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