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/smr.h> 73 #include <sys/stat.h> 74 #include <sys/sx.h> 75 #include <sys/syscallsubr.h> 76 #include <sys/sysctl.h> 77 #include <sys/sysproto.h> 78 #include <sys/unistd.h> 79 #include <sys/user.h> 80 #include <sys/vnode.h> 81 #ifdef KTRACE 82 #include <sys/ktrace.h> 83 #endif 84 85 #include <net/vnet.h> 86 87 #include <security/audit/audit.h> 88 89 #include <vm/uma.h> 90 #include <vm/vm.h> 91 92 #include <ddb/ddb.h> 93 94 static MALLOC_DEFINE(M_FILEDESC, "filedesc", "Open file descriptor table"); 95 static MALLOC_DEFINE(M_PWD, "pwd", "Descriptor table vnodes"); 96 static MALLOC_DEFINE(M_PWDDESC, "pwddesc", "Pwd descriptors"); 97 static MALLOC_DEFINE(M_FILEDESC_TO_LEADER, "filedesc_to_leader", 98 "file desc to leader structures"); 99 static MALLOC_DEFINE(M_SIGIO, "sigio", "sigio structures"); 100 MALLOC_DEFINE(M_FILECAPS, "filecaps", "descriptor capabilities"); 101 102 MALLOC_DECLARE(M_FADVISE); 103 104 static __read_mostly uma_zone_t file_zone; 105 static __read_mostly uma_zone_t filedesc0_zone; 106 __read_mostly uma_zone_t pwd_zone; 107 VFS_SMR_DECLARE; 108 109 static int closefp(struct filedesc *fdp, int fd, struct file *fp, 110 struct thread *td, bool holdleaders, bool audit); 111 static int fd_first_free(struct filedesc *fdp, int low, int size); 112 static void fdgrowtable(struct filedesc *fdp, int nfd); 113 static void fdgrowtable_exp(struct filedesc *fdp, int nfd); 114 static void fdunused(struct filedesc *fdp, int fd); 115 static void fdused(struct filedesc *fdp, int fd); 116 static int getmaxfd(struct thread *td); 117 static u_long *filecaps_copy_prep(const struct filecaps *src); 118 static void filecaps_copy_finish(const struct filecaps *src, 119 struct filecaps *dst, u_long *ioctls); 120 static u_long *filecaps_free_prep(struct filecaps *fcaps); 121 static void filecaps_free_finish(u_long *ioctls); 122 123 static struct pwd *pwd_alloc(void); 124 125 /* 126 * Each process has: 127 * 128 * - An array of open file descriptors (fd_ofiles) 129 * - An array of file flags (fd_ofileflags) 130 * - A bitmap recording which descriptors are in use (fd_map) 131 * 132 * A process starts out with NDFILE descriptors. The value of NDFILE has 133 * been selected based the historical limit of 20 open files, and an 134 * assumption that the majority of processes, especially short-lived 135 * processes like shells, will never need more. 136 * 137 * If this initial allocation is exhausted, a larger descriptor table and 138 * map are allocated dynamically, and the pointers in the process's struct 139 * filedesc are updated to point to those. This is repeated every time 140 * the process runs out of file descriptors (provided it hasn't hit its 141 * resource limit). 142 * 143 * Since threads may hold references to individual descriptor table 144 * entries, the tables are never freed. Instead, they are placed on a 145 * linked list and freed only when the struct filedesc is released. 146 */ 147 #define NDFILE 20 148 #define NDSLOTSIZE sizeof(NDSLOTTYPE) 149 #define NDENTRIES (NDSLOTSIZE * __CHAR_BIT) 150 #define NDSLOT(x) ((x) / NDENTRIES) 151 #define NDBIT(x) ((NDSLOTTYPE)1 << ((x) % NDENTRIES)) 152 #define NDSLOTS(x) (((x) + NDENTRIES - 1) / NDENTRIES) 153 154 /* 155 * SLIST entry used to keep track of ofiles which must be reclaimed when 156 * the process exits. 157 */ 158 struct freetable { 159 struct fdescenttbl *ft_table; 160 SLIST_ENTRY(freetable) ft_next; 161 }; 162 163 /* 164 * Initial allocation: a filedesc structure + the head of SLIST used to 165 * keep track of old ofiles + enough space for NDFILE descriptors. 166 */ 167 168 struct fdescenttbl0 { 169 int fdt_nfiles; 170 struct filedescent fdt_ofiles[NDFILE]; 171 }; 172 173 struct filedesc0 { 174 struct filedesc fd_fd; 175 SLIST_HEAD(, freetable) fd_free; 176 struct fdescenttbl0 fd_dfiles; 177 NDSLOTTYPE fd_dmap[NDSLOTS(NDFILE)]; 178 }; 179 180 /* 181 * Descriptor management. 182 */ 183 static int __exclusive_cache_line openfiles; /* actual number of open files */ 184 struct mtx sigio_lock; /* mtx to protect pointers to sigio */ 185 void __read_mostly (*mq_fdclose)(struct thread *td, int fd, struct file *fp); 186 187 /* 188 * If low >= size, just return low. Otherwise find the first zero bit in the 189 * given bitmap, starting at low and not exceeding size - 1. Return size if 190 * not found. 191 */ 192 static int 193 fd_first_free(struct filedesc *fdp, int low, int size) 194 { 195 NDSLOTTYPE *map = fdp->fd_map; 196 NDSLOTTYPE mask; 197 int off, maxoff; 198 199 if (low >= size) 200 return (low); 201 202 off = NDSLOT(low); 203 if (low % NDENTRIES) { 204 mask = ~(~(NDSLOTTYPE)0 >> (NDENTRIES - (low % NDENTRIES))); 205 if ((mask &= ~map[off]) != 0UL) 206 return (off * NDENTRIES + ffsl(mask) - 1); 207 ++off; 208 } 209 for (maxoff = NDSLOTS(size); off < maxoff; ++off) 210 if (map[off] != ~0UL) 211 return (off * NDENTRIES + ffsl(~map[off]) - 1); 212 return (size); 213 } 214 215 /* 216 * Find the last used fd. 217 * 218 * Call this variant if fdp can't be modified by anyone else (e.g, during exec). 219 * Otherwise use fdlastfile. 220 */ 221 int 222 fdlastfile_single(struct filedesc *fdp) 223 { 224 NDSLOTTYPE *map = fdp->fd_map; 225 int off, minoff; 226 227 off = NDSLOT(fdp->fd_nfiles - 1); 228 for (minoff = NDSLOT(0); off >= minoff; --off) 229 if (map[off] != 0) 230 return (off * NDENTRIES + flsl(map[off]) - 1); 231 return (-1); 232 } 233 234 int 235 fdlastfile(struct filedesc *fdp) 236 { 237 238 FILEDESC_LOCK_ASSERT(fdp); 239 return (fdlastfile_single(fdp)); 240 } 241 242 static int 243 fdisused(struct filedesc *fdp, int fd) 244 { 245 246 KASSERT(fd >= 0 && fd < fdp->fd_nfiles, 247 ("file descriptor %d out of range (0, %d)", fd, fdp->fd_nfiles)); 248 249 return ((fdp->fd_map[NDSLOT(fd)] & NDBIT(fd)) != 0); 250 } 251 252 /* 253 * Mark a file descriptor as used. 254 */ 255 static void 256 fdused_init(struct filedesc *fdp, int fd) 257 { 258 259 KASSERT(!fdisused(fdp, fd), ("fd=%d is already used", fd)); 260 261 fdp->fd_map[NDSLOT(fd)] |= NDBIT(fd); 262 } 263 264 static void 265 fdused(struct filedesc *fdp, int fd) 266 { 267 268 FILEDESC_XLOCK_ASSERT(fdp); 269 270 fdused_init(fdp, fd); 271 if (fd == fdp->fd_freefile) 272 fdp->fd_freefile++; 273 } 274 275 /* 276 * Mark a file descriptor as unused. 277 */ 278 static void 279 fdunused(struct filedesc *fdp, int fd) 280 { 281 282 FILEDESC_XLOCK_ASSERT(fdp); 283 284 KASSERT(fdisused(fdp, fd), ("fd=%d is already unused", fd)); 285 KASSERT(fdp->fd_ofiles[fd].fde_file == NULL, 286 ("fd=%d is still in use", fd)); 287 288 fdp->fd_map[NDSLOT(fd)] &= ~NDBIT(fd); 289 if (fd < fdp->fd_freefile) 290 fdp->fd_freefile = fd; 291 } 292 293 /* 294 * Free a file descriptor. 295 * 296 * Avoid some work if fdp is about to be destroyed. 297 */ 298 static inline void 299 fdefree_last(struct filedescent *fde) 300 { 301 302 filecaps_free(&fde->fde_caps); 303 } 304 305 static inline void 306 fdfree(struct filedesc *fdp, int fd) 307 { 308 struct filedescent *fde; 309 310 FILEDESC_XLOCK_ASSERT(fdp); 311 fde = &fdp->fd_ofiles[fd]; 312 #ifdef CAPABILITIES 313 seqc_write_begin(&fde->fde_seqc); 314 #endif 315 fde->fde_file = NULL; 316 #ifdef CAPABILITIES 317 seqc_write_end(&fde->fde_seqc); 318 #endif 319 fdefree_last(fde); 320 fdunused(fdp, fd); 321 } 322 323 /* 324 * System calls on descriptors. 325 */ 326 #ifndef _SYS_SYSPROTO_H_ 327 struct getdtablesize_args { 328 int dummy; 329 }; 330 #endif 331 /* ARGSUSED */ 332 int 333 sys_getdtablesize(struct thread *td, struct getdtablesize_args *uap) 334 { 335 #ifdef RACCT 336 uint64_t lim; 337 #endif 338 339 td->td_retval[0] = getmaxfd(td); 340 #ifdef RACCT 341 PROC_LOCK(td->td_proc); 342 lim = racct_get_limit(td->td_proc, RACCT_NOFILE); 343 PROC_UNLOCK(td->td_proc); 344 if (lim < td->td_retval[0]) 345 td->td_retval[0] = lim; 346 #endif 347 return (0); 348 } 349 350 /* 351 * Duplicate a file descriptor to a particular value. 352 * 353 * Note: keep in mind that a potential race condition exists when closing 354 * descriptors from a shared descriptor table (via rfork). 355 */ 356 #ifndef _SYS_SYSPROTO_H_ 357 struct dup2_args { 358 u_int from; 359 u_int to; 360 }; 361 #endif 362 /* ARGSUSED */ 363 int 364 sys_dup2(struct thread *td, struct dup2_args *uap) 365 { 366 367 return (kern_dup(td, FDDUP_FIXED, 0, (int)uap->from, (int)uap->to)); 368 } 369 370 /* 371 * Duplicate a file descriptor. 372 */ 373 #ifndef _SYS_SYSPROTO_H_ 374 struct dup_args { 375 u_int fd; 376 }; 377 #endif 378 /* ARGSUSED */ 379 int 380 sys_dup(struct thread *td, struct dup_args *uap) 381 { 382 383 return (kern_dup(td, FDDUP_NORMAL, 0, (int)uap->fd, 0)); 384 } 385 386 /* 387 * The file control system call. 388 */ 389 #ifndef _SYS_SYSPROTO_H_ 390 struct fcntl_args { 391 int fd; 392 int cmd; 393 long arg; 394 }; 395 #endif 396 /* ARGSUSED */ 397 int 398 sys_fcntl(struct thread *td, struct fcntl_args *uap) 399 { 400 401 return (kern_fcntl_freebsd(td, uap->fd, uap->cmd, uap->arg)); 402 } 403 404 int 405 kern_fcntl_freebsd(struct thread *td, int fd, int cmd, long arg) 406 { 407 struct flock fl; 408 struct __oflock ofl; 409 intptr_t arg1; 410 int error, newcmd; 411 412 error = 0; 413 newcmd = cmd; 414 switch (cmd) { 415 case F_OGETLK: 416 case F_OSETLK: 417 case F_OSETLKW: 418 /* 419 * Convert old flock structure to new. 420 */ 421 error = copyin((void *)(intptr_t)arg, &ofl, sizeof(ofl)); 422 fl.l_start = ofl.l_start; 423 fl.l_len = ofl.l_len; 424 fl.l_pid = ofl.l_pid; 425 fl.l_type = ofl.l_type; 426 fl.l_whence = ofl.l_whence; 427 fl.l_sysid = 0; 428 429 switch (cmd) { 430 case F_OGETLK: 431 newcmd = F_GETLK; 432 break; 433 case F_OSETLK: 434 newcmd = F_SETLK; 435 break; 436 case F_OSETLKW: 437 newcmd = F_SETLKW; 438 break; 439 } 440 arg1 = (intptr_t)&fl; 441 break; 442 case F_GETLK: 443 case F_SETLK: 444 case F_SETLKW: 445 case F_SETLK_REMOTE: 446 error = copyin((void *)(intptr_t)arg, &fl, sizeof(fl)); 447 arg1 = (intptr_t)&fl; 448 break; 449 default: 450 arg1 = arg; 451 break; 452 } 453 if (error) 454 return (error); 455 error = kern_fcntl(td, fd, newcmd, arg1); 456 if (error) 457 return (error); 458 if (cmd == F_OGETLK) { 459 ofl.l_start = fl.l_start; 460 ofl.l_len = fl.l_len; 461 ofl.l_pid = fl.l_pid; 462 ofl.l_type = fl.l_type; 463 ofl.l_whence = fl.l_whence; 464 error = copyout(&ofl, (void *)(intptr_t)arg, sizeof(ofl)); 465 } else if (cmd == F_GETLK) { 466 error = copyout(&fl, (void *)(intptr_t)arg, sizeof(fl)); 467 } 468 return (error); 469 } 470 471 int 472 kern_fcntl(struct thread *td, int fd, int cmd, intptr_t arg) 473 { 474 struct filedesc *fdp; 475 struct flock *flp; 476 struct file *fp, *fp2; 477 struct filedescent *fde; 478 struct proc *p; 479 struct vnode *vp; 480 struct mount *mp; 481 int error, flg, seals, tmp; 482 uint64_t bsize; 483 off_t foffset; 484 485 error = 0; 486 flg = F_POSIX; 487 p = td->td_proc; 488 fdp = p->p_fd; 489 490 AUDIT_ARG_FD(cmd); 491 AUDIT_ARG_CMD(cmd); 492 switch (cmd) { 493 case F_DUPFD: 494 tmp = arg; 495 error = kern_dup(td, FDDUP_FCNTL, 0, fd, tmp); 496 break; 497 498 case F_DUPFD_CLOEXEC: 499 tmp = arg; 500 error = kern_dup(td, FDDUP_FCNTL, FDDUP_FLAG_CLOEXEC, fd, tmp); 501 break; 502 503 case F_DUP2FD: 504 tmp = arg; 505 error = kern_dup(td, FDDUP_FIXED, 0, fd, tmp); 506 break; 507 508 case F_DUP2FD_CLOEXEC: 509 tmp = arg; 510 error = kern_dup(td, FDDUP_FIXED, FDDUP_FLAG_CLOEXEC, fd, tmp); 511 break; 512 513 case F_GETFD: 514 error = EBADF; 515 FILEDESC_SLOCK(fdp); 516 fde = fdeget_locked(fdp, fd); 517 if (fde != NULL) { 518 td->td_retval[0] = 519 (fde->fde_flags & UF_EXCLOSE) ? FD_CLOEXEC : 0; 520 error = 0; 521 } 522 FILEDESC_SUNLOCK(fdp); 523 break; 524 525 case F_SETFD: 526 error = EBADF; 527 FILEDESC_XLOCK(fdp); 528 fde = fdeget_locked(fdp, fd); 529 if (fde != NULL) { 530 fde->fde_flags = (fde->fde_flags & ~UF_EXCLOSE) | 531 (arg & FD_CLOEXEC ? UF_EXCLOSE : 0); 532 error = 0; 533 } 534 FILEDESC_XUNLOCK(fdp); 535 break; 536 537 case F_GETFL: 538 error = fget_fcntl(td, fd, &cap_fcntl_rights, F_GETFL, &fp); 539 if (error != 0) 540 break; 541 td->td_retval[0] = OFLAGS(fp->f_flag); 542 fdrop(fp, td); 543 break; 544 545 case F_SETFL: 546 error = fget_fcntl(td, fd, &cap_fcntl_rights, F_SETFL, &fp); 547 if (error != 0) 548 break; 549 do { 550 tmp = flg = fp->f_flag; 551 tmp &= ~FCNTLFLAGS; 552 tmp |= FFLAGS(arg & ~O_ACCMODE) & FCNTLFLAGS; 553 } while(atomic_cmpset_int(&fp->f_flag, flg, tmp) == 0); 554 tmp = fp->f_flag & FNONBLOCK; 555 error = fo_ioctl(fp, FIONBIO, &tmp, td->td_ucred, td); 556 if (error != 0) { 557 fdrop(fp, td); 558 break; 559 } 560 tmp = fp->f_flag & FASYNC; 561 error = fo_ioctl(fp, FIOASYNC, &tmp, td->td_ucred, td); 562 if (error == 0) { 563 fdrop(fp, td); 564 break; 565 } 566 atomic_clear_int(&fp->f_flag, FNONBLOCK); 567 tmp = 0; 568 (void)fo_ioctl(fp, FIONBIO, &tmp, td->td_ucred, td); 569 fdrop(fp, td); 570 break; 571 572 case F_GETOWN: 573 error = fget_fcntl(td, fd, &cap_fcntl_rights, F_GETOWN, &fp); 574 if (error != 0) 575 break; 576 error = fo_ioctl(fp, FIOGETOWN, &tmp, td->td_ucred, td); 577 if (error == 0) 578 td->td_retval[0] = tmp; 579 fdrop(fp, td); 580 break; 581 582 case F_SETOWN: 583 error = fget_fcntl(td, fd, &cap_fcntl_rights, F_SETOWN, &fp); 584 if (error != 0) 585 break; 586 tmp = arg; 587 error = fo_ioctl(fp, FIOSETOWN, &tmp, td->td_ucred, td); 588 fdrop(fp, td); 589 break; 590 591 case F_SETLK_REMOTE: 592 error = priv_check(td, PRIV_NFS_LOCKD); 593 if (error != 0) 594 return (error); 595 flg = F_REMOTE; 596 goto do_setlk; 597 598 case F_SETLKW: 599 flg |= F_WAIT; 600 /* FALLTHROUGH F_SETLK */ 601 602 case F_SETLK: 603 do_setlk: 604 flp = (struct flock *)arg; 605 if ((flg & F_REMOTE) != 0 && flp->l_sysid == 0) { 606 error = EINVAL; 607 break; 608 } 609 610 error = fget_unlocked(fdp, fd, &cap_flock_rights, &fp); 611 if (error != 0) 612 break; 613 if (fp->f_type != DTYPE_VNODE) { 614 error = EBADF; 615 fdrop(fp, td); 616 break; 617 } 618 619 if (flp->l_whence == SEEK_CUR) { 620 foffset = foffset_get(fp); 621 if (foffset < 0 || 622 (flp->l_start > 0 && 623 foffset > OFF_MAX - flp->l_start)) { 624 error = EOVERFLOW; 625 fdrop(fp, td); 626 break; 627 } 628 flp->l_start += foffset; 629 } 630 631 vp = fp->f_vnode; 632 switch (flp->l_type) { 633 case F_RDLCK: 634 if ((fp->f_flag & FREAD) == 0) { 635 error = EBADF; 636 break; 637 } 638 if ((p->p_leader->p_flag & P_ADVLOCK) == 0) { 639 PROC_LOCK(p->p_leader); 640 p->p_leader->p_flag |= P_ADVLOCK; 641 PROC_UNLOCK(p->p_leader); 642 } 643 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_SETLK, 644 flp, flg); 645 break; 646 case F_WRLCK: 647 if ((fp->f_flag & FWRITE) == 0) { 648 error = EBADF; 649 break; 650 } 651 if ((p->p_leader->p_flag & P_ADVLOCK) == 0) { 652 PROC_LOCK(p->p_leader); 653 p->p_leader->p_flag |= P_ADVLOCK; 654 PROC_UNLOCK(p->p_leader); 655 } 656 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_SETLK, 657 flp, flg); 658 break; 659 case F_UNLCK: 660 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_UNLCK, 661 flp, flg); 662 break; 663 case F_UNLCKSYS: 664 if (flg != F_REMOTE) { 665 error = EINVAL; 666 break; 667 } 668 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, 669 F_UNLCKSYS, flp, flg); 670 break; 671 default: 672 error = EINVAL; 673 break; 674 } 675 if (error != 0 || flp->l_type == F_UNLCK || 676 flp->l_type == F_UNLCKSYS) { 677 fdrop(fp, td); 678 break; 679 } 680 681 /* 682 * Check for a race with close. 683 * 684 * The vnode is now advisory locked (or unlocked, but this case 685 * is not really important) as the caller requested. 686 * We had to drop the filedesc lock, so we need to recheck if 687 * the descriptor is still valid, because if it was closed 688 * in the meantime we need to remove advisory lock from the 689 * vnode - close on any descriptor leading to an advisory 690 * locked vnode, removes that lock. 691 * We will return 0 on purpose in that case, as the result of 692 * successful advisory lock might have been externally visible 693 * already. This is fine - effectively we pretend to the caller 694 * that the closing thread was a bit slower and that the 695 * advisory lock succeeded before the close. 696 */ 697 error = fget_unlocked(fdp, fd, &cap_no_rights, &fp2); 698 if (error != 0) { 699 fdrop(fp, td); 700 break; 701 } 702 if (fp != fp2) { 703 flp->l_whence = SEEK_SET; 704 flp->l_start = 0; 705 flp->l_len = 0; 706 flp->l_type = F_UNLCK; 707 (void) VOP_ADVLOCK(vp, (caddr_t)p->p_leader, 708 F_UNLCK, flp, F_POSIX); 709 } 710 fdrop(fp, td); 711 fdrop(fp2, td); 712 break; 713 714 case F_GETLK: 715 error = fget_unlocked(fdp, fd, &cap_flock_rights, &fp); 716 if (error != 0) 717 break; 718 if (fp->f_type != DTYPE_VNODE) { 719 error = EBADF; 720 fdrop(fp, td); 721 break; 722 } 723 flp = (struct flock *)arg; 724 if (flp->l_type != F_RDLCK && flp->l_type != F_WRLCK && 725 flp->l_type != F_UNLCK) { 726 error = EINVAL; 727 fdrop(fp, td); 728 break; 729 } 730 if (flp->l_whence == SEEK_CUR) { 731 foffset = foffset_get(fp); 732 if ((flp->l_start > 0 && 733 foffset > OFF_MAX - flp->l_start) || 734 (flp->l_start < 0 && 735 foffset < OFF_MIN - flp->l_start)) { 736 error = EOVERFLOW; 737 fdrop(fp, td); 738 break; 739 } 740 flp->l_start += foffset; 741 } 742 vp = fp->f_vnode; 743 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_GETLK, flp, 744 F_POSIX); 745 fdrop(fp, td); 746 break; 747 748 case F_ADD_SEALS: 749 error = fget_unlocked(fdp, fd, &cap_no_rights, &fp); 750 if (error != 0) 751 break; 752 error = fo_add_seals(fp, arg); 753 fdrop(fp, td); 754 break; 755 756 case F_GET_SEALS: 757 error = fget_unlocked(fdp, fd, &cap_no_rights, &fp); 758 if (error != 0) 759 break; 760 if (fo_get_seals(fp, &seals) == 0) 761 td->td_retval[0] = seals; 762 else 763 error = EINVAL; 764 fdrop(fp, td); 765 break; 766 767 case F_RDAHEAD: 768 arg = arg ? 128 * 1024: 0; 769 /* FALLTHROUGH */ 770 case F_READAHEAD: 771 error = fget_unlocked(fdp, fd, &cap_no_rights, &fp); 772 if (error != 0) 773 break; 774 if (fp->f_type != DTYPE_VNODE) { 775 fdrop(fp, td); 776 error = EBADF; 777 break; 778 } 779 vp = fp->f_vnode; 780 if (vp->v_type != VREG) { 781 fdrop(fp, td); 782 error = ENOTTY; 783 break; 784 } 785 786 /* 787 * Exclusive lock synchronizes against f_seqcount reads and 788 * writes in sequential_heuristic(). 789 */ 790 error = vn_lock(vp, LK_EXCLUSIVE); 791 if (error != 0) { 792 fdrop(fp, td); 793 break; 794 } 795 if (arg >= 0) { 796 bsize = fp->f_vnode->v_mount->mnt_stat.f_iosize; 797 arg = MIN(arg, INT_MAX - bsize + 1); 798 fp->f_seqcount[UIO_READ] = MIN(IO_SEQMAX, 799 (arg + bsize - 1) / bsize); 800 atomic_set_int(&fp->f_flag, FRDAHEAD); 801 } else { 802 atomic_clear_int(&fp->f_flag, FRDAHEAD); 803 } 804 VOP_UNLOCK(vp); 805 fdrop(fp, td); 806 break; 807 808 case F_ISUNIONSTACK: 809 /* 810 * Check if the vnode is part of a union stack (either the 811 * "union" flag from mount(2) or unionfs). 812 * 813 * Prior to introduction of this op libc's readdir would call 814 * fstatfs(2), in effect unnecessarily copying kilobytes of 815 * data just to check fs name and a mount flag. 816 * 817 * Fixing the code to handle everything in the kernel instead 818 * is a non-trivial endeavor and has low priority, thus this 819 * horrible kludge facilitates the current behavior in a much 820 * cheaper manner until someone(tm) sorts this out. 821 */ 822 error = fget_unlocked(fdp, fd, &cap_no_rights, &fp); 823 if (error != 0) 824 break; 825 if (fp->f_type != DTYPE_VNODE) { 826 fdrop(fp, td); 827 error = EBADF; 828 break; 829 } 830 vp = fp->f_vnode; 831 /* 832 * Since we don't prevent dooming the vnode even non-null mp 833 * found can become immediately stale. This is tolerable since 834 * mount points are type-stable (providing safe memory access) 835 * and any vfs op on this vnode going forward will return an 836 * error (meaning return value in this case is meaningless). 837 */ 838 mp = atomic_load_ptr(&vp->v_mount); 839 if (__predict_false(mp == NULL)) { 840 fdrop(fp, td); 841 error = EBADF; 842 break; 843 } 844 td->td_retval[0] = 0; 845 if (mp->mnt_kern_flag & MNTK_UNIONFS || 846 mp->mnt_flag & MNT_UNION) 847 td->td_retval[0] = 1; 848 fdrop(fp, td); 849 break; 850 851 default: 852 error = EINVAL; 853 break; 854 } 855 return (error); 856 } 857 858 static int 859 getmaxfd(struct thread *td) 860 { 861 862 return (min((int)lim_cur(td, RLIMIT_NOFILE), maxfilesperproc)); 863 } 864 865 /* 866 * Common code for dup, dup2, fcntl(F_DUPFD) and fcntl(F_DUP2FD). 867 */ 868 int 869 kern_dup(struct thread *td, u_int mode, int flags, int old, int new) 870 { 871 struct filedesc *fdp; 872 struct filedescent *oldfde, *newfde; 873 struct proc *p; 874 struct file *delfp, *oldfp; 875 u_long *oioctls, *nioctls; 876 int error, maxfd; 877 878 p = td->td_proc; 879 fdp = p->p_fd; 880 oioctls = NULL; 881 882 MPASS((flags & ~(FDDUP_FLAG_CLOEXEC)) == 0); 883 MPASS(mode < FDDUP_LASTMODE); 884 885 AUDIT_ARG_FD(old); 886 /* XXXRW: if (flags & FDDUP_FIXED) AUDIT_ARG_FD2(new); */ 887 888 /* 889 * Verify we have a valid descriptor to dup from and possibly to 890 * dup to. Unlike dup() and dup2(), fcntl()'s F_DUPFD should 891 * return EINVAL when the new descriptor is out of bounds. 892 */ 893 if (old < 0) 894 return (EBADF); 895 if (new < 0) 896 return (mode == FDDUP_FCNTL ? EINVAL : EBADF); 897 maxfd = getmaxfd(td); 898 if (new >= maxfd) 899 return (mode == FDDUP_FCNTL ? EINVAL : EBADF); 900 901 error = EBADF; 902 FILEDESC_XLOCK(fdp); 903 if (fget_locked(fdp, old) == NULL) 904 goto unlock; 905 if ((mode == FDDUP_FIXED || mode == FDDUP_MUSTREPLACE) && old == new) { 906 td->td_retval[0] = new; 907 if (flags & FDDUP_FLAG_CLOEXEC) 908 fdp->fd_ofiles[new].fde_flags |= UF_EXCLOSE; 909 error = 0; 910 goto unlock; 911 } 912 913 oldfde = &fdp->fd_ofiles[old]; 914 oldfp = oldfde->fde_file; 915 if (!fhold(oldfp)) 916 goto unlock; 917 918 /* 919 * If the caller specified a file descriptor, make sure the file 920 * table is large enough to hold it, and grab it. Otherwise, just 921 * allocate a new descriptor the usual way. 922 */ 923 switch (mode) { 924 case FDDUP_NORMAL: 925 case FDDUP_FCNTL: 926 if ((error = fdalloc(td, new, &new)) != 0) { 927 fdrop(oldfp, td); 928 goto unlock; 929 } 930 break; 931 case FDDUP_MUSTREPLACE: 932 /* Target file descriptor must exist. */ 933 if (fget_locked(fdp, new) == NULL) { 934 fdrop(oldfp, td); 935 goto unlock; 936 } 937 break; 938 case FDDUP_FIXED: 939 if (new >= fdp->fd_nfiles) { 940 /* 941 * The resource limits are here instead of e.g. 942 * fdalloc(), because the file descriptor table may be 943 * shared between processes, so we can't really use 944 * racct_add()/racct_sub(). Instead of counting the 945 * number of actually allocated descriptors, just put 946 * the limit on the size of the file descriptor table. 947 */ 948 #ifdef RACCT 949 if (RACCT_ENABLED()) { 950 error = racct_set_unlocked(p, RACCT_NOFILE, new + 1); 951 if (error != 0) { 952 error = EMFILE; 953 fdrop(oldfp, td); 954 goto unlock; 955 } 956 } 957 #endif 958 fdgrowtable_exp(fdp, new + 1); 959 } 960 if (!fdisused(fdp, new)) 961 fdused(fdp, new); 962 break; 963 default: 964 KASSERT(0, ("%s unsupported mode %d", __func__, mode)); 965 } 966 967 KASSERT(old != new, ("new fd is same as old")); 968 969 /* Refetch oldfde because the table may have grown and old one freed. */ 970 oldfde = &fdp->fd_ofiles[old]; 971 KASSERT(oldfp == oldfde->fde_file, 972 ("fdt_ofiles shift from growth observed at fd %d", 973 old)); 974 975 newfde = &fdp->fd_ofiles[new]; 976 delfp = newfde->fde_file; 977 978 nioctls = filecaps_copy_prep(&oldfde->fde_caps); 979 980 /* 981 * Duplicate the source descriptor. 982 */ 983 #ifdef CAPABILITIES 984 seqc_write_begin(&newfde->fde_seqc); 985 #endif 986 oioctls = filecaps_free_prep(&newfde->fde_caps); 987 memcpy(newfde, oldfde, fde_change_size); 988 filecaps_copy_finish(&oldfde->fde_caps, &newfde->fde_caps, 989 nioctls); 990 if ((flags & FDDUP_FLAG_CLOEXEC) != 0) 991 newfde->fde_flags = oldfde->fde_flags | UF_EXCLOSE; 992 else 993 newfde->fde_flags = oldfde->fde_flags & ~UF_EXCLOSE; 994 #ifdef CAPABILITIES 995 seqc_write_end(&newfde->fde_seqc); 996 #endif 997 td->td_retval[0] = new; 998 999 error = 0; 1000 1001 if (delfp != NULL) { 1002 (void) closefp(fdp, new, delfp, td, true, false); 1003 FILEDESC_UNLOCK_ASSERT(fdp); 1004 } else { 1005 unlock: 1006 FILEDESC_XUNLOCK(fdp); 1007 } 1008 1009 filecaps_free_finish(oioctls); 1010 return (error); 1011 } 1012 1013 static void 1014 sigiofree(struct sigio *sigio) 1015 { 1016 crfree(sigio->sio_ucred); 1017 free(sigio, M_SIGIO); 1018 } 1019 1020 static struct sigio * 1021 funsetown_locked(struct sigio *sigio) 1022 { 1023 struct proc *p; 1024 struct pgrp *pg; 1025 1026 SIGIO_ASSERT_LOCKED(); 1027 1028 if (sigio == NULL) 1029 return (NULL); 1030 *(sigio->sio_myref) = NULL; 1031 if (sigio->sio_pgid < 0) { 1032 pg = sigio->sio_pgrp; 1033 PGRP_LOCK(pg); 1034 SLIST_REMOVE(&sigio->sio_pgrp->pg_sigiolst, sigio, 1035 sigio, sio_pgsigio); 1036 PGRP_UNLOCK(pg); 1037 } else { 1038 p = sigio->sio_proc; 1039 PROC_LOCK(p); 1040 SLIST_REMOVE(&sigio->sio_proc->p_sigiolst, sigio, 1041 sigio, sio_pgsigio); 1042 PROC_UNLOCK(p); 1043 } 1044 return (sigio); 1045 } 1046 1047 /* 1048 * If sigio is on the list associated with a process or process group, 1049 * disable signalling from the device, remove sigio from the list and 1050 * free sigio. 1051 */ 1052 void 1053 funsetown(struct sigio **sigiop) 1054 { 1055 struct sigio *sigio; 1056 1057 /* Racy check, consumers must provide synchronization. */ 1058 if (*sigiop == NULL) 1059 return; 1060 1061 SIGIO_LOCK(); 1062 sigio = funsetown_locked(*sigiop); 1063 SIGIO_UNLOCK(); 1064 if (sigio != NULL) 1065 sigiofree(sigio); 1066 } 1067 1068 /* 1069 * Free a list of sigio structures. The caller must ensure that new sigio 1070 * structures cannot be added after this point. For process groups this is 1071 * guaranteed using the proctree lock; for processes, the P_WEXIT flag serves 1072 * as an interlock. 1073 */ 1074 void 1075 funsetownlst(struct sigiolst *sigiolst) 1076 { 1077 struct proc *p; 1078 struct pgrp *pg; 1079 struct sigio *sigio, *tmp; 1080 1081 /* Racy check. */ 1082 sigio = SLIST_FIRST(sigiolst); 1083 if (sigio == NULL) 1084 return; 1085 1086 p = NULL; 1087 pg = NULL; 1088 1089 SIGIO_LOCK(); 1090 sigio = SLIST_FIRST(sigiolst); 1091 if (sigio == NULL) { 1092 SIGIO_UNLOCK(); 1093 return; 1094 } 1095 1096 /* 1097 * Every entry of the list should belong to a single proc or pgrp. 1098 */ 1099 if (sigio->sio_pgid < 0) { 1100 pg = sigio->sio_pgrp; 1101 sx_assert(&proctree_lock, SX_XLOCKED); 1102 PGRP_LOCK(pg); 1103 } else /* if (sigio->sio_pgid > 0) */ { 1104 p = sigio->sio_proc; 1105 PROC_LOCK(p); 1106 KASSERT((p->p_flag & P_WEXIT) != 0, 1107 ("%s: process %p is not exiting", __func__, p)); 1108 } 1109 1110 SLIST_FOREACH(sigio, sigiolst, sio_pgsigio) { 1111 *sigio->sio_myref = NULL; 1112 if (pg != NULL) { 1113 KASSERT(sigio->sio_pgid < 0, 1114 ("Proc sigio in pgrp sigio list")); 1115 KASSERT(sigio->sio_pgrp == pg, 1116 ("Bogus pgrp in sigio list")); 1117 } else /* if (p != NULL) */ { 1118 KASSERT(sigio->sio_pgid > 0, 1119 ("Pgrp sigio in proc sigio list")); 1120 KASSERT(sigio->sio_proc == p, 1121 ("Bogus proc in sigio list")); 1122 } 1123 } 1124 1125 if (pg != NULL) 1126 PGRP_UNLOCK(pg); 1127 else 1128 PROC_UNLOCK(p); 1129 SIGIO_UNLOCK(); 1130 1131 SLIST_FOREACH_SAFE(sigio, sigiolst, sio_pgsigio, tmp) 1132 sigiofree(sigio); 1133 } 1134 1135 /* 1136 * This is common code for FIOSETOWN ioctl called by fcntl(fd, F_SETOWN, arg). 1137 * 1138 * After permission checking, add a sigio structure to the sigio list for 1139 * the process or process group. 1140 */ 1141 int 1142 fsetown(pid_t pgid, struct sigio **sigiop) 1143 { 1144 struct proc *proc; 1145 struct pgrp *pgrp; 1146 struct sigio *osigio, *sigio; 1147 int ret; 1148 1149 if (pgid == 0) { 1150 funsetown(sigiop); 1151 return (0); 1152 } 1153 1154 ret = 0; 1155 1156 sigio = malloc(sizeof(struct sigio), M_SIGIO, M_WAITOK); 1157 sigio->sio_pgid = pgid; 1158 sigio->sio_ucred = crhold(curthread->td_ucred); 1159 sigio->sio_myref = sigiop; 1160 1161 sx_slock(&proctree_lock); 1162 SIGIO_LOCK(); 1163 osigio = funsetown_locked(*sigiop); 1164 if (pgid > 0) { 1165 proc = pfind(pgid); 1166 if (proc == NULL) { 1167 ret = ESRCH; 1168 goto fail; 1169 } 1170 1171 /* 1172 * Policy - Don't allow a process to FSETOWN a process 1173 * in another session. 1174 * 1175 * Remove this test to allow maximum flexibility or 1176 * restrict FSETOWN to the current process or process 1177 * group for maximum safety. 1178 */ 1179 if (proc->p_session != curthread->td_proc->p_session) { 1180 PROC_UNLOCK(proc); 1181 ret = EPERM; 1182 goto fail; 1183 } 1184 1185 sigio->sio_proc = proc; 1186 SLIST_INSERT_HEAD(&proc->p_sigiolst, sigio, sio_pgsigio); 1187 PROC_UNLOCK(proc); 1188 } else /* if (pgid < 0) */ { 1189 pgrp = pgfind(-pgid); 1190 if (pgrp == NULL) { 1191 ret = ESRCH; 1192 goto fail; 1193 } 1194 1195 /* 1196 * Policy - Don't allow a process to FSETOWN a process 1197 * in another session. 1198 * 1199 * Remove this test to allow maximum flexibility or 1200 * restrict FSETOWN to the current process or process 1201 * group for maximum safety. 1202 */ 1203 if (pgrp->pg_session != curthread->td_proc->p_session) { 1204 PGRP_UNLOCK(pgrp); 1205 ret = EPERM; 1206 goto fail; 1207 } 1208 1209 SLIST_INSERT_HEAD(&pgrp->pg_sigiolst, sigio, sio_pgsigio); 1210 sigio->sio_pgrp = pgrp; 1211 PGRP_UNLOCK(pgrp); 1212 } 1213 sx_sunlock(&proctree_lock); 1214 *sigiop = sigio; 1215 SIGIO_UNLOCK(); 1216 if (osigio != NULL) 1217 sigiofree(osigio); 1218 return (0); 1219 1220 fail: 1221 SIGIO_UNLOCK(); 1222 sx_sunlock(&proctree_lock); 1223 sigiofree(sigio); 1224 if (osigio != NULL) 1225 sigiofree(osigio); 1226 return (ret); 1227 } 1228 1229 /* 1230 * This is common code for FIOGETOWN ioctl called by fcntl(fd, F_GETOWN, arg). 1231 */ 1232 pid_t 1233 fgetown(struct sigio **sigiop) 1234 { 1235 pid_t pgid; 1236 1237 SIGIO_LOCK(); 1238 pgid = (*sigiop != NULL) ? (*sigiop)->sio_pgid : 0; 1239 SIGIO_UNLOCK(); 1240 return (pgid); 1241 } 1242 1243 static int 1244 closefp_impl(struct filedesc *fdp, int fd, struct file *fp, struct thread *td, 1245 bool audit) 1246 { 1247 int error; 1248 1249 FILEDESC_XLOCK_ASSERT(fdp); 1250 1251 /* 1252 * We now hold the fp reference that used to be owned by the 1253 * descriptor array. We have to unlock the FILEDESC *AFTER* 1254 * knote_fdclose to prevent a race of the fd getting opened, a knote 1255 * added, and deleteing a knote for the new fd. 1256 */ 1257 if (__predict_false(!TAILQ_EMPTY(&fdp->fd_kqlist))) 1258 knote_fdclose(td, fd); 1259 1260 /* 1261 * We need to notify mqueue if the object is of type mqueue. 1262 */ 1263 if (__predict_false(fp->f_type == DTYPE_MQUEUE)) 1264 mq_fdclose(td, fd, fp); 1265 FILEDESC_XUNLOCK(fdp); 1266 1267 #ifdef AUDIT 1268 if (AUDITING_TD(td) && audit) 1269 audit_sysclose(td, fd, fp); 1270 #endif 1271 error = closef(fp, td); 1272 1273 /* 1274 * All paths leading up to closefp() will have already removed or 1275 * replaced the fd in the filedesc table, so a restart would not 1276 * operate on the same file. 1277 */ 1278 if (error == ERESTART) 1279 error = EINTR; 1280 1281 return (error); 1282 } 1283 1284 static int 1285 closefp_hl(struct filedesc *fdp, int fd, struct file *fp, struct thread *td, 1286 bool holdleaders, bool audit) 1287 { 1288 int error; 1289 1290 FILEDESC_XLOCK_ASSERT(fdp); 1291 1292 if (holdleaders) { 1293 if (td->td_proc->p_fdtol != NULL) { 1294 /* 1295 * Ask fdfree() to sleep to ensure that all relevant 1296 * process leaders can be traversed in closef(). 1297 */ 1298 fdp->fd_holdleaderscount++; 1299 } else { 1300 holdleaders = false; 1301 } 1302 } 1303 1304 error = closefp_impl(fdp, fd, fp, td, audit); 1305 if (holdleaders) { 1306 FILEDESC_XLOCK(fdp); 1307 fdp->fd_holdleaderscount--; 1308 if (fdp->fd_holdleaderscount == 0 && 1309 fdp->fd_holdleaderswakeup != 0) { 1310 fdp->fd_holdleaderswakeup = 0; 1311 wakeup(&fdp->fd_holdleaderscount); 1312 } 1313 FILEDESC_XUNLOCK(fdp); 1314 } 1315 return (error); 1316 } 1317 1318 static int 1319 closefp(struct filedesc *fdp, int fd, struct file *fp, struct thread *td, 1320 bool holdleaders, bool audit) 1321 { 1322 1323 FILEDESC_XLOCK_ASSERT(fdp); 1324 1325 if (__predict_false(td->td_proc->p_fdtol != NULL)) { 1326 return (closefp_hl(fdp, fd, fp, td, holdleaders, audit)); 1327 } else { 1328 return (closefp_impl(fdp, fd, fp, td, audit)); 1329 } 1330 } 1331 1332 /* 1333 * Close a file descriptor. 1334 */ 1335 #ifndef _SYS_SYSPROTO_H_ 1336 struct close_args { 1337 int fd; 1338 }; 1339 #endif 1340 /* ARGSUSED */ 1341 int 1342 sys_close(struct thread *td, struct close_args *uap) 1343 { 1344 1345 return (kern_close(td, uap->fd)); 1346 } 1347 1348 int 1349 kern_close(struct thread *td, int fd) 1350 { 1351 struct filedesc *fdp; 1352 struct file *fp; 1353 1354 fdp = td->td_proc->p_fd; 1355 1356 FILEDESC_XLOCK(fdp); 1357 if ((fp = fget_locked(fdp, fd)) == NULL) { 1358 FILEDESC_XUNLOCK(fdp); 1359 return (EBADF); 1360 } 1361 fdfree(fdp, fd); 1362 1363 /* closefp() drops the FILEDESC lock for us. */ 1364 return (closefp(fdp, fd, fp, td, true, true)); 1365 } 1366 1367 int 1368 kern_close_range(struct thread *td, u_int lowfd, u_int highfd) 1369 { 1370 struct filedesc *fdp; 1371 const struct fdescenttbl *fdt; 1372 struct file *fp; 1373 int fd; 1374 1375 /* 1376 * Check this prior to clamping; closefrom(3) with only fd 0, 1, and 2 1377 * open should not be a usage error. From a close_range() perspective, 1378 * close_range(3, ~0U, 0) in the same scenario should also likely not 1379 * be a usage error as all fd above 3 are in-fact already closed. 1380 */ 1381 if (highfd < lowfd) { 1382 return (EINVAL); 1383 } 1384 1385 fdp = td->td_proc->p_fd; 1386 FILEDESC_XLOCK(fdp); 1387 fdt = atomic_load_ptr(&fdp->fd_files); 1388 highfd = MIN(highfd, fdt->fdt_nfiles - 1); 1389 fd = lowfd; 1390 if (__predict_false(fd > highfd)) { 1391 goto out_locked; 1392 } 1393 for (;;) { 1394 fp = fdt->fdt_ofiles[fd].fde_file; 1395 if (fp == NULL) { 1396 if (fd == highfd) 1397 goto out_locked; 1398 } else { 1399 fdfree(fdp, fd); 1400 (void) closefp(fdp, fd, fp, td, true, true); 1401 if (fd == highfd) 1402 goto out_unlocked; 1403 FILEDESC_XLOCK(fdp); 1404 fdt = atomic_load_ptr(&fdp->fd_files); 1405 } 1406 fd++; 1407 } 1408 out_locked: 1409 FILEDESC_XUNLOCK(fdp); 1410 out_unlocked: 1411 return (0); 1412 } 1413 1414 #ifndef _SYS_SYSPROTO_H_ 1415 struct close_range_args { 1416 u_int lowfd; 1417 u_int highfd; 1418 int flags; 1419 }; 1420 #endif 1421 int 1422 sys_close_range(struct thread *td, struct close_range_args *uap) 1423 { 1424 1425 /* No flags currently defined */ 1426 if (uap->flags != 0) 1427 return (EINVAL); 1428 return (kern_close_range(td, uap->lowfd, uap->highfd)); 1429 } 1430 1431 #ifdef COMPAT_FREEBSD12 1432 /* 1433 * Close open file descriptors. 1434 */ 1435 #ifndef _SYS_SYSPROTO_H_ 1436 struct freebsd12_closefrom_args { 1437 int lowfd; 1438 }; 1439 #endif 1440 /* ARGSUSED */ 1441 int 1442 freebsd12_closefrom(struct thread *td, struct freebsd12_closefrom_args *uap) 1443 { 1444 u_int lowfd; 1445 1446 AUDIT_ARG_FD(uap->lowfd); 1447 1448 /* 1449 * Treat negative starting file descriptor values identical to 1450 * closefrom(0) which closes all files. 1451 */ 1452 lowfd = MAX(0, uap->lowfd); 1453 return (kern_close_range(td, lowfd, ~0U)); 1454 } 1455 #endif /* COMPAT_FREEBSD12 */ 1456 1457 #if defined(COMPAT_43) 1458 /* 1459 * Return status information about a file descriptor. 1460 */ 1461 #ifndef _SYS_SYSPROTO_H_ 1462 struct ofstat_args { 1463 int fd; 1464 struct ostat *sb; 1465 }; 1466 #endif 1467 /* ARGSUSED */ 1468 int 1469 ofstat(struct thread *td, struct ofstat_args *uap) 1470 { 1471 struct ostat oub; 1472 struct stat ub; 1473 int error; 1474 1475 error = kern_fstat(td, uap->fd, &ub); 1476 if (error == 0) { 1477 cvtstat(&ub, &oub); 1478 error = copyout(&oub, uap->sb, sizeof(oub)); 1479 } 1480 return (error); 1481 } 1482 #endif /* COMPAT_43 */ 1483 1484 #if defined(COMPAT_FREEBSD11) 1485 int 1486 freebsd11_fstat(struct thread *td, struct freebsd11_fstat_args *uap) 1487 { 1488 struct stat sb; 1489 struct freebsd11_stat osb; 1490 int error; 1491 1492 error = kern_fstat(td, uap->fd, &sb); 1493 if (error != 0) 1494 return (error); 1495 error = freebsd11_cvtstat(&sb, &osb); 1496 if (error == 0) 1497 error = copyout(&osb, uap->sb, sizeof(osb)); 1498 return (error); 1499 } 1500 #endif /* COMPAT_FREEBSD11 */ 1501 1502 /* 1503 * Return status information about a file descriptor. 1504 */ 1505 #ifndef _SYS_SYSPROTO_H_ 1506 struct fstat_args { 1507 int fd; 1508 struct stat *sb; 1509 }; 1510 #endif 1511 /* ARGSUSED */ 1512 int 1513 sys_fstat(struct thread *td, struct fstat_args *uap) 1514 { 1515 struct stat ub; 1516 int error; 1517 1518 error = kern_fstat(td, uap->fd, &ub); 1519 if (error == 0) 1520 error = copyout(&ub, uap->sb, sizeof(ub)); 1521 return (error); 1522 } 1523 1524 int 1525 kern_fstat(struct thread *td, int fd, struct stat *sbp) 1526 { 1527 struct file *fp; 1528 int error; 1529 1530 AUDIT_ARG_FD(fd); 1531 1532 error = fget(td, fd, &cap_fstat_rights, &fp); 1533 if (__predict_false(error != 0)) 1534 return (error); 1535 1536 AUDIT_ARG_FILE(td->td_proc, fp); 1537 1538 error = fo_stat(fp, sbp, td->td_ucred, td); 1539 fdrop(fp, td); 1540 #ifdef __STAT_TIME_T_EXT 1541 sbp->st_atim_ext = 0; 1542 sbp->st_mtim_ext = 0; 1543 sbp->st_ctim_ext = 0; 1544 sbp->st_btim_ext = 0; 1545 #endif 1546 #ifdef KTRACE 1547 if (KTRPOINT(td, KTR_STRUCT)) 1548 ktrstat_error(sbp, error); 1549 #endif 1550 return (error); 1551 } 1552 1553 #if defined(COMPAT_FREEBSD11) 1554 /* 1555 * Return status information about a file descriptor. 1556 */ 1557 #ifndef _SYS_SYSPROTO_H_ 1558 struct freebsd11_nfstat_args { 1559 int fd; 1560 struct nstat *sb; 1561 }; 1562 #endif 1563 /* ARGSUSED */ 1564 int 1565 freebsd11_nfstat(struct thread *td, struct freebsd11_nfstat_args *uap) 1566 { 1567 struct nstat nub; 1568 struct stat ub; 1569 int error; 1570 1571 error = kern_fstat(td, uap->fd, &ub); 1572 if (error == 0) { 1573 freebsd11_cvtnstat(&ub, &nub); 1574 error = copyout(&nub, uap->sb, sizeof(nub)); 1575 } 1576 return (error); 1577 } 1578 #endif /* COMPAT_FREEBSD11 */ 1579 1580 /* 1581 * Return pathconf information about a file descriptor. 1582 */ 1583 #ifndef _SYS_SYSPROTO_H_ 1584 struct fpathconf_args { 1585 int fd; 1586 int name; 1587 }; 1588 #endif 1589 /* ARGSUSED */ 1590 int 1591 sys_fpathconf(struct thread *td, struct fpathconf_args *uap) 1592 { 1593 long value; 1594 int error; 1595 1596 error = kern_fpathconf(td, uap->fd, uap->name, &value); 1597 if (error == 0) 1598 td->td_retval[0] = value; 1599 return (error); 1600 } 1601 1602 int 1603 kern_fpathconf(struct thread *td, int fd, int name, long *valuep) 1604 { 1605 struct file *fp; 1606 struct vnode *vp; 1607 int error; 1608 1609 error = fget(td, fd, &cap_fpathconf_rights, &fp); 1610 if (error != 0) 1611 return (error); 1612 1613 if (name == _PC_ASYNC_IO) { 1614 *valuep = _POSIX_ASYNCHRONOUS_IO; 1615 goto out; 1616 } 1617 vp = fp->f_vnode; 1618 if (vp != NULL) { 1619 vn_lock(vp, LK_SHARED | LK_RETRY); 1620 error = VOP_PATHCONF(vp, name, valuep); 1621 VOP_UNLOCK(vp); 1622 } else if (fp->f_type == DTYPE_PIPE || fp->f_type == DTYPE_SOCKET) { 1623 if (name != _PC_PIPE_BUF) { 1624 error = EINVAL; 1625 } else { 1626 *valuep = PIPE_BUF; 1627 error = 0; 1628 } 1629 } else { 1630 error = EOPNOTSUPP; 1631 } 1632 out: 1633 fdrop(fp, td); 1634 return (error); 1635 } 1636 1637 /* 1638 * Copy filecaps structure allocating memory for ioctls array if needed. 1639 * 1640 * The last parameter indicates whether the fdtable is locked. If it is not and 1641 * ioctls are encountered, copying fails and the caller must lock the table. 1642 * 1643 * Note that if the table was not locked, the caller has to check the relevant 1644 * sequence counter to determine whether the operation was successful. 1645 */ 1646 bool 1647 filecaps_copy(const struct filecaps *src, struct filecaps *dst, bool locked) 1648 { 1649 size_t size; 1650 1651 if (src->fc_ioctls != NULL && !locked) 1652 return (false); 1653 memcpy(dst, src, sizeof(*src)); 1654 if (src->fc_ioctls == NULL) 1655 return (true); 1656 1657 KASSERT(src->fc_nioctls > 0, 1658 ("fc_ioctls != NULL, but fc_nioctls=%hd", src->fc_nioctls)); 1659 1660 size = sizeof(src->fc_ioctls[0]) * src->fc_nioctls; 1661 dst->fc_ioctls = malloc(size, M_FILECAPS, M_WAITOK); 1662 memcpy(dst->fc_ioctls, src->fc_ioctls, size); 1663 return (true); 1664 } 1665 1666 static u_long * 1667 filecaps_copy_prep(const struct filecaps *src) 1668 { 1669 u_long *ioctls; 1670 size_t size; 1671 1672 if (__predict_true(src->fc_ioctls == NULL)) 1673 return (NULL); 1674 1675 KASSERT(src->fc_nioctls > 0, 1676 ("fc_ioctls != NULL, but fc_nioctls=%hd", src->fc_nioctls)); 1677 1678 size = sizeof(src->fc_ioctls[0]) * src->fc_nioctls; 1679 ioctls = malloc(size, M_FILECAPS, M_WAITOK); 1680 return (ioctls); 1681 } 1682 1683 static void 1684 filecaps_copy_finish(const struct filecaps *src, struct filecaps *dst, 1685 u_long *ioctls) 1686 { 1687 size_t size; 1688 1689 *dst = *src; 1690 if (__predict_true(src->fc_ioctls == NULL)) { 1691 MPASS(ioctls == NULL); 1692 return; 1693 } 1694 1695 size = sizeof(src->fc_ioctls[0]) * src->fc_nioctls; 1696 dst->fc_ioctls = ioctls; 1697 bcopy(src->fc_ioctls, dst->fc_ioctls, size); 1698 } 1699 1700 /* 1701 * Move filecaps structure to the new place and clear the old place. 1702 */ 1703 void 1704 filecaps_move(struct filecaps *src, struct filecaps *dst) 1705 { 1706 1707 *dst = *src; 1708 bzero(src, sizeof(*src)); 1709 } 1710 1711 /* 1712 * Fill the given filecaps structure with full rights. 1713 */ 1714 static void 1715 filecaps_fill(struct filecaps *fcaps) 1716 { 1717 1718 CAP_ALL(&fcaps->fc_rights); 1719 fcaps->fc_ioctls = NULL; 1720 fcaps->fc_nioctls = -1; 1721 fcaps->fc_fcntls = CAP_FCNTL_ALL; 1722 } 1723 1724 /* 1725 * Free memory allocated within filecaps structure. 1726 */ 1727 void 1728 filecaps_free(struct filecaps *fcaps) 1729 { 1730 1731 free(fcaps->fc_ioctls, M_FILECAPS); 1732 bzero(fcaps, sizeof(*fcaps)); 1733 } 1734 1735 static u_long * 1736 filecaps_free_prep(struct filecaps *fcaps) 1737 { 1738 u_long *ioctls; 1739 1740 ioctls = fcaps->fc_ioctls; 1741 bzero(fcaps, sizeof(*fcaps)); 1742 return (ioctls); 1743 } 1744 1745 static void 1746 filecaps_free_finish(u_long *ioctls) 1747 { 1748 1749 free(ioctls, M_FILECAPS); 1750 } 1751 1752 /* 1753 * Validate the given filecaps structure. 1754 */ 1755 static void 1756 filecaps_validate(const struct filecaps *fcaps, const char *func) 1757 { 1758 1759 KASSERT(cap_rights_is_valid(&fcaps->fc_rights), 1760 ("%s: invalid rights", func)); 1761 KASSERT((fcaps->fc_fcntls & ~CAP_FCNTL_ALL) == 0, 1762 ("%s: invalid fcntls", func)); 1763 KASSERT(fcaps->fc_fcntls == 0 || 1764 cap_rights_is_set(&fcaps->fc_rights, CAP_FCNTL), 1765 ("%s: fcntls without CAP_FCNTL", func)); 1766 KASSERT(fcaps->fc_ioctls != NULL ? fcaps->fc_nioctls > 0 : 1767 (fcaps->fc_nioctls == -1 || fcaps->fc_nioctls == 0), 1768 ("%s: invalid ioctls", func)); 1769 KASSERT(fcaps->fc_nioctls == 0 || 1770 cap_rights_is_set(&fcaps->fc_rights, CAP_IOCTL), 1771 ("%s: ioctls without CAP_IOCTL", func)); 1772 } 1773 1774 static void 1775 fdgrowtable_exp(struct filedesc *fdp, int nfd) 1776 { 1777 int nfd1; 1778 1779 FILEDESC_XLOCK_ASSERT(fdp); 1780 1781 nfd1 = fdp->fd_nfiles * 2; 1782 if (nfd1 < nfd) 1783 nfd1 = nfd; 1784 fdgrowtable(fdp, nfd1); 1785 } 1786 1787 /* 1788 * Grow the file table to accommodate (at least) nfd descriptors. 1789 */ 1790 static void 1791 fdgrowtable(struct filedesc *fdp, int nfd) 1792 { 1793 struct filedesc0 *fdp0; 1794 struct freetable *ft; 1795 struct fdescenttbl *ntable; 1796 struct fdescenttbl *otable; 1797 int nnfiles, onfiles; 1798 NDSLOTTYPE *nmap, *omap; 1799 1800 KASSERT(fdp->fd_nfiles > 0, ("zero-length file table")); 1801 1802 /* save old values */ 1803 onfiles = fdp->fd_nfiles; 1804 otable = fdp->fd_files; 1805 omap = fdp->fd_map; 1806 1807 /* compute the size of the new table */ 1808 nnfiles = NDSLOTS(nfd) * NDENTRIES; /* round up */ 1809 if (nnfiles <= onfiles) 1810 /* the table is already large enough */ 1811 return; 1812 1813 /* 1814 * Allocate a new table. We need enough space for the number of 1815 * entries, file entries themselves and the struct freetable we will use 1816 * when we decommission the table and place it on the freelist. 1817 * We place the struct freetable in the middle so we don't have 1818 * to worry about padding. 1819 */ 1820 ntable = malloc(offsetof(struct fdescenttbl, fdt_ofiles) + 1821 nnfiles * sizeof(ntable->fdt_ofiles[0]) + 1822 sizeof(struct freetable), 1823 M_FILEDESC, M_ZERO | M_WAITOK); 1824 /* copy the old data */ 1825 ntable->fdt_nfiles = nnfiles; 1826 memcpy(ntable->fdt_ofiles, otable->fdt_ofiles, 1827 onfiles * sizeof(ntable->fdt_ofiles[0])); 1828 1829 /* 1830 * Allocate a new map only if the old is not large enough. It will 1831 * grow at a slower rate than the table as it can map more 1832 * entries than the table can hold. 1833 */ 1834 if (NDSLOTS(nnfiles) > NDSLOTS(onfiles)) { 1835 nmap = malloc(NDSLOTS(nnfiles) * NDSLOTSIZE, M_FILEDESC, 1836 M_ZERO | M_WAITOK); 1837 /* copy over the old data and update the pointer */ 1838 memcpy(nmap, omap, NDSLOTS(onfiles) * sizeof(*omap)); 1839 fdp->fd_map = nmap; 1840 } 1841 1842 /* 1843 * Make sure that ntable is correctly initialized before we replace 1844 * fd_files poiner. Otherwise fget_unlocked() may see inconsistent 1845 * data. 1846 */ 1847 atomic_store_rel_ptr((volatile void *)&fdp->fd_files, (uintptr_t)ntable); 1848 1849 /* 1850 * Free the old file table when not shared by other threads or processes. 1851 * The old file table is considered to be shared when either are true: 1852 * - The process has more than one thread. 1853 * - The file descriptor table has been shared via fdshare(). 1854 * 1855 * When shared, the old file table will be placed on a freelist 1856 * which will be processed when the struct filedesc is released. 1857 * 1858 * Note that if onfiles == NDFILE, we're dealing with the original 1859 * static allocation contained within (struct filedesc0 *)fdp, 1860 * which must not be freed. 1861 */ 1862 if (onfiles > NDFILE) { 1863 if (curproc->p_numthreads == 1 && 1864 refcount_load(&fdp->fd_refcnt) == 1) 1865 free(otable, M_FILEDESC); 1866 else { 1867 ft = (struct freetable *)&otable->fdt_ofiles[onfiles]; 1868 fdp0 = (struct filedesc0 *)fdp; 1869 ft->ft_table = otable; 1870 SLIST_INSERT_HEAD(&fdp0->fd_free, ft, ft_next); 1871 } 1872 } 1873 /* 1874 * The map does not have the same possibility of threads still 1875 * holding references to it. So always free it as long as it 1876 * does not reference the original static allocation. 1877 */ 1878 if (NDSLOTS(onfiles) > NDSLOTS(NDFILE)) 1879 free(omap, M_FILEDESC); 1880 } 1881 1882 /* 1883 * Allocate a file descriptor for the process. 1884 */ 1885 int 1886 fdalloc(struct thread *td, int minfd, int *result) 1887 { 1888 struct proc *p = td->td_proc; 1889 struct filedesc *fdp = p->p_fd; 1890 int fd, maxfd, allocfd; 1891 #ifdef RACCT 1892 int error; 1893 #endif 1894 1895 FILEDESC_XLOCK_ASSERT(fdp); 1896 1897 if (fdp->fd_freefile > minfd) 1898 minfd = fdp->fd_freefile; 1899 1900 maxfd = getmaxfd(td); 1901 1902 /* 1903 * Search the bitmap for a free descriptor starting at minfd. 1904 * If none is found, grow the file table. 1905 */ 1906 fd = fd_first_free(fdp, minfd, fdp->fd_nfiles); 1907 if (__predict_false(fd >= maxfd)) 1908 return (EMFILE); 1909 if (__predict_false(fd >= fdp->fd_nfiles)) { 1910 allocfd = min(fd * 2, maxfd); 1911 #ifdef RACCT 1912 if (RACCT_ENABLED()) { 1913 error = racct_set_unlocked(p, RACCT_NOFILE, allocfd); 1914 if (error != 0) 1915 return (EMFILE); 1916 } 1917 #endif 1918 /* 1919 * fd is already equal to first free descriptor >= minfd, so 1920 * we only need to grow the table and we are done. 1921 */ 1922 fdgrowtable_exp(fdp, allocfd); 1923 } 1924 1925 /* 1926 * Perform some sanity checks, then mark the file descriptor as 1927 * used and return it to the caller. 1928 */ 1929 KASSERT(fd >= 0 && fd < min(maxfd, fdp->fd_nfiles), 1930 ("invalid descriptor %d", fd)); 1931 KASSERT(!fdisused(fdp, fd), 1932 ("fd_first_free() returned non-free descriptor")); 1933 KASSERT(fdp->fd_ofiles[fd].fde_file == NULL, 1934 ("file descriptor isn't free")); 1935 fdused(fdp, fd); 1936 *result = fd; 1937 return (0); 1938 } 1939 1940 /* 1941 * Allocate n file descriptors for the process. 1942 */ 1943 int 1944 fdallocn(struct thread *td, int minfd, int *fds, int n) 1945 { 1946 struct proc *p = td->td_proc; 1947 struct filedesc *fdp = p->p_fd; 1948 int i; 1949 1950 FILEDESC_XLOCK_ASSERT(fdp); 1951 1952 for (i = 0; i < n; i++) 1953 if (fdalloc(td, 0, &fds[i]) != 0) 1954 break; 1955 1956 if (i < n) { 1957 for (i--; i >= 0; i--) 1958 fdunused(fdp, fds[i]); 1959 return (EMFILE); 1960 } 1961 1962 return (0); 1963 } 1964 1965 /* 1966 * Create a new open file structure and allocate a file descriptor for the 1967 * process that refers to it. We add one reference to the file for the 1968 * descriptor table and one reference for resultfp. This is to prevent us 1969 * being preempted and the entry in the descriptor table closed after we 1970 * release the FILEDESC lock. 1971 */ 1972 int 1973 falloc_caps(struct thread *td, struct file **resultfp, int *resultfd, int flags, 1974 struct filecaps *fcaps) 1975 { 1976 struct file *fp; 1977 int error, fd; 1978 1979 MPASS(resultfp != NULL); 1980 MPASS(resultfd != NULL); 1981 1982 error = _falloc_noinstall(td, &fp, 2); 1983 if (__predict_false(error != 0)) { 1984 return (error); 1985 } 1986 1987 error = finstall_refed(td, fp, &fd, flags, fcaps); 1988 if (__predict_false(error != 0)) { 1989 falloc_abort(td, fp); 1990 return (error); 1991 } 1992 1993 *resultfp = fp; 1994 *resultfd = fd; 1995 1996 return (0); 1997 } 1998 1999 /* 2000 * Create a new open file structure without allocating a file descriptor. 2001 */ 2002 int 2003 _falloc_noinstall(struct thread *td, struct file **resultfp, u_int n) 2004 { 2005 struct file *fp; 2006 int maxuserfiles = maxfiles - (maxfiles / 20); 2007 int openfiles_new; 2008 static struct timeval lastfail; 2009 static int curfail; 2010 2011 KASSERT(resultfp != NULL, ("%s: resultfp == NULL", __func__)); 2012 MPASS(n > 0); 2013 2014 openfiles_new = atomic_fetchadd_int(&openfiles, 1) + 1; 2015 if ((openfiles_new >= maxuserfiles && 2016 priv_check(td, PRIV_MAXFILES) != 0) || 2017 openfiles_new >= maxfiles) { 2018 atomic_subtract_int(&openfiles, 1); 2019 if (ppsratecheck(&lastfail, &curfail, 1)) { 2020 printf("kern.maxfiles limit exceeded by uid %i, (%s) " 2021 "please see tuning(7).\n", td->td_ucred->cr_ruid, td->td_proc->p_comm); 2022 } 2023 return (ENFILE); 2024 } 2025 fp = uma_zalloc(file_zone, M_WAITOK); 2026 bzero(fp, sizeof(*fp)); 2027 refcount_init(&fp->f_count, n); 2028 fp->f_cred = crhold(td->td_ucred); 2029 fp->f_ops = &badfileops; 2030 *resultfp = fp; 2031 return (0); 2032 } 2033 2034 void 2035 falloc_abort(struct thread *td, struct file *fp) 2036 { 2037 2038 /* 2039 * For assertion purposes. 2040 */ 2041 refcount_init(&fp->f_count, 0); 2042 _fdrop(fp, td); 2043 } 2044 2045 /* 2046 * Install a file in a file descriptor table. 2047 */ 2048 void 2049 _finstall(struct filedesc *fdp, struct file *fp, int fd, int flags, 2050 struct filecaps *fcaps) 2051 { 2052 struct filedescent *fde; 2053 2054 MPASS(fp != NULL); 2055 if (fcaps != NULL) 2056 filecaps_validate(fcaps, __func__); 2057 FILEDESC_XLOCK_ASSERT(fdp); 2058 2059 fde = &fdp->fd_ofiles[fd]; 2060 #ifdef CAPABILITIES 2061 seqc_write_begin(&fde->fde_seqc); 2062 #endif 2063 fde->fde_file = fp; 2064 fde->fde_flags = (flags & O_CLOEXEC) != 0 ? UF_EXCLOSE : 0; 2065 if (fcaps != NULL) 2066 filecaps_move(fcaps, &fde->fde_caps); 2067 else 2068 filecaps_fill(&fde->fde_caps); 2069 #ifdef CAPABILITIES 2070 seqc_write_end(&fde->fde_seqc); 2071 #endif 2072 } 2073 2074 int 2075 finstall_refed(struct thread *td, struct file *fp, int *fd, int flags, 2076 struct filecaps *fcaps) 2077 { 2078 struct filedesc *fdp = td->td_proc->p_fd; 2079 int error; 2080 2081 MPASS(fd != NULL); 2082 2083 FILEDESC_XLOCK(fdp); 2084 error = fdalloc(td, 0, fd); 2085 if (__predict_true(error == 0)) { 2086 _finstall(fdp, fp, *fd, flags, fcaps); 2087 } 2088 FILEDESC_XUNLOCK(fdp); 2089 return (error); 2090 } 2091 2092 int 2093 finstall(struct thread *td, struct file *fp, int *fd, int flags, 2094 struct filecaps *fcaps) 2095 { 2096 int error; 2097 2098 MPASS(fd != NULL); 2099 2100 if (!fhold(fp)) 2101 return (EBADF); 2102 error = finstall_refed(td, fp, fd, flags, fcaps); 2103 if (__predict_false(error != 0)) { 2104 fdrop(fp, td); 2105 } 2106 return (error); 2107 } 2108 2109 /* 2110 * Build a new filedesc structure from another. 2111 * 2112 * If fdp is not NULL, return with it shared locked. 2113 */ 2114 struct filedesc * 2115 fdinit(struct filedesc *fdp, bool prepfiles, int *lastfile) 2116 { 2117 struct filedesc0 *newfdp0; 2118 struct filedesc *newfdp; 2119 2120 if (prepfiles) 2121 MPASS(lastfile != NULL); 2122 else 2123 MPASS(lastfile == NULL); 2124 2125 newfdp0 = uma_zalloc(filedesc0_zone, M_WAITOK | M_ZERO); 2126 newfdp = &newfdp0->fd_fd; 2127 2128 /* Create the file descriptor table. */ 2129 FILEDESC_LOCK_INIT(newfdp); 2130 refcount_init(&newfdp->fd_refcnt, 1); 2131 refcount_init(&newfdp->fd_holdcnt, 1); 2132 newfdp->fd_map = newfdp0->fd_dmap; 2133 newfdp->fd_files = (struct fdescenttbl *)&newfdp0->fd_dfiles; 2134 newfdp->fd_files->fdt_nfiles = NDFILE; 2135 2136 if (fdp == NULL) 2137 return (newfdp); 2138 2139 FILEDESC_SLOCK(fdp); 2140 if (!prepfiles) { 2141 FILEDESC_SUNLOCK(fdp); 2142 return (newfdp); 2143 } 2144 2145 for (;;) { 2146 *lastfile = fdlastfile(fdp); 2147 if (*lastfile < newfdp->fd_nfiles) 2148 break; 2149 FILEDESC_SUNLOCK(fdp); 2150 fdgrowtable(newfdp, *lastfile + 1); 2151 FILEDESC_SLOCK(fdp); 2152 } 2153 2154 return (newfdp); 2155 } 2156 2157 /* 2158 * Build a pwddesc structure from another. 2159 * Copy the current, root, and jail root vnode references. 2160 * 2161 * If pdp is not NULL, return with it shared locked. 2162 */ 2163 struct pwddesc * 2164 pdinit(struct pwddesc *pdp, bool keeplock) 2165 { 2166 struct pwddesc *newpdp; 2167 struct pwd *newpwd; 2168 2169 newpdp = malloc(sizeof(*newpdp), M_PWDDESC, M_WAITOK | M_ZERO); 2170 2171 PWDDESC_LOCK_INIT(newpdp); 2172 refcount_init(&newpdp->pd_refcount, 1); 2173 newpdp->pd_cmask = CMASK; 2174 2175 if (pdp == NULL) { 2176 newpwd = pwd_alloc(); 2177 smr_serialized_store(&newpdp->pd_pwd, newpwd, true); 2178 return (newpdp); 2179 } 2180 2181 PWDDESC_XLOCK(pdp); 2182 newpwd = pwd_hold_pwddesc(pdp); 2183 smr_serialized_store(&newpdp->pd_pwd, newpwd, true); 2184 if (!keeplock) 2185 PWDDESC_XUNLOCK(pdp); 2186 return (newpdp); 2187 } 2188 2189 static struct filedesc * 2190 fdhold(struct proc *p) 2191 { 2192 struct filedesc *fdp; 2193 2194 PROC_LOCK_ASSERT(p, MA_OWNED); 2195 fdp = p->p_fd; 2196 if (fdp != NULL) 2197 refcount_acquire(&fdp->fd_holdcnt); 2198 return (fdp); 2199 } 2200 2201 static struct pwddesc * 2202 pdhold(struct proc *p) 2203 { 2204 struct pwddesc *pdp; 2205 2206 PROC_LOCK_ASSERT(p, MA_OWNED); 2207 pdp = p->p_pd; 2208 if (pdp != NULL) 2209 refcount_acquire(&pdp->pd_refcount); 2210 return (pdp); 2211 } 2212 2213 static void 2214 fddrop(struct filedesc *fdp) 2215 { 2216 2217 if (refcount_load(&fdp->fd_holdcnt) > 1) { 2218 if (refcount_release(&fdp->fd_holdcnt) == 0) 2219 return; 2220 } 2221 2222 FILEDESC_LOCK_DESTROY(fdp); 2223 uma_zfree(filedesc0_zone, fdp); 2224 } 2225 2226 static void 2227 pddrop(struct pwddesc *pdp) 2228 { 2229 struct pwd *pwd; 2230 2231 if (refcount_release_if_not_last(&pdp->pd_refcount)) 2232 return; 2233 2234 PWDDESC_XLOCK(pdp); 2235 if (refcount_release(&pdp->pd_refcount) == 0) { 2236 PWDDESC_XUNLOCK(pdp); 2237 return; 2238 } 2239 pwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); 2240 pwd_set(pdp, NULL); 2241 PWDDESC_XUNLOCK(pdp); 2242 pwd_drop(pwd); 2243 2244 PWDDESC_LOCK_DESTROY(pdp); 2245 free(pdp, M_PWDDESC); 2246 } 2247 2248 /* 2249 * Share a filedesc structure. 2250 */ 2251 struct filedesc * 2252 fdshare(struct filedesc *fdp) 2253 { 2254 2255 refcount_acquire(&fdp->fd_refcnt); 2256 return (fdp); 2257 } 2258 2259 /* 2260 * Share a pwddesc structure. 2261 */ 2262 struct pwddesc * 2263 pdshare(struct pwddesc *pdp) 2264 { 2265 refcount_acquire(&pdp->pd_refcount); 2266 return (pdp); 2267 } 2268 2269 /* 2270 * Unshare a filedesc structure, if necessary by making a copy 2271 */ 2272 void 2273 fdunshare(struct thread *td) 2274 { 2275 struct filedesc *tmp; 2276 struct proc *p = td->td_proc; 2277 2278 if (refcount_load(&p->p_fd->fd_refcnt) == 1) 2279 return; 2280 2281 tmp = fdcopy(p->p_fd); 2282 fdescfree(td); 2283 p->p_fd = tmp; 2284 } 2285 2286 /* 2287 * Unshare a pwddesc structure. 2288 */ 2289 void 2290 pdunshare(struct thread *td) 2291 { 2292 struct pwddesc *pdp; 2293 struct proc *p; 2294 2295 p = td->td_proc; 2296 /* Not shared. */ 2297 if (p->p_pd->pd_refcount == 1) 2298 return; 2299 2300 pdp = pdcopy(p->p_pd); 2301 pdescfree(td); 2302 p->p_pd = pdp; 2303 } 2304 2305 void 2306 fdinstall_remapped(struct thread *td, struct filedesc *fdp) 2307 { 2308 2309 fdescfree(td); 2310 td->td_proc->p_fd = fdp; 2311 } 2312 2313 /* 2314 * Copy a filedesc structure. A NULL pointer in returns a NULL reference, 2315 * this is to ease callers, not catch errors. 2316 */ 2317 struct filedesc * 2318 fdcopy(struct filedesc *fdp) 2319 { 2320 struct filedesc *newfdp; 2321 struct filedescent *nfde, *ofde; 2322 int i, lastfile; 2323 2324 MPASS(fdp != NULL); 2325 2326 newfdp = fdinit(fdp, true, &lastfile); 2327 /* copy all passable descriptors (i.e. not kqueue) */ 2328 newfdp->fd_freefile = -1; 2329 for (i = 0; i <= lastfile; ++i) { 2330 ofde = &fdp->fd_ofiles[i]; 2331 if (ofde->fde_file == NULL || 2332 (ofde->fde_file->f_ops->fo_flags & DFLAG_PASSABLE) == 0 || 2333 !fhold(ofde->fde_file)) { 2334 if (newfdp->fd_freefile == -1) 2335 newfdp->fd_freefile = i; 2336 continue; 2337 } 2338 nfde = &newfdp->fd_ofiles[i]; 2339 *nfde = *ofde; 2340 filecaps_copy(&ofde->fde_caps, &nfde->fde_caps, true); 2341 fdused_init(newfdp, i); 2342 } 2343 if (newfdp->fd_freefile == -1) 2344 newfdp->fd_freefile = i; 2345 FILEDESC_SUNLOCK(fdp); 2346 return (newfdp); 2347 } 2348 2349 /* 2350 * Copy a pwddesc structure. 2351 */ 2352 struct pwddesc * 2353 pdcopy(struct pwddesc *pdp) 2354 { 2355 struct pwddesc *newpdp; 2356 2357 MPASS(pdp != NULL); 2358 2359 newpdp = pdinit(pdp, true); 2360 newpdp->pd_cmask = pdp->pd_cmask; 2361 PWDDESC_XUNLOCK(pdp); 2362 return (newpdp); 2363 } 2364 2365 /* 2366 * Copies a filedesc structure, while remapping all file descriptors 2367 * stored inside using a translation table. 2368 * 2369 * File descriptors are copied over to the new file descriptor table, 2370 * regardless of whether the close-on-exec flag is set. 2371 */ 2372 int 2373 fdcopy_remapped(struct filedesc *fdp, const int *fds, size_t nfds, 2374 struct filedesc **ret) 2375 { 2376 struct filedesc *newfdp; 2377 struct filedescent *nfde, *ofde; 2378 int error, i, lastfile; 2379 2380 MPASS(fdp != NULL); 2381 2382 newfdp = fdinit(fdp, true, &lastfile); 2383 if (nfds > lastfile + 1) { 2384 /* New table cannot be larger than the old one. */ 2385 error = E2BIG; 2386 goto bad; 2387 } 2388 /* Copy all passable descriptors (i.e. not kqueue). */ 2389 newfdp->fd_freefile = nfds; 2390 for (i = 0; i < nfds; ++i) { 2391 if (fds[i] < 0 || fds[i] > lastfile) { 2392 /* File descriptor out of bounds. */ 2393 error = EBADF; 2394 goto bad; 2395 } 2396 ofde = &fdp->fd_ofiles[fds[i]]; 2397 if (ofde->fde_file == NULL) { 2398 /* Unused file descriptor. */ 2399 error = EBADF; 2400 goto bad; 2401 } 2402 if ((ofde->fde_file->f_ops->fo_flags & DFLAG_PASSABLE) == 0) { 2403 /* File descriptor cannot be passed. */ 2404 error = EINVAL; 2405 goto bad; 2406 } 2407 if (!fhold(ofde->fde_file)) { 2408 error = EBADF; 2409 goto bad; 2410 } 2411 nfde = &newfdp->fd_ofiles[i]; 2412 *nfde = *ofde; 2413 filecaps_copy(&ofde->fde_caps, &nfde->fde_caps, true); 2414 fdused_init(newfdp, i); 2415 } 2416 FILEDESC_SUNLOCK(fdp); 2417 *ret = newfdp; 2418 return (0); 2419 bad: 2420 FILEDESC_SUNLOCK(fdp); 2421 fdescfree_remapped(newfdp); 2422 return (error); 2423 } 2424 2425 /* 2426 * Clear POSIX style locks. This is only used when fdp looses a reference (i.e. 2427 * one of processes using it exits) and the table used to be shared. 2428 */ 2429 static void 2430 fdclearlocks(struct thread *td) 2431 { 2432 struct filedesc *fdp; 2433 struct filedesc_to_leader *fdtol; 2434 struct flock lf; 2435 struct file *fp; 2436 struct proc *p; 2437 struct vnode *vp; 2438 int i, lastfile; 2439 2440 p = td->td_proc; 2441 fdp = p->p_fd; 2442 fdtol = p->p_fdtol; 2443 MPASS(fdtol != NULL); 2444 2445 FILEDESC_XLOCK(fdp); 2446 KASSERT(fdtol->fdl_refcount > 0, 2447 ("filedesc_to_refcount botch: fdl_refcount=%d", 2448 fdtol->fdl_refcount)); 2449 if (fdtol->fdl_refcount == 1 && 2450 (p->p_leader->p_flag & P_ADVLOCK) != 0) { 2451 lastfile = fdlastfile(fdp); 2452 for (i = 0; i <= lastfile; i++) { 2453 fp = fdp->fd_ofiles[i].fde_file; 2454 if (fp == NULL || fp->f_type != DTYPE_VNODE || 2455 !fhold(fp)) 2456 continue; 2457 FILEDESC_XUNLOCK(fdp); 2458 lf.l_whence = SEEK_SET; 2459 lf.l_start = 0; 2460 lf.l_len = 0; 2461 lf.l_type = F_UNLCK; 2462 vp = fp->f_vnode; 2463 (void) VOP_ADVLOCK(vp, 2464 (caddr_t)p->p_leader, F_UNLCK, 2465 &lf, F_POSIX); 2466 FILEDESC_XLOCK(fdp); 2467 fdrop(fp, td); 2468 } 2469 } 2470 retry: 2471 if (fdtol->fdl_refcount == 1) { 2472 if (fdp->fd_holdleaderscount > 0 && 2473 (p->p_leader->p_flag & P_ADVLOCK) != 0) { 2474 /* 2475 * close() or kern_dup() has cleared a reference 2476 * in a shared file descriptor table. 2477 */ 2478 fdp->fd_holdleaderswakeup = 1; 2479 sx_sleep(&fdp->fd_holdleaderscount, 2480 FILEDESC_LOCK(fdp), PLOCK, "fdlhold", 0); 2481 goto retry; 2482 } 2483 if (fdtol->fdl_holdcount > 0) { 2484 /* 2485 * Ensure that fdtol->fdl_leader remains 2486 * valid in closef(). 2487 */ 2488 fdtol->fdl_wakeup = 1; 2489 sx_sleep(fdtol, FILEDESC_LOCK(fdp), PLOCK, 2490 "fdlhold", 0); 2491 goto retry; 2492 } 2493 } 2494 fdtol->fdl_refcount--; 2495 if (fdtol->fdl_refcount == 0 && 2496 fdtol->fdl_holdcount == 0) { 2497 fdtol->fdl_next->fdl_prev = fdtol->fdl_prev; 2498 fdtol->fdl_prev->fdl_next = fdtol->fdl_next; 2499 } else 2500 fdtol = NULL; 2501 p->p_fdtol = NULL; 2502 FILEDESC_XUNLOCK(fdp); 2503 if (fdtol != NULL) 2504 free(fdtol, M_FILEDESC_TO_LEADER); 2505 } 2506 2507 /* 2508 * Release a filedesc structure. 2509 */ 2510 static void 2511 fdescfree_fds(struct thread *td, struct filedesc *fdp, bool needclose) 2512 { 2513 struct filedesc0 *fdp0; 2514 struct freetable *ft, *tft; 2515 struct filedescent *fde; 2516 struct file *fp; 2517 int i, lastfile; 2518 2519 KASSERT(refcount_load(&fdp->fd_refcnt) == 0, 2520 ("%s: fd table %p carries references", __func__, fdp)); 2521 2522 /* 2523 * Serialize with threads iterating over the table, if any. 2524 */ 2525 if (refcount_load(&fdp->fd_holdcnt) > 1) { 2526 FILEDESC_XLOCK(fdp); 2527 FILEDESC_XUNLOCK(fdp); 2528 } 2529 2530 lastfile = fdlastfile_single(fdp); 2531 for (i = 0; i <= lastfile; i++) { 2532 fde = &fdp->fd_ofiles[i]; 2533 fp = fde->fde_file; 2534 if (fp != NULL) { 2535 fdefree_last(fde); 2536 if (needclose) 2537 (void) closef(fp, td); 2538 else 2539 fdrop(fp, td); 2540 } 2541 } 2542 2543 if (NDSLOTS(fdp->fd_nfiles) > NDSLOTS(NDFILE)) 2544 free(fdp->fd_map, M_FILEDESC); 2545 if (fdp->fd_nfiles > NDFILE) 2546 free(fdp->fd_files, M_FILEDESC); 2547 2548 fdp0 = (struct filedesc0 *)fdp; 2549 SLIST_FOREACH_SAFE(ft, &fdp0->fd_free, ft_next, tft) 2550 free(ft->ft_table, M_FILEDESC); 2551 2552 fddrop(fdp); 2553 } 2554 2555 void 2556 fdescfree(struct thread *td) 2557 { 2558 struct proc *p; 2559 struct filedesc *fdp; 2560 2561 p = td->td_proc; 2562 fdp = p->p_fd; 2563 MPASS(fdp != NULL); 2564 2565 #ifdef RACCT 2566 if (RACCT_ENABLED()) 2567 racct_set_unlocked(p, RACCT_NOFILE, 0); 2568 #endif 2569 2570 if (p->p_fdtol != NULL) 2571 fdclearlocks(td); 2572 2573 PROC_LOCK(p); 2574 p->p_fd = NULL; 2575 PROC_UNLOCK(p); 2576 2577 if (refcount_release(&fdp->fd_refcnt) == 0) 2578 return; 2579 2580 fdescfree_fds(td, fdp, 1); 2581 } 2582 2583 void 2584 pdescfree(struct thread *td) 2585 { 2586 struct proc *p; 2587 struct pwddesc *pdp; 2588 2589 p = td->td_proc; 2590 pdp = p->p_pd; 2591 MPASS(pdp != NULL); 2592 2593 PROC_LOCK(p); 2594 p->p_pd = NULL; 2595 PROC_UNLOCK(p); 2596 2597 pddrop(pdp); 2598 } 2599 2600 void 2601 fdescfree_remapped(struct filedesc *fdp) 2602 { 2603 #ifdef INVARIANTS 2604 /* fdescfree_fds() asserts that fd_refcnt == 0. */ 2605 if (!refcount_release(&fdp->fd_refcnt)) 2606 panic("%s: fd table %p has extra references", __func__, fdp); 2607 #endif 2608 fdescfree_fds(curthread, fdp, 0); 2609 } 2610 2611 /* 2612 * For setugid programs, we don't want to people to use that setugidness 2613 * to generate error messages which write to a file which otherwise would 2614 * otherwise be off-limits to the process. We check for filesystems where 2615 * the vnode can change out from under us after execve (like [lin]procfs). 2616 * 2617 * Since fdsetugidsafety calls this only for fd 0, 1 and 2, this check is 2618 * sufficient. We also don't check for setugidness since we know we are. 2619 */ 2620 static bool 2621 is_unsafe(struct file *fp) 2622 { 2623 struct vnode *vp; 2624 2625 if (fp->f_type != DTYPE_VNODE) 2626 return (false); 2627 2628 vp = fp->f_vnode; 2629 return ((vp->v_vflag & VV_PROCDEP) != 0); 2630 } 2631 2632 /* 2633 * Make this setguid thing safe, if at all possible. 2634 */ 2635 void 2636 fdsetugidsafety(struct thread *td) 2637 { 2638 struct filedesc *fdp; 2639 struct file *fp; 2640 int i; 2641 2642 fdp = td->td_proc->p_fd; 2643 KASSERT(refcount_load(&fdp->fd_refcnt) == 1, 2644 ("the fdtable should not be shared")); 2645 MPASS(fdp->fd_nfiles >= 3); 2646 for (i = 0; i <= 2; i++) { 2647 fp = fdp->fd_ofiles[i].fde_file; 2648 if (fp != NULL && is_unsafe(fp)) { 2649 FILEDESC_XLOCK(fdp); 2650 knote_fdclose(td, i); 2651 /* 2652 * NULL-out descriptor prior to close to avoid 2653 * a race while close blocks. 2654 */ 2655 fdfree(fdp, i); 2656 FILEDESC_XUNLOCK(fdp); 2657 (void) closef(fp, td); 2658 } 2659 } 2660 } 2661 2662 /* 2663 * If a specific file object occupies a specific file descriptor, close the 2664 * file descriptor entry and drop a reference on the file object. This is a 2665 * convenience function to handle a subsequent error in a function that calls 2666 * falloc() that handles the race that another thread might have closed the 2667 * file descriptor out from under the thread creating the file object. 2668 */ 2669 void 2670 fdclose(struct thread *td, struct file *fp, int idx) 2671 { 2672 struct filedesc *fdp = td->td_proc->p_fd; 2673 2674 FILEDESC_XLOCK(fdp); 2675 if (fdp->fd_ofiles[idx].fde_file == fp) { 2676 fdfree(fdp, idx); 2677 FILEDESC_XUNLOCK(fdp); 2678 fdrop(fp, td); 2679 } else 2680 FILEDESC_XUNLOCK(fdp); 2681 } 2682 2683 /* 2684 * Close any files on exec? 2685 */ 2686 void 2687 fdcloseexec(struct thread *td) 2688 { 2689 struct filedesc *fdp; 2690 struct filedescent *fde; 2691 struct file *fp; 2692 int i, lastfile; 2693 2694 fdp = td->td_proc->p_fd; 2695 KASSERT(refcount_load(&fdp->fd_refcnt) == 1, 2696 ("the fdtable should not be shared")); 2697 lastfile = fdlastfile_single(fdp); 2698 for (i = 0; i <= lastfile; i++) { 2699 fde = &fdp->fd_ofiles[i]; 2700 fp = fde->fde_file; 2701 if (fp != NULL && (fp->f_type == DTYPE_MQUEUE || 2702 (fde->fde_flags & UF_EXCLOSE))) { 2703 FILEDESC_XLOCK(fdp); 2704 fdfree(fdp, i); 2705 (void) closefp(fdp, i, fp, td, false, false); 2706 FILEDESC_UNLOCK_ASSERT(fdp); 2707 } 2708 } 2709 } 2710 2711 /* 2712 * It is unsafe for set[ug]id processes to be started with file 2713 * descriptors 0..2 closed, as these descriptors are given implicit 2714 * significance in the Standard C library. fdcheckstd() will create a 2715 * descriptor referencing /dev/null for each of stdin, stdout, and 2716 * stderr that is not already open. 2717 */ 2718 int 2719 fdcheckstd(struct thread *td) 2720 { 2721 struct filedesc *fdp; 2722 register_t save; 2723 int i, error, devnull; 2724 2725 fdp = td->td_proc->p_fd; 2726 KASSERT(refcount_load(&fdp->fd_refcnt) == 1, 2727 ("the fdtable should not be shared")); 2728 MPASS(fdp->fd_nfiles >= 3); 2729 devnull = -1; 2730 for (i = 0; i <= 2; i++) { 2731 if (fdp->fd_ofiles[i].fde_file != NULL) 2732 continue; 2733 2734 save = td->td_retval[0]; 2735 if (devnull != -1) { 2736 error = kern_dup(td, FDDUP_FIXED, 0, devnull, i); 2737 } else { 2738 error = kern_openat(td, AT_FDCWD, "/dev/null", 2739 UIO_SYSSPACE, O_RDWR, 0); 2740 if (error == 0) { 2741 devnull = td->td_retval[0]; 2742 KASSERT(devnull == i, ("we didn't get our fd")); 2743 } 2744 } 2745 td->td_retval[0] = save; 2746 if (error != 0) 2747 return (error); 2748 } 2749 return (0); 2750 } 2751 2752 /* 2753 * Internal form of close. Decrement reference count on file structure. 2754 * Note: td may be NULL when closing a file that was being passed in a 2755 * message. 2756 */ 2757 int 2758 closef(struct file *fp, struct thread *td) 2759 { 2760 struct vnode *vp; 2761 struct flock lf; 2762 struct filedesc_to_leader *fdtol; 2763 struct filedesc *fdp; 2764 2765 MPASS(td != NULL); 2766 2767 /* 2768 * POSIX record locking dictates that any close releases ALL 2769 * locks owned by this process. This is handled by setting 2770 * a flag in the unlock to free ONLY locks obeying POSIX 2771 * semantics, and not to free BSD-style file locks. 2772 * If the descriptor was in a message, POSIX-style locks 2773 * aren't passed with the descriptor, and the thread pointer 2774 * will be NULL. Callers should be careful only to pass a 2775 * NULL thread pointer when there really is no owning 2776 * context that might have locks, or the locks will be 2777 * leaked. 2778 */ 2779 if (fp->f_type == DTYPE_VNODE) { 2780 vp = fp->f_vnode; 2781 if ((td->td_proc->p_leader->p_flag & P_ADVLOCK) != 0) { 2782 lf.l_whence = SEEK_SET; 2783 lf.l_start = 0; 2784 lf.l_len = 0; 2785 lf.l_type = F_UNLCK; 2786 (void) VOP_ADVLOCK(vp, (caddr_t)td->td_proc->p_leader, 2787 F_UNLCK, &lf, F_POSIX); 2788 } 2789 fdtol = td->td_proc->p_fdtol; 2790 if (fdtol != NULL) { 2791 /* 2792 * Handle special case where file descriptor table is 2793 * shared between multiple process leaders. 2794 */ 2795 fdp = td->td_proc->p_fd; 2796 FILEDESC_XLOCK(fdp); 2797 for (fdtol = fdtol->fdl_next; 2798 fdtol != td->td_proc->p_fdtol; 2799 fdtol = fdtol->fdl_next) { 2800 if ((fdtol->fdl_leader->p_flag & 2801 P_ADVLOCK) == 0) 2802 continue; 2803 fdtol->fdl_holdcount++; 2804 FILEDESC_XUNLOCK(fdp); 2805 lf.l_whence = SEEK_SET; 2806 lf.l_start = 0; 2807 lf.l_len = 0; 2808 lf.l_type = F_UNLCK; 2809 vp = fp->f_vnode; 2810 (void) VOP_ADVLOCK(vp, 2811 (caddr_t)fdtol->fdl_leader, F_UNLCK, &lf, 2812 F_POSIX); 2813 FILEDESC_XLOCK(fdp); 2814 fdtol->fdl_holdcount--; 2815 if (fdtol->fdl_holdcount == 0 && 2816 fdtol->fdl_wakeup != 0) { 2817 fdtol->fdl_wakeup = 0; 2818 wakeup(fdtol); 2819 } 2820 } 2821 FILEDESC_XUNLOCK(fdp); 2822 } 2823 } 2824 return (fdrop_close(fp, td)); 2825 } 2826 2827 /* 2828 * Hack for file descriptor passing code. 2829 */ 2830 void 2831 closef_nothread(struct file *fp) 2832 { 2833 2834 fdrop(fp, NULL); 2835 } 2836 2837 /* 2838 * Initialize the file pointer with the specified properties. 2839 * 2840 * The ops are set with release semantics to be certain that the flags, type, 2841 * and data are visible when ops is. This is to prevent ops methods from being 2842 * called with bad data. 2843 */ 2844 void 2845 finit(struct file *fp, u_int flag, short type, void *data, struct fileops *ops) 2846 { 2847 fp->f_data = data; 2848 fp->f_flag = flag; 2849 fp->f_type = type; 2850 atomic_store_rel_ptr((volatile uintptr_t *)&fp->f_ops, (uintptr_t)ops); 2851 } 2852 2853 void 2854 finit_vnode(struct file *fp, u_int flag, void *data, struct fileops *ops) 2855 { 2856 fp->f_seqcount[UIO_READ] = 1; 2857 fp->f_seqcount[UIO_WRITE] = 1; 2858 finit(fp, (flag & FMASK) | (fp->f_flag & FHASLOCK), DTYPE_VNODE, 2859 data, ops); 2860 } 2861 2862 int 2863 fget_cap_locked(struct filedesc *fdp, int fd, cap_rights_t *needrightsp, 2864 struct file **fpp, struct filecaps *havecapsp) 2865 { 2866 struct filedescent *fde; 2867 int error; 2868 2869 FILEDESC_LOCK_ASSERT(fdp); 2870 2871 fde = fdeget_locked(fdp, fd); 2872 if (fde == NULL) { 2873 error = EBADF; 2874 goto out; 2875 } 2876 2877 #ifdef CAPABILITIES 2878 error = cap_check(cap_rights_fde_inline(fde), needrightsp); 2879 if (error != 0) 2880 goto out; 2881 #endif 2882 2883 if (havecapsp != NULL) 2884 filecaps_copy(&fde->fde_caps, havecapsp, true); 2885 2886 *fpp = fde->fde_file; 2887 2888 error = 0; 2889 out: 2890 return (error); 2891 } 2892 2893 int 2894 fget_cap(struct thread *td, int fd, cap_rights_t *needrightsp, 2895 struct file **fpp, struct filecaps *havecapsp) 2896 { 2897 struct filedesc *fdp = td->td_proc->p_fd; 2898 int error; 2899 #ifndef CAPABILITIES 2900 error = fget_unlocked(fdp, fd, needrightsp, fpp); 2901 if (havecapsp != NULL && error == 0) 2902 filecaps_fill(havecapsp); 2903 #else 2904 struct file *fp; 2905 seqc_t seq; 2906 2907 *fpp = NULL; 2908 for (;;) { 2909 error = fget_unlocked_seq(fdp, fd, needrightsp, &fp, &seq); 2910 if (error != 0) 2911 return (error); 2912 2913 if (havecapsp != NULL) { 2914 if (!filecaps_copy(&fdp->fd_ofiles[fd].fde_caps, 2915 havecapsp, false)) { 2916 fdrop(fp, td); 2917 goto get_locked; 2918 } 2919 } 2920 2921 if (!fd_modified(fdp, fd, seq)) 2922 break; 2923 fdrop(fp, td); 2924 } 2925 2926 *fpp = fp; 2927 return (0); 2928 2929 get_locked: 2930 FILEDESC_SLOCK(fdp); 2931 error = fget_cap_locked(fdp, fd, needrightsp, fpp, havecapsp); 2932 if (error == 0 && !fhold(*fpp)) 2933 error = EBADF; 2934 FILEDESC_SUNLOCK(fdp); 2935 #endif 2936 return (error); 2937 } 2938 2939 #ifdef CAPABILITIES 2940 int 2941 fgetvp_lookup_smr(int fd, struct nameidata *ndp, struct vnode **vpp, bool *fsearch) 2942 { 2943 const struct filedescent *fde; 2944 const struct fdescenttbl *fdt; 2945 struct filedesc *fdp; 2946 struct file *fp; 2947 struct vnode *vp; 2948 const cap_rights_t *haverights; 2949 cap_rights_t rights; 2950 seqc_t seq; 2951 2952 VFS_SMR_ASSERT_ENTERED(); 2953 2954 rights = *ndp->ni_rightsneeded; 2955 cap_rights_set_one(&rights, CAP_LOOKUP); 2956 2957 fdp = curproc->p_fd; 2958 fdt = fdp->fd_files; 2959 if (__predict_false((u_int)fd >= fdt->fdt_nfiles)) 2960 return (EBADF); 2961 seq = seqc_read_notmodify(fd_seqc(fdt, fd)); 2962 fde = &fdt->fdt_ofiles[fd]; 2963 haverights = cap_rights_fde_inline(fde); 2964 fp = fde->fde_file; 2965 if (__predict_false(fp == NULL)) 2966 return (EAGAIN); 2967 if (__predict_false(cap_check_inline_transient(haverights, &rights))) 2968 return (EAGAIN); 2969 *fsearch = ((fp->f_flag & FSEARCH) != 0); 2970 vp = fp->f_vnode; 2971 if (__predict_false(vp == NULL || vp->v_type != VDIR)) { 2972 return (EAGAIN); 2973 } 2974 if (!filecaps_copy(&fde->fde_caps, &ndp->ni_filecaps, false)) { 2975 return (EAGAIN); 2976 } 2977 /* 2978 * Use an acquire barrier to force re-reading of fdt so it is 2979 * refreshed for verification. 2980 */ 2981 atomic_thread_fence_acq(); 2982 fdt = fdp->fd_files; 2983 if (__predict_false(!seqc_consistent_nomb(fd_seqc(fdt, fd), seq))) 2984 return (EAGAIN); 2985 /* 2986 * If file descriptor doesn't have all rights, 2987 * all lookups relative to it must also be 2988 * strictly relative. 2989 * 2990 * Not yet supported by fast path. 2991 */ 2992 CAP_ALL(&rights); 2993 if (!cap_rights_contains(&ndp->ni_filecaps.fc_rights, &rights) || 2994 ndp->ni_filecaps.fc_fcntls != CAP_FCNTL_ALL || 2995 ndp->ni_filecaps.fc_nioctls != -1) { 2996 #ifdef notyet 2997 ndp->ni_lcf |= NI_LCF_STRICTRELATIVE; 2998 #else 2999 return (EAGAIN); 3000 #endif 3001 } 3002 *vpp = vp; 3003 return (0); 3004 } 3005 #else 3006 int 3007 fgetvp_lookup_smr(int fd, struct nameidata *ndp, struct vnode **vpp, bool *fsearch) 3008 { 3009 const struct fdescenttbl *fdt; 3010 struct filedesc *fdp; 3011 struct file *fp; 3012 struct vnode *vp; 3013 3014 VFS_SMR_ASSERT_ENTERED(); 3015 3016 fdp = curproc->p_fd; 3017 fdt = fdp->fd_files; 3018 if (__predict_false((u_int)fd >= fdt->fdt_nfiles)) 3019 return (EBADF); 3020 fp = fdt->fdt_ofiles[fd].fde_file; 3021 if (__predict_false(fp == NULL)) 3022 return (EAGAIN); 3023 *fsearch = ((fp->f_flag & FSEARCH) != 0); 3024 vp = fp->f_vnode; 3025 if (__predict_false(vp == NULL || vp->v_type != VDIR)) { 3026 return (EAGAIN); 3027 } 3028 /* 3029 * Use an acquire barrier to force re-reading of fdt so it is 3030 * refreshed for verification. 3031 */ 3032 atomic_thread_fence_acq(); 3033 fdt = fdp->fd_files; 3034 if (__predict_false(fp != fdt->fdt_ofiles[fd].fde_file)) 3035 return (EAGAIN); 3036 filecaps_fill(&ndp->ni_filecaps); 3037 *vpp = vp; 3038 return (0); 3039 } 3040 #endif 3041 3042 int 3043 fget_unlocked_seq(struct filedesc *fdp, int fd, cap_rights_t *needrightsp, 3044 struct file **fpp, seqc_t *seqp) 3045 { 3046 #ifdef CAPABILITIES 3047 const struct filedescent *fde; 3048 #endif 3049 const struct fdescenttbl *fdt; 3050 struct file *fp; 3051 #ifdef CAPABILITIES 3052 seqc_t seq; 3053 cap_rights_t haverights; 3054 int error; 3055 #endif 3056 3057 fdt = fdp->fd_files; 3058 if (__predict_false((u_int)fd >= fdt->fdt_nfiles)) 3059 return (EBADF); 3060 /* 3061 * Fetch the descriptor locklessly. We avoid fdrop() races by 3062 * never raising a refcount above 0. To accomplish this we have 3063 * to use a cmpset loop rather than an atomic_add. The descriptor 3064 * must be re-verified once we acquire a reference to be certain 3065 * that the identity is still correct and we did not lose a race 3066 * due to preemption. 3067 */ 3068 for (;;) { 3069 #ifdef CAPABILITIES 3070 seq = seqc_read_notmodify(fd_seqc(fdt, fd)); 3071 fde = &fdt->fdt_ofiles[fd]; 3072 haverights = *cap_rights_fde_inline(fde); 3073 fp = fde->fde_file; 3074 if (!seqc_consistent(fd_seqc(fdt, fd), seq)) 3075 continue; 3076 #else 3077 fp = fdt->fdt_ofiles[fd].fde_file; 3078 #endif 3079 if (fp == NULL) 3080 return (EBADF); 3081 #ifdef CAPABILITIES 3082 error = cap_check_inline(&haverights, needrightsp); 3083 if (error != 0) 3084 return (error); 3085 #endif 3086 if (__predict_false(!refcount_acquire_if_not_zero(&fp->f_count))) { 3087 /* 3088 * Force a reload. Other thread could reallocate the 3089 * table before this fd was closed, so it is possible 3090 * that there is a stale fp pointer in cached version. 3091 */ 3092 fdt = atomic_load_ptr(&fdp->fd_files); 3093 continue; 3094 } 3095 /* 3096 * Use an acquire barrier to force re-reading of fdt so it is 3097 * refreshed for verification. 3098 */ 3099 atomic_thread_fence_acq(); 3100 fdt = fdp->fd_files; 3101 #ifdef CAPABILITIES 3102 if (seqc_consistent_nomb(fd_seqc(fdt, fd), seq)) 3103 #else 3104 if (fp == fdt->fdt_ofiles[fd].fde_file) 3105 #endif 3106 break; 3107 fdrop(fp, curthread); 3108 } 3109 *fpp = fp; 3110 if (seqp != NULL) { 3111 #ifdef CAPABILITIES 3112 *seqp = seq; 3113 #endif 3114 } 3115 return (0); 3116 } 3117 3118 /* 3119 * See the comments in fget_unlocked_seq for an explanation of how this works. 3120 * 3121 * This is a simplified variant which bails out to the aforementioned routine 3122 * if anything goes wrong. In practice this only happens when userspace is 3123 * racing with itself. 3124 */ 3125 int 3126 fget_unlocked(struct filedesc *fdp, int fd, cap_rights_t *needrightsp, 3127 struct file **fpp) 3128 { 3129 #ifdef CAPABILITIES 3130 const struct filedescent *fde; 3131 #endif 3132 const struct fdescenttbl *fdt; 3133 struct file *fp; 3134 #ifdef CAPABILITIES 3135 seqc_t seq; 3136 const cap_rights_t *haverights; 3137 #endif 3138 3139 fdt = fdp->fd_files; 3140 if (__predict_false((u_int)fd >= fdt->fdt_nfiles)) 3141 return (EBADF); 3142 #ifdef CAPABILITIES 3143 seq = seqc_read_notmodify(fd_seqc(fdt, fd)); 3144 fde = &fdt->fdt_ofiles[fd]; 3145 haverights = cap_rights_fde_inline(fde); 3146 fp = fde->fde_file; 3147 #else 3148 fp = fdt->fdt_ofiles[fd].fde_file; 3149 #endif 3150 if (__predict_false(fp == NULL)) 3151 goto out_fallback; 3152 #ifdef CAPABILITIES 3153 if (__predict_false(cap_check_inline_transient(haverights, needrightsp))) 3154 goto out_fallback; 3155 #endif 3156 if (__predict_false(!refcount_acquire_if_not_zero(&fp->f_count))) 3157 goto out_fallback; 3158 3159 /* 3160 * Use an acquire barrier to force re-reading of fdt so it is 3161 * refreshed for verification. 3162 */ 3163 atomic_thread_fence_acq(); 3164 fdt = fdp->fd_files; 3165 #ifdef CAPABILITIES 3166 if (__predict_false(!seqc_consistent_nomb(fd_seqc(fdt, fd), seq))) 3167 #else 3168 if (__predict_false(fp != fdt->fdt_ofiles[fd].fde_file)) 3169 #endif 3170 goto out_fdrop; 3171 *fpp = fp; 3172 return (0); 3173 out_fdrop: 3174 fdrop(fp, curthread); 3175 out_fallback: 3176 return (fget_unlocked_seq(fdp, fd, needrightsp, fpp, NULL)); 3177 } 3178 3179 /* 3180 * Extract the file pointer associated with the specified descriptor for the 3181 * current user process. 3182 * 3183 * If the descriptor doesn't exist or doesn't match 'flags', EBADF is 3184 * returned. 3185 * 3186 * File's rights will be checked against the capability rights mask. 3187 * 3188 * If an error occurred the non-zero error is returned and *fpp is set to 3189 * NULL. Otherwise *fpp is held and set and zero is returned. Caller is 3190 * responsible for fdrop(). 3191 */ 3192 static __inline int 3193 _fget(struct thread *td, int fd, struct file **fpp, int flags, 3194 cap_rights_t *needrightsp) 3195 { 3196 struct filedesc *fdp; 3197 struct file *fp; 3198 int error; 3199 3200 *fpp = NULL; 3201 fdp = td->td_proc->p_fd; 3202 error = fget_unlocked(fdp, fd, needrightsp, &fp); 3203 if (__predict_false(error != 0)) 3204 return (error); 3205 if (__predict_false(fp->f_ops == &badfileops)) { 3206 fdrop(fp, td); 3207 return (EBADF); 3208 } 3209 3210 /* 3211 * FREAD and FWRITE failure return EBADF as per POSIX. 3212 */ 3213 error = 0; 3214 switch (flags) { 3215 case FREAD: 3216 case FWRITE: 3217 if ((fp->f_flag & flags) == 0) 3218 error = EBADF; 3219 break; 3220 case FEXEC: 3221 if ((fp->f_flag & (FREAD | FEXEC)) == 0 || 3222 ((fp->f_flag & FWRITE) != 0)) 3223 error = EBADF; 3224 break; 3225 case 0: 3226 break; 3227 default: 3228 KASSERT(0, ("wrong flags")); 3229 } 3230 3231 if (error != 0) { 3232 fdrop(fp, td); 3233 return (error); 3234 } 3235 3236 *fpp = fp; 3237 return (0); 3238 } 3239 3240 int 3241 fget(struct thread *td, int fd, cap_rights_t *rightsp, struct file **fpp) 3242 { 3243 3244 return (_fget(td, fd, fpp, 0, rightsp)); 3245 } 3246 3247 int 3248 fget_mmap(struct thread *td, int fd, cap_rights_t *rightsp, vm_prot_t *maxprotp, 3249 struct file **fpp) 3250 { 3251 int error; 3252 #ifndef CAPABILITIES 3253 error = _fget(td, fd, fpp, 0, rightsp); 3254 if (maxprotp != NULL) 3255 *maxprotp = VM_PROT_ALL; 3256 return (error); 3257 #else 3258 cap_rights_t fdrights; 3259 struct filedesc *fdp; 3260 struct file *fp; 3261 seqc_t seq; 3262 3263 *fpp = NULL; 3264 fdp = td->td_proc->p_fd; 3265 MPASS(cap_rights_is_set(rightsp, CAP_MMAP)); 3266 for (;;) { 3267 error = fget_unlocked_seq(fdp, fd, rightsp, &fp, &seq); 3268 if (__predict_false(error != 0)) 3269 return (error); 3270 if (__predict_false(fp->f_ops == &badfileops)) { 3271 fdrop(fp, td); 3272 return (EBADF); 3273 } 3274 if (maxprotp != NULL) 3275 fdrights = *cap_rights(fdp, fd); 3276 if (!fd_modified(fdp, fd, seq)) 3277 break; 3278 fdrop(fp, td); 3279 } 3280 3281 /* 3282 * If requested, convert capability rights to access flags. 3283 */ 3284 if (maxprotp != NULL) 3285 *maxprotp = cap_rights_to_vmprot(&fdrights); 3286 *fpp = fp; 3287 return (0); 3288 #endif 3289 } 3290 3291 int 3292 fget_read(struct thread *td, int fd, cap_rights_t *rightsp, struct file **fpp) 3293 { 3294 3295 return (_fget(td, fd, fpp, FREAD, rightsp)); 3296 } 3297 3298 int 3299 fget_write(struct thread *td, int fd, cap_rights_t *rightsp, struct file **fpp) 3300 { 3301 3302 return (_fget(td, fd, fpp, FWRITE, rightsp)); 3303 } 3304 3305 int 3306 fget_fcntl(struct thread *td, int fd, cap_rights_t *rightsp, int needfcntl, 3307 struct file **fpp) 3308 { 3309 struct filedesc *fdp = td->td_proc->p_fd; 3310 #ifndef CAPABILITIES 3311 return (fget_unlocked(fdp, fd, rightsp, fpp)); 3312 #else 3313 struct file *fp; 3314 int error; 3315 seqc_t seq; 3316 3317 *fpp = NULL; 3318 MPASS(cap_rights_is_set(rightsp, CAP_FCNTL)); 3319 for (;;) { 3320 error = fget_unlocked_seq(fdp, fd, rightsp, &fp, &seq); 3321 if (error != 0) 3322 return (error); 3323 error = cap_fcntl_check(fdp, fd, needfcntl); 3324 if (!fd_modified(fdp, fd, seq)) 3325 break; 3326 fdrop(fp, td); 3327 } 3328 if (error != 0) { 3329 fdrop(fp, td); 3330 return (error); 3331 } 3332 *fpp = fp; 3333 return (0); 3334 #endif 3335 } 3336 3337 /* 3338 * Like fget() but loads the underlying vnode, or returns an error if the 3339 * descriptor does not represent a vnode. Note that pipes use vnodes but 3340 * never have VM objects. The returned vnode will be vref()'d. 3341 * 3342 * XXX: what about the unused flags ? 3343 */ 3344 static __inline int 3345 _fgetvp(struct thread *td, int fd, int flags, cap_rights_t *needrightsp, 3346 struct vnode **vpp) 3347 { 3348 struct file *fp; 3349 int error; 3350 3351 *vpp = NULL; 3352 error = _fget(td, fd, &fp, flags, needrightsp); 3353 if (error != 0) 3354 return (error); 3355 if (fp->f_vnode == NULL) { 3356 error = EINVAL; 3357 } else { 3358 *vpp = fp->f_vnode; 3359 vrefact(*vpp); 3360 } 3361 fdrop(fp, td); 3362 3363 return (error); 3364 } 3365 3366 int 3367 fgetvp(struct thread *td, int fd, cap_rights_t *rightsp, struct vnode **vpp) 3368 { 3369 3370 return (_fgetvp(td, fd, 0, rightsp, vpp)); 3371 } 3372 3373 int 3374 fgetvp_rights(struct thread *td, int fd, cap_rights_t *needrightsp, 3375 struct filecaps *havecaps, struct vnode **vpp) 3376 { 3377 struct filecaps caps; 3378 struct file *fp; 3379 int error; 3380 3381 error = fget_cap(td, fd, needrightsp, &fp, &caps); 3382 if (error != 0) 3383 return (error); 3384 if (fp->f_ops == &badfileops) { 3385 error = EBADF; 3386 goto out; 3387 } 3388 if (fp->f_vnode == NULL) { 3389 error = EINVAL; 3390 goto out; 3391 } 3392 3393 *havecaps = caps; 3394 *vpp = fp->f_vnode; 3395 vrefact(*vpp); 3396 fdrop(fp, td); 3397 3398 return (0); 3399 out: 3400 filecaps_free(&caps); 3401 fdrop(fp, td); 3402 return (error); 3403 } 3404 3405 int 3406 fgetvp_read(struct thread *td, int fd, cap_rights_t *rightsp, struct vnode **vpp) 3407 { 3408 3409 return (_fgetvp(td, fd, FREAD, rightsp, vpp)); 3410 } 3411 3412 int 3413 fgetvp_exec(struct thread *td, int fd, cap_rights_t *rightsp, struct vnode **vpp) 3414 { 3415 3416 return (_fgetvp(td, fd, FEXEC, rightsp, vpp)); 3417 } 3418 3419 #ifdef notyet 3420 int 3421 fgetvp_write(struct thread *td, int fd, cap_rights_t *rightsp, 3422 struct vnode **vpp) 3423 { 3424 3425 return (_fgetvp(td, fd, FWRITE, rightsp, vpp)); 3426 } 3427 #endif 3428 3429 /* 3430 * Handle the last reference to a file being closed. 3431 * 3432 * Without the noinline attribute clang keeps inlining the func thorough this 3433 * file when fdrop is used. 3434 */ 3435 int __noinline 3436 _fdrop(struct file *fp, struct thread *td) 3437 { 3438 int error; 3439 #ifdef INVARIANTS 3440 int count; 3441 3442 count = refcount_load(&fp->f_count); 3443 if (count != 0) 3444 panic("fdrop: fp %p count %d", fp, count); 3445 #endif 3446 error = fo_close(fp, td); 3447 atomic_subtract_int(&openfiles, 1); 3448 crfree(fp->f_cred); 3449 free(fp->f_advice, M_FADVISE); 3450 uma_zfree(file_zone, fp); 3451 3452 return (error); 3453 } 3454 3455 /* 3456 * Apply an advisory lock on a file descriptor. 3457 * 3458 * Just attempt to get a record lock of the requested type on the entire file 3459 * (l_whence = SEEK_SET, l_start = 0, l_len = 0). 3460 */ 3461 #ifndef _SYS_SYSPROTO_H_ 3462 struct flock_args { 3463 int fd; 3464 int how; 3465 }; 3466 #endif 3467 /* ARGSUSED */ 3468 int 3469 sys_flock(struct thread *td, struct flock_args *uap) 3470 { 3471 struct file *fp; 3472 struct vnode *vp; 3473 struct flock lf; 3474 int error; 3475 3476 error = fget(td, uap->fd, &cap_flock_rights, &fp); 3477 if (error != 0) 3478 return (error); 3479 if (fp->f_type != DTYPE_VNODE) { 3480 fdrop(fp, td); 3481 return (EOPNOTSUPP); 3482 } 3483 3484 vp = fp->f_vnode; 3485 lf.l_whence = SEEK_SET; 3486 lf.l_start = 0; 3487 lf.l_len = 0; 3488 if (uap->how & LOCK_UN) { 3489 lf.l_type = F_UNLCK; 3490 atomic_clear_int(&fp->f_flag, FHASLOCK); 3491 error = VOP_ADVLOCK(vp, (caddr_t)fp, F_UNLCK, &lf, F_FLOCK); 3492 goto done2; 3493 } 3494 if (uap->how & LOCK_EX) 3495 lf.l_type = F_WRLCK; 3496 else if (uap->how & LOCK_SH) 3497 lf.l_type = F_RDLCK; 3498 else { 3499 error = EBADF; 3500 goto done2; 3501 } 3502 atomic_set_int(&fp->f_flag, FHASLOCK); 3503 error = VOP_ADVLOCK(vp, (caddr_t)fp, F_SETLK, &lf, 3504 (uap->how & LOCK_NB) ? F_FLOCK : F_FLOCK | F_WAIT); 3505 done2: 3506 fdrop(fp, td); 3507 return (error); 3508 } 3509 /* 3510 * Duplicate the specified descriptor to a free descriptor. 3511 */ 3512 int 3513 dupfdopen(struct thread *td, struct filedesc *fdp, int dfd, int mode, 3514 int openerror, int *indxp) 3515 { 3516 struct filedescent *newfde, *oldfde; 3517 struct file *fp; 3518 u_long *ioctls; 3519 int error, indx; 3520 3521 KASSERT(openerror == ENODEV || openerror == ENXIO, 3522 ("unexpected error %d in %s", openerror, __func__)); 3523 3524 /* 3525 * If the to-be-dup'd fd number is greater than the allowed number 3526 * of file descriptors, or the fd to be dup'd has already been 3527 * closed, then reject. 3528 */ 3529 FILEDESC_XLOCK(fdp); 3530 if ((fp = fget_locked(fdp, dfd)) == NULL) { 3531 FILEDESC_XUNLOCK(fdp); 3532 return (EBADF); 3533 } 3534 3535 error = fdalloc(td, 0, &indx); 3536 if (error != 0) { 3537 FILEDESC_XUNLOCK(fdp); 3538 return (error); 3539 } 3540 3541 /* 3542 * There are two cases of interest here. 3543 * 3544 * For ENODEV simply dup (dfd) to file descriptor (indx) and return. 3545 * 3546 * For ENXIO steal away the file structure from (dfd) and store it in 3547 * (indx). (dfd) is effectively closed by this operation. 3548 */ 3549 switch (openerror) { 3550 case ENODEV: 3551 /* 3552 * Check that the mode the file is being opened for is a 3553 * subset of the mode of the existing descriptor. 3554 */ 3555 if (((mode & (FREAD|FWRITE)) | fp->f_flag) != fp->f_flag) { 3556 fdunused(fdp, indx); 3557 FILEDESC_XUNLOCK(fdp); 3558 return (EACCES); 3559 } 3560 if (!fhold(fp)) { 3561 fdunused(fdp, indx); 3562 FILEDESC_XUNLOCK(fdp); 3563 return (EBADF); 3564 } 3565 newfde = &fdp->fd_ofiles[indx]; 3566 oldfde = &fdp->fd_ofiles[dfd]; 3567 ioctls = filecaps_copy_prep(&oldfde->fde_caps); 3568 #ifdef CAPABILITIES 3569 seqc_write_begin(&newfde->fde_seqc); 3570 #endif 3571 memcpy(newfde, oldfde, fde_change_size); 3572 filecaps_copy_finish(&oldfde->fde_caps, &newfde->fde_caps, 3573 ioctls); 3574 #ifdef CAPABILITIES 3575 seqc_write_end(&newfde->fde_seqc); 3576 #endif 3577 break; 3578 case ENXIO: 3579 /* 3580 * Steal away the file pointer from dfd and stuff it into indx. 3581 */ 3582 newfde = &fdp->fd_ofiles[indx]; 3583 oldfde = &fdp->fd_ofiles[dfd]; 3584 #ifdef CAPABILITIES 3585 seqc_write_begin(&newfde->fde_seqc); 3586 #endif 3587 memcpy(newfde, oldfde, fde_change_size); 3588 oldfde->fde_file = NULL; 3589 fdunused(fdp, dfd); 3590 #ifdef CAPABILITIES 3591 seqc_write_end(&newfde->fde_seqc); 3592 #endif 3593 break; 3594 } 3595 FILEDESC_XUNLOCK(fdp); 3596 *indxp = indx; 3597 return (0); 3598 } 3599 3600 /* 3601 * This sysctl determines if we will allow a process to chroot(2) if it 3602 * has a directory open: 3603 * 0: disallowed for all processes. 3604 * 1: allowed for processes that were not already chroot(2)'ed. 3605 * 2: allowed for all processes. 3606 */ 3607 3608 static int chroot_allow_open_directories = 1; 3609 3610 SYSCTL_INT(_kern, OID_AUTO, chroot_allow_open_directories, CTLFLAG_RW, 3611 &chroot_allow_open_directories, 0, 3612 "Allow a process to chroot(2) if it has a directory open"); 3613 3614 /* 3615 * Helper function for raised chroot(2) security function: Refuse if 3616 * any filedescriptors are open directories. 3617 */ 3618 static int 3619 chroot_refuse_vdir_fds(struct filedesc *fdp) 3620 { 3621 struct vnode *vp; 3622 struct file *fp; 3623 int fd, lastfile; 3624 3625 FILEDESC_LOCK_ASSERT(fdp); 3626 3627 lastfile = fdlastfile(fdp); 3628 for (fd = 0; fd <= lastfile; fd++) { 3629 fp = fget_locked(fdp, fd); 3630 if (fp == NULL) 3631 continue; 3632 if (fp->f_type == DTYPE_VNODE) { 3633 vp = fp->f_vnode; 3634 if (vp->v_type == VDIR) 3635 return (EPERM); 3636 } 3637 } 3638 return (0); 3639 } 3640 3641 static void 3642 pwd_fill(struct pwd *oldpwd, struct pwd *newpwd) 3643 { 3644 3645 if (newpwd->pwd_cdir == NULL && oldpwd->pwd_cdir != NULL) { 3646 vrefact(oldpwd->pwd_cdir); 3647 newpwd->pwd_cdir = oldpwd->pwd_cdir; 3648 } 3649 3650 if (newpwd->pwd_rdir == NULL && oldpwd->pwd_rdir != NULL) { 3651 vrefact(oldpwd->pwd_rdir); 3652 newpwd->pwd_rdir = oldpwd->pwd_rdir; 3653 } 3654 3655 if (newpwd->pwd_jdir == NULL && oldpwd->pwd_jdir != NULL) { 3656 vrefact(oldpwd->pwd_jdir); 3657 newpwd->pwd_jdir = oldpwd->pwd_jdir; 3658 } 3659 } 3660 3661 struct pwd * 3662 pwd_hold_pwddesc(struct pwddesc *pdp) 3663 { 3664 struct pwd *pwd; 3665 3666 PWDDESC_ASSERT_XLOCKED(pdp); 3667 pwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); 3668 if (pwd != NULL) 3669 refcount_acquire(&pwd->pwd_refcount); 3670 return (pwd); 3671 } 3672 3673 bool 3674 pwd_hold_smr(struct pwd *pwd) 3675 { 3676 3677 MPASS(pwd != NULL); 3678 if (__predict_true(refcount_acquire_if_not_zero(&pwd->pwd_refcount))) { 3679 return (true); 3680 } 3681 return (false); 3682 } 3683 3684 struct pwd * 3685 pwd_hold(struct thread *td) 3686 { 3687 struct pwddesc *pdp; 3688 struct pwd *pwd; 3689 3690 pdp = td->td_proc->p_pd; 3691 3692 vfs_smr_enter(); 3693 pwd = vfs_smr_entered_load(&pdp->pd_pwd); 3694 if (pwd_hold_smr(pwd)) { 3695 vfs_smr_exit(); 3696 return (pwd); 3697 } 3698 vfs_smr_exit(); 3699 PWDDESC_XLOCK(pdp); 3700 pwd = pwd_hold_pwddesc(pdp); 3701 MPASS(pwd != NULL); 3702 PWDDESC_XUNLOCK(pdp); 3703 return (pwd); 3704 } 3705 3706 static struct pwd * 3707 pwd_alloc(void) 3708 { 3709 struct pwd *pwd; 3710 3711 pwd = uma_zalloc_smr(pwd_zone, M_WAITOK); 3712 bzero(pwd, sizeof(*pwd)); 3713 refcount_init(&pwd->pwd_refcount, 1); 3714 return (pwd); 3715 } 3716 3717 void 3718 pwd_drop(struct pwd *pwd) 3719 { 3720 3721 if (!refcount_release(&pwd->pwd_refcount)) 3722 return; 3723 3724 if (pwd->pwd_cdir != NULL) 3725 vrele(pwd->pwd_cdir); 3726 if (pwd->pwd_rdir != NULL) 3727 vrele(pwd->pwd_rdir); 3728 if (pwd->pwd_jdir != NULL) 3729 vrele(pwd->pwd_jdir); 3730 uma_zfree_smr(pwd_zone, pwd); 3731 } 3732 3733 /* 3734 * Common routine for kern_chroot() and jail_attach(). The caller is 3735 * responsible for invoking priv_check() and mac_vnode_check_chroot() to 3736 * authorize this operation. 3737 */ 3738 int 3739 pwd_chroot(struct thread *td, struct vnode *vp) 3740 { 3741 struct pwddesc *pdp; 3742 struct filedesc *fdp; 3743 struct pwd *newpwd, *oldpwd; 3744 int error; 3745 3746 fdp = td->td_proc->p_fd; 3747 pdp = td->td_proc->p_pd; 3748 newpwd = pwd_alloc(); 3749 FILEDESC_SLOCK(fdp); 3750 PWDDESC_XLOCK(pdp); 3751 oldpwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); 3752 if (chroot_allow_open_directories == 0 || 3753 (chroot_allow_open_directories == 1 && 3754 oldpwd->pwd_rdir != rootvnode)) { 3755 error = chroot_refuse_vdir_fds(fdp); 3756 FILEDESC_SUNLOCK(fdp); 3757 if (error != 0) { 3758 PWDDESC_XUNLOCK(pdp); 3759 pwd_drop(newpwd); 3760 return (error); 3761 } 3762 } else { 3763 FILEDESC_SUNLOCK(fdp); 3764 } 3765 3766 vrefact(vp); 3767 newpwd->pwd_rdir = vp; 3768 if (oldpwd->pwd_jdir == NULL) { 3769 vrefact(vp); 3770 newpwd->pwd_jdir = vp; 3771 } 3772 pwd_fill(oldpwd, newpwd); 3773 pwd_set(pdp, newpwd); 3774 PWDDESC_XUNLOCK(pdp); 3775 pwd_drop(oldpwd); 3776 return (0); 3777 } 3778 3779 void 3780 pwd_chdir(struct thread *td, struct vnode *vp) 3781 { 3782 struct pwddesc *pdp; 3783 struct pwd *newpwd, *oldpwd; 3784 3785 VNPASS(vp->v_usecount > 0, vp); 3786 3787 newpwd = pwd_alloc(); 3788 pdp = td->td_proc->p_pd; 3789 PWDDESC_XLOCK(pdp); 3790 oldpwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); 3791 newpwd->pwd_cdir = vp; 3792 pwd_fill(oldpwd, newpwd); 3793 pwd_set(pdp, newpwd); 3794 PWDDESC_XUNLOCK(pdp); 3795 pwd_drop(oldpwd); 3796 } 3797 3798 void 3799 pwd_ensure_dirs(void) 3800 { 3801 struct pwddesc *pdp; 3802 struct pwd *oldpwd, *newpwd; 3803 3804 pdp = curproc->p_pd; 3805 PWDDESC_XLOCK(pdp); 3806 oldpwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); 3807 if (oldpwd->pwd_cdir != NULL && oldpwd->pwd_rdir != NULL) { 3808 PWDDESC_XUNLOCK(pdp); 3809 return; 3810 } 3811 PWDDESC_XUNLOCK(pdp); 3812 3813 newpwd = pwd_alloc(); 3814 PWDDESC_XLOCK(pdp); 3815 oldpwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); 3816 pwd_fill(oldpwd, newpwd); 3817 if (newpwd->pwd_cdir == NULL) { 3818 vrefact(rootvnode); 3819 newpwd->pwd_cdir = rootvnode; 3820 } 3821 if (newpwd->pwd_rdir == NULL) { 3822 vrefact(rootvnode); 3823 newpwd->pwd_rdir = rootvnode; 3824 } 3825 pwd_set(pdp, newpwd); 3826 PWDDESC_XUNLOCK(pdp); 3827 pwd_drop(oldpwd); 3828 } 3829 3830 void 3831 pwd_set_rootvnode(void) 3832 { 3833 struct pwddesc *pdp; 3834 struct pwd *oldpwd, *newpwd; 3835 3836 pdp = curproc->p_pd; 3837 3838 newpwd = pwd_alloc(); 3839 PWDDESC_XLOCK(pdp); 3840 oldpwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); 3841 vrefact(rootvnode); 3842 newpwd->pwd_cdir = rootvnode; 3843 vrefact(rootvnode); 3844 newpwd->pwd_rdir = rootvnode; 3845 pwd_fill(oldpwd, newpwd); 3846 pwd_set(pdp, newpwd); 3847 PWDDESC_XUNLOCK(pdp); 3848 pwd_drop(oldpwd); 3849 } 3850 3851 /* 3852 * Scan all active processes and prisons to see if any of them have a current 3853 * or root directory of `olddp'. If so, replace them with the new mount point. 3854 */ 3855 void 3856 mountcheckdirs(struct vnode *olddp, struct vnode *newdp) 3857 { 3858 struct pwddesc *pdp; 3859 struct pwd *newpwd, *oldpwd; 3860 struct prison *pr; 3861 struct proc *p; 3862 int nrele; 3863 3864 if (vrefcnt(olddp) == 1) 3865 return; 3866 nrele = 0; 3867 newpwd = pwd_alloc(); 3868 sx_slock(&allproc_lock); 3869 FOREACH_PROC_IN_SYSTEM(p) { 3870 PROC_LOCK(p); 3871 pdp = pdhold(p); 3872 PROC_UNLOCK(p); 3873 if (pdp == NULL) 3874 continue; 3875 PWDDESC_XLOCK(pdp); 3876 oldpwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); 3877 if (oldpwd == NULL || 3878 (oldpwd->pwd_cdir != olddp && 3879 oldpwd->pwd_rdir != olddp && 3880 oldpwd->pwd_jdir != olddp)) { 3881 PWDDESC_XUNLOCK(pdp); 3882 pddrop(pdp); 3883 continue; 3884 } 3885 if (oldpwd->pwd_cdir == olddp) { 3886 vrefact(newdp); 3887 newpwd->pwd_cdir = newdp; 3888 } 3889 if (oldpwd->pwd_rdir == olddp) { 3890 vrefact(newdp); 3891 newpwd->pwd_rdir = newdp; 3892 } 3893 if (oldpwd->pwd_jdir == olddp) { 3894 vrefact(newdp); 3895 newpwd->pwd_jdir = newdp; 3896 } 3897 pwd_fill(oldpwd, newpwd); 3898 pwd_set(pdp, newpwd); 3899 PWDDESC_XUNLOCK(pdp); 3900 pwd_drop(oldpwd); 3901 pddrop(pdp); 3902 newpwd = pwd_alloc(); 3903 } 3904 sx_sunlock(&allproc_lock); 3905 pwd_drop(newpwd); 3906 if (rootvnode == olddp) { 3907 vrefact(newdp); 3908 rootvnode = newdp; 3909 nrele++; 3910 } 3911 mtx_lock(&prison0.pr_mtx); 3912 if (prison0.pr_root == olddp) { 3913 vrefact(newdp); 3914 prison0.pr_root = newdp; 3915 nrele++; 3916 } 3917 mtx_unlock(&prison0.pr_mtx); 3918 sx_slock(&allprison_lock); 3919 TAILQ_FOREACH(pr, &allprison, pr_list) { 3920 mtx_lock(&pr->pr_mtx); 3921 if (pr->pr_root == olddp) { 3922 vrefact(newdp); 3923 pr->pr_root = newdp; 3924 nrele++; 3925 } 3926 mtx_unlock(&pr->pr_mtx); 3927 } 3928 sx_sunlock(&allprison_lock); 3929 while (nrele--) 3930 vrele(olddp); 3931 } 3932 3933 struct filedesc_to_leader * 3934 filedesc_to_leader_alloc(struct filedesc_to_leader *old, struct filedesc *fdp, struct proc *leader) 3935 { 3936 struct filedesc_to_leader *fdtol; 3937 3938 fdtol = malloc(sizeof(struct filedesc_to_leader), 3939 M_FILEDESC_TO_LEADER, M_WAITOK); 3940 fdtol->fdl_refcount = 1; 3941 fdtol->fdl_holdcount = 0; 3942 fdtol->fdl_wakeup = 0; 3943 fdtol->fdl_leader = leader; 3944 if (old != NULL) { 3945 FILEDESC_XLOCK(fdp); 3946 fdtol->fdl_next = old->fdl_next; 3947 fdtol->fdl_prev = old; 3948 old->fdl_next = fdtol; 3949 fdtol->fdl_next->fdl_prev = fdtol; 3950 FILEDESC_XUNLOCK(fdp); 3951 } else { 3952 fdtol->fdl_next = fdtol; 3953 fdtol->fdl_prev = fdtol; 3954 } 3955 return (fdtol); 3956 } 3957 3958 static int 3959 sysctl_kern_proc_nfds(SYSCTL_HANDLER_ARGS) 3960 { 3961 NDSLOTTYPE *map; 3962 struct filedesc *fdp; 3963 int count, off, minoff; 3964 3965 if (*(int *)arg1 != 0) 3966 return (EINVAL); 3967 3968 fdp = curproc->p_fd; 3969 count = 0; 3970 FILEDESC_SLOCK(fdp); 3971 map = fdp->fd_map; 3972 off = NDSLOT(fdp->fd_nfiles - 1); 3973 for (minoff = NDSLOT(0); off >= minoff; --off) 3974 count += bitcountl(map[off]); 3975 FILEDESC_SUNLOCK(fdp); 3976 3977 return (SYSCTL_OUT(req, &count, sizeof(count))); 3978 } 3979 3980 static SYSCTL_NODE(_kern_proc, KERN_PROC_NFDS, nfds, 3981 CTLFLAG_RD|CTLFLAG_CAPRD|CTLFLAG_MPSAFE, sysctl_kern_proc_nfds, 3982 "Number of open file descriptors"); 3983 3984 /* 3985 * Get file structures globally. 3986 */ 3987 static int 3988 sysctl_kern_file(SYSCTL_HANDLER_ARGS) 3989 { 3990 struct xfile xf; 3991 struct filedesc *fdp; 3992 struct file *fp; 3993 struct proc *p; 3994 int error, n, lastfile; 3995 3996 error = sysctl_wire_old_buffer(req, 0); 3997 if (error != 0) 3998 return (error); 3999 if (req->oldptr == NULL) { 4000 n = 0; 4001 sx_slock(&allproc_lock); 4002 FOREACH_PROC_IN_SYSTEM(p) { 4003 PROC_LOCK(p); 4004 if (p->p_state == PRS_NEW) { 4005 PROC_UNLOCK(p); 4006 continue; 4007 } 4008 fdp = fdhold(p); 4009 PROC_UNLOCK(p); 4010 if (fdp == NULL) 4011 continue; 4012 /* overestimates sparse tables. */ 4013 n += fdp->fd_nfiles; 4014 fddrop(fdp); 4015 } 4016 sx_sunlock(&allproc_lock); 4017 return (SYSCTL_OUT(req, 0, n * sizeof(xf))); 4018 } 4019 error = 0; 4020 bzero(&xf, sizeof(xf)); 4021 xf.xf_size = sizeof(xf); 4022 sx_slock(&allproc_lock); 4023 FOREACH_PROC_IN_SYSTEM(p) { 4024 PROC_LOCK(p); 4025 if (p->p_state == PRS_NEW) { 4026 PROC_UNLOCK(p); 4027 continue; 4028 } 4029 if (p_cansee(req->td, p) != 0) { 4030 PROC_UNLOCK(p); 4031 continue; 4032 } 4033 xf.xf_pid = p->p_pid; 4034 xf.xf_uid = p->p_ucred->cr_uid; 4035 fdp = fdhold(p); 4036 PROC_UNLOCK(p); 4037 if (fdp == NULL) 4038 continue; 4039 FILEDESC_SLOCK(fdp); 4040 lastfile = fdlastfile(fdp); 4041 for (n = 0; refcount_load(&fdp->fd_refcnt) > 0 && n <= lastfile; 4042 n++) { 4043 if ((fp = fdp->fd_ofiles[n].fde_file) == NULL) 4044 continue; 4045 xf.xf_fd = n; 4046 xf.xf_file = (uintptr_t)fp; 4047 xf.xf_data = (uintptr_t)fp->f_data; 4048 xf.xf_vnode = (uintptr_t)fp->f_vnode; 4049 xf.xf_type = (uintptr_t)fp->f_type; 4050 xf.xf_count = refcount_load(&fp->f_count); 4051 xf.xf_msgcount = 0; 4052 xf.xf_offset = foffset_get(fp); 4053 xf.xf_flag = fp->f_flag; 4054 error = SYSCTL_OUT(req, &xf, sizeof(xf)); 4055 if (error) 4056 break; 4057 } 4058 FILEDESC_SUNLOCK(fdp); 4059 fddrop(fdp); 4060 if (error) 4061 break; 4062 } 4063 sx_sunlock(&allproc_lock); 4064 return (error); 4065 } 4066 4067 SYSCTL_PROC(_kern, KERN_FILE, file, CTLTYPE_OPAQUE|CTLFLAG_RD|CTLFLAG_MPSAFE, 4068 0, 0, sysctl_kern_file, "S,xfile", "Entire file table"); 4069 4070 #ifdef KINFO_FILE_SIZE 4071 CTASSERT(sizeof(struct kinfo_file) == KINFO_FILE_SIZE); 4072 #endif 4073 4074 static int 4075 xlate_fflags(int fflags) 4076 { 4077 static const struct { 4078 int fflag; 4079 int kf_fflag; 4080 } fflags_table[] = { 4081 { FAPPEND, KF_FLAG_APPEND }, 4082 { FASYNC, KF_FLAG_ASYNC }, 4083 { FFSYNC, KF_FLAG_FSYNC }, 4084 { FHASLOCK, KF_FLAG_HASLOCK }, 4085 { FNONBLOCK, KF_FLAG_NONBLOCK }, 4086 { FREAD, KF_FLAG_READ }, 4087 { FWRITE, KF_FLAG_WRITE }, 4088 { O_CREAT, KF_FLAG_CREAT }, 4089 { O_DIRECT, KF_FLAG_DIRECT }, 4090 { O_EXCL, KF_FLAG_EXCL }, 4091 { O_EXEC, KF_FLAG_EXEC }, 4092 { O_EXLOCK, KF_FLAG_EXLOCK }, 4093 { O_NOFOLLOW, KF_FLAG_NOFOLLOW }, 4094 { O_SHLOCK, KF_FLAG_SHLOCK }, 4095 { O_TRUNC, KF_FLAG_TRUNC } 4096 }; 4097 unsigned int i; 4098 int kflags; 4099 4100 kflags = 0; 4101 for (i = 0; i < nitems(fflags_table); i++) 4102 if (fflags & fflags_table[i].fflag) 4103 kflags |= fflags_table[i].kf_fflag; 4104 return (kflags); 4105 } 4106 4107 /* Trim unused data from kf_path by truncating the structure size. */ 4108 void 4109 pack_kinfo(struct kinfo_file *kif) 4110 { 4111 4112 kif->kf_structsize = offsetof(struct kinfo_file, kf_path) + 4113 strlen(kif->kf_path) + 1; 4114 kif->kf_structsize = roundup(kif->kf_structsize, sizeof(uint64_t)); 4115 } 4116 4117 static void 4118 export_file_to_kinfo(struct file *fp, int fd, cap_rights_t *rightsp, 4119 struct kinfo_file *kif, struct filedesc *fdp, int flags) 4120 { 4121 int error; 4122 4123 bzero(kif, sizeof(*kif)); 4124 4125 /* Set a default type to allow for empty fill_kinfo() methods. */ 4126 kif->kf_type = KF_TYPE_UNKNOWN; 4127 kif->kf_flags = xlate_fflags(fp->f_flag); 4128 if (rightsp != NULL) 4129 kif->kf_cap_rights = *rightsp; 4130 else 4131 cap_rights_init_zero(&kif->kf_cap_rights); 4132 kif->kf_fd = fd; 4133 kif->kf_ref_count = refcount_load(&fp->f_count); 4134 kif->kf_offset = foffset_get(fp); 4135 4136 /* 4137 * This may drop the filedesc lock, so the 'fp' cannot be 4138 * accessed after this call. 4139 */ 4140 error = fo_fill_kinfo(fp, kif, fdp); 4141 if (error == 0) 4142 kif->kf_status |= KF_ATTR_VALID; 4143 if ((flags & KERN_FILEDESC_PACK_KINFO) != 0) 4144 pack_kinfo(kif); 4145 else 4146 kif->kf_structsize = roundup2(sizeof(*kif), sizeof(uint64_t)); 4147 } 4148 4149 static void 4150 export_vnode_to_kinfo(struct vnode *vp, int fd, int fflags, 4151 struct kinfo_file *kif, int flags) 4152 { 4153 int error; 4154 4155 bzero(kif, sizeof(*kif)); 4156 4157 kif->kf_type = KF_TYPE_VNODE; 4158 error = vn_fill_kinfo_vnode(vp, kif); 4159 if (error == 0) 4160 kif->kf_status |= KF_ATTR_VALID; 4161 kif->kf_flags = xlate_fflags(fflags); 4162 cap_rights_init_zero(&kif->kf_cap_rights); 4163 kif->kf_fd = fd; 4164 kif->kf_ref_count = -1; 4165 kif->kf_offset = -1; 4166 if ((flags & KERN_FILEDESC_PACK_KINFO) != 0) 4167 pack_kinfo(kif); 4168 else 4169 kif->kf_structsize = roundup2(sizeof(*kif), sizeof(uint64_t)); 4170 vrele(vp); 4171 } 4172 4173 struct export_fd_buf { 4174 struct filedesc *fdp; 4175 struct pwddesc *pdp; 4176 struct sbuf *sb; 4177 ssize_t remainder; 4178 struct kinfo_file kif; 4179 int flags; 4180 }; 4181 4182 static int 4183 export_kinfo_to_sb(struct export_fd_buf *efbuf) 4184 { 4185 struct kinfo_file *kif; 4186 4187 kif = &efbuf->kif; 4188 if (efbuf->remainder != -1) { 4189 if (efbuf->remainder < kif->kf_structsize) { 4190 /* Terminate export. */ 4191 efbuf->remainder = 0; 4192 return (0); 4193 } 4194 efbuf->remainder -= kif->kf_structsize; 4195 } 4196 return (sbuf_bcat(efbuf->sb, kif, kif->kf_structsize) == 0 ? 0 : ENOMEM); 4197 } 4198 4199 static int 4200 export_file_to_sb(struct file *fp, int fd, cap_rights_t *rightsp, 4201 struct export_fd_buf *efbuf) 4202 { 4203 int error; 4204 4205 if (efbuf->remainder == 0) 4206 return (0); 4207 export_file_to_kinfo(fp, fd, rightsp, &efbuf->kif, efbuf->fdp, 4208 efbuf->flags); 4209 FILEDESC_SUNLOCK(efbuf->fdp); 4210 error = export_kinfo_to_sb(efbuf); 4211 FILEDESC_SLOCK(efbuf->fdp); 4212 return (error); 4213 } 4214 4215 static int 4216 export_vnode_to_sb(struct vnode *vp, int fd, int fflags, 4217 struct export_fd_buf *efbuf) 4218 { 4219 int error; 4220 4221 if (efbuf->remainder == 0) 4222 return (0); 4223 if (efbuf->pdp != NULL) 4224 PWDDESC_XUNLOCK(efbuf->pdp); 4225 export_vnode_to_kinfo(vp, fd, fflags, &efbuf->kif, efbuf->flags); 4226 error = export_kinfo_to_sb(efbuf); 4227 if (efbuf->pdp != NULL) 4228 PWDDESC_XLOCK(efbuf->pdp); 4229 return (error); 4230 } 4231 4232 /* 4233 * Store a process file descriptor information to sbuf. 4234 * 4235 * Takes a locked proc as argument, and returns with the proc unlocked. 4236 */ 4237 int 4238 kern_proc_filedesc_out(struct proc *p, struct sbuf *sb, ssize_t maxlen, 4239 int flags) 4240 { 4241 struct file *fp; 4242 struct filedesc *fdp; 4243 struct pwddesc *pdp; 4244 struct export_fd_buf *efbuf; 4245 struct vnode *cttyvp, *textvp, *tracevp; 4246 struct pwd *pwd; 4247 int error, i, lastfile; 4248 cap_rights_t rights; 4249 4250 PROC_LOCK_ASSERT(p, MA_OWNED); 4251 4252 /* ktrace vnode */ 4253 tracevp = p->p_tracevp; 4254 if (tracevp != NULL) 4255 vrefact(tracevp); 4256 /* text vnode */ 4257 textvp = p->p_textvp; 4258 if (textvp != NULL) 4259 vrefact(textvp); 4260 /* Controlling tty. */ 4261 cttyvp = NULL; 4262 if (p->p_pgrp != NULL && p->p_pgrp->pg_session != NULL) { 4263 cttyvp = p->p_pgrp->pg_session->s_ttyvp; 4264 if (cttyvp != NULL) 4265 vrefact(cttyvp); 4266 } 4267 fdp = fdhold(p); 4268 pdp = pdhold(p); 4269 PROC_UNLOCK(p); 4270 efbuf = malloc(sizeof(*efbuf), M_TEMP, M_WAITOK); 4271 efbuf->fdp = NULL; 4272 efbuf->pdp = NULL; 4273 efbuf->sb = sb; 4274 efbuf->remainder = maxlen; 4275 efbuf->flags = flags; 4276 if (tracevp != NULL) 4277 export_vnode_to_sb(tracevp, KF_FD_TYPE_TRACE, FREAD | FWRITE, 4278 efbuf); 4279 if (textvp != NULL) 4280 export_vnode_to_sb(textvp, KF_FD_TYPE_TEXT, FREAD, efbuf); 4281 if (cttyvp != NULL) 4282 export_vnode_to_sb(cttyvp, KF_FD_TYPE_CTTY, FREAD | FWRITE, 4283 efbuf); 4284 error = 0; 4285 if (pdp == NULL || fdp == NULL) 4286 goto fail; 4287 efbuf->fdp = fdp; 4288 efbuf->pdp = pdp; 4289 PWDDESC_XLOCK(pdp); 4290 pwd = pwd_hold_pwddesc(pdp); 4291 if (pwd != NULL) { 4292 /* working directory */ 4293 if (pwd->pwd_cdir != NULL) { 4294 vrefact(pwd->pwd_cdir); 4295 export_vnode_to_sb(pwd->pwd_cdir, KF_FD_TYPE_CWD, FREAD, efbuf); 4296 } 4297 /* root directory */ 4298 if (pwd->pwd_rdir != NULL) { 4299 vrefact(pwd->pwd_rdir); 4300 export_vnode_to_sb(pwd->pwd_rdir, KF_FD_TYPE_ROOT, FREAD, efbuf); 4301 } 4302 /* jail directory */ 4303 if (pwd->pwd_jdir != NULL) { 4304 vrefact(pwd->pwd_jdir); 4305 export_vnode_to_sb(pwd->pwd_jdir, KF_FD_TYPE_JAIL, FREAD, efbuf); 4306 } 4307 } 4308 PWDDESC_XUNLOCK(pdp); 4309 if (pwd != NULL) 4310 pwd_drop(pwd); 4311 FILEDESC_SLOCK(fdp); 4312 lastfile = fdlastfile(fdp); 4313 for (i = 0; refcount_load(&fdp->fd_refcnt) > 0 && i <= lastfile; i++) { 4314 if ((fp = fdp->fd_ofiles[i].fde_file) == NULL) 4315 continue; 4316 #ifdef CAPABILITIES 4317 rights = *cap_rights(fdp, i); 4318 #else /* !CAPABILITIES */ 4319 rights = cap_no_rights; 4320 #endif 4321 /* 4322 * Create sysctl entry. It is OK to drop the filedesc 4323 * lock inside of export_file_to_sb() as we will 4324 * re-validate and re-evaluate its properties when the 4325 * loop continues. 4326 */ 4327 error = export_file_to_sb(fp, i, &rights, efbuf); 4328 if (error != 0 || efbuf->remainder == 0) 4329 break; 4330 } 4331 FILEDESC_SUNLOCK(fdp); 4332 fail: 4333 if (fdp != NULL) 4334 fddrop(fdp); 4335 if (pdp != NULL) 4336 pddrop(pdp); 4337 free(efbuf, M_TEMP); 4338 return (error); 4339 } 4340 4341 #define FILEDESC_SBUF_SIZE (sizeof(struct kinfo_file) * 5) 4342 4343 /* 4344 * Get per-process file descriptors for use by procstat(1), et al. 4345 */ 4346 static int 4347 sysctl_kern_proc_filedesc(SYSCTL_HANDLER_ARGS) 4348 { 4349 struct sbuf sb; 4350 struct proc *p; 4351 ssize_t maxlen; 4352 int error, error2, *name; 4353 4354 name = (int *)arg1; 4355 4356 sbuf_new_for_sysctl(&sb, NULL, FILEDESC_SBUF_SIZE, req); 4357 sbuf_clear_flags(&sb, SBUF_INCLUDENUL); 4358 error = pget((pid_t)name[0], PGET_CANDEBUG | PGET_NOTWEXIT, &p); 4359 if (error != 0) { 4360 sbuf_delete(&sb); 4361 return (error); 4362 } 4363 maxlen = req->oldptr != NULL ? req->oldlen : -1; 4364 error = kern_proc_filedesc_out(p, &sb, maxlen, 4365 KERN_FILEDESC_PACK_KINFO); 4366 error2 = sbuf_finish(&sb); 4367 sbuf_delete(&sb); 4368 return (error != 0 ? error : error2); 4369 } 4370 4371 #ifdef COMPAT_FREEBSD7 4372 #ifdef KINFO_OFILE_SIZE 4373 CTASSERT(sizeof(struct kinfo_ofile) == KINFO_OFILE_SIZE); 4374 #endif 4375 4376 static void 4377 kinfo_to_okinfo(struct kinfo_file *kif, struct kinfo_ofile *okif) 4378 { 4379 4380 okif->kf_structsize = sizeof(*okif); 4381 okif->kf_type = kif->kf_type; 4382 okif->kf_fd = kif->kf_fd; 4383 okif->kf_ref_count = kif->kf_ref_count; 4384 okif->kf_flags = kif->kf_flags & (KF_FLAG_READ | KF_FLAG_WRITE | 4385 KF_FLAG_APPEND | KF_FLAG_ASYNC | KF_FLAG_FSYNC | KF_FLAG_NONBLOCK | 4386 KF_FLAG_DIRECT | KF_FLAG_HASLOCK); 4387 okif->kf_offset = kif->kf_offset; 4388 if (kif->kf_type == KF_TYPE_VNODE) 4389 okif->kf_vnode_type = kif->kf_un.kf_file.kf_file_type; 4390 else 4391 okif->kf_vnode_type = KF_VTYPE_VNON; 4392 strlcpy(okif->kf_path, kif->kf_path, sizeof(okif->kf_path)); 4393 if (kif->kf_type == KF_TYPE_SOCKET) { 4394 okif->kf_sock_domain = kif->kf_un.kf_sock.kf_sock_domain0; 4395 okif->kf_sock_type = kif->kf_un.kf_sock.kf_sock_type0; 4396 okif->kf_sock_protocol = kif->kf_un.kf_sock.kf_sock_protocol0; 4397 okif->kf_sa_local = kif->kf_un.kf_sock.kf_sa_local; 4398 okif->kf_sa_peer = kif->kf_un.kf_sock.kf_sa_peer; 4399 } else { 4400 okif->kf_sa_local.ss_family = AF_UNSPEC; 4401 okif->kf_sa_peer.ss_family = AF_UNSPEC; 4402 } 4403 } 4404 4405 static int 4406 export_vnode_for_osysctl(struct vnode *vp, int type, struct kinfo_file *kif, 4407 struct kinfo_ofile *okif, struct pwddesc *pdp, struct sysctl_req *req) 4408 { 4409 int error; 4410 4411 vrefact(vp); 4412 PWDDESC_XUNLOCK(pdp); 4413 export_vnode_to_kinfo(vp, type, 0, kif, KERN_FILEDESC_PACK_KINFO); 4414 kinfo_to_okinfo(kif, okif); 4415 error = SYSCTL_OUT(req, okif, sizeof(*okif)); 4416 PWDDESC_XLOCK(pdp); 4417 return (error); 4418 } 4419 4420 /* 4421 * Get per-process file descriptors for use by procstat(1), et al. 4422 */ 4423 static int 4424 sysctl_kern_proc_ofiledesc(SYSCTL_HANDLER_ARGS) 4425 { 4426 struct kinfo_ofile *okif; 4427 struct kinfo_file *kif; 4428 struct filedesc *fdp; 4429 struct pwddesc *pdp; 4430 struct pwd *pwd; 4431 int error, i, lastfile, *name; 4432 struct file *fp; 4433 struct proc *p; 4434 4435 name = (int *)arg1; 4436 error = pget((pid_t)name[0], PGET_CANDEBUG | PGET_NOTWEXIT, &p); 4437 if (error != 0) 4438 return (error); 4439 fdp = fdhold(p); 4440 if (fdp != NULL) 4441 pdp = pdhold(p); 4442 PROC_UNLOCK(p); 4443 if (fdp == NULL || pdp == NULL) { 4444 if (fdp != NULL) 4445 fddrop(fdp); 4446 return (ENOENT); 4447 } 4448 kif = malloc(sizeof(*kif), M_TEMP, M_WAITOK); 4449 okif = malloc(sizeof(*okif), M_TEMP, M_WAITOK); 4450 PWDDESC_XLOCK(pdp); 4451 pwd = pwd_hold_pwddesc(pdp); 4452 if (pwd != NULL) { 4453 if (pwd->pwd_cdir != NULL) 4454 export_vnode_for_osysctl(pwd->pwd_cdir, KF_FD_TYPE_CWD, kif, 4455 okif, pdp, req); 4456 if (pwd->pwd_rdir != NULL) 4457 export_vnode_for_osysctl(pwd->pwd_rdir, KF_FD_TYPE_ROOT, kif, 4458 okif, pdp, req); 4459 if (pwd->pwd_jdir != NULL) 4460 export_vnode_for_osysctl(pwd->pwd_jdir, KF_FD_TYPE_JAIL, kif, 4461 okif, pdp, req); 4462 } 4463 PWDDESC_XUNLOCK(pdp); 4464 if (pwd != NULL) 4465 pwd_drop(pwd); 4466 FILEDESC_SLOCK(fdp); 4467 lastfile = fdlastfile(fdp); 4468 for (i = 0; refcount_load(&fdp->fd_refcnt) > 0 && i <= lastfile; i++) { 4469 if ((fp = fdp->fd_ofiles[i].fde_file) == NULL) 4470 continue; 4471 export_file_to_kinfo(fp, i, NULL, kif, fdp, 4472 KERN_FILEDESC_PACK_KINFO); 4473 FILEDESC_SUNLOCK(fdp); 4474 kinfo_to_okinfo(kif, okif); 4475 error = SYSCTL_OUT(req, okif, sizeof(*okif)); 4476 FILEDESC_SLOCK(fdp); 4477 if (error) 4478 break; 4479 } 4480 FILEDESC_SUNLOCK(fdp); 4481 fddrop(fdp); 4482 pddrop(pdp); 4483 free(kif, M_TEMP); 4484 free(okif, M_TEMP); 4485 return (0); 4486 } 4487 4488 static SYSCTL_NODE(_kern_proc, KERN_PROC_OFILEDESC, ofiledesc, 4489 CTLFLAG_RD|CTLFLAG_MPSAFE, sysctl_kern_proc_ofiledesc, 4490 "Process ofiledesc entries"); 4491 #endif /* COMPAT_FREEBSD7 */ 4492 4493 int 4494 vntype_to_kinfo(int vtype) 4495 { 4496 struct { 4497 int vtype; 4498 int kf_vtype; 4499 } vtypes_table[] = { 4500 { VBAD, KF_VTYPE_VBAD }, 4501 { VBLK, KF_VTYPE_VBLK }, 4502 { VCHR, KF_VTYPE_VCHR }, 4503 { VDIR, KF_VTYPE_VDIR }, 4504 { VFIFO, KF_VTYPE_VFIFO }, 4505 { VLNK, KF_VTYPE_VLNK }, 4506 { VNON, KF_VTYPE_VNON }, 4507 { VREG, KF_VTYPE_VREG }, 4508 { VSOCK, KF_VTYPE_VSOCK } 4509 }; 4510 unsigned int i; 4511 4512 /* 4513 * Perform vtype translation. 4514 */ 4515 for (i = 0; i < nitems(vtypes_table); i++) 4516 if (vtypes_table[i].vtype == vtype) 4517 return (vtypes_table[i].kf_vtype); 4518 4519 return (KF_VTYPE_UNKNOWN); 4520 } 4521 4522 static SYSCTL_NODE(_kern_proc, KERN_PROC_FILEDESC, filedesc, 4523 CTLFLAG_RD|CTLFLAG_MPSAFE, sysctl_kern_proc_filedesc, 4524 "Process filedesc entries"); 4525 4526 /* 4527 * Store a process current working directory information to sbuf. 4528 * 4529 * Takes a locked proc as argument, and returns with the proc unlocked. 4530 */ 4531 int 4532 kern_proc_cwd_out(struct proc *p, struct sbuf *sb, ssize_t maxlen) 4533 { 4534 struct pwddesc *pdp; 4535 struct pwd *pwd; 4536 struct export_fd_buf *efbuf; 4537 struct vnode *cdir; 4538 int error; 4539 4540 PROC_LOCK_ASSERT(p, MA_OWNED); 4541 4542 pdp = pdhold(p); 4543 PROC_UNLOCK(p); 4544 if (pdp == NULL) 4545 return (EINVAL); 4546 4547 efbuf = malloc(sizeof(*efbuf), M_TEMP, M_WAITOK); 4548 efbuf->pdp = pdp; 4549 efbuf->sb = sb; 4550 efbuf->remainder = maxlen; 4551 4552 PWDDESC_XLOCK(pdp); 4553 pwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); 4554 cdir = pwd->pwd_cdir; 4555 if (cdir == NULL) { 4556 error = EINVAL; 4557 } else { 4558 vrefact(cdir); 4559 error = export_vnode_to_sb(cdir, KF_FD_TYPE_CWD, FREAD, efbuf); 4560 } 4561 PWDDESC_XUNLOCK(pdp); 4562 pddrop(pdp); 4563 free(efbuf, M_TEMP); 4564 return (error); 4565 } 4566 4567 /* 4568 * Get per-process current working directory. 4569 */ 4570 static int 4571 sysctl_kern_proc_cwd(SYSCTL_HANDLER_ARGS) 4572 { 4573 struct sbuf sb; 4574 struct proc *p; 4575 ssize_t maxlen; 4576 int error, error2, *name; 4577 4578 name = (int *)arg1; 4579 4580 sbuf_new_for_sysctl(&sb, NULL, sizeof(struct kinfo_file), req); 4581 sbuf_clear_flags(&sb, SBUF_INCLUDENUL); 4582 error = pget((pid_t)name[0], PGET_CANDEBUG | PGET_NOTWEXIT, &p); 4583 if (error != 0) { 4584 sbuf_delete(&sb); 4585 return (error); 4586 } 4587 maxlen = req->oldptr != NULL ? req->oldlen : -1; 4588 error = kern_proc_cwd_out(p, &sb, maxlen); 4589 error2 = sbuf_finish(&sb); 4590 sbuf_delete(&sb); 4591 return (error != 0 ? error : error2); 4592 } 4593 4594 static SYSCTL_NODE(_kern_proc, KERN_PROC_CWD, cwd, CTLFLAG_RD|CTLFLAG_MPSAFE, 4595 sysctl_kern_proc_cwd, "Process current working directory"); 4596 4597 #ifdef DDB 4598 /* 4599 * For the purposes of debugging, generate a human-readable string for the 4600 * file type. 4601 */ 4602 static const char * 4603 file_type_to_name(short type) 4604 { 4605 4606 switch (type) { 4607 case 0: 4608 return ("zero"); 4609 case DTYPE_VNODE: 4610 return ("vnode"); 4611 case DTYPE_SOCKET: 4612 return ("socket"); 4613 case DTYPE_PIPE: 4614 return ("pipe"); 4615 case DTYPE_FIFO: 4616 return ("fifo"); 4617 case DTYPE_KQUEUE: 4618 return ("kqueue"); 4619 case DTYPE_CRYPTO: 4620 return ("crypto"); 4621 case DTYPE_MQUEUE: 4622 return ("mqueue"); 4623 case DTYPE_SHM: 4624 return ("shm"); 4625 case DTYPE_SEM: 4626 return ("ksem"); 4627 case DTYPE_PTS: 4628 return ("pts"); 4629 case DTYPE_DEV: 4630 return ("dev"); 4631 case DTYPE_PROCDESC: 4632 return ("proc"); 4633 case DTYPE_EVENTFD: 4634 return ("eventfd"); 4635 case DTYPE_LINUXTFD: 4636 return ("ltimer"); 4637 default: 4638 return ("unkn"); 4639 } 4640 } 4641 4642 /* 4643 * For the purposes of debugging, identify a process (if any, perhaps one of 4644 * many) that references the passed file in its file descriptor array. Return 4645 * NULL if none. 4646 */ 4647 static struct proc * 4648 file_to_first_proc(struct file *fp) 4649 { 4650 struct filedesc *fdp; 4651 struct proc *p; 4652 int n; 4653 4654 FOREACH_PROC_IN_SYSTEM(p) { 4655 if (p->p_state == PRS_NEW) 4656 continue; 4657 fdp = p->p_fd; 4658 if (fdp == NULL) 4659 continue; 4660 for (n = 0; n < fdp->fd_nfiles; n++) { 4661 if (fp == fdp->fd_ofiles[n].fde_file) 4662 return (p); 4663 } 4664 } 4665 return (NULL); 4666 } 4667 4668 static void 4669 db_print_file(struct file *fp, int header) 4670 { 4671 #define XPTRWIDTH ((int)howmany(sizeof(void *) * NBBY, 4)) 4672 struct proc *p; 4673 4674 if (header) 4675 db_printf("%*s %6s %*s %8s %4s %5s %6s %*s %5s %s\n", 4676 XPTRWIDTH, "File", "Type", XPTRWIDTH, "Data", "Flag", 4677 "GCFl", "Count", "MCount", XPTRWIDTH, "Vnode", "FPID", 4678 "FCmd"); 4679 p = file_to_first_proc(fp); 4680 db_printf("%*p %6s %*p %08x %04x %5d %6d %*p %5d %s\n", XPTRWIDTH, 4681 fp, file_type_to_name(fp->f_type), XPTRWIDTH, fp->f_data, 4682 fp->f_flag, 0, refcount_load(&fp->f_count), 0, XPTRWIDTH, fp->f_vnode, 4683 p != NULL ? p->p_pid : -1, p != NULL ? p->p_comm : "-"); 4684 4685 #undef XPTRWIDTH 4686 } 4687 4688 DB_SHOW_COMMAND(file, db_show_file) 4689 { 4690 struct file *fp; 4691 4692 if (!have_addr) { 4693 db_printf("usage: show file <addr>\n"); 4694 return; 4695 } 4696 fp = (struct file *)addr; 4697 db_print_file(fp, 1); 4698 } 4699 4700 DB_SHOW_COMMAND(files, db_show_files) 4701 { 4702 struct filedesc *fdp; 4703 struct file *fp; 4704 struct proc *p; 4705 int header; 4706 int n; 4707 4708 header = 1; 4709 FOREACH_PROC_IN_SYSTEM(p) { 4710 if (p->p_state == PRS_NEW) 4711 continue; 4712 if ((fdp = p->p_fd) == NULL) 4713 continue; 4714 for (n = 0; n < fdp->fd_nfiles; ++n) { 4715 if ((fp = fdp->fd_ofiles[n].fde_file) == NULL) 4716 continue; 4717 db_print_file(fp, header); 4718 header = 0; 4719 } 4720 } 4721 } 4722 #endif 4723 4724 SYSCTL_INT(_kern, KERN_MAXFILESPERPROC, maxfilesperproc, CTLFLAG_RW, 4725 &maxfilesperproc, 0, "Maximum files allowed open per process"); 4726 4727 SYSCTL_INT(_kern, KERN_MAXFILES, maxfiles, CTLFLAG_RW, 4728 &maxfiles, 0, "Maximum number of files"); 4729 4730 SYSCTL_INT(_kern, OID_AUTO, openfiles, CTLFLAG_RD, 4731 &openfiles, 0, "System-wide number of open files"); 4732 4733 /* ARGSUSED*/ 4734 static void 4735 filelistinit(void *dummy) 4736 { 4737 4738 file_zone = uma_zcreate("Files", sizeof(struct file), NULL, NULL, 4739 NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE); 4740 filedesc0_zone = uma_zcreate("filedesc0", sizeof(struct filedesc0), 4741 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0); 4742 pwd_zone = uma_zcreate("PWD", sizeof(struct pwd), NULL, NULL, 4743 NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_SMR); 4744 /* 4745 * XXXMJG this is a temporary hack due to boot ordering issues against 4746 * the vnode zone. 4747 */ 4748 vfs_smr = uma_zone_get_smr(pwd_zone); 4749 mtx_init(&sigio_lock, "sigio lock", NULL, MTX_DEF); 4750 } 4751 SYSINIT(select, SI_SUB_LOCK, SI_ORDER_FIRST, filelistinit, NULL); 4752 4753 /*-------------------------------------------------------------------*/ 4754 4755 static int 4756 badfo_readwrite(struct file *fp, struct uio *uio, struct ucred *active_cred, 4757 int flags, struct thread *td) 4758 { 4759 4760 return (EBADF); 4761 } 4762 4763 static int 4764 badfo_truncate(struct file *fp, off_t length, struct ucred *active_cred, 4765 struct thread *td) 4766 { 4767 4768 return (EINVAL); 4769 } 4770 4771 static int 4772 badfo_ioctl(struct file *fp, u_long com, void *data, struct ucred *active_cred, 4773 struct thread *td) 4774 { 4775 4776 return (EBADF); 4777 } 4778 4779 static int 4780 badfo_poll(struct file *fp, int events, struct ucred *active_cred, 4781 struct thread *td) 4782 { 4783 4784 return (0); 4785 } 4786 4787 static int 4788 badfo_kqfilter(struct file *fp, struct knote *kn) 4789 { 4790 4791 return (EBADF); 4792 } 4793 4794 static int 4795 badfo_stat(struct file *fp, struct stat *sb, struct ucred *active_cred, 4796 struct thread *td) 4797 { 4798 4799 return (EBADF); 4800 } 4801 4802 static int 4803 badfo_close(struct file *fp, struct thread *td) 4804 { 4805 4806 return (0); 4807 } 4808 4809 static int 4810 badfo_chmod(struct file *fp, mode_t mode, struct ucred *active_cred, 4811 struct thread *td) 4812 { 4813 4814 return (EBADF); 4815 } 4816 4817 static int 4818 badfo_chown(struct file *fp, uid_t uid, gid_t gid, struct ucred *active_cred, 4819 struct thread *td) 4820 { 4821 4822 return (EBADF); 4823 } 4824 4825 static int 4826 badfo_sendfile(struct file *fp, int sockfd, struct uio *hdr_uio, 4827 struct uio *trl_uio, off_t offset, size_t nbytes, off_t *sent, int flags, 4828 struct thread *td) 4829 { 4830 4831 return (EBADF); 4832 } 4833 4834 static int 4835 badfo_fill_kinfo(struct file *fp, struct kinfo_file *kif, struct filedesc *fdp) 4836 { 4837 4838 return (0); 4839 } 4840 4841 struct fileops badfileops = { 4842 .fo_read = badfo_readwrite, 4843 .fo_write = badfo_readwrite, 4844 .fo_truncate = badfo_truncate, 4845 .fo_ioctl = badfo_ioctl, 4846 .fo_poll = badfo_poll, 4847 .fo_kqfilter = badfo_kqfilter, 4848 .fo_stat = badfo_stat, 4849 .fo_close = badfo_close, 4850 .fo_chmod = badfo_chmod, 4851 .fo_chown = badfo_chown, 4852 .fo_sendfile = badfo_sendfile, 4853 .fo_fill_kinfo = badfo_fill_kinfo, 4854 }; 4855 4856 int 4857 invfo_rdwr(struct file *fp, struct uio *uio, struct ucred *active_cred, 4858 int flags, struct thread *td) 4859 { 4860 4861 return (EOPNOTSUPP); 4862 } 4863 4864 int 4865 invfo_truncate(struct file *fp, off_t length, struct ucred *active_cred, 4866 struct thread *td) 4867 { 4868 4869 return (EINVAL); 4870 } 4871 4872 int 4873 invfo_ioctl(struct file *fp, u_long com, void *data, 4874 struct ucred *active_cred, struct thread *td) 4875 { 4876 4877 return (ENOTTY); 4878 } 4879 4880 int 4881 invfo_poll(struct file *fp, int events, struct ucred *active_cred, 4882 struct thread *td) 4883 { 4884 4885 return (poll_no_poll(events)); 4886 } 4887 4888 int 4889 invfo_kqfilter(struct file *fp, struct knote *kn) 4890 { 4891 4892 return (EINVAL); 4893 } 4894 4895 int 4896 invfo_chmod(struct file *fp, mode_t mode, struct ucred *active_cred, 4897 struct thread *td) 4898 { 4899 4900 return (EINVAL); 4901 } 4902 4903 int 4904 invfo_chown(struct file *fp, uid_t uid, gid_t gid, struct ucred *active_cred, 4905 struct thread *td) 4906 { 4907 4908 return (EINVAL); 4909 } 4910 4911 int 4912 invfo_sendfile(struct file *fp, int sockfd, struct uio *hdr_uio, 4913 struct uio *trl_uio, off_t offset, size_t nbytes, off_t *sent, int flags, 4914 struct thread *td) 4915 { 4916 4917 return (EINVAL); 4918 } 4919 4920 /*-------------------------------------------------------------------*/ 4921 4922 /* 4923 * File Descriptor pseudo-device driver (/dev/fd/). 4924 * 4925 * Opening minor device N dup()s the file (if any) connected to file 4926 * descriptor N belonging to the calling process. Note that this driver 4927 * consists of only the ``open()'' routine, because all subsequent 4928 * references to this file will be direct to the other driver. 4929 * 4930 * XXX: we could give this one a cloning event handler if necessary. 4931 */ 4932 4933 /* ARGSUSED */ 4934 static int 4935 fdopen(struct cdev *dev, int mode, int type, struct thread *td) 4936 { 4937 4938 /* 4939 * XXX Kludge: set curthread->td_dupfd to contain the value of the 4940 * the file descriptor being sought for duplication. The error 4941 * return ensures that the vnode for this device will be released 4942 * by vn_open. Open will detect this special error and take the 4943 * actions in dupfdopen below. Other callers of vn_open or VOP_OPEN 4944 * will simply report the error. 4945 */ 4946 td->td_dupfd = dev2unit(dev); 4947 return (ENODEV); 4948 } 4949 4950 static struct cdevsw fildesc_cdevsw = { 4951 .d_version = D_VERSION, 4952 .d_open = fdopen, 4953 .d_name = "FD", 4954 }; 4955 4956 static void 4957 fildesc_drvinit(void *unused) 4958 { 4959 struct cdev *dev; 4960 4961 dev = make_dev_credf(MAKEDEV_ETERNAL, &fildesc_cdevsw, 0, NULL, 4962 UID_ROOT, GID_WHEEL, 0666, "fd/0"); 4963 make_dev_alias(dev, "stdin"); 4964 dev = make_dev_credf(MAKEDEV_ETERNAL, &fildesc_cdevsw, 1, NULL, 4965 UID_ROOT, GID_WHEEL, 0666, "fd/1"); 4966 make_dev_alias(dev, "stdout"); 4967 dev = make_dev_credf(MAKEDEV_ETERNAL, &fildesc_cdevsw, 2, NULL, 4968 UID_ROOT, GID_WHEEL, 0666, "fd/2"); 4969 make_dev_alias(dev, "stderr"); 4970 } 4971 4972 SYSINIT(fildescdev, SI_SUB_DRIVERS, SI_ORDER_MIDDLE, fildesc_drvinit, NULL); 4973