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 freebsd11_cvtnstat(&ub, &nub); 1566 error = copyout(&nub, uap->sb, sizeof(nub)); 1567 } 1568 return (error); 1569 } 1570 #endif /* COMPAT_FREEBSD11 */ 1571 1572 /* 1573 * Return pathconf information about a file descriptor. 1574 */ 1575 #ifndef _SYS_SYSPROTO_H_ 1576 struct fpathconf_args { 1577 int fd; 1578 int name; 1579 }; 1580 #endif 1581 /* ARGSUSED */ 1582 int 1583 sys_fpathconf(struct thread *td, struct fpathconf_args *uap) 1584 { 1585 long value; 1586 int error; 1587 1588 error = kern_fpathconf(td, uap->fd, uap->name, &value); 1589 if (error == 0) 1590 td->td_retval[0] = value; 1591 return (error); 1592 } 1593 1594 int 1595 kern_fpathconf(struct thread *td, int fd, int name, long *valuep) 1596 { 1597 struct file *fp; 1598 struct vnode *vp; 1599 int error; 1600 1601 error = fget(td, fd, &cap_fpathconf_rights, &fp); 1602 if (error != 0) 1603 return (error); 1604 1605 if (name == _PC_ASYNC_IO) { 1606 *valuep = _POSIX_ASYNCHRONOUS_IO; 1607 goto out; 1608 } 1609 vp = fp->f_vnode; 1610 if (vp != NULL) { 1611 vn_lock(vp, LK_SHARED | LK_RETRY); 1612 error = VOP_PATHCONF(vp, name, valuep); 1613 VOP_UNLOCK(vp); 1614 } else if (fp->f_type == DTYPE_PIPE || fp->f_type == DTYPE_SOCKET) { 1615 if (name != _PC_PIPE_BUF) { 1616 error = EINVAL; 1617 } else { 1618 *valuep = PIPE_BUF; 1619 error = 0; 1620 } 1621 } else { 1622 error = EOPNOTSUPP; 1623 } 1624 out: 1625 fdrop(fp, td); 1626 return (error); 1627 } 1628 1629 /* 1630 * Copy filecaps structure allocating memory for ioctls array if needed. 1631 * 1632 * The last parameter indicates whether the fdtable is locked. If it is not and 1633 * ioctls are encountered, copying fails and the caller must lock the table. 1634 * 1635 * Note that if the table was not locked, the caller has to check the relevant 1636 * sequence counter to determine whether the operation was successful. 1637 */ 1638 bool 1639 filecaps_copy(const struct filecaps *src, struct filecaps *dst, bool locked) 1640 { 1641 size_t size; 1642 1643 if (src->fc_ioctls != NULL && !locked) 1644 return (false); 1645 memcpy(dst, src, sizeof(*src)); 1646 if (src->fc_ioctls == NULL) 1647 return (true); 1648 1649 KASSERT(src->fc_nioctls > 0, 1650 ("fc_ioctls != NULL, but fc_nioctls=%hd", src->fc_nioctls)); 1651 1652 size = sizeof(src->fc_ioctls[0]) * src->fc_nioctls; 1653 dst->fc_ioctls = malloc(size, M_FILECAPS, M_WAITOK); 1654 memcpy(dst->fc_ioctls, src->fc_ioctls, size); 1655 return (true); 1656 } 1657 1658 static u_long * 1659 filecaps_copy_prep(const struct filecaps *src) 1660 { 1661 u_long *ioctls; 1662 size_t size; 1663 1664 if (__predict_true(src->fc_ioctls == NULL)) 1665 return (NULL); 1666 1667 KASSERT(src->fc_nioctls > 0, 1668 ("fc_ioctls != NULL, but fc_nioctls=%hd", src->fc_nioctls)); 1669 1670 size = sizeof(src->fc_ioctls[0]) * src->fc_nioctls; 1671 ioctls = malloc(size, M_FILECAPS, M_WAITOK); 1672 return (ioctls); 1673 } 1674 1675 static void 1676 filecaps_copy_finish(const struct filecaps *src, struct filecaps *dst, 1677 u_long *ioctls) 1678 { 1679 size_t size; 1680 1681 *dst = *src; 1682 if (__predict_true(src->fc_ioctls == NULL)) { 1683 MPASS(ioctls == NULL); 1684 return; 1685 } 1686 1687 size = sizeof(src->fc_ioctls[0]) * src->fc_nioctls; 1688 dst->fc_ioctls = ioctls; 1689 bcopy(src->fc_ioctls, dst->fc_ioctls, size); 1690 } 1691 1692 /* 1693 * Move filecaps structure to the new place and clear the old place. 1694 */ 1695 void 1696 filecaps_move(struct filecaps *src, struct filecaps *dst) 1697 { 1698 1699 *dst = *src; 1700 bzero(src, sizeof(*src)); 1701 } 1702 1703 /* 1704 * Fill the given filecaps structure with full rights. 1705 */ 1706 static void 1707 filecaps_fill(struct filecaps *fcaps) 1708 { 1709 1710 CAP_ALL(&fcaps->fc_rights); 1711 fcaps->fc_ioctls = NULL; 1712 fcaps->fc_nioctls = -1; 1713 fcaps->fc_fcntls = CAP_FCNTL_ALL; 1714 } 1715 1716 /* 1717 * Free memory allocated within filecaps structure. 1718 */ 1719 void 1720 filecaps_free(struct filecaps *fcaps) 1721 { 1722 1723 free(fcaps->fc_ioctls, M_FILECAPS); 1724 bzero(fcaps, sizeof(*fcaps)); 1725 } 1726 1727 static u_long * 1728 filecaps_free_prep(struct filecaps *fcaps) 1729 { 1730 u_long *ioctls; 1731 1732 ioctls = fcaps->fc_ioctls; 1733 bzero(fcaps, sizeof(*fcaps)); 1734 return (ioctls); 1735 } 1736 1737 static void 1738 filecaps_free_finish(u_long *ioctls) 1739 { 1740 1741 free(ioctls, M_FILECAPS); 1742 } 1743 1744 /* 1745 * Validate the given filecaps structure. 1746 */ 1747 static void 1748 filecaps_validate(const struct filecaps *fcaps, const char *func) 1749 { 1750 1751 KASSERT(cap_rights_is_valid(&fcaps->fc_rights), 1752 ("%s: invalid rights", func)); 1753 KASSERT((fcaps->fc_fcntls & ~CAP_FCNTL_ALL) == 0, 1754 ("%s: invalid fcntls", func)); 1755 KASSERT(fcaps->fc_fcntls == 0 || 1756 cap_rights_is_set(&fcaps->fc_rights, CAP_FCNTL), 1757 ("%s: fcntls without CAP_FCNTL", func)); 1758 KASSERT(fcaps->fc_ioctls != NULL ? fcaps->fc_nioctls > 0 : 1759 (fcaps->fc_nioctls == -1 || fcaps->fc_nioctls == 0), 1760 ("%s: invalid ioctls", func)); 1761 KASSERT(fcaps->fc_nioctls == 0 || 1762 cap_rights_is_set(&fcaps->fc_rights, CAP_IOCTL), 1763 ("%s: ioctls without CAP_IOCTL", func)); 1764 } 1765 1766 static void 1767 fdgrowtable_exp(struct filedesc *fdp, int nfd) 1768 { 1769 int nfd1; 1770 1771 FILEDESC_XLOCK_ASSERT(fdp); 1772 1773 nfd1 = fdp->fd_nfiles * 2; 1774 if (nfd1 < nfd) 1775 nfd1 = nfd; 1776 fdgrowtable(fdp, nfd1); 1777 } 1778 1779 /* 1780 * Grow the file table to accommodate (at least) nfd descriptors. 1781 */ 1782 static void 1783 fdgrowtable(struct filedesc *fdp, int nfd) 1784 { 1785 struct filedesc0 *fdp0; 1786 struct freetable *ft; 1787 struct fdescenttbl *ntable; 1788 struct fdescenttbl *otable; 1789 int nnfiles, onfiles; 1790 NDSLOTTYPE *nmap, *omap; 1791 1792 KASSERT(fdp->fd_nfiles > 0, ("zero-length file table")); 1793 1794 /* save old values */ 1795 onfiles = fdp->fd_nfiles; 1796 otable = fdp->fd_files; 1797 omap = fdp->fd_map; 1798 1799 /* compute the size of the new table */ 1800 nnfiles = NDSLOTS(nfd) * NDENTRIES; /* round up */ 1801 if (nnfiles <= onfiles) 1802 /* the table is already large enough */ 1803 return; 1804 1805 /* 1806 * Allocate a new table. We need enough space for the number of 1807 * entries, file entries themselves and the struct freetable we will use 1808 * when we decommission the table and place it on the freelist. 1809 * We place the struct freetable in the middle so we don't have 1810 * to worry about padding. 1811 */ 1812 ntable = malloc(offsetof(struct fdescenttbl, fdt_ofiles) + 1813 nnfiles * sizeof(ntable->fdt_ofiles[0]) + 1814 sizeof(struct freetable), 1815 M_FILEDESC, M_ZERO | M_WAITOK); 1816 /* copy the old data */ 1817 ntable->fdt_nfiles = nnfiles; 1818 memcpy(ntable->fdt_ofiles, otable->fdt_ofiles, 1819 onfiles * sizeof(ntable->fdt_ofiles[0])); 1820 1821 /* 1822 * Allocate a new map only if the old is not large enough. It will 1823 * grow at a slower rate than the table as it can map more 1824 * entries than the table can hold. 1825 */ 1826 if (NDSLOTS(nnfiles) > NDSLOTS(onfiles)) { 1827 nmap = malloc(NDSLOTS(nnfiles) * NDSLOTSIZE, M_FILEDESC, 1828 M_ZERO | M_WAITOK); 1829 /* copy over the old data and update the pointer */ 1830 memcpy(nmap, omap, NDSLOTS(onfiles) * sizeof(*omap)); 1831 fdp->fd_map = nmap; 1832 } 1833 1834 /* 1835 * Make sure that ntable is correctly initialized before we replace 1836 * fd_files poiner. Otherwise fget_unlocked() may see inconsistent 1837 * data. 1838 */ 1839 atomic_store_rel_ptr((volatile void *)&fdp->fd_files, (uintptr_t)ntable); 1840 1841 /* 1842 * Free the old file table when not shared by other threads or processes. 1843 * The old file table is considered to be shared when either are true: 1844 * - The process has more than one thread. 1845 * - The file descriptor table has been shared via fdshare(). 1846 * 1847 * When shared, the old file table will be placed on a freelist 1848 * which will be processed when the struct filedesc is released. 1849 * 1850 * Note that if onfiles == NDFILE, we're dealing with the original 1851 * static allocation contained within (struct filedesc0 *)fdp, 1852 * which must not be freed. 1853 */ 1854 if (onfiles > NDFILE) { 1855 /* 1856 * Note we may be called here from fdinit while allocating a 1857 * table for a new process in which case ->p_fd points 1858 * elsewhere. 1859 */ 1860 if (curproc->p_fd != fdp || FILEDESC_IS_ONLY_USER(fdp)) { 1861 free(otable, M_FILEDESC); 1862 } else { 1863 ft = (struct freetable *)&otable->fdt_ofiles[onfiles]; 1864 fdp0 = (struct filedesc0 *)fdp; 1865 ft->ft_table = otable; 1866 SLIST_INSERT_HEAD(&fdp0->fd_free, ft, ft_next); 1867 } 1868 } 1869 /* 1870 * The map does not have the same possibility of threads still 1871 * holding references to it. So always free it as long as it 1872 * does not reference the original static allocation. 1873 */ 1874 if (NDSLOTS(onfiles) > NDSLOTS(NDFILE)) 1875 free(omap, M_FILEDESC); 1876 } 1877 1878 /* 1879 * Allocate a file descriptor for the process. 1880 */ 1881 int 1882 fdalloc(struct thread *td, int minfd, int *result) 1883 { 1884 struct proc *p = td->td_proc; 1885 struct filedesc *fdp = p->p_fd; 1886 int fd, maxfd, allocfd; 1887 #ifdef RACCT 1888 int error; 1889 #endif 1890 1891 FILEDESC_XLOCK_ASSERT(fdp); 1892 1893 if (fdp->fd_freefile > minfd) 1894 minfd = fdp->fd_freefile; 1895 1896 maxfd = getmaxfd(td); 1897 1898 /* 1899 * Search the bitmap for a free descriptor starting at minfd. 1900 * If none is found, grow the file table. 1901 */ 1902 fd = fd_first_free(fdp, minfd, fdp->fd_nfiles); 1903 if (__predict_false(fd >= maxfd)) 1904 return (EMFILE); 1905 if (__predict_false(fd >= fdp->fd_nfiles)) { 1906 allocfd = min(fd * 2, maxfd); 1907 #ifdef RACCT 1908 if (RACCT_ENABLED()) { 1909 error = racct_set_unlocked(p, RACCT_NOFILE, allocfd); 1910 if (error != 0) 1911 return (EMFILE); 1912 } 1913 #endif 1914 /* 1915 * fd is already equal to first free descriptor >= minfd, so 1916 * we only need to grow the table and we are done. 1917 */ 1918 fdgrowtable_exp(fdp, allocfd); 1919 } 1920 1921 /* 1922 * Perform some sanity checks, then mark the file descriptor as 1923 * used and return it to the caller. 1924 */ 1925 KASSERT(fd >= 0 && fd < min(maxfd, fdp->fd_nfiles), 1926 ("invalid descriptor %d", fd)); 1927 KASSERT(!fdisused(fdp, fd), 1928 ("fd_first_free() returned non-free descriptor")); 1929 KASSERT(fdp->fd_ofiles[fd].fde_file == NULL, 1930 ("file descriptor isn't free")); 1931 fdused(fdp, fd); 1932 *result = fd; 1933 return (0); 1934 } 1935 1936 /* 1937 * Allocate n file descriptors for the process. 1938 */ 1939 int 1940 fdallocn(struct thread *td, int minfd, int *fds, int n) 1941 { 1942 struct proc *p = td->td_proc; 1943 struct filedesc *fdp = p->p_fd; 1944 int i; 1945 1946 FILEDESC_XLOCK_ASSERT(fdp); 1947 1948 for (i = 0; i < n; i++) 1949 if (fdalloc(td, 0, &fds[i]) != 0) 1950 break; 1951 1952 if (i < n) { 1953 for (i--; i >= 0; i--) 1954 fdunused(fdp, fds[i]); 1955 return (EMFILE); 1956 } 1957 1958 return (0); 1959 } 1960 1961 /* 1962 * Create a new open file structure and allocate a file descriptor for the 1963 * process that refers to it. We add one reference to the file for the 1964 * descriptor table and one reference for resultfp. This is to prevent us 1965 * being preempted and the entry in the descriptor table closed after we 1966 * release the FILEDESC lock. 1967 */ 1968 int 1969 falloc_caps(struct thread *td, struct file **resultfp, int *resultfd, int flags, 1970 struct filecaps *fcaps) 1971 { 1972 struct file *fp; 1973 int error, fd; 1974 1975 MPASS(resultfp != NULL); 1976 MPASS(resultfd != NULL); 1977 1978 error = _falloc_noinstall(td, &fp, 2); 1979 if (__predict_false(error != 0)) { 1980 return (error); 1981 } 1982 1983 error = finstall_refed(td, fp, &fd, flags, fcaps); 1984 if (__predict_false(error != 0)) { 1985 falloc_abort(td, fp); 1986 return (error); 1987 } 1988 1989 *resultfp = fp; 1990 *resultfd = fd; 1991 1992 return (0); 1993 } 1994 1995 /* 1996 * Create a new open file structure without allocating a file descriptor. 1997 */ 1998 int 1999 _falloc_noinstall(struct thread *td, struct file **resultfp, u_int n) 2000 { 2001 struct file *fp; 2002 int maxuserfiles = maxfiles - (maxfiles / 20); 2003 int openfiles_new; 2004 static struct timeval lastfail; 2005 static int curfail; 2006 2007 KASSERT(resultfp != NULL, ("%s: resultfp == NULL", __func__)); 2008 MPASS(n > 0); 2009 2010 openfiles_new = atomic_fetchadd_int(&openfiles, 1) + 1; 2011 if ((openfiles_new >= maxuserfiles && 2012 priv_check(td, PRIV_MAXFILES) != 0) || 2013 openfiles_new >= maxfiles) { 2014 atomic_subtract_int(&openfiles, 1); 2015 if (ppsratecheck(&lastfail, &curfail, 1)) { 2016 printf("kern.maxfiles limit exceeded by uid %i, (%s) " 2017 "please see tuning(7).\n", td->td_ucred->cr_ruid, td->td_proc->p_comm); 2018 } 2019 return (ENFILE); 2020 } 2021 fp = uma_zalloc(file_zone, M_WAITOK); 2022 bzero(fp, sizeof(*fp)); 2023 refcount_init(&fp->f_count, n); 2024 fp->f_cred = crhold(td->td_ucred); 2025 fp->f_ops = &badfileops; 2026 *resultfp = fp; 2027 return (0); 2028 } 2029 2030 void 2031 falloc_abort(struct thread *td, struct file *fp) 2032 { 2033 2034 /* 2035 * For assertion purposes. 2036 */ 2037 refcount_init(&fp->f_count, 0); 2038 _fdrop(fp, td); 2039 } 2040 2041 /* 2042 * Install a file in a file descriptor table. 2043 */ 2044 void 2045 _finstall(struct filedesc *fdp, struct file *fp, int fd, int flags, 2046 struct filecaps *fcaps) 2047 { 2048 struct filedescent *fde; 2049 2050 MPASS(fp != NULL); 2051 if (fcaps != NULL) 2052 filecaps_validate(fcaps, __func__); 2053 FILEDESC_XLOCK_ASSERT(fdp); 2054 2055 fde = &fdp->fd_ofiles[fd]; 2056 #ifdef CAPABILITIES 2057 seqc_write_begin(&fde->fde_seqc); 2058 #endif 2059 fde->fde_file = fp; 2060 fde->fde_flags = (flags & O_CLOEXEC) != 0 ? UF_EXCLOSE : 0; 2061 if (fcaps != NULL) 2062 filecaps_move(fcaps, &fde->fde_caps); 2063 else 2064 filecaps_fill(&fde->fde_caps); 2065 #ifdef CAPABILITIES 2066 seqc_write_end(&fde->fde_seqc); 2067 #endif 2068 } 2069 2070 int 2071 finstall_refed(struct thread *td, struct file *fp, int *fd, int flags, 2072 struct filecaps *fcaps) 2073 { 2074 struct filedesc *fdp = td->td_proc->p_fd; 2075 int error; 2076 2077 MPASS(fd != NULL); 2078 2079 FILEDESC_XLOCK(fdp); 2080 error = fdalloc(td, 0, fd); 2081 if (__predict_true(error == 0)) { 2082 _finstall(fdp, fp, *fd, flags, fcaps); 2083 } 2084 FILEDESC_XUNLOCK(fdp); 2085 return (error); 2086 } 2087 2088 int 2089 finstall(struct thread *td, struct file *fp, int *fd, int flags, 2090 struct filecaps *fcaps) 2091 { 2092 int error; 2093 2094 MPASS(fd != NULL); 2095 2096 if (!fhold(fp)) 2097 return (EBADF); 2098 error = finstall_refed(td, fp, fd, flags, fcaps); 2099 if (__predict_false(error != 0)) { 2100 fdrop(fp, td); 2101 } 2102 return (error); 2103 } 2104 2105 /* 2106 * Build a new filedesc structure from another. 2107 * 2108 * If fdp is not NULL, return with it shared locked. 2109 */ 2110 struct filedesc * 2111 fdinit(struct filedesc *fdp, bool prepfiles, int *lastfile) 2112 { 2113 struct filedesc0 *newfdp0; 2114 struct filedesc *newfdp; 2115 2116 if (prepfiles) 2117 MPASS(lastfile != NULL); 2118 else 2119 MPASS(lastfile == NULL); 2120 2121 newfdp0 = uma_zalloc(filedesc0_zone, M_WAITOK | M_ZERO); 2122 newfdp = &newfdp0->fd_fd; 2123 2124 /* Create the file descriptor table. */ 2125 FILEDESC_LOCK_INIT(newfdp); 2126 refcount_init(&newfdp->fd_refcnt, 1); 2127 refcount_init(&newfdp->fd_holdcnt, 1); 2128 newfdp->fd_map = newfdp0->fd_dmap; 2129 newfdp->fd_files = (struct fdescenttbl *)&newfdp0->fd_dfiles; 2130 newfdp->fd_files->fdt_nfiles = NDFILE; 2131 2132 if (fdp == NULL) 2133 return (newfdp); 2134 2135 FILEDESC_SLOCK(fdp); 2136 if (!prepfiles) { 2137 FILEDESC_SUNLOCK(fdp); 2138 return (newfdp); 2139 } 2140 2141 for (;;) { 2142 *lastfile = fdlastfile(fdp); 2143 if (*lastfile < newfdp->fd_nfiles) 2144 break; 2145 FILEDESC_SUNLOCK(fdp); 2146 fdgrowtable(newfdp, *lastfile + 1); 2147 FILEDESC_SLOCK(fdp); 2148 } 2149 2150 return (newfdp); 2151 } 2152 2153 /* 2154 * Build a pwddesc structure from another. 2155 * Copy the current, root, and jail root vnode references. 2156 * 2157 * If pdp is not NULL, return with it shared locked. 2158 */ 2159 struct pwddesc * 2160 pdinit(struct pwddesc *pdp, bool keeplock) 2161 { 2162 struct pwddesc *newpdp; 2163 struct pwd *newpwd; 2164 2165 newpdp = malloc(sizeof(*newpdp), M_PWDDESC, M_WAITOK | M_ZERO); 2166 2167 PWDDESC_LOCK_INIT(newpdp); 2168 refcount_init(&newpdp->pd_refcount, 1); 2169 newpdp->pd_cmask = CMASK; 2170 2171 if (pdp == NULL) { 2172 newpwd = pwd_alloc(); 2173 smr_serialized_store(&newpdp->pd_pwd, newpwd, true); 2174 return (newpdp); 2175 } 2176 2177 PWDDESC_XLOCK(pdp); 2178 newpwd = pwd_hold_pwddesc(pdp); 2179 smr_serialized_store(&newpdp->pd_pwd, newpwd, true); 2180 if (!keeplock) 2181 PWDDESC_XUNLOCK(pdp); 2182 return (newpdp); 2183 } 2184 2185 /* 2186 * Hold either filedesc or pwddesc of the passed process. 2187 * 2188 * The process lock is used to synchronize against the target exiting and 2189 * freeing the data. 2190 * 2191 * Clearing can be ilustrated in 3 steps: 2192 * 1. set the pointer to NULL. Either routine can race against it, hence 2193 * atomic_load_ptr. 2194 * 2. observe the process lock as not taken. Until then fdhold/pdhold can 2195 * race to either still see the pointer or find NULL. It is still safe to 2196 * grab a reference as clearing is stalled. 2197 * 3. after the lock is observed as not taken, any fdhold/pdhold calls are 2198 * guaranteed to see NULL, making it safe to finish clearing 2199 */ 2200 static struct filedesc * 2201 fdhold(struct proc *p) 2202 { 2203 struct filedesc *fdp; 2204 2205 PROC_LOCK_ASSERT(p, MA_OWNED); 2206 fdp = atomic_load_ptr(&p->p_fd); 2207 if (fdp != NULL) 2208 refcount_acquire(&fdp->fd_holdcnt); 2209 return (fdp); 2210 } 2211 2212 static struct pwddesc * 2213 pdhold(struct proc *p) 2214 { 2215 struct pwddesc *pdp; 2216 2217 PROC_LOCK_ASSERT(p, MA_OWNED); 2218 pdp = atomic_load_ptr(&p->p_pd); 2219 if (pdp != NULL) 2220 refcount_acquire(&pdp->pd_refcount); 2221 return (pdp); 2222 } 2223 2224 static void 2225 fddrop(struct filedesc *fdp) 2226 { 2227 2228 if (refcount_load(&fdp->fd_holdcnt) > 1) { 2229 if (refcount_release(&fdp->fd_holdcnt) == 0) 2230 return; 2231 } 2232 2233 FILEDESC_LOCK_DESTROY(fdp); 2234 uma_zfree(filedesc0_zone, fdp); 2235 } 2236 2237 static void 2238 pddrop(struct pwddesc *pdp) 2239 { 2240 struct pwd *pwd; 2241 2242 if (refcount_release_if_not_last(&pdp->pd_refcount)) 2243 return; 2244 2245 PWDDESC_XLOCK(pdp); 2246 if (refcount_release(&pdp->pd_refcount) == 0) { 2247 PWDDESC_XUNLOCK(pdp); 2248 return; 2249 } 2250 pwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); 2251 pwd_set(pdp, NULL); 2252 PWDDESC_XUNLOCK(pdp); 2253 pwd_drop(pwd); 2254 2255 PWDDESC_LOCK_DESTROY(pdp); 2256 free(pdp, M_PWDDESC); 2257 } 2258 2259 /* 2260 * Share a filedesc structure. 2261 */ 2262 struct filedesc * 2263 fdshare(struct filedesc *fdp) 2264 { 2265 2266 refcount_acquire(&fdp->fd_refcnt); 2267 return (fdp); 2268 } 2269 2270 /* 2271 * Share a pwddesc structure. 2272 */ 2273 struct pwddesc * 2274 pdshare(struct pwddesc *pdp) 2275 { 2276 refcount_acquire(&pdp->pd_refcount); 2277 return (pdp); 2278 } 2279 2280 /* 2281 * Unshare a filedesc structure, if necessary by making a copy 2282 */ 2283 void 2284 fdunshare(struct thread *td) 2285 { 2286 struct filedesc *tmp; 2287 struct proc *p = td->td_proc; 2288 2289 if (refcount_load(&p->p_fd->fd_refcnt) == 1) 2290 return; 2291 2292 tmp = fdcopy(p->p_fd); 2293 fdescfree(td); 2294 p->p_fd = tmp; 2295 } 2296 2297 /* 2298 * Unshare a pwddesc structure. 2299 */ 2300 void 2301 pdunshare(struct thread *td) 2302 { 2303 struct pwddesc *pdp; 2304 struct proc *p; 2305 2306 p = td->td_proc; 2307 /* Not shared. */ 2308 if (p->p_pd->pd_refcount == 1) 2309 return; 2310 2311 pdp = pdcopy(p->p_pd); 2312 pdescfree(td); 2313 p->p_pd = pdp; 2314 } 2315 2316 /* 2317 * Copy a filedesc structure. A NULL pointer in returns a NULL reference, 2318 * this is to ease callers, not catch errors. 2319 */ 2320 struct filedesc * 2321 fdcopy(struct filedesc *fdp) 2322 { 2323 struct filedesc *newfdp; 2324 struct filedescent *nfde, *ofde; 2325 int i, lastfile; 2326 2327 MPASS(fdp != NULL); 2328 2329 newfdp = fdinit(fdp, true, &lastfile); 2330 /* copy all passable descriptors (i.e. not kqueue) */ 2331 newfdp->fd_freefile = -1; 2332 for (i = 0; i <= lastfile; ++i) { 2333 ofde = &fdp->fd_ofiles[i]; 2334 if (ofde->fde_file == NULL || 2335 (ofde->fde_file->f_ops->fo_flags & DFLAG_PASSABLE) == 0 || 2336 !fhold(ofde->fde_file)) { 2337 if (newfdp->fd_freefile == -1) 2338 newfdp->fd_freefile = i; 2339 continue; 2340 } 2341 nfde = &newfdp->fd_ofiles[i]; 2342 *nfde = *ofde; 2343 filecaps_copy(&ofde->fde_caps, &nfde->fde_caps, true); 2344 fdused_init(newfdp, i); 2345 } 2346 if (newfdp->fd_freefile == -1) 2347 newfdp->fd_freefile = i; 2348 FILEDESC_SUNLOCK(fdp); 2349 return (newfdp); 2350 } 2351 2352 /* 2353 * Copy a pwddesc structure. 2354 */ 2355 struct pwddesc * 2356 pdcopy(struct pwddesc *pdp) 2357 { 2358 struct pwddesc *newpdp; 2359 2360 MPASS(pdp != NULL); 2361 2362 newpdp = pdinit(pdp, true); 2363 newpdp->pd_cmask = pdp->pd_cmask; 2364 PWDDESC_XUNLOCK(pdp); 2365 return (newpdp); 2366 } 2367 2368 /* 2369 * Clear POSIX style locks. This is only used when fdp looses a reference (i.e. 2370 * one of processes using it exits) and the table used to be shared. 2371 */ 2372 static void 2373 fdclearlocks(struct thread *td) 2374 { 2375 struct filedesc *fdp; 2376 struct filedesc_to_leader *fdtol; 2377 struct flock lf; 2378 struct file *fp; 2379 struct proc *p; 2380 struct vnode *vp; 2381 int i, lastfile; 2382 2383 p = td->td_proc; 2384 fdp = p->p_fd; 2385 fdtol = p->p_fdtol; 2386 MPASS(fdtol != NULL); 2387 2388 FILEDESC_XLOCK(fdp); 2389 KASSERT(fdtol->fdl_refcount > 0, 2390 ("filedesc_to_refcount botch: fdl_refcount=%d", 2391 fdtol->fdl_refcount)); 2392 if (fdtol->fdl_refcount == 1 && 2393 (p->p_leader->p_flag & P_ADVLOCK) != 0) { 2394 lastfile = fdlastfile(fdp); 2395 for (i = 0; i <= lastfile; i++) { 2396 fp = fdp->fd_ofiles[i].fde_file; 2397 if (fp == NULL || fp->f_type != DTYPE_VNODE || 2398 !fhold(fp)) 2399 continue; 2400 FILEDESC_XUNLOCK(fdp); 2401 lf.l_whence = SEEK_SET; 2402 lf.l_start = 0; 2403 lf.l_len = 0; 2404 lf.l_type = F_UNLCK; 2405 vp = fp->f_vnode; 2406 (void) VOP_ADVLOCK(vp, 2407 (caddr_t)p->p_leader, F_UNLCK, 2408 &lf, F_POSIX); 2409 FILEDESC_XLOCK(fdp); 2410 fdrop(fp, td); 2411 } 2412 } 2413 retry: 2414 if (fdtol->fdl_refcount == 1) { 2415 if (fdp->fd_holdleaderscount > 0 && 2416 (p->p_leader->p_flag & P_ADVLOCK) != 0) { 2417 /* 2418 * close() or kern_dup() has cleared a reference 2419 * in a shared file descriptor table. 2420 */ 2421 fdp->fd_holdleaderswakeup = 1; 2422 sx_sleep(&fdp->fd_holdleaderscount, 2423 FILEDESC_LOCK(fdp), PLOCK, "fdlhold", 0); 2424 goto retry; 2425 } 2426 if (fdtol->fdl_holdcount > 0) { 2427 /* 2428 * Ensure that fdtol->fdl_leader remains 2429 * valid in closef(). 2430 */ 2431 fdtol->fdl_wakeup = 1; 2432 sx_sleep(fdtol, FILEDESC_LOCK(fdp), PLOCK, 2433 "fdlhold", 0); 2434 goto retry; 2435 } 2436 } 2437 fdtol->fdl_refcount--; 2438 if (fdtol->fdl_refcount == 0 && 2439 fdtol->fdl_holdcount == 0) { 2440 fdtol->fdl_next->fdl_prev = fdtol->fdl_prev; 2441 fdtol->fdl_prev->fdl_next = fdtol->fdl_next; 2442 } else 2443 fdtol = NULL; 2444 p->p_fdtol = NULL; 2445 FILEDESC_XUNLOCK(fdp); 2446 if (fdtol != NULL) 2447 free(fdtol, M_FILEDESC_TO_LEADER); 2448 } 2449 2450 /* 2451 * Release a filedesc structure. 2452 */ 2453 static void 2454 fdescfree_fds(struct thread *td, struct filedesc *fdp) 2455 { 2456 struct filedesc0 *fdp0; 2457 struct freetable *ft, *tft; 2458 struct filedescent *fde; 2459 struct file *fp; 2460 int i, lastfile; 2461 2462 KASSERT(refcount_load(&fdp->fd_refcnt) == 0, 2463 ("%s: fd table %p carries references", __func__, fdp)); 2464 2465 /* 2466 * Serialize with threads iterating over the table, if any. 2467 */ 2468 if (refcount_load(&fdp->fd_holdcnt) > 1) { 2469 FILEDESC_XLOCK(fdp); 2470 FILEDESC_XUNLOCK(fdp); 2471 } 2472 2473 lastfile = fdlastfile_single(fdp); 2474 for (i = 0; i <= lastfile; i++) { 2475 fde = &fdp->fd_ofiles[i]; 2476 fp = fde->fde_file; 2477 if (fp != NULL) { 2478 fdefree_last(fde); 2479 (void) closef(fp, td); 2480 } 2481 } 2482 2483 if (NDSLOTS(fdp->fd_nfiles) > NDSLOTS(NDFILE)) 2484 free(fdp->fd_map, M_FILEDESC); 2485 if (fdp->fd_nfiles > NDFILE) 2486 free(fdp->fd_files, M_FILEDESC); 2487 2488 fdp0 = (struct filedesc0 *)fdp; 2489 SLIST_FOREACH_SAFE(ft, &fdp0->fd_free, ft_next, tft) 2490 free(ft->ft_table, M_FILEDESC); 2491 2492 fddrop(fdp); 2493 } 2494 2495 void 2496 fdescfree(struct thread *td) 2497 { 2498 struct proc *p; 2499 struct filedesc *fdp; 2500 2501 p = td->td_proc; 2502 fdp = p->p_fd; 2503 MPASS(fdp != NULL); 2504 2505 #ifdef RACCT 2506 if (RACCT_ENABLED()) 2507 racct_set_unlocked(p, RACCT_NOFILE, 0); 2508 #endif 2509 2510 if (p->p_fdtol != NULL) 2511 fdclearlocks(td); 2512 2513 /* 2514 * Check fdhold for an explanation. 2515 */ 2516 atomic_store_ptr(&p->p_fd, NULL); 2517 atomic_thread_fence_seq_cst(); 2518 PROC_WAIT_UNLOCKED(p); 2519 2520 if (refcount_release(&fdp->fd_refcnt) == 0) 2521 return; 2522 2523 fdescfree_fds(td, fdp); 2524 } 2525 2526 void 2527 pdescfree(struct thread *td) 2528 { 2529 struct proc *p; 2530 struct pwddesc *pdp; 2531 2532 p = td->td_proc; 2533 pdp = p->p_pd; 2534 MPASS(pdp != NULL); 2535 2536 /* 2537 * Check pdhold for an explanation. 2538 */ 2539 atomic_store_ptr(&p->p_pd, NULL); 2540 atomic_thread_fence_seq_cst(); 2541 PROC_WAIT_UNLOCKED(p); 2542 2543 pddrop(pdp); 2544 } 2545 2546 /* 2547 * For setugid programs, we don't want to people to use that setugidness 2548 * to generate error messages which write to a file which otherwise would 2549 * otherwise be off-limits to the process. We check for filesystems where 2550 * the vnode can change out from under us after execve (like [lin]procfs). 2551 * 2552 * Since fdsetugidsafety calls this only for fd 0, 1 and 2, this check is 2553 * sufficient. We also don't check for setugidness since we know we are. 2554 */ 2555 static bool 2556 is_unsafe(struct file *fp) 2557 { 2558 struct vnode *vp; 2559 2560 if (fp->f_type != DTYPE_VNODE) 2561 return (false); 2562 2563 vp = fp->f_vnode; 2564 return ((vp->v_vflag & VV_PROCDEP) != 0); 2565 } 2566 2567 /* 2568 * Make this setguid thing safe, if at all possible. 2569 */ 2570 void 2571 fdsetugidsafety(struct thread *td) 2572 { 2573 struct filedesc *fdp; 2574 struct file *fp; 2575 int i; 2576 2577 fdp = td->td_proc->p_fd; 2578 KASSERT(refcount_load(&fdp->fd_refcnt) == 1, 2579 ("the fdtable should not be shared")); 2580 MPASS(fdp->fd_nfiles >= 3); 2581 for (i = 0; i <= 2; i++) { 2582 fp = fdp->fd_ofiles[i].fde_file; 2583 if (fp != NULL && is_unsafe(fp)) { 2584 FILEDESC_XLOCK(fdp); 2585 knote_fdclose(td, i); 2586 /* 2587 * NULL-out descriptor prior to close to avoid 2588 * a race while close blocks. 2589 */ 2590 fdfree(fdp, i); 2591 FILEDESC_XUNLOCK(fdp); 2592 (void) closef(fp, td); 2593 } 2594 } 2595 } 2596 2597 /* 2598 * If a specific file object occupies a specific file descriptor, close the 2599 * file descriptor entry and drop a reference on the file object. This is a 2600 * convenience function to handle a subsequent error in a function that calls 2601 * falloc() that handles the race that another thread might have closed the 2602 * file descriptor out from under the thread creating the file object. 2603 */ 2604 void 2605 fdclose(struct thread *td, struct file *fp, int idx) 2606 { 2607 struct filedesc *fdp = td->td_proc->p_fd; 2608 2609 FILEDESC_XLOCK(fdp); 2610 if (fdp->fd_ofiles[idx].fde_file == fp) { 2611 fdfree(fdp, idx); 2612 FILEDESC_XUNLOCK(fdp); 2613 fdrop(fp, td); 2614 } else 2615 FILEDESC_XUNLOCK(fdp); 2616 } 2617 2618 /* 2619 * Close any files on exec? 2620 */ 2621 void 2622 fdcloseexec(struct thread *td) 2623 { 2624 struct filedesc *fdp; 2625 struct filedescent *fde; 2626 struct file *fp; 2627 int i, lastfile; 2628 2629 fdp = td->td_proc->p_fd; 2630 KASSERT(refcount_load(&fdp->fd_refcnt) == 1, 2631 ("the fdtable should not be shared")); 2632 lastfile = fdlastfile_single(fdp); 2633 for (i = 0; i <= lastfile; i++) { 2634 fde = &fdp->fd_ofiles[i]; 2635 fp = fde->fde_file; 2636 if (fp != NULL && (fp->f_type == DTYPE_MQUEUE || 2637 (fde->fde_flags & UF_EXCLOSE))) { 2638 FILEDESC_XLOCK(fdp); 2639 fdfree(fdp, i); 2640 (void) closefp(fdp, i, fp, td, false, false); 2641 FILEDESC_UNLOCK_ASSERT(fdp); 2642 } 2643 } 2644 } 2645 2646 /* 2647 * It is unsafe for set[ug]id processes to be started with file 2648 * descriptors 0..2 closed, as these descriptors are given implicit 2649 * significance in the Standard C library. fdcheckstd() will create a 2650 * descriptor referencing /dev/null for each of stdin, stdout, and 2651 * stderr that is not already open. 2652 */ 2653 int 2654 fdcheckstd(struct thread *td) 2655 { 2656 struct filedesc *fdp; 2657 register_t save; 2658 int i, error, devnull; 2659 2660 fdp = td->td_proc->p_fd; 2661 KASSERT(refcount_load(&fdp->fd_refcnt) == 1, 2662 ("the fdtable should not be shared")); 2663 MPASS(fdp->fd_nfiles >= 3); 2664 devnull = -1; 2665 for (i = 0; i <= 2; i++) { 2666 if (fdp->fd_ofiles[i].fde_file != NULL) 2667 continue; 2668 2669 save = td->td_retval[0]; 2670 if (devnull != -1) { 2671 error = kern_dup(td, FDDUP_FIXED, 0, devnull, i); 2672 } else { 2673 error = kern_openat(td, AT_FDCWD, "/dev/null", 2674 UIO_SYSSPACE, O_RDWR, 0); 2675 if (error == 0) { 2676 devnull = td->td_retval[0]; 2677 KASSERT(devnull == i, ("we didn't get our fd")); 2678 } 2679 } 2680 td->td_retval[0] = save; 2681 if (error != 0) 2682 return (error); 2683 } 2684 return (0); 2685 } 2686 2687 /* 2688 * Internal form of close. Decrement reference count on file structure. 2689 * Note: td may be NULL when closing a file that was being passed in a 2690 * message. 2691 */ 2692 int 2693 closef(struct file *fp, struct thread *td) 2694 { 2695 struct vnode *vp; 2696 struct flock lf; 2697 struct filedesc_to_leader *fdtol; 2698 struct filedesc *fdp; 2699 2700 MPASS(td != NULL); 2701 2702 /* 2703 * POSIX record locking dictates that any close releases ALL 2704 * locks owned by this process. This is handled by setting 2705 * a flag in the unlock to free ONLY locks obeying POSIX 2706 * semantics, and not to free BSD-style file locks. 2707 * If the descriptor was in a message, POSIX-style locks 2708 * aren't passed with the descriptor, and the thread pointer 2709 * will be NULL. Callers should be careful only to pass a 2710 * NULL thread pointer when there really is no owning 2711 * context that might have locks, or the locks will be 2712 * leaked. 2713 */ 2714 if (fp->f_type == DTYPE_VNODE) { 2715 vp = fp->f_vnode; 2716 if ((td->td_proc->p_leader->p_flag & P_ADVLOCK) != 0) { 2717 lf.l_whence = SEEK_SET; 2718 lf.l_start = 0; 2719 lf.l_len = 0; 2720 lf.l_type = F_UNLCK; 2721 (void) VOP_ADVLOCK(vp, (caddr_t)td->td_proc->p_leader, 2722 F_UNLCK, &lf, F_POSIX); 2723 } 2724 fdtol = td->td_proc->p_fdtol; 2725 if (fdtol != NULL) { 2726 /* 2727 * Handle special case where file descriptor table is 2728 * shared between multiple process leaders. 2729 */ 2730 fdp = td->td_proc->p_fd; 2731 FILEDESC_XLOCK(fdp); 2732 for (fdtol = fdtol->fdl_next; 2733 fdtol != td->td_proc->p_fdtol; 2734 fdtol = fdtol->fdl_next) { 2735 if ((fdtol->fdl_leader->p_flag & 2736 P_ADVLOCK) == 0) 2737 continue; 2738 fdtol->fdl_holdcount++; 2739 FILEDESC_XUNLOCK(fdp); 2740 lf.l_whence = SEEK_SET; 2741 lf.l_start = 0; 2742 lf.l_len = 0; 2743 lf.l_type = F_UNLCK; 2744 vp = fp->f_vnode; 2745 (void) VOP_ADVLOCK(vp, 2746 (caddr_t)fdtol->fdl_leader, F_UNLCK, &lf, 2747 F_POSIX); 2748 FILEDESC_XLOCK(fdp); 2749 fdtol->fdl_holdcount--; 2750 if (fdtol->fdl_holdcount == 0 && 2751 fdtol->fdl_wakeup != 0) { 2752 fdtol->fdl_wakeup = 0; 2753 wakeup(fdtol); 2754 } 2755 } 2756 FILEDESC_XUNLOCK(fdp); 2757 } 2758 } 2759 return (fdrop_close(fp, td)); 2760 } 2761 2762 /* 2763 * Hack for file descriptor passing code. 2764 */ 2765 void 2766 closef_nothread(struct file *fp) 2767 { 2768 2769 fdrop(fp, NULL); 2770 } 2771 2772 /* 2773 * Initialize the file pointer with the specified properties. 2774 * 2775 * The ops are set with release semantics to be certain that the flags, type, 2776 * and data are visible when ops is. This is to prevent ops methods from being 2777 * called with bad data. 2778 */ 2779 void 2780 finit(struct file *fp, u_int flag, short type, void *data, struct fileops *ops) 2781 { 2782 fp->f_data = data; 2783 fp->f_flag = flag; 2784 fp->f_type = type; 2785 atomic_store_rel_ptr((volatile uintptr_t *)&fp->f_ops, (uintptr_t)ops); 2786 } 2787 2788 void 2789 finit_vnode(struct file *fp, u_int flag, void *data, struct fileops *ops) 2790 { 2791 fp->f_seqcount[UIO_READ] = 1; 2792 fp->f_seqcount[UIO_WRITE] = 1; 2793 finit(fp, (flag & FMASK) | (fp->f_flag & FHASLOCK), DTYPE_VNODE, 2794 data, ops); 2795 } 2796 2797 int 2798 fget_cap_locked(struct filedesc *fdp, int fd, cap_rights_t *needrightsp, 2799 struct file **fpp, struct filecaps *havecapsp) 2800 { 2801 struct filedescent *fde; 2802 int error; 2803 2804 FILEDESC_LOCK_ASSERT(fdp); 2805 2806 fde = fdeget_locked(fdp, fd); 2807 if (fde == NULL) { 2808 error = EBADF; 2809 goto out; 2810 } 2811 2812 #ifdef CAPABILITIES 2813 error = cap_check(cap_rights_fde_inline(fde), needrightsp); 2814 if (error != 0) 2815 goto out; 2816 #endif 2817 2818 if (havecapsp != NULL) 2819 filecaps_copy(&fde->fde_caps, havecapsp, true); 2820 2821 *fpp = fde->fde_file; 2822 2823 error = 0; 2824 out: 2825 return (error); 2826 } 2827 2828 int 2829 fget_cap(struct thread *td, int fd, cap_rights_t *needrightsp, 2830 struct file **fpp, struct filecaps *havecapsp) 2831 { 2832 struct filedesc *fdp = td->td_proc->p_fd; 2833 int error; 2834 #ifndef CAPABILITIES 2835 error = fget_unlocked(fdp, fd, needrightsp, fpp); 2836 if (havecapsp != NULL && error == 0) 2837 filecaps_fill(havecapsp); 2838 #else 2839 struct file *fp; 2840 seqc_t seq; 2841 2842 *fpp = NULL; 2843 for (;;) { 2844 error = fget_unlocked_seq(fdp, fd, needrightsp, &fp, &seq); 2845 if (error != 0) 2846 return (error); 2847 2848 if (havecapsp != NULL) { 2849 if (!filecaps_copy(&fdp->fd_ofiles[fd].fde_caps, 2850 havecapsp, false)) { 2851 fdrop(fp, td); 2852 goto get_locked; 2853 } 2854 } 2855 2856 if (!fd_modified(fdp, fd, seq)) 2857 break; 2858 fdrop(fp, td); 2859 } 2860 2861 *fpp = fp; 2862 return (0); 2863 2864 get_locked: 2865 FILEDESC_SLOCK(fdp); 2866 error = fget_cap_locked(fdp, fd, needrightsp, fpp, havecapsp); 2867 if (error == 0 && !fhold(*fpp)) 2868 error = EBADF; 2869 FILEDESC_SUNLOCK(fdp); 2870 #endif 2871 return (error); 2872 } 2873 2874 #ifdef CAPABILITIES 2875 int 2876 fgetvp_lookup_smr(int fd, struct nameidata *ndp, struct vnode **vpp, bool *fsearch) 2877 { 2878 const struct filedescent *fde; 2879 const struct fdescenttbl *fdt; 2880 struct filedesc *fdp; 2881 struct file *fp; 2882 struct vnode *vp; 2883 const cap_rights_t *haverights; 2884 cap_rights_t rights; 2885 seqc_t seq; 2886 2887 VFS_SMR_ASSERT_ENTERED(); 2888 2889 rights = *ndp->ni_rightsneeded; 2890 cap_rights_set_one(&rights, CAP_LOOKUP); 2891 2892 fdp = curproc->p_fd; 2893 fdt = fdp->fd_files; 2894 if (__predict_false((u_int)fd >= fdt->fdt_nfiles)) 2895 return (EBADF); 2896 seq = seqc_read_notmodify(fd_seqc(fdt, fd)); 2897 fde = &fdt->fdt_ofiles[fd]; 2898 haverights = cap_rights_fde_inline(fde); 2899 fp = fde->fde_file; 2900 if (__predict_false(fp == NULL)) 2901 return (EAGAIN); 2902 if (__predict_false(cap_check_inline_transient(haverights, &rights))) 2903 return (EAGAIN); 2904 *fsearch = ((fp->f_flag & FSEARCH) != 0); 2905 vp = fp->f_vnode; 2906 if (__predict_false(vp == NULL || vp->v_type != VDIR)) { 2907 return (EAGAIN); 2908 } 2909 if (!filecaps_copy(&fde->fde_caps, &ndp->ni_filecaps, false)) { 2910 return (EAGAIN); 2911 } 2912 /* 2913 * Use an acquire barrier to force re-reading of fdt so it is 2914 * refreshed for verification. 2915 */ 2916 atomic_thread_fence_acq(); 2917 fdt = fdp->fd_files; 2918 if (__predict_false(!seqc_consistent_nomb(fd_seqc(fdt, fd), seq))) 2919 return (EAGAIN); 2920 /* 2921 * If file descriptor doesn't have all rights, 2922 * all lookups relative to it must also be 2923 * strictly relative. 2924 * 2925 * Not yet supported by fast path. 2926 */ 2927 CAP_ALL(&rights); 2928 if (!cap_rights_contains(&ndp->ni_filecaps.fc_rights, &rights) || 2929 ndp->ni_filecaps.fc_fcntls != CAP_FCNTL_ALL || 2930 ndp->ni_filecaps.fc_nioctls != -1) { 2931 #ifdef notyet 2932 ndp->ni_lcf |= NI_LCF_STRICTRELATIVE; 2933 #else 2934 return (EAGAIN); 2935 #endif 2936 } 2937 *vpp = vp; 2938 return (0); 2939 } 2940 #else 2941 int 2942 fgetvp_lookup_smr(int fd, struct nameidata *ndp, struct vnode **vpp, bool *fsearch) 2943 { 2944 const struct fdescenttbl *fdt; 2945 struct filedesc *fdp; 2946 struct file *fp; 2947 struct vnode *vp; 2948 2949 VFS_SMR_ASSERT_ENTERED(); 2950 2951 fdp = curproc->p_fd; 2952 fdt = fdp->fd_files; 2953 if (__predict_false((u_int)fd >= fdt->fdt_nfiles)) 2954 return (EBADF); 2955 fp = fdt->fdt_ofiles[fd].fde_file; 2956 if (__predict_false(fp == NULL)) 2957 return (EAGAIN); 2958 *fsearch = ((fp->f_flag & FSEARCH) != 0); 2959 vp = fp->f_vnode; 2960 if (__predict_false(vp == NULL || vp->v_type != VDIR)) { 2961 return (EAGAIN); 2962 } 2963 /* 2964 * Use an acquire barrier to force re-reading of fdt so it is 2965 * refreshed for verification. 2966 */ 2967 atomic_thread_fence_acq(); 2968 fdt = fdp->fd_files; 2969 if (__predict_false(fp != fdt->fdt_ofiles[fd].fde_file)) 2970 return (EAGAIN); 2971 filecaps_fill(&ndp->ni_filecaps); 2972 *vpp = vp; 2973 return (0); 2974 } 2975 #endif 2976 2977 int 2978 fget_unlocked_seq(struct filedesc *fdp, int fd, cap_rights_t *needrightsp, 2979 struct file **fpp, seqc_t *seqp) 2980 { 2981 #ifdef CAPABILITIES 2982 const struct filedescent *fde; 2983 #endif 2984 const struct fdescenttbl *fdt; 2985 struct file *fp; 2986 #ifdef CAPABILITIES 2987 seqc_t seq; 2988 cap_rights_t haverights; 2989 int error; 2990 #endif 2991 2992 fdt = fdp->fd_files; 2993 if (__predict_false((u_int)fd >= fdt->fdt_nfiles)) 2994 return (EBADF); 2995 /* 2996 * Fetch the descriptor locklessly. We avoid fdrop() races by 2997 * never raising a refcount above 0. To accomplish this we have 2998 * to use a cmpset loop rather than an atomic_add. The descriptor 2999 * must be re-verified once we acquire a reference to be certain 3000 * that the identity is still correct and we did not lose a race 3001 * due to preemption. 3002 */ 3003 for (;;) { 3004 #ifdef CAPABILITIES 3005 seq = seqc_read_notmodify(fd_seqc(fdt, fd)); 3006 fde = &fdt->fdt_ofiles[fd]; 3007 haverights = *cap_rights_fde_inline(fde); 3008 fp = fde->fde_file; 3009 if (!seqc_consistent(fd_seqc(fdt, fd), seq)) 3010 continue; 3011 #else 3012 fp = fdt->fdt_ofiles[fd].fde_file; 3013 #endif 3014 if (fp == NULL) 3015 return (EBADF); 3016 #ifdef CAPABILITIES 3017 error = cap_check_inline(&haverights, needrightsp); 3018 if (error != 0) 3019 return (error); 3020 #endif 3021 if (__predict_false(!refcount_acquire_if_not_zero(&fp->f_count))) { 3022 /* 3023 * Force a reload. Other thread could reallocate the 3024 * table before this fd was closed, so it is possible 3025 * that there is a stale fp pointer in cached version. 3026 */ 3027 fdt = atomic_load_ptr(&fdp->fd_files); 3028 continue; 3029 } 3030 /* 3031 * Use an acquire barrier to force re-reading of fdt so it is 3032 * refreshed for verification. 3033 */ 3034 atomic_thread_fence_acq(); 3035 fdt = fdp->fd_files; 3036 #ifdef CAPABILITIES 3037 if (seqc_consistent_nomb(fd_seqc(fdt, fd), seq)) 3038 #else 3039 if (fp == fdt->fdt_ofiles[fd].fde_file) 3040 #endif 3041 break; 3042 fdrop(fp, curthread); 3043 } 3044 *fpp = fp; 3045 if (seqp != NULL) { 3046 #ifdef CAPABILITIES 3047 *seqp = seq; 3048 #endif 3049 } 3050 return (0); 3051 } 3052 3053 /* 3054 * See the comments in fget_unlocked_seq for an explanation of how this works. 3055 * 3056 * This is a simplified variant which bails out to the aforementioned routine 3057 * if anything goes wrong. In practice this only happens when userspace is 3058 * racing with itself. 3059 */ 3060 int 3061 fget_unlocked(struct filedesc *fdp, int fd, cap_rights_t *needrightsp, 3062 struct file **fpp) 3063 { 3064 #ifdef CAPABILITIES 3065 const struct filedescent *fde; 3066 #endif 3067 const struct fdescenttbl *fdt; 3068 struct file *fp; 3069 #ifdef CAPABILITIES 3070 seqc_t seq; 3071 const cap_rights_t *haverights; 3072 #endif 3073 3074 fdt = fdp->fd_files; 3075 if (__predict_false((u_int)fd >= fdt->fdt_nfiles)) 3076 return (EBADF); 3077 #ifdef CAPABILITIES 3078 seq = seqc_read_notmodify(fd_seqc(fdt, fd)); 3079 fde = &fdt->fdt_ofiles[fd]; 3080 haverights = cap_rights_fde_inline(fde); 3081 fp = fde->fde_file; 3082 #else 3083 fp = fdt->fdt_ofiles[fd].fde_file; 3084 #endif 3085 if (__predict_false(fp == NULL)) 3086 goto out_fallback; 3087 #ifdef CAPABILITIES 3088 if (__predict_false(cap_check_inline_transient(haverights, needrightsp))) 3089 goto out_fallback; 3090 #endif 3091 if (__predict_false(!refcount_acquire_if_not_zero(&fp->f_count))) 3092 goto out_fallback; 3093 3094 /* 3095 * Use an acquire barrier to force re-reading of fdt so it is 3096 * refreshed for verification. 3097 */ 3098 atomic_thread_fence_acq(); 3099 fdt = fdp->fd_files; 3100 #ifdef CAPABILITIES 3101 if (__predict_false(!seqc_consistent_nomb(fd_seqc(fdt, fd), seq))) 3102 #else 3103 if (__predict_false(fp != fdt->fdt_ofiles[fd].fde_file)) 3104 #endif 3105 goto out_fdrop; 3106 *fpp = fp; 3107 return (0); 3108 out_fdrop: 3109 fdrop(fp, curthread); 3110 out_fallback: 3111 return (fget_unlocked_seq(fdp, fd, needrightsp, fpp, NULL)); 3112 } 3113 3114 /* 3115 * Translate fd -> file when the caller guarantees the file descriptor table 3116 * can't be changed by others. 3117 * 3118 * Note this does not mean the file object itself is only visible to the caller, 3119 * merely that it wont disappear without having to be referenced. 3120 * 3121 * Must be paired with fput_only_user. 3122 */ 3123 #ifdef CAPABILITIES 3124 int 3125 fget_only_user(struct filedesc *fdp, int fd, cap_rights_t *needrightsp, 3126 struct file **fpp) 3127 { 3128 const struct filedescent *fde; 3129 const struct fdescenttbl *fdt; 3130 const cap_rights_t *haverights; 3131 struct file *fp; 3132 int error; 3133 3134 MPASS(FILEDESC_IS_ONLY_USER(fdp)); 3135 3136 if (__predict_false(fd >= fdp->fd_nfiles)) 3137 return (EBADF); 3138 3139 fdt = fdp->fd_files; 3140 fde = &fdt->fdt_ofiles[fd]; 3141 fp = fde->fde_file; 3142 if (__predict_false(fp == NULL)) 3143 return (EBADF); 3144 MPASS(refcount_load(&fp->f_count) > 0); 3145 haverights = cap_rights_fde_inline(fde); 3146 error = cap_check_inline(haverights, needrightsp); 3147 if (__predict_false(error != 0)) 3148 return (error); 3149 *fpp = fp; 3150 return (0); 3151 } 3152 #else 3153 int 3154 fget_only_user(struct filedesc *fdp, int fd, cap_rights_t *needrightsp, 3155 struct file **fpp) 3156 { 3157 struct file *fp; 3158 3159 MPASS(FILEDESC_IS_ONLY_USER(fdp)); 3160 3161 if (__predict_false(fd >= fdp->fd_nfiles)) 3162 return (EBADF); 3163 3164 fp = fdp->fd_ofiles[fd].fde_file; 3165 if (__predict_false(fp == NULL)) 3166 return (EBADF); 3167 3168 MPASS(refcount_load(&fp->f_count) > 0); 3169 *fpp = fp; 3170 return (0); 3171 } 3172 #endif 3173 3174 /* 3175 * Extract the file pointer associated with the specified descriptor for the 3176 * current user process. 3177 * 3178 * If the descriptor doesn't exist or doesn't match 'flags', EBADF is 3179 * returned. 3180 * 3181 * File's rights will be checked against the capability rights mask. 3182 * 3183 * If an error occurred the non-zero error is returned and *fpp is set to 3184 * NULL. Otherwise *fpp is held and set and zero is returned. Caller is 3185 * responsible for fdrop(). 3186 */ 3187 static __inline int 3188 _fget(struct thread *td, int fd, struct file **fpp, int flags, 3189 cap_rights_t *needrightsp) 3190 { 3191 struct filedesc *fdp; 3192 struct file *fp; 3193 int error; 3194 3195 *fpp = NULL; 3196 fdp = td->td_proc->p_fd; 3197 error = fget_unlocked(fdp, fd, needrightsp, &fp); 3198 if (__predict_false(error != 0)) 3199 return (error); 3200 if (__predict_false(fp->f_ops == &badfileops)) { 3201 fdrop(fp, td); 3202 return (EBADF); 3203 } 3204 3205 /* 3206 * FREAD and FWRITE failure return EBADF as per POSIX. 3207 */ 3208 error = 0; 3209 switch (flags) { 3210 case FREAD: 3211 case FWRITE: 3212 if ((fp->f_flag & flags) == 0) 3213 error = EBADF; 3214 break; 3215 case FEXEC: 3216 if ((fp->f_flag & (FREAD | FEXEC)) == 0 || 3217 ((fp->f_flag & FWRITE) != 0)) 3218 error = EBADF; 3219 break; 3220 case 0: 3221 break; 3222 default: 3223 KASSERT(0, ("wrong flags")); 3224 } 3225 3226 if (error != 0) { 3227 fdrop(fp, td); 3228 return (error); 3229 } 3230 3231 *fpp = fp; 3232 return (0); 3233 } 3234 3235 int 3236 fget(struct thread *td, int fd, cap_rights_t *rightsp, struct file **fpp) 3237 { 3238 3239 return (_fget(td, fd, fpp, 0, rightsp)); 3240 } 3241 3242 int 3243 fget_mmap(struct thread *td, int fd, cap_rights_t *rightsp, vm_prot_t *maxprotp, 3244 struct file **fpp) 3245 { 3246 int error; 3247 #ifndef CAPABILITIES 3248 error = _fget(td, fd, fpp, 0, rightsp); 3249 if (maxprotp != NULL) 3250 *maxprotp = VM_PROT_ALL; 3251 return (error); 3252 #else 3253 cap_rights_t fdrights; 3254 struct filedesc *fdp; 3255 struct file *fp; 3256 seqc_t seq; 3257 3258 *fpp = NULL; 3259 fdp = td->td_proc->p_fd; 3260 MPASS(cap_rights_is_set(rightsp, CAP_MMAP)); 3261 for (;;) { 3262 error = fget_unlocked_seq(fdp, fd, rightsp, &fp, &seq); 3263 if (__predict_false(error != 0)) 3264 return (error); 3265 if (__predict_false(fp->f_ops == &badfileops)) { 3266 fdrop(fp, td); 3267 return (EBADF); 3268 } 3269 if (maxprotp != NULL) 3270 fdrights = *cap_rights(fdp, fd); 3271 if (!fd_modified(fdp, fd, seq)) 3272 break; 3273 fdrop(fp, td); 3274 } 3275 3276 /* 3277 * If requested, convert capability rights to access flags. 3278 */ 3279 if (maxprotp != NULL) 3280 *maxprotp = cap_rights_to_vmprot(&fdrights); 3281 *fpp = fp; 3282 return (0); 3283 #endif 3284 } 3285 3286 int 3287 fget_read(struct thread *td, int fd, cap_rights_t *rightsp, struct file **fpp) 3288 { 3289 3290 return (_fget(td, fd, fpp, FREAD, rightsp)); 3291 } 3292 3293 int 3294 fget_write(struct thread *td, int fd, cap_rights_t *rightsp, struct file **fpp) 3295 { 3296 3297 return (_fget(td, fd, fpp, FWRITE, rightsp)); 3298 } 3299 3300 int 3301 fget_fcntl(struct thread *td, int fd, cap_rights_t *rightsp, int needfcntl, 3302 struct file **fpp) 3303 { 3304 struct filedesc *fdp = td->td_proc->p_fd; 3305 #ifndef CAPABILITIES 3306 return (fget_unlocked(fdp, fd, rightsp, fpp)); 3307 #else 3308 struct file *fp; 3309 int error; 3310 seqc_t seq; 3311 3312 *fpp = NULL; 3313 MPASS(cap_rights_is_set(rightsp, CAP_FCNTL)); 3314 for (;;) { 3315 error = fget_unlocked_seq(fdp, fd, rightsp, &fp, &seq); 3316 if (error != 0) 3317 return (error); 3318 error = cap_fcntl_check(fdp, fd, needfcntl); 3319 if (!fd_modified(fdp, fd, seq)) 3320 break; 3321 fdrop(fp, td); 3322 } 3323 if (error != 0) { 3324 fdrop(fp, td); 3325 return (error); 3326 } 3327 *fpp = fp; 3328 return (0); 3329 #endif 3330 } 3331 3332 /* 3333 * Like fget() but loads the underlying vnode, or returns an error if the 3334 * descriptor does not represent a vnode. Note that pipes use vnodes but 3335 * never have VM objects. The returned vnode will be vref()'d. 3336 * 3337 * XXX: what about the unused flags ? 3338 */ 3339 static __inline int 3340 _fgetvp(struct thread *td, int fd, int flags, cap_rights_t *needrightsp, 3341 struct vnode **vpp) 3342 { 3343 struct file *fp; 3344 int error; 3345 3346 *vpp = NULL; 3347 error = _fget(td, fd, &fp, flags, needrightsp); 3348 if (error != 0) 3349 return (error); 3350 if (fp->f_vnode == NULL) { 3351 error = EINVAL; 3352 } else { 3353 *vpp = fp->f_vnode; 3354 vref(*vpp); 3355 } 3356 fdrop(fp, td); 3357 3358 return (error); 3359 } 3360 3361 int 3362 fgetvp(struct thread *td, int fd, cap_rights_t *rightsp, struct vnode **vpp) 3363 { 3364 3365 return (_fgetvp(td, fd, 0, rightsp, vpp)); 3366 } 3367 3368 int 3369 fgetvp_rights(struct thread *td, int fd, cap_rights_t *needrightsp, 3370 struct filecaps *havecaps, struct vnode **vpp) 3371 { 3372 struct filecaps caps; 3373 struct file *fp; 3374 int error; 3375 3376 error = fget_cap(td, fd, needrightsp, &fp, &caps); 3377 if (error != 0) 3378 return (error); 3379 if (fp->f_ops == &badfileops) { 3380 error = EBADF; 3381 goto out; 3382 } 3383 if (fp->f_vnode == NULL) { 3384 error = EINVAL; 3385 goto out; 3386 } 3387 3388 *havecaps = caps; 3389 *vpp = fp->f_vnode; 3390 vref(*vpp); 3391 fdrop(fp, td); 3392 3393 return (0); 3394 out: 3395 filecaps_free(&caps); 3396 fdrop(fp, td); 3397 return (error); 3398 } 3399 3400 int 3401 fgetvp_read(struct thread *td, int fd, cap_rights_t *rightsp, struct vnode **vpp) 3402 { 3403 3404 return (_fgetvp(td, fd, FREAD, rightsp, vpp)); 3405 } 3406 3407 int 3408 fgetvp_exec(struct thread *td, int fd, cap_rights_t *rightsp, struct vnode **vpp) 3409 { 3410 3411 return (_fgetvp(td, fd, FEXEC, rightsp, vpp)); 3412 } 3413 3414 #ifdef notyet 3415 int 3416 fgetvp_write(struct thread *td, int fd, cap_rights_t *rightsp, 3417 struct vnode **vpp) 3418 { 3419 3420 return (_fgetvp(td, fd, FWRITE, rightsp, vpp)); 3421 } 3422 #endif 3423 3424 /* 3425 * Handle the last reference to a file being closed. 3426 * 3427 * Without the noinline attribute clang keeps inlining the func thorough this 3428 * file when fdrop is used. 3429 */ 3430 int __noinline 3431 _fdrop(struct file *fp, struct thread *td) 3432 { 3433 int error; 3434 #ifdef INVARIANTS 3435 int count; 3436 3437 count = refcount_load(&fp->f_count); 3438 if (count != 0) 3439 panic("fdrop: fp %p count %d", fp, count); 3440 #endif 3441 error = fo_close(fp, td); 3442 atomic_subtract_int(&openfiles, 1); 3443 crfree(fp->f_cred); 3444 free(fp->f_advice, M_FADVISE); 3445 uma_zfree(file_zone, fp); 3446 3447 return (error); 3448 } 3449 3450 /* 3451 * Apply an advisory lock on a file descriptor. 3452 * 3453 * Just attempt to get a record lock of the requested type on the entire file 3454 * (l_whence = SEEK_SET, l_start = 0, l_len = 0). 3455 */ 3456 #ifndef _SYS_SYSPROTO_H_ 3457 struct flock_args { 3458 int fd; 3459 int how; 3460 }; 3461 #endif 3462 /* ARGSUSED */ 3463 int 3464 sys_flock(struct thread *td, struct flock_args *uap) 3465 { 3466 struct file *fp; 3467 struct vnode *vp; 3468 struct flock lf; 3469 int error; 3470 3471 error = fget(td, uap->fd, &cap_flock_rights, &fp); 3472 if (error != 0) 3473 return (error); 3474 error = EOPNOTSUPP; 3475 if (fp->f_type != DTYPE_VNODE && fp->f_type != DTYPE_FIFO) { 3476 goto done; 3477 } 3478 if (fp->f_ops == &path_fileops) { 3479 goto done; 3480 } 3481 3482 error = 0; 3483 vp = fp->f_vnode; 3484 lf.l_whence = SEEK_SET; 3485 lf.l_start = 0; 3486 lf.l_len = 0; 3487 if (uap->how & LOCK_UN) { 3488 lf.l_type = F_UNLCK; 3489 atomic_clear_int(&fp->f_flag, FHASLOCK); 3490 error = VOP_ADVLOCK(vp, (caddr_t)fp, F_UNLCK, &lf, F_FLOCK); 3491 goto done; 3492 } 3493 if (uap->how & LOCK_EX) 3494 lf.l_type = F_WRLCK; 3495 else if (uap->how & LOCK_SH) 3496 lf.l_type = F_RDLCK; 3497 else { 3498 error = EBADF; 3499 goto done; 3500 } 3501 atomic_set_int(&fp->f_flag, FHASLOCK); 3502 error = VOP_ADVLOCK(vp, (caddr_t)fp, F_SETLK, &lf, 3503 (uap->how & LOCK_NB) ? F_FLOCK : F_FLOCK | F_WAIT); 3504 done: 3505 fdrop(fp, td); 3506 return (error); 3507 } 3508 /* 3509 * Duplicate the specified descriptor to a free descriptor. 3510 */ 3511 int 3512 dupfdopen(struct thread *td, struct filedesc *fdp, int dfd, int mode, 3513 int openerror, int *indxp) 3514 { 3515 struct filedescent *newfde, *oldfde; 3516 struct file *fp; 3517 u_long *ioctls; 3518 int error, indx; 3519 3520 KASSERT(openerror == ENODEV || openerror == ENXIO, 3521 ("unexpected error %d in %s", openerror, __func__)); 3522 3523 /* 3524 * If the to-be-dup'd fd number is greater than the allowed number 3525 * of file descriptors, or the fd to be dup'd has already been 3526 * closed, then reject. 3527 */ 3528 FILEDESC_XLOCK(fdp); 3529 if ((fp = fget_locked(fdp, dfd)) == NULL) { 3530 FILEDESC_XUNLOCK(fdp); 3531 return (EBADF); 3532 } 3533 3534 error = fdalloc(td, 0, &indx); 3535 if (error != 0) { 3536 FILEDESC_XUNLOCK(fdp); 3537 return (error); 3538 } 3539 3540 /* 3541 * There are two cases of interest here. 3542 * 3543 * For ENODEV simply dup (dfd) to file descriptor (indx) and return. 3544 * 3545 * For ENXIO steal away the file structure from (dfd) and store it in 3546 * (indx). (dfd) is effectively closed by this operation. 3547 */ 3548 switch (openerror) { 3549 case ENODEV: 3550 /* 3551 * Check that the mode the file is being opened for is a 3552 * subset of the mode of the existing descriptor. 3553 */ 3554 if (((mode & (FREAD|FWRITE)) | fp->f_flag) != fp->f_flag) { 3555 fdunused(fdp, indx); 3556 FILEDESC_XUNLOCK(fdp); 3557 return (EACCES); 3558 } 3559 if (!fhold(fp)) { 3560 fdunused(fdp, indx); 3561 FILEDESC_XUNLOCK(fdp); 3562 return (EBADF); 3563 } 3564 newfde = &fdp->fd_ofiles[indx]; 3565 oldfde = &fdp->fd_ofiles[dfd]; 3566 ioctls = filecaps_copy_prep(&oldfde->fde_caps); 3567 #ifdef CAPABILITIES 3568 seqc_write_begin(&newfde->fde_seqc); 3569 #endif 3570 memcpy(newfde, oldfde, fde_change_size); 3571 filecaps_copy_finish(&oldfde->fde_caps, &newfde->fde_caps, 3572 ioctls); 3573 #ifdef CAPABILITIES 3574 seqc_write_end(&newfde->fde_seqc); 3575 #endif 3576 break; 3577 case ENXIO: 3578 /* 3579 * Steal away the file pointer from dfd and stuff it into indx. 3580 */ 3581 newfde = &fdp->fd_ofiles[indx]; 3582 oldfde = &fdp->fd_ofiles[dfd]; 3583 #ifdef CAPABILITIES 3584 seqc_write_begin(&newfde->fde_seqc); 3585 #endif 3586 memcpy(newfde, oldfde, fde_change_size); 3587 oldfde->fde_file = NULL; 3588 fdunused(fdp, dfd); 3589 #ifdef CAPABILITIES 3590 seqc_write_end(&newfde->fde_seqc); 3591 #endif 3592 break; 3593 } 3594 FILEDESC_XUNLOCK(fdp); 3595 *indxp = indx; 3596 return (0); 3597 } 3598 3599 /* 3600 * This sysctl determines if we will allow a process to chroot(2) if it 3601 * has a directory open: 3602 * 0: disallowed for all processes. 3603 * 1: allowed for processes that were not already chroot(2)'ed. 3604 * 2: allowed for all processes. 3605 */ 3606 3607 static int chroot_allow_open_directories = 1; 3608 3609 SYSCTL_INT(_kern, OID_AUTO, chroot_allow_open_directories, CTLFLAG_RW, 3610 &chroot_allow_open_directories, 0, 3611 "Allow a process to chroot(2) if it has a directory open"); 3612 3613 /* 3614 * Helper function for raised chroot(2) security function: Refuse if 3615 * any filedescriptors are open directories. 3616 */ 3617 static int 3618 chroot_refuse_vdir_fds(struct filedesc *fdp) 3619 { 3620 struct vnode *vp; 3621 struct file *fp; 3622 int fd, lastfile; 3623 3624 FILEDESC_LOCK_ASSERT(fdp); 3625 3626 lastfile = fdlastfile(fdp); 3627 for (fd = 0; fd <= lastfile; fd++) { 3628 fp = fget_locked(fdp, fd); 3629 if (fp == NULL) 3630 continue; 3631 if (fp->f_type == DTYPE_VNODE) { 3632 vp = fp->f_vnode; 3633 if (vp->v_type == VDIR) 3634 return (EPERM); 3635 } 3636 } 3637 return (0); 3638 } 3639 3640 static void 3641 pwd_fill(struct pwd *oldpwd, struct pwd *newpwd) 3642 { 3643 3644 if (newpwd->pwd_cdir == NULL && oldpwd->pwd_cdir != NULL) { 3645 vrefact(oldpwd->pwd_cdir); 3646 newpwd->pwd_cdir = oldpwd->pwd_cdir; 3647 } 3648 3649 if (newpwd->pwd_rdir == NULL && oldpwd->pwd_rdir != NULL) { 3650 vrefact(oldpwd->pwd_rdir); 3651 newpwd->pwd_rdir = oldpwd->pwd_rdir; 3652 } 3653 3654 if (newpwd->pwd_jdir == NULL && oldpwd->pwd_jdir != NULL) { 3655 vrefact(oldpwd->pwd_jdir); 3656 newpwd->pwd_jdir = oldpwd->pwd_jdir; 3657 } 3658 } 3659 3660 struct pwd * 3661 pwd_hold_pwddesc(struct pwddesc *pdp) 3662 { 3663 struct pwd *pwd; 3664 3665 PWDDESC_ASSERT_XLOCKED(pdp); 3666 pwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); 3667 if (pwd != NULL) 3668 refcount_acquire(&pwd->pwd_refcount); 3669 return (pwd); 3670 } 3671 3672 bool 3673 pwd_hold_smr(struct pwd *pwd) 3674 { 3675 3676 MPASS(pwd != NULL); 3677 if (__predict_true(refcount_acquire_if_not_zero(&pwd->pwd_refcount))) { 3678 return (true); 3679 } 3680 return (false); 3681 } 3682 3683 struct pwd * 3684 pwd_hold(struct thread *td) 3685 { 3686 struct pwddesc *pdp; 3687 struct pwd *pwd; 3688 3689 pdp = td->td_proc->p_pd; 3690 3691 vfs_smr_enter(); 3692 pwd = vfs_smr_entered_load(&pdp->pd_pwd); 3693 if (pwd_hold_smr(pwd)) { 3694 vfs_smr_exit(); 3695 return (pwd); 3696 } 3697 vfs_smr_exit(); 3698 PWDDESC_XLOCK(pdp); 3699 pwd = pwd_hold_pwddesc(pdp); 3700 MPASS(pwd != NULL); 3701 PWDDESC_XUNLOCK(pdp); 3702 return (pwd); 3703 } 3704 3705 struct pwd * 3706 pwd_hold_proc(struct proc *p) 3707 { 3708 struct pwddesc *pdp; 3709 struct pwd *pwd; 3710 3711 PROC_ASSERT_HELD(p); 3712 PROC_LOCK(p); 3713 pdp = pdhold(p); 3714 MPASS(pdp != NULL); 3715 PROC_UNLOCK(p); 3716 3717 PWDDESC_XLOCK(pdp); 3718 pwd = pwd_hold_pwddesc(pdp); 3719 MPASS(pwd != NULL); 3720 PWDDESC_XUNLOCK(pdp); 3721 pddrop(pdp); 3722 return (pwd); 3723 } 3724 3725 static struct pwd * 3726 pwd_alloc(void) 3727 { 3728 struct pwd *pwd; 3729 3730 pwd = uma_zalloc_smr(pwd_zone, M_WAITOK); 3731 bzero(pwd, sizeof(*pwd)); 3732 refcount_init(&pwd->pwd_refcount, 1); 3733 return (pwd); 3734 } 3735 3736 void 3737 pwd_drop(struct pwd *pwd) 3738 { 3739 3740 if (!refcount_release(&pwd->pwd_refcount)) 3741 return; 3742 3743 if (pwd->pwd_cdir != NULL) 3744 vrele(pwd->pwd_cdir); 3745 if (pwd->pwd_rdir != NULL) 3746 vrele(pwd->pwd_rdir); 3747 if (pwd->pwd_jdir != NULL) 3748 vrele(pwd->pwd_jdir); 3749 uma_zfree_smr(pwd_zone, pwd); 3750 } 3751 3752 /* 3753 * The caller is responsible for invoking priv_check() and 3754 * mac_vnode_check_chroot() to authorize this operation. 3755 */ 3756 int 3757 pwd_chroot(struct thread *td, struct vnode *vp) 3758 { 3759 struct pwddesc *pdp; 3760 struct filedesc *fdp; 3761 struct pwd *newpwd, *oldpwd; 3762 int error; 3763 3764 fdp = td->td_proc->p_fd; 3765 pdp = td->td_proc->p_pd; 3766 newpwd = pwd_alloc(); 3767 FILEDESC_SLOCK(fdp); 3768 PWDDESC_XLOCK(pdp); 3769 oldpwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); 3770 if (chroot_allow_open_directories == 0 || 3771 (chroot_allow_open_directories == 1 && 3772 oldpwd->pwd_rdir != rootvnode)) { 3773 error = chroot_refuse_vdir_fds(fdp); 3774 FILEDESC_SUNLOCK(fdp); 3775 if (error != 0) { 3776 PWDDESC_XUNLOCK(pdp); 3777 pwd_drop(newpwd); 3778 return (error); 3779 } 3780 } else { 3781 FILEDESC_SUNLOCK(fdp); 3782 } 3783 3784 vrefact(vp); 3785 newpwd->pwd_rdir = vp; 3786 if (oldpwd->pwd_jdir == NULL) { 3787 vrefact(vp); 3788 newpwd->pwd_jdir = vp; 3789 } 3790 pwd_fill(oldpwd, newpwd); 3791 pwd_set(pdp, newpwd); 3792 PWDDESC_XUNLOCK(pdp); 3793 pwd_drop(oldpwd); 3794 return (0); 3795 } 3796 3797 void 3798 pwd_chdir(struct thread *td, struct vnode *vp) 3799 { 3800 struct pwddesc *pdp; 3801 struct pwd *newpwd, *oldpwd; 3802 3803 VNPASS(vp->v_usecount > 0, vp); 3804 3805 newpwd = pwd_alloc(); 3806 pdp = td->td_proc->p_pd; 3807 PWDDESC_XLOCK(pdp); 3808 oldpwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); 3809 newpwd->pwd_cdir = vp; 3810 pwd_fill(oldpwd, newpwd); 3811 pwd_set(pdp, newpwd); 3812 PWDDESC_XUNLOCK(pdp); 3813 pwd_drop(oldpwd); 3814 } 3815 3816 /* 3817 * jail_attach(2) changes both root and working directories. 3818 */ 3819 int 3820 pwd_chroot_chdir(struct thread *td, struct vnode *vp) 3821 { 3822 struct pwddesc *pdp; 3823 struct filedesc *fdp; 3824 struct pwd *newpwd, *oldpwd; 3825 int error; 3826 3827 fdp = td->td_proc->p_fd; 3828 pdp = td->td_proc->p_pd; 3829 newpwd = pwd_alloc(); 3830 FILEDESC_SLOCK(fdp); 3831 PWDDESC_XLOCK(pdp); 3832 oldpwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); 3833 error = chroot_refuse_vdir_fds(fdp); 3834 FILEDESC_SUNLOCK(fdp); 3835 if (error != 0) { 3836 PWDDESC_XUNLOCK(pdp); 3837 pwd_drop(newpwd); 3838 return (error); 3839 } 3840 3841 vrefact(vp); 3842 newpwd->pwd_rdir = vp; 3843 vrefact(vp); 3844 newpwd->pwd_cdir = vp; 3845 if (oldpwd->pwd_jdir == NULL) { 3846 vrefact(vp); 3847 newpwd->pwd_jdir = vp; 3848 } 3849 pwd_fill(oldpwd, newpwd); 3850 pwd_set(pdp, newpwd); 3851 PWDDESC_XUNLOCK(pdp); 3852 pwd_drop(oldpwd); 3853 return (0); 3854 } 3855 3856 void 3857 pwd_ensure_dirs(void) 3858 { 3859 struct pwddesc *pdp; 3860 struct pwd *oldpwd, *newpwd; 3861 3862 pdp = curproc->p_pd; 3863 PWDDESC_XLOCK(pdp); 3864 oldpwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); 3865 if (oldpwd->pwd_cdir != NULL && oldpwd->pwd_rdir != NULL) { 3866 PWDDESC_XUNLOCK(pdp); 3867 return; 3868 } 3869 PWDDESC_XUNLOCK(pdp); 3870 3871 newpwd = pwd_alloc(); 3872 PWDDESC_XLOCK(pdp); 3873 oldpwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); 3874 pwd_fill(oldpwd, newpwd); 3875 if (newpwd->pwd_cdir == NULL) { 3876 vrefact(rootvnode); 3877 newpwd->pwd_cdir = rootvnode; 3878 } 3879 if (newpwd->pwd_rdir == NULL) { 3880 vrefact(rootvnode); 3881 newpwd->pwd_rdir = rootvnode; 3882 } 3883 pwd_set(pdp, newpwd); 3884 PWDDESC_XUNLOCK(pdp); 3885 pwd_drop(oldpwd); 3886 } 3887 3888 void 3889 pwd_set_rootvnode(void) 3890 { 3891 struct pwddesc *pdp; 3892 struct pwd *oldpwd, *newpwd; 3893 3894 pdp = curproc->p_pd; 3895 3896 newpwd = pwd_alloc(); 3897 PWDDESC_XLOCK(pdp); 3898 oldpwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); 3899 vrefact(rootvnode); 3900 newpwd->pwd_cdir = rootvnode; 3901 vrefact(rootvnode); 3902 newpwd->pwd_rdir = rootvnode; 3903 pwd_fill(oldpwd, newpwd); 3904 pwd_set(pdp, newpwd); 3905 PWDDESC_XUNLOCK(pdp); 3906 pwd_drop(oldpwd); 3907 } 3908 3909 /* 3910 * Scan all active processes and prisons to see if any of them have a current 3911 * or root directory of `olddp'. If so, replace them with the new mount point. 3912 */ 3913 void 3914 mountcheckdirs(struct vnode *olddp, struct vnode *newdp) 3915 { 3916 struct pwddesc *pdp; 3917 struct pwd *newpwd, *oldpwd; 3918 struct prison *pr; 3919 struct proc *p; 3920 int nrele; 3921 3922 if (vrefcnt(olddp) == 1) 3923 return; 3924 nrele = 0; 3925 newpwd = pwd_alloc(); 3926 sx_slock(&allproc_lock); 3927 FOREACH_PROC_IN_SYSTEM(p) { 3928 PROC_LOCK(p); 3929 pdp = pdhold(p); 3930 PROC_UNLOCK(p); 3931 if (pdp == NULL) 3932 continue; 3933 PWDDESC_XLOCK(pdp); 3934 oldpwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); 3935 if (oldpwd == NULL || 3936 (oldpwd->pwd_cdir != olddp && 3937 oldpwd->pwd_rdir != olddp && 3938 oldpwd->pwd_jdir != olddp)) { 3939 PWDDESC_XUNLOCK(pdp); 3940 pddrop(pdp); 3941 continue; 3942 } 3943 if (oldpwd->pwd_cdir == olddp) { 3944 vrefact(newdp); 3945 newpwd->pwd_cdir = newdp; 3946 } 3947 if (oldpwd->pwd_rdir == olddp) { 3948 vrefact(newdp); 3949 newpwd->pwd_rdir = newdp; 3950 } 3951 if (oldpwd->pwd_jdir == olddp) { 3952 vrefact(newdp); 3953 newpwd->pwd_jdir = newdp; 3954 } 3955 pwd_fill(oldpwd, newpwd); 3956 pwd_set(pdp, newpwd); 3957 PWDDESC_XUNLOCK(pdp); 3958 pwd_drop(oldpwd); 3959 pddrop(pdp); 3960 newpwd = pwd_alloc(); 3961 } 3962 sx_sunlock(&allproc_lock); 3963 pwd_drop(newpwd); 3964 if (rootvnode == olddp) { 3965 vrefact(newdp); 3966 rootvnode = newdp; 3967 nrele++; 3968 } 3969 mtx_lock(&prison0.pr_mtx); 3970 if (prison0.pr_root == olddp) { 3971 vrefact(newdp); 3972 prison0.pr_root = newdp; 3973 nrele++; 3974 } 3975 mtx_unlock(&prison0.pr_mtx); 3976 sx_slock(&allprison_lock); 3977 TAILQ_FOREACH(pr, &allprison, pr_list) { 3978 mtx_lock(&pr->pr_mtx); 3979 if (pr->pr_root == olddp) { 3980 vrefact(newdp); 3981 pr->pr_root = newdp; 3982 nrele++; 3983 } 3984 mtx_unlock(&pr->pr_mtx); 3985 } 3986 sx_sunlock(&allprison_lock); 3987 while (nrele--) 3988 vrele(olddp); 3989 } 3990 3991 struct filedesc_to_leader * 3992 filedesc_to_leader_alloc(struct filedesc_to_leader *old, struct filedesc *fdp, struct proc *leader) 3993 { 3994 struct filedesc_to_leader *fdtol; 3995 3996 fdtol = malloc(sizeof(struct filedesc_to_leader), 3997 M_FILEDESC_TO_LEADER, M_WAITOK); 3998 fdtol->fdl_refcount = 1; 3999 fdtol->fdl_holdcount = 0; 4000 fdtol->fdl_wakeup = 0; 4001 fdtol->fdl_leader = leader; 4002 if (old != NULL) { 4003 FILEDESC_XLOCK(fdp); 4004 fdtol->fdl_next = old->fdl_next; 4005 fdtol->fdl_prev = old; 4006 old->fdl_next = fdtol; 4007 fdtol->fdl_next->fdl_prev = fdtol; 4008 FILEDESC_XUNLOCK(fdp); 4009 } else { 4010 fdtol->fdl_next = fdtol; 4011 fdtol->fdl_prev = fdtol; 4012 } 4013 return (fdtol); 4014 } 4015 4016 static int 4017 sysctl_kern_proc_nfds(SYSCTL_HANDLER_ARGS) 4018 { 4019 NDSLOTTYPE *map; 4020 struct filedesc *fdp; 4021 u_int namelen; 4022 int count, off, minoff; 4023 4024 namelen = arg2; 4025 if (namelen != 1) 4026 return (EINVAL); 4027 4028 if (*(int *)arg1 != 0) 4029 return (EINVAL); 4030 4031 fdp = curproc->p_fd; 4032 count = 0; 4033 FILEDESC_SLOCK(fdp); 4034 map = fdp->fd_map; 4035 off = NDSLOT(fdp->fd_nfiles - 1); 4036 for (minoff = NDSLOT(0); off >= minoff; --off) 4037 count += bitcountl(map[off]); 4038 FILEDESC_SUNLOCK(fdp); 4039 4040 return (SYSCTL_OUT(req, &count, sizeof(count))); 4041 } 4042 4043 static SYSCTL_NODE(_kern_proc, KERN_PROC_NFDS, nfds, 4044 CTLFLAG_RD|CTLFLAG_CAPRD|CTLFLAG_MPSAFE, sysctl_kern_proc_nfds, 4045 "Number of open file descriptors"); 4046 4047 /* 4048 * Get file structures globally. 4049 */ 4050 static int 4051 sysctl_kern_file(SYSCTL_HANDLER_ARGS) 4052 { 4053 struct xfile xf; 4054 struct filedesc *fdp; 4055 struct file *fp; 4056 struct proc *p; 4057 int error, n, lastfile; 4058 4059 error = sysctl_wire_old_buffer(req, 0); 4060 if (error != 0) 4061 return (error); 4062 if (req->oldptr == NULL) { 4063 n = 0; 4064 sx_slock(&allproc_lock); 4065 FOREACH_PROC_IN_SYSTEM(p) { 4066 PROC_LOCK(p); 4067 if (p->p_state == PRS_NEW) { 4068 PROC_UNLOCK(p); 4069 continue; 4070 } 4071 fdp = fdhold(p); 4072 PROC_UNLOCK(p); 4073 if (fdp == NULL) 4074 continue; 4075 /* overestimates sparse tables. */ 4076 n += fdp->fd_nfiles; 4077 fddrop(fdp); 4078 } 4079 sx_sunlock(&allproc_lock); 4080 return (SYSCTL_OUT(req, 0, n * sizeof(xf))); 4081 } 4082 error = 0; 4083 bzero(&xf, sizeof(xf)); 4084 xf.xf_size = sizeof(xf); 4085 sx_slock(&allproc_lock); 4086 FOREACH_PROC_IN_SYSTEM(p) { 4087 PROC_LOCK(p); 4088 if (p->p_state == PRS_NEW) { 4089 PROC_UNLOCK(p); 4090 continue; 4091 } 4092 if (p_cansee(req->td, p) != 0) { 4093 PROC_UNLOCK(p); 4094 continue; 4095 } 4096 xf.xf_pid = p->p_pid; 4097 xf.xf_uid = p->p_ucred->cr_uid; 4098 fdp = fdhold(p); 4099 PROC_UNLOCK(p); 4100 if (fdp == NULL) 4101 continue; 4102 FILEDESC_SLOCK(fdp); 4103 lastfile = fdlastfile(fdp); 4104 for (n = 0; refcount_load(&fdp->fd_refcnt) > 0 && n <= lastfile; 4105 n++) { 4106 if ((fp = fdp->fd_ofiles[n].fde_file) == NULL) 4107 continue; 4108 xf.xf_fd = n; 4109 xf.xf_file = (uintptr_t)fp; 4110 xf.xf_data = (uintptr_t)fp->f_data; 4111 xf.xf_vnode = (uintptr_t)fp->f_vnode; 4112 xf.xf_type = (uintptr_t)fp->f_type; 4113 xf.xf_count = refcount_load(&fp->f_count); 4114 xf.xf_msgcount = 0; 4115 xf.xf_offset = foffset_get(fp); 4116 xf.xf_flag = fp->f_flag; 4117 error = SYSCTL_OUT(req, &xf, sizeof(xf)); 4118 if (error) 4119 break; 4120 } 4121 FILEDESC_SUNLOCK(fdp); 4122 fddrop(fdp); 4123 if (error) 4124 break; 4125 } 4126 sx_sunlock(&allproc_lock); 4127 return (error); 4128 } 4129 4130 SYSCTL_PROC(_kern, KERN_FILE, file, CTLTYPE_OPAQUE|CTLFLAG_RD|CTLFLAG_MPSAFE, 4131 0, 0, sysctl_kern_file, "S,xfile", "Entire file table"); 4132 4133 #ifdef KINFO_FILE_SIZE 4134 CTASSERT(sizeof(struct kinfo_file) == KINFO_FILE_SIZE); 4135 #endif 4136 4137 static int 4138 xlate_fflags(int fflags) 4139 { 4140 static const struct { 4141 int fflag; 4142 int kf_fflag; 4143 } fflags_table[] = { 4144 { FAPPEND, KF_FLAG_APPEND }, 4145 { FASYNC, KF_FLAG_ASYNC }, 4146 { FFSYNC, KF_FLAG_FSYNC }, 4147 { FHASLOCK, KF_FLAG_HASLOCK }, 4148 { FNONBLOCK, KF_FLAG_NONBLOCK }, 4149 { FREAD, KF_FLAG_READ }, 4150 { FWRITE, KF_FLAG_WRITE }, 4151 { O_CREAT, KF_FLAG_CREAT }, 4152 { O_DIRECT, KF_FLAG_DIRECT }, 4153 { O_EXCL, KF_FLAG_EXCL }, 4154 { O_EXEC, KF_FLAG_EXEC }, 4155 { O_EXLOCK, KF_FLAG_EXLOCK }, 4156 { O_NOFOLLOW, KF_FLAG_NOFOLLOW }, 4157 { O_SHLOCK, KF_FLAG_SHLOCK }, 4158 { O_TRUNC, KF_FLAG_TRUNC } 4159 }; 4160 unsigned int i; 4161 int kflags; 4162 4163 kflags = 0; 4164 for (i = 0; i < nitems(fflags_table); i++) 4165 if (fflags & fflags_table[i].fflag) 4166 kflags |= fflags_table[i].kf_fflag; 4167 return (kflags); 4168 } 4169 4170 /* Trim unused data from kf_path by truncating the structure size. */ 4171 void 4172 pack_kinfo(struct kinfo_file *kif) 4173 { 4174 4175 kif->kf_structsize = offsetof(struct kinfo_file, kf_path) + 4176 strlen(kif->kf_path) + 1; 4177 kif->kf_structsize = roundup(kif->kf_structsize, sizeof(uint64_t)); 4178 } 4179 4180 static void 4181 export_file_to_kinfo(struct file *fp, int fd, cap_rights_t *rightsp, 4182 struct kinfo_file *kif, struct filedesc *fdp, int flags) 4183 { 4184 int error; 4185 4186 bzero(kif, sizeof(*kif)); 4187 4188 /* Set a default type to allow for empty fill_kinfo() methods. */ 4189 kif->kf_type = KF_TYPE_UNKNOWN; 4190 kif->kf_flags = xlate_fflags(fp->f_flag); 4191 if (rightsp != NULL) 4192 kif->kf_cap_rights = *rightsp; 4193 else 4194 cap_rights_init_zero(&kif->kf_cap_rights); 4195 kif->kf_fd = fd; 4196 kif->kf_ref_count = refcount_load(&fp->f_count); 4197 kif->kf_offset = foffset_get(fp); 4198 4199 /* 4200 * This may drop the filedesc lock, so the 'fp' cannot be 4201 * accessed after this call. 4202 */ 4203 error = fo_fill_kinfo(fp, kif, fdp); 4204 if (error == 0) 4205 kif->kf_status |= KF_ATTR_VALID; 4206 if ((flags & KERN_FILEDESC_PACK_KINFO) != 0) 4207 pack_kinfo(kif); 4208 else 4209 kif->kf_structsize = roundup2(sizeof(*kif), sizeof(uint64_t)); 4210 } 4211 4212 static void 4213 export_vnode_to_kinfo(struct vnode *vp, int fd, int fflags, 4214 struct kinfo_file *kif, int flags) 4215 { 4216 int error; 4217 4218 bzero(kif, sizeof(*kif)); 4219 4220 kif->kf_type = KF_TYPE_VNODE; 4221 error = vn_fill_kinfo_vnode(vp, kif); 4222 if (error == 0) 4223 kif->kf_status |= KF_ATTR_VALID; 4224 kif->kf_flags = xlate_fflags(fflags); 4225 cap_rights_init_zero(&kif->kf_cap_rights); 4226 kif->kf_fd = fd; 4227 kif->kf_ref_count = -1; 4228 kif->kf_offset = -1; 4229 if ((flags & KERN_FILEDESC_PACK_KINFO) != 0) 4230 pack_kinfo(kif); 4231 else 4232 kif->kf_structsize = roundup2(sizeof(*kif), sizeof(uint64_t)); 4233 vrele(vp); 4234 } 4235 4236 struct export_fd_buf { 4237 struct filedesc *fdp; 4238 struct pwddesc *pdp; 4239 struct sbuf *sb; 4240 ssize_t remainder; 4241 struct kinfo_file kif; 4242 int flags; 4243 }; 4244 4245 static int 4246 export_kinfo_to_sb(struct export_fd_buf *efbuf) 4247 { 4248 struct kinfo_file *kif; 4249 4250 kif = &efbuf->kif; 4251 if (efbuf->remainder != -1) { 4252 if (efbuf->remainder < kif->kf_structsize) { 4253 /* Terminate export. */ 4254 efbuf->remainder = 0; 4255 return (0); 4256 } 4257 efbuf->remainder -= kif->kf_structsize; 4258 } 4259 return (sbuf_bcat(efbuf->sb, kif, kif->kf_structsize) == 0 ? 0 : ENOMEM); 4260 } 4261 4262 static int 4263 export_file_to_sb(struct file *fp, int fd, cap_rights_t *rightsp, 4264 struct export_fd_buf *efbuf) 4265 { 4266 int error; 4267 4268 if (efbuf->remainder == 0) 4269 return (0); 4270 export_file_to_kinfo(fp, fd, rightsp, &efbuf->kif, efbuf->fdp, 4271 efbuf->flags); 4272 FILEDESC_SUNLOCK(efbuf->fdp); 4273 error = export_kinfo_to_sb(efbuf); 4274 FILEDESC_SLOCK(efbuf->fdp); 4275 return (error); 4276 } 4277 4278 static int 4279 export_vnode_to_sb(struct vnode *vp, int fd, int fflags, 4280 struct export_fd_buf *efbuf) 4281 { 4282 int error; 4283 4284 if (efbuf->remainder == 0) 4285 return (0); 4286 if (efbuf->pdp != NULL) 4287 PWDDESC_XUNLOCK(efbuf->pdp); 4288 export_vnode_to_kinfo(vp, fd, fflags, &efbuf->kif, efbuf->flags); 4289 error = export_kinfo_to_sb(efbuf); 4290 if (efbuf->pdp != NULL) 4291 PWDDESC_XLOCK(efbuf->pdp); 4292 return (error); 4293 } 4294 4295 /* 4296 * Store a process file descriptor information to sbuf. 4297 * 4298 * Takes a locked proc as argument, and returns with the proc unlocked. 4299 */ 4300 int 4301 kern_proc_filedesc_out(struct proc *p, struct sbuf *sb, ssize_t maxlen, 4302 int flags) 4303 { 4304 struct file *fp; 4305 struct filedesc *fdp; 4306 struct pwddesc *pdp; 4307 struct export_fd_buf *efbuf; 4308 struct vnode *cttyvp, *textvp, *tracevp; 4309 struct pwd *pwd; 4310 int error, i, lastfile; 4311 cap_rights_t rights; 4312 4313 PROC_LOCK_ASSERT(p, MA_OWNED); 4314 4315 /* ktrace vnode */ 4316 tracevp = ktr_get_tracevp(p, true); 4317 /* text vnode */ 4318 textvp = p->p_textvp; 4319 if (textvp != NULL) 4320 vrefact(textvp); 4321 /* Controlling tty. */ 4322 cttyvp = NULL; 4323 if (p->p_pgrp != NULL && p->p_pgrp->pg_session != NULL) { 4324 cttyvp = p->p_pgrp->pg_session->s_ttyvp; 4325 if (cttyvp != NULL) 4326 vrefact(cttyvp); 4327 } 4328 fdp = fdhold(p); 4329 pdp = pdhold(p); 4330 PROC_UNLOCK(p); 4331 efbuf = malloc(sizeof(*efbuf), M_TEMP, M_WAITOK); 4332 efbuf->fdp = NULL; 4333 efbuf->pdp = NULL; 4334 efbuf->sb = sb; 4335 efbuf->remainder = maxlen; 4336 efbuf->flags = flags; 4337 if (tracevp != NULL) 4338 export_vnode_to_sb(tracevp, KF_FD_TYPE_TRACE, FREAD | FWRITE, 4339 efbuf); 4340 if (textvp != NULL) 4341 export_vnode_to_sb(textvp, KF_FD_TYPE_TEXT, FREAD, efbuf); 4342 if (cttyvp != NULL) 4343 export_vnode_to_sb(cttyvp, KF_FD_TYPE_CTTY, FREAD | FWRITE, 4344 efbuf); 4345 error = 0; 4346 if (pdp == NULL || fdp == NULL) 4347 goto fail; 4348 efbuf->fdp = fdp; 4349 efbuf->pdp = pdp; 4350 PWDDESC_XLOCK(pdp); 4351 pwd = pwd_hold_pwddesc(pdp); 4352 if (pwd != NULL) { 4353 /* working directory */ 4354 if (pwd->pwd_cdir != NULL) { 4355 vrefact(pwd->pwd_cdir); 4356 export_vnode_to_sb(pwd->pwd_cdir, KF_FD_TYPE_CWD, 4357 FREAD, efbuf); 4358 } 4359 /* root directory */ 4360 if (pwd->pwd_rdir != NULL) { 4361 vrefact(pwd->pwd_rdir); 4362 export_vnode_to_sb(pwd->pwd_rdir, KF_FD_TYPE_ROOT, 4363 FREAD, efbuf); 4364 } 4365 /* jail directory */ 4366 if (pwd->pwd_jdir != NULL) { 4367 vrefact(pwd->pwd_jdir); 4368 export_vnode_to_sb(pwd->pwd_jdir, KF_FD_TYPE_JAIL, 4369 FREAD, efbuf); 4370 } 4371 } 4372 PWDDESC_XUNLOCK(pdp); 4373 if (pwd != NULL) 4374 pwd_drop(pwd); 4375 FILEDESC_SLOCK(fdp); 4376 lastfile = fdlastfile(fdp); 4377 for (i = 0; refcount_load(&fdp->fd_refcnt) > 0 && i <= lastfile; i++) { 4378 if ((fp = fdp->fd_ofiles[i].fde_file) == NULL) 4379 continue; 4380 #ifdef CAPABILITIES 4381 rights = *cap_rights(fdp, i); 4382 #else /* !CAPABILITIES */ 4383 rights = cap_no_rights; 4384 #endif 4385 /* 4386 * Create sysctl entry. It is OK to drop the filedesc 4387 * lock inside of export_file_to_sb() as we will 4388 * re-validate and re-evaluate its properties when the 4389 * loop continues. 4390 */ 4391 error = export_file_to_sb(fp, i, &rights, efbuf); 4392 if (error != 0 || efbuf->remainder == 0) 4393 break; 4394 } 4395 FILEDESC_SUNLOCK(fdp); 4396 fail: 4397 if (fdp != NULL) 4398 fddrop(fdp); 4399 if (pdp != NULL) 4400 pddrop(pdp); 4401 free(efbuf, M_TEMP); 4402 return (error); 4403 } 4404 4405 #define FILEDESC_SBUF_SIZE (sizeof(struct kinfo_file) * 5) 4406 4407 /* 4408 * Get per-process file descriptors for use by procstat(1), et al. 4409 */ 4410 static int 4411 sysctl_kern_proc_filedesc(SYSCTL_HANDLER_ARGS) 4412 { 4413 struct sbuf sb; 4414 struct proc *p; 4415 ssize_t maxlen; 4416 u_int namelen; 4417 int error, error2, *name; 4418 4419 namelen = arg2; 4420 if (namelen != 1) 4421 return (EINVAL); 4422 4423 name = (int *)arg1; 4424 4425 sbuf_new_for_sysctl(&sb, NULL, FILEDESC_SBUF_SIZE, req); 4426 sbuf_clear_flags(&sb, SBUF_INCLUDENUL); 4427 error = pget((pid_t)name[0], PGET_CANDEBUG | PGET_NOTWEXIT, &p); 4428 if (error != 0) { 4429 sbuf_delete(&sb); 4430 return (error); 4431 } 4432 maxlen = req->oldptr != NULL ? req->oldlen : -1; 4433 error = kern_proc_filedesc_out(p, &sb, maxlen, 4434 KERN_FILEDESC_PACK_KINFO); 4435 error2 = sbuf_finish(&sb); 4436 sbuf_delete(&sb); 4437 return (error != 0 ? error : error2); 4438 } 4439 4440 #ifdef COMPAT_FREEBSD7 4441 #ifdef KINFO_OFILE_SIZE 4442 CTASSERT(sizeof(struct kinfo_ofile) == KINFO_OFILE_SIZE); 4443 #endif 4444 4445 static void 4446 kinfo_to_okinfo(struct kinfo_file *kif, struct kinfo_ofile *okif) 4447 { 4448 4449 okif->kf_structsize = sizeof(*okif); 4450 okif->kf_type = kif->kf_type; 4451 okif->kf_fd = kif->kf_fd; 4452 okif->kf_ref_count = kif->kf_ref_count; 4453 okif->kf_flags = kif->kf_flags & (KF_FLAG_READ | KF_FLAG_WRITE | 4454 KF_FLAG_APPEND | KF_FLAG_ASYNC | KF_FLAG_FSYNC | KF_FLAG_NONBLOCK | 4455 KF_FLAG_DIRECT | KF_FLAG_HASLOCK); 4456 okif->kf_offset = kif->kf_offset; 4457 if (kif->kf_type == KF_TYPE_VNODE) 4458 okif->kf_vnode_type = kif->kf_un.kf_file.kf_file_type; 4459 else 4460 okif->kf_vnode_type = KF_VTYPE_VNON; 4461 strlcpy(okif->kf_path, kif->kf_path, sizeof(okif->kf_path)); 4462 if (kif->kf_type == KF_TYPE_SOCKET) { 4463 okif->kf_sock_domain = kif->kf_un.kf_sock.kf_sock_domain0; 4464 okif->kf_sock_type = kif->kf_un.kf_sock.kf_sock_type0; 4465 okif->kf_sock_protocol = kif->kf_un.kf_sock.kf_sock_protocol0; 4466 okif->kf_sa_local = kif->kf_un.kf_sock.kf_sa_local; 4467 okif->kf_sa_peer = kif->kf_un.kf_sock.kf_sa_peer; 4468 } else { 4469 okif->kf_sa_local.ss_family = AF_UNSPEC; 4470 okif->kf_sa_peer.ss_family = AF_UNSPEC; 4471 } 4472 } 4473 4474 static int 4475 export_vnode_for_osysctl(struct vnode *vp, int type, struct kinfo_file *kif, 4476 struct kinfo_ofile *okif, struct pwddesc *pdp, struct sysctl_req *req) 4477 { 4478 int error; 4479 4480 vrefact(vp); 4481 PWDDESC_XUNLOCK(pdp); 4482 export_vnode_to_kinfo(vp, type, 0, kif, KERN_FILEDESC_PACK_KINFO); 4483 kinfo_to_okinfo(kif, okif); 4484 error = SYSCTL_OUT(req, okif, sizeof(*okif)); 4485 PWDDESC_XLOCK(pdp); 4486 return (error); 4487 } 4488 4489 /* 4490 * Get per-process file descriptors for use by procstat(1), et al. 4491 */ 4492 static int 4493 sysctl_kern_proc_ofiledesc(SYSCTL_HANDLER_ARGS) 4494 { 4495 struct kinfo_ofile *okif; 4496 struct kinfo_file *kif; 4497 struct filedesc *fdp; 4498 struct pwddesc *pdp; 4499 struct pwd *pwd; 4500 u_int namelen; 4501 int error, i, lastfile, *name; 4502 struct file *fp; 4503 struct proc *p; 4504 4505 namelen = arg2; 4506 if (namelen != 1) 4507 return (EINVAL); 4508 4509 name = (int *)arg1; 4510 error = pget((pid_t)name[0], PGET_CANDEBUG | PGET_NOTWEXIT, &p); 4511 if (error != 0) 4512 return (error); 4513 fdp = fdhold(p); 4514 if (fdp != NULL) 4515 pdp = pdhold(p); 4516 PROC_UNLOCK(p); 4517 if (fdp == NULL || pdp == NULL) { 4518 if (fdp != NULL) 4519 fddrop(fdp); 4520 return (ENOENT); 4521 } 4522 kif = malloc(sizeof(*kif), M_TEMP, M_WAITOK); 4523 okif = malloc(sizeof(*okif), M_TEMP, M_WAITOK); 4524 PWDDESC_XLOCK(pdp); 4525 pwd = pwd_hold_pwddesc(pdp); 4526 if (pwd != NULL) { 4527 if (pwd->pwd_cdir != NULL) 4528 export_vnode_for_osysctl(pwd->pwd_cdir, KF_FD_TYPE_CWD, kif, 4529 okif, pdp, req); 4530 if (pwd->pwd_rdir != NULL) 4531 export_vnode_for_osysctl(pwd->pwd_rdir, KF_FD_TYPE_ROOT, kif, 4532 okif, pdp, req); 4533 if (pwd->pwd_jdir != NULL) 4534 export_vnode_for_osysctl(pwd->pwd_jdir, KF_FD_TYPE_JAIL, kif, 4535 okif, pdp, req); 4536 } 4537 PWDDESC_XUNLOCK(pdp); 4538 if (pwd != NULL) 4539 pwd_drop(pwd); 4540 FILEDESC_SLOCK(fdp); 4541 lastfile = fdlastfile(fdp); 4542 for (i = 0; refcount_load(&fdp->fd_refcnt) > 0 && i <= lastfile; i++) { 4543 if ((fp = fdp->fd_ofiles[i].fde_file) == NULL) 4544 continue; 4545 export_file_to_kinfo(fp, i, NULL, kif, fdp, 4546 KERN_FILEDESC_PACK_KINFO); 4547 FILEDESC_SUNLOCK(fdp); 4548 kinfo_to_okinfo(kif, okif); 4549 error = SYSCTL_OUT(req, okif, sizeof(*okif)); 4550 FILEDESC_SLOCK(fdp); 4551 if (error) 4552 break; 4553 } 4554 FILEDESC_SUNLOCK(fdp); 4555 fddrop(fdp); 4556 pddrop(pdp); 4557 free(kif, M_TEMP); 4558 free(okif, M_TEMP); 4559 return (0); 4560 } 4561 4562 static SYSCTL_NODE(_kern_proc, KERN_PROC_OFILEDESC, ofiledesc, 4563 CTLFLAG_RD|CTLFLAG_MPSAFE, sysctl_kern_proc_ofiledesc, 4564 "Process ofiledesc entries"); 4565 #endif /* COMPAT_FREEBSD7 */ 4566 4567 int 4568 vntype_to_kinfo(int vtype) 4569 { 4570 struct { 4571 int vtype; 4572 int kf_vtype; 4573 } vtypes_table[] = { 4574 { VBAD, KF_VTYPE_VBAD }, 4575 { VBLK, KF_VTYPE_VBLK }, 4576 { VCHR, KF_VTYPE_VCHR }, 4577 { VDIR, KF_VTYPE_VDIR }, 4578 { VFIFO, KF_VTYPE_VFIFO }, 4579 { VLNK, KF_VTYPE_VLNK }, 4580 { VNON, KF_VTYPE_VNON }, 4581 { VREG, KF_VTYPE_VREG }, 4582 { VSOCK, KF_VTYPE_VSOCK } 4583 }; 4584 unsigned int i; 4585 4586 /* 4587 * Perform vtype translation. 4588 */ 4589 for (i = 0; i < nitems(vtypes_table); i++) 4590 if (vtypes_table[i].vtype == vtype) 4591 return (vtypes_table[i].kf_vtype); 4592 4593 return (KF_VTYPE_UNKNOWN); 4594 } 4595 4596 static SYSCTL_NODE(_kern_proc, KERN_PROC_FILEDESC, filedesc, 4597 CTLFLAG_RD|CTLFLAG_MPSAFE, sysctl_kern_proc_filedesc, 4598 "Process filedesc entries"); 4599 4600 /* 4601 * Store a process current working directory information to sbuf. 4602 * 4603 * Takes a locked proc as argument, and returns with the proc unlocked. 4604 */ 4605 int 4606 kern_proc_cwd_out(struct proc *p, struct sbuf *sb, ssize_t maxlen) 4607 { 4608 struct pwddesc *pdp; 4609 struct pwd *pwd; 4610 struct export_fd_buf *efbuf; 4611 struct vnode *cdir; 4612 int error; 4613 4614 PROC_LOCK_ASSERT(p, MA_OWNED); 4615 4616 pdp = pdhold(p); 4617 PROC_UNLOCK(p); 4618 if (pdp == NULL) 4619 return (EINVAL); 4620 4621 efbuf = malloc(sizeof(*efbuf), M_TEMP, M_WAITOK); 4622 efbuf->pdp = pdp; 4623 efbuf->sb = sb; 4624 efbuf->remainder = maxlen; 4625 4626 PWDDESC_XLOCK(pdp); 4627 pwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); 4628 cdir = pwd->pwd_cdir; 4629 if (cdir == NULL) { 4630 error = EINVAL; 4631 } else { 4632 vrefact(cdir); 4633 error = export_vnode_to_sb(cdir, KF_FD_TYPE_CWD, FREAD, efbuf); 4634 } 4635 PWDDESC_XUNLOCK(pdp); 4636 pddrop(pdp); 4637 free(efbuf, M_TEMP); 4638 return (error); 4639 } 4640 4641 /* 4642 * Get per-process current working directory. 4643 */ 4644 static int 4645 sysctl_kern_proc_cwd(SYSCTL_HANDLER_ARGS) 4646 { 4647 struct sbuf sb; 4648 struct proc *p; 4649 ssize_t maxlen; 4650 u_int namelen; 4651 int error, error2, *name; 4652 4653 namelen = arg2; 4654 if (namelen != 1) 4655 return (EINVAL); 4656 4657 name = (int *)arg1; 4658 4659 sbuf_new_for_sysctl(&sb, NULL, sizeof(struct kinfo_file), req); 4660 sbuf_clear_flags(&sb, SBUF_INCLUDENUL); 4661 error = pget((pid_t)name[0], PGET_CANDEBUG | PGET_NOTWEXIT, &p); 4662 if (error != 0) { 4663 sbuf_delete(&sb); 4664 return (error); 4665 } 4666 maxlen = req->oldptr != NULL ? req->oldlen : -1; 4667 error = kern_proc_cwd_out(p, &sb, maxlen); 4668 error2 = sbuf_finish(&sb); 4669 sbuf_delete(&sb); 4670 return (error != 0 ? error : error2); 4671 } 4672 4673 static SYSCTL_NODE(_kern_proc, KERN_PROC_CWD, cwd, CTLFLAG_RD|CTLFLAG_MPSAFE, 4674 sysctl_kern_proc_cwd, "Process current working directory"); 4675 4676 #ifdef DDB 4677 /* 4678 * For the purposes of debugging, generate a human-readable string for the 4679 * file type. 4680 */ 4681 static const char * 4682 file_type_to_name(short type) 4683 { 4684 4685 switch (type) { 4686 case 0: 4687 return ("zero"); 4688 case DTYPE_VNODE: 4689 return ("vnode"); 4690 case DTYPE_SOCKET: 4691 return ("socket"); 4692 case DTYPE_PIPE: 4693 return ("pipe"); 4694 case DTYPE_FIFO: 4695 return ("fifo"); 4696 case DTYPE_KQUEUE: 4697 return ("kqueue"); 4698 case DTYPE_CRYPTO: 4699 return ("crypto"); 4700 case DTYPE_MQUEUE: 4701 return ("mqueue"); 4702 case DTYPE_SHM: 4703 return ("shm"); 4704 case DTYPE_SEM: 4705 return ("ksem"); 4706 case DTYPE_PTS: 4707 return ("pts"); 4708 case DTYPE_DEV: 4709 return ("dev"); 4710 case DTYPE_PROCDESC: 4711 return ("proc"); 4712 case DTYPE_EVENTFD: 4713 return ("eventfd"); 4714 case DTYPE_LINUXTFD: 4715 return ("ltimer"); 4716 default: 4717 return ("unkn"); 4718 } 4719 } 4720 4721 /* 4722 * For the purposes of debugging, identify a process (if any, perhaps one of 4723 * many) that references the passed file in its file descriptor array. Return 4724 * NULL if none. 4725 */ 4726 static struct proc * 4727 file_to_first_proc(struct file *fp) 4728 { 4729 struct filedesc *fdp; 4730 struct proc *p; 4731 int n; 4732 4733 FOREACH_PROC_IN_SYSTEM(p) { 4734 if (p->p_state == PRS_NEW) 4735 continue; 4736 fdp = p->p_fd; 4737 if (fdp == NULL) 4738 continue; 4739 for (n = 0; n < fdp->fd_nfiles; n++) { 4740 if (fp == fdp->fd_ofiles[n].fde_file) 4741 return (p); 4742 } 4743 } 4744 return (NULL); 4745 } 4746 4747 static void 4748 db_print_file(struct file *fp, int header) 4749 { 4750 #define XPTRWIDTH ((int)howmany(sizeof(void *) * NBBY, 4)) 4751 struct proc *p; 4752 4753 if (header) 4754 db_printf("%*s %6s %*s %8s %4s %5s %6s %*s %5s %s\n", 4755 XPTRWIDTH, "File", "Type", XPTRWIDTH, "Data", "Flag", 4756 "GCFl", "Count", "MCount", XPTRWIDTH, "Vnode", "FPID", 4757 "FCmd"); 4758 p = file_to_first_proc(fp); 4759 db_printf("%*p %6s %*p %08x %04x %5d %6d %*p %5d %s\n", XPTRWIDTH, 4760 fp, file_type_to_name(fp->f_type), XPTRWIDTH, fp->f_data, 4761 fp->f_flag, 0, refcount_load(&fp->f_count), 0, XPTRWIDTH, fp->f_vnode, 4762 p != NULL ? p->p_pid : -1, p != NULL ? p->p_comm : "-"); 4763 4764 #undef XPTRWIDTH 4765 } 4766 4767 DB_SHOW_COMMAND(file, db_show_file) 4768 { 4769 struct file *fp; 4770 4771 if (!have_addr) { 4772 db_printf("usage: show file <addr>\n"); 4773 return; 4774 } 4775 fp = (struct file *)addr; 4776 db_print_file(fp, 1); 4777 } 4778 4779 DB_SHOW_COMMAND(files, db_show_files) 4780 { 4781 struct filedesc *fdp; 4782 struct file *fp; 4783 struct proc *p; 4784 int header; 4785 int n; 4786 4787 header = 1; 4788 FOREACH_PROC_IN_SYSTEM(p) { 4789 if (p->p_state == PRS_NEW) 4790 continue; 4791 if ((fdp = p->p_fd) == NULL) 4792 continue; 4793 for (n = 0; n < fdp->fd_nfiles; ++n) { 4794 if ((fp = fdp->fd_ofiles[n].fde_file) == NULL) 4795 continue; 4796 db_print_file(fp, header); 4797 header = 0; 4798 } 4799 } 4800 } 4801 #endif 4802 4803 SYSCTL_INT(_kern, KERN_MAXFILESPERPROC, maxfilesperproc, CTLFLAG_RW, 4804 &maxfilesperproc, 0, "Maximum files allowed open per process"); 4805 4806 SYSCTL_INT(_kern, KERN_MAXFILES, maxfiles, CTLFLAG_RW, 4807 &maxfiles, 0, "Maximum number of files"); 4808 4809 SYSCTL_INT(_kern, OID_AUTO, openfiles, CTLFLAG_RD, 4810 &openfiles, 0, "System-wide number of open files"); 4811 4812 /* ARGSUSED*/ 4813 static void 4814 filelistinit(void *dummy) 4815 { 4816 4817 file_zone = uma_zcreate("Files", sizeof(struct file), NULL, NULL, 4818 NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE); 4819 filedesc0_zone = uma_zcreate("filedesc0", sizeof(struct filedesc0), 4820 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0); 4821 pwd_zone = uma_zcreate("PWD", sizeof(struct pwd), NULL, NULL, 4822 NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_SMR); 4823 /* 4824 * XXXMJG this is a temporary hack due to boot ordering issues against 4825 * the vnode zone. 4826 */ 4827 vfs_smr = uma_zone_get_smr(pwd_zone); 4828 mtx_init(&sigio_lock, "sigio lock", NULL, MTX_DEF); 4829 } 4830 SYSINIT(select, SI_SUB_LOCK, SI_ORDER_FIRST, filelistinit, NULL); 4831 4832 /*-------------------------------------------------------------------*/ 4833 4834 static int 4835 badfo_readwrite(struct file *fp, struct uio *uio, struct ucred *active_cred, 4836 int flags, struct thread *td) 4837 { 4838 4839 return (EBADF); 4840 } 4841 4842 static int 4843 badfo_truncate(struct file *fp, off_t length, struct ucred *active_cred, 4844 struct thread *td) 4845 { 4846 4847 return (EINVAL); 4848 } 4849 4850 static int 4851 badfo_ioctl(struct file *fp, u_long com, void *data, struct ucred *active_cred, 4852 struct thread *td) 4853 { 4854 4855 return (EBADF); 4856 } 4857 4858 static int 4859 badfo_poll(struct file *fp, int events, struct ucred *active_cred, 4860 struct thread *td) 4861 { 4862 4863 return (0); 4864 } 4865 4866 static int 4867 badfo_kqfilter(struct file *fp, struct knote *kn) 4868 { 4869 4870 return (EBADF); 4871 } 4872 4873 static int 4874 badfo_stat(struct file *fp, struct stat *sb, struct ucred *active_cred) 4875 { 4876 4877 return (EBADF); 4878 } 4879 4880 static int 4881 badfo_close(struct file *fp, struct thread *td) 4882 { 4883 4884 return (0); 4885 } 4886 4887 static int 4888 badfo_chmod(struct file *fp, mode_t mode, struct ucred *active_cred, 4889 struct thread *td) 4890 { 4891 4892 return (EBADF); 4893 } 4894 4895 static int 4896 badfo_chown(struct file *fp, uid_t uid, gid_t gid, struct ucred *active_cred, 4897 struct thread *td) 4898 { 4899 4900 return (EBADF); 4901 } 4902 4903 static int 4904 badfo_sendfile(struct file *fp, int sockfd, struct uio *hdr_uio, 4905 struct uio *trl_uio, off_t offset, size_t nbytes, off_t *sent, int flags, 4906 struct thread *td) 4907 { 4908 4909 return (EBADF); 4910 } 4911 4912 static int 4913 badfo_fill_kinfo(struct file *fp, struct kinfo_file *kif, struct filedesc *fdp) 4914 { 4915 4916 return (0); 4917 } 4918 4919 struct fileops badfileops = { 4920 .fo_read = badfo_readwrite, 4921 .fo_write = badfo_readwrite, 4922 .fo_truncate = badfo_truncate, 4923 .fo_ioctl = badfo_ioctl, 4924 .fo_poll = badfo_poll, 4925 .fo_kqfilter = badfo_kqfilter, 4926 .fo_stat = badfo_stat, 4927 .fo_close = badfo_close, 4928 .fo_chmod = badfo_chmod, 4929 .fo_chown = badfo_chown, 4930 .fo_sendfile = badfo_sendfile, 4931 .fo_fill_kinfo = badfo_fill_kinfo, 4932 }; 4933 4934 static int 4935 path_poll(struct file *fp, int events, struct ucred *active_cred, 4936 struct thread *td) 4937 { 4938 return (POLLNVAL); 4939 } 4940 4941 static int 4942 path_close(struct file *fp, struct thread *td) 4943 { 4944 MPASS(fp->f_type == DTYPE_VNODE); 4945 fp->f_ops = &badfileops; 4946 vdrop(fp->f_vnode); 4947 return (0); 4948 } 4949 4950 struct fileops path_fileops = { 4951 .fo_read = badfo_readwrite, 4952 .fo_write = badfo_readwrite, 4953 .fo_truncate = badfo_truncate, 4954 .fo_ioctl = badfo_ioctl, 4955 .fo_poll = path_poll, 4956 .fo_kqfilter = vn_kqfilter_opath, 4957 .fo_stat = vn_statfile, 4958 .fo_close = path_close, 4959 .fo_chmod = badfo_chmod, 4960 .fo_chown = badfo_chown, 4961 .fo_sendfile = badfo_sendfile, 4962 .fo_fill_kinfo = vn_fill_kinfo, 4963 .fo_flags = DFLAG_PASSABLE, 4964 }; 4965 4966 int 4967 invfo_rdwr(struct file *fp, struct uio *uio, struct ucred *active_cred, 4968 int flags, struct thread *td) 4969 { 4970 4971 return (EOPNOTSUPP); 4972 } 4973 4974 int 4975 invfo_truncate(struct file *fp, off_t length, struct ucred *active_cred, 4976 struct thread *td) 4977 { 4978 4979 return (EINVAL); 4980 } 4981 4982 int 4983 invfo_ioctl(struct file *fp, u_long com, void *data, 4984 struct ucred *active_cred, struct thread *td) 4985 { 4986 4987 return (ENOTTY); 4988 } 4989 4990 int 4991 invfo_poll(struct file *fp, int events, struct ucred *active_cred, 4992 struct thread *td) 4993 { 4994 4995 return (poll_no_poll(events)); 4996 } 4997 4998 int 4999 invfo_kqfilter(struct file *fp, struct knote *kn) 5000 { 5001 5002 return (EINVAL); 5003 } 5004 5005 int 5006 invfo_chmod(struct file *fp, mode_t mode, struct ucred *active_cred, 5007 struct thread *td) 5008 { 5009 5010 return (EINVAL); 5011 } 5012 5013 int 5014 invfo_chown(struct file *fp, uid_t uid, gid_t gid, struct ucred *active_cred, 5015 struct thread *td) 5016 { 5017 5018 return (EINVAL); 5019 } 5020 5021 int 5022 invfo_sendfile(struct file *fp, int sockfd, struct uio *hdr_uio, 5023 struct uio *trl_uio, off_t offset, size_t nbytes, off_t *sent, int flags, 5024 struct thread *td) 5025 { 5026 5027 return (EINVAL); 5028 } 5029 5030 /*-------------------------------------------------------------------*/ 5031 5032 /* 5033 * File Descriptor pseudo-device driver (/dev/fd/). 5034 * 5035 * Opening minor device N dup()s the file (if any) connected to file 5036 * descriptor N belonging to the calling process. Note that this driver 5037 * consists of only the ``open()'' routine, because all subsequent 5038 * references to this file will be direct to the other driver. 5039 * 5040 * XXX: we could give this one a cloning event handler if necessary. 5041 */ 5042 5043 /* ARGSUSED */ 5044 static int 5045 fdopen(struct cdev *dev, int mode, int type, struct thread *td) 5046 { 5047 5048 /* 5049 * XXX Kludge: set curthread->td_dupfd to contain the value of the 5050 * the file descriptor being sought for duplication. The error 5051 * return ensures that the vnode for this device will be released 5052 * by vn_open. Open will detect this special error and take the 5053 * actions in dupfdopen below. Other callers of vn_open or VOP_OPEN 5054 * will simply report the error. 5055 */ 5056 td->td_dupfd = dev2unit(dev); 5057 return (ENODEV); 5058 } 5059 5060 static struct cdevsw fildesc_cdevsw = { 5061 .d_version = D_VERSION, 5062 .d_open = fdopen, 5063 .d_name = "FD", 5064 }; 5065 5066 static void 5067 fildesc_drvinit(void *unused) 5068 { 5069 struct cdev *dev; 5070 5071 dev = make_dev_credf(MAKEDEV_ETERNAL, &fildesc_cdevsw, 0, NULL, 5072 UID_ROOT, GID_WHEEL, 0666, "fd/0"); 5073 make_dev_alias(dev, "stdin"); 5074 dev = make_dev_credf(MAKEDEV_ETERNAL, &fildesc_cdevsw, 1, NULL, 5075 UID_ROOT, GID_WHEEL, 0666, "fd/1"); 5076 make_dev_alias(dev, "stdout"); 5077 dev = make_dev_credf(MAKEDEV_ETERNAL, &fildesc_cdevsw, 2, NULL, 5078 UID_ROOT, GID_WHEEL, 0666, "fd/2"); 5079 make_dev_alias(dev, "stderr"); 5080 } 5081 5082 SYSINIT(fildescdev, SI_SUB_DRIVERS, SI_ORDER_MIDDLE, fildesc_drvinit, NULL); 5083