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/poll.h> 65 #include <sys/priv.h> 66 #include <sys/proc.h> 67 #include <sys/protosw.h> 68 #include <sys/racct.h> 69 #include <sys/resourcevar.h> 70 #include <sys/sbuf.h> 71 #include <sys/signalvar.h> 72 #include <sys/kdb.h> 73 #include <sys/smr.h> 74 #include <sys/stat.h> 75 #include <sys/sx.h> 76 #include <sys/syscallsubr.h> 77 #include <sys/sysctl.h> 78 #include <sys/sysproto.h> 79 #include <sys/unistd.h> 80 #include <sys/user.h> 81 #include <sys/vnode.h> 82 #include <sys/ktrace.h> 83 84 #include <net/vnet.h> 85 86 #include <security/audit/audit.h> 87 88 #include <vm/uma.h> 89 #include <vm/vm.h> 90 91 #include <ddb/ddb.h> 92 93 static MALLOC_DEFINE(M_FILEDESC, "filedesc", "Open file descriptor table"); 94 static MALLOC_DEFINE(M_PWD, "pwd", "Descriptor table vnodes"); 95 static MALLOC_DEFINE(M_PWDDESC, "pwddesc", "Pwd descriptors"); 96 static MALLOC_DEFINE(M_FILEDESC_TO_LEADER, "filedesc_to_leader", 97 "file desc to leader structures"); 98 static MALLOC_DEFINE(M_SIGIO, "sigio", "sigio structures"); 99 MALLOC_DEFINE(M_FILECAPS, "filecaps", "descriptor capabilities"); 100 101 MALLOC_DECLARE(M_FADVISE); 102 103 static __read_mostly uma_zone_t file_zone; 104 static __read_mostly uma_zone_t filedesc0_zone; 105 __read_mostly uma_zone_t pwd_zone; 106 VFS_SMR_DECLARE; 107 108 static int closefp(struct filedesc *fdp, int fd, struct file *fp, 109 struct thread *td, bool holdleaders, bool audit); 110 static int fd_first_free(struct filedesc *fdp, int low, int size); 111 static void fdgrowtable(struct filedesc *fdp, int nfd); 112 static void fdgrowtable_exp(struct filedesc *fdp, int nfd); 113 static void fdunused(struct filedesc *fdp, int fd); 114 static void fdused(struct filedesc *fdp, int fd); 115 static int getmaxfd(struct thread *td); 116 static u_long *filecaps_copy_prep(const struct filecaps *src); 117 static void filecaps_copy_finish(const struct filecaps *src, 118 struct filecaps *dst, u_long *ioctls); 119 static u_long *filecaps_free_prep(struct filecaps *fcaps); 120 static void filecaps_free_finish(u_long *ioctls); 121 122 static struct pwd *pwd_alloc(void); 123 124 /* 125 * Each process has: 126 * 127 * - An array of open file descriptors (fd_ofiles) 128 * - An array of file flags (fd_ofileflags) 129 * - A bitmap recording which descriptors are in use (fd_map) 130 * 131 * A process starts out with NDFILE descriptors. The value of NDFILE has 132 * been selected based the historical limit of 20 open files, and an 133 * assumption that the majority of processes, especially short-lived 134 * processes like shells, will never need more. 135 * 136 * If this initial allocation is exhausted, a larger descriptor table and 137 * map are allocated dynamically, and the pointers in the process's struct 138 * filedesc are updated to point to those. This is repeated every time 139 * the process runs out of file descriptors (provided it hasn't hit its 140 * resource limit). 141 * 142 * Since threads may hold references to individual descriptor table 143 * entries, the tables are never freed. Instead, they are placed on a 144 * linked list and freed only when the struct filedesc is released. 145 */ 146 #define NDFILE 20 147 #define NDSLOTSIZE sizeof(NDSLOTTYPE) 148 #define NDENTRIES (NDSLOTSIZE * __CHAR_BIT) 149 #define NDSLOT(x) ((x) / NDENTRIES) 150 #define NDBIT(x) ((NDSLOTTYPE)1 << ((x) % NDENTRIES)) 151 #define NDSLOTS(x) (((x) + NDENTRIES - 1) / NDENTRIES) 152 153 /* 154 * SLIST entry used to keep track of ofiles which must be reclaimed when 155 * the process exits. 156 */ 157 struct freetable { 158 struct fdescenttbl *ft_table; 159 SLIST_ENTRY(freetable) ft_next; 160 }; 161 162 /* 163 * Initial allocation: a filedesc structure + the head of SLIST used to 164 * keep track of old ofiles + enough space for NDFILE descriptors. 165 */ 166 167 struct fdescenttbl0 { 168 int fdt_nfiles; 169 struct filedescent fdt_ofiles[NDFILE]; 170 }; 171 172 struct filedesc0 { 173 struct filedesc fd_fd; 174 SLIST_HEAD(, freetable) fd_free; 175 struct fdescenttbl0 fd_dfiles; 176 NDSLOTTYPE fd_dmap[NDSLOTS(NDFILE)]; 177 }; 178 179 /* 180 * Descriptor management. 181 */ 182 static int __exclusive_cache_line openfiles; /* actual number of open files */ 183 struct mtx sigio_lock; /* mtx to protect pointers to sigio */ 184 void __read_mostly (*mq_fdclose)(struct thread *td, int fd, struct file *fp); 185 186 /* 187 * If low >= size, just return low. Otherwise find the first zero bit in the 188 * given bitmap, starting at low and not exceeding size - 1. Return size if 189 * not found. 190 */ 191 static int 192 fd_first_free(struct filedesc *fdp, int low, int size) 193 { 194 NDSLOTTYPE *map = fdp->fd_map; 195 NDSLOTTYPE mask; 196 int off, maxoff; 197 198 if (low >= size) 199 return (low); 200 201 off = NDSLOT(low); 202 if (low % NDENTRIES) { 203 mask = ~(~(NDSLOTTYPE)0 >> (NDENTRIES - (low % NDENTRIES))); 204 if ((mask &= ~map[off]) != 0UL) 205 return (off * NDENTRIES + ffsl(mask) - 1); 206 ++off; 207 } 208 for (maxoff = NDSLOTS(size); off < maxoff; ++off) 209 if (map[off] != ~0UL) 210 return (off * NDENTRIES + ffsl(~map[off]) - 1); 211 return (size); 212 } 213 214 /* 215 * Find the last used fd. 216 * 217 * Call this variant if fdp can't be modified by anyone else (e.g, during exec). 218 * Otherwise use fdlastfile. 219 */ 220 int 221 fdlastfile_single(struct filedesc *fdp) 222 { 223 NDSLOTTYPE *map = fdp->fd_map; 224 int off, minoff; 225 226 off = NDSLOT(fdp->fd_nfiles - 1); 227 for (minoff = NDSLOT(0); off >= minoff; --off) 228 if (map[off] != 0) 229 return (off * NDENTRIES + flsl(map[off]) - 1); 230 return (-1); 231 } 232 233 int 234 fdlastfile(struct filedesc *fdp) 235 { 236 237 FILEDESC_LOCK_ASSERT(fdp); 238 return (fdlastfile_single(fdp)); 239 } 240 241 static int 242 fdisused(struct filedesc *fdp, int fd) 243 { 244 245 KASSERT(fd >= 0 && fd < fdp->fd_nfiles, 246 ("file descriptor %d out of range (0, %d)", fd, fdp->fd_nfiles)); 247 248 return ((fdp->fd_map[NDSLOT(fd)] & NDBIT(fd)) != 0); 249 } 250 251 /* 252 * Mark a file descriptor as used. 253 */ 254 static void 255 fdused_init(struct filedesc *fdp, int fd) 256 { 257 258 KASSERT(!fdisused(fdp, fd), ("fd=%d is already used", fd)); 259 260 fdp->fd_map[NDSLOT(fd)] |= NDBIT(fd); 261 } 262 263 static void 264 fdused(struct filedesc *fdp, int fd) 265 { 266 267 FILEDESC_XLOCK_ASSERT(fdp); 268 269 fdused_init(fdp, fd); 270 if (fd == fdp->fd_freefile) 271 fdp->fd_freefile++; 272 } 273 274 /* 275 * Mark a file descriptor as unused. 276 */ 277 static void 278 fdunused(struct filedesc *fdp, int fd) 279 { 280 281 FILEDESC_XLOCK_ASSERT(fdp); 282 283 KASSERT(fdisused(fdp, fd), ("fd=%d is already unused", fd)); 284 KASSERT(fdp->fd_ofiles[fd].fde_file == NULL, 285 ("fd=%d is still in use", fd)); 286 287 fdp->fd_map[NDSLOT(fd)] &= ~NDBIT(fd); 288 if (fd < fdp->fd_freefile) 289 fdp->fd_freefile = fd; 290 } 291 292 /* 293 * Free a file descriptor. 294 * 295 * Avoid some work if fdp is about to be destroyed. 296 */ 297 static inline void 298 fdefree_last(struct filedescent *fde) 299 { 300 301 filecaps_free(&fde->fde_caps); 302 } 303 304 static inline void 305 fdfree(struct filedesc *fdp, int fd) 306 { 307 struct filedescent *fde; 308 309 FILEDESC_XLOCK_ASSERT(fdp); 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 if (fp->f_ops == &path_fileops) { 549 fdrop(fp, td); 550 error = EBADF; 551 break; 552 } 553 do { 554 tmp = flg = fp->f_flag; 555 tmp &= ~FCNTLFLAGS; 556 tmp |= FFLAGS(arg & ~O_ACCMODE) & FCNTLFLAGS; 557 } while (atomic_cmpset_int(&fp->f_flag, flg, tmp) == 0); 558 tmp = fp->f_flag & FNONBLOCK; 559 error = fo_ioctl(fp, FIONBIO, &tmp, td->td_ucred, td); 560 if (error != 0) { 561 fdrop(fp, td); 562 break; 563 } 564 tmp = fp->f_flag & FASYNC; 565 error = fo_ioctl(fp, FIOASYNC, &tmp, td->td_ucred, td); 566 if (error == 0) { 567 fdrop(fp, td); 568 break; 569 } 570 atomic_clear_int(&fp->f_flag, FNONBLOCK); 571 tmp = 0; 572 (void)fo_ioctl(fp, FIONBIO, &tmp, td->td_ucred, td); 573 fdrop(fp, td); 574 break; 575 576 case F_GETOWN: 577 error = fget_fcntl(td, fd, &cap_fcntl_rights, F_GETOWN, &fp); 578 if (error != 0) 579 break; 580 error = fo_ioctl(fp, FIOGETOWN, &tmp, td->td_ucred, td); 581 if (error == 0) 582 td->td_retval[0] = tmp; 583 fdrop(fp, td); 584 break; 585 586 case F_SETOWN: 587 error = fget_fcntl(td, fd, &cap_fcntl_rights, F_SETOWN, &fp); 588 if (error != 0) 589 break; 590 tmp = arg; 591 error = fo_ioctl(fp, FIOSETOWN, &tmp, td->td_ucred, td); 592 fdrop(fp, td); 593 break; 594 595 case F_SETLK_REMOTE: 596 error = priv_check(td, PRIV_NFS_LOCKD); 597 if (error != 0) 598 return (error); 599 flg = F_REMOTE; 600 goto do_setlk; 601 602 case F_SETLKW: 603 flg |= F_WAIT; 604 /* FALLTHROUGH F_SETLK */ 605 606 case F_SETLK: 607 do_setlk: 608 flp = (struct flock *)arg; 609 if ((flg & F_REMOTE) != 0 && flp->l_sysid == 0) { 610 error = EINVAL; 611 break; 612 } 613 614 error = fget_unlocked(fdp, fd, &cap_flock_rights, &fp); 615 if (error != 0) 616 break; 617 if (fp->f_type != DTYPE_VNODE || fp->f_ops == &path_fileops) { 618 error = EBADF; 619 fdrop(fp, td); 620 break; 621 } 622 623 if (flp->l_whence == SEEK_CUR) { 624 foffset = foffset_get(fp); 625 if (foffset < 0 || 626 (flp->l_start > 0 && 627 foffset > OFF_MAX - flp->l_start)) { 628 error = EOVERFLOW; 629 fdrop(fp, td); 630 break; 631 } 632 flp->l_start += foffset; 633 } 634 635 vp = fp->f_vnode; 636 switch (flp->l_type) { 637 case F_RDLCK: 638 if ((fp->f_flag & FREAD) == 0) { 639 error = EBADF; 640 break; 641 } 642 if ((p->p_leader->p_flag & P_ADVLOCK) == 0) { 643 PROC_LOCK(p->p_leader); 644 p->p_leader->p_flag |= P_ADVLOCK; 645 PROC_UNLOCK(p->p_leader); 646 } 647 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_SETLK, 648 flp, flg); 649 break; 650 case F_WRLCK: 651 if ((fp->f_flag & FWRITE) == 0) { 652 error = EBADF; 653 break; 654 } 655 if ((p->p_leader->p_flag & P_ADVLOCK) == 0) { 656 PROC_LOCK(p->p_leader); 657 p->p_leader->p_flag |= P_ADVLOCK; 658 PROC_UNLOCK(p->p_leader); 659 } 660 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_SETLK, 661 flp, flg); 662 break; 663 case F_UNLCK: 664 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_UNLCK, 665 flp, flg); 666 break; 667 case F_UNLCKSYS: 668 if (flg != F_REMOTE) { 669 error = EINVAL; 670 break; 671 } 672 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, 673 F_UNLCKSYS, flp, flg); 674 break; 675 default: 676 error = EINVAL; 677 break; 678 } 679 if (error != 0 || flp->l_type == F_UNLCK || 680 flp->l_type == F_UNLCKSYS) { 681 fdrop(fp, td); 682 break; 683 } 684 685 /* 686 * Check for a race with close. 687 * 688 * The vnode is now advisory locked (or unlocked, but this case 689 * is not really important) as the caller requested. 690 * We had to drop the filedesc lock, so we need to recheck if 691 * the descriptor is still valid, because if it was closed 692 * in the meantime we need to remove advisory lock from the 693 * vnode - close on any descriptor leading to an advisory 694 * locked vnode, removes that lock. 695 * We will return 0 on purpose in that case, as the result of 696 * successful advisory lock might have been externally visible 697 * already. This is fine - effectively we pretend to the caller 698 * that the closing thread was a bit slower and that the 699 * advisory lock succeeded before the close. 700 */ 701 error = fget_unlocked(fdp, fd, &cap_no_rights, &fp2); 702 if (error != 0) { 703 fdrop(fp, td); 704 break; 705 } 706 if (fp != fp2) { 707 flp->l_whence = SEEK_SET; 708 flp->l_start = 0; 709 flp->l_len = 0; 710 flp->l_type = F_UNLCK; 711 (void) VOP_ADVLOCK(vp, (caddr_t)p->p_leader, 712 F_UNLCK, flp, F_POSIX); 713 } 714 fdrop(fp, td); 715 fdrop(fp2, td); 716 break; 717 718 case F_GETLK: 719 error = fget_unlocked(fdp, fd, &cap_flock_rights, &fp); 720 if (error != 0) 721 break; 722 if (fp->f_type != DTYPE_VNODE || fp->f_ops == &path_fileops) { 723 error = EBADF; 724 fdrop(fp, td); 725 break; 726 } 727 flp = (struct flock *)arg; 728 if (flp->l_type != F_RDLCK && flp->l_type != F_WRLCK && 729 flp->l_type != F_UNLCK) { 730 error = EINVAL; 731 fdrop(fp, td); 732 break; 733 } 734 if (flp->l_whence == SEEK_CUR) { 735 foffset = foffset_get(fp); 736 if ((flp->l_start > 0 && 737 foffset > OFF_MAX - flp->l_start) || 738 (flp->l_start < 0 && 739 foffset < OFF_MIN - flp->l_start)) { 740 error = EOVERFLOW; 741 fdrop(fp, td); 742 break; 743 } 744 flp->l_start += foffset; 745 } 746 vp = fp->f_vnode; 747 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_GETLK, flp, 748 F_POSIX); 749 fdrop(fp, td); 750 break; 751 752 case F_ADD_SEALS: 753 error = fget_unlocked(fdp, fd, &cap_no_rights, &fp); 754 if (error != 0) 755 break; 756 error = fo_add_seals(fp, arg); 757 fdrop(fp, td); 758 break; 759 760 case F_GET_SEALS: 761 error = fget_unlocked(fdp, fd, &cap_no_rights, &fp); 762 if (error != 0) 763 break; 764 if (fo_get_seals(fp, &seals) == 0) 765 td->td_retval[0] = seals; 766 else 767 error = EINVAL; 768 fdrop(fp, td); 769 break; 770 771 case F_RDAHEAD: 772 arg = arg ? 128 * 1024: 0; 773 /* FALLTHROUGH */ 774 case F_READAHEAD: 775 error = fget_unlocked(fdp, fd, &cap_no_rights, &fp); 776 if (error != 0) 777 break; 778 if (fp->f_type != DTYPE_VNODE || fp->f_ops == &path_fileops) { 779 fdrop(fp, td); 780 error = EBADF; 781 break; 782 } 783 vp = fp->f_vnode; 784 if (vp->v_type != VREG) { 785 fdrop(fp, td); 786 error = ENOTTY; 787 break; 788 } 789 790 /* 791 * Exclusive lock synchronizes against f_seqcount reads and 792 * writes in sequential_heuristic(). 793 */ 794 error = vn_lock(vp, LK_EXCLUSIVE); 795 if (error != 0) { 796 fdrop(fp, td); 797 break; 798 } 799 if (arg >= 0) { 800 bsize = fp->f_vnode->v_mount->mnt_stat.f_iosize; 801 arg = MIN(arg, INT_MAX - bsize + 1); 802 fp->f_seqcount[UIO_READ] = MIN(IO_SEQMAX, 803 (arg + bsize - 1) / bsize); 804 atomic_set_int(&fp->f_flag, FRDAHEAD); 805 } else { 806 atomic_clear_int(&fp->f_flag, FRDAHEAD); 807 } 808 VOP_UNLOCK(vp); 809 fdrop(fp, td); 810 break; 811 812 case F_ISUNIONSTACK: 813 /* 814 * Check if the vnode is part of a union stack (either the 815 * "union" flag from mount(2) or unionfs). 816 * 817 * Prior to introduction of this op libc's readdir would call 818 * fstatfs(2), in effect unnecessarily copying kilobytes of 819 * data just to check fs name and a mount flag. 820 * 821 * Fixing the code to handle everything in the kernel instead 822 * is a non-trivial endeavor and has low priority, thus this 823 * horrible kludge facilitates the current behavior in a much 824 * cheaper manner until someone(tm) sorts this out. 825 */ 826 error = fget_unlocked(fdp, fd, &cap_no_rights, &fp); 827 if (error != 0) 828 break; 829 if (fp->f_type != DTYPE_VNODE) { 830 fdrop(fp, td); 831 error = EBADF; 832 break; 833 } 834 vp = fp->f_vnode; 835 /* 836 * Since we don't prevent dooming the vnode even non-null mp 837 * found can become immediately stale. This is tolerable since 838 * mount points are type-stable (providing safe memory access) 839 * and any vfs op on this vnode going forward will return an 840 * error (meaning return value in this case is meaningless). 841 */ 842 mp = atomic_load_ptr(&vp->v_mount); 843 if (__predict_false(mp == NULL)) { 844 fdrop(fp, td); 845 error = EBADF; 846 break; 847 } 848 td->td_retval[0] = 0; 849 if (mp->mnt_kern_flag & MNTK_UNIONFS || 850 mp->mnt_flag & MNT_UNION) 851 td->td_retval[0] = 1; 852 fdrop(fp, td); 853 break; 854 855 default: 856 error = EINVAL; 857 break; 858 } 859 return (error); 860 } 861 862 static int 863 getmaxfd(struct thread *td) 864 { 865 866 return (min((int)lim_cur(td, RLIMIT_NOFILE), maxfilesperproc)); 867 } 868 869 /* 870 * Common code for dup, dup2, fcntl(F_DUPFD) and fcntl(F_DUP2FD). 871 */ 872 int 873 kern_dup(struct thread *td, u_int mode, int flags, int old, int new) 874 { 875 struct filedesc *fdp; 876 struct filedescent *oldfde, *newfde; 877 struct proc *p; 878 struct file *delfp, *oldfp; 879 u_long *oioctls, *nioctls; 880 int error, maxfd; 881 882 p = td->td_proc; 883 fdp = p->p_fd; 884 oioctls = NULL; 885 886 MPASS((flags & ~(FDDUP_FLAG_CLOEXEC)) == 0); 887 MPASS(mode < FDDUP_LASTMODE); 888 889 AUDIT_ARG_FD(old); 890 /* XXXRW: if (flags & FDDUP_FIXED) AUDIT_ARG_FD2(new); */ 891 892 /* 893 * Verify we have a valid descriptor to dup from and possibly to 894 * dup to. Unlike dup() and dup2(), fcntl()'s F_DUPFD should 895 * return EINVAL when the new descriptor is out of bounds. 896 */ 897 if (old < 0) 898 return (EBADF); 899 if (new < 0) 900 return (mode == FDDUP_FCNTL ? EINVAL : EBADF); 901 maxfd = getmaxfd(td); 902 if (new >= maxfd) 903 return (mode == FDDUP_FCNTL ? EINVAL : EBADF); 904 905 error = EBADF; 906 FILEDESC_XLOCK(fdp); 907 if (fget_locked(fdp, old) == NULL) 908 goto unlock; 909 if (mode == FDDUP_FIXED && old == new) { 910 td->td_retval[0] = new; 911 if (flags & FDDUP_FLAG_CLOEXEC) 912 fdp->fd_ofiles[new].fde_flags |= UF_EXCLOSE; 913 error = 0; 914 goto unlock; 915 } 916 917 oldfde = &fdp->fd_ofiles[old]; 918 oldfp = oldfde->fde_file; 919 if (!fhold(oldfp)) 920 goto unlock; 921 922 /* 923 * If the caller specified a file descriptor, make sure the file 924 * table is large enough to hold it, and grab it. Otherwise, just 925 * allocate a new descriptor the usual way. 926 */ 927 switch (mode) { 928 case FDDUP_NORMAL: 929 case FDDUP_FCNTL: 930 if ((error = fdalloc(td, new, &new)) != 0) { 931 fdrop(oldfp, td); 932 goto unlock; 933 } 934 break; 935 case FDDUP_FIXED: 936 if (new >= fdp->fd_nfiles) { 937 /* 938 * The resource limits are here instead of e.g. 939 * fdalloc(), because the file descriptor table may be 940 * shared between processes, so we can't really use 941 * racct_add()/racct_sub(). Instead of counting the 942 * number of actually allocated descriptors, just put 943 * the limit on the size of the file descriptor table. 944 */ 945 #ifdef RACCT 946 if (RACCT_ENABLED()) { 947 error = racct_set_unlocked(p, RACCT_NOFILE, new + 1); 948 if (error != 0) { 949 error = EMFILE; 950 fdrop(oldfp, td); 951 goto unlock; 952 } 953 } 954 #endif 955 fdgrowtable_exp(fdp, new + 1); 956 } 957 if (!fdisused(fdp, new)) 958 fdused(fdp, new); 959 break; 960 default: 961 KASSERT(0, ("%s unsupported mode %d", __func__, mode)); 962 } 963 964 KASSERT(old != new, ("new fd is same as old")); 965 966 /* Refetch oldfde because the table may have grown and old one freed. */ 967 oldfde = &fdp->fd_ofiles[old]; 968 KASSERT(oldfp == oldfde->fde_file, 969 ("fdt_ofiles shift from growth observed at fd %d", 970 old)); 971 972 newfde = &fdp->fd_ofiles[new]; 973 delfp = newfde->fde_file; 974 975 nioctls = filecaps_copy_prep(&oldfde->fde_caps); 976 977 /* 978 * Duplicate the source descriptor. 979 */ 980 #ifdef CAPABILITIES 981 seqc_write_begin(&newfde->fde_seqc); 982 #endif 983 oioctls = filecaps_free_prep(&newfde->fde_caps); 984 memcpy(newfde, oldfde, fde_change_size); 985 filecaps_copy_finish(&oldfde->fde_caps, &newfde->fde_caps, 986 nioctls); 987 if ((flags & FDDUP_FLAG_CLOEXEC) != 0) 988 newfde->fde_flags = oldfde->fde_flags | UF_EXCLOSE; 989 else 990 newfde->fde_flags = oldfde->fde_flags & ~UF_EXCLOSE; 991 #ifdef CAPABILITIES 992 seqc_write_end(&newfde->fde_seqc); 993 #endif 994 td->td_retval[0] = new; 995 996 error = 0; 997 998 if (delfp != NULL) { 999 (void) closefp(fdp, new, delfp, td, true, false); 1000 FILEDESC_UNLOCK_ASSERT(fdp); 1001 } else { 1002 unlock: 1003 FILEDESC_XUNLOCK(fdp); 1004 } 1005 1006 filecaps_free_finish(oioctls); 1007 return (error); 1008 } 1009 1010 static void 1011 sigiofree(struct sigio *sigio) 1012 { 1013 crfree(sigio->sio_ucred); 1014 free(sigio, M_SIGIO); 1015 } 1016 1017 static struct sigio * 1018 funsetown_locked(struct sigio *sigio) 1019 { 1020 struct proc *p; 1021 struct pgrp *pg; 1022 1023 SIGIO_ASSERT_LOCKED(); 1024 1025 if (sigio == NULL) 1026 return (NULL); 1027 *sigio->sio_myref = NULL; 1028 if (sigio->sio_pgid < 0) { 1029 pg = sigio->sio_pgrp; 1030 PGRP_LOCK(pg); 1031 SLIST_REMOVE(&pg->pg_sigiolst, sigio, sigio, sio_pgsigio); 1032 PGRP_UNLOCK(pg); 1033 } else { 1034 p = sigio->sio_proc; 1035 PROC_LOCK(p); 1036 SLIST_REMOVE(&p->p_sigiolst, sigio, sigio, sio_pgsigio); 1037 PROC_UNLOCK(p); 1038 } 1039 return (sigio); 1040 } 1041 1042 /* 1043 * If sigio is on the list associated with a process or process group, 1044 * disable signalling from the device, remove sigio from the list and 1045 * free sigio. 1046 */ 1047 void 1048 funsetown(struct sigio **sigiop) 1049 { 1050 struct sigio *sigio; 1051 1052 /* Racy check, consumers must provide synchronization. */ 1053 if (*sigiop == NULL) 1054 return; 1055 1056 SIGIO_LOCK(); 1057 sigio = funsetown_locked(*sigiop); 1058 SIGIO_UNLOCK(); 1059 if (sigio != NULL) 1060 sigiofree(sigio); 1061 } 1062 1063 /* 1064 * Free a list of sigio structures. The caller must ensure that new sigio 1065 * structures cannot be added after this point. For process groups this is 1066 * guaranteed using the proctree lock; for processes, the P_WEXIT flag serves 1067 * as an interlock. 1068 */ 1069 void 1070 funsetownlst(struct sigiolst *sigiolst) 1071 { 1072 struct proc *p; 1073 struct pgrp *pg; 1074 struct sigio *sigio, *tmp; 1075 1076 /* Racy check. */ 1077 sigio = SLIST_FIRST(sigiolst); 1078 if (sigio == NULL) 1079 return; 1080 1081 p = NULL; 1082 pg = NULL; 1083 1084 SIGIO_LOCK(); 1085 sigio = SLIST_FIRST(sigiolst); 1086 if (sigio == NULL) { 1087 SIGIO_UNLOCK(); 1088 return; 1089 } 1090 1091 /* 1092 * Every entry of the list should belong to a single proc or pgrp. 1093 */ 1094 if (sigio->sio_pgid < 0) { 1095 pg = sigio->sio_pgrp; 1096 sx_assert(&proctree_lock, SX_XLOCKED); 1097 PGRP_LOCK(pg); 1098 } else /* if (sigio->sio_pgid > 0) */ { 1099 p = sigio->sio_proc; 1100 PROC_LOCK(p); 1101 KASSERT((p->p_flag & P_WEXIT) != 0, 1102 ("%s: process %p is not exiting", __func__, p)); 1103 } 1104 1105 SLIST_FOREACH(sigio, sigiolst, sio_pgsigio) { 1106 *sigio->sio_myref = NULL; 1107 if (pg != NULL) { 1108 KASSERT(sigio->sio_pgid < 0, 1109 ("Proc sigio in pgrp sigio list")); 1110 KASSERT(sigio->sio_pgrp == pg, 1111 ("Bogus pgrp in sigio list")); 1112 } else /* if (p != NULL) */ { 1113 KASSERT(sigio->sio_pgid > 0, 1114 ("Pgrp sigio in proc sigio list")); 1115 KASSERT(sigio->sio_proc == p, 1116 ("Bogus proc in sigio list")); 1117 } 1118 } 1119 1120 if (pg != NULL) 1121 PGRP_UNLOCK(pg); 1122 else 1123 PROC_UNLOCK(p); 1124 SIGIO_UNLOCK(); 1125 1126 SLIST_FOREACH_SAFE(sigio, sigiolst, sio_pgsigio, tmp) 1127 sigiofree(sigio); 1128 } 1129 1130 /* 1131 * This is common code for FIOSETOWN ioctl called by fcntl(fd, F_SETOWN, arg). 1132 * 1133 * After permission checking, add a sigio structure to the sigio list for 1134 * the process or process group. 1135 */ 1136 int 1137 fsetown(pid_t pgid, struct sigio **sigiop) 1138 { 1139 struct proc *proc; 1140 struct pgrp *pgrp; 1141 struct sigio *osigio, *sigio; 1142 int ret; 1143 1144 if (pgid == 0) { 1145 funsetown(sigiop); 1146 return (0); 1147 } 1148 1149 sigio = malloc(sizeof(struct sigio), M_SIGIO, M_WAITOK); 1150 sigio->sio_pgid = pgid; 1151 sigio->sio_ucred = crhold(curthread->td_ucred); 1152 sigio->sio_myref = sigiop; 1153 1154 ret = 0; 1155 if (pgid > 0) { 1156 ret = pget(pgid, PGET_NOTWEXIT | PGET_NOTID | PGET_HOLD, &proc); 1157 SIGIO_LOCK(); 1158 osigio = funsetown_locked(*sigiop); 1159 if (ret == 0) { 1160 PROC_LOCK(proc); 1161 _PRELE(proc); 1162 if ((proc->p_flag & P_WEXIT) != 0) { 1163 ret = ESRCH; 1164 } else if (proc->p_session != 1165 curthread->td_proc->p_session) { 1166 /* 1167 * Policy - Don't allow a process to FSETOWN a 1168 * process in another session. 1169 * 1170 * Remove this test to allow maximum flexibility 1171 * or restrict FSETOWN to the current process or 1172 * process group for maximum safety. 1173 */ 1174 ret = EPERM; 1175 } else { 1176 sigio->sio_proc = proc; 1177 SLIST_INSERT_HEAD(&proc->p_sigiolst, sigio, 1178 sio_pgsigio); 1179 } 1180 PROC_UNLOCK(proc); 1181 } 1182 } else /* if (pgid < 0) */ { 1183 sx_slock(&proctree_lock); 1184 SIGIO_LOCK(); 1185 osigio = funsetown_locked(*sigiop); 1186 pgrp = pgfind(-pgid); 1187 if (pgrp == NULL) { 1188 ret = ESRCH; 1189 } else { 1190 if (pgrp->pg_session != curthread->td_proc->p_session) { 1191 /* 1192 * Policy - Don't allow a process to FSETOWN a 1193 * process in another session. 1194 * 1195 * Remove this test to allow maximum flexibility 1196 * or restrict FSETOWN to the current process or 1197 * process group for maximum safety. 1198 */ 1199 ret = EPERM; 1200 } else { 1201 sigio->sio_pgrp = pgrp; 1202 SLIST_INSERT_HEAD(&pgrp->pg_sigiolst, sigio, 1203 sio_pgsigio); 1204 } 1205 PGRP_UNLOCK(pgrp); 1206 } 1207 sx_sunlock(&proctree_lock); 1208 } 1209 if (ret == 0) 1210 *sigiop = sigio; 1211 SIGIO_UNLOCK(); 1212 if (osigio != NULL) 1213 sigiofree(osigio); 1214 return (ret); 1215 } 1216 1217 /* 1218 * This is common code for FIOGETOWN ioctl called by fcntl(fd, F_GETOWN, arg). 1219 */ 1220 pid_t 1221 fgetown(struct sigio **sigiop) 1222 { 1223 pid_t pgid; 1224 1225 SIGIO_LOCK(); 1226 pgid = (*sigiop != NULL) ? (*sigiop)->sio_pgid : 0; 1227 SIGIO_UNLOCK(); 1228 return (pgid); 1229 } 1230 1231 static int 1232 closefp_impl(struct filedesc *fdp, int fd, struct file *fp, struct thread *td, 1233 bool audit) 1234 { 1235 int error; 1236 1237 FILEDESC_XLOCK_ASSERT(fdp); 1238 1239 /* 1240 * We now hold the fp reference that used to be owned by the 1241 * descriptor array. We have to unlock the FILEDESC *AFTER* 1242 * knote_fdclose to prevent a race of the fd getting opened, a knote 1243 * added, and deleteing a knote for the new fd. 1244 */ 1245 if (__predict_false(!TAILQ_EMPTY(&fdp->fd_kqlist))) 1246 knote_fdclose(td, fd); 1247 1248 /* 1249 * We need to notify mqueue if the object is of type mqueue. 1250 */ 1251 if (__predict_false(fp->f_type == DTYPE_MQUEUE)) 1252 mq_fdclose(td, fd, fp); 1253 FILEDESC_XUNLOCK(fdp); 1254 1255 #ifdef AUDIT 1256 if (AUDITING_TD(td) && audit) 1257 audit_sysclose(td, fd, fp); 1258 #endif 1259 error = closef(fp, td); 1260 1261 /* 1262 * All paths leading up to closefp() will have already removed or 1263 * replaced the fd in the filedesc table, so a restart would not 1264 * operate on the same file. 1265 */ 1266 if (error == ERESTART) 1267 error = EINTR; 1268 1269 return (error); 1270 } 1271 1272 static int 1273 closefp_hl(struct filedesc *fdp, int fd, struct file *fp, struct thread *td, 1274 bool holdleaders, bool audit) 1275 { 1276 int error; 1277 1278 FILEDESC_XLOCK_ASSERT(fdp); 1279 1280 if (holdleaders) { 1281 if (td->td_proc->p_fdtol != NULL) { 1282 /* 1283 * Ask fdfree() to sleep to ensure that all relevant 1284 * process leaders can be traversed in closef(). 1285 */ 1286 fdp->fd_holdleaderscount++; 1287 } else { 1288 holdleaders = false; 1289 } 1290 } 1291 1292 error = closefp_impl(fdp, fd, fp, td, audit); 1293 if (holdleaders) { 1294 FILEDESC_XLOCK(fdp); 1295 fdp->fd_holdleaderscount--; 1296 if (fdp->fd_holdleaderscount == 0 && 1297 fdp->fd_holdleaderswakeup != 0) { 1298 fdp->fd_holdleaderswakeup = 0; 1299 wakeup(&fdp->fd_holdleaderscount); 1300 } 1301 FILEDESC_XUNLOCK(fdp); 1302 } 1303 return (error); 1304 } 1305 1306 static int 1307 closefp(struct filedesc *fdp, int fd, struct file *fp, struct thread *td, 1308 bool holdleaders, bool audit) 1309 { 1310 1311 FILEDESC_XLOCK_ASSERT(fdp); 1312 1313 if (__predict_false(td->td_proc->p_fdtol != NULL)) { 1314 return (closefp_hl(fdp, fd, fp, td, holdleaders, audit)); 1315 } else { 1316 return (closefp_impl(fdp, fd, fp, td, audit)); 1317 } 1318 } 1319 1320 /* 1321 * Close a file descriptor. 1322 */ 1323 #ifndef _SYS_SYSPROTO_H_ 1324 struct close_args { 1325 int fd; 1326 }; 1327 #endif 1328 /* ARGSUSED */ 1329 int 1330 sys_close(struct thread *td, struct close_args *uap) 1331 { 1332 1333 return (kern_close(td, uap->fd)); 1334 } 1335 1336 int 1337 kern_close(struct thread *td, int fd) 1338 { 1339 struct filedesc *fdp; 1340 struct file *fp; 1341 1342 fdp = td->td_proc->p_fd; 1343 1344 FILEDESC_XLOCK(fdp); 1345 if ((fp = fget_locked(fdp, fd)) == NULL) { 1346 FILEDESC_XUNLOCK(fdp); 1347 return (EBADF); 1348 } 1349 fdfree(fdp, fd); 1350 1351 /* closefp() drops the FILEDESC lock for us. */ 1352 return (closefp(fdp, fd, fp, td, true, true)); 1353 } 1354 1355 int 1356 kern_close_range(struct thread *td, u_int lowfd, u_int highfd) 1357 { 1358 struct filedesc *fdp; 1359 const struct fdescenttbl *fdt; 1360 struct file *fp; 1361 int fd; 1362 1363 /* 1364 * Check this prior to clamping; closefrom(3) with only fd 0, 1, and 2 1365 * open should not be a usage error. From a close_range() perspective, 1366 * close_range(3, ~0U, 0) in the same scenario should also likely not 1367 * be a usage error as all fd above 3 are in-fact already closed. 1368 */ 1369 if (highfd < lowfd) { 1370 return (EINVAL); 1371 } 1372 1373 fdp = td->td_proc->p_fd; 1374 FILEDESC_XLOCK(fdp); 1375 fdt = atomic_load_ptr(&fdp->fd_files); 1376 highfd = MIN(highfd, fdt->fdt_nfiles - 1); 1377 fd = lowfd; 1378 if (__predict_false(fd > highfd)) { 1379 goto out_locked; 1380 } 1381 for (;;) { 1382 fp = fdt->fdt_ofiles[fd].fde_file; 1383 if (fp == NULL) { 1384 if (fd == highfd) 1385 goto out_locked; 1386 } else { 1387 fdfree(fdp, fd); 1388 (void) closefp(fdp, fd, fp, td, true, true); 1389 if (fd == highfd) 1390 goto out_unlocked; 1391 FILEDESC_XLOCK(fdp); 1392 fdt = atomic_load_ptr(&fdp->fd_files); 1393 } 1394 fd++; 1395 } 1396 out_locked: 1397 FILEDESC_XUNLOCK(fdp); 1398 out_unlocked: 1399 return (0); 1400 } 1401 1402 #ifndef _SYS_SYSPROTO_H_ 1403 struct close_range_args { 1404 u_int lowfd; 1405 u_int highfd; 1406 int flags; 1407 }; 1408 #endif 1409 int 1410 sys_close_range(struct thread *td, struct close_range_args *uap) 1411 { 1412 1413 AUDIT_ARG_FD(uap->lowfd); 1414 AUDIT_ARG_CMD(uap->highfd); 1415 AUDIT_ARG_FFLAGS(uap->flags); 1416 1417 /* No flags currently defined */ 1418 if (uap->flags != 0) 1419 return (EINVAL); 1420 return (kern_close_range(td, uap->lowfd, uap->highfd)); 1421 } 1422 1423 #ifdef COMPAT_FREEBSD12 1424 /* 1425 * Close open file descriptors. 1426 */ 1427 #ifndef _SYS_SYSPROTO_H_ 1428 struct freebsd12_closefrom_args { 1429 int lowfd; 1430 }; 1431 #endif 1432 /* ARGSUSED */ 1433 int 1434 freebsd12_closefrom(struct thread *td, struct freebsd12_closefrom_args *uap) 1435 { 1436 u_int lowfd; 1437 1438 AUDIT_ARG_FD(uap->lowfd); 1439 1440 /* 1441 * Treat negative starting file descriptor values identical to 1442 * closefrom(0) which closes all files. 1443 */ 1444 lowfd = MAX(0, uap->lowfd); 1445 return (kern_close_range(td, lowfd, ~0U)); 1446 } 1447 #endif /* COMPAT_FREEBSD12 */ 1448 1449 #if defined(COMPAT_43) 1450 /* 1451 * Return status information about a file descriptor. 1452 */ 1453 #ifndef _SYS_SYSPROTO_H_ 1454 struct ofstat_args { 1455 int fd; 1456 struct ostat *sb; 1457 }; 1458 #endif 1459 /* ARGSUSED */ 1460 int 1461 ofstat(struct thread *td, struct ofstat_args *uap) 1462 { 1463 struct ostat oub; 1464 struct stat ub; 1465 int error; 1466 1467 error = kern_fstat(td, uap->fd, &ub); 1468 if (error == 0) { 1469 cvtstat(&ub, &oub); 1470 error = copyout(&oub, uap->sb, sizeof(oub)); 1471 } 1472 return (error); 1473 } 1474 #endif /* COMPAT_43 */ 1475 1476 #if defined(COMPAT_FREEBSD11) 1477 int 1478 freebsd11_fstat(struct thread *td, struct freebsd11_fstat_args *uap) 1479 { 1480 struct stat sb; 1481 struct freebsd11_stat osb; 1482 int error; 1483 1484 error = kern_fstat(td, uap->fd, &sb); 1485 if (error != 0) 1486 return (error); 1487 error = freebsd11_cvtstat(&sb, &osb); 1488 if (error == 0) 1489 error = copyout(&osb, uap->sb, sizeof(osb)); 1490 return (error); 1491 } 1492 #endif /* COMPAT_FREEBSD11 */ 1493 1494 /* 1495 * Return status information about a file descriptor. 1496 */ 1497 #ifndef _SYS_SYSPROTO_H_ 1498 struct fstat_args { 1499 int fd; 1500 struct stat *sb; 1501 }; 1502 #endif 1503 /* ARGSUSED */ 1504 int 1505 sys_fstat(struct thread *td, struct fstat_args *uap) 1506 { 1507 struct stat ub; 1508 int error; 1509 1510 error = kern_fstat(td, uap->fd, &ub); 1511 if (error == 0) 1512 error = copyout(&ub, uap->sb, sizeof(ub)); 1513 return (error); 1514 } 1515 1516 int 1517 kern_fstat(struct thread *td, int fd, struct stat *sbp) 1518 { 1519 struct file *fp; 1520 int error; 1521 1522 AUDIT_ARG_FD(fd); 1523 1524 error = fget(td, fd, &cap_fstat_rights, &fp); 1525 if (__predict_false(error != 0)) 1526 return (error); 1527 1528 AUDIT_ARG_FILE(td->td_proc, fp); 1529 1530 error = fo_stat(fp, sbp, td->td_ucred); 1531 fdrop(fp, td); 1532 #ifdef __STAT_TIME_T_EXT 1533 sbp->st_atim_ext = 0; 1534 sbp->st_mtim_ext = 0; 1535 sbp->st_ctim_ext = 0; 1536 sbp->st_btim_ext = 0; 1537 #endif 1538 #ifdef KTRACE 1539 if (KTRPOINT(td, KTR_STRUCT)) 1540 ktrstat_error(sbp, error); 1541 #endif 1542 return (error); 1543 } 1544 1545 #if defined(COMPAT_FREEBSD11) 1546 /* 1547 * Return status information about a file descriptor. 1548 */ 1549 #ifndef _SYS_SYSPROTO_H_ 1550 struct freebsd11_nfstat_args { 1551 int fd; 1552 struct nstat *sb; 1553 }; 1554 #endif 1555 /* ARGSUSED */ 1556 int 1557 freebsd11_nfstat(struct thread *td, struct freebsd11_nfstat_args *uap) 1558 { 1559 struct nstat nub; 1560 struct stat ub; 1561 int error; 1562 1563 error = kern_fstat(td, uap->fd, &ub); 1564 if (error != 0) 1565 return (error); 1566 error = freebsd11_cvtnstat(&ub, &nub); 1567 if (error != 0) 1568 error = copyout(&nub, uap->sb, sizeof(nub)); 1569 return (error); 1570 } 1571 #endif /* COMPAT_FREEBSD11 */ 1572 1573 /* 1574 * Return pathconf information about a file descriptor. 1575 */ 1576 #ifndef _SYS_SYSPROTO_H_ 1577 struct fpathconf_args { 1578 int fd; 1579 int name; 1580 }; 1581 #endif 1582 /* ARGSUSED */ 1583 int 1584 sys_fpathconf(struct thread *td, struct fpathconf_args *uap) 1585 { 1586 long value; 1587 int error; 1588 1589 error = kern_fpathconf(td, uap->fd, uap->name, &value); 1590 if (error == 0) 1591 td->td_retval[0] = value; 1592 return (error); 1593 } 1594 1595 int 1596 kern_fpathconf(struct thread *td, int fd, int name, long *valuep) 1597 { 1598 struct file *fp; 1599 struct vnode *vp; 1600 int error; 1601 1602 error = fget(td, fd, &cap_fpathconf_rights, &fp); 1603 if (error != 0) 1604 return (error); 1605 1606 if (name == _PC_ASYNC_IO) { 1607 *valuep = _POSIX_ASYNCHRONOUS_IO; 1608 goto out; 1609 } 1610 vp = fp->f_vnode; 1611 if (vp != NULL) { 1612 vn_lock(vp, LK_SHARED | LK_RETRY); 1613 error = VOP_PATHCONF(vp, name, valuep); 1614 VOP_UNLOCK(vp); 1615 } else if (fp->f_type == DTYPE_PIPE || fp->f_type == DTYPE_SOCKET) { 1616 if (name != _PC_PIPE_BUF) { 1617 error = EINVAL; 1618 } else { 1619 *valuep = PIPE_BUF; 1620 error = 0; 1621 } 1622 } else { 1623 error = EOPNOTSUPP; 1624 } 1625 out: 1626 fdrop(fp, td); 1627 return (error); 1628 } 1629 1630 /* 1631 * Copy filecaps structure allocating memory for ioctls array if needed. 1632 * 1633 * The last parameter indicates whether the fdtable is locked. If it is not and 1634 * ioctls are encountered, copying fails and the caller must lock the table. 1635 * 1636 * Note that if the table was not locked, the caller has to check the relevant 1637 * sequence counter to determine whether the operation was successful. 1638 */ 1639 bool 1640 filecaps_copy(const struct filecaps *src, struct filecaps *dst, bool locked) 1641 { 1642 size_t size; 1643 1644 if (src->fc_ioctls != NULL && !locked) 1645 return (false); 1646 memcpy(dst, src, sizeof(*src)); 1647 if (src->fc_ioctls == NULL) 1648 return (true); 1649 1650 KASSERT(src->fc_nioctls > 0, 1651 ("fc_ioctls != NULL, but fc_nioctls=%hd", src->fc_nioctls)); 1652 1653 size = sizeof(src->fc_ioctls[0]) * src->fc_nioctls; 1654 dst->fc_ioctls = malloc(size, M_FILECAPS, M_WAITOK); 1655 memcpy(dst->fc_ioctls, src->fc_ioctls, size); 1656 return (true); 1657 } 1658 1659 static u_long * 1660 filecaps_copy_prep(const struct filecaps *src) 1661 { 1662 u_long *ioctls; 1663 size_t size; 1664 1665 if (__predict_true(src->fc_ioctls == NULL)) 1666 return (NULL); 1667 1668 KASSERT(src->fc_nioctls > 0, 1669 ("fc_ioctls != NULL, but fc_nioctls=%hd", src->fc_nioctls)); 1670 1671 size = sizeof(src->fc_ioctls[0]) * src->fc_nioctls; 1672 ioctls = malloc(size, M_FILECAPS, M_WAITOK); 1673 return (ioctls); 1674 } 1675 1676 static void 1677 filecaps_copy_finish(const struct filecaps *src, struct filecaps *dst, 1678 u_long *ioctls) 1679 { 1680 size_t size; 1681 1682 *dst = *src; 1683 if (__predict_true(src->fc_ioctls == NULL)) { 1684 MPASS(ioctls == NULL); 1685 return; 1686 } 1687 1688 size = sizeof(src->fc_ioctls[0]) * src->fc_nioctls; 1689 dst->fc_ioctls = ioctls; 1690 bcopy(src->fc_ioctls, dst->fc_ioctls, size); 1691 } 1692 1693 /* 1694 * Move filecaps structure to the new place and clear the old place. 1695 */ 1696 void 1697 filecaps_move(struct filecaps *src, struct filecaps *dst) 1698 { 1699 1700 *dst = *src; 1701 bzero(src, sizeof(*src)); 1702 } 1703 1704 /* 1705 * Fill the given filecaps structure with full rights. 1706 */ 1707 static void 1708 filecaps_fill(struct filecaps *fcaps) 1709 { 1710 1711 CAP_ALL(&fcaps->fc_rights); 1712 fcaps->fc_ioctls = NULL; 1713 fcaps->fc_nioctls = -1; 1714 fcaps->fc_fcntls = CAP_FCNTL_ALL; 1715 } 1716 1717 /* 1718 * Free memory allocated within filecaps structure. 1719 */ 1720 void 1721 filecaps_free(struct filecaps *fcaps) 1722 { 1723 1724 free(fcaps->fc_ioctls, M_FILECAPS); 1725 bzero(fcaps, sizeof(*fcaps)); 1726 } 1727 1728 static u_long * 1729 filecaps_free_prep(struct filecaps *fcaps) 1730 { 1731 u_long *ioctls; 1732 1733 ioctls = fcaps->fc_ioctls; 1734 bzero(fcaps, sizeof(*fcaps)); 1735 return (ioctls); 1736 } 1737 1738 static void 1739 filecaps_free_finish(u_long *ioctls) 1740 { 1741 1742 free(ioctls, M_FILECAPS); 1743 } 1744 1745 /* 1746 * Validate the given filecaps structure. 1747 */ 1748 static void 1749 filecaps_validate(const struct filecaps *fcaps, const char *func) 1750 { 1751 1752 KASSERT(cap_rights_is_valid(&fcaps->fc_rights), 1753 ("%s: invalid rights", func)); 1754 KASSERT((fcaps->fc_fcntls & ~CAP_FCNTL_ALL) == 0, 1755 ("%s: invalid fcntls", func)); 1756 KASSERT(fcaps->fc_fcntls == 0 || 1757 cap_rights_is_set(&fcaps->fc_rights, CAP_FCNTL), 1758 ("%s: fcntls without CAP_FCNTL", func)); 1759 KASSERT(fcaps->fc_ioctls != NULL ? fcaps->fc_nioctls > 0 : 1760 (fcaps->fc_nioctls == -1 || fcaps->fc_nioctls == 0), 1761 ("%s: invalid ioctls", func)); 1762 KASSERT(fcaps->fc_nioctls == 0 || 1763 cap_rights_is_set(&fcaps->fc_rights, CAP_IOCTL), 1764 ("%s: ioctls without CAP_IOCTL", func)); 1765 } 1766 1767 static void 1768 fdgrowtable_exp(struct filedesc *fdp, int nfd) 1769 { 1770 int nfd1; 1771 1772 FILEDESC_XLOCK_ASSERT(fdp); 1773 1774 nfd1 = fdp->fd_nfiles * 2; 1775 if (nfd1 < nfd) 1776 nfd1 = nfd; 1777 fdgrowtable(fdp, nfd1); 1778 } 1779 1780 /* 1781 * Grow the file table to accommodate (at least) nfd descriptors. 1782 */ 1783 static void 1784 fdgrowtable(struct filedesc *fdp, int nfd) 1785 { 1786 struct filedesc0 *fdp0; 1787 struct freetable *ft; 1788 struct fdescenttbl *ntable; 1789 struct fdescenttbl *otable; 1790 int nnfiles, onfiles; 1791 NDSLOTTYPE *nmap, *omap; 1792 1793 KASSERT(fdp->fd_nfiles > 0, ("zero-length file table")); 1794 1795 /* save old values */ 1796 onfiles = fdp->fd_nfiles; 1797 otable = fdp->fd_files; 1798 omap = fdp->fd_map; 1799 1800 /* compute the size of the new table */ 1801 nnfiles = NDSLOTS(nfd) * NDENTRIES; /* round up */ 1802 if (nnfiles <= onfiles) 1803 /* the table is already large enough */ 1804 return; 1805 1806 /* 1807 * Allocate a new table. We need enough space for the number of 1808 * entries, file entries themselves and the struct freetable we will use 1809 * when we decommission the table and place it on the freelist. 1810 * We place the struct freetable in the middle so we don't have 1811 * to worry about padding. 1812 */ 1813 ntable = malloc(offsetof(struct fdescenttbl, fdt_ofiles) + 1814 nnfiles * sizeof(ntable->fdt_ofiles[0]) + 1815 sizeof(struct freetable), 1816 M_FILEDESC, M_ZERO | M_WAITOK); 1817 /* copy the old data */ 1818 ntable->fdt_nfiles = nnfiles; 1819 memcpy(ntable->fdt_ofiles, otable->fdt_ofiles, 1820 onfiles * sizeof(ntable->fdt_ofiles[0])); 1821 1822 /* 1823 * Allocate a new map only if the old is not large enough. It will 1824 * grow at a slower rate than the table as it can map more 1825 * entries than the table can hold. 1826 */ 1827 if (NDSLOTS(nnfiles) > NDSLOTS(onfiles)) { 1828 nmap = malloc(NDSLOTS(nnfiles) * NDSLOTSIZE, M_FILEDESC, 1829 M_ZERO | M_WAITOK); 1830 /* copy over the old data and update the pointer */ 1831 memcpy(nmap, omap, NDSLOTS(onfiles) * sizeof(*omap)); 1832 fdp->fd_map = nmap; 1833 } 1834 1835 /* 1836 * Make sure that ntable is correctly initialized before we replace 1837 * fd_files poiner. Otherwise fget_unlocked() may see inconsistent 1838 * data. 1839 */ 1840 atomic_store_rel_ptr((volatile void *)&fdp->fd_files, (uintptr_t)ntable); 1841 1842 /* 1843 * Free the old file table when not shared by other threads or processes. 1844 * The old file table is considered to be shared when either are true: 1845 * - The process has more than one thread. 1846 * - The file descriptor table has been shared via fdshare(). 1847 * 1848 * When shared, the old file table will be placed on a freelist 1849 * which will be processed when the struct filedesc is released. 1850 * 1851 * Note that if onfiles == NDFILE, we're dealing with the original 1852 * static allocation contained within (struct filedesc0 *)fdp, 1853 * which must not be freed. 1854 */ 1855 if (onfiles > NDFILE) { 1856 /* 1857 * Note we may be called here from fdinit while allocating a 1858 * table for a new process in which case ->p_fd points 1859 * elsewhere. 1860 */ 1861 if (curproc->p_fd != fdp || FILEDESC_IS_ONLY_USER(fdp)) { 1862 free(otable, M_FILEDESC); 1863 } else { 1864 ft = (struct freetable *)&otable->fdt_ofiles[onfiles]; 1865 fdp0 = (struct filedesc0 *)fdp; 1866 ft->ft_table = otable; 1867 SLIST_INSERT_HEAD(&fdp0->fd_free, ft, ft_next); 1868 } 1869 } 1870 /* 1871 * The map does not have the same possibility of threads still 1872 * holding references to it. So always free it as long as it 1873 * does not reference the original static allocation. 1874 */ 1875 if (NDSLOTS(onfiles) > NDSLOTS(NDFILE)) 1876 free(omap, M_FILEDESC); 1877 } 1878 1879 /* 1880 * Allocate a file descriptor for the process. 1881 */ 1882 int 1883 fdalloc(struct thread *td, int minfd, int *result) 1884 { 1885 struct proc *p = td->td_proc; 1886 struct filedesc *fdp = p->p_fd; 1887 int fd, maxfd, allocfd; 1888 #ifdef RACCT 1889 int error; 1890 #endif 1891 1892 FILEDESC_XLOCK_ASSERT(fdp); 1893 1894 if (fdp->fd_freefile > minfd) 1895 minfd = fdp->fd_freefile; 1896 1897 maxfd = getmaxfd(td); 1898 1899 /* 1900 * Search the bitmap for a free descriptor starting at minfd. 1901 * If none is found, grow the file table. 1902 */ 1903 fd = fd_first_free(fdp, minfd, fdp->fd_nfiles); 1904 if (__predict_false(fd >= maxfd)) 1905 return (EMFILE); 1906 if (__predict_false(fd >= fdp->fd_nfiles)) { 1907 allocfd = min(fd * 2, maxfd); 1908 #ifdef RACCT 1909 if (RACCT_ENABLED()) { 1910 error = racct_set_unlocked(p, RACCT_NOFILE, allocfd); 1911 if (error != 0) 1912 return (EMFILE); 1913 } 1914 #endif 1915 /* 1916 * fd is already equal to first free descriptor >= minfd, so 1917 * we only need to grow the table and we are done. 1918 */ 1919 fdgrowtable_exp(fdp, allocfd); 1920 } 1921 1922 /* 1923 * Perform some sanity checks, then mark the file descriptor as 1924 * used and return it to the caller. 1925 */ 1926 KASSERT(fd >= 0 && fd < min(maxfd, fdp->fd_nfiles), 1927 ("invalid descriptor %d", fd)); 1928 KASSERT(!fdisused(fdp, fd), 1929 ("fd_first_free() returned non-free descriptor")); 1930 KASSERT(fdp->fd_ofiles[fd].fde_file == NULL, 1931 ("file descriptor isn't free")); 1932 fdused(fdp, fd); 1933 *result = fd; 1934 return (0); 1935 } 1936 1937 /* 1938 * Allocate n file descriptors for the process. 1939 */ 1940 int 1941 fdallocn(struct thread *td, int minfd, int *fds, int n) 1942 { 1943 struct proc *p = td->td_proc; 1944 struct filedesc *fdp = p->p_fd; 1945 int i; 1946 1947 FILEDESC_XLOCK_ASSERT(fdp); 1948 1949 for (i = 0; i < n; i++) 1950 if (fdalloc(td, 0, &fds[i]) != 0) 1951 break; 1952 1953 if (i < n) { 1954 for (i--; i >= 0; i--) 1955 fdunused(fdp, fds[i]); 1956 return (EMFILE); 1957 } 1958 1959 return (0); 1960 } 1961 1962 /* 1963 * Create a new open file structure and allocate a file descriptor for the 1964 * process that refers to it. We add one reference to the file for the 1965 * descriptor table and one reference for resultfp. This is to prevent us 1966 * being preempted and the entry in the descriptor table closed after we 1967 * release the FILEDESC lock. 1968 */ 1969 int 1970 falloc_caps(struct thread *td, struct file **resultfp, int *resultfd, int flags, 1971 struct filecaps *fcaps) 1972 { 1973 struct file *fp; 1974 int error, fd; 1975 1976 MPASS(resultfp != NULL); 1977 MPASS(resultfd != NULL); 1978 1979 error = _falloc_noinstall(td, &fp, 2); 1980 if (__predict_false(error != 0)) { 1981 return (error); 1982 } 1983 1984 error = finstall_refed(td, fp, &fd, flags, fcaps); 1985 if (__predict_false(error != 0)) { 1986 falloc_abort(td, fp); 1987 return (error); 1988 } 1989 1990 *resultfp = fp; 1991 *resultfd = fd; 1992 1993 return (0); 1994 } 1995 1996 /* 1997 * Create a new open file structure without allocating a file descriptor. 1998 */ 1999 int 2000 _falloc_noinstall(struct thread *td, struct file **resultfp, u_int n) 2001 { 2002 struct file *fp; 2003 int maxuserfiles = maxfiles - (maxfiles / 20); 2004 int openfiles_new; 2005 static struct timeval lastfail; 2006 static int curfail; 2007 2008 KASSERT(resultfp != NULL, ("%s: resultfp == NULL", __func__)); 2009 MPASS(n > 0); 2010 2011 openfiles_new = atomic_fetchadd_int(&openfiles, 1) + 1; 2012 if ((openfiles_new >= maxuserfiles && 2013 priv_check(td, PRIV_MAXFILES) != 0) || 2014 openfiles_new >= maxfiles) { 2015 atomic_subtract_int(&openfiles, 1); 2016 if (ppsratecheck(&lastfail, &curfail, 1)) { 2017 printf("kern.maxfiles limit exceeded by uid %i, (%s) " 2018 "please see tuning(7).\n", td->td_ucred->cr_ruid, td->td_proc->p_comm); 2019 } 2020 return (ENFILE); 2021 } 2022 fp = uma_zalloc(file_zone, M_WAITOK); 2023 bzero(fp, sizeof(*fp)); 2024 refcount_init(&fp->f_count, n); 2025 fp->f_cred = crhold(td->td_ucred); 2026 fp->f_ops = &badfileops; 2027 *resultfp = fp; 2028 return (0); 2029 } 2030 2031 void 2032 falloc_abort(struct thread *td, struct file *fp) 2033 { 2034 2035 /* 2036 * For assertion purposes. 2037 */ 2038 refcount_init(&fp->f_count, 0); 2039 _fdrop(fp, td); 2040 } 2041 2042 /* 2043 * Install a file in a file descriptor table. 2044 */ 2045 void 2046 _finstall(struct filedesc *fdp, struct file *fp, int fd, int flags, 2047 struct filecaps *fcaps) 2048 { 2049 struct filedescent *fde; 2050 2051 MPASS(fp != NULL); 2052 if (fcaps != NULL) 2053 filecaps_validate(fcaps, __func__); 2054 FILEDESC_XLOCK_ASSERT(fdp); 2055 2056 fde = &fdp->fd_ofiles[fd]; 2057 #ifdef CAPABILITIES 2058 seqc_write_begin(&fde->fde_seqc); 2059 #endif 2060 fde->fde_file = fp; 2061 fde->fde_flags = (flags & O_CLOEXEC) != 0 ? UF_EXCLOSE : 0; 2062 if (fcaps != NULL) 2063 filecaps_move(fcaps, &fde->fde_caps); 2064 else 2065 filecaps_fill(&fde->fde_caps); 2066 #ifdef CAPABILITIES 2067 seqc_write_end(&fde->fde_seqc); 2068 #endif 2069 } 2070 2071 int 2072 finstall_refed(struct thread *td, struct file *fp, int *fd, int flags, 2073 struct filecaps *fcaps) 2074 { 2075 struct filedesc *fdp = td->td_proc->p_fd; 2076 int error; 2077 2078 MPASS(fd != NULL); 2079 2080 FILEDESC_XLOCK(fdp); 2081 error = fdalloc(td, 0, fd); 2082 if (__predict_true(error == 0)) { 2083 _finstall(fdp, fp, *fd, flags, fcaps); 2084 } 2085 FILEDESC_XUNLOCK(fdp); 2086 return (error); 2087 } 2088 2089 int 2090 finstall(struct thread *td, struct file *fp, int *fd, int flags, 2091 struct filecaps *fcaps) 2092 { 2093 int error; 2094 2095 MPASS(fd != NULL); 2096 2097 if (!fhold(fp)) 2098 return (EBADF); 2099 error = finstall_refed(td, fp, fd, flags, fcaps); 2100 if (__predict_false(error != 0)) { 2101 fdrop(fp, td); 2102 } 2103 return (error); 2104 } 2105 2106 /* 2107 * Build a new filedesc structure from another. 2108 * 2109 * If fdp is not NULL, return with it shared locked. 2110 */ 2111 struct filedesc * 2112 fdinit(struct filedesc *fdp, bool prepfiles, int *lastfile) 2113 { 2114 struct filedesc0 *newfdp0; 2115 struct filedesc *newfdp; 2116 2117 if (prepfiles) 2118 MPASS(lastfile != NULL); 2119 else 2120 MPASS(lastfile == NULL); 2121 2122 newfdp0 = uma_zalloc(filedesc0_zone, M_WAITOK | M_ZERO); 2123 newfdp = &newfdp0->fd_fd; 2124 2125 /* Create the file descriptor table. */ 2126 FILEDESC_LOCK_INIT(newfdp); 2127 refcount_init(&newfdp->fd_refcnt, 1); 2128 refcount_init(&newfdp->fd_holdcnt, 1); 2129 newfdp->fd_map = newfdp0->fd_dmap; 2130 newfdp->fd_files = (struct fdescenttbl *)&newfdp0->fd_dfiles; 2131 newfdp->fd_files->fdt_nfiles = NDFILE; 2132 2133 if (fdp == NULL) 2134 return (newfdp); 2135 2136 FILEDESC_SLOCK(fdp); 2137 if (!prepfiles) { 2138 FILEDESC_SUNLOCK(fdp); 2139 return (newfdp); 2140 } 2141 2142 for (;;) { 2143 *lastfile = fdlastfile(fdp); 2144 if (*lastfile < newfdp->fd_nfiles) 2145 break; 2146 FILEDESC_SUNLOCK(fdp); 2147 fdgrowtable(newfdp, *lastfile + 1); 2148 FILEDESC_SLOCK(fdp); 2149 } 2150 2151 return (newfdp); 2152 } 2153 2154 /* 2155 * Build a pwddesc structure from another. 2156 * Copy the current, root, and jail root vnode references. 2157 * 2158 * If pdp is not NULL, return with it shared locked. 2159 */ 2160 struct pwddesc * 2161 pdinit(struct pwddesc *pdp, bool keeplock) 2162 { 2163 struct pwddesc *newpdp; 2164 struct pwd *newpwd; 2165 2166 newpdp = malloc(sizeof(*newpdp), M_PWDDESC, M_WAITOK | M_ZERO); 2167 2168 PWDDESC_LOCK_INIT(newpdp); 2169 refcount_init(&newpdp->pd_refcount, 1); 2170 newpdp->pd_cmask = CMASK; 2171 2172 if (pdp == NULL) { 2173 newpwd = pwd_alloc(); 2174 smr_serialized_store(&newpdp->pd_pwd, newpwd, true); 2175 return (newpdp); 2176 } 2177 2178 PWDDESC_XLOCK(pdp); 2179 newpwd = pwd_hold_pwddesc(pdp); 2180 smr_serialized_store(&newpdp->pd_pwd, newpwd, true); 2181 if (!keeplock) 2182 PWDDESC_XUNLOCK(pdp); 2183 return (newpdp); 2184 } 2185 2186 /* 2187 * Hold either filedesc or pwddesc of the passed process. 2188 * 2189 * The process lock is used to synchronize against the target exiting and 2190 * freeing the data. 2191 * 2192 * Clearing can be ilustrated in 3 steps: 2193 * 1. set the pointer to NULL. Either routine can race against it, hence 2194 * atomic_load_ptr. 2195 * 2. observe the process lock as not taken. Until then fdhold/pdhold can 2196 * race to either still see the pointer or find NULL. It is still safe to 2197 * grab a reference as clearing is stalled. 2198 * 3. after the lock is observed as not taken, any fdhold/pdhold calls are 2199 * guaranteed to see NULL, making it safe to finish clearing 2200 */ 2201 static struct filedesc * 2202 fdhold(struct proc *p) 2203 { 2204 struct filedesc *fdp; 2205 2206 PROC_LOCK_ASSERT(p, MA_OWNED); 2207 fdp = atomic_load_ptr(&p->p_fd); 2208 if (fdp != NULL) 2209 refcount_acquire(&fdp->fd_holdcnt); 2210 return (fdp); 2211 } 2212 2213 static struct pwddesc * 2214 pdhold(struct proc *p) 2215 { 2216 struct pwddesc *pdp; 2217 2218 PROC_LOCK_ASSERT(p, MA_OWNED); 2219 pdp = atomic_load_ptr(&p->p_pd); 2220 if (pdp != NULL) 2221 refcount_acquire(&pdp->pd_refcount); 2222 return (pdp); 2223 } 2224 2225 static void 2226 fddrop(struct filedesc *fdp) 2227 { 2228 2229 if (refcount_load(&fdp->fd_holdcnt) > 1) { 2230 if (refcount_release(&fdp->fd_holdcnt) == 0) 2231 return; 2232 } 2233 2234 FILEDESC_LOCK_DESTROY(fdp); 2235 uma_zfree(filedesc0_zone, fdp); 2236 } 2237 2238 static void 2239 pddrop(struct pwddesc *pdp) 2240 { 2241 struct pwd *pwd; 2242 2243 if (refcount_release_if_not_last(&pdp->pd_refcount)) 2244 return; 2245 2246 PWDDESC_XLOCK(pdp); 2247 if (refcount_release(&pdp->pd_refcount) == 0) { 2248 PWDDESC_XUNLOCK(pdp); 2249 return; 2250 } 2251 pwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); 2252 pwd_set(pdp, NULL); 2253 PWDDESC_XUNLOCK(pdp); 2254 pwd_drop(pwd); 2255 2256 PWDDESC_LOCK_DESTROY(pdp); 2257 free(pdp, M_PWDDESC); 2258 } 2259 2260 /* 2261 * Share a filedesc structure. 2262 */ 2263 struct filedesc * 2264 fdshare(struct filedesc *fdp) 2265 { 2266 2267 refcount_acquire(&fdp->fd_refcnt); 2268 return (fdp); 2269 } 2270 2271 /* 2272 * Share a pwddesc structure. 2273 */ 2274 struct pwddesc * 2275 pdshare(struct pwddesc *pdp) 2276 { 2277 refcount_acquire(&pdp->pd_refcount); 2278 return (pdp); 2279 } 2280 2281 /* 2282 * Unshare a filedesc structure, if necessary by making a copy 2283 */ 2284 void 2285 fdunshare(struct thread *td) 2286 { 2287 struct filedesc *tmp; 2288 struct proc *p = td->td_proc; 2289 2290 if (refcount_load(&p->p_fd->fd_refcnt) == 1) 2291 return; 2292 2293 tmp = fdcopy(p->p_fd); 2294 fdescfree(td); 2295 p->p_fd = tmp; 2296 } 2297 2298 /* 2299 * Unshare a pwddesc structure. 2300 */ 2301 void 2302 pdunshare(struct thread *td) 2303 { 2304 struct pwddesc *pdp; 2305 struct proc *p; 2306 2307 p = td->td_proc; 2308 /* Not shared. */ 2309 if (p->p_pd->pd_refcount == 1) 2310 return; 2311 2312 pdp = pdcopy(p->p_pd); 2313 pdescfree(td); 2314 p->p_pd = pdp; 2315 } 2316 2317 /* 2318 * Copy a filedesc structure. A NULL pointer in returns a NULL reference, 2319 * this is to ease callers, not catch errors. 2320 */ 2321 struct filedesc * 2322 fdcopy(struct filedesc *fdp) 2323 { 2324 struct filedesc *newfdp; 2325 struct filedescent *nfde, *ofde; 2326 int i, lastfile; 2327 2328 MPASS(fdp != NULL); 2329 2330 newfdp = fdinit(fdp, true, &lastfile); 2331 /* copy all passable descriptors (i.e. not kqueue) */ 2332 newfdp->fd_freefile = -1; 2333 for (i = 0; i <= lastfile; ++i) { 2334 ofde = &fdp->fd_ofiles[i]; 2335 if (ofde->fde_file == NULL || 2336 (ofde->fde_file->f_ops->fo_flags & DFLAG_PASSABLE) == 0 || 2337 !fhold(ofde->fde_file)) { 2338 if (newfdp->fd_freefile == -1) 2339 newfdp->fd_freefile = i; 2340 continue; 2341 } 2342 nfde = &newfdp->fd_ofiles[i]; 2343 *nfde = *ofde; 2344 filecaps_copy(&ofde->fde_caps, &nfde->fde_caps, true); 2345 fdused_init(newfdp, i); 2346 } 2347 if (newfdp->fd_freefile == -1) 2348 newfdp->fd_freefile = i; 2349 FILEDESC_SUNLOCK(fdp); 2350 return (newfdp); 2351 } 2352 2353 /* 2354 * Copy a pwddesc structure. 2355 */ 2356 struct pwddesc * 2357 pdcopy(struct pwddesc *pdp) 2358 { 2359 struct pwddesc *newpdp; 2360 2361 MPASS(pdp != NULL); 2362 2363 newpdp = pdinit(pdp, true); 2364 newpdp->pd_cmask = pdp->pd_cmask; 2365 PWDDESC_XUNLOCK(pdp); 2366 return (newpdp); 2367 } 2368 2369 /* 2370 * Clear POSIX style locks. This is only used when fdp looses a reference (i.e. 2371 * one of processes using it exits) and the table used to be shared. 2372 */ 2373 static void 2374 fdclearlocks(struct thread *td) 2375 { 2376 struct filedesc *fdp; 2377 struct filedesc_to_leader *fdtol; 2378 struct flock lf; 2379 struct file *fp; 2380 struct proc *p; 2381 struct vnode *vp; 2382 int i, lastfile; 2383 2384 p = td->td_proc; 2385 fdp = p->p_fd; 2386 fdtol = p->p_fdtol; 2387 MPASS(fdtol != NULL); 2388 2389 FILEDESC_XLOCK(fdp); 2390 KASSERT(fdtol->fdl_refcount > 0, 2391 ("filedesc_to_refcount botch: fdl_refcount=%d", 2392 fdtol->fdl_refcount)); 2393 if (fdtol->fdl_refcount == 1 && 2394 (p->p_leader->p_flag & P_ADVLOCK) != 0) { 2395 lastfile = fdlastfile(fdp); 2396 for (i = 0; i <= lastfile; i++) { 2397 fp = fdp->fd_ofiles[i].fde_file; 2398 if (fp == NULL || fp->f_type != DTYPE_VNODE || 2399 !fhold(fp)) 2400 continue; 2401 FILEDESC_XUNLOCK(fdp); 2402 lf.l_whence = SEEK_SET; 2403 lf.l_start = 0; 2404 lf.l_len = 0; 2405 lf.l_type = F_UNLCK; 2406 vp = fp->f_vnode; 2407 (void) VOP_ADVLOCK(vp, 2408 (caddr_t)p->p_leader, F_UNLCK, 2409 &lf, F_POSIX); 2410 FILEDESC_XLOCK(fdp); 2411 fdrop(fp, td); 2412 } 2413 } 2414 retry: 2415 if (fdtol->fdl_refcount == 1) { 2416 if (fdp->fd_holdleaderscount > 0 && 2417 (p->p_leader->p_flag & P_ADVLOCK) != 0) { 2418 /* 2419 * close() or kern_dup() has cleared a reference 2420 * in a shared file descriptor table. 2421 */ 2422 fdp->fd_holdleaderswakeup = 1; 2423 sx_sleep(&fdp->fd_holdleaderscount, 2424 FILEDESC_LOCK(fdp), PLOCK, "fdlhold", 0); 2425 goto retry; 2426 } 2427 if (fdtol->fdl_holdcount > 0) { 2428 /* 2429 * Ensure that fdtol->fdl_leader remains 2430 * valid in closef(). 2431 */ 2432 fdtol->fdl_wakeup = 1; 2433 sx_sleep(fdtol, FILEDESC_LOCK(fdp), PLOCK, 2434 "fdlhold", 0); 2435 goto retry; 2436 } 2437 } 2438 fdtol->fdl_refcount--; 2439 if (fdtol->fdl_refcount == 0 && 2440 fdtol->fdl_holdcount == 0) { 2441 fdtol->fdl_next->fdl_prev = fdtol->fdl_prev; 2442 fdtol->fdl_prev->fdl_next = fdtol->fdl_next; 2443 } else 2444 fdtol = NULL; 2445 p->p_fdtol = NULL; 2446 FILEDESC_XUNLOCK(fdp); 2447 if (fdtol != NULL) 2448 free(fdtol, M_FILEDESC_TO_LEADER); 2449 } 2450 2451 /* 2452 * Release a filedesc structure. 2453 */ 2454 static void 2455 fdescfree_fds(struct thread *td, struct filedesc *fdp) 2456 { 2457 struct filedesc0 *fdp0; 2458 struct freetable *ft, *tft; 2459 struct filedescent *fde; 2460 struct file *fp; 2461 int i, lastfile; 2462 2463 KASSERT(refcount_load(&fdp->fd_refcnt) == 0, 2464 ("%s: fd table %p carries references", __func__, fdp)); 2465 2466 /* 2467 * Serialize with threads iterating over the table, if any. 2468 */ 2469 if (refcount_load(&fdp->fd_holdcnt) > 1) { 2470 FILEDESC_XLOCK(fdp); 2471 FILEDESC_XUNLOCK(fdp); 2472 } 2473 2474 lastfile = fdlastfile_single(fdp); 2475 for (i = 0; i <= lastfile; i++) { 2476 fde = &fdp->fd_ofiles[i]; 2477 fp = fde->fde_file; 2478 if (fp != NULL) { 2479 fdefree_last(fde); 2480 (void) closef(fp, td); 2481 } 2482 } 2483 2484 if (NDSLOTS(fdp->fd_nfiles) > NDSLOTS(NDFILE)) 2485 free(fdp->fd_map, M_FILEDESC); 2486 if (fdp->fd_nfiles > NDFILE) 2487 free(fdp->fd_files, M_FILEDESC); 2488 2489 fdp0 = (struct filedesc0 *)fdp; 2490 SLIST_FOREACH_SAFE(ft, &fdp0->fd_free, ft_next, tft) 2491 free(ft->ft_table, M_FILEDESC); 2492 2493 fddrop(fdp); 2494 } 2495 2496 void 2497 fdescfree(struct thread *td) 2498 { 2499 struct proc *p; 2500 struct filedesc *fdp; 2501 2502 p = td->td_proc; 2503 fdp = p->p_fd; 2504 MPASS(fdp != NULL); 2505 2506 #ifdef RACCT 2507 if (RACCT_ENABLED()) 2508 racct_set_unlocked(p, RACCT_NOFILE, 0); 2509 #endif 2510 2511 if (p->p_fdtol != NULL) 2512 fdclearlocks(td); 2513 2514 /* 2515 * Check fdhold for an explanation. 2516 */ 2517 atomic_store_ptr(&p->p_fd, NULL); 2518 atomic_thread_fence_seq_cst(); 2519 PROC_WAIT_UNLOCKED(p); 2520 2521 if (refcount_release(&fdp->fd_refcnt) == 0) 2522 return; 2523 2524 fdescfree_fds(td, fdp); 2525 } 2526 2527 void 2528 pdescfree(struct thread *td) 2529 { 2530 struct proc *p; 2531 struct pwddesc *pdp; 2532 2533 p = td->td_proc; 2534 pdp = p->p_pd; 2535 MPASS(pdp != NULL); 2536 2537 /* 2538 * Check pdhold for an explanation. 2539 */ 2540 atomic_store_ptr(&p->p_pd, NULL); 2541 atomic_thread_fence_seq_cst(); 2542 PROC_WAIT_UNLOCKED(p); 2543 2544 pddrop(pdp); 2545 } 2546 2547 /* 2548 * For setugid programs, we don't want to people to use that setugidness 2549 * to generate error messages which write to a file which otherwise would 2550 * otherwise be off-limits to the process. We check for filesystems where 2551 * the vnode can change out from under us after execve (like [lin]procfs). 2552 * 2553 * Since fdsetugidsafety calls this only for fd 0, 1 and 2, this check is 2554 * sufficient. We also don't check for setugidness since we know we are. 2555 */ 2556 static bool 2557 is_unsafe(struct file *fp) 2558 { 2559 struct vnode *vp; 2560 2561 if (fp->f_type != DTYPE_VNODE) 2562 return (false); 2563 2564 vp = fp->f_vnode; 2565 return ((vp->v_vflag & VV_PROCDEP) != 0); 2566 } 2567 2568 /* 2569 * Make this setguid thing safe, if at all possible. 2570 */ 2571 void 2572 fdsetugidsafety(struct thread *td) 2573 { 2574 struct filedesc *fdp; 2575 struct file *fp; 2576 int i; 2577 2578 fdp = td->td_proc->p_fd; 2579 KASSERT(refcount_load(&fdp->fd_refcnt) == 1, 2580 ("the fdtable should not be shared")); 2581 MPASS(fdp->fd_nfiles >= 3); 2582 for (i = 0; i <= 2; i++) { 2583 fp = fdp->fd_ofiles[i].fde_file; 2584 if (fp != NULL && is_unsafe(fp)) { 2585 FILEDESC_XLOCK(fdp); 2586 knote_fdclose(td, i); 2587 /* 2588 * NULL-out descriptor prior to close to avoid 2589 * a race while close blocks. 2590 */ 2591 fdfree(fdp, i); 2592 FILEDESC_XUNLOCK(fdp); 2593 (void) closef(fp, td); 2594 } 2595 } 2596 } 2597 2598 /* 2599 * If a specific file object occupies a specific file descriptor, close the 2600 * file descriptor entry and drop a reference on the file object. This is a 2601 * convenience function to handle a subsequent error in a function that calls 2602 * falloc() that handles the race that another thread might have closed the 2603 * file descriptor out from under the thread creating the file object. 2604 */ 2605 void 2606 fdclose(struct thread *td, struct file *fp, int idx) 2607 { 2608 struct filedesc *fdp = td->td_proc->p_fd; 2609 2610 FILEDESC_XLOCK(fdp); 2611 if (fdp->fd_ofiles[idx].fde_file == fp) { 2612 fdfree(fdp, idx); 2613 FILEDESC_XUNLOCK(fdp); 2614 fdrop(fp, td); 2615 } else 2616 FILEDESC_XUNLOCK(fdp); 2617 } 2618 2619 /* 2620 * Close any files on exec? 2621 */ 2622 void 2623 fdcloseexec(struct thread *td) 2624 { 2625 struct filedesc *fdp; 2626 struct filedescent *fde; 2627 struct file *fp; 2628 int i, lastfile; 2629 2630 fdp = td->td_proc->p_fd; 2631 KASSERT(refcount_load(&fdp->fd_refcnt) == 1, 2632 ("the fdtable should not be shared")); 2633 lastfile = fdlastfile_single(fdp); 2634 for (i = 0; i <= lastfile; i++) { 2635 fde = &fdp->fd_ofiles[i]; 2636 fp = fde->fde_file; 2637 if (fp != NULL && (fp->f_type == DTYPE_MQUEUE || 2638 (fde->fde_flags & UF_EXCLOSE))) { 2639 FILEDESC_XLOCK(fdp); 2640 fdfree(fdp, i); 2641 (void) closefp(fdp, i, fp, td, false, false); 2642 FILEDESC_UNLOCK_ASSERT(fdp); 2643 } 2644 } 2645 } 2646 2647 /* 2648 * It is unsafe for set[ug]id processes to be started with file 2649 * descriptors 0..2 closed, as these descriptors are given implicit 2650 * significance in the Standard C library. fdcheckstd() will create a 2651 * descriptor referencing /dev/null for each of stdin, stdout, and 2652 * stderr that is not already open. 2653 */ 2654 int 2655 fdcheckstd(struct thread *td) 2656 { 2657 struct filedesc *fdp; 2658 register_t save; 2659 int i, error, devnull; 2660 2661 fdp = td->td_proc->p_fd; 2662 KASSERT(refcount_load(&fdp->fd_refcnt) == 1, 2663 ("the fdtable should not be shared")); 2664 MPASS(fdp->fd_nfiles >= 3); 2665 devnull = -1; 2666 for (i = 0; i <= 2; i++) { 2667 if (fdp->fd_ofiles[i].fde_file != NULL) 2668 continue; 2669 2670 save = td->td_retval[0]; 2671 if (devnull != -1) { 2672 error = kern_dup(td, FDDUP_FIXED, 0, devnull, i); 2673 } else { 2674 error = kern_openat(td, AT_FDCWD, "/dev/null", 2675 UIO_SYSSPACE, O_RDWR, 0); 2676 if (error == 0) { 2677 devnull = td->td_retval[0]; 2678 KASSERT(devnull == i, ("we didn't get our fd")); 2679 } 2680 } 2681 td->td_retval[0] = save; 2682 if (error != 0) 2683 return (error); 2684 } 2685 return (0); 2686 } 2687 2688 /* 2689 * Internal form of close. Decrement reference count on file structure. 2690 * Note: td may be NULL when closing a file that was being passed in a 2691 * message. 2692 */ 2693 int 2694 closef(struct file *fp, struct thread *td) 2695 { 2696 struct vnode *vp; 2697 struct flock lf; 2698 struct filedesc_to_leader *fdtol; 2699 struct filedesc *fdp; 2700 2701 MPASS(td != NULL); 2702 2703 /* 2704 * POSIX record locking dictates that any close releases ALL 2705 * locks owned by this process. This is handled by setting 2706 * a flag in the unlock to free ONLY locks obeying POSIX 2707 * semantics, and not to free BSD-style file locks. 2708 * If the descriptor was in a message, POSIX-style locks 2709 * aren't passed with the descriptor, and the thread pointer 2710 * will be NULL. Callers should be careful only to pass a 2711 * NULL thread pointer when there really is no owning 2712 * context that might have locks, or the locks will be 2713 * leaked. 2714 */ 2715 if (fp->f_type == DTYPE_VNODE) { 2716 vp = fp->f_vnode; 2717 if ((td->td_proc->p_leader->p_flag & P_ADVLOCK) != 0) { 2718 lf.l_whence = SEEK_SET; 2719 lf.l_start = 0; 2720 lf.l_len = 0; 2721 lf.l_type = F_UNLCK; 2722 (void) VOP_ADVLOCK(vp, (caddr_t)td->td_proc->p_leader, 2723 F_UNLCK, &lf, F_POSIX); 2724 } 2725 fdtol = td->td_proc->p_fdtol; 2726 if (fdtol != NULL) { 2727 /* 2728 * Handle special case where file descriptor table is 2729 * shared between multiple process leaders. 2730 */ 2731 fdp = td->td_proc->p_fd; 2732 FILEDESC_XLOCK(fdp); 2733 for (fdtol = fdtol->fdl_next; 2734 fdtol != td->td_proc->p_fdtol; 2735 fdtol = fdtol->fdl_next) { 2736 if ((fdtol->fdl_leader->p_flag & 2737 P_ADVLOCK) == 0) 2738 continue; 2739 fdtol->fdl_holdcount++; 2740 FILEDESC_XUNLOCK(fdp); 2741 lf.l_whence = SEEK_SET; 2742 lf.l_start = 0; 2743 lf.l_len = 0; 2744 lf.l_type = F_UNLCK; 2745 vp = fp->f_vnode; 2746 (void) VOP_ADVLOCK(vp, 2747 (caddr_t)fdtol->fdl_leader, F_UNLCK, &lf, 2748 F_POSIX); 2749 FILEDESC_XLOCK(fdp); 2750 fdtol->fdl_holdcount--; 2751 if (fdtol->fdl_holdcount == 0 && 2752 fdtol->fdl_wakeup != 0) { 2753 fdtol->fdl_wakeup = 0; 2754 wakeup(fdtol); 2755 } 2756 } 2757 FILEDESC_XUNLOCK(fdp); 2758 } 2759 } 2760 return (fdrop_close(fp, td)); 2761 } 2762 2763 /* 2764 * Hack for file descriptor passing code. 2765 */ 2766 void 2767 closef_nothread(struct file *fp) 2768 { 2769 2770 fdrop(fp, NULL); 2771 } 2772 2773 /* 2774 * Initialize the file pointer with the specified properties. 2775 * 2776 * The ops are set with release semantics to be certain that the flags, type, 2777 * and data are visible when ops is. This is to prevent ops methods from being 2778 * called with bad data. 2779 */ 2780 void 2781 finit(struct file *fp, u_int flag, short type, void *data, struct fileops *ops) 2782 { 2783 fp->f_data = data; 2784 fp->f_flag = flag; 2785 fp->f_type = type; 2786 atomic_store_rel_ptr((volatile uintptr_t *)&fp->f_ops, (uintptr_t)ops); 2787 } 2788 2789 void 2790 finit_vnode(struct file *fp, u_int flag, void *data, struct fileops *ops) 2791 { 2792 fp->f_seqcount[UIO_READ] = 1; 2793 fp->f_seqcount[UIO_WRITE] = 1; 2794 finit(fp, (flag & FMASK) | (fp->f_flag & FHASLOCK), DTYPE_VNODE, 2795 data, ops); 2796 } 2797 2798 int 2799 fget_cap_locked(struct filedesc *fdp, int fd, cap_rights_t *needrightsp, 2800 struct file **fpp, struct filecaps *havecapsp) 2801 { 2802 struct filedescent *fde; 2803 int error; 2804 2805 FILEDESC_LOCK_ASSERT(fdp); 2806 2807 fde = fdeget_locked(fdp, fd); 2808 if (fde == NULL) { 2809 error = EBADF; 2810 goto out; 2811 } 2812 2813 #ifdef CAPABILITIES 2814 error = cap_check(cap_rights_fde_inline(fde), needrightsp); 2815 if (error != 0) 2816 goto out; 2817 #endif 2818 2819 if (havecapsp != NULL) 2820 filecaps_copy(&fde->fde_caps, havecapsp, true); 2821 2822 *fpp = fde->fde_file; 2823 2824 error = 0; 2825 out: 2826 return (error); 2827 } 2828 2829 int 2830 fget_cap(struct thread *td, int fd, cap_rights_t *needrightsp, 2831 struct file **fpp, struct filecaps *havecapsp) 2832 { 2833 struct filedesc *fdp = td->td_proc->p_fd; 2834 int error; 2835 #ifndef CAPABILITIES 2836 error = fget_unlocked(fdp, fd, needrightsp, fpp); 2837 if (havecapsp != NULL && error == 0) 2838 filecaps_fill(havecapsp); 2839 #else 2840 struct file *fp; 2841 seqc_t seq; 2842 2843 *fpp = NULL; 2844 for (;;) { 2845 error = fget_unlocked_seq(fdp, fd, needrightsp, &fp, &seq); 2846 if (error != 0) 2847 return (error); 2848 2849 if (havecapsp != NULL) { 2850 if (!filecaps_copy(&fdp->fd_ofiles[fd].fde_caps, 2851 havecapsp, false)) { 2852 fdrop(fp, td); 2853 goto get_locked; 2854 } 2855 } 2856 2857 if (!fd_modified(fdp, fd, seq)) 2858 break; 2859 fdrop(fp, td); 2860 } 2861 2862 *fpp = fp; 2863 return (0); 2864 2865 get_locked: 2866 FILEDESC_SLOCK(fdp); 2867 error = fget_cap_locked(fdp, fd, needrightsp, fpp, havecapsp); 2868 if (error == 0 && !fhold(*fpp)) 2869 error = EBADF; 2870 FILEDESC_SUNLOCK(fdp); 2871 #endif 2872 return (error); 2873 } 2874 2875 #ifdef CAPABILITIES 2876 int 2877 fgetvp_lookup_smr(int fd, struct nameidata *ndp, struct vnode **vpp, bool *fsearch) 2878 { 2879 const struct filedescent *fde; 2880 const struct fdescenttbl *fdt; 2881 struct filedesc *fdp; 2882 struct file *fp; 2883 struct vnode *vp; 2884 const cap_rights_t *haverights; 2885 cap_rights_t rights; 2886 seqc_t seq; 2887 2888 VFS_SMR_ASSERT_ENTERED(); 2889 2890 rights = *ndp->ni_rightsneeded; 2891 cap_rights_set_one(&rights, CAP_LOOKUP); 2892 2893 fdp = curproc->p_fd; 2894 fdt = fdp->fd_files; 2895 if (__predict_false((u_int)fd >= fdt->fdt_nfiles)) 2896 return (EBADF); 2897 seq = seqc_read_notmodify(fd_seqc(fdt, fd)); 2898 fde = &fdt->fdt_ofiles[fd]; 2899 haverights = cap_rights_fde_inline(fde); 2900 fp = fde->fde_file; 2901 if (__predict_false(fp == NULL)) 2902 return (EAGAIN); 2903 if (__predict_false(cap_check_inline_transient(haverights, &rights))) 2904 return (EAGAIN); 2905 *fsearch = ((fp->f_flag & FSEARCH) != 0); 2906 vp = fp->f_vnode; 2907 if (__predict_false(vp == NULL)) { 2908 return (EAGAIN); 2909 } 2910 if (!filecaps_copy(&fde->fde_caps, &ndp->ni_filecaps, false)) { 2911 return (EAGAIN); 2912 } 2913 /* 2914 * Use an acquire barrier to force re-reading of fdt so it is 2915 * refreshed for verification. 2916 */ 2917 atomic_thread_fence_acq(); 2918 fdt = fdp->fd_files; 2919 if (__predict_false(!seqc_consistent_nomb(fd_seqc(fdt, fd), seq))) 2920 return (EAGAIN); 2921 /* 2922 * If file descriptor doesn't have all rights, 2923 * all lookups relative to it must also be 2924 * strictly relative. 2925 * 2926 * Not yet supported by fast path. 2927 */ 2928 CAP_ALL(&rights); 2929 if (!cap_rights_contains(&ndp->ni_filecaps.fc_rights, &rights) || 2930 ndp->ni_filecaps.fc_fcntls != CAP_FCNTL_ALL || 2931 ndp->ni_filecaps.fc_nioctls != -1) { 2932 #ifdef notyet 2933 ndp->ni_lcf |= NI_LCF_STRICTRELATIVE; 2934 #else 2935 return (EAGAIN); 2936 #endif 2937 } 2938 *vpp = vp; 2939 return (0); 2940 } 2941 #else 2942 int 2943 fgetvp_lookup_smr(int fd, struct nameidata *ndp, struct vnode **vpp, bool *fsearch) 2944 { 2945 const struct fdescenttbl *fdt; 2946 struct filedesc *fdp; 2947 struct file *fp; 2948 struct vnode *vp; 2949 2950 VFS_SMR_ASSERT_ENTERED(); 2951 2952 fdp = curproc->p_fd; 2953 fdt = fdp->fd_files; 2954 if (__predict_false((u_int)fd >= fdt->fdt_nfiles)) 2955 return (EBADF); 2956 fp = fdt->fdt_ofiles[fd].fde_file; 2957 if (__predict_false(fp == NULL)) 2958 return (EAGAIN); 2959 *fsearch = ((fp->f_flag & FSEARCH) != 0); 2960 vp = fp->f_vnode; 2961 if (__predict_false(vp == NULL || vp->v_type != VDIR)) { 2962 return (EAGAIN); 2963 } 2964 /* 2965 * Use an acquire barrier to force re-reading of fdt so it is 2966 * refreshed for verification. 2967 */ 2968 atomic_thread_fence_acq(); 2969 fdt = fdp->fd_files; 2970 if (__predict_false(fp != fdt->fdt_ofiles[fd].fde_file)) 2971 return (EAGAIN); 2972 filecaps_fill(&ndp->ni_filecaps); 2973 *vpp = vp; 2974 return (0); 2975 } 2976 #endif 2977 2978 int 2979 fget_unlocked_seq(struct filedesc *fdp, int fd, cap_rights_t *needrightsp, 2980 struct file **fpp, seqc_t *seqp) 2981 { 2982 #ifdef CAPABILITIES 2983 const struct filedescent *fde; 2984 #endif 2985 const struct fdescenttbl *fdt; 2986 struct file *fp; 2987 #ifdef CAPABILITIES 2988 seqc_t seq; 2989 cap_rights_t haverights; 2990 int error; 2991 #endif 2992 2993 fdt = fdp->fd_files; 2994 if (__predict_false((u_int)fd >= fdt->fdt_nfiles)) 2995 return (EBADF); 2996 /* 2997 * Fetch the descriptor locklessly. We avoid fdrop() races by 2998 * never raising a refcount above 0. To accomplish this we have 2999 * to use a cmpset loop rather than an atomic_add. The descriptor 3000 * must be re-verified once we acquire a reference to be certain 3001 * that the identity is still correct and we did not lose a race 3002 * due to preemption. 3003 */ 3004 for (;;) { 3005 #ifdef CAPABILITIES 3006 seq = seqc_read_notmodify(fd_seqc(fdt, fd)); 3007 fde = &fdt->fdt_ofiles[fd]; 3008 haverights = *cap_rights_fde_inline(fde); 3009 fp = fde->fde_file; 3010 if (!seqc_consistent(fd_seqc(fdt, fd), seq)) 3011 continue; 3012 #else 3013 fp = fdt->fdt_ofiles[fd].fde_file; 3014 #endif 3015 if (fp == NULL) 3016 return (EBADF); 3017 #ifdef CAPABILITIES 3018 error = cap_check_inline(&haverights, needrightsp); 3019 if (error != 0) 3020 return (error); 3021 #endif 3022 if (__predict_false(!refcount_acquire_if_not_zero(&fp->f_count))) { 3023 /* 3024 * Force a reload. Other thread could reallocate the 3025 * table before this fd was closed, so it is possible 3026 * that there is a stale fp pointer in cached version. 3027 */ 3028 fdt = atomic_load_ptr(&fdp->fd_files); 3029 continue; 3030 } 3031 /* 3032 * Use an acquire barrier to force re-reading of fdt so it is 3033 * refreshed for verification. 3034 */ 3035 atomic_thread_fence_acq(); 3036 fdt = fdp->fd_files; 3037 #ifdef CAPABILITIES 3038 if (seqc_consistent_nomb(fd_seqc(fdt, fd), seq)) 3039 #else 3040 if (fp == fdt->fdt_ofiles[fd].fde_file) 3041 #endif 3042 break; 3043 fdrop(fp, curthread); 3044 } 3045 *fpp = fp; 3046 if (seqp != NULL) { 3047 #ifdef CAPABILITIES 3048 *seqp = seq; 3049 #endif 3050 } 3051 return (0); 3052 } 3053 3054 /* 3055 * See the comments in fget_unlocked_seq for an explanation of how this works. 3056 * 3057 * This is a simplified variant which bails out to the aforementioned routine 3058 * if anything goes wrong. In practice this only happens when userspace is 3059 * racing with itself. 3060 */ 3061 int 3062 fget_unlocked(struct filedesc *fdp, int fd, cap_rights_t *needrightsp, 3063 struct file **fpp) 3064 { 3065 #ifdef CAPABILITIES 3066 const struct filedescent *fde; 3067 #endif 3068 const struct fdescenttbl *fdt; 3069 struct file *fp; 3070 #ifdef CAPABILITIES 3071 seqc_t seq; 3072 const cap_rights_t *haverights; 3073 #endif 3074 3075 fdt = fdp->fd_files; 3076 if (__predict_false((u_int)fd >= fdt->fdt_nfiles)) 3077 return (EBADF); 3078 #ifdef CAPABILITIES 3079 seq = seqc_read_notmodify(fd_seqc(fdt, fd)); 3080 fde = &fdt->fdt_ofiles[fd]; 3081 haverights = cap_rights_fde_inline(fde); 3082 fp = fde->fde_file; 3083 #else 3084 fp = fdt->fdt_ofiles[fd].fde_file; 3085 #endif 3086 if (__predict_false(fp == NULL)) 3087 goto out_fallback; 3088 #ifdef CAPABILITIES 3089 if (__predict_false(cap_check_inline_transient(haverights, needrightsp))) 3090 goto out_fallback; 3091 #endif 3092 if (__predict_false(!refcount_acquire_if_not_zero(&fp->f_count))) 3093 goto out_fallback; 3094 3095 /* 3096 * Use an acquire barrier to force re-reading of fdt so it is 3097 * refreshed for verification. 3098 */ 3099 atomic_thread_fence_acq(); 3100 fdt = fdp->fd_files; 3101 #ifdef CAPABILITIES 3102 if (__predict_false(!seqc_consistent_nomb(fd_seqc(fdt, fd), seq))) 3103 #else 3104 if (__predict_false(fp != fdt->fdt_ofiles[fd].fde_file)) 3105 #endif 3106 goto out_fdrop; 3107 *fpp = fp; 3108 return (0); 3109 out_fdrop: 3110 fdrop(fp, curthread); 3111 out_fallback: 3112 return (fget_unlocked_seq(fdp, fd, needrightsp, fpp, NULL)); 3113 } 3114 3115 /* 3116 * Translate fd -> file when the caller guarantees the file descriptor table 3117 * can't be changed by others. 3118 * 3119 * Note this does not mean the file object itself is only visible to the caller, 3120 * merely that it wont disappear without having to be referenced. 3121 * 3122 * Must be paired with fput_only_user. 3123 */ 3124 #ifdef CAPABILITIES 3125 int 3126 fget_only_user(struct filedesc *fdp, int fd, cap_rights_t *needrightsp, 3127 struct file **fpp) 3128 { 3129 const struct filedescent *fde; 3130 const struct fdescenttbl *fdt; 3131 const cap_rights_t *haverights; 3132 struct file *fp; 3133 int error; 3134 3135 MPASS(FILEDESC_IS_ONLY_USER(fdp)); 3136 3137 if (__predict_false(fd >= fdp->fd_nfiles)) 3138 return (EBADF); 3139 3140 fdt = fdp->fd_files; 3141 fde = &fdt->fdt_ofiles[fd]; 3142 fp = fde->fde_file; 3143 if (__predict_false(fp == NULL)) 3144 return (EBADF); 3145 MPASS(refcount_load(&fp->f_count) > 0); 3146 haverights = cap_rights_fde_inline(fde); 3147 error = cap_check_inline(haverights, needrightsp); 3148 if (__predict_false(error != 0)) 3149 return (error); 3150 *fpp = fp; 3151 return (0); 3152 } 3153 #else 3154 int 3155 fget_only_user(struct filedesc *fdp, int fd, cap_rights_t *needrightsp, 3156 struct file **fpp) 3157 { 3158 struct file *fp; 3159 3160 MPASS(FILEDESC_IS_ONLY_USER(fdp)); 3161 3162 if (__predict_false(fd >= fdp->fd_nfiles)) 3163 return (EBADF); 3164 3165 fp = fdp->fd_ofiles[fd].fde_file; 3166 if (__predict_false(fp == NULL)) 3167 return (EBADF); 3168 3169 MPASS(refcount_load(&fp->f_count) > 0); 3170 *fpp = fp; 3171 return (0); 3172 } 3173 #endif 3174 3175 /* 3176 * Extract the file pointer associated with the specified descriptor for the 3177 * current user process. 3178 * 3179 * If the descriptor doesn't exist or doesn't match 'flags', EBADF is 3180 * returned. 3181 * 3182 * File's rights will be checked against the capability rights mask. 3183 * 3184 * If an error occurred the non-zero error is returned and *fpp is set to 3185 * NULL. Otherwise *fpp is held and set and zero is returned. Caller is 3186 * responsible for fdrop(). 3187 */ 3188 static __inline int 3189 _fget(struct thread *td, int fd, struct file **fpp, int flags, 3190 cap_rights_t *needrightsp) 3191 { 3192 struct filedesc *fdp; 3193 struct file *fp; 3194 int error; 3195 3196 *fpp = NULL; 3197 fdp = td->td_proc->p_fd; 3198 error = fget_unlocked(fdp, fd, needrightsp, &fp); 3199 if (__predict_false(error != 0)) 3200 return (error); 3201 if (__predict_false(fp->f_ops == &badfileops)) { 3202 fdrop(fp, td); 3203 return (EBADF); 3204 } 3205 3206 /* 3207 * FREAD and FWRITE failure return EBADF as per POSIX. 3208 */ 3209 error = 0; 3210 switch (flags) { 3211 case FREAD: 3212 case FWRITE: 3213 if ((fp->f_flag & flags) == 0) 3214 error = EBADF; 3215 break; 3216 case FEXEC: 3217 if (fp->f_ops != &path_fileops && 3218 ((fp->f_flag & (FREAD | FEXEC)) == 0 || 3219 (fp->f_flag & FWRITE) != 0)) 3220 error = EBADF; 3221 break; 3222 case 0: 3223 break; 3224 default: 3225 KASSERT(0, ("wrong flags")); 3226 } 3227 3228 if (error != 0) { 3229 fdrop(fp, td); 3230 return (error); 3231 } 3232 3233 *fpp = fp; 3234 return (0); 3235 } 3236 3237 int 3238 fget(struct thread *td, int fd, cap_rights_t *rightsp, struct file **fpp) 3239 { 3240 3241 return (_fget(td, fd, fpp, 0, rightsp)); 3242 } 3243 3244 int 3245 fget_mmap(struct thread *td, int fd, cap_rights_t *rightsp, vm_prot_t *maxprotp, 3246 struct file **fpp) 3247 { 3248 int error; 3249 #ifndef CAPABILITIES 3250 error = _fget(td, fd, fpp, 0, rightsp); 3251 if (maxprotp != NULL) 3252 *maxprotp = VM_PROT_ALL; 3253 return (error); 3254 #else 3255 cap_rights_t fdrights; 3256 struct filedesc *fdp; 3257 struct file *fp; 3258 seqc_t seq; 3259 3260 *fpp = NULL; 3261 fdp = td->td_proc->p_fd; 3262 MPASS(cap_rights_is_set(rightsp, CAP_MMAP)); 3263 for (;;) { 3264 error = fget_unlocked_seq(fdp, fd, rightsp, &fp, &seq); 3265 if (__predict_false(error != 0)) 3266 return (error); 3267 if (__predict_false(fp->f_ops == &badfileops)) { 3268 fdrop(fp, td); 3269 return (EBADF); 3270 } 3271 if (maxprotp != NULL) 3272 fdrights = *cap_rights(fdp, fd); 3273 if (!fd_modified(fdp, fd, seq)) 3274 break; 3275 fdrop(fp, td); 3276 } 3277 3278 /* 3279 * If requested, convert capability rights to access flags. 3280 */ 3281 if (maxprotp != NULL) 3282 *maxprotp = cap_rights_to_vmprot(&fdrights); 3283 *fpp = fp; 3284 return (0); 3285 #endif 3286 } 3287 3288 int 3289 fget_read(struct thread *td, int fd, cap_rights_t *rightsp, struct file **fpp) 3290 { 3291 3292 return (_fget(td, fd, fpp, FREAD, rightsp)); 3293 } 3294 3295 int 3296 fget_write(struct thread *td, int fd, cap_rights_t *rightsp, struct file **fpp) 3297 { 3298 3299 return (_fget(td, fd, fpp, FWRITE, rightsp)); 3300 } 3301 3302 int 3303 fget_fcntl(struct thread *td, int fd, cap_rights_t *rightsp, int needfcntl, 3304 struct file **fpp) 3305 { 3306 struct filedesc *fdp = td->td_proc->p_fd; 3307 #ifndef CAPABILITIES 3308 return (fget_unlocked(fdp, fd, rightsp, fpp)); 3309 #else 3310 struct file *fp; 3311 int error; 3312 seqc_t seq; 3313 3314 *fpp = NULL; 3315 MPASS(cap_rights_is_set(rightsp, CAP_FCNTL)); 3316 for (;;) { 3317 error = fget_unlocked_seq(fdp, fd, rightsp, &fp, &seq); 3318 if (error != 0) 3319 return (error); 3320 error = cap_fcntl_check(fdp, fd, needfcntl); 3321 if (!fd_modified(fdp, fd, seq)) 3322 break; 3323 fdrop(fp, td); 3324 } 3325 if (error != 0) { 3326 fdrop(fp, td); 3327 return (error); 3328 } 3329 *fpp = fp; 3330 return (0); 3331 #endif 3332 } 3333 3334 /* 3335 * Like fget() but loads the underlying vnode, or returns an error if the 3336 * descriptor does not represent a vnode. Note that pipes use vnodes but 3337 * never have VM objects. The returned vnode will be vref()'d. 3338 * 3339 * XXX: what about the unused flags ? 3340 */ 3341 static __inline int 3342 _fgetvp(struct thread *td, int fd, int flags, cap_rights_t *needrightsp, 3343 struct vnode **vpp) 3344 { 3345 struct file *fp; 3346 int error; 3347 3348 *vpp = NULL; 3349 error = _fget(td, fd, &fp, flags, needrightsp); 3350 if (error != 0) 3351 return (error); 3352 if (fp->f_vnode == NULL) { 3353 error = EINVAL; 3354 } else { 3355 *vpp = fp->f_vnode; 3356 vref(*vpp); 3357 } 3358 fdrop(fp, td); 3359 3360 return (error); 3361 } 3362 3363 int 3364 fgetvp(struct thread *td, int fd, cap_rights_t *rightsp, struct vnode **vpp) 3365 { 3366 3367 return (_fgetvp(td, fd, 0, rightsp, vpp)); 3368 } 3369 3370 int 3371 fgetvp_rights(struct thread *td, int fd, cap_rights_t *needrightsp, 3372 struct filecaps *havecaps, struct vnode **vpp) 3373 { 3374 struct filecaps caps; 3375 struct file *fp; 3376 int error; 3377 3378 error = fget_cap(td, fd, needrightsp, &fp, &caps); 3379 if (error != 0) 3380 return (error); 3381 if (fp->f_ops == &badfileops) { 3382 error = EBADF; 3383 goto out; 3384 } 3385 if (fp->f_vnode == NULL) { 3386 error = EINVAL; 3387 goto out; 3388 } 3389 3390 *havecaps = caps; 3391 *vpp = fp->f_vnode; 3392 vref(*vpp); 3393 fdrop(fp, td); 3394 3395 return (0); 3396 out: 3397 filecaps_free(&caps); 3398 fdrop(fp, td); 3399 return (error); 3400 } 3401 3402 int 3403 fgetvp_read(struct thread *td, int fd, cap_rights_t *rightsp, struct vnode **vpp) 3404 { 3405 3406 return (_fgetvp(td, fd, FREAD, rightsp, vpp)); 3407 } 3408 3409 int 3410 fgetvp_exec(struct thread *td, int fd, cap_rights_t *rightsp, struct vnode **vpp) 3411 { 3412 3413 return (_fgetvp(td, fd, FEXEC, rightsp, vpp)); 3414 } 3415 3416 #ifdef notyet 3417 int 3418 fgetvp_write(struct thread *td, int fd, cap_rights_t *rightsp, 3419 struct vnode **vpp) 3420 { 3421 3422 return (_fgetvp(td, fd, FWRITE, rightsp, vpp)); 3423 } 3424 #endif 3425 3426 /* 3427 * Handle the last reference to a file being closed. 3428 * 3429 * Without the noinline attribute clang keeps inlining the func thorough this 3430 * file when fdrop is used. 3431 */ 3432 int __noinline 3433 _fdrop(struct file *fp, struct thread *td) 3434 { 3435 int error; 3436 #ifdef INVARIANTS 3437 int count; 3438 3439 count = refcount_load(&fp->f_count); 3440 if (count != 0) 3441 panic("fdrop: fp %p count %d", fp, count); 3442 #endif 3443 error = fo_close(fp, td); 3444 atomic_subtract_int(&openfiles, 1); 3445 crfree(fp->f_cred); 3446 free(fp->f_advice, M_FADVISE); 3447 uma_zfree(file_zone, fp); 3448 3449 return (error); 3450 } 3451 3452 /* 3453 * Apply an advisory lock on a file descriptor. 3454 * 3455 * Just attempt to get a record lock of the requested type on the entire file 3456 * (l_whence = SEEK_SET, l_start = 0, l_len = 0). 3457 */ 3458 #ifndef _SYS_SYSPROTO_H_ 3459 struct flock_args { 3460 int fd; 3461 int how; 3462 }; 3463 #endif 3464 /* ARGSUSED */ 3465 int 3466 sys_flock(struct thread *td, struct flock_args *uap) 3467 { 3468 struct file *fp; 3469 struct vnode *vp; 3470 struct flock lf; 3471 int error; 3472 3473 error = fget(td, uap->fd, &cap_flock_rights, &fp); 3474 if (error != 0) 3475 return (error); 3476 error = EOPNOTSUPP; 3477 if (fp->f_type != DTYPE_VNODE && fp->f_type != DTYPE_FIFO) { 3478 goto done; 3479 } 3480 if (fp->f_ops == &path_fileops) { 3481 goto done; 3482 } 3483 3484 error = 0; 3485 vp = fp->f_vnode; 3486 lf.l_whence = SEEK_SET; 3487 lf.l_start = 0; 3488 lf.l_len = 0; 3489 if (uap->how & LOCK_UN) { 3490 lf.l_type = F_UNLCK; 3491 atomic_clear_int(&fp->f_flag, FHASLOCK); 3492 error = VOP_ADVLOCK(vp, (caddr_t)fp, F_UNLCK, &lf, F_FLOCK); 3493 goto done; 3494 } 3495 if (uap->how & LOCK_EX) 3496 lf.l_type = F_WRLCK; 3497 else if (uap->how & LOCK_SH) 3498 lf.l_type = F_RDLCK; 3499 else { 3500 error = EBADF; 3501 goto done; 3502 } 3503 atomic_set_int(&fp->f_flag, FHASLOCK); 3504 error = VOP_ADVLOCK(vp, (caddr_t)fp, F_SETLK, &lf, 3505 (uap->how & LOCK_NB) ? F_FLOCK : F_FLOCK | F_WAIT); 3506 done: 3507 fdrop(fp, td); 3508 return (error); 3509 } 3510 /* 3511 * Duplicate the specified descriptor to a free descriptor. 3512 */ 3513 int 3514 dupfdopen(struct thread *td, struct filedesc *fdp, int dfd, int mode, 3515 int openerror, int *indxp) 3516 { 3517 struct filedescent *newfde, *oldfde; 3518 struct file *fp; 3519 u_long *ioctls; 3520 int error, indx; 3521 3522 KASSERT(openerror == ENODEV || openerror == ENXIO, 3523 ("unexpected error %d in %s", openerror, __func__)); 3524 3525 /* 3526 * If the to-be-dup'd fd number is greater than the allowed number 3527 * of file descriptors, or the fd to be dup'd has already been 3528 * closed, then reject. 3529 */ 3530 FILEDESC_XLOCK(fdp); 3531 if ((fp = fget_locked(fdp, dfd)) == NULL) { 3532 FILEDESC_XUNLOCK(fdp); 3533 return (EBADF); 3534 } 3535 3536 error = fdalloc(td, 0, &indx); 3537 if (error != 0) { 3538 FILEDESC_XUNLOCK(fdp); 3539 return (error); 3540 } 3541 3542 /* 3543 * There are two cases of interest here. 3544 * 3545 * For ENODEV simply dup (dfd) to file descriptor (indx) and return. 3546 * 3547 * For ENXIO steal away the file structure from (dfd) and store it in 3548 * (indx). (dfd) is effectively closed by this operation. 3549 */ 3550 switch (openerror) { 3551 case ENODEV: 3552 /* 3553 * Check that the mode the file is being opened for is a 3554 * subset of the mode of the existing descriptor. 3555 */ 3556 if (((mode & (FREAD|FWRITE)) | fp->f_flag) != fp->f_flag) { 3557 fdunused(fdp, indx); 3558 FILEDESC_XUNLOCK(fdp); 3559 return (EACCES); 3560 } 3561 if (!fhold(fp)) { 3562 fdunused(fdp, indx); 3563 FILEDESC_XUNLOCK(fdp); 3564 return (EBADF); 3565 } 3566 newfde = &fdp->fd_ofiles[indx]; 3567 oldfde = &fdp->fd_ofiles[dfd]; 3568 ioctls = filecaps_copy_prep(&oldfde->fde_caps); 3569 #ifdef CAPABILITIES 3570 seqc_write_begin(&newfde->fde_seqc); 3571 #endif 3572 memcpy(newfde, oldfde, fde_change_size); 3573 filecaps_copy_finish(&oldfde->fde_caps, &newfde->fde_caps, 3574 ioctls); 3575 #ifdef CAPABILITIES 3576 seqc_write_end(&newfde->fde_seqc); 3577 #endif 3578 break; 3579 case ENXIO: 3580 /* 3581 * Steal away the file pointer from dfd and stuff it into indx. 3582 */ 3583 newfde = &fdp->fd_ofiles[indx]; 3584 oldfde = &fdp->fd_ofiles[dfd]; 3585 #ifdef CAPABILITIES 3586 seqc_write_begin(&newfde->fde_seqc); 3587 #endif 3588 memcpy(newfde, oldfde, fde_change_size); 3589 oldfde->fde_file = NULL; 3590 fdunused(fdp, dfd); 3591 #ifdef CAPABILITIES 3592 seqc_write_end(&newfde->fde_seqc); 3593 #endif 3594 break; 3595 } 3596 FILEDESC_XUNLOCK(fdp); 3597 *indxp = indx; 3598 return (0); 3599 } 3600 3601 /* 3602 * This sysctl determines if we will allow a process to chroot(2) if it 3603 * has a directory open: 3604 * 0: disallowed for all processes. 3605 * 1: allowed for processes that were not already chroot(2)'ed. 3606 * 2: allowed for all processes. 3607 */ 3608 3609 static int chroot_allow_open_directories = 1; 3610 3611 SYSCTL_INT(_kern, OID_AUTO, chroot_allow_open_directories, CTLFLAG_RW, 3612 &chroot_allow_open_directories, 0, 3613 "Allow a process to chroot(2) if it has a directory open"); 3614 3615 /* 3616 * Helper function for raised chroot(2) security function: Refuse if 3617 * any filedescriptors are open directories. 3618 */ 3619 static int 3620 chroot_refuse_vdir_fds(struct filedesc *fdp) 3621 { 3622 struct vnode *vp; 3623 struct file *fp; 3624 int fd, lastfile; 3625 3626 FILEDESC_LOCK_ASSERT(fdp); 3627 3628 lastfile = fdlastfile(fdp); 3629 for (fd = 0; fd <= lastfile; fd++) { 3630 fp = fget_locked(fdp, fd); 3631 if (fp == NULL) 3632 continue; 3633 if (fp->f_type == DTYPE_VNODE) { 3634 vp = fp->f_vnode; 3635 if (vp->v_type == VDIR) 3636 return (EPERM); 3637 } 3638 } 3639 return (0); 3640 } 3641 3642 static void 3643 pwd_fill(struct pwd *oldpwd, struct pwd *newpwd) 3644 { 3645 3646 if (newpwd->pwd_cdir == NULL && oldpwd->pwd_cdir != NULL) { 3647 vrefact(oldpwd->pwd_cdir); 3648 newpwd->pwd_cdir = oldpwd->pwd_cdir; 3649 } 3650 3651 if (newpwd->pwd_rdir == NULL && oldpwd->pwd_rdir != NULL) { 3652 vrefact(oldpwd->pwd_rdir); 3653 newpwd->pwd_rdir = oldpwd->pwd_rdir; 3654 } 3655 3656 if (newpwd->pwd_jdir == NULL && oldpwd->pwd_jdir != NULL) { 3657 vrefact(oldpwd->pwd_jdir); 3658 newpwd->pwd_jdir = oldpwd->pwd_jdir; 3659 } 3660 } 3661 3662 struct pwd * 3663 pwd_hold_pwddesc(struct pwddesc *pdp) 3664 { 3665 struct pwd *pwd; 3666 3667 PWDDESC_ASSERT_XLOCKED(pdp); 3668 pwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); 3669 if (pwd != NULL) 3670 refcount_acquire(&pwd->pwd_refcount); 3671 return (pwd); 3672 } 3673 3674 bool 3675 pwd_hold_smr(struct pwd *pwd) 3676 { 3677 3678 MPASS(pwd != NULL); 3679 if (__predict_true(refcount_acquire_if_not_zero(&pwd->pwd_refcount))) { 3680 return (true); 3681 } 3682 return (false); 3683 } 3684 3685 struct pwd * 3686 pwd_hold(struct thread *td) 3687 { 3688 struct pwddesc *pdp; 3689 struct pwd *pwd; 3690 3691 pdp = td->td_proc->p_pd; 3692 3693 vfs_smr_enter(); 3694 pwd = vfs_smr_entered_load(&pdp->pd_pwd); 3695 if (pwd_hold_smr(pwd)) { 3696 vfs_smr_exit(); 3697 return (pwd); 3698 } 3699 vfs_smr_exit(); 3700 PWDDESC_XLOCK(pdp); 3701 pwd = pwd_hold_pwddesc(pdp); 3702 MPASS(pwd != NULL); 3703 PWDDESC_XUNLOCK(pdp); 3704 return (pwd); 3705 } 3706 3707 struct pwd * 3708 pwd_hold_proc(struct proc *p) 3709 { 3710 struct pwddesc *pdp; 3711 struct pwd *pwd; 3712 3713 PROC_ASSERT_HELD(p); 3714 PROC_LOCK(p); 3715 pdp = pdhold(p); 3716 MPASS(pdp != NULL); 3717 PROC_UNLOCK(p); 3718 3719 PWDDESC_XLOCK(pdp); 3720 pwd = pwd_hold_pwddesc(pdp); 3721 MPASS(pwd != NULL); 3722 PWDDESC_XUNLOCK(pdp); 3723 pddrop(pdp); 3724 return (pwd); 3725 } 3726 3727 static struct pwd * 3728 pwd_alloc(void) 3729 { 3730 struct pwd *pwd; 3731 3732 pwd = uma_zalloc_smr(pwd_zone, M_WAITOK); 3733 bzero(pwd, sizeof(*pwd)); 3734 refcount_init(&pwd->pwd_refcount, 1); 3735 return (pwd); 3736 } 3737 3738 void 3739 pwd_drop(struct pwd *pwd) 3740 { 3741 3742 if (!refcount_release(&pwd->pwd_refcount)) 3743 return; 3744 3745 if (pwd->pwd_cdir != NULL) 3746 vrele(pwd->pwd_cdir); 3747 if (pwd->pwd_rdir != NULL) 3748 vrele(pwd->pwd_rdir); 3749 if (pwd->pwd_jdir != NULL) 3750 vrele(pwd->pwd_jdir); 3751 uma_zfree_smr(pwd_zone, pwd); 3752 } 3753 3754 /* 3755 * The caller is responsible for invoking priv_check() and 3756 * mac_vnode_check_chroot() to authorize this operation. 3757 */ 3758 int 3759 pwd_chroot(struct thread *td, struct vnode *vp) 3760 { 3761 struct pwddesc *pdp; 3762 struct filedesc *fdp; 3763 struct pwd *newpwd, *oldpwd; 3764 int error; 3765 3766 fdp = td->td_proc->p_fd; 3767 pdp = td->td_proc->p_pd; 3768 newpwd = pwd_alloc(); 3769 FILEDESC_SLOCK(fdp); 3770 PWDDESC_XLOCK(pdp); 3771 oldpwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); 3772 if (chroot_allow_open_directories == 0 || 3773 (chroot_allow_open_directories == 1 && 3774 oldpwd->pwd_rdir != rootvnode)) { 3775 error = chroot_refuse_vdir_fds(fdp); 3776 FILEDESC_SUNLOCK(fdp); 3777 if (error != 0) { 3778 PWDDESC_XUNLOCK(pdp); 3779 pwd_drop(newpwd); 3780 return (error); 3781 } 3782 } else { 3783 FILEDESC_SUNLOCK(fdp); 3784 } 3785 3786 vrefact(vp); 3787 newpwd->pwd_rdir = vp; 3788 if (oldpwd->pwd_jdir == NULL) { 3789 vrefact(vp); 3790 newpwd->pwd_jdir = vp; 3791 } 3792 pwd_fill(oldpwd, newpwd); 3793 pwd_set(pdp, newpwd); 3794 PWDDESC_XUNLOCK(pdp); 3795 pwd_drop(oldpwd); 3796 return (0); 3797 } 3798 3799 void 3800 pwd_chdir(struct thread *td, struct vnode *vp) 3801 { 3802 struct pwddesc *pdp; 3803 struct pwd *newpwd, *oldpwd; 3804 3805 VNPASS(vp->v_usecount > 0, vp); 3806 3807 newpwd = pwd_alloc(); 3808 pdp = td->td_proc->p_pd; 3809 PWDDESC_XLOCK(pdp); 3810 oldpwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); 3811 newpwd->pwd_cdir = vp; 3812 pwd_fill(oldpwd, newpwd); 3813 pwd_set(pdp, newpwd); 3814 PWDDESC_XUNLOCK(pdp); 3815 pwd_drop(oldpwd); 3816 } 3817 3818 /* 3819 * jail_attach(2) changes both root and working directories. 3820 */ 3821 int 3822 pwd_chroot_chdir(struct thread *td, struct vnode *vp) 3823 { 3824 struct pwddesc *pdp; 3825 struct filedesc *fdp; 3826 struct pwd *newpwd, *oldpwd; 3827 int error; 3828 3829 fdp = td->td_proc->p_fd; 3830 pdp = td->td_proc->p_pd; 3831 newpwd = pwd_alloc(); 3832 FILEDESC_SLOCK(fdp); 3833 PWDDESC_XLOCK(pdp); 3834 oldpwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); 3835 error = chroot_refuse_vdir_fds(fdp); 3836 FILEDESC_SUNLOCK(fdp); 3837 if (error != 0) { 3838 PWDDESC_XUNLOCK(pdp); 3839 pwd_drop(newpwd); 3840 return (error); 3841 } 3842 3843 vrefact(vp); 3844 newpwd->pwd_rdir = vp; 3845 vrefact(vp); 3846 newpwd->pwd_cdir = vp; 3847 if (oldpwd->pwd_jdir == NULL) { 3848 vrefact(vp); 3849 newpwd->pwd_jdir = vp; 3850 } 3851 pwd_fill(oldpwd, newpwd); 3852 pwd_set(pdp, newpwd); 3853 PWDDESC_XUNLOCK(pdp); 3854 pwd_drop(oldpwd); 3855 return (0); 3856 } 3857 3858 void 3859 pwd_ensure_dirs(void) 3860 { 3861 struct pwddesc *pdp; 3862 struct pwd *oldpwd, *newpwd; 3863 3864 pdp = curproc->p_pd; 3865 PWDDESC_XLOCK(pdp); 3866 oldpwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); 3867 if (oldpwd->pwd_cdir != NULL && oldpwd->pwd_rdir != NULL) { 3868 PWDDESC_XUNLOCK(pdp); 3869 return; 3870 } 3871 PWDDESC_XUNLOCK(pdp); 3872 3873 newpwd = pwd_alloc(); 3874 PWDDESC_XLOCK(pdp); 3875 oldpwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); 3876 pwd_fill(oldpwd, newpwd); 3877 if (newpwd->pwd_cdir == NULL) { 3878 vrefact(rootvnode); 3879 newpwd->pwd_cdir = rootvnode; 3880 } 3881 if (newpwd->pwd_rdir == NULL) { 3882 vrefact(rootvnode); 3883 newpwd->pwd_rdir = rootvnode; 3884 } 3885 pwd_set(pdp, newpwd); 3886 PWDDESC_XUNLOCK(pdp); 3887 pwd_drop(oldpwd); 3888 } 3889 3890 void 3891 pwd_set_rootvnode(void) 3892 { 3893 struct pwddesc *pdp; 3894 struct pwd *oldpwd, *newpwd; 3895 3896 pdp = curproc->p_pd; 3897 3898 newpwd = pwd_alloc(); 3899 PWDDESC_XLOCK(pdp); 3900 oldpwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); 3901 vrefact(rootvnode); 3902 newpwd->pwd_cdir = rootvnode; 3903 vrefact(rootvnode); 3904 newpwd->pwd_rdir = rootvnode; 3905 pwd_fill(oldpwd, newpwd); 3906 pwd_set(pdp, newpwd); 3907 PWDDESC_XUNLOCK(pdp); 3908 pwd_drop(oldpwd); 3909 } 3910 3911 /* 3912 * Scan all active processes and prisons to see if any of them have a current 3913 * or root directory of `olddp'. If so, replace them with the new mount point. 3914 */ 3915 void 3916 mountcheckdirs(struct vnode *olddp, struct vnode *newdp) 3917 { 3918 struct pwddesc *pdp; 3919 struct pwd *newpwd, *oldpwd; 3920 struct prison *pr; 3921 struct proc *p; 3922 int nrele; 3923 3924 if (vrefcnt(olddp) == 1) 3925 return; 3926 nrele = 0; 3927 newpwd = pwd_alloc(); 3928 sx_slock(&allproc_lock); 3929 FOREACH_PROC_IN_SYSTEM(p) { 3930 PROC_LOCK(p); 3931 pdp = pdhold(p); 3932 PROC_UNLOCK(p); 3933 if (pdp == NULL) 3934 continue; 3935 PWDDESC_XLOCK(pdp); 3936 oldpwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); 3937 if (oldpwd == NULL || 3938 (oldpwd->pwd_cdir != olddp && 3939 oldpwd->pwd_rdir != olddp && 3940 oldpwd->pwd_jdir != olddp)) { 3941 PWDDESC_XUNLOCK(pdp); 3942 pddrop(pdp); 3943 continue; 3944 } 3945 if (oldpwd->pwd_cdir == olddp) { 3946 vrefact(newdp); 3947 newpwd->pwd_cdir = newdp; 3948 } 3949 if (oldpwd->pwd_rdir == olddp) { 3950 vrefact(newdp); 3951 newpwd->pwd_rdir = newdp; 3952 } 3953 if (oldpwd->pwd_jdir == olddp) { 3954 vrefact(newdp); 3955 newpwd->pwd_jdir = newdp; 3956 } 3957 pwd_fill(oldpwd, newpwd); 3958 pwd_set(pdp, newpwd); 3959 PWDDESC_XUNLOCK(pdp); 3960 pwd_drop(oldpwd); 3961 pddrop(pdp); 3962 newpwd = pwd_alloc(); 3963 } 3964 sx_sunlock(&allproc_lock); 3965 pwd_drop(newpwd); 3966 if (rootvnode == olddp) { 3967 vrefact(newdp); 3968 rootvnode = newdp; 3969 nrele++; 3970 } 3971 mtx_lock(&prison0.pr_mtx); 3972 if (prison0.pr_root == olddp) { 3973 vrefact(newdp); 3974 prison0.pr_root = newdp; 3975 nrele++; 3976 } 3977 mtx_unlock(&prison0.pr_mtx); 3978 sx_slock(&allprison_lock); 3979 TAILQ_FOREACH(pr, &allprison, pr_list) { 3980 mtx_lock(&pr->pr_mtx); 3981 if (pr->pr_root == olddp) { 3982 vrefact(newdp); 3983 pr->pr_root = newdp; 3984 nrele++; 3985 } 3986 mtx_unlock(&pr->pr_mtx); 3987 } 3988 sx_sunlock(&allprison_lock); 3989 while (nrele--) 3990 vrele(olddp); 3991 } 3992 3993 struct filedesc_to_leader * 3994 filedesc_to_leader_alloc(struct filedesc_to_leader *old, struct filedesc *fdp, struct proc *leader) 3995 { 3996 struct filedesc_to_leader *fdtol; 3997 3998 fdtol = malloc(sizeof(struct filedesc_to_leader), 3999 M_FILEDESC_TO_LEADER, M_WAITOK); 4000 fdtol->fdl_refcount = 1; 4001 fdtol->fdl_holdcount = 0; 4002 fdtol->fdl_wakeup = 0; 4003 fdtol->fdl_leader = leader; 4004 if (old != NULL) { 4005 FILEDESC_XLOCK(fdp); 4006 fdtol->fdl_next = old->fdl_next; 4007 fdtol->fdl_prev = old; 4008 old->fdl_next = fdtol; 4009 fdtol->fdl_next->fdl_prev = fdtol; 4010 FILEDESC_XUNLOCK(fdp); 4011 } else { 4012 fdtol->fdl_next = fdtol; 4013 fdtol->fdl_prev = fdtol; 4014 } 4015 return (fdtol); 4016 } 4017 4018 static int 4019 sysctl_kern_proc_nfds(SYSCTL_HANDLER_ARGS) 4020 { 4021 NDSLOTTYPE *map; 4022 struct filedesc *fdp; 4023 u_int namelen; 4024 int count, off, minoff; 4025 4026 namelen = arg2; 4027 if (namelen != 1) 4028 return (EINVAL); 4029 4030 if (*(int *)arg1 != 0) 4031 return (EINVAL); 4032 4033 fdp = curproc->p_fd; 4034 count = 0; 4035 FILEDESC_SLOCK(fdp); 4036 map = fdp->fd_map; 4037 off = NDSLOT(fdp->fd_nfiles - 1); 4038 for (minoff = NDSLOT(0); off >= minoff; --off) 4039 count += bitcountl(map[off]); 4040 FILEDESC_SUNLOCK(fdp); 4041 4042 return (SYSCTL_OUT(req, &count, sizeof(count))); 4043 } 4044 4045 static SYSCTL_NODE(_kern_proc, KERN_PROC_NFDS, nfds, 4046 CTLFLAG_RD|CTLFLAG_CAPRD|CTLFLAG_MPSAFE, sysctl_kern_proc_nfds, 4047 "Number of open file descriptors"); 4048 4049 /* 4050 * Get file structures globally. 4051 */ 4052 static int 4053 sysctl_kern_file(SYSCTL_HANDLER_ARGS) 4054 { 4055 struct xfile xf; 4056 struct filedesc *fdp; 4057 struct file *fp; 4058 struct proc *p; 4059 int error, n, lastfile; 4060 4061 error = sysctl_wire_old_buffer(req, 0); 4062 if (error != 0) 4063 return (error); 4064 if (req->oldptr == NULL) { 4065 n = 0; 4066 sx_slock(&allproc_lock); 4067 FOREACH_PROC_IN_SYSTEM(p) { 4068 PROC_LOCK(p); 4069 if (p->p_state == PRS_NEW) { 4070 PROC_UNLOCK(p); 4071 continue; 4072 } 4073 fdp = fdhold(p); 4074 PROC_UNLOCK(p); 4075 if (fdp == NULL) 4076 continue; 4077 /* overestimates sparse tables. */ 4078 n += fdp->fd_nfiles; 4079 fddrop(fdp); 4080 } 4081 sx_sunlock(&allproc_lock); 4082 return (SYSCTL_OUT(req, 0, n * sizeof(xf))); 4083 } 4084 error = 0; 4085 bzero(&xf, sizeof(xf)); 4086 xf.xf_size = sizeof(xf); 4087 sx_slock(&allproc_lock); 4088 FOREACH_PROC_IN_SYSTEM(p) { 4089 PROC_LOCK(p); 4090 if (p->p_state == PRS_NEW) { 4091 PROC_UNLOCK(p); 4092 continue; 4093 } 4094 if (p_cansee(req->td, p) != 0) { 4095 PROC_UNLOCK(p); 4096 continue; 4097 } 4098 xf.xf_pid = p->p_pid; 4099 xf.xf_uid = p->p_ucred->cr_uid; 4100 fdp = fdhold(p); 4101 PROC_UNLOCK(p); 4102 if (fdp == NULL) 4103 continue; 4104 FILEDESC_SLOCK(fdp); 4105 lastfile = fdlastfile(fdp); 4106 for (n = 0; refcount_load(&fdp->fd_refcnt) > 0 && n <= lastfile; 4107 n++) { 4108 if ((fp = fdp->fd_ofiles[n].fde_file) == NULL) 4109 continue; 4110 xf.xf_fd = n; 4111 xf.xf_file = (uintptr_t)fp; 4112 xf.xf_data = (uintptr_t)fp->f_data; 4113 xf.xf_vnode = (uintptr_t)fp->f_vnode; 4114 xf.xf_type = (uintptr_t)fp->f_type; 4115 xf.xf_count = refcount_load(&fp->f_count); 4116 xf.xf_msgcount = 0; 4117 xf.xf_offset = foffset_get(fp); 4118 xf.xf_flag = fp->f_flag; 4119 error = SYSCTL_OUT(req, &xf, sizeof(xf)); 4120 if (error) 4121 break; 4122 } 4123 FILEDESC_SUNLOCK(fdp); 4124 fddrop(fdp); 4125 if (error) 4126 break; 4127 } 4128 sx_sunlock(&allproc_lock); 4129 return (error); 4130 } 4131 4132 SYSCTL_PROC(_kern, KERN_FILE, file, CTLTYPE_OPAQUE|CTLFLAG_RD|CTLFLAG_MPSAFE, 4133 0, 0, sysctl_kern_file, "S,xfile", "Entire file table"); 4134 4135 #ifdef KINFO_FILE_SIZE 4136 CTASSERT(sizeof(struct kinfo_file) == KINFO_FILE_SIZE); 4137 #endif 4138 4139 static int 4140 xlate_fflags(int fflags) 4141 { 4142 static const struct { 4143 int fflag; 4144 int kf_fflag; 4145 } fflags_table[] = { 4146 { FAPPEND, KF_FLAG_APPEND }, 4147 { FASYNC, KF_FLAG_ASYNC }, 4148 { FFSYNC, KF_FLAG_FSYNC }, 4149 { FHASLOCK, KF_FLAG_HASLOCK }, 4150 { FNONBLOCK, KF_FLAG_NONBLOCK }, 4151 { FREAD, KF_FLAG_READ }, 4152 { FWRITE, KF_FLAG_WRITE }, 4153 { O_CREAT, KF_FLAG_CREAT }, 4154 { O_DIRECT, KF_FLAG_DIRECT }, 4155 { O_EXCL, KF_FLAG_EXCL }, 4156 { O_EXEC, KF_FLAG_EXEC }, 4157 { O_EXLOCK, KF_FLAG_EXLOCK }, 4158 { O_NOFOLLOW, KF_FLAG_NOFOLLOW }, 4159 { O_SHLOCK, KF_FLAG_SHLOCK }, 4160 { O_TRUNC, KF_FLAG_TRUNC } 4161 }; 4162 unsigned int i; 4163 int kflags; 4164 4165 kflags = 0; 4166 for (i = 0; i < nitems(fflags_table); i++) 4167 if (fflags & fflags_table[i].fflag) 4168 kflags |= fflags_table[i].kf_fflag; 4169 return (kflags); 4170 } 4171 4172 /* Trim unused data from kf_path by truncating the structure size. */ 4173 void 4174 pack_kinfo(struct kinfo_file *kif) 4175 { 4176 4177 kif->kf_structsize = offsetof(struct kinfo_file, kf_path) + 4178 strlen(kif->kf_path) + 1; 4179 kif->kf_structsize = roundup(kif->kf_structsize, sizeof(uint64_t)); 4180 } 4181 4182 static void 4183 export_file_to_kinfo(struct file *fp, int fd, cap_rights_t *rightsp, 4184 struct kinfo_file *kif, struct filedesc *fdp, int flags) 4185 { 4186 int error; 4187 4188 bzero(kif, sizeof(*kif)); 4189 4190 /* Set a default type to allow for empty fill_kinfo() methods. */ 4191 kif->kf_type = KF_TYPE_UNKNOWN; 4192 kif->kf_flags = xlate_fflags(fp->f_flag); 4193 if (rightsp != NULL) 4194 kif->kf_cap_rights = *rightsp; 4195 else 4196 cap_rights_init_zero(&kif->kf_cap_rights); 4197 kif->kf_fd = fd; 4198 kif->kf_ref_count = refcount_load(&fp->f_count); 4199 kif->kf_offset = foffset_get(fp); 4200 4201 /* 4202 * This may drop the filedesc lock, so the 'fp' cannot be 4203 * accessed after this call. 4204 */ 4205 error = fo_fill_kinfo(fp, kif, fdp); 4206 if (error == 0) 4207 kif->kf_status |= KF_ATTR_VALID; 4208 if ((flags & KERN_FILEDESC_PACK_KINFO) != 0) 4209 pack_kinfo(kif); 4210 else 4211 kif->kf_structsize = roundup2(sizeof(*kif), sizeof(uint64_t)); 4212 } 4213 4214 static void 4215 export_vnode_to_kinfo(struct vnode *vp, int fd, int fflags, 4216 struct kinfo_file *kif, int flags) 4217 { 4218 int error; 4219 4220 bzero(kif, sizeof(*kif)); 4221 4222 kif->kf_type = KF_TYPE_VNODE; 4223 error = vn_fill_kinfo_vnode(vp, kif); 4224 if (error == 0) 4225 kif->kf_status |= KF_ATTR_VALID; 4226 kif->kf_flags = xlate_fflags(fflags); 4227 cap_rights_init_zero(&kif->kf_cap_rights); 4228 kif->kf_fd = fd; 4229 kif->kf_ref_count = -1; 4230 kif->kf_offset = -1; 4231 if ((flags & KERN_FILEDESC_PACK_KINFO) != 0) 4232 pack_kinfo(kif); 4233 else 4234 kif->kf_structsize = roundup2(sizeof(*kif), sizeof(uint64_t)); 4235 vrele(vp); 4236 } 4237 4238 struct export_fd_buf { 4239 struct filedesc *fdp; 4240 struct pwddesc *pdp; 4241 struct sbuf *sb; 4242 ssize_t remainder; 4243 struct kinfo_file kif; 4244 int flags; 4245 }; 4246 4247 static int 4248 export_kinfo_to_sb(struct export_fd_buf *efbuf) 4249 { 4250 struct kinfo_file *kif; 4251 4252 kif = &efbuf->kif; 4253 if (efbuf->remainder != -1) { 4254 if (efbuf->remainder < kif->kf_structsize) { 4255 /* Terminate export. */ 4256 efbuf->remainder = 0; 4257 return (0); 4258 } 4259 efbuf->remainder -= kif->kf_structsize; 4260 } 4261 return (sbuf_bcat(efbuf->sb, kif, kif->kf_structsize) == 0 ? 0 : ENOMEM); 4262 } 4263 4264 static int 4265 export_file_to_sb(struct file *fp, int fd, cap_rights_t *rightsp, 4266 struct export_fd_buf *efbuf) 4267 { 4268 int error; 4269 4270 if (efbuf->remainder == 0) 4271 return (0); 4272 export_file_to_kinfo(fp, fd, rightsp, &efbuf->kif, efbuf->fdp, 4273 efbuf->flags); 4274 FILEDESC_SUNLOCK(efbuf->fdp); 4275 error = export_kinfo_to_sb(efbuf); 4276 FILEDESC_SLOCK(efbuf->fdp); 4277 return (error); 4278 } 4279 4280 static int 4281 export_vnode_to_sb(struct vnode *vp, int fd, int fflags, 4282 struct export_fd_buf *efbuf) 4283 { 4284 int error; 4285 4286 if (efbuf->remainder == 0) 4287 return (0); 4288 if (efbuf->pdp != NULL) 4289 PWDDESC_XUNLOCK(efbuf->pdp); 4290 export_vnode_to_kinfo(vp, fd, fflags, &efbuf->kif, efbuf->flags); 4291 error = export_kinfo_to_sb(efbuf); 4292 if (efbuf->pdp != NULL) 4293 PWDDESC_XLOCK(efbuf->pdp); 4294 return (error); 4295 } 4296 4297 /* 4298 * Store a process file descriptor information to sbuf. 4299 * 4300 * Takes a locked proc as argument, and returns with the proc unlocked. 4301 */ 4302 int 4303 kern_proc_filedesc_out(struct proc *p, struct sbuf *sb, ssize_t maxlen, 4304 int flags) 4305 { 4306 struct file *fp; 4307 struct filedesc *fdp; 4308 struct pwddesc *pdp; 4309 struct export_fd_buf *efbuf; 4310 struct vnode *cttyvp, *textvp, *tracevp; 4311 struct pwd *pwd; 4312 int error, i, lastfile; 4313 cap_rights_t rights; 4314 4315 PROC_LOCK_ASSERT(p, MA_OWNED); 4316 4317 /* ktrace vnode */ 4318 tracevp = ktr_get_tracevp(p, true); 4319 /* text vnode */ 4320 textvp = p->p_textvp; 4321 if (textvp != NULL) 4322 vrefact(textvp); 4323 /* Controlling tty. */ 4324 cttyvp = NULL; 4325 if (p->p_pgrp != NULL && p->p_pgrp->pg_session != NULL) { 4326 cttyvp = p->p_pgrp->pg_session->s_ttyvp; 4327 if (cttyvp != NULL) 4328 vrefact(cttyvp); 4329 } 4330 fdp = fdhold(p); 4331 pdp = pdhold(p); 4332 PROC_UNLOCK(p); 4333 efbuf = malloc(sizeof(*efbuf), M_TEMP, M_WAITOK); 4334 efbuf->fdp = NULL; 4335 efbuf->pdp = NULL; 4336 efbuf->sb = sb; 4337 efbuf->remainder = maxlen; 4338 efbuf->flags = flags; 4339 if (tracevp != NULL) 4340 export_vnode_to_sb(tracevp, KF_FD_TYPE_TRACE, FREAD | FWRITE, 4341 efbuf); 4342 if (textvp != NULL) 4343 export_vnode_to_sb(textvp, KF_FD_TYPE_TEXT, FREAD, efbuf); 4344 if (cttyvp != NULL) 4345 export_vnode_to_sb(cttyvp, KF_FD_TYPE_CTTY, FREAD | FWRITE, 4346 efbuf); 4347 error = 0; 4348 if (pdp == NULL || fdp == NULL) 4349 goto fail; 4350 efbuf->fdp = fdp; 4351 efbuf->pdp = pdp; 4352 PWDDESC_XLOCK(pdp); 4353 pwd = pwd_hold_pwddesc(pdp); 4354 if (pwd != NULL) { 4355 /* working directory */ 4356 if (pwd->pwd_cdir != NULL) { 4357 vrefact(pwd->pwd_cdir); 4358 export_vnode_to_sb(pwd->pwd_cdir, KF_FD_TYPE_CWD, 4359 FREAD, efbuf); 4360 } 4361 /* root directory */ 4362 if (pwd->pwd_rdir != NULL) { 4363 vrefact(pwd->pwd_rdir); 4364 export_vnode_to_sb(pwd->pwd_rdir, KF_FD_TYPE_ROOT, 4365 FREAD, efbuf); 4366 } 4367 /* jail directory */ 4368 if (pwd->pwd_jdir != NULL) { 4369 vrefact(pwd->pwd_jdir); 4370 export_vnode_to_sb(pwd->pwd_jdir, KF_FD_TYPE_JAIL, 4371 FREAD, efbuf); 4372 } 4373 } 4374 PWDDESC_XUNLOCK(pdp); 4375 if (pwd != NULL) 4376 pwd_drop(pwd); 4377 FILEDESC_SLOCK(fdp); 4378 lastfile = fdlastfile(fdp); 4379 for (i = 0; refcount_load(&fdp->fd_refcnt) > 0 && i <= lastfile; i++) { 4380 if ((fp = fdp->fd_ofiles[i].fde_file) == NULL) 4381 continue; 4382 #ifdef CAPABILITIES 4383 rights = *cap_rights(fdp, i); 4384 #else /* !CAPABILITIES */ 4385 rights = cap_no_rights; 4386 #endif 4387 /* 4388 * Create sysctl entry. It is OK to drop the filedesc 4389 * lock inside of export_file_to_sb() as we will 4390 * re-validate and re-evaluate its properties when the 4391 * loop continues. 4392 */ 4393 error = export_file_to_sb(fp, i, &rights, efbuf); 4394 if (error != 0 || efbuf->remainder == 0) 4395 break; 4396 } 4397 FILEDESC_SUNLOCK(fdp); 4398 fail: 4399 if (fdp != NULL) 4400 fddrop(fdp); 4401 if (pdp != NULL) 4402 pddrop(pdp); 4403 free(efbuf, M_TEMP); 4404 return (error); 4405 } 4406 4407 #define FILEDESC_SBUF_SIZE (sizeof(struct kinfo_file) * 5) 4408 4409 /* 4410 * Get per-process file descriptors for use by procstat(1), et al. 4411 */ 4412 static int 4413 sysctl_kern_proc_filedesc(SYSCTL_HANDLER_ARGS) 4414 { 4415 struct sbuf sb; 4416 struct proc *p; 4417 ssize_t maxlen; 4418 u_int namelen; 4419 int error, error2, *name; 4420 4421 namelen = arg2; 4422 if (namelen != 1) 4423 return (EINVAL); 4424 4425 name = (int *)arg1; 4426 4427 sbuf_new_for_sysctl(&sb, NULL, FILEDESC_SBUF_SIZE, req); 4428 sbuf_clear_flags(&sb, SBUF_INCLUDENUL); 4429 error = pget((pid_t)name[0], PGET_CANDEBUG | PGET_NOTWEXIT, &p); 4430 if (error != 0) { 4431 sbuf_delete(&sb); 4432 return (error); 4433 } 4434 maxlen = req->oldptr != NULL ? req->oldlen : -1; 4435 error = kern_proc_filedesc_out(p, &sb, maxlen, 4436 KERN_FILEDESC_PACK_KINFO); 4437 error2 = sbuf_finish(&sb); 4438 sbuf_delete(&sb); 4439 return (error != 0 ? error : error2); 4440 } 4441 4442 #ifdef COMPAT_FREEBSD7 4443 #ifdef KINFO_OFILE_SIZE 4444 CTASSERT(sizeof(struct kinfo_ofile) == KINFO_OFILE_SIZE); 4445 #endif 4446 4447 static void 4448 kinfo_to_okinfo(struct kinfo_file *kif, struct kinfo_ofile *okif) 4449 { 4450 4451 okif->kf_structsize = sizeof(*okif); 4452 okif->kf_type = kif->kf_type; 4453 okif->kf_fd = kif->kf_fd; 4454 okif->kf_ref_count = kif->kf_ref_count; 4455 okif->kf_flags = kif->kf_flags & (KF_FLAG_READ | KF_FLAG_WRITE | 4456 KF_FLAG_APPEND | KF_FLAG_ASYNC | KF_FLAG_FSYNC | KF_FLAG_NONBLOCK | 4457 KF_FLAG_DIRECT | KF_FLAG_HASLOCK); 4458 okif->kf_offset = kif->kf_offset; 4459 if (kif->kf_type == KF_TYPE_VNODE) 4460 okif->kf_vnode_type = kif->kf_un.kf_file.kf_file_type; 4461 else 4462 okif->kf_vnode_type = KF_VTYPE_VNON; 4463 strlcpy(okif->kf_path, kif->kf_path, sizeof(okif->kf_path)); 4464 if (kif->kf_type == KF_TYPE_SOCKET) { 4465 okif->kf_sock_domain = kif->kf_un.kf_sock.kf_sock_domain0; 4466 okif->kf_sock_type = kif->kf_un.kf_sock.kf_sock_type0; 4467 okif->kf_sock_protocol = kif->kf_un.kf_sock.kf_sock_protocol0; 4468 okif->kf_sa_local = kif->kf_un.kf_sock.kf_sa_local; 4469 okif->kf_sa_peer = kif->kf_un.kf_sock.kf_sa_peer; 4470 } else { 4471 okif->kf_sa_local.ss_family = AF_UNSPEC; 4472 okif->kf_sa_peer.ss_family = AF_UNSPEC; 4473 } 4474 } 4475 4476 static int 4477 export_vnode_for_osysctl(struct vnode *vp, int type, struct kinfo_file *kif, 4478 struct kinfo_ofile *okif, struct pwddesc *pdp, struct sysctl_req *req) 4479 { 4480 int error; 4481 4482 vrefact(vp); 4483 PWDDESC_XUNLOCK(pdp); 4484 export_vnode_to_kinfo(vp, type, 0, kif, KERN_FILEDESC_PACK_KINFO); 4485 kinfo_to_okinfo(kif, okif); 4486 error = SYSCTL_OUT(req, okif, sizeof(*okif)); 4487 PWDDESC_XLOCK(pdp); 4488 return (error); 4489 } 4490 4491 /* 4492 * Get per-process file descriptors for use by procstat(1), et al. 4493 */ 4494 static int 4495 sysctl_kern_proc_ofiledesc(SYSCTL_HANDLER_ARGS) 4496 { 4497 struct kinfo_ofile *okif; 4498 struct kinfo_file *kif; 4499 struct filedesc *fdp; 4500 struct pwddesc *pdp; 4501 struct pwd *pwd; 4502 u_int namelen; 4503 int error, i, lastfile, *name; 4504 struct file *fp; 4505 struct proc *p; 4506 4507 namelen = arg2; 4508 if (namelen != 1) 4509 return (EINVAL); 4510 4511 name = (int *)arg1; 4512 error = pget((pid_t)name[0], PGET_CANDEBUG | PGET_NOTWEXIT, &p); 4513 if (error != 0) 4514 return (error); 4515 fdp = fdhold(p); 4516 if (fdp != NULL) 4517 pdp = pdhold(p); 4518 PROC_UNLOCK(p); 4519 if (fdp == NULL || pdp == NULL) { 4520 if (fdp != NULL) 4521 fddrop(fdp); 4522 return (ENOENT); 4523 } 4524 kif = malloc(sizeof(*kif), M_TEMP, M_WAITOK); 4525 okif = malloc(sizeof(*okif), M_TEMP, M_WAITOK); 4526 PWDDESC_XLOCK(pdp); 4527 pwd = pwd_hold_pwddesc(pdp); 4528 if (pwd != NULL) { 4529 if (pwd->pwd_cdir != NULL) 4530 export_vnode_for_osysctl(pwd->pwd_cdir, KF_FD_TYPE_CWD, kif, 4531 okif, pdp, req); 4532 if (pwd->pwd_rdir != NULL) 4533 export_vnode_for_osysctl(pwd->pwd_rdir, KF_FD_TYPE_ROOT, kif, 4534 okif, pdp, req); 4535 if (pwd->pwd_jdir != NULL) 4536 export_vnode_for_osysctl(pwd->pwd_jdir, KF_FD_TYPE_JAIL, kif, 4537 okif, pdp, req); 4538 } 4539 PWDDESC_XUNLOCK(pdp); 4540 if (pwd != NULL) 4541 pwd_drop(pwd); 4542 FILEDESC_SLOCK(fdp); 4543 lastfile = fdlastfile(fdp); 4544 for (i = 0; refcount_load(&fdp->fd_refcnt) > 0 && i <= lastfile; i++) { 4545 if ((fp = fdp->fd_ofiles[i].fde_file) == NULL) 4546 continue; 4547 export_file_to_kinfo(fp, i, NULL, kif, fdp, 4548 KERN_FILEDESC_PACK_KINFO); 4549 FILEDESC_SUNLOCK(fdp); 4550 kinfo_to_okinfo(kif, okif); 4551 error = SYSCTL_OUT(req, okif, sizeof(*okif)); 4552 FILEDESC_SLOCK(fdp); 4553 if (error) 4554 break; 4555 } 4556 FILEDESC_SUNLOCK(fdp); 4557 fddrop(fdp); 4558 pddrop(pdp); 4559 free(kif, M_TEMP); 4560 free(okif, M_TEMP); 4561 return (0); 4562 } 4563 4564 static SYSCTL_NODE(_kern_proc, KERN_PROC_OFILEDESC, ofiledesc, 4565 CTLFLAG_RD|CTLFLAG_MPSAFE, sysctl_kern_proc_ofiledesc, 4566 "Process ofiledesc entries"); 4567 #endif /* COMPAT_FREEBSD7 */ 4568 4569 int 4570 vntype_to_kinfo(int vtype) 4571 { 4572 struct { 4573 int vtype; 4574 int kf_vtype; 4575 } vtypes_table[] = { 4576 { VBAD, KF_VTYPE_VBAD }, 4577 { VBLK, KF_VTYPE_VBLK }, 4578 { VCHR, KF_VTYPE_VCHR }, 4579 { VDIR, KF_VTYPE_VDIR }, 4580 { VFIFO, KF_VTYPE_VFIFO }, 4581 { VLNK, KF_VTYPE_VLNK }, 4582 { VNON, KF_VTYPE_VNON }, 4583 { VREG, KF_VTYPE_VREG }, 4584 { VSOCK, KF_VTYPE_VSOCK } 4585 }; 4586 unsigned int i; 4587 4588 /* 4589 * Perform vtype translation. 4590 */ 4591 for (i = 0; i < nitems(vtypes_table); i++) 4592 if (vtypes_table[i].vtype == vtype) 4593 return (vtypes_table[i].kf_vtype); 4594 4595 return (KF_VTYPE_UNKNOWN); 4596 } 4597 4598 static SYSCTL_NODE(_kern_proc, KERN_PROC_FILEDESC, filedesc, 4599 CTLFLAG_RD|CTLFLAG_MPSAFE, sysctl_kern_proc_filedesc, 4600 "Process filedesc entries"); 4601 4602 /* 4603 * Store a process current working directory information to sbuf. 4604 * 4605 * Takes a locked proc as argument, and returns with the proc unlocked. 4606 */ 4607 int 4608 kern_proc_cwd_out(struct proc *p, struct sbuf *sb, ssize_t maxlen) 4609 { 4610 struct pwddesc *pdp; 4611 struct pwd *pwd; 4612 struct export_fd_buf *efbuf; 4613 struct vnode *cdir; 4614 int error; 4615 4616 PROC_LOCK_ASSERT(p, MA_OWNED); 4617 4618 pdp = pdhold(p); 4619 PROC_UNLOCK(p); 4620 if (pdp == NULL) 4621 return (EINVAL); 4622 4623 efbuf = malloc(sizeof(*efbuf), M_TEMP, M_WAITOK); 4624 efbuf->pdp = pdp; 4625 efbuf->sb = sb; 4626 efbuf->remainder = maxlen; 4627 4628 PWDDESC_XLOCK(pdp); 4629 pwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); 4630 cdir = pwd->pwd_cdir; 4631 if (cdir == NULL) { 4632 error = EINVAL; 4633 } else { 4634 vrefact(cdir); 4635 error = export_vnode_to_sb(cdir, KF_FD_TYPE_CWD, FREAD, efbuf); 4636 } 4637 PWDDESC_XUNLOCK(pdp); 4638 pddrop(pdp); 4639 free(efbuf, M_TEMP); 4640 return (error); 4641 } 4642 4643 /* 4644 * Get per-process current working directory. 4645 */ 4646 static int 4647 sysctl_kern_proc_cwd(SYSCTL_HANDLER_ARGS) 4648 { 4649 struct sbuf sb; 4650 struct proc *p; 4651 ssize_t maxlen; 4652 u_int namelen; 4653 int error, error2, *name; 4654 4655 namelen = arg2; 4656 if (namelen != 1) 4657 return (EINVAL); 4658 4659 name = (int *)arg1; 4660 4661 sbuf_new_for_sysctl(&sb, NULL, sizeof(struct kinfo_file), req); 4662 sbuf_clear_flags(&sb, SBUF_INCLUDENUL); 4663 error = pget((pid_t)name[0], PGET_CANDEBUG | PGET_NOTWEXIT, &p); 4664 if (error != 0) { 4665 sbuf_delete(&sb); 4666 return (error); 4667 } 4668 maxlen = req->oldptr != NULL ? req->oldlen : -1; 4669 error = kern_proc_cwd_out(p, &sb, maxlen); 4670 error2 = sbuf_finish(&sb); 4671 sbuf_delete(&sb); 4672 return (error != 0 ? error : error2); 4673 } 4674 4675 static SYSCTL_NODE(_kern_proc, KERN_PROC_CWD, cwd, CTLFLAG_RD|CTLFLAG_MPSAFE, 4676 sysctl_kern_proc_cwd, "Process current working directory"); 4677 4678 #ifdef DDB 4679 /* 4680 * For the purposes of debugging, generate a human-readable string for the 4681 * file type. 4682 */ 4683 static const char * 4684 file_type_to_name(short type) 4685 { 4686 4687 switch (type) { 4688 case 0: 4689 return ("zero"); 4690 case DTYPE_VNODE: 4691 return ("vnode"); 4692 case DTYPE_SOCKET: 4693 return ("socket"); 4694 case DTYPE_PIPE: 4695 return ("pipe"); 4696 case DTYPE_FIFO: 4697 return ("fifo"); 4698 case DTYPE_KQUEUE: 4699 return ("kqueue"); 4700 case DTYPE_CRYPTO: 4701 return ("crypto"); 4702 case DTYPE_MQUEUE: 4703 return ("mqueue"); 4704 case DTYPE_SHM: 4705 return ("shm"); 4706 case DTYPE_SEM: 4707 return ("ksem"); 4708 case DTYPE_PTS: 4709 return ("pts"); 4710 case DTYPE_DEV: 4711 return ("dev"); 4712 case DTYPE_PROCDESC: 4713 return ("proc"); 4714 case DTYPE_EVENTFD: 4715 return ("eventfd"); 4716 case DTYPE_LINUXTFD: 4717 return ("ltimer"); 4718 default: 4719 return ("unkn"); 4720 } 4721 } 4722 4723 /* 4724 * For the purposes of debugging, identify a process (if any, perhaps one of 4725 * many) that references the passed file in its file descriptor array. Return 4726 * NULL if none. 4727 */ 4728 static struct proc * 4729 file_to_first_proc(struct file *fp) 4730 { 4731 struct filedesc *fdp; 4732 struct proc *p; 4733 int n; 4734 4735 FOREACH_PROC_IN_SYSTEM(p) { 4736 if (p->p_state == PRS_NEW) 4737 continue; 4738 fdp = p->p_fd; 4739 if (fdp == NULL) 4740 continue; 4741 for (n = 0; n < fdp->fd_nfiles; n++) { 4742 if (fp == fdp->fd_ofiles[n].fde_file) 4743 return (p); 4744 } 4745 } 4746 return (NULL); 4747 } 4748 4749 static void 4750 db_print_file(struct file *fp, int header) 4751 { 4752 #define XPTRWIDTH ((int)howmany(sizeof(void *) * NBBY, 4)) 4753 struct proc *p; 4754 4755 if (header) 4756 db_printf("%*s %6s %*s %8s %4s %5s %6s %*s %5s %s\n", 4757 XPTRWIDTH, "File", "Type", XPTRWIDTH, "Data", "Flag", 4758 "GCFl", "Count", "MCount", XPTRWIDTH, "Vnode", "FPID", 4759 "FCmd"); 4760 p = file_to_first_proc(fp); 4761 db_printf("%*p %6s %*p %08x %04x %5d %6d %*p %5d %s\n", XPTRWIDTH, 4762 fp, file_type_to_name(fp->f_type), XPTRWIDTH, fp->f_data, 4763 fp->f_flag, 0, refcount_load(&fp->f_count), 0, XPTRWIDTH, fp->f_vnode, 4764 p != NULL ? p->p_pid : -1, p != NULL ? p->p_comm : "-"); 4765 4766 #undef XPTRWIDTH 4767 } 4768 4769 DB_SHOW_COMMAND(file, db_show_file) 4770 { 4771 struct file *fp; 4772 4773 if (!have_addr) { 4774 db_printf("usage: show file <addr>\n"); 4775 return; 4776 } 4777 fp = (struct file *)addr; 4778 db_print_file(fp, 1); 4779 } 4780 4781 DB_SHOW_COMMAND(files, db_show_files) 4782 { 4783 struct filedesc *fdp; 4784 struct file *fp; 4785 struct proc *p; 4786 int header; 4787 int n; 4788 4789 header = 1; 4790 FOREACH_PROC_IN_SYSTEM(p) { 4791 if (p->p_state == PRS_NEW) 4792 continue; 4793 if ((fdp = p->p_fd) == NULL) 4794 continue; 4795 for (n = 0; n < fdp->fd_nfiles; ++n) { 4796 if ((fp = fdp->fd_ofiles[n].fde_file) == NULL) 4797 continue; 4798 db_print_file(fp, header); 4799 header = 0; 4800 } 4801 } 4802 } 4803 #endif 4804 4805 SYSCTL_INT(_kern, KERN_MAXFILESPERPROC, maxfilesperproc, CTLFLAG_RW, 4806 &maxfilesperproc, 0, "Maximum files allowed open per process"); 4807 4808 SYSCTL_INT(_kern, KERN_MAXFILES, maxfiles, CTLFLAG_RW, 4809 &maxfiles, 0, "Maximum number of files"); 4810 4811 SYSCTL_INT(_kern, OID_AUTO, openfiles, CTLFLAG_RD, 4812 &openfiles, 0, "System-wide number of open files"); 4813 4814 /* ARGSUSED*/ 4815 static void 4816 filelistinit(void *dummy) 4817 { 4818 4819 file_zone = uma_zcreate("Files", sizeof(struct file), NULL, NULL, 4820 NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE); 4821 filedesc0_zone = uma_zcreate("filedesc0", sizeof(struct filedesc0), 4822 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0); 4823 pwd_zone = uma_zcreate("PWD", sizeof(struct pwd), NULL, NULL, 4824 NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_SMR); 4825 /* 4826 * XXXMJG this is a temporary hack due to boot ordering issues against 4827 * the vnode zone. 4828 */ 4829 vfs_smr = uma_zone_get_smr(pwd_zone); 4830 mtx_init(&sigio_lock, "sigio lock", NULL, MTX_DEF); 4831 } 4832 SYSINIT(select, SI_SUB_LOCK, SI_ORDER_FIRST, filelistinit, NULL); 4833 4834 /*-------------------------------------------------------------------*/ 4835 4836 static int 4837 badfo_readwrite(struct file *fp, struct uio *uio, struct ucred *active_cred, 4838 int flags, struct thread *td) 4839 { 4840 4841 return (EBADF); 4842 } 4843 4844 static int 4845 badfo_truncate(struct file *fp, off_t length, struct ucred *active_cred, 4846 struct thread *td) 4847 { 4848 4849 return (EINVAL); 4850 } 4851 4852 static int 4853 badfo_ioctl(struct file *fp, u_long com, void *data, struct ucred *active_cred, 4854 struct thread *td) 4855 { 4856 4857 return (EBADF); 4858 } 4859 4860 static int 4861 badfo_poll(struct file *fp, int events, struct ucred *active_cred, 4862 struct thread *td) 4863 { 4864 4865 return (0); 4866 } 4867 4868 static int 4869 badfo_kqfilter(struct file *fp, struct knote *kn) 4870 { 4871 4872 return (EBADF); 4873 } 4874 4875 static int 4876 badfo_stat(struct file *fp, struct stat *sb, struct ucred *active_cred) 4877 { 4878 4879 return (EBADF); 4880 } 4881 4882 static int 4883 badfo_close(struct file *fp, struct thread *td) 4884 { 4885 4886 return (0); 4887 } 4888 4889 static int 4890 badfo_chmod(struct file *fp, mode_t mode, struct ucred *active_cred, 4891 struct thread *td) 4892 { 4893 4894 return (EBADF); 4895 } 4896 4897 static int 4898 badfo_chown(struct file *fp, uid_t uid, gid_t gid, struct ucred *active_cred, 4899 struct thread *td) 4900 { 4901 4902 return (EBADF); 4903 } 4904 4905 static int 4906 badfo_sendfile(struct file *fp, int sockfd, struct uio *hdr_uio, 4907 struct uio *trl_uio, off_t offset, size_t nbytes, off_t *sent, int flags, 4908 struct thread *td) 4909 { 4910 4911 return (EBADF); 4912 } 4913 4914 static int 4915 badfo_fill_kinfo(struct file *fp, struct kinfo_file *kif, struct filedesc *fdp) 4916 { 4917 4918 return (0); 4919 } 4920 4921 struct fileops badfileops = { 4922 .fo_read = badfo_readwrite, 4923 .fo_write = badfo_readwrite, 4924 .fo_truncate = badfo_truncate, 4925 .fo_ioctl = badfo_ioctl, 4926 .fo_poll = badfo_poll, 4927 .fo_kqfilter = badfo_kqfilter, 4928 .fo_stat = badfo_stat, 4929 .fo_close = badfo_close, 4930 .fo_chmod = badfo_chmod, 4931 .fo_chown = badfo_chown, 4932 .fo_sendfile = badfo_sendfile, 4933 .fo_fill_kinfo = badfo_fill_kinfo, 4934 }; 4935 4936 static int 4937 path_poll(struct file *fp, int events, struct ucred *active_cred, 4938 struct thread *td) 4939 { 4940 return (POLLNVAL); 4941 } 4942 4943 static int 4944 path_close(struct file *fp, struct thread *td) 4945 { 4946 MPASS(fp->f_type == DTYPE_VNODE); 4947 fp->f_ops = &badfileops; 4948 vdrop(fp->f_vnode); 4949 return (0); 4950 } 4951 4952 struct fileops path_fileops = { 4953 .fo_read = badfo_readwrite, 4954 .fo_write = badfo_readwrite, 4955 .fo_truncate = badfo_truncate, 4956 .fo_ioctl = badfo_ioctl, 4957 .fo_poll = path_poll, 4958 .fo_kqfilter = vn_kqfilter_opath, 4959 .fo_stat = vn_statfile, 4960 .fo_close = path_close, 4961 .fo_chmod = badfo_chmod, 4962 .fo_chown = badfo_chown, 4963 .fo_sendfile = badfo_sendfile, 4964 .fo_fill_kinfo = vn_fill_kinfo, 4965 .fo_flags = DFLAG_PASSABLE, 4966 }; 4967 4968 int 4969 invfo_rdwr(struct file *fp, struct uio *uio, struct ucred *active_cred, 4970 int flags, struct thread *td) 4971 { 4972 4973 return (EOPNOTSUPP); 4974 } 4975 4976 int 4977 invfo_truncate(struct file *fp, off_t length, struct ucred *active_cred, 4978 struct thread *td) 4979 { 4980 4981 return (EINVAL); 4982 } 4983 4984 int 4985 invfo_ioctl(struct file *fp, u_long com, void *data, 4986 struct ucred *active_cred, struct thread *td) 4987 { 4988 4989 return (ENOTTY); 4990 } 4991 4992 int 4993 invfo_poll(struct file *fp, int events, struct ucred *active_cred, 4994 struct thread *td) 4995 { 4996 4997 return (poll_no_poll(events)); 4998 } 4999 5000 int 5001 invfo_kqfilter(struct file *fp, struct knote *kn) 5002 { 5003 5004 return (EINVAL); 5005 } 5006 5007 int 5008 invfo_chmod(struct file *fp, mode_t mode, struct ucred *active_cred, 5009 struct thread *td) 5010 { 5011 5012 return (EINVAL); 5013 } 5014 5015 int 5016 invfo_chown(struct file *fp, uid_t uid, gid_t gid, struct ucred *active_cred, 5017 struct thread *td) 5018 { 5019 5020 return (EINVAL); 5021 } 5022 5023 int 5024 invfo_sendfile(struct file *fp, int sockfd, struct uio *hdr_uio, 5025 struct uio *trl_uio, off_t offset, size_t nbytes, off_t *sent, int flags, 5026 struct thread *td) 5027 { 5028 5029 return (EINVAL); 5030 } 5031 5032 /*-------------------------------------------------------------------*/ 5033 5034 /* 5035 * File Descriptor pseudo-device driver (/dev/fd/). 5036 * 5037 * Opening minor device N dup()s the file (if any) connected to file 5038 * descriptor N belonging to the calling process. Note that this driver 5039 * consists of only the ``open()'' routine, because all subsequent 5040 * references to this file will be direct to the other driver. 5041 * 5042 * XXX: we could give this one a cloning event handler if necessary. 5043 */ 5044 5045 /* ARGSUSED */ 5046 static int 5047 fdopen(struct cdev *dev, int mode, int type, struct thread *td) 5048 { 5049 5050 /* 5051 * XXX Kludge: set curthread->td_dupfd to contain the value of the 5052 * the file descriptor being sought for duplication. The error 5053 * return ensures that the vnode for this device will be released 5054 * by vn_open. Open will detect this special error and take the 5055 * actions in dupfdopen below. Other callers of vn_open or VOP_OPEN 5056 * will simply report the error. 5057 */ 5058 td->td_dupfd = dev2unit(dev); 5059 return (ENODEV); 5060 } 5061 5062 static struct cdevsw fildesc_cdevsw = { 5063 .d_version = D_VERSION, 5064 .d_open = fdopen, 5065 .d_name = "FD", 5066 }; 5067 5068 static void 5069 fildesc_drvinit(void *unused) 5070 { 5071 struct cdev *dev; 5072 5073 dev = make_dev_credf(MAKEDEV_ETERNAL, &fildesc_cdevsw, 0, NULL, 5074 UID_ROOT, GID_WHEEL, 0666, "fd/0"); 5075 make_dev_alias(dev, "stdin"); 5076 dev = make_dev_credf(MAKEDEV_ETERNAL, &fildesc_cdevsw, 1, NULL, 5077 UID_ROOT, GID_WHEEL, 0666, "fd/1"); 5078 make_dev_alias(dev, "stdout"); 5079 dev = make_dev_credf(MAKEDEV_ETERNAL, &fildesc_cdevsw, 2, NULL, 5080 UID_ROOT, GID_WHEEL, 0666, "fd/2"); 5081 make_dev_alias(dev, "stderr"); 5082 } 5083 5084 SYSINIT(fildescdev, SI_SUB_DRIVERS, SI_ORDER_MIDDLE, fildesc_drvinit, NULL); 5085