1 /*- 2 * SPDX-License-Identifier: BSD-3-Clause 3 * 4 * Copyright (c) 1982, 1986, 1989, 1991, 1993 5 * The Regents of the University of California. All rights reserved. 6 * (c) UNIX System Laboratories, Inc. 7 * All or some portions of this file are derived from material licensed 8 * to the University of California by American Telephone and Telegraph 9 * Co. or Unix System Laboratories, Inc. and are reproduced herein with 10 * the permission of UNIX System Laboratories, Inc. 11 * 12 * Redistribution and use in source and binary forms, with or without 13 * modification, are permitted provided that the following conditions 14 * are met: 15 * 1. Redistributions of source code must retain the above copyright 16 * notice, this list of conditions and the following disclaimer. 17 * 2. Redistributions in binary form must reproduce the above copyright 18 * notice, this list of conditions and the following disclaimer in the 19 * documentation and/or other materials provided with the distribution. 20 * 3. Neither the name of the University nor the names of its contributors 21 * may be used to endorse or promote products derived from this software 22 * without specific prior written permission. 23 * 24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34 * SUCH DAMAGE. 35 * 36 * @(#)kern_descrip.c 8.6 (Berkeley) 4/19/94 37 */ 38 39 #include <sys/cdefs.h> 40 __FBSDID("$FreeBSD$"); 41 42 #include "opt_capsicum.h" 43 #include "opt_ddb.h" 44 #include "opt_ktrace.h" 45 46 #include <sys/param.h> 47 #include <sys/systm.h> 48 49 #include <sys/capsicum.h> 50 #include <sys/conf.h> 51 #include <sys/fcntl.h> 52 #include <sys/file.h> 53 #include <sys/filedesc.h> 54 #include <sys/filio.h> 55 #include <sys/jail.h> 56 #include <sys/kernel.h> 57 #include <sys/limits.h> 58 #include <sys/lock.h> 59 #include <sys/malloc.h> 60 #include <sys/mount.h> 61 #include <sys/mutex.h> 62 #include <sys/namei.h> 63 #include <sys/selinfo.h> 64 #include <sys/priv.h> 65 #include <sys/proc.h> 66 #include <sys/protosw.h> 67 #include <sys/racct.h> 68 #include <sys/resourcevar.h> 69 #include <sys/sbuf.h> 70 #include <sys/signalvar.h> 71 #include <sys/kdb.h> 72 #include <sys/stat.h> 73 #include <sys/sx.h> 74 #include <sys/syscallsubr.h> 75 #include <sys/sysctl.h> 76 #include <sys/sysproto.h> 77 #include <sys/unistd.h> 78 #include <sys/user.h> 79 #include <sys/vnode.h> 80 #ifdef KTRACE 81 #include <sys/ktrace.h> 82 #endif 83 84 #include <net/vnet.h> 85 86 #include <security/audit/audit.h> 87 88 #include <vm/uma.h> 89 #include <vm/vm.h> 90 91 #include <ddb/ddb.h> 92 93 static MALLOC_DEFINE(M_FILEDESC, "filedesc", "Open file descriptor table"); 94 static MALLOC_DEFINE(M_FILEDESC_TO_LEADER, "filedesc_to_leader", 95 "file desc to leader structures"); 96 static MALLOC_DEFINE(M_SIGIO, "sigio", "sigio structures"); 97 MALLOC_DEFINE(M_FILECAPS, "filecaps", "descriptor capabilities"); 98 99 MALLOC_DECLARE(M_FADVISE); 100 101 static __read_mostly uma_zone_t file_zone; 102 static __read_mostly uma_zone_t filedesc0_zone; 103 104 static int closefp(struct filedesc *fdp, int fd, struct file *fp, 105 struct thread *td, int holdleaders); 106 static int fd_first_free(struct filedesc *fdp, int low, int size); 107 static int fd_last_used(struct filedesc *fdp, int size); 108 static void fdgrowtable(struct filedesc *fdp, int nfd); 109 static void fdgrowtable_exp(struct filedesc *fdp, int nfd); 110 static void fdunused(struct filedesc *fdp, int fd); 111 static void fdused(struct filedesc *fdp, int fd); 112 static int getmaxfd(struct thread *td); 113 static u_long *filecaps_copy_prep(const struct filecaps *src); 114 static void filecaps_copy_finish(const struct filecaps *src, 115 struct filecaps *dst, u_long *ioctls); 116 static u_long *filecaps_free_prep(struct filecaps *fcaps); 117 static void filecaps_free_finish(u_long *ioctls); 118 119 /* 120 * Each process has: 121 * 122 * - An array of open file descriptors (fd_ofiles) 123 * - An array of file flags (fd_ofileflags) 124 * - A bitmap recording which descriptors are in use (fd_map) 125 * 126 * A process starts out with NDFILE descriptors. The value of NDFILE has 127 * been selected based the historical limit of 20 open files, and an 128 * assumption that the majority of processes, especially short-lived 129 * processes like shells, will never need more. 130 * 131 * If this initial allocation is exhausted, a larger descriptor table and 132 * map are allocated dynamically, and the pointers in the process's struct 133 * filedesc are updated to point to those. This is repeated every time 134 * the process runs out of file descriptors (provided it hasn't hit its 135 * resource limit). 136 * 137 * Since threads may hold references to individual descriptor table 138 * entries, the tables are never freed. Instead, they are placed on a 139 * linked list and freed only when the struct filedesc is released. 140 */ 141 #define NDFILE 20 142 #define NDSLOTSIZE sizeof(NDSLOTTYPE) 143 #define NDENTRIES (NDSLOTSIZE * __CHAR_BIT) 144 #define NDSLOT(x) ((x) / NDENTRIES) 145 #define NDBIT(x) ((NDSLOTTYPE)1 << ((x) % NDENTRIES)) 146 #define NDSLOTS(x) (((x) + NDENTRIES - 1) / NDENTRIES) 147 148 /* 149 * SLIST entry used to keep track of ofiles which must be reclaimed when 150 * the process exits. 151 */ 152 struct freetable { 153 struct fdescenttbl *ft_table; 154 SLIST_ENTRY(freetable) ft_next; 155 }; 156 157 /* 158 * Initial allocation: a filedesc structure + the head of SLIST used to 159 * keep track of old ofiles + enough space for NDFILE descriptors. 160 */ 161 162 struct fdescenttbl0 { 163 int fdt_nfiles; 164 struct filedescent fdt_ofiles[NDFILE]; 165 }; 166 167 struct filedesc0 { 168 struct filedesc fd_fd; 169 SLIST_HEAD(, freetable) fd_free; 170 struct fdescenttbl0 fd_dfiles; 171 NDSLOTTYPE fd_dmap[NDSLOTS(NDFILE)]; 172 }; 173 174 /* 175 * Descriptor management. 176 */ 177 volatile int __exclusive_cache_line openfiles; /* actual number of open files */ 178 struct mtx sigio_lock; /* mtx to protect pointers to sigio */ 179 void __read_mostly (*mq_fdclose)(struct thread *td, int fd, struct file *fp); 180 181 /* 182 * If low >= size, just return low. Otherwise find the first zero bit in the 183 * given bitmap, starting at low and not exceeding size - 1. Return size if 184 * not found. 185 */ 186 static int 187 fd_first_free(struct filedesc *fdp, int low, int size) 188 { 189 NDSLOTTYPE *map = fdp->fd_map; 190 NDSLOTTYPE mask; 191 int off, maxoff; 192 193 if (low >= size) 194 return (low); 195 196 off = NDSLOT(low); 197 if (low % NDENTRIES) { 198 mask = ~(~(NDSLOTTYPE)0 >> (NDENTRIES - (low % NDENTRIES))); 199 if ((mask &= ~map[off]) != 0UL) 200 return (off * NDENTRIES + ffsl(mask) - 1); 201 ++off; 202 } 203 for (maxoff = NDSLOTS(size); off < maxoff; ++off) 204 if (map[off] != ~0UL) 205 return (off * NDENTRIES + ffsl(~map[off]) - 1); 206 return (size); 207 } 208 209 /* 210 * Find the highest non-zero bit in the given bitmap, starting at 0 and 211 * not exceeding size - 1. Return -1 if not found. 212 */ 213 static int 214 fd_last_used(struct filedesc *fdp, int size) 215 { 216 NDSLOTTYPE *map = fdp->fd_map; 217 NDSLOTTYPE mask; 218 int off, minoff; 219 220 off = NDSLOT(size); 221 if (size % NDENTRIES) { 222 mask = ~(~(NDSLOTTYPE)0 << (size % NDENTRIES)); 223 if ((mask &= map[off]) != 0) 224 return (off * NDENTRIES + flsl(mask) - 1); 225 --off; 226 } 227 for (minoff = NDSLOT(0); off >= minoff; --off) 228 if (map[off] != 0) 229 return (off * NDENTRIES + flsl(map[off]) - 1); 230 return (-1); 231 } 232 233 static int 234 fdisused(struct filedesc *fdp, int fd) 235 { 236 237 KASSERT(fd >= 0 && fd < fdp->fd_nfiles, 238 ("file descriptor %d out of range (0, %d)", fd, fdp->fd_nfiles)); 239 240 return ((fdp->fd_map[NDSLOT(fd)] & NDBIT(fd)) != 0); 241 } 242 243 /* 244 * Mark a file descriptor as used. 245 */ 246 static void 247 fdused_init(struct filedesc *fdp, int fd) 248 { 249 250 KASSERT(!fdisused(fdp, fd), ("fd=%d is already used", fd)); 251 252 fdp->fd_map[NDSLOT(fd)] |= NDBIT(fd); 253 } 254 255 static void 256 fdused(struct filedesc *fdp, int fd) 257 { 258 259 FILEDESC_XLOCK_ASSERT(fdp); 260 261 fdused_init(fdp, fd); 262 if (fd > fdp->fd_lastfile) 263 fdp->fd_lastfile = fd; 264 if (fd == fdp->fd_freefile) 265 fdp->fd_freefile++; 266 } 267 268 /* 269 * Mark a file descriptor as unused. 270 */ 271 static void 272 fdunused(struct filedesc *fdp, int fd) 273 { 274 275 FILEDESC_XLOCK_ASSERT(fdp); 276 277 KASSERT(fdisused(fdp, fd), ("fd=%d is already unused", fd)); 278 KASSERT(fdp->fd_ofiles[fd].fde_file == NULL, 279 ("fd=%d is still in use", fd)); 280 281 fdp->fd_map[NDSLOT(fd)] &= ~NDBIT(fd); 282 if (fd < fdp->fd_freefile) 283 fdp->fd_freefile = fd; 284 if (fd == fdp->fd_lastfile) 285 fdp->fd_lastfile = fd_last_used(fdp, fd); 286 } 287 288 /* 289 * Free a file descriptor. 290 * 291 * Avoid some work if fdp is about to be destroyed. 292 */ 293 static inline void 294 fdefree_last(struct filedescent *fde) 295 { 296 297 filecaps_free(&fde->fde_caps); 298 } 299 300 static inline void 301 fdfree(struct filedesc *fdp, int fd) 302 { 303 struct filedescent *fde; 304 305 fde = &fdp->fd_ofiles[fd]; 306 #ifdef CAPABILITIES 307 seqc_write_begin(&fde->fde_seqc); 308 #endif 309 fde->fde_file = NULL; 310 #ifdef CAPABILITIES 311 seqc_write_end(&fde->fde_seqc); 312 #endif 313 fdefree_last(fde); 314 fdunused(fdp, fd); 315 } 316 317 void 318 pwd_ensure_dirs(void) 319 { 320 struct filedesc *fdp; 321 322 fdp = curproc->p_fd; 323 FILEDESC_XLOCK(fdp); 324 if (fdp->fd_cdir == NULL) { 325 fdp->fd_cdir = rootvnode; 326 vrefact(rootvnode); 327 } 328 if (fdp->fd_rdir == NULL) { 329 fdp->fd_rdir = rootvnode; 330 vrefact(rootvnode); 331 } 332 FILEDESC_XUNLOCK(fdp); 333 } 334 335 /* 336 * System calls on descriptors. 337 */ 338 #ifndef _SYS_SYSPROTO_H_ 339 struct getdtablesize_args { 340 int dummy; 341 }; 342 #endif 343 /* ARGSUSED */ 344 int 345 sys_getdtablesize(struct thread *td, struct getdtablesize_args *uap) 346 { 347 #ifdef RACCT 348 uint64_t lim; 349 #endif 350 351 td->td_retval[0] = getmaxfd(td); 352 #ifdef RACCT 353 PROC_LOCK(td->td_proc); 354 lim = racct_get_limit(td->td_proc, RACCT_NOFILE); 355 PROC_UNLOCK(td->td_proc); 356 if (lim < td->td_retval[0]) 357 td->td_retval[0] = lim; 358 #endif 359 return (0); 360 } 361 362 /* 363 * Duplicate a file descriptor to a particular value. 364 * 365 * Note: keep in mind that a potential race condition exists when closing 366 * descriptors from a shared descriptor table (via rfork). 367 */ 368 #ifndef _SYS_SYSPROTO_H_ 369 struct dup2_args { 370 u_int from; 371 u_int to; 372 }; 373 #endif 374 /* ARGSUSED */ 375 int 376 sys_dup2(struct thread *td, struct dup2_args *uap) 377 { 378 379 return (kern_dup(td, FDDUP_FIXED, 0, (int)uap->from, (int)uap->to)); 380 } 381 382 /* 383 * Duplicate a file descriptor. 384 */ 385 #ifndef _SYS_SYSPROTO_H_ 386 struct dup_args { 387 u_int fd; 388 }; 389 #endif 390 /* ARGSUSED */ 391 int 392 sys_dup(struct thread *td, struct dup_args *uap) 393 { 394 395 return (kern_dup(td, FDDUP_NORMAL, 0, (int)uap->fd, 0)); 396 } 397 398 /* 399 * The file control system call. 400 */ 401 #ifndef _SYS_SYSPROTO_H_ 402 struct fcntl_args { 403 int fd; 404 int cmd; 405 long arg; 406 }; 407 #endif 408 /* ARGSUSED */ 409 int 410 sys_fcntl(struct thread *td, struct fcntl_args *uap) 411 { 412 413 return (kern_fcntl_freebsd(td, uap->fd, uap->cmd, uap->arg)); 414 } 415 416 int 417 kern_fcntl_freebsd(struct thread *td, int fd, int cmd, long arg) 418 { 419 struct flock fl; 420 struct __oflock ofl; 421 intptr_t arg1; 422 int error, newcmd; 423 424 error = 0; 425 newcmd = cmd; 426 switch (cmd) { 427 case F_OGETLK: 428 case F_OSETLK: 429 case F_OSETLKW: 430 /* 431 * Convert old flock structure to new. 432 */ 433 error = copyin((void *)(intptr_t)arg, &ofl, sizeof(ofl)); 434 fl.l_start = ofl.l_start; 435 fl.l_len = ofl.l_len; 436 fl.l_pid = ofl.l_pid; 437 fl.l_type = ofl.l_type; 438 fl.l_whence = ofl.l_whence; 439 fl.l_sysid = 0; 440 441 switch (cmd) { 442 case F_OGETLK: 443 newcmd = F_GETLK; 444 break; 445 case F_OSETLK: 446 newcmd = F_SETLK; 447 break; 448 case F_OSETLKW: 449 newcmd = F_SETLKW; 450 break; 451 } 452 arg1 = (intptr_t)&fl; 453 break; 454 case F_GETLK: 455 case F_SETLK: 456 case F_SETLKW: 457 case F_SETLK_REMOTE: 458 error = copyin((void *)(intptr_t)arg, &fl, sizeof(fl)); 459 arg1 = (intptr_t)&fl; 460 break; 461 default: 462 arg1 = arg; 463 break; 464 } 465 if (error) 466 return (error); 467 error = kern_fcntl(td, fd, newcmd, arg1); 468 if (error) 469 return (error); 470 if (cmd == F_OGETLK) { 471 ofl.l_start = fl.l_start; 472 ofl.l_len = fl.l_len; 473 ofl.l_pid = fl.l_pid; 474 ofl.l_type = fl.l_type; 475 ofl.l_whence = fl.l_whence; 476 error = copyout(&ofl, (void *)(intptr_t)arg, sizeof(ofl)); 477 } else if (cmd == F_GETLK) { 478 error = copyout(&fl, (void *)(intptr_t)arg, sizeof(fl)); 479 } 480 return (error); 481 } 482 483 int 484 kern_fcntl(struct thread *td, int fd, int cmd, intptr_t arg) 485 { 486 struct filedesc *fdp; 487 struct flock *flp; 488 struct file *fp, *fp2; 489 struct filedescent *fde; 490 struct proc *p; 491 struct vnode *vp; 492 int error, flg, 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 /* 792 * Exclusive lock synchronizes against f_seqcount reads and 793 * writes in sequential_heuristic(). 794 */ 795 error = vn_lock(vp, LK_EXCLUSIVE); 796 if (error != 0) { 797 fdrop(fp, td); 798 break; 799 } 800 if (arg >= 0) { 801 bsize = fp->f_vnode->v_mount->mnt_stat.f_iosize; 802 arg = MIN(arg, INT_MAX - bsize + 1); 803 fp->f_seqcount = MIN(IO_SEQMAX, 804 (arg + bsize - 1) / bsize); 805 atomic_set_int(&fp->f_flag, FRDAHEAD); 806 } else { 807 atomic_clear_int(&fp->f_flag, FRDAHEAD); 808 } 809 VOP_UNLOCK(vp, 0); 810 fdrop(fp, td); 811 break; 812 813 default: 814 error = EINVAL; 815 break; 816 } 817 return (error); 818 } 819 820 static int 821 getmaxfd(struct thread *td) 822 { 823 824 return (min((int)lim_cur(td, RLIMIT_NOFILE), maxfilesperproc)); 825 } 826 827 /* 828 * Common code for dup, dup2, fcntl(F_DUPFD) and fcntl(F_DUP2FD). 829 */ 830 int 831 kern_dup(struct thread *td, u_int mode, int flags, int old, int new) 832 { 833 struct filedesc *fdp; 834 struct filedescent *oldfde, *newfde; 835 struct proc *p; 836 struct file *delfp; 837 u_long *oioctls, *nioctls; 838 int error, maxfd; 839 840 p = td->td_proc; 841 fdp = p->p_fd; 842 oioctls = NULL; 843 844 MPASS((flags & ~(FDDUP_FLAG_CLOEXEC)) == 0); 845 MPASS(mode < FDDUP_LASTMODE); 846 847 AUDIT_ARG_FD(old); 848 /* XXXRW: if (flags & FDDUP_FIXED) AUDIT_ARG_FD2(new); */ 849 850 /* 851 * Verify we have a valid descriptor to dup from and possibly to 852 * dup to. Unlike dup() and dup2(), fcntl()'s F_DUPFD should 853 * return EINVAL when the new descriptor is out of bounds. 854 */ 855 if (old < 0) 856 return (EBADF); 857 if (new < 0) 858 return (mode == FDDUP_FCNTL ? EINVAL : EBADF); 859 maxfd = getmaxfd(td); 860 if (new >= maxfd) 861 return (mode == FDDUP_FCNTL ? EINVAL : EBADF); 862 863 error = EBADF; 864 FILEDESC_XLOCK(fdp); 865 if (fget_locked(fdp, old) == NULL) 866 goto unlock; 867 if ((mode == FDDUP_FIXED || mode == FDDUP_MUSTREPLACE) && old == new) { 868 td->td_retval[0] = new; 869 if (flags & FDDUP_FLAG_CLOEXEC) 870 fdp->fd_ofiles[new].fde_flags |= UF_EXCLOSE; 871 error = 0; 872 goto unlock; 873 } 874 875 oldfde = &fdp->fd_ofiles[old]; 876 if (!fhold(oldfde->fde_file)) 877 goto unlock; 878 879 /* 880 * If the caller specified a file descriptor, make sure the file 881 * table is large enough to hold it, and grab it. Otherwise, just 882 * allocate a new descriptor the usual way. 883 */ 884 switch (mode) { 885 case FDDUP_NORMAL: 886 case FDDUP_FCNTL: 887 if ((error = fdalloc(td, new, &new)) != 0) { 888 fdrop(oldfde->fde_file, td); 889 goto unlock; 890 } 891 break; 892 case FDDUP_MUSTREPLACE: 893 /* Target file descriptor must exist. */ 894 if (fget_locked(fdp, new) == NULL) { 895 fdrop(oldfde->fde_file, td); 896 goto unlock; 897 } 898 break; 899 case FDDUP_FIXED: 900 if (new >= fdp->fd_nfiles) { 901 /* 902 * The resource limits are here instead of e.g. 903 * fdalloc(), because the file descriptor table may be 904 * shared between processes, so we can't really use 905 * racct_add()/racct_sub(). Instead of counting the 906 * number of actually allocated descriptors, just put 907 * the limit on the size of the file descriptor table. 908 */ 909 #ifdef RACCT 910 if (RACCT_ENABLED()) { 911 error = racct_set_unlocked(p, RACCT_NOFILE, new + 1); 912 if (error != 0) { 913 error = EMFILE; 914 fdrop(oldfde->fde_file, td); 915 goto unlock; 916 } 917 } 918 #endif 919 fdgrowtable_exp(fdp, new + 1); 920 } 921 if (!fdisused(fdp, new)) 922 fdused(fdp, new); 923 break; 924 default: 925 KASSERT(0, ("%s unsupported mode %d", __func__, mode)); 926 } 927 928 KASSERT(old != new, ("new fd is same as old")); 929 930 newfde = &fdp->fd_ofiles[new]; 931 delfp = newfde->fde_file; 932 933 oioctls = filecaps_free_prep(&newfde->fde_caps); 934 nioctls = filecaps_copy_prep(&oldfde->fde_caps); 935 936 /* 937 * Duplicate the source descriptor. 938 */ 939 #ifdef CAPABILITIES 940 seqc_write_begin(&newfde->fde_seqc); 941 #endif 942 memcpy(newfde, oldfde, fde_change_size); 943 filecaps_copy_finish(&oldfde->fde_caps, &newfde->fde_caps, 944 nioctls); 945 if ((flags & FDDUP_FLAG_CLOEXEC) != 0) 946 newfde->fde_flags = oldfde->fde_flags | UF_EXCLOSE; 947 else 948 newfde->fde_flags = oldfde->fde_flags & ~UF_EXCLOSE; 949 #ifdef CAPABILITIES 950 seqc_write_end(&newfde->fde_seqc); 951 #endif 952 td->td_retval[0] = new; 953 954 error = 0; 955 956 if (delfp != NULL) { 957 (void) closefp(fdp, new, delfp, td, 1); 958 FILEDESC_UNLOCK_ASSERT(fdp); 959 } else { 960 unlock: 961 FILEDESC_XUNLOCK(fdp); 962 } 963 964 filecaps_free_finish(oioctls); 965 return (error); 966 } 967 968 /* 969 * If sigio is on the list associated with a process or process group, 970 * disable signalling from the device, remove sigio from the list and 971 * free sigio. 972 */ 973 void 974 funsetown(struct sigio **sigiop) 975 { 976 struct sigio *sigio; 977 978 if (*sigiop == NULL) 979 return; 980 SIGIO_LOCK(); 981 sigio = *sigiop; 982 if (sigio == NULL) { 983 SIGIO_UNLOCK(); 984 return; 985 } 986 *(sigio->sio_myref) = NULL; 987 if ((sigio)->sio_pgid < 0) { 988 struct pgrp *pg = (sigio)->sio_pgrp; 989 PGRP_LOCK(pg); 990 SLIST_REMOVE(&sigio->sio_pgrp->pg_sigiolst, sigio, 991 sigio, sio_pgsigio); 992 PGRP_UNLOCK(pg); 993 } else { 994 struct proc *p = (sigio)->sio_proc; 995 PROC_LOCK(p); 996 SLIST_REMOVE(&sigio->sio_proc->p_sigiolst, sigio, 997 sigio, sio_pgsigio); 998 PROC_UNLOCK(p); 999 } 1000 SIGIO_UNLOCK(); 1001 crfree(sigio->sio_ucred); 1002 free(sigio, M_SIGIO); 1003 } 1004 1005 /* 1006 * Free a list of sigio structures. 1007 * We only need to lock the SIGIO_LOCK because we have made ourselves 1008 * inaccessible to callers of fsetown and therefore do not need to lock 1009 * the proc or pgrp struct for the list manipulation. 1010 */ 1011 void 1012 funsetownlst(struct sigiolst *sigiolst) 1013 { 1014 struct proc *p; 1015 struct pgrp *pg; 1016 struct sigio *sigio; 1017 1018 sigio = SLIST_FIRST(sigiolst); 1019 if (sigio == NULL) 1020 return; 1021 p = NULL; 1022 pg = NULL; 1023 1024 /* 1025 * Every entry of the list should belong 1026 * to a single proc or pgrp. 1027 */ 1028 if (sigio->sio_pgid < 0) { 1029 pg = sigio->sio_pgrp; 1030 PGRP_LOCK_ASSERT(pg, MA_NOTOWNED); 1031 } else /* if (sigio->sio_pgid > 0) */ { 1032 p = sigio->sio_proc; 1033 PROC_LOCK_ASSERT(p, MA_NOTOWNED); 1034 } 1035 1036 SIGIO_LOCK(); 1037 while ((sigio = SLIST_FIRST(sigiolst)) != NULL) { 1038 *(sigio->sio_myref) = NULL; 1039 if (pg != NULL) { 1040 KASSERT(sigio->sio_pgid < 0, 1041 ("Proc sigio in pgrp sigio list")); 1042 KASSERT(sigio->sio_pgrp == pg, 1043 ("Bogus pgrp in sigio list")); 1044 PGRP_LOCK(pg); 1045 SLIST_REMOVE(&pg->pg_sigiolst, sigio, sigio, 1046 sio_pgsigio); 1047 PGRP_UNLOCK(pg); 1048 } else /* if (p != NULL) */ { 1049 KASSERT(sigio->sio_pgid > 0, 1050 ("Pgrp sigio in proc sigio list")); 1051 KASSERT(sigio->sio_proc == p, 1052 ("Bogus proc in sigio list")); 1053 PROC_LOCK(p); 1054 SLIST_REMOVE(&p->p_sigiolst, sigio, sigio, 1055 sio_pgsigio); 1056 PROC_UNLOCK(p); 1057 } 1058 SIGIO_UNLOCK(); 1059 crfree(sigio->sio_ucred); 1060 free(sigio, M_SIGIO); 1061 SIGIO_LOCK(); 1062 } 1063 SIGIO_UNLOCK(); 1064 } 1065 1066 /* 1067 * This is common code for FIOSETOWN ioctl called by fcntl(fd, F_SETOWN, arg). 1068 * 1069 * After permission checking, add a sigio structure to the sigio list for 1070 * the process or process group. 1071 */ 1072 int 1073 fsetown(pid_t pgid, struct sigio **sigiop) 1074 { 1075 struct proc *proc; 1076 struct pgrp *pgrp; 1077 struct sigio *sigio; 1078 int ret; 1079 1080 if (pgid == 0) { 1081 funsetown(sigiop); 1082 return (0); 1083 } 1084 1085 ret = 0; 1086 1087 /* Allocate and fill in the new sigio out of locks. */ 1088 sigio = malloc(sizeof(struct sigio), M_SIGIO, M_WAITOK); 1089 sigio->sio_pgid = pgid; 1090 sigio->sio_ucred = crhold(curthread->td_ucred); 1091 sigio->sio_myref = sigiop; 1092 1093 sx_slock(&proctree_lock); 1094 if (pgid > 0) { 1095 proc = pfind(pgid); 1096 if (proc == NULL) { 1097 ret = ESRCH; 1098 goto fail; 1099 } 1100 1101 /* 1102 * Policy - Don't allow a process to FSETOWN a process 1103 * in another session. 1104 * 1105 * Remove this test to allow maximum flexibility or 1106 * restrict FSETOWN to the current process or process 1107 * group for maximum safety. 1108 */ 1109 PROC_UNLOCK(proc); 1110 if (proc->p_session != curthread->td_proc->p_session) { 1111 ret = EPERM; 1112 goto fail; 1113 } 1114 1115 pgrp = NULL; 1116 } else /* if (pgid < 0) */ { 1117 pgrp = pgfind(-pgid); 1118 if (pgrp == NULL) { 1119 ret = ESRCH; 1120 goto fail; 1121 } 1122 PGRP_UNLOCK(pgrp); 1123 1124 /* 1125 * Policy - Don't allow a process to FSETOWN a process 1126 * in another session. 1127 * 1128 * Remove this test to allow maximum flexibility or 1129 * restrict FSETOWN to the current process or process 1130 * group for maximum safety. 1131 */ 1132 if (pgrp->pg_session != curthread->td_proc->p_session) { 1133 ret = EPERM; 1134 goto fail; 1135 } 1136 1137 proc = NULL; 1138 } 1139 funsetown(sigiop); 1140 if (pgid > 0) { 1141 PROC_LOCK(proc); 1142 /* 1143 * Since funsetownlst() is called without the proctree 1144 * locked, we need to check for P_WEXIT. 1145 * XXX: is ESRCH correct? 1146 */ 1147 if ((proc->p_flag & P_WEXIT) != 0) { 1148 PROC_UNLOCK(proc); 1149 ret = ESRCH; 1150 goto fail; 1151 } 1152 SLIST_INSERT_HEAD(&proc->p_sigiolst, sigio, sio_pgsigio); 1153 sigio->sio_proc = proc; 1154 PROC_UNLOCK(proc); 1155 } else { 1156 PGRP_LOCK(pgrp); 1157 SLIST_INSERT_HEAD(&pgrp->pg_sigiolst, sigio, sio_pgsigio); 1158 sigio->sio_pgrp = pgrp; 1159 PGRP_UNLOCK(pgrp); 1160 } 1161 sx_sunlock(&proctree_lock); 1162 SIGIO_LOCK(); 1163 *sigiop = sigio; 1164 SIGIO_UNLOCK(); 1165 return (0); 1166 1167 fail: 1168 sx_sunlock(&proctree_lock); 1169 crfree(sigio->sio_ucred); 1170 free(sigio, M_SIGIO); 1171 return (ret); 1172 } 1173 1174 /* 1175 * This is common code for FIOGETOWN ioctl called by fcntl(fd, F_GETOWN, arg). 1176 */ 1177 pid_t 1178 fgetown(struct sigio **sigiop) 1179 { 1180 pid_t pgid; 1181 1182 SIGIO_LOCK(); 1183 pgid = (*sigiop != NULL) ? (*sigiop)->sio_pgid : 0; 1184 SIGIO_UNLOCK(); 1185 return (pgid); 1186 } 1187 1188 /* 1189 * Function drops the filedesc lock on return. 1190 */ 1191 static int 1192 closefp(struct filedesc *fdp, int fd, struct file *fp, struct thread *td, 1193 int holdleaders) 1194 { 1195 int error; 1196 1197 FILEDESC_XLOCK_ASSERT(fdp); 1198 1199 if (holdleaders) { 1200 if (td->td_proc->p_fdtol != NULL) { 1201 /* 1202 * Ask fdfree() to sleep to ensure that all relevant 1203 * process leaders can be traversed in closef(). 1204 */ 1205 fdp->fd_holdleaderscount++; 1206 } else { 1207 holdleaders = 0; 1208 } 1209 } 1210 1211 /* 1212 * We now hold the fp reference that used to be owned by the 1213 * descriptor array. We have to unlock the FILEDESC *AFTER* 1214 * knote_fdclose to prevent a race of the fd getting opened, a knote 1215 * added, and deleteing a knote for the new fd. 1216 */ 1217 if (__predict_false(!TAILQ_EMPTY(&fdp->fd_kqlist))) 1218 knote_fdclose(td, fd); 1219 1220 /* 1221 * We need to notify mqueue if the object is of type mqueue. 1222 */ 1223 if (__predict_false(fp->f_type == DTYPE_MQUEUE)) 1224 mq_fdclose(td, fd, fp); 1225 FILEDESC_XUNLOCK(fdp); 1226 1227 error = closef(fp, td); 1228 if (holdleaders) { 1229 FILEDESC_XLOCK(fdp); 1230 fdp->fd_holdleaderscount--; 1231 if (fdp->fd_holdleaderscount == 0 && 1232 fdp->fd_holdleaderswakeup != 0) { 1233 fdp->fd_holdleaderswakeup = 0; 1234 wakeup(&fdp->fd_holdleaderscount); 1235 } 1236 FILEDESC_XUNLOCK(fdp); 1237 } 1238 return (error); 1239 } 1240 1241 /* 1242 * Close a file descriptor. 1243 */ 1244 #ifndef _SYS_SYSPROTO_H_ 1245 struct close_args { 1246 int fd; 1247 }; 1248 #endif 1249 /* ARGSUSED */ 1250 int 1251 sys_close(struct thread *td, struct close_args *uap) 1252 { 1253 1254 return (kern_close(td, uap->fd)); 1255 } 1256 1257 int 1258 kern_close(struct thread *td, int fd) 1259 { 1260 struct filedesc *fdp; 1261 struct file *fp; 1262 1263 fdp = td->td_proc->p_fd; 1264 1265 AUDIT_SYSCLOSE(td, fd); 1266 1267 FILEDESC_XLOCK(fdp); 1268 if ((fp = fget_locked(fdp, fd)) == NULL) { 1269 FILEDESC_XUNLOCK(fdp); 1270 return (EBADF); 1271 } 1272 fdfree(fdp, fd); 1273 1274 /* closefp() drops the FILEDESC lock for us. */ 1275 return (closefp(fdp, fd, fp, td, 1)); 1276 } 1277 1278 /* 1279 * Close open file descriptors. 1280 */ 1281 #ifndef _SYS_SYSPROTO_H_ 1282 struct closefrom_args { 1283 int lowfd; 1284 }; 1285 #endif 1286 /* ARGSUSED */ 1287 int 1288 sys_closefrom(struct thread *td, struct closefrom_args *uap) 1289 { 1290 struct filedesc *fdp; 1291 int fd; 1292 1293 fdp = td->td_proc->p_fd; 1294 AUDIT_ARG_FD(uap->lowfd); 1295 1296 /* 1297 * Treat negative starting file descriptor values identical to 1298 * closefrom(0) which closes all files. 1299 */ 1300 if (uap->lowfd < 0) 1301 uap->lowfd = 0; 1302 FILEDESC_SLOCK(fdp); 1303 for (fd = uap->lowfd; fd <= fdp->fd_lastfile; fd++) { 1304 if (fdp->fd_ofiles[fd].fde_file != NULL) { 1305 FILEDESC_SUNLOCK(fdp); 1306 (void)kern_close(td, fd); 1307 FILEDESC_SLOCK(fdp); 1308 } 1309 } 1310 FILEDESC_SUNLOCK(fdp); 1311 return (0); 1312 } 1313 1314 #if defined(COMPAT_43) 1315 /* 1316 * Return status information about a file descriptor. 1317 */ 1318 #ifndef _SYS_SYSPROTO_H_ 1319 struct ofstat_args { 1320 int fd; 1321 struct ostat *sb; 1322 }; 1323 #endif 1324 /* ARGSUSED */ 1325 int 1326 ofstat(struct thread *td, struct ofstat_args *uap) 1327 { 1328 struct ostat oub; 1329 struct stat ub; 1330 int error; 1331 1332 error = kern_fstat(td, uap->fd, &ub); 1333 if (error == 0) { 1334 cvtstat(&ub, &oub); 1335 error = copyout(&oub, uap->sb, sizeof(oub)); 1336 } 1337 return (error); 1338 } 1339 #endif /* COMPAT_43 */ 1340 1341 #if defined(COMPAT_FREEBSD11) 1342 int 1343 freebsd11_fstat(struct thread *td, struct freebsd11_fstat_args *uap) 1344 { 1345 struct stat sb; 1346 struct freebsd11_stat osb; 1347 int error; 1348 1349 error = kern_fstat(td, uap->fd, &sb); 1350 if (error != 0) 1351 return (error); 1352 error = freebsd11_cvtstat(&sb, &osb); 1353 if (error == 0) 1354 error = copyout(&osb, uap->sb, sizeof(osb)); 1355 return (error); 1356 } 1357 #endif /* COMPAT_FREEBSD11 */ 1358 1359 /* 1360 * Return status information about a file descriptor. 1361 */ 1362 #ifndef _SYS_SYSPROTO_H_ 1363 struct fstat_args { 1364 int fd; 1365 struct stat *sb; 1366 }; 1367 #endif 1368 /* ARGSUSED */ 1369 int 1370 sys_fstat(struct thread *td, struct fstat_args *uap) 1371 { 1372 struct stat ub; 1373 int error; 1374 1375 error = kern_fstat(td, uap->fd, &ub); 1376 if (error == 0) 1377 error = copyout(&ub, uap->sb, sizeof(ub)); 1378 return (error); 1379 } 1380 1381 int 1382 kern_fstat(struct thread *td, int fd, struct stat *sbp) 1383 { 1384 struct file *fp; 1385 int error; 1386 1387 AUDIT_ARG_FD(fd); 1388 1389 error = fget(td, fd, &cap_fstat_rights, &fp); 1390 if (error != 0) 1391 return (error); 1392 1393 AUDIT_ARG_FILE(td->td_proc, fp); 1394 1395 error = fo_stat(fp, sbp, td->td_ucred, td); 1396 fdrop(fp, td); 1397 #ifdef __STAT_TIME_T_EXT 1398 if (error == 0) { 1399 sbp->st_atim_ext = 0; 1400 sbp->st_mtim_ext = 0; 1401 sbp->st_ctim_ext = 0; 1402 sbp->st_btim_ext = 0; 1403 } 1404 #endif 1405 #ifdef KTRACE 1406 if (error == 0 && KTRPOINT(td, KTR_STRUCT)) 1407 ktrstat(sbp); 1408 #endif 1409 return (error); 1410 } 1411 1412 #if defined(COMPAT_FREEBSD11) 1413 /* 1414 * Return status information about a file descriptor. 1415 */ 1416 #ifndef _SYS_SYSPROTO_H_ 1417 struct freebsd11_nfstat_args { 1418 int fd; 1419 struct nstat *sb; 1420 }; 1421 #endif 1422 /* ARGSUSED */ 1423 int 1424 freebsd11_nfstat(struct thread *td, struct freebsd11_nfstat_args *uap) 1425 { 1426 struct nstat nub; 1427 struct stat ub; 1428 int error; 1429 1430 error = kern_fstat(td, uap->fd, &ub); 1431 if (error == 0) { 1432 freebsd11_cvtnstat(&ub, &nub); 1433 error = copyout(&nub, uap->sb, sizeof(nub)); 1434 } 1435 return (error); 1436 } 1437 #endif /* COMPAT_FREEBSD11 */ 1438 1439 /* 1440 * Return pathconf information about a file descriptor. 1441 */ 1442 #ifndef _SYS_SYSPROTO_H_ 1443 struct fpathconf_args { 1444 int fd; 1445 int name; 1446 }; 1447 #endif 1448 /* ARGSUSED */ 1449 int 1450 sys_fpathconf(struct thread *td, struct fpathconf_args *uap) 1451 { 1452 long value; 1453 int error; 1454 1455 error = kern_fpathconf(td, uap->fd, uap->name, &value); 1456 if (error == 0) 1457 td->td_retval[0] = value; 1458 return (error); 1459 } 1460 1461 int 1462 kern_fpathconf(struct thread *td, int fd, int name, long *valuep) 1463 { 1464 struct file *fp; 1465 struct vnode *vp; 1466 int error; 1467 1468 error = fget(td, fd, &cap_fpathconf_rights, &fp); 1469 if (error != 0) 1470 return (error); 1471 1472 if (name == _PC_ASYNC_IO) { 1473 *valuep = _POSIX_ASYNCHRONOUS_IO; 1474 goto out; 1475 } 1476 vp = fp->f_vnode; 1477 if (vp != NULL) { 1478 vn_lock(vp, LK_SHARED | LK_RETRY); 1479 error = VOP_PATHCONF(vp, name, valuep); 1480 VOP_UNLOCK(vp, 0); 1481 } else if (fp->f_type == DTYPE_PIPE || fp->f_type == DTYPE_SOCKET) { 1482 if (name != _PC_PIPE_BUF) { 1483 error = EINVAL; 1484 } else { 1485 *valuep = PIPE_BUF; 1486 error = 0; 1487 } 1488 } else { 1489 error = EOPNOTSUPP; 1490 } 1491 out: 1492 fdrop(fp, td); 1493 return (error); 1494 } 1495 1496 /* 1497 * Copy filecaps structure allocating memory for ioctls array if needed. 1498 * 1499 * The last parameter indicates whether the fdtable is locked. If it is not and 1500 * ioctls are encountered, copying fails and the caller must lock the table. 1501 * 1502 * Note that if the table was not locked, the caller has to check the relevant 1503 * sequence counter to determine whether the operation was successful. 1504 */ 1505 bool 1506 filecaps_copy(const struct filecaps *src, struct filecaps *dst, bool locked) 1507 { 1508 size_t size; 1509 1510 if (src->fc_ioctls != NULL && !locked) 1511 return (false); 1512 memcpy(dst, src, sizeof(*src)); 1513 if (src->fc_ioctls == NULL) 1514 return (true); 1515 1516 KASSERT(src->fc_nioctls > 0, 1517 ("fc_ioctls != NULL, but fc_nioctls=%hd", src->fc_nioctls)); 1518 1519 size = sizeof(src->fc_ioctls[0]) * src->fc_nioctls; 1520 dst->fc_ioctls = malloc(size, M_FILECAPS, M_WAITOK); 1521 memcpy(dst->fc_ioctls, src->fc_ioctls, size); 1522 return (true); 1523 } 1524 1525 static u_long * 1526 filecaps_copy_prep(const struct filecaps *src) 1527 { 1528 u_long *ioctls; 1529 size_t size; 1530 1531 if (__predict_true(src->fc_ioctls == NULL)) 1532 return (NULL); 1533 1534 KASSERT(src->fc_nioctls > 0, 1535 ("fc_ioctls != NULL, but fc_nioctls=%hd", src->fc_nioctls)); 1536 1537 size = sizeof(src->fc_ioctls[0]) * src->fc_nioctls; 1538 ioctls = malloc(size, M_FILECAPS, M_WAITOK); 1539 return (ioctls); 1540 } 1541 1542 static void 1543 filecaps_copy_finish(const struct filecaps *src, struct filecaps *dst, 1544 u_long *ioctls) 1545 { 1546 size_t size; 1547 1548 *dst = *src; 1549 if (__predict_true(src->fc_ioctls == NULL)) { 1550 MPASS(ioctls == NULL); 1551 return; 1552 } 1553 1554 size = sizeof(src->fc_ioctls[0]) * src->fc_nioctls; 1555 dst->fc_ioctls = ioctls; 1556 bcopy(src->fc_ioctls, dst->fc_ioctls, size); 1557 } 1558 1559 /* 1560 * Move filecaps structure to the new place and clear the old place. 1561 */ 1562 void 1563 filecaps_move(struct filecaps *src, struct filecaps *dst) 1564 { 1565 1566 *dst = *src; 1567 bzero(src, sizeof(*src)); 1568 } 1569 1570 /* 1571 * Fill the given filecaps structure with full rights. 1572 */ 1573 static void 1574 filecaps_fill(struct filecaps *fcaps) 1575 { 1576 1577 CAP_ALL(&fcaps->fc_rights); 1578 fcaps->fc_ioctls = NULL; 1579 fcaps->fc_nioctls = -1; 1580 fcaps->fc_fcntls = CAP_FCNTL_ALL; 1581 } 1582 1583 /* 1584 * Free memory allocated within filecaps structure. 1585 */ 1586 void 1587 filecaps_free(struct filecaps *fcaps) 1588 { 1589 1590 free(fcaps->fc_ioctls, M_FILECAPS); 1591 bzero(fcaps, sizeof(*fcaps)); 1592 } 1593 1594 static u_long * 1595 filecaps_free_prep(struct filecaps *fcaps) 1596 { 1597 u_long *ioctls; 1598 1599 ioctls = fcaps->fc_ioctls; 1600 bzero(fcaps, sizeof(*fcaps)); 1601 return (ioctls); 1602 } 1603 1604 static void 1605 filecaps_free_finish(u_long *ioctls) 1606 { 1607 1608 free(ioctls, M_FILECAPS); 1609 } 1610 1611 /* 1612 * Validate the given filecaps structure. 1613 */ 1614 static void 1615 filecaps_validate(const struct filecaps *fcaps, const char *func) 1616 { 1617 1618 KASSERT(cap_rights_is_valid(&fcaps->fc_rights), 1619 ("%s: invalid rights", func)); 1620 KASSERT((fcaps->fc_fcntls & ~CAP_FCNTL_ALL) == 0, 1621 ("%s: invalid fcntls", func)); 1622 KASSERT(fcaps->fc_fcntls == 0 || 1623 cap_rights_is_set(&fcaps->fc_rights, CAP_FCNTL), 1624 ("%s: fcntls without CAP_FCNTL", func)); 1625 KASSERT(fcaps->fc_ioctls != NULL ? fcaps->fc_nioctls > 0 : 1626 (fcaps->fc_nioctls == -1 || fcaps->fc_nioctls == 0), 1627 ("%s: invalid ioctls", func)); 1628 KASSERT(fcaps->fc_nioctls == 0 || 1629 cap_rights_is_set(&fcaps->fc_rights, CAP_IOCTL), 1630 ("%s: ioctls without CAP_IOCTL", func)); 1631 } 1632 1633 static void 1634 fdgrowtable_exp(struct filedesc *fdp, int nfd) 1635 { 1636 int nfd1; 1637 1638 FILEDESC_XLOCK_ASSERT(fdp); 1639 1640 nfd1 = fdp->fd_nfiles * 2; 1641 if (nfd1 < nfd) 1642 nfd1 = nfd; 1643 fdgrowtable(fdp, nfd1); 1644 } 1645 1646 /* 1647 * Grow the file table to accommodate (at least) nfd descriptors. 1648 */ 1649 static void 1650 fdgrowtable(struct filedesc *fdp, int nfd) 1651 { 1652 struct filedesc0 *fdp0; 1653 struct freetable *ft; 1654 struct fdescenttbl *ntable; 1655 struct fdescenttbl *otable; 1656 int nnfiles, onfiles; 1657 NDSLOTTYPE *nmap, *omap; 1658 1659 /* 1660 * If lastfile is -1 this struct filedesc was just allocated and we are 1661 * growing it to accommodate for the one we are going to copy from. There 1662 * is no need to have a lock on this one as it's not visible to anyone. 1663 */ 1664 if (fdp->fd_lastfile != -1) 1665 FILEDESC_XLOCK_ASSERT(fdp); 1666 1667 KASSERT(fdp->fd_nfiles > 0, ("zero-length file table")); 1668 1669 /* save old values */ 1670 onfiles = fdp->fd_nfiles; 1671 otable = fdp->fd_files; 1672 omap = fdp->fd_map; 1673 1674 /* compute the size of the new table */ 1675 nnfiles = NDSLOTS(nfd) * NDENTRIES; /* round up */ 1676 if (nnfiles <= onfiles) 1677 /* the table is already large enough */ 1678 return; 1679 1680 /* 1681 * Allocate a new table. We need enough space for the number of 1682 * entries, file entries themselves and the struct freetable we will use 1683 * when we decommission the table and place it on the freelist. 1684 * We place the struct freetable in the middle so we don't have 1685 * to worry about padding. 1686 */ 1687 ntable = malloc(offsetof(struct fdescenttbl, fdt_ofiles) + 1688 nnfiles * sizeof(ntable->fdt_ofiles[0]) + 1689 sizeof(struct freetable), 1690 M_FILEDESC, M_ZERO | M_WAITOK); 1691 /* copy the old data */ 1692 ntable->fdt_nfiles = nnfiles; 1693 memcpy(ntable->fdt_ofiles, otable->fdt_ofiles, 1694 onfiles * sizeof(ntable->fdt_ofiles[0])); 1695 1696 /* 1697 * Allocate a new map only if the old is not large enough. It will 1698 * grow at a slower rate than the table as it can map more 1699 * entries than the table can hold. 1700 */ 1701 if (NDSLOTS(nnfiles) > NDSLOTS(onfiles)) { 1702 nmap = malloc(NDSLOTS(nnfiles) * NDSLOTSIZE, M_FILEDESC, 1703 M_ZERO | M_WAITOK); 1704 /* copy over the old data and update the pointer */ 1705 memcpy(nmap, omap, NDSLOTS(onfiles) * sizeof(*omap)); 1706 fdp->fd_map = nmap; 1707 } 1708 1709 /* 1710 * Make sure that ntable is correctly initialized before we replace 1711 * fd_files poiner. Otherwise fget_unlocked() may see inconsistent 1712 * data. 1713 */ 1714 atomic_store_rel_ptr((volatile void *)&fdp->fd_files, (uintptr_t)ntable); 1715 1716 /* 1717 * Do not free the old file table, as some threads may still 1718 * reference entries within it. Instead, place it on a freelist 1719 * which will be processed when the struct filedesc is released. 1720 * 1721 * Note that if onfiles == NDFILE, we're dealing with the original 1722 * static allocation contained within (struct filedesc0 *)fdp, 1723 * which must not be freed. 1724 */ 1725 if (onfiles > NDFILE) { 1726 ft = (struct freetable *)&otable->fdt_ofiles[onfiles]; 1727 fdp0 = (struct filedesc0 *)fdp; 1728 ft->ft_table = otable; 1729 SLIST_INSERT_HEAD(&fdp0->fd_free, ft, ft_next); 1730 } 1731 /* 1732 * The map does not have the same possibility of threads still 1733 * holding references to it. So always free it as long as it 1734 * does not reference the original static allocation. 1735 */ 1736 if (NDSLOTS(onfiles) > NDSLOTS(NDFILE)) 1737 free(omap, M_FILEDESC); 1738 } 1739 1740 /* 1741 * Allocate a file descriptor for the process. 1742 */ 1743 int 1744 fdalloc(struct thread *td, int minfd, int *result) 1745 { 1746 struct proc *p = td->td_proc; 1747 struct filedesc *fdp = p->p_fd; 1748 int fd, maxfd, allocfd; 1749 #ifdef RACCT 1750 int error; 1751 #endif 1752 1753 FILEDESC_XLOCK_ASSERT(fdp); 1754 1755 if (fdp->fd_freefile > minfd) 1756 minfd = fdp->fd_freefile; 1757 1758 maxfd = getmaxfd(td); 1759 1760 /* 1761 * Search the bitmap for a free descriptor starting at minfd. 1762 * If none is found, grow the file table. 1763 */ 1764 fd = fd_first_free(fdp, minfd, fdp->fd_nfiles); 1765 if (fd >= maxfd) 1766 return (EMFILE); 1767 if (fd >= fdp->fd_nfiles) { 1768 allocfd = min(fd * 2, maxfd); 1769 #ifdef RACCT 1770 if (RACCT_ENABLED()) { 1771 error = racct_set_unlocked(p, RACCT_NOFILE, allocfd); 1772 if (error != 0) 1773 return (EMFILE); 1774 } 1775 #endif 1776 /* 1777 * fd is already equal to first free descriptor >= minfd, so 1778 * we only need to grow the table and we are done. 1779 */ 1780 fdgrowtable_exp(fdp, allocfd); 1781 } 1782 1783 /* 1784 * Perform some sanity checks, then mark the file descriptor as 1785 * used and return it to the caller. 1786 */ 1787 KASSERT(fd >= 0 && fd < min(maxfd, fdp->fd_nfiles), 1788 ("invalid descriptor %d", fd)); 1789 KASSERT(!fdisused(fdp, fd), 1790 ("fd_first_free() returned non-free descriptor")); 1791 KASSERT(fdp->fd_ofiles[fd].fde_file == NULL, 1792 ("file descriptor isn't free")); 1793 fdused(fdp, fd); 1794 *result = fd; 1795 return (0); 1796 } 1797 1798 /* 1799 * Allocate n file descriptors for the process. 1800 */ 1801 int 1802 fdallocn(struct thread *td, int minfd, int *fds, int n) 1803 { 1804 struct proc *p = td->td_proc; 1805 struct filedesc *fdp = p->p_fd; 1806 int i; 1807 1808 FILEDESC_XLOCK_ASSERT(fdp); 1809 1810 for (i = 0; i < n; i++) 1811 if (fdalloc(td, 0, &fds[i]) != 0) 1812 break; 1813 1814 if (i < n) { 1815 for (i--; i >= 0; i--) 1816 fdunused(fdp, fds[i]); 1817 return (EMFILE); 1818 } 1819 1820 return (0); 1821 } 1822 1823 /* 1824 * Create a new open file structure and allocate a file descriptor for the 1825 * process that refers to it. We add one reference to the file for the 1826 * descriptor table and one reference for resultfp. This is to prevent us 1827 * being preempted and the entry in the descriptor table closed after we 1828 * release the FILEDESC lock. 1829 */ 1830 int 1831 falloc_caps(struct thread *td, struct file **resultfp, int *resultfd, int flags, 1832 struct filecaps *fcaps) 1833 { 1834 struct file *fp; 1835 int error, fd; 1836 1837 error = falloc_noinstall(td, &fp); 1838 if (error) 1839 return (error); /* no reference held on error */ 1840 1841 error = finstall(td, fp, &fd, flags, fcaps); 1842 if (error) { 1843 fdrop(fp, td); /* one reference (fp only) */ 1844 return (error); 1845 } 1846 1847 if (resultfp != NULL) 1848 *resultfp = fp; /* copy out result */ 1849 else 1850 fdrop(fp, td); /* release local reference */ 1851 1852 if (resultfd != NULL) 1853 *resultfd = fd; 1854 1855 return (0); 1856 } 1857 1858 /* 1859 * Create a new open file structure without allocating a file descriptor. 1860 */ 1861 int 1862 falloc_noinstall(struct thread *td, struct file **resultfp) 1863 { 1864 struct file *fp; 1865 int maxuserfiles = maxfiles - (maxfiles / 20); 1866 int openfiles_new; 1867 static struct timeval lastfail; 1868 static int curfail; 1869 1870 KASSERT(resultfp != NULL, ("%s: resultfp == NULL", __func__)); 1871 1872 openfiles_new = atomic_fetchadd_int(&openfiles, 1) + 1; 1873 if ((openfiles_new >= maxuserfiles && 1874 priv_check(td, PRIV_MAXFILES) != 0) || 1875 openfiles_new >= maxfiles) { 1876 atomic_subtract_int(&openfiles, 1); 1877 if (ppsratecheck(&lastfail, &curfail, 1)) { 1878 printf("kern.maxfiles limit exceeded by uid %i, (%s) " 1879 "please see tuning(7).\n", td->td_ucred->cr_ruid, td->td_proc->p_comm); 1880 } 1881 return (ENFILE); 1882 } 1883 fp = uma_zalloc(file_zone, M_WAITOK); 1884 bzero(fp, sizeof(*fp)); 1885 refcount_init(&fp->f_count, 1); 1886 fp->f_cred = crhold(td->td_ucred); 1887 fp->f_ops = &badfileops; 1888 *resultfp = fp; 1889 return (0); 1890 } 1891 1892 /* 1893 * Install a file in a file descriptor table. 1894 */ 1895 void 1896 _finstall(struct filedesc *fdp, struct file *fp, int fd, int flags, 1897 struct filecaps *fcaps) 1898 { 1899 struct filedescent *fde; 1900 1901 MPASS(fp != NULL); 1902 if (fcaps != NULL) 1903 filecaps_validate(fcaps, __func__); 1904 FILEDESC_XLOCK_ASSERT(fdp); 1905 1906 fde = &fdp->fd_ofiles[fd]; 1907 #ifdef CAPABILITIES 1908 seqc_write_begin(&fde->fde_seqc); 1909 #endif 1910 fde->fde_file = fp; 1911 fde->fde_flags = (flags & O_CLOEXEC) != 0 ? UF_EXCLOSE : 0; 1912 if (fcaps != NULL) 1913 filecaps_move(fcaps, &fde->fde_caps); 1914 else 1915 filecaps_fill(&fde->fde_caps); 1916 #ifdef CAPABILITIES 1917 seqc_write_end(&fde->fde_seqc); 1918 #endif 1919 } 1920 1921 int 1922 finstall(struct thread *td, struct file *fp, int *fd, int flags, 1923 struct filecaps *fcaps) 1924 { 1925 struct filedesc *fdp = td->td_proc->p_fd; 1926 int error; 1927 1928 MPASS(fd != NULL); 1929 1930 if (!fhold(fp)) 1931 return (EBADF); 1932 FILEDESC_XLOCK(fdp); 1933 if ((error = fdalloc(td, 0, fd))) { 1934 FILEDESC_XUNLOCK(fdp); 1935 fdrop(fp, td); 1936 return (error); 1937 } 1938 _finstall(fdp, fp, *fd, flags, fcaps); 1939 FILEDESC_XUNLOCK(fdp); 1940 return (0); 1941 } 1942 1943 /* 1944 * Build a new filedesc structure from another. 1945 * Copy the current, root, and jail root vnode references. 1946 * 1947 * If fdp is not NULL, return with it shared locked. 1948 */ 1949 struct filedesc * 1950 fdinit(struct filedesc *fdp, bool prepfiles) 1951 { 1952 struct filedesc0 *newfdp0; 1953 struct filedesc *newfdp; 1954 1955 newfdp0 = uma_zalloc(filedesc0_zone, M_WAITOK | M_ZERO); 1956 newfdp = &newfdp0->fd_fd; 1957 1958 /* Create the file descriptor table. */ 1959 FILEDESC_LOCK_INIT(newfdp); 1960 refcount_init(&newfdp->fd_refcnt, 1); 1961 refcount_init(&newfdp->fd_holdcnt, 1); 1962 newfdp->fd_cmask = CMASK; 1963 newfdp->fd_map = newfdp0->fd_dmap; 1964 newfdp->fd_lastfile = -1; 1965 newfdp->fd_files = (struct fdescenttbl *)&newfdp0->fd_dfiles; 1966 newfdp->fd_files->fdt_nfiles = NDFILE; 1967 1968 if (fdp == NULL) 1969 return (newfdp); 1970 1971 if (prepfiles && fdp->fd_lastfile >= newfdp->fd_nfiles) 1972 fdgrowtable(newfdp, fdp->fd_lastfile + 1); 1973 1974 FILEDESC_SLOCK(fdp); 1975 newfdp->fd_cdir = fdp->fd_cdir; 1976 if (newfdp->fd_cdir) 1977 vrefact(newfdp->fd_cdir); 1978 newfdp->fd_rdir = fdp->fd_rdir; 1979 if (newfdp->fd_rdir) 1980 vrefact(newfdp->fd_rdir); 1981 newfdp->fd_jdir = fdp->fd_jdir; 1982 if (newfdp->fd_jdir) 1983 vrefact(newfdp->fd_jdir); 1984 1985 if (!prepfiles) { 1986 FILEDESC_SUNLOCK(fdp); 1987 } else { 1988 while (fdp->fd_lastfile >= newfdp->fd_nfiles) { 1989 FILEDESC_SUNLOCK(fdp); 1990 fdgrowtable(newfdp, fdp->fd_lastfile + 1); 1991 FILEDESC_SLOCK(fdp); 1992 } 1993 } 1994 1995 return (newfdp); 1996 } 1997 1998 static struct filedesc * 1999 fdhold(struct proc *p) 2000 { 2001 struct filedesc *fdp; 2002 2003 PROC_LOCK_ASSERT(p, MA_OWNED); 2004 fdp = p->p_fd; 2005 if (fdp != NULL) 2006 refcount_acquire(&fdp->fd_holdcnt); 2007 return (fdp); 2008 } 2009 2010 static void 2011 fddrop(struct filedesc *fdp) 2012 { 2013 2014 if (fdp->fd_holdcnt > 1) { 2015 if (refcount_release(&fdp->fd_holdcnt) == 0) 2016 return; 2017 } 2018 2019 FILEDESC_LOCK_DESTROY(fdp); 2020 uma_zfree(filedesc0_zone, fdp); 2021 } 2022 2023 /* 2024 * Share a filedesc structure. 2025 */ 2026 struct filedesc * 2027 fdshare(struct filedesc *fdp) 2028 { 2029 2030 refcount_acquire(&fdp->fd_refcnt); 2031 return (fdp); 2032 } 2033 2034 /* 2035 * Unshare a filedesc structure, if necessary by making a copy 2036 */ 2037 void 2038 fdunshare(struct thread *td) 2039 { 2040 struct filedesc *tmp; 2041 struct proc *p = td->td_proc; 2042 2043 if (p->p_fd->fd_refcnt == 1) 2044 return; 2045 2046 tmp = fdcopy(p->p_fd); 2047 fdescfree(td); 2048 p->p_fd = tmp; 2049 } 2050 2051 void 2052 fdinstall_remapped(struct thread *td, struct filedesc *fdp) 2053 { 2054 2055 fdescfree(td); 2056 td->td_proc->p_fd = fdp; 2057 } 2058 2059 /* 2060 * Copy a filedesc structure. A NULL pointer in returns a NULL reference, 2061 * this is to ease callers, not catch errors. 2062 */ 2063 struct filedesc * 2064 fdcopy(struct filedesc *fdp) 2065 { 2066 struct filedesc *newfdp; 2067 struct filedescent *nfde, *ofde; 2068 int i; 2069 2070 MPASS(fdp != NULL); 2071 2072 newfdp = fdinit(fdp, true); 2073 /* copy all passable descriptors (i.e. not kqueue) */ 2074 newfdp->fd_freefile = -1; 2075 for (i = 0; i <= fdp->fd_lastfile; ++i) { 2076 ofde = &fdp->fd_ofiles[i]; 2077 if (ofde->fde_file == NULL || 2078 (ofde->fde_file->f_ops->fo_flags & DFLAG_PASSABLE) == 0 || 2079 !fhold(ofde->fde_file)) { 2080 if (newfdp->fd_freefile == -1) 2081 newfdp->fd_freefile = i; 2082 continue; 2083 } 2084 nfde = &newfdp->fd_ofiles[i]; 2085 *nfde = *ofde; 2086 filecaps_copy(&ofde->fde_caps, &nfde->fde_caps, true); 2087 fdused_init(newfdp, i); 2088 newfdp->fd_lastfile = i; 2089 } 2090 if (newfdp->fd_freefile == -1) 2091 newfdp->fd_freefile = i; 2092 newfdp->fd_cmask = fdp->fd_cmask; 2093 FILEDESC_SUNLOCK(fdp); 2094 return (newfdp); 2095 } 2096 2097 /* 2098 * Copies a filedesc structure, while remapping all file descriptors 2099 * stored inside using a translation table. 2100 * 2101 * File descriptors are copied over to the new file descriptor table, 2102 * regardless of whether the close-on-exec flag is set. 2103 */ 2104 int 2105 fdcopy_remapped(struct filedesc *fdp, const int *fds, size_t nfds, 2106 struct filedesc **ret) 2107 { 2108 struct filedesc *newfdp; 2109 struct filedescent *nfde, *ofde; 2110 int error, i; 2111 2112 MPASS(fdp != NULL); 2113 2114 newfdp = fdinit(fdp, true); 2115 if (nfds > fdp->fd_lastfile + 1) { 2116 /* New table cannot be larger than the old one. */ 2117 error = E2BIG; 2118 goto bad; 2119 } 2120 /* Copy all passable descriptors (i.e. not kqueue). */ 2121 newfdp->fd_freefile = nfds; 2122 for (i = 0; i < nfds; ++i) { 2123 if (fds[i] < 0 || fds[i] > fdp->fd_lastfile) { 2124 /* File descriptor out of bounds. */ 2125 error = EBADF; 2126 goto bad; 2127 } 2128 ofde = &fdp->fd_ofiles[fds[i]]; 2129 if (ofde->fde_file == NULL) { 2130 /* Unused file descriptor. */ 2131 error = EBADF; 2132 goto bad; 2133 } 2134 if ((ofde->fde_file->f_ops->fo_flags & DFLAG_PASSABLE) == 0) { 2135 /* File descriptor cannot be passed. */ 2136 error = EINVAL; 2137 goto bad; 2138 } 2139 if (!fhold(nfde->fde_file)) { 2140 error = EBADF; 2141 goto bad; 2142 } 2143 nfde = &newfdp->fd_ofiles[i]; 2144 *nfde = *ofde; 2145 filecaps_copy(&ofde->fde_caps, &nfde->fde_caps, true); 2146 fdused_init(newfdp, i); 2147 newfdp->fd_lastfile = i; 2148 } 2149 newfdp->fd_cmask = fdp->fd_cmask; 2150 FILEDESC_SUNLOCK(fdp); 2151 *ret = newfdp; 2152 return (0); 2153 bad: 2154 FILEDESC_SUNLOCK(fdp); 2155 fdescfree_remapped(newfdp); 2156 return (error); 2157 } 2158 2159 /* 2160 * Clear POSIX style locks. This is only used when fdp looses a reference (i.e. 2161 * one of processes using it exits) and the table used to be shared. 2162 */ 2163 static void 2164 fdclearlocks(struct thread *td) 2165 { 2166 struct filedesc *fdp; 2167 struct filedesc_to_leader *fdtol; 2168 struct flock lf; 2169 struct file *fp; 2170 struct proc *p; 2171 struct vnode *vp; 2172 int i; 2173 2174 p = td->td_proc; 2175 fdp = p->p_fd; 2176 fdtol = p->p_fdtol; 2177 MPASS(fdtol != NULL); 2178 2179 FILEDESC_XLOCK(fdp); 2180 KASSERT(fdtol->fdl_refcount > 0, 2181 ("filedesc_to_refcount botch: fdl_refcount=%d", 2182 fdtol->fdl_refcount)); 2183 if (fdtol->fdl_refcount == 1 && 2184 (p->p_leader->p_flag & P_ADVLOCK) != 0) { 2185 for (i = 0; i <= fdp->fd_lastfile; i++) { 2186 fp = fdp->fd_ofiles[i].fde_file; 2187 if (fp == NULL || fp->f_type != DTYPE_VNODE || 2188 !fhold(fp)) 2189 continue; 2190 FILEDESC_XUNLOCK(fdp); 2191 lf.l_whence = SEEK_SET; 2192 lf.l_start = 0; 2193 lf.l_len = 0; 2194 lf.l_type = F_UNLCK; 2195 vp = fp->f_vnode; 2196 (void) VOP_ADVLOCK(vp, 2197 (caddr_t)p->p_leader, F_UNLCK, 2198 &lf, F_POSIX); 2199 FILEDESC_XLOCK(fdp); 2200 fdrop(fp, td); 2201 } 2202 } 2203 retry: 2204 if (fdtol->fdl_refcount == 1) { 2205 if (fdp->fd_holdleaderscount > 0 && 2206 (p->p_leader->p_flag & P_ADVLOCK) != 0) { 2207 /* 2208 * close() or kern_dup() has cleared a reference 2209 * in a shared file descriptor table. 2210 */ 2211 fdp->fd_holdleaderswakeup = 1; 2212 sx_sleep(&fdp->fd_holdleaderscount, 2213 FILEDESC_LOCK(fdp), PLOCK, "fdlhold", 0); 2214 goto retry; 2215 } 2216 if (fdtol->fdl_holdcount > 0) { 2217 /* 2218 * Ensure that fdtol->fdl_leader remains 2219 * valid in closef(). 2220 */ 2221 fdtol->fdl_wakeup = 1; 2222 sx_sleep(fdtol, FILEDESC_LOCK(fdp), PLOCK, 2223 "fdlhold", 0); 2224 goto retry; 2225 } 2226 } 2227 fdtol->fdl_refcount--; 2228 if (fdtol->fdl_refcount == 0 && 2229 fdtol->fdl_holdcount == 0) { 2230 fdtol->fdl_next->fdl_prev = fdtol->fdl_prev; 2231 fdtol->fdl_prev->fdl_next = fdtol->fdl_next; 2232 } else 2233 fdtol = NULL; 2234 p->p_fdtol = NULL; 2235 FILEDESC_XUNLOCK(fdp); 2236 if (fdtol != NULL) 2237 free(fdtol, M_FILEDESC_TO_LEADER); 2238 } 2239 2240 /* 2241 * Release a filedesc structure. 2242 */ 2243 static void 2244 fdescfree_fds(struct thread *td, struct filedesc *fdp, bool needclose) 2245 { 2246 struct filedesc0 *fdp0; 2247 struct freetable *ft, *tft; 2248 struct filedescent *fde; 2249 struct file *fp; 2250 int i; 2251 2252 for (i = 0; i <= fdp->fd_lastfile; i++) { 2253 fde = &fdp->fd_ofiles[i]; 2254 fp = fde->fde_file; 2255 if (fp != NULL) { 2256 fdefree_last(fde); 2257 if (needclose) 2258 (void) closef(fp, td); 2259 else 2260 fdrop(fp, td); 2261 } 2262 } 2263 2264 if (NDSLOTS(fdp->fd_nfiles) > NDSLOTS(NDFILE)) 2265 free(fdp->fd_map, M_FILEDESC); 2266 if (fdp->fd_nfiles > NDFILE) 2267 free(fdp->fd_files, M_FILEDESC); 2268 2269 fdp0 = (struct filedesc0 *)fdp; 2270 SLIST_FOREACH_SAFE(ft, &fdp0->fd_free, ft_next, tft) 2271 free(ft->ft_table, M_FILEDESC); 2272 2273 fddrop(fdp); 2274 } 2275 2276 void 2277 fdescfree(struct thread *td) 2278 { 2279 struct proc *p; 2280 struct filedesc *fdp; 2281 struct vnode *cdir, *jdir, *rdir; 2282 2283 p = td->td_proc; 2284 fdp = p->p_fd; 2285 MPASS(fdp != NULL); 2286 2287 #ifdef RACCT 2288 if (RACCT_ENABLED()) 2289 racct_set_unlocked(p, RACCT_NOFILE, 0); 2290 #endif 2291 2292 if (p->p_fdtol != NULL) 2293 fdclearlocks(td); 2294 2295 PROC_LOCK(p); 2296 p->p_fd = NULL; 2297 PROC_UNLOCK(p); 2298 2299 if (refcount_release(&fdp->fd_refcnt) == 0) 2300 return; 2301 2302 FILEDESC_XLOCK(fdp); 2303 cdir = fdp->fd_cdir; 2304 fdp->fd_cdir = NULL; 2305 rdir = fdp->fd_rdir; 2306 fdp->fd_rdir = NULL; 2307 jdir = fdp->fd_jdir; 2308 fdp->fd_jdir = NULL; 2309 FILEDESC_XUNLOCK(fdp); 2310 2311 if (cdir != NULL) 2312 vrele(cdir); 2313 if (rdir != NULL) 2314 vrele(rdir); 2315 if (jdir != NULL) 2316 vrele(jdir); 2317 2318 fdescfree_fds(td, fdp, 1); 2319 } 2320 2321 void 2322 fdescfree_remapped(struct filedesc *fdp) 2323 { 2324 2325 if (fdp->fd_cdir != NULL) 2326 vrele(fdp->fd_cdir); 2327 if (fdp->fd_rdir != NULL) 2328 vrele(fdp->fd_rdir); 2329 if (fdp->fd_jdir != NULL) 2330 vrele(fdp->fd_jdir); 2331 2332 fdescfree_fds(curthread, fdp, 0); 2333 } 2334 2335 /* 2336 * For setugid programs, we don't want to people to use that setugidness 2337 * to generate error messages which write to a file which otherwise would 2338 * otherwise be off-limits to the process. We check for filesystems where 2339 * the vnode can change out from under us after execve (like [lin]procfs). 2340 * 2341 * Since fdsetugidsafety calls this only for fd 0, 1 and 2, this check is 2342 * sufficient. We also don't check for setugidness since we know we are. 2343 */ 2344 static bool 2345 is_unsafe(struct file *fp) 2346 { 2347 struct vnode *vp; 2348 2349 if (fp->f_type != DTYPE_VNODE) 2350 return (false); 2351 2352 vp = fp->f_vnode; 2353 return ((vp->v_vflag & VV_PROCDEP) != 0); 2354 } 2355 2356 /* 2357 * Make this setguid thing safe, if at all possible. 2358 */ 2359 void 2360 fdsetugidsafety(struct thread *td) 2361 { 2362 struct filedesc *fdp; 2363 struct file *fp; 2364 int i; 2365 2366 fdp = td->td_proc->p_fd; 2367 KASSERT(fdp->fd_refcnt == 1, ("the fdtable should not be shared")); 2368 MPASS(fdp->fd_nfiles >= 3); 2369 for (i = 0; i <= 2; i++) { 2370 fp = fdp->fd_ofiles[i].fde_file; 2371 if (fp != NULL && is_unsafe(fp)) { 2372 FILEDESC_XLOCK(fdp); 2373 knote_fdclose(td, i); 2374 /* 2375 * NULL-out descriptor prior to close to avoid 2376 * a race while close blocks. 2377 */ 2378 fdfree(fdp, i); 2379 FILEDESC_XUNLOCK(fdp); 2380 (void) closef(fp, td); 2381 } 2382 } 2383 } 2384 2385 /* 2386 * If a specific file object occupies a specific file descriptor, close the 2387 * file descriptor entry and drop a reference on the file object. This is a 2388 * convenience function to handle a subsequent error in a function that calls 2389 * falloc() that handles the race that another thread might have closed the 2390 * file descriptor out from under the thread creating the file object. 2391 */ 2392 void 2393 fdclose(struct thread *td, struct file *fp, int idx) 2394 { 2395 struct filedesc *fdp = td->td_proc->p_fd; 2396 2397 FILEDESC_XLOCK(fdp); 2398 if (fdp->fd_ofiles[idx].fde_file == fp) { 2399 fdfree(fdp, idx); 2400 FILEDESC_XUNLOCK(fdp); 2401 fdrop(fp, td); 2402 } else 2403 FILEDESC_XUNLOCK(fdp); 2404 } 2405 2406 /* 2407 * Close any files on exec? 2408 */ 2409 void 2410 fdcloseexec(struct thread *td) 2411 { 2412 struct filedesc *fdp; 2413 struct filedescent *fde; 2414 struct file *fp; 2415 int i; 2416 2417 fdp = td->td_proc->p_fd; 2418 KASSERT(fdp->fd_refcnt == 1, ("the fdtable should not be shared")); 2419 for (i = 0; i <= fdp->fd_lastfile; i++) { 2420 fde = &fdp->fd_ofiles[i]; 2421 fp = fde->fde_file; 2422 if (fp != NULL && (fp->f_type == DTYPE_MQUEUE || 2423 (fde->fde_flags & UF_EXCLOSE))) { 2424 FILEDESC_XLOCK(fdp); 2425 fdfree(fdp, i); 2426 (void) closefp(fdp, i, fp, td, 0); 2427 FILEDESC_UNLOCK_ASSERT(fdp); 2428 } 2429 } 2430 } 2431 2432 /* 2433 * It is unsafe for set[ug]id processes to be started with file 2434 * descriptors 0..2 closed, as these descriptors are given implicit 2435 * significance in the Standard C library. fdcheckstd() will create a 2436 * descriptor referencing /dev/null for each of stdin, stdout, and 2437 * stderr that is not already open. 2438 */ 2439 int 2440 fdcheckstd(struct thread *td) 2441 { 2442 struct filedesc *fdp; 2443 register_t save; 2444 int i, error, devnull; 2445 2446 fdp = td->td_proc->p_fd; 2447 KASSERT(fdp->fd_refcnt == 1, ("the fdtable should not be shared")); 2448 MPASS(fdp->fd_nfiles >= 3); 2449 devnull = -1; 2450 for (i = 0; i <= 2; i++) { 2451 if (fdp->fd_ofiles[i].fde_file != NULL) 2452 continue; 2453 2454 save = td->td_retval[0]; 2455 if (devnull != -1) { 2456 error = kern_dup(td, FDDUP_FIXED, 0, devnull, i); 2457 } else { 2458 error = kern_openat(td, AT_FDCWD, "/dev/null", 2459 UIO_SYSSPACE, O_RDWR, 0); 2460 if (error == 0) { 2461 devnull = td->td_retval[0]; 2462 KASSERT(devnull == i, ("we didn't get our fd")); 2463 } 2464 } 2465 td->td_retval[0] = save; 2466 if (error != 0) 2467 return (error); 2468 } 2469 return (0); 2470 } 2471 2472 /* 2473 * Internal form of close. Decrement reference count on file structure. 2474 * Note: td may be NULL when closing a file that was being passed in a 2475 * message. 2476 */ 2477 int 2478 closef(struct file *fp, struct thread *td) 2479 { 2480 struct vnode *vp; 2481 struct flock lf; 2482 struct filedesc_to_leader *fdtol; 2483 struct filedesc *fdp; 2484 2485 /* 2486 * POSIX record locking dictates that any close releases ALL 2487 * locks owned by this process. This is handled by setting 2488 * a flag in the unlock to free ONLY locks obeying POSIX 2489 * semantics, and not to free BSD-style file locks. 2490 * If the descriptor was in a message, POSIX-style locks 2491 * aren't passed with the descriptor, and the thread pointer 2492 * will be NULL. Callers should be careful only to pass a 2493 * NULL thread pointer when there really is no owning 2494 * context that might have locks, or the locks will be 2495 * leaked. 2496 */ 2497 if (fp->f_type == DTYPE_VNODE && td != NULL) { 2498 vp = fp->f_vnode; 2499 if ((td->td_proc->p_leader->p_flag & P_ADVLOCK) != 0) { 2500 lf.l_whence = SEEK_SET; 2501 lf.l_start = 0; 2502 lf.l_len = 0; 2503 lf.l_type = F_UNLCK; 2504 (void) VOP_ADVLOCK(vp, (caddr_t)td->td_proc->p_leader, 2505 F_UNLCK, &lf, F_POSIX); 2506 } 2507 fdtol = td->td_proc->p_fdtol; 2508 if (fdtol != NULL) { 2509 /* 2510 * Handle special case where file descriptor table is 2511 * shared between multiple process leaders. 2512 */ 2513 fdp = td->td_proc->p_fd; 2514 FILEDESC_XLOCK(fdp); 2515 for (fdtol = fdtol->fdl_next; 2516 fdtol != td->td_proc->p_fdtol; 2517 fdtol = fdtol->fdl_next) { 2518 if ((fdtol->fdl_leader->p_flag & 2519 P_ADVLOCK) == 0) 2520 continue; 2521 fdtol->fdl_holdcount++; 2522 FILEDESC_XUNLOCK(fdp); 2523 lf.l_whence = SEEK_SET; 2524 lf.l_start = 0; 2525 lf.l_len = 0; 2526 lf.l_type = F_UNLCK; 2527 vp = fp->f_vnode; 2528 (void) VOP_ADVLOCK(vp, 2529 (caddr_t)fdtol->fdl_leader, F_UNLCK, &lf, 2530 F_POSIX); 2531 FILEDESC_XLOCK(fdp); 2532 fdtol->fdl_holdcount--; 2533 if (fdtol->fdl_holdcount == 0 && 2534 fdtol->fdl_wakeup != 0) { 2535 fdtol->fdl_wakeup = 0; 2536 wakeup(fdtol); 2537 } 2538 } 2539 FILEDESC_XUNLOCK(fdp); 2540 } 2541 } 2542 return (fdrop(fp, td)); 2543 } 2544 2545 /* 2546 * Initialize the file pointer with the specified properties. 2547 * 2548 * The ops are set with release semantics to be certain that the flags, type, 2549 * and data are visible when ops is. This is to prevent ops methods from being 2550 * called with bad data. 2551 */ 2552 void 2553 finit(struct file *fp, u_int flag, short type, void *data, struct fileops *ops) 2554 { 2555 fp->f_data = data; 2556 fp->f_flag = flag; 2557 fp->f_type = type; 2558 atomic_store_rel_ptr((volatile uintptr_t *)&fp->f_ops, (uintptr_t)ops); 2559 } 2560 2561 int 2562 fget_cap_locked(struct filedesc *fdp, int fd, cap_rights_t *needrightsp, 2563 struct file **fpp, struct filecaps *havecapsp) 2564 { 2565 struct filedescent *fde; 2566 int error; 2567 2568 FILEDESC_LOCK_ASSERT(fdp); 2569 2570 fde = fdeget_locked(fdp, fd); 2571 if (fde == NULL) { 2572 error = EBADF; 2573 goto out; 2574 } 2575 2576 #ifdef CAPABILITIES 2577 error = cap_check(cap_rights_fde_inline(fde), needrightsp); 2578 if (error != 0) 2579 goto out; 2580 #endif 2581 2582 if (havecapsp != NULL) 2583 filecaps_copy(&fde->fde_caps, havecapsp, true); 2584 2585 *fpp = fde->fde_file; 2586 2587 error = 0; 2588 out: 2589 return (error); 2590 } 2591 2592 int 2593 fget_cap(struct thread *td, int fd, cap_rights_t *needrightsp, 2594 struct file **fpp, struct filecaps *havecapsp) 2595 { 2596 struct filedesc *fdp = td->td_proc->p_fd; 2597 int error; 2598 #ifndef CAPABILITIES 2599 error = fget_unlocked(fdp, fd, needrightsp, fpp, NULL); 2600 if (error == 0 && havecapsp != NULL) 2601 filecaps_fill(havecapsp); 2602 #else 2603 struct file *fp; 2604 seqc_t seq; 2605 2606 for (;;) { 2607 error = fget_unlocked(fdp, fd, needrightsp, &fp, &seq); 2608 if (error != 0) 2609 return (error); 2610 2611 if (havecapsp != NULL) { 2612 if (!filecaps_copy(&fdp->fd_ofiles[fd].fde_caps, 2613 havecapsp, false)) { 2614 fdrop(fp, td); 2615 goto get_locked; 2616 } 2617 } 2618 2619 if (!fd_modified(fdp, fd, seq)) 2620 break; 2621 fdrop(fp, td); 2622 } 2623 2624 *fpp = fp; 2625 return (0); 2626 2627 get_locked: 2628 FILEDESC_SLOCK(fdp); 2629 error = fget_cap_locked(fdp, fd, needrightsp, fpp, havecapsp); 2630 if (error == 0 && !fhold(*fpp)) 2631 error = EBADF; 2632 FILEDESC_SUNLOCK(fdp); 2633 #endif 2634 return (error); 2635 } 2636 2637 int 2638 fget_unlocked(struct filedesc *fdp, int fd, cap_rights_t *needrightsp, 2639 struct file **fpp, seqc_t *seqp) 2640 { 2641 #ifdef CAPABILITIES 2642 const struct filedescent *fde; 2643 #endif 2644 const struct fdescenttbl *fdt; 2645 struct file *fp; 2646 u_int count; 2647 #ifdef CAPABILITIES 2648 seqc_t seq; 2649 cap_rights_t haverights; 2650 int error; 2651 #endif 2652 2653 fdt = fdp->fd_files; 2654 if (__predict_false((u_int)fd >= fdt->fdt_nfiles)) 2655 return (EBADF); 2656 /* 2657 * Fetch the descriptor locklessly. We avoid fdrop() races by 2658 * never raising a refcount above 0. To accomplish this we have 2659 * to use a cmpset loop rather than an atomic_add. The descriptor 2660 * must be re-verified once we acquire a reference to be certain 2661 * that the identity is still correct and we did not lose a race 2662 * due to preemption. 2663 */ 2664 for (;;) { 2665 #ifdef CAPABILITIES 2666 seq = seqc_read(fd_seqc(fdt, fd)); 2667 fde = &fdt->fdt_ofiles[fd]; 2668 haverights = *cap_rights_fde_inline(fde); 2669 fp = fde->fde_file; 2670 if (!seqc_consistent(fd_seqc(fdt, fd), seq)) 2671 continue; 2672 #else 2673 fp = fdt->fdt_ofiles[fd].fde_file; 2674 #endif 2675 if (fp == NULL) 2676 return (EBADF); 2677 #ifdef CAPABILITIES 2678 error = cap_check(&haverights, needrightsp); 2679 if (error != 0) 2680 return (error); 2681 #endif 2682 count = fp->f_count; 2683 retry: 2684 if (count == 0) { 2685 /* 2686 * Force a reload. Other thread could reallocate the 2687 * table before this fd was closed, so it possible that 2688 * there is a stale fp pointer in cached version. 2689 */ 2690 fdt = *(const struct fdescenttbl * const volatile *) 2691 &(fdp->fd_files); 2692 continue; 2693 } 2694 if (__predict_false(count + 1 < count)) 2695 return (EBADF); 2696 2697 /* 2698 * Use an acquire barrier to force re-reading of fdt so it is 2699 * refreshed for verification. 2700 */ 2701 if (__predict_false(atomic_fcmpset_acq_int(&fp->f_count, 2702 &count, count + 1) == 0)) 2703 goto retry; 2704 fdt = fdp->fd_files; 2705 #ifdef CAPABILITIES 2706 if (seqc_consistent_nomb(fd_seqc(fdt, fd), seq)) 2707 #else 2708 if (fp == fdt->fdt_ofiles[fd].fde_file) 2709 #endif 2710 break; 2711 fdrop(fp, curthread); 2712 } 2713 *fpp = fp; 2714 if (seqp != NULL) { 2715 #ifdef CAPABILITIES 2716 *seqp = seq; 2717 #endif 2718 } 2719 return (0); 2720 } 2721 2722 /* 2723 * Extract the file pointer associated with the specified descriptor for the 2724 * current user process. 2725 * 2726 * If the descriptor doesn't exist or doesn't match 'flags', EBADF is 2727 * returned. 2728 * 2729 * File's rights will be checked against the capability rights mask. 2730 * 2731 * If an error occurred the non-zero error is returned and *fpp is set to 2732 * NULL. Otherwise *fpp is held and set and zero is returned. Caller is 2733 * responsible for fdrop(). 2734 */ 2735 static __inline int 2736 _fget(struct thread *td, int fd, struct file **fpp, int flags, 2737 cap_rights_t *needrightsp, seqc_t *seqp) 2738 { 2739 struct filedesc *fdp; 2740 struct file *fp; 2741 int error; 2742 2743 *fpp = NULL; 2744 fdp = td->td_proc->p_fd; 2745 error = fget_unlocked(fdp, fd, needrightsp, &fp, seqp); 2746 if (error != 0) 2747 return (error); 2748 if (fp->f_ops == &badfileops) { 2749 fdrop(fp, td); 2750 return (EBADF); 2751 } 2752 2753 /* 2754 * FREAD and FWRITE failure return EBADF as per POSIX. 2755 */ 2756 error = 0; 2757 switch (flags) { 2758 case FREAD: 2759 case FWRITE: 2760 if ((fp->f_flag & flags) == 0) 2761 error = EBADF; 2762 break; 2763 case FEXEC: 2764 if ((fp->f_flag & (FREAD | FEXEC)) == 0 || 2765 ((fp->f_flag & FWRITE) != 0)) 2766 error = EBADF; 2767 break; 2768 case 0: 2769 break; 2770 default: 2771 KASSERT(0, ("wrong flags")); 2772 } 2773 2774 if (error != 0) { 2775 fdrop(fp, td); 2776 return (error); 2777 } 2778 2779 *fpp = fp; 2780 return (0); 2781 } 2782 2783 int 2784 fget(struct thread *td, int fd, cap_rights_t *rightsp, struct file **fpp) 2785 { 2786 2787 return (_fget(td, fd, fpp, 0, rightsp, NULL)); 2788 } 2789 2790 int 2791 fget_mmap(struct thread *td, int fd, cap_rights_t *rightsp, u_char *maxprotp, 2792 struct file **fpp) 2793 { 2794 int error; 2795 #ifndef CAPABILITIES 2796 error = _fget(td, fd, fpp, 0, rightsp, NULL); 2797 if (maxprotp != NULL) 2798 *maxprotp = VM_PROT_ALL; 2799 #else 2800 cap_rights_t fdrights; 2801 struct filedesc *fdp = td->td_proc->p_fd; 2802 seqc_t seq; 2803 2804 MPASS(cap_rights_is_set(rightsp, CAP_MMAP)); 2805 for (;;) { 2806 error = _fget(td, fd, fpp, 0, rightsp, &seq); 2807 if (error != 0) 2808 return (error); 2809 if (maxprotp != NULL) 2810 fdrights = *cap_rights(fdp, fd); 2811 if (!fd_modified(fdp, fd, seq)) 2812 break; 2813 fdrop(*fpp, td); 2814 } 2815 2816 /* 2817 * If requested, convert capability rights to access flags. 2818 */ 2819 if (maxprotp != NULL) 2820 *maxprotp = cap_rights_to_vmprot(&fdrights); 2821 #endif 2822 return (error); 2823 } 2824 2825 int 2826 fget_read(struct thread *td, int fd, cap_rights_t *rightsp, struct file **fpp) 2827 { 2828 2829 return (_fget(td, fd, fpp, FREAD, rightsp, NULL)); 2830 } 2831 2832 int 2833 fget_write(struct thread *td, int fd, cap_rights_t *rightsp, struct file **fpp) 2834 { 2835 2836 return (_fget(td, fd, fpp, FWRITE, rightsp, NULL)); 2837 } 2838 2839 int 2840 fget_fcntl(struct thread *td, int fd, cap_rights_t *rightsp, int needfcntl, 2841 struct file **fpp) 2842 { 2843 struct filedesc *fdp = td->td_proc->p_fd; 2844 #ifndef CAPABILITIES 2845 return (fget_unlocked(fdp, fd, rightsp, fpp, NULL)); 2846 #else 2847 int error; 2848 seqc_t seq; 2849 2850 MPASS(cap_rights_is_set(rightsp, CAP_FCNTL)); 2851 for (;;) { 2852 error = fget_unlocked(fdp, fd, rightsp, fpp, &seq); 2853 if (error != 0) 2854 return (error); 2855 error = cap_fcntl_check(fdp, fd, needfcntl); 2856 if (!fd_modified(fdp, fd, seq)) 2857 break; 2858 fdrop(*fpp, td); 2859 } 2860 if (error != 0) { 2861 fdrop(*fpp, td); 2862 *fpp = NULL; 2863 } 2864 return (error); 2865 #endif 2866 } 2867 2868 /* 2869 * Like fget() but loads the underlying vnode, or returns an error if the 2870 * descriptor does not represent a vnode. Note that pipes use vnodes but 2871 * never have VM objects. The returned vnode will be vref()'d. 2872 * 2873 * XXX: what about the unused flags ? 2874 */ 2875 static __inline int 2876 _fgetvp(struct thread *td, int fd, int flags, cap_rights_t *needrightsp, 2877 struct vnode **vpp) 2878 { 2879 struct file *fp; 2880 int error; 2881 2882 *vpp = NULL; 2883 error = _fget(td, fd, &fp, flags, needrightsp, NULL); 2884 if (error != 0) 2885 return (error); 2886 if (fp->f_vnode == NULL) { 2887 error = EINVAL; 2888 } else { 2889 *vpp = fp->f_vnode; 2890 vrefact(*vpp); 2891 } 2892 fdrop(fp, td); 2893 2894 return (error); 2895 } 2896 2897 int 2898 fgetvp(struct thread *td, int fd, cap_rights_t *rightsp, struct vnode **vpp) 2899 { 2900 2901 return (_fgetvp(td, fd, 0, rightsp, vpp)); 2902 } 2903 2904 int 2905 fgetvp_rights(struct thread *td, int fd, cap_rights_t *needrightsp, 2906 struct filecaps *havecaps, struct vnode **vpp) 2907 { 2908 struct filedesc *fdp; 2909 struct filecaps caps; 2910 struct file *fp; 2911 int error; 2912 2913 fdp = td->td_proc->p_fd; 2914 error = fget_cap_locked(fdp, fd, needrightsp, &fp, &caps); 2915 if (error != 0) 2916 return (error); 2917 if (fp->f_ops == &badfileops) { 2918 error = EBADF; 2919 goto out; 2920 } 2921 if (fp->f_vnode == NULL) { 2922 error = EINVAL; 2923 goto out; 2924 } 2925 2926 *havecaps = caps; 2927 *vpp = fp->f_vnode; 2928 vrefact(*vpp); 2929 2930 return (0); 2931 out: 2932 filecaps_free(&caps); 2933 return (error); 2934 } 2935 2936 int 2937 fgetvp_read(struct thread *td, int fd, cap_rights_t *rightsp, struct vnode **vpp) 2938 { 2939 2940 return (_fgetvp(td, fd, FREAD, rightsp, vpp)); 2941 } 2942 2943 int 2944 fgetvp_exec(struct thread *td, int fd, cap_rights_t *rightsp, struct vnode **vpp) 2945 { 2946 2947 return (_fgetvp(td, fd, FEXEC, rightsp, vpp)); 2948 } 2949 2950 #ifdef notyet 2951 int 2952 fgetvp_write(struct thread *td, int fd, cap_rights_t *rightsp, 2953 struct vnode **vpp) 2954 { 2955 2956 return (_fgetvp(td, fd, FWRITE, rightsp, vpp)); 2957 } 2958 #endif 2959 2960 /* 2961 * Handle the last reference to a file being closed. 2962 * 2963 * Without the noinline attribute clang keeps inlining the func thorough this 2964 * file when fdrop is used. 2965 */ 2966 int __noinline 2967 _fdrop(struct file *fp, struct thread *td) 2968 { 2969 int error; 2970 2971 if (fp->f_count != 0) 2972 panic("fdrop: count %d", fp->f_count); 2973 error = fo_close(fp, td); 2974 atomic_subtract_int(&openfiles, 1); 2975 crfree(fp->f_cred); 2976 free(fp->f_advice, M_FADVISE); 2977 uma_zfree(file_zone, fp); 2978 2979 return (error); 2980 } 2981 2982 /* 2983 * Apply an advisory lock on a file descriptor. 2984 * 2985 * Just attempt to get a record lock of the requested type on the entire file 2986 * (l_whence = SEEK_SET, l_start = 0, l_len = 0). 2987 */ 2988 #ifndef _SYS_SYSPROTO_H_ 2989 struct flock_args { 2990 int fd; 2991 int how; 2992 }; 2993 #endif 2994 /* ARGSUSED */ 2995 int 2996 sys_flock(struct thread *td, struct flock_args *uap) 2997 { 2998 struct file *fp; 2999 struct vnode *vp; 3000 struct flock lf; 3001 int error; 3002 3003 error = fget(td, uap->fd, &cap_flock_rights, &fp); 3004 if (error != 0) 3005 return (error); 3006 if (fp->f_type != DTYPE_VNODE) { 3007 fdrop(fp, td); 3008 return (EOPNOTSUPP); 3009 } 3010 3011 vp = fp->f_vnode; 3012 lf.l_whence = SEEK_SET; 3013 lf.l_start = 0; 3014 lf.l_len = 0; 3015 if (uap->how & LOCK_UN) { 3016 lf.l_type = F_UNLCK; 3017 atomic_clear_int(&fp->f_flag, FHASLOCK); 3018 error = VOP_ADVLOCK(vp, (caddr_t)fp, F_UNLCK, &lf, F_FLOCK); 3019 goto done2; 3020 } 3021 if (uap->how & LOCK_EX) 3022 lf.l_type = F_WRLCK; 3023 else if (uap->how & LOCK_SH) 3024 lf.l_type = F_RDLCK; 3025 else { 3026 error = EBADF; 3027 goto done2; 3028 } 3029 atomic_set_int(&fp->f_flag, FHASLOCK); 3030 error = VOP_ADVLOCK(vp, (caddr_t)fp, F_SETLK, &lf, 3031 (uap->how & LOCK_NB) ? F_FLOCK : F_FLOCK | F_WAIT); 3032 done2: 3033 fdrop(fp, td); 3034 return (error); 3035 } 3036 /* 3037 * Duplicate the specified descriptor to a free descriptor. 3038 */ 3039 int 3040 dupfdopen(struct thread *td, struct filedesc *fdp, int dfd, int mode, 3041 int openerror, int *indxp) 3042 { 3043 struct filedescent *newfde, *oldfde; 3044 struct file *fp; 3045 u_long *ioctls; 3046 int error, indx; 3047 3048 KASSERT(openerror == ENODEV || openerror == ENXIO, 3049 ("unexpected error %d in %s", openerror, __func__)); 3050 3051 /* 3052 * If the to-be-dup'd fd number is greater than the allowed number 3053 * of file descriptors, or the fd to be dup'd has already been 3054 * closed, then reject. 3055 */ 3056 FILEDESC_XLOCK(fdp); 3057 if ((fp = fget_locked(fdp, dfd)) == NULL) { 3058 FILEDESC_XUNLOCK(fdp); 3059 return (EBADF); 3060 } 3061 3062 error = fdalloc(td, 0, &indx); 3063 if (error != 0) { 3064 FILEDESC_XUNLOCK(fdp); 3065 return (error); 3066 } 3067 3068 /* 3069 * There are two cases of interest here. 3070 * 3071 * For ENODEV simply dup (dfd) to file descriptor (indx) and return. 3072 * 3073 * For ENXIO steal away the file structure from (dfd) and store it in 3074 * (indx). (dfd) is effectively closed by this operation. 3075 */ 3076 switch (openerror) { 3077 case ENODEV: 3078 /* 3079 * Check that the mode the file is being opened for is a 3080 * subset of the mode of the existing descriptor. 3081 */ 3082 if (((mode & (FREAD|FWRITE)) | fp->f_flag) != fp->f_flag) { 3083 fdunused(fdp, indx); 3084 FILEDESC_XUNLOCK(fdp); 3085 return (EACCES); 3086 } 3087 if (!fhold(fp)) { 3088 fdunused(fdp, indx); 3089 FILEDESC_XUNLOCK(fdp); 3090 return (EBADF); 3091 } 3092 newfde = &fdp->fd_ofiles[indx]; 3093 oldfde = &fdp->fd_ofiles[dfd]; 3094 ioctls = filecaps_copy_prep(&oldfde->fde_caps); 3095 #ifdef CAPABILITIES 3096 seqc_write_begin(&newfde->fde_seqc); 3097 #endif 3098 memcpy(newfde, oldfde, fde_change_size); 3099 filecaps_copy_finish(&oldfde->fde_caps, &newfde->fde_caps, 3100 ioctls); 3101 #ifdef CAPABILITIES 3102 seqc_write_end(&newfde->fde_seqc); 3103 #endif 3104 break; 3105 case ENXIO: 3106 /* 3107 * Steal away the file pointer from dfd and stuff it into indx. 3108 */ 3109 newfde = &fdp->fd_ofiles[indx]; 3110 oldfde = &fdp->fd_ofiles[dfd]; 3111 #ifdef CAPABILITIES 3112 seqc_write_begin(&newfde->fde_seqc); 3113 #endif 3114 memcpy(newfde, oldfde, fde_change_size); 3115 oldfde->fde_file = NULL; 3116 fdunused(fdp, dfd); 3117 #ifdef CAPABILITIES 3118 seqc_write_end(&newfde->fde_seqc); 3119 #endif 3120 break; 3121 } 3122 FILEDESC_XUNLOCK(fdp); 3123 *indxp = indx; 3124 return (0); 3125 } 3126 3127 /* 3128 * This sysctl determines if we will allow a process to chroot(2) if it 3129 * has a directory open: 3130 * 0: disallowed for all processes. 3131 * 1: allowed for processes that were not already chroot(2)'ed. 3132 * 2: allowed for all processes. 3133 */ 3134 3135 static int chroot_allow_open_directories = 1; 3136 3137 SYSCTL_INT(_kern, OID_AUTO, chroot_allow_open_directories, CTLFLAG_RW, 3138 &chroot_allow_open_directories, 0, 3139 "Allow a process to chroot(2) if it has a directory open"); 3140 3141 /* 3142 * Helper function for raised chroot(2) security function: Refuse if 3143 * any filedescriptors are open directories. 3144 */ 3145 static int 3146 chroot_refuse_vdir_fds(struct filedesc *fdp) 3147 { 3148 struct vnode *vp; 3149 struct file *fp; 3150 int fd; 3151 3152 FILEDESC_LOCK_ASSERT(fdp); 3153 3154 for (fd = 0; fd <= fdp->fd_lastfile; fd++) { 3155 fp = fget_locked(fdp, fd); 3156 if (fp == NULL) 3157 continue; 3158 if (fp->f_type == DTYPE_VNODE) { 3159 vp = fp->f_vnode; 3160 if (vp->v_type == VDIR) 3161 return (EPERM); 3162 } 3163 } 3164 return (0); 3165 } 3166 3167 /* 3168 * Common routine for kern_chroot() and jail_attach(). The caller is 3169 * responsible for invoking priv_check() and mac_vnode_check_chroot() to 3170 * authorize this operation. 3171 */ 3172 int 3173 pwd_chroot(struct thread *td, struct vnode *vp) 3174 { 3175 struct filedesc *fdp; 3176 struct vnode *oldvp; 3177 int error; 3178 3179 fdp = td->td_proc->p_fd; 3180 FILEDESC_XLOCK(fdp); 3181 if (chroot_allow_open_directories == 0 || 3182 (chroot_allow_open_directories == 1 && fdp->fd_rdir != rootvnode)) { 3183 error = chroot_refuse_vdir_fds(fdp); 3184 if (error != 0) { 3185 FILEDESC_XUNLOCK(fdp); 3186 return (error); 3187 } 3188 } 3189 oldvp = fdp->fd_rdir; 3190 vrefact(vp); 3191 fdp->fd_rdir = vp; 3192 if (fdp->fd_jdir == NULL) { 3193 vrefact(vp); 3194 fdp->fd_jdir = vp; 3195 } 3196 FILEDESC_XUNLOCK(fdp); 3197 vrele(oldvp); 3198 return (0); 3199 } 3200 3201 void 3202 pwd_chdir(struct thread *td, struct vnode *vp) 3203 { 3204 struct filedesc *fdp; 3205 struct vnode *oldvp; 3206 3207 fdp = td->td_proc->p_fd; 3208 FILEDESC_XLOCK(fdp); 3209 VNASSERT(vp->v_usecount > 0, vp, 3210 ("chdir to a vnode with zero usecount")); 3211 oldvp = fdp->fd_cdir; 3212 fdp->fd_cdir = vp; 3213 FILEDESC_XUNLOCK(fdp); 3214 vrele(oldvp); 3215 } 3216 3217 /* 3218 * Scan all active processes and prisons to see if any of them have a current 3219 * or root directory of `olddp'. If so, replace them with the new mount point. 3220 */ 3221 void 3222 mountcheckdirs(struct vnode *olddp, struct vnode *newdp) 3223 { 3224 struct filedesc *fdp; 3225 struct prison *pr; 3226 struct proc *p; 3227 int nrele; 3228 3229 if (vrefcnt(olddp) == 1) 3230 return; 3231 nrele = 0; 3232 sx_slock(&allproc_lock); 3233 FOREACH_PROC_IN_SYSTEM(p) { 3234 PROC_LOCK(p); 3235 fdp = fdhold(p); 3236 PROC_UNLOCK(p); 3237 if (fdp == NULL) 3238 continue; 3239 FILEDESC_XLOCK(fdp); 3240 if (fdp->fd_cdir == olddp) { 3241 vrefact(newdp); 3242 fdp->fd_cdir = newdp; 3243 nrele++; 3244 } 3245 if (fdp->fd_rdir == olddp) { 3246 vrefact(newdp); 3247 fdp->fd_rdir = newdp; 3248 nrele++; 3249 } 3250 if (fdp->fd_jdir == olddp) { 3251 vrefact(newdp); 3252 fdp->fd_jdir = newdp; 3253 nrele++; 3254 } 3255 FILEDESC_XUNLOCK(fdp); 3256 fddrop(fdp); 3257 } 3258 sx_sunlock(&allproc_lock); 3259 if (rootvnode == olddp) { 3260 vrefact(newdp); 3261 rootvnode = newdp; 3262 nrele++; 3263 } 3264 mtx_lock(&prison0.pr_mtx); 3265 if (prison0.pr_root == olddp) { 3266 vrefact(newdp); 3267 prison0.pr_root = newdp; 3268 nrele++; 3269 } 3270 mtx_unlock(&prison0.pr_mtx); 3271 sx_slock(&allprison_lock); 3272 TAILQ_FOREACH(pr, &allprison, pr_list) { 3273 mtx_lock(&pr->pr_mtx); 3274 if (pr->pr_root == olddp) { 3275 vrefact(newdp); 3276 pr->pr_root = newdp; 3277 nrele++; 3278 } 3279 mtx_unlock(&pr->pr_mtx); 3280 } 3281 sx_sunlock(&allprison_lock); 3282 while (nrele--) 3283 vrele(olddp); 3284 } 3285 3286 struct filedesc_to_leader * 3287 filedesc_to_leader_alloc(struct filedesc_to_leader *old, struct filedesc *fdp, struct proc *leader) 3288 { 3289 struct filedesc_to_leader *fdtol; 3290 3291 fdtol = malloc(sizeof(struct filedesc_to_leader), 3292 M_FILEDESC_TO_LEADER, M_WAITOK); 3293 fdtol->fdl_refcount = 1; 3294 fdtol->fdl_holdcount = 0; 3295 fdtol->fdl_wakeup = 0; 3296 fdtol->fdl_leader = leader; 3297 if (old != NULL) { 3298 FILEDESC_XLOCK(fdp); 3299 fdtol->fdl_next = old->fdl_next; 3300 fdtol->fdl_prev = old; 3301 old->fdl_next = fdtol; 3302 fdtol->fdl_next->fdl_prev = fdtol; 3303 FILEDESC_XUNLOCK(fdp); 3304 } else { 3305 fdtol->fdl_next = fdtol; 3306 fdtol->fdl_prev = fdtol; 3307 } 3308 return (fdtol); 3309 } 3310 3311 static int 3312 sysctl_kern_proc_nfds(SYSCTL_HANDLER_ARGS) 3313 { 3314 struct filedesc *fdp; 3315 int i, count, slots; 3316 3317 if (*(int *)arg1 != 0) 3318 return (EINVAL); 3319 3320 fdp = curproc->p_fd; 3321 count = 0; 3322 FILEDESC_SLOCK(fdp); 3323 slots = NDSLOTS(fdp->fd_lastfile + 1); 3324 for (i = 0; i < slots; i++) 3325 count += bitcountl(fdp->fd_map[i]); 3326 FILEDESC_SUNLOCK(fdp); 3327 3328 return (SYSCTL_OUT(req, &count, sizeof(count))); 3329 } 3330 3331 static SYSCTL_NODE(_kern_proc, KERN_PROC_NFDS, nfds, 3332 CTLFLAG_RD|CTLFLAG_CAPRD|CTLFLAG_MPSAFE, sysctl_kern_proc_nfds, 3333 "Number of open file descriptors"); 3334 3335 /* 3336 * Get file structures globally. 3337 */ 3338 static int 3339 sysctl_kern_file(SYSCTL_HANDLER_ARGS) 3340 { 3341 struct xfile xf; 3342 struct filedesc *fdp; 3343 struct file *fp; 3344 struct proc *p; 3345 int error, n; 3346 3347 error = sysctl_wire_old_buffer(req, 0); 3348 if (error != 0) 3349 return (error); 3350 if (req->oldptr == NULL) { 3351 n = 0; 3352 sx_slock(&allproc_lock); 3353 FOREACH_PROC_IN_SYSTEM(p) { 3354 PROC_LOCK(p); 3355 if (p->p_state == PRS_NEW) { 3356 PROC_UNLOCK(p); 3357 continue; 3358 } 3359 fdp = fdhold(p); 3360 PROC_UNLOCK(p); 3361 if (fdp == NULL) 3362 continue; 3363 /* overestimates sparse tables. */ 3364 if (fdp->fd_lastfile > 0) 3365 n += fdp->fd_lastfile; 3366 fddrop(fdp); 3367 } 3368 sx_sunlock(&allproc_lock); 3369 return (SYSCTL_OUT(req, 0, n * sizeof(xf))); 3370 } 3371 error = 0; 3372 bzero(&xf, sizeof(xf)); 3373 xf.xf_size = sizeof(xf); 3374 sx_slock(&allproc_lock); 3375 FOREACH_PROC_IN_SYSTEM(p) { 3376 PROC_LOCK(p); 3377 if (p->p_state == PRS_NEW) { 3378 PROC_UNLOCK(p); 3379 continue; 3380 } 3381 if (p_cansee(req->td, p) != 0) { 3382 PROC_UNLOCK(p); 3383 continue; 3384 } 3385 xf.xf_pid = p->p_pid; 3386 xf.xf_uid = p->p_ucred->cr_uid; 3387 fdp = fdhold(p); 3388 PROC_UNLOCK(p); 3389 if (fdp == NULL) 3390 continue; 3391 FILEDESC_SLOCK(fdp); 3392 for (n = 0; fdp->fd_refcnt > 0 && n <= fdp->fd_lastfile; ++n) { 3393 if ((fp = fdp->fd_ofiles[n].fde_file) == NULL) 3394 continue; 3395 xf.xf_fd = n; 3396 xf.xf_file = (uintptr_t)fp; 3397 xf.xf_data = (uintptr_t)fp->f_data; 3398 xf.xf_vnode = (uintptr_t)fp->f_vnode; 3399 xf.xf_type = (uintptr_t)fp->f_type; 3400 xf.xf_count = fp->f_count; 3401 xf.xf_msgcount = 0; 3402 xf.xf_offset = foffset_get(fp); 3403 xf.xf_flag = fp->f_flag; 3404 error = SYSCTL_OUT(req, &xf, sizeof(xf)); 3405 if (error) 3406 break; 3407 } 3408 FILEDESC_SUNLOCK(fdp); 3409 fddrop(fdp); 3410 if (error) 3411 break; 3412 } 3413 sx_sunlock(&allproc_lock); 3414 return (error); 3415 } 3416 3417 SYSCTL_PROC(_kern, KERN_FILE, file, CTLTYPE_OPAQUE|CTLFLAG_RD|CTLFLAG_MPSAFE, 3418 0, 0, sysctl_kern_file, "S,xfile", "Entire file table"); 3419 3420 #ifdef KINFO_FILE_SIZE 3421 CTASSERT(sizeof(struct kinfo_file) == KINFO_FILE_SIZE); 3422 #endif 3423 3424 static int 3425 xlate_fflags(int fflags) 3426 { 3427 static const struct { 3428 int fflag; 3429 int kf_fflag; 3430 } fflags_table[] = { 3431 { FAPPEND, KF_FLAG_APPEND }, 3432 { FASYNC, KF_FLAG_ASYNC }, 3433 { FFSYNC, KF_FLAG_FSYNC }, 3434 { FHASLOCK, KF_FLAG_HASLOCK }, 3435 { FNONBLOCK, KF_FLAG_NONBLOCK }, 3436 { FREAD, KF_FLAG_READ }, 3437 { FWRITE, KF_FLAG_WRITE }, 3438 { O_CREAT, KF_FLAG_CREAT }, 3439 { O_DIRECT, KF_FLAG_DIRECT }, 3440 { O_EXCL, KF_FLAG_EXCL }, 3441 { O_EXEC, KF_FLAG_EXEC }, 3442 { O_EXLOCK, KF_FLAG_EXLOCK }, 3443 { O_NOFOLLOW, KF_FLAG_NOFOLLOW }, 3444 { O_SHLOCK, KF_FLAG_SHLOCK }, 3445 { O_TRUNC, KF_FLAG_TRUNC } 3446 }; 3447 unsigned int i; 3448 int kflags; 3449 3450 kflags = 0; 3451 for (i = 0; i < nitems(fflags_table); i++) 3452 if (fflags & fflags_table[i].fflag) 3453 kflags |= fflags_table[i].kf_fflag; 3454 return (kflags); 3455 } 3456 3457 /* Trim unused data from kf_path by truncating the structure size. */ 3458 void 3459 pack_kinfo(struct kinfo_file *kif) 3460 { 3461 3462 kif->kf_structsize = offsetof(struct kinfo_file, kf_path) + 3463 strlen(kif->kf_path) + 1; 3464 kif->kf_structsize = roundup(kif->kf_structsize, sizeof(uint64_t)); 3465 } 3466 3467 static void 3468 export_file_to_kinfo(struct file *fp, int fd, cap_rights_t *rightsp, 3469 struct kinfo_file *kif, struct filedesc *fdp, int flags) 3470 { 3471 int error; 3472 3473 bzero(kif, sizeof(*kif)); 3474 3475 /* Set a default type to allow for empty fill_kinfo() methods. */ 3476 kif->kf_type = KF_TYPE_UNKNOWN; 3477 kif->kf_flags = xlate_fflags(fp->f_flag); 3478 if (rightsp != NULL) 3479 kif->kf_cap_rights = *rightsp; 3480 else 3481 cap_rights_init(&kif->kf_cap_rights); 3482 kif->kf_fd = fd; 3483 kif->kf_ref_count = fp->f_count; 3484 kif->kf_offset = foffset_get(fp); 3485 3486 /* 3487 * This may drop the filedesc lock, so the 'fp' cannot be 3488 * accessed after this call. 3489 */ 3490 error = fo_fill_kinfo(fp, kif, fdp); 3491 if (error == 0) 3492 kif->kf_status |= KF_ATTR_VALID; 3493 if ((flags & KERN_FILEDESC_PACK_KINFO) != 0) 3494 pack_kinfo(kif); 3495 else 3496 kif->kf_structsize = roundup2(sizeof(*kif), sizeof(uint64_t)); 3497 } 3498 3499 static void 3500 export_vnode_to_kinfo(struct vnode *vp, int fd, int fflags, 3501 struct kinfo_file *kif, int flags) 3502 { 3503 int error; 3504 3505 bzero(kif, sizeof(*kif)); 3506 3507 kif->kf_type = KF_TYPE_VNODE; 3508 error = vn_fill_kinfo_vnode(vp, kif); 3509 if (error == 0) 3510 kif->kf_status |= KF_ATTR_VALID; 3511 kif->kf_flags = xlate_fflags(fflags); 3512 cap_rights_init(&kif->kf_cap_rights); 3513 kif->kf_fd = fd; 3514 kif->kf_ref_count = -1; 3515 kif->kf_offset = -1; 3516 if ((flags & KERN_FILEDESC_PACK_KINFO) != 0) 3517 pack_kinfo(kif); 3518 else 3519 kif->kf_structsize = roundup2(sizeof(*kif), sizeof(uint64_t)); 3520 vrele(vp); 3521 } 3522 3523 struct export_fd_buf { 3524 struct filedesc *fdp; 3525 struct sbuf *sb; 3526 ssize_t remainder; 3527 struct kinfo_file kif; 3528 int flags; 3529 }; 3530 3531 static int 3532 export_kinfo_to_sb(struct export_fd_buf *efbuf) 3533 { 3534 struct kinfo_file *kif; 3535 3536 kif = &efbuf->kif; 3537 if (efbuf->remainder != -1) { 3538 if (efbuf->remainder < kif->kf_structsize) { 3539 /* Terminate export. */ 3540 efbuf->remainder = 0; 3541 return (0); 3542 } 3543 efbuf->remainder -= kif->kf_structsize; 3544 } 3545 return (sbuf_bcat(efbuf->sb, kif, kif->kf_structsize) == 0 ? 0 : ENOMEM); 3546 } 3547 3548 static int 3549 export_file_to_sb(struct file *fp, int fd, cap_rights_t *rightsp, 3550 struct export_fd_buf *efbuf) 3551 { 3552 int error; 3553 3554 if (efbuf->remainder == 0) 3555 return (0); 3556 export_file_to_kinfo(fp, fd, rightsp, &efbuf->kif, efbuf->fdp, 3557 efbuf->flags); 3558 FILEDESC_SUNLOCK(efbuf->fdp); 3559 error = export_kinfo_to_sb(efbuf); 3560 FILEDESC_SLOCK(efbuf->fdp); 3561 return (error); 3562 } 3563 3564 static int 3565 export_vnode_to_sb(struct vnode *vp, int fd, int fflags, 3566 struct export_fd_buf *efbuf) 3567 { 3568 int error; 3569 3570 if (efbuf->remainder == 0) 3571 return (0); 3572 if (efbuf->fdp != NULL) 3573 FILEDESC_SUNLOCK(efbuf->fdp); 3574 export_vnode_to_kinfo(vp, fd, fflags, &efbuf->kif, efbuf->flags); 3575 error = export_kinfo_to_sb(efbuf); 3576 if (efbuf->fdp != NULL) 3577 FILEDESC_SLOCK(efbuf->fdp); 3578 return (error); 3579 } 3580 3581 /* 3582 * Store a process file descriptor information to sbuf. 3583 * 3584 * Takes a locked proc as argument, and returns with the proc unlocked. 3585 */ 3586 int 3587 kern_proc_filedesc_out(struct proc *p, struct sbuf *sb, ssize_t maxlen, 3588 int flags) 3589 { 3590 struct file *fp; 3591 struct filedesc *fdp; 3592 struct export_fd_buf *efbuf; 3593 struct vnode *cttyvp, *textvp, *tracevp; 3594 int error, i; 3595 cap_rights_t rights; 3596 3597 PROC_LOCK_ASSERT(p, MA_OWNED); 3598 3599 /* ktrace vnode */ 3600 tracevp = p->p_tracevp; 3601 if (tracevp != NULL) 3602 vrefact(tracevp); 3603 /* text vnode */ 3604 textvp = p->p_textvp; 3605 if (textvp != NULL) 3606 vrefact(textvp); 3607 /* Controlling tty. */ 3608 cttyvp = NULL; 3609 if (p->p_pgrp != NULL && p->p_pgrp->pg_session != NULL) { 3610 cttyvp = p->p_pgrp->pg_session->s_ttyvp; 3611 if (cttyvp != NULL) 3612 vrefact(cttyvp); 3613 } 3614 fdp = fdhold(p); 3615 PROC_UNLOCK(p); 3616 efbuf = malloc(sizeof(*efbuf), M_TEMP, M_WAITOK); 3617 efbuf->fdp = NULL; 3618 efbuf->sb = sb; 3619 efbuf->remainder = maxlen; 3620 efbuf->flags = flags; 3621 if (tracevp != NULL) 3622 export_vnode_to_sb(tracevp, KF_FD_TYPE_TRACE, FREAD | FWRITE, 3623 efbuf); 3624 if (textvp != NULL) 3625 export_vnode_to_sb(textvp, KF_FD_TYPE_TEXT, FREAD, efbuf); 3626 if (cttyvp != NULL) 3627 export_vnode_to_sb(cttyvp, KF_FD_TYPE_CTTY, FREAD | FWRITE, 3628 efbuf); 3629 error = 0; 3630 if (fdp == NULL) 3631 goto fail; 3632 efbuf->fdp = fdp; 3633 FILEDESC_SLOCK(fdp); 3634 /* working directory */ 3635 if (fdp->fd_cdir != NULL) { 3636 vrefact(fdp->fd_cdir); 3637 export_vnode_to_sb(fdp->fd_cdir, KF_FD_TYPE_CWD, FREAD, efbuf); 3638 } 3639 /* root directory */ 3640 if (fdp->fd_rdir != NULL) { 3641 vrefact(fdp->fd_rdir); 3642 export_vnode_to_sb(fdp->fd_rdir, KF_FD_TYPE_ROOT, FREAD, efbuf); 3643 } 3644 /* jail directory */ 3645 if (fdp->fd_jdir != NULL) { 3646 vrefact(fdp->fd_jdir); 3647 export_vnode_to_sb(fdp->fd_jdir, KF_FD_TYPE_JAIL, FREAD, efbuf); 3648 } 3649 for (i = 0; fdp->fd_refcnt > 0 && i <= fdp->fd_lastfile; i++) { 3650 if ((fp = fdp->fd_ofiles[i].fde_file) == NULL) 3651 continue; 3652 #ifdef CAPABILITIES 3653 rights = *cap_rights(fdp, i); 3654 #else /* !CAPABILITIES */ 3655 rights = cap_no_rights; 3656 #endif 3657 /* 3658 * Create sysctl entry. It is OK to drop the filedesc 3659 * lock inside of export_file_to_sb() as we will 3660 * re-validate and re-evaluate its properties when the 3661 * loop continues. 3662 */ 3663 error = export_file_to_sb(fp, i, &rights, efbuf); 3664 if (error != 0 || efbuf->remainder == 0) 3665 break; 3666 } 3667 FILEDESC_SUNLOCK(fdp); 3668 fddrop(fdp); 3669 fail: 3670 free(efbuf, M_TEMP); 3671 return (error); 3672 } 3673 3674 #define FILEDESC_SBUF_SIZE (sizeof(struct kinfo_file) * 5) 3675 3676 /* 3677 * Get per-process file descriptors for use by procstat(1), et al. 3678 */ 3679 static int 3680 sysctl_kern_proc_filedesc(SYSCTL_HANDLER_ARGS) 3681 { 3682 struct sbuf sb; 3683 struct proc *p; 3684 ssize_t maxlen; 3685 int error, error2, *name; 3686 3687 name = (int *)arg1; 3688 3689 sbuf_new_for_sysctl(&sb, NULL, FILEDESC_SBUF_SIZE, req); 3690 sbuf_clear_flags(&sb, SBUF_INCLUDENUL); 3691 error = pget((pid_t)name[0], PGET_CANDEBUG | PGET_NOTWEXIT, &p); 3692 if (error != 0) { 3693 sbuf_delete(&sb); 3694 return (error); 3695 } 3696 maxlen = req->oldptr != NULL ? req->oldlen : -1; 3697 error = kern_proc_filedesc_out(p, &sb, maxlen, 3698 KERN_FILEDESC_PACK_KINFO); 3699 error2 = sbuf_finish(&sb); 3700 sbuf_delete(&sb); 3701 return (error != 0 ? error : error2); 3702 } 3703 3704 #ifdef COMPAT_FREEBSD7 3705 #ifdef KINFO_OFILE_SIZE 3706 CTASSERT(sizeof(struct kinfo_ofile) == KINFO_OFILE_SIZE); 3707 #endif 3708 3709 static void 3710 kinfo_to_okinfo(struct kinfo_file *kif, struct kinfo_ofile *okif) 3711 { 3712 3713 okif->kf_structsize = sizeof(*okif); 3714 okif->kf_type = kif->kf_type; 3715 okif->kf_fd = kif->kf_fd; 3716 okif->kf_ref_count = kif->kf_ref_count; 3717 okif->kf_flags = kif->kf_flags & (KF_FLAG_READ | KF_FLAG_WRITE | 3718 KF_FLAG_APPEND | KF_FLAG_ASYNC | KF_FLAG_FSYNC | KF_FLAG_NONBLOCK | 3719 KF_FLAG_DIRECT | KF_FLAG_HASLOCK); 3720 okif->kf_offset = kif->kf_offset; 3721 if (kif->kf_type == KF_TYPE_VNODE) 3722 okif->kf_vnode_type = kif->kf_un.kf_file.kf_file_type; 3723 else 3724 okif->kf_vnode_type = KF_VTYPE_VNON; 3725 strlcpy(okif->kf_path, kif->kf_path, sizeof(okif->kf_path)); 3726 if (kif->kf_type == KF_TYPE_SOCKET) { 3727 okif->kf_sock_domain = kif->kf_un.kf_sock.kf_sock_domain0; 3728 okif->kf_sock_type = kif->kf_un.kf_sock.kf_sock_type0; 3729 okif->kf_sock_protocol = kif->kf_un.kf_sock.kf_sock_protocol0; 3730 okif->kf_sa_local = kif->kf_un.kf_sock.kf_sa_local; 3731 okif->kf_sa_peer = kif->kf_un.kf_sock.kf_sa_peer; 3732 } else { 3733 okif->kf_sa_local.ss_family = AF_UNSPEC; 3734 okif->kf_sa_peer.ss_family = AF_UNSPEC; 3735 } 3736 } 3737 3738 static int 3739 export_vnode_for_osysctl(struct vnode *vp, int type, struct kinfo_file *kif, 3740 struct kinfo_ofile *okif, struct filedesc *fdp, struct sysctl_req *req) 3741 { 3742 int error; 3743 3744 vrefact(vp); 3745 FILEDESC_SUNLOCK(fdp); 3746 export_vnode_to_kinfo(vp, type, 0, kif, KERN_FILEDESC_PACK_KINFO); 3747 kinfo_to_okinfo(kif, okif); 3748 error = SYSCTL_OUT(req, okif, sizeof(*okif)); 3749 FILEDESC_SLOCK(fdp); 3750 return (error); 3751 } 3752 3753 /* 3754 * Get per-process file descriptors for use by procstat(1), et al. 3755 */ 3756 static int 3757 sysctl_kern_proc_ofiledesc(SYSCTL_HANDLER_ARGS) 3758 { 3759 struct kinfo_ofile *okif; 3760 struct kinfo_file *kif; 3761 struct filedesc *fdp; 3762 int error, i, *name; 3763 struct file *fp; 3764 struct proc *p; 3765 3766 name = (int *)arg1; 3767 error = pget((pid_t)name[0], PGET_CANDEBUG | PGET_NOTWEXIT, &p); 3768 if (error != 0) 3769 return (error); 3770 fdp = fdhold(p); 3771 PROC_UNLOCK(p); 3772 if (fdp == NULL) 3773 return (ENOENT); 3774 kif = malloc(sizeof(*kif), M_TEMP, M_WAITOK); 3775 okif = malloc(sizeof(*okif), M_TEMP, M_WAITOK); 3776 FILEDESC_SLOCK(fdp); 3777 if (fdp->fd_cdir != NULL) 3778 export_vnode_for_osysctl(fdp->fd_cdir, KF_FD_TYPE_CWD, kif, 3779 okif, fdp, req); 3780 if (fdp->fd_rdir != NULL) 3781 export_vnode_for_osysctl(fdp->fd_rdir, KF_FD_TYPE_ROOT, kif, 3782 okif, fdp, req); 3783 if (fdp->fd_jdir != NULL) 3784 export_vnode_for_osysctl(fdp->fd_jdir, KF_FD_TYPE_JAIL, kif, 3785 okif, fdp, req); 3786 for (i = 0; fdp->fd_refcnt > 0 && i <= fdp->fd_lastfile; i++) { 3787 if ((fp = fdp->fd_ofiles[i].fde_file) == NULL) 3788 continue; 3789 export_file_to_kinfo(fp, i, NULL, kif, fdp, 3790 KERN_FILEDESC_PACK_KINFO); 3791 FILEDESC_SUNLOCK(fdp); 3792 kinfo_to_okinfo(kif, okif); 3793 error = SYSCTL_OUT(req, okif, sizeof(*okif)); 3794 FILEDESC_SLOCK(fdp); 3795 if (error) 3796 break; 3797 } 3798 FILEDESC_SUNLOCK(fdp); 3799 fddrop(fdp); 3800 free(kif, M_TEMP); 3801 free(okif, M_TEMP); 3802 return (0); 3803 } 3804 3805 static SYSCTL_NODE(_kern_proc, KERN_PROC_OFILEDESC, ofiledesc, 3806 CTLFLAG_RD|CTLFLAG_MPSAFE, sysctl_kern_proc_ofiledesc, 3807 "Process ofiledesc entries"); 3808 #endif /* COMPAT_FREEBSD7 */ 3809 3810 int 3811 vntype_to_kinfo(int vtype) 3812 { 3813 struct { 3814 int vtype; 3815 int kf_vtype; 3816 } vtypes_table[] = { 3817 { VBAD, KF_VTYPE_VBAD }, 3818 { VBLK, KF_VTYPE_VBLK }, 3819 { VCHR, KF_VTYPE_VCHR }, 3820 { VDIR, KF_VTYPE_VDIR }, 3821 { VFIFO, KF_VTYPE_VFIFO }, 3822 { VLNK, KF_VTYPE_VLNK }, 3823 { VNON, KF_VTYPE_VNON }, 3824 { VREG, KF_VTYPE_VREG }, 3825 { VSOCK, KF_VTYPE_VSOCK } 3826 }; 3827 unsigned int i; 3828 3829 /* 3830 * Perform vtype translation. 3831 */ 3832 for (i = 0; i < nitems(vtypes_table); i++) 3833 if (vtypes_table[i].vtype == vtype) 3834 return (vtypes_table[i].kf_vtype); 3835 3836 return (KF_VTYPE_UNKNOWN); 3837 } 3838 3839 static SYSCTL_NODE(_kern_proc, KERN_PROC_FILEDESC, filedesc, 3840 CTLFLAG_RD|CTLFLAG_MPSAFE, sysctl_kern_proc_filedesc, 3841 "Process filedesc entries"); 3842 3843 /* 3844 * Store a process current working directory information to sbuf. 3845 * 3846 * Takes a locked proc as argument, and returns with the proc unlocked. 3847 */ 3848 int 3849 kern_proc_cwd_out(struct proc *p, struct sbuf *sb, ssize_t maxlen) 3850 { 3851 struct filedesc *fdp; 3852 struct export_fd_buf *efbuf; 3853 int error; 3854 3855 PROC_LOCK_ASSERT(p, MA_OWNED); 3856 3857 fdp = fdhold(p); 3858 PROC_UNLOCK(p); 3859 if (fdp == NULL) 3860 return (EINVAL); 3861 3862 efbuf = malloc(sizeof(*efbuf), M_TEMP, M_WAITOK); 3863 efbuf->fdp = fdp; 3864 efbuf->sb = sb; 3865 efbuf->remainder = maxlen; 3866 3867 FILEDESC_SLOCK(fdp); 3868 if (fdp->fd_cdir == NULL) 3869 error = EINVAL; 3870 else { 3871 vrefact(fdp->fd_cdir); 3872 error = export_vnode_to_sb(fdp->fd_cdir, KF_FD_TYPE_CWD, 3873 FREAD, efbuf); 3874 } 3875 FILEDESC_SUNLOCK(fdp); 3876 fddrop(fdp); 3877 free(efbuf, M_TEMP); 3878 return (error); 3879 } 3880 3881 /* 3882 * Get per-process current working directory. 3883 */ 3884 static int 3885 sysctl_kern_proc_cwd(SYSCTL_HANDLER_ARGS) 3886 { 3887 struct sbuf sb; 3888 struct proc *p; 3889 ssize_t maxlen; 3890 int error, error2, *name; 3891 3892 name = (int *)arg1; 3893 3894 sbuf_new_for_sysctl(&sb, NULL, sizeof(struct kinfo_file), req); 3895 sbuf_clear_flags(&sb, SBUF_INCLUDENUL); 3896 error = pget((pid_t)name[0], PGET_CANDEBUG | PGET_NOTWEXIT, &p); 3897 if (error != 0) { 3898 sbuf_delete(&sb); 3899 return (error); 3900 } 3901 maxlen = req->oldptr != NULL ? req->oldlen : -1; 3902 error = kern_proc_cwd_out(p, &sb, maxlen); 3903 error2 = sbuf_finish(&sb); 3904 sbuf_delete(&sb); 3905 return (error != 0 ? error : error2); 3906 } 3907 3908 static SYSCTL_NODE(_kern_proc, KERN_PROC_CWD, cwd, CTLFLAG_RD|CTLFLAG_MPSAFE, 3909 sysctl_kern_proc_cwd, "Process current working directory"); 3910 3911 #ifdef DDB 3912 /* 3913 * For the purposes of debugging, generate a human-readable string for the 3914 * file type. 3915 */ 3916 static const char * 3917 file_type_to_name(short type) 3918 { 3919 3920 switch (type) { 3921 case 0: 3922 return ("zero"); 3923 case DTYPE_VNODE: 3924 return ("vnode"); 3925 case DTYPE_SOCKET: 3926 return ("socket"); 3927 case DTYPE_PIPE: 3928 return ("pipe"); 3929 case DTYPE_FIFO: 3930 return ("fifo"); 3931 case DTYPE_KQUEUE: 3932 return ("kqueue"); 3933 case DTYPE_CRYPTO: 3934 return ("crypto"); 3935 case DTYPE_MQUEUE: 3936 return ("mqueue"); 3937 case DTYPE_SHM: 3938 return ("shm"); 3939 case DTYPE_SEM: 3940 return ("ksem"); 3941 case DTYPE_PTS: 3942 return ("pts"); 3943 case DTYPE_DEV: 3944 return ("dev"); 3945 case DTYPE_PROCDESC: 3946 return ("proc"); 3947 case DTYPE_LINUXEFD: 3948 return ("levent"); 3949 case DTYPE_LINUXTFD: 3950 return ("ltimer"); 3951 default: 3952 return ("unkn"); 3953 } 3954 } 3955 3956 /* 3957 * For the purposes of debugging, identify a process (if any, perhaps one of 3958 * many) that references the passed file in its file descriptor array. Return 3959 * NULL if none. 3960 */ 3961 static struct proc * 3962 file_to_first_proc(struct file *fp) 3963 { 3964 struct filedesc *fdp; 3965 struct proc *p; 3966 int n; 3967 3968 FOREACH_PROC_IN_SYSTEM(p) { 3969 if (p->p_state == PRS_NEW) 3970 continue; 3971 fdp = p->p_fd; 3972 if (fdp == NULL) 3973 continue; 3974 for (n = 0; n <= fdp->fd_lastfile; n++) { 3975 if (fp == fdp->fd_ofiles[n].fde_file) 3976 return (p); 3977 } 3978 } 3979 return (NULL); 3980 } 3981 3982 static void 3983 db_print_file(struct file *fp, int header) 3984 { 3985 #define XPTRWIDTH ((int)howmany(sizeof(void *) * NBBY, 4)) 3986 struct proc *p; 3987 3988 if (header) 3989 db_printf("%*s %6s %*s %8s %4s %5s %6s %*s %5s %s\n", 3990 XPTRWIDTH, "File", "Type", XPTRWIDTH, "Data", "Flag", 3991 "GCFl", "Count", "MCount", XPTRWIDTH, "Vnode", "FPID", 3992 "FCmd"); 3993 p = file_to_first_proc(fp); 3994 db_printf("%*p %6s %*p %08x %04x %5d %6d %*p %5d %s\n", XPTRWIDTH, 3995 fp, file_type_to_name(fp->f_type), XPTRWIDTH, fp->f_data, 3996 fp->f_flag, 0, fp->f_count, 0, XPTRWIDTH, fp->f_vnode, 3997 p != NULL ? p->p_pid : -1, p != NULL ? p->p_comm : "-"); 3998 3999 #undef XPTRWIDTH 4000 } 4001 4002 DB_SHOW_COMMAND(file, db_show_file) 4003 { 4004 struct file *fp; 4005 4006 if (!have_addr) { 4007 db_printf("usage: show file <addr>\n"); 4008 return; 4009 } 4010 fp = (struct file *)addr; 4011 db_print_file(fp, 1); 4012 } 4013 4014 DB_SHOW_COMMAND(files, db_show_files) 4015 { 4016 struct filedesc *fdp; 4017 struct file *fp; 4018 struct proc *p; 4019 int header; 4020 int n; 4021 4022 header = 1; 4023 FOREACH_PROC_IN_SYSTEM(p) { 4024 if (p->p_state == PRS_NEW) 4025 continue; 4026 if ((fdp = p->p_fd) == NULL) 4027 continue; 4028 for (n = 0; n <= fdp->fd_lastfile; ++n) { 4029 if ((fp = fdp->fd_ofiles[n].fde_file) == NULL) 4030 continue; 4031 db_print_file(fp, header); 4032 header = 0; 4033 } 4034 } 4035 } 4036 #endif 4037 4038 SYSCTL_INT(_kern, KERN_MAXFILESPERPROC, maxfilesperproc, CTLFLAG_RW, 4039 &maxfilesperproc, 0, "Maximum files allowed open per process"); 4040 4041 SYSCTL_INT(_kern, KERN_MAXFILES, maxfiles, CTLFLAG_RW, 4042 &maxfiles, 0, "Maximum number of files"); 4043 4044 SYSCTL_INT(_kern, OID_AUTO, openfiles, CTLFLAG_RD, 4045 __DEVOLATILE(int *, &openfiles), 0, "System-wide number of open files"); 4046 4047 /* ARGSUSED*/ 4048 static void 4049 filelistinit(void *dummy) 4050 { 4051 4052 file_zone = uma_zcreate("Files", sizeof(struct file), NULL, NULL, 4053 NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE); 4054 filedesc0_zone = uma_zcreate("filedesc0", sizeof(struct filedesc0), 4055 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0); 4056 mtx_init(&sigio_lock, "sigio lock", NULL, MTX_DEF); 4057 } 4058 SYSINIT(select, SI_SUB_LOCK, SI_ORDER_FIRST, filelistinit, NULL); 4059 4060 /*-------------------------------------------------------------------*/ 4061 4062 static int 4063 badfo_readwrite(struct file *fp, struct uio *uio, struct ucred *active_cred, 4064 int flags, struct thread *td) 4065 { 4066 4067 return (EBADF); 4068 } 4069 4070 static int 4071 badfo_truncate(struct file *fp, off_t length, struct ucred *active_cred, 4072 struct thread *td) 4073 { 4074 4075 return (EINVAL); 4076 } 4077 4078 static int 4079 badfo_ioctl(struct file *fp, u_long com, void *data, struct ucred *active_cred, 4080 struct thread *td) 4081 { 4082 4083 return (EBADF); 4084 } 4085 4086 static int 4087 badfo_poll(struct file *fp, int events, struct ucred *active_cred, 4088 struct thread *td) 4089 { 4090 4091 return (0); 4092 } 4093 4094 static int 4095 badfo_kqfilter(struct file *fp, struct knote *kn) 4096 { 4097 4098 return (EBADF); 4099 } 4100 4101 static int 4102 badfo_stat(struct file *fp, struct stat *sb, struct ucred *active_cred, 4103 struct thread *td) 4104 { 4105 4106 return (EBADF); 4107 } 4108 4109 static int 4110 badfo_close(struct file *fp, struct thread *td) 4111 { 4112 4113 return (0); 4114 } 4115 4116 static int 4117 badfo_chmod(struct file *fp, mode_t mode, struct ucred *active_cred, 4118 struct thread *td) 4119 { 4120 4121 return (EBADF); 4122 } 4123 4124 static int 4125 badfo_chown(struct file *fp, uid_t uid, gid_t gid, struct ucred *active_cred, 4126 struct thread *td) 4127 { 4128 4129 return (EBADF); 4130 } 4131 4132 static int 4133 badfo_sendfile(struct file *fp, int sockfd, struct uio *hdr_uio, 4134 struct uio *trl_uio, off_t offset, size_t nbytes, off_t *sent, int flags, 4135 struct thread *td) 4136 { 4137 4138 return (EBADF); 4139 } 4140 4141 static int 4142 badfo_fill_kinfo(struct file *fp, struct kinfo_file *kif, struct filedesc *fdp) 4143 { 4144 4145 return (0); 4146 } 4147 4148 struct fileops badfileops = { 4149 .fo_read = badfo_readwrite, 4150 .fo_write = badfo_readwrite, 4151 .fo_truncate = badfo_truncate, 4152 .fo_ioctl = badfo_ioctl, 4153 .fo_poll = badfo_poll, 4154 .fo_kqfilter = badfo_kqfilter, 4155 .fo_stat = badfo_stat, 4156 .fo_close = badfo_close, 4157 .fo_chmod = badfo_chmod, 4158 .fo_chown = badfo_chown, 4159 .fo_sendfile = badfo_sendfile, 4160 .fo_fill_kinfo = badfo_fill_kinfo, 4161 }; 4162 4163 int 4164 invfo_rdwr(struct file *fp, struct uio *uio, struct ucred *active_cred, 4165 int flags, struct thread *td) 4166 { 4167 4168 return (EOPNOTSUPP); 4169 } 4170 4171 int 4172 invfo_truncate(struct file *fp, off_t length, struct ucred *active_cred, 4173 struct thread *td) 4174 { 4175 4176 return (EINVAL); 4177 } 4178 4179 int 4180 invfo_ioctl(struct file *fp, u_long com, void *data, 4181 struct ucred *active_cred, struct thread *td) 4182 { 4183 4184 return (ENOTTY); 4185 } 4186 4187 int 4188 invfo_poll(struct file *fp, int events, struct ucred *active_cred, 4189 struct thread *td) 4190 { 4191 4192 return (poll_no_poll(events)); 4193 } 4194 4195 int 4196 invfo_kqfilter(struct file *fp, struct knote *kn) 4197 { 4198 4199 return (EINVAL); 4200 } 4201 4202 int 4203 invfo_chmod(struct file *fp, mode_t mode, struct ucred *active_cred, 4204 struct thread *td) 4205 { 4206 4207 return (EINVAL); 4208 } 4209 4210 int 4211 invfo_chown(struct file *fp, uid_t uid, gid_t gid, struct ucred *active_cred, 4212 struct thread *td) 4213 { 4214 4215 return (EINVAL); 4216 } 4217 4218 int 4219 invfo_sendfile(struct file *fp, int sockfd, struct uio *hdr_uio, 4220 struct uio *trl_uio, off_t offset, size_t nbytes, off_t *sent, int flags, 4221 struct thread *td) 4222 { 4223 4224 return (EINVAL); 4225 } 4226 4227 /*-------------------------------------------------------------------*/ 4228 4229 /* 4230 * File Descriptor pseudo-device driver (/dev/fd/). 4231 * 4232 * Opening minor device N dup()s the file (if any) connected to file 4233 * descriptor N belonging to the calling process. Note that this driver 4234 * consists of only the ``open()'' routine, because all subsequent 4235 * references to this file will be direct to the other driver. 4236 * 4237 * XXX: we could give this one a cloning event handler if necessary. 4238 */ 4239 4240 /* ARGSUSED */ 4241 static int 4242 fdopen(struct cdev *dev, int mode, int type, struct thread *td) 4243 { 4244 4245 /* 4246 * XXX Kludge: set curthread->td_dupfd to contain the value of the 4247 * the file descriptor being sought for duplication. The error 4248 * return ensures that the vnode for this device will be released 4249 * by vn_open. Open will detect this special error and take the 4250 * actions in dupfdopen below. Other callers of vn_open or VOP_OPEN 4251 * will simply report the error. 4252 */ 4253 td->td_dupfd = dev2unit(dev); 4254 return (ENODEV); 4255 } 4256 4257 static struct cdevsw fildesc_cdevsw = { 4258 .d_version = D_VERSION, 4259 .d_open = fdopen, 4260 .d_name = "FD", 4261 }; 4262 4263 static void 4264 fildesc_drvinit(void *unused) 4265 { 4266 struct cdev *dev; 4267 4268 dev = make_dev_credf(MAKEDEV_ETERNAL, &fildesc_cdevsw, 0, NULL, 4269 UID_ROOT, GID_WHEEL, 0666, "fd/0"); 4270 make_dev_alias(dev, "stdin"); 4271 dev = make_dev_credf(MAKEDEV_ETERNAL, &fildesc_cdevsw, 1, NULL, 4272 UID_ROOT, GID_WHEEL, 0666, "fd/1"); 4273 make_dev_alias(dev, "stdout"); 4274 dev = make_dev_credf(MAKEDEV_ETERNAL, &fildesc_cdevsw, 2, NULL, 4275 UID_ROOT, GID_WHEEL, 0666, "fd/2"); 4276 make_dev_alias(dev, "stderr"); 4277 } 4278 4279 SYSINIT(fildescdev, SI_SUB_DRIVERS, SI_ORDER_MIDDLE, fildesc_drvinit, NULL); 4280