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/priv.h> 65 #include <sys/proc.h> 66 #include <sys/protosw.h> 67 #include <sys/racct.h> 68 #include <sys/resourcevar.h> 69 #include <sys/sbuf.h> 70 #include <sys/signalvar.h> 71 #include <sys/kdb.h> 72 #include <sys/stat.h> 73 #include <sys/sx.h> 74 #include <sys/syscallsubr.h> 75 #include <sys/sysctl.h> 76 #include <sys/sysproto.h> 77 #include <sys/unistd.h> 78 #include <sys/user.h> 79 #include <sys/vnode.h> 80 #ifdef KTRACE 81 #include <sys/ktrace.h> 82 #endif 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_FILEDESC_TO_LEADER, "filedesc_to_leader", 95 "file desc to leader structures"); 96 static MALLOC_DEFINE(M_SIGIO, "sigio", "sigio structures"); 97 MALLOC_DEFINE(M_FILECAPS, "filecaps", "descriptor capabilities"); 98 99 MALLOC_DECLARE(M_FADVISE); 100 101 static __read_mostly uma_zone_t file_zone; 102 static __read_mostly uma_zone_t filedesc0_zone; 103 104 static int closefp(struct filedesc *fdp, int fd, struct file *fp, 105 struct thread *td, int holdleaders); 106 static int fd_first_free(struct filedesc *fdp, int low, int size); 107 static int fd_last_used(struct filedesc *fdp, int size); 108 static void fdgrowtable(struct filedesc *fdp, int nfd); 109 static void fdgrowtable_exp(struct filedesc *fdp, int nfd); 110 static void fdunused(struct filedesc *fdp, int fd); 111 static void fdused(struct filedesc *fdp, int fd); 112 static int getmaxfd(struct thread *td); 113 static u_long *filecaps_copy_prep(const struct filecaps *src); 114 static void filecaps_copy_finish(const struct filecaps *src, 115 struct filecaps *dst, u_long *ioctls); 116 static u_long *filecaps_free_prep(struct filecaps *fcaps); 117 static void filecaps_free_finish(u_long *ioctls); 118 119 /* 120 * Each process has: 121 * 122 * - An array of open file descriptors (fd_ofiles) 123 * - An array of file flags (fd_ofileflags) 124 * - A bitmap recording which descriptors are in use (fd_map) 125 * 126 * A process starts out with NDFILE descriptors. The value of NDFILE has 127 * been selected based the historical limit of 20 open files, and an 128 * assumption that the majority of processes, especially short-lived 129 * processes like shells, will never need more. 130 * 131 * If this initial allocation is exhausted, a larger descriptor table and 132 * map are allocated dynamically, and the pointers in the process's struct 133 * filedesc are updated to point to those. This is repeated every time 134 * the process runs out of file descriptors (provided it hasn't hit its 135 * resource limit). 136 * 137 * Since threads may hold references to individual descriptor table 138 * entries, the tables are never freed. Instead, they are placed on a 139 * linked list and freed only when the struct filedesc is released. 140 */ 141 #define NDFILE 20 142 #define NDSLOTSIZE sizeof(NDSLOTTYPE) 143 #define NDENTRIES (NDSLOTSIZE * __CHAR_BIT) 144 #define NDSLOT(x) ((x) / NDENTRIES) 145 #define NDBIT(x) ((NDSLOTTYPE)1 << ((x) % NDENTRIES)) 146 #define NDSLOTS(x) (((x) + NDENTRIES - 1) / NDENTRIES) 147 148 /* 149 * SLIST entry used to keep track of ofiles which must be reclaimed when 150 * the process exits. 151 */ 152 struct freetable { 153 struct fdescenttbl *ft_table; 154 SLIST_ENTRY(freetable) ft_next; 155 }; 156 157 /* 158 * Initial allocation: a filedesc structure + the head of SLIST used to 159 * keep track of old ofiles + enough space for NDFILE descriptors. 160 */ 161 162 struct fdescenttbl0 { 163 int fdt_nfiles; 164 struct filedescent fdt_ofiles[NDFILE]; 165 }; 166 167 struct filedesc0 { 168 struct filedesc fd_fd; 169 SLIST_HEAD(, freetable) fd_free; 170 struct fdescenttbl0 fd_dfiles; 171 NDSLOTTYPE fd_dmap[NDSLOTS(NDFILE)]; 172 }; 173 174 /* 175 * Descriptor management. 176 */ 177 volatile int __exclusive_cache_line openfiles; /* actual number of open files */ 178 struct mtx sigio_lock; /* mtx to protect pointers to sigio */ 179 void __read_mostly (*mq_fdclose)(struct thread *td, int fd, struct file *fp); 180 181 /* 182 * If low >= size, just return low. Otherwise find the first zero bit in the 183 * given bitmap, starting at low and not exceeding size - 1. Return size if 184 * not found. 185 */ 186 static int 187 fd_first_free(struct filedesc *fdp, int low, int size) 188 { 189 NDSLOTTYPE *map = fdp->fd_map; 190 NDSLOTTYPE mask; 191 int off, maxoff; 192 193 if (low >= size) 194 return (low); 195 196 off = NDSLOT(low); 197 if (low % NDENTRIES) { 198 mask = ~(~(NDSLOTTYPE)0 >> (NDENTRIES - (low % NDENTRIES))); 199 if ((mask &= ~map[off]) != 0UL) 200 return (off * NDENTRIES + ffsl(mask) - 1); 201 ++off; 202 } 203 for (maxoff = NDSLOTS(size); off < maxoff; ++off) 204 if (map[off] != ~0UL) 205 return (off * NDENTRIES + ffsl(~map[off]) - 1); 206 return (size); 207 } 208 209 /* 210 * Find the highest non-zero bit in the given bitmap, starting at 0 and 211 * not exceeding size - 1. Return -1 if not found. 212 */ 213 static int 214 fd_last_used(struct filedesc *fdp, int size) 215 { 216 NDSLOTTYPE *map = fdp->fd_map; 217 NDSLOTTYPE mask; 218 int off, minoff; 219 220 off = NDSLOT(size); 221 if (size % NDENTRIES) { 222 mask = ~(~(NDSLOTTYPE)0 << (size % NDENTRIES)); 223 if ((mask &= map[off]) != 0) 224 return (off * NDENTRIES + flsl(mask) - 1); 225 --off; 226 } 227 for (minoff = NDSLOT(0); off >= minoff; --off) 228 if (map[off] != 0) 229 return (off * NDENTRIES + flsl(map[off]) - 1); 230 return (-1); 231 } 232 233 static int 234 fdisused(struct filedesc *fdp, int fd) 235 { 236 237 KASSERT(fd >= 0 && fd < fdp->fd_nfiles, 238 ("file descriptor %d out of range (0, %d)", fd, fdp->fd_nfiles)); 239 240 return ((fdp->fd_map[NDSLOT(fd)] & NDBIT(fd)) != 0); 241 } 242 243 /* 244 * Mark a file descriptor as used. 245 */ 246 static void 247 fdused_init(struct filedesc *fdp, int fd) 248 { 249 250 KASSERT(!fdisused(fdp, fd), ("fd=%d is already used", fd)); 251 252 fdp->fd_map[NDSLOT(fd)] |= NDBIT(fd); 253 } 254 255 static void 256 fdused(struct filedesc *fdp, int fd) 257 { 258 259 FILEDESC_XLOCK_ASSERT(fdp); 260 261 fdused_init(fdp, fd); 262 if (fd > fdp->fd_lastfile) 263 fdp->fd_lastfile = fd; 264 if (fd == fdp->fd_freefile) 265 fdp->fd_freefile++; 266 } 267 268 /* 269 * Mark a file descriptor as unused. 270 */ 271 static void 272 fdunused(struct filedesc *fdp, int fd) 273 { 274 275 FILEDESC_XLOCK_ASSERT(fdp); 276 277 KASSERT(fdisused(fdp, fd), ("fd=%d is already unused", fd)); 278 KASSERT(fdp->fd_ofiles[fd].fde_file == NULL, 279 ("fd=%d is still in use", fd)); 280 281 fdp->fd_map[NDSLOT(fd)] &= ~NDBIT(fd); 282 if (fd < fdp->fd_freefile) 283 fdp->fd_freefile = fd; 284 if (fd == fdp->fd_lastfile) 285 fdp->fd_lastfile = fd_last_used(fdp, fd); 286 } 287 288 /* 289 * Free a file descriptor. 290 * 291 * Avoid some work if fdp is about to be destroyed. 292 */ 293 static inline void 294 fdefree_last(struct filedescent *fde) 295 { 296 297 filecaps_free(&fde->fde_caps); 298 } 299 300 static inline void 301 fdfree(struct filedesc *fdp, int fd) 302 { 303 struct filedescent *fde; 304 305 fde = &fdp->fd_ofiles[fd]; 306 #ifdef CAPABILITIES 307 seqc_write_begin(&fde->fde_seqc); 308 #endif 309 fde->fde_file = NULL; 310 #ifdef CAPABILITIES 311 seqc_write_end(&fde->fde_seqc); 312 #endif 313 fdefree_last(fde); 314 fdunused(fdp, fd); 315 } 316 317 void 318 pwd_ensure_dirs(void) 319 { 320 struct filedesc *fdp; 321 322 fdp = curproc->p_fd; 323 FILEDESC_XLOCK(fdp); 324 if (fdp->fd_cdir == NULL) { 325 fdp->fd_cdir = rootvnode; 326 vrefact(rootvnode); 327 } 328 if (fdp->fd_rdir == NULL) { 329 fdp->fd_rdir = rootvnode; 330 vrefact(rootvnode); 331 } 332 FILEDESC_XUNLOCK(fdp); 333 } 334 335 /* 336 * System calls on descriptors. 337 */ 338 #ifndef _SYS_SYSPROTO_H_ 339 struct getdtablesize_args { 340 int dummy; 341 }; 342 #endif 343 /* ARGSUSED */ 344 int 345 sys_getdtablesize(struct thread *td, struct getdtablesize_args *uap) 346 { 347 #ifdef RACCT 348 uint64_t lim; 349 #endif 350 351 td->td_retval[0] = getmaxfd(td); 352 #ifdef RACCT 353 PROC_LOCK(td->td_proc); 354 lim = racct_get_limit(td->td_proc, RACCT_NOFILE); 355 PROC_UNLOCK(td->td_proc); 356 if (lim < td->td_retval[0]) 357 td->td_retval[0] = lim; 358 #endif 359 return (0); 360 } 361 362 /* 363 * Duplicate a file descriptor to a particular value. 364 * 365 * Note: keep in mind that a potential race condition exists when closing 366 * descriptors from a shared descriptor table (via rfork). 367 */ 368 #ifndef _SYS_SYSPROTO_H_ 369 struct dup2_args { 370 u_int from; 371 u_int to; 372 }; 373 #endif 374 /* ARGSUSED */ 375 int 376 sys_dup2(struct thread *td, struct dup2_args *uap) 377 { 378 379 return (kern_dup(td, FDDUP_FIXED, 0, (int)uap->from, (int)uap->to)); 380 } 381 382 /* 383 * Duplicate a file descriptor. 384 */ 385 #ifndef _SYS_SYSPROTO_H_ 386 struct dup_args { 387 u_int fd; 388 }; 389 #endif 390 /* ARGSUSED */ 391 int 392 sys_dup(struct thread *td, struct dup_args *uap) 393 { 394 395 return (kern_dup(td, FDDUP_NORMAL, 0, (int)uap->fd, 0)); 396 } 397 398 /* 399 * The file control system call. 400 */ 401 #ifndef _SYS_SYSPROTO_H_ 402 struct fcntl_args { 403 int fd; 404 int cmd; 405 long arg; 406 }; 407 #endif 408 /* ARGSUSED */ 409 int 410 sys_fcntl(struct thread *td, struct fcntl_args *uap) 411 { 412 413 return (kern_fcntl_freebsd(td, uap->fd, uap->cmd, uap->arg)); 414 } 415 416 int 417 kern_fcntl_freebsd(struct thread *td, int fd, int cmd, long arg) 418 { 419 struct flock fl; 420 struct __oflock ofl; 421 intptr_t arg1; 422 int error, newcmd; 423 424 error = 0; 425 newcmd = cmd; 426 switch (cmd) { 427 case F_OGETLK: 428 case F_OSETLK: 429 case F_OSETLKW: 430 /* 431 * Convert old flock structure to new. 432 */ 433 error = copyin((void *)(intptr_t)arg, &ofl, sizeof(ofl)); 434 fl.l_start = ofl.l_start; 435 fl.l_len = ofl.l_len; 436 fl.l_pid = ofl.l_pid; 437 fl.l_type = ofl.l_type; 438 fl.l_whence = ofl.l_whence; 439 fl.l_sysid = 0; 440 441 switch (cmd) { 442 case F_OGETLK: 443 newcmd = F_GETLK; 444 break; 445 case F_OSETLK: 446 newcmd = F_SETLK; 447 break; 448 case F_OSETLKW: 449 newcmd = F_SETLKW; 450 break; 451 } 452 arg1 = (intptr_t)&fl; 453 break; 454 case F_GETLK: 455 case F_SETLK: 456 case F_SETLKW: 457 case F_SETLK_REMOTE: 458 error = copyin((void *)(intptr_t)arg, &fl, sizeof(fl)); 459 arg1 = (intptr_t)&fl; 460 break; 461 default: 462 arg1 = arg; 463 break; 464 } 465 if (error) 466 return (error); 467 error = kern_fcntl(td, fd, newcmd, arg1); 468 if (error) 469 return (error); 470 if (cmd == F_OGETLK) { 471 ofl.l_start = fl.l_start; 472 ofl.l_len = fl.l_len; 473 ofl.l_pid = fl.l_pid; 474 ofl.l_type = fl.l_type; 475 ofl.l_whence = fl.l_whence; 476 error = copyout(&ofl, (void *)(intptr_t)arg, sizeof(ofl)); 477 } else if (cmd == F_GETLK) { 478 error = copyout(&fl, (void *)(intptr_t)arg, sizeof(fl)); 479 } 480 return (error); 481 } 482 483 int 484 kern_fcntl(struct thread *td, int fd, int cmd, intptr_t arg) 485 { 486 struct filedesc *fdp; 487 struct flock *flp; 488 struct file *fp, *fp2; 489 struct filedescent *fde; 490 struct proc *p; 491 struct vnode *vp; 492 int error, flg, tmp; 493 uint64_t bsize; 494 off_t foffset; 495 496 error = 0; 497 flg = F_POSIX; 498 p = td->td_proc; 499 fdp = p->p_fd; 500 501 AUDIT_ARG_FD(cmd); 502 AUDIT_ARG_CMD(cmd); 503 switch (cmd) { 504 case F_DUPFD: 505 tmp = arg; 506 error = kern_dup(td, FDDUP_FCNTL, 0, fd, tmp); 507 break; 508 509 case F_DUPFD_CLOEXEC: 510 tmp = arg; 511 error = kern_dup(td, FDDUP_FCNTL, FDDUP_FLAG_CLOEXEC, fd, tmp); 512 break; 513 514 case F_DUP2FD: 515 tmp = arg; 516 error = kern_dup(td, FDDUP_FIXED, 0, fd, tmp); 517 break; 518 519 case F_DUP2FD_CLOEXEC: 520 tmp = arg; 521 error = kern_dup(td, FDDUP_FIXED, FDDUP_FLAG_CLOEXEC, fd, tmp); 522 break; 523 524 case F_GETFD: 525 error = EBADF; 526 FILEDESC_SLOCK(fdp); 527 fde = fdeget_locked(fdp, fd); 528 if (fde != NULL) { 529 td->td_retval[0] = 530 (fde->fde_flags & UF_EXCLOSE) ? FD_CLOEXEC : 0; 531 error = 0; 532 } 533 FILEDESC_SUNLOCK(fdp); 534 break; 535 536 case F_SETFD: 537 error = EBADF; 538 FILEDESC_XLOCK(fdp); 539 fde = fdeget_locked(fdp, fd); 540 if (fde != NULL) { 541 fde->fde_flags = (fde->fde_flags & ~UF_EXCLOSE) | 542 (arg & FD_CLOEXEC ? UF_EXCLOSE : 0); 543 error = 0; 544 } 545 FILEDESC_XUNLOCK(fdp); 546 break; 547 548 case F_GETFL: 549 error = fget_fcntl(td, fd, &cap_fcntl_rights, F_GETFL, &fp); 550 if (error != 0) 551 break; 552 td->td_retval[0] = OFLAGS(fp->f_flag); 553 fdrop(fp, td); 554 break; 555 556 case F_SETFL: 557 error = fget_fcntl(td, fd, &cap_fcntl_rights, F_SETFL, &fp); 558 if (error != 0) 559 break; 560 do { 561 tmp = flg = fp->f_flag; 562 tmp &= ~FCNTLFLAGS; 563 tmp |= FFLAGS(arg & ~O_ACCMODE) & FCNTLFLAGS; 564 } while(atomic_cmpset_int(&fp->f_flag, flg, tmp) == 0); 565 tmp = fp->f_flag & FNONBLOCK; 566 error = fo_ioctl(fp, FIONBIO, &tmp, td->td_ucred, td); 567 if (error != 0) { 568 fdrop(fp, td); 569 break; 570 } 571 tmp = fp->f_flag & FASYNC; 572 error = fo_ioctl(fp, FIOASYNC, &tmp, td->td_ucred, td); 573 if (error == 0) { 574 fdrop(fp, td); 575 break; 576 } 577 atomic_clear_int(&fp->f_flag, FNONBLOCK); 578 tmp = 0; 579 (void)fo_ioctl(fp, FIONBIO, &tmp, td->td_ucred, td); 580 fdrop(fp, td); 581 break; 582 583 case F_GETOWN: 584 error = fget_fcntl(td, fd, &cap_fcntl_rights, F_GETOWN, &fp); 585 if (error != 0) 586 break; 587 error = fo_ioctl(fp, FIOGETOWN, &tmp, td->td_ucred, td); 588 if (error == 0) 589 td->td_retval[0] = tmp; 590 fdrop(fp, td); 591 break; 592 593 case F_SETOWN: 594 error = fget_fcntl(td, fd, &cap_fcntl_rights, F_SETOWN, &fp); 595 if (error != 0) 596 break; 597 tmp = arg; 598 error = fo_ioctl(fp, FIOSETOWN, &tmp, td->td_ucred, td); 599 fdrop(fp, td); 600 break; 601 602 case F_SETLK_REMOTE: 603 error = priv_check(td, PRIV_NFS_LOCKD); 604 if (error != 0) 605 return (error); 606 flg = F_REMOTE; 607 goto do_setlk; 608 609 case F_SETLKW: 610 flg |= F_WAIT; 611 /* FALLTHROUGH F_SETLK */ 612 613 case F_SETLK: 614 do_setlk: 615 flp = (struct flock *)arg; 616 if ((flg & F_REMOTE) != 0 && flp->l_sysid == 0) { 617 error = EINVAL; 618 break; 619 } 620 621 error = fget_unlocked(fdp, fd, &cap_flock_rights, &fp, NULL); 622 if (error != 0) 623 break; 624 if (fp->f_type != DTYPE_VNODE) { 625 error = EBADF; 626 fdrop(fp, td); 627 break; 628 } 629 630 if (flp->l_whence == SEEK_CUR) { 631 foffset = foffset_get(fp); 632 if (foffset < 0 || 633 (flp->l_start > 0 && 634 foffset > OFF_MAX - flp->l_start)) { 635 error = EOVERFLOW; 636 fdrop(fp, td); 637 break; 638 } 639 flp->l_start += foffset; 640 } 641 642 vp = fp->f_vnode; 643 switch (flp->l_type) { 644 case F_RDLCK: 645 if ((fp->f_flag & FREAD) == 0) { 646 error = EBADF; 647 break; 648 } 649 if ((p->p_leader->p_flag & P_ADVLOCK) == 0) { 650 PROC_LOCK(p->p_leader); 651 p->p_leader->p_flag |= P_ADVLOCK; 652 PROC_UNLOCK(p->p_leader); 653 } 654 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_SETLK, 655 flp, flg); 656 break; 657 case F_WRLCK: 658 if ((fp->f_flag & FWRITE) == 0) { 659 error = EBADF; 660 break; 661 } 662 if ((p->p_leader->p_flag & P_ADVLOCK) == 0) { 663 PROC_LOCK(p->p_leader); 664 p->p_leader->p_flag |= P_ADVLOCK; 665 PROC_UNLOCK(p->p_leader); 666 } 667 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_SETLK, 668 flp, flg); 669 break; 670 case F_UNLCK: 671 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_UNLCK, 672 flp, flg); 673 break; 674 case F_UNLCKSYS: 675 if (flg != F_REMOTE) { 676 error = EINVAL; 677 break; 678 } 679 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, 680 F_UNLCKSYS, flp, flg); 681 break; 682 default: 683 error = EINVAL; 684 break; 685 } 686 if (error != 0 || flp->l_type == F_UNLCK || 687 flp->l_type == F_UNLCKSYS) { 688 fdrop(fp, td); 689 break; 690 } 691 692 /* 693 * Check for a race with close. 694 * 695 * The vnode is now advisory locked (or unlocked, but this case 696 * is not really important) as the caller requested. 697 * We had to drop the filedesc lock, so we need to recheck if 698 * the descriptor is still valid, because if it was closed 699 * in the meantime we need to remove advisory lock from the 700 * vnode - close on any descriptor leading to an advisory 701 * locked vnode, removes that lock. 702 * We will return 0 on purpose in that case, as the result of 703 * successful advisory lock might have been externally visible 704 * already. This is fine - effectively we pretend to the caller 705 * that the closing thread was a bit slower and that the 706 * advisory lock succeeded before the close. 707 */ 708 error = fget_unlocked(fdp, fd, &cap_no_rights, &fp2, NULL); 709 if (error != 0) { 710 fdrop(fp, td); 711 break; 712 } 713 if (fp != fp2) { 714 flp->l_whence = SEEK_SET; 715 flp->l_start = 0; 716 flp->l_len = 0; 717 flp->l_type = F_UNLCK; 718 (void) VOP_ADVLOCK(vp, (caddr_t)p->p_leader, 719 F_UNLCK, flp, F_POSIX); 720 } 721 fdrop(fp, td); 722 fdrop(fp2, td); 723 break; 724 725 case F_GETLK: 726 error = fget_unlocked(fdp, fd, &cap_flock_rights, &fp, NULL); 727 if (error != 0) 728 break; 729 if (fp->f_type != DTYPE_VNODE) { 730 error = EBADF; 731 fdrop(fp, td); 732 break; 733 } 734 flp = (struct flock *)arg; 735 if (flp->l_type != F_RDLCK && flp->l_type != F_WRLCK && 736 flp->l_type != F_UNLCK) { 737 error = EINVAL; 738 fdrop(fp, td); 739 break; 740 } 741 if (flp->l_whence == SEEK_CUR) { 742 foffset = foffset_get(fp); 743 if ((flp->l_start > 0 && 744 foffset > OFF_MAX - flp->l_start) || 745 (flp->l_start < 0 && 746 foffset < OFF_MIN - flp->l_start)) { 747 error = EOVERFLOW; 748 fdrop(fp, td); 749 break; 750 } 751 flp->l_start += foffset; 752 } 753 vp = fp->f_vnode; 754 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_GETLK, flp, 755 F_POSIX); 756 fdrop(fp, td); 757 break; 758 759 case F_RDAHEAD: 760 arg = arg ? 128 * 1024: 0; 761 /* FALLTHROUGH */ 762 case F_READAHEAD: 763 error = fget_unlocked(fdp, fd, &cap_no_rights, &fp, NULL); 764 if (error != 0) 765 break; 766 if (fp->f_type != DTYPE_VNODE) { 767 fdrop(fp, td); 768 error = EBADF; 769 break; 770 } 771 vp = fp->f_vnode; 772 /* 773 * Exclusive lock synchronizes against f_seqcount reads and 774 * writes in sequential_heuristic(). 775 */ 776 error = vn_lock(vp, LK_EXCLUSIVE); 777 if (error != 0) { 778 fdrop(fp, td); 779 break; 780 } 781 if (arg >= 0) { 782 bsize = fp->f_vnode->v_mount->mnt_stat.f_iosize; 783 arg = MIN(arg, INT_MAX - bsize + 1); 784 fp->f_seqcount = MIN(IO_SEQMAX, 785 (arg + bsize - 1) / bsize); 786 atomic_set_int(&fp->f_flag, FRDAHEAD); 787 } else { 788 atomic_clear_int(&fp->f_flag, FRDAHEAD); 789 } 790 VOP_UNLOCK(vp, 0); 791 fdrop(fp, td); 792 break; 793 794 default: 795 error = EINVAL; 796 break; 797 } 798 return (error); 799 } 800 801 static int 802 getmaxfd(struct thread *td) 803 { 804 805 return (min((int)lim_cur(td, RLIMIT_NOFILE), maxfilesperproc)); 806 } 807 808 /* 809 * Common code for dup, dup2, fcntl(F_DUPFD) and fcntl(F_DUP2FD). 810 */ 811 int 812 kern_dup(struct thread *td, u_int mode, int flags, int old, int new) 813 { 814 struct filedesc *fdp; 815 struct filedescent *oldfde, *newfde; 816 struct proc *p; 817 struct file *delfp; 818 u_long *oioctls, *nioctls; 819 int error, maxfd; 820 821 p = td->td_proc; 822 fdp = p->p_fd; 823 oioctls = NULL; 824 825 MPASS((flags & ~(FDDUP_FLAG_CLOEXEC)) == 0); 826 MPASS(mode < FDDUP_LASTMODE); 827 828 AUDIT_ARG_FD(old); 829 /* XXXRW: if (flags & FDDUP_FIXED) AUDIT_ARG_FD2(new); */ 830 831 /* 832 * Verify we have a valid descriptor to dup from and possibly to 833 * dup to. Unlike dup() and dup2(), fcntl()'s F_DUPFD should 834 * return EINVAL when the new descriptor is out of bounds. 835 */ 836 if (old < 0) 837 return (EBADF); 838 if (new < 0) 839 return (mode == FDDUP_FCNTL ? EINVAL : EBADF); 840 maxfd = getmaxfd(td); 841 if (new >= maxfd) 842 return (mode == FDDUP_FCNTL ? EINVAL : EBADF); 843 844 error = EBADF; 845 FILEDESC_XLOCK(fdp); 846 if (fget_locked(fdp, old) == NULL) 847 goto unlock; 848 if ((mode == FDDUP_FIXED || mode == FDDUP_MUSTREPLACE) && old == new) { 849 td->td_retval[0] = new; 850 if (flags & FDDUP_FLAG_CLOEXEC) 851 fdp->fd_ofiles[new].fde_flags |= UF_EXCLOSE; 852 error = 0; 853 goto unlock; 854 } 855 856 oldfde = &fdp->fd_ofiles[old]; 857 if (!fhold(oldfde->fde_file)) 858 goto unlock; 859 860 /* 861 * If the caller specified a file descriptor, make sure the file 862 * table is large enough to hold it, and grab it. Otherwise, just 863 * allocate a new descriptor the usual way. 864 */ 865 switch (mode) { 866 case FDDUP_NORMAL: 867 case FDDUP_FCNTL: 868 if ((error = fdalloc(td, new, &new)) != 0) { 869 fdrop(oldfde->fde_file, td); 870 goto unlock; 871 } 872 break; 873 case FDDUP_MUSTREPLACE: 874 /* Target file descriptor must exist. */ 875 if (fget_locked(fdp, new) == NULL) { 876 fdrop(oldfde->fde_file, td); 877 goto unlock; 878 } 879 break; 880 case FDDUP_FIXED: 881 if (new >= fdp->fd_nfiles) { 882 /* 883 * The resource limits are here instead of e.g. 884 * fdalloc(), because the file descriptor table may be 885 * shared between processes, so we can't really use 886 * racct_add()/racct_sub(). Instead of counting the 887 * number of actually allocated descriptors, just put 888 * the limit on the size of the file descriptor table. 889 */ 890 #ifdef RACCT 891 if (RACCT_ENABLED()) { 892 error = racct_set_unlocked(p, RACCT_NOFILE, new + 1); 893 if (error != 0) { 894 error = EMFILE; 895 fdrop(oldfde->fde_file, td); 896 goto unlock; 897 } 898 } 899 #endif 900 fdgrowtable_exp(fdp, new + 1); 901 } 902 if (!fdisused(fdp, new)) 903 fdused(fdp, new); 904 break; 905 default: 906 KASSERT(0, ("%s unsupported mode %d", __func__, mode)); 907 } 908 909 KASSERT(old != new, ("new fd is same as old")); 910 911 newfde = &fdp->fd_ofiles[new]; 912 delfp = newfde->fde_file; 913 914 oioctls = filecaps_free_prep(&newfde->fde_caps); 915 nioctls = filecaps_copy_prep(&oldfde->fde_caps); 916 917 /* 918 * Duplicate the source descriptor. 919 */ 920 #ifdef CAPABILITIES 921 seqc_write_begin(&newfde->fde_seqc); 922 #endif 923 memcpy(newfde, oldfde, fde_change_size); 924 filecaps_copy_finish(&oldfde->fde_caps, &newfde->fde_caps, 925 nioctls); 926 if ((flags & FDDUP_FLAG_CLOEXEC) != 0) 927 newfde->fde_flags = oldfde->fde_flags | UF_EXCLOSE; 928 else 929 newfde->fde_flags = oldfde->fde_flags & ~UF_EXCLOSE; 930 #ifdef CAPABILITIES 931 seqc_write_end(&newfde->fde_seqc); 932 #endif 933 td->td_retval[0] = new; 934 935 error = 0; 936 937 if (delfp != NULL) { 938 (void) closefp(fdp, new, delfp, td, 1); 939 FILEDESC_UNLOCK_ASSERT(fdp); 940 } else { 941 unlock: 942 FILEDESC_XUNLOCK(fdp); 943 } 944 945 filecaps_free_finish(oioctls); 946 return (error); 947 } 948 949 /* 950 * If sigio is on the list associated with a process or process group, 951 * disable signalling from the device, remove sigio from the list and 952 * free sigio. 953 */ 954 void 955 funsetown(struct sigio **sigiop) 956 { 957 struct sigio *sigio; 958 959 if (*sigiop == NULL) 960 return; 961 SIGIO_LOCK(); 962 sigio = *sigiop; 963 if (sigio == NULL) { 964 SIGIO_UNLOCK(); 965 return; 966 } 967 *(sigio->sio_myref) = NULL; 968 if ((sigio)->sio_pgid < 0) { 969 struct pgrp *pg = (sigio)->sio_pgrp; 970 PGRP_LOCK(pg); 971 SLIST_REMOVE(&sigio->sio_pgrp->pg_sigiolst, sigio, 972 sigio, sio_pgsigio); 973 PGRP_UNLOCK(pg); 974 } else { 975 struct proc *p = (sigio)->sio_proc; 976 PROC_LOCK(p); 977 SLIST_REMOVE(&sigio->sio_proc->p_sigiolst, sigio, 978 sigio, sio_pgsigio); 979 PROC_UNLOCK(p); 980 } 981 SIGIO_UNLOCK(); 982 crfree(sigio->sio_ucred); 983 free(sigio, M_SIGIO); 984 } 985 986 /* 987 * Free a list of sigio structures. 988 * We only need to lock the SIGIO_LOCK because we have made ourselves 989 * inaccessible to callers of fsetown and therefore do not need to lock 990 * the proc or pgrp struct for the list manipulation. 991 */ 992 void 993 funsetownlst(struct sigiolst *sigiolst) 994 { 995 struct proc *p; 996 struct pgrp *pg; 997 struct sigio *sigio; 998 999 sigio = SLIST_FIRST(sigiolst); 1000 if (sigio == NULL) 1001 return; 1002 p = NULL; 1003 pg = NULL; 1004 1005 /* 1006 * Every entry of the list should belong 1007 * to a single proc or pgrp. 1008 */ 1009 if (sigio->sio_pgid < 0) { 1010 pg = sigio->sio_pgrp; 1011 PGRP_LOCK_ASSERT(pg, MA_NOTOWNED); 1012 } else /* if (sigio->sio_pgid > 0) */ { 1013 p = sigio->sio_proc; 1014 PROC_LOCK_ASSERT(p, MA_NOTOWNED); 1015 } 1016 1017 SIGIO_LOCK(); 1018 while ((sigio = SLIST_FIRST(sigiolst)) != NULL) { 1019 *(sigio->sio_myref) = NULL; 1020 if (pg != NULL) { 1021 KASSERT(sigio->sio_pgid < 0, 1022 ("Proc sigio in pgrp sigio list")); 1023 KASSERT(sigio->sio_pgrp == pg, 1024 ("Bogus pgrp in sigio list")); 1025 PGRP_LOCK(pg); 1026 SLIST_REMOVE(&pg->pg_sigiolst, sigio, sigio, 1027 sio_pgsigio); 1028 PGRP_UNLOCK(pg); 1029 } else /* if (p != NULL) */ { 1030 KASSERT(sigio->sio_pgid > 0, 1031 ("Pgrp sigio in proc sigio list")); 1032 KASSERT(sigio->sio_proc == p, 1033 ("Bogus proc in sigio list")); 1034 PROC_LOCK(p); 1035 SLIST_REMOVE(&p->p_sigiolst, sigio, sigio, 1036 sio_pgsigio); 1037 PROC_UNLOCK(p); 1038 } 1039 SIGIO_UNLOCK(); 1040 crfree(sigio->sio_ucred); 1041 free(sigio, M_SIGIO); 1042 SIGIO_LOCK(); 1043 } 1044 SIGIO_UNLOCK(); 1045 } 1046 1047 /* 1048 * This is common code for FIOSETOWN ioctl called by fcntl(fd, F_SETOWN, arg). 1049 * 1050 * After permission checking, add a sigio structure to the sigio list for 1051 * the process or process group. 1052 */ 1053 int 1054 fsetown(pid_t pgid, struct sigio **sigiop) 1055 { 1056 struct proc *proc; 1057 struct pgrp *pgrp; 1058 struct sigio *sigio; 1059 int ret; 1060 1061 if (pgid == 0) { 1062 funsetown(sigiop); 1063 return (0); 1064 } 1065 1066 ret = 0; 1067 1068 /* Allocate and fill in the new sigio out of locks. */ 1069 sigio = malloc(sizeof(struct sigio), M_SIGIO, M_WAITOK); 1070 sigio->sio_pgid = pgid; 1071 sigio->sio_ucred = crhold(curthread->td_ucred); 1072 sigio->sio_myref = sigiop; 1073 1074 sx_slock(&proctree_lock); 1075 if (pgid > 0) { 1076 proc = pfind(pgid); 1077 if (proc == NULL) { 1078 ret = ESRCH; 1079 goto fail; 1080 } 1081 1082 /* 1083 * Policy - Don't allow a process to FSETOWN a process 1084 * in another session. 1085 * 1086 * Remove this test to allow maximum flexibility or 1087 * restrict FSETOWN to the current process or process 1088 * group for maximum safety. 1089 */ 1090 PROC_UNLOCK(proc); 1091 if (proc->p_session != curthread->td_proc->p_session) { 1092 ret = EPERM; 1093 goto fail; 1094 } 1095 1096 pgrp = NULL; 1097 } else /* if (pgid < 0) */ { 1098 pgrp = pgfind(-pgid); 1099 if (pgrp == NULL) { 1100 ret = ESRCH; 1101 goto fail; 1102 } 1103 PGRP_UNLOCK(pgrp); 1104 1105 /* 1106 * Policy - Don't allow a process to FSETOWN a process 1107 * in another session. 1108 * 1109 * Remove this test to allow maximum flexibility or 1110 * restrict FSETOWN to the current process or process 1111 * group for maximum safety. 1112 */ 1113 if (pgrp->pg_session != curthread->td_proc->p_session) { 1114 ret = EPERM; 1115 goto fail; 1116 } 1117 1118 proc = NULL; 1119 } 1120 funsetown(sigiop); 1121 if (pgid > 0) { 1122 PROC_LOCK(proc); 1123 /* 1124 * Since funsetownlst() is called without the proctree 1125 * locked, we need to check for P_WEXIT. 1126 * XXX: is ESRCH correct? 1127 */ 1128 if ((proc->p_flag & P_WEXIT) != 0) { 1129 PROC_UNLOCK(proc); 1130 ret = ESRCH; 1131 goto fail; 1132 } 1133 SLIST_INSERT_HEAD(&proc->p_sigiolst, sigio, sio_pgsigio); 1134 sigio->sio_proc = proc; 1135 PROC_UNLOCK(proc); 1136 } else { 1137 PGRP_LOCK(pgrp); 1138 SLIST_INSERT_HEAD(&pgrp->pg_sigiolst, sigio, sio_pgsigio); 1139 sigio->sio_pgrp = pgrp; 1140 PGRP_UNLOCK(pgrp); 1141 } 1142 sx_sunlock(&proctree_lock); 1143 SIGIO_LOCK(); 1144 *sigiop = sigio; 1145 SIGIO_UNLOCK(); 1146 return (0); 1147 1148 fail: 1149 sx_sunlock(&proctree_lock); 1150 crfree(sigio->sio_ucred); 1151 free(sigio, M_SIGIO); 1152 return (ret); 1153 } 1154 1155 /* 1156 * This is common code for FIOGETOWN ioctl called by fcntl(fd, F_GETOWN, arg). 1157 */ 1158 pid_t 1159 fgetown(struct sigio **sigiop) 1160 { 1161 pid_t pgid; 1162 1163 SIGIO_LOCK(); 1164 pgid = (*sigiop != NULL) ? (*sigiop)->sio_pgid : 0; 1165 SIGIO_UNLOCK(); 1166 return (pgid); 1167 } 1168 1169 /* 1170 * Function drops the filedesc lock on return. 1171 */ 1172 static int 1173 closefp(struct filedesc *fdp, int fd, struct file *fp, struct thread *td, 1174 int holdleaders) 1175 { 1176 int error; 1177 1178 FILEDESC_XLOCK_ASSERT(fdp); 1179 1180 if (holdleaders) { 1181 if (td->td_proc->p_fdtol != NULL) { 1182 /* 1183 * Ask fdfree() to sleep to ensure that all relevant 1184 * process leaders can be traversed in closef(). 1185 */ 1186 fdp->fd_holdleaderscount++; 1187 } else { 1188 holdleaders = 0; 1189 } 1190 } 1191 1192 /* 1193 * We now hold the fp reference that used to be owned by the 1194 * descriptor array. We have to unlock the FILEDESC *AFTER* 1195 * knote_fdclose to prevent a race of the fd getting opened, a knote 1196 * added, and deleteing a knote for the new fd. 1197 */ 1198 if (__predict_false(!TAILQ_EMPTY(&fdp->fd_kqlist))) 1199 knote_fdclose(td, fd); 1200 1201 /* 1202 * We need to notify mqueue if the object is of type mqueue. 1203 */ 1204 if (__predict_false(fp->f_type == DTYPE_MQUEUE)) 1205 mq_fdclose(td, fd, fp); 1206 FILEDESC_XUNLOCK(fdp); 1207 1208 error = closef(fp, td); 1209 if (holdleaders) { 1210 FILEDESC_XLOCK(fdp); 1211 fdp->fd_holdleaderscount--; 1212 if (fdp->fd_holdleaderscount == 0 && 1213 fdp->fd_holdleaderswakeup != 0) { 1214 fdp->fd_holdleaderswakeup = 0; 1215 wakeup(&fdp->fd_holdleaderscount); 1216 } 1217 FILEDESC_XUNLOCK(fdp); 1218 } 1219 return (error); 1220 } 1221 1222 /* 1223 * Close a file descriptor. 1224 */ 1225 #ifndef _SYS_SYSPROTO_H_ 1226 struct close_args { 1227 int fd; 1228 }; 1229 #endif 1230 /* ARGSUSED */ 1231 int 1232 sys_close(struct thread *td, struct close_args *uap) 1233 { 1234 1235 return (kern_close(td, uap->fd)); 1236 } 1237 1238 int 1239 kern_close(struct thread *td, int fd) 1240 { 1241 struct filedesc *fdp; 1242 struct file *fp; 1243 1244 fdp = td->td_proc->p_fd; 1245 1246 AUDIT_SYSCLOSE(td, fd); 1247 1248 FILEDESC_XLOCK(fdp); 1249 if ((fp = fget_locked(fdp, fd)) == NULL) { 1250 FILEDESC_XUNLOCK(fdp); 1251 return (EBADF); 1252 } 1253 fdfree(fdp, fd); 1254 1255 /* closefp() drops the FILEDESC lock for us. */ 1256 return (closefp(fdp, fd, fp, td, 1)); 1257 } 1258 1259 /* 1260 * Close open file descriptors. 1261 */ 1262 #ifndef _SYS_SYSPROTO_H_ 1263 struct closefrom_args { 1264 int lowfd; 1265 }; 1266 #endif 1267 /* ARGSUSED */ 1268 int 1269 sys_closefrom(struct thread *td, struct closefrom_args *uap) 1270 { 1271 struct filedesc *fdp; 1272 int fd; 1273 1274 fdp = td->td_proc->p_fd; 1275 AUDIT_ARG_FD(uap->lowfd); 1276 1277 /* 1278 * Treat negative starting file descriptor values identical to 1279 * closefrom(0) which closes all files. 1280 */ 1281 if (uap->lowfd < 0) 1282 uap->lowfd = 0; 1283 FILEDESC_SLOCK(fdp); 1284 for (fd = uap->lowfd; fd <= fdp->fd_lastfile; fd++) { 1285 if (fdp->fd_ofiles[fd].fde_file != NULL) { 1286 FILEDESC_SUNLOCK(fdp); 1287 (void)kern_close(td, fd); 1288 FILEDESC_SLOCK(fdp); 1289 } 1290 } 1291 FILEDESC_SUNLOCK(fdp); 1292 return (0); 1293 } 1294 1295 #if defined(COMPAT_43) 1296 /* 1297 * Return status information about a file descriptor. 1298 */ 1299 #ifndef _SYS_SYSPROTO_H_ 1300 struct ofstat_args { 1301 int fd; 1302 struct ostat *sb; 1303 }; 1304 #endif 1305 /* ARGSUSED */ 1306 int 1307 ofstat(struct thread *td, struct ofstat_args *uap) 1308 { 1309 struct ostat oub; 1310 struct stat ub; 1311 int error; 1312 1313 error = kern_fstat(td, uap->fd, &ub); 1314 if (error == 0) { 1315 cvtstat(&ub, &oub); 1316 error = copyout(&oub, uap->sb, sizeof(oub)); 1317 } 1318 return (error); 1319 } 1320 #endif /* COMPAT_43 */ 1321 1322 #if defined(COMPAT_FREEBSD11) 1323 int 1324 freebsd11_fstat(struct thread *td, struct freebsd11_fstat_args *uap) 1325 { 1326 struct stat sb; 1327 struct freebsd11_stat osb; 1328 int error; 1329 1330 error = kern_fstat(td, uap->fd, &sb); 1331 if (error != 0) 1332 return (error); 1333 error = freebsd11_cvtstat(&sb, &osb); 1334 if (error == 0) 1335 error = copyout(&osb, uap->sb, sizeof(osb)); 1336 return (error); 1337 } 1338 #endif /* COMPAT_FREEBSD11 */ 1339 1340 /* 1341 * Return status information about a file descriptor. 1342 */ 1343 #ifndef _SYS_SYSPROTO_H_ 1344 struct fstat_args { 1345 int fd; 1346 struct stat *sb; 1347 }; 1348 #endif 1349 /* ARGSUSED */ 1350 int 1351 sys_fstat(struct thread *td, struct fstat_args *uap) 1352 { 1353 struct stat ub; 1354 int error; 1355 1356 error = kern_fstat(td, uap->fd, &ub); 1357 if (error == 0) 1358 error = copyout(&ub, uap->sb, sizeof(ub)); 1359 return (error); 1360 } 1361 1362 int 1363 kern_fstat(struct thread *td, int fd, struct stat *sbp) 1364 { 1365 struct file *fp; 1366 int error; 1367 1368 AUDIT_ARG_FD(fd); 1369 1370 error = fget(td, fd, &cap_fstat_rights, &fp); 1371 if (error != 0) 1372 return (error); 1373 1374 AUDIT_ARG_FILE(td->td_proc, fp); 1375 1376 error = fo_stat(fp, sbp, td->td_ucred, td); 1377 fdrop(fp, td); 1378 #ifdef __STAT_TIME_T_EXT 1379 if (error == 0) { 1380 sbp->st_atim_ext = 0; 1381 sbp->st_mtim_ext = 0; 1382 sbp->st_ctim_ext = 0; 1383 sbp->st_btim_ext = 0; 1384 } 1385 #endif 1386 #ifdef KTRACE 1387 if (error == 0 && KTRPOINT(td, KTR_STRUCT)) 1388 ktrstat(sbp); 1389 #endif 1390 return (error); 1391 } 1392 1393 #if defined(COMPAT_FREEBSD11) 1394 /* 1395 * Return status information about a file descriptor. 1396 */ 1397 #ifndef _SYS_SYSPROTO_H_ 1398 struct freebsd11_nfstat_args { 1399 int fd; 1400 struct nstat *sb; 1401 }; 1402 #endif 1403 /* ARGSUSED */ 1404 int 1405 freebsd11_nfstat(struct thread *td, struct freebsd11_nfstat_args *uap) 1406 { 1407 struct nstat nub; 1408 struct stat ub; 1409 int error; 1410 1411 error = kern_fstat(td, uap->fd, &ub); 1412 if (error == 0) { 1413 freebsd11_cvtnstat(&ub, &nub); 1414 error = copyout(&nub, uap->sb, sizeof(nub)); 1415 } 1416 return (error); 1417 } 1418 #endif /* COMPAT_FREEBSD11 */ 1419 1420 /* 1421 * Return pathconf information about a file descriptor. 1422 */ 1423 #ifndef _SYS_SYSPROTO_H_ 1424 struct fpathconf_args { 1425 int fd; 1426 int name; 1427 }; 1428 #endif 1429 /* ARGSUSED */ 1430 int 1431 sys_fpathconf(struct thread *td, struct fpathconf_args *uap) 1432 { 1433 long value; 1434 int error; 1435 1436 error = kern_fpathconf(td, uap->fd, uap->name, &value); 1437 if (error == 0) 1438 td->td_retval[0] = value; 1439 return (error); 1440 } 1441 1442 int 1443 kern_fpathconf(struct thread *td, int fd, int name, long *valuep) 1444 { 1445 struct file *fp; 1446 struct vnode *vp; 1447 int error; 1448 1449 error = fget(td, fd, &cap_fpathconf_rights, &fp); 1450 if (error != 0) 1451 return (error); 1452 1453 if (name == _PC_ASYNC_IO) { 1454 *valuep = _POSIX_ASYNCHRONOUS_IO; 1455 goto out; 1456 } 1457 vp = fp->f_vnode; 1458 if (vp != NULL) { 1459 vn_lock(vp, LK_SHARED | LK_RETRY); 1460 error = VOP_PATHCONF(vp, name, valuep); 1461 VOP_UNLOCK(vp, 0); 1462 } else if (fp->f_type == DTYPE_PIPE || fp->f_type == DTYPE_SOCKET) { 1463 if (name != _PC_PIPE_BUF) { 1464 error = EINVAL; 1465 } else { 1466 *valuep = PIPE_BUF; 1467 error = 0; 1468 } 1469 } else { 1470 error = EOPNOTSUPP; 1471 } 1472 out: 1473 fdrop(fp, td); 1474 return (error); 1475 } 1476 1477 /* 1478 * Copy filecaps structure allocating memory for ioctls array if needed. 1479 * 1480 * The last parameter indicates whether the fdtable is locked. If it is not and 1481 * ioctls are encountered, copying fails and the caller must lock the table. 1482 * 1483 * Note that if the table was not locked, the caller has to check the relevant 1484 * sequence counter to determine whether the operation was successful. 1485 */ 1486 bool 1487 filecaps_copy(const struct filecaps *src, struct filecaps *dst, bool locked) 1488 { 1489 size_t size; 1490 1491 if (src->fc_ioctls != NULL && !locked) 1492 return (false); 1493 memcpy(dst, src, sizeof(*src)); 1494 if (src->fc_ioctls == NULL) 1495 return (true); 1496 1497 KASSERT(src->fc_nioctls > 0, 1498 ("fc_ioctls != NULL, but fc_nioctls=%hd", src->fc_nioctls)); 1499 1500 size = sizeof(src->fc_ioctls[0]) * src->fc_nioctls; 1501 dst->fc_ioctls = malloc(size, M_FILECAPS, M_WAITOK); 1502 memcpy(dst->fc_ioctls, src->fc_ioctls, size); 1503 return (true); 1504 } 1505 1506 static u_long * 1507 filecaps_copy_prep(const struct filecaps *src) 1508 { 1509 u_long *ioctls; 1510 size_t size; 1511 1512 if (__predict_true(src->fc_ioctls == NULL)) 1513 return (NULL); 1514 1515 KASSERT(src->fc_nioctls > 0, 1516 ("fc_ioctls != NULL, but fc_nioctls=%hd", src->fc_nioctls)); 1517 1518 size = sizeof(src->fc_ioctls[0]) * src->fc_nioctls; 1519 ioctls = malloc(size, M_FILECAPS, M_WAITOK); 1520 return (ioctls); 1521 } 1522 1523 static void 1524 filecaps_copy_finish(const struct filecaps *src, struct filecaps *dst, 1525 u_long *ioctls) 1526 { 1527 size_t size; 1528 1529 *dst = *src; 1530 if (__predict_true(src->fc_ioctls == NULL)) { 1531 MPASS(ioctls == NULL); 1532 return; 1533 } 1534 1535 size = sizeof(src->fc_ioctls[0]) * src->fc_nioctls; 1536 dst->fc_ioctls = ioctls; 1537 bcopy(src->fc_ioctls, dst->fc_ioctls, size); 1538 } 1539 1540 /* 1541 * Move filecaps structure to the new place and clear the old place. 1542 */ 1543 void 1544 filecaps_move(struct filecaps *src, struct filecaps *dst) 1545 { 1546 1547 *dst = *src; 1548 bzero(src, sizeof(*src)); 1549 } 1550 1551 /* 1552 * Fill the given filecaps structure with full rights. 1553 */ 1554 static void 1555 filecaps_fill(struct filecaps *fcaps) 1556 { 1557 1558 CAP_ALL(&fcaps->fc_rights); 1559 fcaps->fc_ioctls = NULL; 1560 fcaps->fc_nioctls = -1; 1561 fcaps->fc_fcntls = CAP_FCNTL_ALL; 1562 } 1563 1564 /* 1565 * Free memory allocated within filecaps structure. 1566 */ 1567 void 1568 filecaps_free(struct filecaps *fcaps) 1569 { 1570 1571 free(fcaps->fc_ioctls, M_FILECAPS); 1572 bzero(fcaps, sizeof(*fcaps)); 1573 } 1574 1575 static u_long * 1576 filecaps_free_prep(struct filecaps *fcaps) 1577 { 1578 u_long *ioctls; 1579 1580 ioctls = fcaps->fc_ioctls; 1581 bzero(fcaps, sizeof(*fcaps)); 1582 return (ioctls); 1583 } 1584 1585 static void 1586 filecaps_free_finish(u_long *ioctls) 1587 { 1588 1589 free(ioctls, M_FILECAPS); 1590 } 1591 1592 /* 1593 * Validate the given filecaps structure. 1594 */ 1595 static void 1596 filecaps_validate(const struct filecaps *fcaps, const char *func) 1597 { 1598 1599 KASSERT(cap_rights_is_valid(&fcaps->fc_rights), 1600 ("%s: invalid rights", func)); 1601 KASSERT((fcaps->fc_fcntls & ~CAP_FCNTL_ALL) == 0, 1602 ("%s: invalid fcntls", func)); 1603 KASSERT(fcaps->fc_fcntls == 0 || 1604 cap_rights_is_set(&fcaps->fc_rights, CAP_FCNTL), 1605 ("%s: fcntls without CAP_FCNTL", func)); 1606 KASSERT(fcaps->fc_ioctls != NULL ? fcaps->fc_nioctls > 0 : 1607 (fcaps->fc_nioctls == -1 || fcaps->fc_nioctls == 0), 1608 ("%s: invalid ioctls", func)); 1609 KASSERT(fcaps->fc_nioctls == 0 || 1610 cap_rights_is_set(&fcaps->fc_rights, CAP_IOCTL), 1611 ("%s: ioctls without CAP_IOCTL", func)); 1612 } 1613 1614 static void 1615 fdgrowtable_exp(struct filedesc *fdp, int nfd) 1616 { 1617 int nfd1; 1618 1619 FILEDESC_XLOCK_ASSERT(fdp); 1620 1621 nfd1 = fdp->fd_nfiles * 2; 1622 if (nfd1 < nfd) 1623 nfd1 = nfd; 1624 fdgrowtable(fdp, nfd1); 1625 } 1626 1627 /* 1628 * Grow the file table to accommodate (at least) nfd descriptors. 1629 */ 1630 static void 1631 fdgrowtable(struct filedesc *fdp, int nfd) 1632 { 1633 struct filedesc0 *fdp0; 1634 struct freetable *ft; 1635 struct fdescenttbl *ntable; 1636 struct fdescenttbl *otable; 1637 int nnfiles, onfiles; 1638 NDSLOTTYPE *nmap, *omap; 1639 1640 /* 1641 * If lastfile is -1 this struct filedesc was just allocated and we are 1642 * growing it to accommodate for the one we are going to copy from. There 1643 * is no need to have a lock on this one as it's not visible to anyone. 1644 */ 1645 if (fdp->fd_lastfile != -1) 1646 FILEDESC_XLOCK_ASSERT(fdp); 1647 1648 KASSERT(fdp->fd_nfiles > 0, ("zero-length file table")); 1649 1650 /* save old values */ 1651 onfiles = fdp->fd_nfiles; 1652 otable = fdp->fd_files; 1653 omap = fdp->fd_map; 1654 1655 /* compute the size of the new table */ 1656 nnfiles = NDSLOTS(nfd) * NDENTRIES; /* round up */ 1657 if (nnfiles <= onfiles) 1658 /* the table is already large enough */ 1659 return; 1660 1661 /* 1662 * Allocate a new table. We need enough space for the number of 1663 * entries, file entries themselves and the struct freetable we will use 1664 * when we decommission the table and place it on the freelist. 1665 * We place the struct freetable in the middle so we don't have 1666 * to worry about padding. 1667 */ 1668 ntable = malloc(offsetof(struct fdescenttbl, fdt_ofiles) + 1669 nnfiles * sizeof(ntable->fdt_ofiles[0]) + 1670 sizeof(struct freetable), 1671 M_FILEDESC, M_ZERO | M_WAITOK); 1672 /* copy the old data */ 1673 ntable->fdt_nfiles = nnfiles; 1674 memcpy(ntable->fdt_ofiles, otable->fdt_ofiles, 1675 onfiles * sizeof(ntable->fdt_ofiles[0])); 1676 1677 /* 1678 * Allocate a new map only if the old is not large enough. It will 1679 * grow at a slower rate than the table as it can map more 1680 * entries than the table can hold. 1681 */ 1682 if (NDSLOTS(nnfiles) > NDSLOTS(onfiles)) { 1683 nmap = malloc(NDSLOTS(nnfiles) * NDSLOTSIZE, M_FILEDESC, 1684 M_ZERO | M_WAITOK); 1685 /* copy over the old data and update the pointer */ 1686 memcpy(nmap, omap, NDSLOTS(onfiles) * sizeof(*omap)); 1687 fdp->fd_map = nmap; 1688 } 1689 1690 /* 1691 * Make sure that ntable is correctly initialized before we replace 1692 * fd_files poiner. Otherwise fget_unlocked() may see inconsistent 1693 * data. 1694 */ 1695 atomic_store_rel_ptr((volatile void *)&fdp->fd_files, (uintptr_t)ntable); 1696 1697 /* 1698 * Do not free the old file table, as some threads may still 1699 * reference entries within it. Instead, place it on a freelist 1700 * which will be processed when the struct filedesc is released. 1701 * 1702 * Note that if onfiles == NDFILE, we're dealing with the original 1703 * static allocation contained within (struct filedesc0 *)fdp, 1704 * which must not be freed. 1705 */ 1706 if (onfiles > NDFILE) { 1707 ft = (struct freetable *)&otable->fdt_ofiles[onfiles]; 1708 fdp0 = (struct filedesc0 *)fdp; 1709 ft->ft_table = otable; 1710 SLIST_INSERT_HEAD(&fdp0->fd_free, ft, ft_next); 1711 } 1712 /* 1713 * The map does not have the same possibility of threads still 1714 * holding references to it. So always free it as long as it 1715 * does not reference the original static allocation. 1716 */ 1717 if (NDSLOTS(onfiles) > NDSLOTS(NDFILE)) 1718 free(omap, M_FILEDESC); 1719 } 1720 1721 /* 1722 * Allocate a file descriptor for the process. 1723 */ 1724 int 1725 fdalloc(struct thread *td, int minfd, int *result) 1726 { 1727 struct proc *p = td->td_proc; 1728 struct filedesc *fdp = p->p_fd; 1729 int fd, maxfd, allocfd; 1730 #ifdef RACCT 1731 int error; 1732 #endif 1733 1734 FILEDESC_XLOCK_ASSERT(fdp); 1735 1736 if (fdp->fd_freefile > minfd) 1737 minfd = fdp->fd_freefile; 1738 1739 maxfd = getmaxfd(td); 1740 1741 /* 1742 * Search the bitmap for a free descriptor starting at minfd. 1743 * If none is found, grow the file table. 1744 */ 1745 fd = fd_first_free(fdp, minfd, fdp->fd_nfiles); 1746 if (fd >= maxfd) 1747 return (EMFILE); 1748 if (fd >= fdp->fd_nfiles) { 1749 allocfd = min(fd * 2, maxfd); 1750 #ifdef RACCT 1751 if (RACCT_ENABLED()) { 1752 error = racct_set_unlocked(p, RACCT_NOFILE, allocfd); 1753 if (error != 0) 1754 return (EMFILE); 1755 } 1756 #endif 1757 /* 1758 * fd is already equal to first free descriptor >= minfd, so 1759 * we only need to grow the table and we are done. 1760 */ 1761 fdgrowtable_exp(fdp, allocfd); 1762 } 1763 1764 /* 1765 * Perform some sanity checks, then mark the file descriptor as 1766 * used and return it to the caller. 1767 */ 1768 KASSERT(fd >= 0 && fd < min(maxfd, fdp->fd_nfiles), 1769 ("invalid descriptor %d", fd)); 1770 KASSERT(!fdisused(fdp, fd), 1771 ("fd_first_free() returned non-free descriptor")); 1772 KASSERT(fdp->fd_ofiles[fd].fde_file == NULL, 1773 ("file descriptor isn't free")); 1774 fdused(fdp, fd); 1775 *result = fd; 1776 return (0); 1777 } 1778 1779 /* 1780 * Allocate n file descriptors for the process. 1781 */ 1782 int 1783 fdallocn(struct thread *td, int minfd, int *fds, int n) 1784 { 1785 struct proc *p = td->td_proc; 1786 struct filedesc *fdp = p->p_fd; 1787 int i; 1788 1789 FILEDESC_XLOCK_ASSERT(fdp); 1790 1791 for (i = 0; i < n; i++) 1792 if (fdalloc(td, 0, &fds[i]) != 0) 1793 break; 1794 1795 if (i < n) { 1796 for (i--; i >= 0; i--) 1797 fdunused(fdp, fds[i]); 1798 return (EMFILE); 1799 } 1800 1801 return (0); 1802 } 1803 1804 /* 1805 * Create a new open file structure and allocate a file descriptor for the 1806 * process that refers to it. We add one reference to the file for the 1807 * descriptor table and one reference for resultfp. This is to prevent us 1808 * being preempted and the entry in the descriptor table closed after we 1809 * release the FILEDESC lock. 1810 */ 1811 int 1812 falloc_caps(struct thread *td, struct file **resultfp, int *resultfd, int flags, 1813 struct filecaps *fcaps) 1814 { 1815 struct file *fp; 1816 int error, fd; 1817 1818 error = falloc_noinstall(td, &fp); 1819 if (error) 1820 return (error); /* no reference held on error */ 1821 1822 error = finstall(td, fp, &fd, flags, fcaps); 1823 if (error) { 1824 fdrop(fp, td); /* one reference (fp only) */ 1825 return (error); 1826 } 1827 1828 if (resultfp != NULL) 1829 *resultfp = fp; /* copy out result */ 1830 else 1831 fdrop(fp, td); /* release local reference */ 1832 1833 if (resultfd != NULL) 1834 *resultfd = fd; 1835 1836 return (0); 1837 } 1838 1839 /* 1840 * Create a new open file structure without allocating a file descriptor. 1841 */ 1842 int 1843 falloc_noinstall(struct thread *td, struct file **resultfp) 1844 { 1845 struct file *fp; 1846 int maxuserfiles = maxfiles - (maxfiles / 20); 1847 int openfiles_new; 1848 static struct timeval lastfail; 1849 static int curfail; 1850 1851 KASSERT(resultfp != NULL, ("%s: resultfp == NULL", __func__)); 1852 1853 openfiles_new = atomic_fetchadd_int(&openfiles, 1) + 1; 1854 if ((openfiles_new >= maxuserfiles && 1855 priv_check(td, PRIV_MAXFILES) != 0) || 1856 openfiles_new >= maxfiles) { 1857 atomic_subtract_int(&openfiles, 1); 1858 if (ppsratecheck(&lastfail, &curfail, 1)) { 1859 printf("kern.maxfiles limit exceeded by uid %i, (%s) " 1860 "please see tuning(7).\n", td->td_ucred->cr_ruid, td->td_proc->p_comm); 1861 } 1862 return (ENFILE); 1863 } 1864 fp = uma_zalloc(file_zone, M_WAITOK); 1865 bzero(fp, sizeof(*fp)); 1866 refcount_init(&fp->f_count, 1); 1867 fp->f_cred = crhold(td->td_ucred); 1868 fp->f_ops = &badfileops; 1869 *resultfp = fp; 1870 return (0); 1871 } 1872 1873 /* 1874 * Install a file in a file descriptor table. 1875 */ 1876 void 1877 _finstall(struct filedesc *fdp, struct file *fp, int fd, int flags, 1878 struct filecaps *fcaps) 1879 { 1880 struct filedescent *fde; 1881 1882 MPASS(fp != NULL); 1883 if (fcaps != NULL) 1884 filecaps_validate(fcaps, __func__); 1885 FILEDESC_XLOCK_ASSERT(fdp); 1886 1887 fde = &fdp->fd_ofiles[fd]; 1888 #ifdef CAPABILITIES 1889 seqc_write_begin(&fde->fde_seqc); 1890 #endif 1891 fde->fde_file = fp; 1892 fde->fde_flags = (flags & O_CLOEXEC) != 0 ? UF_EXCLOSE : 0; 1893 if (fcaps != NULL) 1894 filecaps_move(fcaps, &fde->fde_caps); 1895 else 1896 filecaps_fill(&fde->fde_caps); 1897 #ifdef CAPABILITIES 1898 seqc_write_end(&fde->fde_seqc); 1899 #endif 1900 } 1901 1902 int 1903 finstall(struct thread *td, struct file *fp, int *fd, int flags, 1904 struct filecaps *fcaps) 1905 { 1906 struct filedesc *fdp = td->td_proc->p_fd; 1907 int error; 1908 1909 MPASS(fd != NULL); 1910 1911 if (!fhold(fp)) 1912 return (EBADF); 1913 FILEDESC_XLOCK(fdp); 1914 if ((error = fdalloc(td, 0, fd))) { 1915 FILEDESC_XUNLOCK(fdp); 1916 fdrop(fp, td); 1917 return (error); 1918 } 1919 _finstall(fdp, fp, *fd, flags, fcaps); 1920 FILEDESC_XUNLOCK(fdp); 1921 return (0); 1922 } 1923 1924 /* 1925 * Build a new filedesc structure from another. 1926 * Copy the current, root, and jail root vnode references. 1927 * 1928 * If fdp is not NULL, return with it shared locked. 1929 */ 1930 struct filedesc * 1931 fdinit(struct filedesc *fdp, bool prepfiles) 1932 { 1933 struct filedesc0 *newfdp0; 1934 struct filedesc *newfdp; 1935 1936 newfdp0 = uma_zalloc(filedesc0_zone, M_WAITOK | M_ZERO); 1937 newfdp = &newfdp0->fd_fd; 1938 1939 /* Create the file descriptor table. */ 1940 FILEDESC_LOCK_INIT(newfdp); 1941 refcount_init(&newfdp->fd_refcnt, 1); 1942 refcount_init(&newfdp->fd_holdcnt, 1); 1943 newfdp->fd_cmask = CMASK; 1944 newfdp->fd_map = newfdp0->fd_dmap; 1945 newfdp->fd_lastfile = -1; 1946 newfdp->fd_files = (struct fdescenttbl *)&newfdp0->fd_dfiles; 1947 newfdp->fd_files->fdt_nfiles = NDFILE; 1948 1949 if (fdp == NULL) 1950 return (newfdp); 1951 1952 if (prepfiles && fdp->fd_lastfile >= newfdp->fd_nfiles) 1953 fdgrowtable(newfdp, fdp->fd_lastfile + 1); 1954 1955 FILEDESC_SLOCK(fdp); 1956 newfdp->fd_cdir = fdp->fd_cdir; 1957 if (newfdp->fd_cdir) 1958 vrefact(newfdp->fd_cdir); 1959 newfdp->fd_rdir = fdp->fd_rdir; 1960 if (newfdp->fd_rdir) 1961 vrefact(newfdp->fd_rdir); 1962 newfdp->fd_jdir = fdp->fd_jdir; 1963 if (newfdp->fd_jdir) 1964 vrefact(newfdp->fd_jdir); 1965 1966 if (!prepfiles) { 1967 FILEDESC_SUNLOCK(fdp); 1968 } else { 1969 while (fdp->fd_lastfile >= newfdp->fd_nfiles) { 1970 FILEDESC_SUNLOCK(fdp); 1971 fdgrowtable(newfdp, fdp->fd_lastfile + 1); 1972 FILEDESC_SLOCK(fdp); 1973 } 1974 } 1975 1976 return (newfdp); 1977 } 1978 1979 static struct filedesc * 1980 fdhold(struct proc *p) 1981 { 1982 struct filedesc *fdp; 1983 1984 PROC_LOCK_ASSERT(p, MA_OWNED); 1985 fdp = p->p_fd; 1986 if (fdp != NULL) 1987 refcount_acquire(&fdp->fd_holdcnt); 1988 return (fdp); 1989 } 1990 1991 static void 1992 fddrop(struct filedesc *fdp) 1993 { 1994 1995 if (fdp->fd_holdcnt > 1) { 1996 if (refcount_release(&fdp->fd_holdcnt) == 0) 1997 return; 1998 } 1999 2000 FILEDESC_LOCK_DESTROY(fdp); 2001 uma_zfree(filedesc0_zone, fdp); 2002 } 2003 2004 /* 2005 * Share a filedesc structure. 2006 */ 2007 struct filedesc * 2008 fdshare(struct filedesc *fdp) 2009 { 2010 2011 refcount_acquire(&fdp->fd_refcnt); 2012 return (fdp); 2013 } 2014 2015 /* 2016 * Unshare a filedesc structure, if necessary by making a copy 2017 */ 2018 void 2019 fdunshare(struct thread *td) 2020 { 2021 struct filedesc *tmp; 2022 struct proc *p = td->td_proc; 2023 2024 if (p->p_fd->fd_refcnt == 1) 2025 return; 2026 2027 tmp = fdcopy(p->p_fd); 2028 fdescfree(td); 2029 p->p_fd = tmp; 2030 } 2031 2032 void 2033 fdinstall_remapped(struct thread *td, struct filedesc *fdp) 2034 { 2035 2036 fdescfree(td); 2037 td->td_proc->p_fd = fdp; 2038 } 2039 2040 /* 2041 * Copy a filedesc structure. A NULL pointer in returns a NULL reference, 2042 * this is to ease callers, not catch errors. 2043 */ 2044 struct filedesc * 2045 fdcopy(struct filedesc *fdp) 2046 { 2047 struct filedesc *newfdp; 2048 struct filedescent *nfde, *ofde; 2049 int i; 2050 2051 MPASS(fdp != NULL); 2052 2053 newfdp = fdinit(fdp, true); 2054 /* copy all passable descriptors (i.e. not kqueue) */ 2055 newfdp->fd_freefile = -1; 2056 for (i = 0; i <= fdp->fd_lastfile; ++i) { 2057 ofde = &fdp->fd_ofiles[i]; 2058 if (ofde->fde_file == NULL || 2059 (ofde->fde_file->f_ops->fo_flags & DFLAG_PASSABLE) == 0 || 2060 !fhold(ofde->fde_file)) { 2061 if (newfdp->fd_freefile == -1) 2062 newfdp->fd_freefile = i; 2063 continue; 2064 } 2065 nfde = &newfdp->fd_ofiles[i]; 2066 *nfde = *ofde; 2067 filecaps_copy(&ofde->fde_caps, &nfde->fde_caps, true); 2068 fdused_init(newfdp, i); 2069 newfdp->fd_lastfile = i; 2070 } 2071 if (newfdp->fd_freefile == -1) 2072 newfdp->fd_freefile = i; 2073 newfdp->fd_cmask = fdp->fd_cmask; 2074 FILEDESC_SUNLOCK(fdp); 2075 return (newfdp); 2076 } 2077 2078 /* 2079 * Copies a filedesc structure, while remapping all file descriptors 2080 * stored inside using a translation table. 2081 * 2082 * File descriptors are copied over to the new file descriptor table, 2083 * regardless of whether the close-on-exec flag is set. 2084 */ 2085 int 2086 fdcopy_remapped(struct filedesc *fdp, const int *fds, size_t nfds, 2087 struct filedesc **ret) 2088 { 2089 struct filedesc *newfdp; 2090 struct filedescent *nfde, *ofde; 2091 int error, i; 2092 2093 MPASS(fdp != NULL); 2094 2095 newfdp = fdinit(fdp, true); 2096 if (nfds > fdp->fd_lastfile + 1) { 2097 /* New table cannot be larger than the old one. */ 2098 error = E2BIG; 2099 goto bad; 2100 } 2101 /* Copy all passable descriptors (i.e. not kqueue). */ 2102 newfdp->fd_freefile = nfds; 2103 for (i = 0; i < nfds; ++i) { 2104 if (fds[i] < 0 || fds[i] > fdp->fd_lastfile) { 2105 /* File descriptor out of bounds. */ 2106 error = EBADF; 2107 goto bad; 2108 } 2109 ofde = &fdp->fd_ofiles[fds[i]]; 2110 if (ofde->fde_file == NULL) { 2111 /* Unused file descriptor. */ 2112 error = EBADF; 2113 goto bad; 2114 } 2115 if ((ofde->fde_file->f_ops->fo_flags & DFLAG_PASSABLE) == 0) { 2116 /* File descriptor cannot be passed. */ 2117 error = EINVAL; 2118 goto bad; 2119 } 2120 if (!fhold(nfde->fde_file)) { 2121 error = EBADF; 2122 goto bad; 2123 } 2124 nfde = &newfdp->fd_ofiles[i]; 2125 *nfde = *ofde; 2126 filecaps_copy(&ofde->fde_caps, &nfde->fde_caps, true); 2127 fdused_init(newfdp, i); 2128 newfdp->fd_lastfile = i; 2129 } 2130 newfdp->fd_cmask = fdp->fd_cmask; 2131 FILEDESC_SUNLOCK(fdp); 2132 *ret = newfdp; 2133 return (0); 2134 bad: 2135 FILEDESC_SUNLOCK(fdp); 2136 fdescfree_remapped(newfdp); 2137 return (error); 2138 } 2139 2140 /* 2141 * Clear POSIX style locks. This is only used when fdp looses a reference (i.e. 2142 * one of processes using it exits) and the table used to be shared. 2143 */ 2144 static void 2145 fdclearlocks(struct thread *td) 2146 { 2147 struct filedesc *fdp; 2148 struct filedesc_to_leader *fdtol; 2149 struct flock lf; 2150 struct file *fp; 2151 struct proc *p; 2152 struct vnode *vp; 2153 int i; 2154 2155 p = td->td_proc; 2156 fdp = p->p_fd; 2157 fdtol = p->p_fdtol; 2158 MPASS(fdtol != NULL); 2159 2160 FILEDESC_XLOCK(fdp); 2161 KASSERT(fdtol->fdl_refcount > 0, 2162 ("filedesc_to_refcount botch: fdl_refcount=%d", 2163 fdtol->fdl_refcount)); 2164 if (fdtol->fdl_refcount == 1 && 2165 (p->p_leader->p_flag & P_ADVLOCK) != 0) { 2166 for (i = 0; i <= fdp->fd_lastfile; i++) { 2167 fp = fdp->fd_ofiles[i].fde_file; 2168 if (fp == NULL || fp->f_type != DTYPE_VNODE || 2169 !fhold(fp)) 2170 continue; 2171 FILEDESC_XUNLOCK(fdp); 2172 lf.l_whence = SEEK_SET; 2173 lf.l_start = 0; 2174 lf.l_len = 0; 2175 lf.l_type = F_UNLCK; 2176 vp = fp->f_vnode; 2177 (void) VOP_ADVLOCK(vp, 2178 (caddr_t)p->p_leader, F_UNLCK, 2179 &lf, F_POSIX); 2180 FILEDESC_XLOCK(fdp); 2181 fdrop(fp, td); 2182 } 2183 } 2184 retry: 2185 if (fdtol->fdl_refcount == 1) { 2186 if (fdp->fd_holdleaderscount > 0 && 2187 (p->p_leader->p_flag & P_ADVLOCK) != 0) { 2188 /* 2189 * close() or kern_dup() has cleared a reference 2190 * in a shared file descriptor table. 2191 */ 2192 fdp->fd_holdleaderswakeup = 1; 2193 sx_sleep(&fdp->fd_holdleaderscount, 2194 FILEDESC_LOCK(fdp), PLOCK, "fdlhold", 0); 2195 goto retry; 2196 } 2197 if (fdtol->fdl_holdcount > 0) { 2198 /* 2199 * Ensure that fdtol->fdl_leader remains 2200 * valid in closef(). 2201 */ 2202 fdtol->fdl_wakeup = 1; 2203 sx_sleep(fdtol, FILEDESC_LOCK(fdp), PLOCK, 2204 "fdlhold", 0); 2205 goto retry; 2206 } 2207 } 2208 fdtol->fdl_refcount--; 2209 if (fdtol->fdl_refcount == 0 && 2210 fdtol->fdl_holdcount == 0) { 2211 fdtol->fdl_next->fdl_prev = fdtol->fdl_prev; 2212 fdtol->fdl_prev->fdl_next = fdtol->fdl_next; 2213 } else 2214 fdtol = NULL; 2215 p->p_fdtol = NULL; 2216 FILEDESC_XUNLOCK(fdp); 2217 if (fdtol != NULL) 2218 free(fdtol, M_FILEDESC_TO_LEADER); 2219 } 2220 2221 /* 2222 * Release a filedesc structure. 2223 */ 2224 static void 2225 fdescfree_fds(struct thread *td, struct filedesc *fdp, bool needclose) 2226 { 2227 struct filedesc0 *fdp0; 2228 struct freetable *ft, *tft; 2229 struct filedescent *fde; 2230 struct file *fp; 2231 int i; 2232 2233 for (i = 0; i <= fdp->fd_lastfile; i++) { 2234 fde = &fdp->fd_ofiles[i]; 2235 fp = fde->fde_file; 2236 if (fp != NULL) { 2237 fdefree_last(fde); 2238 if (needclose) 2239 (void) closef(fp, td); 2240 else 2241 fdrop(fp, td); 2242 } 2243 } 2244 2245 if (NDSLOTS(fdp->fd_nfiles) > NDSLOTS(NDFILE)) 2246 free(fdp->fd_map, M_FILEDESC); 2247 if (fdp->fd_nfiles > NDFILE) 2248 free(fdp->fd_files, M_FILEDESC); 2249 2250 fdp0 = (struct filedesc0 *)fdp; 2251 SLIST_FOREACH_SAFE(ft, &fdp0->fd_free, ft_next, tft) 2252 free(ft->ft_table, M_FILEDESC); 2253 2254 fddrop(fdp); 2255 } 2256 2257 void 2258 fdescfree(struct thread *td) 2259 { 2260 struct proc *p; 2261 struct filedesc *fdp; 2262 struct vnode *cdir, *jdir, *rdir; 2263 2264 p = td->td_proc; 2265 fdp = p->p_fd; 2266 MPASS(fdp != NULL); 2267 2268 #ifdef RACCT 2269 if (RACCT_ENABLED()) 2270 racct_set_unlocked(p, RACCT_NOFILE, 0); 2271 #endif 2272 2273 if (p->p_fdtol != NULL) 2274 fdclearlocks(td); 2275 2276 PROC_LOCK(p); 2277 p->p_fd = NULL; 2278 PROC_UNLOCK(p); 2279 2280 if (refcount_release(&fdp->fd_refcnt) == 0) 2281 return; 2282 2283 FILEDESC_XLOCK(fdp); 2284 cdir = fdp->fd_cdir; 2285 fdp->fd_cdir = NULL; 2286 rdir = fdp->fd_rdir; 2287 fdp->fd_rdir = NULL; 2288 jdir = fdp->fd_jdir; 2289 fdp->fd_jdir = NULL; 2290 FILEDESC_XUNLOCK(fdp); 2291 2292 if (cdir != NULL) 2293 vrele(cdir); 2294 if (rdir != NULL) 2295 vrele(rdir); 2296 if (jdir != NULL) 2297 vrele(jdir); 2298 2299 fdescfree_fds(td, fdp, 1); 2300 } 2301 2302 void 2303 fdescfree_remapped(struct filedesc *fdp) 2304 { 2305 2306 if (fdp->fd_cdir != NULL) 2307 vrele(fdp->fd_cdir); 2308 if (fdp->fd_rdir != NULL) 2309 vrele(fdp->fd_rdir); 2310 if (fdp->fd_jdir != NULL) 2311 vrele(fdp->fd_jdir); 2312 2313 fdescfree_fds(curthread, fdp, 0); 2314 } 2315 2316 /* 2317 * For setugid programs, we don't want to people to use that setugidness 2318 * to generate error messages which write to a file which otherwise would 2319 * otherwise be off-limits to the process. We check for filesystems where 2320 * the vnode can change out from under us after execve (like [lin]procfs). 2321 * 2322 * Since fdsetugidsafety calls this only for fd 0, 1 and 2, this check is 2323 * sufficient. We also don't check for setugidness since we know we are. 2324 */ 2325 static bool 2326 is_unsafe(struct file *fp) 2327 { 2328 struct vnode *vp; 2329 2330 if (fp->f_type != DTYPE_VNODE) 2331 return (false); 2332 2333 vp = fp->f_vnode; 2334 return ((vp->v_vflag & VV_PROCDEP) != 0); 2335 } 2336 2337 /* 2338 * Make this setguid thing safe, if at all possible. 2339 */ 2340 void 2341 fdsetugidsafety(struct thread *td) 2342 { 2343 struct filedesc *fdp; 2344 struct file *fp; 2345 int i; 2346 2347 fdp = td->td_proc->p_fd; 2348 KASSERT(fdp->fd_refcnt == 1, ("the fdtable should not be shared")); 2349 MPASS(fdp->fd_nfiles >= 3); 2350 for (i = 0; i <= 2; i++) { 2351 fp = fdp->fd_ofiles[i].fde_file; 2352 if (fp != NULL && is_unsafe(fp)) { 2353 FILEDESC_XLOCK(fdp); 2354 knote_fdclose(td, i); 2355 /* 2356 * NULL-out descriptor prior to close to avoid 2357 * a race while close blocks. 2358 */ 2359 fdfree(fdp, i); 2360 FILEDESC_XUNLOCK(fdp); 2361 (void) closef(fp, td); 2362 } 2363 } 2364 } 2365 2366 /* 2367 * If a specific file object occupies a specific file descriptor, close the 2368 * file descriptor entry and drop a reference on the file object. This is a 2369 * convenience function to handle a subsequent error in a function that calls 2370 * falloc() that handles the race that another thread might have closed the 2371 * file descriptor out from under the thread creating the file object. 2372 */ 2373 void 2374 fdclose(struct thread *td, struct file *fp, int idx) 2375 { 2376 struct filedesc *fdp = td->td_proc->p_fd; 2377 2378 FILEDESC_XLOCK(fdp); 2379 if (fdp->fd_ofiles[idx].fde_file == fp) { 2380 fdfree(fdp, idx); 2381 FILEDESC_XUNLOCK(fdp); 2382 fdrop(fp, td); 2383 } else 2384 FILEDESC_XUNLOCK(fdp); 2385 } 2386 2387 /* 2388 * Close any files on exec? 2389 */ 2390 void 2391 fdcloseexec(struct thread *td) 2392 { 2393 struct filedesc *fdp; 2394 struct filedescent *fde; 2395 struct file *fp; 2396 int i; 2397 2398 fdp = td->td_proc->p_fd; 2399 KASSERT(fdp->fd_refcnt == 1, ("the fdtable should not be shared")); 2400 for (i = 0; i <= fdp->fd_lastfile; i++) { 2401 fde = &fdp->fd_ofiles[i]; 2402 fp = fde->fde_file; 2403 if (fp != NULL && (fp->f_type == DTYPE_MQUEUE || 2404 (fde->fde_flags & UF_EXCLOSE))) { 2405 FILEDESC_XLOCK(fdp); 2406 fdfree(fdp, i); 2407 (void) closefp(fdp, i, fp, td, 0); 2408 FILEDESC_UNLOCK_ASSERT(fdp); 2409 } 2410 } 2411 } 2412 2413 /* 2414 * It is unsafe for set[ug]id processes to be started with file 2415 * descriptors 0..2 closed, as these descriptors are given implicit 2416 * significance in the Standard C library. fdcheckstd() will create a 2417 * descriptor referencing /dev/null for each of stdin, stdout, and 2418 * stderr that is not already open. 2419 */ 2420 int 2421 fdcheckstd(struct thread *td) 2422 { 2423 struct filedesc *fdp; 2424 register_t save; 2425 int i, error, devnull; 2426 2427 fdp = td->td_proc->p_fd; 2428 KASSERT(fdp->fd_refcnt == 1, ("the fdtable should not be shared")); 2429 MPASS(fdp->fd_nfiles >= 3); 2430 devnull = -1; 2431 for (i = 0; i <= 2; i++) { 2432 if (fdp->fd_ofiles[i].fde_file != NULL) 2433 continue; 2434 2435 save = td->td_retval[0]; 2436 if (devnull != -1) { 2437 error = kern_dup(td, FDDUP_FIXED, 0, devnull, i); 2438 } else { 2439 error = kern_openat(td, AT_FDCWD, "/dev/null", 2440 UIO_SYSSPACE, O_RDWR, 0); 2441 if (error == 0) { 2442 devnull = td->td_retval[0]; 2443 KASSERT(devnull == i, ("we didn't get our fd")); 2444 } 2445 } 2446 td->td_retval[0] = save; 2447 if (error != 0) 2448 return (error); 2449 } 2450 return (0); 2451 } 2452 2453 /* 2454 * Internal form of close. Decrement reference count on file structure. 2455 * Note: td may be NULL when closing a file that was being passed in a 2456 * message. 2457 */ 2458 int 2459 closef(struct file *fp, struct thread *td) 2460 { 2461 struct vnode *vp; 2462 struct flock lf; 2463 struct filedesc_to_leader *fdtol; 2464 struct filedesc *fdp; 2465 2466 /* 2467 * POSIX record locking dictates that any close releases ALL 2468 * locks owned by this process. This is handled by setting 2469 * a flag in the unlock to free ONLY locks obeying POSIX 2470 * semantics, and not to free BSD-style file locks. 2471 * If the descriptor was in a message, POSIX-style locks 2472 * aren't passed with the descriptor, and the thread pointer 2473 * will be NULL. Callers should be careful only to pass a 2474 * NULL thread pointer when there really is no owning 2475 * context that might have locks, or the locks will be 2476 * leaked. 2477 */ 2478 if (fp->f_type == DTYPE_VNODE && td != NULL) { 2479 vp = fp->f_vnode; 2480 if ((td->td_proc->p_leader->p_flag & P_ADVLOCK) != 0) { 2481 lf.l_whence = SEEK_SET; 2482 lf.l_start = 0; 2483 lf.l_len = 0; 2484 lf.l_type = F_UNLCK; 2485 (void) VOP_ADVLOCK(vp, (caddr_t)td->td_proc->p_leader, 2486 F_UNLCK, &lf, F_POSIX); 2487 } 2488 fdtol = td->td_proc->p_fdtol; 2489 if (fdtol != NULL) { 2490 /* 2491 * Handle special case where file descriptor table is 2492 * shared between multiple process leaders. 2493 */ 2494 fdp = td->td_proc->p_fd; 2495 FILEDESC_XLOCK(fdp); 2496 for (fdtol = fdtol->fdl_next; 2497 fdtol != td->td_proc->p_fdtol; 2498 fdtol = fdtol->fdl_next) { 2499 if ((fdtol->fdl_leader->p_flag & 2500 P_ADVLOCK) == 0) 2501 continue; 2502 fdtol->fdl_holdcount++; 2503 FILEDESC_XUNLOCK(fdp); 2504 lf.l_whence = SEEK_SET; 2505 lf.l_start = 0; 2506 lf.l_len = 0; 2507 lf.l_type = F_UNLCK; 2508 vp = fp->f_vnode; 2509 (void) VOP_ADVLOCK(vp, 2510 (caddr_t)fdtol->fdl_leader, F_UNLCK, &lf, 2511 F_POSIX); 2512 FILEDESC_XLOCK(fdp); 2513 fdtol->fdl_holdcount--; 2514 if (fdtol->fdl_holdcount == 0 && 2515 fdtol->fdl_wakeup != 0) { 2516 fdtol->fdl_wakeup = 0; 2517 wakeup(fdtol); 2518 } 2519 } 2520 FILEDESC_XUNLOCK(fdp); 2521 } 2522 } 2523 return (fdrop(fp, td)); 2524 } 2525 2526 /* 2527 * Initialize the file pointer with the specified properties. 2528 * 2529 * The ops are set with release semantics to be certain that the flags, type, 2530 * and data are visible when ops is. This is to prevent ops methods from being 2531 * called with bad data. 2532 */ 2533 void 2534 finit(struct file *fp, u_int flag, short type, void *data, struct fileops *ops) 2535 { 2536 fp->f_data = data; 2537 fp->f_flag = flag; 2538 fp->f_type = type; 2539 atomic_store_rel_ptr((volatile uintptr_t *)&fp->f_ops, (uintptr_t)ops); 2540 } 2541 2542 int 2543 fget_cap_locked(struct filedesc *fdp, int fd, cap_rights_t *needrightsp, 2544 struct file **fpp, struct filecaps *havecapsp) 2545 { 2546 struct filedescent *fde; 2547 int error; 2548 2549 FILEDESC_LOCK_ASSERT(fdp); 2550 2551 fde = fdeget_locked(fdp, fd); 2552 if (fde == NULL) { 2553 error = EBADF; 2554 goto out; 2555 } 2556 2557 #ifdef CAPABILITIES 2558 error = cap_check(cap_rights_fde_inline(fde), needrightsp); 2559 if (error != 0) 2560 goto out; 2561 #endif 2562 2563 if (havecapsp != NULL) 2564 filecaps_copy(&fde->fde_caps, havecapsp, true); 2565 2566 *fpp = fde->fde_file; 2567 2568 error = 0; 2569 out: 2570 return (error); 2571 } 2572 2573 int 2574 fget_cap(struct thread *td, int fd, cap_rights_t *needrightsp, 2575 struct file **fpp, struct filecaps *havecapsp) 2576 { 2577 struct filedesc *fdp = td->td_proc->p_fd; 2578 int error; 2579 #ifndef CAPABILITIES 2580 error = fget_unlocked(fdp, fd, needrightsp, fpp, NULL); 2581 if (error == 0 && havecapsp != NULL) 2582 filecaps_fill(havecapsp); 2583 #else 2584 struct file *fp; 2585 seqc_t seq; 2586 2587 for (;;) { 2588 error = fget_unlocked(fdp, fd, needrightsp, &fp, &seq); 2589 if (error != 0) 2590 return (error); 2591 2592 if (havecapsp != NULL) { 2593 if (!filecaps_copy(&fdp->fd_ofiles[fd].fde_caps, 2594 havecapsp, false)) { 2595 fdrop(fp, td); 2596 goto get_locked; 2597 } 2598 } 2599 2600 if (!fd_modified(fdp, fd, seq)) 2601 break; 2602 fdrop(fp, td); 2603 } 2604 2605 *fpp = fp; 2606 return (0); 2607 2608 get_locked: 2609 FILEDESC_SLOCK(fdp); 2610 error = fget_cap_locked(fdp, fd, needrightsp, fpp, havecapsp); 2611 if (error == 0 && !fhold(*fpp)) 2612 error = EBADF; 2613 FILEDESC_SUNLOCK(fdp); 2614 #endif 2615 return (error); 2616 } 2617 2618 int 2619 fget_unlocked(struct filedesc *fdp, int fd, cap_rights_t *needrightsp, 2620 struct file **fpp, seqc_t *seqp) 2621 { 2622 #ifdef CAPABILITIES 2623 const struct filedescent *fde; 2624 #endif 2625 const struct fdescenttbl *fdt; 2626 struct file *fp; 2627 u_int count; 2628 #ifdef CAPABILITIES 2629 seqc_t seq; 2630 cap_rights_t haverights; 2631 int error; 2632 #endif 2633 2634 fdt = fdp->fd_files; 2635 if (__predict_false((u_int)fd >= fdt->fdt_nfiles)) 2636 return (EBADF); 2637 /* 2638 * Fetch the descriptor locklessly. We avoid fdrop() races by 2639 * never raising a refcount above 0. To accomplish this we have 2640 * to use a cmpset loop rather than an atomic_add. The descriptor 2641 * must be re-verified once we acquire a reference to be certain 2642 * that the identity is still correct and we did not lose a race 2643 * due to preemption. 2644 */ 2645 for (;;) { 2646 #ifdef CAPABILITIES 2647 seq = seqc_read(fd_seqc(fdt, fd)); 2648 fde = &fdt->fdt_ofiles[fd]; 2649 haverights = *cap_rights_fde_inline(fde); 2650 fp = fde->fde_file; 2651 if (!seqc_consistent(fd_seqc(fdt, fd), seq)) 2652 continue; 2653 #else 2654 fp = fdt->fdt_ofiles[fd].fde_file; 2655 #endif 2656 if (fp == NULL) 2657 return (EBADF); 2658 #ifdef CAPABILITIES 2659 error = cap_check(&haverights, needrightsp); 2660 if (error != 0) 2661 return (error); 2662 #endif 2663 count = fp->f_count; 2664 retry: 2665 if (count == 0) { 2666 /* 2667 * Force a reload. Other thread could reallocate the 2668 * table before this fd was closed, so it possible that 2669 * there is a stale fp pointer in cached version. 2670 */ 2671 fdt = *(const struct fdescenttbl * const volatile *) 2672 &(fdp->fd_files); 2673 continue; 2674 } 2675 if (__predict_false(count + 1 < count)) 2676 return (EBADF); 2677 2678 /* 2679 * Use an acquire barrier to force re-reading of fdt so it is 2680 * refreshed for verification. 2681 */ 2682 if (__predict_false(atomic_fcmpset_acq_int(&fp->f_count, 2683 &count, count + 1) == 0)) 2684 goto retry; 2685 fdt = fdp->fd_files; 2686 #ifdef CAPABILITIES 2687 if (seqc_consistent_nomb(fd_seqc(fdt, fd), seq)) 2688 #else 2689 if (fp == fdt->fdt_ofiles[fd].fde_file) 2690 #endif 2691 break; 2692 fdrop(fp, curthread); 2693 } 2694 *fpp = fp; 2695 if (seqp != NULL) { 2696 #ifdef CAPABILITIES 2697 *seqp = seq; 2698 #endif 2699 } 2700 return (0); 2701 } 2702 2703 /* 2704 * Extract the file pointer associated with the specified descriptor for the 2705 * current user process. 2706 * 2707 * If the descriptor doesn't exist or doesn't match 'flags', EBADF is 2708 * returned. 2709 * 2710 * File's rights will be checked against the capability rights mask. 2711 * 2712 * If an error occurred the non-zero error is returned and *fpp is set to 2713 * NULL. Otherwise *fpp is held and set and zero is returned. Caller is 2714 * responsible for fdrop(). 2715 */ 2716 static __inline int 2717 _fget(struct thread *td, int fd, struct file **fpp, int flags, 2718 cap_rights_t *needrightsp, seqc_t *seqp) 2719 { 2720 struct filedesc *fdp; 2721 struct file *fp; 2722 int error; 2723 2724 *fpp = NULL; 2725 fdp = td->td_proc->p_fd; 2726 error = fget_unlocked(fdp, fd, needrightsp, &fp, seqp); 2727 if (error != 0) 2728 return (error); 2729 if (fp->f_ops == &badfileops) { 2730 fdrop(fp, td); 2731 return (EBADF); 2732 } 2733 2734 /* 2735 * FREAD and FWRITE failure return EBADF as per POSIX. 2736 */ 2737 error = 0; 2738 switch (flags) { 2739 case FREAD: 2740 case FWRITE: 2741 if ((fp->f_flag & flags) == 0) 2742 error = EBADF; 2743 break; 2744 case FEXEC: 2745 if ((fp->f_flag & (FREAD | FEXEC)) == 0 || 2746 ((fp->f_flag & FWRITE) != 0)) 2747 error = EBADF; 2748 break; 2749 case 0: 2750 break; 2751 default: 2752 KASSERT(0, ("wrong flags")); 2753 } 2754 2755 if (error != 0) { 2756 fdrop(fp, td); 2757 return (error); 2758 } 2759 2760 *fpp = fp; 2761 return (0); 2762 } 2763 2764 int 2765 fget(struct thread *td, int fd, cap_rights_t *rightsp, struct file **fpp) 2766 { 2767 2768 return (_fget(td, fd, fpp, 0, rightsp, NULL)); 2769 } 2770 2771 int 2772 fget_mmap(struct thread *td, int fd, cap_rights_t *rightsp, u_char *maxprotp, 2773 struct file **fpp) 2774 { 2775 int error; 2776 #ifndef CAPABILITIES 2777 error = _fget(td, fd, fpp, 0, rightsp, NULL); 2778 if (maxprotp != NULL) 2779 *maxprotp = VM_PROT_ALL; 2780 #else 2781 cap_rights_t fdrights; 2782 struct filedesc *fdp = td->td_proc->p_fd; 2783 seqc_t seq; 2784 2785 MPASS(cap_rights_is_set(rightsp, CAP_MMAP)); 2786 for (;;) { 2787 error = _fget(td, fd, fpp, 0, rightsp, &seq); 2788 if (error != 0) 2789 return (error); 2790 if (maxprotp != NULL) 2791 fdrights = *cap_rights(fdp, fd); 2792 if (!fd_modified(fdp, fd, seq)) 2793 break; 2794 fdrop(*fpp, td); 2795 } 2796 2797 /* 2798 * If requested, convert capability rights to access flags. 2799 */ 2800 if (maxprotp != NULL) 2801 *maxprotp = cap_rights_to_vmprot(&fdrights); 2802 #endif 2803 return (error); 2804 } 2805 2806 int 2807 fget_read(struct thread *td, int fd, cap_rights_t *rightsp, struct file **fpp) 2808 { 2809 2810 return (_fget(td, fd, fpp, FREAD, rightsp, NULL)); 2811 } 2812 2813 int 2814 fget_write(struct thread *td, int fd, cap_rights_t *rightsp, struct file **fpp) 2815 { 2816 2817 return (_fget(td, fd, fpp, FWRITE, rightsp, NULL)); 2818 } 2819 2820 int 2821 fget_fcntl(struct thread *td, int fd, cap_rights_t *rightsp, int needfcntl, 2822 struct file **fpp) 2823 { 2824 struct filedesc *fdp = td->td_proc->p_fd; 2825 #ifndef CAPABILITIES 2826 return (fget_unlocked(fdp, fd, rightsp, fpp, NULL)); 2827 #else 2828 int error; 2829 seqc_t seq; 2830 2831 MPASS(cap_rights_is_set(rightsp, CAP_FCNTL)); 2832 for (;;) { 2833 error = fget_unlocked(fdp, fd, rightsp, fpp, &seq); 2834 if (error != 0) 2835 return (error); 2836 error = cap_fcntl_check(fdp, fd, needfcntl); 2837 if (!fd_modified(fdp, fd, seq)) 2838 break; 2839 fdrop(*fpp, td); 2840 } 2841 if (error != 0) { 2842 fdrop(*fpp, td); 2843 *fpp = NULL; 2844 } 2845 return (error); 2846 #endif 2847 } 2848 2849 /* 2850 * Like fget() but loads the underlying vnode, or returns an error if the 2851 * descriptor does not represent a vnode. Note that pipes use vnodes but 2852 * never have VM objects. The returned vnode will be vref()'d. 2853 * 2854 * XXX: what about the unused flags ? 2855 */ 2856 static __inline int 2857 _fgetvp(struct thread *td, int fd, int flags, cap_rights_t *needrightsp, 2858 struct vnode **vpp) 2859 { 2860 struct file *fp; 2861 int error; 2862 2863 *vpp = NULL; 2864 error = _fget(td, fd, &fp, flags, needrightsp, NULL); 2865 if (error != 0) 2866 return (error); 2867 if (fp->f_vnode == NULL) { 2868 error = EINVAL; 2869 } else { 2870 *vpp = fp->f_vnode; 2871 vrefact(*vpp); 2872 } 2873 fdrop(fp, td); 2874 2875 return (error); 2876 } 2877 2878 int 2879 fgetvp(struct thread *td, int fd, cap_rights_t *rightsp, struct vnode **vpp) 2880 { 2881 2882 return (_fgetvp(td, fd, 0, rightsp, vpp)); 2883 } 2884 2885 int 2886 fgetvp_rights(struct thread *td, int fd, cap_rights_t *needrightsp, 2887 struct filecaps *havecaps, struct vnode **vpp) 2888 { 2889 struct filedesc *fdp; 2890 struct filecaps caps; 2891 struct file *fp; 2892 int error; 2893 2894 fdp = td->td_proc->p_fd; 2895 error = fget_cap_locked(fdp, fd, needrightsp, &fp, &caps); 2896 if (error != 0) 2897 return (error); 2898 if (fp->f_ops == &badfileops) { 2899 error = EBADF; 2900 goto out; 2901 } 2902 if (fp->f_vnode == NULL) { 2903 error = EINVAL; 2904 goto out; 2905 } 2906 2907 *havecaps = caps; 2908 *vpp = fp->f_vnode; 2909 vrefact(*vpp); 2910 2911 return (0); 2912 out: 2913 filecaps_free(&caps); 2914 return (error); 2915 } 2916 2917 int 2918 fgetvp_read(struct thread *td, int fd, cap_rights_t *rightsp, struct vnode **vpp) 2919 { 2920 2921 return (_fgetvp(td, fd, FREAD, rightsp, vpp)); 2922 } 2923 2924 int 2925 fgetvp_exec(struct thread *td, int fd, cap_rights_t *rightsp, struct vnode **vpp) 2926 { 2927 2928 return (_fgetvp(td, fd, FEXEC, rightsp, vpp)); 2929 } 2930 2931 #ifdef notyet 2932 int 2933 fgetvp_write(struct thread *td, int fd, cap_rights_t *rightsp, 2934 struct vnode **vpp) 2935 { 2936 2937 return (_fgetvp(td, fd, FWRITE, rightsp, vpp)); 2938 } 2939 #endif 2940 2941 /* 2942 * Handle the last reference to a file being closed. 2943 * 2944 * Without the noinline attribute clang keeps inlining the func thorough this 2945 * file when fdrop is used. 2946 */ 2947 int __noinline 2948 _fdrop(struct file *fp, struct thread *td) 2949 { 2950 int error; 2951 2952 if (fp->f_count != 0) 2953 panic("fdrop: count %d", fp->f_count); 2954 error = fo_close(fp, td); 2955 atomic_subtract_int(&openfiles, 1); 2956 crfree(fp->f_cred); 2957 free(fp->f_advice, M_FADVISE); 2958 uma_zfree(file_zone, fp); 2959 2960 return (error); 2961 } 2962 2963 /* 2964 * Apply an advisory lock on a file descriptor. 2965 * 2966 * Just attempt to get a record lock of the requested type on the entire file 2967 * (l_whence = SEEK_SET, l_start = 0, l_len = 0). 2968 */ 2969 #ifndef _SYS_SYSPROTO_H_ 2970 struct flock_args { 2971 int fd; 2972 int how; 2973 }; 2974 #endif 2975 /* ARGSUSED */ 2976 int 2977 sys_flock(struct thread *td, struct flock_args *uap) 2978 { 2979 struct file *fp; 2980 struct vnode *vp; 2981 struct flock lf; 2982 int error; 2983 2984 error = fget(td, uap->fd, &cap_flock_rights, &fp); 2985 if (error != 0) 2986 return (error); 2987 if (fp->f_type != DTYPE_VNODE) { 2988 fdrop(fp, td); 2989 return (EOPNOTSUPP); 2990 } 2991 2992 vp = fp->f_vnode; 2993 lf.l_whence = SEEK_SET; 2994 lf.l_start = 0; 2995 lf.l_len = 0; 2996 if (uap->how & LOCK_UN) { 2997 lf.l_type = F_UNLCK; 2998 atomic_clear_int(&fp->f_flag, FHASLOCK); 2999 error = VOP_ADVLOCK(vp, (caddr_t)fp, F_UNLCK, &lf, F_FLOCK); 3000 goto done2; 3001 } 3002 if (uap->how & LOCK_EX) 3003 lf.l_type = F_WRLCK; 3004 else if (uap->how & LOCK_SH) 3005 lf.l_type = F_RDLCK; 3006 else { 3007 error = EBADF; 3008 goto done2; 3009 } 3010 atomic_set_int(&fp->f_flag, FHASLOCK); 3011 error = VOP_ADVLOCK(vp, (caddr_t)fp, F_SETLK, &lf, 3012 (uap->how & LOCK_NB) ? F_FLOCK : F_FLOCK | F_WAIT); 3013 done2: 3014 fdrop(fp, td); 3015 return (error); 3016 } 3017 /* 3018 * Duplicate the specified descriptor to a free descriptor. 3019 */ 3020 int 3021 dupfdopen(struct thread *td, struct filedesc *fdp, int dfd, int mode, 3022 int openerror, int *indxp) 3023 { 3024 struct filedescent *newfde, *oldfde; 3025 struct file *fp; 3026 u_long *ioctls; 3027 int error, indx; 3028 3029 KASSERT(openerror == ENODEV || openerror == ENXIO, 3030 ("unexpected error %d in %s", openerror, __func__)); 3031 3032 /* 3033 * If the to-be-dup'd fd number is greater than the allowed number 3034 * of file descriptors, or the fd to be dup'd has already been 3035 * closed, then reject. 3036 */ 3037 FILEDESC_XLOCK(fdp); 3038 if ((fp = fget_locked(fdp, dfd)) == NULL) { 3039 FILEDESC_XUNLOCK(fdp); 3040 return (EBADF); 3041 } 3042 3043 error = fdalloc(td, 0, &indx); 3044 if (error != 0) { 3045 FILEDESC_XUNLOCK(fdp); 3046 return (error); 3047 } 3048 3049 /* 3050 * There are two cases of interest here. 3051 * 3052 * For ENODEV simply dup (dfd) to file descriptor (indx) and return. 3053 * 3054 * For ENXIO steal away the file structure from (dfd) and store it in 3055 * (indx). (dfd) is effectively closed by this operation. 3056 */ 3057 switch (openerror) { 3058 case ENODEV: 3059 /* 3060 * Check that the mode the file is being opened for is a 3061 * subset of the mode of the existing descriptor. 3062 */ 3063 if (((mode & (FREAD|FWRITE)) | fp->f_flag) != fp->f_flag) { 3064 fdunused(fdp, indx); 3065 FILEDESC_XUNLOCK(fdp); 3066 return (EACCES); 3067 } 3068 if (!fhold(fp)) { 3069 fdunused(fdp, indx); 3070 FILEDESC_XUNLOCK(fdp); 3071 return (EBADF); 3072 } 3073 newfde = &fdp->fd_ofiles[indx]; 3074 oldfde = &fdp->fd_ofiles[dfd]; 3075 ioctls = filecaps_copy_prep(&oldfde->fde_caps); 3076 #ifdef CAPABILITIES 3077 seqc_write_begin(&newfde->fde_seqc); 3078 #endif 3079 memcpy(newfde, oldfde, fde_change_size); 3080 filecaps_copy_finish(&oldfde->fde_caps, &newfde->fde_caps, 3081 ioctls); 3082 #ifdef CAPABILITIES 3083 seqc_write_end(&newfde->fde_seqc); 3084 #endif 3085 break; 3086 case ENXIO: 3087 /* 3088 * Steal away the file pointer from dfd and stuff it into indx. 3089 */ 3090 newfde = &fdp->fd_ofiles[indx]; 3091 oldfde = &fdp->fd_ofiles[dfd]; 3092 #ifdef CAPABILITIES 3093 seqc_write_begin(&newfde->fde_seqc); 3094 #endif 3095 memcpy(newfde, oldfde, fde_change_size); 3096 oldfde->fde_file = NULL; 3097 fdunused(fdp, dfd); 3098 #ifdef CAPABILITIES 3099 seqc_write_end(&newfde->fde_seqc); 3100 #endif 3101 break; 3102 } 3103 FILEDESC_XUNLOCK(fdp); 3104 *indxp = indx; 3105 return (0); 3106 } 3107 3108 /* 3109 * This sysctl determines if we will allow a process to chroot(2) if it 3110 * has a directory open: 3111 * 0: disallowed for all processes. 3112 * 1: allowed for processes that were not already chroot(2)'ed. 3113 * 2: allowed for all processes. 3114 */ 3115 3116 static int chroot_allow_open_directories = 1; 3117 3118 SYSCTL_INT(_kern, OID_AUTO, chroot_allow_open_directories, CTLFLAG_RW, 3119 &chroot_allow_open_directories, 0, 3120 "Allow a process to chroot(2) if it has a directory open"); 3121 3122 /* 3123 * Helper function for raised chroot(2) security function: Refuse if 3124 * any filedescriptors are open directories. 3125 */ 3126 static int 3127 chroot_refuse_vdir_fds(struct filedesc *fdp) 3128 { 3129 struct vnode *vp; 3130 struct file *fp; 3131 int fd; 3132 3133 FILEDESC_LOCK_ASSERT(fdp); 3134 3135 for (fd = 0; fd <= fdp->fd_lastfile; fd++) { 3136 fp = fget_locked(fdp, fd); 3137 if (fp == NULL) 3138 continue; 3139 if (fp->f_type == DTYPE_VNODE) { 3140 vp = fp->f_vnode; 3141 if (vp->v_type == VDIR) 3142 return (EPERM); 3143 } 3144 } 3145 return (0); 3146 } 3147 3148 /* 3149 * Common routine for kern_chroot() and jail_attach(). The caller is 3150 * responsible for invoking priv_check() and mac_vnode_check_chroot() to 3151 * authorize this operation. 3152 */ 3153 int 3154 pwd_chroot(struct thread *td, struct vnode *vp) 3155 { 3156 struct filedesc *fdp; 3157 struct vnode *oldvp; 3158 int error; 3159 3160 fdp = td->td_proc->p_fd; 3161 FILEDESC_XLOCK(fdp); 3162 if (chroot_allow_open_directories == 0 || 3163 (chroot_allow_open_directories == 1 && fdp->fd_rdir != rootvnode)) { 3164 error = chroot_refuse_vdir_fds(fdp); 3165 if (error != 0) { 3166 FILEDESC_XUNLOCK(fdp); 3167 return (error); 3168 } 3169 } 3170 oldvp = fdp->fd_rdir; 3171 vrefact(vp); 3172 fdp->fd_rdir = vp; 3173 if (fdp->fd_jdir == NULL) { 3174 vrefact(vp); 3175 fdp->fd_jdir = vp; 3176 } 3177 FILEDESC_XUNLOCK(fdp); 3178 vrele(oldvp); 3179 return (0); 3180 } 3181 3182 void 3183 pwd_chdir(struct thread *td, struct vnode *vp) 3184 { 3185 struct filedesc *fdp; 3186 struct vnode *oldvp; 3187 3188 fdp = td->td_proc->p_fd; 3189 FILEDESC_XLOCK(fdp); 3190 VNASSERT(vp->v_usecount > 0, vp, 3191 ("chdir to a vnode with zero usecount")); 3192 oldvp = fdp->fd_cdir; 3193 fdp->fd_cdir = vp; 3194 FILEDESC_XUNLOCK(fdp); 3195 vrele(oldvp); 3196 } 3197 3198 /* 3199 * Scan all active processes and prisons to see if any of them have a current 3200 * or root directory of `olddp'. If so, replace them with the new mount point. 3201 */ 3202 void 3203 mountcheckdirs(struct vnode *olddp, struct vnode *newdp) 3204 { 3205 struct filedesc *fdp; 3206 struct prison *pr; 3207 struct proc *p; 3208 int nrele; 3209 3210 if (vrefcnt(olddp) == 1) 3211 return; 3212 nrele = 0; 3213 sx_slock(&allproc_lock); 3214 FOREACH_PROC_IN_SYSTEM(p) { 3215 PROC_LOCK(p); 3216 fdp = fdhold(p); 3217 PROC_UNLOCK(p); 3218 if (fdp == NULL) 3219 continue; 3220 FILEDESC_XLOCK(fdp); 3221 if (fdp->fd_cdir == olddp) { 3222 vrefact(newdp); 3223 fdp->fd_cdir = newdp; 3224 nrele++; 3225 } 3226 if (fdp->fd_rdir == olddp) { 3227 vrefact(newdp); 3228 fdp->fd_rdir = newdp; 3229 nrele++; 3230 } 3231 if (fdp->fd_jdir == olddp) { 3232 vrefact(newdp); 3233 fdp->fd_jdir = newdp; 3234 nrele++; 3235 } 3236 FILEDESC_XUNLOCK(fdp); 3237 fddrop(fdp); 3238 } 3239 sx_sunlock(&allproc_lock); 3240 if (rootvnode == olddp) { 3241 vrefact(newdp); 3242 rootvnode = newdp; 3243 nrele++; 3244 } 3245 mtx_lock(&prison0.pr_mtx); 3246 if (prison0.pr_root == olddp) { 3247 vrefact(newdp); 3248 prison0.pr_root = newdp; 3249 nrele++; 3250 } 3251 mtx_unlock(&prison0.pr_mtx); 3252 sx_slock(&allprison_lock); 3253 TAILQ_FOREACH(pr, &allprison, pr_list) { 3254 mtx_lock(&pr->pr_mtx); 3255 if (pr->pr_root == olddp) { 3256 vrefact(newdp); 3257 pr->pr_root = newdp; 3258 nrele++; 3259 } 3260 mtx_unlock(&pr->pr_mtx); 3261 } 3262 sx_sunlock(&allprison_lock); 3263 while (nrele--) 3264 vrele(olddp); 3265 } 3266 3267 struct filedesc_to_leader * 3268 filedesc_to_leader_alloc(struct filedesc_to_leader *old, struct filedesc *fdp, struct proc *leader) 3269 { 3270 struct filedesc_to_leader *fdtol; 3271 3272 fdtol = malloc(sizeof(struct filedesc_to_leader), 3273 M_FILEDESC_TO_LEADER, M_WAITOK); 3274 fdtol->fdl_refcount = 1; 3275 fdtol->fdl_holdcount = 0; 3276 fdtol->fdl_wakeup = 0; 3277 fdtol->fdl_leader = leader; 3278 if (old != NULL) { 3279 FILEDESC_XLOCK(fdp); 3280 fdtol->fdl_next = old->fdl_next; 3281 fdtol->fdl_prev = old; 3282 old->fdl_next = fdtol; 3283 fdtol->fdl_next->fdl_prev = fdtol; 3284 FILEDESC_XUNLOCK(fdp); 3285 } else { 3286 fdtol->fdl_next = fdtol; 3287 fdtol->fdl_prev = fdtol; 3288 } 3289 return (fdtol); 3290 } 3291 3292 static int 3293 sysctl_kern_proc_nfds(SYSCTL_HANDLER_ARGS) 3294 { 3295 struct filedesc *fdp; 3296 int i, count, slots; 3297 3298 if (*(int *)arg1 != 0) 3299 return (EINVAL); 3300 3301 fdp = curproc->p_fd; 3302 count = 0; 3303 FILEDESC_SLOCK(fdp); 3304 slots = NDSLOTS(fdp->fd_lastfile + 1); 3305 for (i = 0; i < slots; i++) 3306 count += bitcountl(fdp->fd_map[i]); 3307 FILEDESC_SUNLOCK(fdp); 3308 3309 return (SYSCTL_OUT(req, &count, sizeof(count))); 3310 } 3311 3312 static SYSCTL_NODE(_kern_proc, KERN_PROC_NFDS, nfds, 3313 CTLFLAG_RD|CTLFLAG_CAPRD|CTLFLAG_MPSAFE, sysctl_kern_proc_nfds, 3314 "Number of open file descriptors"); 3315 3316 /* 3317 * Get file structures globally. 3318 */ 3319 static int 3320 sysctl_kern_file(SYSCTL_HANDLER_ARGS) 3321 { 3322 struct xfile xf; 3323 struct filedesc *fdp; 3324 struct file *fp; 3325 struct proc *p; 3326 int error, n; 3327 3328 error = sysctl_wire_old_buffer(req, 0); 3329 if (error != 0) 3330 return (error); 3331 if (req->oldptr == NULL) { 3332 n = 0; 3333 sx_slock(&allproc_lock); 3334 FOREACH_PROC_IN_SYSTEM(p) { 3335 PROC_LOCK(p); 3336 if (p->p_state == PRS_NEW) { 3337 PROC_UNLOCK(p); 3338 continue; 3339 } 3340 fdp = fdhold(p); 3341 PROC_UNLOCK(p); 3342 if (fdp == NULL) 3343 continue; 3344 /* overestimates sparse tables. */ 3345 if (fdp->fd_lastfile > 0) 3346 n += fdp->fd_lastfile; 3347 fddrop(fdp); 3348 } 3349 sx_sunlock(&allproc_lock); 3350 return (SYSCTL_OUT(req, 0, n * sizeof(xf))); 3351 } 3352 error = 0; 3353 bzero(&xf, sizeof(xf)); 3354 xf.xf_size = sizeof(xf); 3355 sx_slock(&allproc_lock); 3356 FOREACH_PROC_IN_SYSTEM(p) { 3357 PROC_LOCK(p); 3358 if (p->p_state == PRS_NEW) { 3359 PROC_UNLOCK(p); 3360 continue; 3361 } 3362 if (p_cansee(req->td, p) != 0) { 3363 PROC_UNLOCK(p); 3364 continue; 3365 } 3366 xf.xf_pid = p->p_pid; 3367 xf.xf_uid = p->p_ucred->cr_uid; 3368 fdp = fdhold(p); 3369 PROC_UNLOCK(p); 3370 if (fdp == NULL) 3371 continue; 3372 FILEDESC_SLOCK(fdp); 3373 for (n = 0; fdp->fd_refcnt > 0 && n <= fdp->fd_lastfile; ++n) { 3374 if ((fp = fdp->fd_ofiles[n].fde_file) == NULL) 3375 continue; 3376 xf.xf_fd = n; 3377 xf.xf_file = (uintptr_t)fp; 3378 xf.xf_data = (uintptr_t)fp->f_data; 3379 xf.xf_vnode = (uintptr_t)fp->f_vnode; 3380 xf.xf_type = (uintptr_t)fp->f_type; 3381 xf.xf_count = fp->f_count; 3382 xf.xf_msgcount = 0; 3383 xf.xf_offset = foffset_get(fp); 3384 xf.xf_flag = fp->f_flag; 3385 error = SYSCTL_OUT(req, &xf, sizeof(xf)); 3386 if (error) 3387 break; 3388 } 3389 FILEDESC_SUNLOCK(fdp); 3390 fddrop(fdp); 3391 if (error) 3392 break; 3393 } 3394 sx_sunlock(&allproc_lock); 3395 return (error); 3396 } 3397 3398 SYSCTL_PROC(_kern, KERN_FILE, file, CTLTYPE_OPAQUE|CTLFLAG_RD|CTLFLAG_MPSAFE, 3399 0, 0, sysctl_kern_file, "S,xfile", "Entire file table"); 3400 3401 #ifdef KINFO_FILE_SIZE 3402 CTASSERT(sizeof(struct kinfo_file) == KINFO_FILE_SIZE); 3403 #endif 3404 3405 static int 3406 xlate_fflags(int fflags) 3407 { 3408 static const struct { 3409 int fflag; 3410 int kf_fflag; 3411 } fflags_table[] = { 3412 { FAPPEND, KF_FLAG_APPEND }, 3413 { FASYNC, KF_FLAG_ASYNC }, 3414 { FFSYNC, KF_FLAG_FSYNC }, 3415 { FHASLOCK, KF_FLAG_HASLOCK }, 3416 { FNONBLOCK, KF_FLAG_NONBLOCK }, 3417 { FREAD, KF_FLAG_READ }, 3418 { FWRITE, KF_FLAG_WRITE }, 3419 { O_CREAT, KF_FLAG_CREAT }, 3420 { O_DIRECT, KF_FLAG_DIRECT }, 3421 { O_EXCL, KF_FLAG_EXCL }, 3422 { O_EXEC, KF_FLAG_EXEC }, 3423 { O_EXLOCK, KF_FLAG_EXLOCK }, 3424 { O_NOFOLLOW, KF_FLAG_NOFOLLOW }, 3425 { O_SHLOCK, KF_FLAG_SHLOCK }, 3426 { O_TRUNC, KF_FLAG_TRUNC } 3427 }; 3428 unsigned int i; 3429 int kflags; 3430 3431 kflags = 0; 3432 for (i = 0; i < nitems(fflags_table); i++) 3433 if (fflags & fflags_table[i].fflag) 3434 kflags |= fflags_table[i].kf_fflag; 3435 return (kflags); 3436 } 3437 3438 /* Trim unused data from kf_path by truncating the structure size. */ 3439 void 3440 pack_kinfo(struct kinfo_file *kif) 3441 { 3442 3443 kif->kf_structsize = offsetof(struct kinfo_file, kf_path) + 3444 strlen(kif->kf_path) + 1; 3445 kif->kf_structsize = roundup(kif->kf_structsize, sizeof(uint64_t)); 3446 } 3447 3448 static void 3449 export_file_to_kinfo(struct file *fp, int fd, cap_rights_t *rightsp, 3450 struct kinfo_file *kif, struct filedesc *fdp, int flags) 3451 { 3452 int error; 3453 3454 bzero(kif, sizeof(*kif)); 3455 3456 /* Set a default type to allow for empty fill_kinfo() methods. */ 3457 kif->kf_type = KF_TYPE_UNKNOWN; 3458 kif->kf_flags = xlate_fflags(fp->f_flag); 3459 if (rightsp != NULL) 3460 kif->kf_cap_rights = *rightsp; 3461 else 3462 cap_rights_init(&kif->kf_cap_rights); 3463 kif->kf_fd = fd; 3464 kif->kf_ref_count = fp->f_count; 3465 kif->kf_offset = foffset_get(fp); 3466 3467 /* 3468 * This may drop the filedesc lock, so the 'fp' cannot be 3469 * accessed after this call. 3470 */ 3471 error = fo_fill_kinfo(fp, kif, fdp); 3472 if (error == 0) 3473 kif->kf_status |= KF_ATTR_VALID; 3474 if ((flags & KERN_FILEDESC_PACK_KINFO) != 0) 3475 pack_kinfo(kif); 3476 else 3477 kif->kf_structsize = roundup2(sizeof(*kif), sizeof(uint64_t)); 3478 } 3479 3480 static void 3481 export_vnode_to_kinfo(struct vnode *vp, int fd, int fflags, 3482 struct kinfo_file *kif, int flags) 3483 { 3484 int error; 3485 3486 bzero(kif, sizeof(*kif)); 3487 3488 kif->kf_type = KF_TYPE_VNODE; 3489 error = vn_fill_kinfo_vnode(vp, kif); 3490 if (error == 0) 3491 kif->kf_status |= KF_ATTR_VALID; 3492 kif->kf_flags = xlate_fflags(fflags); 3493 cap_rights_init(&kif->kf_cap_rights); 3494 kif->kf_fd = fd; 3495 kif->kf_ref_count = -1; 3496 kif->kf_offset = -1; 3497 if ((flags & KERN_FILEDESC_PACK_KINFO) != 0) 3498 pack_kinfo(kif); 3499 else 3500 kif->kf_structsize = roundup2(sizeof(*kif), sizeof(uint64_t)); 3501 vrele(vp); 3502 } 3503 3504 struct export_fd_buf { 3505 struct filedesc *fdp; 3506 struct sbuf *sb; 3507 ssize_t remainder; 3508 struct kinfo_file kif; 3509 int flags; 3510 }; 3511 3512 static int 3513 export_kinfo_to_sb(struct export_fd_buf *efbuf) 3514 { 3515 struct kinfo_file *kif; 3516 3517 kif = &efbuf->kif; 3518 if (efbuf->remainder != -1) { 3519 if (efbuf->remainder < kif->kf_structsize) { 3520 /* Terminate export. */ 3521 efbuf->remainder = 0; 3522 return (0); 3523 } 3524 efbuf->remainder -= kif->kf_structsize; 3525 } 3526 return (sbuf_bcat(efbuf->sb, kif, kif->kf_structsize) == 0 ? 0 : ENOMEM); 3527 } 3528 3529 static int 3530 export_file_to_sb(struct file *fp, int fd, cap_rights_t *rightsp, 3531 struct export_fd_buf *efbuf) 3532 { 3533 int error; 3534 3535 if (efbuf->remainder == 0) 3536 return (0); 3537 export_file_to_kinfo(fp, fd, rightsp, &efbuf->kif, efbuf->fdp, 3538 efbuf->flags); 3539 FILEDESC_SUNLOCK(efbuf->fdp); 3540 error = export_kinfo_to_sb(efbuf); 3541 FILEDESC_SLOCK(efbuf->fdp); 3542 return (error); 3543 } 3544 3545 static int 3546 export_vnode_to_sb(struct vnode *vp, int fd, int fflags, 3547 struct export_fd_buf *efbuf) 3548 { 3549 int error; 3550 3551 if (efbuf->remainder == 0) 3552 return (0); 3553 if (efbuf->fdp != NULL) 3554 FILEDESC_SUNLOCK(efbuf->fdp); 3555 export_vnode_to_kinfo(vp, fd, fflags, &efbuf->kif, efbuf->flags); 3556 error = export_kinfo_to_sb(efbuf); 3557 if (efbuf->fdp != NULL) 3558 FILEDESC_SLOCK(efbuf->fdp); 3559 return (error); 3560 } 3561 3562 /* 3563 * Store a process file descriptor information to sbuf. 3564 * 3565 * Takes a locked proc as argument, and returns with the proc unlocked. 3566 */ 3567 int 3568 kern_proc_filedesc_out(struct proc *p, struct sbuf *sb, ssize_t maxlen, 3569 int flags) 3570 { 3571 struct file *fp; 3572 struct filedesc *fdp; 3573 struct export_fd_buf *efbuf; 3574 struct vnode *cttyvp, *textvp, *tracevp; 3575 int error, i; 3576 cap_rights_t rights; 3577 3578 PROC_LOCK_ASSERT(p, MA_OWNED); 3579 3580 /* ktrace vnode */ 3581 tracevp = p->p_tracevp; 3582 if (tracevp != NULL) 3583 vrefact(tracevp); 3584 /* text vnode */ 3585 textvp = p->p_textvp; 3586 if (textvp != NULL) 3587 vrefact(textvp); 3588 /* Controlling tty. */ 3589 cttyvp = NULL; 3590 if (p->p_pgrp != NULL && p->p_pgrp->pg_session != NULL) { 3591 cttyvp = p->p_pgrp->pg_session->s_ttyvp; 3592 if (cttyvp != NULL) 3593 vrefact(cttyvp); 3594 } 3595 fdp = fdhold(p); 3596 PROC_UNLOCK(p); 3597 efbuf = malloc(sizeof(*efbuf), M_TEMP, M_WAITOK); 3598 efbuf->fdp = NULL; 3599 efbuf->sb = sb; 3600 efbuf->remainder = maxlen; 3601 efbuf->flags = flags; 3602 if (tracevp != NULL) 3603 export_vnode_to_sb(tracevp, KF_FD_TYPE_TRACE, FREAD | FWRITE, 3604 efbuf); 3605 if (textvp != NULL) 3606 export_vnode_to_sb(textvp, KF_FD_TYPE_TEXT, FREAD, efbuf); 3607 if (cttyvp != NULL) 3608 export_vnode_to_sb(cttyvp, KF_FD_TYPE_CTTY, FREAD | FWRITE, 3609 efbuf); 3610 error = 0; 3611 if (fdp == NULL) 3612 goto fail; 3613 efbuf->fdp = fdp; 3614 FILEDESC_SLOCK(fdp); 3615 /* working directory */ 3616 if (fdp->fd_cdir != NULL) { 3617 vrefact(fdp->fd_cdir); 3618 export_vnode_to_sb(fdp->fd_cdir, KF_FD_TYPE_CWD, FREAD, efbuf); 3619 } 3620 /* root directory */ 3621 if (fdp->fd_rdir != NULL) { 3622 vrefact(fdp->fd_rdir); 3623 export_vnode_to_sb(fdp->fd_rdir, KF_FD_TYPE_ROOT, FREAD, efbuf); 3624 } 3625 /* jail directory */ 3626 if (fdp->fd_jdir != NULL) { 3627 vrefact(fdp->fd_jdir); 3628 export_vnode_to_sb(fdp->fd_jdir, KF_FD_TYPE_JAIL, FREAD, efbuf); 3629 } 3630 for (i = 0; fdp->fd_refcnt > 0 && i <= fdp->fd_lastfile; i++) { 3631 if ((fp = fdp->fd_ofiles[i].fde_file) == NULL) 3632 continue; 3633 #ifdef CAPABILITIES 3634 rights = *cap_rights(fdp, i); 3635 #else /* !CAPABILITIES */ 3636 rights = cap_no_rights; 3637 #endif 3638 /* 3639 * Create sysctl entry. It is OK to drop the filedesc 3640 * lock inside of export_file_to_sb() as we will 3641 * re-validate and re-evaluate its properties when the 3642 * loop continues. 3643 */ 3644 error = export_file_to_sb(fp, i, &rights, efbuf); 3645 if (error != 0 || efbuf->remainder == 0) 3646 break; 3647 } 3648 FILEDESC_SUNLOCK(fdp); 3649 fddrop(fdp); 3650 fail: 3651 free(efbuf, M_TEMP); 3652 return (error); 3653 } 3654 3655 #define FILEDESC_SBUF_SIZE (sizeof(struct kinfo_file) * 5) 3656 3657 /* 3658 * Get per-process file descriptors for use by procstat(1), et al. 3659 */ 3660 static int 3661 sysctl_kern_proc_filedesc(SYSCTL_HANDLER_ARGS) 3662 { 3663 struct sbuf sb; 3664 struct proc *p; 3665 ssize_t maxlen; 3666 int error, error2, *name; 3667 3668 name = (int *)arg1; 3669 3670 sbuf_new_for_sysctl(&sb, NULL, FILEDESC_SBUF_SIZE, req); 3671 sbuf_clear_flags(&sb, SBUF_INCLUDENUL); 3672 error = pget((pid_t)name[0], PGET_CANDEBUG | PGET_NOTWEXIT, &p); 3673 if (error != 0) { 3674 sbuf_delete(&sb); 3675 return (error); 3676 } 3677 maxlen = req->oldptr != NULL ? req->oldlen : -1; 3678 error = kern_proc_filedesc_out(p, &sb, maxlen, 3679 KERN_FILEDESC_PACK_KINFO); 3680 error2 = sbuf_finish(&sb); 3681 sbuf_delete(&sb); 3682 return (error != 0 ? error : error2); 3683 } 3684 3685 #ifdef COMPAT_FREEBSD7 3686 #ifdef KINFO_OFILE_SIZE 3687 CTASSERT(sizeof(struct kinfo_ofile) == KINFO_OFILE_SIZE); 3688 #endif 3689 3690 static void 3691 kinfo_to_okinfo(struct kinfo_file *kif, struct kinfo_ofile *okif) 3692 { 3693 3694 okif->kf_structsize = sizeof(*okif); 3695 okif->kf_type = kif->kf_type; 3696 okif->kf_fd = kif->kf_fd; 3697 okif->kf_ref_count = kif->kf_ref_count; 3698 okif->kf_flags = kif->kf_flags & (KF_FLAG_READ | KF_FLAG_WRITE | 3699 KF_FLAG_APPEND | KF_FLAG_ASYNC | KF_FLAG_FSYNC | KF_FLAG_NONBLOCK | 3700 KF_FLAG_DIRECT | KF_FLAG_HASLOCK); 3701 okif->kf_offset = kif->kf_offset; 3702 if (kif->kf_type == KF_TYPE_VNODE) 3703 okif->kf_vnode_type = kif->kf_un.kf_file.kf_file_type; 3704 else 3705 okif->kf_vnode_type = KF_VTYPE_VNON; 3706 strlcpy(okif->kf_path, kif->kf_path, sizeof(okif->kf_path)); 3707 if (kif->kf_type == KF_TYPE_SOCKET) { 3708 okif->kf_sock_domain = kif->kf_un.kf_sock.kf_sock_domain0; 3709 okif->kf_sock_type = kif->kf_un.kf_sock.kf_sock_type0; 3710 okif->kf_sock_protocol = kif->kf_un.kf_sock.kf_sock_protocol0; 3711 okif->kf_sa_local = kif->kf_un.kf_sock.kf_sa_local; 3712 okif->kf_sa_peer = kif->kf_un.kf_sock.kf_sa_peer; 3713 } else { 3714 okif->kf_sa_local.ss_family = AF_UNSPEC; 3715 okif->kf_sa_peer.ss_family = AF_UNSPEC; 3716 } 3717 } 3718 3719 static int 3720 export_vnode_for_osysctl(struct vnode *vp, int type, struct kinfo_file *kif, 3721 struct kinfo_ofile *okif, struct filedesc *fdp, struct sysctl_req *req) 3722 { 3723 int error; 3724 3725 vrefact(vp); 3726 FILEDESC_SUNLOCK(fdp); 3727 export_vnode_to_kinfo(vp, type, 0, kif, KERN_FILEDESC_PACK_KINFO); 3728 kinfo_to_okinfo(kif, okif); 3729 error = SYSCTL_OUT(req, okif, sizeof(*okif)); 3730 FILEDESC_SLOCK(fdp); 3731 return (error); 3732 } 3733 3734 /* 3735 * Get per-process file descriptors for use by procstat(1), et al. 3736 */ 3737 static int 3738 sysctl_kern_proc_ofiledesc(SYSCTL_HANDLER_ARGS) 3739 { 3740 struct kinfo_ofile *okif; 3741 struct kinfo_file *kif; 3742 struct filedesc *fdp; 3743 int error, i, *name; 3744 struct file *fp; 3745 struct proc *p; 3746 3747 name = (int *)arg1; 3748 error = pget((pid_t)name[0], PGET_CANDEBUG | PGET_NOTWEXIT, &p); 3749 if (error != 0) 3750 return (error); 3751 fdp = fdhold(p); 3752 PROC_UNLOCK(p); 3753 if (fdp == NULL) 3754 return (ENOENT); 3755 kif = malloc(sizeof(*kif), M_TEMP, M_WAITOK); 3756 okif = malloc(sizeof(*okif), M_TEMP, M_WAITOK); 3757 FILEDESC_SLOCK(fdp); 3758 if (fdp->fd_cdir != NULL) 3759 export_vnode_for_osysctl(fdp->fd_cdir, KF_FD_TYPE_CWD, kif, 3760 okif, fdp, req); 3761 if (fdp->fd_rdir != NULL) 3762 export_vnode_for_osysctl(fdp->fd_rdir, KF_FD_TYPE_ROOT, kif, 3763 okif, fdp, req); 3764 if (fdp->fd_jdir != NULL) 3765 export_vnode_for_osysctl(fdp->fd_jdir, KF_FD_TYPE_JAIL, kif, 3766 okif, fdp, req); 3767 for (i = 0; fdp->fd_refcnt > 0 && i <= fdp->fd_lastfile; i++) { 3768 if ((fp = fdp->fd_ofiles[i].fde_file) == NULL) 3769 continue; 3770 export_file_to_kinfo(fp, i, NULL, kif, fdp, 3771 KERN_FILEDESC_PACK_KINFO); 3772 FILEDESC_SUNLOCK(fdp); 3773 kinfo_to_okinfo(kif, okif); 3774 error = SYSCTL_OUT(req, okif, sizeof(*okif)); 3775 FILEDESC_SLOCK(fdp); 3776 if (error) 3777 break; 3778 } 3779 FILEDESC_SUNLOCK(fdp); 3780 fddrop(fdp); 3781 free(kif, M_TEMP); 3782 free(okif, M_TEMP); 3783 return (0); 3784 } 3785 3786 static SYSCTL_NODE(_kern_proc, KERN_PROC_OFILEDESC, ofiledesc, 3787 CTLFLAG_RD|CTLFLAG_MPSAFE, sysctl_kern_proc_ofiledesc, 3788 "Process ofiledesc entries"); 3789 #endif /* COMPAT_FREEBSD7 */ 3790 3791 int 3792 vntype_to_kinfo(int vtype) 3793 { 3794 struct { 3795 int vtype; 3796 int kf_vtype; 3797 } vtypes_table[] = { 3798 { VBAD, KF_VTYPE_VBAD }, 3799 { VBLK, KF_VTYPE_VBLK }, 3800 { VCHR, KF_VTYPE_VCHR }, 3801 { VDIR, KF_VTYPE_VDIR }, 3802 { VFIFO, KF_VTYPE_VFIFO }, 3803 { VLNK, KF_VTYPE_VLNK }, 3804 { VNON, KF_VTYPE_VNON }, 3805 { VREG, KF_VTYPE_VREG }, 3806 { VSOCK, KF_VTYPE_VSOCK } 3807 }; 3808 unsigned int i; 3809 3810 /* 3811 * Perform vtype translation. 3812 */ 3813 for (i = 0; i < nitems(vtypes_table); i++) 3814 if (vtypes_table[i].vtype == vtype) 3815 return (vtypes_table[i].kf_vtype); 3816 3817 return (KF_VTYPE_UNKNOWN); 3818 } 3819 3820 static SYSCTL_NODE(_kern_proc, KERN_PROC_FILEDESC, filedesc, 3821 CTLFLAG_RD|CTLFLAG_MPSAFE, sysctl_kern_proc_filedesc, 3822 "Process filedesc entries"); 3823 3824 /* 3825 * Store a process current working directory information to sbuf. 3826 * 3827 * Takes a locked proc as argument, and returns with the proc unlocked. 3828 */ 3829 int 3830 kern_proc_cwd_out(struct proc *p, struct sbuf *sb, ssize_t maxlen) 3831 { 3832 struct filedesc *fdp; 3833 struct export_fd_buf *efbuf; 3834 int error; 3835 3836 PROC_LOCK_ASSERT(p, MA_OWNED); 3837 3838 fdp = fdhold(p); 3839 PROC_UNLOCK(p); 3840 if (fdp == NULL) 3841 return (EINVAL); 3842 3843 efbuf = malloc(sizeof(*efbuf), M_TEMP, M_WAITOK); 3844 efbuf->fdp = fdp; 3845 efbuf->sb = sb; 3846 efbuf->remainder = maxlen; 3847 3848 FILEDESC_SLOCK(fdp); 3849 if (fdp->fd_cdir == NULL) 3850 error = EINVAL; 3851 else { 3852 vrefact(fdp->fd_cdir); 3853 error = export_vnode_to_sb(fdp->fd_cdir, KF_FD_TYPE_CWD, 3854 FREAD, efbuf); 3855 } 3856 FILEDESC_SUNLOCK(fdp); 3857 fddrop(fdp); 3858 free(efbuf, M_TEMP); 3859 return (error); 3860 } 3861 3862 /* 3863 * Get per-process current working directory. 3864 */ 3865 static int 3866 sysctl_kern_proc_cwd(SYSCTL_HANDLER_ARGS) 3867 { 3868 struct sbuf sb; 3869 struct proc *p; 3870 ssize_t maxlen; 3871 int error, error2, *name; 3872 3873 name = (int *)arg1; 3874 3875 sbuf_new_for_sysctl(&sb, NULL, sizeof(struct kinfo_file), req); 3876 sbuf_clear_flags(&sb, SBUF_INCLUDENUL); 3877 error = pget((pid_t)name[0], PGET_CANDEBUG | PGET_NOTWEXIT, &p); 3878 if (error != 0) { 3879 sbuf_delete(&sb); 3880 return (error); 3881 } 3882 maxlen = req->oldptr != NULL ? req->oldlen : -1; 3883 error = kern_proc_cwd_out(p, &sb, maxlen); 3884 error2 = sbuf_finish(&sb); 3885 sbuf_delete(&sb); 3886 return (error != 0 ? error : error2); 3887 } 3888 3889 static SYSCTL_NODE(_kern_proc, KERN_PROC_CWD, cwd, CTLFLAG_RD|CTLFLAG_MPSAFE, 3890 sysctl_kern_proc_cwd, "Process current working directory"); 3891 3892 #ifdef DDB 3893 /* 3894 * For the purposes of debugging, generate a human-readable string for the 3895 * file type. 3896 */ 3897 static const char * 3898 file_type_to_name(short type) 3899 { 3900 3901 switch (type) { 3902 case 0: 3903 return ("zero"); 3904 case DTYPE_VNODE: 3905 return ("vnode"); 3906 case DTYPE_SOCKET: 3907 return ("socket"); 3908 case DTYPE_PIPE: 3909 return ("pipe"); 3910 case DTYPE_FIFO: 3911 return ("fifo"); 3912 case DTYPE_KQUEUE: 3913 return ("kqueue"); 3914 case DTYPE_CRYPTO: 3915 return ("crypto"); 3916 case DTYPE_MQUEUE: 3917 return ("mqueue"); 3918 case DTYPE_SHM: 3919 return ("shm"); 3920 case DTYPE_SEM: 3921 return ("ksem"); 3922 case DTYPE_PTS: 3923 return ("pts"); 3924 case DTYPE_DEV: 3925 return ("dev"); 3926 case DTYPE_PROCDESC: 3927 return ("proc"); 3928 case DTYPE_LINUXEFD: 3929 return ("levent"); 3930 case DTYPE_LINUXTFD: 3931 return ("ltimer"); 3932 default: 3933 return ("unkn"); 3934 } 3935 } 3936 3937 /* 3938 * For the purposes of debugging, identify a process (if any, perhaps one of 3939 * many) that references the passed file in its file descriptor array. Return 3940 * NULL if none. 3941 */ 3942 static struct proc * 3943 file_to_first_proc(struct file *fp) 3944 { 3945 struct filedesc *fdp; 3946 struct proc *p; 3947 int n; 3948 3949 FOREACH_PROC_IN_SYSTEM(p) { 3950 if (p->p_state == PRS_NEW) 3951 continue; 3952 fdp = p->p_fd; 3953 if (fdp == NULL) 3954 continue; 3955 for (n = 0; n <= fdp->fd_lastfile; n++) { 3956 if (fp == fdp->fd_ofiles[n].fde_file) 3957 return (p); 3958 } 3959 } 3960 return (NULL); 3961 } 3962 3963 static void 3964 db_print_file(struct file *fp, int header) 3965 { 3966 #define XPTRWIDTH ((int)howmany(sizeof(void *) * NBBY, 4)) 3967 struct proc *p; 3968 3969 if (header) 3970 db_printf("%*s %6s %*s %8s %4s %5s %6s %*s %5s %s\n", 3971 XPTRWIDTH, "File", "Type", XPTRWIDTH, "Data", "Flag", 3972 "GCFl", "Count", "MCount", XPTRWIDTH, "Vnode", "FPID", 3973 "FCmd"); 3974 p = file_to_first_proc(fp); 3975 db_printf("%*p %6s %*p %08x %04x %5d %6d %*p %5d %s\n", XPTRWIDTH, 3976 fp, file_type_to_name(fp->f_type), XPTRWIDTH, fp->f_data, 3977 fp->f_flag, 0, fp->f_count, 0, XPTRWIDTH, fp->f_vnode, 3978 p != NULL ? p->p_pid : -1, p != NULL ? p->p_comm : "-"); 3979 3980 #undef XPTRWIDTH 3981 } 3982 3983 DB_SHOW_COMMAND(file, db_show_file) 3984 { 3985 struct file *fp; 3986 3987 if (!have_addr) { 3988 db_printf("usage: show file <addr>\n"); 3989 return; 3990 } 3991 fp = (struct file *)addr; 3992 db_print_file(fp, 1); 3993 } 3994 3995 DB_SHOW_COMMAND(files, db_show_files) 3996 { 3997 struct filedesc *fdp; 3998 struct file *fp; 3999 struct proc *p; 4000 int header; 4001 int n; 4002 4003 header = 1; 4004 FOREACH_PROC_IN_SYSTEM(p) { 4005 if (p->p_state == PRS_NEW) 4006 continue; 4007 if ((fdp = p->p_fd) == NULL) 4008 continue; 4009 for (n = 0; n <= fdp->fd_lastfile; ++n) { 4010 if ((fp = fdp->fd_ofiles[n].fde_file) == NULL) 4011 continue; 4012 db_print_file(fp, header); 4013 header = 0; 4014 } 4015 } 4016 } 4017 #endif 4018 4019 SYSCTL_INT(_kern, KERN_MAXFILESPERPROC, maxfilesperproc, CTLFLAG_RW, 4020 &maxfilesperproc, 0, "Maximum files allowed open per process"); 4021 4022 SYSCTL_INT(_kern, KERN_MAXFILES, maxfiles, CTLFLAG_RW, 4023 &maxfiles, 0, "Maximum number of files"); 4024 4025 SYSCTL_INT(_kern, OID_AUTO, openfiles, CTLFLAG_RD, 4026 __DEVOLATILE(int *, &openfiles), 0, "System-wide number of open files"); 4027 4028 /* ARGSUSED*/ 4029 static void 4030 filelistinit(void *dummy) 4031 { 4032 4033 file_zone = uma_zcreate("Files", sizeof(struct file), NULL, NULL, 4034 NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE); 4035 filedesc0_zone = uma_zcreate("filedesc0", sizeof(struct filedesc0), 4036 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0); 4037 mtx_init(&sigio_lock, "sigio lock", NULL, MTX_DEF); 4038 } 4039 SYSINIT(select, SI_SUB_LOCK, SI_ORDER_FIRST, filelistinit, NULL); 4040 4041 /*-------------------------------------------------------------------*/ 4042 4043 static int 4044 badfo_readwrite(struct file *fp, struct uio *uio, struct ucred *active_cred, 4045 int flags, struct thread *td) 4046 { 4047 4048 return (EBADF); 4049 } 4050 4051 static int 4052 badfo_truncate(struct file *fp, off_t length, struct ucred *active_cred, 4053 struct thread *td) 4054 { 4055 4056 return (EINVAL); 4057 } 4058 4059 static int 4060 badfo_ioctl(struct file *fp, u_long com, void *data, struct ucred *active_cred, 4061 struct thread *td) 4062 { 4063 4064 return (EBADF); 4065 } 4066 4067 static int 4068 badfo_poll(struct file *fp, int events, struct ucred *active_cred, 4069 struct thread *td) 4070 { 4071 4072 return (0); 4073 } 4074 4075 static int 4076 badfo_kqfilter(struct file *fp, struct knote *kn) 4077 { 4078 4079 return (EBADF); 4080 } 4081 4082 static int 4083 badfo_stat(struct file *fp, struct stat *sb, struct ucred *active_cred, 4084 struct thread *td) 4085 { 4086 4087 return (EBADF); 4088 } 4089 4090 static int 4091 badfo_close(struct file *fp, struct thread *td) 4092 { 4093 4094 return (0); 4095 } 4096 4097 static int 4098 badfo_chmod(struct file *fp, mode_t mode, struct ucred *active_cred, 4099 struct thread *td) 4100 { 4101 4102 return (EBADF); 4103 } 4104 4105 static int 4106 badfo_chown(struct file *fp, uid_t uid, gid_t gid, struct ucred *active_cred, 4107 struct thread *td) 4108 { 4109 4110 return (EBADF); 4111 } 4112 4113 static int 4114 badfo_sendfile(struct file *fp, int sockfd, struct uio *hdr_uio, 4115 struct uio *trl_uio, off_t offset, size_t nbytes, off_t *sent, int flags, 4116 struct thread *td) 4117 { 4118 4119 return (EBADF); 4120 } 4121 4122 static int 4123 badfo_fill_kinfo(struct file *fp, struct kinfo_file *kif, struct filedesc *fdp) 4124 { 4125 4126 return (0); 4127 } 4128 4129 struct fileops badfileops = { 4130 .fo_read = badfo_readwrite, 4131 .fo_write = badfo_readwrite, 4132 .fo_truncate = badfo_truncate, 4133 .fo_ioctl = badfo_ioctl, 4134 .fo_poll = badfo_poll, 4135 .fo_kqfilter = badfo_kqfilter, 4136 .fo_stat = badfo_stat, 4137 .fo_close = badfo_close, 4138 .fo_chmod = badfo_chmod, 4139 .fo_chown = badfo_chown, 4140 .fo_sendfile = badfo_sendfile, 4141 .fo_fill_kinfo = badfo_fill_kinfo, 4142 }; 4143 4144 int 4145 invfo_rdwr(struct file *fp, struct uio *uio, struct ucred *active_cred, 4146 int flags, struct thread *td) 4147 { 4148 4149 return (EOPNOTSUPP); 4150 } 4151 4152 int 4153 invfo_truncate(struct file *fp, off_t length, struct ucred *active_cred, 4154 struct thread *td) 4155 { 4156 4157 return (EINVAL); 4158 } 4159 4160 int 4161 invfo_ioctl(struct file *fp, u_long com, void *data, 4162 struct ucred *active_cred, struct thread *td) 4163 { 4164 4165 return (ENOTTY); 4166 } 4167 4168 int 4169 invfo_poll(struct file *fp, int events, struct ucred *active_cred, 4170 struct thread *td) 4171 { 4172 4173 return (poll_no_poll(events)); 4174 } 4175 4176 int 4177 invfo_kqfilter(struct file *fp, struct knote *kn) 4178 { 4179 4180 return (EINVAL); 4181 } 4182 4183 int 4184 invfo_chmod(struct file *fp, mode_t mode, struct ucred *active_cred, 4185 struct thread *td) 4186 { 4187 4188 return (EINVAL); 4189 } 4190 4191 int 4192 invfo_chown(struct file *fp, uid_t uid, gid_t gid, struct ucred *active_cred, 4193 struct thread *td) 4194 { 4195 4196 return (EINVAL); 4197 } 4198 4199 int 4200 invfo_sendfile(struct file *fp, int sockfd, struct uio *hdr_uio, 4201 struct uio *trl_uio, off_t offset, size_t nbytes, off_t *sent, int flags, 4202 struct thread *td) 4203 { 4204 4205 return (EINVAL); 4206 } 4207 4208 /*-------------------------------------------------------------------*/ 4209 4210 /* 4211 * File Descriptor pseudo-device driver (/dev/fd/). 4212 * 4213 * Opening minor device N dup()s the file (if any) connected to file 4214 * descriptor N belonging to the calling process. Note that this driver 4215 * consists of only the ``open()'' routine, because all subsequent 4216 * references to this file will be direct to the other driver. 4217 * 4218 * XXX: we could give this one a cloning event handler if necessary. 4219 */ 4220 4221 /* ARGSUSED */ 4222 static int 4223 fdopen(struct cdev *dev, int mode, int type, struct thread *td) 4224 { 4225 4226 /* 4227 * XXX Kludge: set curthread->td_dupfd to contain the value of the 4228 * the file descriptor being sought for duplication. The error 4229 * return ensures that the vnode for this device will be released 4230 * by vn_open. Open will detect this special error and take the 4231 * actions in dupfdopen below. Other callers of vn_open or VOP_OPEN 4232 * will simply report the error. 4233 */ 4234 td->td_dupfd = dev2unit(dev); 4235 return (ENODEV); 4236 } 4237 4238 static struct cdevsw fildesc_cdevsw = { 4239 .d_version = D_VERSION, 4240 .d_open = fdopen, 4241 .d_name = "FD", 4242 }; 4243 4244 static void 4245 fildesc_drvinit(void *unused) 4246 { 4247 struct cdev *dev; 4248 4249 dev = make_dev_credf(MAKEDEV_ETERNAL, &fildesc_cdevsw, 0, NULL, 4250 UID_ROOT, GID_WHEEL, 0666, "fd/0"); 4251 make_dev_alias(dev, "stdin"); 4252 dev = make_dev_credf(MAKEDEV_ETERNAL, &fildesc_cdevsw, 1, NULL, 4253 UID_ROOT, GID_WHEEL, 0666, "fd/1"); 4254 make_dev_alias(dev, "stdout"); 4255 dev = make_dev_credf(MAKEDEV_ETERNAL, &fildesc_cdevsw, 2, NULL, 4256 UID_ROOT, GID_WHEEL, 0666, "fd/2"); 4257 make_dev_alias(dev, "stderr"); 4258 } 4259 4260 SYSINIT(fildescdev, SI_SUB_DRIVERS, SI_ORDER_MIDDLE, fildesc_drvinit, NULL); 4261