static struct filedesc * 2241 fdhold(struct proc *p) 2242 { 2243 struct filedesc *fdp; 2244 2245 PROC_LOCK_ASSERT(p, MA_OWNED); 2246 fdp = atomic_load_ptr(&p->p_fd); 2247 if (fdp != NULL) 2248 refcount_acquire(&fdp->fd_holdcnt); 2249 return (fdp); 2250 } 2251 2252 static struct pwddesc * 2253 pdhold(struct proc *p) 2254 { 2255 struct pwddesc *pdp; 2256 2257 PROC_LOCK_ASSERT(p, MA_OWNED); 2258 pdp = atomic_load_ptr(&p->p_pd); 2259 if (pdp != NULL) 2260 refcount_acquire(&pdp->pd_refcount); 2261 return (pdp); 2262 } 2263 2264 static void 2265 fddrop(struct filedesc *fdp) 2266 { 2267 2268 if (refcount_load(&fdp->fd_holdcnt) > 1) { 2269 if (refcount_release(&fdp->fd_holdcnt) == 0) 2270 return; 2271 } 2272 2273 FILEDESC_LOCK_DESTROY(fdp); 2274 uma_zfree(filedesc0_zone, fdp); 2275 } 2276 2277 static void 2278 pddrop(struct pwddesc *pdp) 2279 { 2280 struct pwd *pwd; 2281 2282 if (refcount_release_if_not_last(&pdp->pd_refcount)) 2283 return; 2284 2285 PWDDESC_XLOCK(pdp); 2286 if (refcount_release(&pdp->pd_refcount) == 0) { 2287 PWDDESC_XUNLOCK(pdp); 2288 return; 2289 } 2290 pwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); 2291 pwd_set(pdp, NULL); 2292 PWDDESC_XUNLOCK(pdp); 2293 pwd_drop(pwd); 2294 2295 PWDDESC_LOCK_DESTROY(pdp); 2296 free(pdp, M_PWDDESC); 2297 } 2298 2299 /* 2300 * Share a filedesc structure. 2301 */ 2302 struct filedesc * 2303 fdshare(struct filedesc *fdp) 2304 { 2305 2306 refcount_acquire(&fdp->fd_refcnt); 2307 return (fdp); 2308 } 2309 2310 /* 2311 * Share a pwddesc structure. 2312 */ 2313 struct pwddesc * 2314 pdshare(struct pwddesc *pdp) 2315 { 2316 refcount_acquire(&pdp->pd_refcount); 2317 return (pdp); 2318 } 2319 2320 /* 2321 * Unshare a filedesc structure, if necessary by making a copy 2322 */ 2323 void 2324 fdunshare(struct thread *td) 2325 { 2326 struct filedesc *tmp; 2327 struct proc *p = td->td_proc; 2328 2329 if (refcount_load(&p->p_fd->fd_refcnt) == 1) 2330 return; 2331 2332 tmp = fdcopy(p->p_fd); 2333 fdescfree(td); 2334 p->p_fd = tmp; 2335 } 2336 2337 /* 2338 * Unshare a pwddesc structure. 2339 */ 2340 void 2341 pdunshare(struct thread *td) 2342 { 2343 struct pwddesc *pdp; 2344 struct proc *p; 2345 2346 p = td->td_proc; 2347 /* Not shared. */ 2348 if (p->p_pd->pd_refcount == 1) 2349 return; 2350 2351 pdp = pdcopy(p->p_pd); 2352 pdescfree(td); 2353 p->p_pd = pdp; 2354 } 2355 2356 /* 2357 * Copy a filedesc structure. A NULL pointer in returns a NULL reference, 2358 * this is to ease callers, not catch errors. 2359 */ 2360 struct filedesc * 2361 fdcopy(struct filedesc *fdp) 2362 { 2363 struct filedesc *newfdp; 2364 struct filedescent *nfde, *ofde; 2365 int i, lastfile; 2366 2367 MPASS(fdp != NULL); 2368 2369 newfdp = fdinit(fdp, true, &lastfile); 2370 /* copy all passable descriptors (i.e. not kqueue) */ 2371 newfdp->fd_freefile = -1; 2372 for (i = 0; i <= lastfile; ++i) { 2373 ofde = &fdp->fd_ofiles[i]; 2374 if (ofde->fde_file == NULL || 2375 (ofde->fde_file->f_ops->fo_flags & DFLAG_PASSABLE) == 0 || 2376 !fhold(ofde->fde_file)) { 2377 if (newfdp->fd_freefile == -1) 2378 newfdp->fd_freefile = i; 2379 continue; 2380 } 2381 nfde = &newfdp->fd_ofiles[i]; 2382 *nfde = *ofde; 2383 filecaps_copy(&ofde->fde_caps, &nfde->fde_caps, true); 2384 fdused_init(newfdp, i); 2385 } 2386 if (newfdp->fd_freefile == -1) 2387 newfdp->fd_freefile = i; 2388 FILEDESC_SUNLOCK(fdp); 2389 return (newfdp); 2390 } 2391 2392 /* 2393 * Copy a pwddesc structure. 2394 */ 2395 struct pwddesc * 2396 pdcopy(struct pwddesc *pdp) 2397 { 2398 struct pwddesc *newpdp; 2399 2400 MPASS(pdp != NULL); 2401 2402 newpdp = pdinit(pdp, true); 2403 newpdp->pd_cmask = pdp->pd_cmask; 2404 PWDDESC_XUNLOCK(pdp); 2405 return (newpdp); 2406 } 2407 2408 /* 2409 * Clear POSIX style locks. This is only used when fdp looses a reference (i.e. 2410 * one of processes using it exits) and the table used to be shared. 2411 */ 2412 static void 2413 fdclearlocks(struct thread *td) 2414 { 2415 struct filedesc *fdp; 2416 struct filedesc_to_leader *fdtol; 2417 struct flock lf; 2418 struct file *fp; 2419 struct proc *p; 2420 struct vnode *vp; 2421 int i, lastfile; 2422 2423 p = td->td_proc; 2424 fdp = p->p_fd; 2425 fdtol = p->p_fdtol; 2426 MPASS(fdtol != NULL); 2427 2428 FILEDESC_XLOCK(fdp); 2429 KASSERT(fdtol->fdl_refcount > 0, 2430 ("filedesc_to_refcount botch: fdl_refcount=%d", 2431 fdtol->fdl_refcount)); 2432 if (fdtol->fdl_refcount == 1 && 2433 (p->p_leader->p_flag & P_ADVLOCK) != 0) { 2434 lastfile = fdlastfile(fdp); 2435 for (i = 0; i <= lastfile; i++) { 2436 fp = fdp->fd_ofiles[i].fde_file; 2437 if (fp == NULL || fp->f_type != DTYPE_VNODE || 2438 !fhold(fp)) 2439 continue; 2440 FILEDESC_XUNLOCK(fdp); 2441 lf.l_whence = SEEK_SET; 2442 lf.l_start = 0; 2443 lf.l_len = 0; 2444 lf.l_type = F_UNLCK; 2445 vp = fp->f_vnode; 2446 (void) VOP_ADVLOCK(vp, 2447 (caddr_t)p->p_leader, F_UNLCK, 2448 &lf, F_POSIX); 2449 FILEDESC_XLOCK(fdp); 2450 fdrop(fp, td); 2451 } 2452 } 2453 retry: 2454 if (fdtol->fdl_refcount == 1) { 2455 if (fdp->fd_holdleaderscount > 0 && 2456 (p->p_leader->p_flag & P_ADVLOCK) != 0) { 2457 /* 2458 * close() or kern_dup() has cleared a reference 2459 * in a shared file descriptor table. 2460 */ 2461 fdp->fd_holdleaderswakeup = 1; 2462 sx_sleep(&fdp->fd_holdleaderscount, 2463 FILEDESC_LOCK(fdp), PLOCK, "fdlhold", 0); 2464 goto retry; 2465 } 2466 if (fdtol->fdl_holdcount > 0) { 2467 /* 2468 * Ensure that fdtol->fdl_leader remains 2469 * valid in closef(). 2470 */ 2471 fdtol->fdl_wakeup = 1; 2472 sx_sleep(fdtol, FILEDESC_LOCK(fdp), PLOCK, 2473 "fdlhold", 0); 2474 goto retry; 2475 } 2476 } 2477 fdtol->fdl_refcount--; 2478 if (fdtol->fdl_refcount == 0 && 2479 fdtol->fdl_holdcount == 0) { 2480 fdtol->fdl_next->fdl_prev = fdtol->fdl_prev; 2481 fdtol->fdl_prev->fdl_next = fdtol->fdl_next; 2482 } else 2483 fdtol = NULL; 2484 p->p_fdtol = NULL; 2485 FILEDESC_XUNLOCK(fdp); 2486 if (fdtol != NULL) 2487 free(fdtol, M_FILEDESC_TO_LEADER); 2488 } 2489 2490 /* 2491 * Release a filedesc structure. 2492 */ 2493 static void 2494 fdescfree_fds(struct thread *td, struct filedesc *fdp) 2495 { 2496 struct filedesc0 *fdp0; 2497 struct freetable *ft, *tft; 2498 struct filedescent *fde; 2499 struct file *fp; 2500 int i, lastfile; 2501 2502 KASSERT(refcount_load(&fdp->fd_refcnt) == 0, 2503 ("%s: fd table %p carries references", __func__, fdp)); 2504 2505 /* 2506 * Serialize with threads iterating over the table, if any. 2507 */ 2508 if (refcount_load(&fdp->fd_holdcnt) > 1) { 2509 FILEDESC_XLOCK(fdp); 2510 FILEDESC_XUNLOCK(fdp); 2511 } 2512 2513 lastfile = fdlastfile_single(fdp); 2514 for (i = 0; i <= lastfile; i++) { 2515 fde = &fdp->fd_ofiles[i]; 2516 fp = fde->fde_file; 2517 if (fp != NULL) { 2518 fdefree_last(fde); 2519 (void) closef(fp, td); 2520 } 2521 } 2522 2523 if (NDSLOTS(fdp->fd_nfiles) > NDSLOTS(NDFILE)) 2524 free(fdp->fd_map, M_FILEDESC); 2525 if (fdp->fd_nfiles > NDFILE) 2526 free(fdp->fd_files, M_FILEDESC); 2527 2528 fdp0 = (struct filedesc0 *)fdp; 2529 SLIST_FOREACH_SAFE(ft, &fdp0->fd_free, ft_next, tft) 2530 free(ft->ft_table, M_FILEDESC); 2531 2532 fddrop(fdp); 2533 } 2534 2535 void 2536 fdescfree(struct thread *td) 2537 { 2538 struct proc *p; 2539 struct filedesc *fdp; 2540 2541 p = td->td_proc; 2542 fdp = p->p_fd; 2543 MPASS(fdp != NULL); 2544 2545 #ifdef RACCT 2546 if (RACCT_ENABLED()) 2547 racct_set_unlocked(p, RACCT_NOFILE, 0); 2548 #endif 2549 2550 if (p->p_fdtol != NULL) 2551 fdclearlocks(td); 2552 2553 /* 2554 * Check fdhold for an explanation. 2555 */ 2556 atomic_store_ptr(&p->p_fd, NULL); 2557 atomic_thread_fence_seq_cst(); 2558 PROC_WAIT_UNLOCKED(p); 2559 2560 if (refcount_release(&fdp->fd_refcnt) == 0) 2561 return; 2562 2563 fdescfree_fds(td, fdp); 2564 } 2565 2566 void 2567 pdescfree(struct thread *td) 2568 { 2569 struct proc *p; 2570 struct pwddesc *pdp; 2571 2572 p = td->td_proc; 2573 pdp = p->p_pd; 2574 MPASS(pdp != NULL); 2575 2576 /* 2577 * Check pdhold for an explanation. 2578 */ 2579 atomic_store_ptr(&p->p_pd, NULL); 2580 atomic_thread_fence_seq_cst(); 2581 PROC_WAIT_UNLOCKED(p); 2582 2583 pddrop(pdp); 2584 } 2585 2586 /* 2587 * For setugid programs, we don't want to people to use that setugidness 2588 * to generate error messages which write to a file which otherwise would 2589 * otherwise be off-limits to the process. We check for filesystems where 2590 * the vnode can change out from under us after execve (like [lin]procfs). 2591 * 2592 * Since fdsetugidsafety calls this only for fd 0, 1 and 2, this check is 2593 * sufficient. We also don't check for setugidness since we know we are. 2594 */ 2595 static bool 2596 is_unsafe(struct file *fp) 2597 { 2598 struct vnode *vp; 2599 2600 if (fp->f_type != DTYPE_VNODE) 2601 return (false); 2602 2603 vp = fp->f_vnode; 2604 return ((vp->v_vflag & VV_PROCDEP) != 0); 2605 } 2606 2607 /* 2608 * Make this setguid thing safe, if at all possible. 2609 */ 2610 void 2611 fdsetugidsafety(struct thread *td) 2612 { 2613 struct filedesc *fdp; 2614 struct file *fp; 2615 int i; 2616 2617 fdp = td->td_proc->p_fd; 2618 KASSERT(refcount_load(&fdp->fd_refcnt) == 1, 2619 ("the fdtable should not be shared")); 2620 MPASS(fdp->fd_nfiles >= 3); 2621 for (i = 0; i <= 2; i++) { 2622 fp = fdp->fd_ofiles[i].fde_file; 2623 if (fp != NULL && is_unsafe(fp)) { 2624 FILEDESC_XLOCK(fdp); 2625 knote_fdclose(td, i); 2626 /* 2627 * NULL-out descriptor prior to close to avoid 2628 * a race while close blocks. 2629 */ 2630 fdfree(fdp, i); 2631 FILEDESC_XUNLOCK(fdp); 2632 (void) closef(fp, td); 2633 } 2634 } 2635 } 2636 2637 /* 2638 * If a specific file object occupies a specific file descriptor, close the 2639 * file descriptor entry and drop a reference on the file object. This is a 2640 * convenience function to handle a subsequent error in a function that calls 2641 * falloc() that handles the race that another thread might have closed the 2642 * file descriptor out from under the thread creating the file object. 2643 */ 2644 void 2645 fdclose(struct thread *td, struct file *fp, int idx) 2646 { 2647 struct filedesc *fdp = td->td_proc->p_fd; 2648 2649 FILEDESC_XLOCK(fdp); 2650 if (fdp->fd_ofiles[idx].fde_file == fp) { 2651 fdfree(fdp, idx); 2652 FILEDESC_XUNLOCK(fdp); 2653 fdrop(fp, td); 2654 } else 2655 FILEDESC_XUNLOCK(fdp); 2656 } 2657 2658 /* 2659 * Close any files on exec? 2660 */ 2661 void 2662 fdcloseexec(struct thread *td) 2663 { 2664 struct filedesc *fdp; 2665 struct filedescent *fde; 2666 struct file *fp; 2667 int i, lastfile; 2668 2669 fdp = td->td_proc->p_fd; 2670 KASSERT(refcount_load(&fdp->fd_refcnt) == 1, 2671 ("the fdtable should not be shared")); 2672 lastfile = fdlastfile_single(fdp); 2673 for (i = 0; i <= lastfile; i++) { 2674 fde = &fdp->fd_ofiles[i]; 2675 fp = fde->fde_file; 2676 if (fp != NULL && (fp->f_type == DTYPE_MQUEUE || 2677 (fde->fde_flags & UF_EXCLOSE))) { 2678 FILEDESC_XLOCK(fdp); 2679 fdfree(fdp, i); 2680 (void) closefp(fdp, i, fp, td, false, false); 2681 FILEDESC_UNLOCK_ASSERT(fdp); 2682 } 2683 } 2684 } 2685 2686 /* 2687 * It is unsafe for set[ug]id processes to be started with file 2688 * descriptors 0..2 closed, as these descriptors are given implicit 2689 * significance in the Standard C library. fdcheckstd() will create a 2690 * descriptor referencing /dev/null for each of stdin, stdout, and 2691 * stderr that is not already open. 2692 */ 2693 int 2694 fdcheckstd(struct thread *td) 2695 { 2696 struct filedesc *fdp; 2697 register_t save; 2698 int i, error, devnull; 2699 2700 fdp = td->td_proc->p_fd; 2701 KASSERT(refcount_load(&fdp->fd_refcnt) == 1, 2702 ("the fdtable should not be shared")); 2703 MPASS(fdp->fd_nfiles >= 3); 2704 devnull = -1; 2705 for (i = 0; i <= 2; i++) { 2706 if (fdp->fd_ofiles[i].fde_file != NULL) 2707 continue; 2708 2709 save = td->td_retval[0]; 2710 if (devnull != -1) { 2711 error = kern_dup(td, FDDUP_FIXED, 0, devnull, i); 2712 } else { 2713 error = kern_openat(td, AT_FDCWD, "/dev/null", 2714 UIO_SYSSPACE, O_RDWR, 0); 2715 if (error == 0) { 2716 devnull = td->td_retval[0]; 2717 KASSERT(devnull == i, ("we didn't get our fd")); 2718 } 2719 } 2720 td->td_retval[0] = save; 2721 if (error != 0) 2722 return (error); 2723 } 2724 return (0); 2725 } 2726 2727 /* 2728 * Internal form of close. Decrement reference count on file structure. 2729 * Note: td may be NULL when closing a file that was being passed in a 2730 * message. 2731 */ 2732 int 2733 closef(struct file *fp, struct thread *td) 2734 { 2735 struct vnode *vp; 2736 struct flock lf; 2737 struct filedesc_to_leader *fdtol; 2738 struct filedesc *fdp; 2739 2740 MPASS(td != NULL); 2741 2742 /* 2743 * POSIX record locking dictates that any close releases ALL 2744 * locks owned by this process. This is handled by setting 2745 * a flag in the unlock to free ONLY locks obeying POSIX 2746 * semantics, and not to free BSD-style file locks. 2747 * If the descriptor was in a message, POSIX-style locks 2748 * aren't passed with the descriptor, and the thread pointer 2749 * will be NULL. Callers should be careful only to pass a 2750 * NULL thread pointer when there really is no owning 2751 * context that might have locks, or the locks will be 2752 * leaked. 2753 */ 2754 if (fp->f_type == DTYPE_VNODE) { 2755 vp = fp->f_vnode; 2756 if ((td->td_proc->p_leader->p_flag & P_ADVLOCK) != 0) { 2757 lf.l_whence = SEEK_SET; 2758 lf.l_start = 0; 2759 lf.l_len = 0; 2760 lf.l_type = F_UNLCK; 2761 (void) VOP_ADVLOCK(vp, (caddr_t)td->td_proc->p_leader, 2762 F_UNLCK, &lf, F_POSIX); 2763 } 2764 fdtol = td->td_proc->p_fdtol; 2765 if (fdtol != NULL) { 2766 /* 2767 * Handle special case where file descriptor table is 2768 * shared between multiple process leaders. 2769 */ 2770 fdp = td->td_proc->p_fd; 2771 FILEDESC_XLOCK(fdp); 2772 for (fdtol = fdtol->fdl_next; 2773 fdtol != td->td_proc->p_fdtol; 2774 fdtol = fdtol->fdl_next) { 2775 if ((fdtol->fdl_leader->p_flag & 2776 P_ADVLOCK) == 0) 2777 continue; 2778 fdtol->fdl_holdcount++; 2779 FILEDESC_XUNLOCK(fdp); 2780 lf.l_whence = SEEK_SET; 2781 lf.l_start = 0; 2782 lf.l_len = 0; 2783 lf.l_type = F_UNLCK; 2784 vp = fp->f_vnode; 2785 (void) VOP_ADVLOCK(vp, 2786 (caddr_t)fdtol->fdl_leader, F_UNLCK, &lf, 2787 F_POSIX); 2788 FILEDESC_XLOCK(fdp); 2789 fdtol->fdl_holdcount--; 2790 if (fdtol->fdl_holdcount == 0 && 2791 fdtol->fdl_wakeup != 0) { 2792 fdtol->fdl_wakeup = 0; 2793 wakeup(fdtol); 2794 } 2795 } 2796 FILEDESC_XUNLOCK(fdp); 2797 } 2798 } 2799 return (fdrop_close(fp, td)); 2800 } 2801 2802 /* 2803 * Hack for file descriptor passing code. 2804 */ 2805 void 2806 closef_nothread(struct file *fp) 2807 { 2808 2809 fdrop(fp, NULL); 2810 } 2811 2812 /* 2813 * Initialize the file pointer with the specified properties. 2814 * 2815 * The ops are set with release semantics to be certain that the flags, type, 2816 * and data are visible when ops is. This is to prevent ops methods from being 2817 * called with bad data. 2818 */ 2819 void 2820 finit(struct file *fp, u_int flag, short type, void *data, struct fileops *ops) 2821 { 2822 fp->f_data = data; 2823 fp->f_flag = flag; 2824 fp->f_type = type; 2825 atomic_store_rel_ptr((volatile uintptr_t *)&fp->f_ops, (uintptr_t)ops); 2826 } 2827 2828 void 2829 finit_vnode(struct file *fp, u_int flag, void *data, struct fileops *ops) 2830 { 2831 fp->f_seqcount[UIO_READ] = 1; 2832 fp->f_seqcount[UIO_WRITE] = 1; 2833 finit(fp, (flag & FMASK) | (fp->f_flag & FHASLOCK), DTYPE_VNODE, 2834 data, ops); 2835 } 2836 2837 int 2838 fget_cap_locked(struct filedesc *fdp, int fd, cap_rights_t *needrightsp, 2839 struct file **fpp, struct filecaps *havecapsp) 2840 { 2841 struct filedescent *fde; 2842 int error; 2843 2844 FILEDESC_LOCK_ASSERT(fdp); 2845 2846 fde = fdeget_locked(fdp, fd); 2847 if (fde == NULL) { 2848 error = EBADF; 2849 goto out; 2850 } 2851 2852 #ifdef CAPABILITIES 2853 error = cap_check(cap_rights_fde_inline(fde), needrightsp); 2854 if (error != 0) 2855 goto out; 2856 #endif 2857 2858 if (havecapsp != NULL) 2859 filecaps_copy(&fde->fde_caps, havecapsp, true); 2860 2861 *fpp = fde->fde_file; 2862 2863 error = 0; 2864 out: 2865 return (error); 2866 } 2867 2868 int 2869 fget_cap(struct thread *td, int fd, cap_rights_t *needrightsp, 2870 struct file **fpp, struct filecaps *havecapsp) 2871 { 2872 struct filedesc *fdp = td->td_proc->p_fd; 2873 int error; 2874 #ifndef CAPABILITIES 2875 error = fget_unlocked(fdp, fd, needrightsp, fpp); 2876 if (havecapsp != NULL && error == 0) 2877 filecaps_fill(havecapsp); 2878 #else 2879 struct file *fp; 2880 seqc_t seq; 2881 2882 *fpp = NULL; 2883 for (;;) { 2884 error = fget_unlocked_seq(fdp, fd, needrightsp, &fp, &seq); 2885 if (error != 0) 2886 return (error); 2887 2888 if (havecapsp != NULL) { 2889 if (!filecaps_copy(&fdp->fd_ofiles[fd].fde_caps, 2890 havecapsp, false)) { 2891 fdrop(fp, td); 2892 goto get_locked; 2893 } 2894 } 2895 2896 if (!fd_modified(fdp, fd, seq)) 2897 break; 2898 fdrop(fp, td); 2899 } 2900 2901 *fpp = fp; 2902 return (0); 2903 2904 get_locked: 2905 FILEDESC_SLOCK(fdp); 2906 error = fget_cap_locked(fdp, fd, needrightsp, fpp, havecapsp); 2907 if (error == 0 && !fhold(*fpp)) 2908 error = EBADF; 2909 FILEDESC_SUNLOCK(fdp); 2910 #endif 2911 return (error); 2912 } 2913 2914 #ifdef CAPABILITIES 2915 int 2916 fgetvp_lookup_smr(int fd, struct nameidata *ndp, struct vnode **vpp, bool *fsearch) 2917 { 2918 const struct filedescent *fde; 2919 const struct fdescenttbl *fdt; 2920 struct filedesc *fdp; 2921 struct file *fp; 2922 struct vnode *vp; 2923 const cap_rights_t *haverights; 2924 cap_rights_t rights; 2925 seqc_t seq; 2926 2927 VFS_SMR_ASSERT_ENTERED(); 2928 2929 rights = *ndp->ni_rightsneeded; 2930 cap_rights_set_one(&rights, CAP_LOOKUP); 2931 2932 fdp = curproc->p_fd; 2933 fdt = fdp->fd_files; 2934 if (__predict_false((u_int)fd >= fdt->fdt_nfiles)) 2935 return (EBADF); 2936 seq = seqc_read_notmodify(fd_seqc(fdt, fd)); 2937 fde = &fdt->fdt_ofiles[fd]; 2938 haverights = cap_rights_fde_inline(fde); 2939 fp = fde->fde_file; 2940 if (__predict_false(fp == NULL)) 2941 return (EAGAIN); 2942 if (__predict_false(cap_check_inline_transient(haverights, &rights))) 2943 return (EAGAIN); 2944 *fsearch = ((fp->f_flag & FSEARCH) != 0); 2945 vp = fp->f_vnode; 2946 if (__predict_false(vp == NULL)) { 2947 return (EAGAIN); 2948 } 2949 if (!filecaps_copy(&fde->fde_caps, &ndp->ni_filecaps, false)) { 2950 return (EAGAIN); 2951 } 2952 /* 2953 * Use an acquire barrier to force re-reading of fdt so it is 2954 * refreshed for verification. 2955 */ 2956 atomic_thread_fence_acq(); 2957 fdt = fdp->fd_files; 2958 if (__predict_false(!seqc_consistent_nomb(fd_seqc(fdt, fd), seq))) 2959 return (EAGAIN); 2960 /* 2961 * If file descriptor doesn't have all rights, 2962 * all lookups relative to it must also be 2963 * strictly relative. 2964 * 2965 * Not yet supported by fast path. 2966 */ 2967 CAP_ALL(&rights); 2968 if (!cap_rights_contains(&ndp->ni_filecaps.fc_rights, &rights) || 2969 ndp->ni_filecaps.fc_fcntls != CAP_FCNTL_ALL || 2970 ndp->ni_filecaps.fc_nioctls != -1) { 2971 #ifdef notyet 2972 ndp->ni_lcf |= NI_LCF_STRICTRELATIVE; 2973 #else 2974 return (EAGAIN); 2975 #endif 2976 } 2977 *vpp = vp; 2978 return (0); 2979 } 2980 #else 2981 int 2982 fgetvp_lookup_smr(int fd, struct nameidata *ndp, struct vnode **vpp, bool *fsearch) 2983 { 2984 const struct fdescenttbl *fdt; 2985 struct filedesc *fdp; 2986 struct file *fp; 2987 struct vnode *vp; 2988 2989 VFS_SMR_ASSERT_ENTERED(); 2990 2991 fdp = curproc->p_fd; 2992 fdt = fdp->fd_files; 2993 if (__predict_false((u_int)fd >= fdt->fdt_nfiles)) 2994 return (EBADF); 2995 fp = fdt->fdt_ofiles[fd].fde_file; 2996 if (__predict_false(fp == NULL)) 2997 return (EAGAIN); 2998 *fsearch = ((fp->f_flag & FSEARCH) != 0); 2999 vp = fp->f_vnode; 3000 if (__predict_false(vp == NULL || vp->v_type != VDIR)) { 3001 return (EAGAIN); 3002 } 3003 /* 3004 * Use an acquire barrier to force re-reading of fdt so it is 3005 * refreshed for verification. 3006 */ 3007 atomic_thread_fence_acq(); 3008 fdt = fdp->fd_files; 3009 if (__predict_false(fp != fdt->fdt_ofiles[fd].fde_file)) 3010 return (EAGAIN); 3011 filecaps_fill(&ndp->ni_filecaps); 3012 *vpp = vp; 3013 return (0); 3014 } 3015 #endif 3016 3017 int 3018 fget_unlocked_seq(struct filedesc *fdp, int fd, cap_rights_t *needrightsp, 3019 struct file **fpp, seqc_t *seqp) 3020 { 3021 #ifdef CAPABILITIES 3022 const struct filedescent *fde; 3023 #endif 3024 const struct fdescenttbl *fdt; 3025 struct file *fp; 3026 #ifdef CAPABILITIES 3027 seqc_t seq; 3028 cap_rights_t haverights; 3029 int error; 3030 #endif 3031 3032 fdt = fdp->fd_files; 3033 if (__predict_false((u_int)fd >= fdt->fdt_nfiles)) 3034 return (EBADF); 3035 /* 3036 * Fetch the descriptor locklessly. We avoid fdrop() races by 3037 * never raising a refcount above 0. To accomplish this we have 3038 * to use a cmpset loop rather than an atomic_add. The descriptor 3039 * must be re-verified once we acquire a reference to be certain 3040 * that the identity is still correct and we did not lose a race 3041 * due to preemption. 3042 */ 3043 for (;;) { 3044 #ifdef CAPABILITIES 3045 seq = seqc_read_notmodify(fd_seqc(fdt, fd)); 3046 fde = &fdt->fdt_ofiles[fd]; 3047 haverights = *cap_rights_fde_inline(fde); 3048 fp = fde->fde_file; 3049 if (!seqc_consistent(fd_seqc(fdt, fd), seq)) 3050 continue; 3051 #else 3052 fp = fdt->fdt_ofiles[fd].fde_file; 3053 #endif 3054 if (fp == NULL) 3055 return (EBADF); 3056 #ifdef CAPABILITIES 3057 error = cap_check_inline(&haverights, needrightsp); 3058 if (error != 0) 3059 return (error); 3060 #endif 3061 if (__predict_false(!refcount_acquire_if_not_zero(&fp->f_count))) { 3062 /* 3063 * Force a reload. Other thread could reallocate the 3064 * table before this fd was closed, so it is possible 3065 * that there is a stale fp pointer in cached version. 3066 */ 3067 fdt = atomic_load_ptr(&fdp->fd_files); 3068 continue; 3069 } 3070 /* 3071 * Use an acquire barrier to force re-reading of fdt so it is 3072 * refreshed for verification. 3073 */ 3074 atomic_thread_fence_acq(); 3075 fdt = fdp->fd_files; 3076 #ifdef CAPABILITIES 3077 if (seqc_consistent_nomb(fd_seqc(fdt, fd), seq)) 3078 #else 3079 if (fp == fdt->fdt_ofiles[fd].fde_file) 3080 #endif 3081 break; 3082 fdrop(fp, curthread); 3083 } 3084 *fpp = fp; 3085 if (seqp != NULL) { 3086 #ifdef CAPABILITIES 3087 *seqp = seq; 3088 #endif 3089 } 3090 return (0); 3091 } 3092 3093 /* 3094 * See the comments in fget_unlocked_seq for an explanation of how this works. 3095 * 3096 * This is a simplified variant which bails out to the aforementioned routine 3097 * if anything goes wrong. In practice this only happens when userspace is 3098 * racing with itself. 3099 */ 3100 int 3101 fget_unlocked(struct filedesc *fdp, int fd, cap_rights_t *needrightsp, 3102 struct file **fpp) 3103 { 3104 #ifdef CAPABILITIES 3105 const struct filedescent *fde; 3106 #endif 3107 const struct fdescenttbl *fdt; 3108 struct file *fp; 3109 #ifdef CAPABILITIES 3110 seqc_t seq; 3111 const cap_rights_t *haverights; 3112 #endif 3113 3114 fdt = fdp->fd_files; 3115 if (__predict_false((u_int)fd >= fdt->fdt_nfiles)) 3116 return (EBADF); 3117 #ifdef CAPABILITIES 3118 seq = seqc_read_notmodify(fd_seqc(fdt, fd)); 3119 fde = &fdt->fdt_ofiles[fd]; 3120 haverights = cap_rights_fde_inline(fde); 3121 fp = fde->fde_file; 3122 #else 3123 fp = fdt->fdt_ofiles[fd].fde_file; 3124 #endif 3125 if (__predict_false(fp == NULL)) 3126 goto out_fallback; 3127 #ifdef CAPABILITIES 3128 if (__predict_false(cap_check_inline_transient(haverights, needrightsp))) 3129 goto out_fallback; 3130 #endif 3131 if (__predict_false(!refcount_acquire_if_not_zero(&fp->f_count))) 3132 goto out_fallback; 3133 3134 /* 3135 * Use an acquire barrier to force re-reading of fdt so it is 3136 * refreshed for verification. 3137 */ 3138 atomic_thread_fence_acq(); 3139 fdt = fdp->fd_files; 3140 #ifdef CAPABILITIES 3141 if (__predict_false(!seqc_consistent_nomb(fd_seqc(fdt, fd), seq))) 3142 #else 3143 if (__predict_false(fp != fdt->fdt_ofiles[fd].fde_file)) 3144 #endif 3145 goto out_fdrop; 3146 *fpp = fp; 3147 return (0); 3148 out_fdrop: 3149 fdrop(fp, curthread); 3150 out_fallback: 3151 return (fget_unlocked_seq(fdp, fd, needrightsp, fpp, NULL)); 3152 } 3153 3154 /* 3155 * Translate fd -> file when the caller guarantees the file descriptor table 3156 * can't be changed by others. 3157 * 3158 * Note this does not mean the file object itself is only visible to the caller, 3159 * merely that it wont disappear without having to be referenced. 3160 * 3161 * Must be paired with fput_only_user. 3162 */ 3163 #ifdef CAPABILITIES 3164 int 3165 fget_only_user(struct filedesc *fdp, int fd, cap_rights_t *needrightsp, 3166 struct file **fpp) 3167 { 3168 const struct filedescent *fde; 3169 const struct fdescenttbl *fdt; 3170 const cap_rights_t *haverights; 3171 struct file *fp; 3172 int error; 3173 3174 MPASS(FILEDESC_IS_ONLY_USER(fdp)); 3175 3176 if (__predict_false(fd >= fdp->fd_nfiles)) 3177 return (EBADF); 3178 3179 fdt = fdp->fd_files; 3180 fde = &fdt->fdt_ofiles[fd]; 3181 fp = fde->fde_file; 3182 if (__predict_false(fp == NULL)) 3183 return (EBADF); 3184 MPASS(refcount_load(&fp->f_count) > 0); 3185 haverights = cap_rights_fde_inline(fde); 3186 error = cap_check_inline(haverights, needrightsp); 3187 if (__predict_false(error != 0)) 3188 return (error); 3189 *fpp = fp; 3190 return (0); 3191 } 3192 #else 3193 int 3194 fget_only_user(struct filedesc *fdp, int fd, cap_rights_t *needrightsp, 3195 struct file **fpp) 3196 { 3197 struct file *fp; 3198 3199 MPASS(FILEDESC_IS_ONLY_USER(fdp)); 3200 3201 if (__predict_false(fd >= fdp->fd_nfiles)) 3202 return (EBADF); 3203 3204 fp = fdp->fd_ofiles[fd].fde_file; 3205 if (__predict_false(fp == NULL)) 3206 return (EBADF); 3207 3208 MPASS(refcount_load(&fp->f_count) > 0); 3209 *fpp = fp; 3210 return (0); 3211 } 3212 #endif 3213 3214 /* 3215 * Extract the file pointer associated with the specified descriptor for the 3216 * current user process. 3217 * 3218 * If the descriptor doesn't exist or doesn't match 'flags', EBADF is 3219 * returned. 3220 * 3221 * File's rights will be checked against the capability rights mask. 3222 * 3223 * If an error occurred the non-zero error is returned and *fpp is set to 3224 * NULL. Otherwise *fpp is held and set and zero is returned. Caller is 3225 * responsible for fdrop(). 3226 */ 3227 static __inline int 3228 _fget(struct thread *td, int fd, struct file **fpp, int flags, 3229 cap_rights_t *needrightsp) 3230 { 3231 struct filedesc *fdp; 3232 struct file *fp; 3233 int error; 3234 3235 *fpp = NULL; 3236 fdp = td->td_proc->p_fd; 3237 error = fget_unlocked(fdp, fd, needrightsp, &fp); 3238 if (__predict_false(error != 0)) 3239 return (error); 3240 if (__predict_false(fp->f_ops == &badfileops)) { 3241 fdrop(fp, td); 3242 return (EBADF); 3243 } 3244 3245 /* 3246 * FREAD and FWRITE failure return EBADF as per POSIX. 3247 */ 3248 error = 0; 3249 switch (flags) { 3250 case FREAD: 3251 case FWRITE: 3252 if ((fp->f_flag & flags) == 0) 3253 error = EBADF; 3254 break; 3255 case FEXEC: 3256 if (fp->f_ops != &path_fileops && 3257 ((fp->f_flag & (FREAD | FEXEC)) == 0 || 3258 (fp->f_flag & FWRITE) != 0)) 3259 error = EBADF; 3260 break; 3261 case 0: 3262 break; 3263 default: 3264 KASSERT(0, ("wrong flags")); 3265 } 3266 3267 if (error != 0) { 3268 fdrop(fp, td); 3269 return (error); 3270 } 3271 3272 *fpp = fp; 3273 return (0); 3274 } 3275 3276 int 3277 fget(struct thread *td, int fd, cap_rights_t *rightsp, struct file **fpp) 3278 { 3279 3280 return (_fget(td, fd, fpp, 0, rightsp)); 3281 } 3282 3283 int 3284 fget_mmap(struct thread *td, int fd, cap_rights_t *rightsp, vm_prot_t *maxprotp, 3285 struct file **fpp) 3286 { 3287 int error; 3288 #ifndef CAPABILITIES 3289 error = _fget(td, fd, fpp, 0, rightsp); 3290 if (maxprotp != NULL) 3291 *maxprotp = VM_PROT_ALL; 3292 return (error); 3293 #else 3294 cap_rights_t fdrights; 3295 struct filedesc *fdp; 3296 struct file *fp; 3297 seqc_t seq; 3298 3299 *fpp = NULL; 3300 fdp = td->td_proc->p_fd; 3301 MPASS(cap_rights_is_set(rightsp, CAP_MMAP)); 3302 for (;;) { 3303 error = fget_unlocked_seq(fdp, fd, rightsp, &fp, &seq); 3304 if (__predict_false(error != 0)) 3305 return (error); 3306 if (__predict_false(fp->f_ops == &badfileops)) { 3307 fdrop(fp, td); 3308 return (EBADF); 3309 } 3310 if (maxprotp != NULL) 3311 fdrights = *cap_rights(fdp, fd); 3312 if (!fd_modified(fdp, fd, seq)) 3313 break; 3314 fdrop(fp, td); 3315 } 3316 3317 /* 3318 * If requested, convert capability rights to access flags. 3319 */ 3320 if (maxprotp != NULL) 3321 *maxprotp = cap_rights_to_vmprot(&fdrights); 3322 *fpp = fp; 3323 return (0); 3324 #endif 3325 } 3326 3327 int 3328 fget_read(struct thread *td, int fd, cap_rights_t *rightsp, struct file **fpp) 3329 { 3330 3331 return (_fget(td, fd, fpp, FREAD, rightsp)); 3332 } 3333 3334 int 3335 fget_write(struct thread *td, int fd, cap_rights_t *rightsp, struct file **fpp) 3336 { 3337 3338 return (_fget(td, fd, fpp, FWRITE, rightsp)); 3339 } 3340 3341 int 3342 fget_fcntl(struct thread *td, int fd, cap_rights_t *rightsp, int needfcntl, 3343 struct file **fpp) 3344 { 3345 struct filedesc *fdp = td->td_proc->p_fd; 3346 #ifndef CAPABILITIES 3347 return (fget_unlocked(fdp, fd, rightsp, fpp)); 3348 #else 3349 struct file *fp; 3350 int error; 3351 seqc_t seq; 3352 3353 *fpp = NULL; 3354 MPASS(cap_rights_is_set(rightsp, CAP_FCNTL)); 3355 for (;;) { 3356 error = fget_unlocked_seq(fdp, fd, rightsp, &fp, &seq); 3357 if (error != 0) 3358 return (error); 3359 error = cap_fcntl_check(fdp, fd, needfcntl); 3360 if (!fd_modified(fdp, fd, seq)) 3361 break; 3362 fdrop(fp, td); 3363 } 3364 if (error != 0) { 3365 fdrop(fp, td); 3366 return (error); 3367 } 3368 *fpp = fp; 3369 return (0); 3370 #endif 3371 } 3372 3373 /* 3374 * Like fget() but loads the underlying vnode, or returns an error if the 3375 * descriptor does not represent a vnode. Note that pipes use vnodes but 3376 * never have VM objects. The returned vnode will be vref()'d. 3377 * 3378 * XXX: what about the unused flags ? 3379 */ 3380 static __inline int 3381 _fgetvp(struct thread *td, int fd, int flags, cap_rights_t *needrightsp, 3382 struct vnode **vpp) 3383 { 3384 struct file *fp; 3385 int error; 3386 3387 *vpp = NULL; 3388 error = _fget(td, fd, &fp, flags, needrightsp); 3389 if (error != 0) 3390 return (error); 3391 if (fp->f_vnode == NULL) { 3392 error = EINVAL; 3393 } else { 3394 *vpp = fp->f_vnode; 3395 vref(*vpp); 3396 } 3397 fdrop(fp, td); 3398 3399 return (error); 3400 } 3401 3402 int 3403 fgetvp(struct thread *td, int fd, cap_rights_t *rightsp, struct vnode **vpp) 3404 { 3405 3406 return (_fgetvp(td, fd, 0, rightsp, vpp)); 3407 } 3408 3409 int 3410 fgetvp_rights(struct thread *td, int fd, cap_rights_t *needrightsp, 3411 struct filecaps *havecaps, struct vnode **vpp) 3412 { 3413 struct filecaps caps; 3414 struct file *fp; 3415 int error; 3416 3417 error = fget_cap(td, fd, needrightsp, &fp, &caps); 3418 if (error != 0) 3419 return (error); 3420 if (fp->f_ops == &badfileops) { 3421 error = EBADF; 3422 goto out; 3423 } 3424 if (fp->f_vnode == NULL) { 3425 error = EINVAL; 3426 goto out; 3427 } 3428 3429 *havecaps = caps; 3430 *vpp = fp->f_vnode; 3431 vref(*vpp); 3432 fdrop(fp, td); 3433 3434 return (0); 3435 out: 3436 filecaps_free(&caps); 3437 fdrop(fp, td); 3438 return (error); 3439 } 3440 3441 int 3442 fgetvp_read(struct thread *td, int fd, cap_rights_t *rightsp, struct vnode **vpp) 3443 { 3444 3445 return (_fgetvp(td, fd, FREAD, rightsp, vpp)); 3446 } 3447 3448 int 3449 fgetvp_exec(struct thread *td, int fd, cap_rights_t *rightsp, struct vnode **vpp) 3450 { 3451 3452 return (_fgetvp(td, fd, FEXEC, rightsp, vpp)); 3453 } 3454 3455 #ifdef notyet 3456 int 3457 fgetvp_write(struct thread *td, int fd, cap_rights_t *rightsp, 3458 struct vnode **vpp) 3459 { 3460 3461 return (_fgetvp(td, fd, FWRITE, rightsp, vpp)); 3462 } 3463 #endif 3464 3465 /* 3466 * Handle the last reference to a file being closed. 3467 * 3468 * Without the noinline attribute clang keeps inlining the func thorough this 3469 * file when fdrop is used. 3470 */ 3471 int __noinline 3472 _fdrop(struct file *fp, struct thread *td) 3473 { 3474 int error; 3475 #ifdef INVARIANTS 3476 int count; 3477 3478 count = refcount_load(&fp->f_count); 3479 if (count != 0) 3480 panic("fdrop: fp %p count %d", fp, count); 3481 #endif 3482 error = fo_close(fp, td); 3483 atomic_subtract_int(&openfiles, 1); 3484 crfree(fp->f_cred); 3485 free(fp->f_advice, M_FADVISE); 3486 uma_zfree(file_zone, fp); 3487 3488 return (error); 3489 } 3490 3491 /* 3492 * Apply an advisory lock on a file descriptor. 3493 * 3494 * Just attempt to get a record lock of the requested type on the entire file 3495 * (l_whence = SEEK_SET, l_start = 0, l_len = 0). 3496 */ 3497 #ifndef _SYS_SYSPROTO_H_ 3498 struct flock_args { 3499 int fd; 3500 int how; 3501 }; 3502 #endif 3503 /* ARGSUSED */ 3504 int 3505 sys_flock(struct thread *td, struct flock_args *uap) 3506 { 3507 struct file *fp; 3508 struct vnode *vp; 3509 struct flock lf; 3510 int error; 3511 3512 error = fget(td, uap->fd, &cap_flock_rights, &fp); 3513 if (error != 0) 3514 return (error); 3515 error = EOPNOTSUPP; 3516 if (fp->f_type != DTYPE_VNODE && fp->f_type != DTYPE_FIFO) { 3517 goto done; 3518 } 3519 if (fp->f_ops == &path_fileops) { 3520 goto done; 3521 } 3522 3523 error = 0; 3524 vp = fp->f_vnode; 3525 lf.l_whence = SEEK_SET; 3526 lf.l_start = 0; 3527 lf.l_len = 0; 3528 if (uap->how & LOCK_UN) { 3529 lf.l_type = F_UNLCK; 3530 atomic_clear_int(&fp->f_flag, FHASLOCK); 3531 error = VOP_ADVLOCK(vp, (caddr_t)fp, F_UNLCK, &lf, F_FLOCK); 3532 goto done; 3533 } 3534 if (uap->how & LOCK_EX) 3535 lf.l_type = F_WRLCK; 3536 else if (uap->how & LOCK_SH) 3537 lf.l_type = F_RDLCK; 3538 else { 3539 error = EBADF; 3540 goto done; 3541 } 3542 atomic_set_int(&fp->f_flag, FHASLOCK); 3543 error = VOP_ADVLOCK(vp, (caddr_t)fp, F_SETLK, &lf, 3544 (uap->how & LOCK_NB) ? F_FLOCK : F_FLOCK | F_WAIT); 3545 done: 3546 fdrop(fp, td); 3547 return (error); 3548 } 3549 /* 3550 * Duplicate the specified descriptor to a free descriptor. 3551 */ 3552 int 3553 dupfdopen(struct thread *td, struct filedesc *fdp, int dfd, int mode, 3554 int openerror, int *indxp) 3555 { 3556 struct filedescent *newfde, *oldfde; 3557 struct file *fp; 3558 u_long *ioctls; 3559 int error, indx; 3560 3561 KASSERT(openerror == ENODEV || openerror == ENXIO, 3562 ("unexpected error %d in %s", openerror, __func__)); 3563 3564 /* 3565 * If the to-be-dup'd fd number is greater than the allowed number 3566 * of file descriptors, or the fd to be dup'd has already been 3567 * closed, then reject. 3568 */ 3569 FILEDESC_XLOCK(fdp); 3570 if ((fp = fget_locked(fdp, dfd)) == NULL) { 3571 FILEDESC_XUNLOCK(fdp); 3572 return (EBADF); 3573 } 3574 3575 error = fdalloc(td, 0, &indx); 3576 if (error != 0) { 3577 FILEDESC_XUNLOCK(fdp); 3578 return (error); 3579 } 3580 3581 /* 3582 * There are two cases of interest here. 3583 * 3584 * For ENODEV simply dup (dfd) to file descriptor (indx) and return. 3585 * 3586 * For ENXIO steal away the file structure from (dfd) and store it in 3587 * (indx). (dfd) is effectively closed by this operation. 3588 */ 3589 switch (openerror) { 3590 case ENODEV: 3591 /* 3592 * Check that the mode the file is being opened for is a 3593 * subset of the mode of the existing descriptor. 3594 */ 3595 if (((mode & (FREAD|FWRITE)) | fp->f_flag) != fp->f_flag) { 3596 fdunused(fdp, indx); 3597 FILEDESC_XUNLOCK(fdp); 3598 return (EACCES); 3599 } 3600 if (!fhold(fp)) { 3601 fdunused(fdp, indx); 3602 FILEDESC_XUNLOCK(fdp); 3603 return (EBADF); 3604 } 3605 newfde = &fdp->fd_ofiles[indx]; 3606 oldfde = &fdp->fd_ofiles[dfd]; 3607 ioctls = filecaps_copy_prep(&oldfde->fde_caps); 3608 #ifdef CAPABILITIES 3609 seqc_write_begin(&newfde->fde_seqc); 3610 #endif 3611 memcpy(newfde, oldfde, fde_change_size); 3612 filecaps_copy_finish(&oldfde->fde_caps, &newfde->fde_caps, 3613 ioctls); 3614 #ifdef CAPABILITIES 3615 seqc_write_end(&newfde->fde_seqc); 3616 #endif 3617 break; 3618 case ENXIO: 3619 /* 3620 * Steal away the file pointer from dfd and stuff it into indx. 3621 */ 3622 newfde = &fdp->fd_ofiles[indx]; 3623 oldfde = &fdp->fd_ofiles[dfd]; 3624 #ifdef CAPABILITIES 3625 seqc_write_begin(&newfde->fde_seqc); 3626 #endif 3627 memcpy(newfde, oldfde, fde_change_size); 3628 oldfde->fde_file = NULL; 3629 fdunused(fdp, dfd); 3630 #ifdef CAPABILITIES 3631 seqc_write_end(&newfde->fde_seqc); 3632 #endif 3633 break; 3634 } 3635 FILEDESC_XUNLOCK(fdp); 3636 *indxp = indx; 3637 return (0); 3638 } 3639 3640 /* 3641 * This sysctl determines if we will allow a process to chroot(2) if it 3642 * has a directory open: 3643 * 0: disallowed for all processes. 3644 * 1: allowed for processes that were not already chroot(2)'ed. 3645 * 2: allowed for all processes. 3646 */ 3647 3648 static int chroot_allow_open_directories = 1; 3649 3650 SYSCTL_INT(_kern, OID_AUTO, chroot_allow_open_directories, CTLFLAG_RW, 3651 &chroot_allow_open_directories, 0, 3652 "Allow a process to chroot(2) if it has a directory open"); 3653 3654 /* 3655 * Helper function for raised chroot(2) security function: Refuse if 3656 * any filedescriptors are open directories. 3657 */ 3658 static int 3659 chroot_refuse_vdir_fds(struct filedesc *fdp) 3660 { 3661 struct vnode *vp; 3662 struct file *fp; 3663 int fd, lastfile; 3664 3665 FILEDESC_LOCK_ASSERT(fdp); 3666 3667 lastfile = fdlastfile(fdp); 3668 for (fd = 0; fd <= lastfile; fd++) { 3669 fp = fget_locked(fdp, fd); 3670 if (fp == NULL) 3671 continue; 3672 if (fp->f_type == DTYPE_VNODE) { 3673 vp = fp->f_vnode; 3674 if (vp->v_type == VDIR) 3675 return (EPERM); 3676 } 3677 } 3678 return (0); 3679 } 3680 3681 static void 3682 pwd_fill(struct pwd *oldpwd, struct pwd *newpwd) 3683 { 3684 3685 if (newpwd->pwd_cdir == NULL && oldpwd->pwd_cdir != NULL) { 3686 vrefact(oldpwd->pwd_cdir); 3687 newpwd->pwd_cdir = oldpwd->pwd_cdir; 3688 } 3689 3690 if (newpwd->pwd_rdir == NULL && oldpwd->pwd_rdir != NULL) { 3691 vrefact(oldpwd->pwd_rdir); 3692 newpwd->pwd_rdir = oldpwd->pwd_rdir; 3693 } 3694 3695 if (newpwd->pwd_jdir == NULL && oldpwd->pwd_jdir != NULL) { 3696 vrefact(oldpwd->pwd_jdir); 3697 newpwd->pwd_jdir = oldpwd->pwd_jdir; 3698 } 3699 } 3700 3701 struct pwd * 3702 pwd_hold_pwddesc(struct pwddesc *pdp) 3703 { 3704 struct pwd *pwd; 3705 3706 PWDDESC_ASSERT_XLOCKED(pdp); 3707 pwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); 3708 if (pwd != NULL) 3709 refcount_acquire(&pwd->pwd_refcount); 3710 return (pwd); 3711 } 3712 3713 bool 3714 pwd_hold_smr(struct pwd *pwd) 3715 { 3716 3717 MPASS(pwd != NULL); 3718 if (__predict_true(refcount_acquire_if_not_zero(&pwd->pwd_refcount))) { 3719 return (true); 3720 } 3721 return (false); 3722 } 3723 3724 struct pwd * 3725 pwd_hold(struct thread *td) 3726 { 3727 struct pwddesc *pdp; 3728 struct pwd *pwd; 3729 3730 pdp = td->td_proc->p_pd; 3731 3732 vfs_smr_enter(); 3733 pwd = vfs_smr_entered_load(&pdp->pd_pwd); 3734 if (pwd_hold_smr(pwd)) { 3735 vfs_smr_exit(); 3736 return (pwd); 3737 } 3738 vfs_smr_exit(); 3739 PWDDESC_XLOCK(pdp); 3740 pwd = pwd_hold_pwddesc(pdp); 3741 MPASS(pwd != NULL); 3742 PWDDESC_XUNLOCK(pdp); 3743 return (pwd); 3744 } 3745 3746 struct pwd * 3747 pwd_hold_proc(struct proc *p) 3748 { 3749 struct pwddesc *pdp; 3750 struct pwd *pwd; 3751 3752 PROC_ASSERT_HELD(p); 3753 PROC_LOCK(p); 3754 pdp = pdhold(p); 3755 MPASS(pdp != NULL); 3756 PROC_UNLOCK(p); 3757 3758 PWDDESC_XLOCK(pdp); 3759 pwd = pwd_hold_pwddesc(pdp); 3760 MPASS(pwd != NULL); 3761 PWDDESC_XUNLOCK(pdp); 3762 pddrop(pdp); 3763 return (pwd); 3764 } 3765 3766 static struct pwd * 3767 pwd_alloc(void) 3768 { 3769 struct pwd *pwd; 3770 3771 pwd = uma_zalloc_smr(pwd_zone, M_WAITOK); 3772 bzero(pwd, sizeof(*pwd)); 3773 refcount_init(&pwd->pwd_refcount, 1); 3774 return (pwd); 3775 } 3776 3777 void 3778 pwd_drop(struct pwd *pwd) 3779 { 3780 3781 if (!refcount_release(&pwd->pwd_refcount)) 3782 return; 3783 3784 if (pwd->pwd_cdir != NULL) 3785 vrele(pwd->pwd_cdir); 3786 if (pwd->pwd_rdir != NULL) 3787 vrele(pwd->pwd_rdir); 3788 if (pwd->pwd_jdir != NULL) 3789 vrele(pwd->pwd_jdir); 3790 uma_zfree_smr(pwd_zone, pwd); 3791 } 3792 3793 /* 3794 * The caller is responsible for invoking priv_check() and 3795 * mac_vnode_check_chroot() to authorize this operation. 3796 */ 3797 int 3798 pwd_chroot(struct thread *td, struct vnode *vp) 3799 { 3800 struct pwddesc *pdp; 3801 struct filedesc *fdp; 3802 struct pwd *newpwd, *oldpwd; 3803 int error; 3804 3805 fdp = td->td_proc->p_fd; 3806 pdp = td->td_proc->p_pd; 3807 newpwd = pwd_alloc(); 3808 FILEDESC_SLOCK(fdp); 3809 PWDDESC_XLOCK(pdp); 3810 oldpwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); 3811 if (chroot_allow_open_directories == 0 || 3812 (chroot_allow_open_directories == 1 && 3813 oldpwd->pwd_rdir != rootvnode)) { 3814 error = chroot_refuse_vdir_fds(fdp); 3815 FILEDESC_SUNLOCK(fdp); 3816 if (error != 0) { 3817 PWDDESC_XUNLOCK(pdp); 3818 pwd_drop(newpwd); 3819 return (error); 3820 } 3821 } else { 3822 FILEDESC_SUNLOCK(fdp); 3823 } 3824 3825 vrefact(vp); 3826 newpwd->pwd_rdir = vp; 3827 if (oldpwd->pwd_jdir == NULL) { 3828 vrefact(vp); 3829 newpwd->pwd_jdir = vp; 3830 } 3831 pwd_fill(oldpwd, newpwd); 3832 pwd_set(pdp, newpwd); 3833 PWDDESC_XUNLOCK(pdp); 3834 pwd_drop(oldpwd); 3835 return (0); 3836 } 3837 3838 void 3839 pwd_chdir(struct thread *td, struct vnode *vp) 3840 { 3841 struct pwddesc *pdp; 3842 struct pwd *newpwd, *oldpwd; 3843 3844 VNPASS(vp->v_usecount > 0, vp); 3845 3846 newpwd = pwd_alloc(); 3847 pdp = td->td_proc->p_pd; 3848 PWDDESC_XLOCK(pdp); 3849 oldpwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); 3850 newpwd->pwd_cdir = vp; 3851 pwd_fill(oldpwd, newpwd); 3852 pwd_set(pdp, newpwd); 3853 PWDDESC_XUNLOCK(pdp); 3854 pwd_drop(oldpwd); 3855 } 3856 3857 /* 3858 * jail_attach(2) changes both root and working directories. 3859 */ 3860 int 3861 pwd_chroot_chdir(struct thread *td, struct vnode *vp) 3862 { 3863 struct pwddesc *pdp; 3864 struct filedesc *fdp; 3865 struct pwd *newpwd, *oldpwd; 3866 int error; 3867 3868 fdp = td->td_proc->p_fd; 3869 pdp = td->td_proc->p_pd; 3870 newpwd = pwd_alloc(); 3871 FILEDESC_SLOCK(fdp); 3872 PWDDESC_XLOCK(pdp); 3873 oldpwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); 3874 error = chroot_refuse_vdir_fds(fdp); 3875 FILEDESC_SUNLOCK(fdp); 3876 if (error != 0) { 3877 PWDDESC_XUNLOCK(pdp); 3878 pwd_drop(newpwd); 3879 return (error); 3880 } 3881 3882 vrefact(vp); 3883 newpwd->pwd_rdir = vp; 3884 vrefact(vp); 3885 newpwd->pwd_cdir = vp; 3886 if (oldpwd->pwd_jdir == NULL) { 3887 vrefact(vp); 3888 newpwd->pwd_jdir = vp; 3889 } 3890 pwd_fill(oldpwd, newpwd); 3891 pwd_set(pdp, newpwd); 3892 PWDDESC_XUNLOCK(pdp); 3893 pwd_drop(oldpwd); 3894 return (0); 3895 } 3896 3897 void 3898 pwd_ensure_dirs(void) 3899 { 3900 struct pwddesc *pdp; 3901 struct pwd *oldpwd, *newpwd; 3902 3903 pdp = curproc->p_pd; 3904 PWDDESC_XLOCK(pdp); 3905 oldpwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); 3906 if (oldpwd->pwd_cdir != NULL && oldpwd->pwd_rdir != NULL) { 3907 PWDDESC_XUNLOCK(pdp); 3908 return; 3909 } 3910 PWDDESC_XUNLOCK(pdp); 3911 3912 newpwd = pwd_alloc(); 3913 PWDDESC_XLOCK(pdp); 3914 oldpwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); 3915 pwd_fill(oldpwd, newpwd); 3916 if (newpwd->pwd_cdir == NULL) { 3917 vrefact(rootvnode); 3918 newpwd->pwd_cdir = rootvnode; 3919 } 3920 if (newpwd->pwd_rdir == NULL) { 3921 vrefact(rootvnode); 3922 newpwd->pwd_rdir = rootvnode; 3923 } 3924 pwd_set(pdp, newpwd); 3925 PWDDESC_XUNLOCK(pdp); 3926 pwd_drop(oldpwd); 3927 } 3928 3929 void 3930 pwd_set_rootvnode(void) 3931 { 3932 struct pwddesc *pdp; 3933 struct pwd *oldpwd, *newpwd; 3934 3935 pdp = curproc->p_pd; 3936 3937 newpwd = pwd_alloc(); 3938 PWDDESC_XLOCK(pdp); 3939 oldpwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); 3940 vrefact(rootvnode); 3941 newpwd->pwd_cdir = rootvnode; 3942 vrefact(rootvnode); 3943 newpwd->pwd_rdir = rootvnode; 3944 pwd_fill(oldpwd, newpwd); 3945 pwd_set(pdp, newpwd); 3946 PWDDESC_XUNLOCK(pdp); 3947 pwd_drop(oldpwd); 3948 } 3949 3950 /* 3951 * Scan all active processes and prisons to see if any of them have a current 3952 * or root directory of `olddp'. If so, replace them with the new mount point. 3953 */ 3954 void 3955 mountcheckdirs(struct vnode *olddp, struct vnode *newdp) 3956 { 3957 struct pwddesc *pdp; 3958 struct pwd *newpwd, *oldpwd; 3959 struct prison *pr; 3960 struct proc *p; 3961 int nrele; 3962 3963 if (vrefcnt(olddp) == 1) 3964 return; 3965 nrele = 0; 3966 newpwd = pwd_alloc(); 3967 sx_slock(&allproc_lock); 3968 FOREACH_PROC_IN_SYSTEM(p) { 3969 PROC_LOCK(p); 3970 pdp = pdhold(p); 3971 PROC_UNLOCK(p); 3972 if (pdp == NULL) 3973 continue; 3974 PWDDESC_XLOCK(pdp); 3975 oldpwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); 3976 if (oldpwd == NULL || 3977 (oldpwd->pwd_cdir != olddp && 3978 oldpwd->pwd_rdir != olddp && 3979 oldpwd->pwd_jdir != olddp)) { 3980 PWDDESC_XUNLOCK(pdp); 3981 pddrop(pdp); 3982 continue; 3983 } 3984 if (oldpwd->pwd_cdir == olddp) { 3985 vrefact(newdp); 3986 newpwd->pwd_cdir = newdp; 3987 } 3988 if (oldpwd->pwd_rdir == olddp) { 3989 vrefact(newdp); 3990 newpwd->pwd_rdir = newdp; 3991 } 3992 if (oldpwd->pwd_jdir == olddp) { 3993 vrefact(newdp); 3994 newpwd->pwd_jdir = newdp; 3995 } 3996 pwd_fill(oldpwd, newpwd); 3997 pwd_set(pdp, newpwd); 3998 PWDDESC_XUNLOCK(pdp); 3999 pwd_drop(oldpwd); 4000 pddrop(pdp); 4001 newpwd = pwd_alloc(); 4002 } 4003 sx_sunlock(&allproc_lock); 4004 pwd_drop(newpwd); 4005 if (rootvnode == olddp) { 4006 vrefact(newdp); 4007 rootvnode = newdp; 4008 nrele++; 4009 } 4010 mtx_lock(&prison0.pr_mtx); 4011 if (prison0.pr_root == olddp) { 4012 vrefact(newdp); 4013 prison0.pr_root = newdp; 4014 nrele++; 4015 } 4016 mtx_unlock(&prison0.pr_mtx); 4017 sx_slock(&allprison_lock); 4018 TAILQ_FOREACH(pr, &allprison, pr_list) { 4019 mtx_lock(&pr->pr_mtx); 4020 if (pr->pr_root == olddp) { 4021 vrefact(newdp); 4022 pr->pr_root = newdp; 4023 nrele++; 4024 } 4025 mtx_unlock(&pr->pr_mtx); 4026 } 4027 sx_sunlock(&allprison_lock); 4028 while (nrele--) 4029 vrele(olddp); 4030 } 4031 4032 struct filedesc_to_leader * 4033 filedesc_to_leader_alloc(struct filedesc_to_leader *old, struct filedesc *fdp, struct proc *leader) 4034 { 4035 struct filedesc_to_leader *fdtol; 4036 4037 fdtol = malloc(sizeof(struct filedesc_to_leader), 4038 M_FILEDESC_TO_LEADER, M_WAITOK); 4039 fdtol->fdl_refcount = 1; 4040 fdtol->fdl_holdcount = 0; 4041 fdtol->fdl_wakeup = 0; 4042 fdtol->fdl_leader = leader; 4043 if (old != NULL) { 4044 FILEDESC_XLOCK(fdp); 4045 fdtol->fdl_next = old->fdl_next; 4046 fdtol->fdl_prev = old; 4047 old->fdl_next = fdtol; 4048 fdtol->fdl_next->fdl_prev = fdtol; 4049 FILEDESC_XUNLOCK(fdp); 4050 } else { 4051 fdtol->fdl_next = fdtol; 4052 fdtol->fdl_prev = fdtol; 4053 } 4054 return (fdtol); 4055 } 4056 4057 static int 4058 sysctl_kern_proc_nfds(SYSCTL_HANDLER_ARGS) 4059 { 4060 NDSLOTTYPE *map; 4061 struct filedesc *fdp; 4062 u_int namelen; 4063 int count, off, minoff; 4064 4065 namelen = arg2; 4066 if (namelen != 1) 4067 return (EINVAL); 4068 4069 if (*(int *)arg1 != 0) 4070 return (EINVAL); 4071 4072 fdp = curproc->p_fd; 4073 count = 0; 4074 FILEDESC_SLOCK(fdp); 4075 map = fdp->fd_map; 4076 off = NDSLOT(fdp->fd_nfiles - 1); 4077 for (minoff = NDSLOT(0); off >= minoff; --off) 4078 count += bitcountl(map[off]); 4079 FILEDESC_SUNLOCK(fdp); 4080 4081 return (SYSCTL_OUT(req, &count, sizeof(count))); 4082 } 4083 4084 static SYSCTL_NODE(_kern_proc, KERN_PROC_NFDS, nfds, 4085 CTLFLAG_RD|CTLFLAG_CAPRD|CTLFLAG_MPSAFE, sysctl_kern_proc_nfds, 4086 "Number of open file descriptors"); 4087 4088 /* 4089 * Get file structures globally. 4090 */ 4091 static int 4092 sysctl_kern_file(SYSCTL_HANDLER_ARGS) 4093 { 4094 struct xfile xf; 4095 struct filedesc *fdp; 4096 struct file *fp; 4097 struct proc *p; 4098 int error, n, lastfile; 4099 4100 error = sysctl_wire_old_buffer(req, 0); 4101 if (error != 0) 4102 return (error); 4103 if (req->oldptr == NULL) { 4104 n = 0; 4105 sx_slock(&allproc_lock); 4106 FOREACH_PROC_IN_SYSTEM(p) { 4107 PROC_LOCK(p); 4108 if (p->p_state == PRS_NEW) { 4109 PROC_UNLOCK(p); 4110 continue; 4111 } 4112 fdp = fdhold(p); 4113 PROC_UNLOCK(p); 4114 if (fdp == NULL) 4115 continue; 4116 /* overestimates sparse tables. */ 4117 n += fdp->fd_nfiles; 4118 fddrop(fdp); 4119 } 4120 sx_sunlock(&allproc_lock); 4121 return (SYSCTL_OUT(req, 0, n * sizeof(xf))); 4122 } 4123 error = 0; 4124 bzero(&xf, sizeof(xf)); 4125 xf.xf_size = sizeof(xf); 4126 sx_slock(&allproc_lock); 4127 FOREACH_PROC_IN_SYSTEM(p) { 4128 PROC_LOCK(p); 4129 if (p->p_state == PRS_NEW) { 4130 PROC_UNLOCK(p); 4131 continue; 4132 } 4133 if (p_cansee(req->td, p) != 0) { 4134 PROC_UNLOCK(p); 4135 continue; 4136 } 4137 xf.xf_pid = p->p_pid; 4138 xf.xf_uid = p->p_ucred->cr_uid; 4139 fdp = fdhold(p); 4140 PROC_UNLOCK(p); 4141 if (fdp == NULL) 4142 continue; 4143 FILEDESC_SLOCK(fdp); 4144 lastfile = fdlastfile(fdp); 4145 for (n = 0; refcount_load(&fdp->fd_refcnt) > 0 && n <= lastfile; 4146 n++) { 4147 if ((fp = fdp->fd_ofiles[n].fde_file) == NULL) 4148 continue; 4149 xf.xf_fd = n; 4150 xf.xf_file = (uintptr_t)fp; 4151 xf.xf_data = (uintptr_t)fp->f_data; 4152 xf.xf_vnode = (uintptr_t)fp->f_vnode; 4153 xf.xf_type = (uintptr_t)fp->f_type; 4154 xf.xf_count = refcount_load(&fp->f_count); 4155 xf.xf_msgcount = 0; 4156 xf.xf_offset = foffset_get(fp); 4157 xf.xf_flag = fp->f_flag; 4158 error = SYSCTL_OUT(req, &xf, sizeof(xf)); 4159 if (error) 4160 break; 4161 } 4162 FILEDESC_SUNLOCK(fdp); 4163 fddrop(fdp); 4164 if (error) 4165 break; 4166 } 4167 sx_sunlock(&allproc_lock); 4168 return (error); 4169 } 4170 4171 SYSCTL_PROC(_kern, KERN_FILE, file, CTLTYPE_OPAQUE|CTLFLAG_RD|CTLFLAG_MPSAFE, 4172 0, 0, sysctl_kern_file, "S,xfile", "Entire file table"); 4173 4174 #ifdef KINFO_FILE_SIZE 4175 CTASSERT(sizeof(struct kinfo_file) == KINFO_FILE_SIZE); 4176 #endif 4177 4178 static int 4179 xlate_fflags(int fflags) 4180 { 4181 static const struct { 4182 int fflag; 4183 int kf_fflag; 4184 } fflags_table[] = { 4185 { FAPPEND, KF_FLAG_APPEND }, 4186 { FASYNC, KF_FLAG_ASYNC }, 4187 { FFSYNC, KF_FLAG_FSYNC }, 4188 { FHASLOCK, KF_FLAG_HASLOCK }, 4189 { FNONBLOCK, KF_FLAG_NONBLOCK }, 4190 { FREAD, KF_FLAG_READ }, 4191 { FWRITE, KF_FLAG_WRITE }, 4192 { O_CREAT, KF_FLAG_CREAT }, 4193 { O_DIRECT, KF_FLAG_DIRECT }, 4194 { O_EXCL, KF_FLAG_EXCL }, 4195 { O_EXEC, KF_FLAG_EXEC }, 4196 { O_EXLOCK, KF_FLAG_EXLOCK }, 4197 { O_NOFOLLOW, KF_FLAG_NOFOLLOW }, 4198 { O_SHLOCK, KF_FLAG_SHLOCK }, 4199 { O_TRUNC, KF_FLAG_TRUNC } 4200 }; 4201 unsigned int i; 4202 int kflags; 4203 4204 kflags = 0; 4205 for (i = 0; i < nitems(fflags_table); i++) 4206 if (fflags & fflags_table[i].fflag) 4207 kflags |= fflags_table[i].kf_fflag; 4208 return (kflags); 4209 } 4210 4211 /* Trim unused data from kf_path by truncating the structure size. */ 4212 void 4213 pack_kinfo(struct kinfo_file *kif) 4214 { 4215 4216 kif->kf_structsize = offsetof(struct kinfo_file, kf_path) + 4217 strlen(kif->kf_path) + 1; 4218 kif->kf_structsize = roundup(kif->kf_structsize, sizeof(uint64_t)); 4219 } 4220 4221 static void 4222 export_file_to_kinfo(struct file *fp, int fd, cap_rights_t *rightsp, 4223 struct kinfo_file *kif, struct filedesc *fdp, int flags) 4224 { 4225 int error; 4226 4227 bzero(kif, sizeof(*kif)); 4228 4229 /* Set a default type to allow for empty fill_kinfo() methods. */ 4230 kif->kf_type = KF_TYPE_UNKNOWN; 4231 kif->kf_flags = xlate_fflags(fp->f_flag); 4232 if (rightsp != NULL) 4233 kif->kf_cap_rights = *rightsp; 4234 else 4235 cap_rights_init_zero(&kif->kf_cap_rights); 4236 kif->kf_fd = fd; 4237 kif->kf_ref_count = refcount_load(&fp->f_count); 4238 kif->kf_offset = foffset_get(fp); 4239 4240 /* 4241 * This may drop the filedesc lock, so the 'fp' cannot be 4242 * accessed after this call. 4243 */ 4244 error = fo_fill_kinfo(fp, kif, fdp); 4245 if (error == 0) 4246 kif->kf_status |= KF_ATTR_VALID; 4247 if ((flags & KERN_FILEDESC_PACK_KINFO) != 0) 4248 pack_kinfo(kif); 4249 else 4250 kif->kf_structsize = roundup2(sizeof(*kif), sizeof(uint64_t)); 4251 } 4252 4253 static void 4254 export_vnode_to_kinfo(struct vnode *vp, int fd, int fflags, 4255 struct kinfo_file *kif, int flags) 4256 { 4257 int error; 4258 4259 bzero(kif, sizeof(*kif)); 4260 4261 kif->kf_type = KF_TYPE_VNODE; 4262 error = vn_fill_kinfo_vnode(vp, kif); 4263 if (error == 0) 4264 kif->kf_status |= KF_ATTR_VALID; 4265 kif->kf_flags = xlate_fflags(fflags); 4266 cap_rights_init_zero(&kif->kf_cap_rights); 4267 kif->kf_fd = fd; 4268 kif->kf_ref_count = -1; 4269 kif->kf_offset = -1; 4270 if ((flags & KERN_FILEDESC_PACK_KINFO) != 0) 4271 pack_kinfo(kif); 4272 else 4273 kif->kf_structsize = roundup2(sizeof(*kif), sizeof(uint64_t)); 4274 vrele(vp); 4275 } 4276 4277 struct export_fd_buf { 4278 struct filedesc *fdp; 4279 struct pwddesc *pdp; 4280 struct sbuf *sb; 4281 ssize_t remainder; 4282 struct kinfo_file kif; 4283 int flags; 4284 }; 4285 4286 static int 4287 export_kinfo_to_sb(struct export_fd_buf *efbuf) 4288 { 4289 struct kinfo_file *kif; 4290 4291 kif = &efbuf->kif; 4292 if (efbuf->remainder != -1) { 4293 if (efbuf->remainder < kif->kf_structsize) { 4294 /* Terminate export. */ 4295 efbuf->remainder = 0; 4296 return (0); 4297 } 4298 efbuf->remainder -= kif->kf_structsize; 4299 } 4300 return (sbuf_bcat(efbuf->sb, kif, kif->kf_structsize) == 0 ? 0 : ENOMEM); 4301 } 4302 4303 static int 4304 export_file_to_sb(struct file *fp, int fd, cap_rights_t *rightsp, 4305 struct export_fd_buf *efbuf) 4306 { 4307 int error; 4308 4309 if (efbuf->remainder == 0) 4310 return (0); 4311 export_file_to_kinfo(fp, fd, rightsp, &efbuf->kif, efbuf->fdp, 4312 efbuf->flags); 4313 FILEDESC_SUNLOCK(efbuf->fdp); 4314 error = export_kinfo_to_sb(efbuf); 4315 FILEDESC_SLOCK(efbuf->fdp); 4316 return (error); 4317 } 4318 4319 static int 4320 export_vnode_to_sb(struct vnode *vp, int fd, int fflags, 4321 struct export_fd_buf *efbuf) 4322 { 4323 int error; 4324 4325 if (efbuf->remainder == 0) 4326 return (0); 4327 if (efbuf->pdp != NULL) 4328 PWDDESC_XUNLOCK(efbuf->pdp); 4329 export_vnode_to_kinfo(vp, fd, fflags, &efbuf->kif, efbuf->flags); 4330 error = export_kinfo_to_sb(efbuf); 4331 if (efbuf->pdp != NULL) 4332 PWDDESC_XLOCK(efbuf->pdp); 4333 return (error); 4334 } 4335 4336 /* 4337 * Store a process file descriptor information to sbuf. 4338 * 4339 * Takes a locked proc as argument, and returns with the proc unlocked. 4340 */ 4341 int 4342 kern_proc_filedesc_out(struct proc *p, struct sbuf *sb, ssize_t maxlen, 4343 int flags) 4344 { 4345 struct file *fp; 4346 struct filedesc *fdp; 4347 struct pwddesc *pdp; 4348 struct export_fd_buf *efbuf; 4349 struct vnode *cttyvp, *textvp, *tracevp; 4350 struct pwd *pwd; 4351 int error, i, lastfile; 4352 cap_rights_t rights; 4353 4354 PROC_LOCK_ASSERT(p, MA_OWNED); 4355 4356 /* ktrace vnode */ 4357 tracevp = ktr_get_tracevp(p, true); 4358 /* text vnode */ 4359 textvp = p->p_textvp; 4360 if (textvp != NULL) 4361 vrefact(textvp); 4362 /* Controlling tty. */ 4363 cttyvp = NULL; 4364 if (p->p_pgrp != NULL && p->p_pgrp->pg_session != NULL) { 4365 cttyvp = p->p_pgrp->pg_session->s_ttyvp; 4366 if (cttyvp != NULL) 4367 vrefact(cttyvp); 4368 } 4369 fdp = fdhold(p); 4370 pdp = pdhold(p); 4371 PROC_UNLOCK(p); 4372 efbuf = malloc(sizeof(*efbuf), M_TEMP, M_WAITOK); 4373 efbuf->fdp = NULL; 4374 efbuf->pdp = NULL; 4375 efbuf->sb = sb; 4376 efbuf->remainder = maxlen; 4377 efbuf->flags = flags; 4378 if (tracevp != NULL) 4379 export_vnode_to_sb(tracevp, KF_FD_TYPE_TRACE, FREAD | FWRITE, 4380 efbuf); 4381 if (textvp != NULL) 4382 export_vnode_to_sb(textvp, KF_FD_TYPE_TEXT, FREAD, efbuf); 4383 if (cttyvp != NULL) 4384 export_vnode_to_sb(cttyvp, KF_FD_TYPE_CTTY, FREAD | FWRITE, 4385 efbuf); 4386 error = 0; 4387 if (pdp == NULL || fdp == NULL) 4388 goto fail; 4389 efbuf->fdp = fdp; 4390 efbuf->pdp = pdp; 4391 PWDDESC_XLOCK(pdp); 4392 pwd = pwd_hold_pwddesc(pdp); 4393 if (pwd != NULL) { 4394 /* working directory */ 4395 if (pwd->pwd_cdir != NULL) { 4396 vrefact(pwd->pwd_cdir); 4397 export_vnode_to_sb(pwd->pwd_cdir, KF_FD_TYPE_CWD, 4398 FREAD, efbuf); 4399 } 4400 /* root directory */ 4401 if (pwd->pwd_rdir != NULL) { 4402 vrefact(pwd->pwd_rdir); 4403 export_vnode_to_sb(pwd->pwd_rdir, KF_FD_TYPE_ROOT, 4404 FREAD, efbuf); 4405 } 4406 /* jail directory */ 4407 if (pwd->pwd_jdir != NULL) { 4408 vrefact(pwd->pwd_jdir); 4409 export_vnode_to_sb(pwd->pwd_jdir, KF_FD_TYPE_JAIL, 4410 FREAD, efbuf); 4411 } 4412 } 4413 PWDDESC_XUNLOCK(pdp); 4414 if (pwd != NULL) 4415 pwd_drop(pwd); 4416 FILEDESC_SLOCK(fdp); 4417 lastfile = fdlastfile(fdp); 4418 for (i = 0; refcount_load(&fdp->fd_refcnt) > 0 && i <= lastfile; i++) { 4419 if ((fp = fdp->fd_ofiles[i].fde_file) == NULL) 4420 continue; 4421 #ifdef CAPABILITIES 4422 rights = *cap_rights(fdp, i); 4423 #else /* !CAPABILITIES */ 4424 rights = cap_no_rights; 4425 #endif 4426 /* 4427 * Create sysctl entry. It is OK to drop the filedesc 4428 * lock inside of export_file_to_sb() as we will 4429 * re-validate and re-evaluate its properties when the 4430 * loop continues. 4431 */ 4432 error = export_file_to_sb(fp, i, &rights, efbuf); 4433 if (error != 0 || efbuf->remainder == 0) 4434 break; 4435 } 4436 FILEDESC_SUNLOCK(fdp); 4437 fail: 4438 if (fdp != NULL) 4439 fddrop(fdp); 4440 if (pdp != NULL) 4441 pddrop(pdp); 4442 free(efbuf, M_TEMP); 4443 return (error); 4444 } 4445 4446 #define FILEDESC_SBUF_SIZE (sizeof(struct kinfo_file) * 5) 4447 4448 /* 4449 * Get per-process file descriptors for use by procstat(1), et al. 4450 */ 4451 static int 4452 sysctl_kern_proc_filedesc(SYSCTL_HANDLER_ARGS) 4453 { 4454 struct sbuf sb; 4455 struct proc *p; 4456 ssize_t maxlen; 4457 u_int namelen; 4458 int error, error2, *name; 4459 4460 namelen = arg2; 4461 if (namelen != 1) 4462 return (EINVAL); 4463 4464 name = (int *)arg1; 4465 4466 sbuf_new_for_sysctl(&sb, NULL, FILEDESC_SBUF_SIZE, req); 4467 sbuf_clear_flags(&sb, SBUF_INCLUDENUL); 4468 error = pget((pid_t)name[0], PGET_CANDEBUG | PGET_NOTWEXIT, &p); 4469 if (error != 0) { 4470 sbuf_delete(&sb); 4471 return (error); 4472 } 4473 maxlen = req->oldptr != NULL ? req->oldlen : -1; 4474 error = kern_proc_filedesc_out(p, &sb, maxlen, 4475 KERN_FILEDESC_PACK_KINFO); 4476 error2 = sbuf_finish(&sb); 4477 sbuf_delete(&sb); 4478 return (error != 0 ? error : error2); 4479 } 4480 4481 #ifdef COMPAT_FREEBSD7 4482 #ifdef KINFO_OFILE_SIZE 4483 CTASSERT(sizeof(struct kinfo_ofile) == KINFO_OFILE_SIZE); 4484 #endif 4485 4486 static void 4487 kinfo_to_okinfo(struct kinfo_file *kif, struct kinfo_ofile *okif) 4488 { 4489 4490 okif->kf_structsize = sizeof(*okif); 4491 okif->kf_type = kif->kf_type; 4492 okif->kf_fd = kif->kf_fd; 4493 okif->kf_ref_count = kif->kf_ref_count; 4494 okif->kf_flags = kif->kf_flags & (KF_FLAG_READ | KF_FLAG_WRITE | 4495 KF_FLAG_APPEND | KF_FLAG_ASYNC | KF_FLAG_FSYNC | KF_FLAG_NONBLOCK | 4496 KF_FLAG_DIRECT | KF_FLAG_HASLOCK); 4497 okif->kf_offset = kif->kf_offset; 4498 if (kif->kf_type == KF_TYPE_VNODE) 4499 okif->kf_vnode_type = kif->kf_un.kf_file.kf_file_type; 4500 else 4501 okif->kf_vnode_type = KF_VTYPE_VNON; 4502 strlcpy(okif->kf_path, kif->kf_path, sizeof(okif->kf_path)); 4503 if (kif->kf_type == KF_TYPE_SOCKET) { 4504 okif->kf_sock_domain = kif->kf_un.kf_sock.kf_sock_domain0; 4505 okif->kf_sock_type = kif->kf_un.kf_sock.kf_sock_type0; 4506 okif->kf_sock_protocol = kif->kf_un.kf_sock.kf_sock_protocol0; 4507 okif->kf_sa_local = kif->kf_un.kf_sock.kf_sa_local; 4508 okif->kf_sa_peer = kif->kf_un.kf_sock.kf_sa_peer; 4509 } else { 4510 okif->kf_sa_local.ss_family = AF_UNSPEC; 4511 okif->kf_sa_peer.ss_family = AF_UNSPEC; 4512 } 4513 } 4514 4515 static int 4516 export_vnode_for_osysctl(struct vnode *vp, int type, struct kinfo_file *kif, 4517 struct kinfo_ofile *okif, struct pwddesc *pdp, struct sysctl_req *req) 4518 { 4519 int error; 4520 4521 vrefact(vp); 4522 PWDDESC_XUNLOCK(pdp); 4523 export_vnode_to_kinfo(vp, type, 0, kif, KERN_FILEDESC_PACK_KINFO); 4524 kinfo_to_okinfo(kif, okif); 4525 error = SYSCTL_OUT(req, okif, sizeof(*okif)); 4526 PWDDESC_XLOCK(pdp); 4527 return (error); 4528 } 4529 4530 /* 4531 * Get per-process file descriptors for use by procstat(1), et al. 4532 */ 4533 static int 4534 sysctl_kern_proc_ofiledesc(SYSCTL_HANDLER_ARGS) 4535 { 4536 struct kinfo_ofile *okif; 4537 struct kinfo_file *kif; 4538 struct filedesc *fdp; 4539 struct pwddesc *pdp; 4540 struct pwd *pwd; 4541 u_int namelen; 4542 int error, i, lastfile, *name; 4543 struct file *fp; 4544 struct proc *p; 4545 4546 namelen = arg2; 4547 if (namelen != 1) 4548 return (EINVAL); 4549 4550 name = (int *)arg1; 4551 error = pget((pid_t)name[0], PGET_CANDEBUG | PGET_NOTWEXIT, &p); 4552 if (error != 0) 4553 return (error); 4554 fdp = fdhold(p); 4555 if (fdp != NULL) 4556 pdp = pdhold(p); 4557 PROC_UNLOCK(p); 4558 if (fdp == NULL || pdp == NULL) { 4559 if (fdp != NULL) 4560 fddrop(fdp); 4561 return (ENOENT); 4562 } 4563 kif = malloc(sizeof(*kif), M_TEMP, M_WAITOK); 4564 okif = malloc(sizeof(*okif), M_TEMP, M_WAITOK); 4565 PWDDESC_XLOCK(pdp); 4566 pwd = pwd_hold_pwddesc(pdp); 4567 if (pwd != NULL) { 4568 if (pwd->pwd_cdir != NULL) 4569 export_vnode_for_osysctl(pwd->pwd_cdir, KF_FD_TYPE_CWD, kif, 4570 okif, pdp, req); 4571 if (pwd->pwd_rdir != NULL) 4572 export_vnode_for_osysctl(pwd->pwd_rdir, KF_FD_TYPE_ROOT, kif, 4573 okif, pdp, req); 4574 if (pwd->pwd_jdir != NULL) 4575 export_vnode_for_osysctl(pwd->pwd_jdir, KF_FD_TYPE_JAIL, kif, 4576 okif, pdp, req); 4577 } 4578 PWDDESC_XUNLOCK(pdp); 4579 if (pwd != NULL) 4580 pwd_drop(pwd); 4581 FILEDESC_SLOCK(fdp); 4582 lastfile = fdlastfile(fdp); 4583 for (i = 0; refcount_load(&fdp->fd_refcnt) > 0 && i <= lastfile; i++) { 4584 if ((fp = fdp->fd_ofiles[i].fde_file) == NULL) 4585 continue; 4586 export_file_to_kinfo(fp, i, NULL, kif, fdp, 4587 KERN_FILEDESC_PACK_KINFO); 4588 FILEDESC_SUNLOCK(fdp); 4589 kinfo_to_okinfo(kif, okif); 4590 error = SYSCTL_OUT(req, okif, sizeof(*okif)); 4591 FILEDESC_SLOCK(fdp); 4592 if (error) 4593 break; 4594 } 4595 FILEDESC_SUNLOCK(fdp); 4596 fddrop(fdp); 4597 pddrop(pdp); 4598 free(kif, M_TEMP); 4599 free(okif, M_TEMP); 4600 return (0); 4601 } 4602 4603 static SYSCTL_NODE(_kern_proc, KERN_PROC_OFILEDESC, ofiledesc, 4604 CTLFLAG_RD|CTLFLAG_MPSAFE, sysctl_kern_proc_ofiledesc, 4605 "Process ofiledesc entries"); 4606 #endif /* COMPAT_FREEBSD7 */ 4607 4608 int 4609 vntype_to_kinfo(int vtype) 4610 { 4611 struct { 4612 int vtype; 4613 int kf_vtype; 4614 } vtypes_table[] = { 4615 { VBAD, KF_VTYPE_VBAD }, 4616 { VBLK, KF_VTYPE_VBLK }, 4617 { VCHR, KF_VTYPE_VCHR }, 4618 { VDIR, KF_VTYPE_VDIR }, 4619 { VFIFO, KF_VTYPE_VFIFO }, 4620 { VLNK, KF_VTYPE_VLNK }, 4621 { VNON, KF_VTYPE_VNON }, 4622 { VREG, KF_VTYPE_VREG }, 4623 { VSOCK, KF_VTYPE_VSOCK } 4624 }; 4625 unsigned int i; 4626 4627 /* 4628 * Perform vtype translation. 4629 */ 4630 for (i = 0; i < nitems(vtypes_table); i++) 4631 if (vtypes_table[i].vtype == vtype) 4632 return (vtypes_table[i].kf_vtype); 4633 4634 return (KF_VTYPE_UNKNOWN); 4635 } 4636 4637 static SYSCTL_NODE(_kern_proc, KERN_PROC_FILEDESC, filedesc, 4638 CTLFLAG_RD|CTLFLAG_MPSAFE, sysctl_kern_proc_filedesc, 4639 "Process filedesc entries"); 4640 4641 /* 4642 * Store a process current working directory information to sbuf. 4643 * 4644 * Takes a locked proc as argument, and returns with the proc unlocked. 4645 */ 4646 int 4647 kern_proc_cwd_out(struct proc *p, struct sbuf *sb, ssize_t maxlen) 4648 { 4649 struct pwddesc *pdp; 4650 struct pwd *pwd; 4651 struct export_fd_buf *efbuf; 4652 struct vnode *cdir; 4653 int error; 4654 4655 PROC_LOCK_ASSERT(p, MA_OWNED); 4656 4657 pdp = pdhold(p); 4658 PROC_UNLOCK(p); 4659 if (pdp == NULL) 4660 return (EINVAL); 4661 4662 efbuf = malloc(sizeof(*efbuf), M_TEMP, M_WAITOK); 4663 efbuf->pdp = pdp; 4664 efbuf->sb = sb; 4665 efbuf->remainder = maxlen; 4666 4667 PWDDESC_XLOCK(pdp); 4668 pwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); 4669 cdir = pwd->pwd_cdir; 4670 if (cdir == NULL) { 4671 error = EINVAL; 4672 } else { 4673 vrefact(cdir); 4674 error = export_vnode_to_sb(cdir, KF_FD_TYPE_CWD, FREAD, efbuf); 4675 } 4676 PWDDESC_XUNLOCK(pdp); 4677 pddrop(pdp); 4678 free(efbuf, M_TEMP); 4679 return (error); 4680 } 4681 4682 /* 4683 * Get per-process current working directory. 4684 */ 4685 static int 4686 sysctl_kern_proc_cwd(SYSCTL_HANDLER_ARGS) 4687 { 4688 struct sbuf sb; 4689 struct proc *p; 4690 ssize_t maxlen; 4691 u_int namelen; 4692 int error, error2, *name; 4693 4694 namelen = arg2; 4695 if (namelen != 1) 4696 return (EINVAL); 4697 4698 name = (int *)arg1; 4699 4700 sbuf_new_for_sysctl(&sb, NULL, sizeof(struct kinfo_file), req); 4701 sbuf_clear_flags(&sb, SBUF_INCLUDENUL); 4702 error = pget((pid_t)name[0], PGET_CANDEBUG | PGET_NOTWEXIT, &p); 4703 if (error != 0) { 4704 sbuf_delete(&sb); 4705 return (error); 4706 } 4707 maxlen = req->oldptr != NULL ? req->oldlen : -1; 4708 error = kern_proc_cwd_out(p, &sb, maxlen); 4709 error2 = sbuf_finish(&sb); 4710 sbuf_delete(&sb); 4711 return (error != 0 ? error : error2); 4712 } 4713 4714 static SYSCTL_NODE(_kern_proc, KERN_PROC_CWD, cwd, CTLFLAG_RD|CTLFLAG_MPSAFE, 4715 sysctl_kern_proc_cwd, "Process current working directory"); 4716 4717 #ifdef DDB 4718 /* 4719 * For the purposes of debugging, generate a human-readable string for the 4720 * file type. 4721 */ 4722 static const char * 4723 file_type_to_name(short type) 4724 { 4725 4726 switch (type) { 4727 case 0: 4728 return ("zero"); 4729 case DTYPE_VNODE: 4730 return ("vnode"); 4731 case DTYPE_SOCKET: 4732 return ("socket"); 4733 case DTYPE_PIPE: 4734 return ("pipe"); 4735 case DTYPE_FIFO: 4736 return ("fifo"); 4737 case DTYPE_KQUEUE: 4738 return ("kqueue"); 4739 case DTYPE_CRYPTO: 4740 return ("crypto"); 4741 case DTYPE_MQUEUE: 4742 return ("mqueue"); 4743 case DTYPE_SHM: 4744 return ("shm"); 4745 case DTYPE_SEM: 4746 return ("ksem"); 4747 case DTYPE_PTS: 4748 return ("pts"); 4749 case DTYPE_DEV: 4750 return ("dev"); 4751 case DTYPE_PROCDESC: 4752 return ("proc"); 4753 case DTYPE_EVENTFD: 4754 return ("eventfd"); 4755 case DTYPE_LINUXTFD: 4756 return ("ltimer"); 4757 default: 4758 return ("unkn"); 4759 } 4760 } 4761 4762 /* 4763 * For the purposes of debugging, identify a process (if any, perhaps one of 4764 * many) that references the passed file in its file descriptor array. Return 4765 * NULL if none. 4766 */ 4767 static struct proc * 4768 file_to_first_proc(struct file *fp) 4769 { 4770 struct filedesc *fdp; 4771 struct proc *p; 4772 int n; 4773 4774 FOREACH_PROC_IN_SYSTEM(p) { 4775 if (p->p_state == PRS_NEW) 4776 continue; 4777 fdp = p->p_fd; 4778 if (fdp == NULL) 4779 continue; 4780 for (n = 0; n < fdp->fd_nfiles; n++) { 4781 if (fp == fdp->fd_ofiles[n].fde_file) 4782 return (p); 4783 } 4784 } 4785 return (NULL); 4786 } 4787 4788 static void 4789 db_print_file(struct file *fp, int header) 4790 { 4791 #define XPTRWIDTH ((int)howmany(sizeof(void *) * NBBY, 4)) 4792 struct proc *p; 4793 4794 if (header) 4795 db_printf("%*s %6s %*s %8s %4s %5s %6s %*s %5s %s\n", 4796 XPTRWIDTH, "File", "Type", XPTRWIDTH, "Data", "Flag", 4797 "GCFl", "Count", "MCount", XPTRWIDTH, "Vnode", "FPID", 4798 "FCmd"); 4799 p = file_to_first_proc(fp); 4800 db_printf("%*p %6s %*p %08x %04x %5d %6d %*p %5d %s\n", XPTRWIDTH, 4801 fp, file_type_to_name(fp->f_type), XPTRWIDTH, fp->f_data, 4802 fp->f_flag, 0, refcount_load(&fp->f_count), 0, XPTRWIDTH, fp->f_vnode, 4803 p != NULL ? p->p_pid : -1, p != NULL ? p->p_comm : "-"); 4804 4805 #undef XPTRWIDTH 4806 } 4807 4808 DB_SHOW_COMMAND(file, db_show_file) 4809 { 4810 struct file *fp; 4811 4812 if (!have_addr) { 4813 db_printf("usage: show file <addr>\n"); 4814 return; 4815 } 4816 fp = (struct file *)addr; 4817 db_print_file(fp, 1); 4818 } 4819 4820 DB_SHOW_COMMAND(files, db_show_files) 4821 { 4822 struct filedesc *fdp; 4823 struct file *fp; 4824 struct proc *p; 4825 int header; 4826 int n; 4827 4828 header = 1; 4829 FOREACH_PROC_IN_SYSTEM(p) { 4830 if (p->p_state == PRS_NEW) 4831 continue; 4832 if ((fdp = p->p_fd) == NULL) 4833 continue; 4834 for (n = 0; n < fdp->fd_nfiles; ++n) { 4835 if ((fp = fdp->fd_ofiles[n].fde_file) == NULL) 4836 continue; 4837 db_print_file(fp, header); 4838 header = 0; 4839 } 4840 } 4841 } 4842 #endif 4843 4844 SYSCTL_INT(_kern, KERN_MAXFILESPERPROC, maxfilesperproc, CTLFLAG_RW, 4845 &maxfilesperproc, 0, "Maximum files allowed open per process"); 4846 4847 SYSCTL_INT(_kern, KERN_MAXFILES, maxfiles, CTLFLAG_RW, 4848 &maxfiles, 0, "Maximum number of files"); 4849 4850 SYSCTL_INT(_kern, OID_AUTO, openfiles, CTLFLAG_RD, 4851 &openfiles, 0, "System-wide number of open files"); 4852 4853 /* ARGSUSED*/ 4854 static void 4855 filelistinit(void *dummy) 4856 { 4857 4858 file_zone = uma_zcreate("Files", sizeof(struct file), NULL, NULL, 4859 NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE); 4860 filedesc0_zone = uma_zcreate("filedesc0", sizeof(struct filedesc0), 4861 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0); 4862 pwd_zone = uma_zcreate("PWD", sizeof(struct pwd), NULL, NULL, 4863 NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_SMR); 4864 /* 4865 * XXXMJG this is a temporary hack due to boot ordering issues against 4866 * the vnode zone. 4867 */ 4868 vfs_smr = uma_zone_get_smr(pwd_zone); 4869 mtx_init(&sigio_lock, "sigio lock", NULL, MTX_DEF); 4870 } 4871 SYSINIT(select, SI_SUB_LOCK, SI_ORDER_FIRST, filelistinit, NULL); 4872 4873 /*-------------------------------------------------------------------*/ 4874 4875 static int 4876 badfo_readwrite(struct file *fp, struct uio *uio, struct ucred *active_cred, 4877 int flags, struct thread *td) 4878 { 4879 4880 return (EBADF); 4881 } 4882 4883 static int 4884 badfo_truncate(struct file *fp, off_t length, struct ucred *active_cred, 4885 struct thread *td) 4886 { 4887 4888 return (EINVAL); 4889 } 4890 4891 static int 4892 badfo_ioctl(struct file *fp, u_long com, void *data, struct ucred *active_cred, 4893 struct thread *td) 4894 { 4895 4896 return (EBADF); 4897 } 4898 4899 static int 4900 badfo_poll(struct file *fp, int events, struct ucred *active_cred, 4901 struct thread *td) 4902 { 4903 4904 return (0); 4905 } 4906 4907 static int 4908 badfo_kqfilter(struct file *fp, struct knote *kn) 4909 { 4910 4911 return (EBADF); 4912 } 4913 4914 static int 4915 badfo_stat(struct file *fp, struct stat *sb, struct ucred *active_cred) 4916 { 4917 4918 return (EBADF); 4919 } 4920 4921 static int 4922 badfo_close(struct file *fp, struct thread *td) 4923 { 4924 4925 return (0); 4926 } 4927 4928 static int 4929 badfo_chmod(struct file *fp, mode_t mode, struct ucred *active_cred, 4930 struct thread *td) 4931 { 4932 4933 return (EBADF); 4934 } 4935 4936 static int 4937 badfo_chown(struct file *fp, uid_t uid, gid_t gid, struct ucred *active_cred, 4938 struct thread *td) 4939 { 4940 4941 return (EBADF); 4942 } 4943 4944 static int 4945 badfo_sendfile(struct file *fp, int sockfd, struct uio *hdr_uio, 4946 struct uio *trl_uio, off_t offset, size_t nbytes, off_t *sent, int flags, 4947 struct thread *td) 4948 { 4949 4950 return (EBADF); 4951 } 4952 4953 static int 4954 badfo_fill_kinfo(struct file *fp, struct kinfo_file *kif, struct filedesc *fdp) 4955 { 4956 4957 return (0); 4958 } 4959 4960 struct fileops badfileops = { 4961 .fo_read = badfo_readwrite, 4962 .fo_write = badfo_readwrite, 4963 .fo_truncate = badfo_truncate, 4964 .fo_ioctl = badfo_ioctl, 4965 .fo_poll = badfo_poll, 4966 .fo_kqfilter = badfo_kqfilter, 4967 .fo_stat = badfo_stat, 4968 .fo_close = badfo_close, 4969 .fo_chmod = badfo_chmod, 4970 .fo_chown = badfo_chown, 4971 .fo_sendfile = badfo_sendfile, 4972 .fo_fill_kinfo = badfo_fill_kinfo, 4973 }; 4974 4975 static int 4976 path_poll(struct file *fp, int events, struct ucred *active_cred, 4977 struct thread *td) 4978 { 4979 return (POLLNVAL); 4980 } 4981 4982 static int 4983 path_close(struct file *fp, struct thread *td) 4984 { 4985 MPASS(fp->f_type == DTYPE_VNODE); 4986 fp->f_ops = &badfileops; 4987 vdrop(fp->f_vnode); 4988 return (0); 4989 } 4990 4991 struct fileops path_fileops = { 4992 .fo_read = badfo_readwrite, 4993 .fo_write = badfo_readwrite, 4994 .fo_truncate = badfo_truncate, 4995 .fo_ioctl = badfo_ioctl, 4996 .fo_poll = path_poll, 4997 .fo_kqfilter = vn_kqfilter_opath, 4998 .fo_stat = vn_statfile, 4999 .fo_close = path_close, 5000 .fo_chmod = badfo_chmod, 5001 .fo_chown = badfo_chown, 5002 .fo_sendfile = badfo_sendfile, 5003 .fo_fill_kinfo = vn_fill_kinfo, 5004 .fo_flags = DFLAG_PASSABLE, 5005 }; 5006 5007 int 5008 invfo_rdwr(struct file *fp, struct uio *uio, struct ucred *active_cred, 5009 int flags, struct thread *td) 5010 { 5011 5012 return (EOPNOTSUPP); 5013 } 5014 5015 int 5016 invfo_truncate(struct file *fp, off_t length, struct ucred *active_cred, 5017 struct thread *td) 5018 { 5019 5020 return (EINVAL); 5021 } 5022 5023 int 5024 invfo_ioctl(struct file *fp, u_long com, void *data, 5025 struct ucred *active_cred, struct thread *td) 5026 { 5027 5028 return (ENOTTY); 5029 } 5030 5031 int 5032 invfo_poll(struct file *fp, int events, struct ucred *active_cred, 5033 struct thread *td) 5034 { 5035 5036 return (poll_no_poll(events)); 5037 } 5038 5039 int 5040 invfo_kqfilter(struct file *fp, struct knote *kn) 5041 { 5042 5043 return (EINVAL); 5044 } 5045 5046 int 5047 invfo_chmod(struct file *fp, mode_t mode, struct ucred *active_cred, 5048 struct thread *td) 5049 { 5050 5051 return (EINVAL); 5052 } 5053 5054 int 5055 invfo_chown(struct file *fp, uid_t uid, gid_t gid, struct ucred *active_cred, 5056 struct thread *td) 5057 { 5058 5059 return (EINVAL); 5060 } 5061 5062 int 5063 invfo_sendfile(struct file *fp, int sockfd, struct uio *hdr_uio, 5064 struct uio *trl_uio, off_t offset, size_t nbytes, off_t *sent, int flags, 5065 struct thread *td) 5066 { 5067 5068 return (EINVAL); 5069 } 5070 5071 /*-------------------------------------------------------------------*/ 5072 5073 /* 5074 * File Descriptor pseudo-device driver (/dev/fd/). 5075 * 5076 * Opening minor device N dup()s the file (if any) connected to file 5077 * descriptor N belonging to the calling process. Note that this driver 5078 * consists of only the ``open()'' routine, because all subsequent 5079 * references to this file will be direct to the other driver. 5080 * 5081 * XXX: we could give this one a cloning event handler if necessary. 5082 */ 5083 5084 /* ARGSUSED */ 5085 static int 5086 fdopen(struct cdev *dev, int mode, int type, struct thread *td) 5087 { 5088 5089 /* 5090 * XXX Kludge: set curthread->td_dupfd to contain the value of the 5091 * the file descriptor being sought for duplication. The error 5092 * return ensures that the vnode for this device will be released 5093 * by vn_open. Open will detect this special error and take the 5094 * actions in dupfdopen below. Other callers of vn_open or VOP_OPEN 5095 * will simply report the error. 5096 */ 5097 td->td_dupfd = dev2unit(dev); 5098 return (ENODEV); 5099 } 5100 5101 static struct cdevsw fildesc_cdevsw = { 5102 .d_version = D_VERSION, 5103 .d_open = fdopen, 5104 .d_name = "FD", 5105 }; 5106 5107 static void 5108 fildesc_drvinit(void *unused) 5109 { 5110 struct cdev *dev; 5111 5112 dev = make_dev_credf(MAKEDEV_ETERNAL, &fildesc_cdevsw, 0, NULL, 5113 UID_ROOT, GID_WHEEL, 0666, "fd/0"); 5114 make_dev_alias(dev, "stdin"); 5115 dev = make_dev_credf(MAKEDEV_ETERNAL, &fildesc_cdevsw, 1, NULL, 5116 UID_ROOT, GID_WHEEL, 0666, "fd/1"); 5117 make_dev_alias(dev, "stdout"); 5118 dev = make_dev_credf(MAKEDEV_ETERNAL, &fildesc_cdevsw, 2, NULL, 5119 UID_ROOT, GID_WHEEL, 0666, "fd/2"); 5120 make_dev_alias(dev, "stderr"); 5121 } 5122 5123 SYSINIT(fildescdev, SI_SUB_DRIVERS, SI_ORDER_MIDDLE, fildesc_drvinit, NULL); 5124