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 error = falloc_noinstall(td, &fp); 1980 if (error) 1981 return (error); /* no reference held on error */ 1982 1983 error = finstall(td, fp, &fd, flags, fcaps); 1984 if (error) { 1985 fdrop(fp, td); /* one reference (fp only) */ 1986 return (error); 1987 } 1988 1989 if (resultfp != NULL) 1990 *resultfp = fp; /* copy out result */ 1991 else 1992 fdrop(fp, td); /* release local reference */ 1993 1994 if (resultfd != NULL) 1995 *resultfd = fd; 1996 1997 return (0); 1998 } 1999 2000 /* 2001 * Create a new open file structure without allocating a file descriptor. 2002 */ 2003 int 2004 falloc_noinstall(struct thread *td, struct file **resultfp) 2005 { 2006 struct file *fp; 2007 int maxuserfiles = maxfiles - (maxfiles / 20); 2008 int openfiles_new; 2009 static struct timeval lastfail; 2010 static int curfail; 2011 2012 KASSERT(resultfp != NULL, ("%s: resultfp == NULL", __func__)); 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, 1); 2028 fp->f_cred = crhold(td->td_ucred); 2029 fp->f_ops = &badfileops; 2030 *resultfp = fp; 2031 return (0); 2032 } 2033 2034 /* 2035 * Install a file in a file descriptor table. 2036 */ 2037 void 2038 _finstall(struct filedesc *fdp, struct file *fp, int fd, int flags, 2039 struct filecaps *fcaps) 2040 { 2041 struct filedescent *fde; 2042 2043 MPASS(fp != NULL); 2044 if (fcaps != NULL) 2045 filecaps_validate(fcaps, __func__); 2046 FILEDESC_XLOCK_ASSERT(fdp); 2047 2048 fde = &fdp->fd_ofiles[fd]; 2049 #ifdef CAPABILITIES 2050 seqc_write_begin(&fde->fde_seqc); 2051 #endif 2052 fde->fde_file = fp; 2053 fde->fde_flags = (flags & O_CLOEXEC) != 0 ? UF_EXCLOSE : 0; 2054 if (fcaps != NULL) 2055 filecaps_move(fcaps, &fde->fde_caps); 2056 else 2057 filecaps_fill(&fde->fde_caps); 2058 #ifdef CAPABILITIES 2059 seqc_write_end(&fde->fde_seqc); 2060 #endif 2061 } 2062 2063 int 2064 finstall(struct thread *td, struct file *fp, int *fd, int flags, 2065 struct filecaps *fcaps) 2066 { 2067 struct filedesc *fdp = td->td_proc->p_fd; 2068 int error; 2069 2070 MPASS(fd != NULL); 2071 2072 if (!fhold(fp)) 2073 return (EBADF); 2074 FILEDESC_XLOCK(fdp); 2075 error = fdalloc(td, 0, fd); 2076 if (__predict_false(error != 0)) { 2077 FILEDESC_XUNLOCK(fdp); 2078 fdrop(fp, td); 2079 return (error); 2080 } 2081 _finstall(fdp, fp, *fd, flags, fcaps); 2082 FILEDESC_XUNLOCK(fdp); 2083 return (0); 2084 } 2085 2086 /* 2087 * Build a new filedesc structure from another. 2088 * 2089 * If fdp is not NULL, return with it shared locked. 2090 */ 2091 struct filedesc * 2092 fdinit(struct filedesc *fdp, bool prepfiles, int *lastfile) 2093 { 2094 struct filedesc0 *newfdp0; 2095 struct filedesc *newfdp; 2096 2097 if (prepfiles) 2098 MPASS(lastfile != NULL); 2099 else 2100 MPASS(lastfile == NULL); 2101 2102 newfdp0 = uma_zalloc(filedesc0_zone, M_WAITOK | M_ZERO); 2103 newfdp = &newfdp0->fd_fd; 2104 2105 /* Create the file descriptor table. */ 2106 FILEDESC_LOCK_INIT(newfdp); 2107 refcount_init(&newfdp->fd_refcnt, 1); 2108 refcount_init(&newfdp->fd_holdcnt, 1); 2109 newfdp->fd_map = newfdp0->fd_dmap; 2110 newfdp->fd_files = (struct fdescenttbl *)&newfdp0->fd_dfiles; 2111 newfdp->fd_files->fdt_nfiles = NDFILE; 2112 2113 if (fdp == NULL) 2114 return (newfdp); 2115 2116 FILEDESC_SLOCK(fdp); 2117 if (!prepfiles) { 2118 FILEDESC_SUNLOCK(fdp); 2119 return (newfdp); 2120 } 2121 2122 for (;;) { 2123 *lastfile = fdlastfile(fdp); 2124 if (*lastfile < newfdp->fd_nfiles) 2125 break; 2126 FILEDESC_SUNLOCK(fdp); 2127 fdgrowtable(newfdp, *lastfile + 1); 2128 FILEDESC_SLOCK(fdp); 2129 } 2130 2131 return (newfdp); 2132 } 2133 2134 /* 2135 * Build a pwddesc structure from another. 2136 * Copy the current, root, and jail root vnode references. 2137 * 2138 * If pdp is not NULL, return with it shared locked. 2139 */ 2140 struct pwddesc * 2141 pdinit(struct pwddesc *pdp, bool keeplock) 2142 { 2143 struct pwddesc *newpdp; 2144 struct pwd *newpwd; 2145 2146 newpdp = malloc(sizeof(*newpdp), M_PWDDESC, M_WAITOK | M_ZERO); 2147 2148 PWDDESC_LOCK_INIT(newpdp); 2149 refcount_init(&newpdp->pd_refcount, 1); 2150 newpdp->pd_cmask = CMASK; 2151 2152 if (pdp == NULL) { 2153 newpwd = pwd_alloc(); 2154 smr_serialized_store(&newpdp->pd_pwd, newpwd, true); 2155 return (newpdp); 2156 } 2157 2158 PWDDESC_XLOCK(pdp); 2159 newpwd = pwd_hold_pwddesc(pdp); 2160 smr_serialized_store(&newpdp->pd_pwd, newpwd, true); 2161 if (!keeplock) 2162 PWDDESC_XUNLOCK(pdp); 2163 return (newpdp); 2164 } 2165 2166 static struct filedesc * 2167 fdhold(struct proc *p) 2168 { 2169 struct filedesc *fdp; 2170 2171 PROC_LOCK_ASSERT(p, MA_OWNED); 2172 fdp = p->p_fd; 2173 if (fdp != NULL) 2174 refcount_acquire(&fdp->fd_holdcnt); 2175 return (fdp); 2176 } 2177 2178 static struct pwddesc * 2179 pdhold(struct proc *p) 2180 { 2181 struct pwddesc *pdp; 2182 2183 PROC_LOCK_ASSERT(p, MA_OWNED); 2184 pdp = p->p_pd; 2185 if (pdp != NULL) 2186 refcount_acquire(&pdp->pd_refcount); 2187 return (pdp); 2188 } 2189 2190 static void 2191 fddrop(struct filedesc *fdp) 2192 { 2193 2194 if (refcount_load(&fdp->fd_holdcnt) > 1) { 2195 if (refcount_release(&fdp->fd_holdcnt) == 0) 2196 return; 2197 } 2198 2199 FILEDESC_LOCK_DESTROY(fdp); 2200 uma_zfree(filedesc0_zone, fdp); 2201 } 2202 2203 static void 2204 pddrop(struct pwddesc *pdp) 2205 { 2206 struct pwd *pwd; 2207 2208 if (refcount_release_if_not_last(&pdp->pd_refcount)) 2209 return; 2210 2211 PWDDESC_XLOCK(pdp); 2212 if (refcount_release(&pdp->pd_refcount) == 0) { 2213 PWDDESC_XUNLOCK(pdp); 2214 return; 2215 } 2216 pwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); 2217 pwd_set(pdp, NULL); 2218 PWDDESC_XUNLOCK(pdp); 2219 pwd_drop(pwd); 2220 2221 PWDDESC_LOCK_DESTROY(pdp); 2222 free(pdp, M_PWDDESC); 2223 } 2224 2225 /* 2226 * Share a filedesc structure. 2227 */ 2228 struct filedesc * 2229 fdshare(struct filedesc *fdp) 2230 { 2231 2232 refcount_acquire(&fdp->fd_refcnt); 2233 return (fdp); 2234 } 2235 2236 /* 2237 * Share a pwddesc structure. 2238 */ 2239 struct pwddesc * 2240 pdshare(struct pwddesc *pdp) 2241 { 2242 refcount_acquire(&pdp->pd_refcount); 2243 return (pdp); 2244 } 2245 2246 /* 2247 * Unshare a filedesc structure, if necessary by making a copy 2248 */ 2249 void 2250 fdunshare(struct thread *td) 2251 { 2252 struct filedesc *tmp; 2253 struct proc *p = td->td_proc; 2254 2255 if (refcount_load(&p->p_fd->fd_refcnt) == 1) 2256 return; 2257 2258 tmp = fdcopy(p->p_fd); 2259 fdescfree(td); 2260 p->p_fd = tmp; 2261 } 2262 2263 /* 2264 * Unshare a pwddesc structure. 2265 */ 2266 void 2267 pdunshare(struct thread *td) 2268 { 2269 struct pwddesc *pdp; 2270 struct proc *p; 2271 2272 p = td->td_proc; 2273 /* Not shared. */ 2274 if (p->p_pd->pd_refcount == 1) 2275 return; 2276 2277 pdp = pdcopy(p->p_pd); 2278 pdescfree(td); 2279 p->p_pd = pdp; 2280 } 2281 2282 void 2283 fdinstall_remapped(struct thread *td, struct filedesc *fdp) 2284 { 2285 2286 fdescfree(td); 2287 td->td_proc->p_fd = fdp; 2288 } 2289 2290 /* 2291 * Copy a filedesc structure. A NULL pointer in returns a NULL reference, 2292 * this is to ease callers, not catch errors. 2293 */ 2294 struct filedesc * 2295 fdcopy(struct filedesc *fdp) 2296 { 2297 struct filedesc *newfdp; 2298 struct filedescent *nfde, *ofde; 2299 int i, lastfile; 2300 2301 MPASS(fdp != NULL); 2302 2303 newfdp = fdinit(fdp, true, &lastfile); 2304 /* copy all passable descriptors (i.e. not kqueue) */ 2305 newfdp->fd_freefile = -1; 2306 for (i = 0; i <= lastfile; ++i) { 2307 ofde = &fdp->fd_ofiles[i]; 2308 if (ofde->fde_file == NULL || 2309 (ofde->fde_file->f_ops->fo_flags & DFLAG_PASSABLE) == 0 || 2310 !fhold(ofde->fde_file)) { 2311 if (newfdp->fd_freefile == -1) 2312 newfdp->fd_freefile = i; 2313 continue; 2314 } 2315 nfde = &newfdp->fd_ofiles[i]; 2316 *nfde = *ofde; 2317 filecaps_copy(&ofde->fde_caps, &nfde->fde_caps, true); 2318 fdused_init(newfdp, i); 2319 } 2320 if (newfdp->fd_freefile == -1) 2321 newfdp->fd_freefile = i; 2322 FILEDESC_SUNLOCK(fdp); 2323 return (newfdp); 2324 } 2325 2326 /* 2327 * Copy a pwddesc structure. 2328 */ 2329 struct pwddesc * 2330 pdcopy(struct pwddesc *pdp) 2331 { 2332 struct pwddesc *newpdp; 2333 2334 MPASS(pdp != NULL); 2335 2336 newpdp = pdinit(pdp, true); 2337 newpdp->pd_cmask = pdp->pd_cmask; 2338 PWDDESC_XUNLOCK(pdp); 2339 return (newpdp); 2340 } 2341 2342 /* 2343 * Copies a filedesc structure, while remapping all file descriptors 2344 * stored inside using a translation table. 2345 * 2346 * File descriptors are copied over to the new file descriptor table, 2347 * regardless of whether the close-on-exec flag is set. 2348 */ 2349 int 2350 fdcopy_remapped(struct filedesc *fdp, const int *fds, size_t nfds, 2351 struct filedesc **ret) 2352 { 2353 struct filedesc *newfdp; 2354 struct filedescent *nfde, *ofde; 2355 int error, i, lastfile; 2356 2357 MPASS(fdp != NULL); 2358 2359 newfdp = fdinit(fdp, true, &lastfile); 2360 if (nfds > lastfile + 1) { 2361 /* New table cannot be larger than the old one. */ 2362 error = E2BIG; 2363 goto bad; 2364 } 2365 /* Copy all passable descriptors (i.e. not kqueue). */ 2366 newfdp->fd_freefile = nfds; 2367 for (i = 0; i < nfds; ++i) { 2368 if (fds[i] < 0 || fds[i] > lastfile) { 2369 /* File descriptor out of bounds. */ 2370 error = EBADF; 2371 goto bad; 2372 } 2373 ofde = &fdp->fd_ofiles[fds[i]]; 2374 if (ofde->fde_file == NULL) { 2375 /* Unused file descriptor. */ 2376 error = EBADF; 2377 goto bad; 2378 } 2379 if ((ofde->fde_file->f_ops->fo_flags & DFLAG_PASSABLE) == 0) { 2380 /* File descriptor cannot be passed. */ 2381 error = EINVAL; 2382 goto bad; 2383 } 2384 if (!fhold(ofde->fde_file)) { 2385 error = EBADF; 2386 goto bad; 2387 } 2388 nfde = &newfdp->fd_ofiles[i]; 2389 *nfde = *ofde; 2390 filecaps_copy(&ofde->fde_caps, &nfde->fde_caps, true); 2391 fdused_init(newfdp, i); 2392 } 2393 FILEDESC_SUNLOCK(fdp); 2394 *ret = newfdp; 2395 return (0); 2396 bad: 2397 FILEDESC_SUNLOCK(fdp); 2398 fdescfree_remapped(newfdp); 2399 return (error); 2400 } 2401 2402 /* 2403 * Clear POSIX style locks. This is only used when fdp looses a reference (i.e. 2404 * one of processes using it exits) and the table used to be shared. 2405 */ 2406 static void 2407 fdclearlocks(struct thread *td) 2408 { 2409 struct filedesc *fdp; 2410 struct filedesc_to_leader *fdtol; 2411 struct flock lf; 2412 struct file *fp; 2413 struct proc *p; 2414 struct vnode *vp; 2415 int i, lastfile; 2416 2417 p = td->td_proc; 2418 fdp = p->p_fd; 2419 fdtol = p->p_fdtol; 2420 MPASS(fdtol != NULL); 2421 2422 FILEDESC_XLOCK(fdp); 2423 KASSERT(fdtol->fdl_refcount > 0, 2424 ("filedesc_to_refcount botch: fdl_refcount=%d", 2425 fdtol->fdl_refcount)); 2426 if (fdtol->fdl_refcount == 1 && 2427 (p->p_leader->p_flag & P_ADVLOCK) != 0) { 2428 lastfile = fdlastfile(fdp); 2429 for (i = 0; i <= lastfile; i++) { 2430 fp = fdp->fd_ofiles[i].fde_file; 2431 if (fp == NULL || fp->f_type != DTYPE_VNODE || 2432 !fhold(fp)) 2433 continue; 2434 FILEDESC_XUNLOCK(fdp); 2435 lf.l_whence = SEEK_SET; 2436 lf.l_start = 0; 2437 lf.l_len = 0; 2438 lf.l_type = F_UNLCK; 2439 vp = fp->f_vnode; 2440 (void) VOP_ADVLOCK(vp, 2441 (caddr_t)p->p_leader, F_UNLCK, 2442 &lf, F_POSIX); 2443 FILEDESC_XLOCK(fdp); 2444 fdrop(fp, td); 2445 } 2446 } 2447 retry: 2448 if (fdtol->fdl_refcount == 1) { 2449 if (fdp->fd_holdleaderscount > 0 && 2450 (p->p_leader->p_flag & P_ADVLOCK) != 0) { 2451 /* 2452 * close() or kern_dup() has cleared a reference 2453 * in a shared file descriptor table. 2454 */ 2455 fdp->fd_holdleaderswakeup = 1; 2456 sx_sleep(&fdp->fd_holdleaderscount, 2457 FILEDESC_LOCK(fdp), PLOCK, "fdlhold", 0); 2458 goto retry; 2459 } 2460 if (fdtol->fdl_holdcount > 0) { 2461 /* 2462 * Ensure that fdtol->fdl_leader remains 2463 * valid in closef(). 2464 */ 2465 fdtol->fdl_wakeup = 1; 2466 sx_sleep(fdtol, FILEDESC_LOCK(fdp), PLOCK, 2467 "fdlhold", 0); 2468 goto retry; 2469 } 2470 } 2471 fdtol->fdl_refcount--; 2472 if (fdtol->fdl_refcount == 0 && 2473 fdtol->fdl_holdcount == 0) { 2474 fdtol->fdl_next->fdl_prev = fdtol->fdl_prev; 2475 fdtol->fdl_prev->fdl_next = fdtol->fdl_next; 2476 } else 2477 fdtol = NULL; 2478 p->p_fdtol = NULL; 2479 FILEDESC_XUNLOCK(fdp); 2480 if (fdtol != NULL) 2481 free(fdtol, M_FILEDESC_TO_LEADER); 2482 } 2483 2484 /* 2485 * Release a filedesc structure. 2486 */ 2487 static void 2488 fdescfree_fds(struct thread *td, struct filedesc *fdp, bool needclose) 2489 { 2490 struct filedesc0 *fdp0; 2491 struct freetable *ft, *tft; 2492 struct filedescent *fde; 2493 struct file *fp; 2494 int i, lastfile; 2495 2496 KASSERT(refcount_load(&fdp->fd_refcnt) == 0, 2497 ("%s: fd table %p carries references", __func__, fdp)); 2498 2499 /* 2500 * Serialize with threads iterating over the table, if any. 2501 */ 2502 if (refcount_load(&fdp->fd_holdcnt) > 1) { 2503 FILEDESC_XLOCK(fdp); 2504 FILEDESC_XUNLOCK(fdp); 2505 } 2506 2507 lastfile = fdlastfile_single(fdp); 2508 for (i = 0; i <= lastfile; i++) { 2509 fde = &fdp->fd_ofiles[i]; 2510 fp = fde->fde_file; 2511 if (fp != NULL) { 2512 fdefree_last(fde); 2513 if (needclose) 2514 (void) closef(fp, td); 2515 else 2516 fdrop(fp, td); 2517 } 2518 } 2519 2520 if (NDSLOTS(fdp->fd_nfiles) > NDSLOTS(NDFILE)) 2521 free(fdp->fd_map, M_FILEDESC); 2522 if (fdp->fd_nfiles > NDFILE) 2523 free(fdp->fd_files, M_FILEDESC); 2524 2525 fdp0 = (struct filedesc0 *)fdp; 2526 SLIST_FOREACH_SAFE(ft, &fdp0->fd_free, ft_next, tft) 2527 free(ft->ft_table, M_FILEDESC); 2528 2529 fddrop(fdp); 2530 } 2531 2532 void 2533 fdescfree(struct thread *td) 2534 { 2535 struct proc *p; 2536 struct filedesc *fdp; 2537 2538 p = td->td_proc; 2539 fdp = p->p_fd; 2540 MPASS(fdp != NULL); 2541 2542 #ifdef RACCT 2543 if (RACCT_ENABLED()) 2544 racct_set_unlocked(p, RACCT_NOFILE, 0); 2545 #endif 2546 2547 if (p->p_fdtol != NULL) 2548 fdclearlocks(td); 2549 2550 PROC_LOCK(p); 2551 p->p_fd = NULL; 2552 PROC_UNLOCK(p); 2553 2554 if (refcount_release(&fdp->fd_refcnt) == 0) 2555 return; 2556 2557 fdescfree_fds(td, fdp, 1); 2558 } 2559 2560 void 2561 pdescfree(struct thread *td) 2562 { 2563 struct proc *p; 2564 struct pwddesc *pdp; 2565 2566 p = td->td_proc; 2567 pdp = p->p_pd; 2568 MPASS(pdp != NULL); 2569 2570 PROC_LOCK(p); 2571 p->p_pd = NULL; 2572 PROC_UNLOCK(p); 2573 2574 pddrop(pdp); 2575 } 2576 2577 void 2578 fdescfree_remapped(struct filedesc *fdp) 2579 { 2580 #ifdef INVARIANTS 2581 /* fdescfree_fds() asserts that fd_refcnt == 0. */ 2582 if (!refcount_release(&fdp->fd_refcnt)) 2583 panic("%s: fd table %p has extra references", __func__, fdp); 2584 #endif 2585 fdescfree_fds(curthread, fdp, 0); 2586 } 2587 2588 /* 2589 * For setugid programs, we don't want to people to use that setugidness 2590 * to generate error messages which write to a file which otherwise would 2591 * otherwise be off-limits to the process. We check for filesystems where 2592 * the vnode can change out from under us after execve (like [lin]procfs). 2593 * 2594 * Since fdsetugidsafety calls this only for fd 0, 1 and 2, this check is 2595 * sufficient. We also don't check for setugidness since we know we are. 2596 */ 2597 static bool 2598 is_unsafe(struct file *fp) 2599 { 2600 struct vnode *vp; 2601 2602 if (fp->f_type != DTYPE_VNODE) 2603 return (false); 2604 2605 vp = fp->f_vnode; 2606 return ((vp->v_vflag & VV_PROCDEP) != 0); 2607 } 2608 2609 /* 2610 * Make this setguid thing safe, if at all possible. 2611 */ 2612 void 2613 fdsetugidsafety(struct thread *td) 2614 { 2615 struct filedesc *fdp; 2616 struct file *fp; 2617 int i; 2618 2619 fdp = td->td_proc->p_fd; 2620 KASSERT(refcount_load(&fdp->fd_refcnt) == 1, 2621 ("the fdtable should not be shared")); 2622 MPASS(fdp->fd_nfiles >= 3); 2623 for (i = 0; i <= 2; i++) { 2624 fp = fdp->fd_ofiles[i].fde_file; 2625 if (fp != NULL && is_unsafe(fp)) { 2626 FILEDESC_XLOCK(fdp); 2627 knote_fdclose(td, i); 2628 /* 2629 * NULL-out descriptor prior to close to avoid 2630 * a race while close blocks. 2631 */ 2632 fdfree(fdp, i); 2633 FILEDESC_XUNLOCK(fdp); 2634 (void) closef(fp, td); 2635 } 2636 } 2637 } 2638 2639 /* 2640 * If a specific file object occupies a specific file descriptor, close the 2641 * file descriptor entry and drop a reference on the file object. This is a 2642 * convenience function to handle a subsequent error in a function that calls 2643 * falloc() that handles the race that another thread might have closed the 2644 * file descriptor out from under the thread creating the file object. 2645 */ 2646 void 2647 fdclose(struct thread *td, struct file *fp, int idx) 2648 { 2649 struct filedesc *fdp = td->td_proc->p_fd; 2650 2651 FILEDESC_XLOCK(fdp); 2652 if (fdp->fd_ofiles[idx].fde_file == fp) { 2653 fdfree(fdp, idx); 2654 FILEDESC_XUNLOCK(fdp); 2655 fdrop(fp, td); 2656 } else 2657 FILEDESC_XUNLOCK(fdp); 2658 } 2659 2660 /* 2661 * Close any files on exec? 2662 */ 2663 void 2664 fdcloseexec(struct thread *td) 2665 { 2666 struct filedesc *fdp; 2667 struct filedescent *fde; 2668 struct file *fp; 2669 int i, lastfile; 2670 2671 fdp = td->td_proc->p_fd; 2672 KASSERT(refcount_load(&fdp->fd_refcnt) == 1, 2673 ("the fdtable should not be shared")); 2674 lastfile = fdlastfile_single(fdp); 2675 for (i = 0; i <= lastfile; i++) { 2676 fde = &fdp->fd_ofiles[i]; 2677 fp = fde->fde_file; 2678 if (fp != NULL && (fp->f_type == DTYPE_MQUEUE || 2679 (fde->fde_flags & UF_EXCLOSE))) { 2680 FILEDESC_XLOCK(fdp); 2681 fdfree(fdp, i); 2682 (void) closefp(fdp, i, fp, td, false, false); 2683 FILEDESC_UNLOCK_ASSERT(fdp); 2684 } 2685 } 2686 } 2687 2688 /* 2689 * It is unsafe for set[ug]id processes to be started with file 2690 * descriptors 0..2 closed, as these descriptors are given implicit 2691 * significance in the Standard C library. fdcheckstd() will create a 2692 * descriptor referencing /dev/null for each of stdin, stdout, and 2693 * stderr that is not already open. 2694 */ 2695 int 2696 fdcheckstd(struct thread *td) 2697 { 2698 struct filedesc *fdp; 2699 register_t save; 2700 int i, error, devnull; 2701 2702 fdp = td->td_proc->p_fd; 2703 KASSERT(refcount_load(&fdp->fd_refcnt) == 1, 2704 ("the fdtable should not be shared")); 2705 MPASS(fdp->fd_nfiles >= 3); 2706 devnull = -1; 2707 for (i = 0; i <= 2; i++) { 2708 if (fdp->fd_ofiles[i].fde_file != NULL) 2709 continue; 2710 2711 save = td->td_retval[0]; 2712 if (devnull != -1) { 2713 error = kern_dup(td, FDDUP_FIXED, 0, devnull, i); 2714 } else { 2715 error = kern_openat(td, AT_FDCWD, "/dev/null", 2716 UIO_SYSSPACE, O_RDWR, 0); 2717 if (error == 0) { 2718 devnull = td->td_retval[0]; 2719 KASSERT(devnull == i, ("we didn't get our fd")); 2720 } 2721 } 2722 td->td_retval[0] = save; 2723 if (error != 0) 2724 return (error); 2725 } 2726 return (0); 2727 } 2728 2729 /* 2730 * Internal form of close. Decrement reference count on file structure. 2731 * Note: td may be NULL when closing a file that was being passed in a 2732 * message. 2733 */ 2734 int 2735 closef(struct file *fp, struct thread *td) 2736 { 2737 struct vnode *vp; 2738 struct flock lf; 2739 struct filedesc_to_leader *fdtol; 2740 struct filedesc *fdp; 2741 2742 /* 2743 * POSIX record locking dictates that any close releases ALL 2744 * locks owned by this process. This is handled by setting 2745 * a flag in the unlock to free ONLY locks obeying POSIX 2746 * semantics, and not to free BSD-style file locks. 2747 * If the descriptor was in a message, POSIX-style locks 2748 * aren't passed with the descriptor, and the thread pointer 2749 * will be NULL. Callers should be careful only to pass a 2750 * NULL thread pointer when there really is no owning 2751 * context that might have locks, or the locks will be 2752 * leaked. 2753 */ 2754 if (fp->f_type == DTYPE_VNODE && td != NULL) { 2755 vp = fp->f_vnode; 2756 if ((td->td_proc->p_leader->p_flag & P_ADVLOCK) != 0) { 2757 lf.l_whence = SEEK_SET; 2758 lf.l_start = 0; 2759 lf.l_len = 0; 2760 lf.l_type = F_UNLCK; 2761 (void) VOP_ADVLOCK(vp, (caddr_t)td->td_proc->p_leader, 2762 F_UNLCK, &lf, F_POSIX); 2763 } 2764 fdtol = td->td_proc->p_fdtol; 2765 if (fdtol != NULL) { 2766 /* 2767 * Handle special case where file descriptor table is 2768 * shared between multiple process leaders. 2769 */ 2770 fdp = td->td_proc->p_fd; 2771 FILEDESC_XLOCK(fdp); 2772 for (fdtol = fdtol->fdl_next; 2773 fdtol != td->td_proc->p_fdtol; 2774 fdtol = fdtol->fdl_next) { 2775 if ((fdtol->fdl_leader->p_flag & 2776 P_ADVLOCK) == 0) 2777 continue; 2778 fdtol->fdl_holdcount++; 2779 FILEDESC_XUNLOCK(fdp); 2780 lf.l_whence = SEEK_SET; 2781 lf.l_start = 0; 2782 lf.l_len = 0; 2783 lf.l_type = F_UNLCK; 2784 vp = fp->f_vnode; 2785 (void) VOP_ADVLOCK(vp, 2786 (caddr_t)fdtol->fdl_leader, F_UNLCK, &lf, 2787 F_POSIX); 2788 FILEDESC_XLOCK(fdp); 2789 fdtol->fdl_holdcount--; 2790 if (fdtol->fdl_holdcount == 0 && 2791 fdtol->fdl_wakeup != 0) { 2792 fdtol->fdl_wakeup = 0; 2793 wakeup(fdtol); 2794 } 2795 } 2796 FILEDESC_XUNLOCK(fdp); 2797 } 2798 } 2799 return (fdrop_close(fp, td)); 2800 } 2801 2802 /* 2803 * Initialize the file pointer with the specified properties. 2804 * 2805 * The ops are set with release semantics to be certain that the flags, type, 2806 * and data are visible when ops is. This is to prevent ops methods from being 2807 * called with bad data. 2808 */ 2809 void 2810 finit(struct file *fp, u_int flag, short type, void *data, struct fileops *ops) 2811 { 2812 fp->f_data = data; 2813 fp->f_flag = flag; 2814 fp->f_type = type; 2815 atomic_store_rel_ptr((volatile uintptr_t *)&fp->f_ops, (uintptr_t)ops); 2816 } 2817 2818 void 2819 finit_vnode(struct file *fp, u_int flag, void *data, struct fileops *ops) 2820 { 2821 fp->f_seqcount[UIO_READ] = 1; 2822 fp->f_seqcount[UIO_WRITE] = 1; 2823 finit(fp, (flag & FMASK) | (fp->f_flag & FHASLOCK), DTYPE_VNODE, 2824 data, ops); 2825 } 2826 2827 int 2828 fget_cap_locked(struct filedesc *fdp, int fd, cap_rights_t *needrightsp, 2829 struct file **fpp, struct filecaps *havecapsp) 2830 { 2831 struct filedescent *fde; 2832 int error; 2833 2834 FILEDESC_LOCK_ASSERT(fdp); 2835 2836 fde = fdeget_locked(fdp, fd); 2837 if (fde == NULL) { 2838 error = EBADF; 2839 goto out; 2840 } 2841 2842 #ifdef CAPABILITIES 2843 error = cap_check(cap_rights_fde_inline(fde), needrightsp); 2844 if (error != 0) 2845 goto out; 2846 #endif 2847 2848 if (havecapsp != NULL) 2849 filecaps_copy(&fde->fde_caps, havecapsp, true); 2850 2851 *fpp = fde->fde_file; 2852 2853 error = 0; 2854 out: 2855 return (error); 2856 } 2857 2858 int 2859 fget_cap(struct thread *td, int fd, cap_rights_t *needrightsp, 2860 struct file **fpp, struct filecaps *havecapsp) 2861 { 2862 struct filedesc *fdp = td->td_proc->p_fd; 2863 int error; 2864 #ifndef CAPABILITIES 2865 error = fget_unlocked(fdp, fd, needrightsp, fpp); 2866 if (havecapsp != NULL && error == 0) 2867 filecaps_fill(havecapsp); 2868 #else 2869 struct file *fp; 2870 seqc_t seq; 2871 2872 *fpp = NULL; 2873 for (;;) { 2874 error = fget_unlocked_seq(fdp, fd, needrightsp, &fp, &seq); 2875 if (error != 0) 2876 return (error); 2877 2878 if (havecapsp != NULL) { 2879 if (!filecaps_copy(&fdp->fd_ofiles[fd].fde_caps, 2880 havecapsp, false)) { 2881 fdrop(fp, td); 2882 goto get_locked; 2883 } 2884 } 2885 2886 if (!fd_modified(fdp, fd, seq)) 2887 break; 2888 fdrop(fp, td); 2889 } 2890 2891 *fpp = fp; 2892 return (0); 2893 2894 get_locked: 2895 FILEDESC_SLOCK(fdp); 2896 error = fget_cap_locked(fdp, fd, needrightsp, fpp, havecapsp); 2897 if (error == 0 && !fhold(*fpp)) 2898 error = EBADF; 2899 FILEDESC_SUNLOCK(fdp); 2900 #endif 2901 return (error); 2902 } 2903 2904 #ifdef CAPABILITIES 2905 int 2906 fgetvp_lookup_smr(int fd, struct nameidata *ndp, struct vnode **vpp, bool *fsearch) 2907 { 2908 const struct filedescent *fde; 2909 const struct fdescenttbl *fdt; 2910 struct filedesc *fdp; 2911 struct file *fp; 2912 struct vnode *vp; 2913 const cap_rights_t *haverights; 2914 cap_rights_t rights; 2915 seqc_t seq; 2916 2917 VFS_SMR_ASSERT_ENTERED(); 2918 2919 rights = *ndp->ni_rightsneeded; 2920 cap_rights_set_one(&rights, CAP_LOOKUP); 2921 2922 fdp = curproc->p_fd; 2923 fdt = fdp->fd_files; 2924 if (__predict_false((u_int)fd >= fdt->fdt_nfiles)) 2925 return (EBADF); 2926 seq = seqc_read_any(fd_seqc(fdt, fd)); 2927 if (__predict_false(seqc_in_modify(seq))) 2928 return (EAGAIN); 2929 fde = &fdt->fdt_ofiles[fd]; 2930 haverights = cap_rights_fde_inline(fde); 2931 fp = fde->fde_file; 2932 if (__predict_false(fp == NULL)) 2933 return (EAGAIN); 2934 if (__predict_false(cap_check_inline_transient(haverights, &rights))) 2935 return (EAGAIN); 2936 *fsearch = ((fp->f_flag & FSEARCH) != 0); 2937 vp = fp->f_vnode; 2938 if (__predict_false(vp == NULL || vp->v_type != VDIR)) { 2939 return (EAGAIN); 2940 } 2941 if (!filecaps_copy(&fde->fde_caps, &ndp->ni_filecaps, false)) { 2942 return (EAGAIN); 2943 } 2944 /* 2945 * Use an acquire barrier to force re-reading of fdt so it is 2946 * refreshed for verification. 2947 */ 2948 atomic_thread_fence_acq(); 2949 fdt = fdp->fd_files; 2950 if (__predict_false(!seqc_consistent_nomb(fd_seqc(fdt, fd), seq))) 2951 return (EAGAIN); 2952 /* 2953 * If file descriptor doesn't have all rights, 2954 * all lookups relative to it must also be 2955 * strictly relative. 2956 * 2957 * Not yet supported by fast path. 2958 */ 2959 CAP_ALL(&rights); 2960 if (!cap_rights_contains(&ndp->ni_filecaps.fc_rights, &rights) || 2961 ndp->ni_filecaps.fc_fcntls != CAP_FCNTL_ALL || 2962 ndp->ni_filecaps.fc_nioctls != -1) { 2963 #ifdef notyet 2964 ndp->ni_lcf |= NI_LCF_STRICTRELATIVE; 2965 #else 2966 return (EAGAIN); 2967 #endif 2968 } 2969 *vpp = vp; 2970 return (0); 2971 } 2972 #else 2973 int 2974 fgetvp_lookup_smr(int fd, struct nameidata *ndp, struct vnode **vpp, bool *fsearch) 2975 { 2976 const struct fdescenttbl *fdt; 2977 struct filedesc *fdp; 2978 struct file *fp; 2979 struct vnode *vp; 2980 2981 VFS_SMR_ASSERT_ENTERED(); 2982 2983 fdp = curproc->p_fd; 2984 fdt = fdp->fd_files; 2985 if (__predict_false((u_int)fd >= fdt->fdt_nfiles)) 2986 return (EBADF); 2987 fp = fdt->fdt_ofiles[fd].fde_file; 2988 if (__predict_false(fp == NULL)) 2989 return (EAGAIN); 2990 *fsearch = ((fp->f_flag & FSEARCH) != 0); 2991 vp = fp->f_vnode; 2992 if (__predict_false(vp == NULL || vp->v_type != VDIR)) { 2993 return (EAGAIN); 2994 } 2995 /* 2996 * Use an acquire barrier to force re-reading of fdt so it is 2997 * refreshed for verification. 2998 */ 2999 atomic_thread_fence_acq(); 3000 fdt = fdp->fd_files; 3001 if (__predict_false(fp != fdt->fdt_ofiles[fd].fde_file)) 3002 return (EAGAIN); 3003 filecaps_fill(&ndp->ni_filecaps); 3004 *vpp = vp; 3005 return (0); 3006 } 3007 #endif 3008 3009 int 3010 fget_unlocked_seq(struct filedesc *fdp, int fd, cap_rights_t *needrightsp, 3011 struct file **fpp, seqc_t *seqp) 3012 { 3013 #ifdef CAPABILITIES 3014 const struct filedescent *fde; 3015 #endif 3016 const struct fdescenttbl *fdt; 3017 struct file *fp; 3018 #ifdef CAPABILITIES 3019 seqc_t seq; 3020 cap_rights_t haverights; 3021 int error; 3022 #endif 3023 3024 fdt = fdp->fd_files; 3025 if (__predict_false((u_int)fd >= fdt->fdt_nfiles)) 3026 return (EBADF); 3027 /* 3028 * Fetch the descriptor locklessly. We avoid fdrop() races by 3029 * never raising a refcount above 0. To accomplish this we have 3030 * to use a cmpset loop rather than an atomic_add. The descriptor 3031 * must be re-verified once we acquire a reference to be certain 3032 * that the identity is still correct and we did not lose a race 3033 * due to preemption. 3034 */ 3035 for (;;) { 3036 #ifdef CAPABILITIES 3037 seq = seqc_read(fd_seqc(fdt, fd)); 3038 fde = &fdt->fdt_ofiles[fd]; 3039 haverights = *cap_rights_fde_inline(fde); 3040 fp = fde->fde_file; 3041 if (!seqc_consistent(fd_seqc(fdt, fd), seq)) 3042 continue; 3043 #else 3044 fp = fdt->fdt_ofiles[fd].fde_file; 3045 #endif 3046 if (fp == NULL) 3047 return (EBADF); 3048 #ifdef CAPABILITIES 3049 error = cap_check_inline(&haverights, needrightsp); 3050 if (error != 0) 3051 return (error); 3052 #endif 3053 if (__predict_false(!refcount_acquire_if_not_zero(&fp->f_count))) { 3054 /* 3055 * Force a reload. Other thread could reallocate the 3056 * table before this fd was closed, so it is possible 3057 * that there is a stale fp pointer in cached version. 3058 */ 3059 fdt = atomic_load_ptr(&fdp->fd_files); 3060 continue; 3061 } 3062 /* 3063 * Use an acquire barrier to force re-reading of fdt so it is 3064 * refreshed for verification. 3065 */ 3066 atomic_thread_fence_acq(); 3067 fdt = fdp->fd_files; 3068 #ifdef CAPABILITIES 3069 if (seqc_consistent_nomb(fd_seqc(fdt, fd), seq)) 3070 #else 3071 if (fp == fdt->fdt_ofiles[fd].fde_file) 3072 #endif 3073 break; 3074 fdrop(fp, curthread); 3075 } 3076 *fpp = fp; 3077 if (seqp != NULL) { 3078 #ifdef CAPABILITIES 3079 *seqp = seq; 3080 #endif 3081 } 3082 return (0); 3083 } 3084 3085 /* 3086 * See the comments in fget_unlocked_seq for an explanation of how this works. 3087 * 3088 * This is a simplified variant which bails out to the aforementioned routine 3089 * if anything goes wrong. In practice this only happens when userspace is 3090 * racing with itself. 3091 */ 3092 int 3093 fget_unlocked(struct filedesc *fdp, int fd, cap_rights_t *needrightsp, 3094 struct file **fpp) 3095 { 3096 #ifdef CAPABILITIES 3097 const struct filedescent *fde; 3098 #endif 3099 const struct fdescenttbl *fdt; 3100 struct file *fp; 3101 #ifdef CAPABILITIES 3102 seqc_t seq; 3103 const cap_rights_t *haverights; 3104 #endif 3105 3106 fdt = fdp->fd_files; 3107 if (__predict_false((u_int)fd >= fdt->fdt_nfiles)) 3108 return (EBADF); 3109 #ifdef CAPABILITIES 3110 seq = seqc_read_any(fd_seqc(fdt, fd)); 3111 if (__predict_false(seqc_in_modify(seq))) 3112 goto out_fallback; 3113 fde = &fdt->fdt_ofiles[fd]; 3114 haverights = cap_rights_fde_inline(fde); 3115 fp = fde->fde_file; 3116 #else 3117 fp = fdt->fdt_ofiles[fd].fde_file; 3118 #endif 3119 if (__predict_false(fp == NULL)) 3120 goto out_fallback; 3121 #ifdef CAPABILITIES 3122 if (__predict_false(cap_check_inline_transient(haverights, needrightsp))) 3123 goto out_fallback; 3124 #endif 3125 if (__predict_false(!refcount_acquire_if_not_zero(&fp->f_count))) 3126 goto out_fallback; 3127 3128 /* 3129 * Use an acquire barrier to force re-reading of fdt so it is 3130 * refreshed for verification. 3131 */ 3132 atomic_thread_fence_acq(); 3133 fdt = fdp->fd_files; 3134 #ifdef CAPABILITIES 3135 if (__predict_false(!seqc_consistent_nomb(fd_seqc(fdt, fd), seq))) 3136 #else 3137 if (__predict_false(fp != fdt->fdt_ofiles[fd].fde_file)) 3138 #endif 3139 goto out_fdrop; 3140 *fpp = fp; 3141 return (0); 3142 out_fdrop: 3143 fdrop(fp, curthread); 3144 out_fallback: 3145 return (fget_unlocked_seq(fdp, fd, needrightsp, fpp, NULL)); 3146 } 3147 3148 /* 3149 * Extract the file pointer associated with the specified descriptor for the 3150 * current user process. 3151 * 3152 * If the descriptor doesn't exist or doesn't match 'flags', EBADF is 3153 * returned. 3154 * 3155 * File's rights will be checked against the capability rights mask. 3156 * 3157 * If an error occurred the non-zero error is returned and *fpp is set to 3158 * NULL. Otherwise *fpp is held and set and zero is returned. Caller is 3159 * responsible for fdrop(). 3160 */ 3161 static __inline int 3162 _fget(struct thread *td, int fd, struct file **fpp, int flags, 3163 cap_rights_t *needrightsp) 3164 { 3165 struct filedesc *fdp; 3166 struct file *fp; 3167 int error; 3168 3169 *fpp = NULL; 3170 fdp = td->td_proc->p_fd; 3171 error = fget_unlocked(fdp, fd, needrightsp, &fp); 3172 if (__predict_false(error != 0)) 3173 return (error); 3174 if (__predict_false(fp->f_ops == &badfileops)) { 3175 fdrop(fp, td); 3176 return (EBADF); 3177 } 3178 3179 /* 3180 * FREAD and FWRITE failure return EBADF as per POSIX. 3181 */ 3182 error = 0; 3183 switch (flags) { 3184 case FREAD: 3185 case FWRITE: 3186 if ((fp->f_flag & flags) == 0) 3187 error = EBADF; 3188 break; 3189 case FEXEC: 3190 if ((fp->f_flag & (FREAD | FEXEC)) == 0 || 3191 ((fp->f_flag & FWRITE) != 0)) 3192 error = EBADF; 3193 break; 3194 case 0: 3195 break; 3196 default: 3197 KASSERT(0, ("wrong flags")); 3198 } 3199 3200 if (error != 0) { 3201 fdrop(fp, td); 3202 return (error); 3203 } 3204 3205 *fpp = fp; 3206 return (0); 3207 } 3208 3209 int 3210 fget(struct thread *td, int fd, cap_rights_t *rightsp, struct file **fpp) 3211 { 3212 3213 return (_fget(td, fd, fpp, 0, rightsp)); 3214 } 3215 3216 int 3217 fget_mmap(struct thread *td, int fd, cap_rights_t *rightsp, vm_prot_t *maxprotp, 3218 struct file **fpp) 3219 { 3220 int error; 3221 #ifndef CAPABILITIES 3222 error = _fget(td, fd, fpp, 0, rightsp); 3223 if (maxprotp != NULL) 3224 *maxprotp = VM_PROT_ALL; 3225 return (error); 3226 #else 3227 cap_rights_t fdrights; 3228 struct filedesc *fdp; 3229 struct file *fp; 3230 seqc_t seq; 3231 3232 *fpp = NULL; 3233 fdp = td->td_proc->p_fd; 3234 MPASS(cap_rights_is_set(rightsp, CAP_MMAP)); 3235 for (;;) { 3236 error = fget_unlocked_seq(fdp, fd, rightsp, &fp, &seq); 3237 if (__predict_false(error != 0)) 3238 return (error); 3239 if (__predict_false(fp->f_ops == &badfileops)) { 3240 fdrop(fp, td); 3241 return (EBADF); 3242 } 3243 if (maxprotp != NULL) 3244 fdrights = *cap_rights(fdp, fd); 3245 if (!fd_modified(fdp, fd, seq)) 3246 break; 3247 fdrop(fp, td); 3248 } 3249 3250 /* 3251 * If requested, convert capability rights to access flags. 3252 */ 3253 if (maxprotp != NULL) 3254 *maxprotp = cap_rights_to_vmprot(&fdrights); 3255 *fpp = fp; 3256 return (0); 3257 #endif 3258 } 3259 3260 int 3261 fget_read(struct thread *td, int fd, cap_rights_t *rightsp, struct file **fpp) 3262 { 3263 3264 return (_fget(td, fd, fpp, FREAD, rightsp)); 3265 } 3266 3267 int 3268 fget_write(struct thread *td, int fd, cap_rights_t *rightsp, struct file **fpp) 3269 { 3270 3271 return (_fget(td, fd, fpp, FWRITE, rightsp)); 3272 } 3273 3274 int 3275 fget_fcntl(struct thread *td, int fd, cap_rights_t *rightsp, int needfcntl, 3276 struct file **fpp) 3277 { 3278 struct filedesc *fdp = td->td_proc->p_fd; 3279 #ifndef CAPABILITIES 3280 return (fget_unlocked(fdp, fd, rightsp, fpp)); 3281 #else 3282 struct file *fp; 3283 int error; 3284 seqc_t seq; 3285 3286 *fpp = NULL; 3287 MPASS(cap_rights_is_set(rightsp, CAP_FCNTL)); 3288 for (;;) { 3289 error = fget_unlocked_seq(fdp, fd, rightsp, &fp, &seq); 3290 if (error != 0) 3291 return (error); 3292 error = cap_fcntl_check(fdp, fd, needfcntl); 3293 if (!fd_modified(fdp, fd, seq)) 3294 break; 3295 fdrop(fp, td); 3296 } 3297 if (error != 0) { 3298 fdrop(fp, td); 3299 return (error); 3300 } 3301 *fpp = fp; 3302 return (0); 3303 #endif 3304 } 3305 3306 /* 3307 * Like fget() but loads the underlying vnode, or returns an error if the 3308 * descriptor does not represent a vnode. Note that pipes use vnodes but 3309 * never have VM objects. The returned vnode will be vref()'d. 3310 * 3311 * XXX: what about the unused flags ? 3312 */ 3313 static __inline int 3314 _fgetvp(struct thread *td, int fd, int flags, cap_rights_t *needrightsp, 3315 struct vnode **vpp) 3316 { 3317 struct file *fp; 3318 int error; 3319 3320 *vpp = NULL; 3321 error = _fget(td, fd, &fp, flags, needrightsp); 3322 if (error != 0) 3323 return (error); 3324 if (fp->f_vnode == NULL) { 3325 error = EINVAL; 3326 } else { 3327 *vpp = fp->f_vnode; 3328 vrefact(*vpp); 3329 } 3330 fdrop(fp, td); 3331 3332 return (error); 3333 } 3334 3335 int 3336 fgetvp(struct thread *td, int fd, cap_rights_t *rightsp, struct vnode **vpp) 3337 { 3338 3339 return (_fgetvp(td, fd, 0, rightsp, vpp)); 3340 } 3341 3342 int 3343 fgetvp_rights(struct thread *td, int fd, cap_rights_t *needrightsp, 3344 struct filecaps *havecaps, struct vnode **vpp) 3345 { 3346 struct filecaps caps; 3347 struct file *fp; 3348 int error; 3349 3350 error = fget_cap(td, fd, needrightsp, &fp, &caps); 3351 if (error != 0) 3352 return (error); 3353 if (fp->f_ops == &badfileops) { 3354 error = EBADF; 3355 goto out; 3356 } 3357 if (fp->f_vnode == NULL) { 3358 error = EINVAL; 3359 goto out; 3360 } 3361 3362 *havecaps = caps; 3363 *vpp = fp->f_vnode; 3364 vrefact(*vpp); 3365 fdrop(fp, td); 3366 3367 return (0); 3368 out: 3369 filecaps_free(&caps); 3370 fdrop(fp, td); 3371 return (error); 3372 } 3373 3374 int 3375 fgetvp_read(struct thread *td, int fd, cap_rights_t *rightsp, struct vnode **vpp) 3376 { 3377 3378 return (_fgetvp(td, fd, FREAD, rightsp, vpp)); 3379 } 3380 3381 int 3382 fgetvp_exec(struct thread *td, int fd, cap_rights_t *rightsp, struct vnode **vpp) 3383 { 3384 3385 return (_fgetvp(td, fd, FEXEC, rightsp, vpp)); 3386 } 3387 3388 #ifdef notyet 3389 int 3390 fgetvp_write(struct thread *td, int fd, cap_rights_t *rightsp, 3391 struct vnode **vpp) 3392 { 3393 3394 return (_fgetvp(td, fd, FWRITE, rightsp, vpp)); 3395 } 3396 #endif 3397 3398 /* 3399 * Handle the last reference to a file being closed. 3400 * 3401 * Without the noinline attribute clang keeps inlining the func thorough this 3402 * file when fdrop is used. 3403 */ 3404 int __noinline 3405 _fdrop(struct file *fp, struct thread *td) 3406 { 3407 int error; 3408 #ifdef INVARIANTS 3409 int count; 3410 3411 count = refcount_load(&fp->f_count); 3412 if (count != 0) 3413 panic("fdrop: fp %p count %d", fp, count); 3414 #endif 3415 error = fo_close(fp, td); 3416 atomic_subtract_int(&openfiles, 1); 3417 crfree(fp->f_cred); 3418 free(fp->f_advice, M_FADVISE); 3419 uma_zfree(file_zone, fp); 3420 3421 return (error); 3422 } 3423 3424 /* 3425 * Apply an advisory lock on a file descriptor. 3426 * 3427 * Just attempt to get a record lock of the requested type on the entire file 3428 * (l_whence = SEEK_SET, l_start = 0, l_len = 0). 3429 */ 3430 #ifndef _SYS_SYSPROTO_H_ 3431 struct flock_args { 3432 int fd; 3433 int how; 3434 }; 3435 #endif 3436 /* ARGSUSED */ 3437 int 3438 sys_flock(struct thread *td, struct flock_args *uap) 3439 { 3440 struct file *fp; 3441 struct vnode *vp; 3442 struct flock lf; 3443 int error; 3444 3445 error = fget(td, uap->fd, &cap_flock_rights, &fp); 3446 if (error != 0) 3447 return (error); 3448 if (fp->f_type != DTYPE_VNODE) { 3449 fdrop(fp, td); 3450 return (EOPNOTSUPP); 3451 } 3452 3453 vp = fp->f_vnode; 3454 lf.l_whence = SEEK_SET; 3455 lf.l_start = 0; 3456 lf.l_len = 0; 3457 if (uap->how & LOCK_UN) { 3458 lf.l_type = F_UNLCK; 3459 atomic_clear_int(&fp->f_flag, FHASLOCK); 3460 error = VOP_ADVLOCK(vp, (caddr_t)fp, F_UNLCK, &lf, F_FLOCK); 3461 goto done2; 3462 } 3463 if (uap->how & LOCK_EX) 3464 lf.l_type = F_WRLCK; 3465 else if (uap->how & LOCK_SH) 3466 lf.l_type = F_RDLCK; 3467 else { 3468 error = EBADF; 3469 goto done2; 3470 } 3471 atomic_set_int(&fp->f_flag, FHASLOCK); 3472 error = VOP_ADVLOCK(vp, (caddr_t)fp, F_SETLK, &lf, 3473 (uap->how & LOCK_NB) ? F_FLOCK : F_FLOCK | F_WAIT); 3474 done2: 3475 fdrop(fp, td); 3476 return (error); 3477 } 3478 /* 3479 * Duplicate the specified descriptor to a free descriptor. 3480 */ 3481 int 3482 dupfdopen(struct thread *td, struct filedesc *fdp, int dfd, int mode, 3483 int openerror, int *indxp) 3484 { 3485 struct filedescent *newfde, *oldfde; 3486 struct file *fp; 3487 u_long *ioctls; 3488 int error, indx; 3489 3490 KASSERT(openerror == ENODEV || openerror == ENXIO, 3491 ("unexpected error %d in %s", openerror, __func__)); 3492 3493 /* 3494 * If the to-be-dup'd fd number is greater than the allowed number 3495 * of file descriptors, or the fd to be dup'd has already been 3496 * closed, then reject. 3497 */ 3498 FILEDESC_XLOCK(fdp); 3499 if ((fp = fget_locked(fdp, dfd)) == NULL) { 3500 FILEDESC_XUNLOCK(fdp); 3501 return (EBADF); 3502 } 3503 3504 error = fdalloc(td, 0, &indx); 3505 if (error != 0) { 3506 FILEDESC_XUNLOCK(fdp); 3507 return (error); 3508 } 3509 3510 /* 3511 * There are two cases of interest here. 3512 * 3513 * For ENODEV simply dup (dfd) to file descriptor (indx) and return. 3514 * 3515 * For ENXIO steal away the file structure from (dfd) and store it in 3516 * (indx). (dfd) is effectively closed by this operation. 3517 */ 3518 switch (openerror) { 3519 case ENODEV: 3520 /* 3521 * Check that the mode the file is being opened for is a 3522 * subset of the mode of the existing descriptor. 3523 */ 3524 if (((mode & (FREAD|FWRITE)) | fp->f_flag) != fp->f_flag) { 3525 fdunused(fdp, indx); 3526 FILEDESC_XUNLOCK(fdp); 3527 return (EACCES); 3528 } 3529 if (!fhold(fp)) { 3530 fdunused(fdp, indx); 3531 FILEDESC_XUNLOCK(fdp); 3532 return (EBADF); 3533 } 3534 newfde = &fdp->fd_ofiles[indx]; 3535 oldfde = &fdp->fd_ofiles[dfd]; 3536 ioctls = filecaps_copy_prep(&oldfde->fde_caps); 3537 #ifdef CAPABILITIES 3538 seqc_write_begin(&newfde->fde_seqc); 3539 #endif 3540 memcpy(newfde, oldfde, fde_change_size); 3541 filecaps_copy_finish(&oldfde->fde_caps, &newfde->fde_caps, 3542 ioctls); 3543 #ifdef CAPABILITIES 3544 seqc_write_end(&newfde->fde_seqc); 3545 #endif 3546 break; 3547 case ENXIO: 3548 /* 3549 * Steal away the file pointer from dfd and stuff it into indx. 3550 */ 3551 newfde = &fdp->fd_ofiles[indx]; 3552 oldfde = &fdp->fd_ofiles[dfd]; 3553 #ifdef CAPABILITIES 3554 seqc_write_begin(&newfde->fde_seqc); 3555 #endif 3556 memcpy(newfde, oldfde, fde_change_size); 3557 oldfde->fde_file = NULL; 3558 fdunused(fdp, dfd); 3559 #ifdef CAPABILITIES 3560 seqc_write_end(&newfde->fde_seqc); 3561 #endif 3562 break; 3563 } 3564 FILEDESC_XUNLOCK(fdp); 3565 *indxp = indx; 3566 return (0); 3567 } 3568 3569 /* 3570 * This sysctl determines if we will allow a process to chroot(2) if it 3571 * has a directory open: 3572 * 0: disallowed for all processes. 3573 * 1: allowed for processes that were not already chroot(2)'ed. 3574 * 2: allowed for all processes. 3575 */ 3576 3577 static int chroot_allow_open_directories = 1; 3578 3579 SYSCTL_INT(_kern, OID_AUTO, chroot_allow_open_directories, CTLFLAG_RW, 3580 &chroot_allow_open_directories, 0, 3581 "Allow a process to chroot(2) if it has a directory open"); 3582 3583 /* 3584 * Helper function for raised chroot(2) security function: Refuse if 3585 * any filedescriptors are open directories. 3586 */ 3587 static int 3588 chroot_refuse_vdir_fds(struct filedesc *fdp) 3589 { 3590 struct vnode *vp; 3591 struct file *fp; 3592 int fd, lastfile; 3593 3594 FILEDESC_LOCK_ASSERT(fdp); 3595 3596 lastfile = fdlastfile(fdp); 3597 for (fd = 0; fd <= lastfile; fd++) { 3598 fp = fget_locked(fdp, fd); 3599 if (fp == NULL) 3600 continue; 3601 if (fp->f_type == DTYPE_VNODE) { 3602 vp = fp->f_vnode; 3603 if (vp->v_type == VDIR) 3604 return (EPERM); 3605 } 3606 } 3607 return (0); 3608 } 3609 3610 static void 3611 pwd_fill(struct pwd *oldpwd, struct pwd *newpwd) 3612 { 3613 3614 if (newpwd->pwd_cdir == NULL && oldpwd->pwd_cdir != NULL) { 3615 vrefact(oldpwd->pwd_cdir); 3616 newpwd->pwd_cdir = oldpwd->pwd_cdir; 3617 } 3618 3619 if (newpwd->pwd_rdir == NULL && oldpwd->pwd_rdir != NULL) { 3620 vrefact(oldpwd->pwd_rdir); 3621 newpwd->pwd_rdir = oldpwd->pwd_rdir; 3622 } 3623 3624 if (newpwd->pwd_jdir == NULL && oldpwd->pwd_jdir != NULL) { 3625 vrefact(oldpwd->pwd_jdir); 3626 newpwd->pwd_jdir = oldpwd->pwd_jdir; 3627 } 3628 } 3629 3630 struct pwd * 3631 pwd_hold_pwddesc(struct pwddesc *pdp) 3632 { 3633 struct pwd *pwd; 3634 3635 PWDDESC_ASSERT_XLOCKED(pdp); 3636 pwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); 3637 if (pwd != NULL) 3638 refcount_acquire(&pwd->pwd_refcount); 3639 return (pwd); 3640 } 3641 3642 bool 3643 pwd_hold_smr(struct pwd *pwd) 3644 { 3645 3646 MPASS(pwd != NULL); 3647 if (__predict_true(refcount_acquire_if_not_zero(&pwd->pwd_refcount))) { 3648 return (true); 3649 } 3650 return (false); 3651 } 3652 3653 struct pwd * 3654 pwd_hold(struct thread *td) 3655 { 3656 struct pwddesc *pdp; 3657 struct pwd *pwd; 3658 3659 pdp = td->td_proc->p_pd; 3660 3661 vfs_smr_enter(); 3662 pwd = vfs_smr_entered_load(&pdp->pd_pwd); 3663 if (pwd_hold_smr(pwd)) { 3664 vfs_smr_exit(); 3665 return (pwd); 3666 } 3667 vfs_smr_exit(); 3668 PWDDESC_XLOCK(pdp); 3669 pwd = pwd_hold_pwddesc(pdp); 3670 MPASS(pwd != NULL); 3671 PWDDESC_XUNLOCK(pdp); 3672 return (pwd); 3673 } 3674 3675 struct pwd * 3676 pwd_get_smr(void) 3677 { 3678 struct pwd *pwd; 3679 3680 pwd = vfs_smr_entered_load(&curproc->p_pd->pd_pwd); 3681 MPASS(pwd != NULL); 3682 return (pwd); 3683 } 3684 3685 static struct pwd * 3686 pwd_alloc(void) 3687 { 3688 struct pwd *pwd; 3689 3690 pwd = uma_zalloc_smr(pwd_zone, M_WAITOK); 3691 bzero(pwd, sizeof(*pwd)); 3692 refcount_init(&pwd->pwd_refcount, 1); 3693 return (pwd); 3694 } 3695 3696 void 3697 pwd_drop(struct pwd *pwd) 3698 { 3699 3700 if (!refcount_release(&pwd->pwd_refcount)) 3701 return; 3702 3703 if (pwd->pwd_cdir != NULL) 3704 vrele(pwd->pwd_cdir); 3705 if (pwd->pwd_rdir != NULL) 3706 vrele(pwd->pwd_rdir); 3707 if (pwd->pwd_jdir != NULL) 3708 vrele(pwd->pwd_jdir); 3709 uma_zfree_smr(pwd_zone, pwd); 3710 } 3711 3712 /* 3713 * Common routine for kern_chroot() and jail_attach(). The caller is 3714 * responsible for invoking priv_check() and mac_vnode_check_chroot() to 3715 * authorize this operation. 3716 */ 3717 int 3718 pwd_chroot(struct thread *td, struct vnode *vp) 3719 { 3720 struct pwddesc *pdp; 3721 struct filedesc *fdp; 3722 struct pwd *newpwd, *oldpwd; 3723 int error; 3724 3725 fdp = td->td_proc->p_fd; 3726 pdp = td->td_proc->p_pd; 3727 newpwd = pwd_alloc(); 3728 FILEDESC_SLOCK(fdp); 3729 PWDDESC_XLOCK(pdp); 3730 oldpwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); 3731 if (chroot_allow_open_directories == 0 || 3732 (chroot_allow_open_directories == 1 && 3733 oldpwd->pwd_rdir != rootvnode)) { 3734 error = chroot_refuse_vdir_fds(fdp); 3735 FILEDESC_SUNLOCK(fdp); 3736 if (error != 0) { 3737 PWDDESC_XUNLOCK(pdp); 3738 pwd_drop(newpwd); 3739 return (error); 3740 } 3741 } else { 3742 FILEDESC_SUNLOCK(fdp); 3743 } 3744 3745 vrefact(vp); 3746 newpwd->pwd_rdir = vp; 3747 if (oldpwd->pwd_jdir == NULL) { 3748 vrefact(vp); 3749 newpwd->pwd_jdir = vp; 3750 } 3751 pwd_fill(oldpwd, newpwd); 3752 pwd_set(pdp, newpwd); 3753 PWDDESC_XUNLOCK(pdp); 3754 pwd_drop(oldpwd); 3755 return (0); 3756 } 3757 3758 void 3759 pwd_chdir(struct thread *td, struct vnode *vp) 3760 { 3761 struct pwddesc *pdp; 3762 struct pwd *newpwd, *oldpwd; 3763 3764 VNPASS(vp->v_usecount > 0, vp); 3765 3766 newpwd = pwd_alloc(); 3767 pdp = td->td_proc->p_pd; 3768 PWDDESC_XLOCK(pdp); 3769 oldpwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); 3770 newpwd->pwd_cdir = vp; 3771 pwd_fill(oldpwd, newpwd); 3772 pwd_set(pdp, newpwd); 3773 PWDDESC_XUNLOCK(pdp); 3774 pwd_drop(oldpwd); 3775 } 3776 3777 void 3778 pwd_ensure_dirs(void) 3779 { 3780 struct pwddesc *pdp; 3781 struct pwd *oldpwd, *newpwd; 3782 3783 pdp = curproc->p_pd; 3784 PWDDESC_XLOCK(pdp); 3785 oldpwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); 3786 if (oldpwd->pwd_cdir != NULL && oldpwd->pwd_rdir != NULL) { 3787 PWDDESC_XUNLOCK(pdp); 3788 return; 3789 } 3790 PWDDESC_XUNLOCK(pdp); 3791 3792 newpwd = pwd_alloc(); 3793 PWDDESC_XLOCK(pdp); 3794 oldpwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); 3795 pwd_fill(oldpwd, newpwd); 3796 if (newpwd->pwd_cdir == NULL) { 3797 vrefact(rootvnode); 3798 newpwd->pwd_cdir = rootvnode; 3799 } 3800 if (newpwd->pwd_rdir == NULL) { 3801 vrefact(rootvnode); 3802 newpwd->pwd_rdir = rootvnode; 3803 } 3804 pwd_set(pdp, newpwd); 3805 PWDDESC_XUNLOCK(pdp); 3806 pwd_drop(oldpwd); 3807 } 3808 3809 void 3810 pwd_set_rootvnode(void) 3811 { 3812 struct pwddesc *pdp; 3813 struct pwd *oldpwd, *newpwd; 3814 3815 pdp = curproc->p_pd; 3816 3817 newpwd = pwd_alloc(); 3818 PWDDESC_XLOCK(pdp); 3819 oldpwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); 3820 vrefact(rootvnode); 3821 newpwd->pwd_cdir = rootvnode; 3822 vrefact(rootvnode); 3823 newpwd->pwd_rdir = rootvnode; 3824 pwd_fill(oldpwd, newpwd); 3825 pwd_set(pdp, newpwd); 3826 PWDDESC_XUNLOCK(pdp); 3827 pwd_drop(oldpwd); 3828 } 3829 3830 /* 3831 * Scan all active processes and prisons to see if any of them have a current 3832 * or root directory of `olddp'. If so, replace them with the new mount point. 3833 */ 3834 void 3835 mountcheckdirs(struct vnode *olddp, struct vnode *newdp) 3836 { 3837 struct pwddesc *pdp; 3838 struct pwd *newpwd, *oldpwd; 3839 struct prison *pr; 3840 struct proc *p; 3841 int nrele; 3842 3843 if (vrefcnt(olddp) == 1) 3844 return; 3845 nrele = 0; 3846 newpwd = pwd_alloc(); 3847 sx_slock(&allproc_lock); 3848 FOREACH_PROC_IN_SYSTEM(p) { 3849 PROC_LOCK(p); 3850 pdp = pdhold(p); 3851 PROC_UNLOCK(p); 3852 if (pdp == NULL) 3853 continue; 3854 PWDDESC_XLOCK(pdp); 3855 oldpwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); 3856 if (oldpwd == NULL || 3857 (oldpwd->pwd_cdir != olddp && 3858 oldpwd->pwd_rdir != olddp && 3859 oldpwd->pwd_jdir != olddp)) { 3860 PWDDESC_XUNLOCK(pdp); 3861 pddrop(pdp); 3862 continue; 3863 } 3864 if (oldpwd->pwd_cdir == olddp) { 3865 vrefact(newdp); 3866 newpwd->pwd_cdir = newdp; 3867 } 3868 if (oldpwd->pwd_rdir == olddp) { 3869 vrefact(newdp); 3870 newpwd->pwd_rdir = newdp; 3871 } 3872 if (oldpwd->pwd_jdir == olddp) { 3873 vrefact(newdp); 3874 newpwd->pwd_jdir = newdp; 3875 } 3876 pwd_fill(oldpwd, newpwd); 3877 pwd_set(pdp, newpwd); 3878 PWDDESC_XUNLOCK(pdp); 3879 pwd_drop(oldpwd); 3880 pddrop(pdp); 3881 newpwd = pwd_alloc(); 3882 } 3883 sx_sunlock(&allproc_lock); 3884 pwd_drop(newpwd); 3885 if (rootvnode == olddp) { 3886 vrefact(newdp); 3887 rootvnode = newdp; 3888 nrele++; 3889 } 3890 mtx_lock(&prison0.pr_mtx); 3891 if (prison0.pr_root == olddp) { 3892 vrefact(newdp); 3893 prison0.pr_root = newdp; 3894 nrele++; 3895 } 3896 mtx_unlock(&prison0.pr_mtx); 3897 sx_slock(&allprison_lock); 3898 TAILQ_FOREACH(pr, &allprison, pr_list) { 3899 mtx_lock(&pr->pr_mtx); 3900 if (pr->pr_root == olddp) { 3901 vrefact(newdp); 3902 pr->pr_root = newdp; 3903 nrele++; 3904 } 3905 mtx_unlock(&pr->pr_mtx); 3906 } 3907 sx_sunlock(&allprison_lock); 3908 while (nrele--) 3909 vrele(olddp); 3910 } 3911 3912 struct filedesc_to_leader * 3913 filedesc_to_leader_alloc(struct filedesc_to_leader *old, struct filedesc *fdp, struct proc *leader) 3914 { 3915 struct filedesc_to_leader *fdtol; 3916 3917 fdtol = malloc(sizeof(struct filedesc_to_leader), 3918 M_FILEDESC_TO_LEADER, M_WAITOK); 3919 fdtol->fdl_refcount = 1; 3920 fdtol->fdl_holdcount = 0; 3921 fdtol->fdl_wakeup = 0; 3922 fdtol->fdl_leader = leader; 3923 if (old != NULL) { 3924 FILEDESC_XLOCK(fdp); 3925 fdtol->fdl_next = old->fdl_next; 3926 fdtol->fdl_prev = old; 3927 old->fdl_next = fdtol; 3928 fdtol->fdl_next->fdl_prev = fdtol; 3929 FILEDESC_XUNLOCK(fdp); 3930 } else { 3931 fdtol->fdl_next = fdtol; 3932 fdtol->fdl_prev = fdtol; 3933 } 3934 return (fdtol); 3935 } 3936 3937 static int 3938 sysctl_kern_proc_nfds(SYSCTL_HANDLER_ARGS) 3939 { 3940 NDSLOTTYPE *map; 3941 struct filedesc *fdp; 3942 int count, off, minoff; 3943 3944 if (*(int *)arg1 != 0) 3945 return (EINVAL); 3946 3947 fdp = curproc->p_fd; 3948 count = 0; 3949 FILEDESC_SLOCK(fdp); 3950 map = fdp->fd_map; 3951 off = NDSLOT(fdp->fd_nfiles - 1); 3952 for (minoff = NDSLOT(0); off >= minoff; --off) 3953 count += bitcountl(map[off]); 3954 FILEDESC_SUNLOCK(fdp); 3955 3956 return (SYSCTL_OUT(req, &count, sizeof(count))); 3957 } 3958 3959 static SYSCTL_NODE(_kern_proc, KERN_PROC_NFDS, nfds, 3960 CTLFLAG_RD|CTLFLAG_CAPRD|CTLFLAG_MPSAFE, sysctl_kern_proc_nfds, 3961 "Number of open file descriptors"); 3962 3963 /* 3964 * Get file structures globally. 3965 */ 3966 static int 3967 sysctl_kern_file(SYSCTL_HANDLER_ARGS) 3968 { 3969 struct xfile xf; 3970 struct filedesc *fdp; 3971 struct file *fp; 3972 struct proc *p; 3973 int error, n, lastfile; 3974 3975 error = sysctl_wire_old_buffer(req, 0); 3976 if (error != 0) 3977 return (error); 3978 if (req->oldptr == NULL) { 3979 n = 0; 3980 sx_slock(&allproc_lock); 3981 FOREACH_PROC_IN_SYSTEM(p) { 3982 PROC_LOCK(p); 3983 if (p->p_state == PRS_NEW) { 3984 PROC_UNLOCK(p); 3985 continue; 3986 } 3987 fdp = fdhold(p); 3988 PROC_UNLOCK(p); 3989 if (fdp == NULL) 3990 continue; 3991 /* overestimates sparse tables. */ 3992 n += fdp->fd_nfiles; 3993 fddrop(fdp); 3994 } 3995 sx_sunlock(&allproc_lock); 3996 return (SYSCTL_OUT(req, 0, n * sizeof(xf))); 3997 } 3998 error = 0; 3999 bzero(&xf, sizeof(xf)); 4000 xf.xf_size = sizeof(xf); 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 if (p_cansee(req->td, p) != 0) { 4009 PROC_UNLOCK(p); 4010 continue; 4011 } 4012 xf.xf_pid = p->p_pid; 4013 xf.xf_uid = p->p_ucred->cr_uid; 4014 fdp = fdhold(p); 4015 PROC_UNLOCK(p); 4016 if (fdp == NULL) 4017 continue; 4018 FILEDESC_SLOCK(fdp); 4019 lastfile = fdlastfile(fdp); 4020 for (n = 0; refcount_load(&fdp->fd_refcnt) > 0 && n <= lastfile; 4021 n++) { 4022 if ((fp = fdp->fd_ofiles[n].fde_file) == NULL) 4023 continue; 4024 xf.xf_fd = n; 4025 xf.xf_file = (uintptr_t)fp; 4026 xf.xf_data = (uintptr_t)fp->f_data; 4027 xf.xf_vnode = (uintptr_t)fp->f_vnode; 4028 xf.xf_type = (uintptr_t)fp->f_type; 4029 xf.xf_count = refcount_load(&fp->f_count); 4030 xf.xf_msgcount = 0; 4031 xf.xf_offset = foffset_get(fp); 4032 xf.xf_flag = fp->f_flag; 4033 error = SYSCTL_OUT(req, &xf, sizeof(xf)); 4034 if (error) 4035 break; 4036 } 4037 FILEDESC_SUNLOCK(fdp); 4038 fddrop(fdp); 4039 if (error) 4040 break; 4041 } 4042 sx_sunlock(&allproc_lock); 4043 return (error); 4044 } 4045 4046 SYSCTL_PROC(_kern, KERN_FILE, file, CTLTYPE_OPAQUE|CTLFLAG_RD|CTLFLAG_MPSAFE, 4047 0, 0, sysctl_kern_file, "S,xfile", "Entire file table"); 4048 4049 #ifdef KINFO_FILE_SIZE 4050 CTASSERT(sizeof(struct kinfo_file) == KINFO_FILE_SIZE); 4051 #endif 4052 4053 static int 4054 xlate_fflags(int fflags) 4055 { 4056 static const struct { 4057 int fflag; 4058 int kf_fflag; 4059 } fflags_table[] = { 4060 { FAPPEND, KF_FLAG_APPEND }, 4061 { FASYNC, KF_FLAG_ASYNC }, 4062 { FFSYNC, KF_FLAG_FSYNC }, 4063 { FHASLOCK, KF_FLAG_HASLOCK }, 4064 { FNONBLOCK, KF_FLAG_NONBLOCK }, 4065 { FREAD, KF_FLAG_READ }, 4066 { FWRITE, KF_FLAG_WRITE }, 4067 { O_CREAT, KF_FLAG_CREAT }, 4068 { O_DIRECT, KF_FLAG_DIRECT }, 4069 { O_EXCL, KF_FLAG_EXCL }, 4070 { O_EXEC, KF_FLAG_EXEC }, 4071 { O_EXLOCK, KF_FLAG_EXLOCK }, 4072 { O_NOFOLLOW, KF_FLAG_NOFOLLOW }, 4073 { O_SHLOCK, KF_FLAG_SHLOCK }, 4074 { O_TRUNC, KF_FLAG_TRUNC } 4075 }; 4076 unsigned int i; 4077 int kflags; 4078 4079 kflags = 0; 4080 for (i = 0; i < nitems(fflags_table); i++) 4081 if (fflags & fflags_table[i].fflag) 4082 kflags |= fflags_table[i].kf_fflag; 4083 return (kflags); 4084 } 4085 4086 /* Trim unused data from kf_path by truncating the structure size. */ 4087 void 4088 pack_kinfo(struct kinfo_file *kif) 4089 { 4090 4091 kif->kf_structsize = offsetof(struct kinfo_file, kf_path) + 4092 strlen(kif->kf_path) + 1; 4093 kif->kf_structsize = roundup(kif->kf_structsize, sizeof(uint64_t)); 4094 } 4095 4096 static void 4097 export_file_to_kinfo(struct file *fp, int fd, cap_rights_t *rightsp, 4098 struct kinfo_file *kif, struct filedesc *fdp, int flags) 4099 { 4100 int error; 4101 4102 bzero(kif, sizeof(*kif)); 4103 4104 /* Set a default type to allow for empty fill_kinfo() methods. */ 4105 kif->kf_type = KF_TYPE_UNKNOWN; 4106 kif->kf_flags = xlate_fflags(fp->f_flag); 4107 if (rightsp != NULL) 4108 kif->kf_cap_rights = *rightsp; 4109 else 4110 cap_rights_init_zero(&kif->kf_cap_rights); 4111 kif->kf_fd = fd; 4112 kif->kf_ref_count = refcount_load(&fp->f_count); 4113 kif->kf_offset = foffset_get(fp); 4114 4115 /* 4116 * This may drop the filedesc lock, so the 'fp' cannot be 4117 * accessed after this call. 4118 */ 4119 error = fo_fill_kinfo(fp, kif, fdp); 4120 if (error == 0) 4121 kif->kf_status |= KF_ATTR_VALID; 4122 if ((flags & KERN_FILEDESC_PACK_KINFO) != 0) 4123 pack_kinfo(kif); 4124 else 4125 kif->kf_structsize = roundup2(sizeof(*kif), sizeof(uint64_t)); 4126 } 4127 4128 static void 4129 export_vnode_to_kinfo(struct vnode *vp, int fd, int fflags, 4130 struct kinfo_file *kif, int flags) 4131 { 4132 int error; 4133 4134 bzero(kif, sizeof(*kif)); 4135 4136 kif->kf_type = KF_TYPE_VNODE; 4137 error = vn_fill_kinfo_vnode(vp, kif); 4138 if (error == 0) 4139 kif->kf_status |= KF_ATTR_VALID; 4140 kif->kf_flags = xlate_fflags(fflags); 4141 cap_rights_init_zero(&kif->kf_cap_rights); 4142 kif->kf_fd = fd; 4143 kif->kf_ref_count = -1; 4144 kif->kf_offset = -1; 4145 if ((flags & KERN_FILEDESC_PACK_KINFO) != 0) 4146 pack_kinfo(kif); 4147 else 4148 kif->kf_structsize = roundup2(sizeof(*kif), sizeof(uint64_t)); 4149 vrele(vp); 4150 } 4151 4152 struct export_fd_buf { 4153 struct filedesc *fdp; 4154 struct pwddesc *pdp; 4155 struct sbuf *sb; 4156 ssize_t remainder; 4157 struct kinfo_file kif; 4158 int flags; 4159 }; 4160 4161 static int 4162 export_kinfo_to_sb(struct export_fd_buf *efbuf) 4163 { 4164 struct kinfo_file *kif; 4165 4166 kif = &efbuf->kif; 4167 if (efbuf->remainder != -1) { 4168 if (efbuf->remainder < kif->kf_structsize) { 4169 /* Terminate export. */ 4170 efbuf->remainder = 0; 4171 return (0); 4172 } 4173 efbuf->remainder -= kif->kf_structsize; 4174 } 4175 return (sbuf_bcat(efbuf->sb, kif, kif->kf_structsize) == 0 ? 0 : ENOMEM); 4176 } 4177 4178 static int 4179 export_file_to_sb(struct file *fp, int fd, cap_rights_t *rightsp, 4180 struct export_fd_buf *efbuf) 4181 { 4182 int error; 4183 4184 if (efbuf->remainder == 0) 4185 return (0); 4186 export_file_to_kinfo(fp, fd, rightsp, &efbuf->kif, efbuf->fdp, 4187 efbuf->flags); 4188 FILEDESC_SUNLOCK(efbuf->fdp); 4189 error = export_kinfo_to_sb(efbuf); 4190 FILEDESC_SLOCK(efbuf->fdp); 4191 return (error); 4192 } 4193 4194 static int 4195 export_vnode_to_sb(struct vnode *vp, int fd, int fflags, 4196 struct export_fd_buf *efbuf) 4197 { 4198 int error; 4199 4200 if (efbuf->remainder == 0) 4201 return (0); 4202 if (efbuf->pdp != NULL) 4203 PWDDESC_XUNLOCK(efbuf->pdp); 4204 export_vnode_to_kinfo(vp, fd, fflags, &efbuf->kif, efbuf->flags); 4205 error = export_kinfo_to_sb(efbuf); 4206 if (efbuf->pdp != NULL) 4207 PWDDESC_XLOCK(efbuf->pdp); 4208 return (error); 4209 } 4210 4211 /* 4212 * Store a process file descriptor information to sbuf. 4213 * 4214 * Takes a locked proc as argument, and returns with the proc unlocked. 4215 */ 4216 int 4217 kern_proc_filedesc_out(struct proc *p, struct sbuf *sb, ssize_t maxlen, 4218 int flags) 4219 { 4220 struct file *fp; 4221 struct filedesc *fdp; 4222 struct pwddesc *pdp; 4223 struct export_fd_buf *efbuf; 4224 struct vnode *cttyvp, *textvp, *tracevp; 4225 struct pwd *pwd; 4226 int error, i, lastfile; 4227 cap_rights_t rights; 4228 4229 PROC_LOCK_ASSERT(p, MA_OWNED); 4230 4231 /* ktrace vnode */ 4232 tracevp = p->p_tracevp; 4233 if (tracevp != NULL) 4234 vrefact(tracevp); 4235 /* text vnode */ 4236 textvp = p->p_textvp; 4237 if (textvp != NULL) 4238 vrefact(textvp); 4239 /* Controlling tty. */ 4240 cttyvp = NULL; 4241 if (p->p_pgrp != NULL && p->p_pgrp->pg_session != NULL) { 4242 cttyvp = p->p_pgrp->pg_session->s_ttyvp; 4243 if (cttyvp != NULL) 4244 vrefact(cttyvp); 4245 } 4246 fdp = fdhold(p); 4247 pdp = pdhold(p); 4248 PROC_UNLOCK(p); 4249 efbuf = malloc(sizeof(*efbuf), M_TEMP, M_WAITOK); 4250 efbuf->fdp = NULL; 4251 efbuf->pdp = NULL; 4252 efbuf->sb = sb; 4253 efbuf->remainder = maxlen; 4254 efbuf->flags = flags; 4255 if (tracevp != NULL) 4256 export_vnode_to_sb(tracevp, KF_FD_TYPE_TRACE, FREAD | FWRITE, 4257 efbuf); 4258 if (textvp != NULL) 4259 export_vnode_to_sb(textvp, KF_FD_TYPE_TEXT, FREAD, efbuf); 4260 if (cttyvp != NULL) 4261 export_vnode_to_sb(cttyvp, KF_FD_TYPE_CTTY, FREAD | FWRITE, 4262 efbuf); 4263 error = 0; 4264 if (pdp == NULL || fdp == NULL) 4265 goto fail; 4266 efbuf->fdp = fdp; 4267 efbuf->pdp = pdp; 4268 PWDDESC_XLOCK(pdp); 4269 pwd = pwd_hold_pwddesc(pdp); 4270 if (pwd != NULL) { 4271 /* working directory */ 4272 if (pwd->pwd_cdir != NULL) { 4273 vrefact(pwd->pwd_cdir); 4274 export_vnode_to_sb(pwd->pwd_cdir, KF_FD_TYPE_CWD, FREAD, efbuf); 4275 } 4276 /* root directory */ 4277 if (pwd->pwd_rdir != NULL) { 4278 vrefact(pwd->pwd_rdir); 4279 export_vnode_to_sb(pwd->pwd_rdir, KF_FD_TYPE_ROOT, FREAD, efbuf); 4280 } 4281 /* jail directory */ 4282 if (pwd->pwd_jdir != NULL) { 4283 vrefact(pwd->pwd_jdir); 4284 export_vnode_to_sb(pwd->pwd_jdir, KF_FD_TYPE_JAIL, FREAD, efbuf); 4285 } 4286 } 4287 PWDDESC_XUNLOCK(pdp); 4288 if (pwd != NULL) 4289 pwd_drop(pwd); 4290 FILEDESC_SLOCK(fdp); 4291 lastfile = fdlastfile(fdp); 4292 for (i = 0; refcount_load(&fdp->fd_refcnt) > 0 && i <= lastfile; i++) { 4293 if ((fp = fdp->fd_ofiles[i].fde_file) == NULL) 4294 continue; 4295 #ifdef CAPABILITIES 4296 rights = *cap_rights(fdp, i); 4297 #else /* !CAPABILITIES */ 4298 rights = cap_no_rights; 4299 #endif 4300 /* 4301 * Create sysctl entry. It is OK to drop the filedesc 4302 * lock inside of export_file_to_sb() as we will 4303 * re-validate and re-evaluate its properties when the 4304 * loop continues. 4305 */ 4306 error = export_file_to_sb(fp, i, &rights, efbuf); 4307 if (error != 0 || efbuf->remainder == 0) 4308 break; 4309 } 4310 FILEDESC_SUNLOCK(fdp); 4311 fail: 4312 if (fdp != NULL) 4313 fddrop(fdp); 4314 if (pdp != NULL) 4315 pddrop(pdp); 4316 free(efbuf, M_TEMP); 4317 return (error); 4318 } 4319 4320 #define FILEDESC_SBUF_SIZE (sizeof(struct kinfo_file) * 5) 4321 4322 /* 4323 * Get per-process file descriptors for use by procstat(1), et al. 4324 */ 4325 static int 4326 sysctl_kern_proc_filedesc(SYSCTL_HANDLER_ARGS) 4327 { 4328 struct sbuf sb; 4329 struct proc *p; 4330 ssize_t maxlen; 4331 int error, error2, *name; 4332 4333 name = (int *)arg1; 4334 4335 sbuf_new_for_sysctl(&sb, NULL, FILEDESC_SBUF_SIZE, req); 4336 sbuf_clear_flags(&sb, SBUF_INCLUDENUL); 4337 error = pget((pid_t)name[0], PGET_CANDEBUG | PGET_NOTWEXIT, &p); 4338 if (error != 0) { 4339 sbuf_delete(&sb); 4340 return (error); 4341 } 4342 maxlen = req->oldptr != NULL ? req->oldlen : -1; 4343 error = kern_proc_filedesc_out(p, &sb, maxlen, 4344 KERN_FILEDESC_PACK_KINFO); 4345 error2 = sbuf_finish(&sb); 4346 sbuf_delete(&sb); 4347 return (error != 0 ? error : error2); 4348 } 4349 4350 #ifdef COMPAT_FREEBSD7 4351 #ifdef KINFO_OFILE_SIZE 4352 CTASSERT(sizeof(struct kinfo_ofile) == KINFO_OFILE_SIZE); 4353 #endif 4354 4355 static void 4356 kinfo_to_okinfo(struct kinfo_file *kif, struct kinfo_ofile *okif) 4357 { 4358 4359 okif->kf_structsize = sizeof(*okif); 4360 okif->kf_type = kif->kf_type; 4361 okif->kf_fd = kif->kf_fd; 4362 okif->kf_ref_count = kif->kf_ref_count; 4363 okif->kf_flags = kif->kf_flags & (KF_FLAG_READ | KF_FLAG_WRITE | 4364 KF_FLAG_APPEND | KF_FLAG_ASYNC | KF_FLAG_FSYNC | KF_FLAG_NONBLOCK | 4365 KF_FLAG_DIRECT | KF_FLAG_HASLOCK); 4366 okif->kf_offset = kif->kf_offset; 4367 if (kif->kf_type == KF_TYPE_VNODE) 4368 okif->kf_vnode_type = kif->kf_un.kf_file.kf_file_type; 4369 else 4370 okif->kf_vnode_type = KF_VTYPE_VNON; 4371 strlcpy(okif->kf_path, kif->kf_path, sizeof(okif->kf_path)); 4372 if (kif->kf_type == KF_TYPE_SOCKET) { 4373 okif->kf_sock_domain = kif->kf_un.kf_sock.kf_sock_domain0; 4374 okif->kf_sock_type = kif->kf_un.kf_sock.kf_sock_type0; 4375 okif->kf_sock_protocol = kif->kf_un.kf_sock.kf_sock_protocol0; 4376 okif->kf_sa_local = kif->kf_un.kf_sock.kf_sa_local; 4377 okif->kf_sa_peer = kif->kf_un.kf_sock.kf_sa_peer; 4378 } else { 4379 okif->kf_sa_local.ss_family = AF_UNSPEC; 4380 okif->kf_sa_peer.ss_family = AF_UNSPEC; 4381 } 4382 } 4383 4384 static int 4385 export_vnode_for_osysctl(struct vnode *vp, int type, struct kinfo_file *kif, 4386 struct kinfo_ofile *okif, struct pwddesc *pdp, struct sysctl_req *req) 4387 { 4388 int error; 4389 4390 vrefact(vp); 4391 PWDDESC_XUNLOCK(pdp); 4392 export_vnode_to_kinfo(vp, type, 0, kif, KERN_FILEDESC_PACK_KINFO); 4393 kinfo_to_okinfo(kif, okif); 4394 error = SYSCTL_OUT(req, okif, sizeof(*okif)); 4395 PWDDESC_XLOCK(pdp); 4396 return (error); 4397 } 4398 4399 /* 4400 * Get per-process file descriptors for use by procstat(1), et al. 4401 */ 4402 static int 4403 sysctl_kern_proc_ofiledesc(SYSCTL_HANDLER_ARGS) 4404 { 4405 struct kinfo_ofile *okif; 4406 struct kinfo_file *kif; 4407 struct filedesc *fdp; 4408 struct pwddesc *pdp; 4409 struct pwd *pwd; 4410 int error, i, lastfile, *name; 4411 struct file *fp; 4412 struct proc *p; 4413 4414 name = (int *)arg1; 4415 error = pget((pid_t)name[0], PGET_CANDEBUG | PGET_NOTWEXIT, &p); 4416 if (error != 0) 4417 return (error); 4418 fdp = fdhold(p); 4419 if (fdp != NULL) 4420 pdp = pdhold(p); 4421 PROC_UNLOCK(p); 4422 if (fdp == NULL || pdp == NULL) { 4423 if (fdp != NULL) 4424 fddrop(fdp); 4425 return (ENOENT); 4426 } 4427 kif = malloc(sizeof(*kif), M_TEMP, M_WAITOK); 4428 okif = malloc(sizeof(*okif), M_TEMP, M_WAITOK); 4429 PWDDESC_XLOCK(pdp); 4430 pwd = pwd_hold_pwddesc(pdp); 4431 if (pwd != NULL) { 4432 if (pwd->pwd_cdir != NULL) 4433 export_vnode_for_osysctl(pwd->pwd_cdir, KF_FD_TYPE_CWD, kif, 4434 okif, pdp, req); 4435 if (pwd->pwd_rdir != NULL) 4436 export_vnode_for_osysctl(pwd->pwd_rdir, KF_FD_TYPE_ROOT, kif, 4437 okif, pdp, req); 4438 if (pwd->pwd_jdir != NULL) 4439 export_vnode_for_osysctl(pwd->pwd_jdir, KF_FD_TYPE_JAIL, kif, 4440 okif, pdp, req); 4441 } 4442 PWDDESC_XUNLOCK(pdp); 4443 if (pwd != NULL) 4444 pwd_drop(pwd); 4445 FILEDESC_SLOCK(fdp); 4446 lastfile = fdlastfile(fdp); 4447 for (i = 0; refcount_load(&fdp->fd_refcnt) > 0 && i <= lastfile; i++) { 4448 if ((fp = fdp->fd_ofiles[i].fde_file) == NULL) 4449 continue; 4450 export_file_to_kinfo(fp, i, NULL, kif, fdp, 4451 KERN_FILEDESC_PACK_KINFO); 4452 FILEDESC_SUNLOCK(fdp); 4453 kinfo_to_okinfo(kif, okif); 4454 error = SYSCTL_OUT(req, okif, sizeof(*okif)); 4455 FILEDESC_SLOCK(fdp); 4456 if (error) 4457 break; 4458 } 4459 FILEDESC_SUNLOCK(fdp); 4460 fddrop(fdp); 4461 pddrop(pdp); 4462 free(kif, M_TEMP); 4463 free(okif, M_TEMP); 4464 return (0); 4465 } 4466 4467 static SYSCTL_NODE(_kern_proc, KERN_PROC_OFILEDESC, ofiledesc, 4468 CTLFLAG_RD|CTLFLAG_MPSAFE, sysctl_kern_proc_ofiledesc, 4469 "Process ofiledesc entries"); 4470 #endif /* COMPAT_FREEBSD7 */ 4471 4472 int 4473 vntype_to_kinfo(int vtype) 4474 { 4475 struct { 4476 int vtype; 4477 int kf_vtype; 4478 } vtypes_table[] = { 4479 { VBAD, KF_VTYPE_VBAD }, 4480 { VBLK, KF_VTYPE_VBLK }, 4481 { VCHR, KF_VTYPE_VCHR }, 4482 { VDIR, KF_VTYPE_VDIR }, 4483 { VFIFO, KF_VTYPE_VFIFO }, 4484 { VLNK, KF_VTYPE_VLNK }, 4485 { VNON, KF_VTYPE_VNON }, 4486 { VREG, KF_VTYPE_VREG }, 4487 { VSOCK, KF_VTYPE_VSOCK } 4488 }; 4489 unsigned int i; 4490 4491 /* 4492 * Perform vtype translation. 4493 */ 4494 for (i = 0; i < nitems(vtypes_table); i++) 4495 if (vtypes_table[i].vtype == vtype) 4496 return (vtypes_table[i].kf_vtype); 4497 4498 return (KF_VTYPE_UNKNOWN); 4499 } 4500 4501 static SYSCTL_NODE(_kern_proc, KERN_PROC_FILEDESC, filedesc, 4502 CTLFLAG_RD|CTLFLAG_MPSAFE, sysctl_kern_proc_filedesc, 4503 "Process filedesc entries"); 4504 4505 /* 4506 * Store a process current working directory information to sbuf. 4507 * 4508 * Takes a locked proc as argument, and returns with the proc unlocked. 4509 */ 4510 int 4511 kern_proc_cwd_out(struct proc *p, struct sbuf *sb, ssize_t maxlen) 4512 { 4513 struct pwddesc *pdp; 4514 struct pwd *pwd; 4515 struct export_fd_buf *efbuf; 4516 struct vnode *cdir; 4517 int error; 4518 4519 PROC_LOCK_ASSERT(p, MA_OWNED); 4520 4521 pdp = pdhold(p); 4522 PROC_UNLOCK(p); 4523 if (pdp == NULL) 4524 return (EINVAL); 4525 4526 efbuf = malloc(sizeof(*efbuf), M_TEMP, M_WAITOK); 4527 efbuf->pdp = pdp; 4528 efbuf->sb = sb; 4529 efbuf->remainder = maxlen; 4530 4531 PWDDESC_XLOCK(pdp); 4532 pwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); 4533 cdir = pwd->pwd_cdir; 4534 if (cdir == NULL) { 4535 error = EINVAL; 4536 } else { 4537 vrefact(cdir); 4538 error = export_vnode_to_sb(cdir, KF_FD_TYPE_CWD, FREAD, efbuf); 4539 } 4540 PWDDESC_XUNLOCK(pdp); 4541 pddrop(pdp); 4542 free(efbuf, M_TEMP); 4543 return (error); 4544 } 4545 4546 /* 4547 * Get per-process current working directory. 4548 */ 4549 static int 4550 sysctl_kern_proc_cwd(SYSCTL_HANDLER_ARGS) 4551 { 4552 struct sbuf sb; 4553 struct proc *p; 4554 ssize_t maxlen; 4555 int error, error2, *name; 4556 4557 name = (int *)arg1; 4558 4559 sbuf_new_for_sysctl(&sb, NULL, sizeof(struct kinfo_file), req); 4560 sbuf_clear_flags(&sb, SBUF_INCLUDENUL); 4561 error = pget((pid_t)name[0], PGET_CANDEBUG | PGET_NOTWEXIT, &p); 4562 if (error != 0) { 4563 sbuf_delete(&sb); 4564 return (error); 4565 } 4566 maxlen = req->oldptr != NULL ? req->oldlen : -1; 4567 error = kern_proc_cwd_out(p, &sb, maxlen); 4568 error2 = sbuf_finish(&sb); 4569 sbuf_delete(&sb); 4570 return (error != 0 ? error : error2); 4571 } 4572 4573 static SYSCTL_NODE(_kern_proc, KERN_PROC_CWD, cwd, CTLFLAG_RD|CTLFLAG_MPSAFE, 4574 sysctl_kern_proc_cwd, "Process current working directory"); 4575 4576 #ifdef DDB 4577 /* 4578 * For the purposes of debugging, generate a human-readable string for the 4579 * file type. 4580 */ 4581 static const char * 4582 file_type_to_name(short type) 4583 { 4584 4585 switch (type) { 4586 case 0: 4587 return ("zero"); 4588 case DTYPE_VNODE: 4589 return ("vnode"); 4590 case DTYPE_SOCKET: 4591 return ("socket"); 4592 case DTYPE_PIPE: 4593 return ("pipe"); 4594 case DTYPE_FIFO: 4595 return ("fifo"); 4596 case DTYPE_KQUEUE: 4597 return ("kqueue"); 4598 case DTYPE_CRYPTO: 4599 return ("crypto"); 4600 case DTYPE_MQUEUE: 4601 return ("mqueue"); 4602 case DTYPE_SHM: 4603 return ("shm"); 4604 case DTYPE_SEM: 4605 return ("ksem"); 4606 case DTYPE_PTS: 4607 return ("pts"); 4608 case DTYPE_DEV: 4609 return ("dev"); 4610 case DTYPE_PROCDESC: 4611 return ("proc"); 4612 case DTYPE_LINUXEFD: 4613 return ("levent"); 4614 case DTYPE_LINUXTFD: 4615 return ("ltimer"); 4616 default: 4617 return ("unkn"); 4618 } 4619 } 4620 4621 /* 4622 * For the purposes of debugging, identify a process (if any, perhaps one of 4623 * many) that references the passed file in its file descriptor array. Return 4624 * NULL if none. 4625 */ 4626 static struct proc * 4627 file_to_first_proc(struct file *fp) 4628 { 4629 struct filedesc *fdp; 4630 struct proc *p; 4631 int n; 4632 4633 FOREACH_PROC_IN_SYSTEM(p) { 4634 if (p->p_state == PRS_NEW) 4635 continue; 4636 fdp = p->p_fd; 4637 if (fdp == NULL) 4638 continue; 4639 for (n = 0; n < fdp->fd_nfiles; n++) { 4640 if (fp == fdp->fd_ofiles[n].fde_file) 4641 return (p); 4642 } 4643 } 4644 return (NULL); 4645 } 4646 4647 static void 4648 db_print_file(struct file *fp, int header) 4649 { 4650 #define XPTRWIDTH ((int)howmany(sizeof(void *) * NBBY, 4)) 4651 struct proc *p; 4652 4653 if (header) 4654 db_printf("%*s %6s %*s %8s %4s %5s %6s %*s %5s %s\n", 4655 XPTRWIDTH, "File", "Type", XPTRWIDTH, "Data", "Flag", 4656 "GCFl", "Count", "MCount", XPTRWIDTH, "Vnode", "FPID", 4657 "FCmd"); 4658 p = file_to_first_proc(fp); 4659 db_printf("%*p %6s %*p %08x %04x %5d %6d %*p %5d %s\n", XPTRWIDTH, 4660 fp, file_type_to_name(fp->f_type), XPTRWIDTH, fp->f_data, 4661 fp->f_flag, 0, refcount_load(&fp->f_count), 0, XPTRWIDTH, fp->f_vnode, 4662 p != NULL ? p->p_pid : -1, p != NULL ? p->p_comm : "-"); 4663 4664 #undef XPTRWIDTH 4665 } 4666 4667 DB_SHOW_COMMAND(file, db_show_file) 4668 { 4669 struct file *fp; 4670 4671 if (!have_addr) { 4672 db_printf("usage: show file <addr>\n"); 4673 return; 4674 } 4675 fp = (struct file *)addr; 4676 db_print_file(fp, 1); 4677 } 4678 4679 DB_SHOW_COMMAND(files, db_show_files) 4680 { 4681 struct filedesc *fdp; 4682 struct file *fp; 4683 struct proc *p; 4684 int header; 4685 int n; 4686 4687 header = 1; 4688 FOREACH_PROC_IN_SYSTEM(p) { 4689 if (p->p_state == PRS_NEW) 4690 continue; 4691 if ((fdp = p->p_fd) == NULL) 4692 continue; 4693 for (n = 0; n < fdp->fd_nfiles; ++n) { 4694 if ((fp = fdp->fd_ofiles[n].fde_file) == NULL) 4695 continue; 4696 db_print_file(fp, header); 4697 header = 0; 4698 } 4699 } 4700 } 4701 #endif 4702 4703 SYSCTL_INT(_kern, KERN_MAXFILESPERPROC, maxfilesperproc, CTLFLAG_RW, 4704 &maxfilesperproc, 0, "Maximum files allowed open per process"); 4705 4706 SYSCTL_INT(_kern, KERN_MAXFILES, maxfiles, CTLFLAG_RW, 4707 &maxfiles, 0, "Maximum number of files"); 4708 4709 SYSCTL_INT(_kern, OID_AUTO, openfiles, CTLFLAG_RD, 4710 &openfiles, 0, "System-wide number of open files"); 4711 4712 /* ARGSUSED*/ 4713 static void 4714 filelistinit(void *dummy) 4715 { 4716 4717 file_zone = uma_zcreate("Files", sizeof(struct file), NULL, NULL, 4718 NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE); 4719 filedesc0_zone = uma_zcreate("filedesc0", sizeof(struct filedesc0), 4720 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0); 4721 pwd_zone = uma_zcreate("PWD", sizeof(struct pwd), NULL, NULL, 4722 NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_SMR); 4723 /* 4724 * XXXMJG this is a temporary hack due to boot ordering issues against 4725 * the vnode zone. 4726 */ 4727 vfs_smr = uma_zone_get_smr(pwd_zone); 4728 mtx_init(&sigio_lock, "sigio lock", NULL, MTX_DEF); 4729 } 4730 SYSINIT(select, SI_SUB_LOCK, SI_ORDER_FIRST, filelistinit, NULL); 4731 4732 /*-------------------------------------------------------------------*/ 4733 4734 static int 4735 badfo_readwrite(struct file *fp, struct uio *uio, struct ucred *active_cred, 4736 int flags, struct thread *td) 4737 { 4738 4739 return (EBADF); 4740 } 4741 4742 static int 4743 badfo_truncate(struct file *fp, off_t length, struct ucred *active_cred, 4744 struct thread *td) 4745 { 4746 4747 return (EINVAL); 4748 } 4749 4750 static int 4751 badfo_ioctl(struct file *fp, u_long com, void *data, struct ucred *active_cred, 4752 struct thread *td) 4753 { 4754 4755 return (EBADF); 4756 } 4757 4758 static int 4759 badfo_poll(struct file *fp, int events, struct ucred *active_cred, 4760 struct thread *td) 4761 { 4762 4763 return (0); 4764 } 4765 4766 static int 4767 badfo_kqfilter(struct file *fp, struct knote *kn) 4768 { 4769 4770 return (EBADF); 4771 } 4772 4773 static int 4774 badfo_stat(struct file *fp, struct stat *sb, struct ucred *active_cred, 4775 struct thread *td) 4776 { 4777 4778 return (EBADF); 4779 } 4780 4781 static int 4782 badfo_close(struct file *fp, struct thread *td) 4783 { 4784 4785 return (0); 4786 } 4787 4788 static int 4789 badfo_chmod(struct file *fp, mode_t mode, struct ucred *active_cred, 4790 struct thread *td) 4791 { 4792 4793 return (EBADF); 4794 } 4795 4796 static int 4797 badfo_chown(struct file *fp, uid_t uid, gid_t gid, struct ucred *active_cred, 4798 struct thread *td) 4799 { 4800 4801 return (EBADF); 4802 } 4803 4804 static int 4805 badfo_sendfile(struct file *fp, int sockfd, struct uio *hdr_uio, 4806 struct uio *trl_uio, off_t offset, size_t nbytes, off_t *sent, int flags, 4807 struct thread *td) 4808 { 4809 4810 return (EBADF); 4811 } 4812 4813 static int 4814 badfo_fill_kinfo(struct file *fp, struct kinfo_file *kif, struct filedesc *fdp) 4815 { 4816 4817 return (0); 4818 } 4819 4820 struct fileops badfileops = { 4821 .fo_read = badfo_readwrite, 4822 .fo_write = badfo_readwrite, 4823 .fo_truncate = badfo_truncate, 4824 .fo_ioctl = badfo_ioctl, 4825 .fo_poll = badfo_poll, 4826 .fo_kqfilter = badfo_kqfilter, 4827 .fo_stat = badfo_stat, 4828 .fo_close = badfo_close, 4829 .fo_chmod = badfo_chmod, 4830 .fo_chown = badfo_chown, 4831 .fo_sendfile = badfo_sendfile, 4832 .fo_fill_kinfo = badfo_fill_kinfo, 4833 }; 4834 4835 int 4836 invfo_rdwr(struct file *fp, struct uio *uio, struct ucred *active_cred, 4837 int flags, struct thread *td) 4838 { 4839 4840 return (EOPNOTSUPP); 4841 } 4842 4843 int 4844 invfo_truncate(struct file *fp, off_t length, struct ucred *active_cred, 4845 struct thread *td) 4846 { 4847 4848 return (EINVAL); 4849 } 4850 4851 int 4852 invfo_ioctl(struct file *fp, u_long com, void *data, 4853 struct ucred *active_cred, struct thread *td) 4854 { 4855 4856 return (ENOTTY); 4857 } 4858 4859 int 4860 invfo_poll(struct file *fp, int events, struct ucred *active_cred, 4861 struct thread *td) 4862 { 4863 4864 return (poll_no_poll(events)); 4865 } 4866 4867 int 4868 invfo_kqfilter(struct file *fp, struct knote *kn) 4869 { 4870 4871 return (EINVAL); 4872 } 4873 4874 int 4875 invfo_chmod(struct file *fp, mode_t mode, struct ucred *active_cred, 4876 struct thread *td) 4877 { 4878 4879 return (EINVAL); 4880 } 4881 4882 int 4883 invfo_chown(struct file *fp, uid_t uid, gid_t gid, struct ucred *active_cred, 4884 struct thread *td) 4885 { 4886 4887 return (EINVAL); 4888 } 4889 4890 int 4891 invfo_sendfile(struct file *fp, int sockfd, struct uio *hdr_uio, 4892 struct uio *trl_uio, off_t offset, size_t nbytes, off_t *sent, int flags, 4893 struct thread *td) 4894 { 4895 4896 return (EINVAL); 4897 } 4898 4899 /*-------------------------------------------------------------------*/ 4900 4901 /* 4902 * File Descriptor pseudo-device driver (/dev/fd/). 4903 * 4904 * Opening minor device N dup()s the file (if any) connected to file 4905 * descriptor N belonging to the calling process. Note that this driver 4906 * consists of only the ``open()'' routine, because all subsequent 4907 * references to this file will be direct to the other driver. 4908 * 4909 * XXX: we could give this one a cloning event handler if necessary. 4910 */ 4911 4912 /* ARGSUSED */ 4913 static int 4914 fdopen(struct cdev *dev, int mode, int type, struct thread *td) 4915 { 4916 4917 /* 4918 * XXX Kludge: set curthread->td_dupfd to contain the value of the 4919 * the file descriptor being sought for duplication. The error 4920 * return ensures that the vnode for this device will be released 4921 * by vn_open. Open will detect this special error and take the 4922 * actions in dupfdopen below. Other callers of vn_open or VOP_OPEN 4923 * will simply report the error. 4924 */ 4925 td->td_dupfd = dev2unit(dev); 4926 return (ENODEV); 4927 } 4928 4929 static struct cdevsw fildesc_cdevsw = { 4930 .d_version = D_VERSION, 4931 .d_open = fdopen, 4932 .d_name = "FD", 4933 }; 4934 4935 static void 4936 fildesc_drvinit(void *unused) 4937 { 4938 struct cdev *dev; 4939 4940 dev = make_dev_credf(MAKEDEV_ETERNAL, &fildesc_cdevsw, 0, NULL, 4941 UID_ROOT, GID_WHEEL, 0666, "fd/0"); 4942 make_dev_alias(dev, "stdin"); 4943 dev = make_dev_credf(MAKEDEV_ETERNAL, &fildesc_cdevsw, 1, NULL, 4944 UID_ROOT, GID_WHEEL, 0666, "fd/1"); 4945 make_dev_alias(dev, "stdout"); 4946 dev = make_dev_credf(MAKEDEV_ETERNAL, &fildesc_cdevsw, 2, NULL, 4947 UID_ROOT, GID_WHEEL, 0666, "fd/2"); 4948 make_dev_alias(dev, "stderr"); 4949 } 4950 4951 SYSINIT(fildescdev, SI_SUB_DRIVERS, SI_ORDER_MIDDLE, fildesc_drvinit, NULL); 4952