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