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 || mode == FDDUP_MUSTREPLACE) && 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_MUSTREPLACE: 936 /* Target file descriptor must exist. */ 937 if (fget_locked(fdp, new) == NULL) { 938 fdrop(oldfp, td); 939 goto unlock; 940 } 941 break; 942 case FDDUP_FIXED: 943 if (new >= fdp->fd_nfiles) { 944 /* 945 * The resource limits are here instead of e.g. 946 * fdalloc(), because the file descriptor table may be 947 * shared between processes, so we can't really use 948 * racct_add()/racct_sub(). Instead of counting the 949 * number of actually allocated descriptors, just put 950 * the limit on the size of the file descriptor table. 951 */ 952 #ifdef RACCT 953 if (RACCT_ENABLED()) { 954 error = racct_set_unlocked(p, RACCT_NOFILE, new + 1); 955 if (error != 0) { 956 error = EMFILE; 957 fdrop(oldfp, td); 958 goto unlock; 959 } 960 } 961 #endif 962 fdgrowtable_exp(fdp, new + 1); 963 } 964 if (!fdisused(fdp, new)) 965 fdused(fdp, new); 966 break; 967 default: 968 KASSERT(0, ("%s unsupported mode %d", __func__, mode)); 969 } 970 971 KASSERT(old != new, ("new fd is same as old")); 972 973 /* Refetch oldfde because the table may have grown and old one freed. */ 974 oldfde = &fdp->fd_ofiles[old]; 975 KASSERT(oldfp == oldfde->fde_file, 976 ("fdt_ofiles shift from growth observed at fd %d", 977 old)); 978 979 newfde = &fdp->fd_ofiles[new]; 980 delfp = newfde->fde_file; 981 982 nioctls = filecaps_copy_prep(&oldfde->fde_caps); 983 984 /* 985 * Duplicate the source descriptor. 986 */ 987 #ifdef CAPABILITIES 988 seqc_write_begin(&newfde->fde_seqc); 989 #endif 990 oioctls = filecaps_free_prep(&newfde->fde_caps); 991 memcpy(newfde, oldfde, fde_change_size); 992 filecaps_copy_finish(&oldfde->fde_caps, &newfde->fde_caps, 993 nioctls); 994 if ((flags & FDDUP_FLAG_CLOEXEC) != 0) 995 newfde->fde_flags = oldfde->fde_flags | UF_EXCLOSE; 996 else 997 newfde->fde_flags = oldfde->fde_flags & ~UF_EXCLOSE; 998 #ifdef CAPABILITIES 999 seqc_write_end(&newfde->fde_seqc); 1000 #endif 1001 td->td_retval[0] = new; 1002 1003 error = 0; 1004 1005 if (delfp != NULL) { 1006 (void) closefp(fdp, new, delfp, td, true, false); 1007 FILEDESC_UNLOCK_ASSERT(fdp); 1008 } else { 1009 unlock: 1010 FILEDESC_XUNLOCK(fdp); 1011 } 1012 1013 filecaps_free_finish(oioctls); 1014 return (error); 1015 } 1016 1017 static void 1018 sigiofree(struct sigio *sigio) 1019 { 1020 crfree(sigio->sio_ucred); 1021 free(sigio, M_SIGIO); 1022 } 1023 1024 static struct sigio * 1025 funsetown_locked(struct sigio *sigio) 1026 { 1027 struct proc *p; 1028 struct pgrp *pg; 1029 1030 SIGIO_ASSERT_LOCKED(); 1031 1032 if (sigio == NULL) 1033 return (NULL); 1034 *sigio->sio_myref = NULL; 1035 if (sigio->sio_pgid < 0) { 1036 pg = sigio->sio_pgrp; 1037 PGRP_LOCK(pg); 1038 SLIST_REMOVE(&pg->pg_sigiolst, sigio, sigio, sio_pgsigio); 1039 PGRP_UNLOCK(pg); 1040 } else { 1041 p = sigio->sio_proc; 1042 PROC_LOCK(p); 1043 SLIST_REMOVE(&p->p_sigiolst, sigio, sigio, sio_pgsigio); 1044 PROC_UNLOCK(p); 1045 } 1046 return (sigio); 1047 } 1048 1049 /* 1050 * If sigio is on the list associated with a process or process group, 1051 * disable signalling from the device, remove sigio from the list and 1052 * free sigio. 1053 */ 1054 void 1055 funsetown(struct sigio **sigiop) 1056 { 1057 struct sigio *sigio; 1058 1059 /* Racy check, consumers must provide synchronization. */ 1060 if (*sigiop == NULL) 1061 return; 1062 1063 SIGIO_LOCK(); 1064 sigio = funsetown_locked(*sigiop); 1065 SIGIO_UNLOCK(); 1066 if (sigio != NULL) 1067 sigiofree(sigio); 1068 } 1069 1070 /* 1071 * Free a list of sigio structures. The caller must ensure that new sigio 1072 * structures cannot be added after this point. For process groups this is 1073 * guaranteed using the proctree lock; for processes, the P_WEXIT flag serves 1074 * as an interlock. 1075 */ 1076 void 1077 funsetownlst(struct sigiolst *sigiolst) 1078 { 1079 struct proc *p; 1080 struct pgrp *pg; 1081 struct sigio *sigio, *tmp; 1082 1083 /* Racy check. */ 1084 sigio = SLIST_FIRST(sigiolst); 1085 if (sigio == NULL) 1086 return; 1087 1088 p = NULL; 1089 pg = NULL; 1090 1091 SIGIO_LOCK(); 1092 sigio = SLIST_FIRST(sigiolst); 1093 if (sigio == NULL) { 1094 SIGIO_UNLOCK(); 1095 return; 1096 } 1097 1098 /* 1099 * Every entry of the list should belong to a single proc or pgrp. 1100 */ 1101 if (sigio->sio_pgid < 0) { 1102 pg = sigio->sio_pgrp; 1103 sx_assert(&proctree_lock, SX_XLOCKED); 1104 PGRP_LOCK(pg); 1105 } else /* if (sigio->sio_pgid > 0) */ { 1106 p = sigio->sio_proc; 1107 PROC_LOCK(p); 1108 KASSERT((p->p_flag & P_WEXIT) != 0, 1109 ("%s: process %p is not exiting", __func__, p)); 1110 } 1111 1112 SLIST_FOREACH(sigio, sigiolst, sio_pgsigio) { 1113 *sigio->sio_myref = NULL; 1114 if (pg != NULL) { 1115 KASSERT(sigio->sio_pgid < 0, 1116 ("Proc sigio in pgrp sigio list")); 1117 KASSERT(sigio->sio_pgrp == pg, 1118 ("Bogus pgrp in sigio list")); 1119 } else /* if (p != NULL) */ { 1120 KASSERT(sigio->sio_pgid > 0, 1121 ("Pgrp sigio in proc sigio list")); 1122 KASSERT(sigio->sio_proc == p, 1123 ("Bogus proc in sigio list")); 1124 } 1125 } 1126 1127 if (pg != NULL) 1128 PGRP_UNLOCK(pg); 1129 else 1130 PROC_UNLOCK(p); 1131 SIGIO_UNLOCK(); 1132 1133 SLIST_FOREACH_SAFE(sigio, sigiolst, sio_pgsigio, tmp) 1134 sigiofree(sigio); 1135 } 1136 1137 /* 1138 * This is common code for FIOSETOWN ioctl called by fcntl(fd, F_SETOWN, arg). 1139 * 1140 * After permission checking, add a sigio structure to the sigio list for 1141 * the process or process group. 1142 */ 1143 int 1144 fsetown(pid_t pgid, struct sigio **sigiop) 1145 { 1146 struct proc *proc; 1147 struct pgrp *pgrp; 1148 struct sigio *osigio, *sigio; 1149 int ret; 1150 1151 if (pgid == 0) { 1152 funsetown(sigiop); 1153 return (0); 1154 } 1155 1156 sigio = malloc(sizeof(struct sigio), M_SIGIO, M_WAITOK); 1157 sigio->sio_pgid = pgid; 1158 sigio->sio_ucred = crhold(curthread->td_ucred); 1159 sigio->sio_myref = sigiop; 1160 1161 ret = 0; 1162 if (pgid > 0) { 1163 ret = pget(pgid, PGET_NOTWEXIT | PGET_NOTID | PGET_HOLD, &proc); 1164 SIGIO_LOCK(); 1165 osigio = funsetown_locked(*sigiop); 1166 if (ret == 0) { 1167 PROC_LOCK(proc); 1168 _PRELE(proc); 1169 if ((proc->p_flag & P_WEXIT) != 0) { 1170 ret = ESRCH; 1171 } else if (proc->p_session != 1172 curthread->td_proc->p_session) { 1173 /* 1174 * Policy - Don't allow a process to FSETOWN a 1175 * process in another session. 1176 * 1177 * Remove this test to allow maximum flexibility 1178 * or restrict FSETOWN to the current process or 1179 * process group for maximum safety. 1180 */ 1181 ret = EPERM; 1182 } else { 1183 sigio->sio_proc = proc; 1184 SLIST_INSERT_HEAD(&proc->p_sigiolst, sigio, 1185 sio_pgsigio); 1186 } 1187 PROC_UNLOCK(proc); 1188 } 1189 } else /* if (pgid < 0) */ { 1190 sx_slock(&proctree_lock); 1191 SIGIO_LOCK(); 1192 osigio = funsetown_locked(*sigiop); 1193 pgrp = pgfind(-pgid); 1194 if (pgrp == NULL) { 1195 ret = ESRCH; 1196 } else { 1197 if (pgrp->pg_session != curthread->td_proc->p_session) { 1198 /* 1199 * Policy - Don't allow a process to FSETOWN a 1200 * process in another session. 1201 * 1202 * Remove this test to allow maximum flexibility 1203 * or restrict FSETOWN to the current process or 1204 * process group for maximum safety. 1205 */ 1206 ret = EPERM; 1207 } else { 1208 sigio->sio_pgrp = pgrp; 1209 SLIST_INSERT_HEAD(&pgrp->pg_sigiolst, sigio, 1210 sio_pgsigio); 1211 } 1212 PGRP_UNLOCK(pgrp); 1213 } 1214 sx_sunlock(&proctree_lock); 1215 } 1216 if (ret == 0) 1217 *sigiop = sigio; 1218 SIGIO_UNLOCK(); 1219 if (osigio != NULL) 1220 sigiofree(osigio); 1221 return (ret); 1222 } 1223 1224 /* 1225 * This is common code for FIOGETOWN ioctl called by fcntl(fd, F_GETOWN, arg). 1226 */ 1227 pid_t 1228 fgetown(struct sigio **sigiop) 1229 { 1230 pid_t pgid; 1231 1232 SIGIO_LOCK(); 1233 pgid = (*sigiop != NULL) ? (*sigiop)->sio_pgid : 0; 1234 SIGIO_UNLOCK(); 1235 return (pgid); 1236 } 1237 1238 static int 1239 closefp_impl(struct filedesc *fdp, int fd, struct file *fp, struct thread *td, 1240 bool audit) 1241 { 1242 int error; 1243 1244 FILEDESC_XLOCK_ASSERT(fdp); 1245 1246 /* 1247 * We now hold the fp reference that used to be owned by the 1248 * descriptor array. We have to unlock the FILEDESC *AFTER* 1249 * knote_fdclose to prevent a race of the fd getting opened, a knote 1250 * added, and deleteing a knote for the new fd. 1251 */ 1252 if (__predict_false(!TAILQ_EMPTY(&fdp->fd_kqlist))) 1253 knote_fdclose(td, fd); 1254 1255 /* 1256 * We need to notify mqueue if the object is of type mqueue. 1257 */ 1258 if (__predict_false(fp->f_type == DTYPE_MQUEUE)) 1259 mq_fdclose(td, fd, fp); 1260 FILEDESC_XUNLOCK(fdp); 1261 1262 #ifdef AUDIT 1263 if (AUDITING_TD(td) && audit) 1264 audit_sysclose(td, fd, fp); 1265 #endif 1266 error = closef(fp, td); 1267 1268 /* 1269 * All paths leading up to closefp() will have already removed or 1270 * replaced the fd in the filedesc table, so a restart would not 1271 * operate on the same file. 1272 */ 1273 if (error == ERESTART) 1274 error = EINTR; 1275 1276 return (error); 1277 } 1278 1279 static int 1280 closefp_hl(struct filedesc *fdp, int fd, struct file *fp, struct thread *td, 1281 bool holdleaders, bool audit) 1282 { 1283 int error; 1284 1285 FILEDESC_XLOCK_ASSERT(fdp); 1286 1287 if (holdleaders) { 1288 if (td->td_proc->p_fdtol != NULL) { 1289 /* 1290 * Ask fdfree() to sleep to ensure that all relevant 1291 * process leaders can be traversed in closef(). 1292 */ 1293 fdp->fd_holdleaderscount++; 1294 } else { 1295 holdleaders = false; 1296 } 1297 } 1298 1299 error = closefp_impl(fdp, fd, fp, td, audit); 1300 if (holdleaders) { 1301 FILEDESC_XLOCK(fdp); 1302 fdp->fd_holdleaderscount--; 1303 if (fdp->fd_holdleaderscount == 0 && 1304 fdp->fd_holdleaderswakeup != 0) { 1305 fdp->fd_holdleaderswakeup = 0; 1306 wakeup(&fdp->fd_holdleaderscount); 1307 } 1308 FILEDESC_XUNLOCK(fdp); 1309 } 1310 return (error); 1311 } 1312 1313 static int 1314 closefp(struct filedesc *fdp, int fd, struct file *fp, struct thread *td, 1315 bool holdleaders, bool audit) 1316 { 1317 1318 FILEDESC_XLOCK_ASSERT(fdp); 1319 1320 if (__predict_false(td->td_proc->p_fdtol != NULL)) { 1321 return (closefp_hl(fdp, fd, fp, td, holdleaders, audit)); 1322 } else { 1323 return (closefp_impl(fdp, fd, fp, td, audit)); 1324 } 1325 } 1326 1327 /* 1328 * Close a file descriptor. 1329 */ 1330 #ifndef _SYS_SYSPROTO_H_ 1331 struct close_args { 1332 int fd; 1333 }; 1334 #endif 1335 /* ARGSUSED */ 1336 int 1337 sys_close(struct thread *td, struct close_args *uap) 1338 { 1339 1340 return (kern_close(td, uap->fd)); 1341 } 1342 1343 int 1344 kern_close(struct thread *td, int fd) 1345 { 1346 struct filedesc *fdp; 1347 struct file *fp; 1348 1349 fdp = td->td_proc->p_fd; 1350 1351 FILEDESC_XLOCK(fdp); 1352 if ((fp = fget_locked(fdp, fd)) == NULL) { 1353 FILEDESC_XUNLOCK(fdp); 1354 return (EBADF); 1355 } 1356 fdfree(fdp, fd); 1357 1358 /* closefp() drops the FILEDESC lock for us. */ 1359 return (closefp(fdp, fd, fp, td, true, true)); 1360 } 1361 1362 int 1363 kern_close_range(struct thread *td, u_int lowfd, u_int highfd) 1364 { 1365 struct filedesc *fdp; 1366 const struct fdescenttbl *fdt; 1367 struct file *fp; 1368 int fd; 1369 1370 /* 1371 * Check this prior to clamping; closefrom(3) with only fd 0, 1, and 2 1372 * open should not be a usage error. From a close_range() perspective, 1373 * close_range(3, ~0U, 0) in the same scenario should also likely not 1374 * be a usage error as all fd above 3 are in-fact already closed. 1375 */ 1376 if (highfd < lowfd) { 1377 return (EINVAL); 1378 } 1379 1380 fdp = td->td_proc->p_fd; 1381 FILEDESC_XLOCK(fdp); 1382 fdt = atomic_load_ptr(&fdp->fd_files); 1383 highfd = MIN(highfd, fdt->fdt_nfiles - 1); 1384 fd = lowfd; 1385 if (__predict_false(fd > highfd)) { 1386 goto out_locked; 1387 } 1388 for (;;) { 1389 fp = fdt->fdt_ofiles[fd].fde_file; 1390 if (fp == NULL) { 1391 if (fd == highfd) 1392 goto out_locked; 1393 } else { 1394 fdfree(fdp, fd); 1395 (void) closefp(fdp, fd, fp, td, true, true); 1396 if (fd == highfd) 1397 goto out_unlocked; 1398 FILEDESC_XLOCK(fdp); 1399 fdt = atomic_load_ptr(&fdp->fd_files); 1400 } 1401 fd++; 1402 } 1403 out_locked: 1404 FILEDESC_XUNLOCK(fdp); 1405 out_unlocked: 1406 return (0); 1407 } 1408 1409 #ifndef _SYS_SYSPROTO_H_ 1410 struct close_range_args { 1411 u_int lowfd; 1412 u_int highfd; 1413 int flags; 1414 }; 1415 #endif 1416 int 1417 sys_close_range(struct thread *td, struct close_range_args *uap) 1418 { 1419 1420 AUDIT_ARG_FD(uap->lowfd); 1421 AUDIT_ARG_CMD(uap->highfd); 1422 AUDIT_ARG_FFLAGS(uap->flags); 1423 1424 /* No flags currently defined */ 1425 if (uap->flags != 0) 1426 return (EINVAL); 1427 return (kern_close_range(td, uap->lowfd, uap->highfd)); 1428 } 1429 1430 #ifdef COMPAT_FREEBSD12 1431 /* 1432 * Close open file descriptors. 1433 */ 1434 #ifndef _SYS_SYSPROTO_H_ 1435 struct freebsd12_closefrom_args { 1436 int lowfd; 1437 }; 1438 #endif 1439 /* ARGSUSED */ 1440 int 1441 freebsd12_closefrom(struct thread *td, struct freebsd12_closefrom_args *uap) 1442 { 1443 u_int lowfd; 1444 1445 AUDIT_ARG_FD(uap->lowfd); 1446 1447 /* 1448 * Treat negative starting file descriptor values identical to 1449 * closefrom(0) which closes all files. 1450 */ 1451 lowfd = MAX(0, uap->lowfd); 1452 return (kern_close_range(td, lowfd, ~0U)); 1453 } 1454 #endif /* COMPAT_FREEBSD12 */ 1455 1456 #if defined(COMPAT_43) 1457 /* 1458 * Return status information about a file descriptor. 1459 */ 1460 #ifndef _SYS_SYSPROTO_H_ 1461 struct ofstat_args { 1462 int fd; 1463 struct ostat *sb; 1464 }; 1465 #endif 1466 /* ARGSUSED */ 1467 int 1468 ofstat(struct thread *td, struct ofstat_args *uap) 1469 { 1470 struct ostat oub; 1471 struct stat ub; 1472 int error; 1473 1474 error = kern_fstat(td, uap->fd, &ub); 1475 if (error == 0) { 1476 cvtstat(&ub, &oub); 1477 error = copyout(&oub, uap->sb, sizeof(oub)); 1478 } 1479 return (error); 1480 } 1481 #endif /* COMPAT_43 */ 1482 1483 #if defined(COMPAT_FREEBSD11) 1484 int 1485 freebsd11_fstat(struct thread *td, struct freebsd11_fstat_args *uap) 1486 { 1487 struct stat sb; 1488 struct freebsd11_stat osb; 1489 int error; 1490 1491 error = kern_fstat(td, uap->fd, &sb); 1492 if (error != 0) 1493 return (error); 1494 error = freebsd11_cvtstat(&sb, &osb); 1495 if (error == 0) 1496 error = copyout(&osb, uap->sb, sizeof(osb)); 1497 return (error); 1498 } 1499 #endif /* COMPAT_FREEBSD11 */ 1500 1501 /* 1502 * Return status information about a file descriptor. 1503 */ 1504 #ifndef _SYS_SYSPROTO_H_ 1505 struct fstat_args { 1506 int fd; 1507 struct stat *sb; 1508 }; 1509 #endif 1510 /* ARGSUSED */ 1511 int 1512 sys_fstat(struct thread *td, struct fstat_args *uap) 1513 { 1514 struct stat ub; 1515 int error; 1516 1517 error = kern_fstat(td, uap->fd, &ub); 1518 if (error == 0) 1519 error = copyout(&ub, uap->sb, sizeof(ub)); 1520 return (error); 1521 } 1522 1523 int 1524 kern_fstat(struct thread *td, int fd, struct stat *sbp) 1525 { 1526 struct file *fp; 1527 int error; 1528 1529 AUDIT_ARG_FD(fd); 1530 1531 error = fget(td, fd, &cap_fstat_rights, &fp); 1532 if (__predict_false(error != 0)) 1533 return (error); 1534 1535 AUDIT_ARG_FILE(td->td_proc, fp); 1536 1537 error = fo_stat(fp, sbp, td->td_ucred, td); 1538 fdrop(fp, td); 1539 #ifdef __STAT_TIME_T_EXT 1540 sbp->st_atim_ext = 0; 1541 sbp->st_mtim_ext = 0; 1542 sbp->st_ctim_ext = 0; 1543 sbp->st_btim_ext = 0; 1544 #endif 1545 #ifdef KTRACE 1546 if (KTRPOINT(td, KTR_STRUCT)) 1547 ktrstat_error(sbp, error); 1548 #endif 1549 return (error); 1550 } 1551 1552 #if defined(COMPAT_FREEBSD11) 1553 /* 1554 * Return status information about a file descriptor. 1555 */ 1556 #ifndef _SYS_SYSPROTO_H_ 1557 struct freebsd11_nfstat_args { 1558 int fd; 1559 struct nstat *sb; 1560 }; 1561 #endif 1562 /* ARGSUSED */ 1563 int 1564 freebsd11_nfstat(struct thread *td, struct freebsd11_nfstat_args *uap) 1565 { 1566 struct nstat nub; 1567 struct stat ub; 1568 int error; 1569 1570 error = kern_fstat(td, uap->fd, &ub); 1571 if (error == 0) { 1572 freebsd11_cvtnstat(&ub, &nub); 1573 error = copyout(&nub, uap->sb, sizeof(nub)); 1574 } 1575 return (error); 1576 } 1577 #endif /* COMPAT_FREEBSD11 */ 1578 1579 /* 1580 * Return pathconf information about a file descriptor. 1581 */ 1582 #ifndef _SYS_SYSPROTO_H_ 1583 struct fpathconf_args { 1584 int fd; 1585 int name; 1586 }; 1587 #endif 1588 /* ARGSUSED */ 1589 int 1590 sys_fpathconf(struct thread *td, struct fpathconf_args *uap) 1591 { 1592 long value; 1593 int error; 1594 1595 error = kern_fpathconf(td, uap->fd, uap->name, &value); 1596 if (error == 0) 1597 td->td_retval[0] = value; 1598 return (error); 1599 } 1600 1601 int 1602 kern_fpathconf(struct thread *td, int fd, int name, long *valuep) 1603 { 1604 struct file *fp; 1605 struct vnode *vp; 1606 int error; 1607 1608 error = fget(td, fd, &cap_fpathconf_rights, &fp); 1609 if (error != 0) 1610 return (error); 1611 1612 if (name == _PC_ASYNC_IO) { 1613 *valuep = _POSIX_ASYNCHRONOUS_IO; 1614 goto out; 1615 } 1616 vp = fp->f_vnode; 1617 if (vp != NULL) { 1618 vn_lock(vp, LK_SHARED | LK_RETRY); 1619 error = VOP_PATHCONF(vp, name, valuep); 1620 VOP_UNLOCK(vp); 1621 } else if (fp->f_type == DTYPE_PIPE || fp->f_type == DTYPE_SOCKET) { 1622 if (name != _PC_PIPE_BUF) { 1623 error = EINVAL; 1624 } else { 1625 *valuep = PIPE_BUF; 1626 error = 0; 1627 } 1628 } else { 1629 error = EOPNOTSUPP; 1630 } 1631 out: 1632 fdrop(fp, td); 1633 return (error); 1634 } 1635 1636 /* 1637 * Copy filecaps structure allocating memory for ioctls array if needed. 1638 * 1639 * The last parameter indicates whether the fdtable is locked. If it is not and 1640 * ioctls are encountered, copying fails and the caller must lock the table. 1641 * 1642 * Note that if the table was not locked, the caller has to check the relevant 1643 * sequence counter to determine whether the operation was successful. 1644 */ 1645 bool 1646 filecaps_copy(const struct filecaps *src, struct filecaps *dst, bool locked) 1647 { 1648 size_t size; 1649 1650 if (src->fc_ioctls != NULL && !locked) 1651 return (false); 1652 memcpy(dst, src, sizeof(*src)); 1653 if (src->fc_ioctls == NULL) 1654 return (true); 1655 1656 KASSERT(src->fc_nioctls > 0, 1657 ("fc_ioctls != NULL, but fc_nioctls=%hd", src->fc_nioctls)); 1658 1659 size = sizeof(src->fc_ioctls[0]) * src->fc_nioctls; 1660 dst->fc_ioctls = malloc(size, M_FILECAPS, M_WAITOK); 1661 memcpy(dst->fc_ioctls, src->fc_ioctls, size); 1662 return (true); 1663 } 1664 1665 static u_long * 1666 filecaps_copy_prep(const struct filecaps *src) 1667 { 1668 u_long *ioctls; 1669 size_t size; 1670 1671 if (__predict_true(src->fc_ioctls == NULL)) 1672 return (NULL); 1673 1674 KASSERT(src->fc_nioctls > 0, 1675 ("fc_ioctls != NULL, but fc_nioctls=%hd", src->fc_nioctls)); 1676 1677 size = sizeof(src->fc_ioctls[0]) * src->fc_nioctls; 1678 ioctls = malloc(size, M_FILECAPS, M_WAITOK); 1679 return (ioctls); 1680 } 1681 1682 static void 1683 filecaps_copy_finish(const struct filecaps *src, struct filecaps *dst, 1684 u_long *ioctls) 1685 { 1686 size_t size; 1687 1688 *dst = *src; 1689 if (__predict_true(src->fc_ioctls == NULL)) { 1690 MPASS(ioctls == NULL); 1691 return; 1692 } 1693 1694 size = sizeof(src->fc_ioctls[0]) * src->fc_nioctls; 1695 dst->fc_ioctls = ioctls; 1696 bcopy(src->fc_ioctls, dst->fc_ioctls, size); 1697 } 1698 1699 /* 1700 * Move filecaps structure to the new place and clear the old place. 1701 */ 1702 void 1703 filecaps_move(struct filecaps *src, struct filecaps *dst) 1704 { 1705 1706 *dst = *src; 1707 bzero(src, sizeof(*src)); 1708 } 1709 1710 /* 1711 * Fill the given filecaps structure with full rights. 1712 */ 1713 static void 1714 filecaps_fill(struct filecaps *fcaps) 1715 { 1716 1717 CAP_ALL(&fcaps->fc_rights); 1718 fcaps->fc_ioctls = NULL; 1719 fcaps->fc_nioctls = -1; 1720 fcaps->fc_fcntls = CAP_FCNTL_ALL; 1721 } 1722 1723 /* 1724 * Free memory allocated within filecaps structure. 1725 */ 1726 void 1727 filecaps_free(struct filecaps *fcaps) 1728 { 1729 1730 free(fcaps->fc_ioctls, M_FILECAPS); 1731 bzero(fcaps, sizeof(*fcaps)); 1732 } 1733 1734 static u_long * 1735 filecaps_free_prep(struct filecaps *fcaps) 1736 { 1737 u_long *ioctls; 1738 1739 ioctls = fcaps->fc_ioctls; 1740 bzero(fcaps, sizeof(*fcaps)); 1741 return (ioctls); 1742 } 1743 1744 static void 1745 filecaps_free_finish(u_long *ioctls) 1746 { 1747 1748 free(ioctls, M_FILECAPS); 1749 } 1750 1751 /* 1752 * Validate the given filecaps structure. 1753 */ 1754 static void 1755 filecaps_validate(const struct filecaps *fcaps, const char *func) 1756 { 1757 1758 KASSERT(cap_rights_is_valid(&fcaps->fc_rights), 1759 ("%s: invalid rights", func)); 1760 KASSERT((fcaps->fc_fcntls & ~CAP_FCNTL_ALL) == 0, 1761 ("%s: invalid fcntls", func)); 1762 KASSERT(fcaps->fc_fcntls == 0 || 1763 cap_rights_is_set(&fcaps->fc_rights, CAP_FCNTL), 1764 ("%s: fcntls without CAP_FCNTL", func)); 1765 KASSERT(fcaps->fc_ioctls != NULL ? fcaps->fc_nioctls > 0 : 1766 (fcaps->fc_nioctls == -1 || fcaps->fc_nioctls == 0), 1767 ("%s: invalid ioctls", func)); 1768 KASSERT(fcaps->fc_nioctls == 0 || 1769 cap_rights_is_set(&fcaps->fc_rights, CAP_IOCTL), 1770 ("%s: ioctls without CAP_IOCTL", func)); 1771 } 1772 1773 static void 1774 fdgrowtable_exp(struct filedesc *fdp, int nfd) 1775 { 1776 int nfd1; 1777 1778 FILEDESC_XLOCK_ASSERT(fdp); 1779 1780 nfd1 = fdp->fd_nfiles * 2; 1781 if (nfd1 < nfd) 1782 nfd1 = nfd; 1783 fdgrowtable(fdp, nfd1); 1784 } 1785 1786 /* 1787 * Grow the file table to accommodate (at least) nfd descriptors. 1788 */ 1789 static void 1790 fdgrowtable(struct filedesc *fdp, int nfd) 1791 { 1792 struct filedesc0 *fdp0; 1793 struct freetable *ft; 1794 struct fdescenttbl *ntable; 1795 struct fdescenttbl *otable; 1796 int nnfiles, onfiles; 1797 NDSLOTTYPE *nmap, *omap; 1798 1799 KASSERT(fdp->fd_nfiles > 0, ("zero-length file table")); 1800 1801 /* save old values */ 1802 onfiles = fdp->fd_nfiles; 1803 otable = fdp->fd_files; 1804 omap = fdp->fd_map; 1805 1806 /* compute the size of the new table */ 1807 nnfiles = NDSLOTS(nfd) * NDENTRIES; /* round up */ 1808 if (nnfiles <= onfiles) 1809 /* the table is already large enough */ 1810 return; 1811 1812 /* 1813 * Allocate a new table. We need enough space for the number of 1814 * entries, file entries themselves and the struct freetable we will use 1815 * when we decommission the table and place it on the freelist. 1816 * We place the struct freetable in the middle so we don't have 1817 * to worry about padding. 1818 */ 1819 ntable = malloc(offsetof(struct fdescenttbl, fdt_ofiles) + 1820 nnfiles * sizeof(ntable->fdt_ofiles[0]) + 1821 sizeof(struct freetable), 1822 M_FILEDESC, M_ZERO | M_WAITOK); 1823 /* copy the old data */ 1824 ntable->fdt_nfiles = nnfiles; 1825 memcpy(ntable->fdt_ofiles, otable->fdt_ofiles, 1826 onfiles * sizeof(ntable->fdt_ofiles[0])); 1827 1828 /* 1829 * Allocate a new map only if the old is not large enough. It will 1830 * grow at a slower rate than the table as it can map more 1831 * entries than the table can hold. 1832 */ 1833 if (NDSLOTS(nnfiles) > NDSLOTS(onfiles)) { 1834 nmap = malloc(NDSLOTS(nnfiles) * NDSLOTSIZE, M_FILEDESC, 1835 M_ZERO | M_WAITOK); 1836 /* copy over the old data and update the pointer */ 1837 memcpy(nmap, omap, NDSLOTS(onfiles) * sizeof(*omap)); 1838 fdp->fd_map = nmap; 1839 } 1840 1841 /* 1842 * Make sure that ntable is correctly initialized before we replace 1843 * fd_files poiner. Otherwise fget_unlocked() may see inconsistent 1844 * data. 1845 */ 1846 atomic_store_rel_ptr((volatile void *)&fdp->fd_files, (uintptr_t)ntable); 1847 1848 /* 1849 * Free the old file table when not shared by other threads or processes. 1850 * The old file table is considered to be shared when either are true: 1851 * - The process has more than one thread. 1852 * - The file descriptor table has been shared via fdshare(). 1853 * 1854 * When shared, the old file table will be placed on a freelist 1855 * which will be processed when the struct filedesc is released. 1856 * 1857 * Note that if onfiles == NDFILE, we're dealing with the original 1858 * static allocation contained within (struct filedesc0 *)fdp, 1859 * which must not be freed. 1860 */ 1861 if (onfiles > NDFILE) { 1862 /* 1863 * Note we may be called here from fdinit while allocating a 1864 * table for a new process in which case ->p_fd points 1865 * elsewhere. 1866 */ 1867 if (curproc->p_fd != fdp || FILEDESC_IS_ONLY_USER(fdp)) { 1868 free(otable, M_FILEDESC); 1869 } else { 1870 ft = (struct freetable *)&otable->fdt_ofiles[onfiles]; 1871 fdp0 = (struct filedesc0 *)fdp; 1872 ft->ft_table = otable; 1873 SLIST_INSERT_HEAD(&fdp0->fd_free, ft, ft_next); 1874 } 1875 } 1876 /* 1877 * The map does not have the same possibility of threads still 1878 * holding references to it. So always free it as long as it 1879 * does not reference the original static allocation. 1880 */ 1881 if (NDSLOTS(onfiles) > NDSLOTS(NDFILE)) 1882 free(omap, M_FILEDESC); 1883 } 1884 1885 /* 1886 * Allocate a file descriptor for the process. 1887 */ 1888 int 1889 fdalloc(struct thread *td, int minfd, int *result) 1890 { 1891 struct proc *p = td->td_proc; 1892 struct filedesc *fdp = p->p_fd; 1893 int fd, maxfd, allocfd; 1894 #ifdef RACCT 1895 int error; 1896 #endif 1897 1898 FILEDESC_XLOCK_ASSERT(fdp); 1899 1900 if (fdp->fd_freefile > minfd) 1901 minfd = fdp->fd_freefile; 1902 1903 maxfd = getmaxfd(td); 1904 1905 /* 1906 * Search the bitmap for a free descriptor starting at minfd. 1907 * If none is found, grow the file table. 1908 */ 1909 fd = fd_first_free(fdp, minfd, fdp->fd_nfiles); 1910 if (__predict_false(fd >= maxfd)) 1911 return (EMFILE); 1912 if (__predict_false(fd >= fdp->fd_nfiles)) { 1913 allocfd = min(fd * 2, maxfd); 1914 #ifdef RACCT 1915 if (RACCT_ENABLED()) { 1916 error = racct_set_unlocked(p, RACCT_NOFILE, allocfd); 1917 if (error != 0) 1918 return (EMFILE); 1919 } 1920 #endif 1921 /* 1922 * fd is already equal to first free descriptor >= minfd, so 1923 * we only need to grow the table and we are done. 1924 */ 1925 fdgrowtable_exp(fdp, allocfd); 1926 } 1927 1928 /* 1929 * Perform some sanity checks, then mark the file descriptor as 1930 * used and return it to the caller. 1931 */ 1932 KASSERT(fd >= 0 && fd < min(maxfd, fdp->fd_nfiles), 1933 ("invalid descriptor %d", fd)); 1934 KASSERT(!fdisused(fdp, fd), 1935 ("fd_first_free() returned non-free descriptor")); 1936 KASSERT(fdp->fd_ofiles[fd].fde_file == NULL, 1937 ("file descriptor isn't free")); 1938 fdused(fdp, fd); 1939 *result = fd; 1940 return (0); 1941 } 1942 1943 /* 1944 * Allocate n file descriptors for the process. 1945 */ 1946 int 1947 fdallocn(struct thread *td, int minfd, int *fds, int n) 1948 { 1949 struct proc *p = td->td_proc; 1950 struct filedesc *fdp = p->p_fd; 1951 int i; 1952 1953 FILEDESC_XLOCK_ASSERT(fdp); 1954 1955 for (i = 0; i < n; i++) 1956 if (fdalloc(td, 0, &fds[i]) != 0) 1957 break; 1958 1959 if (i < n) { 1960 for (i--; i >= 0; i--) 1961 fdunused(fdp, fds[i]); 1962 return (EMFILE); 1963 } 1964 1965 return (0); 1966 } 1967 1968 /* 1969 * Create a new open file structure and allocate a file descriptor for the 1970 * process that refers to it. We add one reference to the file for the 1971 * descriptor table and one reference for resultfp. This is to prevent us 1972 * being preempted and the entry in the descriptor table closed after we 1973 * release the FILEDESC lock. 1974 */ 1975 int 1976 falloc_caps(struct thread *td, struct file **resultfp, int *resultfd, int flags, 1977 struct filecaps *fcaps) 1978 { 1979 struct file *fp; 1980 int error, fd; 1981 1982 MPASS(resultfp != NULL); 1983 MPASS(resultfd != NULL); 1984 1985 error = _falloc_noinstall(td, &fp, 2); 1986 if (__predict_false(error != 0)) { 1987 return (error); 1988 } 1989 1990 error = finstall_refed(td, fp, &fd, flags, fcaps); 1991 if (__predict_false(error != 0)) { 1992 falloc_abort(td, fp); 1993 return (error); 1994 } 1995 1996 *resultfp = fp; 1997 *resultfd = fd; 1998 1999 return (0); 2000 } 2001 2002 /* 2003 * Create a new open file structure without allocating a file descriptor. 2004 */ 2005 int 2006 _falloc_noinstall(struct thread *td, struct file **resultfp, u_int n) 2007 { 2008 struct file *fp; 2009 int maxuserfiles = maxfiles - (maxfiles / 20); 2010 int openfiles_new; 2011 static struct timeval lastfail; 2012 static int curfail; 2013 2014 KASSERT(resultfp != NULL, ("%s: resultfp == NULL", __func__)); 2015 MPASS(n > 0); 2016 2017 openfiles_new = atomic_fetchadd_int(&openfiles, 1) + 1; 2018 if ((openfiles_new >= maxuserfiles && 2019 priv_check(td, PRIV_MAXFILES) != 0) || 2020 openfiles_new >= maxfiles) { 2021 atomic_subtract_int(&openfiles, 1); 2022 if (ppsratecheck(&lastfail, &curfail, 1)) { 2023 printf("kern.maxfiles limit exceeded by uid %i, (%s) " 2024 "please see tuning(7).\n", td->td_ucred->cr_ruid, td->td_proc->p_comm); 2025 } 2026 return (ENFILE); 2027 } 2028 fp = uma_zalloc(file_zone, M_WAITOK); 2029 bzero(fp, sizeof(*fp)); 2030 refcount_init(&fp->f_count, n); 2031 fp->f_cred = crhold(td->td_ucred); 2032 fp->f_ops = &badfileops; 2033 *resultfp = fp; 2034 return (0); 2035 } 2036 2037 void 2038 falloc_abort(struct thread *td, struct file *fp) 2039 { 2040 2041 /* 2042 * For assertion purposes. 2043 */ 2044 refcount_init(&fp->f_count, 0); 2045 _fdrop(fp, td); 2046 } 2047 2048 /* 2049 * Install a file in a file descriptor table. 2050 */ 2051 void 2052 _finstall(struct filedesc *fdp, struct file *fp, int fd, int flags, 2053 struct filecaps *fcaps) 2054 { 2055 struct filedescent *fde; 2056 2057 MPASS(fp != NULL); 2058 if (fcaps != NULL) 2059 filecaps_validate(fcaps, __func__); 2060 FILEDESC_XLOCK_ASSERT(fdp); 2061 2062 fde = &fdp->fd_ofiles[fd]; 2063 #ifdef CAPABILITIES 2064 seqc_write_begin(&fde->fde_seqc); 2065 #endif 2066 fde->fde_file = fp; 2067 fde->fde_flags = (flags & O_CLOEXEC) != 0 ? UF_EXCLOSE : 0; 2068 if (fcaps != NULL) 2069 filecaps_move(fcaps, &fde->fde_caps); 2070 else 2071 filecaps_fill(&fde->fde_caps); 2072 #ifdef CAPABILITIES 2073 seqc_write_end(&fde->fde_seqc); 2074 #endif 2075 } 2076 2077 int 2078 finstall_refed(struct thread *td, struct file *fp, int *fd, int flags, 2079 struct filecaps *fcaps) 2080 { 2081 struct filedesc *fdp = td->td_proc->p_fd; 2082 int error; 2083 2084 MPASS(fd != NULL); 2085 2086 FILEDESC_XLOCK(fdp); 2087 error = fdalloc(td, 0, fd); 2088 if (__predict_true(error == 0)) { 2089 _finstall(fdp, fp, *fd, flags, fcaps); 2090 } 2091 FILEDESC_XUNLOCK(fdp); 2092 return (error); 2093 } 2094 2095 int 2096 finstall(struct thread *td, struct file *fp, int *fd, int flags, 2097 struct filecaps *fcaps) 2098 { 2099 int error; 2100 2101 MPASS(fd != NULL); 2102 2103 if (!fhold(fp)) 2104 return (EBADF); 2105 error = finstall_refed(td, fp, fd, flags, fcaps); 2106 if (__predict_false(error != 0)) { 2107 fdrop(fp, td); 2108 } 2109 return (error); 2110 } 2111 2112 /* 2113 * Build a new filedesc structure from another. 2114 * 2115 * If fdp is not NULL, return with it shared locked. 2116 */ 2117 struct filedesc * 2118 fdinit(struct filedesc *fdp, bool prepfiles, int *lastfile) 2119 { 2120 struct filedesc0 *newfdp0; 2121 struct filedesc *newfdp; 2122 2123 if (prepfiles) 2124 MPASS(lastfile != NULL); 2125 else 2126 MPASS(lastfile == NULL); 2127 2128 newfdp0 = uma_zalloc(filedesc0_zone, M_WAITOK | M_ZERO); 2129 newfdp = &newfdp0->fd_fd; 2130 2131 /* Create the file descriptor table. */ 2132 FILEDESC_LOCK_INIT(newfdp); 2133 refcount_init(&newfdp->fd_refcnt, 1); 2134 refcount_init(&newfdp->fd_holdcnt, 1); 2135 newfdp->fd_map = newfdp0->fd_dmap; 2136 newfdp->fd_files = (struct fdescenttbl *)&newfdp0->fd_dfiles; 2137 newfdp->fd_files->fdt_nfiles = NDFILE; 2138 2139 if (fdp == NULL) 2140 return (newfdp); 2141 2142 FILEDESC_SLOCK(fdp); 2143 if (!prepfiles) { 2144 FILEDESC_SUNLOCK(fdp); 2145 return (newfdp); 2146 } 2147 2148 for (;;) { 2149 *lastfile = fdlastfile(fdp); 2150 if (*lastfile < newfdp->fd_nfiles) 2151 break; 2152 FILEDESC_SUNLOCK(fdp); 2153 fdgrowtable(newfdp, *lastfile + 1); 2154 FILEDESC_SLOCK(fdp); 2155 } 2156 2157 return (newfdp); 2158 } 2159 2160 /* 2161 * Build a pwddesc structure from another. 2162 * Copy the current, root, and jail root vnode references. 2163 * 2164 * If pdp is not NULL, return with it shared locked. 2165 */ 2166 struct pwddesc * 2167 pdinit(struct pwddesc *pdp, bool keeplock) 2168 { 2169 struct pwddesc *newpdp; 2170 struct pwd *newpwd; 2171 2172 newpdp = malloc(sizeof(*newpdp), M_PWDDESC, M_WAITOK | M_ZERO); 2173 2174 PWDDESC_LOCK_INIT(newpdp); 2175 refcount_init(&newpdp->pd_refcount, 1); 2176 newpdp->pd_cmask = CMASK; 2177 2178 if (pdp == NULL) { 2179 newpwd = pwd_alloc(); 2180 smr_serialized_store(&newpdp->pd_pwd, newpwd, true); 2181 return (newpdp); 2182 } 2183 2184 PWDDESC_XLOCK(pdp); 2185 newpwd = pwd_hold_pwddesc(pdp); 2186 smr_serialized_store(&newpdp->pd_pwd, newpwd, true); 2187 if (!keeplock) 2188 PWDDESC_XUNLOCK(pdp); 2189 return (newpdp); 2190 } 2191 2192 /* 2193 * Hold either filedesc or pwddesc of the passed process. 2194 * 2195 * The process lock is used to synchronize against the target exiting and 2196 * freeing the data. 2197 * 2198 * Clearing can be ilustrated in 3 steps: 2199 * 1. set the pointer to NULL. Either routine can race against it, hence 2200 * atomic_load_ptr. 2201 * 2. observe the process lock as not taken. Until then fdhold/pdhold can 2202 * race to either still see the pointer or find NULL. It is still safe to 2203 * grab a reference as clearing is stalled. 2204 * 3. after the lock is observed as not taken, any fdhold/pdhold calls are 2205 * guaranteed to see NULL, making it safe to finish clearing 2206 */ 2207 static struct filedesc * 2208 fdhold(struct proc *p) 2209 { 2210 struct filedesc *fdp; 2211 2212 PROC_LOCK_ASSERT(p, MA_OWNED); 2213 fdp = atomic_load_ptr(&p->p_fd); 2214 if (fdp != NULL) 2215 refcount_acquire(&fdp->fd_holdcnt); 2216 return (fdp); 2217 } 2218 2219 static struct pwddesc * 2220 pdhold(struct proc *p) 2221 { 2222 struct pwddesc *pdp; 2223 2224 PROC_LOCK_ASSERT(p, MA_OWNED); 2225 pdp = atomic_load_ptr(&p->p_pd); 2226 if (pdp != NULL) 2227 refcount_acquire(&pdp->pd_refcount); 2228 return (pdp); 2229 } 2230 2231 static void 2232 fddrop(struct filedesc *fdp) 2233 { 2234 2235 if (refcount_load(&fdp->fd_holdcnt) > 1) { 2236 if (refcount_release(&fdp->fd_holdcnt) == 0) 2237 return; 2238 } 2239 2240 FILEDESC_LOCK_DESTROY(fdp); 2241 uma_zfree(filedesc0_zone, fdp); 2242 } 2243 2244 static void 2245 pddrop(struct pwddesc *pdp) 2246 { 2247 struct pwd *pwd; 2248 2249 if (refcount_release_if_not_last(&pdp->pd_refcount)) 2250 return; 2251 2252 PWDDESC_XLOCK(pdp); 2253 if (refcount_release(&pdp->pd_refcount) == 0) { 2254 PWDDESC_XUNLOCK(pdp); 2255 return; 2256 } 2257 pwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); 2258 pwd_set(pdp, NULL); 2259 PWDDESC_XUNLOCK(pdp); 2260 pwd_drop(pwd); 2261 2262 PWDDESC_LOCK_DESTROY(pdp); 2263 free(pdp, M_PWDDESC); 2264 } 2265 2266 /* 2267 * Share a filedesc structure. 2268 */ 2269 struct filedesc * 2270 fdshare(struct filedesc *fdp) 2271 { 2272 2273 refcount_acquire(&fdp->fd_refcnt); 2274 return (fdp); 2275 } 2276 2277 /* 2278 * Share a pwddesc structure. 2279 */ 2280 struct pwddesc * 2281 pdshare(struct pwddesc *pdp) 2282 { 2283 refcount_acquire(&pdp->pd_refcount); 2284 return (pdp); 2285 } 2286 2287 /* 2288 * Unshare a filedesc structure, if necessary by making a copy 2289 */ 2290 void 2291 fdunshare(struct thread *td) 2292 { 2293 struct filedesc *tmp; 2294 struct proc *p = td->td_proc; 2295 2296 if (refcount_load(&p->p_fd->fd_refcnt) == 1) 2297 return; 2298 2299 tmp = fdcopy(p->p_fd); 2300 fdescfree(td); 2301 p->p_fd = tmp; 2302 } 2303 2304 /* 2305 * Unshare a pwddesc structure. 2306 */ 2307 void 2308 pdunshare(struct thread *td) 2309 { 2310 struct pwddesc *pdp; 2311 struct proc *p; 2312 2313 p = td->td_proc; 2314 /* Not shared. */ 2315 if (p->p_pd->pd_refcount == 1) 2316 return; 2317 2318 pdp = pdcopy(p->p_pd); 2319 pdescfree(td); 2320 p->p_pd = pdp; 2321 } 2322 2323 void 2324 fdinstall_remapped(struct thread *td, struct filedesc *fdp) 2325 { 2326 2327 fdescfree(td); 2328 td->td_proc->p_fd = fdp; 2329 } 2330 2331 /* 2332 * Copy a filedesc structure. A NULL pointer in returns a NULL reference, 2333 * this is to ease callers, not catch errors. 2334 */ 2335 struct filedesc * 2336 fdcopy(struct filedesc *fdp) 2337 { 2338 struct filedesc *newfdp; 2339 struct filedescent *nfde, *ofde; 2340 int i, lastfile; 2341 2342 MPASS(fdp != NULL); 2343 2344 newfdp = fdinit(fdp, true, &lastfile); 2345 /* copy all passable descriptors (i.e. not kqueue) */ 2346 newfdp->fd_freefile = -1; 2347 for (i = 0; i <= lastfile; ++i) { 2348 ofde = &fdp->fd_ofiles[i]; 2349 if (ofde->fde_file == NULL || 2350 (ofde->fde_file->f_ops->fo_flags & DFLAG_PASSABLE) == 0 || 2351 !fhold(ofde->fde_file)) { 2352 if (newfdp->fd_freefile == -1) 2353 newfdp->fd_freefile = i; 2354 continue; 2355 } 2356 nfde = &newfdp->fd_ofiles[i]; 2357 *nfde = *ofde; 2358 filecaps_copy(&ofde->fde_caps, &nfde->fde_caps, true); 2359 fdused_init(newfdp, i); 2360 } 2361 if (newfdp->fd_freefile == -1) 2362 newfdp->fd_freefile = i; 2363 FILEDESC_SUNLOCK(fdp); 2364 return (newfdp); 2365 } 2366 2367 /* 2368 * Copy a pwddesc structure. 2369 */ 2370 struct pwddesc * 2371 pdcopy(struct pwddesc *pdp) 2372 { 2373 struct pwddesc *newpdp; 2374 2375 MPASS(pdp != NULL); 2376 2377 newpdp = pdinit(pdp, true); 2378 newpdp->pd_cmask = pdp->pd_cmask; 2379 PWDDESC_XUNLOCK(pdp); 2380 return (newpdp); 2381 } 2382 2383 /* 2384 * Copies a filedesc structure, while remapping all file descriptors 2385 * stored inside using a translation table. 2386 * 2387 * File descriptors are copied over to the new file descriptor table, 2388 * regardless of whether the close-on-exec flag is set. 2389 */ 2390 int 2391 fdcopy_remapped(struct filedesc *fdp, const int *fds, size_t nfds, 2392 struct filedesc **ret) 2393 { 2394 struct filedesc *newfdp; 2395 struct filedescent *nfde, *ofde; 2396 int error, i, lastfile; 2397 2398 MPASS(fdp != NULL); 2399 2400 newfdp = fdinit(fdp, true, &lastfile); 2401 if (nfds > lastfile + 1) { 2402 /* New table cannot be larger than the old one. */ 2403 error = E2BIG; 2404 goto bad; 2405 } 2406 /* Copy all passable descriptors (i.e. not kqueue). */ 2407 newfdp->fd_freefile = nfds; 2408 for (i = 0; i < nfds; ++i) { 2409 if (fds[i] < 0 || fds[i] > lastfile) { 2410 /* File descriptor out of bounds. */ 2411 error = EBADF; 2412 goto bad; 2413 } 2414 ofde = &fdp->fd_ofiles[fds[i]]; 2415 if (ofde->fde_file == NULL) { 2416 /* Unused file descriptor. */ 2417 error = EBADF; 2418 goto bad; 2419 } 2420 if ((ofde->fde_file->f_ops->fo_flags & DFLAG_PASSABLE) == 0) { 2421 /* File descriptor cannot be passed. */ 2422 error = EINVAL; 2423 goto bad; 2424 } 2425 if (!fhold(ofde->fde_file)) { 2426 error = EBADF; 2427 goto bad; 2428 } 2429 nfde = &newfdp->fd_ofiles[i]; 2430 *nfde = *ofde; 2431 filecaps_copy(&ofde->fde_caps, &nfde->fde_caps, true); 2432 fdused_init(newfdp, i); 2433 } 2434 FILEDESC_SUNLOCK(fdp); 2435 *ret = newfdp; 2436 return (0); 2437 bad: 2438 FILEDESC_SUNLOCK(fdp); 2439 fdescfree_remapped(newfdp); 2440 return (error); 2441 } 2442 2443 /* 2444 * Clear POSIX style locks. This is only used when fdp looses a reference (i.e. 2445 * one of processes using it exits) and the table used to be shared. 2446 */ 2447 static void 2448 fdclearlocks(struct thread *td) 2449 { 2450 struct filedesc *fdp; 2451 struct filedesc_to_leader *fdtol; 2452 struct flock lf; 2453 struct file *fp; 2454 struct proc *p; 2455 struct vnode *vp; 2456 int i, lastfile; 2457 2458 p = td->td_proc; 2459 fdp = p->p_fd; 2460 fdtol = p->p_fdtol; 2461 MPASS(fdtol != NULL); 2462 2463 FILEDESC_XLOCK(fdp); 2464 KASSERT(fdtol->fdl_refcount > 0, 2465 ("filedesc_to_refcount botch: fdl_refcount=%d", 2466 fdtol->fdl_refcount)); 2467 if (fdtol->fdl_refcount == 1 && 2468 (p->p_leader->p_flag & P_ADVLOCK) != 0) { 2469 lastfile = fdlastfile(fdp); 2470 for (i = 0; i <= lastfile; i++) { 2471 fp = fdp->fd_ofiles[i].fde_file; 2472 if (fp == NULL || fp->f_type != DTYPE_VNODE || 2473 !fhold(fp)) 2474 continue; 2475 FILEDESC_XUNLOCK(fdp); 2476 lf.l_whence = SEEK_SET; 2477 lf.l_start = 0; 2478 lf.l_len = 0; 2479 lf.l_type = F_UNLCK; 2480 vp = fp->f_vnode; 2481 (void) VOP_ADVLOCK(vp, 2482 (caddr_t)p->p_leader, F_UNLCK, 2483 &lf, F_POSIX); 2484 FILEDESC_XLOCK(fdp); 2485 fdrop(fp, td); 2486 } 2487 } 2488 retry: 2489 if (fdtol->fdl_refcount == 1) { 2490 if (fdp->fd_holdleaderscount > 0 && 2491 (p->p_leader->p_flag & P_ADVLOCK) != 0) { 2492 /* 2493 * close() or kern_dup() has cleared a reference 2494 * in a shared file descriptor table. 2495 */ 2496 fdp->fd_holdleaderswakeup = 1; 2497 sx_sleep(&fdp->fd_holdleaderscount, 2498 FILEDESC_LOCK(fdp), PLOCK, "fdlhold", 0); 2499 goto retry; 2500 } 2501 if (fdtol->fdl_holdcount > 0) { 2502 /* 2503 * Ensure that fdtol->fdl_leader remains 2504 * valid in closef(). 2505 */ 2506 fdtol->fdl_wakeup = 1; 2507 sx_sleep(fdtol, FILEDESC_LOCK(fdp), PLOCK, 2508 "fdlhold", 0); 2509 goto retry; 2510 } 2511 } 2512 fdtol->fdl_refcount--; 2513 if (fdtol->fdl_refcount == 0 && 2514 fdtol->fdl_holdcount == 0) { 2515 fdtol->fdl_next->fdl_prev = fdtol->fdl_prev; 2516 fdtol->fdl_prev->fdl_next = fdtol->fdl_next; 2517 } else 2518 fdtol = NULL; 2519 p->p_fdtol = NULL; 2520 FILEDESC_XUNLOCK(fdp); 2521 if (fdtol != NULL) 2522 free(fdtol, M_FILEDESC_TO_LEADER); 2523 } 2524 2525 /* 2526 * Release a filedesc structure. 2527 */ 2528 static void 2529 fdescfree_fds(struct thread *td, struct filedesc *fdp, bool needclose) 2530 { 2531 struct filedesc0 *fdp0; 2532 struct freetable *ft, *tft; 2533 struct filedescent *fde; 2534 struct file *fp; 2535 int i, lastfile; 2536 2537 KASSERT(refcount_load(&fdp->fd_refcnt) == 0, 2538 ("%s: fd table %p carries references", __func__, fdp)); 2539 2540 /* 2541 * Serialize with threads iterating over the table, if any. 2542 */ 2543 if (refcount_load(&fdp->fd_holdcnt) > 1) { 2544 FILEDESC_XLOCK(fdp); 2545 FILEDESC_XUNLOCK(fdp); 2546 } 2547 2548 lastfile = fdlastfile_single(fdp); 2549 for (i = 0; i <= lastfile; i++) { 2550 fde = &fdp->fd_ofiles[i]; 2551 fp = fde->fde_file; 2552 if (fp != NULL) { 2553 fdefree_last(fde); 2554 if (needclose) 2555 (void) closef(fp, td); 2556 else 2557 fdrop(fp, td); 2558 } 2559 } 2560 2561 if (NDSLOTS(fdp->fd_nfiles) > NDSLOTS(NDFILE)) 2562 free(fdp->fd_map, M_FILEDESC); 2563 if (fdp->fd_nfiles > NDFILE) 2564 free(fdp->fd_files, M_FILEDESC); 2565 2566 fdp0 = (struct filedesc0 *)fdp; 2567 SLIST_FOREACH_SAFE(ft, &fdp0->fd_free, ft_next, tft) 2568 free(ft->ft_table, M_FILEDESC); 2569 2570 fddrop(fdp); 2571 } 2572 2573 void 2574 fdescfree(struct thread *td) 2575 { 2576 struct proc *p; 2577 struct filedesc *fdp; 2578 2579 p = td->td_proc; 2580 fdp = p->p_fd; 2581 MPASS(fdp != NULL); 2582 2583 #ifdef RACCT 2584 if (RACCT_ENABLED()) 2585 racct_set_unlocked(p, RACCT_NOFILE, 0); 2586 #endif 2587 2588 if (p->p_fdtol != NULL) 2589 fdclearlocks(td); 2590 2591 /* 2592 * Check fdhold for an explanation. 2593 */ 2594 atomic_store_ptr(&p->p_fd, NULL); 2595 atomic_thread_fence_seq_cst(); 2596 PROC_WAIT_UNLOCKED(p); 2597 2598 if (refcount_release(&fdp->fd_refcnt) == 0) 2599 return; 2600 2601 fdescfree_fds(td, fdp, 1); 2602 } 2603 2604 void 2605 pdescfree(struct thread *td) 2606 { 2607 struct proc *p; 2608 struct pwddesc *pdp; 2609 2610 p = td->td_proc; 2611 pdp = p->p_pd; 2612 MPASS(pdp != NULL); 2613 2614 /* 2615 * Check pdhold for an explanation. 2616 */ 2617 atomic_store_ptr(&p->p_pd, NULL); 2618 atomic_thread_fence_seq_cst(); 2619 PROC_WAIT_UNLOCKED(p); 2620 2621 pddrop(pdp); 2622 } 2623 2624 void 2625 fdescfree_remapped(struct filedesc *fdp) 2626 { 2627 #ifdef INVARIANTS 2628 /* fdescfree_fds() asserts that fd_refcnt == 0. */ 2629 if (!refcount_release(&fdp->fd_refcnt)) 2630 panic("%s: fd table %p has extra references", __func__, fdp); 2631 #endif 2632 fdescfree_fds(curthread, fdp, 0); 2633 } 2634 2635 /* 2636 * For setugid programs, we don't want to people to use that setugidness 2637 * to generate error messages which write to a file which otherwise would 2638 * otherwise be off-limits to the process. We check for filesystems where 2639 * the vnode can change out from under us after execve (like [lin]procfs). 2640 * 2641 * Since fdsetugidsafety calls this only for fd 0, 1 and 2, this check is 2642 * sufficient. We also don't check for setugidness since we know we are. 2643 */ 2644 static bool 2645 is_unsafe(struct file *fp) 2646 { 2647 struct vnode *vp; 2648 2649 if (fp->f_type != DTYPE_VNODE) 2650 return (false); 2651 2652 vp = fp->f_vnode; 2653 return ((vp->v_vflag & VV_PROCDEP) != 0); 2654 } 2655 2656 /* 2657 * Make this setguid thing safe, if at all possible. 2658 */ 2659 void 2660 fdsetugidsafety(struct thread *td) 2661 { 2662 struct filedesc *fdp; 2663 struct file *fp; 2664 int i; 2665 2666 fdp = td->td_proc->p_fd; 2667 KASSERT(refcount_load(&fdp->fd_refcnt) == 1, 2668 ("the fdtable should not be shared")); 2669 MPASS(fdp->fd_nfiles >= 3); 2670 for (i = 0; i <= 2; i++) { 2671 fp = fdp->fd_ofiles[i].fde_file; 2672 if (fp != NULL && is_unsafe(fp)) { 2673 FILEDESC_XLOCK(fdp); 2674 knote_fdclose(td, i); 2675 /* 2676 * NULL-out descriptor prior to close to avoid 2677 * a race while close blocks. 2678 */ 2679 fdfree(fdp, i); 2680 FILEDESC_XUNLOCK(fdp); 2681 (void) closef(fp, td); 2682 } 2683 } 2684 } 2685 2686 /* 2687 * If a specific file object occupies a specific file descriptor, close the 2688 * file descriptor entry and drop a reference on the file object. This is a 2689 * convenience function to handle a subsequent error in a function that calls 2690 * falloc() that handles the race that another thread might have closed the 2691 * file descriptor out from under the thread creating the file object. 2692 */ 2693 void 2694 fdclose(struct thread *td, struct file *fp, int idx) 2695 { 2696 struct filedesc *fdp = td->td_proc->p_fd; 2697 2698 FILEDESC_XLOCK(fdp); 2699 if (fdp->fd_ofiles[idx].fde_file == fp) { 2700 fdfree(fdp, idx); 2701 FILEDESC_XUNLOCK(fdp); 2702 fdrop(fp, td); 2703 } else 2704 FILEDESC_XUNLOCK(fdp); 2705 } 2706 2707 /* 2708 * Close any files on exec? 2709 */ 2710 void 2711 fdcloseexec(struct thread *td) 2712 { 2713 struct filedesc *fdp; 2714 struct filedescent *fde; 2715 struct file *fp; 2716 int i, lastfile; 2717 2718 fdp = td->td_proc->p_fd; 2719 KASSERT(refcount_load(&fdp->fd_refcnt) == 1, 2720 ("the fdtable should not be shared")); 2721 lastfile = fdlastfile_single(fdp); 2722 for (i = 0; i <= lastfile; i++) { 2723 fde = &fdp->fd_ofiles[i]; 2724 fp = fde->fde_file; 2725 if (fp != NULL && (fp->f_type == DTYPE_MQUEUE || 2726 (fde->fde_flags & UF_EXCLOSE))) { 2727 FILEDESC_XLOCK(fdp); 2728 fdfree(fdp, i); 2729 (void) closefp(fdp, i, fp, td, false, false); 2730 FILEDESC_UNLOCK_ASSERT(fdp); 2731 } 2732 } 2733 } 2734 2735 /* 2736 * It is unsafe for set[ug]id processes to be started with file 2737 * descriptors 0..2 closed, as these descriptors are given implicit 2738 * significance in the Standard C library. fdcheckstd() will create a 2739 * descriptor referencing /dev/null for each of stdin, stdout, and 2740 * stderr that is not already open. 2741 */ 2742 int 2743 fdcheckstd(struct thread *td) 2744 { 2745 struct filedesc *fdp; 2746 register_t save; 2747 int i, error, devnull; 2748 2749 fdp = td->td_proc->p_fd; 2750 KASSERT(refcount_load(&fdp->fd_refcnt) == 1, 2751 ("the fdtable should not be shared")); 2752 MPASS(fdp->fd_nfiles >= 3); 2753 devnull = -1; 2754 for (i = 0; i <= 2; i++) { 2755 if (fdp->fd_ofiles[i].fde_file != NULL) 2756 continue; 2757 2758 save = td->td_retval[0]; 2759 if (devnull != -1) { 2760 error = kern_dup(td, FDDUP_FIXED, 0, devnull, i); 2761 } else { 2762 error = kern_openat(td, AT_FDCWD, "/dev/null", 2763 UIO_SYSSPACE, O_RDWR, 0); 2764 if (error == 0) { 2765 devnull = td->td_retval[0]; 2766 KASSERT(devnull == i, ("we didn't get our fd")); 2767 } 2768 } 2769 td->td_retval[0] = save; 2770 if (error != 0) 2771 return (error); 2772 } 2773 return (0); 2774 } 2775 2776 /* 2777 * Internal form of close. Decrement reference count on file structure. 2778 * Note: td may be NULL when closing a file that was being passed in a 2779 * message. 2780 */ 2781 int 2782 closef(struct file *fp, struct thread *td) 2783 { 2784 struct vnode *vp; 2785 struct flock lf; 2786 struct filedesc_to_leader *fdtol; 2787 struct filedesc *fdp; 2788 2789 MPASS(td != NULL); 2790 2791 /* 2792 * POSIX record locking dictates that any close releases ALL 2793 * locks owned by this process. This is handled by setting 2794 * a flag in the unlock to free ONLY locks obeying POSIX 2795 * semantics, and not to free BSD-style file locks. 2796 * If the descriptor was in a message, POSIX-style locks 2797 * aren't passed with the descriptor, and the thread pointer 2798 * will be NULL. Callers should be careful only to pass a 2799 * NULL thread pointer when there really is no owning 2800 * context that might have locks, or the locks will be 2801 * leaked. 2802 */ 2803 if (fp->f_type == DTYPE_VNODE) { 2804 vp = fp->f_vnode; 2805 if ((td->td_proc->p_leader->p_flag & P_ADVLOCK) != 0) { 2806 lf.l_whence = SEEK_SET; 2807 lf.l_start = 0; 2808 lf.l_len = 0; 2809 lf.l_type = F_UNLCK; 2810 (void) VOP_ADVLOCK(vp, (caddr_t)td->td_proc->p_leader, 2811 F_UNLCK, &lf, F_POSIX); 2812 } 2813 fdtol = td->td_proc->p_fdtol; 2814 if (fdtol != NULL) { 2815 /* 2816 * Handle special case where file descriptor table is 2817 * shared between multiple process leaders. 2818 */ 2819 fdp = td->td_proc->p_fd; 2820 FILEDESC_XLOCK(fdp); 2821 for (fdtol = fdtol->fdl_next; 2822 fdtol != td->td_proc->p_fdtol; 2823 fdtol = fdtol->fdl_next) { 2824 if ((fdtol->fdl_leader->p_flag & 2825 P_ADVLOCK) == 0) 2826 continue; 2827 fdtol->fdl_holdcount++; 2828 FILEDESC_XUNLOCK(fdp); 2829 lf.l_whence = SEEK_SET; 2830 lf.l_start = 0; 2831 lf.l_len = 0; 2832 lf.l_type = F_UNLCK; 2833 vp = fp->f_vnode; 2834 (void) VOP_ADVLOCK(vp, 2835 (caddr_t)fdtol->fdl_leader, F_UNLCK, &lf, 2836 F_POSIX); 2837 FILEDESC_XLOCK(fdp); 2838 fdtol->fdl_holdcount--; 2839 if (fdtol->fdl_holdcount == 0 && 2840 fdtol->fdl_wakeup != 0) { 2841 fdtol->fdl_wakeup = 0; 2842 wakeup(fdtol); 2843 } 2844 } 2845 FILEDESC_XUNLOCK(fdp); 2846 } 2847 } 2848 return (fdrop_close(fp, td)); 2849 } 2850 2851 /* 2852 * Hack for file descriptor passing code. 2853 */ 2854 void 2855 closef_nothread(struct file *fp) 2856 { 2857 2858 fdrop(fp, NULL); 2859 } 2860 2861 /* 2862 * Initialize the file pointer with the specified properties. 2863 * 2864 * The ops are set with release semantics to be certain that the flags, type, 2865 * and data are visible when ops is. This is to prevent ops methods from being 2866 * called with bad data. 2867 */ 2868 void 2869 finit(struct file *fp, u_int flag, short type, void *data, struct fileops *ops) 2870 { 2871 fp->f_data = data; 2872 fp->f_flag = flag; 2873 fp->f_type = type; 2874 atomic_store_rel_ptr((volatile uintptr_t *)&fp->f_ops, (uintptr_t)ops); 2875 } 2876 2877 void 2878 finit_vnode(struct file *fp, u_int flag, void *data, struct fileops *ops) 2879 { 2880 fp->f_seqcount[UIO_READ] = 1; 2881 fp->f_seqcount[UIO_WRITE] = 1; 2882 finit(fp, (flag & FMASK) | (fp->f_flag & FHASLOCK), DTYPE_VNODE, 2883 data, ops); 2884 } 2885 2886 int 2887 fget_cap_locked(struct filedesc *fdp, int fd, cap_rights_t *needrightsp, 2888 struct file **fpp, struct filecaps *havecapsp) 2889 { 2890 struct filedescent *fde; 2891 int error; 2892 2893 FILEDESC_LOCK_ASSERT(fdp); 2894 2895 fde = fdeget_locked(fdp, fd); 2896 if (fde == NULL) { 2897 error = EBADF; 2898 goto out; 2899 } 2900 2901 #ifdef CAPABILITIES 2902 error = cap_check(cap_rights_fde_inline(fde), needrightsp); 2903 if (error != 0) 2904 goto out; 2905 #endif 2906 2907 if (havecapsp != NULL) 2908 filecaps_copy(&fde->fde_caps, havecapsp, true); 2909 2910 *fpp = fde->fde_file; 2911 2912 error = 0; 2913 out: 2914 return (error); 2915 } 2916 2917 int 2918 fget_cap(struct thread *td, int fd, cap_rights_t *needrightsp, 2919 struct file **fpp, struct filecaps *havecapsp) 2920 { 2921 struct filedesc *fdp = td->td_proc->p_fd; 2922 int error; 2923 #ifndef CAPABILITIES 2924 error = fget_unlocked(fdp, fd, needrightsp, fpp); 2925 if (havecapsp != NULL && error == 0) 2926 filecaps_fill(havecapsp); 2927 #else 2928 struct file *fp; 2929 seqc_t seq; 2930 2931 *fpp = NULL; 2932 for (;;) { 2933 error = fget_unlocked_seq(fdp, fd, needrightsp, &fp, &seq); 2934 if (error != 0) 2935 return (error); 2936 2937 if (havecapsp != NULL) { 2938 if (!filecaps_copy(&fdp->fd_ofiles[fd].fde_caps, 2939 havecapsp, false)) { 2940 fdrop(fp, td); 2941 goto get_locked; 2942 } 2943 } 2944 2945 if (!fd_modified(fdp, fd, seq)) 2946 break; 2947 fdrop(fp, td); 2948 } 2949 2950 *fpp = fp; 2951 return (0); 2952 2953 get_locked: 2954 FILEDESC_SLOCK(fdp); 2955 error = fget_cap_locked(fdp, fd, needrightsp, fpp, havecapsp); 2956 if (error == 0 && !fhold(*fpp)) 2957 error = EBADF; 2958 FILEDESC_SUNLOCK(fdp); 2959 #endif 2960 return (error); 2961 } 2962 2963 #ifdef CAPABILITIES 2964 int 2965 fgetvp_lookup_smr(int fd, struct nameidata *ndp, struct vnode **vpp, bool *fsearch) 2966 { 2967 const struct filedescent *fde; 2968 const struct fdescenttbl *fdt; 2969 struct filedesc *fdp; 2970 struct file *fp; 2971 struct vnode *vp; 2972 const cap_rights_t *haverights; 2973 cap_rights_t rights; 2974 seqc_t seq; 2975 2976 VFS_SMR_ASSERT_ENTERED(); 2977 2978 rights = *ndp->ni_rightsneeded; 2979 cap_rights_set_one(&rights, CAP_LOOKUP); 2980 2981 fdp = curproc->p_fd; 2982 fdt = fdp->fd_files; 2983 if (__predict_false((u_int)fd >= fdt->fdt_nfiles)) 2984 return (EBADF); 2985 seq = seqc_read_notmodify(fd_seqc(fdt, fd)); 2986 fde = &fdt->fdt_ofiles[fd]; 2987 haverights = cap_rights_fde_inline(fde); 2988 fp = fde->fde_file; 2989 if (__predict_false(fp == NULL)) 2990 return (EAGAIN); 2991 if (__predict_false(cap_check_inline_transient(haverights, &rights))) 2992 return (EAGAIN); 2993 *fsearch = ((fp->f_flag & FSEARCH) != 0); 2994 vp = fp->f_vnode; 2995 if (__predict_false(vp == NULL || vp->v_type != VDIR)) { 2996 return (EAGAIN); 2997 } 2998 if (!filecaps_copy(&fde->fde_caps, &ndp->ni_filecaps, false)) { 2999 return (EAGAIN); 3000 } 3001 /* 3002 * Use an acquire barrier to force re-reading of fdt so it is 3003 * refreshed for verification. 3004 */ 3005 atomic_thread_fence_acq(); 3006 fdt = fdp->fd_files; 3007 if (__predict_false(!seqc_consistent_nomb(fd_seqc(fdt, fd), seq))) 3008 return (EAGAIN); 3009 /* 3010 * If file descriptor doesn't have all rights, 3011 * all lookups relative to it must also be 3012 * strictly relative. 3013 * 3014 * Not yet supported by fast path. 3015 */ 3016 CAP_ALL(&rights); 3017 if (!cap_rights_contains(&ndp->ni_filecaps.fc_rights, &rights) || 3018 ndp->ni_filecaps.fc_fcntls != CAP_FCNTL_ALL || 3019 ndp->ni_filecaps.fc_nioctls != -1) { 3020 #ifdef notyet 3021 ndp->ni_lcf |= NI_LCF_STRICTRELATIVE; 3022 #else 3023 return (EAGAIN); 3024 #endif 3025 } 3026 *vpp = vp; 3027 return (0); 3028 } 3029 #else 3030 int 3031 fgetvp_lookup_smr(int fd, struct nameidata *ndp, struct vnode **vpp, bool *fsearch) 3032 { 3033 const struct fdescenttbl *fdt; 3034 struct filedesc *fdp; 3035 struct file *fp; 3036 struct vnode *vp; 3037 3038 VFS_SMR_ASSERT_ENTERED(); 3039 3040 fdp = curproc->p_fd; 3041 fdt = fdp->fd_files; 3042 if (__predict_false((u_int)fd >= fdt->fdt_nfiles)) 3043 return (EBADF); 3044 fp = fdt->fdt_ofiles[fd].fde_file; 3045 if (__predict_false(fp == NULL)) 3046 return (EAGAIN); 3047 *fsearch = ((fp->f_flag & FSEARCH) != 0); 3048 vp = fp->f_vnode; 3049 if (__predict_false(vp == NULL || vp->v_type != VDIR)) { 3050 return (EAGAIN); 3051 } 3052 /* 3053 * Use an acquire barrier to force re-reading of fdt so it is 3054 * refreshed for verification. 3055 */ 3056 atomic_thread_fence_acq(); 3057 fdt = fdp->fd_files; 3058 if (__predict_false(fp != fdt->fdt_ofiles[fd].fde_file)) 3059 return (EAGAIN); 3060 filecaps_fill(&ndp->ni_filecaps); 3061 *vpp = vp; 3062 return (0); 3063 } 3064 #endif 3065 3066 int 3067 fget_unlocked_seq(struct filedesc *fdp, int fd, cap_rights_t *needrightsp, 3068 struct file **fpp, seqc_t *seqp) 3069 { 3070 #ifdef CAPABILITIES 3071 const struct filedescent *fde; 3072 #endif 3073 const struct fdescenttbl *fdt; 3074 struct file *fp; 3075 #ifdef CAPABILITIES 3076 seqc_t seq; 3077 cap_rights_t haverights; 3078 int error; 3079 #endif 3080 3081 fdt = fdp->fd_files; 3082 if (__predict_false((u_int)fd >= fdt->fdt_nfiles)) 3083 return (EBADF); 3084 /* 3085 * Fetch the descriptor locklessly. We avoid fdrop() races by 3086 * never raising a refcount above 0. To accomplish this we have 3087 * to use a cmpset loop rather than an atomic_add. The descriptor 3088 * must be re-verified once we acquire a reference to be certain 3089 * that the identity is still correct and we did not lose a race 3090 * due to preemption. 3091 */ 3092 for (;;) { 3093 #ifdef CAPABILITIES 3094 seq = seqc_read_notmodify(fd_seqc(fdt, fd)); 3095 fde = &fdt->fdt_ofiles[fd]; 3096 haverights = *cap_rights_fde_inline(fde); 3097 fp = fde->fde_file; 3098 if (!seqc_consistent(fd_seqc(fdt, fd), seq)) 3099 continue; 3100 #else 3101 fp = fdt->fdt_ofiles[fd].fde_file; 3102 #endif 3103 if (fp == NULL) 3104 return (EBADF); 3105 #ifdef CAPABILITIES 3106 error = cap_check_inline(&haverights, needrightsp); 3107 if (error != 0) 3108 return (error); 3109 #endif 3110 if (__predict_false(!refcount_acquire_if_not_zero(&fp->f_count))) { 3111 /* 3112 * Force a reload. Other thread could reallocate the 3113 * table before this fd was closed, so it is possible 3114 * that there is a stale fp pointer in cached version. 3115 */ 3116 fdt = atomic_load_ptr(&fdp->fd_files); 3117 continue; 3118 } 3119 /* 3120 * Use an acquire barrier to force re-reading of fdt so it is 3121 * refreshed for verification. 3122 */ 3123 atomic_thread_fence_acq(); 3124 fdt = fdp->fd_files; 3125 #ifdef CAPABILITIES 3126 if (seqc_consistent_nomb(fd_seqc(fdt, fd), seq)) 3127 #else 3128 if (fp == fdt->fdt_ofiles[fd].fde_file) 3129 #endif 3130 break; 3131 fdrop(fp, curthread); 3132 } 3133 *fpp = fp; 3134 if (seqp != NULL) { 3135 #ifdef CAPABILITIES 3136 *seqp = seq; 3137 #endif 3138 } 3139 return (0); 3140 } 3141 3142 /* 3143 * See the comments in fget_unlocked_seq for an explanation of how this works. 3144 * 3145 * This is a simplified variant which bails out to the aforementioned routine 3146 * if anything goes wrong. In practice this only happens when userspace is 3147 * racing with itself. 3148 */ 3149 int 3150 fget_unlocked(struct filedesc *fdp, int fd, cap_rights_t *needrightsp, 3151 struct file **fpp) 3152 { 3153 #ifdef CAPABILITIES 3154 const struct filedescent *fde; 3155 #endif 3156 const struct fdescenttbl *fdt; 3157 struct file *fp; 3158 #ifdef CAPABILITIES 3159 seqc_t seq; 3160 const cap_rights_t *haverights; 3161 #endif 3162 3163 fdt = fdp->fd_files; 3164 if (__predict_false((u_int)fd >= fdt->fdt_nfiles)) 3165 return (EBADF); 3166 #ifdef CAPABILITIES 3167 seq = seqc_read_notmodify(fd_seqc(fdt, fd)); 3168 fde = &fdt->fdt_ofiles[fd]; 3169 haverights = cap_rights_fde_inline(fde); 3170 fp = fde->fde_file; 3171 #else 3172 fp = fdt->fdt_ofiles[fd].fde_file; 3173 #endif 3174 if (__predict_false(fp == NULL)) 3175 goto out_fallback; 3176 #ifdef CAPABILITIES 3177 if (__predict_false(cap_check_inline_transient(haverights, needrightsp))) 3178 goto out_fallback; 3179 #endif 3180 if (__predict_false(!refcount_acquire_if_not_zero(&fp->f_count))) 3181 goto out_fallback; 3182 3183 /* 3184 * Use an acquire barrier to force re-reading of fdt so it is 3185 * refreshed for verification. 3186 */ 3187 atomic_thread_fence_acq(); 3188 fdt = fdp->fd_files; 3189 #ifdef CAPABILITIES 3190 if (__predict_false(!seqc_consistent_nomb(fd_seqc(fdt, fd), seq))) 3191 #else 3192 if (__predict_false(fp != fdt->fdt_ofiles[fd].fde_file)) 3193 #endif 3194 goto out_fdrop; 3195 *fpp = fp; 3196 return (0); 3197 out_fdrop: 3198 fdrop(fp, curthread); 3199 out_fallback: 3200 return (fget_unlocked_seq(fdp, fd, needrightsp, fpp, NULL)); 3201 } 3202 3203 /* 3204 * Translate fd -> file when the caller guarantees the file descriptor table 3205 * can't be changed by others. 3206 * 3207 * Note this does not mean the file object itself is only visible to the caller, 3208 * merely that it wont disappear without having to be referenced. 3209 * 3210 * Must be paired with fput_only_user. 3211 */ 3212 #ifdef CAPABILITIES 3213 int 3214 fget_only_user(struct filedesc *fdp, int fd, cap_rights_t *needrightsp, 3215 struct file **fpp) 3216 { 3217 const struct filedescent *fde; 3218 const struct fdescenttbl *fdt; 3219 const cap_rights_t *haverights; 3220 struct file *fp; 3221 int error; 3222 3223 MPASS(FILEDESC_IS_ONLY_USER(fdp)); 3224 3225 if (__predict_false(fd >= fdp->fd_nfiles)) 3226 return (EBADF); 3227 3228 fdt = fdp->fd_files; 3229 fde = &fdt->fdt_ofiles[fd]; 3230 fp = fde->fde_file; 3231 if (__predict_false(fp == NULL)) 3232 return (EBADF); 3233 MPASS(refcount_load(&fp->f_count) > 0); 3234 haverights = cap_rights_fde_inline(fde); 3235 error = cap_check_inline(haverights, needrightsp); 3236 if (__predict_false(error != 0)) 3237 return (error); 3238 *fpp = fp; 3239 return (0); 3240 } 3241 #else 3242 int 3243 fget_only_user(struct filedesc *fdp, int fd, cap_rights_t *needrightsp, 3244 struct file **fpp) 3245 { 3246 struct file *fp; 3247 3248 MPASS(FILEDESC_IS_ONLY_USER(fdp)); 3249 3250 if (__predict_false(fd >= fdp->fd_nfiles)) 3251 return (EBADF); 3252 3253 fp = fdp->fd_ofiles[fd].fde_file; 3254 if (__predict_false(fp == NULL)) 3255 return (EBADF); 3256 3257 MPASS(refcount_load(&fp->f_count) > 0); 3258 *fpp = fp; 3259 return (0); 3260 } 3261 #endif 3262 3263 /* 3264 * Extract the file pointer associated with the specified descriptor for the 3265 * current user process. 3266 * 3267 * If the descriptor doesn't exist or doesn't match 'flags', EBADF is 3268 * returned. 3269 * 3270 * File's rights will be checked against the capability rights mask. 3271 * 3272 * If an error occurred the non-zero error is returned and *fpp is set to 3273 * NULL. Otherwise *fpp is held and set and zero is returned. Caller is 3274 * responsible for fdrop(). 3275 */ 3276 static __inline int 3277 _fget(struct thread *td, int fd, struct file **fpp, int flags, 3278 cap_rights_t *needrightsp) 3279 { 3280 struct filedesc *fdp; 3281 struct file *fp; 3282 int error; 3283 3284 *fpp = NULL; 3285 fdp = td->td_proc->p_fd; 3286 error = fget_unlocked(fdp, fd, needrightsp, &fp); 3287 if (__predict_false(error != 0)) 3288 return (error); 3289 if (__predict_false(fp->f_ops == &badfileops)) { 3290 fdrop(fp, td); 3291 return (EBADF); 3292 } 3293 3294 /* 3295 * FREAD and FWRITE failure return EBADF as per POSIX. 3296 */ 3297 error = 0; 3298 switch (flags) { 3299 case FREAD: 3300 case FWRITE: 3301 if ((fp->f_flag & flags) == 0) 3302 error = EBADF; 3303 break; 3304 case FEXEC: 3305 if ((fp->f_flag & (FREAD | FEXEC)) == 0 || 3306 ((fp->f_flag & FWRITE) != 0)) 3307 error = EBADF; 3308 break; 3309 case 0: 3310 break; 3311 default: 3312 KASSERT(0, ("wrong flags")); 3313 } 3314 3315 if (error != 0) { 3316 fdrop(fp, td); 3317 return (error); 3318 } 3319 3320 *fpp = fp; 3321 return (0); 3322 } 3323 3324 int 3325 fget(struct thread *td, int fd, cap_rights_t *rightsp, struct file **fpp) 3326 { 3327 3328 return (_fget(td, fd, fpp, 0, rightsp)); 3329 } 3330 3331 int 3332 fget_mmap(struct thread *td, int fd, cap_rights_t *rightsp, vm_prot_t *maxprotp, 3333 struct file **fpp) 3334 { 3335 int error; 3336 #ifndef CAPABILITIES 3337 error = _fget(td, fd, fpp, 0, rightsp); 3338 if (maxprotp != NULL) 3339 *maxprotp = VM_PROT_ALL; 3340 return (error); 3341 #else 3342 cap_rights_t fdrights; 3343 struct filedesc *fdp; 3344 struct file *fp; 3345 seqc_t seq; 3346 3347 *fpp = NULL; 3348 fdp = td->td_proc->p_fd; 3349 MPASS(cap_rights_is_set(rightsp, CAP_MMAP)); 3350 for (;;) { 3351 error = fget_unlocked_seq(fdp, fd, rightsp, &fp, &seq); 3352 if (__predict_false(error != 0)) 3353 return (error); 3354 if (__predict_false(fp->f_ops == &badfileops)) { 3355 fdrop(fp, td); 3356 return (EBADF); 3357 } 3358 if (maxprotp != NULL) 3359 fdrights = *cap_rights(fdp, fd); 3360 if (!fd_modified(fdp, fd, seq)) 3361 break; 3362 fdrop(fp, td); 3363 } 3364 3365 /* 3366 * If requested, convert capability rights to access flags. 3367 */ 3368 if (maxprotp != NULL) 3369 *maxprotp = cap_rights_to_vmprot(&fdrights); 3370 *fpp = fp; 3371 return (0); 3372 #endif 3373 } 3374 3375 int 3376 fget_read(struct thread *td, int fd, cap_rights_t *rightsp, struct file **fpp) 3377 { 3378 3379 return (_fget(td, fd, fpp, FREAD, rightsp)); 3380 } 3381 3382 int 3383 fget_write(struct thread *td, int fd, cap_rights_t *rightsp, struct file **fpp) 3384 { 3385 3386 return (_fget(td, fd, fpp, FWRITE, rightsp)); 3387 } 3388 3389 int 3390 fget_fcntl(struct thread *td, int fd, cap_rights_t *rightsp, int needfcntl, 3391 struct file **fpp) 3392 { 3393 struct filedesc *fdp = td->td_proc->p_fd; 3394 #ifndef CAPABILITIES 3395 return (fget_unlocked(fdp, fd, rightsp, fpp)); 3396 #else 3397 struct file *fp; 3398 int error; 3399 seqc_t seq; 3400 3401 *fpp = NULL; 3402 MPASS(cap_rights_is_set(rightsp, CAP_FCNTL)); 3403 for (;;) { 3404 error = fget_unlocked_seq(fdp, fd, rightsp, &fp, &seq); 3405 if (error != 0) 3406 return (error); 3407 error = cap_fcntl_check(fdp, fd, needfcntl); 3408 if (!fd_modified(fdp, fd, seq)) 3409 break; 3410 fdrop(fp, td); 3411 } 3412 if (error != 0) { 3413 fdrop(fp, td); 3414 return (error); 3415 } 3416 *fpp = fp; 3417 return (0); 3418 #endif 3419 } 3420 3421 /* 3422 * Like fget() but loads the underlying vnode, or returns an error if the 3423 * descriptor does not represent a vnode. Note that pipes use vnodes but 3424 * never have VM objects. The returned vnode will be vref()'d. 3425 * 3426 * XXX: what about the unused flags ? 3427 */ 3428 static __inline int 3429 _fgetvp(struct thread *td, int fd, int flags, cap_rights_t *needrightsp, 3430 struct vnode **vpp) 3431 { 3432 struct file *fp; 3433 int error; 3434 3435 *vpp = NULL; 3436 error = _fget(td, fd, &fp, flags, needrightsp); 3437 if (error != 0) 3438 return (error); 3439 if (fp->f_vnode == NULL) { 3440 error = EINVAL; 3441 } else { 3442 *vpp = fp->f_vnode; 3443 vref(*vpp); 3444 } 3445 fdrop(fp, td); 3446 3447 return (error); 3448 } 3449 3450 int 3451 fgetvp(struct thread *td, int fd, cap_rights_t *rightsp, struct vnode **vpp) 3452 { 3453 3454 return (_fgetvp(td, fd, 0, rightsp, vpp)); 3455 } 3456 3457 int 3458 fgetvp_rights(struct thread *td, int fd, cap_rights_t *needrightsp, 3459 struct filecaps *havecaps, struct vnode **vpp) 3460 { 3461 struct filecaps caps; 3462 struct file *fp; 3463 int error; 3464 3465 error = fget_cap(td, fd, needrightsp, &fp, &caps); 3466 if (error != 0) 3467 return (error); 3468 if (fp->f_ops == &badfileops) { 3469 error = EBADF; 3470 goto out; 3471 } 3472 if (fp->f_vnode == NULL) { 3473 error = EINVAL; 3474 goto out; 3475 } 3476 3477 *havecaps = caps; 3478 *vpp = fp->f_vnode; 3479 vref(*vpp); 3480 fdrop(fp, td); 3481 3482 return (0); 3483 out: 3484 filecaps_free(&caps); 3485 fdrop(fp, td); 3486 return (error); 3487 } 3488 3489 int 3490 fgetvp_read(struct thread *td, int fd, cap_rights_t *rightsp, struct vnode **vpp) 3491 { 3492 3493 return (_fgetvp(td, fd, FREAD, rightsp, vpp)); 3494 } 3495 3496 int 3497 fgetvp_exec(struct thread *td, int fd, cap_rights_t *rightsp, struct vnode **vpp) 3498 { 3499 3500 return (_fgetvp(td, fd, FEXEC, rightsp, vpp)); 3501 } 3502 3503 #ifdef notyet 3504 int 3505 fgetvp_write(struct thread *td, int fd, cap_rights_t *rightsp, 3506 struct vnode **vpp) 3507 { 3508 3509 return (_fgetvp(td, fd, FWRITE, rightsp, vpp)); 3510 } 3511 #endif 3512 3513 /* 3514 * Handle the last reference to a file being closed. 3515 * 3516 * Without the noinline attribute clang keeps inlining the func thorough this 3517 * file when fdrop is used. 3518 */ 3519 int __noinline 3520 _fdrop(struct file *fp, struct thread *td) 3521 { 3522 int error; 3523 #ifdef INVARIANTS 3524 int count; 3525 3526 count = refcount_load(&fp->f_count); 3527 if (count != 0) 3528 panic("fdrop: fp %p count %d", fp, count); 3529 #endif 3530 error = fo_close(fp, td); 3531 atomic_subtract_int(&openfiles, 1); 3532 crfree(fp->f_cred); 3533 free(fp->f_advice, M_FADVISE); 3534 uma_zfree(file_zone, fp); 3535 3536 return (error); 3537 } 3538 3539 /* 3540 * Apply an advisory lock on a file descriptor. 3541 * 3542 * Just attempt to get a record lock of the requested type on the entire file 3543 * (l_whence = SEEK_SET, l_start = 0, l_len = 0). 3544 */ 3545 #ifndef _SYS_SYSPROTO_H_ 3546 struct flock_args { 3547 int fd; 3548 int how; 3549 }; 3550 #endif 3551 /* ARGSUSED */ 3552 int 3553 sys_flock(struct thread *td, struct flock_args *uap) 3554 { 3555 struct file *fp; 3556 struct vnode *vp; 3557 struct flock lf; 3558 int error; 3559 3560 error = fget(td, uap->fd, &cap_flock_rights, &fp); 3561 if (error != 0) 3562 return (error); 3563 error = EOPNOTSUPP; 3564 if (fp->f_type != DTYPE_VNODE && fp->f_type != DTYPE_FIFO) { 3565 goto done; 3566 } 3567 if (fp->f_ops == &path_fileops) { 3568 goto done; 3569 } 3570 3571 error = 0; 3572 vp = fp->f_vnode; 3573 lf.l_whence = SEEK_SET; 3574 lf.l_start = 0; 3575 lf.l_len = 0; 3576 if (uap->how & LOCK_UN) { 3577 lf.l_type = F_UNLCK; 3578 atomic_clear_int(&fp->f_flag, FHASLOCK); 3579 error = VOP_ADVLOCK(vp, (caddr_t)fp, F_UNLCK, &lf, F_FLOCK); 3580 goto done; 3581 } 3582 if (uap->how & LOCK_EX) 3583 lf.l_type = F_WRLCK; 3584 else if (uap->how & LOCK_SH) 3585 lf.l_type = F_RDLCK; 3586 else { 3587 error = EBADF; 3588 goto done; 3589 } 3590 atomic_set_int(&fp->f_flag, FHASLOCK); 3591 error = VOP_ADVLOCK(vp, (caddr_t)fp, F_SETLK, &lf, 3592 (uap->how & LOCK_NB) ? F_FLOCK : F_FLOCK | F_WAIT); 3593 done: 3594 fdrop(fp, td); 3595 return (error); 3596 } 3597 /* 3598 * Duplicate the specified descriptor to a free descriptor. 3599 */ 3600 int 3601 dupfdopen(struct thread *td, struct filedesc *fdp, int dfd, int mode, 3602 int openerror, int *indxp) 3603 { 3604 struct filedescent *newfde, *oldfde; 3605 struct file *fp; 3606 u_long *ioctls; 3607 int error, indx; 3608 3609 KASSERT(openerror == ENODEV || openerror == ENXIO, 3610 ("unexpected error %d in %s", openerror, __func__)); 3611 3612 /* 3613 * If the to-be-dup'd fd number is greater than the allowed number 3614 * of file descriptors, or the fd to be dup'd has already been 3615 * closed, then reject. 3616 */ 3617 FILEDESC_XLOCK(fdp); 3618 if ((fp = fget_locked(fdp, dfd)) == NULL) { 3619 FILEDESC_XUNLOCK(fdp); 3620 return (EBADF); 3621 } 3622 3623 error = fdalloc(td, 0, &indx); 3624 if (error != 0) { 3625 FILEDESC_XUNLOCK(fdp); 3626 return (error); 3627 } 3628 3629 /* 3630 * There are two cases of interest here. 3631 * 3632 * For ENODEV simply dup (dfd) to file descriptor (indx) and return. 3633 * 3634 * For ENXIO steal away the file structure from (dfd) and store it in 3635 * (indx). (dfd) is effectively closed by this operation. 3636 */ 3637 switch (openerror) { 3638 case ENODEV: 3639 /* 3640 * Check that the mode the file is being opened for is a 3641 * subset of the mode of the existing descriptor. 3642 */ 3643 if (((mode & (FREAD|FWRITE)) | fp->f_flag) != fp->f_flag) { 3644 fdunused(fdp, indx); 3645 FILEDESC_XUNLOCK(fdp); 3646 return (EACCES); 3647 } 3648 if (!fhold(fp)) { 3649 fdunused(fdp, indx); 3650 FILEDESC_XUNLOCK(fdp); 3651 return (EBADF); 3652 } 3653 newfde = &fdp->fd_ofiles[indx]; 3654 oldfde = &fdp->fd_ofiles[dfd]; 3655 ioctls = filecaps_copy_prep(&oldfde->fde_caps); 3656 #ifdef CAPABILITIES 3657 seqc_write_begin(&newfde->fde_seqc); 3658 #endif 3659 memcpy(newfde, oldfde, fde_change_size); 3660 filecaps_copy_finish(&oldfde->fde_caps, &newfde->fde_caps, 3661 ioctls); 3662 #ifdef CAPABILITIES 3663 seqc_write_end(&newfde->fde_seqc); 3664 #endif 3665 break; 3666 case ENXIO: 3667 /* 3668 * Steal away the file pointer from dfd and stuff it into indx. 3669 */ 3670 newfde = &fdp->fd_ofiles[indx]; 3671 oldfde = &fdp->fd_ofiles[dfd]; 3672 #ifdef CAPABILITIES 3673 seqc_write_begin(&newfde->fde_seqc); 3674 #endif 3675 memcpy(newfde, oldfde, fde_change_size); 3676 oldfde->fde_file = NULL; 3677 fdunused(fdp, dfd); 3678 #ifdef CAPABILITIES 3679 seqc_write_end(&newfde->fde_seqc); 3680 #endif 3681 break; 3682 } 3683 FILEDESC_XUNLOCK(fdp); 3684 *indxp = indx; 3685 return (0); 3686 } 3687 3688 /* 3689 * This sysctl determines if we will allow a process to chroot(2) if it 3690 * has a directory open: 3691 * 0: disallowed for all processes. 3692 * 1: allowed for processes that were not already chroot(2)'ed. 3693 * 2: allowed for all processes. 3694 */ 3695 3696 static int chroot_allow_open_directories = 1; 3697 3698 SYSCTL_INT(_kern, OID_AUTO, chroot_allow_open_directories, CTLFLAG_RW, 3699 &chroot_allow_open_directories, 0, 3700 "Allow a process to chroot(2) if it has a directory open"); 3701 3702 /* 3703 * Helper function for raised chroot(2) security function: Refuse if 3704 * any filedescriptors are open directories. 3705 */ 3706 static int 3707 chroot_refuse_vdir_fds(struct filedesc *fdp) 3708 { 3709 struct vnode *vp; 3710 struct file *fp; 3711 int fd, lastfile; 3712 3713 FILEDESC_LOCK_ASSERT(fdp); 3714 3715 lastfile = fdlastfile(fdp); 3716 for (fd = 0; fd <= lastfile; fd++) { 3717 fp = fget_locked(fdp, fd); 3718 if (fp == NULL) 3719 continue; 3720 if (fp->f_type == DTYPE_VNODE) { 3721 vp = fp->f_vnode; 3722 if (vp->v_type == VDIR) 3723 return (EPERM); 3724 } 3725 } 3726 return (0); 3727 } 3728 3729 static void 3730 pwd_fill(struct pwd *oldpwd, struct pwd *newpwd) 3731 { 3732 3733 if (newpwd->pwd_cdir == NULL && oldpwd->pwd_cdir != NULL) { 3734 vrefact(oldpwd->pwd_cdir); 3735 newpwd->pwd_cdir = oldpwd->pwd_cdir; 3736 } 3737 3738 if (newpwd->pwd_rdir == NULL && oldpwd->pwd_rdir != NULL) { 3739 vrefact(oldpwd->pwd_rdir); 3740 newpwd->pwd_rdir = oldpwd->pwd_rdir; 3741 } 3742 3743 if (newpwd->pwd_jdir == NULL && oldpwd->pwd_jdir != NULL) { 3744 vrefact(oldpwd->pwd_jdir); 3745 newpwd->pwd_jdir = oldpwd->pwd_jdir; 3746 } 3747 } 3748 3749 struct pwd * 3750 pwd_hold_pwddesc(struct pwddesc *pdp) 3751 { 3752 struct pwd *pwd; 3753 3754 PWDDESC_ASSERT_XLOCKED(pdp); 3755 pwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); 3756 if (pwd != NULL) 3757 refcount_acquire(&pwd->pwd_refcount); 3758 return (pwd); 3759 } 3760 3761 bool 3762 pwd_hold_smr(struct pwd *pwd) 3763 { 3764 3765 MPASS(pwd != NULL); 3766 if (__predict_true(refcount_acquire_if_not_zero(&pwd->pwd_refcount))) { 3767 return (true); 3768 } 3769 return (false); 3770 } 3771 3772 struct pwd * 3773 pwd_hold(struct thread *td) 3774 { 3775 struct pwddesc *pdp; 3776 struct pwd *pwd; 3777 3778 pdp = td->td_proc->p_pd; 3779 3780 vfs_smr_enter(); 3781 pwd = vfs_smr_entered_load(&pdp->pd_pwd); 3782 if (pwd_hold_smr(pwd)) { 3783 vfs_smr_exit(); 3784 return (pwd); 3785 } 3786 vfs_smr_exit(); 3787 PWDDESC_XLOCK(pdp); 3788 pwd = pwd_hold_pwddesc(pdp); 3789 MPASS(pwd != NULL); 3790 PWDDESC_XUNLOCK(pdp); 3791 return (pwd); 3792 } 3793 3794 struct pwd * 3795 pwd_hold_proc(struct proc *p) 3796 { 3797 struct pwddesc *pdp; 3798 struct pwd *pwd; 3799 3800 PROC_ASSERT_HELD(p); 3801 PROC_LOCK(p); 3802 pdp = pdhold(p); 3803 MPASS(pdp != NULL); 3804 PROC_UNLOCK(p); 3805 3806 PWDDESC_XLOCK(pdp); 3807 pwd = pwd_hold_pwddesc(pdp); 3808 MPASS(pwd != NULL); 3809 PWDDESC_XUNLOCK(pdp); 3810 pddrop(pdp); 3811 return (pwd); 3812 } 3813 3814 static struct pwd * 3815 pwd_alloc(void) 3816 { 3817 struct pwd *pwd; 3818 3819 pwd = uma_zalloc_smr(pwd_zone, M_WAITOK); 3820 bzero(pwd, sizeof(*pwd)); 3821 refcount_init(&pwd->pwd_refcount, 1); 3822 return (pwd); 3823 } 3824 3825 void 3826 pwd_drop(struct pwd *pwd) 3827 { 3828 3829 if (!refcount_release(&pwd->pwd_refcount)) 3830 return; 3831 3832 if (pwd->pwd_cdir != NULL) 3833 vrele(pwd->pwd_cdir); 3834 if (pwd->pwd_rdir != NULL) 3835 vrele(pwd->pwd_rdir); 3836 if (pwd->pwd_jdir != NULL) 3837 vrele(pwd->pwd_jdir); 3838 uma_zfree_smr(pwd_zone, pwd); 3839 } 3840 3841 /* 3842 * The caller is responsible for invoking priv_check() and 3843 * mac_vnode_check_chroot() to authorize this operation. 3844 */ 3845 int 3846 pwd_chroot(struct thread *td, struct vnode *vp) 3847 { 3848 struct pwddesc *pdp; 3849 struct filedesc *fdp; 3850 struct pwd *newpwd, *oldpwd; 3851 int error; 3852 3853 fdp = td->td_proc->p_fd; 3854 pdp = td->td_proc->p_pd; 3855 newpwd = pwd_alloc(); 3856 FILEDESC_SLOCK(fdp); 3857 PWDDESC_XLOCK(pdp); 3858 oldpwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); 3859 if (chroot_allow_open_directories == 0 || 3860 (chroot_allow_open_directories == 1 && 3861 oldpwd->pwd_rdir != rootvnode)) { 3862 error = chroot_refuse_vdir_fds(fdp); 3863 FILEDESC_SUNLOCK(fdp); 3864 if (error != 0) { 3865 PWDDESC_XUNLOCK(pdp); 3866 pwd_drop(newpwd); 3867 return (error); 3868 } 3869 } else { 3870 FILEDESC_SUNLOCK(fdp); 3871 } 3872 3873 vrefact(vp); 3874 newpwd->pwd_rdir = vp; 3875 if (oldpwd->pwd_jdir == NULL) { 3876 vrefact(vp); 3877 newpwd->pwd_jdir = vp; 3878 } 3879 pwd_fill(oldpwd, newpwd); 3880 pwd_set(pdp, newpwd); 3881 PWDDESC_XUNLOCK(pdp); 3882 pwd_drop(oldpwd); 3883 return (0); 3884 } 3885 3886 void 3887 pwd_chdir(struct thread *td, struct vnode *vp) 3888 { 3889 struct pwddesc *pdp; 3890 struct pwd *newpwd, *oldpwd; 3891 3892 VNPASS(vp->v_usecount > 0, vp); 3893 3894 newpwd = pwd_alloc(); 3895 pdp = td->td_proc->p_pd; 3896 PWDDESC_XLOCK(pdp); 3897 oldpwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); 3898 newpwd->pwd_cdir = vp; 3899 pwd_fill(oldpwd, newpwd); 3900 pwd_set(pdp, newpwd); 3901 PWDDESC_XUNLOCK(pdp); 3902 pwd_drop(oldpwd); 3903 } 3904 3905 /* 3906 * jail_attach(2) changes both root and working directories. 3907 */ 3908 int 3909 pwd_chroot_chdir(struct thread *td, struct vnode *vp) 3910 { 3911 struct pwddesc *pdp; 3912 struct filedesc *fdp; 3913 struct pwd *newpwd, *oldpwd; 3914 int error; 3915 3916 fdp = td->td_proc->p_fd; 3917 pdp = td->td_proc->p_pd; 3918 newpwd = pwd_alloc(); 3919 FILEDESC_SLOCK(fdp); 3920 PWDDESC_XLOCK(pdp); 3921 oldpwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); 3922 error = chroot_refuse_vdir_fds(fdp); 3923 FILEDESC_SUNLOCK(fdp); 3924 if (error != 0) { 3925 PWDDESC_XUNLOCK(pdp); 3926 pwd_drop(newpwd); 3927 return (error); 3928 } 3929 3930 vrefact(vp); 3931 newpwd->pwd_rdir = vp; 3932 vrefact(vp); 3933 newpwd->pwd_cdir = vp; 3934 if (oldpwd->pwd_jdir == NULL) { 3935 vrefact(vp); 3936 newpwd->pwd_jdir = vp; 3937 } 3938 pwd_fill(oldpwd, newpwd); 3939 pwd_set(pdp, newpwd); 3940 PWDDESC_XUNLOCK(pdp); 3941 pwd_drop(oldpwd); 3942 return (0); 3943 } 3944 3945 void 3946 pwd_ensure_dirs(void) 3947 { 3948 struct pwddesc *pdp; 3949 struct pwd *oldpwd, *newpwd; 3950 3951 pdp = curproc->p_pd; 3952 PWDDESC_XLOCK(pdp); 3953 oldpwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); 3954 if (oldpwd->pwd_cdir != NULL && oldpwd->pwd_rdir != NULL) { 3955 PWDDESC_XUNLOCK(pdp); 3956 return; 3957 } 3958 PWDDESC_XUNLOCK(pdp); 3959 3960 newpwd = pwd_alloc(); 3961 PWDDESC_XLOCK(pdp); 3962 oldpwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); 3963 pwd_fill(oldpwd, newpwd); 3964 if (newpwd->pwd_cdir == NULL) { 3965 vrefact(rootvnode); 3966 newpwd->pwd_cdir = rootvnode; 3967 } 3968 if (newpwd->pwd_rdir == NULL) { 3969 vrefact(rootvnode); 3970 newpwd->pwd_rdir = rootvnode; 3971 } 3972 pwd_set(pdp, newpwd); 3973 PWDDESC_XUNLOCK(pdp); 3974 pwd_drop(oldpwd); 3975 } 3976 3977 void 3978 pwd_set_rootvnode(void) 3979 { 3980 struct pwddesc *pdp; 3981 struct pwd *oldpwd, *newpwd; 3982 3983 pdp = curproc->p_pd; 3984 3985 newpwd = pwd_alloc(); 3986 PWDDESC_XLOCK(pdp); 3987 oldpwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); 3988 vrefact(rootvnode); 3989 newpwd->pwd_cdir = rootvnode; 3990 vrefact(rootvnode); 3991 newpwd->pwd_rdir = rootvnode; 3992 pwd_fill(oldpwd, newpwd); 3993 pwd_set(pdp, newpwd); 3994 PWDDESC_XUNLOCK(pdp); 3995 pwd_drop(oldpwd); 3996 } 3997 3998 /* 3999 * Scan all active processes and prisons to see if any of them have a current 4000 * or root directory of `olddp'. If so, replace them with the new mount point. 4001 */ 4002 void 4003 mountcheckdirs(struct vnode *olddp, struct vnode *newdp) 4004 { 4005 struct pwddesc *pdp; 4006 struct pwd *newpwd, *oldpwd; 4007 struct prison *pr; 4008 struct proc *p; 4009 int nrele; 4010 4011 if (vrefcnt(olddp) == 1) 4012 return; 4013 nrele = 0; 4014 newpwd = pwd_alloc(); 4015 sx_slock(&allproc_lock); 4016 FOREACH_PROC_IN_SYSTEM(p) { 4017 PROC_LOCK(p); 4018 pdp = pdhold(p); 4019 PROC_UNLOCK(p); 4020 if (pdp == NULL) 4021 continue; 4022 PWDDESC_XLOCK(pdp); 4023 oldpwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); 4024 if (oldpwd == NULL || 4025 (oldpwd->pwd_cdir != olddp && 4026 oldpwd->pwd_rdir != olddp && 4027 oldpwd->pwd_jdir != olddp)) { 4028 PWDDESC_XUNLOCK(pdp); 4029 pddrop(pdp); 4030 continue; 4031 } 4032 if (oldpwd->pwd_cdir == olddp) { 4033 vrefact(newdp); 4034 newpwd->pwd_cdir = newdp; 4035 } 4036 if (oldpwd->pwd_rdir == olddp) { 4037 vrefact(newdp); 4038 newpwd->pwd_rdir = newdp; 4039 } 4040 if (oldpwd->pwd_jdir == olddp) { 4041 vrefact(newdp); 4042 newpwd->pwd_jdir = newdp; 4043 } 4044 pwd_fill(oldpwd, newpwd); 4045 pwd_set(pdp, newpwd); 4046 PWDDESC_XUNLOCK(pdp); 4047 pwd_drop(oldpwd); 4048 pddrop(pdp); 4049 newpwd = pwd_alloc(); 4050 } 4051 sx_sunlock(&allproc_lock); 4052 pwd_drop(newpwd); 4053 if (rootvnode == olddp) { 4054 vrefact(newdp); 4055 rootvnode = newdp; 4056 nrele++; 4057 } 4058 mtx_lock(&prison0.pr_mtx); 4059 if (prison0.pr_root == olddp) { 4060 vrefact(newdp); 4061 prison0.pr_root = newdp; 4062 nrele++; 4063 } 4064 mtx_unlock(&prison0.pr_mtx); 4065 sx_slock(&allprison_lock); 4066 TAILQ_FOREACH(pr, &allprison, pr_list) { 4067 mtx_lock(&pr->pr_mtx); 4068 if (pr->pr_root == olddp) { 4069 vrefact(newdp); 4070 pr->pr_root = newdp; 4071 nrele++; 4072 } 4073 mtx_unlock(&pr->pr_mtx); 4074 } 4075 sx_sunlock(&allprison_lock); 4076 while (nrele--) 4077 vrele(olddp); 4078 } 4079 4080 struct filedesc_to_leader * 4081 filedesc_to_leader_alloc(struct filedesc_to_leader *old, struct filedesc *fdp, struct proc *leader) 4082 { 4083 struct filedesc_to_leader *fdtol; 4084 4085 fdtol = malloc(sizeof(struct filedesc_to_leader), 4086 M_FILEDESC_TO_LEADER, M_WAITOK); 4087 fdtol->fdl_refcount = 1; 4088 fdtol->fdl_holdcount = 0; 4089 fdtol->fdl_wakeup = 0; 4090 fdtol->fdl_leader = leader; 4091 if (old != NULL) { 4092 FILEDESC_XLOCK(fdp); 4093 fdtol->fdl_next = old->fdl_next; 4094 fdtol->fdl_prev = old; 4095 old->fdl_next = fdtol; 4096 fdtol->fdl_next->fdl_prev = fdtol; 4097 FILEDESC_XUNLOCK(fdp); 4098 } else { 4099 fdtol->fdl_next = fdtol; 4100 fdtol->fdl_prev = fdtol; 4101 } 4102 return (fdtol); 4103 } 4104 4105 static int 4106 sysctl_kern_proc_nfds(SYSCTL_HANDLER_ARGS) 4107 { 4108 NDSLOTTYPE *map; 4109 struct filedesc *fdp; 4110 u_int namelen; 4111 int count, off, minoff; 4112 4113 namelen = arg2; 4114 if (namelen != 1) 4115 return (EINVAL); 4116 4117 if (*(int *)arg1 != 0) 4118 return (EINVAL); 4119 4120 fdp = curproc->p_fd; 4121 count = 0; 4122 FILEDESC_SLOCK(fdp); 4123 map = fdp->fd_map; 4124 off = NDSLOT(fdp->fd_nfiles - 1); 4125 for (minoff = NDSLOT(0); off >= minoff; --off) 4126 count += bitcountl(map[off]); 4127 FILEDESC_SUNLOCK(fdp); 4128 4129 return (SYSCTL_OUT(req, &count, sizeof(count))); 4130 } 4131 4132 static SYSCTL_NODE(_kern_proc, KERN_PROC_NFDS, nfds, 4133 CTLFLAG_RD|CTLFLAG_CAPRD|CTLFLAG_MPSAFE, sysctl_kern_proc_nfds, 4134 "Number of open file descriptors"); 4135 4136 /* 4137 * Get file structures globally. 4138 */ 4139 static int 4140 sysctl_kern_file(SYSCTL_HANDLER_ARGS) 4141 { 4142 struct xfile xf; 4143 struct filedesc *fdp; 4144 struct file *fp; 4145 struct proc *p; 4146 int error, n, lastfile; 4147 4148 error = sysctl_wire_old_buffer(req, 0); 4149 if (error != 0) 4150 return (error); 4151 if (req->oldptr == NULL) { 4152 n = 0; 4153 sx_slock(&allproc_lock); 4154 FOREACH_PROC_IN_SYSTEM(p) { 4155 PROC_LOCK(p); 4156 if (p->p_state == PRS_NEW) { 4157 PROC_UNLOCK(p); 4158 continue; 4159 } 4160 fdp = fdhold(p); 4161 PROC_UNLOCK(p); 4162 if (fdp == NULL) 4163 continue; 4164 /* overestimates sparse tables. */ 4165 n += fdp->fd_nfiles; 4166 fddrop(fdp); 4167 } 4168 sx_sunlock(&allproc_lock); 4169 return (SYSCTL_OUT(req, 0, n * sizeof(xf))); 4170 } 4171 error = 0; 4172 bzero(&xf, sizeof(xf)); 4173 xf.xf_size = sizeof(xf); 4174 sx_slock(&allproc_lock); 4175 FOREACH_PROC_IN_SYSTEM(p) { 4176 PROC_LOCK(p); 4177 if (p->p_state == PRS_NEW) { 4178 PROC_UNLOCK(p); 4179 continue; 4180 } 4181 if (p_cansee(req->td, p) != 0) { 4182 PROC_UNLOCK(p); 4183 continue; 4184 } 4185 xf.xf_pid = p->p_pid; 4186 xf.xf_uid = p->p_ucred->cr_uid; 4187 fdp = fdhold(p); 4188 PROC_UNLOCK(p); 4189 if (fdp == NULL) 4190 continue; 4191 FILEDESC_SLOCK(fdp); 4192 lastfile = fdlastfile(fdp); 4193 for (n = 0; refcount_load(&fdp->fd_refcnt) > 0 && n <= lastfile; 4194 n++) { 4195 if ((fp = fdp->fd_ofiles[n].fde_file) == NULL) 4196 continue; 4197 xf.xf_fd = n; 4198 xf.xf_file = (uintptr_t)fp; 4199 xf.xf_data = (uintptr_t)fp->f_data; 4200 xf.xf_vnode = (uintptr_t)fp->f_vnode; 4201 xf.xf_type = (uintptr_t)fp->f_type; 4202 xf.xf_count = refcount_load(&fp->f_count); 4203 xf.xf_msgcount = 0; 4204 xf.xf_offset = foffset_get(fp); 4205 xf.xf_flag = fp->f_flag; 4206 error = SYSCTL_OUT(req, &xf, sizeof(xf)); 4207 if (error) 4208 break; 4209 } 4210 FILEDESC_SUNLOCK(fdp); 4211 fddrop(fdp); 4212 if (error) 4213 break; 4214 } 4215 sx_sunlock(&allproc_lock); 4216 return (error); 4217 } 4218 4219 SYSCTL_PROC(_kern, KERN_FILE, file, CTLTYPE_OPAQUE|CTLFLAG_RD|CTLFLAG_MPSAFE, 4220 0, 0, sysctl_kern_file, "S,xfile", "Entire file table"); 4221 4222 #ifdef KINFO_FILE_SIZE 4223 CTASSERT(sizeof(struct kinfo_file) == KINFO_FILE_SIZE); 4224 #endif 4225 4226 static int 4227 xlate_fflags(int fflags) 4228 { 4229 static const struct { 4230 int fflag; 4231 int kf_fflag; 4232 } fflags_table[] = { 4233 { FAPPEND, KF_FLAG_APPEND }, 4234 { FASYNC, KF_FLAG_ASYNC }, 4235 { FFSYNC, KF_FLAG_FSYNC }, 4236 { FHASLOCK, KF_FLAG_HASLOCK }, 4237 { FNONBLOCK, KF_FLAG_NONBLOCK }, 4238 { FREAD, KF_FLAG_READ }, 4239 { FWRITE, KF_FLAG_WRITE }, 4240 { O_CREAT, KF_FLAG_CREAT }, 4241 { O_DIRECT, KF_FLAG_DIRECT }, 4242 { O_EXCL, KF_FLAG_EXCL }, 4243 { O_EXEC, KF_FLAG_EXEC }, 4244 { O_EXLOCK, KF_FLAG_EXLOCK }, 4245 { O_NOFOLLOW, KF_FLAG_NOFOLLOW }, 4246 { O_SHLOCK, KF_FLAG_SHLOCK }, 4247 { O_TRUNC, KF_FLAG_TRUNC } 4248 }; 4249 unsigned int i; 4250 int kflags; 4251 4252 kflags = 0; 4253 for (i = 0; i < nitems(fflags_table); i++) 4254 if (fflags & fflags_table[i].fflag) 4255 kflags |= fflags_table[i].kf_fflag; 4256 return (kflags); 4257 } 4258 4259 /* Trim unused data from kf_path by truncating the structure size. */ 4260 void 4261 pack_kinfo(struct kinfo_file *kif) 4262 { 4263 4264 kif->kf_structsize = offsetof(struct kinfo_file, kf_path) + 4265 strlen(kif->kf_path) + 1; 4266 kif->kf_structsize = roundup(kif->kf_structsize, sizeof(uint64_t)); 4267 } 4268 4269 static void 4270 export_file_to_kinfo(struct file *fp, int fd, cap_rights_t *rightsp, 4271 struct kinfo_file *kif, struct filedesc *fdp, int flags) 4272 { 4273 int error; 4274 4275 bzero(kif, sizeof(*kif)); 4276 4277 /* Set a default type to allow for empty fill_kinfo() methods. */ 4278 kif->kf_type = KF_TYPE_UNKNOWN; 4279 kif->kf_flags = xlate_fflags(fp->f_flag); 4280 if (rightsp != NULL) 4281 kif->kf_cap_rights = *rightsp; 4282 else 4283 cap_rights_init_zero(&kif->kf_cap_rights); 4284 kif->kf_fd = fd; 4285 kif->kf_ref_count = refcount_load(&fp->f_count); 4286 kif->kf_offset = foffset_get(fp); 4287 4288 /* 4289 * This may drop the filedesc lock, so the 'fp' cannot be 4290 * accessed after this call. 4291 */ 4292 error = fo_fill_kinfo(fp, kif, fdp); 4293 if (error == 0) 4294 kif->kf_status |= KF_ATTR_VALID; 4295 if ((flags & KERN_FILEDESC_PACK_KINFO) != 0) 4296 pack_kinfo(kif); 4297 else 4298 kif->kf_structsize = roundup2(sizeof(*kif), sizeof(uint64_t)); 4299 } 4300 4301 static void 4302 export_vnode_to_kinfo(struct vnode *vp, int fd, int fflags, 4303 struct kinfo_file *kif, int flags) 4304 { 4305 int error; 4306 4307 bzero(kif, sizeof(*kif)); 4308 4309 kif->kf_type = KF_TYPE_VNODE; 4310 error = vn_fill_kinfo_vnode(vp, kif); 4311 if (error == 0) 4312 kif->kf_status |= KF_ATTR_VALID; 4313 kif->kf_flags = xlate_fflags(fflags); 4314 cap_rights_init_zero(&kif->kf_cap_rights); 4315 kif->kf_fd = fd; 4316 kif->kf_ref_count = -1; 4317 kif->kf_offset = -1; 4318 if ((flags & KERN_FILEDESC_PACK_KINFO) != 0) 4319 pack_kinfo(kif); 4320 else 4321 kif->kf_structsize = roundup2(sizeof(*kif), sizeof(uint64_t)); 4322 vrele(vp); 4323 } 4324 4325 struct export_fd_buf { 4326 struct filedesc *fdp; 4327 struct pwddesc *pdp; 4328 struct sbuf *sb; 4329 ssize_t remainder; 4330 struct kinfo_file kif; 4331 int flags; 4332 }; 4333 4334 static int 4335 export_kinfo_to_sb(struct export_fd_buf *efbuf) 4336 { 4337 struct kinfo_file *kif; 4338 4339 kif = &efbuf->kif; 4340 if (efbuf->remainder != -1) { 4341 if (efbuf->remainder < kif->kf_structsize) { 4342 /* Terminate export. */ 4343 efbuf->remainder = 0; 4344 return (0); 4345 } 4346 efbuf->remainder -= kif->kf_structsize; 4347 } 4348 return (sbuf_bcat(efbuf->sb, kif, kif->kf_structsize) == 0 ? 0 : ENOMEM); 4349 } 4350 4351 static int 4352 export_file_to_sb(struct file *fp, int fd, cap_rights_t *rightsp, 4353 struct export_fd_buf *efbuf) 4354 { 4355 int error; 4356 4357 if (efbuf->remainder == 0) 4358 return (0); 4359 export_file_to_kinfo(fp, fd, rightsp, &efbuf->kif, efbuf->fdp, 4360 efbuf->flags); 4361 FILEDESC_SUNLOCK(efbuf->fdp); 4362 error = export_kinfo_to_sb(efbuf); 4363 FILEDESC_SLOCK(efbuf->fdp); 4364 return (error); 4365 } 4366 4367 static int 4368 export_vnode_to_sb(struct vnode *vp, int fd, int fflags, 4369 struct export_fd_buf *efbuf) 4370 { 4371 int error; 4372 4373 if (efbuf->remainder == 0) 4374 return (0); 4375 if (efbuf->pdp != NULL) 4376 PWDDESC_XUNLOCK(efbuf->pdp); 4377 export_vnode_to_kinfo(vp, fd, fflags, &efbuf->kif, efbuf->flags); 4378 error = export_kinfo_to_sb(efbuf); 4379 if (efbuf->pdp != NULL) 4380 PWDDESC_XLOCK(efbuf->pdp); 4381 return (error); 4382 } 4383 4384 /* 4385 * Store a process file descriptor information to sbuf. 4386 * 4387 * Takes a locked proc as argument, and returns with the proc unlocked. 4388 */ 4389 int 4390 kern_proc_filedesc_out(struct proc *p, struct sbuf *sb, ssize_t maxlen, 4391 int flags) 4392 { 4393 struct file *fp; 4394 struct filedesc *fdp; 4395 struct pwddesc *pdp; 4396 struct export_fd_buf *efbuf; 4397 struct vnode *cttyvp, *textvp, *tracevp; 4398 struct pwd *pwd; 4399 int error, i, lastfile; 4400 cap_rights_t rights; 4401 4402 PROC_LOCK_ASSERT(p, MA_OWNED); 4403 4404 /* ktrace vnode */ 4405 tracevp = ktr_get_tracevp(p, true); 4406 /* text vnode */ 4407 textvp = p->p_textvp; 4408 if (textvp != NULL) 4409 vrefact(textvp); 4410 /* Controlling tty. */ 4411 cttyvp = NULL; 4412 if (p->p_pgrp != NULL && p->p_pgrp->pg_session != NULL) { 4413 cttyvp = p->p_pgrp->pg_session->s_ttyvp; 4414 if (cttyvp != NULL) 4415 vrefact(cttyvp); 4416 } 4417 fdp = fdhold(p); 4418 pdp = pdhold(p); 4419 PROC_UNLOCK(p); 4420 efbuf = malloc(sizeof(*efbuf), M_TEMP, M_WAITOK); 4421 efbuf->fdp = NULL; 4422 efbuf->pdp = NULL; 4423 efbuf->sb = sb; 4424 efbuf->remainder = maxlen; 4425 efbuf->flags = flags; 4426 if (tracevp != NULL) 4427 export_vnode_to_sb(tracevp, KF_FD_TYPE_TRACE, FREAD | FWRITE, 4428 efbuf); 4429 if (textvp != NULL) 4430 export_vnode_to_sb(textvp, KF_FD_TYPE_TEXT, FREAD, efbuf); 4431 if (cttyvp != NULL) 4432 export_vnode_to_sb(cttyvp, KF_FD_TYPE_CTTY, FREAD | FWRITE, 4433 efbuf); 4434 error = 0; 4435 if (pdp == NULL || fdp == NULL) 4436 goto fail; 4437 efbuf->fdp = fdp; 4438 efbuf->pdp = pdp; 4439 PWDDESC_XLOCK(pdp); 4440 pwd = pwd_hold_pwddesc(pdp); 4441 if (pwd != NULL) { 4442 /* working directory */ 4443 if (pwd->pwd_cdir != NULL) { 4444 vrefact(pwd->pwd_cdir); 4445 export_vnode_to_sb(pwd->pwd_cdir, KF_FD_TYPE_CWD, 4446 FREAD, efbuf); 4447 } 4448 /* root directory */ 4449 if (pwd->pwd_rdir != NULL) { 4450 vrefact(pwd->pwd_rdir); 4451 export_vnode_to_sb(pwd->pwd_rdir, KF_FD_TYPE_ROOT, 4452 FREAD, efbuf); 4453 } 4454 /* jail directory */ 4455 if (pwd->pwd_jdir != NULL) { 4456 vrefact(pwd->pwd_jdir); 4457 export_vnode_to_sb(pwd->pwd_jdir, KF_FD_TYPE_JAIL, 4458 FREAD, efbuf); 4459 } 4460 } 4461 PWDDESC_XUNLOCK(pdp); 4462 if (pwd != NULL) 4463 pwd_drop(pwd); 4464 FILEDESC_SLOCK(fdp); 4465 lastfile = fdlastfile(fdp); 4466 for (i = 0; refcount_load(&fdp->fd_refcnt) > 0 && i <= lastfile; i++) { 4467 if ((fp = fdp->fd_ofiles[i].fde_file) == NULL) 4468 continue; 4469 #ifdef CAPABILITIES 4470 rights = *cap_rights(fdp, i); 4471 #else /* !CAPABILITIES */ 4472 rights = cap_no_rights; 4473 #endif 4474 /* 4475 * Create sysctl entry. It is OK to drop the filedesc 4476 * lock inside of export_file_to_sb() as we will 4477 * re-validate and re-evaluate its properties when the 4478 * loop continues. 4479 */ 4480 error = export_file_to_sb(fp, i, &rights, efbuf); 4481 if (error != 0 || efbuf->remainder == 0) 4482 break; 4483 } 4484 FILEDESC_SUNLOCK(fdp); 4485 fail: 4486 if (fdp != NULL) 4487 fddrop(fdp); 4488 if (pdp != NULL) 4489 pddrop(pdp); 4490 free(efbuf, M_TEMP); 4491 return (error); 4492 } 4493 4494 #define FILEDESC_SBUF_SIZE (sizeof(struct kinfo_file) * 5) 4495 4496 /* 4497 * Get per-process file descriptors for use by procstat(1), et al. 4498 */ 4499 static int 4500 sysctl_kern_proc_filedesc(SYSCTL_HANDLER_ARGS) 4501 { 4502 struct sbuf sb; 4503 struct proc *p; 4504 ssize_t maxlen; 4505 u_int namelen; 4506 int error, error2, *name; 4507 4508 namelen = arg2; 4509 if (namelen != 1) 4510 return (EINVAL); 4511 4512 name = (int *)arg1; 4513 4514 sbuf_new_for_sysctl(&sb, NULL, FILEDESC_SBUF_SIZE, req); 4515 sbuf_clear_flags(&sb, SBUF_INCLUDENUL); 4516 error = pget((pid_t)name[0], PGET_CANDEBUG | PGET_NOTWEXIT, &p); 4517 if (error != 0) { 4518 sbuf_delete(&sb); 4519 return (error); 4520 } 4521 maxlen = req->oldptr != NULL ? req->oldlen : -1; 4522 error = kern_proc_filedesc_out(p, &sb, maxlen, 4523 KERN_FILEDESC_PACK_KINFO); 4524 error2 = sbuf_finish(&sb); 4525 sbuf_delete(&sb); 4526 return (error != 0 ? error : error2); 4527 } 4528 4529 #ifdef COMPAT_FREEBSD7 4530 #ifdef KINFO_OFILE_SIZE 4531 CTASSERT(sizeof(struct kinfo_ofile) == KINFO_OFILE_SIZE); 4532 #endif 4533 4534 static void 4535 kinfo_to_okinfo(struct kinfo_file *kif, struct kinfo_ofile *okif) 4536 { 4537 4538 okif->kf_structsize = sizeof(*okif); 4539 okif->kf_type = kif->kf_type; 4540 okif->kf_fd = kif->kf_fd; 4541 okif->kf_ref_count = kif->kf_ref_count; 4542 okif->kf_flags = kif->kf_flags & (KF_FLAG_READ | KF_FLAG_WRITE | 4543 KF_FLAG_APPEND | KF_FLAG_ASYNC | KF_FLAG_FSYNC | KF_FLAG_NONBLOCK | 4544 KF_FLAG_DIRECT | KF_FLAG_HASLOCK); 4545 okif->kf_offset = kif->kf_offset; 4546 if (kif->kf_type == KF_TYPE_VNODE) 4547 okif->kf_vnode_type = kif->kf_un.kf_file.kf_file_type; 4548 else 4549 okif->kf_vnode_type = KF_VTYPE_VNON; 4550 strlcpy(okif->kf_path, kif->kf_path, sizeof(okif->kf_path)); 4551 if (kif->kf_type == KF_TYPE_SOCKET) { 4552 okif->kf_sock_domain = kif->kf_un.kf_sock.kf_sock_domain0; 4553 okif->kf_sock_type = kif->kf_un.kf_sock.kf_sock_type0; 4554 okif->kf_sock_protocol = kif->kf_un.kf_sock.kf_sock_protocol0; 4555 okif->kf_sa_local = kif->kf_un.kf_sock.kf_sa_local; 4556 okif->kf_sa_peer = kif->kf_un.kf_sock.kf_sa_peer; 4557 } else { 4558 okif->kf_sa_local.ss_family = AF_UNSPEC; 4559 okif->kf_sa_peer.ss_family = AF_UNSPEC; 4560 } 4561 } 4562 4563 static int 4564 export_vnode_for_osysctl(struct vnode *vp, int type, struct kinfo_file *kif, 4565 struct kinfo_ofile *okif, struct pwddesc *pdp, struct sysctl_req *req) 4566 { 4567 int error; 4568 4569 vrefact(vp); 4570 PWDDESC_XUNLOCK(pdp); 4571 export_vnode_to_kinfo(vp, type, 0, kif, KERN_FILEDESC_PACK_KINFO); 4572 kinfo_to_okinfo(kif, okif); 4573 error = SYSCTL_OUT(req, okif, sizeof(*okif)); 4574 PWDDESC_XLOCK(pdp); 4575 return (error); 4576 } 4577 4578 /* 4579 * Get per-process file descriptors for use by procstat(1), et al. 4580 */ 4581 static int 4582 sysctl_kern_proc_ofiledesc(SYSCTL_HANDLER_ARGS) 4583 { 4584 struct kinfo_ofile *okif; 4585 struct kinfo_file *kif; 4586 struct filedesc *fdp; 4587 struct pwddesc *pdp; 4588 struct pwd *pwd; 4589 u_int namelen; 4590 int error, i, lastfile, *name; 4591 struct file *fp; 4592 struct proc *p; 4593 4594 namelen = arg2; 4595 if (namelen != 1) 4596 return (EINVAL); 4597 4598 name = (int *)arg1; 4599 error = pget((pid_t)name[0], PGET_CANDEBUG | PGET_NOTWEXIT, &p); 4600 if (error != 0) 4601 return (error); 4602 fdp = fdhold(p); 4603 if (fdp != NULL) 4604 pdp = pdhold(p); 4605 PROC_UNLOCK(p); 4606 if (fdp == NULL || pdp == NULL) { 4607 if (fdp != NULL) 4608 fddrop(fdp); 4609 return (ENOENT); 4610 } 4611 kif = malloc(sizeof(*kif), M_TEMP, M_WAITOK); 4612 okif = malloc(sizeof(*okif), M_TEMP, M_WAITOK); 4613 PWDDESC_XLOCK(pdp); 4614 pwd = pwd_hold_pwddesc(pdp); 4615 if (pwd != NULL) { 4616 if (pwd->pwd_cdir != NULL) 4617 export_vnode_for_osysctl(pwd->pwd_cdir, KF_FD_TYPE_CWD, kif, 4618 okif, pdp, req); 4619 if (pwd->pwd_rdir != NULL) 4620 export_vnode_for_osysctl(pwd->pwd_rdir, KF_FD_TYPE_ROOT, kif, 4621 okif, pdp, req); 4622 if (pwd->pwd_jdir != NULL) 4623 export_vnode_for_osysctl(pwd->pwd_jdir, KF_FD_TYPE_JAIL, kif, 4624 okif, pdp, req); 4625 } 4626 PWDDESC_XUNLOCK(pdp); 4627 if (pwd != NULL) 4628 pwd_drop(pwd); 4629 FILEDESC_SLOCK(fdp); 4630 lastfile = fdlastfile(fdp); 4631 for (i = 0; refcount_load(&fdp->fd_refcnt) > 0 && i <= lastfile; i++) { 4632 if ((fp = fdp->fd_ofiles[i].fde_file) == NULL) 4633 continue; 4634 export_file_to_kinfo(fp, i, NULL, kif, fdp, 4635 KERN_FILEDESC_PACK_KINFO); 4636 FILEDESC_SUNLOCK(fdp); 4637 kinfo_to_okinfo(kif, okif); 4638 error = SYSCTL_OUT(req, okif, sizeof(*okif)); 4639 FILEDESC_SLOCK(fdp); 4640 if (error) 4641 break; 4642 } 4643 FILEDESC_SUNLOCK(fdp); 4644 fddrop(fdp); 4645 pddrop(pdp); 4646 free(kif, M_TEMP); 4647 free(okif, M_TEMP); 4648 return (0); 4649 } 4650 4651 static SYSCTL_NODE(_kern_proc, KERN_PROC_OFILEDESC, ofiledesc, 4652 CTLFLAG_RD|CTLFLAG_MPSAFE, sysctl_kern_proc_ofiledesc, 4653 "Process ofiledesc entries"); 4654 #endif /* COMPAT_FREEBSD7 */ 4655 4656 int 4657 vntype_to_kinfo(int vtype) 4658 { 4659 struct { 4660 int vtype; 4661 int kf_vtype; 4662 } vtypes_table[] = { 4663 { VBAD, KF_VTYPE_VBAD }, 4664 { VBLK, KF_VTYPE_VBLK }, 4665 { VCHR, KF_VTYPE_VCHR }, 4666 { VDIR, KF_VTYPE_VDIR }, 4667 { VFIFO, KF_VTYPE_VFIFO }, 4668 { VLNK, KF_VTYPE_VLNK }, 4669 { VNON, KF_VTYPE_VNON }, 4670 { VREG, KF_VTYPE_VREG }, 4671 { VSOCK, KF_VTYPE_VSOCK } 4672 }; 4673 unsigned int i; 4674 4675 /* 4676 * Perform vtype translation. 4677 */ 4678 for (i = 0; i < nitems(vtypes_table); i++) 4679 if (vtypes_table[i].vtype == vtype) 4680 return (vtypes_table[i].kf_vtype); 4681 4682 return (KF_VTYPE_UNKNOWN); 4683 } 4684 4685 static SYSCTL_NODE(_kern_proc, KERN_PROC_FILEDESC, filedesc, 4686 CTLFLAG_RD|CTLFLAG_MPSAFE, sysctl_kern_proc_filedesc, 4687 "Process filedesc entries"); 4688 4689 /* 4690 * Store a process current working directory information to sbuf. 4691 * 4692 * Takes a locked proc as argument, and returns with the proc unlocked. 4693 */ 4694 int 4695 kern_proc_cwd_out(struct proc *p, struct sbuf *sb, ssize_t maxlen) 4696 { 4697 struct pwddesc *pdp; 4698 struct pwd *pwd; 4699 struct export_fd_buf *efbuf; 4700 struct vnode *cdir; 4701 int error; 4702 4703 PROC_LOCK_ASSERT(p, MA_OWNED); 4704 4705 pdp = pdhold(p); 4706 PROC_UNLOCK(p); 4707 if (pdp == NULL) 4708 return (EINVAL); 4709 4710 efbuf = malloc(sizeof(*efbuf), M_TEMP, M_WAITOK); 4711 efbuf->pdp = pdp; 4712 efbuf->sb = sb; 4713 efbuf->remainder = maxlen; 4714 4715 PWDDESC_XLOCK(pdp); 4716 pwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); 4717 cdir = pwd->pwd_cdir; 4718 if (cdir == NULL) { 4719 error = EINVAL; 4720 } else { 4721 vrefact(cdir); 4722 error = export_vnode_to_sb(cdir, KF_FD_TYPE_CWD, FREAD, efbuf); 4723 } 4724 PWDDESC_XUNLOCK(pdp); 4725 pddrop(pdp); 4726 free(efbuf, M_TEMP); 4727 return (error); 4728 } 4729 4730 /* 4731 * Get per-process current working directory. 4732 */ 4733 static int 4734 sysctl_kern_proc_cwd(SYSCTL_HANDLER_ARGS) 4735 { 4736 struct sbuf sb; 4737 struct proc *p; 4738 ssize_t maxlen; 4739 u_int namelen; 4740 int error, error2, *name; 4741 4742 namelen = arg2; 4743 if (namelen != 1) 4744 return (EINVAL); 4745 4746 name = (int *)arg1; 4747 4748 sbuf_new_for_sysctl(&sb, NULL, sizeof(struct kinfo_file), req); 4749 sbuf_clear_flags(&sb, SBUF_INCLUDENUL); 4750 error = pget((pid_t)name[0], PGET_CANDEBUG | PGET_NOTWEXIT, &p); 4751 if (error != 0) { 4752 sbuf_delete(&sb); 4753 return (error); 4754 } 4755 maxlen = req->oldptr != NULL ? req->oldlen : -1; 4756 error = kern_proc_cwd_out(p, &sb, maxlen); 4757 error2 = sbuf_finish(&sb); 4758 sbuf_delete(&sb); 4759 return (error != 0 ? error : error2); 4760 } 4761 4762 static SYSCTL_NODE(_kern_proc, KERN_PROC_CWD, cwd, CTLFLAG_RD|CTLFLAG_MPSAFE, 4763 sysctl_kern_proc_cwd, "Process current working directory"); 4764 4765 #ifdef DDB 4766 /* 4767 * For the purposes of debugging, generate a human-readable string for the 4768 * file type. 4769 */ 4770 static const char * 4771 file_type_to_name(short type) 4772 { 4773 4774 switch (type) { 4775 case 0: 4776 return ("zero"); 4777 case DTYPE_VNODE: 4778 return ("vnode"); 4779 case DTYPE_SOCKET: 4780 return ("socket"); 4781 case DTYPE_PIPE: 4782 return ("pipe"); 4783 case DTYPE_FIFO: 4784 return ("fifo"); 4785 case DTYPE_KQUEUE: 4786 return ("kqueue"); 4787 case DTYPE_CRYPTO: 4788 return ("crypto"); 4789 case DTYPE_MQUEUE: 4790 return ("mqueue"); 4791 case DTYPE_SHM: 4792 return ("shm"); 4793 case DTYPE_SEM: 4794 return ("ksem"); 4795 case DTYPE_PTS: 4796 return ("pts"); 4797 case DTYPE_DEV: 4798 return ("dev"); 4799 case DTYPE_PROCDESC: 4800 return ("proc"); 4801 case DTYPE_EVENTFD: 4802 return ("eventfd"); 4803 case DTYPE_LINUXTFD: 4804 return ("ltimer"); 4805 default: 4806 return ("unkn"); 4807 } 4808 } 4809 4810 /* 4811 * For the purposes of debugging, identify a process (if any, perhaps one of 4812 * many) that references the passed file in its file descriptor array. Return 4813 * NULL if none. 4814 */ 4815 static struct proc * 4816 file_to_first_proc(struct file *fp) 4817 { 4818 struct filedesc *fdp; 4819 struct proc *p; 4820 int n; 4821 4822 FOREACH_PROC_IN_SYSTEM(p) { 4823 if (p->p_state == PRS_NEW) 4824 continue; 4825 fdp = p->p_fd; 4826 if (fdp == NULL) 4827 continue; 4828 for (n = 0; n < fdp->fd_nfiles; n++) { 4829 if (fp == fdp->fd_ofiles[n].fde_file) 4830 return (p); 4831 } 4832 } 4833 return (NULL); 4834 } 4835 4836 static void 4837 db_print_file(struct file *fp, int header) 4838 { 4839 #define XPTRWIDTH ((int)howmany(sizeof(void *) * NBBY, 4)) 4840 struct proc *p; 4841 4842 if (header) 4843 db_printf("%*s %6s %*s %8s %4s %5s %6s %*s %5s %s\n", 4844 XPTRWIDTH, "File", "Type", XPTRWIDTH, "Data", "Flag", 4845 "GCFl", "Count", "MCount", XPTRWIDTH, "Vnode", "FPID", 4846 "FCmd"); 4847 p = file_to_first_proc(fp); 4848 db_printf("%*p %6s %*p %08x %04x %5d %6d %*p %5d %s\n", XPTRWIDTH, 4849 fp, file_type_to_name(fp->f_type), XPTRWIDTH, fp->f_data, 4850 fp->f_flag, 0, refcount_load(&fp->f_count), 0, XPTRWIDTH, fp->f_vnode, 4851 p != NULL ? p->p_pid : -1, p != NULL ? p->p_comm : "-"); 4852 4853 #undef XPTRWIDTH 4854 } 4855 4856 DB_SHOW_COMMAND(file, db_show_file) 4857 { 4858 struct file *fp; 4859 4860 if (!have_addr) { 4861 db_printf("usage: show file <addr>\n"); 4862 return; 4863 } 4864 fp = (struct file *)addr; 4865 db_print_file(fp, 1); 4866 } 4867 4868 DB_SHOW_COMMAND(files, db_show_files) 4869 { 4870 struct filedesc *fdp; 4871 struct file *fp; 4872 struct proc *p; 4873 int header; 4874 int n; 4875 4876 header = 1; 4877 FOREACH_PROC_IN_SYSTEM(p) { 4878 if (p->p_state == PRS_NEW) 4879 continue; 4880 if ((fdp = p->p_fd) == NULL) 4881 continue; 4882 for (n = 0; n < fdp->fd_nfiles; ++n) { 4883 if ((fp = fdp->fd_ofiles[n].fde_file) == NULL) 4884 continue; 4885 db_print_file(fp, header); 4886 header = 0; 4887 } 4888 } 4889 } 4890 #endif 4891 4892 SYSCTL_INT(_kern, KERN_MAXFILESPERPROC, maxfilesperproc, CTLFLAG_RW, 4893 &maxfilesperproc, 0, "Maximum files allowed open per process"); 4894 4895 SYSCTL_INT(_kern, KERN_MAXFILES, maxfiles, CTLFLAG_RW, 4896 &maxfiles, 0, "Maximum number of files"); 4897 4898 SYSCTL_INT(_kern, OID_AUTO, openfiles, CTLFLAG_RD, 4899 &openfiles, 0, "System-wide number of open files"); 4900 4901 /* ARGSUSED*/ 4902 static void 4903 filelistinit(void *dummy) 4904 { 4905 4906 file_zone = uma_zcreate("Files", sizeof(struct file), NULL, NULL, 4907 NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE); 4908 filedesc0_zone = uma_zcreate("filedesc0", sizeof(struct filedesc0), 4909 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0); 4910 pwd_zone = uma_zcreate("PWD", sizeof(struct pwd), NULL, NULL, 4911 NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_SMR); 4912 /* 4913 * XXXMJG this is a temporary hack due to boot ordering issues against 4914 * the vnode zone. 4915 */ 4916 vfs_smr = uma_zone_get_smr(pwd_zone); 4917 mtx_init(&sigio_lock, "sigio lock", NULL, MTX_DEF); 4918 } 4919 SYSINIT(select, SI_SUB_LOCK, SI_ORDER_FIRST, filelistinit, NULL); 4920 4921 /*-------------------------------------------------------------------*/ 4922 4923 static int 4924 badfo_readwrite(struct file *fp, struct uio *uio, struct ucred *active_cred, 4925 int flags, struct thread *td) 4926 { 4927 4928 return (EBADF); 4929 } 4930 4931 static int 4932 badfo_truncate(struct file *fp, off_t length, struct ucred *active_cred, 4933 struct thread *td) 4934 { 4935 4936 return (EINVAL); 4937 } 4938 4939 static int 4940 badfo_ioctl(struct file *fp, u_long com, void *data, struct ucred *active_cred, 4941 struct thread *td) 4942 { 4943 4944 return (EBADF); 4945 } 4946 4947 static int 4948 badfo_poll(struct file *fp, int events, struct ucred *active_cred, 4949 struct thread *td) 4950 { 4951 4952 return (0); 4953 } 4954 4955 static int 4956 badfo_kqfilter(struct file *fp, struct knote *kn) 4957 { 4958 4959 return (EBADF); 4960 } 4961 4962 static int 4963 badfo_stat(struct file *fp, struct stat *sb, struct ucred *active_cred, 4964 struct thread *td) 4965 { 4966 4967 return (EBADF); 4968 } 4969 4970 static int 4971 badfo_close(struct file *fp, struct thread *td) 4972 { 4973 4974 return (0); 4975 } 4976 4977 static int 4978 badfo_chmod(struct file *fp, mode_t mode, struct ucred *active_cred, 4979 struct thread *td) 4980 { 4981 4982 return (EBADF); 4983 } 4984 4985 static int 4986 badfo_chown(struct file *fp, uid_t uid, gid_t gid, struct ucred *active_cred, 4987 struct thread *td) 4988 { 4989 4990 return (EBADF); 4991 } 4992 4993 static int 4994 badfo_sendfile(struct file *fp, int sockfd, struct uio *hdr_uio, 4995 struct uio *trl_uio, off_t offset, size_t nbytes, off_t *sent, int flags, 4996 struct thread *td) 4997 { 4998 4999 return (EBADF); 5000 } 5001 5002 static int 5003 badfo_fill_kinfo(struct file *fp, struct kinfo_file *kif, struct filedesc *fdp) 5004 { 5005 5006 return (0); 5007 } 5008 5009 struct fileops badfileops = { 5010 .fo_read = badfo_readwrite, 5011 .fo_write = badfo_readwrite, 5012 .fo_truncate = badfo_truncate, 5013 .fo_ioctl = badfo_ioctl, 5014 .fo_poll = badfo_poll, 5015 .fo_kqfilter = badfo_kqfilter, 5016 .fo_stat = badfo_stat, 5017 .fo_close = badfo_close, 5018 .fo_chmod = badfo_chmod, 5019 .fo_chown = badfo_chown, 5020 .fo_sendfile = badfo_sendfile, 5021 .fo_fill_kinfo = badfo_fill_kinfo, 5022 }; 5023 5024 static int 5025 path_poll(struct file *fp, int events, struct ucred *active_cred, 5026 struct thread *td) 5027 { 5028 return (POLLNVAL); 5029 } 5030 5031 static int 5032 path_close(struct file *fp, struct thread *td) 5033 { 5034 MPASS(fp->f_type == DTYPE_VNODE); 5035 fp->f_ops = &badfileops; 5036 vdrop(fp->f_vnode); 5037 return (0); 5038 } 5039 5040 struct fileops path_fileops = { 5041 .fo_read = badfo_readwrite, 5042 .fo_write = badfo_readwrite, 5043 .fo_truncate = badfo_truncate, 5044 .fo_ioctl = badfo_ioctl, 5045 .fo_poll = path_poll, 5046 .fo_kqfilter = vn_kqfilter_opath, 5047 .fo_stat = vn_statfile, 5048 .fo_close = path_close, 5049 .fo_chmod = badfo_chmod, 5050 .fo_chown = badfo_chown, 5051 .fo_sendfile = badfo_sendfile, 5052 .fo_fill_kinfo = vn_fill_kinfo, 5053 .fo_flags = DFLAG_PASSABLE, 5054 }; 5055 5056 int 5057 invfo_rdwr(struct file *fp, struct uio *uio, struct ucred *active_cred, 5058 int flags, struct thread *td) 5059 { 5060 5061 return (EOPNOTSUPP); 5062 } 5063 5064 int 5065 invfo_truncate(struct file *fp, off_t length, struct ucred *active_cred, 5066 struct thread *td) 5067 { 5068 5069 return (EINVAL); 5070 } 5071 5072 int 5073 invfo_ioctl(struct file *fp, u_long com, void *data, 5074 struct ucred *active_cred, struct thread *td) 5075 { 5076 5077 return (ENOTTY); 5078 } 5079 5080 int 5081 invfo_poll(struct file *fp, int events, struct ucred *active_cred, 5082 struct thread *td) 5083 { 5084 5085 return (poll_no_poll(events)); 5086 } 5087 5088 int 5089 invfo_kqfilter(struct file *fp, struct knote *kn) 5090 { 5091 5092 return (EINVAL); 5093 } 5094 5095 int 5096 invfo_chmod(struct file *fp, mode_t mode, struct ucred *active_cred, 5097 struct thread *td) 5098 { 5099 5100 return (EINVAL); 5101 } 5102 5103 int 5104 invfo_chown(struct file *fp, uid_t uid, gid_t gid, struct ucred *active_cred, 5105 struct thread *td) 5106 { 5107 5108 return (EINVAL); 5109 } 5110 5111 int 5112 invfo_sendfile(struct file *fp, int sockfd, struct uio *hdr_uio, 5113 struct uio *trl_uio, off_t offset, size_t nbytes, off_t *sent, int flags, 5114 struct thread *td) 5115 { 5116 5117 return (EINVAL); 5118 } 5119 5120 /*-------------------------------------------------------------------*/ 5121 5122 /* 5123 * File Descriptor pseudo-device driver (/dev/fd/). 5124 * 5125 * Opening minor device N dup()s the file (if any) connected to file 5126 * descriptor N belonging to the calling process. Note that this driver 5127 * consists of only the ``open()'' routine, because all subsequent 5128 * references to this file will be direct to the other driver. 5129 * 5130 * XXX: we could give this one a cloning event handler if necessary. 5131 */ 5132 5133 /* ARGSUSED */ 5134 static int 5135 fdopen(struct cdev *dev, int mode, int type, struct thread *td) 5136 { 5137 5138 /* 5139 * XXX Kludge: set curthread->td_dupfd to contain the value of the 5140 * the file descriptor being sought for duplication. The error 5141 * return ensures that the vnode for this device will be released 5142 * by vn_open. Open will detect this special error and take the 5143 * actions in dupfdopen below. Other callers of vn_open or VOP_OPEN 5144 * will simply report the error. 5145 */ 5146 td->td_dupfd = dev2unit(dev); 5147 return (ENODEV); 5148 } 5149 5150 static struct cdevsw fildesc_cdevsw = { 5151 .d_version = D_VERSION, 5152 .d_open = fdopen, 5153 .d_name = "FD", 5154 }; 5155 5156 static void 5157 fildesc_drvinit(void *unused) 5158 { 5159 struct cdev *dev; 5160 5161 dev = make_dev_credf(MAKEDEV_ETERNAL, &fildesc_cdevsw, 0, NULL, 5162 UID_ROOT, GID_WHEEL, 0666, "fd/0"); 5163 make_dev_alias(dev, "stdin"); 5164 dev = make_dev_credf(MAKEDEV_ETERNAL, &fildesc_cdevsw, 1, NULL, 5165 UID_ROOT, GID_WHEEL, 0666, "fd/1"); 5166 make_dev_alias(dev, "stdout"); 5167 dev = make_dev_credf(MAKEDEV_ETERNAL, &fildesc_cdevsw, 2, NULL, 5168 UID_ROOT, GID_WHEEL, 0666, "fd/2"); 5169 make_dev_alias(dev, "stderr"); 5170 } 5171 5172 SYSINIT(fildescdev, SI_SUB_DRIVERS, SI_ORDER_MIDDLE, fildesc_drvinit, NULL); 5173