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