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