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 if (holdleaders) { 1283 FILEDESC_XLOCK(fdp); 1284 fdp->fd_holdleaderscount--; 1285 if (fdp->fd_holdleaderscount == 0 && 1286 fdp->fd_holdleaderswakeup != 0) { 1287 fdp->fd_holdleaderswakeup = 0; 1288 wakeup(&fdp->fd_holdleaderscount); 1289 } 1290 FILEDESC_XUNLOCK(fdp); 1291 } 1292 return (error); 1293 } 1294 1295 /* 1296 * Close a file descriptor. 1297 */ 1298 #ifndef _SYS_SYSPROTO_H_ 1299 struct close_args { 1300 int fd; 1301 }; 1302 #endif 1303 /* ARGSUSED */ 1304 int 1305 sys_close(struct thread *td, struct close_args *uap) 1306 { 1307 1308 return (kern_close(td, uap->fd)); 1309 } 1310 1311 int 1312 kern_close(struct thread *td, int fd) 1313 { 1314 struct filedesc *fdp; 1315 struct file *fp; 1316 1317 fdp = td->td_proc->p_fd; 1318 1319 AUDIT_SYSCLOSE(td, fd); 1320 1321 FILEDESC_XLOCK(fdp); 1322 if ((fp = fget_locked(fdp, fd)) == NULL) { 1323 FILEDESC_XUNLOCK(fdp); 1324 return (EBADF); 1325 } 1326 fdfree(fdp, fd); 1327 1328 /* closefp() drops the FILEDESC lock for us. */ 1329 return (closefp(fdp, fd, fp, td, 1)); 1330 } 1331 1332 int 1333 kern_close_range(struct thread *td, u_int lowfd, u_int highfd) 1334 { 1335 struct filedesc *fdp; 1336 int fd, ret, lastfile; 1337 1338 ret = 0; 1339 fdp = td->td_proc->p_fd; 1340 FILEDESC_SLOCK(fdp); 1341 1342 /* 1343 * Check this prior to clamping; closefrom(3) with only fd 0, 1, and 2 1344 * open should not be a usage error. From a close_range() perspective, 1345 * close_range(3, ~0U, 0) in the same scenario should also likely not 1346 * be a usage error as all fd above 3 are in-fact already closed. 1347 */ 1348 if (highfd < lowfd) { 1349 ret = EINVAL; 1350 goto out; 1351 } 1352 1353 /* 1354 * If lastfile == -1, we're dealing with either a fresh file 1355 * table or one in which every fd has been closed. Just return 1356 * successful; there's nothing left to do. 1357 */ 1358 lastfile = fdlastfile(fdp); 1359 if (lastfile == -1) 1360 goto out; 1361 /* Clamped to [lowfd, lastfile] */ 1362 highfd = MIN(highfd, lastfile); 1363 for (fd = lowfd; fd <= highfd; fd++) { 1364 if (fdp->fd_ofiles[fd].fde_file != NULL) { 1365 FILEDESC_SUNLOCK(fdp); 1366 (void)kern_close(td, fd); 1367 FILEDESC_SLOCK(fdp); 1368 } 1369 } 1370 out: 1371 FILEDESC_SUNLOCK(fdp); 1372 return (ret); 1373 } 1374 1375 #ifndef _SYS_SYSPROTO_H_ 1376 struct close_range_args { 1377 u_int lowfd; 1378 u_int highfd; 1379 int flags; 1380 }; 1381 #endif 1382 int 1383 sys_close_range(struct thread *td, struct close_range_args *uap) 1384 { 1385 1386 /* No flags currently defined */ 1387 if (uap->flags != 0) 1388 return (EINVAL); 1389 return (kern_close_range(td, uap->lowfd, uap->highfd)); 1390 } 1391 1392 #ifdef COMPAT_FREEBSD12 1393 /* 1394 * Close open file descriptors. 1395 */ 1396 #ifndef _SYS_SYSPROTO_H_ 1397 struct freebsd12_closefrom_args { 1398 int lowfd; 1399 }; 1400 #endif 1401 /* ARGSUSED */ 1402 int 1403 freebsd12_closefrom(struct thread *td, struct freebsd12_closefrom_args *uap) 1404 { 1405 u_int lowfd; 1406 1407 AUDIT_ARG_FD(uap->lowfd); 1408 1409 /* 1410 * Treat negative starting file descriptor values identical to 1411 * closefrom(0) which closes all files. 1412 */ 1413 lowfd = MAX(0, uap->lowfd); 1414 return (kern_close_range(td, lowfd, ~0U)); 1415 } 1416 #endif /* COMPAT_FREEBSD12 */ 1417 1418 #if defined(COMPAT_43) 1419 /* 1420 * Return status information about a file descriptor. 1421 */ 1422 #ifndef _SYS_SYSPROTO_H_ 1423 struct ofstat_args { 1424 int fd; 1425 struct ostat *sb; 1426 }; 1427 #endif 1428 /* ARGSUSED */ 1429 int 1430 ofstat(struct thread *td, struct ofstat_args *uap) 1431 { 1432 struct ostat oub; 1433 struct stat ub; 1434 int error; 1435 1436 error = kern_fstat(td, uap->fd, &ub); 1437 if (error == 0) { 1438 cvtstat(&ub, &oub); 1439 error = copyout(&oub, uap->sb, sizeof(oub)); 1440 } 1441 return (error); 1442 } 1443 #endif /* COMPAT_43 */ 1444 1445 #if defined(COMPAT_FREEBSD11) 1446 int 1447 freebsd11_fstat(struct thread *td, struct freebsd11_fstat_args *uap) 1448 { 1449 struct stat sb; 1450 struct freebsd11_stat osb; 1451 int error; 1452 1453 error = kern_fstat(td, uap->fd, &sb); 1454 if (error != 0) 1455 return (error); 1456 error = freebsd11_cvtstat(&sb, &osb); 1457 if (error == 0) 1458 error = copyout(&osb, uap->sb, sizeof(osb)); 1459 return (error); 1460 } 1461 #endif /* COMPAT_FREEBSD11 */ 1462 1463 /* 1464 * Return status information about a file descriptor. 1465 */ 1466 #ifndef _SYS_SYSPROTO_H_ 1467 struct fstat_args { 1468 int fd; 1469 struct stat *sb; 1470 }; 1471 #endif 1472 /* ARGSUSED */ 1473 int 1474 sys_fstat(struct thread *td, struct fstat_args *uap) 1475 { 1476 struct stat ub; 1477 int error; 1478 1479 error = kern_fstat(td, uap->fd, &ub); 1480 if (error == 0) 1481 error = copyout(&ub, uap->sb, sizeof(ub)); 1482 return (error); 1483 } 1484 1485 int 1486 kern_fstat(struct thread *td, int fd, struct stat *sbp) 1487 { 1488 struct file *fp; 1489 int error; 1490 1491 AUDIT_ARG_FD(fd); 1492 1493 error = fget(td, fd, &cap_fstat_rights, &fp); 1494 if (__predict_false(error != 0)) 1495 return (error); 1496 1497 AUDIT_ARG_FILE(td->td_proc, fp); 1498 1499 error = fo_stat(fp, sbp, td->td_ucred, td); 1500 fdrop(fp, td); 1501 #ifdef __STAT_TIME_T_EXT 1502 sbp->st_atim_ext = 0; 1503 sbp->st_mtim_ext = 0; 1504 sbp->st_ctim_ext = 0; 1505 sbp->st_btim_ext = 0; 1506 #endif 1507 #ifdef KTRACE 1508 if (KTRPOINT(td, KTR_STRUCT)) 1509 ktrstat_error(sbp, error); 1510 #endif 1511 return (error); 1512 } 1513 1514 #if defined(COMPAT_FREEBSD11) 1515 /* 1516 * Return status information about a file descriptor. 1517 */ 1518 #ifndef _SYS_SYSPROTO_H_ 1519 struct freebsd11_nfstat_args { 1520 int fd; 1521 struct nstat *sb; 1522 }; 1523 #endif 1524 /* ARGSUSED */ 1525 int 1526 freebsd11_nfstat(struct thread *td, struct freebsd11_nfstat_args *uap) 1527 { 1528 struct nstat nub; 1529 struct stat ub; 1530 int error; 1531 1532 error = kern_fstat(td, uap->fd, &ub); 1533 if (error == 0) { 1534 freebsd11_cvtnstat(&ub, &nub); 1535 error = copyout(&nub, uap->sb, sizeof(nub)); 1536 } 1537 return (error); 1538 } 1539 #endif /* COMPAT_FREEBSD11 */ 1540 1541 /* 1542 * Return pathconf information about a file descriptor. 1543 */ 1544 #ifndef _SYS_SYSPROTO_H_ 1545 struct fpathconf_args { 1546 int fd; 1547 int name; 1548 }; 1549 #endif 1550 /* ARGSUSED */ 1551 int 1552 sys_fpathconf(struct thread *td, struct fpathconf_args *uap) 1553 { 1554 long value; 1555 int error; 1556 1557 error = kern_fpathconf(td, uap->fd, uap->name, &value); 1558 if (error == 0) 1559 td->td_retval[0] = value; 1560 return (error); 1561 } 1562 1563 int 1564 kern_fpathconf(struct thread *td, int fd, int name, long *valuep) 1565 { 1566 struct file *fp; 1567 struct vnode *vp; 1568 int error; 1569 1570 error = fget(td, fd, &cap_fpathconf_rights, &fp); 1571 if (error != 0) 1572 return (error); 1573 1574 if (name == _PC_ASYNC_IO) { 1575 *valuep = _POSIX_ASYNCHRONOUS_IO; 1576 goto out; 1577 } 1578 vp = fp->f_vnode; 1579 if (vp != NULL) { 1580 vn_lock(vp, LK_SHARED | LK_RETRY); 1581 error = VOP_PATHCONF(vp, name, valuep); 1582 VOP_UNLOCK(vp); 1583 } else if (fp->f_type == DTYPE_PIPE || fp->f_type == DTYPE_SOCKET) { 1584 if (name != _PC_PIPE_BUF) { 1585 error = EINVAL; 1586 } else { 1587 *valuep = PIPE_BUF; 1588 error = 0; 1589 } 1590 } else { 1591 error = EOPNOTSUPP; 1592 } 1593 out: 1594 fdrop(fp, td); 1595 return (error); 1596 } 1597 1598 /* 1599 * Copy filecaps structure allocating memory for ioctls array if needed. 1600 * 1601 * The last parameter indicates whether the fdtable is locked. If it is not and 1602 * ioctls are encountered, copying fails and the caller must lock the table. 1603 * 1604 * Note that if the table was not locked, the caller has to check the relevant 1605 * sequence counter to determine whether the operation was successful. 1606 */ 1607 bool 1608 filecaps_copy(const struct filecaps *src, struct filecaps *dst, bool locked) 1609 { 1610 size_t size; 1611 1612 if (src->fc_ioctls != NULL && !locked) 1613 return (false); 1614 memcpy(dst, src, sizeof(*src)); 1615 if (src->fc_ioctls == NULL) 1616 return (true); 1617 1618 KASSERT(src->fc_nioctls > 0, 1619 ("fc_ioctls != NULL, but fc_nioctls=%hd", src->fc_nioctls)); 1620 1621 size = sizeof(src->fc_ioctls[0]) * src->fc_nioctls; 1622 dst->fc_ioctls = malloc(size, M_FILECAPS, M_WAITOK); 1623 memcpy(dst->fc_ioctls, src->fc_ioctls, size); 1624 return (true); 1625 } 1626 1627 static u_long * 1628 filecaps_copy_prep(const struct filecaps *src) 1629 { 1630 u_long *ioctls; 1631 size_t size; 1632 1633 if (__predict_true(src->fc_ioctls == NULL)) 1634 return (NULL); 1635 1636 KASSERT(src->fc_nioctls > 0, 1637 ("fc_ioctls != NULL, but fc_nioctls=%hd", src->fc_nioctls)); 1638 1639 size = sizeof(src->fc_ioctls[0]) * src->fc_nioctls; 1640 ioctls = malloc(size, M_FILECAPS, M_WAITOK); 1641 return (ioctls); 1642 } 1643 1644 static void 1645 filecaps_copy_finish(const struct filecaps *src, struct filecaps *dst, 1646 u_long *ioctls) 1647 { 1648 size_t size; 1649 1650 *dst = *src; 1651 if (__predict_true(src->fc_ioctls == NULL)) { 1652 MPASS(ioctls == NULL); 1653 return; 1654 } 1655 1656 size = sizeof(src->fc_ioctls[0]) * src->fc_nioctls; 1657 dst->fc_ioctls = ioctls; 1658 bcopy(src->fc_ioctls, dst->fc_ioctls, size); 1659 } 1660 1661 /* 1662 * Move filecaps structure to the new place and clear the old place. 1663 */ 1664 void 1665 filecaps_move(struct filecaps *src, struct filecaps *dst) 1666 { 1667 1668 *dst = *src; 1669 bzero(src, sizeof(*src)); 1670 } 1671 1672 /* 1673 * Fill the given filecaps structure with full rights. 1674 */ 1675 static void 1676 filecaps_fill(struct filecaps *fcaps) 1677 { 1678 1679 CAP_ALL(&fcaps->fc_rights); 1680 fcaps->fc_ioctls = NULL; 1681 fcaps->fc_nioctls = -1; 1682 fcaps->fc_fcntls = CAP_FCNTL_ALL; 1683 } 1684 1685 /* 1686 * Free memory allocated within filecaps structure. 1687 */ 1688 void 1689 filecaps_free(struct filecaps *fcaps) 1690 { 1691 1692 free(fcaps->fc_ioctls, M_FILECAPS); 1693 bzero(fcaps, sizeof(*fcaps)); 1694 } 1695 1696 static u_long * 1697 filecaps_free_prep(struct filecaps *fcaps) 1698 { 1699 u_long *ioctls; 1700 1701 ioctls = fcaps->fc_ioctls; 1702 bzero(fcaps, sizeof(*fcaps)); 1703 return (ioctls); 1704 } 1705 1706 static void 1707 filecaps_free_finish(u_long *ioctls) 1708 { 1709 1710 free(ioctls, M_FILECAPS); 1711 } 1712 1713 /* 1714 * Validate the given filecaps structure. 1715 */ 1716 static void 1717 filecaps_validate(const struct filecaps *fcaps, const char *func) 1718 { 1719 1720 KASSERT(cap_rights_is_valid(&fcaps->fc_rights), 1721 ("%s: invalid rights", func)); 1722 KASSERT((fcaps->fc_fcntls & ~CAP_FCNTL_ALL) == 0, 1723 ("%s: invalid fcntls", func)); 1724 KASSERT(fcaps->fc_fcntls == 0 || 1725 cap_rights_is_set(&fcaps->fc_rights, CAP_FCNTL), 1726 ("%s: fcntls without CAP_FCNTL", func)); 1727 KASSERT(fcaps->fc_ioctls != NULL ? fcaps->fc_nioctls > 0 : 1728 (fcaps->fc_nioctls == -1 || fcaps->fc_nioctls == 0), 1729 ("%s: invalid ioctls", func)); 1730 KASSERT(fcaps->fc_nioctls == 0 || 1731 cap_rights_is_set(&fcaps->fc_rights, CAP_IOCTL), 1732 ("%s: ioctls without CAP_IOCTL", func)); 1733 } 1734 1735 static void 1736 fdgrowtable_exp(struct filedesc *fdp, int nfd) 1737 { 1738 int nfd1; 1739 1740 FILEDESC_XLOCK_ASSERT(fdp); 1741 1742 nfd1 = fdp->fd_nfiles * 2; 1743 if (nfd1 < nfd) 1744 nfd1 = nfd; 1745 fdgrowtable(fdp, nfd1); 1746 } 1747 1748 /* 1749 * Grow the file table to accommodate (at least) nfd descriptors. 1750 */ 1751 static void 1752 fdgrowtable(struct filedesc *fdp, int nfd) 1753 { 1754 struct filedesc0 *fdp0; 1755 struct freetable *ft; 1756 struct fdescenttbl *ntable; 1757 struct fdescenttbl *otable; 1758 int nnfiles, onfiles; 1759 NDSLOTTYPE *nmap, *omap; 1760 1761 KASSERT(fdp->fd_nfiles > 0, ("zero-length file table")); 1762 1763 /* save old values */ 1764 onfiles = fdp->fd_nfiles; 1765 otable = fdp->fd_files; 1766 omap = fdp->fd_map; 1767 1768 /* compute the size of the new table */ 1769 nnfiles = NDSLOTS(nfd) * NDENTRIES; /* round up */ 1770 if (nnfiles <= onfiles) 1771 /* the table is already large enough */ 1772 return; 1773 1774 /* 1775 * Allocate a new table. We need enough space for the number of 1776 * entries, file entries themselves and the struct freetable we will use 1777 * when we decommission the table and place it on the freelist. 1778 * We place the struct freetable in the middle so we don't have 1779 * to worry about padding. 1780 */ 1781 ntable = malloc(offsetof(struct fdescenttbl, fdt_ofiles) + 1782 nnfiles * sizeof(ntable->fdt_ofiles[0]) + 1783 sizeof(struct freetable), 1784 M_FILEDESC, M_ZERO | M_WAITOK); 1785 /* copy the old data */ 1786 ntable->fdt_nfiles = nnfiles; 1787 memcpy(ntable->fdt_ofiles, otable->fdt_ofiles, 1788 onfiles * sizeof(ntable->fdt_ofiles[0])); 1789 1790 /* 1791 * Allocate a new map only if the old is not large enough. It will 1792 * grow at a slower rate than the table as it can map more 1793 * entries than the table can hold. 1794 */ 1795 if (NDSLOTS(nnfiles) > NDSLOTS(onfiles)) { 1796 nmap = malloc(NDSLOTS(nnfiles) * NDSLOTSIZE, M_FILEDESC, 1797 M_ZERO | M_WAITOK); 1798 /* copy over the old data and update the pointer */ 1799 memcpy(nmap, omap, NDSLOTS(onfiles) * sizeof(*omap)); 1800 fdp->fd_map = nmap; 1801 } 1802 1803 /* 1804 * Make sure that ntable is correctly initialized before we replace 1805 * fd_files poiner. Otherwise fget_unlocked() may see inconsistent 1806 * data. 1807 */ 1808 atomic_store_rel_ptr((volatile void *)&fdp->fd_files, (uintptr_t)ntable); 1809 1810 /* 1811 * Free the old file table when not shared by other threads or processes. 1812 * The old file table is considered to be shared when either are true: 1813 * - The process has more than one thread. 1814 * - The file descriptor table has been shared via fdshare(). 1815 * 1816 * When shared, the old file table will be placed on a freelist 1817 * which will be processed when the struct filedesc is released. 1818 * 1819 * Note that if onfiles == NDFILE, we're dealing with the original 1820 * static allocation contained within (struct filedesc0 *)fdp, 1821 * which must not be freed. 1822 */ 1823 if (onfiles > NDFILE) { 1824 if (curproc->p_numthreads == 1 && fdp->fd_refcnt == 1) 1825 free(otable, M_FILEDESC); 1826 else { 1827 ft = (struct freetable *)&otable->fdt_ofiles[onfiles]; 1828 fdp0 = (struct filedesc0 *)fdp; 1829 ft->ft_table = otable; 1830 SLIST_INSERT_HEAD(&fdp0->fd_free, ft, ft_next); 1831 } 1832 } 1833 /* 1834 * The map does not have the same possibility of threads still 1835 * holding references to it. So always free it as long as it 1836 * does not reference the original static allocation. 1837 */ 1838 if (NDSLOTS(onfiles) > NDSLOTS(NDFILE)) 1839 free(omap, M_FILEDESC); 1840 } 1841 1842 /* 1843 * Allocate a file descriptor for the process. 1844 */ 1845 int 1846 fdalloc(struct thread *td, int minfd, int *result) 1847 { 1848 struct proc *p = td->td_proc; 1849 struct filedesc *fdp = p->p_fd; 1850 int fd, maxfd, allocfd; 1851 #ifdef RACCT 1852 int error; 1853 #endif 1854 1855 FILEDESC_XLOCK_ASSERT(fdp); 1856 1857 if (fdp->fd_freefile > minfd) 1858 minfd = fdp->fd_freefile; 1859 1860 maxfd = getmaxfd(td); 1861 1862 /* 1863 * Search the bitmap for a free descriptor starting at minfd. 1864 * If none is found, grow the file table. 1865 */ 1866 fd = fd_first_free(fdp, minfd, fdp->fd_nfiles); 1867 if (__predict_false(fd >= maxfd)) 1868 return (EMFILE); 1869 if (__predict_false(fd >= fdp->fd_nfiles)) { 1870 allocfd = min(fd * 2, maxfd); 1871 #ifdef RACCT 1872 if (RACCT_ENABLED()) { 1873 error = racct_set_unlocked(p, RACCT_NOFILE, allocfd); 1874 if (error != 0) 1875 return (EMFILE); 1876 } 1877 #endif 1878 /* 1879 * fd is already equal to first free descriptor >= minfd, so 1880 * we only need to grow the table and we are done. 1881 */ 1882 fdgrowtable_exp(fdp, allocfd); 1883 } 1884 1885 /* 1886 * Perform some sanity checks, then mark the file descriptor as 1887 * used and return it to the caller. 1888 */ 1889 KASSERT(fd >= 0 && fd < min(maxfd, fdp->fd_nfiles), 1890 ("invalid descriptor %d", fd)); 1891 KASSERT(!fdisused(fdp, fd), 1892 ("fd_first_free() returned non-free descriptor")); 1893 KASSERT(fdp->fd_ofiles[fd].fde_file == NULL, 1894 ("file descriptor isn't free")); 1895 fdused(fdp, fd); 1896 *result = fd; 1897 return (0); 1898 } 1899 1900 /* 1901 * Allocate n file descriptors for the process. 1902 */ 1903 int 1904 fdallocn(struct thread *td, int minfd, int *fds, int n) 1905 { 1906 struct proc *p = td->td_proc; 1907 struct filedesc *fdp = p->p_fd; 1908 int i; 1909 1910 FILEDESC_XLOCK_ASSERT(fdp); 1911 1912 for (i = 0; i < n; i++) 1913 if (fdalloc(td, 0, &fds[i]) != 0) 1914 break; 1915 1916 if (i < n) { 1917 for (i--; i >= 0; i--) 1918 fdunused(fdp, fds[i]); 1919 return (EMFILE); 1920 } 1921 1922 return (0); 1923 } 1924 1925 /* 1926 * Create a new open file structure and allocate a file descriptor for the 1927 * process that refers to it. We add one reference to the file for the 1928 * descriptor table and one reference for resultfp. This is to prevent us 1929 * being preempted and the entry in the descriptor table closed after we 1930 * release the FILEDESC lock. 1931 */ 1932 int 1933 falloc_caps(struct thread *td, struct file **resultfp, int *resultfd, int flags, 1934 struct filecaps *fcaps) 1935 { 1936 struct file *fp; 1937 int error, fd; 1938 1939 error = falloc_noinstall(td, &fp); 1940 if (error) 1941 return (error); /* no reference held on error */ 1942 1943 error = finstall(td, fp, &fd, flags, fcaps); 1944 if (error) { 1945 fdrop(fp, td); /* one reference (fp only) */ 1946 return (error); 1947 } 1948 1949 if (resultfp != NULL) 1950 *resultfp = fp; /* copy out result */ 1951 else 1952 fdrop(fp, td); /* release local reference */ 1953 1954 if (resultfd != NULL) 1955 *resultfd = fd; 1956 1957 return (0); 1958 } 1959 1960 /* 1961 * Create a new open file structure without allocating a file descriptor. 1962 */ 1963 int 1964 falloc_noinstall(struct thread *td, struct file **resultfp) 1965 { 1966 struct file *fp; 1967 int maxuserfiles = maxfiles - (maxfiles / 20); 1968 int openfiles_new; 1969 static struct timeval lastfail; 1970 static int curfail; 1971 1972 KASSERT(resultfp != NULL, ("%s: resultfp == NULL", __func__)); 1973 1974 openfiles_new = atomic_fetchadd_int(&openfiles, 1) + 1; 1975 if ((openfiles_new >= maxuserfiles && 1976 priv_check(td, PRIV_MAXFILES) != 0) || 1977 openfiles_new >= maxfiles) { 1978 atomic_subtract_int(&openfiles, 1); 1979 if (ppsratecheck(&lastfail, &curfail, 1)) { 1980 printf("kern.maxfiles limit exceeded by uid %i, (%s) " 1981 "please see tuning(7).\n", td->td_ucred->cr_ruid, td->td_proc->p_comm); 1982 } 1983 return (ENFILE); 1984 } 1985 fp = uma_zalloc(file_zone, M_WAITOK); 1986 bzero(fp, sizeof(*fp)); 1987 refcount_init(&fp->f_count, 1); 1988 fp->f_cred = crhold(td->td_ucred); 1989 fp->f_ops = &badfileops; 1990 *resultfp = fp; 1991 return (0); 1992 } 1993 1994 /* 1995 * Install a file in a file descriptor table. 1996 */ 1997 void 1998 _finstall(struct filedesc *fdp, struct file *fp, int fd, int flags, 1999 struct filecaps *fcaps) 2000 { 2001 struct filedescent *fde; 2002 2003 MPASS(fp != NULL); 2004 if (fcaps != NULL) 2005 filecaps_validate(fcaps, __func__); 2006 FILEDESC_XLOCK_ASSERT(fdp); 2007 2008 fde = &fdp->fd_ofiles[fd]; 2009 #ifdef CAPABILITIES 2010 seqc_write_begin(&fde->fde_seqc); 2011 #endif 2012 fde->fde_file = fp; 2013 fde->fde_flags = (flags & O_CLOEXEC) != 0 ? UF_EXCLOSE : 0; 2014 if (fcaps != NULL) 2015 filecaps_move(fcaps, &fde->fde_caps); 2016 else 2017 filecaps_fill(&fde->fde_caps); 2018 #ifdef CAPABILITIES 2019 seqc_write_end(&fde->fde_seqc); 2020 #endif 2021 } 2022 2023 int 2024 finstall(struct thread *td, struct file *fp, int *fd, int flags, 2025 struct filecaps *fcaps) 2026 { 2027 struct filedesc *fdp = td->td_proc->p_fd; 2028 int error; 2029 2030 MPASS(fd != NULL); 2031 2032 if (!fhold(fp)) 2033 return (EBADF); 2034 FILEDESC_XLOCK(fdp); 2035 error = fdalloc(td, 0, fd); 2036 if (__predict_false(error != 0)) { 2037 FILEDESC_XUNLOCK(fdp); 2038 fdrop(fp, td); 2039 return (error); 2040 } 2041 _finstall(fdp, fp, *fd, flags, fcaps); 2042 FILEDESC_XUNLOCK(fdp); 2043 return (0); 2044 } 2045 2046 /* 2047 * Build a new filedesc structure from another. 2048 * 2049 * If fdp is not NULL, return with it shared locked. 2050 */ 2051 struct filedesc * 2052 fdinit(struct filedesc *fdp, bool prepfiles, int *lastfile) 2053 { 2054 struct filedesc0 *newfdp0; 2055 struct filedesc *newfdp; 2056 2057 if (prepfiles) 2058 MPASS(lastfile != NULL); 2059 else 2060 MPASS(lastfile == NULL); 2061 2062 newfdp0 = uma_zalloc(filedesc0_zone, M_WAITOK | M_ZERO); 2063 newfdp = &newfdp0->fd_fd; 2064 2065 /* Create the file descriptor table. */ 2066 FILEDESC_LOCK_INIT(newfdp); 2067 refcount_init(&newfdp->fd_refcnt, 1); 2068 refcount_init(&newfdp->fd_holdcnt, 1); 2069 newfdp->fd_map = newfdp0->fd_dmap; 2070 newfdp->fd_files = (struct fdescenttbl *)&newfdp0->fd_dfiles; 2071 newfdp->fd_files->fdt_nfiles = NDFILE; 2072 2073 if (fdp == NULL) 2074 return (newfdp); 2075 2076 FILEDESC_SLOCK(fdp); 2077 if (!prepfiles) { 2078 FILEDESC_SUNLOCK(fdp); 2079 return (newfdp); 2080 } 2081 2082 for (;;) { 2083 *lastfile = fdlastfile(fdp); 2084 if (*lastfile < newfdp->fd_nfiles) 2085 break; 2086 FILEDESC_SUNLOCK(fdp); 2087 fdgrowtable(newfdp, *lastfile + 1); 2088 FILEDESC_SLOCK(fdp); 2089 } 2090 2091 return (newfdp); 2092 } 2093 2094 /* 2095 * Build a pwddesc structure from another. 2096 * Copy the current, root, and jail root vnode references. 2097 * 2098 * If pdp is not NULL, return with it shared locked. 2099 */ 2100 struct pwddesc * 2101 pdinit(struct pwddesc *pdp, bool keeplock) 2102 { 2103 struct pwddesc *newpdp; 2104 struct pwd *newpwd; 2105 2106 newpdp = malloc(sizeof(*newpdp), M_PWDDESC, M_WAITOK | M_ZERO); 2107 2108 PWDDESC_LOCK_INIT(newpdp); 2109 refcount_init(&newpdp->pd_refcount, 1); 2110 newpdp->pd_cmask = CMASK; 2111 2112 if (pdp == NULL) { 2113 newpwd = pwd_alloc(); 2114 smr_serialized_store(&newpdp->pd_pwd, newpwd, true); 2115 return (newpdp); 2116 } 2117 2118 PWDDESC_XLOCK(pdp); 2119 newpwd = pwd_hold_pwddesc(pdp); 2120 smr_serialized_store(&newpdp->pd_pwd, newpwd, true); 2121 if (!keeplock) 2122 PWDDESC_XUNLOCK(pdp); 2123 return (newpdp); 2124 } 2125 2126 static struct filedesc * 2127 fdhold(struct proc *p) 2128 { 2129 struct filedesc *fdp; 2130 2131 PROC_LOCK_ASSERT(p, MA_OWNED); 2132 fdp = p->p_fd; 2133 if (fdp != NULL) 2134 refcount_acquire(&fdp->fd_holdcnt); 2135 return (fdp); 2136 } 2137 2138 static struct pwddesc * 2139 pdhold(struct proc *p) 2140 { 2141 struct pwddesc *pdp; 2142 2143 PROC_LOCK_ASSERT(p, MA_OWNED); 2144 pdp = p->p_pd; 2145 if (pdp != NULL) 2146 refcount_acquire(&pdp->pd_refcount); 2147 return (pdp); 2148 } 2149 2150 static void 2151 fddrop(struct filedesc *fdp) 2152 { 2153 2154 if (fdp->fd_holdcnt > 1) { 2155 if (refcount_release(&fdp->fd_holdcnt) == 0) 2156 return; 2157 } 2158 2159 FILEDESC_LOCK_DESTROY(fdp); 2160 uma_zfree(filedesc0_zone, fdp); 2161 } 2162 2163 static void 2164 pddrop(struct pwddesc *pdp) 2165 { 2166 struct pwd *pwd; 2167 2168 if (refcount_release_if_not_last(&pdp->pd_refcount)) 2169 return; 2170 2171 PWDDESC_XLOCK(pdp); 2172 if (refcount_release(&pdp->pd_refcount) == 0) { 2173 PWDDESC_XUNLOCK(pdp); 2174 return; 2175 } 2176 pwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); 2177 pwd_set(pdp, NULL); 2178 PWDDESC_XUNLOCK(pdp); 2179 pwd_drop(pwd); 2180 2181 PWDDESC_LOCK_DESTROY(pdp); 2182 free(pdp, M_PWDDESC); 2183 } 2184 2185 /* 2186 * Share a filedesc structure. 2187 */ 2188 struct filedesc * 2189 fdshare(struct filedesc *fdp) 2190 { 2191 2192 refcount_acquire(&fdp->fd_refcnt); 2193 return (fdp); 2194 } 2195 2196 /* 2197 * Share a pwddesc structure. 2198 */ 2199 struct pwddesc * 2200 pdshare(struct pwddesc *pdp) 2201 { 2202 refcount_acquire(&pdp->pd_refcount); 2203 return (pdp); 2204 } 2205 2206 /* 2207 * Unshare a filedesc structure, if necessary by making a copy 2208 */ 2209 void 2210 fdunshare(struct thread *td) 2211 { 2212 struct filedesc *tmp; 2213 struct proc *p = td->td_proc; 2214 2215 if (p->p_fd->fd_refcnt == 1) 2216 return; 2217 2218 tmp = fdcopy(p->p_fd); 2219 fdescfree(td); 2220 p->p_fd = tmp; 2221 } 2222 2223 /* 2224 * Unshare a pwddesc structure. 2225 */ 2226 void 2227 pdunshare(struct thread *td) 2228 { 2229 struct pwddesc *pdp; 2230 struct proc *p; 2231 2232 p = td->td_proc; 2233 /* Not shared. */ 2234 if (p->p_pd->pd_refcount == 1) 2235 return; 2236 2237 pdp = pdcopy(p->p_pd); 2238 pdescfree(td); 2239 p->p_pd = pdp; 2240 } 2241 2242 void 2243 fdinstall_remapped(struct thread *td, struct filedesc *fdp) 2244 { 2245 2246 fdescfree(td); 2247 td->td_proc->p_fd = fdp; 2248 } 2249 2250 /* 2251 * Copy a filedesc structure. A NULL pointer in returns a NULL reference, 2252 * this is to ease callers, not catch errors. 2253 */ 2254 struct filedesc * 2255 fdcopy(struct filedesc *fdp) 2256 { 2257 struct filedesc *newfdp; 2258 struct filedescent *nfde, *ofde; 2259 int i, lastfile; 2260 2261 MPASS(fdp != NULL); 2262 2263 newfdp = fdinit(fdp, true, &lastfile); 2264 /* copy all passable descriptors (i.e. not kqueue) */ 2265 newfdp->fd_freefile = -1; 2266 for (i = 0; i <= lastfile; ++i) { 2267 ofde = &fdp->fd_ofiles[i]; 2268 if (ofde->fde_file == NULL || 2269 (ofde->fde_file->f_ops->fo_flags & DFLAG_PASSABLE) == 0 || 2270 !fhold(ofde->fde_file)) { 2271 if (newfdp->fd_freefile == -1) 2272 newfdp->fd_freefile = i; 2273 continue; 2274 } 2275 nfde = &newfdp->fd_ofiles[i]; 2276 *nfde = *ofde; 2277 filecaps_copy(&ofde->fde_caps, &nfde->fde_caps, true); 2278 fdused_init(newfdp, i); 2279 } 2280 if (newfdp->fd_freefile == -1) 2281 newfdp->fd_freefile = i; 2282 FILEDESC_SUNLOCK(fdp); 2283 return (newfdp); 2284 } 2285 2286 /* 2287 * Copy a pwddesc structure. 2288 */ 2289 struct pwddesc * 2290 pdcopy(struct pwddesc *pdp) 2291 { 2292 struct pwddesc *newpdp; 2293 2294 MPASS(pdp != NULL); 2295 2296 newpdp = pdinit(pdp, true); 2297 newpdp->pd_cmask = pdp->pd_cmask; 2298 PWDDESC_XUNLOCK(pdp); 2299 return (newpdp); 2300 } 2301 2302 /* 2303 * Copies a filedesc structure, while remapping all file descriptors 2304 * stored inside using a translation table. 2305 * 2306 * File descriptors are copied over to the new file descriptor table, 2307 * regardless of whether the close-on-exec flag is set. 2308 */ 2309 int 2310 fdcopy_remapped(struct filedesc *fdp, const int *fds, size_t nfds, 2311 struct filedesc **ret) 2312 { 2313 struct filedesc *newfdp; 2314 struct filedescent *nfde, *ofde; 2315 int error, i, lastfile; 2316 2317 MPASS(fdp != NULL); 2318 2319 newfdp = fdinit(fdp, true, &lastfile); 2320 if (nfds > lastfile + 1) { 2321 /* New table cannot be larger than the old one. */ 2322 error = E2BIG; 2323 goto bad; 2324 } 2325 /* Copy all passable descriptors (i.e. not kqueue). */ 2326 newfdp->fd_freefile = nfds; 2327 for (i = 0; i < nfds; ++i) { 2328 if (fds[i] < 0 || fds[i] > lastfile) { 2329 /* File descriptor out of bounds. */ 2330 error = EBADF; 2331 goto bad; 2332 } 2333 ofde = &fdp->fd_ofiles[fds[i]]; 2334 if (ofde->fde_file == NULL) { 2335 /* Unused file descriptor. */ 2336 error = EBADF; 2337 goto bad; 2338 } 2339 if ((ofde->fde_file->f_ops->fo_flags & DFLAG_PASSABLE) == 0) { 2340 /* File descriptor cannot be passed. */ 2341 error = EINVAL; 2342 goto bad; 2343 } 2344 if (!fhold(ofde->fde_file)) { 2345 error = EBADF; 2346 goto bad; 2347 } 2348 nfde = &newfdp->fd_ofiles[i]; 2349 *nfde = *ofde; 2350 filecaps_copy(&ofde->fde_caps, &nfde->fde_caps, true); 2351 fdused_init(newfdp, i); 2352 } 2353 FILEDESC_SUNLOCK(fdp); 2354 *ret = newfdp; 2355 return (0); 2356 bad: 2357 FILEDESC_SUNLOCK(fdp); 2358 fdescfree_remapped(newfdp); 2359 return (error); 2360 } 2361 2362 /* 2363 * Clear POSIX style locks. This is only used when fdp looses a reference (i.e. 2364 * one of processes using it exits) and the table used to be shared. 2365 */ 2366 static void 2367 fdclearlocks(struct thread *td) 2368 { 2369 struct filedesc *fdp; 2370 struct filedesc_to_leader *fdtol; 2371 struct flock lf; 2372 struct file *fp; 2373 struct proc *p; 2374 struct vnode *vp; 2375 int i, lastfile; 2376 2377 p = td->td_proc; 2378 fdp = p->p_fd; 2379 fdtol = p->p_fdtol; 2380 MPASS(fdtol != NULL); 2381 2382 FILEDESC_XLOCK(fdp); 2383 KASSERT(fdtol->fdl_refcount > 0, 2384 ("filedesc_to_refcount botch: fdl_refcount=%d", 2385 fdtol->fdl_refcount)); 2386 if (fdtol->fdl_refcount == 1 && 2387 (p->p_leader->p_flag & P_ADVLOCK) != 0) { 2388 lastfile = fdlastfile(fdp); 2389 for (i = 0; i <= lastfile; i++) { 2390 fp = fdp->fd_ofiles[i].fde_file; 2391 if (fp == NULL || fp->f_type != DTYPE_VNODE || 2392 !fhold(fp)) 2393 continue; 2394 FILEDESC_XUNLOCK(fdp); 2395 lf.l_whence = SEEK_SET; 2396 lf.l_start = 0; 2397 lf.l_len = 0; 2398 lf.l_type = F_UNLCK; 2399 vp = fp->f_vnode; 2400 (void) VOP_ADVLOCK(vp, 2401 (caddr_t)p->p_leader, F_UNLCK, 2402 &lf, F_POSIX); 2403 FILEDESC_XLOCK(fdp); 2404 fdrop(fp, td); 2405 } 2406 } 2407 retry: 2408 if (fdtol->fdl_refcount == 1) { 2409 if (fdp->fd_holdleaderscount > 0 && 2410 (p->p_leader->p_flag & P_ADVLOCK) != 0) { 2411 /* 2412 * close() or kern_dup() has cleared a reference 2413 * in a shared file descriptor table. 2414 */ 2415 fdp->fd_holdleaderswakeup = 1; 2416 sx_sleep(&fdp->fd_holdleaderscount, 2417 FILEDESC_LOCK(fdp), PLOCK, "fdlhold", 0); 2418 goto retry; 2419 } 2420 if (fdtol->fdl_holdcount > 0) { 2421 /* 2422 * Ensure that fdtol->fdl_leader remains 2423 * valid in closef(). 2424 */ 2425 fdtol->fdl_wakeup = 1; 2426 sx_sleep(fdtol, FILEDESC_LOCK(fdp), PLOCK, 2427 "fdlhold", 0); 2428 goto retry; 2429 } 2430 } 2431 fdtol->fdl_refcount--; 2432 if (fdtol->fdl_refcount == 0 && 2433 fdtol->fdl_holdcount == 0) { 2434 fdtol->fdl_next->fdl_prev = fdtol->fdl_prev; 2435 fdtol->fdl_prev->fdl_next = fdtol->fdl_next; 2436 } else 2437 fdtol = NULL; 2438 p->p_fdtol = NULL; 2439 FILEDESC_XUNLOCK(fdp); 2440 if (fdtol != NULL) 2441 free(fdtol, M_FILEDESC_TO_LEADER); 2442 } 2443 2444 /* 2445 * Release a filedesc structure. 2446 */ 2447 static void 2448 fdescfree_fds(struct thread *td, struct filedesc *fdp, bool needclose) 2449 { 2450 struct filedesc0 *fdp0; 2451 struct freetable *ft, *tft; 2452 struct filedescent *fde; 2453 struct file *fp; 2454 int i, lastfile; 2455 2456 lastfile = fdlastfile_single(fdp); 2457 for (i = 0; i <= lastfile; i++) { 2458 fde = &fdp->fd_ofiles[i]; 2459 fp = fde->fde_file; 2460 if (fp != NULL) { 2461 fdefree_last(fde); 2462 if (needclose) 2463 (void) closef(fp, td); 2464 else 2465 fdrop(fp, td); 2466 } 2467 } 2468 2469 if (NDSLOTS(fdp->fd_nfiles) > NDSLOTS(NDFILE)) 2470 free(fdp->fd_map, M_FILEDESC); 2471 if (fdp->fd_nfiles > NDFILE) 2472 free(fdp->fd_files, M_FILEDESC); 2473 2474 fdp0 = (struct filedesc0 *)fdp; 2475 SLIST_FOREACH_SAFE(ft, &fdp0->fd_free, ft_next, tft) 2476 free(ft->ft_table, M_FILEDESC); 2477 2478 fddrop(fdp); 2479 } 2480 2481 void 2482 fdescfree(struct thread *td) 2483 { 2484 struct proc *p; 2485 struct filedesc *fdp; 2486 2487 p = td->td_proc; 2488 fdp = p->p_fd; 2489 MPASS(fdp != NULL); 2490 2491 #ifdef RACCT 2492 if (RACCT_ENABLED()) 2493 racct_set_unlocked(p, RACCT_NOFILE, 0); 2494 #endif 2495 2496 if (p->p_fdtol != NULL) 2497 fdclearlocks(td); 2498 2499 PROC_LOCK(p); 2500 p->p_fd = NULL; 2501 PROC_UNLOCK(p); 2502 2503 if (refcount_release(&fdp->fd_refcnt) == 0) 2504 return; 2505 2506 fdescfree_fds(td, fdp, 1); 2507 } 2508 2509 void 2510 pdescfree(struct thread *td) 2511 { 2512 struct proc *p; 2513 struct pwddesc *pdp; 2514 2515 p = td->td_proc; 2516 pdp = p->p_pd; 2517 MPASS(pdp != NULL); 2518 2519 PROC_LOCK(p); 2520 p->p_pd = NULL; 2521 PROC_UNLOCK(p); 2522 2523 pddrop(pdp); 2524 } 2525 2526 void 2527 fdescfree_remapped(struct filedesc *fdp) 2528 { 2529 fdescfree_fds(curthread, fdp, 0); 2530 } 2531 2532 /* 2533 * For setugid programs, we don't want to people to use that setugidness 2534 * to generate error messages which write to a file which otherwise would 2535 * otherwise be off-limits to the process. We check for filesystems where 2536 * the vnode can change out from under us after execve (like [lin]procfs). 2537 * 2538 * Since fdsetugidsafety calls this only for fd 0, 1 and 2, this check is 2539 * sufficient. We also don't check for setugidness since we know we are. 2540 */ 2541 static bool 2542 is_unsafe(struct file *fp) 2543 { 2544 struct vnode *vp; 2545 2546 if (fp->f_type != DTYPE_VNODE) 2547 return (false); 2548 2549 vp = fp->f_vnode; 2550 return ((vp->v_vflag & VV_PROCDEP) != 0); 2551 } 2552 2553 /* 2554 * Make this setguid thing safe, if at all possible. 2555 */ 2556 void 2557 fdsetugidsafety(struct thread *td) 2558 { 2559 struct filedesc *fdp; 2560 struct file *fp; 2561 int i; 2562 2563 fdp = td->td_proc->p_fd; 2564 KASSERT(fdp->fd_refcnt == 1, ("the fdtable should not be shared")); 2565 MPASS(fdp->fd_nfiles >= 3); 2566 for (i = 0; i <= 2; i++) { 2567 fp = fdp->fd_ofiles[i].fde_file; 2568 if (fp != NULL && is_unsafe(fp)) { 2569 FILEDESC_XLOCK(fdp); 2570 knote_fdclose(td, i); 2571 /* 2572 * NULL-out descriptor prior to close to avoid 2573 * a race while close blocks. 2574 */ 2575 fdfree(fdp, i); 2576 FILEDESC_XUNLOCK(fdp); 2577 (void) closef(fp, td); 2578 } 2579 } 2580 } 2581 2582 /* 2583 * If a specific file object occupies a specific file descriptor, close the 2584 * file descriptor entry and drop a reference on the file object. This is a 2585 * convenience function to handle a subsequent error in a function that calls 2586 * falloc() that handles the race that another thread might have closed the 2587 * file descriptor out from under the thread creating the file object. 2588 */ 2589 void 2590 fdclose(struct thread *td, struct file *fp, int idx) 2591 { 2592 struct filedesc *fdp = td->td_proc->p_fd; 2593 2594 FILEDESC_XLOCK(fdp); 2595 if (fdp->fd_ofiles[idx].fde_file == fp) { 2596 fdfree(fdp, idx); 2597 FILEDESC_XUNLOCK(fdp); 2598 fdrop(fp, td); 2599 } else 2600 FILEDESC_XUNLOCK(fdp); 2601 } 2602 2603 /* 2604 * Close any files on exec? 2605 */ 2606 void 2607 fdcloseexec(struct thread *td) 2608 { 2609 struct filedesc *fdp; 2610 struct filedescent *fde; 2611 struct file *fp; 2612 int i, lastfile; 2613 2614 fdp = td->td_proc->p_fd; 2615 KASSERT(fdp->fd_refcnt == 1, ("the fdtable should not be shared")); 2616 lastfile = fdlastfile_single(fdp); 2617 for (i = 0; i <= lastfile; i++) { 2618 fde = &fdp->fd_ofiles[i]; 2619 fp = fde->fde_file; 2620 if (fp != NULL && (fp->f_type == DTYPE_MQUEUE || 2621 (fde->fde_flags & UF_EXCLOSE))) { 2622 FILEDESC_XLOCK(fdp); 2623 fdfree(fdp, i); 2624 (void) closefp(fdp, i, fp, td, 0); 2625 FILEDESC_UNLOCK_ASSERT(fdp); 2626 } 2627 } 2628 } 2629 2630 /* 2631 * It is unsafe for set[ug]id processes to be started with file 2632 * descriptors 0..2 closed, as these descriptors are given implicit 2633 * significance in the Standard C library. fdcheckstd() will create a 2634 * descriptor referencing /dev/null for each of stdin, stdout, and 2635 * stderr that is not already open. 2636 */ 2637 int 2638 fdcheckstd(struct thread *td) 2639 { 2640 struct filedesc *fdp; 2641 register_t save; 2642 int i, error, devnull; 2643 2644 fdp = td->td_proc->p_fd; 2645 KASSERT(fdp->fd_refcnt == 1, ("the fdtable should not be shared")); 2646 MPASS(fdp->fd_nfiles >= 3); 2647 devnull = -1; 2648 for (i = 0; i <= 2; i++) { 2649 if (fdp->fd_ofiles[i].fde_file != NULL) 2650 continue; 2651 2652 save = td->td_retval[0]; 2653 if (devnull != -1) { 2654 error = kern_dup(td, FDDUP_FIXED, 0, devnull, i); 2655 } else { 2656 error = kern_openat(td, AT_FDCWD, "/dev/null", 2657 UIO_SYSSPACE, O_RDWR, 0); 2658 if (error == 0) { 2659 devnull = td->td_retval[0]; 2660 KASSERT(devnull == i, ("we didn't get our fd")); 2661 } 2662 } 2663 td->td_retval[0] = save; 2664 if (error != 0) 2665 return (error); 2666 } 2667 return (0); 2668 } 2669 2670 /* 2671 * Internal form of close. Decrement reference count on file structure. 2672 * Note: td may be NULL when closing a file that was being passed in a 2673 * message. 2674 */ 2675 int 2676 closef(struct file *fp, struct thread *td) 2677 { 2678 struct vnode *vp; 2679 struct flock lf; 2680 struct filedesc_to_leader *fdtol; 2681 struct filedesc *fdp; 2682 2683 /* 2684 * POSIX record locking dictates that any close releases ALL 2685 * locks owned by this process. This is handled by setting 2686 * a flag in the unlock to free ONLY locks obeying POSIX 2687 * semantics, and not to free BSD-style file locks. 2688 * If the descriptor was in a message, POSIX-style locks 2689 * aren't passed with the descriptor, and the thread pointer 2690 * will be NULL. Callers should be careful only to pass a 2691 * NULL thread pointer when there really is no owning 2692 * context that might have locks, or the locks will be 2693 * leaked. 2694 */ 2695 if (fp->f_type == DTYPE_VNODE && td != NULL) { 2696 vp = fp->f_vnode; 2697 if ((td->td_proc->p_leader->p_flag & P_ADVLOCK) != 0) { 2698 lf.l_whence = SEEK_SET; 2699 lf.l_start = 0; 2700 lf.l_len = 0; 2701 lf.l_type = F_UNLCK; 2702 (void) VOP_ADVLOCK(vp, (caddr_t)td->td_proc->p_leader, 2703 F_UNLCK, &lf, F_POSIX); 2704 } 2705 fdtol = td->td_proc->p_fdtol; 2706 if (fdtol != NULL) { 2707 /* 2708 * Handle special case where file descriptor table is 2709 * shared between multiple process leaders. 2710 */ 2711 fdp = td->td_proc->p_fd; 2712 FILEDESC_XLOCK(fdp); 2713 for (fdtol = fdtol->fdl_next; 2714 fdtol != td->td_proc->p_fdtol; 2715 fdtol = fdtol->fdl_next) { 2716 if ((fdtol->fdl_leader->p_flag & 2717 P_ADVLOCK) == 0) 2718 continue; 2719 fdtol->fdl_holdcount++; 2720 FILEDESC_XUNLOCK(fdp); 2721 lf.l_whence = SEEK_SET; 2722 lf.l_start = 0; 2723 lf.l_len = 0; 2724 lf.l_type = F_UNLCK; 2725 vp = fp->f_vnode; 2726 (void) VOP_ADVLOCK(vp, 2727 (caddr_t)fdtol->fdl_leader, F_UNLCK, &lf, 2728 F_POSIX); 2729 FILEDESC_XLOCK(fdp); 2730 fdtol->fdl_holdcount--; 2731 if (fdtol->fdl_holdcount == 0 && 2732 fdtol->fdl_wakeup != 0) { 2733 fdtol->fdl_wakeup = 0; 2734 wakeup(fdtol); 2735 } 2736 } 2737 FILEDESC_XUNLOCK(fdp); 2738 } 2739 } 2740 return (fdrop(fp, td)); 2741 } 2742 2743 /* 2744 * Initialize the file pointer with the specified properties. 2745 * 2746 * The ops are set with release semantics to be certain that the flags, type, 2747 * and data are visible when ops is. This is to prevent ops methods from being 2748 * called with bad data. 2749 */ 2750 void 2751 finit(struct file *fp, u_int flag, short type, void *data, struct fileops *ops) 2752 { 2753 fp->f_data = data; 2754 fp->f_flag = flag; 2755 fp->f_type = type; 2756 atomic_store_rel_ptr((volatile uintptr_t *)&fp->f_ops, (uintptr_t)ops); 2757 } 2758 2759 void 2760 finit_vnode(struct file *fp, u_int flag, void *data, struct fileops *ops) 2761 { 2762 fp->f_seqcount[UIO_READ] = 1; 2763 fp->f_seqcount[UIO_WRITE] = 1; 2764 finit(fp, (flag & FMASK) | (fp->f_flag & FHASLOCK), DTYPE_VNODE, 2765 data, ops); 2766 } 2767 2768 int 2769 fget_cap_locked(struct filedesc *fdp, int fd, cap_rights_t *needrightsp, 2770 struct file **fpp, struct filecaps *havecapsp) 2771 { 2772 struct filedescent *fde; 2773 int error; 2774 2775 FILEDESC_LOCK_ASSERT(fdp); 2776 2777 fde = fdeget_locked(fdp, fd); 2778 if (fde == NULL) { 2779 error = EBADF; 2780 goto out; 2781 } 2782 2783 #ifdef CAPABILITIES 2784 error = cap_check(cap_rights_fde_inline(fde), needrightsp); 2785 if (error != 0) 2786 goto out; 2787 #endif 2788 2789 if (havecapsp != NULL) 2790 filecaps_copy(&fde->fde_caps, havecapsp, true); 2791 2792 *fpp = fde->fde_file; 2793 2794 error = 0; 2795 out: 2796 return (error); 2797 } 2798 2799 int 2800 fget_cap(struct thread *td, int fd, cap_rights_t *needrightsp, 2801 struct file **fpp, struct filecaps *havecapsp) 2802 { 2803 struct filedesc *fdp = td->td_proc->p_fd; 2804 int error; 2805 #ifndef CAPABILITIES 2806 error = fget_unlocked(fdp, fd, needrightsp, fpp); 2807 if (havecapsp != NULL && error == 0) 2808 filecaps_fill(havecapsp); 2809 #else 2810 struct file *fp; 2811 seqc_t seq; 2812 2813 *fpp = NULL; 2814 for (;;) { 2815 error = fget_unlocked_seq(fdp, fd, needrightsp, &fp, &seq); 2816 if (error != 0) 2817 return (error); 2818 2819 if (havecapsp != NULL) { 2820 if (!filecaps_copy(&fdp->fd_ofiles[fd].fde_caps, 2821 havecapsp, false)) { 2822 fdrop(fp, td); 2823 goto get_locked; 2824 } 2825 } 2826 2827 if (!fd_modified(fdp, fd, seq)) 2828 break; 2829 fdrop(fp, td); 2830 } 2831 2832 *fpp = fp; 2833 return (0); 2834 2835 get_locked: 2836 FILEDESC_SLOCK(fdp); 2837 error = fget_cap_locked(fdp, fd, needrightsp, fpp, havecapsp); 2838 if (error == 0 && !fhold(*fpp)) 2839 error = EBADF; 2840 FILEDESC_SUNLOCK(fdp); 2841 #endif 2842 return (error); 2843 } 2844 2845 #ifdef CAPABILITIES 2846 int 2847 fgetvp_lookup_smr(int fd, struct nameidata *ndp, struct vnode **vpp, bool *fsearch) 2848 { 2849 const struct filedescent *fde; 2850 const struct fdescenttbl *fdt; 2851 struct filedesc *fdp; 2852 struct file *fp; 2853 struct vnode *vp; 2854 const cap_rights_t *haverights; 2855 cap_rights_t rights; 2856 seqc_t seq; 2857 2858 VFS_SMR_ASSERT_ENTERED(); 2859 2860 rights = *ndp->ni_rightsneeded; 2861 cap_rights_set_one(&rights, CAP_LOOKUP); 2862 2863 fdp = curproc->p_fd; 2864 fdt = fdp->fd_files; 2865 if (__predict_false((u_int)fd >= fdt->fdt_nfiles)) 2866 return (EBADF); 2867 seq = seqc_read_any(fd_seqc(fdt, fd)); 2868 if (__predict_false(seqc_in_modify(seq))) 2869 return (EAGAIN); 2870 fde = &fdt->fdt_ofiles[fd]; 2871 haverights = cap_rights_fde_inline(fde); 2872 fp = fde->fde_file; 2873 if (__predict_false(fp == NULL)) 2874 return (EAGAIN); 2875 if (__predict_false(cap_check_inline_transient(haverights, &rights))) 2876 return (EAGAIN); 2877 *fsearch = ((fp->f_flag & FSEARCH) != 0); 2878 vp = fp->f_vnode; 2879 if (__predict_false(vp == NULL || vp->v_type != VDIR)) { 2880 return (EAGAIN); 2881 } 2882 if (!filecaps_copy(&fde->fde_caps, &ndp->ni_filecaps, false)) { 2883 return (EAGAIN); 2884 } 2885 /* 2886 * Use an acquire barrier to force re-reading of fdt so it is 2887 * refreshed for verification. 2888 */ 2889 atomic_thread_fence_acq(); 2890 fdt = fdp->fd_files; 2891 if (__predict_false(!seqc_consistent_nomb(fd_seqc(fdt, fd), seq))) 2892 return (EAGAIN); 2893 /* 2894 * If file descriptor doesn't have all rights, 2895 * all lookups relative to it must also be 2896 * strictly relative. 2897 * 2898 * Not yet supported by fast path. 2899 */ 2900 CAP_ALL(&rights); 2901 if (!cap_rights_contains(&ndp->ni_filecaps.fc_rights, &rights) || 2902 ndp->ni_filecaps.fc_fcntls != CAP_FCNTL_ALL || 2903 ndp->ni_filecaps.fc_nioctls != -1) { 2904 #ifdef notyet 2905 ndp->ni_lcf |= NI_LCF_STRICTRELATIVE; 2906 #else 2907 return (EAGAIN); 2908 #endif 2909 } 2910 *vpp = vp; 2911 return (0); 2912 } 2913 #else 2914 int 2915 fgetvp_lookup_smr(int fd, struct nameidata *ndp, struct vnode **vpp, bool *fsearch) 2916 { 2917 const struct fdescenttbl *fdt; 2918 struct filedesc *fdp; 2919 struct file *fp; 2920 struct vnode *vp; 2921 2922 VFS_SMR_ASSERT_ENTERED(); 2923 2924 fdp = curproc->p_fd; 2925 fdt = fdp->fd_files; 2926 if (__predict_false((u_int)fd >= fdt->fdt_nfiles)) 2927 return (EBADF); 2928 fp = fdt->fdt_ofiles[fd].fde_file; 2929 if (__predict_false(fp == NULL)) 2930 return (EAGAIN); 2931 *fsearch = ((fp->f_flag & FSEARCH) != 0); 2932 vp = fp->f_vnode; 2933 if (__predict_false(vp == NULL || vp->v_type != VDIR)) { 2934 return (EAGAIN); 2935 } 2936 /* 2937 * Use an acquire barrier to force re-reading of fdt so it is 2938 * refreshed for verification. 2939 */ 2940 atomic_thread_fence_acq(); 2941 fdt = fdp->fd_files; 2942 if (__predict_false(fp != fdt->fdt_ofiles[fd].fde_file)) 2943 return (EAGAIN); 2944 filecaps_fill(&ndp->ni_filecaps); 2945 *vpp = vp; 2946 return (0); 2947 } 2948 #endif 2949 2950 int 2951 fget_unlocked_seq(struct filedesc *fdp, int fd, cap_rights_t *needrightsp, 2952 struct file **fpp, seqc_t *seqp) 2953 { 2954 #ifdef CAPABILITIES 2955 const struct filedescent *fde; 2956 #endif 2957 const struct fdescenttbl *fdt; 2958 struct file *fp; 2959 #ifdef CAPABILITIES 2960 seqc_t seq; 2961 cap_rights_t haverights; 2962 int error; 2963 #endif 2964 2965 fdt = fdp->fd_files; 2966 if (__predict_false((u_int)fd >= fdt->fdt_nfiles)) 2967 return (EBADF); 2968 /* 2969 * Fetch the descriptor locklessly. We avoid fdrop() races by 2970 * never raising a refcount above 0. To accomplish this we have 2971 * to use a cmpset loop rather than an atomic_add. The descriptor 2972 * must be re-verified once we acquire a reference to be certain 2973 * that the identity is still correct and we did not lose a race 2974 * due to preemption. 2975 */ 2976 for (;;) { 2977 #ifdef CAPABILITIES 2978 seq = seqc_read(fd_seqc(fdt, fd)); 2979 fde = &fdt->fdt_ofiles[fd]; 2980 haverights = *cap_rights_fde_inline(fde); 2981 fp = fde->fde_file; 2982 if (!seqc_consistent(fd_seqc(fdt, fd), seq)) 2983 continue; 2984 #else 2985 fp = fdt->fdt_ofiles[fd].fde_file; 2986 #endif 2987 if (fp == NULL) 2988 return (EBADF); 2989 #ifdef CAPABILITIES 2990 error = cap_check_inline(&haverights, needrightsp); 2991 if (error != 0) 2992 return (error); 2993 #endif 2994 if (__predict_false(!refcount_acquire_if_not_zero(&fp->f_count))) { 2995 /* 2996 * The count was found either saturated or zero. 2997 * This re-read is not any more racy than using the 2998 * return value from fcmpset. 2999 */ 3000 if (refcount_load(&fp->f_count) != 0) 3001 return (EBADF); 3002 /* 3003 * Force a reload. Other thread could reallocate the 3004 * table before this fd was closed, so it is possible 3005 * that there is a stale fp pointer in cached version. 3006 */ 3007 fdt = atomic_load_ptr(&fdp->fd_files); 3008 continue; 3009 } 3010 /* 3011 * Use an acquire barrier to force re-reading of fdt so it is 3012 * refreshed for verification. 3013 */ 3014 atomic_thread_fence_acq(); 3015 fdt = fdp->fd_files; 3016 #ifdef CAPABILITIES 3017 if (seqc_consistent_nomb(fd_seqc(fdt, fd), seq)) 3018 #else 3019 if (fp == fdt->fdt_ofiles[fd].fde_file) 3020 #endif 3021 break; 3022 fdrop(fp, curthread); 3023 } 3024 *fpp = fp; 3025 if (seqp != NULL) { 3026 #ifdef CAPABILITIES 3027 *seqp = seq; 3028 #endif 3029 } 3030 return (0); 3031 } 3032 3033 /* 3034 * See the comments in fget_unlocked_seq for an explanation of how this works. 3035 * 3036 * This is a simplified variant which bails out to the aforementioned routine 3037 * if anything goes wrong. In practice this only happens when userspace is 3038 * racing with itself. 3039 */ 3040 int 3041 fget_unlocked(struct filedesc *fdp, int fd, cap_rights_t *needrightsp, 3042 struct file **fpp) 3043 { 3044 #ifdef CAPABILITIES 3045 const struct filedescent *fde; 3046 #endif 3047 const struct fdescenttbl *fdt; 3048 struct file *fp; 3049 #ifdef CAPABILITIES 3050 seqc_t seq; 3051 const cap_rights_t *haverights; 3052 #endif 3053 3054 fdt = fdp->fd_files; 3055 if (__predict_false((u_int)fd >= fdt->fdt_nfiles)) 3056 return (EBADF); 3057 #ifdef CAPABILITIES 3058 seq = seqc_read_any(fd_seqc(fdt, fd)); 3059 if (__predict_false(seqc_in_modify(seq))) 3060 goto out_fallback; 3061 fde = &fdt->fdt_ofiles[fd]; 3062 haverights = cap_rights_fde_inline(fde); 3063 fp = fde->fde_file; 3064 #else 3065 fp = fdt->fdt_ofiles[fd].fde_file; 3066 #endif 3067 if (__predict_false(fp == NULL)) 3068 goto out_fallback; 3069 #ifdef CAPABILITIES 3070 if (__predict_false(cap_check_inline_transient(haverights, needrightsp))) 3071 goto out_fallback; 3072 #endif 3073 if (__predict_false(!refcount_acquire_if_not_zero(&fp->f_count))) 3074 goto out_fallback; 3075 3076 /* 3077 * Use an acquire barrier to force re-reading of fdt so it is 3078 * refreshed for verification. 3079 */ 3080 atomic_thread_fence_acq(); 3081 fdt = fdp->fd_files; 3082 #ifdef CAPABILITIES 3083 if (__predict_false(!seqc_consistent_nomb(fd_seqc(fdt, fd), seq))) 3084 #else 3085 if (__predict_false(fp != fdt->fdt_ofiles[fd].fde_file)) 3086 #endif 3087 goto out_fdrop; 3088 *fpp = fp; 3089 return (0); 3090 out_fdrop: 3091 fdrop(fp, curthread); 3092 out_fallback: 3093 return (fget_unlocked_seq(fdp, fd, needrightsp, fpp, NULL)); 3094 } 3095 3096 /* 3097 * Extract the file pointer associated with the specified descriptor for the 3098 * current user process. 3099 * 3100 * If the descriptor doesn't exist or doesn't match 'flags', EBADF is 3101 * returned. 3102 * 3103 * File's rights will be checked against the capability rights mask. 3104 * 3105 * If an error occurred the non-zero error is returned and *fpp is set to 3106 * NULL. Otherwise *fpp is held and set and zero is returned. Caller is 3107 * responsible for fdrop(). 3108 */ 3109 static __inline int 3110 _fget(struct thread *td, int fd, struct file **fpp, int flags, 3111 cap_rights_t *needrightsp) 3112 { 3113 struct filedesc *fdp; 3114 struct file *fp; 3115 int error; 3116 3117 *fpp = NULL; 3118 fdp = td->td_proc->p_fd; 3119 error = fget_unlocked(fdp, fd, needrightsp, &fp); 3120 if (__predict_false(error != 0)) 3121 return (error); 3122 if (__predict_false(fp->f_ops == &badfileops)) { 3123 fdrop(fp, td); 3124 return (EBADF); 3125 } 3126 3127 /* 3128 * FREAD and FWRITE failure return EBADF as per POSIX. 3129 */ 3130 error = 0; 3131 switch (flags) { 3132 case FREAD: 3133 case FWRITE: 3134 if ((fp->f_flag & flags) == 0) 3135 error = EBADF; 3136 break; 3137 case FEXEC: 3138 if ((fp->f_flag & (FREAD | FEXEC)) == 0 || 3139 ((fp->f_flag & FWRITE) != 0)) 3140 error = EBADF; 3141 break; 3142 case 0: 3143 break; 3144 default: 3145 KASSERT(0, ("wrong flags")); 3146 } 3147 3148 if (error != 0) { 3149 fdrop(fp, td); 3150 return (error); 3151 } 3152 3153 *fpp = fp; 3154 return (0); 3155 } 3156 3157 int 3158 fget(struct thread *td, int fd, cap_rights_t *rightsp, struct file **fpp) 3159 { 3160 3161 return (_fget(td, fd, fpp, 0, rightsp)); 3162 } 3163 3164 int 3165 fget_mmap(struct thread *td, int fd, cap_rights_t *rightsp, vm_prot_t *maxprotp, 3166 struct file **fpp) 3167 { 3168 int error; 3169 #ifndef CAPABILITIES 3170 error = _fget(td, fd, fpp, 0, rightsp); 3171 if (maxprotp != NULL) 3172 *maxprotp = VM_PROT_ALL; 3173 return (error); 3174 #else 3175 cap_rights_t fdrights; 3176 struct filedesc *fdp; 3177 struct file *fp; 3178 seqc_t seq; 3179 3180 *fpp = NULL; 3181 fdp = td->td_proc->p_fd; 3182 MPASS(cap_rights_is_set(rightsp, CAP_MMAP)); 3183 for (;;) { 3184 error = fget_unlocked_seq(fdp, fd, rightsp, &fp, &seq); 3185 if (__predict_false(error != 0)) 3186 return (error); 3187 if (__predict_false(fp->f_ops == &badfileops)) { 3188 fdrop(fp, td); 3189 return (EBADF); 3190 } 3191 if (maxprotp != NULL) 3192 fdrights = *cap_rights(fdp, fd); 3193 if (!fd_modified(fdp, fd, seq)) 3194 break; 3195 fdrop(fp, td); 3196 } 3197 3198 /* 3199 * If requested, convert capability rights to access flags. 3200 */ 3201 if (maxprotp != NULL) 3202 *maxprotp = cap_rights_to_vmprot(&fdrights); 3203 *fpp = fp; 3204 return (0); 3205 #endif 3206 } 3207 3208 int 3209 fget_read(struct thread *td, int fd, cap_rights_t *rightsp, struct file **fpp) 3210 { 3211 3212 return (_fget(td, fd, fpp, FREAD, rightsp)); 3213 } 3214 3215 int 3216 fget_write(struct thread *td, int fd, cap_rights_t *rightsp, struct file **fpp) 3217 { 3218 3219 return (_fget(td, fd, fpp, FWRITE, rightsp)); 3220 } 3221 3222 int 3223 fget_fcntl(struct thread *td, int fd, cap_rights_t *rightsp, int needfcntl, 3224 struct file **fpp) 3225 { 3226 struct filedesc *fdp = td->td_proc->p_fd; 3227 #ifndef CAPABILITIES 3228 return (fget_unlocked(fdp, fd, rightsp, fpp)); 3229 #else 3230 struct file *fp; 3231 int error; 3232 seqc_t seq; 3233 3234 *fpp = NULL; 3235 MPASS(cap_rights_is_set(rightsp, CAP_FCNTL)); 3236 for (;;) { 3237 error = fget_unlocked_seq(fdp, fd, rightsp, &fp, &seq); 3238 if (error != 0) 3239 return (error); 3240 error = cap_fcntl_check(fdp, fd, needfcntl); 3241 if (!fd_modified(fdp, fd, seq)) 3242 break; 3243 fdrop(fp, td); 3244 } 3245 if (error != 0) { 3246 fdrop(fp, td); 3247 return (error); 3248 } 3249 *fpp = fp; 3250 return (0); 3251 #endif 3252 } 3253 3254 /* 3255 * Like fget() but loads the underlying vnode, or returns an error if the 3256 * descriptor does not represent a vnode. Note that pipes use vnodes but 3257 * never have VM objects. The returned vnode will be vref()'d. 3258 * 3259 * XXX: what about the unused flags ? 3260 */ 3261 static __inline int 3262 _fgetvp(struct thread *td, int fd, int flags, cap_rights_t *needrightsp, 3263 struct vnode **vpp) 3264 { 3265 struct file *fp; 3266 int error; 3267 3268 *vpp = NULL; 3269 error = _fget(td, fd, &fp, flags, needrightsp); 3270 if (error != 0) 3271 return (error); 3272 if (fp->f_vnode == NULL) { 3273 error = EINVAL; 3274 } else { 3275 *vpp = fp->f_vnode; 3276 vrefact(*vpp); 3277 } 3278 fdrop(fp, td); 3279 3280 return (error); 3281 } 3282 3283 int 3284 fgetvp(struct thread *td, int fd, cap_rights_t *rightsp, struct vnode **vpp) 3285 { 3286 3287 return (_fgetvp(td, fd, 0, rightsp, vpp)); 3288 } 3289 3290 int 3291 fgetvp_rights(struct thread *td, int fd, cap_rights_t *needrightsp, 3292 struct filecaps *havecaps, struct vnode **vpp) 3293 { 3294 struct filecaps caps; 3295 struct file *fp; 3296 int error; 3297 3298 error = fget_cap(td, fd, needrightsp, &fp, &caps); 3299 if (error != 0) 3300 return (error); 3301 if (fp->f_ops == &badfileops) { 3302 error = EBADF; 3303 goto out; 3304 } 3305 if (fp->f_vnode == NULL) { 3306 error = EINVAL; 3307 goto out; 3308 } 3309 3310 *havecaps = caps; 3311 *vpp = fp->f_vnode; 3312 vrefact(*vpp); 3313 fdrop(fp, td); 3314 3315 return (0); 3316 out: 3317 filecaps_free(&caps); 3318 fdrop(fp, td); 3319 return (error); 3320 } 3321 3322 int 3323 fgetvp_read(struct thread *td, int fd, cap_rights_t *rightsp, struct vnode **vpp) 3324 { 3325 3326 return (_fgetvp(td, fd, FREAD, rightsp, vpp)); 3327 } 3328 3329 int 3330 fgetvp_exec(struct thread *td, int fd, cap_rights_t *rightsp, struct vnode **vpp) 3331 { 3332 3333 return (_fgetvp(td, fd, FEXEC, rightsp, vpp)); 3334 } 3335 3336 #ifdef notyet 3337 int 3338 fgetvp_write(struct thread *td, int fd, cap_rights_t *rightsp, 3339 struct vnode **vpp) 3340 { 3341 3342 return (_fgetvp(td, fd, FWRITE, rightsp, vpp)); 3343 } 3344 #endif 3345 3346 /* 3347 * Handle the last reference to a file being closed. 3348 * 3349 * Without the noinline attribute clang keeps inlining the func thorough this 3350 * file when fdrop is used. 3351 */ 3352 int __noinline 3353 _fdrop(struct file *fp, struct thread *td) 3354 { 3355 int error; 3356 #ifdef INVARIANTS 3357 int count; 3358 3359 count = refcount_load(&fp->f_count); 3360 if (count != 0) 3361 panic("fdrop: fp %p count %d", fp, count); 3362 #endif 3363 error = fo_close(fp, td); 3364 atomic_subtract_int(&openfiles, 1); 3365 crfree(fp->f_cred); 3366 free(fp->f_advice, M_FADVISE); 3367 uma_zfree(file_zone, fp); 3368 3369 return (error); 3370 } 3371 3372 /* 3373 * Apply an advisory lock on a file descriptor. 3374 * 3375 * Just attempt to get a record lock of the requested type on the entire file 3376 * (l_whence = SEEK_SET, l_start = 0, l_len = 0). 3377 */ 3378 #ifndef _SYS_SYSPROTO_H_ 3379 struct flock_args { 3380 int fd; 3381 int how; 3382 }; 3383 #endif 3384 /* ARGSUSED */ 3385 int 3386 sys_flock(struct thread *td, struct flock_args *uap) 3387 { 3388 struct file *fp; 3389 struct vnode *vp; 3390 struct flock lf; 3391 int error; 3392 3393 error = fget(td, uap->fd, &cap_flock_rights, &fp); 3394 if (error != 0) 3395 return (error); 3396 if (fp->f_type != DTYPE_VNODE) { 3397 fdrop(fp, td); 3398 return (EOPNOTSUPP); 3399 } 3400 3401 vp = fp->f_vnode; 3402 lf.l_whence = SEEK_SET; 3403 lf.l_start = 0; 3404 lf.l_len = 0; 3405 if (uap->how & LOCK_UN) { 3406 lf.l_type = F_UNLCK; 3407 atomic_clear_int(&fp->f_flag, FHASLOCK); 3408 error = VOP_ADVLOCK(vp, (caddr_t)fp, F_UNLCK, &lf, F_FLOCK); 3409 goto done2; 3410 } 3411 if (uap->how & LOCK_EX) 3412 lf.l_type = F_WRLCK; 3413 else if (uap->how & LOCK_SH) 3414 lf.l_type = F_RDLCK; 3415 else { 3416 error = EBADF; 3417 goto done2; 3418 } 3419 atomic_set_int(&fp->f_flag, FHASLOCK); 3420 error = VOP_ADVLOCK(vp, (caddr_t)fp, F_SETLK, &lf, 3421 (uap->how & LOCK_NB) ? F_FLOCK : F_FLOCK | F_WAIT); 3422 done2: 3423 fdrop(fp, td); 3424 return (error); 3425 } 3426 /* 3427 * Duplicate the specified descriptor to a free descriptor. 3428 */ 3429 int 3430 dupfdopen(struct thread *td, struct filedesc *fdp, int dfd, int mode, 3431 int openerror, int *indxp) 3432 { 3433 struct filedescent *newfde, *oldfde; 3434 struct file *fp; 3435 u_long *ioctls; 3436 int error, indx; 3437 3438 KASSERT(openerror == ENODEV || openerror == ENXIO, 3439 ("unexpected error %d in %s", openerror, __func__)); 3440 3441 /* 3442 * If the to-be-dup'd fd number is greater than the allowed number 3443 * of file descriptors, or the fd to be dup'd has already been 3444 * closed, then reject. 3445 */ 3446 FILEDESC_XLOCK(fdp); 3447 if ((fp = fget_locked(fdp, dfd)) == NULL) { 3448 FILEDESC_XUNLOCK(fdp); 3449 return (EBADF); 3450 } 3451 3452 error = fdalloc(td, 0, &indx); 3453 if (error != 0) { 3454 FILEDESC_XUNLOCK(fdp); 3455 return (error); 3456 } 3457 3458 /* 3459 * There are two cases of interest here. 3460 * 3461 * For ENODEV simply dup (dfd) to file descriptor (indx) and return. 3462 * 3463 * For ENXIO steal away the file structure from (dfd) and store it in 3464 * (indx). (dfd) is effectively closed by this operation. 3465 */ 3466 switch (openerror) { 3467 case ENODEV: 3468 /* 3469 * Check that the mode the file is being opened for is a 3470 * subset of the mode of the existing descriptor. 3471 */ 3472 if (((mode & (FREAD|FWRITE)) | fp->f_flag) != fp->f_flag) { 3473 fdunused(fdp, indx); 3474 FILEDESC_XUNLOCK(fdp); 3475 return (EACCES); 3476 } 3477 if (!fhold(fp)) { 3478 fdunused(fdp, indx); 3479 FILEDESC_XUNLOCK(fdp); 3480 return (EBADF); 3481 } 3482 newfde = &fdp->fd_ofiles[indx]; 3483 oldfde = &fdp->fd_ofiles[dfd]; 3484 ioctls = filecaps_copy_prep(&oldfde->fde_caps); 3485 #ifdef CAPABILITIES 3486 seqc_write_begin(&newfde->fde_seqc); 3487 #endif 3488 memcpy(newfde, oldfde, fde_change_size); 3489 filecaps_copy_finish(&oldfde->fde_caps, &newfde->fde_caps, 3490 ioctls); 3491 #ifdef CAPABILITIES 3492 seqc_write_end(&newfde->fde_seqc); 3493 #endif 3494 break; 3495 case ENXIO: 3496 /* 3497 * Steal away the file pointer from dfd and stuff it into indx. 3498 */ 3499 newfde = &fdp->fd_ofiles[indx]; 3500 oldfde = &fdp->fd_ofiles[dfd]; 3501 #ifdef CAPABILITIES 3502 seqc_write_begin(&newfde->fde_seqc); 3503 #endif 3504 memcpy(newfde, oldfde, fde_change_size); 3505 oldfde->fde_file = NULL; 3506 fdunused(fdp, dfd); 3507 #ifdef CAPABILITIES 3508 seqc_write_end(&newfde->fde_seqc); 3509 #endif 3510 break; 3511 } 3512 FILEDESC_XUNLOCK(fdp); 3513 *indxp = indx; 3514 return (0); 3515 } 3516 3517 /* 3518 * This sysctl determines if we will allow a process to chroot(2) if it 3519 * has a directory open: 3520 * 0: disallowed for all processes. 3521 * 1: allowed for processes that were not already chroot(2)'ed. 3522 * 2: allowed for all processes. 3523 */ 3524 3525 static int chroot_allow_open_directories = 1; 3526 3527 SYSCTL_INT(_kern, OID_AUTO, chroot_allow_open_directories, CTLFLAG_RW, 3528 &chroot_allow_open_directories, 0, 3529 "Allow a process to chroot(2) if it has a directory open"); 3530 3531 /* 3532 * Helper function for raised chroot(2) security function: Refuse if 3533 * any filedescriptors are open directories. 3534 */ 3535 static int 3536 chroot_refuse_vdir_fds(struct filedesc *fdp) 3537 { 3538 struct vnode *vp; 3539 struct file *fp; 3540 int fd, lastfile; 3541 3542 FILEDESC_LOCK_ASSERT(fdp); 3543 3544 lastfile = fdlastfile(fdp); 3545 for (fd = 0; fd <= lastfile; fd++) { 3546 fp = fget_locked(fdp, fd); 3547 if (fp == NULL) 3548 continue; 3549 if (fp->f_type == DTYPE_VNODE) { 3550 vp = fp->f_vnode; 3551 if (vp->v_type == VDIR) 3552 return (EPERM); 3553 } 3554 } 3555 return (0); 3556 } 3557 3558 static void 3559 pwd_fill(struct pwd *oldpwd, struct pwd *newpwd) 3560 { 3561 3562 if (newpwd->pwd_cdir == NULL && oldpwd->pwd_cdir != NULL) { 3563 vrefact(oldpwd->pwd_cdir); 3564 newpwd->pwd_cdir = oldpwd->pwd_cdir; 3565 } 3566 3567 if (newpwd->pwd_rdir == NULL && oldpwd->pwd_rdir != NULL) { 3568 vrefact(oldpwd->pwd_rdir); 3569 newpwd->pwd_rdir = oldpwd->pwd_rdir; 3570 } 3571 3572 if (newpwd->pwd_jdir == NULL && oldpwd->pwd_jdir != NULL) { 3573 vrefact(oldpwd->pwd_jdir); 3574 newpwd->pwd_jdir = oldpwd->pwd_jdir; 3575 } 3576 } 3577 3578 struct pwd * 3579 pwd_hold_pwddesc(struct pwddesc *pdp) 3580 { 3581 struct pwd *pwd; 3582 3583 PWDDESC_ASSERT_XLOCKED(pdp); 3584 pwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); 3585 if (pwd != NULL) 3586 refcount_acquire(&pwd->pwd_refcount); 3587 return (pwd); 3588 } 3589 3590 bool 3591 pwd_hold_smr(struct pwd *pwd) 3592 { 3593 3594 MPASS(pwd != NULL); 3595 if (__predict_true(refcount_acquire_if_not_zero(&pwd->pwd_refcount))) { 3596 return (true); 3597 } 3598 return (false); 3599 } 3600 3601 struct pwd * 3602 pwd_hold(struct thread *td) 3603 { 3604 struct pwddesc *pdp; 3605 struct pwd *pwd; 3606 3607 pdp = td->td_proc->p_pd; 3608 3609 vfs_smr_enter(); 3610 pwd = vfs_smr_entered_load(&pdp->pd_pwd); 3611 if (pwd_hold_smr(pwd)) { 3612 vfs_smr_exit(); 3613 return (pwd); 3614 } 3615 vfs_smr_exit(); 3616 PWDDESC_XLOCK(pdp); 3617 pwd = pwd_hold_pwddesc(pdp); 3618 MPASS(pwd != NULL); 3619 PWDDESC_XUNLOCK(pdp); 3620 return (pwd); 3621 } 3622 3623 struct pwd * 3624 pwd_get_smr(void) 3625 { 3626 struct pwd *pwd; 3627 3628 pwd = vfs_smr_entered_load(&curproc->p_pd->pd_pwd); 3629 MPASS(pwd != NULL); 3630 return (pwd); 3631 } 3632 3633 static struct pwd * 3634 pwd_alloc(void) 3635 { 3636 struct pwd *pwd; 3637 3638 pwd = uma_zalloc_smr(pwd_zone, M_WAITOK); 3639 bzero(pwd, sizeof(*pwd)); 3640 refcount_init(&pwd->pwd_refcount, 1); 3641 return (pwd); 3642 } 3643 3644 void 3645 pwd_drop(struct pwd *pwd) 3646 { 3647 3648 if (!refcount_release(&pwd->pwd_refcount)) 3649 return; 3650 3651 if (pwd->pwd_cdir != NULL) 3652 vrele(pwd->pwd_cdir); 3653 if (pwd->pwd_rdir != NULL) 3654 vrele(pwd->pwd_rdir); 3655 if (pwd->pwd_jdir != NULL) 3656 vrele(pwd->pwd_jdir); 3657 uma_zfree_smr(pwd_zone, pwd); 3658 } 3659 3660 /* 3661 * Common routine for kern_chroot() and jail_attach(). The caller is 3662 * responsible for invoking priv_check() and mac_vnode_check_chroot() to 3663 * authorize this operation. 3664 */ 3665 int 3666 pwd_chroot(struct thread *td, struct vnode *vp) 3667 { 3668 struct pwddesc *pdp; 3669 struct filedesc *fdp; 3670 struct pwd *newpwd, *oldpwd; 3671 int error; 3672 3673 fdp = td->td_proc->p_fd; 3674 pdp = td->td_proc->p_pd; 3675 newpwd = pwd_alloc(); 3676 FILEDESC_SLOCK(fdp); 3677 PWDDESC_XLOCK(pdp); 3678 oldpwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); 3679 if (chroot_allow_open_directories == 0 || 3680 (chroot_allow_open_directories == 1 && 3681 oldpwd->pwd_rdir != rootvnode)) { 3682 error = chroot_refuse_vdir_fds(fdp); 3683 FILEDESC_SUNLOCK(fdp); 3684 if (error != 0) { 3685 PWDDESC_XUNLOCK(pdp); 3686 pwd_drop(newpwd); 3687 return (error); 3688 } 3689 } else { 3690 FILEDESC_SUNLOCK(fdp); 3691 } 3692 3693 vrefact(vp); 3694 newpwd->pwd_rdir = vp; 3695 if (oldpwd->pwd_jdir == NULL) { 3696 vrefact(vp); 3697 newpwd->pwd_jdir = vp; 3698 } 3699 pwd_fill(oldpwd, newpwd); 3700 pwd_set(pdp, newpwd); 3701 PWDDESC_XUNLOCK(pdp); 3702 pwd_drop(oldpwd); 3703 return (0); 3704 } 3705 3706 void 3707 pwd_chdir(struct thread *td, struct vnode *vp) 3708 { 3709 struct pwddesc *pdp; 3710 struct pwd *newpwd, *oldpwd; 3711 3712 VNPASS(vp->v_usecount > 0, vp); 3713 3714 newpwd = pwd_alloc(); 3715 pdp = td->td_proc->p_pd; 3716 PWDDESC_XLOCK(pdp); 3717 oldpwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); 3718 newpwd->pwd_cdir = vp; 3719 pwd_fill(oldpwd, newpwd); 3720 pwd_set(pdp, newpwd); 3721 PWDDESC_XUNLOCK(pdp); 3722 pwd_drop(oldpwd); 3723 } 3724 3725 void 3726 pwd_ensure_dirs(void) 3727 { 3728 struct pwddesc *pdp; 3729 struct pwd *oldpwd, *newpwd; 3730 3731 pdp = curproc->p_pd; 3732 PWDDESC_XLOCK(pdp); 3733 oldpwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); 3734 if (oldpwd->pwd_cdir != NULL && oldpwd->pwd_rdir != NULL) { 3735 PWDDESC_XUNLOCK(pdp); 3736 return; 3737 } 3738 PWDDESC_XUNLOCK(pdp); 3739 3740 newpwd = pwd_alloc(); 3741 PWDDESC_XLOCK(pdp); 3742 oldpwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); 3743 pwd_fill(oldpwd, newpwd); 3744 if (newpwd->pwd_cdir == NULL) { 3745 vrefact(rootvnode); 3746 newpwd->pwd_cdir = rootvnode; 3747 } 3748 if (newpwd->pwd_rdir == NULL) { 3749 vrefact(rootvnode); 3750 newpwd->pwd_rdir = rootvnode; 3751 } 3752 pwd_set(pdp, newpwd); 3753 PWDDESC_XUNLOCK(pdp); 3754 pwd_drop(oldpwd); 3755 } 3756 3757 void 3758 pwd_set_rootvnode(void) 3759 { 3760 struct pwddesc *pdp; 3761 struct pwd *oldpwd, *newpwd; 3762 3763 pdp = curproc->p_pd; 3764 3765 newpwd = pwd_alloc(); 3766 PWDDESC_XLOCK(pdp); 3767 oldpwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); 3768 vrefact(rootvnode); 3769 newpwd->pwd_cdir = rootvnode; 3770 vrefact(rootvnode); 3771 newpwd->pwd_rdir = rootvnode; 3772 pwd_fill(oldpwd, newpwd); 3773 pwd_set(pdp, newpwd); 3774 PWDDESC_XUNLOCK(pdp); 3775 pwd_drop(oldpwd); 3776 } 3777 3778 /* 3779 * Scan all active processes and prisons to see if any of them have a current 3780 * or root directory of `olddp'. If so, replace them with the new mount point. 3781 */ 3782 void 3783 mountcheckdirs(struct vnode *olddp, struct vnode *newdp) 3784 { 3785 struct pwddesc *pdp; 3786 struct pwd *newpwd, *oldpwd; 3787 struct prison *pr; 3788 struct proc *p; 3789 int nrele; 3790 3791 if (vrefcnt(olddp) == 1) 3792 return; 3793 nrele = 0; 3794 newpwd = pwd_alloc(); 3795 sx_slock(&allproc_lock); 3796 FOREACH_PROC_IN_SYSTEM(p) { 3797 PROC_LOCK(p); 3798 pdp = pdhold(p); 3799 PROC_UNLOCK(p); 3800 if (pdp == NULL) 3801 continue; 3802 PWDDESC_XLOCK(pdp); 3803 oldpwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); 3804 if (oldpwd == NULL || 3805 (oldpwd->pwd_cdir != olddp && 3806 oldpwd->pwd_rdir != olddp && 3807 oldpwd->pwd_jdir != olddp)) { 3808 PWDDESC_XUNLOCK(pdp); 3809 pddrop(pdp); 3810 continue; 3811 } 3812 if (oldpwd->pwd_cdir == olddp) { 3813 vrefact(newdp); 3814 newpwd->pwd_cdir = newdp; 3815 } 3816 if (oldpwd->pwd_rdir == olddp) { 3817 vrefact(newdp); 3818 newpwd->pwd_rdir = newdp; 3819 } 3820 if (oldpwd->pwd_jdir == olddp) { 3821 vrefact(newdp); 3822 newpwd->pwd_jdir = newdp; 3823 } 3824 pwd_fill(oldpwd, newpwd); 3825 pwd_set(pdp, newpwd); 3826 PWDDESC_XUNLOCK(pdp); 3827 pwd_drop(oldpwd); 3828 pddrop(pdp); 3829 newpwd = pwd_alloc(); 3830 } 3831 sx_sunlock(&allproc_lock); 3832 pwd_drop(newpwd); 3833 if (rootvnode == olddp) { 3834 vrefact(newdp); 3835 rootvnode = newdp; 3836 nrele++; 3837 } 3838 mtx_lock(&prison0.pr_mtx); 3839 if (prison0.pr_root == olddp) { 3840 vrefact(newdp); 3841 prison0.pr_root = newdp; 3842 nrele++; 3843 } 3844 mtx_unlock(&prison0.pr_mtx); 3845 sx_slock(&allprison_lock); 3846 TAILQ_FOREACH(pr, &allprison, pr_list) { 3847 mtx_lock(&pr->pr_mtx); 3848 if (pr->pr_root == olddp) { 3849 vrefact(newdp); 3850 pr->pr_root = newdp; 3851 nrele++; 3852 } 3853 mtx_unlock(&pr->pr_mtx); 3854 } 3855 sx_sunlock(&allprison_lock); 3856 while (nrele--) 3857 vrele(olddp); 3858 } 3859 3860 struct filedesc_to_leader * 3861 filedesc_to_leader_alloc(struct filedesc_to_leader *old, struct filedesc *fdp, struct proc *leader) 3862 { 3863 struct filedesc_to_leader *fdtol; 3864 3865 fdtol = malloc(sizeof(struct filedesc_to_leader), 3866 M_FILEDESC_TO_LEADER, M_WAITOK); 3867 fdtol->fdl_refcount = 1; 3868 fdtol->fdl_holdcount = 0; 3869 fdtol->fdl_wakeup = 0; 3870 fdtol->fdl_leader = leader; 3871 if (old != NULL) { 3872 FILEDESC_XLOCK(fdp); 3873 fdtol->fdl_next = old->fdl_next; 3874 fdtol->fdl_prev = old; 3875 old->fdl_next = fdtol; 3876 fdtol->fdl_next->fdl_prev = fdtol; 3877 FILEDESC_XUNLOCK(fdp); 3878 } else { 3879 fdtol->fdl_next = fdtol; 3880 fdtol->fdl_prev = fdtol; 3881 } 3882 return (fdtol); 3883 } 3884 3885 static int 3886 sysctl_kern_proc_nfds(SYSCTL_HANDLER_ARGS) 3887 { 3888 NDSLOTTYPE *map; 3889 struct filedesc *fdp; 3890 int count, off, minoff; 3891 3892 if (*(int *)arg1 != 0) 3893 return (EINVAL); 3894 3895 fdp = curproc->p_fd; 3896 count = 0; 3897 FILEDESC_SLOCK(fdp); 3898 map = fdp->fd_map; 3899 off = NDSLOT(fdp->fd_nfiles - 1); 3900 for (minoff = NDSLOT(0); off >= minoff; --off) 3901 count += bitcountl(map[off]); 3902 FILEDESC_SUNLOCK(fdp); 3903 3904 return (SYSCTL_OUT(req, &count, sizeof(count))); 3905 } 3906 3907 static SYSCTL_NODE(_kern_proc, KERN_PROC_NFDS, nfds, 3908 CTLFLAG_RD|CTLFLAG_CAPRD|CTLFLAG_MPSAFE, sysctl_kern_proc_nfds, 3909 "Number of open file descriptors"); 3910 3911 /* 3912 * Get file structures globally. 3913 */ 3914 static int 3915 sysctl_kern_file(SYSCTL_HANDLER_ARGS) 3916 { 3917 struct xfile xf; 3918 struct filedesc *fdp; 3919 struct file *fp; 3920 struct proc *p; 3921 int error, n, lastfile; 3922 3923 error = sysctl_wire_old_buffer(req, 0); 3924 if (error != 0) 3925 return (error); 3926 if (req->oldptr == NULL) { 3927 n = 0; 3928 sx_slock(&allproc_lock); 3929 FOREACH_PROC_IN_SYSTEM(p) { 3930 PROC_LOCK(p); 3931 if (p->p_state == PRS_NEW) { 3932 PROC_UNLOCK(p); 3933 continue; 3934 } 3935 fdp = fdhold(p); 3936 PROC_UNLOCK(p); 3937 if (fdp == NULL) 3938 continue; 3939 /* overestimates sparse tables. */ 3940 n += fdp->fd_nfiles; 3941 fddrop(fdp); 3942 } 3943 sx_sunlock(&allproc_lock); 3944 return (SYSCTL_OUT(req, 0, n * sizeof(xf))); 3945 } 3946 error = 0; 3947 bzero(&xf, sizeof(xf)); 3948 xf.xf_size = sizeof(xf); 3949 sx_slock(&allproc_lock); 3950 FOREACH_PROC_IN_SYSTEM(p) { 3951 PROC_LOCK(p); 3952 if (p->p_state == PRS_NEW) { 3953 PROC_UNLOCK(p); 3954 continue; 3955 } 3956 if (p_cansee(req->td, p) != 0) { 3957 PROC_UNLOCK(p); 3958 continue; 3959 } 3960 xf.xf_pid = p->p_pid; 3961 xf.xf_uid = p->p_ucred->cr_uid; 3962 fdp = fdhold(p); 3963 PROC_UNLOCK(p); 3964 if (fdp == NULL) 3965 continue; 3966 FILEDESC_SLOCK(fdp); 3967 lastfile = fdlastfile(fdp); 3968 for (n = 0; fdp->fd_refcnt > 0 && n <= lastfile; ++n) { 3969 if ((fp = fdp->fd_ofiles[n].fde_file) == NULL) 3970 continue; 3971 xf.xf_fd = n; 3972 xf.xf_file = (uintptr_t)fp; 3973 xf.xf_data = (uintptr_t)fp->f_data; 3974 xf.xf_vnode = (uintptr_t)fp->f_vnode; 3975 xf.xf_type = (uintptr_t)fp->f_type; 3976 xf.xf_count = refcount_load(&fp->f_count); 3977 xf.xf_msgcount = 0; 3978 xf.xf_offset = foffset_get(fp); 3979 xf.xf_flag = fp->f_flag; 3980 error = SYSCTL_OUT(req, &xf, sizeof(xf)); 3981 if (error) 3982 break; 3983 } 3984 FILEDESC_SUNLOCK(fdp); 3985 fddrop(fdp); 3986 if (error) 3987 break; 3988 } 3989 sx_sunlock(&allproc_lock); 3990 return (error); 3991 } 3992 3993 SYSCTL_PROC(_kern, KERN_FILE, file, CTLTYPE_OPAQUE|CTLFLAG_RD|CTLFLAG_MPSAFE, 3994 0, 0, sysctl_kern_file, "S,xfile", "Entire file table"); 3995 3996 #ifdef KINFO_FILE_SIZE 3997 CTASSERT(sizeof(struct kinfo_file) == KINFO_FILE_SIZE); 3998 #endif 3999 4000 static int 4001 xlate_fflags(int fflags) 4002 { 4003 static const struct { 4004 int fflag; 4005 int kf_fflag; 4006 } fflags_table[] = { 4007 { FAPPEND, KF_FLAG_APPEND }, 4008 { FASYNC, KF_FLAG_ASYNC }, 4009 { FFSYNC, KF_FLAG_FSYNC }, 4010 { FHASLOCK, KF_FLAG_HASLOCK }, 4011 { FNONBLOCK, KF_FLAG_NONBLOCK }, 4012 { FREAD, KF_FLAG_READ }, 4013 { FWRITE, KF_FLAG_WRITE }, 4014 { O_CREAT, KF_FLAG_CREAT }, 4015 { O_DIRECT, KF_FLAG_DIRECT }, 4016 { O_EXCL, KF_FLAG_EXCL }, 4017 { O_EXEC, KF_FLAG_EXEC }, 4018 { O_EXLOCK, KF_FLAG_EXLOCK }, 4019 { O_NOFOLLOW, KF_FLAG_NOFOLLOW }, 4020 { O_SHLOCK, KF_FLAG_SHLOCK }, 4021 { O_TRUNC, KF_FLAG_TRUNC } 4022 }; 4023 unsigned int i; 4024 int kflags; 4025 4026 kflags = 0; 4027 for (i = 0; i < nitems(fflags_table); i++) 4028 if (fflags & fflags_table[i].fflag) 4029 kflags |= fflags_table[i].kf_fflag; 4030 return (kflags); 4031 } 4032 4033 /* Trim unused data from kf_path by truncating the structure size. */ 4034 void 4035 pack_kinfo(struct kinfo_file *kif) 4036 { 4037 4038 kif->kf_structsize = offsetof(struct kinfo_file, kf_path) + 4039 strlen(kif->kf_path) + 1; 4040 kif->kf_structsize = roundup(kif->kf_structsize, sizeof(uint64_t)); 4041 } 4042 4043 static void 4044 export_file_to_kinfo(struct file *fp, int fd, cap_rights_t *rightsp, 4045 struct kinfo_file *kif, struct filedesc *fdp, int flags) 4046 { 4047 int error; 4048 4049 bzero(kif, sizeof(*kif)); 4050 4051 /* Set a default type to allow for empty fill_kinfo() methods. */ 4052 kif->kf_type = KF_TYPE_UNKNOWN; 4053 kif->kf_flags = xlate_fflags(fp->f_flag); 4054 if (rightsp != NULL) 4055 kif->kf_cap_rights = *rightsp; 4056 else 4057 cap_rights_init_zero(&kif->kf_cap_rights); 4058 kif->kf_fd = fd; 4059 kif->kf_ref_count = refcount_load(&fp->f_count); 4060 kif->kf_offset = foffset_get(fp); 4061 4062 /* 4063 * This may drop the filedesc lock, so the 'fp' cannot be 4064 * accessed after this call. 4065 */ 4066 error = fo_fill_kinfo(fp, kif, fdp); 4067 if (error == 0) 4068 kif->kf_status |= KF_ATTR_VALID; 4069 if ((flags & KERN_FILEDESC_PACK_KINFO) != 0) 4070 pack_kinfo(kif); 4071 else 4072 kif->kf_structsize = roundup2(sizeof(*kif), sizeof(uint64_t)); 4073 } 4074 4075 static void 4076 export_vnode_to_kinfo(struct vnode *vp, int fd, int fflags, 4077 struct kinfo_file *kif, int flags) 4078 { 4079 int error; 4080 4081 bzero(kif, sizeof(*kif)); 4082 4083 kif->kf_type = KF_TYPE_VNODE; 4084 error = vn_fill_kinfo_vnode(vp, kif); 4085 if (error == 0) 4086 kif->kf_status |= KF_ATTR_VALID; 4087 kif->kf_flags = xlate_fflags(fflags); 4088 cap_rights_init_zero(&kif->kf_cap_rights); 4089 kif->kf_fd = fd; 4090 kif->kf_ref_count = -1; 4091 kif->kf_offset = -1; 4092 if ((flags & KERN_FILEDESC_PACK_KINFO) != 0) 4093 pack_kinfo(kif); 4094 else 4095 kif->kf_structsize = roundup2(sizeof(*kif), sizeof(uint64_t)); 4096 vrele(vp); 4097 } 4098 4099 struct export_fd_buf { 4100 struct filedesc *fdp; 4101 struct pwddesc *pdp; 4102 struct sbuf *sb; 4103 ssize_t remainder; 4104 struct kinfo_file kif; 4105 int flags; 4106 }; 4107 4108 static int 4109 export_kinfo_to_sb(struct export_fd_buf *efbuf) 4110 { 4111 struct kinfo_file *kif; 4112 4113 kif = &efbuf->kif; 4114 if (efbuf->remainder != -1) { 4115 if (efbuf->remainder < kif->kf_structsize) { 4116 /* Terminate export. */ 4117 efbuf->remainder = 0; 4118 return (0); 4119 } 4120 efbuf->remainder -= kif->kf_structsize; 4121 } 4122 return (sbuf_bcat(efbuf->sb, kif, kif->kf_structsize) == 0 ? 0 : ENOMEM); 4123 } 4124 4125 static int 4126 export_file_to_sb(struct file *fp, int fd, cap_rights_t *rightsp, 4127 struct export_fd_buf *efbuf) 4128 { 4129 int error; 4130 4131 if (efbuf->remainder == 0) 4132 return (0); 4133 export_file_to_kinfo(fp, fd, rightsp, &efbuf->kif, efbuf->fdp, 4134 efbuf->flags); 4135 FILEDESC_SUNLOCK(efbuf->fdp); 4136 error = export_kinfo_to_sb(efbuf); 4137 FILEDESC_SLOCK(efbuf->fdp); 4138 return (error); 4139 } 4140 4141 static int 4142 export_vnode_to_sb(struct vnode *vp, int fd, int fflags, 4143 struct export_fd_buf *efbuf) 4144 { 4145 int error; 4146 4147 if (efbuf->remainder == 0) 4148 return (0); 4149 if (efbuf->pdp != NULL) 4150 PWDDESC_XUNLOCK(efbuf->pdp); 4151 export_vnode_to_kinfo(vp, fd, fflags, &efbuf->kif, efbuf->flags); 4152 error = export_kinfo_to_sb(efbuf); 4153 if (efbuf->pdp != NULL) 4154 PWDDESC_XLOCK(efbuf->pdp); 4155 return (error); 4156 } 4157 4158 /* 4159 * Store a process file descriptor information to sbuf. 4160 * 4161 * Takes a locked proc as argument, and returns with the proc unlocked. 4162 */ 4163 int 4164 kern_proc_filedesc_out(struct proc *p, struct sbuf *sb, ssize_t maxlen, 4165 int flags) 4166 { 4167 struct file *fp; 4168 struct filedesc *fdp; 4169 struct pwddesc *pdp; 4170 struct export_fd_buf *efbuf; 4171 struct vnode *cttyvp, *textvp, *tracevp; 4172 struct pwd *pwd; 4173 int error, i, lastfile; 4174 cap_rights_t rights; 4175 4176 PROC_LOCK_ASSERT(p, MA_OWNED); 4177 4178 /* ktrace vnode */ 4179 tracevp = p->p_tracevp; 4180 if (tracevp != NULL) 4181 vrefact(tracevp); 4182 /* text vnode */ 4183 textvp = p->p_textvp; 4184 if (textvp != NULL) 4185 vrefact(textvp); 4186 /* Controlling tty. */ 4187 cttyvp = NULL; 4188 if (p->p_pgrp != NULL && p->p_pgrp->pg_session != NULL) { 4189 cttyvp = p->p_pgrp->pg_session->s_ttyvp; 4190 if (cttyvp != NULL) 4191 vrefact(cttyvp); 4192 } 4193 fdp = fdhold(p); 4194 pdp = pdhold(p); 4195 PROC_UNLOCK(p); 4196 efbuf = malloc(sizeof(*efbuf), M_TEMP, M_WAITOK); 4197 efbuf->fdp = NULL; 4198 efbuf->pdp = NULL; 4199 efbuf->sb = sb; 4200 efbuf->remainder = maxlen; 4201 efbuf->flags = flags; 4202 if (tracevp != NULL) 4203 export_vnode_to_sb(tracevp, KF_FD_TYPE_TRACE, FREAD | FWRITE, 4204 efbuf); 4205 if (textvp != NULL) 4206 export_vnode_to_sb(textvp, KF_FD_TYPE_TEXT, FREAD, efbuf); 4207 if (cttyvp != NULL) 4208 export_vnode_to_sb(cttyvp, KF_FD_TYPE_CTTY, FREAD | FWRITE, 4209 efbuf); 4210 error = 0; 4211 if (pdp == NULL || fdp == NULL) 4212 goto fail; 4213 efbuf->fdp = fdp; 4214 efbuf->pdp = pdp; 4215 PWDDESC_XLOCK(pdp); 4216 pwd = pwd_hold_pwddesc(pdp); 4217 if (pwd != NULL) { 4218 /* working directory */ 4219 if (pwd->pwd_cdir != NULL) { 4220 vrefact(pwd->pwd_cdir); 4221 export_vnode_to_sb(pwd->pwd_cdir, KF_FD_TYPE_CWD, FREAD, efbuf); 4222 } 4223 /* root directory */ 4224 if (pwd->pwd_rdir != NULL) { 4225 vrefact(pwd->pwd_rdir); 4226 export_vnode_to_sb(pwd->pwd_rdir, KF_FD_TYPE_ROOT, FREAD, efbuf); 4227 } 4228 /* jail directory */ 4229 if (pwd->pwd_jdir != NULL) { 4230 vrefact(pwd->pwd_jdir); 4231 export_vnode_to_sb(pwd->pwd_jdir, KF_FD_TYPE_JAIL, FREAD, efbuf); 4232 } 4233 } 4234 PWDDESC_XUNLOCK(pdp); 4235 if (pwd != NULL) 4236 pwd_drop(pwd); 4237 FILEDESC_SLOCK(fdp); 4238 lastfile = fdlastfile(fdp); 4239 for (i = 0; fdp->fd_refcnt > 0 && i <= lastfile; i++) { 4240 if ((fp = fdp->fd_ofiles[i].fde_file) == NULL) 4241 continue; 4242 #ifdef CAPABILITIES 4243 rights = *cap_rights(fdp, i); 4244 #else /* !CAPABILITIES */ 4245 rights = cap_no_rights; 4246 #endif 4247 /* 4248 * Create sysctl entry. It is OK to drop the filedesc 4249 * lock inside of export_file_to_sb() as we will 4250 * re-validate and re-evaluate its properties when the 4251 * loop continues. 4252 */ 4253 error = export_file_to_sb(fp, i, &rights, efbuf); 4254 if (error != 0 || efbuf->remainder == 0) 4255 break; 4256 } 4257 FILEDESC_SUNLOCK(fdp); 4258 fail: 4259 if (fdp != NULL) 4260 fddrop(fdp); 4261 if (pdp != NULL) 4262 pddrop(pdp); 4263 free(efbuf, M_TEMP); 4264 return (error); 4265 } 4266 4267 #define FILEDESC_SBUF_SIZE (sizeof(struct kinfo_file) * 5) 4268 4269 /* 4270 * Get per-process file descriptors for use by procstat(1), et al. 4271 */ 4272 static int 4273 sysctl_kern_proc_filedesc(SYSCTL_HANDLER_ARGS) 4274 { 4275 struct sbuf sb; 4276 struct proc *p; 4277 ssize_t maxlen; 4278 int error, error2, *name; 4279 4280 name = (int *)arg1; 4281 4282 sbuf_new_for_sysctl(&sb, NULL, FILEDESC_SBUF_SIZE, req); 4283 sbuf_clear_flags(&sb, SBUF_INCLUDENUL); 4284 error = pget((pid_t)name[0], PGET_CANDEBUG | PGET_NOTWEXIT, &p); 4285 if (error != 0) { 4286 sbuf_delete(&sb); 4287 return (error); 4288 } 4289 maxlen = req->oldptr != NULL ? req->oldlen : -1; 4290 error = kern_proc_filedesc_out(p, &sb, maxlen, 4291 KERN_FILEDESC_PACK_KINFO); 4292 error2 = sbuf_finish(&sb); 4293 sbuf_delete(&sb); 4294 return (error != 0 ? error : error2); 4295 } 4296 4297 #ifdef COMPAT_FREEBSD7 4298 #ifdef KINFO_OFILE_SIZE 4299 CTASSERT(sizeof(struct kinfo_ofile) == KINFO_OFILE_SIZE); 4300 #endif 4301 4302 static void 4303 kinfo_to_okinfo(struct kinfo_file *kif, struct kinfo_ofile *okif) 4304 { 4305 4306 okif->kf_structsize = sizeof(*okif); 4307 okif->kf_type = kif->kf_type; 4308 okif->kf_fd = kif->kf_fd; 4309 okif->kf_ref_count = kif->kf_ref_count; 4310 okif->kf_flags = kif->kf_flags & (KF_FLAG_READ | KF_FLAG_WRITE | 4311 KF_FLAG_APPEND | KF_FLAG_ASYNC | KF_FLAG_FSYNC | KF_FLAG_NONBLOCK | 4312 KF_FLAG_DIRECT | KF_FLAG_HASLOCK); 4313 okif->kf_offset = kif->kf_offset; 4314 if (kif->kf_type == KF_TYPE_VNODE) 4315 okif->kf_vnode_type = kif->kf_un.kf_file.kf_file_type; 4316 else 4317 okif->kf_vnode_type = KF_VTYPE_VNON; 4318 strlcpy(okif->kf_path, kif->kf_path, sizeof(okif->kf_path)); 4319 if (kif->kf_type == KF_TYPE_SOCKET) { 4320 okif->kf_sock_domain = kif->kf_un.kf_sock.kf_sock_domain0; 4321 okif->kf_sock_type = kif->kf_un.kf_sock.kf_sock_type0; 4322 okif->kf_sock_protocol = kif->kf_un.kf_sock.kf_sock_protocol0; 4323 okif->kf_sa_local = kif->kf_un.kf_sock.kf_sa_local; 4324 okif->kf_sa_peer = kif->kf_un.kf_sock.kf_sa_peer; 4325 } else { 4326 okif->kf_sa_local.ss_family = AF_UNSPEC; 4327 okif->kf_sa_peer.ss_family = AF_UNSPEC; 4328 } 4329 } 4330 4331 static int 4332 export_vnode_for_osysctl(struct vnode *vp, int type, struct kinfo_file *kif, 4333 struct kinfo_ofile *okif, struct pwddesc *pdp, struct sysctl_req *req) 4334 { 4335 int error; 4336 4337 vrefact(vp); 4338 PWDDESC_XUNLOCK(pdp); 4339 export_vnode_to_kinfo(vp, type, 0, kif, KERN_FILEDESC_PACK_KINFO); 4340 kinfo_to_okinfo(kif, okif); 4341 error = SYSCTL_OUT(req, okif, sizeof(*okif)); 4342 PWDDESC_XLOCK(pdp); 4343 return (error); 4344 } 4345 4346 /* 4347 * Get per-process file descriptors for use by procstat(1), et al. 4348 */ 4349 static int 4350 sysctl_kern_proc_ofiledesc(SYSCTL_HANDLER_ARGS) 4351 { 4352 struct kinfo_ofile *okif; 4353 struct kinfo_file *kif; 4354 struct filedesc *fdp; 4355 struct pwddesc *pdp; 4356 struct pwd *pwd; 4357 int error, i, lastfile, *name; 4358 struct file *fp; 4359 struct proc *p; 4360 4361 name = (int *)arg1; 4362 error = pget((pid_t)name[0], PGET_CANDEBUG | PGET_NOTWEXIT, &p); 4363 if (error != 0) 4364 return (error); 4365 fdp = fdhold(p); 4366 if (fdp != NULL) 4367 pdp = pdhold(p); 4368 PROC_UNLOCK(p); 4369 if (fdp == NULL || pdp == NULL) { 4370 if (fdp != NULL) 4371 fddrop(fdp); 4372 return (ENOENT); 4373 } 4374 kif = malloc(sizeof(*kif), M_TEMP, M_WAITOK); 4375 okif = malloc(sizeof(*okif), M_TEMP, M_WAITOK); 4376 PWDDESC_XLOCK(pdp); 4377 pwd = pwd_hold_pwddesc(pdp); 4378 if (pwd != NULL) { 4379 if (pwd->pwd_cdir != NULL) 4380 export_vnode_for_osysctl(pwd->pwd_cdir, KF_FD_TYPE_CWD, kif, 4381 okif, pdp, req); 4382 if (pwd->pwd_rdir != NULL) 4383 export_vnode_for_osysctl(pwd->pwd_rdir, KF_FD_TYPE_ROOT, kif, 4384 okif, pdp, req); 4385 if (pwd->pwd_jdir != NULL) 4386 export_vnode_for_osysctl(pwd->pwd_jdir, KF_FD_TYPE_JAIL, kif, 4387 okif, pdp, req); 4388 } 4389 PWDDESC_XUNLOCK(pdp); 4390 if (pwd != NULL) 4391 pwd_drop(pwd); 4392 FILEDESC_SLOCK(fdp); 4393 lastfile = fdlastfile(fdp); 4394 for (i = 0; fdp->fd_refcnt > 0 && i <= lastfile; i++) { 4395 if ((fp = fdp->fd_ofiles[i].fde_file) == NULL) 4396 continue; 4397 export_file_to_kinfo(fp, i, NULL, kif, fdp, 4398 KERN_FILEDESC_PACK_KINFO); 4399 FILEDESC_SUNLOCK(fdp); 4400 kinfo_to_okinfo(kif, okif); 4401 error = SYSCTL_OUT(req, okif, sizeof(*okif)); 4402 FILEDESC_SLOCK(fdp); 4403 if (error) 4404 break; 4405 } 4406 FILEDESC_SUNLOCK(fdp); 4407 fddrop(fdp); 4408 pddrop(pdp); 4409 free(kif, M_TEMP); 4410 free(okif, M_TEMP); 4411 return (0); 4412 } 4413 4414 static SYSCTL_NODE(_kern_proc, KERN_PROC_OFILEDESC, ofiledesc, 4415 CTLFLAG_RD|CTLFLAG_MPSAFE, sysctl_kern_proc_ofiledesc, 4416 "Process ofiledesc entries"); 4417 #endif /* COMPAT_FREEBSD7 */ 4418 4419 int 4420 vntype_to_kinfo(int vtype) 4421 { 4422 struct { 4423 int vtype; 4424 int kf_vtype; 4425 } vtypes_table[] = { 4426 { VBAD, KF_VTYPE_VBAD }, 4427 { VBLK, KF_VTYPE_VBLK }, 4428 { VCHR, KF_VTYPE_VCHR }, 4429 { VDIR, KF_VTYPE_VDIR }, 4430 { VFIFO, KF_VTYPE_VFIFO }, 4431 { VLNK, KF_VTYPE_VLNK }, 4432 { VNON, KF_VTYPE_VNON }, 4433 { VREG, KF_VTYPE_VREG }, 4434 { VSOCK, KF_VTYPE_VSOCK } 4435 }; 4436 unsigned int i; 4437 4438 /* 4439 * Perform vtype translation. 4440 */ 4441 for (i = 0; i < nitems(vtypes_table); i++) 4442 if (vtypes_table[i].vtype == vtype) 4443 return (vtypes_table[i].kf_vtype); 4444 4445 return (KF_VTYPE_UNKNOWN); 4446 } 4447 4448 static SYSCTL_NODE(_kern_proc, KERN_PROC_FILEDESC, filedesc, 4449 CTLFLAG_RD|CTLFLAG_MPSAFE, sysctl_kern_proc_filedesc, 4450 "Process filedesc entries"); 4451 4452 /* 4453 * Store a process current working directory information to sbuf. 4454 * 4455 * Takes a locked proc as argument, and returns with the proc unlocked. 4456 */ 4457 int 4458 kern_proc_cwd_out(struct proc *p, struct sbuf *sb, ssize_t maxlen) 4459 { 4460 struct pwddesc *pdp; 4461 struct pwd *pwd; 4462 struct export_fd_buf *efbuf; 4463 struct vnode *cdir; 4464 int error; 4465 4466 PROC_LOCK_ASSERT(p, MA_OWNED); 4467 4468 pdp = pdhold(p); 4469 PROC_UNLOCK(p); 4470 if (pdp == NULL) 4471 return (EINVAL); 4472 4473 efbuf = malloc(sizeof(*efbuf), M_TEMP, M_WAITOK); 4474 efbuf->pdp = pdp; 4475 efbuf->sb = sb; 4476 efbuf->remainder = maxlen; 4477 4478 PWDDESC_XLOCK(pdp); 4479 pwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); 4480 cdir = pwd->pwd_cdir; 4481 if (cdir == NULL) { 4482 error = EINVAL; 4483 } else { 4484 vrefact(cdir); 4485 error = export_vnode_to_sb(cdir, KF_FD_TYPE_CWD, FREAD, efbuf); 4486 } 4487 PWDDESC_XUNLOCK(pdp); 4488 pddrop(pdp); 4489 free(efbuf, M_TEMP); 4490 return (error); 4491 } 4492 4493 /* 4494 * Get per-process current working directory. 4495 */ 4496 static int 4497 sysctl_kern_proc_cwd(SYSCTL_HANDLER_ARGS) 4498 { 4499 struct sbuf sb; 4500 struct proc *p; 4501 ssize_t maxlen; 4502 int error, error2, *name; 4503 4504 name = (int *)arg1; 4505 4506 sbuf_new_for_sysctl(&sb, NULL, sizeof(struct kinfo_file), req); 4507 sbuf_clear_flags(&sb, SBUF_INCLUDENUL); 4508 error = pget((pid_t)name[0], PGET_CANDEBUG | PGET_NOTWEXIT, &p); 4509 if (error != 0) { 4510 sbuf_delete(&sb); 4511 return (error); 4512 } 4513 maxlen = req->oldptr != NULL ? req->oldlen : -1; 4514 error = kern_proc_cwd_out(p, &sb, maxlen); 4515 error2 = sbuf_finish(&sb); 4516 sbuf_delete(&sb); 4517 return (error != 0 ? error : error2); 4518 } 4519 4520 static SYSCTL_NODE(_kern_proc, KERN_PROC_CWD, cwd, CTLFLAG_RD|CTLFLAG_MPSAFE, 4521 sysctl_kern_proc_cwd, "Process current working directory"); 4522 4523 #ifdef DDB 4524 /* 4525 * For the purposes of debugging, generate a human-readable string for the 4526 * file type. 4527 */ 4528 static const char * 4529 file_type_to_name(short type) 4530 { 4531 4532 switch (type) { 4533 case 0: 4534 return ("zero"); 4535 case DTYPE_VNODE: 4536 return ("vnode"); 4537 case DTYPE_SOCKET: 4538 return ("socket"); 4539 case DTYPE_PIPE: 4540 return ("pipe"); 4541 case DTYPE_FIFO: 4542 return ("fifo"); 4543 case DTYPE_KQUEUE: 4544 return ("kqueue"); 4545 case DTYPE_CRYPTO: 4546 return ("crypto"); 4547 case DTYPE_MQUEUE: 4548 return ("mqueue"); 4549 case DTYPE_SHM: 4550 return ("shm"); 4551 case DTYPE_SEM: 4552 return ("ksem"); 4553 case DTYPE_PTS: 4554 return ("pts"); 4555 case DTYPE_DEV: 4556 return ("dev"); 4557 case DTYPE_PROCDESC: 4558 return ("proc"); 4559 case DTYPE_LINUXEFD: 4560 return ("levent"); 4561 case DTYPE_LINUXTFD: 4562 return ("ltimer"); 4563 default: 4564 return ("unkn"); 4565 } 4566 } 4567 4568 /* 4569 * For the purposes of debugging, identify a process (if any, perhaps one of 4570 * many) that references the passed file in its file descriptor array. Return 4571 * NULL if none. 4572 */ 4573 static struct proc * 4574 file_to_first_proc(struct file *fp) 4575 { 4576 struct filedesc *fdp; 4577 struct proc *p; 4578 int n; 4579 4580 FOREACH_PROC_IN_SYSTEM(p) { 4581 if (p->p_state == PRS_NEW) 4582 continue; 4583 fdp = p->p_fd; 4584 if (fdp == NULL) 4585 continue; 4586 for (n = 0; n < fdp->fd_nfiles; n++) { 4587 if (fp == fdp->fd_ofiles[n].fde_file) 4588 return (p); 4589 } 4590 } 4591 return (NULL); 4592 } 4593 4594 static void 4595 db_print_file(struct file *fp, int header) 4596 { 4597 #define XPTRWIDTH ((int)howmany(sizeof(void *) * NBBY, 4)) 4598 struct proc *p; 4599 4600 if (header) 4601 db_printf("%*s %6s %*s %8s %4s %5s %6s %*s %5s %s\n", 4602 XPTRWIDTH, "File", "Type", XPTRWIDTH, "Data", "Flag", 4603 "GCFl", "Count", "MCount", XPTRWIDTH, "Vnode", "FPID", 4604 "FCmd"); 4605 p = file_to_first_proc(fp); 4606 db_printf("%*p %6s %*p %08x %04x %5d %6d %*p %5d %s\n", XPTRWIDTH, 4607 fp, file_type_to_name(fp->f_type), XPTRWIDTH, fp->f_data, 4608 fp->f_flag, 0, refcount_load(&fp->f_count), 0, XPTRWIDTH, fp->f_vnode, 4609 p != NULL ? p->p_pid : -1, p != NULL ? p->p_comm : "-"); 4610 4611 #undef XPTRWIDTH 4612 } 4613 4614 DB_SHOW_COMMAND(file, db_show_file) 4615 { 4616 struct file *fp; 4617 4618 if (!have_addr) { 4619 db_printf("usage: show file <addr>\n"); 4620 return; 4621 } 4622 fp = (struct file *)addr; 4623 db_print_file(fp, 1); 4624 } 4625 4626 DB_SHOW_COMMAND(files, db_show_files) 4627 { 4628 struct filedesc *fdp; 4629 struct file *fp; 4630 struct proc *p; 4631 int header; 4632 int n; 4633 4634 header = 1; 4635 FOREACH_PROC_IN_SYSTEM(p) { 4636 if (p->p_state == PRS_NEW) 4637 continue; 4638 if ((fdp = p->p_fd) == NULL) 4639 continue; 4640 for (n = 0; n < fdp->fd_nfiles; ++n) { 4641 if ((fp = fdp->fd_ofiles[n].fde_file) == NULL) 4642 continue; 4643 db_print_file(fp, header); 4644 header = 0; 4645 } 4646 } 4647 } 4648 #endif 4649 4650 SYSCTL_INT(_kern, KERN_MAXFILESPERPROC, maxfilesperproc, CTLFLAG_RW, 4651 &maxfilesperproc, 0, "Maximum files allowed open per process"); 4652 4653 SYSCTL_INT(_kern, KERN_MAXFILES, maxfiles, CTLFLAG_RW, 4654 &maxfiles, 0, "Maximum number of files"); 4655 4656 SYSCTL_INT(_kern, OID_AUTO, openfiles, CTLFLAG_RD, 4657 &openfiles, 0, "System-wide number of open files"); 4658 4659 /* ARGSUSED*/ 4660 static void 4661 filelistinit(void *dummy) 4662 { 4663 4664 file_zone = uma_zcreate("Files", sizeof(struct file), NULL, NULL, 4665 NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE); 4666 filedesc0_zone = uma_zcreate("filedesc0", sizeof(struct filedesc0), 4667 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0); 4668 pwd_zone = uma_zcreate("PWD", sizeof(struct pwd), NULL, NULL, 4669 NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_SMR); 4670 /* 4671 * XXXMJG this is a temporary hack due to boot ordering issues against 4672 * the vnode zone. 4673 */ 4674 vfs_smr = uma_zone_get_smr(pwd_zone); 4675 mtx_init(&sigio_lock, "sigio lock", NULL, MTX_DEF); 4676 } 4677 SYSINIT(select, SI_SUB_LOCK, SI_ORDER_FIRST, filelistinit, NULL); 4678 4679 /*-------------------------------------------------------------------*/ 4680 4681 static int 4682 badfo_readwrite(struct file *fp, struct uio *uio, struct ucred *active_cred, 4683 int flags, struct thread *td) 4684 { 4685 4686 return (EBADF); 4687 } 4688 4689 static int 4690 badfo_truncate(struct file *fp, off_t length, struct ucred *active_cred, 4691 struct thread *td) 4692 { 4693 4694 return (EINVAL); 4695 } 4696 4697 static int 4698 badfo_ioctl(struct file *fp, u_long com, void *data, struct ucred *active_cred, 4699 struct thread *td) 4700 { 4701 4702 return (EBADF); 4703 } 4704 4705 static int 4706 badfo_poll(struct file *fp, int events, struct ucred *active_cred, 4707 struct thread *td) 4708 { 4709 4710 return (0); 4711 } 4712 4713 static int 4714 badfo_kqfilter(struct file *fp, struct knote *kn) 4715 { 4716 4717 return (EBADF); 4718 } 4719 4720 static int 4721 badfo_stat(struct file *fp, struct stat *sb, struct ucred *active_cred, 4722 struct thread *td) 4723 { 4724 4725 return (EBADF); 4726 } 4727 4728 static int 4729 badfo_close(struct file *fp, struct thread *td) 4730 { 4731 4732 return (0); 4733 } 4734 4735 static int 4736 badfo_chmod(struct file *fp, mode_t mode, struct ucred *active_cred, 4737 struct thread *td) 4738 { 4739 4740 return (EBADF); 4741 } 4742 4743 static int 4744 badfo_chown(struct file *fp, uid_t uid, gid_t gid, struct ucred *active_cred, 4745 struct thread *td) 4746 { 4747 4748 return (EBADF); 4749 } 4750 4751 static int 4752 badfo_sendfile(struct file *fp, int sockfd, struct uio *hdr_uio, 4753 struct uio *trl_uio, off_t offset, size_t nbytes, off_t *sent, int flags, 4754 struct thread *td) 4755 { 4756 4757 return (EBADF); 4758 } 4759 4760 static int 4761 badfo_fill_kinfo(struct file *fp, struct kinfo_file *kif, struct filedesc *fdp) 4762 { 4763 4764 return (0); 4765 } 4766 4767 struct fileops badfileops = { 4768 .fo_read = badfo_readwrite, 4769 .fo_write = badfo_readwrite, 4770 .fo_truncate = badfo_truncate, 4771 .fo_ioctl = badfo_ioctl, 4772 .fo_poll = badfo_poll, 4773 .fo_kqfilter = badfo_kqfilter, 4774 .fo_stat = badfo_stat, 4775 .fo_close = badfo_close, 4776 .fo_chmod = badfo_chmod, 4777 .fo_chown = badfo_chown, 4778 .fo_sendfile = badfo_sendfile, 4779 .fo_fill_kinfo = badfo_fill_kinfo, 4780 }; 4781 4782 int 4783 invfo_rdwr(struct file *fp, struct uio *uio, struct ucred *active_cred, 4784 int flags, struct thread *td) 4785 { 4786 4787 return (EOPNOTSUPP); 4788 } 4789 4790 int 4791 invfo_truncate(struct file *fp, off_t length, struct ucred *active_cred, 4792 struct thread *td) 4793 { 4794 4795 return (EINVAL); 4796 } 4797 4798 int 4799 invfo_ioctl(struct file *fp, u_long com, void *data, 4800 struct ucred *active_cred, struct thread *td) 4801 { 4802 4803 return (ENOTTY); 4804 } 4805 4806 int 4807 invfo_poll(struct file *fp, int events, struct ucred *active_cred, 4808 struct thread *td) 4809 { 4810 4811 return (poll_no_poll(events)); 4812 } 4813 4814 int 4815 invfo_kqfilter(struct file *fp, struct knote *kn) 4816 { 4817 4818 return (EINVAL); 4819 } 4820 4821 int 4822 invfo_chmod(struct file *fp, mode_t mode, struct ucred *active_cred, 4823 struct thread *td) 4824 { 4825 4826 return (EINVAL); 4827 } 4828 4829 int 4830 invfo_chown(struct file *fp, uid_t uid, gid_t gid, struct ucred *active_cred, 4831 struct thread *td) 4832 { 4833 4834 return (EINVAL); 4835 } 4836 4837 int 4838 invfo_sendfile(struct file *fp, int sockfd, struct uio *hdr_uio, 4839 struct uio *trl_uio, off_t offset, size_t nbytes, off_t *sent, int flags, 4840 struct thread *td) 4841 { 4842 4843 return (EINVAL); 4844 } 4845 4846 /*-------------------------------------------------------------------*/ 4847 4848 /* 4849 * File Descriptor pseudo-device driver (/dev/fd/). 4850 * 4851 * Opening minor device N dup()s the file (if any) connected to file 4852 * descriptor N belonging to the calling process. Note that this driver 4853 * consists of only the ``open()'' routine, because all subsequent 4854 * references to this file will be direct to the other driver. 4855 * 4856 * XXX: we could give this one a cloning event handler if necessary. 4857 */ 4858 4859 /* ARGSUSED */ 4860 static int 4861 fdopen(struct cdev *dev, int mode, int type, struct thread *td) 4862 { 4863 4864 /* 4865 * XXX Kludge: set curthread->td_dupfd to contain the value of the 4866 * the file descriptor being sought for duplication. The error 4867 * return ensures that the vnode for this device will be released 4868 * by vn_open. Open will detect this special error and take the 4869 * actions in dupfdopen below. Other callers of vn_open or VOP_OPEN 4870 * will simply report the error. 4871 */ 4872 td->td_dupfd = dev2unit(dev); 4873 return (ENODEV); 4874 } 4875 4876 static struct cdevsw fildesc_cdevsw = { 4877 .d_version = D_VERSION, 4878 .d_open = fdopen, 4879 .d_name = "FD", 4880 }; 4881 4882 static void 4883 fildesc_drvinit(void *unused) 4884 { 4885 struct cdev *dev; 4886 4887 dev = make_dev_credf(MAKEDEV_ETERNAL, &fildesc_cdevsw, 0, NULL, 4888 UID_ROOT, GID_WHEEL, 0666, "fd/0"); 4889 make_dev_alias(dev, "stdin"); 4890 dev = make_dev_credf(MAKEDEV_ETERNAL, &fildesc_cdevsw, 1, NULL, 4891 UID_ROOT, GID_WHEEL, 0666, "fd/1"); 4892 make_dev_alias(dev, "stdout"); 4893 dev = make_dev_credf(MAKEDEV_ETERNAL, &fildesc_cdevsw, 2, NULL, 4894 UID_ROOT, GID_WHEEL, 0666, "fd/2"); 4895 make_dev_alias(dev, "stderr"); 4896 } 4897 4898 SYSINIT(fildescdev, SI_SUB_DRIVERS, SI_ORDER_MIDDLE, fildesc_drvinit, NULL); 4899