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 static int __exclusive_cache_line openfiles; /* actual number of open files */ 178 struct mtx sigio_lock; /* mtx to protect pointers to sigio */ 179 void __read_mostly (*mq_fdclose)(struct thread *td, int fd, struct file *fp); 180 181 /* 182 * If low >= size, just return low. Otherwise find the first zero bit in the 183 * given bitmap, starting at low and not exceeding size - 1. Return size if 184 * not found. 185 */ 186 static int 187 fd_first_free(struct filedesc *fdp, int low, int size) 188 { 189 NDSLOTTYPE *map = fdp->fd_map; 190 NDSLOTTYPE mask; 191 int off, maxoff; 192 193 if (low >= size) 194 return (low); 195 196 off = NDSLOT(low); 197 if (low % NDENTRIES) { 198 mask = ~(~(NDSLOTTYPE)0 >> (NDENTRIES - (low % NDENTRIES))); 199 if ((mask &= ~map[off]) != 0UL) 200 return (off * NDENTRIES + ffsl(mask) - 1); 201 ++off; 202 } 203 for (maxoff = NDSLOTS(size); off < maxoff; ++off) 204 if (map[off] != ~0UL) 205 return (off * NDENTRIES + ffsl(~map[off]) - 1); 206 return (size); 207 } 208 209 /* 210 * Find the highest non-zero bit in the given bitmap, starting at 0 and 211 * not exceeding size - 1. Return -1 if not found. 212 */ 213 static int 214 fd_last_used(struct filedesc *fdp, int size) 215 { 216 NDSLOTTYPE *map = fdp->fd_map; 217 NDSLOTTYPE mask; 218 int off, minoff; 219 220 off = NDSLOT(size); 221 if (size % NDENTRIES) { 222 mask = ~(~(NDSLOTTYPE)0 << (size % NDENTRIES)); 223 if ((mask &= map[off]) != 0) 224 return (off * NDENTRIES + flsl(mask) - 1); 225 --off; 226 } 227 for (minoff = NDSLOT(0); off >= minoff; --off) 228 if (map[off] != 0) 229 return (off * NDENTRIES + flsl(map[off]) - 1); 230 return (-1); 231 } 232 233 static int 234 fdisused(struct filedesc *fdp, int fd) 235 { 236 237 KASSERT(fd >= 0 && fd < fdp->fd_nfiles, 238 ("file descriptor %d out of range (0, %d)", fd, fdp->fd_nfiles)); 239 240 return ((fdp->fd_map[NDSLOT(fd)] & NDBIT(fd)) != 0); 241 } 242 243 /* 244 * Mark a file descriptor as used. 245 */ 246 static void 247 fdused_init(struct filedesc *fdp, int fd) 248 { 249 250 KASSERT(!fdisused(fdp, fd), ("fd=%d is already used", fd)); 251 252 fdp->fd_map[NDSLOT(fd)] |= NDBIT(fd); 253 } 254 255 static void 256 fdused(struct filedesc *fdp, int fd) 257 { 258 259 FILEDESC_XLOCK_ASSERT(fdp); 260 261 fdused_init(fdp, fd); 262 if (fd > fdp->fd_lastfile) 263 fdp->fd_lastfile = fd; 264 if (fd == fdp->fd_freefile) 265 fdp->fd_freefile++; 266 } 267 268 /* 269 * Mark a file descriptor as unused. 270 */ 271 static void 272 fdunused(struct filedesc *fdp, int fd) 273 { 274 275 FILEDESC_XLOCK_ASSERT(fdp); 276 277 KASSERT(fdisused(fdp, fd), ("fd=%d is already unused", fd)); 278 KASSERT(fdp->fd_ofiles[fd].fde_file == NULL, 279 ("fd=%d is still in use", fd)); 280 281 fdp->fd_map[NDSLOT(fd)] &= ~NDBIT(fd); 282 if (fd < fdp->fd_freefile) 283 fdp->fd_freefile = fd; 284 if (fd == fdp->fd_lastfile) 285 fdp->fd_lastfile = fd_last_used(fdp, fd); 286 } 287 288 /* 289 * Free a file descriptor. 290 * 291 * Avoid some work if fdp is about to be destroyed. 292 */ 293 static inline void 294 fdefree_last(struct filedescent *fde) 295 { 296 297 filecaps_free(&fde->fde_caps); 298 } 299 300 static inline void 301 fdfree(struct filedesc *fdp, int fd) 302 { 303 struct filedescent *fde; 304 305 fde = &fdp->fd_ofiles[fd]; 306 #ifdef CAPABILITIES 307 seqc_write_begin(&fde->fde_seqc); 308 #endif 309 fde->fde_file = NULL; 310 #ifdef CAPABILITIES 311 seqc_write_end(&fde->fde_seqc); 312 #endif 313 fdefree_last(fde); 314 fdunused(fdp, fd); 315 } 316 317 void 318 pwd_ensure_dirs(void) 319 { 320 struct filedesc *fdp; 321 322 fdp = curproc->p_fd; 323 FILEDESC_XLOCK(fdp); 324 if (fdp->fd_cdir == NULL) { 325 fdp->fd_cdir = rootvnode; 326 vrefact(rootvnode); 327 } 328 if (fdp->fd_rdir == NULL) { 329 fdp->fd_rdir = rootvnode; 330 vrefact(rootvnode); 331 } 332 FILEDESC_XUNLOCK(fdp); 333 } 334 335 /* 336 * System calls on descriptors. 337 */ 338 #ifndef _SYS_SYSPROTO_H_ 339 struct getdtablesize_args { 340 int dummy; 341 }; 342 #endif 343 /* ARGSUSED */ 344 int 345 sys_getdtablesize(struct thread *td, struct getdtablesize_args *uap) 346 { 347 #ifdef RACCT 348 uint64_t lim; 349 #endif 350 351 td->td_retval[0] = getmaxfd(td); 352 #ifdef RACCT 353 PROC_LOCK(td->td_proc); 354 lim = racct_get_limit(td->td_proc, RACCT_NOFILE); 355 PROC_UNLOCK(td->td_proc); 356 if (lim < td->td_retval[0]) 357 td->td_retval[0] = lim; 358 #endif 359 return (0); 360 } 361 362 /* 363 * Duplicate a file descriptor to a particular value. 364 * 365 * Note: keep in mind that a potential race condition exists when closing 366 * descriptors from a shared descriptor table (via rfork). 367 */ 368 #ifndef _SYS_SYSPROTO_H_ 369 struct dup2_args { 370 u_int from; 371 u_int to; 372 }; 373 #endif 374 /* ARGSUSED */ 375 int 376 sys_dup2(struct thread *td, struct dup2_args *uap) 377 { 378 379 return (kern_dup(td, FDDUP_FIXED, 0, (int)uap->from, (int)uap->to)); 380 } 381 382 /* 383 * Duplicate a file descriptor. 384 */ 385 #ifndef _SYS_SYSPROTO_H_ 386 struct dup_args { 387 u_int fd; 388 }; 389 #endif 390 /* ARGSUSED */ 391 int 392 sys_dup(struct thread *td, struct dup_args *uap) 393 { 394 395 return (kern_dup(td, FDDUP_NORMAL, 0, (int)uap->fd, 0)); 396 } 397 398 /* 399 * The file control system call. 400 */ 401 #ifndef _SYS_SYSPROTO_H_ 402 struct fcntl_args { 403 int fd; 404 int cmd; 405 long arg; 406 }; 407 #endif 408 /* ARGSUSED */ 409 int 410 sys_fcntl(struct thread *td, struct fcntl_args *uap) 411 { 412 413 return (kern_fcntl_freebsd(td, uap->fd, uap->cmd, uap->arg)); 414 } 415 416 int 417 kern_fcntl_freebsd(struct thread *td, int fd, int cmd, long arg) 418 { 419 struct flock fl; 420 struct __oflock ofl; 421 intptr_t arg1; 422 int error, newcmd; 423 424 error = 0; 425 newcmd = cmd; 426 switch (cmd) { 427 case F_OGETLK: 428 case F_OSETLK: 429 case F_OSETLKW: 430 /* 431 * Convert old flock structure to new. 432 */ 433 error = copyin((void *)(intptr_t)arg, &ofl, sizeof(ofl)); 434 fl.l_start = ofl.l_start; 435 fl.l_len = ofl.l_len; 436 fl.l_pid = ofl.l_pid; 437 fl.l_type = ofl.l_type; 438 fl.l_whence = ofl.l_whence; 439 fl.l_sysid = 0; 440 441 switch (cmd) { 442 case F_OGETLK: 443 newcmd = F_GETLK; 444 break; 445 case F_OSETLK: 446 newcmd = F_SETLK; 447 break; 448 case F_OSETLKW: 449 newcmd = F_SETLKW; 450 break; 451 } 452 arg1 = (intptr_t)&fl; 453 break; 454 case F_GETLK: 455 case F_SETLK: 456 case F_SETLKW: 457 case F_SETLK_REMOTE: 458 error = copyin((void *)(intptr_t)arg, &fl, sizeof(fl)); 459 arg1 = (intptr_t)&fl; 460 break; 461 default: 462 arg1 = arg; 463 break; 464 } 465 if (error) 466 return (error); 467 error = kern_fcntl(td, fd, newcmd, arg1); 468 if (error) 469 return (error); 470 if (cmd == F_OGETLK) { 471 ofl.l_start = fl.l_start; 472 ofl.l_len = fl.l_len; 473 ofl.l_pid = fl.l_pid; 474 ofl.l_type = fl.l_type; 475 ofl.l_whence = fl.l_whence; 476 error = copyout(&ofl, (void *)(intptr_t)arg, sizeof(ofl)); 477 } else if (cmd == F_GETLK) { 478 error = copyout(&fl, (void *)(intptr_t)arg, sizeof(fl)); 479 } 480 return (error); 481 } 482 483 int 484 kern_fcntl(struct thread *td, int fd, int cmd, intptr_t arg) 485 { 486 struct filedesc *fdp; 487 struct flock *flp; 488 struct file *fp, *fp2; 489 struct filedescent *fde; 490 struct proc *p; 491 struct vnode *vp; 492 int error, flg, seals, tmp; 493 uint64_t bsize; 494 off_t foffset; 495 496 error = 0; 497 flg = F_POSIX; 498 p = td->td_proc; 499 fdp = p->p_fd; 500 501 AUDIT_ARG_FD(cmd); 502 AUDIT_ARG_CMD(cmd); 503 switch (cmd) { 504 case F_DUPFD: 505 tmp = arg; 506 error = kern_dup(td, FDDUP_FCNTL, 0, fd, tmp); 507 break; 508 509 case F_DUPFD_CLOEXEC: 510 tmp = arg; 511 error = kern_dup(td, FDDUP_FCNTL, FDDUP_FLAG_CLOEXEC, fd, tmp); 512 break; 513 514 case F_DUP2FD: 515 tmp = arg; 516 error = kern_dup(td, FDDUP_FIXED, 0, fd, tmp); 517 break; 518 519 case F_DUP2FD_CLOEXEC: 520 tmp = arg; 521 error = kern_dup(td, FDDUP_FIXED, FDDUP_FLAG_CLOEXEC, fd, tmp); 522 break; 523 524 case F_GETFD: 525 error = EBADF; 526 FILEDESC_SLOCK(fdp); 527 fde = fdeget_locked(fdp, fd); 528 if (fde != NULL) { 529 td->td_retval[0] = 530 (fde->fde_flags & UF_EXCLOSE) ? FD_CLOEXEC : 0; 531 error = 0; 532 } 533 FILEDESC_SUNLOCK(fdp); 534 break; 535 536 case F_SETFD: 537 error = EBADF; 538 FILEDESC_XLOCK(fdp); 539 fde = fdeget_locked(fdp, fd); 540 if (fde != NULL) { 541 fde->fde_flags = (fde->fde_flags & ~UF_EXCLOSE) | 542 (arg & FD_CLOEXEC ? UF_EXCLOSE : 0); 543 error = 0; 544 } 545 FILEDESC_XUNLOCK(fdp); 546 break; 547 548 case F_GETFL: 549 error = fget_fcntl(td, fd, &cap_fcntl_rights, F_GETFL, &fp); 550 if (error != 0) 551 break; 552 td->td_retval[0] = OFLAGS(fp->f_flag); 553 fdrop(fp, td); 554 break; 555 556 case F_SETFL: 557 error = fget_fcntl(td, fd, &cap_fcntl_rights, F_SETFL, &fp); 558 if (error != 0) 559 break; 560 do { 561 tmp = flg = fp->f_flag; 562 tmp &= ~FCNTLFLAGS; 563 tmp |= FFLAGS(arg & ~O_ACCMODE) & FCNTLFLAGS; 564 } while(atomic_cmpset_int(&fp->f_flag, flg, tmp) == 0); 565 tmp = fp->f_flag & FNONBLOCK; 566 error = fo_ioctl(fp, FIONBIO, &tmp, td->td_ucred, td); 567 if (error != 0) { 568 fdrop(fp, td); 569 break; 570 } 571 tmp = fp->f_flag & FASYNC; 572 error = fo_ioctl(fp, FIOASYNC, &tmp, td->td_ucred, td); 573 if (error == 0) { 574 fdrop(fp, td); 575 break; 576 } 577 atomic_clear_int(&fp->f_flag, FNONBLOCK); 578 tmp = 0; 579 (void)fo_ioctl(fp, FIONBIO, &tmp, td->td_ucred, td); 580 fdrop(fp, td); 581 break; 582 583 case F_GETOWN: 584 error = fget_fcntl(td, fd, &cap_fcntl_rights, F_GETOWN, &fp); 585 if (error != 0) 586 break; 587 error = fo_ioctl(fp, FIOGETOWN, &tmp, td->td_ucred, td); 588 if (error == 0) 589 td->td_retval[0] = tmp; 590 fdrop(fp, td); 591 break; 592 593 case F_SETOWN: 594 error = fget_fcntl(td, fd, &cap_fcntl_rights, F_SETOWN, &fp); 595 if (error != 0) 596 break; 597 tmp = arg; 598 error = fo_ioctl(fp, FIOSETOWN, &tmp, td->td_ucred, td); 599 fdrop(fp, td); 600 break; 601 602 case F_SETLK_REMOTE: 603 error = priv_check(td, PRIV_NFS_LOCKD); 604 if (error != 0) 605 return (error); 606 flg = F_REMOTE; 607 goto do_setlk; 608 609 case F_SETLKW: 610 flg |= F_WAIT; 611 /* FALLTHROUGH F_SETLK */ 612 613 case F_SETLK: 614 do_setlk: 615 flp = (struct flock *)arg; 616 if ((flg & F_REMOTE) != 0 && flp->l_sysid == 0) { 617 error = EINVAL; 618 break; 619 } 620 621 error = fget_unlocked(fdp, fd, &cap_flock_rights, &fp, NULL); 622 if (error != 0) 623 break; 624 if (fp->f_type != DTYPE_VNODE) { 625 error = EBADF; 626 fdrop(fp, td); 627 break; 628 } 629 630 if (flp->l_whence == SEEK_CUR) { 631 foffset = foffset_get(fp); 632 if (foffset < 0 || 633 (flp->l_start > 0 && 634 foffset > OFF_MAX - flp->l_start)) { 635 error = EOVERFLOW; 636 fdrop(fp, td); 637 break; 638 } 639 flp->l_start += foffset; 640 } 641 642 vp = fp->f_vnode; 643 switch (flp->l_type) { 644 case F_RDLCK: 645 if ((fp->f_flag & FREAD) == 0) { 646 error = EBADF; 647 break; 648 } 649 if ((p->p_leader->p_flag & P_ADVLOCK) == 0) { 650 PROC_LOCK(p->p_leader); 651 p->p_leader->p_flag |= P_ADVLOCK; 652 PROC_UNLOCK(p->p_leader); 653 } 654 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_SETLK, 655 flp, flg); 656 break; 657 case F_WRLCK: 658 if ((fp->f_flag & FWRITE) == 0) { 659 error = EBADF; 660 break; 661 } 662 if ((p->p_leader->p_flag & P_ADVLOCK) == 0) { 663 PROC_LOCK(p->p_leader); 664 p->p_leader->p_flag |= P_ADVLOCK; 665 PROC_UNLOCK(p->p_leader); 666 } 667 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_SETLK, 668 flp, flg); 669 break; 670 case F_UNLCK: 671 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_UNLCK, 672 flp, flg); 673 break; 674 case F_UNLCKSYS: 675 if (flg != F_REMOTE) { 676 error = EINVAL; 677 break; 678 } 679 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, 680 F_UNLCKSYS, flp, flg); 681 break; 682 default: 683 error = EINVAL; 684 break; 685 } 686 if (error != 0 || flp->l_type == F_UNLCK || 687 flp->l_type == F_UNLCKSYS) { 688 fdrop(fp, td); 689 break; 690 } 691 692 /* 693 * Check for a race with close. 694 * 695 * The vnode is now advisory locked (or unlocked, but this case 696 * is not really important) as the caller requested. 697 * We had to drop the filedesc lock, so we need to recheck if 698 * the descriptor is still valid, because if it was closed 699 * in the meantime we need to remove advisory lock from the 700 * vnode - close on any descriptor leading to an advisory 701 * locked vnode, removes that lock. 702 * We will return 0 on purpose in that case, as the result of 703 * successful advisory lock might have been externally visible 704 * already. This is fine - effectively we pretend to the caller 705 * that the closing thread was a bit slower and that the 706 * advisory lock succeeded before the close. 707 */ 708 error = fget_unlocked(fdp, fd, &cap_no_rights, &fp2, NULL); 709 if (error != 0) { 710 fdrop(fp, td); 711 break; 712 } 713 if (fp != fp2) { 714 flp->l_whence = SEEK_SET; 715 flp->l_start = 0; 716 flp->l_len = 0; 717 flp->l_type = F_UNLCK; 718 (void) VOP_ADVLOCK(vp, (caddr_t)p->p_leader, 719 F_UNLCK, flp, F_POSIX); 720 } 721 fdrop(fp, td); 722 fdrop(fp2, td); 723 break; 724 725 case F_GETLK: 726 error = fget_unlocked(fdp, fd, &cap_flock_rights, &fp, NULL); 727 if (error != 0) 728 break; 729 if (fp->f_type != DTYPE_VNODE) { 730 error = EBADF; 731 fdrop(fp, td); 732 break; 733 } 734 flp = (struct flock *)arg; 735 if (flp->l_type != F_RDLCK && flp->l_type != F_WRLCK && 736 flp->l_type != F_UNLCK) { 737 error = EINVAL; 738 fdrop(fp, td); 739 break; 740 } 741 if (flp->l_whence == SEEK_CUR) { 742 foffset = foffset_get(fp); 743 if ((flp->l_start > 0 && 744 foffset > OFF_MAX - flp->l_start) || 745 (flp->l_start < 0 && 746 foffset < OFF_MIN - flp->l_start)) { 747 error = EOVERFLOW; 748 fdrop(fp, td); 749 break; 750 } 751 flp->l_start += foffset; 752 } 753 vp = fp->f_vnode; 754 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_GETLK, flp, 755 F_POSIX); 756 fdrop(fp, td); 757 break; 758 759 case F_ADD_SEALS: 760 error = fget_unlocked(fdp, fd, &cap_no_rights, &fp, NULL); 761 if (error != 0) 762 break; 763 error = fo_add_seals(fp, arg); 764 fdrop(fp, td); 765 break; 766 767 case F_GET_SEALS: 768 error = fget_unlocked(fdp, fd, &cap_no_rights, &fp, NULL); 769 if (error != 0) 770 break; 771 if (fo_get_seals(fp, &seals) == 0) 772 td->td_retval[0] = seals; 773 else 774 error = EINVAL; 775 fdrop(fp, td); 776 break; 777 778 case F_RDAHEAD: 779 arg = arg ? 128 * 1024: 0; 780 /* FALLTHROUGH */ 781 case F_READAHEAD: 782 error = fget_unlocked(fdp, fd, &cap_no_rights, &fp, NULL); 783 if (error != 0) 784 break; 785 if (fp->f_type != DTYPE_VNODE) { 786 fdrop(fp, td); 787 error = EBADF; 788 break; 789 } 790 vp = fp->f_vnode; 791 if (vp->v_type != VREG) { 792 fdrop(fp, td); 793 error = ENOTTY; 794 break; 795 } 796 797 /* 798 * Exclusive lock synchronizes against f_seqcount reads and 799 * writes in sequential_heuristic(). 800 */ 801 error = vn_lock(vp, LK_EXCLUSIVE); 802 if (error != 0) { 803 fdrop(fp, td); 804 break; 805 } 806 if (arg >= 0) { 807 bsize = fp->f_vnode->v_mount->mnt_stat.f_iosize; 808 arg = MIN(arg, INT_MAX - bsize + 1); 809 fp->f_seqcount = MIN(IO_SEQMAX, 810 (arg + bsize - 1) / bsize); 811 atomic_set_int(&fp->f_flag, FRDAHEAD); 812 } else { 813 atomic_clear_int(&fp->f_flag, FRDAHEAD); 814 } 815 VOP_UNLOCK(vp); 816 fdrop(fp, td); 817 break; 818 819 default: 820 error = EINVAL; 821 break; 822 } 823 return (error); 824 } 825 826 static int 827 getmaxfd(struct thread *td) 828 { 829 830 return (min((int)lim_cur(td, RLIMIT_NOFILE), maxfilesperproc)); 831 } 832 833 /* 834 * Common code for dup, dup2, fcntl(F_DUPFD) and fcntl(F_DUP2FD). 835 */ 836 int 837 kern_dup(struct thread *td, u_int mode, int flags, int old, int new) 838 { 839 struct filedesc *fdp; 840 struct filedescent *oldfde, *newfde; 841 struct proc *p; 842 struct file *delfp; 843 u_long *oioctls, *nioctls; 844 int error, maxfd; 845 846 p = td->td_proc; 847 fdp = p->p_fd; 848 oioctls = NULL; 849 850 MPASS((flags & ~(FDDUP_FLAG_CLOEXEC)) == 0); 851 MPASS(mode < FDDUP_LASTMODE); 852 853 AUDIT_ARG_FD(old); 854 /* XXXRW: if (flags & FDDUP_FIXED) AUDIT_ARG_FD2(new); */ 855 856 /* 857 * Verify we have a valid descriptor to dup from and possibly to 858 * dup to. Unlike dup() and dup2(), fcntl()'s F_DUPFD should 859 * return EINVAL when the new descriptor is out of bounds. 860 */ 861 if (old < 0) 862 return (EBADF); 863 if (new < 0) 864 return (mode == FDDUP_FCNTL ? EINVAL : EBADF); 865 maxfd = getmaxfd(td); 866 if (new >= maxfd) 867 return (mode == FDDUP_FCNTL ? EINVAL : EBADF); 868 869 error = EBADF; 870 FILEDESC_XLOCK(fdp); 871 if (fget_locked(fdp, old) == NULL) 872 goto unlock; 873 if ((mode == FDDUP_FIXED || mode == FDDUP_MUSTREPLACE) && old == new) { 874 td->td_retval[0] = new; 875 if (flags & FDDUP_FLAG_CLOEXEC) 876 fdp->fd_ofiles[new].fde_flags |= UF_EXCLOSE; 877 error = 0; 878 goto unlock; 879 } 880 881 oldfde = &fdp->fd_ofiles[old]; 882 if (!fhold(oldfde->fde_file)) 883 goto unlock; 884 885 /* 886 * If the caller specified a file descriptor, make sure the file 887 * table is large enough to hold it, and grab it. Otherwise, just 888 * allocate a new descriptor the usual way. 889 */ 890 switch (mode) { 891 case FDDUP_NORMAL: 892 case FDDUP_FCNTL: 893 if ((error = fdalloc(td, new, &new)) != 0) { 894 fdrop(oldfde->fde_file, td); 895 goto unlock; 896 } 897 break; 898 case FDDUP_MUSTREPLACE: 899 /* Target file descriptor must exist. */ 900 if (fget_locked(fdp, new) == NULL) { 901 fdrop(oldfde->fde_file, td); 902 goto unlock; 903 } 904 break; 905 case FDDUP_FIXED: 906 if (new >= fdp->fd_nfiles) { 907 /* 908 * The resource limits are here instead of e.g. 909 * fdalloc(), because the file descriptor table may be 910 * shared between processes, so we can't really use 911 * racct_add()/racct_sub(). Instead of counting the 912 * number of actually allocated descriptors, just put 913 * the limit on the size of the file descriptor table. 914 */ 915 #ifdef RACCT 916 if (RACCT_ENABLED()) { 917 error = racct_set_unlocked(p, RACCT_NOFILE, new + 1); 918 if (error != 0) { 919 error = EMFILE; 920 fdrop(oldfde->fde_file, td); 921 goto unlock; 922 } 923 } 924 #endif 925 fdgrowtable_exp(fdp, new + 1); 926 } 927 if (!fdisused(fdp, new)) 928 fdused(fdp, new); 929 break; 930 default: 931 KASSERT(0, ("%s unsupported mode %d", __func__, mode)); 932 } 933 934 KASSERT(old != new, ("new fd is same as old")); 935 936 newfde = &fdp->fd_ofiles[new]; 937 delfp = newfde->fde_file; 938 939 oioctls = filecaps_free_prep(&newfde->fde_caps); 940 nioctls = filecaps_copy_prep(&oldfde->fde_caps); 941 942 /* 943 * Duplicate the source descriptor. 944 */ 945 #ifdef CAPABILITIES 946 seqc_write_begin(&newfde->fde_seqc); 947 #endif 948 memcpy(newfde, oldfde, fde_change_size); 949 filecaps_copy_finish(&oldfde->fde_caps, &newfde->fde_caps, 950 nioctls); 951 if ((flags & FDDUP_FLAG_CLOEXEC) != 0) 952 newfde->fde_flags = oldfde->fde_flags | UF_EXCLOSE; 953 else 954 newfde->fde_flags = oldfde->fde_flags & ~UF_EXCLOSE; 955 #ifdef CAPABILITIES 956 seqc_write_end(&newfde->fde_seqc); 957 #endif 958 td->td_retval[0] = new; 959 960 error = 0; 961 962 if (delfp != NULL) { 963 (void) closefp(fdp, new, delfp, td, 1); 964 FILEDESC_UNLOCK_ASSERT(fdp); 965 } else { 966 unlock: 967 FILEDESC_XUNLOCK(fdp); 968 } 969 970 filecaps_free_finish(oioctls); 971 return (error); 972 } 973 974 /* 975 * If sigio is on the list associated with a process or process group, 976 * disable signalling from the device, remove sigio from the list and 977 * free sigio. 978 */ 979 void 980 funsetown(struct sigio **sigiop) 981 { 982 struct sigio *sigio; 983 984 if (*sigiop == NULL) 985 return; 986 SIGIO_LOCK(); 987 sigio = *sigiop; 988 if (sigio == NULL) { 989 SIGIO_UNLOCK(); 990 return; 991 } 992 *(sigio->sio_myref) = NULL; 993 if ((sigio)->sio_pgid < 0) { 994 struct pgrp *pg = (sigio)->sio_pgrp; 995 PGRP_LOCK(pg); 996 SLIST_REMOVE(&sigio->sio_pgrp->pg_sigiolst, sigio, 997 sigio, sio_pgsigio); 998 PGRP_UNLOCK(pg); 999 } else { 1000 struct proc *p = (sigio)->sio_proc; 1001 PROC_LOCK(p); 1002 SLIST_REMOVE(&sigio->sio_proc->p_sigiolst, sigio, 1003 sigio, sio_pgsigio); 1004 PROC_UNLOCK(p); 1005 } 1006 SIGIO_UNLOCK(); 1007 crfree(sigio->sio_ucred); 1008 free(sigio, M_SIGIO); 1009 } 1010 1011 /* 1012 * Free a list of sigio structures. 1013 * We only need to lock the SIGIO_LOCK because we have made ourselves 1014 * inaccessible to callers of fsetown and therefore do not need to lock 1015 * the proc or pgrp struct for the list manipulation. 1016 */ 1017 void 1018 funsetownlst(struct sigiolst *sigiolst) 1019 { 1020 struct proc *p; 1021 struct pgrp *pg; 1022 struct sigio *sigio; 1023 1024 sigio = SLIST_FIRST(sigiolst); 1025 if (sigio == NULL) 1026 return; 1027 p = NULL; 1028 pg = NULL; 1029 1030 /* 1031 * Every entry of the list should belong 1032 * to a single proc or pgrp. 1033 */ 1034 if (sigio->sio_pgid < 0) { 1035 pg = sigio->sio_pgrp; 1036 PGRP_LOCK_ASSERT(pg, MA_NOTOWNED); 1037 } else /* if (sigio->sio_pgid > 0) */ { 1038 p = sigio->sio_proc; 1039 PROC_LOCK_ASSERT(p, MA_NOTOWNED); 1040 } 1041 1042 SIGIO_LOCK(); 1043 while ((sigio = SLIST_FIRST(sigiolst)) != NULL) { 1044 *(sigio->sio_myref) = NULL; 1045 if (pg != NULL) { 1046 KASSERT(sigio->sio_pgid < 0, 1047 ("Proc sigio in pgrp sigio list")); 1048 KASSERT(sigio->sio_pgrp == pg, 1049 ("Bogus pgrp in sigio list")); 1050 PGRP_LOCK(pg); 1051 SLIST_REMOVE(&pg->pg_sigiolst, sigio, sigio, 1052 sio_pgsigio); 1053 PGRP_UNLOCK(pg); 1054 } else /* if (p != NULL) */ { 1055 KASSERT(sigio->sio_pgid > 0, 1056 ("Pgrp sigio in proc sigio list")); 1057 KASSERT(sigio->sio_proc == p, 1058 ("Bogus proc in sigio list")); 1059 PROC_LOCK(p); 1060 SLIST_REMOVE(&p->p_sigiolst, sigio, sigio, 1061 sio_pgsigio); 1062 PROC_UNLOCK(p); 1063 } 1064 SIGIO_UNLOCK(); 1065 crfree(sigio->sio_ucred); 1066 free(sigio, M_SIGIO); 1067 SIGIO_LOCK(); 1068 } 1069 SIGIO_UNLOCK(); 1070 } 1071 1072 /* 1073 * This is common code for FIOSETOWN ioctl called by fcntl(fd, F_SETOWN, arg). 1074 * 1075 * After permission checking, add a sigio structure to the sigio list for 1076 * the process or process group. 1077 */ 1078 int 1079 fsetown(pid_t pgid, struct sigio **sigiop) 1080 { 1081 struct proc *proc; 1082 struct pgrp *pgrp; 1083 struct sigio *sigio; 1084 int ret; 1085 1086 if (pgid == 0) { 1087 funsetown(sigiop); 1088 return (0); 1089 } 1090 1091 ret = 0; 1092 1093 /* Allocate and fill in the new sigio out of locks. */ 1094 sigio = malloc(sizeof(struct sigio), M_SIGIO, M_WAITOK); 1095 sigio->sio_pgid = pgid; 1096 sigio->sio_ucred = crhold(curthread->td_ucred); 1097 sigio->sio_myref = sigiop; 1098 1099 sx_slock(&proctree_lock); 1100 if (pgid > 0) { 1101 proc = pfind(pgid); 1102 if (proc == NULL) { 1103 ret = ESRCH; 1104 goto fail; 1105 } 1106 1107 /* 1108 * Policy - Don't allow a process to FSETOWN a process 1109 * in another session. 1110 * 1111 * Remove this test to allow maximum flexibility or 1112 * restrict FSETOWN to the current process or process 1113 * group for maximum safety. 1114 */ 1115 PROC_UNLOCK(proc); 1116 if (proc->p_session != curthread->td_proc->p_session) { 1117 ret = EPERM; 1118 goto fail; 1119 } 1120 1121 pgrp = NULL; 1122 } else /* if (pgid < 0) */ { 1123 pgrp = pgfind(-pgid); 1124 if (pgrp == NULL) { 1125 ret = ESRCH; 1126 goto fail; 1127 } 1128 PGRP_UNLOCK(pgrp); 1129 1130 /* 1131 * Policy - Don't allow a process to FSETOWN a process 1132 * in another session. 1133 * 1134 * Remove this test to allow maximum flexibility or 1135 * restrict FSETOWN to the current process or process 1136 * group for maximum safety. 1137 */ 1138 if (pgrp->pg_session != curthread->td_proc->p_session) { 1139 ret = EPERM; 1140 goto fail; 1141 } 1142 1143 proc = NULL; 1144 } 1145 funsetown(sigiop); 1146 if (pgid > 0) { 1147 PROC_LOCK(proc); 1148 /* 1149 * Since funsetownlst() is called without the proctree 1150 * locked, we need to check for P_WEXIT. 1151 * XXX: is ESRCH correct? 1152 */ 1153 if ((proc->p_flag & P_WEXIT) != 0) { 1154 PROC_UNLOCK(proc); 1155 ret = ESRCH; 1156 goto fail; 1157 } 1158 SLIST_INSERT_HEAD(&proc->p_sigiolst, sigio, sio_pgsigio); 1159 sigio->sio_proc = proc; 1160 PROC_UNLOCK(proc); 1161 } else { 1162 PGRP_LOCK(pgrp); 1163 SLIST_INSERT_HEAD(&pgrp->pg_sigiolst, sigio, sio_pgsigio); 1164 sigio->sio_pgrp = pgrp; 1165 PGRP_UNLOCK(pgrp); 1166 } 1167 sx_sunlock(&proctree_lock); 1168 SIGIO_LOCK(); 1169 *sigiop = sigio; 1170 SIGIO_UNLOCK(); 1171 return (0); 1172 1173 fail: 1174 sx_sunlock(&proctree_lock); 1175 crfree(sigio->sio_ucred); 1176 free(sigio, M_SIGIO); 1177 return (ret); 1178 } 1179 1180 /* 1181 * This is common code for FIOGETOWN ioctl called by fcntl(fd, F_GETOWN, arg). 1182 */ 1183 pid_t 1184 fgetown(struct sigio **sigiop) 1185 { 1186 pid_t pgid; 1187 1188 SIGIO_LOCK(); 1189 pgid = (*sigiop != NULL) ? (*sigiop)->sio_pgid : 0; 1190 SIGIO_UNLOCK(); 1191 return (pgid); 1192 } 1193 1194 /* 1195 * Function drops the filedesc lock on return. 1196 */ 1197 static int 1198 closefp(struct filedesc *fdp, int fd, struct file *fp, struct thread *td, 1199 int holdleaders) 1200 { 1201 int error; 1202 1203 FILEDESC_XLOCK_ASSERT(fdp); 1204 1205 if (holdleaders) { 1206 if (td->td_proc->p_fdtol != NULL) { 1207 /* 1208 * Ask fdfree() to sleep to ensure that all relevant 1209 * process leaders can be traversed in closef(). 1210 */ 1211 fdp->fd_holdleaderscount++; 1212 } else { 1213 holdleaders = 0; 1214 } 1215 } 1216 1217 /* 1218 * We now hold the fp reference that used to be owned by the 1219 * descriptor array. We have to unlock the FILEDESC *AFTER* 1220 * knote_fdclose to prevent a race of the fd getting opened, a knote 1221 * added, and deleteing a knote for the new fd. 1222 */ 1223 if (__predict_false(!TAILQ_EMPTY(&fdp->fd_kqlist))) 1224 knote_fdclose(td, fd); 1225 1226 /* 1227 * We need to notify mqueue if the object is of type mqueue. 1228 */ 1229 if (__predict_false(fp->f_type == DTYPE_MQUEUE)) 1230 mq_fdclose(td, fd, fp); 1231 FILEDESC_XUNLOCK(fdp); 1232 1233 error = closef(fp, td); 1234 if (holdleaders) { 1235 FILEDESC_XLOCK(fdp); 1236 fdp->fd_holdleaderscount--; 1237 if (fdp->fd_holdleaderscount == 0 && 1238 fdp->fd_holdleaderswakeup != 0) { 1239 fdp->fd_holdleaderswakeup = 0; 1240 wakeup(&fdp->fd_holdleaderscount); 1241 } 1242 FILEDESC_XUNLOCK(fdp); 1243 } 1244 return (error); 1245 } 1246 1247 /* 1248 * Close a file descriptor. 1249 */ 1250 #ifndef _SYS_SYSPROTO_H_ 1251 struct close_args { 1252 int fd; 1253 }; 1254 #endif 1255 /* ARGSUSED */ 1256 int 1257 sys_close(struct thread *td, struct close_args *uap) 1258 { 1259 1260 return (kern_close(td, uap->fd)); 1261 } 1262 1263 int 1264 kern_close(struct thread *td, int fd) 1265 { 1266 struct filedesc *fdp; 1267 struct file *fp; 1268 1269 fdp = td->td_proc->p_fd; 1270 1271 AUDIT_SYSCLOSE(td, fd); 1272 1273 FILEDESC_XLOCK(fdp); 1274 if ((fp = fget_locked(fdp, fd)) == NULL) { 1275 FILEDESC_XUNLOCK(fdp); 1276 return (EBADF); 1277 } 1278 fdfree(fdp, fd); 1279 1280 /* closefp() drops the FILEDESC lock for us. */ 1281 return (closefp(fdp, fd, fp, td, 1)); 1282 } 1283 1284 /* 1285 * Close open file descriptors. 1286 */ 1287 #ifndef _SYS_SYSPROTO_H_ 1288 struct closefrom_args { 1289 int lowfd; 1290 }; 1291 #endif 1292 /* ARGSUSED */ 1293 int 1294 sys_closefrom(struct thread *td, struct closefrom_args *uap) 1295 { 1296 struct filedesc *fdp; 1297 int fd; 1298 1299 fdp = td->td_proc->p_fd; 1300 AUDIT_ARG_FD(uap->lowfd); 1301 1302 /* 1303 * Treat negative starting file descriptor values identical to 1304 * closefrom(0) which closes all files. 1305 */ 1306 if (uap->lowfd < 0) 1307 uap->lowfd = 0; 1308 FILEDESC_SLOCK(fdp); 1309 for (fd = uap->lowfd; fd <= fdp->fd_lastfile; fd++) { 1310 if (fdp->fd_ofiles[fd].fde_file != NULL) { 1311 FILEDESC_SUNLOCK(fdp); 1312 (void)kern_close(td, fd); 1313 FILEDESC_SLOCK(fdp); 1314 } 1315 } 1316 FILEDESC_SUNLOCK(fdp); 1317 return (0); 1318 } 1319 1320 #if defined(COMPAT_43) 1321 /* 1322 * Return status information about a file descriptor. 1323 */ 1324 #ifndef _SYS_SYSPROTO_H_ 1325 struct ofstat_args { 1326 int fd; 1327 struct ostat *sb; 1328 }; 1329 #endif 1330 /* ARGSUSED */ 1331 int 1332 ofstat(struct thread *td, struct ofstat_args *uap) 1333 { 1334 struct ostat oub; 1335 struct stat ub; 1336 int error; 1337 1338 error = kern_fstat(td, uap->fd, &ub); 1339 if (error == 0) { 1340 cvtstat(&ub, &oub); 1341 error = copyout(&oub, uap->sb, sizeof(oub)); 1342 } 1343 return (error); 1344 } 1345 #endif /* COMPAT_43 */ 1346 1347 #if defined(COMPAT_FREEBSD11) 1348 int 1349 freebsd11_fstat(struct thread *td, struct freebsd11_fstat_args *uap) 1350 { 1351 struct stat sb; 1352 struct freebsd11_stat osb; 1353 int error; 1354 1355 error = kern_fstat(td, uap->fd, &sb); 1356 if (error != 0) 1357 return (error); 1358 error = freebsd11_cvtstat(&sb, &osb); 1359 if (error == 0) 1360 error = copyout(&osb, uap->sb, sizeof(osb)); 1361 return (error); 1362 } 1363 #endif /* COMPAT_FREEBSD11 */ 1364 1365 /* 1366 * Return status information about a file descriptor. 1367 */ 1368 #ifndef _SYS_SYSPROTO_H_ 1369 struct fstat_args { 1370 int fd; 1371 struct stat *sb; 1372 }; 1373 #endif 1374 /* ARGSUSED */ 1375 int 1376 sys_fstat(struct thread *td, struct fstat_args *uap) 1377 { 1378 struct stat ub; 1379 int error; 1380 1381 error = kern_fstat(td, uap->fd, &ub); 1382 if (error == 0) 1383 error = copyout(&ub, uap->sb, sizeof(ub)); 1384 return (error); 1385 } 1386 1387 int 1388 kern_fstat(struct thread *td, int fd, struct stat *sbp) 1389 { 1390 struct file *fp; 1391 int error; 1392 1393 AUDIT_ARG_FD(fd); 1394 1395 error = fget(td, fd, &cap_fstat_rights, &fp); 1396 if (error != 0) 1397 return (error); 1398 1399 AUDIT_ARG_FILE(td->td_proc, fp); 1400 1401 error = fo_stat(fp, sbp, td->td_ucred, td); 1402 fdrop(fp, td); 1403 #ifdef __STAT_TIME_T_EXT 1404 if (error == 0) { 1405 sbp->st_atim_ext = 0; 1406 sbp->st_mtim_ext = 0; 1407 sbp->st_ctim_ext = 0; 1408 sbp->st_btim_ext = 0; 1409 } 1410 #endif 1411 #ifdef KTRACE 1412 if (error == 0 && KTRPOINT(td, KTR_STRUCT)) 1413 ktrstat(sbp); 1414 #endif 1415 return (error); 1416 } 1417 1418 #if defined(COMPAT_FREEBSD11) 1419 /* 1420 * Return status information about a file descriptor. 1421 */ 1422 #ifndef _SYS_SYSPROTO_H_ 1423 struct freebsd11_nfstat_args { 1424 int fd; 1425 struct nstat *sb; 1426 }; 1427 #endif 1428 /* ARGSUSED */ 1429 int 1430 freebsd11_nfstat(struct thread *td, struct freebsd11_nfstat_args *uap) 1431 { 1432 struct nstat nub; 1433 struct stat ub; 1434 int error; 1435 1436 error = kern_fstat(td, uap->fd, &ub); 1437 if (error == 0) { 1438 freebsd11_cvtnstat(&ub, &nub); 1439 error = copyout(&nub, uap->sb, sizeof(nub)); 1440 } 1441 return (error); 1442 } 1443 #endif /* COMPAT_FREEBSD11 */ 1444 1445 /* 1446 * Return pathconf information about a file descriptor. 1447 */ 1448 #ifndef _SYS_SYSPROTO_H_ 1449 struct fpathconf_args { 1450 int fd; 1451 int name; 1452 }; 1453 #endif 1454 /* ARGSUSED */ 1455 int 1456 sys_fpathconf(struct thread *td, struct fpathconf_args *uap) 1457 { 1458 long value; 1459 int error; 1460 1461 error = kern_fpathconf(td, uap->fd, uap->name, &value); 1462 if (error == 0) 1463 td->td_retval[0] = value; 1464 return (error); 1465 } 1466 1467 int 1468 kern_fpathconf(struct thread *td, int fd, int name, long *valuep) 1469 { 1470 struct file *fp; 1471 struct vnode *vp; 1472 int error; 1473 1474 error = fget(td, fd, &cap_fpathconf_rights, &fp); 1475 if (error != 0) 1476 return (error); 1477 1478 if (name == _PC_ASYNC_IO) { 1479 *valuep = _POSIX_ASYNCHRONOUS_IO; 1480 goto out; 1481 } 1482 vp = fp->f_vnode; 1483 if (vp != NULL) { 1484 vn_lock(vp, LK_SHARED | LK_RETRY); 1485 error = VOP_PATHCONF(vp, name, valuep); 1486 VOP_UNLOCK(vp); 1487 } else if (fp->f_type == DTYPE_PIPE || fp->f_type == DTYPE_SOCKET) { 1488 if (name != _PC_PIPE_BUF) { 1489 error = EINVAL; 1490 } else { 1491 *valuep = PIPE_BUF; 1492 error = 0; 1493 } 1494 } else { 1495 error = EOPNOTSUPP; 1496 } 1497 out: 1498 fdrop(fp, td); 1499 return (error); 1500 } 1501 1502 /* 1503 * Copy filecaps structure allocating memory for ioctls array if needed. 1504 * 1505 * The last parameter indicates whether the fdtable is locked. If it is not and 1506 * ioctls are encountered, copying fails and the caller must lock the table. 1507 * 1508 * Note that if the table was not locked, the caller has to check the relevant 1509 * sequence counter to determine whether the operation was successful. 1510 */ 1511 bool 1512 filecaps_copy(const struct filecaps *src, struct filecaps *dst, bool locked) 1513 { 1514 size_t size; 1515 1516 if (src->fc_ioctls != NULL && !locked) 1517 return (false); 1518 memcpy(dst, src, sizeof(*src)); 1519 if (src->fc_ioctls == NULL) 1520 return (true); 1521 1522 KASSERT(src->fc_nioctls > 0, 1523 ("fc_ioctls != NULL, but fc_nioctls=%hd", src->fc_nioctls)); 1524 1525 size = sizeof(src->fc_ioctls[0]) * src->fc_nioctls; 1526 dst->fc_ioctls = malloc(size, M_FILECAPS, M_WAITOK); 1527 memcpy(dst->fc_ioctls, src->fc_ioctls, size); 1528 return (true); 1529 } 1530 1531 static u_long * 1532 filecaps_copy_prep(const struct filecaps *src) 1533 { 1534 u_long *ioctls; 1535 size_t size; 1536 1537 if (__predict_true(src->fc_ioctls == NULL)) 1538 return (NULL); 1539 1540 KASSERT(src->fc_nioctls > 0, 1541 ("fc_ioctls != NULL, but fc_nioctls=%hd", src->fc_nioctls)); 1542 1543 size = sizeof(src->fc_ioctls[0]) * src->fc_nioctls; 1544 ioctls = malloc(size, M_FILECAPS, M_WAITOK); 1545 return (ioctls); 1546 } 1547 1548 static void 1549 filecaps_copy_finish(const struct filecaps *src, struct filecaps *dst, 1550 u_long *ioctls) 1551 { 1552 size_t size; 1553 1554 *dst = *src; 1555 if (__predict_true(src->fc_ioctls == NULL)) { 1556 MPASS(ioctls == NULL); 1557 return; 1558 } 1559 1560 size = sizeof(src->fc_ioctls[0]) * src->fc_nioctls; 1561 dst->fc_ioctls = ioctls; 1562 bcopy(src->fc_ioctls, dst->fc_ioctls, size); 1563 } 1564 1565 /* 1566 * Move filecaps structure to the new place and clear the old place. 1567 */ 1568 void 1569 filecaps_move(struct filecaps *src, struct filecaps *dst) 1570 { 1571 1572 *dst = *src; 1573 bzero(src, sizeof(*src)); 1574 } 1575 1576 /* 1577 * Fill the given filecaps structure with full rights. 1578 */ 1579 static void 1580 filecaps_fill(struct filecaps *fcaps) 1581 { 1582 1583 CAP_ALL(&fcaps->fc_rights); 1584 fcaps->fc_ioctls = NULL; 1585 fcaps->fc_nioctls = -1; 1586 fcaps->fc_fcntls = CAP_FCNTL_ALL; 1587 } 1588 1589 /* 1590 * Free memory allocated within filecaps structure. 1591 */ 1592 void 1593 filecaps_free(struct filecaps *fcaps) 1594 { 1595 1596 free(fcaps->fc_ioctls, M_FILECAPS); 1597 bzero(fcaps, sizeof(*fcaps)); 1598 } 1599 1600 static u_long * 1601 filecaps_free_prep(struct filecaps *fcaps) 1602 { 1603 u_long *ioctls; 1604 1605 ioctls = fcaps->fc_ioctls; 1606 bzero(fcaps, sizeof(*fcaps)); 1607 return (ioctls); 1608 } 1609 1610 static void 1611 filecaps_free_finish(u_long *ioctls) 1612 { 1613 1614 free(ioctls, M_FILECAPS); 1615 } 1616 1617 /* 1618 * Validate the given filecaps structure. 1619 */ 1620 static void 1621 filecaps_validate(const struct filecaps *fcaps, const char *func) 1622 { 1623 1624 KASSERT(cap_rights_is_valid(&fcaps->fc_rights), 1625 ("%s: invalid rights", func)); 1626 KASSERT((fcaps->fc_fcntls & ~CAP_FCNTL_ALL) == 0, 1627 ("%s: invalid fcntls", func)); 1628 KASSERT(fcaps->fc_fcntls == 0 || 1629 cap_rights_is_set(&fcaps->fc_rights, CAP_FCNTL), 1630 ("%s: fcntls without CAP_FCNTL", func)); 1631 KASSERT(fcaps->fc_ioctls != NULL ? fcaps->fc_nioctls > 0 : 1632 (fcaps->fc_nioctls == -1 || fcaps->fc_nioctls == 0), 1633 ("%s: invalid ioctls", func)); 1634 KASSERT(fcaps->fc_nioctls == 0 || 1635 cap_rights_is_set(&fcaps->fc_rights, CAP_IOCTL), 1636 ("%s: ioctls without CAP_IOCTL", func)); 1637 } 1638 1639 static void 1640 fdgrowtable_exp(struct filedesc *fdp, int nfd) 1641 { 1642 int nfd1; 1643 1644 FILEDESC_XLOCK_ASSERT(fdp); 1645 1646 nfd1 = fdp->fd_nfiles * 2; 1647 if (nfd1 < nfd) 1648 nfd1 = nfd; 1649 fdgrowtable(fdp, nfd1); 1650 } 1651 1652 /* 1653 * Grow the file table to accommodate (at least) nfd descriptors. 1654 */ 1655 static void 1656 fdgrowtable(struct filedesc *fdp, int nfd) 1657 { 1658 struct filedesc0 *fdp0; 1659 struct freetable *ft; 1660 struct fdescenttbl *ntable; 1661 struct fdescenttbl *otable; 1662 int nnfiles, onfiles; 1663 NDSLOTTYPE *nmap, *omap; 1664 1665 /* 1666 * If lastfile is -1 this struct filedesc was just allocated and we are 1667 * growing it to accommodate for the one we are going to copy from. There 1668 * is no need to have a lock on this one as it's not visible to anyone. 1669 */ 1670 if (fdp->fd_lastfile != -1) 1671 FILEDESC_XLOCK_ASSERT(fdp); 1672 1673 KASSERT(fdp->fd_nfiles > 0, ("zero-length file table")); 1674 1675 /* save old values */ 1676 onfiles = fdp->fd_nfiles; 1677 otable = fdp->fd_files; 1678 omap = fdp->fd_map; 1679 1680 /* compute the size of the new table */ 1681 nnfiles = NDSLOTS(nfd) * NDENTRIES; /* round up */ 1682 if (nnfiles <= onfiles) 1683 /* the table is already large enough */ 1684 return; 1685 1686 /* 1687 * Allocate a new table. We need enough space for the number of 1688 * entries, file entries themselves and the struct freetable we will use 1689 * when we decommission the table and place it on the freelist. 1690 * We place the struct freetable in the middle so we don't have 1691 * to worry about padding. 1692 */ 1693 ntable = malloc(offsetof(struct fdescenttbl, fdt_ofiles) + 1694 nnfiles * sizeof(ntable->fdt_ofiles[0]) + 1695 sizeof(struct freetable), 1696 M_FILEDESC, M_ZERO | M_WAITOK); 1697 /* copy the old data */ 1698 ntable->fdt_nfiles = nnfiles; 1699 memcpy(ntable->fdt_ofiles, otable->fdt_ofiles, 1700 onfiles * sizeof(ntable->fdt_ofiles[0])); 1701 1702 /* 1703 * Allocate a new map only if the old is not large enough. It will 1704 * grow at a slower rate than the table as it can map more 1705 * entries than the table can hold. 1706 */ 1707 if (NDSLOTS(nnfiles) > NDSLOTS(onfiles)) { 1708 nmap = malloc(NDSLOTS(nnfiles) * NDSLOTSIZE, M_FILEDESC, 1709 M_ZERO | M_WAITOK); 1710 /* copy over the old data and update the pointer */ 1711 memcpy(nmap, omap, NDSLOTS(onfiles) * sizeof(*omap)); 1712 fdp->fd_map = nmap; 1713 } 1714 1715 /* 1716 * Make sure that ntable is correctly initialized before we replace 1717 * fd_files poiner. Otherwise fget_unlocked() may see inconsistent 1718 * data. 1719 */ 1720 atomic_store_rel_ptr((volatile void *)&fdp->fd_files, (uintptr_t)ntable); 1721 1722 /* 1723 * Do not free the old file table, as some threads may still 1724 * reference entries within it. Instead, place it on a freelist 1725 * which will be processed when the struct filedesc is released. 1726 * 1727 * Note that if onfiles == NDFILE, we're dealing with the original 1728 * static allocation contained within (struct filedesc0 *)fdp, 1729 * which must not be freed. 1730 */ 1731 if (onfiles > NDFILE) { 1732 ft = (struct freetable *)&otable->fdt_ofiles[onfiles]; 1733 fdp0 = (struct filedesc0 *)fdp; 1734 ft->ft_table = otable; 1735 SLIST_INSERT_HEAD(&fdp0->fd_free, ft, ft_next); 1736 } 1737 /* 1738 * The map does not have the same possibility of threads still 1739 * holding references to it. So always free it as long as it 1740 * does not reference the original static allocation. 1741 */ 1742 if (NDSLOTS(onfiles) > NDSLOTS(NDFILE)) 1743 free(omap, M_FILEDESC); 1744 } 1745 1746 /* 1747 * Allocate a file descriptor for the process. 1748 */ 1749 int 1750 fdalloc(struct thread *td, int minfd, int *result) 1751 { 1752 struct proc *p = td->td_proc; 1753 struct filedesc *fdp = p->p_fd; 1754 int fd, maxfd, allocfd; 1755 #ifdef RACCT 1756 int error; 1757 #endif 1758 1759 FILEDESC_XLOCK_ASSERT(fdp); 1760 1761 if (fdp->fd_freefile > minfd) 1762 minfd = fdp->fd_freefile; 1763 1764 maxfd = getmaxfd(td); 1765 1766 /* 1767 * Search the bitmap for a free descriptor starting at minfd. 1768 * If none is found, grow the file table. 1769 */ 1770 fd = fd_first_free(fdp, minfd, fdp->fd_nfiles); 1771 if (fd >= maxfd) 1772 return (EMFILE); 1773 if (fd >= fdp->fd_nfiles) { 1774 allocfd = min(fd * 2, maxfd); 1775 #ifdef RACCT 1776 if (RACCT_ENABLED()) { 1777 error = racct_set_unlocked(p, RACCT_NOFILE, allocfd); 1778 if (error != 0) 1779 return (EMFILE); 1780 } 1781 #endif 1782 /* 1783 * fd is already equal to first free descriptor >= minfd, so 1784 * we only need to grow the table and we are done. 1785 */ 1786 fdgrowtable_exp(fdp, allocfd); 1787 } 1788 1789 /* 1790 * Perform some sanity checks, then mark the file descriptor as 1791 * used and return it to the caller. 1792 */ 1793 KASSERT(fd >= 0 && fd < min(maxfd, fdp->fd_nfiles), 1794 ("invalid descriptor %d", fd)); 1795 KASSERT(!fdisused(fdp, fd), 1796 ("fd_first_free() returned non-free descriptor")); 1797 KASSERT(fdp->fd_ofiles[fd].fde_file == NULL, 1798 ("file descriptor isn't free")); 1799 fdused(fdp, fd); 1800 *result = fd; 1801 return (0); 1802 } 1803 1804 /* 1805 * Allocate n file descriptors for the process. 1806 */ 1807 int 1808 fdallocn(struct thread *td, int minfd, int *fds, int n) 1809 { 1810 struct proc *p = td->td_proc; 1811 struct filedesc *fdp = p->p_fd; 1812 int i; 1813 1814 FILEDESC_XLOCK_ASSERT(fdp); 1815 1816 for (i = 0; i < n; i++) 1817 if (fdalloc(td, 0, &fds[i]) != 0) 1818 break; 1819 1820 if (i < n) { 1821 for (i--; i >= 0; i--) 1822 fdunused(fdp, fds[i]); 1823 return (EMFILE); 1824 } 1825 1826 return (0); 1827 } 1828 1829 /* 1830 * Create a new open file structure and allocate a file descriptor for the 1831 * process that refers to it. We add one reference to the file for the 1832 * descriptor table and one reference for resultfp. This is to prevent us 1833 * being preempted and the entry in the descriptor table closed after we 1834 * release the FILEDESC lock. 1835 */ 1836 int 1837 falloc_caps(struct thread *td, struct file **resultfp, int *resultfd, int flags, 1838 struct filecaps *fcaps) 1839 { 1840 struct file *fp; 1841 int error, fd; 1842 1843 error = falloc_noinstall(td, &fp); 1844 if (error) 1845 return (error); /* no reference held on error */ 1846 1847 error = finstall(td, fp, &fd, flags, fcaps); 1848 if (error) { 1849 fdrop(fp, td); /* one reference (fp only) */ 1850 return (error); 1851 } 1852 1853 if (resultfp != NULL) 1854 *resultfp = fp; /* copy out result */ 1855 else 1856 fdrop(fp, td); /* release local reference */ 1857 1858 if (resultfd != NULL) 1859 *resultfd = fd; 1860 1861 return (0); 1862 } 1863 1864 /* 1865 * Create a new open file structure without allocating a file descriptor. 1866 */ 1867 int 1868 falloc_noinstall(struct thread *td, struct file **resultfp) 1869 { 1870 struct file *fp; 1871 int maxuserfiles = maxfiles - (maxfiles / 20); 1872 int openfiles_new; 1873 static struct timeval lastfail; 1874 static int curfail; 1875 1876 KASSERT(resultfp != NULL, ("%s: resultfp == NULL", __func__)); 1877 1878 openfiles_new = atomic_fetchadd_int(&openfiles, 1) + 1; 1879 if ((openfiles_new >= maxuserfiles && 1880 priv_check(td, PRIV_MAXFILES) != 0) || 1881 openfiles_new >= maxfiles) { 1882 atomic_subtract_int(&openfiles, 1); 1883 if (ppsratecheck(&lastfail, &curfail, 1)) { 1884 printf("kern.maxfiles limit exceeded by uid %i, (%s) " 1885 "please see tuning(7).\n", td->td_ucred->cr_ruid, td->td_proc->p_comm); 1886 } 1887 return (ENFILE); 1888 } 1889 fp = uma_zalloc(file_zone, M_WAITOK); 1890 bzero(fp, sizeof(*fp)); 1891 refcount_init(&fp->f_count, 1); 1892 fp->f_cred = crhold(td->td_ucred); 1893 fp->f_ops = &badfileops; 1894 *resultfp = fp; 1895 return (0); 1896 } 1897 1898 /* 1899 * Install a file in a file descriptor table. 1900 */ 1901 void 1902 _finstall(struct filedesc *fdp, struct file *fp, int fd, int flags, 1903 struct filecaps *fcaps) 1904 { 1905 struct filedescent *fde; 1906 1907 MPASS(fp != NULL); 1908 if (fcaps != NULL) 1909 filecaps_validate(fcaps, __func__); 1910 FILEDESC_XLOCK_ASSERT(fdp); 1911 1912 fde = &fdp->fd_ofiles[fd]; 1913 #ifdef CAPABILITIES 1914 seqc_write_begin(&fde->fde_seqc); 1915 #endif 1916 fde->fde_file = fp; 1917 fde->fde_flags = (flags & O_CLOEXEC) != 0 ? UF_EXCLOSE : 0; 1918 if (fcaps != NULL) 1919 filecaps_move(fcaps, &fde->fde_caps); 1920 else 1921 filecaps_fill(&fde->fde_caps); 1922 #ifdef CAPABILITIES 1923 seqc_write_end(&fde->fde_seqc); 1924 #endif 1925 } 1926 1927 int 1928 finstall(struct thread *td, struct file *fp, int *fd, int flags, 1929 struct filecaps *fcaps) 1930 { 1931 struct filedesc *fdp = td->td_proc->p_fd; 1932 int error; 1933 1934 MPASS(fd != NULL); 1935 1936 if (!fhold(fp)) 1937 return (EBADF); 1938 FILEDESC_XLOCK(fdp); 1939 if ((error = fdalloc(td, 0, fd))) { 1940 FILEDESC_XUNLOCK(fdp); 1941 fdrop(fp, td); 1942 return (error); 1943 } 1944 _finstall(fdp, fp, *fd, flags, fcaps); 1945 FILEDESC_XUNLOCK(fdp); 1946 return (0); 1947 } 1948 1949 /* 1950 * Build a new filedesc structure from another. 1951 * Copy the current, root, and jail root vnode references. 1952 * 1953 * If fdp is not NULL, return with it shared locked. 1954 */ 1955 struct filedesc * 1956 fdinit(struct filedesc *fdp, bool prepfiles) 1957 { 1958 struct filedesc0 *newfdp0; 1959 struct filedesc *newfdp; 1960 1961 newfdp0 = uma_zalloc(filedesc0_zone, M_WAITOK | M_ZERO); 1962 newfdp = &newfdp0->fd_fd; 1963 1964 /* Create the file descriptor table. */ 1965 FILEDESC_LOCK_INIT(newfdp); 1966 refcount_init(&newfdp->fd_refcnt, 1); 1967 refcount_init(&newfdp->fd_holdcnt, 1); 1968 newfdp->fd_cmask = CMASK; 1969 newfdp->fd_map = newfdp0->fd_dmap; 1970 newfdp->fd_lastfile = -1; 1971 newfdp->fd_files = (struct fdescenttbl *)&newfdp0->fd_dfiles; 1972 newfdp->fd_files->fdt_nfiles = NDFILE; 1973 1974 if (fdp == NULL) 1975 return (newfdp); 1976 1977 if (prepfiles && fdp->fd_lastfile >= newfdp->fd_nfiles) 1978 fdgrowtable(newfdp, fdp->fd_lastfile + 1); 1979 1980 FILEDESC_SLOCK(fdp); 1981 newfdp->fd_cdir = fdp->fd_cdir; 1982 if (newfdp->fd_cdir) 1983 vrefact(newfdp->fd_cdir); 1984 newfdp->fd_rdir = fdp->fd_rdir; 1985 if (newfdp->fd_rdir) 1986 vrefact(newfdp->fd_rdir); 1987 newfdp->fd_jdir = fdp->fd_jdir; 1988 if (newfdp->fd_jdir) 1989 vrefact(newfdp->fd_jdir); 1990 1991 if (!prepfiles) { 1992 FILEDESC_SUNLOCK(fdp); 1993 } else { 1994 while (fdp->fd_lastfile >= newfdp->fd_nfiles) { 1995 FILEDESC_SUNLOCK(fdp); 1996 fdgrowtable(newfdp, fdp->fd_lastfile + 1); 1997 FILEDESC_SLOCK(fdp); 1998 } 1999 } 2000 2001 return (newfdp); 2002 } 2003 2004 static struct filedesc * 2005 fdhold(struct proc *p) 2006 { 2007 struct filedesc *fdp; 2008 2009 PROC_LOCK_ASSERT(p, MA_OWNED); 2010 fdp = p->p_fd; 2011 if (fdp != NULL) 2012 refcount_acquire(&fdp->fd_holdcnt); 2013 return (fdp); 2014 } 2015 2016 static void 2017 fddrop(struct filedesc *fdp) 2018 { 2019 2020 if (fdp->fd_holdcnt > 1) { 2021 if (refcount_release(&fdp->fd_holdcnt) == 0) 2022 return; 2023 } 2024 2025 FILEDESC_LOCK_DESTROY(fdp); 2026 uma_zfree(filedesc0_zone, fdp); 2027 } 2028 2029 /* 2030 * Share a filedesc structure. 2031 */ 2032 struct filedesc * 2033 fdshare(struct filedesc *fdp) 2034 { 2035 2036 refcount_acquire(&fdp->fd_refcnt); 2037 return (fdp); 2038 } 2039 2040 /* 2041 * Unshare a filedesc structure, if necessary by making a copy 2042 */ 2043 void 2044 fdunshare(struct thread *td) 2045 { 2046 struct filedesc *tmp; 2047 struct proc *p = td->td_proc; 2048 2049 if (p->p_fd->fd_refcnt == 1) 2050 return; 2051 2052 tmp = fdcopy(p->p_fd); 2053 fdescfree(td); 2054 p->p_fd = tmp; 2055 } 2056 2057 void 2058 fdinstall_remapped(struct thread *td, struct filedesc *fdp) 2059 { 2060 2061 fdescfree(td); 2062 td->td_proc->p_fd = fdp; 2063 } 2064 2065 /* 2066 * Copy a filedesc structure. A NULL pointer in returns a NULL reference, 2067 * this is to ease callers, not catch errors. 2068 */ 2069 struct filedesc * 2070 fdcopy(struct filedesc *fdp) 2071 { 2072 struct filedesc *newfdp; 2073 struct filedescent *nfde, *ofde; 2074 int i; 2075 2076 MPASS(fdp != NULL); 2077 2078 newfdp = fdinit(fdp, true); 2079 /* copy all passable descriptors (i.e. not kqueue) */ 2080 newfdp->fd_freefile = -1; 2081 for (i = 0; i <= fdp->fd_lastfile; ++i) { 2082 ofde = &fdp->fd_ofiles[i]; 2083 if (ofde->fde_file == NULL || 2084 (ofde->fde_file->f_ops->fo_flags & DFLAG_PASSABLE) == 0 || 2085 !fhold(ofde->fde_file)) { 2086 if (newfdp->fd_freefile == -1) 2087 newfdp->fd_freefile = i; 2088 continue; 2089 } 2090 nfde = &newfdp->fd_ofiles[i]; 2091 *nfde = *ofde; 2092 filecaps_copy(&ofde->fde_caps, &nfde->fde_caps, true); 2093 fdused_init(newfdp, i); 2094 newfdp->fd_lastfile = i; 2095 } 2096 if (newfdp->fd_freefile == -1) 2097 newfdp->fd_freefile = i; 2098 newfdp->fd_cmask = fdp->fd_cmask; 2099 FILEDESC_SUNLOCK(fdp); 2100 return (newfdp); 2101 } 2102 2103 /* 2104 * Copies a filedesc structure, while remapping all file descriptors 2105 * stored inside using a translation table. 2106 * 2107 * File descriptors are copied over to the new file descriptor table, 2108 * regardless of whether the close-on-exec flag is set. 2109 */ 2110 int 2111 fdcopy_remapped(struct filedesc *fdp, const int *fds, size_t nfds, 2112 struct filedesc **ret) 2113 { 2114 struct filedesc *newfdp; 2115 struct filedescent *nfde, *ofde; 2116 int error, i; 2117 2118 MPASS(fdp != NULL); 2119 2120 newfdp = fdinit(fdp, true); 2121 if (nfds > fdp->fd_lastfile + 1) { 2122 /* New table cannot be larger than the old one. */ 2123 error = E2BIG; 2124 goto bad; 2125 } 2126 /* Copy all passable descriptors (i.e. not kqueue). */ 2127 newfdp->fd_freefile = nfds; 2128 for (i = 0; i < nfds; ++i) { 2129 if (fds[i] < 0 || fds[i] > fdp->fd_lastfile) { 2130 /* File descriptor out of bounds. */ 2131 error = EBADF; 2132 goto bad; 2133 } 2134 ofde = &fdp->fd_ofiles[fds[i]]; 2135 if (ofde->fde_file == NULL) { 2136 /* Unused file descriptor. */ 2137 error = EBADF; 2138 goto bad; 2139 } 2140 if ((ofde->fde_file->f_ops->fo_flags & DFLAG_PASSABLE) == 0) { 2141 /* File descriptor cannot be passed. */ 2142 error = EINVAL; 2143 goto bad; 2144 } 2145 if (!fhold(nfde->fde_file)) { 2146 error = EBADF; 2147 goto bad; 2148 } 2149 nfde = &newfdp->fd_ofiles[i]; 2150 *nfde = *ofde; 2151 filecaps_copy(&ofde->fde_caps, &nfde->fde_caps, true); 2152 fdused_init(newfdp, i); 2153 newfdp->fd_lastfile = i; 2154 } 2155 newfdp->fd_cmask = fdp->fd_cmask; 2156 FILEDESC_SUNLOCK(fdp); 2157 *ret = newfdp; 2158 return (0); 2159 bad: 2160 FILEDESC_SUNLOCK(fdp); 2161 fdescfree_remapped(newfdp); 2162 return (error); 2163 } 2164 2165 /* 2166 * Clear POSIX style locks. This is only used when fdp looses a reference (i.e. 2167 * one of processes using it exits) and the table used to be shared. 2168 */ 2169 static void 2170 fdclearlocks(struct thread *td) 2171 { 2172 struct filedesc *fdp; 2173 struct filedesc_to_leader *fdtol; 2174 struct flock lf; 2175 struct file *fp; 2176 struct proc *p; 2177 struct vnode *vp; 2178 int i; 2179 2180 p = td->td_proc; 2181 fdp = p->p_fd; 2182 fdtol = p->p_fdtol; 2183 MPASS(fdtol != NULL); 2184 2185 FILEDESC_XLOCK(fdp); 2186 KASSERT(fdtol->fdl_refcount > 0, 2187 ("filedesc_to_refcount botch: fdl_refcount=%d", 2188 fdtol->fdl_refcount)); 2189 if (fdtol->fdl_refcount == 1 && 2190 (p->p_leader->p_flag & P_ADVLOCK) != 0) { 2191 for (i = 0; i <= fdp->fd_lastfile; i++) { 2192 fp = fdp->fd_ofiles[i].fde_file; 2193 if (fp == NULL || fp->f_type != DTYPE_VNODE || 2194 !fhold(fp)) 2195 continue; 2196 FILEDESC_XUNLOCK(fdp); 2197 lf.l_whence = SEEK_SET; 2198 lf.l_start = 0; 2199 lf.l_len = 0; 2200 lf.l_type = F_UNLCK; 2201 vp = fp->f_vnode; 2202 (void) VOP_ADVLOCK(vp, 2203 (caddr_t)p->p_leader, F_UNLCK, 2204 &lf, F_POSIX); 2205 FILEDESC_XLOCK(fdp); 2206 fdrop(fp, td); 2207 } 2208 } 2209 retry: 2210 if (fdtol->fdl_refcount == 1) { 2211 if (fdp->fd_holdleaderscount > 0 && 2212 (p->p_leader->p_flag & P_ADVLOCK) != 0) { 2213 /* 2214 * close() or kern_dup() has cleared a reference 2215 * in a shared file descriptor table. 2216 */ 2217 fdp->fd_holdleaderswakeup = 1; 2218 sx_sleep(&fdp->fd_holdleaderscount, 2219 FILEDESC_LOCK(fdp), PLOCK, "fdlhold", 0); 2220 goto retry; 2221 } 2222 if (fdtol->fdl_holdcount > 0) { 2223 /* 2224 * Ensure that fdtol->fdl_leader remains 2225 * valid in closef(). 2226 */ 2227 fdtol->fdl_wakeup = 1; 2228 sx_sleep(fdtol, FILEDESC_LOCK(fdp), PLOCK, 2229 "fdlhold", 0); 2230 goto retry; 2231 } 2232 } 2233 fdtol->fdl_refcount--; 2234 if (fdtol->fdl_refcount == 0 && 2235 fdtol->fdl_holdcount == 0) { 2236 fdtol->fdl_next->fdl_prev = fdtol->fdl_prev; 2237 fdtol->fdl_prev->fdl_next = fdtol->fdl_next; 2238 } else 2239 fdtol = NULL; 2240 p->p_fdtol = NULL; 2241 FILEDESC_XUNLOCK(fdp); 2242 if (fdtol != NULL) 2243 free(fdtol, M_FILEDESC_TO_LEADER); 2244 } 2245 2246 /* 2247 * Release a filedesc structure. 2248 */ 2249 static void 2250 fdescfree_fds(struct thread *td, struct filedesc *fdp, bool needclose) 2251 { 2252 struct filedesc0 *fdp0; 2253 struct freetable *ft, *tft; 2254 struct filedescent *fde; 2255 struct file *fp; 2256 int i; 2257 2258 for (i = 0; i <= fdp->fd_lastfile; i++) { 2259 fde = &fdp->fd_ofiles[i]; 2260 fp = fde->fde_file; 2261 if (fp != NULL) { 2262 fdefree_last(fde); 2263 if (needclose) 2264 (void) closef(fp, td); 2265 else 2266 fdrop(fp, td); 2267 } 2268 } 2269 2270 if (NDSLOTS(fdp->fd_nfiles) > NDSLOTS(NDFILE)) 2271 free(fdp->fd_map, M_FILEDESC); 2272 if (fdp->fd_nfiles > NDFILE) 2273 free(fdp->fd_files, M_FILEDESC); 2274 2275 fdp0 = (struct filedesc0 *)fdp; 2276 SLIST_FOREACH_SAFE(ft, &fdp0->fd_free, ft_next, tft) 2277 free(ft->ft_table, M_FILEDESC); 2278 2279 fddrop(fdp); 2280 } 2281 2282 void 2283 fdescfree(struct thread *td) 2284 { 2285 struct proc *p; 2286 struct filedesc *fdp; 2287 struct vnode *cdir, *jdir, *rdir; 2288 2289 p = td->td_proc; 2290 fdp = p->p_fd; 2291 MPASS(fdp != NULL); 2292 2293 #ifdef RACCT 2294 if (RACCT_ENABLED()) 2295 racct_set_unlocked(p, RACCT_NOFILE, 0); 2296 #endif 2297 2298 if (p->p_fdtol != NULL) 2299 fdclearlocks(td); 2300 2301 PROC_LOCK(p); 2302 p->p_fd = NULL; 2303 PROC_UNLOCK(p); 2304 2305 if (refcount_release(&fdp->fd_refcnt) == 0) 2306 return; 2307 2308 FILEDESC_XLOCK(fdp); 2309 cdir = fdp->fd_cdir; 2310 fdp->fd_cdir = NULL; 2311 rdir = fdp->fd_rdir; 2312 fdp->fd_rdir = NULL; 2313 jdir = fdp->fd_jdir; 2314 fdp->fd_jdir = NULL; 2315 FILEDESC_XUNLOCK(fdp); 2316 2317 if (cdir != NULL) 2318 vrele(cdir); 2319 if (rdir != NULL) 2320 vrele(rdir); 2321 if (jdir != NULL) 2322 vrele(jdir); 2323 2324 fdescfree_fds(td, fdp, 1); 2325 } 2326 2327 void 2328 fdescfree_remapped(struct filedesc *fdp) 2329 { 2330 2331 if (fdp->fd_cdir != NULL) 2332 vrele(fdp->fd_cdir); 2333 if (fdp->fd_rdir != NULL) 2334 vrele(fdp->fd_rdir); 2335 if (fdp->fd_jdir != NULL) 2336 vrele(fdp->fd_jdir); 2337 2338 fdescfree_fds(curthread, fdp, 0); 2339 } 2340 2341 /* 2342 * For setugid programs, we don't want to people to use that setugidness 2343 * to generate error messages which write to a file which otherwise would 2344 * otherwise be off-limits to the process. We check for filesystems where 2345 * the vnode can change out from under us after execve (like [lin]procfs). 2346 * 2347 * Since fdsetugidsafety calls this only for fd 0, 1 and 2, this check is 2348 * sufficient. We also don't check for setugidness since we know we are. 2349 */ 2350 static bool 2351 is_unsafe(struct file *fp) 2352 { 2353 struct vnode *vp; 2354 2355 if (fp->f_type != DTYPE_VNODE) 2356 return (false); 2357 2358 vp = fp->f_vnode; 2359 return ((vp->v_vflag & VV_PROCDEP) != 0); 2360 } 2361 2362 /* 2363 * Make this setguid thing safe, if at all possible. 2364 */ 2365 void 2366 fdsetugidsafety(struct thread *td) 2367 { 2368 struct filedesc *fdp; 2369 struct file *fp; 2370 int i; 2371 2372 fdp = td->td_proc->p_fd; 2373 KASSERT(fdp->fd_refcnt == 1, ("the fdtable should not be shared")); 2374 MPASS(fdp->fd_nfiles >= 3); 2375 for (i = 0; i <= 2; i++) { 2376 fp = fdp->fd_ofiles[i].fde_file; 2377 if (fp != NULL && is_unsafe(fp)) { 2378 FILEDESC_XLOCK(fdp); 2379 knote_fdclose(td, i); 2380 /* 2381 * NULL-out descriptor prior to close to avoid 2382 * a race while close blocks. 2383 */ 2384 fdfree(fdp, i); 2385 FILEDESC_XUNLOCK(fdp); 2386 (void) closef(fp, td); 2387 } 2388 } 2389 } 2390 2391 /* 2392 * If a specific file object occupies a specific file descriptor, close the 2393 * file descriptor entry and drop a reference on the file object. This is a 2394 * convenience function to handle a subsequent error in a function that calls 2395 * falloc() that handles the race that another thread might have closed the 2396 * file descriptor out from under the thread creating the file object. 2397 */ 2398 void 2399 fdclose(struct thread *td, struct file *fp, int idx) 2400 { 2401 struct filedesc *fdp = td->td_proc->p_fd; 2402 2403 FILEDESC_XLOCK(fdp); 2404 if (fdp->fd_ofiles[idx].fde_file == fp) { 2405 fdfree(fdp, idx); 2406 FILEDESC_XUNLOCK(fdp); 2407 fdrop(fp, td); 2408 } else 2409 FILEDESC_XUNLOCK(fdp); 2410 } 2411 2412 /* 2413 * Close any files on exec? 2414 */ 2415 void 2416 fdcloseexec(struct thread *td) 2417 { 2418 struct filedesc *fdp; 2419 struct filedescent *fde; 2420 struct file *fp; 2421 int i; 2422 2423 fdp = td->td_proc->p_fd; 2424 KASSERT(fdp->fd_refcnt == 1, ("the fdtable should not be shared")); 2425 for (i = 0; i <= fdp->fd_lastfile; i++) { 2426 fde = &fdp->fd_ofiles[i]; 2427 fp = fde->fde_file; 2428 if (fp != NULL && (fp->f_type == DTYPE_MQUEUE || 2429 (fde->fde_flags & UF_EXCLOSE))) { 2430 FILEDESC_XLOCK(fdp); 2431 fdfree(fdp, i); 2432 (void) closefp(fdp, i, fp, td, 0); 2433 FILEDESC_UNLOCK_ASSERT(fdp); 2434 } 2435 } 2436 } 2437 2438 /* 2439 * It is unsafe for set[ug]id processes to be started with file 2440 * descriptors 0..2 closed, as these descriptors are given implicit 2441 * significance in the Standard C library. fdcheckstd() will create a 2442 * descriptor referencing /dev/null for each of stdin, stdout, and 2443 * stderr that is not already open. 2444 */ 2445 int 2446 fdcheckstd(struct thread *td) 2447 { 2448 struct filedesc *fdp; 2449 register_t save; 2450 int i, error, devnull; 2451 2452 fdp = td->td_proc->p_fd; 2453 KASSERT(fdp->fd_refcnt == 1, ("the fdtable should not be shared")); 2454 MPASS(fdp->fd_nfiles >= 3); 2455 devnull = -1; 2456 for (i = 0; i <= 2; i++) { 2457 if (fdp->fd_ofiles[i].fde_file != NULL) 2458 continue; 2459 2460 save = td->td_retval[0]; 2461 if (devnull != -1) { 2462 error = kern_dup(td, FDDUP_FIXED, 0, devnull, i); 2463 } else { 2464 error = kern_openat(td, AT_FDCWD, "/dev/null", 2465 UIO_SYSSPACE, O_RDWR, 0); 2466 if (error == 0) { 2467 devnull = td->td_retval[0]; 2468 KASSERT(devnull == i, ("we didn't get our fd")); 2469 } 2470 } 2471 td->td_retval[0] = save; 2472 if (error != 0) 2473 return (error); 2474 } 2475 return (0); 2476 } 2477 2478 /* 2479 * Internal form of close. Decrement reference count on file structure. 2480 * Note: td may be NULL when closing a file that was being passed in a 2481 * message. 2482 */ 2483 int 2484 closef(struct file *fp, struct thread *td) 2485 { 2486 struct vnode *vp; 2487 struct flock lf; 2488 struct filedesc_to_leader *fdtol; 2489 struct filedesc *fdp; 2490 2491 /* 2492 * POSIX record locking dictates that any close releases ALL 2493 * locks owned by this process. This is handled by setting 2494 * a flag in the unlock to free ONLY locks obeying POSIX 2495 * semantics, and not to free BSD-style file locks. 2496 * If the descriptor was in a message, POSIX-style locks 2497 * aren't passed with the descriptor, and the thread pointer 2498 * will be NULL. Callers should be careful only to pass a 2499 * NULL thread pointer when there really is no owning 2500 * context that might have locks, or the locks will be 2501 * leaked. 2502 */ 2503 if (fp->f_type == DTYPE_VNODE && td != NULL) { 2504 vp = fp->f_vnode; 2505 if ((td->td_proc->p_leader->p_flag & P_ADVLOCK) != 0) { 2506 lf.l_whence = SEEK_SET; 2507 lf.l_start = 0; 2508 lf.l_len = 0; 2509 lf.l_type = F_UNLCK; 2510 (void) VOP_ADVLOCK(vp, (caddr_t)td->td_proc->p_leader, 2511 F_UNLCK, &lf, F_POSIX); 2512 } 2513 fdtol = td->td_proc->p_fdtol; 2514 if (fdtol != NULL) { 2515 /* 2516 * Handle special case where file descriptor table is 2517 * shared between multiple process leaders. 2518 */ 2519 fdp = td->td_proc->p_fd; 2520 FILEDESC_XLOCK(fdp); 2521 for (fdtol = fdtol->fdl_next; 2522 fdtol != td->td_proc->p_fdtol; 2523 fdtol = fdtol->fdl_next) { 2524 if ((fdtol->fdl_leader->p_flag & 2525 P_ADVLOCK) == 0) 2526 continue; 2527 fdtol->fdl_holdcount++; 2528 FILEDESC_XUNLOCK(fdp); 2529 lf.l_whence = SEEK_SET; 2530 lf.l_start = 0; 2531 lf.l_len = 0; 2532 lf.l_type = F_UNLCK; 2533 vp = fp->f_vnode; 2534 (void) VOP_ADVLOCK(vp, 2535 (caddr_t)fdtol->fdl_leader, F_UNLCK, &lf, 2536 F_POSIX); 2537 FILEDESC_XLOCK(fdp); 2538 fdtol->fdl_holdcount--; 2539 if (fdtol->fdl_holdcount == 0 && 2540 fdtol->fdl_wakeup != 0) { 2541 fdtol->fdl_wakeup = 0; 2542 wakeup(fdtol); 2543 } 2544 } 2545 FILEDESC_XUNLOCK(fdp); 2546 } 2547 } 2548 return (fdrop(fp, td)); 2549 } 2550 2551 /* 2552 * Initialize the file pointer with the specified properties. 2553 * 2554 * The ops are set with release semantics to be certain that the flags, type, 2555 * and data are visible when ops is. This is to prevent ops methods from being 2556 * called with bad data. 2557 */ 2558 void 2559 finit(struct file *fp, u_int flag, short type, void *data, struct fileops *ops) 2560 { 2561 fp->f_data = data; 2562 fp->f_flag = flag; 2563 fp->f_type = type; 2564 atomic_store_rel_ptr((volatile uintptr_t *)&fp->f_ops, (uintptr_t)ops); 2565 } 2566 2567 int 2568 fget_cap_locked(struct filedesc *fdp, int fd, cap_rights_t *needrightsp, 2569 struct file **fpp, struct filecaps *havecapsp) 2570 { 2571 struct filedescent *fde; 2572 int error; 2573 2574 FILEDESC_LOCK_ASSERT(fdp); 2575 2576 fde = fdeget_locked(fdp, fd); 2577 if (fde == NULL) { 2578 error = EBADF; 2579 goto out; 2580 } 2581 2582 #ifdef CAPABILITIES 2583 error = cap_check(cap_rights_fde_inline(fde), needrightsp); 2584 if (error != 0) 2585 goto out; 2586 #endif 2587 2588 if (havecapsp != NULL) 2589 filecaps_copy(&fde->fde_caps, havecapsp, true); 2590 2591 *fpp = fde->fde_file; 2592 2593 error = 0; 2594 out: 2595 return (error); 2596 } 2597 2598 int 2599 fget_cap(struct thread *td, int fd, cap_rights_t *needrightsp, 2600 struct file **fpp, struct filecaps *havecapsp) 2601 { 2602 struct filedesc *fdp = td->td_proc->p_fd; 2603 int error; 2604 #ifndef CAPABILITIES 2605 error = fget_unlocked(fdp, fd, needrightsp, fpp, NULL); 2606 if (error == 0 && havecapsp != NULL) 2607 filecaps_fill(havecapsp); 2608 #else 2609 struct file *fp; 2610 seqc_t seq; 2611 2612 for (;;) { 2613 error = fget_unlocked(fdp, fd, needrightsp, &fp, &seq); 2614 if (error != 0) 2615 return (error); 2616 2617 if (havecapsp != NULL) { 2618 if (!filecaps_copy(&fdp->fd_ofiles[fd].fde_caps, 2619 havecapsp, false)) { 2620 fdrop(fp, td); 2621 goto get_locked; 2622 } 2623 } 2624 2625 if (!fd_modified(fdp, fd, seq)) 2626 break; 2627 fdrop(fp, td); 2628 } 2629 2630 *fpp = fp; 2631 return (0); 2632 2633 get_locked: 2634 FILEDESC_SLOCK(fdp); 2635 error = fget_cap_locked(fdp, fd, needrightsp, fpp, havecapsp); 2636 if (error == 0 && !fhold(*fpp)) 2637 error = EBADF; 2638 FILEDESC_SUNLOCK(fdp); 2639 #endif 2640 return (error); 2641 } 2642 2643 int 2644 fget_unlocked(struct filedesc *fdp, int fd, cap_rights_t *needrightsp, 2645 struct file **fpp, seqc_t *seqp) 2646 { 2647 #ifdef CAPABILITIES 2648 const struct filedescent *fde; 2649 #endif 2650 const struct fdescenttbl *fdt; 2651 struct file *fp; 2652 u_int count; 2653 #ifdef CAPABILITIES 2654 seqc_t seq; 2655 cap_rights_t haverights; 2656 int error; 2657 #endif 2658 2659 fdt = fdp->fd_files; 2660 if (__predict_false((u_int)fd >= fdt->fdt_nfiles)) 2661 return (EBADF); 2662 /* 2663 * Fetch the descriptor locklessly. We avoid fdrop() races by 2664 * never raising a refcount above 0. To accomplish this we have 2665 * to use a cmpset loop rather than an atomic_add. The descriptor 2666 * must be re-verified once we acquire a reference to be certain 2667 * that the identity is still correct and we did not lose a race 2668 * due to preemption. 2669 */ 2670 for (;;) { 2671 #ifdef CAPABILITIES 2672 seq = seqc_read(fd_seqc(fdt, fd)); 2673 fde = &fdt->fdt_ofiles[fd]; 2674 haverights = *cap_rights_fde_inline(fde); 2675 fp = fde->fde_file; 2676 if (!seqc_consistent(fd_seqc(fdt, fd), seq)) 2677 continue; 2678 #else 2679 fp = fdt->fdt_ofiles[fd].fde_file; 2680 #endif 2681 if (fp == NULL) 2682 return (EBADF); 2683 #ifdef CAPABILITIES 2684 error = cap_check(&haverights, needrightsp); 2685 if (error != 0) 2686 return (error); 2687 #endif 2688 count = fp->f_count; 2689 retry: 2690 if (count == 0) { 2691 /* 2692 * Force a reload. Other thread could reallocate the 2693 * table before this fd was closed, so it possible that 2694 * there is a stale fp pointer in cached version. 2695 */ 2696 fdt = *(const struct fdescenttbl * const volatile *) 2697 &(fdp->fd_files); 2698 continue; 2699 } 2700 if (__predict_false(count + 1 < count)) 2701 return (EBADF); 2702 2703 /* 2704 * Use an acquire barrier to force re-reading of fdt so it is 2705 * refreshed for verification. 2706 */ 2707 if (__predict_false(atomic_fcmpset_acq_int(&fp->f_count, 2708 &count, count + 1) == 0)) 2709 goto retry; 2710 fdt = fdp->fd_files; 2711 #ifdef CAPABILITIES 2712 if (seqc_consistent_nomb(fd_seqc(fdt, fd), seq)) 2713 #else 2714 if (fp == fdt->fdt_ofiles[fd].fde_file) 2715 #endif 2716 break; 2717 fdrop(fp, curthread); 2718 } 2719 *fpp = fp; 2720 if (seqp != NULL) { 2721 #ifdef CAPABILITIES 2722 *seqp = seq; 2723 #endif 2724 } 2725 return (0); 2726 } 2727 2728 /* 2729 * Extract the file pointer associated with the specified descriptor for the 2730 * current user process. 2731 * 2732 * If the descriptor doesn't exist or doesn't match 'flags', EBADF is 2733 * returned. 2734 * 2735 * File's rights will be checked against the capability rights mask. 2736 * 2737 * If an error occurred the non-zero error is returned and *fpp is set to 2738 * NULL. Otherwise *fpp is held and set and zero is returned. Caller is 2739 * responsible for fdrop(). 2740 */ 2741 static __inline int 2742 _fget(struct thread *td, int fd, struct file **fpp, int flags, 2743 cap_rights_t *needrightsp, seqc_t *seqp) 2744 { 2745 struct filedesc *fdp; 2746 struct file *fp; 2747 int error; 2748 2749 *fpp = NULL; 2750 fdp = td->td_proc->p_fd; 2751 error = fget_unlocked(fdp, fd, needrightsp, &fp, seqp); 2752 if (error != 0) 2753 return (error); 2754 if (fp->f_ops == &badfileops) { 2755 fdrop(fp, td); 2756 return (EBADF); 2757 } 2758 2759 /* 2760 * FREAD and FWRITE failure return EBADF as per POSIX. 2761 */ 2762 error = 0; 2763 switch (flags) { 2764 case FREAD: 2765 case FWRITE: 2766 if ((fp->f_flag & flags) == 0) 2767 error = EBADF; 2768 break; 2769 case FEXEC: 2770 if ((fp->f_flag & (FREAD | FEXEC)) == 0 || 2771 ((fp->f_flag & FWRITE) != 0)) 2772 error = EBADF; 2773 break; 2774 case 0: 2775 break; 2776 default: 2777 KASSERT(0, ("wrong flags")); 2778 } 2779 2780 if (error != 0) { 2781 fdrop(fp, td); 2782 return (error); 2783 } 2784 2785 *fpp = fp; 2786 return (0); 2787 } 2788 2789 int 2790 fget(struct thread *td, int fd, cap_rights_t *rightsp, struct file **fpp) 2791 { 2792 2793 return (_fget(td, fd, fpp, 0, rightsp, NULL)); 2794 } 2795 2796 int 2797 fget_mmap(struct thread *td, int fd, cap_rights_t *rightsp, u_char *maxprotp, 2798 struct file **fpp) 2799 { 2800 int error; 2801 #ifndef CAPABILITIES 2802 error = _fget(td, fd, fpp, 0, rightsp, NULL); 2803 if (maxprotp != NULL) 2804 *maxprotp = VM_PROT_ALL; 2805 #else 2806 cap_rights_t fdrights; 2807 struct filedesc *fdp = td->td_proc->p_fd; 2808 seqc_t seq; 2809 2810 MPASS(cap_rights_is_set(rightsp, CAP_MMAP)); 2811 for (;;) { 2812 error = _fget(td, fd, fpp, 0, rightsp, &seq); 2813 if (error != 0) 2814 return (error); 2815 if (maxprotp != NULL) 2816 fdrights = *cap_rights(fdp, fd); 2817 if (!fd_modified(fdp, fd, seq)) 2818 break; 2819 fdrop(*fpp, td); 2820 } 2821 2822 /* 2823 * If requested, convert capability rights to access flags. 2824 */ 2825 if (maxprotp != NULL) 2826 *maxprotp = cap_rights_to_vmprot(&fdrights); 2827 #endif 2828 return (error); 2829 } 2830 2831 int 2832 fget_read(struct thread *td, int fd, cap_rights_t *rightsp, struct file **fpp) 2833 { 2834 2835 return (_fget(td, fd, fpp, FREAD, rightsp, NULL)); 2836 } 2837 2838 int 2839 fget_write(struct thread *td, int fd, cap_rights_t *rightsp, struct file **fpp) 2840 { 2841 2842 return (_fget(td, fd, fpp, FWRITE, rightsp, NULL)); 2843 } 2844 2845 int 2846 fget_fcntl(struct thread *td, int fd, cap_rights_t *rightsp, int needfcntl, 2847 struct file **fpp) 2848 { 2849 struct filedesc *fdp = td->td_proc->p_fd; 2850 #ifndef CAPABILITIES 2851 return (fget_unlocked(fdp, fd, rightsp, fpp, NULL)); 2852 #else 2853 int error; 2854 seqc_t seq; 2855 2856 MPASS(cap_rights_is_set(rightsp, CAP_FCNTL)); 2857 for (;;) { 2858 error = fget_unlocked(fdp, fd, rightsp, fpp, &seq); 2859 if (error != 0) 2860 return (error); 2861 error = cap_fcntl_check(fdp, fd, needfcntl); 2862 if (!fd_modified(fdp, fd, seq)) 2863 break; 2864 fdrop(*fpp, td); 2865 } 2866 if (error != 0) { 2867 fdrop(*fpp, td); 2868 *fpp = NULL; 2869 } 2870 return (error); 2871 #endif 2872 } 2873 2874 /* 2875 * Like fget() but loads the underlying vnode, or returns an error if the 2876 * descriptor does not represent a vnode. Note that pipes use vnodes but 2877 * never have VM objects. The returned vnode will be vref()'d. 2878 * 2879 * XXX: what about the unused flags ? 2880 */ 2881 static __inline int 2882 _fgetvp(struct thread *td, int fd, int flags, cap_rights_t *needrightsp, 2883 struct vnode **vpp) 2884 { 2885 struct file *fp; 2886 int error; 2887 2888 *vpp = NULL; 2889 error = _fget(td, fd, &fp, flags, needrightsp, NULL); 2890 if (error != 0) 2891 return (error); 2892 if (fp->f_vnode == NULL) { 2893 error = EINVAL; 2894 } else { 2895 *vpp = fp->f_vnode; 2896 vrefact(*vpp); 2897 } 2898 fdrop(fp, td); 2899 2900 return (error); 2901 } 2902 2903 int 2904 fgetvp(struct thread *td, int fd, cap_rights_t *rightsp, struct vnode **vpp) 2905 { 2906 2907 return (_fgetvp(td, fd, 0, rightsp, vpp)); 2908 } 2909 2910 int 2911 fgetvp_rights(struct thread *td, int fd, cap_rights_t *needrightsp, 2912 struct filecaps *havecaps, struct vnode **vpp) 2913 { 2914 struct filedesc *fdp; 2915 struct filecaps caps; 2916 struct file *fp; 2917 int error; 2918 2919 fdp = td->td_proc->p_fd; 2920 error = fget_cap_locked(fdp, fd, needrightsp, &fp, &caps); 2921 if (error != 0) 2922 return (error); 2923 if (fp->f_ops == &badfileops) { 2924 error = EBADF; 2925 goto out; 2926 } 2927 if (fp->f_vnode == NULL) { 2928 error = EINVAL; 2929 goto out; 2930 } 2931 2932 *havecaps = caps; 2933 *vpp = fp->f_vnode; 2934 vrefact(*vpp); 2935 2936 return (0); 2937 out: 2938 filecaps_free(&caps); 2939 return (error); 2940 } 2941 2942 int 2943 fgetvp_read(struct thread *td, int fd, cap_rights_t *rightsp, struct vnode **vpp) 2944 { 2945 2946 return (_fgetvp(td, fd, FREAD, rightsp, vpp)); 2947 } 2948 2949 int 2950 fgetvp_exec(struct thread *td, int fd, cap_rights_t *rightsp, struct vnode **vpp) 2951 { 2952 2953 return (_fgetvp(td, fd, FEXEC, rightsp, vpp)); 2954 } 2955 2956 #ifdef notyet 2957 int 2958 fgetvp_write(struct thread *td, int fd, cap_rights_t *rightsp, 2959 struct vnode **vpp) 2960 { 2961 2962 return (_fgetvp(td, fd, FWRITE, rightsp, vpp)); 2963 } 2964 #endif 2965 2966 /* 2967 * Handle the last reference to a file being closed. 2968 * 2969 * Without the noinline attribute clang keeps inlining the func thorough this 2970 * file when fdrop is used. 2971 */ 2972 int __noinline 2973 _fdrop(struct file *fp, struct thread *td) 2974 { 2975 int error; 2976 2977 if (fp->f_count != 0) 2978 panic("fdrop: count %d", fp->f_count); 2979 error = fo_close(fp, td); 2980 atomic_subtract_int(&openfiles, 1); 2981 crfree(fp->f_cred); 2982 free(fp->f_advice, M_FADVISE); 2983 uma_zfree(file_zone, fp); 2984 2985 return (error); 2986 } 2987 2988 /* 2989 * Apply an advisory lock on a file descriptor. 2990 * 2991 * Just attempt to get a record lock of the requested type on the entire file 2992 * (l_whence = SEEK_SET, l_start = 0, l_len = 0). 2993 */ 2994 #ifndef _SYS_SYSPROTO_H_ 2995 struct flock_args { 2996 int fd; 2997 int how; 2998 }; 2999 #endif 3000 /* ARGSUSED */ 3001 int 3002 sys_flock(struct thread *td, struct flock_args *uap) 3003 { 3004 struct file *fp; 3005 struct vnode *vp; 3006 struct flock lf; 3007 int error; 3008 3009 error = fget(td, uap->fd, &cap_flock_rights, &fp); 3010 if (error != 0) 3011 return (error); 3012 if (fp->f_type != DTYPE_VNODE) { 3013 fdrop(fp, td); 3014 return (EOPNOTSUPP); 3015 } 3016 3017 vp = fp->f_vnode; 3018 lf.l_whence = SEEK_SET; 3019 lf.l_start = 0; 3020 lf.l_len = 0; 3021 if (uap->how & LOCK_UN) { 3022 lf.l_type = F_UNLCK; 3023 atomic_clear_int(&fp->f_flag, FHASLOCK); 3024 error = VOP_ADVLOCK(vp, (caddr_t)fp, F_UNLCK, &lf, F_FLOCK); 3025 goto done2; 3026 } 3027 if (uap->how & LOCK_EX) 3028 lf.l_type = F_WRLCK; 3029 else if (uap->how & LOCK_SH) 3030 lf.l_type = F_RDLCK; 3031 else { 3032 error = EBADF; 3033 goto done2; 3034 } 3035 atomic_set_int(&fp->f_flag, FHASLOCK); 3036 error = VOP_ADVLOCK(vp, (caddr_t)fp, F_SETLK, &lf, 3037 (uap->how & LOCK_NB) ? F_FLOCK : F_FLOCK | F_WAIT); 3038 done2: 3039 fdrop(fp, td); 3040 return (error); 3041 } 3042 /* 3043 * Duplicate the specified descriptor to a free descriptor. 3044 */ 3045 int 3046 dupfdopen(struct thread *td, struct filedesc *fdp, int dfd, int mode, 3047 int openerror, int *indxp) 3048 { 3049 struct filedescent *newfde, *oldfde; 3050 struct file *fp; 3051 u_long *ioctls; 3052 int error, indx; 3053 3054 KASSERT(openerror == ENODEV || openerror == ENXIO, 3055 ("unexpected error %d in %s", openerror, __func__)); 3056 3057 /* 3058 * If the to-be-dup'd fd number is greater than the allowed number 3059 * of file descriptors, or the fd to be dup'd has already been 3060 * closed, then reject. 3061 */ 3062 FILEDESC_XLOCK(fdp); 3063 if ((fp = fget_locked(fdp, dfd)) == NULL) { 3064 FILEDESC_XUNLOCK(fdp); 3065 return (EBADF); 3066 } 3067 3068 error = fdalloc(td, 0, &indx); 3069 if (error != 0) { 3070 FILEDESC_XUNLOCK(fdp); 3071 return (error); 3072 } 3073 3074 /* 3075 * There are two cases of interest here. 3076 * 3077 * For ENODEV simply dup (dfd) to file descriptor (indx) and return. 3078 * 3079 * For ENXIO steal away the file structure from (dfd) and store it in 3080 * (indx). (dfd) is effectively closed by this operation. 3081 */ 3082 switch (openerror) { 3083 case ENODEV: 3084 /* 3085 * Check that the mode the file is being opened for is a 3086 * subset of the mode of the existing descriptor. 3087 */ 3088 if (((mode & (FREAD|FWRITE)) | fp->f_flag) != fp->f_flag) { 3089 fdunused(fdp, indx); 3090 FILEDESC_XUNLOCK(fdp); 3091 return (EACCES); 3092 } 3093 if (!fhold(fp)) { 3094 fdunused(fdp, indx); 3095 FILEDESC_XUNLOCK(fdp); 3096 return (EBADF); 3097 } 3098 newfde = &fdp->fd_ofiles[indx]; 3099 oldfde = &fdp->fd_ofiles[dfd]; 3100 ioctls = filecaps_copy_prep(&oldfde->fde_caps); 3101 #ifdef CAPABILITIES 3102 seqc_write_begin(&newfde->fde_seqc); 3103 #endif 3104 memcpy(newfde, oldfde, fde_change_size); 3105 filecaps_copy_finish(&oldfde->fde_caps, &newfde->fde_caps, 3106 ioctls); 3107 #ifdef CAPABILITIES 3108 seqc_write_end(&newfde->fde_seqc); 3109 #endif 3110 break; 3111 case ENXIO: 3112 /* 3113 * Steal away the file pointer from dfd and stuff it into indx. 3114 */ 3115 newfde = &fdp->fd_ofiles[indx]; 3116 oldfde = &fdp->fd_ofiles[dfd]; 3117 #ifdef CAPABILITIES 3118 seqc_write_begin(&newfde->fde_seqc); 3119 #endif 3120 memcpy(newfde, oldfde, fde_change_size); 3121 oldfde->fde_file = NULL; 3122 fdunused(fdp, dfd); 3123 #ifdef CAPABILITIES 3124 seqc_write_end(&newfde->fde_seqc); 3125 #endif 3126 break; 3127 } 3128 FILEDESC_XUNLOCK(fdp); 3129 *indxp = indx; 3130 return (0); 3131 } 3132 3133 /* 3134 * This sysctl determines if we will allow a process to chroot(2) if it 3135 * has a directory open: 3136 * 0: disallowed for all processes. 3137 * 1: allowed for processes that were not already chroot(2)'ed. 3138 * 2: allowed for all processes. 3139 */ 3140 3141 static int chroot_allow_open_directories = 1; 3142 3143 SYSCTL_INT(_kern, OID_AUTO, chroot_allow_open_directories, CTLFLAG_RW, 3144 &chroot_allow_open_directories, 0, 3145 "Allow a process to chroot(2) if it has a directory open"); 3146 3147 /* 3148 * Helper function for raised chroot(2) security function: Refuse if 3149 * any filedescriptors are open directories. 3150 */ 3151 static int 3152 chroot_refuse_vdir_fds(struct filedesc *fdp) 3153 { 3154 struct vnode *vp; 3155 struct file *fp; 3156 int fd; 3157 3158 FILEDESC_LOCK_ASSERT(fdp); 3159 3160 for (fd = 0; fd <= fdp->fd_lastfile; fd++) { 3161 fp = fget_locked(fdp, fd); 3162 if (fp == NULL) 3163 continue; 3164 if (fp->f_type == DTYPE_VNODE) { 3165 vp = fp->f_vnode; 3166 if (vp->v_type == VDIR) 3167 return (EPERM); 3168 } 3169 } 3170 return (0); 3171 } 3172 3173 /* 3174 * Common routine for kern_chroot() and jail_attach(). The caller is 3175 * responsible for invoking priv_check() and mac_vnode_check_chroot() to 3176 * authorize this operation. 3177 */ 3178 int 3179 pwd_chroot(struct thread *td, struct vnode *vp) 3180 { 3181 struct filedesc *fdp; 3182 struct vnode *oldvp; 3183 int error; 3184 3185 fdp = td->td_proc->p_fd; 3186 FILEDESC_XLOCK(fdp); 3187 if (chroot_allow_open_directories == 0 || 3188 (chroot_allow_open_directories == 1 && fdp->fd_rdir != rootvnode)) { 3189 error = chroot_refuse_vdir_fds(fdp); 3190 if (error != 0) { 3191 FILEDESC_XUNLOCK(fdp); 3192 return (error); 3193 } 3194 } 3195 oldvp = fdp->fd_rdir; 3196 vrefact(vp); 3197 fdp->fd_rdir = vp; 3198 if (fdp->fd_jdir == NULL) { 3199 vrefact(vp); 3200 fdp->fd_jdir = vp; 3201 } 3202 FILEDESC_XUNLOCK(fdp); 3203 vrele(oldvp); 3204 return (0); 3205 } 3206 3207 void 3208 pwd_chdir(struct thread *td, struct vnode *vp) 3209 { 3210 struct filedesc *fdp; 3211 struct vnode *oldvp; 3212 3213 fdp = td->td_proc->p_fd; 3214 FILEDESC_XLOCK(fdp); 3215 VNASSERT(vp->v_usecount > 0, vp, 3216 ("chdir to a vnode with zero usecount")); 3217 oldvp = fdp->fd_cdir; 3218 fdp->fd_cdir = vp; 3219 FILEDESC_XUNLOCK(fdp); 3220 vrele(oldvp); 3221 } 3222 3223 /* 3224 * Scan all active processes and prisons to see if any of them have a current 3225 * or root directory of `olddp'. If so, replace them with the new mount point. 3226 */ 3227 void 3228 mountcheckdirs(struct vnode *olddp, struct vnode *newdp) 3229 { 3230 struct filedesc *fdp; 3231 struct prison *pr; 3232 struct proc *p; 3233 int nrele; 3234 3235 if (vrefcnt(olddp) == 1) 3236 return; 3237 nrele = 0; 3238 sx_slock(&allproc_lock); 3239 FOREACH_PROC_IN_SYSTEM(p) { 3240 PROC_LOCK(p); 3241 fdp = fdhold(p); 3242 PROC_UNLOCK(p); 3243 if (fdp == NULL) 3244 continue; 3245 FILEDESC_XLOCK(fdp); 3246 if (fdp->fd_cdir == olddp) { 3247 vrefact(newdp); 3248 fdp->fd_cdir = newdp; 3249 nrele++; 3250 } 3251 if (fdp->fd_rdir == olddp) { 3252 vrefact(newdp); 3253 fdp->fd_rdir = newdp; 3254 nrele++; 3255 } 3256 if (fdp->fd_jdir == olddp) { 3257 vrefact(newdp); 3258 fdp->fd_jdir = newdp; 3259 nrele++; 3260 } 3261 FILEDESC_XUNLOCK(fdp); 3262 fddrop(fdp); 3263 } 3264 sx_sunlock(&allproc_lock); 3265 if (rootvnode == olddp) { 3266 vrefact(newdp); 3267 rootvnode = newdp; 3268 nrele++; 3269 } 3270 mtx_lock(&prison0.pr_mtx); 3271 if (prison0.pr_root == olddp) { 3272 vrefact(newdp); 3273 prison0.pr_root = newdp; 3274 nrele++; 3275 } 3276 mtx_unlock(&prison0.pr_mtx); 3277 sx_slock(&allprison_lock); 3278 TAILQ_FOREACH(pr, &allprison, pr_list) { 3279 mtx_lock(&pr->pr_mtx); 3280 if (pr->pr_root == olddp) { 3281 vrefact(newdp); 3282 pr->pr_root = newdp; 3283 nrele++; 3284 } 3285 mtx_unlock(&pr->pr_mtx); 3286 } 3287 sx_sunlock(&allprison_lock); 3288 while (nrele--) 3289 vrele(olddp); 3290 } 3291 3292 struct filedesc_to_leader * 3293 filedesc_to_leader_alloc(struct filedesc_to_leader *old, struct filedesc *fdp, struct proc *leader) 3294 { 3295 struct filedesc_to_leader *fdtol; 3296 3297 fdtol = malloc(sizeof(struct filedesc_to_leader), 3298 M_FILEDESC_TO_LEADER, M_WAITOK); 3299 fdtol->fdl_refcount = 1; 3300 fdtol->fdl_holdcount = 0; 3301 fdtol->fdl_wakeup = 0; 3302 fdtol->fdl_leader = leader; 3303 if (old != NULL) { 3304 FILEDESC_XLOCK(fdp); 3305 fdtol->fdl_next = old->fdl_next; 3306 fdtol->fdl_prev = old; 3307 old->fdl_next = fdtol; 3308 fdtol->fdl_next->fdl_prev = fdtol; 3309 FILEDESC_XUNLOCK(fdp); 3310 } else { 3311 fdtol->fdl_next = fdtol; 3312 fdtol->fdl_prev = fdtol; 3313 } 3314 return (fdtol); 3315 } 3316 3317 static int 3318 sysctl_kern_proc_nfds(SYSCTL_HANDLER_ARGS) 3319 { 3320 struct filedesc *fdp; 3321 int i, count, slots; 3322 3323 if (*(int *)arg1 != 0) 3324 return (EINVAL); 3325 3326 fdp = curproc->p_fd; 3327 count = 0; 3328 FILEDESC_SLOCK(fdp); 3329 slots = NDSLOTS(fdp->fd_lastfile + 1); 3330 for (i = 0; i < slots; i++) 3331 count += bitcountl(fdp->fd_map[i]); 3332 FILEDESC_SUNLOCK(fdp); 3333 3334 return (SYSCTL_OUT(req, &count, sizeof(count))); 3335 } 3336 3337 static SYSCTL_NODE(_kern_proc, KERN_PROC_NFDS, nfds, 3338 CTLFLAG_RD|CTLFLAG_CAPRD|CTLFLAG_MPSAFE, sysctl_kern_proc_nfds, 3339 "Number of open file descriptors"); 3340 3341 /* 3342 * Get file structures globally. 3343 */ 3344 static int 3345 sysctl_kern_file(SYSCTL_HANDLER_ARGS) 3346 { 3347 struct xfile xf; 3348 struct filedesc *fdp; 3349 struct file *fp; 3350 struct proc *p; 3351 int error, n; 3352 3353 error = sysctl_wire_old_buffer(req, 0); 3354 if (error != 0) 3355 return (error); 3356 if (req->oldptr == NULL) { 3357 n = 0; 3358 sx_slock(&allproc_lock); 3359 FOREACH_PROC_IN_SYSTEM(p) { 3360 PROC_LOCK(p); 3361 if (p->p_state == PRS_NEW) { 3362 PROC_UNLOCK(p); 3363 continue; 3364 } 3365 fdp = fdhold(p); 3366 PROC_UNLOCK(p); 3367 if (fdp == NULL) 3368 continue; 3369 /* overestimates sparse tables. */ 3370 if (fdp->fd_lastfile > 0) 3371 n += fdp->fd_lastfile; 3372 fddrop(fdp); 3373 } 3374 sx_sunlock(&allproc_lock); 3375 return (SYSCTL_OUT(req, 0, n * sizeof(xf))); 3376 } 3377 error = 0; 3378 bzero(&xf, sizeof(xf)); 3379 xf.xf_size = sizeof(xf); 3380 sx_slock(&allproc_lock); 3381 FOREACH_PROC_IN_SYSTEM(p) { 3382 PROC_LOCK(p); 3383 if (p->p_state == PRS_NEW) { 3384 PROC_UNLOCK(p); 3385 continue; 3386 } 3387 if (p_cansee(req->td, p) != 0) { 3388 PROC_UNLOCK(p); 3389 continue; 3390 } 3391 xf.xf_pid = p->p_pid; 3392 xf.xf_uid = p->p_ucred->cr_uid; 3393 fdp = fdhold(p); 3394 PROC_UNLOCK(p); 3395 if (fdp == NULL) 3396 continue; 3397 FILEDESC_SLOCK(fdp); 3398 for (n = 0; fdp->fd_refcnt > 0 && n <= fdp->fd_lastfile; ++n) { 3399 if ((fp = fdp->fd_ofiles[n].fde_file) == NULL) 3400 continue; 3401 xf.xf_fd = n; 3402 xf.xf_file = (uintptr_t)fp; 3403 xf.xf_data = (uintptr_t)fp->f_data; 3404 xf.xf_vnode = (uintptr_t)fp->f_vnode; 3405 xf.xf_type = (uintptr_t)fp->f_type; 3406 xf.xf_count = fp->f_count; 3407 xf.xf_msgcount = 0; 3408 xf.xf_offset = foffset_get(fp); 3409 xf.xf_flag = fp->f_flag; 3410 error = SYSCTL_OUT(req, &xf, sizeof(xf)); 3411 if (error) 3412 break; 3413 } 3414 FILEDESC_SUNLOCK(fdp); 3415 fddrop(fdp); 3416 if (error) 3417 break; 3418 } 3419 sx_sunlock(&allproc_lock); 3420 return (error); 3421 } 3422 3423 SYSCTL_PROC(_kern, KERN_FILE, file, CTLTYPE_OPAQUE|CTLFLAG_RD|CTLFLAG_MPSAFE, 3424 0, 0, sysctl_kern_file, "S,xfile", "Entire file table"); 3425 3426 #ifdef KINFO_FILE_SIZE 3427 CTASSERT(sizeof(struct kinfo_file) == KINFO_FILE_SIZE); 3428 #endif 3429 3430 static int 3431 xlate_fflags(int fflags) 3432 { 3433 static const struct { 3434 int fflag; 3435 int kf_fflag; 3436 } fflags_table[] = { 3437 { FAPPEND, KF_FLAG_APPEND }, 3438 { FASYNC, KF_FLAG_ASYNC }, 3439 { FFSYNC, KF_FLAG_FSYNC }, 3440 { FHASLOCK, KF_FLAG_HASLOCK }, 3441 { FNONBLOCK, KF_FLAG_NONBLOCK }, 3442 { FREAD, KF_FLAG_READ }, 3443 { FWRITE, KF_FLAG_WRITE }, 3444 { O_CREAT, KF_FLAG_CREAT }, 3445 { O_DIRECT, KF_FLAG_DIRECT }, 3446 { O_EXCL, KF_FLAG_EXCL }, 3447 { O_EXEC, KF_FLAG_EXEC }, 3448 { O_EXLOCK, KF_FLAG_EXLOCK }, 3449 { O_NOFOLLOW, KF_FLAG_NOFOLLOW }, 3450 { O_SHLOCK, KF_FLAG_SHLOCK }, 3451 { O_TRUNC, KF_FLAG_TRUNC } 3452 }; 3453 unsigned int i; 3454 int kflags; 3455 3456 kflags = 0; 3457 for (i = 0; i < nitems(fflags_table); i++) 3458 if (fflags & fflags_table[i].fflag) 3459 kflags |= fflags_table[i].kf_fflag; 3460 return (kflags); 3461 } 3462 3463 /* Trim unused data from kf_path by truncating the structure size. */ 3464 void 3465 pack_kinfo(struct kinfo_file *kif) 3466 { 3467 3468 kif->kf_structsize = offsetof(struct kinfo_file, kf_path) + 3469 strlen(kif->kf_path) + 1; 3470 kif->kf_structsize = roundup(kif->kf_structsize, sizeof(uint64_t)); 3471 } 3472 3473 static void 3474 export_file_to_kinfo(struct file *fp, int fd, cap_rights_t *rightsp, 3475 struct kinfo_file *kif, struct filedesc *fdp, int flags) 3476 { 3477 int error; 3478 3479 bzero(kif, sizeof(*kif)); 3480 3481 /* Set a default type to allow for empty fill_kinfo() methods. */ 3482 kif->kf_type = KF_TYPE_UNKNOWN; 3483 kif->kf_flags = xlate_fflags(fp->f_flag); 3484 if (rightsp != NULL) 3485 kif->kf_cap_rights = *rightsp; 3486 else 3487 cap_rights_init(&kif->kf_cap_rights); 3488 kif->kf_fd = fd; 3489 kif->kf_ref_count = fp->f_count; 3490 kif->kf_offset = foffset_get(fp); 3491 3492 /* 3493 * This may drop the filedesc lock, so the 'fp' cannot be 3494 * accessed after this call. 3495 */ 3496 error = fo_fill_kinfo(fp, kif, fdp); 3497 if (error == 0) 3498 kif->kf_status |= KF_ATTR_VALID; 3499 if ((flags & KERN_FILEDESC_PACK_KINFO) != 0) 3500 pack_kinfo(kif); 3501 else 3502 kif->kf_structsize = roundup2(sizeof(*kif), sizeof(uint64_t)); 3503 } 3504 3505 static void 3506 export_vnode_to_kinfo(struct vnode *vp, int fd, int fflags, 3507 struct kinfo_file *kif, int flags) 3508 { 3509 int error; 3510 3511 bzero(kif, sizeof(*kif)); 3512 3513 kif->kf_type = KF_TYPE_VNODE; 3514 error = vn_fill_kinfo_vnode(vp, kif); 3515 if (error == 0) 3516 kif->kf_status |= KF_ATTR_VALID; 3517 kif->kf_flags = xlate_fflags(fflags); 3518 cap_rights_init(&kif->kf_cap_rights); 3519 kif->kf_fd = fd; 3520 kif->kf_ref_count = -1; 3521 kif->kf_offset = -1; 3522 if ((flags & KERN_FILEDESC_PACK_KINFO) != 0) 3523 pack_kinfo(kif); 3524 else 3525 kif->kf_structsize = roundup2(sizeof(*kif), sizeof(uint64_t)); 3526 vrele(vp); 3527 } 3528 3529 struct export_fd_buf { 3530 struct filedesc *fdp; 3531 struct sbuf *sb; 3532 ssize_t remainder; 3533 struct kinfo_file kif; 3534 int flags; 3535 }; 3536 3537 static int 3538 export_kinfo_to_sb(struct export_fd_buf *efbuf) 3539 { 3540 struct kinfo_file *kif; 3541 3542 kif = &efbuf->kif; 3543 if (efbuf->remainder != -1) { 3544 if (efbuf->remainder < kif->kf_structsize) { 3545 /* Terminate export. */ 3546 efbuf->remainder = 0; 3547 return (0); 3548 } 3549 efbuf->remainder -= kif->kf_structsize; 3550 } 3551 return (sbuf_bcat(efbuf->sb, kif, kif->kf_structsize) == 0 ? 0 : ENOMEM); 3552 } 3553 3554 static int 3555 export_file_to_sb(struct file *fp, int fd, cap_rights_t *rightsp, 3556 struct export_fd_buf *efbuf) 3557 { 3558 int error; 3559 3560 if (efbuf->remainder == 0) 3561 return (0); 3562 export_file_to_kinfo(fp, fd, rightsp, &efbuf->kif, efbuf->fdp, 3563 efbuf->flags); 3564 FILEDESC_SUNLOCK(efbuf->fdp); 3565 error = export_kinfo_to_sb(efbuf); 3566 FILEDESC_SLOCK(efbuf->fdp); 3567 return (error); 3568 } 3569 3570 static int 3571 export_vnode_to_sb(struct vnode *vp, int fd, int fflags, 3572 struct export_fd_buf *efbuf) 3573 { 3574 int error; 3575 3576 if (efbuf->remainder == 0) 3577 return (0); 3578 if (efbuf->fdp != NULL) 3579 FILEDESC_SUNLOCK(efbuf->fdp); 3580 export_vnode_to_kinfo(vp, fd, fflags, &efbuf->kif, efbuf->flags); 3581 error = export_kinfo_to_sb(efbuf); 3582 if (efbuf->fdp != NULL) 3583 FILEDESC_SLOCK(efbuf->fdp); 3584 return (error); 3585 } 3586 3587 /* 3588 * Store a process file descriptor information to sbuf. 3589 * 3590 * Takes a locked proc as argument, and returns with the proc unlocked. 3591 */ 3592 int 3593 kern_proc_filedesc_out(struct proc *p, struct sbuf *sb, ssize_t maxlen, 3594 int flags) 3595 { 3596 struct file *fp; 3597 struct filedesc *fdp; 3598 struct export_fd_buf *efbuf; 3599 struct vnode *cttyvp, *textvp, *tracevp; 3600 int error, i; 3601 cap_rights_t rights; 3602 3603 PROC_LOCK_ASSERT(p, MA_OWNED); 3604 3605 /* ktrace vnode */ 3606 tracevp = p->p_tracevp; 3607 if (tracevp != NULL) 3608 vrefact(tracevp); 3609 /* text vnode */ 3610 textvp = p->p_textvp; 3611 if (textvp != NULL) 3612 vrefact(textvp); 3613 /* Controlling tty. */ 3614 cttyvp = NULL; 3615 if (p->p_pgrp != NULL && p->p_pgrp->pg_session != NULL) { 3616 cttyvp = p->p_pgrp->pg_session->s_ttyvp; 3617 if (cttyvp != NULL) 3618 vrefact(cttyvp); 3619 } 3620 fdp = fdhold(p); 3621 PROC_UNLOCK(p); 3622 efbuf = malloc(sizeof(*efbuf), M_TEMP, M_WAITOK); 3623 efbuf->fdp = NULL; 3624 efbuf->sb = sb; 3625 efbuf->remainder = maxlen; 3626 efbuf->flags = flags; 3627 if (tracevp != NULL) 3628 export_vnode_to_sb(tracevp, KF_FD_TYPE_TRACE, FREAD | FWRITE, 3629 efbuf); 3630 if (textvp != NULL) 3631 export_vnode_to_sb(textvp, KF_FD_TYPE_TEXT, FREAD, efbuf); 3632 if (cttyvp != NULL) 3633 export_vnode_to_sb(cttyvp, KF_FD_TYPE_CTTY, FREAD | FWRITE, 3634 efbuf); 3635 error = 0; 3636 if (fdp == NULL) 3637 goto fail; 3638 efbuf->fdp = fdp; 3639 FILEDESC_SLOCK(fdp); 3640 /* working directory */ 3641 if (fdp->fd_cdir != NULL) { 3642 vrefact(fdp->fd_cdir); 3643 export_vnode_to_sb(fdp->fd_cdir, KF_FD_TYPE_CWD, FREAD, efbuf); 3644 } 3645 /* root directory */ 3646 if (fdp->fd_rdir != NULL) { 3647 vrefact(fdp->fd_rdir); 3648 export_vnode_to_sb(fdp->fd_rdir, KF_FD_TYPE_ROOT, FREAD, efbuf); 3649 } 3650 /* jail directory */ 3651 if (fdp->fd_jdir != NULL) { 3652 vrefact(fdp->fd_jdir); 3653 export_vnode_to_sb(fdp->fd_jdir, KF_FD_TYPE_JAIL, FREAD, efbuf); 3654 } 3655 for (i = 0; fdp->fd_refcnt > 0 && i <= fdp->fd_lastfile; i++) { 3656 if ((fp = fdp->fd_ofiles[i].fde_file) == NULL) 3657 continue; 3658 #ifdef CAPABILITIES 3659 rights = *cap_rights(fdp, i); 3660 #else /* !CAPABILITIES */ 3661 rights = cap_no_rights; 3662 #endif 3663 /* 3664 * Create sysctl entry. It is OK to drop the filedesc 3665 * lock inside of export_file_to_sb() as we will 3666 * re-validate and re-evaluate its properties when the 3667 * loop continues. 3668 */ 3669 error = export_file_to_sb(fp, i, &rights, efbuf); 3670 if (error != 0 || efbuf->remainder == 0) 3671 break; 3672 } 3673 FILEDESC_SUNLOCK(fdp); 3674 fddrop(fdp); 3675 fail: 3676 free(efbuf, M_TEMP); 3677 return (error); 3678 } 3679 3680 #define FILEDESC_SBUF_SIZE (sizeof(struct kinfo_file) * 5) 3681 3682 /* 3683 * Get per-process file descriptors for use by procstat(1), et al. 3684 */ 3685 static int 3686 sysctl_kern_proc_filedesc(SYSCTL_HANDLER_ARGS) 3687 { 3688 struct sbuf sb; 3689 struct proc *p; 3690 ssize_t maxlen; 3691 int error, error2, *name; 3692 3693 name = (int *)arg1; 3694 3695 sbuf_new_for_sysctl(&sb, NULL, FILEDESC_SBUF_SIZE, req); 3696 sbuf_clear_flags(&sb, SBUF_INCLUDENUL); 3697 error = pget((pid_t)name[0], PGET_CANDEBUG | PGET_NOTWEXIT, &p); 3698 if (error != 0) { 3699 sbuf_delete(&sb); 3700 return (error); 3701 } 3702 maxlen = req->oldptr != NULL ? req->oldlen : -1; 3703 error = kern_proc_filedesc_out(p, &sb, maxlen, 3704 KERN_FILEDESC_PACK_KINFO); 3705 error2 = sbuf_finish(&sb); 3706 sbuf_delete(&sb); 3707 return (error != 0 ? error : error2); 3708 } 3709 3710 #ifdef COMPAT_FREEBSD7 3711 #ifdef KINFO_OFILE_SIZE 3712 CTASSERT(sizeof(struct kinfo_ofile) == KINFO_OFILE_SIZE); 3713 #endif 3714 3715 static void 3716 kinfo_to_okinfo(struct kinfo_file *kif, struct kinfo_ofile *okif) 3717 { 3718 3719 okif->kf_structsize = sizeof(*okif); 3720 okif->kf_type = kif->kf_type; 3721 okif->kf_fd = kif->kf_fd; 3722 okif->kf_ref_count = kif->kf_ref_count; 3723 okif->kf_flags = kif->kf_flags & (KF_FLAG_READ | KF_FLAG_WRITE | 3724 KF_FLAG_APPEND | KF_FLAG_ASYNC | KF_FLAG_FSYNC | KF_FLAG_NONBLOCK | 3725 KF_FLAG_DIRECT | KF_FLAG_HASLOCK); 3726 okif->kf_offset = kif->kf_offset; 3727 if (kif->kf_type == KF_TYPE_VNODE) 3728 okif->kf_vnode_type = kif->kf_un.kf_file.kf_file_type; 3729 else 3730 okif->kf_vnode_type = KF_VTYPE_VNON; 3731 strlcpy(okif->kf_path, kif->kf_path, sizeof(okif->kf_path)); 3732 if (kif->kf_type == KF_TYPE_SOCKET) { 3733 okif->kf_sock_domain = kif->kf_un.kf_sock.kf_sock_domain0; 3734 okif->kf_sock_type = kif->kf_un.kf_sock.kf_sock_type0; 3735 okif->kf_sock_protocol = kif->kf_un.kf_sock.kf_sock_protocol0; 3736 okif->kf_sa_local = kif->kf_un.kf_sock.kf_sa_local; 3737 okif->kf_sa_peer = kif->kf_un.kf_sock.kf_sa_peer; 3738 } else { 3739 okif->kf_sa_local.ss_family = AF_UNSPEC; 3740 okif->kf_sa_peer.ss_family = AF_UNSPEC; 3741 } 3742 } 3743 3744 static int 3745 export_vnode_for_osysctl(struct vnode *vp, int type, struct kinfo_file *kif, 3746 struct kinfo_ofile *okif, struct filedesc *fdp, struct sysctl_req *req) 3747 { 3748 int error; 3749 3750 vrefact(vp); 3751 FILEDESC_SUNLOCK(fdp); 3752 export_vnode_to_kinfo(vp, type, 0, kif, KERN_FILEDESC_PACK_KINFO); 3753 kinfo_to_okinfo(kif, okif); 3754 error = SYSCTL_OUT(req, okif, sizeof(*okif)); 3755 FILEDESC_SLOCK(fdp); 3756 return (error); 3757 } 3758 3759 /* 3760 * Get per-process file descriptors for use by procstat(1), et al. 3761 */ 3762 static int 3763 sysctl_kern_proc_ofiledesc(SYSCTL_HANDLER_ARGS) 3764 { 3765 struct kinfo_ofile *okif; 3766 struct kinfo_file *kif; 3767 struct filedesc *fdp; 3768 int error, i, *name; 3769 struct file *fp; 3770 struct proc *p; 3771 3772 name = (int *)arg1; 3773 error = pget((pid_t)name[0], PGET_CANDEBUG | PGET_NOTWEXIT, &p); 3774 if (error != 0) 3775 return (error); 3776 fdp = fdhold(p); 3777 PROC_UNLOCK(p); 3778 if (fdp == NULL) 3779 return (ENOENT); 3780 kif = malloc(sizeof(*kif), M_TEMP, M_WAITOK); 3781 okif = malloc(sizeof(*okif), M_TEMP, M_WAITOK); 3782 FILEDESC_SLOCK(fdp); 3783 if (fdp->fd_cdir != NULL) 3784 export_vnode_for_osysctl(fdp->fd_cdir, KF_FD_TYPE_CWD, kif, 3785 okif, fdp, req); 3786 if (fdp->fd_rdir != NULL) 3787 export_vnode_for_osysctl(fdp->fd_rdir, KF_FD_TYPE_ROOT, kif, 3788 okif, fdp, req); 3789 if (fdp->fd_jdir != NULL) 3790 export_vnode_for_osysctl(fdp->fd_jdir, KF_FD_TYPE_JAIL, kif, 3791 okif, fdp, req); 3792 for (i = 0; fdp->fd_refcnt > 0 && i <= fdp->fd_lastfile; i++) { 3793 if ((fp = fdp->fd_ofiles[i].fde_file) == NULL) 3794 continue; 3795 export_file_to_kinfo(fp, i, NULL, kif, fdp, 3796 KERN_FILEDESC_PACK_KINFO); 3797 FILEDESC_SUNLOCK(fdp); 3798 kinfo_to_okinfo(kif, okif); 3799 error = SYSCTL_OUT(req, okif, sizeof(*okif)); 3800 FILEDESC_SLOCK(fdp); 3801 if (error) 3802 break; 3803 } 3804 FILEDESC_SUNLOCK(fdp); 3805 fddrop(fdp); 3806 free(kif, M_TEMP); 3807 free(okif, M_TEMP); 3808 return (0); 3809 } 3810 3811 static SYSCTL_NODE(_kern_proc, KERN_PROC_OFILEDESC, ofiledesc, 3812 CTLFLAG_RD|CTLFLAG_MPSAFE, sysctl_kern_proc_ofiledesc, 3813 "Process ofiledesc entries"); 3814 #endif /* COMPAT_FREEBSD7 */ 3815 3816 int 3817 vntype_to_kinfo(int vtype) 3818 { 3819 struct { 3820 int vtype; 3821 int kf_vtype; 3822 } vtypes_table[] = { 3823 { VBAD, KF_VTYPE_VBAD }, 3824 { VBLK, KF_VTYPE_VBLK }, 3825 { VCHR, KF_VTYPE_VCHR }, 3826 { VDIR, KF_VTYPE_VDIR }, 3827 { VFIFO, KF_VTYPE_VFIFO }, 3828 { VLNK, KF_VTYPE_VLNK }, 3829 { VNON, KF_VTYPE_VNON }, 3830 { VREG, KF_VTYPE_VREG }, 3831 { VSOCK, KF_VTYPE_VSOCK } 3832 }; 3833 unsigned int i; 3834 3835 /* 3836 * Perform vtype translation. 3837 */ 3838 for (i = 0; i < nitems(vtypes_table); i++) 3839 if (vtypes_table[i].vtype == vtype) 3840 return (vtypes_table[i].kf_vtype); 3841 3842 return (KF_VTYPE_UNKNOWN); 3843 } 3844 3845 static SYSCTL_NODE(_kern_proc, KERN_PROC_FILEDESC, filedesc, 3846 CTLFLAG_RD|CTLFLAG_MPSAFE, sysctl_kern_proc_filedesc, 3847 "Process filedesc entries"); 3848 3849 /* 3850 * Store a process current working directory information to sbuf. 3851 * 3852 * Takes a locked proc as argument, and returns with the proc unlocked. 3853 */ 3854 int 3855 kern_proc_cwd_out(struct proc *p, struct sbuf *sb, ssize_t maxlen) 3856 { 3857 struct filedesc *fdp; 3858 struct export_fd_buf *efbuf; 3859 int error; 3860 3861 PROC_LOCK_ASSERT(p, MA_OWNED); 3862 3863 fdp = fdhold(p); 3864 PROC_UNLOCK(p); 3865 if (fdp == NULL) 3866 return (EINVAL); 3867 3868 efbuf = malloc(sizeof(*efbuf), M_TEMP, M_WAITOK); 3869 efbuf->fdp = fdp; 3870 efbuf->sb = sb; 3871 efbuf->remainder = maxlen; 3872 3873 FILEDESC_SLOCK(fdp); 3874 if (fdp->fd_cdir == NULL) 3875 error = EINVAL; 3876 else { 3877 vrefact(fdp->fd_cdir); 3878 error = export_vnode_to_sb(fdp->fd_cdir, KF_FD_TYPE_CWD, 3879 FREAD, efbuf); 3880 } 3881 FILEDESC_SUNLOCK(fdp); 3882 fddrop(fdp); 3883 free(efbuf, M_TEMP); 3884 return (error); 3885 } 3886 3887 /* 3888 * Get per-process current working directory. 3889 */ 3890 static int 3891 sysctl_kern_proc_cwd(SYSCTL_HANDLER_ARGS) 3892 { 3893 struct sbuf sb; 3894 struct proc *p; 3895 ssize_t maxlen; 3896 int error, error2, *name; 3897 3898 name = (int *)arg1; 3899 3900 sbuf_new_for_sysctl(&sb, NULL, sizeof(struct kinfo_file), req); 3901 sbuf_clear_flags(&sb, SBUF_INCLUDENUL); 3902 error = pget((pid_t)name[0], PGET_CANDEBUG | PGET_NOTWEXIT, &p); 3903 if (error != 0) { 3904 sbuf_delete(&sb); 3905 return (error); 3906 } 3907 maxlen = req->oldptr != NULL ? req->oldlen : -1; 3908 error = kern_proc_cwd_out(p, &sb, maxlen); 3909 error2 = sbuf_finish(&sb); 3910 sbuf_delete(&sb); 3911 return (error != 0 ? error : error2); 3912 } 3913 3914 static SYSCTL_NODE(_kern_proc, KERN_PROC_CWD, cwd, CTLFLAG_RD|CTLFLAG_MPSAFE, 3915 sysctl_kern_proc_cwd, "Process current working directory"); 3916 3917 #ifdef DDB 3918 /* 3919 * For the purposes of debugging, generate a human-readable string for the 3920 * file type. 3921 */ 3922 static const char * 3923 file_type_to_name(short type) 3924 { 3925 3926 switch (type) { 3927 case 0: 3928 return ("zero"); 3929 case DTYPE_VNODE: 3930 return ("vnode"); 3931 case DTYPE_SOCKET: 3932 return ("socket"); 3933 case DTYPE_PIPE: 3934 return ("pipe"); 3935 case DTYPE_FIFO: 3936 return ("fifo"); 3937 case DTYPE_KQUEUE: 3938 return ("kqueue"); 3939 case DTYPE_CRYPTO: 3940 return ("crypto"); 3941 case DTYPE_MQUEUE: 3942 return ("mqueue"); 3943 case DTYPE_SHM: 3944 return ("shm"); 3945 case DTYPE_SEM: 3946 return ("ksem"); 3947 case DTYPE_PTS: 3948 return ("pts"); 3949 case DTYPE_DEV: 3950 return ("dev"); 3951 case DTYPE_PROCDESC: 3952 return ("proc"); 3953 case DTYPE_LINUXEFD: 3954 return ("levent"); 3955 case DTYPE_LINUXTFD: 3956 return ("ltimer"); 3957 default: 3958 return ("unkn"); 3959 } 3960 } 3961 3962 /* 3963 * For the purposes of debugging, identify a process (if any, perhaps one of 3964 * many) that references the passed file in its file descriptor array. Return 3965 * NULL if none. 3966 */ 3967 static struct proc * 3968 file_to_first_proc(struct file *fp) 3969 { 3970 struct filedesc *fdp; 3971 struct proc *p; 3972 int n; 3973 3974 FOREACH_PROC_IN_SYSTEM(p) { 3975 if (p->p_state == PRS_NEW) 3976 continue; 3977 fdp = p->p_fd; 3978 if (fdp == NULL) 3979 continue; 3980 for (n = 0; n <= fdp->fd_lastfile; n++) { 3981 if (fp == fdp->fd_ofiles[n].fde_file) 3982 return (p); 3983 } 3984 } 3985 return (NULL); 3986 } 3987 3988 static void 3989 db_print_file(struct file *fp, int header) 3990 { 3991 #define XPTRWIDTH ((int)howmany(sizeof(void *) * NBBY, 4)) 3992 struct proc *p; 3993 3994 if (header) 3995 db_printf("%*s %6s %*s %8s %4s %5s %6s %*s %5s %s\n", 3996 XPTRWIDTH, "File", "Type", XPTRWIDTH, "Data", "Flag", 3997 "GCFl", "Count", "MCount", XPTRWIDTH, "Vnode", "FPID", 3998 "FCmd"); 3999 p = file_to_first_proc(fp); 4000 db_printf("%*p %6s %*p %08x %04x %5d %6d %*p %5d %s\n", XPTRWIDTH, 4001 fp, file_type_to_name(fp->f_type), XPTRWIDTH, fp->f_data, 4002 fp->f_flag, 0, fp->f_count, 0, XPTRWIDTH, fp->f_vnode, 4003 p != NULL ? p->p_pid : -1, p != NULL ? p->p_comm : "-"); 4004 4005 #undef XPTRWIDTH 4006 } 4007 4008 DB_SHOW_COMMAND(file, db_show_file) 4009 { 4010 struct file *fp; 4011 4012 if (!have_addr) { 4013 db_printf("usage: show file <addr>\n"); 4014 return; 4015 } 4016 fp = (struct file *)addr; 4017 db_print_file(fp, 1); 4018 } 4019 4020 DB_SHOW_COMMAND(files, db_show_files) 4021 { 4022 struct filedesc *fdp; 4023 struct file *fp; 4024 struct proc *p; 4025 int header; 4026 int n; 4027 4028 header = 1; 4029 FOREACH_PROC_IN_SYSTEM(p) { 4030 if (p->p_state == PRS_NEW) 4031 continue; 4032 if ((fdp = p->p_fd) == NULL) 4033 continue; 4034 for (n = 0; n <= fdp->fd_lastfile; ++n) { 4035 if ((fp = fdp->fd_ofiles[n].fde_file) == NULL) 4036 continue; 4037 db_print_file(fp, header); 4038 header = 0; 4039 } 4040 } 4041 } 4042 #endif 4043 4044 SYSCTL_INT(_kern, KERN_MAXFILESPERPROC, maxfilesperproc, CTLFLAG_RW, 4045 &maxfilesperproc, 0, "Maximum files allowed open per process"); 4046 4047 SYSCTL_INT(_kern, KERN_MAXFILES, maxfiles, CTLFLAG_RW, 4048 &maxfiles, 0, "Maximum number of files"); 4049 4050 SYSCTL_INT(_kern, OID_AUTO, openfiles, CTLFLAG_RD, 4051 &openfiles, 0, "System-wide number of open files"); 4052 4053 /* ARGSUSED*/ 4054 static void 4055 filelistinit(void *dummy) 4056 { 4057 4058 file_zone = uma_zcreate("Files", sizeof(struct file), NULL, NULL, 4059 NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE); 4060 filedesc0_zone = uma_zcreate("filedesc0", sizeof(struct filedesc0), 4061 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0); 4062 mtx_init(&sigio_lock, "sigio lock", NULL, MTX_DEF); 4063 } 4064 SYSINIT(select, SI_SUB_LOCK, SI_ORDER_FIRST, filelistinit, NULL); 4065 4066 /*-------------------------------------------------------------------*/ 4067 4068 static int 4069 badfo_readwrite(struct file *fp, struct uio *uio, struct ucred *active_cred, 4070 int flags, struct thread *td) 4071 { 4072 4073 return (EBADF); 4074 } 4075 4076 static int 4077 badfo_truncate(struct file *fp, off_t length, struct ucred *active_cred, 4078 struct thread *td) 4079 { 4080 4081 return (EINVAL); 4082 } 4083 4084 static int 4085 badfo_ioctl(struct file *fp, u_long com, void *data, struct ucred *active_cred, 4086 struct thread *td) 4087 { 4088 4089 return (EBADF); 4090 } 4091 4092 static int 4093 badfo_poll(struct file *fp, int events, struct ucred *active_cred, 4094 struct thread *td) 4095 { 4096 4097 return (0); 4098 } 4099 4100 static int 4101 badfo_kqfilter(struct file *fp, struct knote *kn) 4102 { 4103 4104 return (EBADF); 4105 } 4106 4107 static int 4108 badfo_stat(struct file *fp, struct stat *sb, struct ucred *active_cred, 4109 struct thread *td) 4110 { 4111 4112 return (EBADF); 4113 } 4114 4115 static int 4116 badfo_close(struct file *fp, struct thread *td) 4117 { 4118 4119 return (0); 4120 } 4121 4122 static int 4123 badfo_chmod(struct file *fp, mode_t mode, struct ucred *active_cred, 4124 struct thread *td) 4125 { 4126 4127 return (EBADF); 4128 } 4129 4130 static int 4131 badfo_chown(struct file *fp, uid_t uid, gid_t gid, struct ucred *active_cred, 4132 struct thread *td) 4133 { 4134 4135 return (EBADF); 4136 } 4137 4138 static int 4139 badfo_sendfile(struct file *fp, int sockfd, struct uio *hdr_uio, 4140 struct uio *trl_uio, off_t offset, size_t nbytes, off_t *sent, int flags, 4141 struct thread *td) 4142 { 4143 4144 return (EBADF); 4145 } 4146 4147 static int 4148 badfo_fill_kinfo(struct file *fp, struct kinfo_file *kif, struct filedesc *fdp) 4149 { 4150 4151 return (0); 4152 } 4153 4154 struct fileops badfileops = { 4155 .fo_read = badfo_readwrite, 4156 .fo_write = badfo_readwrite, 4157 .fo_truncate = badfo_truncate, 4158 .fo_ioctl = badfo_ioctl, 4159 .fo_poll = badfo_poll, 4160 .fo_kqfilter = badfo_kqfilter, 4161 .fo_stat = badfo_stat, 4162 .fo_close = badfo_close, 4163 .fo_chmod = badfo_chmod, 4164 .fo_chown = badfo_chown, 4165 .fo_sendfile = badfo_sendfile, 4166 .fo_fill_kinfo = badfo_fill_kinfo, 4167 }; 4168 4169 int 4170 invfo_rdwr(struct file *fp, struct uio *uio, struct ucred *active_cred, 4171 int flags, struct thread *td) 4172 { 4173 4174 return (EOPNOTSUPP); 4175 } 4176 4177 int 4178 invfo_truncate(struct file *fp, off_t length, struct ucred *active_cred, 4179 struct thread *td) 4180 { 4181 4182 return (EINVAL); 4183 } 4184 4185 int 4186 invfo_ioctl(struct file *fp, u_long com, void *data, 4187 struct ucred *active_cred, struct thread *td) 4188 { 4189 4190 return (ENOTTY); 4191 } 4192 4193 int 4194 invfo_poll(struct file *fp, int events, struct ucred *active_cred, 4195 struct thread *td) 4196 { 4197 4198 return (poll_no_poll(events)); 4199 } 4200 4201 int 4202 invfo_kqfilter(struct file *fp, struct knote *kn) 4203 { 4204 4205 return (EINVAL); 4206 } 4207 4208 int 4209 invfo_chmod(struct file *fp, mode_t mode, struct ucred *active_cred, 4210 struct thread *td) 4211 { 4212 4213 return (EINVAL); 4214 } 4215 4216 int 4217 invfo_chown(struct file *fp, uid_t uid, gid_t gid, struct ucred *active_cred, 4218 struct thread *td) 4219 { 4220 4221 return (EINVAL); 4222 } 4223 4224 int 4225 invfo_sendfile(struct file *fp, int sockfd, struct uio *hdr_uio, 4226 struct uio *trl_uio, off_t offset, size_t nbytes, off_t *sent, int flags, 4227 struct thread *td) 4228 { 4229 4230 return (EINVAL); 4231 } 4232 4233 /*-------------------------------------------------------------------*/ 4234 4235 /* 4236 * File Descriptor pseudo-device driver (/dev/fd/). 4237 * 4238 * Opening minor device N dup()s the file (if any) connected to file 4239 * descriptor N belonging to the calling process. Note that this driver 4240 * consists of only the ``open()'' routine, because all subsequent 4241 * references to this file will be direct to the other driver. 4242 * 4243 * XXX: we could give this one a cloning event handler if necessary. 4244 */ 4245 4246 /* ARGSUSED */ 4247 static int 4248 fdopen(struct cdev *dev, int mode, int type, struct thread *td) 4249 { 4250 4251 /* 4252 * XXX Kludge: set curthread->td_dupfd to contain the value of the 4253 * the file descriptor being sought for duplication. The error 4254 * return ensures that the vnode for this device will be released 4255 * by vn_open. Open will detect this special error and take the 4256 * actions in dupfdopen below. Other callers of vn_open or VOP_OPEN 4257 * will simply report the error. 4258 */ 4259 td->td_dupfd = dev2unit(dev); 4260 return (ENODEV); 4261 } 4262 4263 static struct cdevsw fildesc_cdevsw = { 4264 .d_version = D_VERSION, 4265 .d_open = fdopen, 4266 .d_name = "FD", 4267 }; 4268 4269 static void 4270 fildesc_drvinit(void *unused) 4271 { 4272 struct cdev *dev; 4273 4274 dev = make_dev_credf(MAKEDEV_ETERNAL, &fildesc_cdevsw, 0, NULL, 4275 UID_ROOT, GID_WHEEL, 0666, "fd/0"); 4276 make_dev_alias(dev, "stdin"); 4277 dev = make_dev_credf(MAKEDEV_ETERNAL, &fildesc_cdevsw, 1, NULL, 4278 UID_ROOT, GID_WHEEL, 0666, "fd/1"); 4279 make_dev_alias(dev, "stdout"); 4280 dev = make_dev_credf(MAKEDEV_ETERNAL, &fildesc_cdevsw, 2, NULL, 4281 UID_ROOT, GID_WHEEL, 0666, "fd/2"); 4282 make_dev_alias(dev, "stderr"); 4283 } 4284 4285 SYSINIT(fildescdev, SI_SUB_DRIVERS, SI_ORDER_MIDDLE, fildesc_drvinit, NULL); 4286