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 void export_file_to_kinfo(struct file *fp, int fd, 111 cap_rights_t *rightsp, struct kinfo_file *kif, 112 struct filedesc *fdp, int flags); 113 static int fd_first_free(struct filedesc *fdp, int low, int size); 114 static void fdgrowtable(struct filedesc *fdp, int nfd); 115 static void fdgrowtable_exp(struct filedesc *fdp, int nfd); 116 static void fdunused(struct filedesc *fdp, int fd); 117 static void fdused(struct filedesc *fdp, int fd); 118 static int fget_unlocked_seq(struct filedesc *fdp, int fd, 119 cap_rights_t *needrightsp, struct file **fpp, seqc_t *seqp); 120 static int getmaxfd(struct thread *td); 121 static u_long *filecaps_copy_prep(const struct filecaps *src); 122 static void filecaps_copy_finish(const struct filecaps *src, 123 struct filecaps *dst, u_long *ioctls); 124 static u_long *filecaps_free_prep(struct filecaps *fcaps); 125 static void filecaps_free_finish(u_long *ioctls); 126 127 static struct pwd *pwd_alloc(void); 128 129 /* 130 * Each process has: 131 * 132 * - An array of open file descriptors (fd_ofiles) 133 * - An array of file flags (fd_ofileflags) 134 * - A bitmap recording which descriptors are in use (fd_map) 135 * 136 * A process starts out with NDFILE descriptors. The value of NDFILE has 137 * been selected based the historical limit of 20 open files, and an 138 * assumption that the majority of processes, especially short-lived 139 * processes like shells, will never need more. 140 * 141 * If this initial allocation is exhausted, a larger descriptor table and 142 * map are allocated dynamically, and the pointers in the process's struct 143 * filedesc are updated to point to those. This is repeated every time 144 * the process runs out of file descriptors (provided it hasn't hit its 145 * resource limit). 146 * 147 * Since threads may hold references to individual descriptor table 148 * entries, the tables are never freed. Instead, they are placed on a 149 * linked list and freed only when the struct filedesc is released. 150 */ 151 #define NDFILE 20 152 #define NDSLOTSIZE sizeof(NDSLOTTYPE) 153 #define NDENTRIES (NDSLOTSIZE * __CHAR_BIT) 154 #define NDSLOT(x) ((x) / NDENTRIES) 155 #define NDBIT(x) ((NDSLOTTYPE)1 << ((x) % NDENTRIES)) 156 #define NDSLOTS(x) (((x) + NDENTRIES - 1) / NDENTRIES) 157 158 /* 159 * SLIST entry used to keep track of ofiles which must be reclaimed when 160 * the process exits. 161 */ 162 struct freetable { 163 struct fdescenttbl *ft_table; 164 SLIST_ENTRY(freetable) ft_next; 165 }; 166 167 /* 168 * Initial allocation: a filedesc structure + the head of SLIST used to 169 * keep track of old ofiles + enough space for NDFILE descriptors. 170 */ 171 172 struct fdescenttbl0 { 173 int fdt_nfiles; 174 struct filedescent fdt_ofiles[NDFILE]; 175 }; 176 177 struct filedesc0 { 178 struct filedesc fd_fd; 179 SLIST_HEAD(, freetable) fd_free; 180 struct fdescenttbl0 fd_dfiles; 181 NDSLOTTYPE fd_dmap[NDSLOTS(NDFILE)]; 182 }; 183 184 /* 185 * Descriptor management. 186 */ 187 static int __exclusive_cache_line openfiles; /* actual number of open files */ 188 struct mtx sigio_lock; /* mtx to protect pointers to sigio */ 189 void __read_mostly (*mq_fdclose)(struct thread *td, int fd, struct file *fp); 190 191 /* 192 * If low >= size, just return low. Otherwise find the first zero bit in the 193 * given bitmap, starting at low and not exceeding size - 1. Return size if 194 * not found. 195 */ 196 static int 197 fd_first_free(struct filedesc *fdp, int low, int size) 198 { 199 NDSLOTTYPE *map = fdp->fd_map; 200 NDSLOTTYPE mask; 201 int off, maxoff; 202 203 if (low >= size) 204 return (low); 205 206 off = NDSLOT(low); 207 if (low % NDENTRIES) { 208 mask = ~(~(NDSLOTTYPE)0 >> (NDENTRIES - (low % NDENTRIES))); 209 if ((mask &= ~map[off]) != 0UL) 210 return (off * NDENTRIES + ffsl(mask) - 1); 211 ++off; 212 } 213 for (maxoff = NDSLOTS(size); off < maxoff; ++off) 214 if (map[off] != ~0UL) 215 return (off * NDENTRIES + ffsl(~map[off]) - 1); 216 return (size); 217 } 218 219 /* 220 * Find the last used fd. 221 * 222 * Call this variant if fdp can't be modified by anyone else (e.g, during exec). 223 * Otherwise use fdlastfile. 224 */ 225 int 226 fdlastfile_single(struct filedesc *fdp) 227 { 228 NDSLOTTYPE *map = fdp->fd_map; 229 int off, minoff; 230 231 off = NDSLOT(fdp->fd_nfiles - 1); 232 for (minoff = NDSLOT(0); off >= minoff; --off) 233 if (map[off] != 0) 234 return (off * NDENTRIES + flsl(map[off]) - 1); 235 return (-1); 236 } 237 238 int 239 fdlastfile(struct filedesc *fdp) 240 { 241 242 FILEDESC_LOCK_ASSERT(fdp); 243 return (fdlastfile_single(fdp)); 244 } 245 246 static int 247 fdisused(struct filedesc *fdp, int fd) 248 { 249 250 KASSERT(fd >= 0 && fd < fdp->fd_nfiles, 251 ("file descriptor %d out of range (0, %d)", fd, fdp->fd_nfiles)); 252 253 return ((fdp->fd_map[NDSLOT(fd)] & NDBIT(fd)) != 0); 254 } 255 256 /* 257 * Mark a file descriptor as used. 258 */ 259 static void 260 fdused_init(struct filedesc *fdp, int fd) 261 { 262 263 KASSERT(!fdisused(fdp, fd), ("fd=%d is already used", fd)); 264 265 fdp->fd_map[NDSLOT(fd)] |= NDBIT(fd); 266 } 267 268 static void 269 fdused(struct filedesc *fdp, int fd) 270 { 271 272 FILEDESC_XLOCK_ASSERT(fdp); 273 274 fdused_init(fdp, fd); 275 if (fd == fdp->fd_freefile) 276 fdp->fd_freefile++; 277 } 278 279 /* 280 * Mark a file descriptor as unused. 281 */ 282 static void 283 fdunused(struct filedesc *fdp, int fd) 284 { 285 286 FILEDESC_XLOCK_ASSERT(fdp); 287 288 KASSERT(fdisused(fdp, fd), ("fd=%d is already unused", fd)); 289 KASSERT(fdp->fd_ofiles[fd].fde_file == NULL, 290 ("fd=%d is still in use", fd)); 291 292 fdp->fd_map[NDSLOT(fd)] &= ~NDBIT(fd); 293 if (fd < fdp->fd_freefile) 294 fdp->fd_freefile = fd; 295 } 296 297 /* 298 * Free a file descriptor. 299 * 300 * Avoid some work if fdp is about to be destroyed. 301 */ 302 static inline void 303 fdefree_last(struct filedescent *fde) 304 { 305 306 filecaps_free(&fde->fde_caps); 307 } 308 309 static inline void 310 fdfree(struct filedesc *fdp, int fd) 311 { 312 struct filedescent *fde; 313 314 FILEDESC_XLOCK_ASSERT(fdp); 315 fde = &fdp->fd_ofiles[fd]; 316 #ifdef CAPABILITIES 317 seqc_write_begin(&fde->fde_seqc); 318 #endif 319 fde->fde_file = NULL; 320 #ifdef CAPABILITIES 321 seqc_write_end(&fde->fde_seqc); 322 #endif 323 fdefree_last(fde); 324 fdunused(fdp, fd); 325 } 326 327 /* 328 * System calls on descriptors. 329 */ 330 #ifndef _SYS_SYSPROTO_H_ 331 struct getdtablesize_args { 332 int dummy; 333 }; 334 #endif 335 /* ARGSUSED */ 336 int 337 sys_getdtablesize(struct thread *td, struct getdtablesize_args *uap) 338 { 339 #ifdef RACCT 340 uint64_t lim; 341 #endif 342 343 td->td_retval[0] = getmaxfd(td); 344 #ifdef RACCT 345 PROC_LOCK(td->td_proc); 346 lim = racct_get_limit(td->td_proc, RACCT_NOFILE); 347 PROC_UNLOCK(td->td_proc); 348 if (lim < td->td_retval[0]) 349 td->td_retval[0] = lim; 350 #endif 351 return (0); 352 } 353 354 /* 355 * Duplicate a file descriptor to a particular value. 356 * 357 * Note: keep in mind that a potential race condition exists when closing 358 * descriptors from a shared descriptor table (via rfork). 359 */ 360 #ifndef _SYS_SYSPROTO_H_ 361 struct dup2_args { 362 u_int from; 363 u_int to; 364 }; 365 #endif 366 /* ARGSUSED */ 367 int 368 sys_dup2(struct thread *td, struct dup2_args *uap) 369 { 370 371 return (kern_dup(td, FDDUP_FIXED, 0, (int)uap->from, (int)uap->to)); 372 } 373 374 /* 375 * Duplicate a file descriptor. 376 */ 377 #ifndef _SYS_SYSPROTO_H_ 378 struct dup_args { 379 u_int fd; 380 }; 381 #endif 382 /* ARGSUSED */ 383 int 384 sys_dup(struct thread *td, struct dup_args *uap) 385 { 386 387 return (kern_dup(td, FDDUP_NORMAL, 0, (int)uap->fd, 0)); 388 } 389 390 /* 391 * The file control system call. 392 */ 393 #ifndef _SYS_SYSPROTO_H_ 394 struct fcntl_args { 395 int fd; 396 int cmd; 397 long arg; 398 }; 399 #endif 400 /* ARGSUSED */ 401 int 402 sys_fcntl(struct thread *td, struct fcntl_args *uap) 403 { 404 405 return (kern_fcntl_freebsd(td, uap->fd, uap->cmd, uap->arg)); 406 } 407 408 int 409 kern_fcntl_freebsd(struct thread *td, int fd, int cmd, long arg) 410 { 411 struct flock fl; 412 struct __oflock ofl; 413 intptr_t arg1; 414 int error, newcmd; 415 416 error = 0; 417 newcmd = cmd; 418 switch (cmd) { 419 case F_OGETLK: 420 case F_OSETLK: 421 case F_OSETLKW: 422 /* 423 * Convert old flock structure to new. 424 */ 425 error = copyin((void *)(intptr_t)arg, &ofl, sizeof(ofl)); 426 fl.l_start = ofl.l_start; 427 fl.l_len = ofl.l_len; 428 fl.l_pid = ofl.l_pid; 429 fl.l_type = ofl.l_type; 430 fl.l_whence = ofl.l_whence; 431 fl.l_sysid = 0; 432 433 switch (cmd) { 434 case F_OGETLK: 435 newcmd = F_GETLK; 436 break; 437 case F_OSETLK: 438 newcmd = F_SETLK; 439 break; 440 case F_OSETLKW: 441 newcmd = F_SETLKW; 442 break; 443 } 444 arg1 = (intptr_t)&fl; 445 break; 446 case F_GETLK: 447 case F_SETLK: 448 case F_SETLKW: 449 case F_SETLK_REMOTE: 450 error = copyin((void *)(intptr_t)arg, &fl, sizeof(fl)); 451 arg1 = (intptr_t)&fl; 452 break; 453 default: 454 arg1 = arg; 455 break; 456 } 457 if (error) 458 return (error); 459 error = kern_fcntl(td, fd, newcmd, arg1); 460 if (error) 461 return (error); 462 if (cmd == F_OGETLK) { 463 ofl.l_start = fl.l_start; 464 ofl.l_len = fl.l_len; 465 ofl.l_pid = fl.l_pid; 466 ofl.l_type = fl.l_type; 467 ofl.l_whence = fl.l_whence; 468 error = copyout(&ofl, (void *)(intptr_t)arg, sizeof(ofl)); 469 } else if (cmd == F_GETLK) { 470 error = copyout(&fl, (void *)(intptr_t)arg, sizeof(fl)); 471 } 472 return (error); 473 } 474 475 int 476 kern_fcntl(struct thread *td, int fd, int cmd, intptr_t arg) 477 { 478 struct filedesc *fdp; 479 struct flock *flp; 480 struct file *fp, *fp2; 481 struct filedescent *fde; 482 struct proc *p; 483 struct vnode *vp; 484 struct mount *mp; 485 struct kinfo_file *kif; 486 int error, flg, kif_sz, seals, tmp; 487 uint64_t bsize; 488 off_t foffset; 489 490 error = 0; 491 flg = F_POSIX; 492 p = td->td_proc; 493 fdp = p->p_fd; 494 495 AUDIT_ARG_FD(cmd); 496 AUDIT_ARG_CMD(cmd); 497 switch (cmd) { 498 case F_DUPFD: 499 tmp = arg; 500 error = kern_dup(td, FDDUP_FCNTL, 0, fd, tmp); 501 break; 502 503 case F_DUPFD_CLOEXEC: 504 tmp = arg; 505 error = kern_dup(td, FDDUP_FCNTL, FDDUP_FLAG_CLOEXEC, fd, tmp); 506 break; 507 508 case F_DUP2FD: 509 tmp = arg; 510 error = kern_dup(td, FDDUP_FIXED, 0, fd, tmp); 511 break; 512 513 case F_DUP2FD_CLOEXEC: 514 tmp = arg; 515 error = kern_dup(td, FDDUP_FIXED, FDDUP_FLAG_CLOEXEC, fd, tmp); 516 break; 517 518 case F_GETFD: 519 error = EBADF; 520 FILEDESC_SLOCK(fdp); 521 fde = fdeget_locked(fdp, fd); 522 if (fde != NULL) { 523 td->td_retval[0] = 524 (fde->fde_flags & UF_EXCLOSE) ? FD_CLOEXEC : 0; 525 error = 0; 526 } 527 FILEDESC_SUNLOCK(fdp); 528 break; 529 530 case F_SETFD: 531 error = EBADF; 532 FILEDESC_XLOCK(fdp); 533 fde = fdeget_locked(fdp, fd); 534 if (fde != NULL) { 535 fde->fde_flags = (fde->fde_flags & ~UF_EXCLOSE) | 536 (arg & FD_CLOEXEC ? UF_EXCLOSE : 0); 537 error = 0; 538 } 539 FILEDESC_XUNLOCK(fdp); 540 break; 541 542 case F_GETFL: 543 error = fget_fcntl(td, fd, &cap_fcntl_rights, F_GETFL, &fp); 544 if (error != 0) 545 break; 546 td->td_retval[0] = OFLAGS(fp->f_flag); 547 fdrop(fp, td); 548 break; 549 550 case F_SETFL: 551 error = fget_fcntl(td, fd, &cap_fcntl_rights, F_SETFL, &fp); 552 if (error != 0) 553 break; 554 if (fp->f_ops == &path_fileops) { 555 fdrop(fp, td); 556 error = EBADF; 557 break; 558 } 559 do { 560 tmp = flg = fp->f_flag; 561 tmp &= ~FCNTLFLAGS; 562 tmp |= FFLAGS(arg & ~O_ACCMODE) & FCNTLFLAGS; 563 } while (atomic_cmpset_int(&fp->f_flag, flg, tmp) == 0); 564 tmp = fp->f_flag & FNONBLOCK; 565 error = fo_ioctl(fp, FIONBIO, &tmp, td->td_ucred, td); 566 if (error != 0) { 567 fdrop(fp, td); 568 break; 569 } 570 tmp = fp->f_flag & FASYNC; 571 error = fo_ioctl(fp, FIOASYNC, &tmp, td->td_ucred, td); 572 if (error == 0) { 573 fdrop(fp, td); 574 break; 575 } 576 atomic_clear_int(&fp->f_flag, FNONBLOCK); 577 tmp = 0; 578 (void)fo_ioctl(fp, FIONBIO, &tmp, td->td_ucred, td); 579 fdrop(fp, td); 580 break; 581 582 case F_GETOWN: 583 error = fget_fcntl(td, fd, &cap_fcntl_rights, F_GETOWN, &fp); 584 if (error != 0) 585 break; 586 error = fo_ioctl(fp, FIOGETOWN, &tmp, td->td_ucred, td); 587 if (error == 0) 588 td->td_retval[0] = tmp; 589 fdrop(fp, td); 590 break; 591 592 case F_SETOWN: 593 error = fget_fcntl(td, fd, &cap_fcntl_rights, F_SETOWN, &fp); 594 if (error != 0) 595 break; 596 tmp = arg; 597 error = fo_ioctl(fp, FIOSETOWN, &tmp, td->td_ucred, td); 598 fdrop(fp, td); 599 break; 600 601 case F_SETLK_REMOTE: 602 error = priv_check(td, PRIV_NFS_LOCKD); 603 if (error != 0) 604 return (error); 605 flg = F_REMOTE; 606 goto do_setlk; 607 608 case F_SETLKW: 609 flg |= F_WAIT; 610 /* FALLTHROUGH F_SETLK */ 611 612 case F_SETLK: 613 do_setlk: 614 flp = (struct flock *)arg; 615 if ((flg & F_REMOTE) != 0 && flp->l_sysid == 0) { 616 error = EINVAL; 617 break; 618 } 619 620 error = fget_unlocked(fdp, fd, &cap_flock_rights, &fp); 621 if (error != 0) 622 break; 623 if (fp->f_type != DTYPE_VNODE || fp->f_ops == &path_fileops) { 624 error = EBADF; 625 fdrop(fp, td); 626 break; 627 } 628 629 if (flp->l_whence == SEEK_CUR) { 630 foffset = foffset_get(fp); 631 if (foffset < 0 || 632 (flp->l_start > 0 && 633 foffset > OFF_MAX - flp->l_start)) { 634 error = EOVERFLOW; 635 fdrop(fp, td); 636 break; 637 } 638 flp->l_start += foffset; 639 } 640 641 vp = fp->f_vnode; 642 switch (flp->l_type) { 643 case F_RDLCK: 644 if ((fp->f_flag & FREAD) == 0) { 645 error = EBADF; 646 break; 647 } 648 if ((p->p_leader->p_flag & P_ADVLOCK) == 0) { 649 PROC_LOCK(p->p_leader); 650 p->p_leader->p_flag |= P_ADVLOCK; 651 PROC_UNLOCK(p->p_leader); 652 } 653 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_SETLK, 654 flp, flg); 655 break; 656 case F_WRLCK: 657 if ((fp->f_flag & FWRITE) == 0) { 658 error = EBADF; 659 break; 660 } 661 if ((p->p_leader->p_flag & P_ADVLOCK) == 0) { 662 PROC_LOCK(p->p_leader); 663 p->p_leader->p_flag |= P_ADVLOCK; 664 PROC_UNLOCK(p->p_leader); 665 } 666 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_SETLK, 667 flp, flg); 668 break; 669 case F_UNLCK: 670 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_UNLCK, 671 flp, flg); 672 break; 673 case F_UNLCKSYS: 674 if (flg != F_REMOTE) { 675 error = EINVAL; 676 break; 677 } 678 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, 679 F_UNLCKSYS, flp, flg); 680 break; 681 default: 682 error = EINVAL; 683 break; 684 } 685 if (error != 0 || flp->l_type == F_UNLCK || 686 flp->l_type == F_UNLCKSYS) { 687 fdrop(fp, td); 688 break; 689 } 690 691 /* 692 * Check for a race with close. 693 * 694 * The vnode is now advisory locked (or unlocked, but this case 695 * is not really important) as the caller requested. 696 * We had to drop the filedesc lock, so we need to recheck if 697 * the descriptor is still valid, because if it was closed 698 * in the meantime we need to remove advisory lock from the 699 * vnode - close on any descriptor leading to an advisory 700 * locked vnode, removes that lock. 701 * We will return 0 on purpose in that case, as the result of 702 * successful advisory lock might have been externally visible 703 * already. This is fine - effectively we pretend to the caller 704 * that the closing thread was a bit slower and that the 705 * advisory lock succeeded before the close. 706 */ 707 error = fget_unlocked(fdp, fd, &cap_no_rights, &fp2); 708 if (error != 0) { 709 fdrop(fp, td); 710 break; 711 } 712 if (fp != fp2) { 713 flp->l_whence = SEEK_SET; 714 flp->l_start = 0; 715 flp->l_len = 0; 716 flp->l_type = F_UNLCK; 717 (void) VOP_ADVLOCK(vp, (caddr_t)p->p_leader, 718 F_UNLCK, flp, F_POSIX); 719 } 720 fdrop(fp, td); 721 fdrop(fp2, td); 722 break; 723 724 case F_GETLK: 725 error = fget_unlocked(fdp, fd, &cap_flock_rights, &fp); 726 if (error != 0) 727 break; 728 if (fp->f_type != DTYPE_VNODE || fp->f_ops == &path_fileops) { 729 error = EBADF; 730 fdrop(fp, td); 731 break; 732 } 733 flp = (struct flock *)arg; 734 if (flp->l_type != F_RDLCK && flp->l_type != F_WRLCK && 735 flp->l_type != F_UNLCK) { 736 error = EINVAL; 737 fdrop(fp, td); 738 break; 739 } 740 if (flp->l_whence == SEEK_CUR) { 741 foffset = foffset_get(fp); 742 if ((flp->l_start > 0 && 743 foffset > OFF_MAX - flp->l_start) || 744 (flp->l_start < 0 && 745 foffset < OFF_MIN - flp->l_start)) { 746 error = EOVERFLOW; 747 fdrop(fp, td); 748 break; 749 } 750 flp->l_start += foffset; 751 } 752 vp = fp->f_vnode; 753 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_GETLK, flp, 754 F_POSIX); 755 fdrop(fp, td); 756 break; 757 758 case F_ADD_SEALS: 759 error = fget_unlocked(fdp, fd, &cap_no_rights, &fp); 760 if (error != 0) 761 break; 762 error = fo_add_seals(fp, arg); 763 fdrop(fp, td); 764 break; 765 766 case F_GET_SEALS: 767 error = fget_unlocked(fdp, fd, &cap_no_rights, &fp); 768 if (error != 0) 769 break; 770 if (fo_get_seals(fp, &seals) == 0) 771 td->td_retval[0] = seals; 772 else 773 error = EINVAL; 774 fdrop(fp, td); 775 break; 776 777 case F_RDAHEAD: 778 arg = arg ? 128 * 1024: 0; 779 /* FALLTHROUGH */ 780 case F_READAHEAD: 781 error = fget_unlocked(fdp, fd, &cap_no_rights, &fp); 782 if (error != 0) 783 break; 784 if (fp->f_type != DTYPE_VNODE || fp->f_ops == &path_fileops) { 785 fdrop(fp, td); 786 error = EBADF; 787 break; 788 } 789 vp = fp->f_vnode; 790 if (vp->v_type != VREG) { 791 fdrop(fp, td); 792 error = ENOTTY; 793 break; 794 } 795 796 /* 797 * Exclusive lock synchronizes against f_seqcount reads and 798 * writes in sequential_heuristic(). 799 */ 800 error = vn_lock(vp, LK_EXCLUSIVE); 801 if (error != 0) { 802 fdrop(fp, td); 803 break; 804 } 805 if (arg >= 0) { 806 bsize = fp->f_vnode->v_mount->mnt_stat.f_iosize; 807 arg = MIN(arg, INT_MAX - bsize + 1); 808 fp->f_seqcount[UIO_READ] = MIN(IO_SEQMAX, 809 (arg + bsize - 1) / bsize); 810 atomic_set_int(&fp->f_flag, FRDAHEAD); 811 } else { 812 atomic_clear_int(&fp->f_flag, FRDAHEAD); 813 } 814 VOP_UNLOCK(vp); 815 fdrop(fp, td); 816 break; 817 818 case F_ISUNIONSTACK: 819 /* 820 * Check if the vnode is part of a union stack (either the 821 * "union" flag from mount(2) or unionfs). 822 * 823 * Prior to introduction of this op libc's readdir would call 824 * fstatfs(2), in effect unnecessarily copying kilobytes of 825 * data just to check fs name and a mount flag. 826 * 827 * Fixing the code to handle everything in the kernel instead 828 * is a non-trivial endeavor and has low priority, thus this 829 * horrible kludge facilitates the current behavior in a much 830 * cheaper manner until someone(tm) sorts this out. 831 */ 832 error = fget_unlocked(fdp, fd, &cap_no_rights, &fp); 833 if (error != 0) 834 break; 835 if (fp->f_type != DTYPE_VNODE) { 836 fdrop(fp, td); 837 error = EBADF; 838 break; 839 } 840 vp = fp->f_vnode; 841 /* 842 * Since we don't prevent dooming the vnode even non-null mp 843 * found can become immediately stale. This is tolerable since 844 * mount points are type-stable (providing safe memory access) 845 * and any vfs op on this vnode going forward will return an 846 * error (meaning return value in this case is meaningless). 847 */ 848 mp = atomic_load_ptr(&vp->v_mount); 849 if (__predict_false(mp == NULL)) { 850 fdrop(fp, td); 851 error = EBADF; 852 break; 853 } 854 td->td_retval[0] = 0; 855 if (mp->mnt_kern_flag & MNTK_UNIONFS || 856 mp->mnt_flag & MNT_UNION) 857 td->td_retval[0] = 1; 858 fdrop(fp, td); 859 break; 860 861 case F_KINFO: 862 #ifdef CAPABILITY_MODE 863 if (IN_CAPABILITY_MODE(td)) { 864 error = ECAPMODE; 865 break; 866 } 867 #endif 868 error = copyin((void *)arg, &kif_sz, sizeof(kif_sz)); 869 if (error != 0) 870 break; 871 if (kif_sz != sizeof(*kif)) { 872 error = EINVAL; 873 break; 874 } 875 kif = malloc(sizeof(*kif), M_TEMP, M_WAITOK | M_ZERO); 876 FILEDESC_SLOCK(fdp); 877 error = fget_cap_locked(fdp, fd, &cap_fcntl_rights, &fp, NULL); 878 if (error == 0 && fhold(fp)) { 879 export_file_to_kinfo(fp, fd, NULL, kif, fdp, 0); 880 FILEDESC_SUNLOCK(fdp); 881 fdrop(fp, td); 882 if ((kif->kf_status & KF_ATTR_VALID) != 0) { 883 kif->kf_structsize = sizeof(*kif); 884 error = copyout(kif, (void *)arg, sizeof(*kif)); 885 } else { 886 error = EBADF; 887 } 888 } else { 889 FILEDESC_SUNLOCK(fdp); 890 if (error == 0) 891 error = EBADF; 892 } 893 free(kif, M_TEMP); 894 break; 895 896 default: 897 error = EINVAL; 898 break; 899 } 900 return (error); 901 } 902 903 static int 904 getmaxfd(struct thread *td) 905 { 906 907 return (min((int)lim_cur(td, RLIMIT_NOFILE), maxfilesperproc)); 908 } 909 910 /* 911 * Common code for dup, dup2, fcntl(F_DUPFD) and fcntl(F_DUP2FD). 912 */ 913 int 914 kern_dup(struct thread *td, u_int mode, int flags, int old, int new) 915 { 916 struct filedesc *fdp; 917 struct filedescent *oldfde, *newfde; 918 struct proc *p; 919 struct file *delfp, *oldfp; 920 u_long *oioctls, *nioctls; 921 int error, maxfd; 922 923 p = td->td_proc; 924 fdp = p->p_fd; 925 oioctls = NULL; 926 927 MPASS((flags & ~(FDDUP_FLAG_CLOEXEC)) == 0); 928 MPASS(mode < FDDUP_LASTMODE); 929 930 AUDIT_ARG_FD(old); 931 /* XXXRW: if (flags & FDDUP_FIXED) AUDIT_ARG_FD2(new); */ 932 933 /* 934 * Verify we have a valid descriptor to dup from and possibly to 935 * dup to. Unlike dup() and dup2(), fcntl()'s F_DUPFD should 936 * return EINVAL when the new descriptor is out of bounds. 937 */ 938 if (old < 0) 939 return (EBADF); 940 if (new < 0) 941 return (mode == FDDUP_FCNTL ? EINVAL : EBADF); 942 maxfd = getmaxfd(td); 943 if (new >= maxfd) 944 return (mode == FDDUP_FCNTL ? EINVAL : EBADF); 945 946 error = EBADF; 947 FILEDESC_XLOCK(fdp); 948 if (fget_locked(fdp, old) == NULL) 949 goto unlock; 950 if (mode == FDDUP_FIXED && old == new) { 951 td->td_retval[0] = new; 952 if (flags & FDDUP_FLAG_CLOEXEC) 953 fdp->fd_ofiles[new].fde_flags |= UF_EXCLOSE; 954 error = 0; 955 goto unlock; 956 } 957 958 oldfde = &fdp->fd_ofiles[old]; 959 oldfp = oldfde->fde_file; 960 if (!fhold(oldfp)) 961 goto unlock; 962 963 /* 964 * If the caller specified a file descriptor, make sure the file 965 * table is large enough to hold it, and grab it. Otherwise, just 966 * allocate a new descriptor the usual way. 967 */ 968 switch (mode) { 969 case FDDUP_NORMAL: 970 case FDDUP_FCNTL: 971 if ((error = fdalloc(td, new, &new)) != 0) { 972 fdrop(oldfp, td); 973 goto unlock; 974 } 975 break; 976 case FDDUP_FIXED: 977 if (new >= fdp->fd_nfiles) { 978 /* 979 * The resource limits are here instead of e.g. 980 * fdalloc(), because the file descriptor table may be 981 * shared between processes, so we can't really use 982 * racct_add()/racct_sub(). Instead of counting the 983 * number of actually allocated descriptors, just put 984 * the limit on the size of the file descriptor table. 985 */ 986 #ifdef RACCT 987 if (RACCT_ENABLED()) { 988 error = racct_set_unlocked(p, RACCT_NOFILE, new + 1); 989 if (error != 0) { 990 error = EMFILE; 991 fdrop(oldfp, td); 992 goto unlock; 993 } 994 } 995 #endif 996 fdgrowtable_exp(fdp, new + 1); 997 } 998 if (!fdisused(fdp, new)) 999 fdused(fdp, new); 1000 break; 1001 default: 1002 KASSERT(0, ("%s unsupported mode %d", __func__, mode)); 1003 } 1004 1005 KASSERT(old != new, ("new fd is same as old")); 1006 1007 /* Refetch oldfde because the table may have grown and old one freed. */ 1008 oldfde = &fdp->fd_ofiles[old]; 1009 KASSERT(oldfp == oldfde->fde_file, 1010 ("fdt_ofiles shift from growth observed at fd %d", 1011 old)); 1012 1013 newfde = &fdp->fd_ofiles[new]; 1014 delfp = newfde->fde_file; 1015 1016 nioctls = filecaps_copy_prep(&oldfde->fde_caps); 1017 1018 /* 1019 * Duplicate the source descriptor. 1020 */ 1021 #ifdef CAPABILITIES 1022 seqc_write_begin(&newfde->fde_seqc); 1023 #endif 1024 oioctls = filecaps_free_prep(&newfde->fde_caps); 1025 memcpy(newfde, oldfde, fde_change_size); 1026 filecaps_copy_finish(&oldfde->fde_caps, &newfde->fde_caps, 1027 nioctls); 1028 if ((flags & FDDUP_FLAG_CLOEXEC) != 0) 1029 newfde->fde_flags = oldfde->fde_flags | UF_EXCLOSE; 1030 else 1031 newfde->fde_flags = oldfde->fde_flags & ~UF_EXCLOSE; 1032 #ifdef CAPABILITIES 1033 seqc_write_end(&newfde->fde_seqc); 1034 #endif 1035 td->td_retval[0] = new; 1036 1037 error = 0; 1038 1039 if (delfp != NULL) { 1040 (void) closefp(fdp, new, delfp, td, true, false); 1041 FILEDESC_UNLOCK_ASSERT(fdp); 1042 } else { 1043 unlock: 1044 FILEDESC_XUNLOCK(fdp); 1045 } 1046 1047 filecaps_free_finish(oioctls); 1048 return (error); 1049 } 1050 1051 static void 1052 sigiofree(struct sigio *sigio) 1053 { 1054 crfree(sigio->sio_ucred); 1055 free(sigio, M_SIGIO); 1056 } 1057 1058 static struct sigio * 1059 funsetown_locked(struct sigio *sigio) 1060 { 1061 struct proc *p; 1062 struct pgrp *pg; 1063 1064 SIGIO_ASSERT_LOCKED(); 1065 1066 if (sigio == NULL) 1067 return (NULL); 1068 *sigio->sio_myref = NULL; 1069 if (sigio->sio_pgid < 0) { 1070 pg = sigio->sio_pgrp; 1071 PGRP_LOCK(pg); 1072 SLIST_REMOVE(&pg->pg_sigiolst, sigio, sigio, sio_pgsigio); 1073 PGRP_UNLOCK(pg); 1074 } else { 1075 p = sigio->sio_proc; 1076 PROC_LOCK(p); 1077 SLIST_REMOVE(&p->p_sigiolst, sigio, sigio, sio_pgsigio); 1078 PROC_UNLOCK(p); 1079 } 1080 return (sigio); 1081 } 1082 1083 /* 1084 * If sigio is on the list associated with a process or process group, 1085 * disable signalling from the device, remove sigio from the list and 1086 * free sigio. 1087 */ 1088 void 1089 funsetown(struct sigio **sigiop) 1090 { 1091 struct sigio *sigio; 1092 1093 /* Racy check, consumers must provide synchronization. */ 1094 if (*sigiop == NULL) 1095 return; 1096 1097 SIGIO_LOCK(); 1098 sigio = funsetown_locked(*sigiop); 1099 SIGIO_UNLOCK(); 1100 if (sigio != NULL) 1101 sigiofree(sigio); 1102 } 1103 1104 /* 1105 * Free a list of sigio structures. The caller must ensure that new sigio 1106 * structures cannot be added after this point. For process groups this is 1107 * guaranteed using the proctree lock; for processes, the P_WEXIT flag serves 1108 * as an interlock. 1109 */ 1110 void 1111 funsetownlst(struct sigiolst *sigiolst) 1112 { 1113 struct proc *p; 1114 struct pgrp *pg; 1115 struct sigio *sigio, *tmp; 1116 1117 /* Racy check. */ 1118 sigio = SLIST_FIRST(sigiolst); 1119 if (sigio == NULL) 1120 return; 1121 1122 p = NULL; 1123 pg = NULL; 1124 1125 SIGIO_LOCK(); 1126 sigio = SLIST_FIRST(sigiolst); 1127 if (sigio == NULL) { 1128 SIGIO_UNLOCK(); 1129 return; 1130 } 1131 1132 /* 1133 * Every entry of the list should belong to a single proc or pgrp. 1134 */ 1135 if (sigio->sio_pgid < 0) { 1136 pg = sigio->sio_pgrp; 1137 sx_assert(&proctree_lock, SX_XLOCKED); 1138 PGRP_LOCK(pg); 1139 } else /* if (sigio->sio_pgid > 0) */ { 1140 p = sigio->sio_proc; 1141 PROC_LOCK(p); 1142 KASSERT((p->p_flag & P_WEXIT) != 0, 1143 ("%s: process %p is not exiting", __func__, p)); 1144 } 1145 1146 SLIST_FOREACH(sigio, sigiolst, sio_pgsigio) { 1147 *sigio->sio_myref = NULL; 1148 if (pg != NULL) { 1149 KASSERT(sigio->sio_pgid < 0, 1150 ("Proc sigio in pgrp sigio list")); 1151 KASSERT(sigio->sio_pgrp == pg, 1152 ("Bogus pgrp in sigio list")); 1153 } else /* if (p != NULL) */ { 1154 KASSERT(sigio->sio_pgid > 0, 1155 ("Pgrp sigio in proc sigio list")); 1156 KASSERT(sigio->sio_proc == p, 1157 ("Bogus proc in sigio list")); 1158 } 1159 } 1160 1161 if (pg != NULL) 1162 PGRP_UNLOCK(pg); 1163 else 1164 PROC_UNLOCK(p); 1165 SIGIO_UNLOCK(); 1166 1167 SLIST_FOREACH_SAFE(sigio, sigiolst, sio_pgsigio, tmp) 1168 sigiofree(sigio); 1169 } 1170 1171 /* 1172 * This is common code for FIOSETOWN ioctl called by fcntl(fd, F_SETOWN, arg). 1173 * 1174 * After permission checking, add a sigio structure to the sigio list for 1175 * the process or process group. 1176 */ 1177 int 1178 fsetown(pid_t pgid, struct sigio **sigiop) 1179 { 1180 struct proc *proc; 1181 struct pgrp *pgrp; 1182 struct sigio *osigio, *sigio; 1183 int ret; 1184 1185 if (pgid == 0) { 1186 funsetown(sigiop); 1187 return (0); 1188 } 1189 1190 sigio = malloc(sizeof(struct sigio), M_SIGIO, M_WAITOK); 1191 sigio->sio_pgid = pgid; 1192 sigio->sio_ucred = crhold(curthread->td_ucred); 1193 sigio->sio_myref = sigiop; 1194 1195 ret = 0; 1196 if (pgid > 0) { 1197 ret = pget(pgid, PGET_NOTWEXIT | PGET_NOTID | PGET_HOLD, &proc); 1198 SIGIO_LOCK(); 1199 osigio = funsetown_locked(*sigiop); 1200 if (ret == 0) { 1201 PROC_LOCK(proc); 1202 _PRELE(proc); 1203 if ((proc->p_flag & P_WEXIT) != 0) { 1204 ret = ESRCH; 1205 } else if (proc->p_session != 1206 curthread->td_proc->p_session) { 1207 /* 1208 * Policy - Don't allow a process to FSETOWN a 1209 * process in another session. 1210 * 1211 * Remove this test to allow maximum flexibility 1212 * or restrict FSETOWN to the current process or 1213 * process group for maximum safety. 1214 */ 1215 ret = EPERM; 1216 } else { 1217 sigio->sio_proc = proc; 1218 SLIST_INSERT_HEAD(&proc->p_sigiolst, sigio, 1219 sio_pgsigio); 1220 } 1221 PROC_UNLOCK(proc); 1222 } 1223 } else /* if (pgid < 0) */ { 1224 sx_slock(&proctree_lock); 1225 SIGIO_LOCK(); 1226 osigio = funsetown_locked(*sigiop); 1227 pgrp = pgfind(-pgid); 1228 if (pgrp == NULL) { 1229 ret = ESRCH; 1230 } else { 1231 if (pgrp->pg_session != curthread->td_proc->p_session) { 1232 /* 1233 * Policy - Don't allow a process to FSETOWN a 1234 * process in another session. 1235 * 1236 * Remove this test to allow maximum flexibility 1237 * or restrict FSETOWN to the current process or 1238 * process group for maximum safety. 1239 */ 1240 ret = EPERM; 1241 } else { 1242 sigio->sio_pgrp = pgrp; 1243 SLIST_INSERT_HEAD(&pgrp->pg_sigiolst, sigio, 1244 sio_pgsigio); 1245 } 1246 PGRP_UNLOCK(pgrp); 1247 } 1248 sx_sunlock(&proctree_lock); 1249 } 1250 if (ret == 0) 1251 *sigiop = sigio; 1252 SIGIO_UNLOCK(); 1253 if (osigio != NULL) 1254 sigiofree(osigio); 1255 return (ret); 1256 } 1257 1258 /* 1259 * This is common code for FIOGETOWN ioctl called by fcntl(fd, F_GETOWN, arg). 1260 */ 1261 pid_t 1262 fgetown(struct sigio **sigiop) 1263 { 1264 pid_t pgid; 1265 1266 SIGIO_LOCK(); 1267 pgid = (*sigiop != NULL) ? (*sigiop)->sio_pgid : 0; 1268 SIGIO_UNLOCK(); 1269 return (pgid); 1270 } 1271 1272 static int 1273 closefp_impl(struct filedesc *fdp, int fd, struct file *fp, struct thread *td, 1274 bool audit) 1275 { 1276 int error; 1277 1278 FILEDESC_XLOCK_ASSERT(fdp); 1279 1280 /* 1281 * We now hold the fp reference that used to be owned by the 1282 * descriptor array. We have to unlock the FILEDESC *AFTER* 1283 * knote_fdclose to prevent a race of the fd getting opened, a knote 1284 * added, and deleteing a knote for the new fd. 1285 */ 1286 if (__predict_false(!TAILQ_EMPTY(&fdp->fd_kqlist))) 1287 knote_fdclose(td, fd); 1288 1289 /* 1290 * We need to notify mqueue if the object is of type mqueue. 1291 */ 1292 if (__predict_false(fp->f_type == DTYPE_MQUEUE)) 1293 mq_fdclose(td, fd, fp); 1294 FILEDESC_XUNLOCK(fdp); 1295 1296 #ifdef AUDIT 1297 if (AUDITING_TD(td) && audit) 1298 audit_sysclose(td, fd, fp); 1299 #endif 1300 error = closef(fp, td); 1301 1302 /* 1303 * All paths leading up to closefp() will have already removed or 1304 * replaced the fd in the filedesc table, so a restart would not 1305 * operate on the same file. 1306 */ 1307 if (error == ERESTART) 1308 error = EINTR; 1309 1310 return (error); 1311 } 1312 1313 static int 1314 closefp_hl(struct filedesc *fdp, int fd, struct file *fp, struct thread *td, 1315 bool holdleaders, bool audit) 1316 { 1317 int error; 1318 1319 FILEDESC_XLOCK_ASSERT(fdp); 1320 1321 if (holdleaders) { 1322 if (td->td_proc->p_fdtol != NULL) { 1323 /* 1324 * Ask fdfree() to sleep to ensure that all relevant 1325 * process leaders can be traversed in closef(). 1326 */ 1327 fdp->fd_holdleaderscount++; 1328 } else { 1329 holdleaders = false; 1330 } 1331 } 1332 1333 error = closefp_impl(fdp, fd, fp, td, audit); 1334 if (holdleaders) { 1335 FILEDESC_XLOCK(fdp); 1336 fdp->fd_holdleaderscount--; 1337 if (fdp->fd_holdleaderscount == 0 && 1338 fdp->fd_holdleaderswakeup != 0) { 1339 fdp->fd_holdleaderswakeup = 0; 1340 wakeup(&fdp->fd_holdleaderscount); 1341 } 1342 FILEDESC_XUNLOCK(fdp); 1343 } 1344 return (error); 1345 } 1346 1347 static int 1348 closefp(struct filedesc *fdp, int fd, struct file *fp, struct thread *td, 1349 bool holdleaders, bool audit) 1350 { 1351 1352 FILEDESC_XLOCK_ASSERT(fdp); 1353 1354 if (__predict_false(td->td_proc->p_fdtol != NULL)) { 1355 return (closefp_hl(fdp, fd, fp, td, holdleaders, audit)); 1356 } else { 1357 return (closefp_impl(fdp, fd, fp, td, audit)); 1358 } 1359 } 1360 1361 /* 1362 * Close a file descriptor. 1363 */ 1364 #ifndef _SYS_SYSPROTO_H_ 1365 struct close_args { 1366 int fd; 1367 }; 1368 #endif 1369 /* ARGSUSED */ 1370 int 1371 sys_close(struct thread *td, struct close_args *uap) 1372 { 1373 1374 return (kern_close(td, uap->fd)); 1375 } 1376 1377 int 1378 kern_close(struct thread *td, int fd) 1379 { 1380 struct filedesc *fdp; 1381 struct file *fp; 1382 1383 fdp = td->td_proc->p_fd; 1384 1385 FILEDESC_XLOCK(fdp); 1386 if ((fp = fget_locked(fdp, fd)) == NULL) { 1387 FILEDESC_XUNLOCK(fdp); 1388 return (EBADF); 1389 } 1390 fdfree(fdp, fd); 1391 1392 /* closefp() drops the FILEDESC lock for us. */ 1393 return (closefp(fdp, fd, fp, td, true, true)); 1394 } 1395 1396 int 1397 kern_close_range(struct thread *td, u_int lowfd, u_int highfd) 1398 { 1399 struct filedesc *fdp; 1400 const struct fdescenttbl *fdt; 1401 struct file *fp; 1402 int fd; 1403 1404 /* 1405 * Check this prior to clamping; closefrom(3) with only fd 0, 1, and 2 1406 * open should not be a usage error. From a close_range() perspective, 1407 * close_range(3, ~0U, 0) in the same scenario should also likely not 1408 * be a usage error as all fd above 3 are in-fact already closed. 1409 */ 1410 if (highfd < lowfd) { 1411 return (EINVAL); 1412 } 1413 1414 fdp = td->td_proc->p_fd; 1415 FILEDESC_XLOCK(fdp); 1416 fdt = atomic_load_ptr(&fdp->fd_files); 1417 highfd = MIN(highfd, fdt->fdt_nfiles - 1); 1418 fd = lowfd; 1419 if (__predict_false(fd > highfd)) { 1420 goto out_locked; 1421 } 1422 for (;;) { 1423 fp = fdt->fdt_ofiles[fd].fde_file; 1424 if (fp == NULL) { 1425 if (fd == highfd) 1426 goto out_locked; 1427 } else { 1428 fdfree(fdp, fd); 1429 (void) closefp(fdp, fd, fp, td, true, true); 1430 if (fd == highfd) 1431 goto out_unlocked; 1432 FILEDESC_XLOCK(fdp); 1433 fdt = atomic_load_ptr(&fdp->fd_files); 1434 } 1435 fd++; 1436 } 1437 out_locked: 1438 FILEDESC_XUNLOCK(fdp); 1439 out_unlocked: 1440 return (0); 1441 } 1442 1443 #ifndef _SYS_SYSPROTO_H_ 1444 struct close_range_args { 1445 u_int lowfd; 1446 u_int highfd; 1447 int flags; 1448 }; 1449 #endif 1450 int 1451 sys_close_range(struct thread *td, struct close_range_args *uap) 1452 { 1453 1454 AUDIT_ARG_FD(uap->lowfd); 1455 AUDIT_ARG_CMD(uap->highfd); 1456 AUDIT_ARG_FFLAGS(uap->flags); 1457 1458 /* No flags currently defined */ 1459 if (uap->flags != 0) 1460 return (EINVAL); 1461 return (kern_close_range(td, uap->lowfd, uap->highfd)); 1462 } 1463 1464 #ifdef COMPAT_FREEBSD12 1465 /* 1466 * Close open file descriptors. 1467 */ 1468 #ifndef _SYS_SYSPROTO_H_ 1469 struct freebsd12_closefrom_args { 1470 int lowfd; 1471 }; 1472 #endif 1473 /* ARGSUSED */ 1474 int 1475 freebsd12_closefrom(struct thread *td, struct freebsd12_closefrom_args *uap) 1476 { 1477 u_int lowfd; 1478 1479 AUDIT_ARG_FD(uap->lowfd); 1480 1481 /* 1482 * Treat negative starting file descriptor values identical to 1483 * closefrom(0) which closes all files. 1484 */ 1485 lowfd = MAX(0, uap->lowfd); 1486 return (kern_close_range(td, lowfd, ~0U)); 1487 } 1488 #endif /* COMPAT_FREEBSD12 */ 1489 1490 #if defined(COMPAT_43) 1491 /* 1492 * Return status information about a file descriptor. 1493 */ 1494 #ifndef _SYS_SYSPROTO_H_ 1495 struct ofstat_args { 1496 int fd; 1497 struct ostat *sb; 1498 }; 1499 #endif 1500 /* ARGSUSED */ 1501 int 1502 ofstat(struct thread *td, struct ofstat_args *uap) 1503 { 1504 struct ostat oub; 1505 struct stat ub; 1506 int error; 1507 1508 error = kern_fstat(td, uap->fd, &ub); 1509 if (error == 0) { 1510 cvtstat(&ub, &oub); 1511 error = copyout(&oub, uap->sb, sizeof(oub)); 1512 } 1513 return (error); 1514 } 1515 #endif /* COMPAT_43 */ 1516 1517 #if defined(COMPAT_FREEBSD11) 1518 int 1519 freebsd11_fstat(struct thread *td, struct freebsd11_fstat_args *uap) 1520 { 1521 struct stat sb; 1522 struct freebsd11_stat osb; 1523 int error; 1524 1525 error = kern_fstat(td, uap->fd, &sb); 1526 if (error != 0) 1527 return (error); 1528 error = freebsd11_cvtstat(&sb, &osb); 1529 if (error == 0) 1530 error = copyout(&osb, uap->sb, sizeof(osb)); 1531 return (error); 1532 } 1533 #endif /* COMPAT_FREEBSD11 */ 1534 1535 /* 1536 * Return status information about a file descriptor. 1537 */ 1538 #ifndef _SYS_SYSPROTO_H_ 1539 struct fstat_args { 1540 int fd; 1541 struct stat *sb; 1542 }; 1543 #endif 1544 /* ARGSUSED */ 1545 int 1546 sys_fstat(struct thread *td, struct fstat_args *uap) 1547 { 1548 struct stat ub; 1549 int error; 1550 1551 error = kern_fstat(td, uap->fd, &ub); 1552 if (error == 0) 1553 error = copyout(&ub, uap->sb, sizeof(ub)); 1554 return (error); 1555 } 1556 1557 int 1558 kern_fstat(struct thread *td, int fd, struct stat *sbp) 1559 { 1560 struct file *fp; 1561 int error; 1562 1563 AUDIT_ARG_FD(fd); 1564 1565 error = fget(td, fd, &cap_fstat_rights, &fp); 1566 if (__predict_false(error != 0)) 1567 return (error); 1568 1569 AUDIT_ARG_FILE(td->td_proc, fp); 1570 1571 error = fo_stat(fp, sbp, td->td_ucred); 1572 fdrop(fp, td); 1573 #ifdef __STAT_TIME_T_EXT 1574 sbp->st_atim_ext = 0; 1575 sbp->st_mtim_ext = 0; 1576 sbp->st_ctim_ext = 0; 1577 sbp->st_btim_ext = 0; 1578 #endif 1579 #ifdef KTRACE 1580 if (KTRPOINT(td, KTR_STRUCT)) 1581 ktrstat_error(sbp, error); 1582 #endif 1583 return (error); 1584 } 1585 1586 #if defined(COMPAT_FREEBSD11) 1587 /* 1588 * Return status information about a file descriptor. 1589 */ 1590 #ifndef _SYS_SYSPROTO_H_ 1591 struct freebsd11_nfstat_args { 1592 int fd; 1593 struct nstat *sb; 1594 }; 1595 #endif 1596 /* ARGSUSED */ 1597 int 1598 freebsd11_nfstat(struct thread *td, struct freebsd11_nfstat_args *uap) 1599 { 1600 struct nstat nub; 1601 struct stat ub; 1602 int error; 1603 1604 error = kern_fstat(td, uap->fd, &ub); 1605 if (error != 0) 1606 return (error); 1607 error = freebsd11_cvtnstat(&ub, &nub); 1608 if (error != 0) 1609 error = copyout(&nub, uap->sb, sizeof(nub)); 1610 return (error); 1611 } 1612 #endif /* COMPAT_FREEBSD11 */ 1613 1614 /* 1615 * Return pathconf information about a file descriptor. 1616 */ 1617 #ifndef _SYS_SYSPROTO_H_ 1618 struct fpathconf_args { 1619 int fd; 1620 int name; 1621 }; 1622 #endif 1623 /* ARGSUSED */ 1624 int 1625 sys_fpathconf(struct thread *td, struct fpathconf_args *uap) 1626 { 1627 long value; 1628 int error; 1629 1630 error = kern_fpathconf(td, uap->fd, uap->name, &value); 1631 if (error == 0) 1632 td->td_retval[0] = value; 1633 return (error); 1634 } 1635 1636 int 1637 kern_fpathconf(struct thread *td, int fd, int name, long *valuep) 1638 { 1639 struct file *fp; 1640 struct vnode *vp; 1641 int error; 1642 1643 error = fget(td, fd, &cap_fpathconf_rights, &fp); 1644 if (error != 0) 1645 return (error); 1646 1647 if (name == _PC_ASYNC_IO) { 1648 *valuep = _POSIX_ASYNCHRONOUS_IO; 1649 goto out; 1650 } 1651 vp = fp->f_vnode; 1652 if (vp != NULL) { 1653 vn_lock(vp, LK_SHARED | LK_RETRY); 1654 error = VOP_PATHCONF(vp, name, valuep); 1655 VOP_UNLOCK(vp); 1656 } else if (fp->f_type == DTYPE_PIPE || fp->f_type == DTYPE_SOCKET) { 1657 if (name != _PC_PIPE_BUF) { 1658 error = EINVAL; 1659 } else { 1660 *valuep = PIPE_BUF; 1661 error = 0; 1662 } 1663 } else { 1664 error = EOPNOTSUPP; 1665 } 1666 out: 1667 fdrop(fp, td); 1668 return (error); 1669 } 1670 1671 /* 1672 * Copy filecaps structure allocating memory for ioctls array if needed. 1673 * 1674 * The last parameter indicates whether the fdtable is locked. If it is not and 1675 * ioctls are encountered, copying fails and the caller must lock the table. 1676 * 1677 * Note that if the table was not locked, the caller has to check the relevant 1678 * sequence counter to determine whether the operation was successful. 1679 */ 1680 bool 1681 filecaps_copy(const struct filecaps *src, struct filecaps *dst, bool locked) 1682 { 1683 size_t size; 1684 1685 if (src->fc_ioctls != NULL && !locked) 1686 return (false); 1687 memcpy(dst, src, sizeof(*src)); 1688 if (src->fc_ioctls == NULL) 1689 return (true); 1690 1691 KASSERT(src->fc_nioctls > 0, 1692 ("fc_ioctls != NULL, but fc_nioctls=%hd", src->fc_nioctls)); 1693 1694 size = sizeof(src->fc_ioctls[0]) * src->fc_nioctls; 1695 dst->fc_ioctls = malloc(size, M_FILECAPS, M_WAITOK); 1696 memcpy(dst->fc_ioctls, src->fc_ioctls, size); 1697 return (true); 1698 } 1699 1700 static u_long * 1701 filecaps_copy_prep(const struct filecaps *src) 1702 { 1703 u_long *ioctls; 1704 size_t size; 1705 1706 if (__predict_true(src->fc_ioctls == NULL)) 1707 return (NULL); 1708 1709 KASSERT(src->fc_nioctls > 0, 1710 ("fc_ioctls != NULL, but fc_nioctls=%hd", src->fc_nioctls)); 1711 1712 size = sizeof(src->fc_ioctls[0]) * src->fc_nioctls; 1713 ioctls = malloc(size, M_FILECAPS, M_WAITOK); 1714 return (ioctls); 1715 } 1716 1717 static void 1718 filecaps_copy_finish(const struct filecaps *src, struct filecaps *dst, 1719 u_long *ioctls) 1720 { 1721 size_t size; 1722 1723 *dst = *src; 1724 if (__predict_true(src->fc_ioctls == NULL)) { 1725 MPASS(ioctls == NULL); 1726 return; 1727 } 1728 1729 size = sizeof(src->fc_ioctls[0]) * src->fc_nioctls; 1730 dst->fc_ioctls = ioctls; 1731 bcopy(src->fc_ioctls, dst->fc_ioctls, size); 1732 } 1733 1734 /* 1735 * Move filecaps structure to the new place and clear the old place. 1736 */ 1737 void 1738 filecaps_move(struct filecaps *src, struct filecaps *dst) 1739 { 1740 1741 *dst = *src; 1742 bzero(src, sizeof(*src)); 1743 } 1744 1745 /* 1746 * Fill the given filecaps structure with full rights. 1747 */ 1748 static void 1749 filecaps_fill(struct filecaps *fcaps) 1750 { 1751 1752 CAP_ALL(&fcaps->fc_rights); 1753 fcaps->fc_ioctls = NULL; 1754 fcaps->fc_nioctls = -1; 1755 fcaps->fc_fcntls = CAP_FCNTL_ALL; 1756 } 1757 1758 /* 1759 * Free memory allocated within filecaps structure. 1760 */ 1761 void 1762 filecaps_free(struct filecaps *fcaps) 1763 { 1764 1765 free(fcaps->fc_ioctls, M_FILECAPS); 1766 bzero(fcaps, sizeof(*fcaps)); 1767 } 1768 1769 static u_long * 1770 filecaps_free_prep(struct filecaps *fcaps) 1771 { 1772 u_long *ioctls; 1773 1774 ioctls = fcaps->fc_ioctls; 1775 bzero(fcaps, sizeof(*fcaps)); 1776 return (ioctls); 1777 } 1778 1779 static void 1780 filecaps_free_finish(u_long *ioctls) 1781 { 1782 1783 free(ioctls, M_FILECAPS); 1784 } 1785 1786 /* 1787 * Validate the given filecaps structure. 1788 */ 1789 static void 1790 filecaps_validate(const struct filecaps *fcaps, const char *func) 1791 { 1792 1793 KASSERT(cap_rights_is_valid(&fcaps->fc_rights), 1794 ("%s: invalid rights", func)); 1795 KASSERT((fcaps->fc_fcntls & ~CAP_FCNTL_ALL) == 0, 1796 ("%s: invalid fcntls", func)); 1797 KASSERT(fcaps->fc_fcntls == 0 || 1798 cap_rights_is_set(&fcaps->fc_rights, CAP_FCNTL), 1799 ("%s: fcntls without CAP_FCNTL", func)); 1800 KASSERT(fcaps->fc_ioctls != NULL ? fcaps->fc_nioctls > 0 : 1801 (fcaps->fc_nioctls == -1 || fcaps->fc_nioctls == 0), 1802 ("%s: invalid ioctls", func)); 1803 KASSERT(fcaps->fc_nioctls == 0 || 1804 cap_rights_is_set(&fcaps->fc_rights, CAP_IOCTL), 1805 ("%s: ioctls without CAP_IOCTL", func)); 1806 } 1807 1808 static void 1809 fdgrowtable_exp(struct filedesc *fdp, int nfd) 1810 { 1811 int nfd1; 1812 1813 FILEDESC_XLOCK_ASSERT(fdp); 1814 1815 nfd1 = fdp->fd_nfiles * 2; 1816 if (nfd1 < nfd) 1817 nfd1 = nfd; 1818 fdgrowtable(fdp, nfd1); 1819 } 1820 1821 /* 1822 * Grow the file table to accommodate (at least) nfd descriptors. 1823 */ 1824 static void 1825 fdgrowtable(struct filedesc *fdp, int nfd) 1826 { 1827 struct filedesc0 *fdp0; 1828 struct freetable *ft; 1829 struct fdescenttbl *ntable; 1830 struct fdescenttbl *otable; 1831 int nnfiles, onfiles; 1832 NDSLOTTYPE *nmap, *omap; 1833 1834 KASSERT(fdp->fd_nfiles > 0, ("zero-length file table")); 1835 1836 /* save old values */ 1837 onfiles = fdp->fd_nfiles; 1838 otable = fdp->fd_files; 1839 omap = fdp->fd_map; 1840 1841 /* compute the size of the new table */ 1842 nnfiles = NDSLOTS(nfd) * NDENTRIES; /* round up */ 1843 if (nnfiles <= onfiles) 1844 /* the table is already large enough */ 1845 return; 1846 1847 /* 1848 * Allocate a new table. We need enough space for the number of 1849 * entries, file entries themselves and the struct freetable we will use 1850 * when we decommission the table and place it on the freelist. 1851 * We place the struct freetable in the middle so we don't have 1852 * to worry about padding. 1853 */ 1854 ntable = malloc(offsetof(struct fdescenttbl, fdt_ofiles) + 1855 nnfiles * sizeof(ntable->fdt_ofiles[0]) + 1856 sizeof(struct freetable), 1857 M_FILEDESC, M_ZERO | M_WAITOK); 1858 /* copy the old data */ 1859 ntable->fdt_nfiles = nnfiles; 1860 memcpy(ntable->fdt_ofiles, otable->fdt_ofiles, 1861 onfiles * sizeof(ntable->fdt_ofiles[0])); 1862 1863 /* 1864 * Allocate a new map only if the old is not large enough. It will 1865 * grow at a slower rate than the table as it can map more 1866 * entries than the table can hold. 1867 */ 1868 if (NDSLOTS(nnfiles) > NDSLOTS(onfiles)) { 1869 nmap = malloc(NDSLOTS(nnfiles) * NDSLOTSIZE, M_FILEDESC, 1870 M_ZERO | M_WAITOK); 1871 /* copy over the old data and update the pointer */ 1872 memcpy(nmap, omap, NDSLOTS(onfiles) * sizeof(*omap)); 1873 fdp->fd_map = nmap; 1874 } 1875 1876 /* 1877 * Make sure that ntable is correctly initialized before we replace 1878 * fd_files poiner. Otherwise fget_unlocked() may see inconsistent 1879 * data. 1880 */ 1881 atomic_store_rel_ptr((volatile void *)&fdp->fd_files, (uintptr_t)ntable); 1882 1883 /* 1884 * Free the old file table when not shared by other threads or processes. 1885 * The old file table is considered to be shared when either are true: 1886 * - The process has more than one thread. 1887 * - The file descriptor table has been shared via fdshare(). 1888 * 1889 * When shared, the old file table will be placed on a freelist 1890 * which will be processed when the struct filedesc is released. 1891 * 1892 * Note that if onfiles == NDFILE, we're dealing with the original 1893 * static allocation contained within (struct filedesc0 *)fdp, 1894 * which must not be freed. 1895 */ 1896 if (onfiles > NDFILE) { 1897 /* 1898 * Note we may be called here from fdinit while allocating a 1899 * table for a new process in which case ->p_fd points 1900 * elsewhere. 1901 */ 1902 if (curproc->p_fd != fdp || FILEDESC_IS_ONLY_USER(fdp)) { 1903 free(otable, M_FILEDESC); 1904 } else { 1905 ft = (struct freetable *)&otable->fdt_ofiles[onfiles]; 1906 fdp0 = (struct filedesc0 *)fdp; 1907 ft->ft_table = otable; 1908 SLIST_INSERT_HEAD(&fdp0->fd_free, ft, ft_next); 1909 } 1910 } 1911 /* 1912 * The map does not have the same possibility of threads still 1913 * holding references to it. So always free it as long as it 1914 * does not reference the original static allocation. 1915 */ 1916 if (NDSLOTS(onfiles) > NDSLOTS(NDFILE)) 1917 free(omap, M_FILEDESC); 1918 } 1919 1920 /* 1921 * Allocate a file descriptor for the process. 1922 */ 1923 int 1924 fdalloc(struct thread *td, int minfd, int *result) 1925 { 1926 struct proc *p = td->td_proc; 1927 struct filedesc *fdp = p->p_fd; 1928 int fd, maxfd, allocfd; 1929 #ifdef RACCT 1930 int error; 1931 #endif 1932 1933 FILEDESC_XLOCK_ASSERT(fdp); 1934 1935 if (fdp->fd_freefile > minfd) 1936 minfd = fdp->fd_freefile; 1937 1938 maxfd = getmaxfd(td); 1939 1940 /* 1941 * Search the bitmap for a free descriptor starting at minfd. 1942 * If none is found, grow the file table. 1943 */ 1944 fd = fd_first_free(fdp, minfd, fdp->fd_nfiles); 1945 if (__predict_false(fd >= maxfd)) 1946 return (EMFILE); 1947 if (__predict_false(fd >= fdp->fd_nfiles)) { 1948 allocfd = min(fd * 2, maxfd); 1949 #ifdef RACCT 1950 if (RACCT_ENABLED()) { 1951 error = racct_set_unlocked(p, RACCT_NOFILE, allocfd); 1952 if (error != 0) 1953 return (EMFILE); 1954 } 1955 #endif 1956 /* 1957 * fd is already equal to first free descriptor >= minfd, so 1958 * we only need to grow the table and we are done. 1959 */ 1960 fdgrowtable_exp(fdp, allocfd); 1961 } 1962 1963 /* 1964 * Perform some sanity checks, then mark the file descriptor as 1965 * used and return it to the caller. 1966 */ 1967 KASSERT(fd >= 0 && fd < min(maxfd, fdp->fd_nfiles), 1968 ("invalid descriptor %d", fd)); 1969 KASSERT(!fdisused(fdp, fd), 1970 ("fd_first_free() returned non-free descriptor")); 1971 KASSERT(fdp->fd_ofiles[fd].fde_file == NULL, 1972 ("file descriptor isn't free")); 1973 fdused(fdp, fd); 1974 *result = fd; 1975 return (0); 1976 } 1977 1978 /* 1979 * Allocate n file descriptors for the process. 1980 */ 1981 int 1982 fdallocn(struct thread *td, int minfd, int *fds, int n) 1983 { 1984 struct proc *p = td->td_proc; 1985 struct filedesc *fdp = p->p_fd; 1986 int i; 1987 1988 FILEDESC_XLOCK_ASSERT(fdp); 1989 1990 for (i = 0; i < n; i++) 1991 if (fdalloc(td, 0, &fds[i]) != 0) 1992 break; 1993 1994 if (i < n) { 1995 for (i--; i >= 0; i--) 1996 fdunused(fdp, fds[i]); 1997 return (EMFILE); 1998 } 1999 2000 return (0); 2001 } 2002 2003 /* 2004 * Create a new open file structure and allocate a file descriptor for the 2005 * process that refers to it. We add one reference to the file for the 2006 * descriptor table and one reference for resultfp. This is to prevent us 2007 * being preempted and the entry in the descriptor table closed after we 2008 * release the FILEDESC lock. 2009 */ 2010 int 2011 falloc_caps(struct thread *td, struct file **resultfp, int *resultfd, int flags, 2012 struct filecaps *fcaps) 2013 { 2014 struct file *fp; 2015 int error, fd; 2016 2017 MPASS(resultfp != NULL); 2018 MPASS(resultfd != NULL); 2019 2020 error = _falloc_noinstall(td, &fp, 2); 2021 if (__predict_false(error != 0)) { 2022 return (error); 2023 } 2024 2025 error = finstall_refed(td, fp, &fd, flags, fcaps); 2026 if (__predict_false(error != 0)) { 2027 falloc_abort(td, fp); 2028 return (error); 2029 } 2030 2031 *resultfp = fp; 2032 *resultfd = fd; 2033 2034 return (0); 2035 } 2036 2037 /* 2038 * Create a new open file structure without allocating a file descriptor. 2039 */ 2040 int 2041 _falloc_noinstall(struct thread *td, struct file **resultfp, u_int n) 2042 { 2043 struct file *fp; 2044 int maxuserfiles = maxfiles - (maxfiles / 20); 2045 int openfiles_new; 2046 static struct timeval lastfail; 2047 static int curfail; 2048 2049 KASSERT(resultfp != NULL, ("%s: resultfp == NULL", __func__)); 2050 MPASS(n > 0); 2051 2052 openfiles_new = atomic_fetchadd_int(&openfiles, 1) + 1; 2053 if ((openfiles_new >= maxuserfiles && 2054 priv_check(td, PRIV_MAXFILES) != 0) || 2055 openfiles_new >= maxfiles) { 2056 atomic_subtract_int(&openfiles, 1); 2057 if (ppsratecheck(&lastfail, &curfail, 1)) { 2058 printf("kern.maxfiles limit exceeded by uid %i, (%s) " 2059 "please see tuning(7).\n", td->td_ucred->cr_ruid, td->td_proc->p_comm); 2060 } 2061 return (ENFILE); 2062 } 2063 fp = uma_zalloc(file_zone, M_WAITOK); 2064 bzero(fp, sizeof(*fp)); 2065 refcount_init(&fp->f_count, n); 2066 fp->f_cred = crhold(td->td_ucred); 2067 fp->f_ops = &badfileops; 2068 *resultfp = fp; 2069 return (0); 2070 } 2071 2072 void 2073 falloc_abort(struct thread *td, struct file *fp) 2074 { 2075 2076 /* 2077 * For assertion purposes. 2078 */ 2079 refcount_init(&fp->f_count, 0); 2080 _fdrop(fp, td); 2081 } 2082 2083 /* 2084 * Install a file in a file descriptor table. 2085 */ 2086 void 2087 _finstall(struct filedesc *fdp, struct file *fp, int fd, int flags, 2088 struct filecaps *fcaps) 2089 { 2090 struct filedescent *fde; 2091 2092 MPASS(fp != NULL); 2093 if (fcaps != NULL) 2094 filecaps_validate(fcaps, __func__); 2095 FILEDESC_XLOCK_ASSERT(fdp); 2096 2097 fde = &fdp->fd_ofiles[fd]; 2098 #ifdef CAPABILITIES 2099 seqc_write_begin(&fde->fde_seqc); 2100 #endif 2101 fde->fde_file = fp; 2102 fde->fde_flags = (flags & O_CLOEXEC) != 0 ? UF_EXCLOSE : 0; 2103 if (fcaps != NULL) 2104 filecaps_move(fcaps, &fde->fde_caps); 2105 else 2106 filecaps_fill(&fde->fde_caps); 2107 #ifdef CAPABILITIES 2108 seqc_write_end(&fde->fde_seqc); 2109 #endif 2110 } 2111 2112 int 2113 finstall_refed(struct thread *td, struct file *fp, int *fd, int flags, 2114 struct filecaps *fcaps) 2115 { 2116 struct filedesc *fdp = td->td_proc->p_fd; 2117 int error; 2118 2119 MPASS(fd != NULL); 2120 2121 FILEDESC_XLOCK(fdp); 2122 error = fdalloc(td, 0, fd); 2123 if (__predict_true(error == 0)) { 2124 _finstall(fdp, fp, *fd, flags, fcaps); 2125 } 2126 FILEDESC_XUNLOCK(fdp); 2127 return (error); 2128 } 2129 2130 int 2131 finstall(struct thread *td, struct file *fp, int *fd, int flags, 2132 struct filecaps *fcaps) 2133 { 2134 int error; 2135 2136 MPASS(fd != NULL); 2137 2138 if (!fhold(fp)) 2139 return (EBADF); 2140 error = finstall_refed(td, fp, fd, flags, fcaps); 2141 if (__predict_false(error != 0)) { 2142 fdrop(fp, td); 2143 } 2144 return (error); 2145 } 2146 2147 /* 2148 * Build a new filedesc structure from another. 2149 * 2150 * If fdp is not NULL, return with it shared locked. 2151 */ 2152 struct filedesc * 2153 fdinit(struct filedesc *fdp, bool prepfiles, int *lastfile) 2154 { 2155 struct filedesc0 *newfdp0; 2156 struct filedesc *newfdp; 2157 2158 if (prepfiles) 2159 MPASS(lastfile != NULL); 2160 else 2161 MPASS(lastfile == NULL); 2162 2163 newfdp0 = uma_zalloc(filedesc0_zone, M_WAITOK | M_ZERO); 2164 newfdp = &newfdp0->fd_fd; 2165 2166 /* Create the file descriptor table. */ 2167 FILEDESC_LOCK_INIT(newfdp); 2168 refcount_init(&newfdp->fd_refcnt, 1); 2169 refcount_init(&newfdp->fd_holdcnt, 1); 2170 newfdp->fd_map = newfdp0->fd_dmap; 2171 newfdp->fd_files = (struct fdescenttbl *)&newfdp0->fd_dfiles; 2172 newfdp->fd_files->fdt_nfiles = NDFILE; 2173 2174 if (fdp == NULL) 2175 return (newfdp); 2176 2177 FILEDESC_SLOCK(fdp); 2178 if (!prepfiles) { 2179 FILEDESC_SUNLOCK(fdp); 2180 return (newfdp); 2181 } 2182 2183 for (;;) { 2184 *lastfile = fdlastfile(fdp); 2185 if (*lastfile < newfdp->fd_nfiles) 2186 break; 2187 FILEDESC_SUNLOCK(fdp); 2188 fdgrowtable(newfdp, *lastfile + 1); 2189 FILEDESC_SLOCK(fdp); 2190 } 2191 2192 return (newfdp); 2193 } 2194 2195 /* 2196 * Build a pwddesc structure from another. 2197 * Copy the current, root, and jail root vnode references. 2198 * 2199 * If pdp is not NULL, return with it shared locked. 2200 */ 2201 struct pwddesc * 2202 pdinit(struct pwddesc *pdp, bool keeplock) 2203 { 2204 struct pwddesc *newpdp; 2205 struct pwd *newpwd; 2206 2207 newpdp = malloc(sizeof(*newpdp), M_PWDDESC, M_WAITOK | M_ZERO); 2208 2209 PWDDESC_LOCK_INIT(newpdp); 2210 refcount_init(&newpdp->pd_refcount, 1); 2211 newpdp->pd_cmask = CMASK; 2212 2213 if (pdp == NULL) { 2214 newpwd = pwd_alloc(); 2215 smr_serialized_store(&newpdp->pd_pwd, newpwd, true); 2216 return (newpdp); 2217 } 2218 2219 PWDDESC_XLOCK(pdp); 2220 newpwd = pwd_hold_pwddesc(pdp); 2221 smr_serialized_store(&newpdp->pd_pwd, newpwd, true); 2222 if (!keeplock) 2223 PWDDESC_XUNLOCK(pdp); 2224 return (newpdp); 2225 } 2226 2227 /* 2228 * Hold either filedesc or pwddesc of the passed process. 2229 * 2230 * The process lock is used to synchronize against the target exiting and 2231 * freeing the data. 2232 * 2233 * Clearing can be ilustrated in 3 steps: 2234 * 1. set the pointer to NULL. Either routine can race against it, hence 2235 * atomic_load_ptr. 2236 * 2. observe the process lock as not taken. Until then fdhold/pdhold can 2237 * race to either still see the pointer or find NULL. It is still safe to 2238 * grab a reference as clearing is stalled. 2239 * 3. after the lock is observed as not taken, any fdhold/pdhold calls are 2240 * guaranteed to see NULL, making it safe to finish clearing 2241 */ 2242 static struct filedesc * 2243 fdhold(struct proc *p) 2244 { 2245 struct filedesc *fdp; 2246 2247 PROC_LOCK_ASSERT(p, MA_OWNED); 2248 fdp = atomic_load_ptr(&p->p_fd); 2249 if (fdp != NULL) 2250 refcount_acquire(&fdp->fd_holdcnt); 2251 return (fdp); 2252 } 2253 2254 static struct pwddesc * 2255 pdhold(struct proc *p) 2256 { 2257 struct pwddesc *pdp; 2258 2259 PROC_LOCK_ASSERT(p, MA_OWNED); 2260 pdp = atomic_load_ptr(&p->p_pd); 2261 if (pdp != NULL) 2262 refcount_acquire(&pdp->pd_refcount); 2263 return (pdp); 2264 } 2265 2266 static void 2267 fddrop(struct filedesc *fdp) 2268 { 2269 2270 if (refcount_load(&fdp->fd_holdcnt) > 1) { 2271 if (refcount_release(&fdp->fd_holdcnt) == 0) 2272 return; 2273 } 2274 2275 FILEDESC_LOCK_DESTROY(fdp); 2276 uma_zfree(filedesc0_zone, fdp); 2277 } 2278 2279 static void 2280 pddrop(struct pwddesc *pdp) 2281 { 2282 struct pwd *pwd; 2283 2284 if (refcount_release_if_not_last(&pdp->pd_refcount)) 2285 return; 2286 2287 PWDDESC_XLOCK(pdp); 2288 if (refcount_release(&pdp->pd_refcount) == 0) { 2289 PWDDESC_XUNLOCK(pdp); 2290 return; 2291 } 2292 pwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); 2293 pwd_set(pdp, NULL); 2294 PWDDESC_XUNLOCK(pdp); 2295 pwd_drop(pwd); 2296 2297 PWDDESC_LOCK_DESTROY(pdp); 2298 free(pdp, M_PWDDESC); 2299 } 2300 2301 /* 2302 * Share a filedesc structure. 2303 */ 2304 struct filedesc * 2305 fdshare(struct filedesc *fdp) 2306 { 2307 2308 refcount_acquire(&fdp->fd_refcnt); 2309 return (fdp); 2310 } 2311 2312 /* 2313 * Share a pwddesc structure. 2314 */ 2315 struct pwddesc * 2316 pdshare(struct pwddesc *pdp) 2317 { 2318 refcount_acquire(&pdp->pd_refcount); 2319 return (pdp); 2320 } 2321 2322 /* 2323 * Unshare a filedesc structure, if necessary by making a copy 2324 */ 2325 void 2326 fdunshare(struct thread *td) 2327 { 2328 struct filedesc *tmp; 2329 struct proc *p = td->td_proc; 2330 2331 if (refcount_load(&p->p_fd->fd_refcnt) == 1) 2332 return; 2333 2334 tmp = fdcopy(p->p_fd); 2335 fdescfree(td); 2336 p->p_fd = tmp; 2337 } 2338 2339 /* 2340 * Unshare a pwddesc structure. 2341 */ 2342 void 2343 pdunshare(struct thread *td) 2344 { 2345 struct pwddesc *pdp; 2346 struct proc *p; 2347 2348 p = td->td_proc; 2349 /* Not shared. */ 2350 if (p->p_pd->pd_refcount == 1) 2351 return; 2352 2353 pdp = pdcopy(p->p_pd); 2354 pdescfree(td); 2355 p->p_pd = pdp; 2356 } 2357 2358 /* 2359 * Copy a filedesc structure. A NULL pointer in returns a NULL reference, 2360 * this is to ease callers, not catch errors. 2361 */ 2362 struct filedesc * 2363 fdcopy(struct filedesc *fdp) 2364 { 2365 struct filedesc *newfdp; 2366 struct filedescent *nfde, *ofde; 2367 int i, lastfile; 2368 2369 MPASS(fdp != NULL); 2370 2371 newfdp = fdinit(fdp, true, &lastfile); 2372 /* copy all passable descriptors (i.e. not kqueue) */ 2373 newfdp->fd_freefile = -1; 2374 for (i = 0; i <= lastfile; ++i) { 2375 ofde = &fdp->fd_ofiles[i]; 2376 if (ofde->fde_file == NULL || 2377 (ofde->fde_file->f_ops->fo_flags & DFLAG_PASSABLE) == 0 || 2378 !fhold(ofde->fde_file)) { 2379 if (newfdp->fd_freefile == -1) 2380 newfdp->fd_freefile = i; 2381 continue; 2382 } 2383 nfde = &newfdp->fd_ofiles[i]; 2384 *nfde = *ofde; 2385 filecaps_copy(&ofde->fde_caps, &nfde->fde_caps, true); 2386 fdused_init(newfdp, i); 2387 } 2388 if (newfdp->fd_freefile == -1) 2389 newfdp->fd_freefile = i; 2390 FILEDESC_SUNLOCK(fdp); 2391 return (newfdp); 2392 } 2393 2394 /* 2395 * Copy a pwddesc structure. 2396 */ 2397 struct pwddesc * 2398 pdcopy(struct pwddesc *pdp) 2399 { 2400 struct pwddesc *newpdp; 2401 2402 MPASS(pdp != NULL); 2403 2404 newpdp = pdinit(pdp, true); 2405 newpdp->pd_cmask = pdp->pd_cmask; 2406 PWDDESC_XUNLOCK(pdp); 2407 return (newpdp); 2408 } 2409 2410 /* 2411 * Clear POSIX style locks. This is only used when fdp looses a reference (i.e. 2412 * one of processes using it exits) and the table used to be shared. 2413 */ 2414 static void 2415 fdclearlocks(struct thread *td) 2416 { 2417 struct filedesc *fdp; 2418 struct filedesc_to_leader *fdtol; 2419 struct flock lf; 2420 struct file *fp; 2421 struct proc *p; 2422 struct vnode *vp; 2423 int i, lastfile; 2424 2425 p = td->td_proc; 2426 fdp = p->p_fd; 2427 fdtol = p->p_fdtol; 2428 MPASS(fdtol != NULL); 2429 2430 FILEDESC_XLOCK(fdp); 2431 KASSERT(fdtol->fdl_refcount > 0, 2432 ("filedesc_to_refcount botch: fdl_refcount=%d", 2433 fdtol->fdl_refcount)); 2434 if (fdtol->fdl_refcount == 1 && 2435 (p->p_leader->p_flag & P_ADVLOCK) != 0) { 2436 lastfile = fdlastfile(fdp); 2437 for (i = 0; i <= lastfile; i++) { 2438 fp = fdp->fd_ofiles[i].fde_file; 2439 if (fp == NULL || fp->f_type != DTYPE_VNODE || 2440 !fhold(fp)) 2441 continue; 2442 FILEDESC_XUNLOCK(fdp); 2443 lf.l_whence = SEEK_SET; 2444 lf.l_start = 0; 2445 lf.l_len = 0; 2446 lf.l_type = F_UNLCK; 2447 vp = fp->f_vnode; 2448 (void) VOP_ADVLOCK(vp, 2449 (caddr_t)p->p_leader, F_UNLCK, 2450 &lf, F_POSIX); 2451 FILEDESC_XLOCK(fdp); 2452 fdrop(fp, td); 2453 } 2454 } 2455 retry: 2456 if (fdtol->fdl_refcount == 1) { 2457 if (fdp->fd_holdleaderscount > 0 && 2458 (p->p_leader->p_flag & P_ADVLOCK) != 0) { 2459 /* 2460 * close() or kern_dup() has cleared a reference 2461 * in a shared file descriptor table. 2462 */ 2463 fdp->fd_holdleaderswakeup = 1; 2464 sx_sleep(&fdp->fd_holdleaderscount, 2465 FILEDESC_LOCK(fdp), PLOCK, "fdlhold", 0); 2466 goto retry; 2467 } 2468 if (fdtol->fdl_holdcount > 0) { 2469 /* 2470 * Ensure that fdtol->fdl_leader remains 2471 * valid in closef(). 2472 */ 2473 fdtol->fdl_wakeup = 1; 2474 sx_sleep(fdtol, FILEDESC_LOCK(fdp), PLOCK, 2475 "fdlhold", 0); 2476 goto retry; 2477 } 2478 } 2479 fdtol->fdl_refcount--; 2480 if (fdtol->fdl_refcount == 0 && 2481 fdtol->fdl_holdcount == 0) { 2482 fdtol->fdl_next->fdl_prev = fdtol->fdl_prev; 2483 fdtol->fdl_prev->fdl_next = fdtol->fdl_next; 2484 } else 2485 fdtol = NULL; 2486 p->p_fdtol = NULL; 2487 FILEDESC_XUNLOCK(fdp); 2488 if (fdtol != NULL) 2489 free(fdtol, M_FILEDESC_TO_LEADER); 2490 } 2491 2492 /* 2493 * Release a filedesc structure. 2494 */ 2495 static void 2496 fdescfree_fds(struct thread *td, struct filedesc *fdp) 2497 { 2498 struct filedesc0 *fdp0; 2499 struct freetable *ft, *tft; 2500 struct filedescent *fde; 2501 struct file *fp; 2502 int i, lastfile; 2503 2504 KASSERT(refcount_load(&fdp->fd_refcnt) == 0, 2505 ("%s: fd table %p carries references", __func__, fdp)); 2506 2507 /* 2508 * Serialize with threads iterating over the table, if any. 2509 */ 2510 if (refcount_load(&fdp->fd_holdcnt) > 1) { 2511 FILEDESC_XLOCK(fdp); 2512 FILEDESC_XUNLOCK(fdp); 2513 } 2514 2515 lastfile = fdlastfile_single(fdp); 2516 for (i = 0; i <= lastfile; i++) { 2517 fde = &fdp->fd_ofiles[i]; 2518 fp = fde->fde_file; 2519 if (fp != NULL) { 2520 fdefree_last(fde); 2521 (void) closef(fp, td); 2522 } 2523 } 2524 2525 if (NDSLOTS(fdp->fd_nfiles) > NDSLOTS(NDFILE)) 2526 free(fdp->fd_map, M_FILEDESC); 2527 if (fdp->fd_nfiles > NDFILE) 2528 free(fdp->fd_files, M_FILEDESC); 2529 2530 fdp0 = (struct filedesc0 *)fdp; 2531 SLIST_FOREACH_SAFE(ft, &fdp0->fd_free, ft_next, tft) 2532 free(ft->ft_table, M_FILEDESC); 2533 2534 fddrop(fdp); 2535 } 2536 2537 void 2538 fdescfree(struct thread *td) 2539 { 2540 struct proc *p; 2541 struct filedesc *fdp; 2542 2543 p = td->td_proc; 2544 fdp = p->p_fd; 2545 MPASS(fdp != NULL); 2546 2547 #ifdef RACCT 2548 if (RACCT_ENABLED()) 2549 racct_set_unlocked(p, RACCT_NOFILE, 0); 2550 #endif 2551 2552 if (p->p_fdtol != NULL) 2553 fdclearlocks(td); 2554 2555 /* 2556 * Check fdhold for an explanation. 2557 */ 2558 atomic_store_ptr(&p->p_fd, NULL); 2559 atomic_thread_fence_seq_cst(); 2560 PROC_WAIT_UNLOCKED(p); 2561 2562 if (refcount_release(&fdp->fd_refcnt) == 0) 2563 return; 2564 2565 fdescfree_fds(td, fdp); 2566 } 2567 2568 void 2569 pdescfree(struct thread *td) 2570 { 2571 struct proc *p; 2572 struct pwddesc *pdp; 2573 2574 p = td->td_proc; 2575 pdp = p->p_pd; 2576 MPASS(pdp != NULL); 2577 2578 /* 2579 * Check pdhold for an explanation. 2580 */ 2581 atomic_store_ptr(&p->p_pd, NULL); 2582 atomic_thread_fence_seq_cst(); 2583 PROC_WAIT_UNLOCKED(p); 2584 2585 pddrop(pdp); 2586 } 2587 2588 /* 2589 * For setugid programs, we don't want to people to use that setugidness 2590 * to generate error messages which write to a file which otherwise would 2591 * otherwise be off-limits to the process. We check for filesystems where 2592 * the vnode can change out from under us after execve (like [lin]procfs). 2593 * 2594 * Since fdsetugidsafety calls this only for fd 0, 1 and 2, this check is 2595 * sufficient. We also don't check for setugidness since we know we are. 2596 */ 2597 static bool 2598 is_unsafe(struct file *fp) 2599 { 2600 struct vnode *vp; 2601 2602 if (fp->f_type != DTYPE_VNODE) 2603 return (false); 2604 2605 vp = fp->f_vnode; 2606 return ((vp->v_vflag & VV_PROCDEP) != 0); 2607 } 2608 2609 /* 2610 * Make this setguid thing safe, if at all possible. 2611 */ 2612 void 2613 fdsetugidsafety(struct thread *td) 2614 { 2615 struct filedesc *fdp; 2616 struct file *fp; 2617 int i; 2618 2619 fdp = td->td_proc->p_fd; 2620 KASSERT(refcount_load(&fdp->fd_refcnt) == 1, 2621 ("the fdtable should not be shared")); 2622 MPASS(fdp->fd_nfiles >= 3); 2623 for (i = 0; i <= 2; i++) { 2624 fp = fdp->fd_ofiles[i].fde_file; 2625 if (fp != NULL && is_unsafe(fp)) { 2626 FILEDESC_XLOCK(fdp); 2627 knote_fdclose(td, i); 2628 /* 2629 * NULL-out descriptor prior to close to avoid 2630 * a race while close blocks. 2631 */ 2632 fdfree(fdp, i); 2633 FILEDESC_XUNLOCK(fdp); 2634 (void) closef(fp, td); 2635 } 2636 } 2637 } 2638 2639 /* 2640 * If a specific file object occupies a specific file descriptor, close the 2641 * file descriptor entry and drop a reference on the file object. This is a 2642 * convenience function to handle a subsequent error in a function that calls 2643 * falloc() that handles the race that another thread might have closed the 2644 * file descriptor out from under the thread creating the file object. 2645 */ 2646 void 2647 fdclose(struct thread *td, struct file *fp, int idx) 2648 { 2649 struct filedesc *fdp = td->td_proc->p_fd; 2650 2651 FILEDESC_XLOCK(fdp); 2652 if (fdp->fd_ofiles[idx].fde_file == fp) { 2653 fdfree(fdp, idx); 2654 FILEDESC_XUNLOCK(fdp); 2655 fdrop(fp, td); 2656 } else 2657 FILEDESC_XUNLOCK(fdp); 2658 } 2659 2660 /* 2661 * Close any files on exec? 2662 */ 2663 void 2664 fdcloseexec(struct thread *td) 2665 { 2666 struct filedesc *fdp; 2667 struct filedescent *fde; 2668 struct file *fp; 2669 int i, lastfile; 2670 2671 fdp = td->td_proc->p_fd; 2672 KASSERT(refcount_load(&fdp->fd_refcnt) == 1, 2673 ("the fdtable should not be shared")); 2674 lastfile = fdlastfile_single(fdp); 2675 for (i = 0; i <= lastfile; i++) { 2676 fde = &fdp->fd_ofiles[i]; 2677 fp = fde->fde_file; 2678 if (fp != NULL && (fp->f_type == DTYPE_MQUEUE || 2679 (fde->fde_flags & UF_EXCLOSE))) { 2680 FILEDESC_XLOCK(fdp); 2681 fdfree(fdp, i); 2682 (void) closefp(fdp, i, fp, td, false, false); 2683 FILEDESC_UNLOCK_ASSERT(fdp); 2684 } 2685 } 2686 } 2687 2688 /* 2689 * It is unsafe for set[ug]id processes to be started with file 2690 * descriptors 0..2 closed, as these descriptors are given implicit 2691 * significance in the Standard C library. fdcheckstd() will create a 2692 * descriptor referencing /dev/null for each of stdin, stdout, and 2693 * stderr that is not already open. 2694 */ 2695 int 2696 fdcheckstd(struct thread *td) 2697 { 2698 struct filedesc *fdp; 2699 register_t save; 2700 int i, error, devnull; 2701 2702 fdp = td->td_proc->p_fd; 2703 KASSERT(refcount_load(&fdp->fd_refcnt) == 1, 2704 ("the fdtable should not be shared")); 2705 MPASS(fdp->fd_nfiles >= 3); 2706 devnull = -1; 2707 for (i = 0; i <= 2; i++) { 2708 if (fdp->fd_ofiles[i].fde_file != NULL) 2709 continue; 2710 2711 save = td->td_retval[0]; 2712 if (devnull != -1) { 2713 error = kern_dup(td, FDDUP_FIXED, 0, devnull, i); 2714 } else { 2715 error = kern_openat(td, AT_FDCWD, "/dev/null", 2716 UIO_SYSSPACE, O_RDWR, 0); 2717 if (error == 0) { 2718 devnull = td->td_retval[0]; 2719 KASSERT(devnull == i, ("we didn't get our fd")); 2720 } 2721 } 2722 td->td_retval[0] = save; 2723 if (error != 0) 2724 return (error); 2725 } 2726 return (0); 2727 } 2728 2729 /* 2730 * Internal form of close. Decrement reference count on file structure. 2731 * Note: td may be NULL when closing a file that was being passed in a 2732 * message. 2733 */ 2734 int 2735 closef(struct file *fp, struct thread *td) 2736 { 2737 struct vnode *vp; 2738 struct flock lf; 2739 struct filedesc_to_leader *fdtol; 2740 struct filedesc *fdp; 2741 2742 MPASS(td != NULL); 2743 2744 /* 2745 * POSIX record locking dictates that any close releases ALL 2746 * locks owned by this process. This is handled by setting 2747 * a flag in the unlock to free ONLY locks obeying POSIX 2748 * semantics, and not to free BSD-style file locks. 2749 * If the descriptor was in a message, POSIX-style locks 2750 * aren't passed with the descriptor, and the thread pointer 2751 * will be NULL. Callers should be careful only to pass a 2752 * NULL thread pointer when there really is no owning 2753 * context that might have locks, or the locks will be 2754 * leaked. 2755 */ 2756 if (fp->f_type == DTYPE_VNODE) { 2757 vp = fp->f_vnode; 2758 if ((td->td_proc->p_leader->p_flag & P_ADVLOCK) != 0) { 2759 lf.l_whence = SEEK_SET; 2760 lf.l_start = 0; 2761 lf.l_len = 0; 2762 lf.l_type = F_UNLCK; 2763 (void) VOP_ADVLOCK(vp, (caddr_t)td->td_proc->p_leader, 2764 F_UNLCK, &lf, F_POSIX); 2765 } 2766 fdtol = td->td_proc->p_fdtol; 2767 if (fdtol != NULL) { 2768 /* 2769 * Handle special case where file descriptor table is 2770 * shared between multiple process leaders. 2771 */ 2772 fdp = td->td_proc->p_fd; 2773 FILEDESC_XLOCK(fdp); 2774 for (fdtol = fdtol->fdl_next; 2775 fdtol != td->td_proc->p_fdtol; 2776 fdtol = fdtol->fdl_next) { 2777 if ((fdtol->fdl_leader->p_flag & 2778 P_ADVLOCK) == 0) 2779 continue; 2780 fdtol->fdl_holdcount++; 2781 FILEDESC_XUNLOCK(fdp); 2782 lf.l_whence = SEEK_SET; 2783 lf.l_start = 0; 2784 lf.l_len = 0; 2785 lf.l_type = F_UNLCK; 2786 vp = fp->f_vnode; 2787 (void) VOP_ADVLOCK(vp, 2788 (caddr_t)fdtol->fdl_leader, F_UNLCK, &lf, 2789 F_POSIX); 2790 FILEDESC_XLOCK(fdp); 2791 fdtol->fdl_holdcount--; 2792 if (fdtol->fdl_holdcount == 0 && 2793 fdtol->fdl_wakeup != 0) { 2794 fdtol->fdl_wakeup = 0; 2795 wakeup(fdtol); 2796 } 2797 } 2798 FILEDESC_XUNLOCK(fdp); 2799 } 2800 } 2801 return (fdrop_close(fp, td)); 2802 } 2803 2804 /* 2805 * Hack for file descriptor passing code. 2806 */ 2807 void 2808 closef_nothread(struct file *fp) 2809 { 2810 2811 fdrop(fp, NULL); 2812 } 2813 2814 /* 2815 * Initialize the file pointer with the specified properties. 2816 * 2817 * The ops are set with release semantics to be certain that the flags, type, 2818 * and data are visible when ops is. This is to prevent ops methods from being 2819 * called with bad data. 2820 */ 2821 void 2822 finit(struct file *fp, u_int flag, short type, void *data, struct fileops *ops) 2823 { 2824 fp->f_data = data; 2825 fp->f_flag = flag; 2826 fp->f_type = type; 2827 atomic_store_rel_ptr((volatile uintptr_t *)&fp->f_ops, (uintptr_t)ops); 2828 } 2829 2830 void 2831 finit_vnode(struct file *fp, u_int flag, void *data, struct fileops *ops) 2832 { 2833 fp->f_seqcount[UIO_READ] = 1; 2834 fp->f_seqcount[UIO_WRITE] = 1; 2835 finit(fp, (flag & FMASK) | (fp->f_flag & FHASLOCK), DTYPE_VNODE, 2836 data, ops); 2837 } 2838 2839 int 2840 fget_cap_locked(struct filedesc *fdp, int fd, cap_rights_t *needrightsp, 2841 struct file **fpp, struct filecaps *havecapsp) 2842 { 2843 struct filedescent *fde; 2844 int error; 2845 2846 FILEDESC_LOCK_ASSERT(fdp); 2847 2848 *fpp = NULL; 2849 fde = fdeget_locked(fdp, fd); 2850 if (fde == NULL) { 2851 error = EBADF; 2852 goto out; 2853 } 2854 2855 #ifdef CAPABILITIES 2856 error = cap_check(cap_rights_fde_inline(fde), needrightsp); 2857 if (error != 0) 2858 goto out; 2859 #endif 2860 2861 if (havecapsp != NULL) 2862 filecaps_copy(&fde->fde_caps, havecapsp, true); 2863 2864 *fpp = fde->fde_file; 2865 2866 error = 0; 2867 out: 2868 return (error); 2869 } 2870 2871 int 2872 fget_cap(struct thread *td, int fd, cap_rights_t *needrightsp, 2873 struct file **fpp, struct filecaps *havecapsp) 2874 { 2875 struct filedesc *fdp = td->td_proc->p_fd; 2876 int error; 2877 #ifndef CAPABILITIES 2878 error = fget_unlocked(fdp, fd, needrightsp, fpp); 2879 if (havecapsp != NULL && error == 0) 2880 filecaps_fill(havecapsp); 2881 #else 2882 struct file *fp; 2883 seqc_t seq; 2884 2885 *fpp = NULL; 2886 for (;;) { 2887 error = fget_unlocked_seq(fdp, fd, needrightsp, &fp, &seq); 2888 if (error != 0) 2889 return (error); 2890 2891 if (havecapsp != NULL) { 2892 if (!filecaps_copy(&fdp->fd_ofiles[fd].fde_caps, 2893 havecapsp, false)) { 2894 fdrop(fp, td); 2895 goto get_locked; 2896 } 2897 } 2898 2899 if (!fd_modified(fdp, fd, seq)) 2900 break; 2901 fdrop(fp, td); 2902 } 2903 2904 *fpp = fp; 2905 return (0); 2906 2907 get_locked: 2908 FILEDESC_SLOCK(fdp); 2909 error = fget_cap_locked(fdp, fd, needrightsp, fpp, havecapsp); 2910 if (error == 0 && !fhold(*fpp)) 2911 error = EBADF; 2912 FILEDESC_SUNLOCK(fdp); 2913 #endif 2914 return (error); 2915 } 2916 2917 #ifdef CAPABILITIES 2918 int 2919 fgetvp_lookup_smr(int fd, struct nameidata *ndp, struct vnode **vpp, bool *fsearch) 2920 { 2921 const struct filedescent *fde; 2922 const struct fdescenttbl *fdt; 2923 struct filedesc *fdp; 2924 struct file *fp; 2925 struct vnode *vp; 2926 const cap_rights_t *haverights; 2927 cap_rights_t rights; 2928 seqc_t seq; 2929 2930 VFS_SMR_ASSERT_ENTERED(); 2931 2932 rights = *ndp->ni_rightsneeded; 2933 cap_rights_set_one(&rights, CAP_LOOKUP); 2934 2935 fdp = curproc->p_fd; 2936 fdt = fdp->fd_files; 2937 if (__predict_false((u_int)fd >= fdt->fdt_nfiles)) 2938 return (EBADF); 2939 seq = seqc_read_notmodify(fd_seqc(fdt, fd)); 2940 fde = &fdt->fdt_ofiles[fd]; 2941 haverights = cap_rights_fde_inline(fde); 2942 fp = fde->fde_file; 2943 if (__predict_false(fp == NULL)) 2944 return (EAGAIN); 2945 if (__predict_false(cap_check_inline_transient(haverights, &rights))) 2946 return (EAGAIN); 2947 *fsearch = ((fp->f_flag & FSEARCH) != 0); 2948 vp = fp->f_vnode; 2949 if (__predict_false(vp == NULL)) { 2950 return (EAGAIN); 2951 } 2952 if (!filecaps_copy(&fde->fde_caps, &ndp->ni_filecaps, false)) { 2953 return (EAGAIN); 2954 } 2955 /* 2956 * Use an acquire barrier to force re-reading of fdt so it is 2957 * refreshed for verification. 2958 */ 2959 atomic_thread_fence_acq(); 2960 fdt = fdp->fd_files; 2961 if (__predict_false(!seqc_consistent_nomb(fd_seqc(fdt, fd), seq))) 2962 return (EAGAIN); 2963 /* 2964 * If file descriptor doesn't have all rights, 2965 * all lookups relative to it must also be 2966 * strictly relative. 2967 * 2968 * Not yet supported by fast path. 2969 */ 2970 CAP_ALL(&rights); 2971 if (!cap_rights_contains(&ndp->ni_filecaps.fc_rights, &rights) || 2972 ndp->ni_filecaps.fc_fcntls != CAP_FCNTL_ALL || 2973 ndp->ni_filecaps.fc_nioctls != -1) { 2974 #ifdef notyet 2975 ndp->ni_lcf |= NI_LCF_STRICTRELATIVE; 2976 #else 2977 return (EAGAIN); 2978 #endif 2979 } 2980 *vpp = vp; 2981 return (0); 2982 } 2983 #else 2984 int 2985 fgetvp_lookup_smr(int fd, struct nameidata *ndp, struct vnode **vpp, bool *fsearch) 2986 { 2987 const struct fdescenttbl *fdt; 2988 struct filedesc *fdp; 2989 struct file *fp; 2990 struct vnode *vp; 2991 2992 VFS_SMR_ASSERT_ENTERED(); 2993 2994 fdp = curproc->p_fd; 2995 fdt = fdp->fd_files; 2996 if (__predict_false((u_int)fd >= fdt->fdt_nfiles)) 2997 return (EBADF); 2998 fp = fdt->fdt_ofiles[fd].fde_file; 2999 if (__predict_false(fp == NULL)) 3000 return (EAGAIN); 3001 *fsearch = ((fp->f_flag & FSEARCH) != 0); 3002 vp = fp->f_vnode; 3003 if (__predict_false(vp == NULL || vp->v_type != VDIR)) { 3004 return (EAGAIN); 3005 } 3006 /* 3007 * Use an acquire barrier to force re-reading of fdt so it is 3008 * refreshed for verification. 3009 */ 3010 atomic_thread_fence_acq(); 3011 fdt = fdp->fd_files; 3012 if (__predict_false(fp != fdt->fdt_ofiles[fd].fde_file)) 3013 return (EAGAIN); 3014 filecaps_fill(&ndp->ni_filecaps); 3015 *vpp = vp; 3016 return (0); 3017 } 3018 #endif 3019 3020 static int 3021 fget_unlocked_seq(struct filedesc *fdp, int fd, cap_rights_t *needrightsp, 3022 struct file **fpp, seqc_t *seqp) 3023 { 3024 #ifdef CAPABILITIES 3025 const struct filedescent *fde; 3026 #endif 3027 const struct fdescenttbl *fdt; 3028 struct file *fp; 3029 #ifdef CAPABILITIES 3030 seqc_t seq; 3031 cap_rights_t haverights; 3032 int error; 3033 #endif 3034 3035 fdt = fdp->fd_files; 3036 if (__predict_false((u_int)fd >= fdt->fdt_nfiles)) 3037 return (EBADF); 3038 /* 3039 * Fetch the descriptor locklessly. We avoid fdrop() races by 3040 * never raising a refcount above 0. To accomplish this we have 3041 * to use a cmpset loop rather than an atomic_add. The descriptor 3042 * must be re-verified once we acquire a reference to be certain 3043 * that the identity is still correct and we did not lose a race 3044 * due to preemption. 3045 */ 3046 for (;;) { 3047 #ifdef CAPABILITIES 3048 seq = seqc_read_notmodify(fd_seqc(fdt, fd)); 3049 fde = &fdt->fdt_ofiles[fd]; 3050 haverights = *cap_rights_fde_inline(fde); 3051 fp = fde->fde_file; 3052 if (!seqc_consistent(fd_seqc(fdt, fd), seq)) 3053 continue; 3054 #else 3055 fp = fdt->fdt_ofiles[fd].fde_file; 3056 #endif 3057 if (fp == NULL) 3058 return (EBADF); 3059 #ifdef CAPABILITIES 3060 error = cap_check_inline(&haverights, needrightsp); 3061 if (error != 0) 3062 return (error); 3063 #endif 3064 if (__predict_false(!refcount_acquire_if_not_zero(&fp->f_count))) { 3065 /* 3066 * Force a reload. Other thread could reallocate the 3067 * table before this fd was closed, so it is possible 3068 * that there is a stale fp pointer in cached version. 3069 */ 3070 fdt = atomic_load_ptr(&fdp->fd_files); 3071 continue; 3072 } 3073 /* 3074 * Use an acquire barrier to force re-reading of fdt so it is 3075 * refreshed for verification. 3076 */ 3077 atomic_thread_fence_acq(); 3078 fdt = fdp->fd_files; 3079 #ifdef CAPABILITIES 3080 if (seqc_consistent_nomb(fd_seqc(fdt, fd), seq)) 3081 #else 3082 if (fp == fdt->fdt_ofiles[fd].fde_file) 3083 #endif 3084 break; 3085 fdrop(fp, curthread); 3086 } 3087 *fpp = fp; 3088 if (seqp != NULL) { 3089 #ifdef CAPABILITIES 3090 *seqp = seq; 3091 #endif 3092 } 3093 return (0); 3094 } 3095 3096 /* 3097 * See the comments in fget_unlocked_seq for an explanation of how this works. 3098 * 3099 * This is a simplified variant which bails out to the aforementioned routine 3100 * if anything goes wrong. In practice this only happens when userspace is 3101 * racing with itself. 3102 */ 3103 int 3104 fget_unlocked(struct filedesc *fdp, int fd, cap_rights_t *needrightsp, 3105 struct file **fpp) 3106 { 3107 #ifdef CAPABILITIES 3108 const struct filedescent *fde; 3109 #endif 3110 const struct fdescenttbl *fdt; 3111 struct file *fp; 3112 #ifdef CAPABILITIES 3113 seqc_t seq; 3114 const cap_rights_t *haverights; 3115 #endif 3116 3117 fdt = fdp->fd_files; 3118 if (__predict_false((u_int)fd >= fdt->fdt_nfiles)) { 3119 *fpp = NULL; 3120 return (EBADF); 3121 } 3122 #ifdef CAPABILITIES 3123 seq = seqc_read_notmodify(fd_seqc(fdt, fd)); 3124 fde = &fdt->fdt_ofiles[fd]; 3125 haverights = cap_rights_fde_inline(fde); 3126 fp = fde->fde_file; 3127 #else 3128 fp = fdt->fdt_ofiles[fd].fde_file; 3129 #endif 3130 if (__predict_false(fp == NULL)) 3131 goto out_fallback; 3132 #ifdef CAPABILITIES 3133 if (__predict_false(cap_check_inline_transient(haverights, needrightsp))) 3134 goto out_fallback; 3135 #endif 3136 if (__predict_false(!refcount_acquire_if_not_zero(&fp->f_count))) 3137 goto out_fallback; 3138 3139 /* 3140 * Use an acquire barrier to force re-reading of fdt so it is 3141 * refreshed for verification. 3142 */ 3143 atomic_thread_fence_acq(); 3144 fdt = fdp->fd_files; 3145 #ifdef CAPABILITIES 3146 if (__predict_false(!seqc_consistent_nomb(fd_seqc(fdt, fd), seq))) 3147 #else 3148 if (__predict_false(fp != fdt->fdt_ofiles[fd].fde_file)) 3149 #endif 3150 goto out_fdrop; 3151 *fpp = fp; 3152 return (0); 3153 out_fdrop: 3154 fdrop(fp, curthread); 3155 out_fallback: 3156 *fpp = NULL; 3157 return (fget_unlocked_seq(fdp, fd, needrightsp, fpp, NULL)); 3158 } 3159 3160 /* 3161 * Translate fd -> file when the caller guarantees the file descriptor table 3162 * can't be changed by others. 3163 * 3164 * Note this does not mean the file object itself is only visible to the caller, 3165 * merely that it wont disappear without having to be referenced. 3166 * 3167 * Must be paired with fput_only_user. 3168 */ 3169 #ifdef CAPABILITIES 3170 int 3171 fget_only_user(struct filedesc *fdp, int fd, cap_rights_t *needrightsp, 3172 struct file **fpp) 3173 { 3174 const struct filedescent *fde; 3175 const struct fdescenttbl *fdt; 3176 const cap_rights_t *haverights; 3177 struct file *fp; 3178 int error; 3179 3180 MPASS(FILEDESC_IS_ONLY_USER(fdp)); 3181 3182 *fpp = NULL; 3183 if (__predict_false(fd >= fdp->fd_nfiles)) 3184 return (EBADF); 3185 3186 fdt = fdp->fd_files; 3187 fde = &fdt->fdt_ofiles[fd]; 3188 fp = fde->fde_file; 3189 if (__predict_false(fp == NULL)) 3190 return (EBADF); 3191 MPASS(refcount_load(&fp->f_count) > 0); 3192 haverights = cap_rights_fde_inline(fde); 3193 error = cap_check_inline(haverights, needrightsp); 3194 if (__predict_false(error != 0)) 3195 return (error); 3196 *fpp = fp; 3197 return (0); 3198 } 3199 #else 3200 int 3201 fget_only_user(struct filedesc *fdp, int fd, cap_rights_t *needrightsp, 3202 struct file **fpp) 3203 { 3204 struct file *fp; 3205 3206 MPASS(FILEDESC_IS_ONLY_USER(fdp)); 3207 3208 *fpp = NULL; 3209 if (__predict_false(fd >= fdp->fd_nfiles)) 3210 return (EBADF); 3211 3212 fp = fdp->fd_ofiles[fd].fde_file; 3213 if (__predict_false(fp == NULL)) 3214 return (EBADF); 3215 3216 MPASS(refcount_load(&fp->f_count) > 0); 3217 *fpp = fp; 3218 return (0); 3219 } 3220 #endif 3221 3222 /* 3223 * Extract the file pointer associated with the specified descriptor for the 3224 * current user process. 3225 * 3226 * If the descriptor doesn't exist or doesn't match 'flags', EBADF is 3227 * returned. 3228 * 3229 * File's rights will be checked against the capability rights mask. 3230 * 3231 * If an error occurred the non-zero error is returned and *fpp is set to 3232 * NULL. Otherwise *fpp is held and set and zero is returned. Caller is 3233 * responsible for fdrop(). 3234 */ 3235 static __inline int 3236 _fget(struct thread *td, int fd, struct file **fpp, int flags, 3237 cap_rights_t *needrightsp) 3238 { 3239 struct filedesc *fdp; 3240 struct file *fp; 3241 int error; 3242 3243 *fpp = NULL; 3244 fdp = td->td_proc->p_fd; 3245 error = fget_unlocked(fdp, fd, needrightsp, &fp); 3246 if (__predict_false(error != 0)) 3247 return (error); 3248 if (__predict_false(fp->f_ops == &badfileops)) { 3249 fdrop(fp, td); 3250 return (EBADF); 3251 } 3252 3253 /* 3254 * FREAD and FWRITE failure return EBADF as per POSIX. 3255 */ 3256 error = 0; 3257 switch (flags) { 3258 case FREAD: 3259 case FWRITE: 3260 if ((fp->f_flag & flags) == 0) 3261 error = EBADF; 3262 break; 3263 case FEXEC: 3264 if (fp->f_ops != &path_fileops && 3265 ((fp->f_flag & (FREAD | FEXEC)) == 0 || 3266 (fp->f_flag & FWRITE) != 0)) 3267 error = EBADF; 3268 break; 3269 case 0: 3270 break; 3271 default: 3272 KASSERT(0, ("wrong flags")); 3273 } 3274 3275 if (error != 0) { 3276 fdrop(fp, td); 3277 return (error); 3278 } 3279 3280 *fpp = fp; 3281 return (0); 3282 } 3283 3284 int 3285 fget(struct thread *td, int fd, cap_rights_t *rightsp, struct file **fpp) 3286 { 3287 3288 return (_fget(td, fd, fpp, 0, rightsp)); 3289 } 3290 3291 int 3292 fget_mmap(struct thread *td, int fd, cap_rights_t *rightsp, vm_prot_t *maxprotp, 3293 struct file **fpp) 3294 { 3295 int error; 3296 #ifndef CAPABILITIES 3297 error = _fget(td, fd, fpp, 0, rightsp); 3298 if (maxprotp != NULL) 3299 *maxprotp = VM_PROT_ALL; 3300 return (error); 3301 #else 3302 cap_rights_t fdrights; 3303 struct filedesc *fdp; 3304 struct file *fp; 3305 seqc_t seq; 3306 3307 *fpp = NULL; 3308 fdp = td->td_proc->p_fd; 3309 MPASS(cap_rights_is_set(rightsp, CAP_MMAP)); 3310 for (;;) { 3311 error = fget_unlocked_seq(fdp, fd, rightsp, &fp, &seq); 3312 if (__predict_false(error != 0)) 3313 return (error); 3314 if (__predict_false(fp->f_ops == &badfileops)) { 3315 fdrop(fp, td); 3316 return (EBADF); 3317 } 3318 if (maxprotp != NULL) 3319 fdrights = *cap_rights(fdp, fd); 3320 if (!fd_modified(fdp, fd, seq)) 3321 break; 3322 fdrop(fp, td); 3323 } 3324 3325 /* 3326 * If requested, convert capability rights to access flags. 3327 */ 3328 if (maxprotp != NULL) 3329 *maxprotp = cap_rights_to_vmprot(&fdrights); 3330 *fpp = fp; 3331 return (0); 3332 #endif 3333 } 3334 3335 int 3336 fget_read(struct thread *td, int fd, cap_rights_t *rightsp, struct file **fpp) 3337 { 3338 3339 return (_fget(td, fd, fpp, FREAD, rightsp)); 3340 } 3341 3342 int 3343 fget_write(struct thread *td, int fd, cap_rights_t *rightsp, struct file **fpp) 3344 { 3345 3346 return (_fget(td, fd, fpp, FWRITE, rightsp)); 3347 } 3348 3349 int 3350 fget_fcntl(struct thread *td, int fd, cap_rights_t *rightsp, int needfcntl, 3351 struct file **fpp) 3352 { 3353 struct filedesc *fdp = td->td_proc->p_fd; 3354 #ifndef CAPABILITIES 3355 return (fget_unlocked(fdp, fd, rightsp, fpp)); 3356 #else 3357 struct file *fp; 3358 int error; 3359 seqc_t seq; 3360 3361 *fpp = NULL; 3362 MPASS(cap_rights_is_set(rightsp, CAP_FCNTL)); 3363 for (;;) { 3364 error = fget_unlocked_seq(fdp, fd, rightsp, &fp, &seq); 3365 if (error != 0) 3366 return (error); 3367 error = cap_fcntl_check(fdp, fd, needfcntl); 3368 if (!fd_modified(fdp, fd, seq)) 3369 break; 3370 fdrop(fp, td); 3371 } 3372 if (error != 0) { 3373 fdrop(fp, td); 3374 return (error); 3375 } 3376 *fpp = fp; 3377 return (0); 3378 #endif 3379 } 3380 3381 /* 3382 * Like fget() but loads the underlying vnode, or returns an error if the 3383 * descriptor does not represent a vnode. Note that pipes use vnodes but 3384 * never have VM objects. The returned vnode will be vref()'d. 3385 * 3386 * XXX: what about the unused flags ? 3387 */ 3388 static __inline int 3389 _fgetvp(struct thread *td, int fd, int flags, cap_rights_t *needrightsp, 3390 struct vnode **vpp) 3391 { 3392 struct file *fp; 3393 int error; 3394 3395 *vpp = NULL; 3396 error = _fget(td, fd, &fp, flags, needrightsp); 3397 if (error != 0) 3398 return (error); 3399 if (fp->f_vnode == NULL) { 3400 error = EINVAL; 3401 } else { 3402 *vpp = fp->f_vnode; 3403 vref(*vpp); 3404 } 3405 fdrop(fp, td); 3406 3407 return (error); 3408 } 3409 3410 int 3411 fgetvp(struct thread *td, int fd, cap_rights_t *rightsp, struct vnode **vpp) 3412 { 3413 3414 return (_fgetvp(td, fd, 0, rightsp, vpp)); 3415 } 3416 3417 int 3418 fgetvp_rights(struct thread *td, int fd, cap_rights_t *needrightsp, 3419 struct filecaps *havecaps, struct vnode **vpp) 3420 { 3421 struct filecaps caps; 3422 struct file *fp; 3423 int error; 3424 3425 error = fget_cap(td, fd, needrightsp, &fp, &caps); 3426 if (error != 0) 3427 return (error); 3428 if (fp->f_ops == &badfileops) { 3429 error = EBADF; 3430 goto out; 3431 } 3432 if (fp->f_vnode == NULL) { 3433 error = EINVAL; 3434 goto out; 3435 } 3436 3437 *havecaps = caps; 3438 *vpp = fp->f_vnode; 3439 vref(*vpp); 3440 fdrop(fp, td); 3441 3442 return (0); 3443 out: 3444 filecaps_free(&caps); 3445 fdrop(fp, td); 3446 return (error); 3447 } 3448 3449 int 3450 fgetvp_read(struct thread *td, int fd, cap_rights_t *rightsp, struct vnode **vpp) 3451 { 3452 3453 return (_fgetvp(td, fd, FREAD, rightsp, vpp)); 3454 } 3455 3456 int 3457 fgetvp_exec(struct thread *td, int fd, cap_rights_t *rightsp, struct vnode **vpp) 3458 { 3459 3460 return (_fgetvp(td, fd, FEXEC, rightsp, vpp)); 3461 } 3462 3463 #ifdef notyet 3464 int 3465 fgetvp_write(struct thread *td, int fd, cap_rights_t *rightsp, 3466 struct vnode **vpp) 3467 { 3468 3469 return (_fgetvp(td, fd, FWRITE, rightsp, vpp)); 3470 } 3471 #endif 3472 3473 /* 3474 * Handle the last reference to a file being closed. 3475 * 3476 * Without the noinline attribute clang keeps inlining the func thorough this 3477 * file when fdrop is used. 3478 */ 3479 int __noinline 3480 _fdrop(struct file *fp, struct thread *td) 3481 { 3482 int error; 3483 #ifdef INVARIANTS 3484 int count; 3485 3486 count = refcount_load(&fp->f_count); 3487 if (count != 0) 3488 panic("fdrop: fp %p count %d", fp, count); 3489 #endif 3490 error = fo_close(fp, td); 3491 atomic_subtract_int(&openfiles, 1); 3492 crfree(fp->f_cred); 3493 free(fp->f_advice, M_FADVISE); 3494 uma_zfree(file_zone, fp); 3495 3496 return (error); 3497 } 3498 3499 /* 3500 * Apply an advisory lock on a file descriptor. 3501 * 3502 * Just attempt to get a record lock of the requested type on the entire file 3503 * (l_whence = SEEK_SET, l_start = 0, l_len = 0). 3504 */ 3505 #ifndef _SYS_SYSPROTO_H_ 3506 struct flock_args { 3507 int fd; 3508 int how; 3509 }; 3510 #endif 3511 /* ARGSUSED */ 3512 int 3513 sys_flock(struct thread *td, struct flock_args *uap) 3514 { 3515 struct file *fp; 3516 struct vnode *vp; 3517 struct flock lf; 3518 int error; 3519 3520 error = fget(td, uap->fd, &cap_flock_rights, &fp); 3521 if (error != 0) 3522 return (error); 3523 error = EOPNOTSUPP; 3524 if (fp->f_type != DTYPE_VNODE && fp->f_type != DTYPE_FIFO) { 3525 goto done; 3526 } 3527 if (fp->f_ops == &path_fileops) { 3528 goto done; 3529 } 3530 3531 error = 0; 3532 vp = fp->f_vnode; 3533 lf.l_whence = SEEK_SET; 3534 lf.l_start = 0; 3535 lf.l_len = 0; 3536 if (uap->how & LOCK_UN) { 3537 lf.l_type = F_UNLCK; 3538 atomic_clear_int(&fp->f_flag, FHASLOCK); 3539 error = VOP_ADVLOCK(vp, (caddr_t)fp, F_UNLCK, &lf, F_FLOCK); 3540 goto done; 3541 } 3542 if (uap->how & LOCK_EX) 3543 lf.l_type = F_WRLCK; 3544 else if (uap->how & LOCK_SH) 3545 lf.l_type = F_RDLCK; 3546 else { 3547 error = EBADF; 3548 goto done; 3549 } 3550 atomic_set_int(&fp->f_flag, FHASLOCK); 3551 error = VOP_ADVLOCK(vp, (caddr_t)fp, F_SETLK, &lf, 3552 (uap->how & LOCK_NB) ? F_FLOCK : F_FLOCK | F_WAIT); 3553 done: 3554 fdrop(fp, td); 3555 return (error); 3556 } 3557 /* 3558 * Duplicate the specified descriptor to a free descriptor. 3559 */ 3560 int 3561 dupfdopen(struct thread *td, struct filedesc *fdp, int dfd, int mode, 3562 int openerror, int *indxp) 3563 { 3564 struct filedescent *newfde, *oldfde; 3565 struct file *fp; 3566 u_long *ioctls; 3567 int error, indx; 3568 3569 KASSERT(openerror == ENODEV || openerror == ENXIO, 3570 ("unexpected error %d in %s", openerror, __func__)); 3571 3572 /* 3573 * If the to-be-dup'd fd number is greater than the allowed number 3574 * of file descriptors, or the fd to be dup'd has already been 3575 * closed, then reject. 3576 */ 3577 FILEDESC_XLOCK(fdp); 3578 if ((fp = fget_locked(fdp, dfd)) == NULL) { 3579 FILEDESC_XUNLOCK(fdp); 3580 return (EBADF); 3581 } 3582 3583 error = fdalloc(td, 0, &indx); 3584 if (error != 0) { 3585 FILEDESC_XUNLOCK(fdp); 3586 return (error); 3587 } 3588 3589 /* 3590 * There are two cases of interest here. 3591 * 3592 * For ENODEV simply dup (dfd) to file descriptor (indx) and return. 3593 * 3594 * For ENXIO steal away the file structure from (dfd) and store it in 3595 * (indx). (dfd) is effectively closed by this operation. 3596 */ 3597 switch (openerror) { 3598 case ENODEV: 3599 /* 3600 * Check that the mode the file is being opened for is a 3601 * subset of the mode of the existing descriptor. 3602 */ 3603 if (((mode & (FREAD|FWRITE)) | fp->f_flag) != fp->f_flag) { 3604 fdunused(fdp, indx); 3605 FILEDESC_XUNLOCK(fdp); 3606 return (EACCES); 3607 } 3608 if (!fhold(fp)) { 3609 fdunused(fdp, indx); 3610 FILEDESC_XUNLOCK(fdp); 3611 return (EBADF); 3612 } 3613 newfde = &fdp->fd_ofiles[indx]; 3614 oldfde = &fdp->fd_ofiles[dfd]; 3615 ioctls = filecaps_copy_prep(&oldfde->fde_caps); 3616 #ifdef CAPABILITIES 3617 seqc_write_begin(&newfde->fde_seqc); 3618 #endif 3619 memcpy(newfde, oldfde, fde_change_size); 3620 filecaps_copy_finish(&oldfde->fde_caps, &newfde->fde_caps, 3621 ioctls); 3622 #ifdef CAPABILITIES 3623 seqc_write_end(&newfde->fde_seqc); 3624 #endif 3625 break; 3626 case ENXIO: 3627 /* 3628 * Steal away the file pointer from dfd and stuff it into indx. 3629 */ 3630 newfde = &fdp->fd_ofiles[indx]; 3631 oldfde = &fdp->fd_ofiles[dfd]; 3632 #ifdef CAPABILITIES 3633 seqc_write_begin(&newfde->fde_seqc); 3634 #endif 3635 memcpy(newfde, oldfde, fde_change_size); 3636 oldfde->fde_file = NULL; 3637 fdunused(fdp, dfd); 3638 #ifdef CAPABILITIES 3639 seqc_write_end(&newfde->fde_seqc); 3640 #endif 3641 break; 3642 } 3643 FILEDESC_XUNLOCK(fdp); 3644 *indxp = indx; 3645 return (0); 3646 } 3647 3648 /* 3649 * This sysctl determines if we will allow a process to chroot(2) if it 3650 * has a directory open: 3651 * 0: disallowed for all processes. 3652 * 1: allowed for processes that were not already chroot(2)'ed. 3653 * 2: allowed for all processes. 3654 */ 3655 3656 static int chroot_allow_open_directories = 1; 3657 3658 SYSCTL_INT(_kern, OID_AUTO, chroot_allow_open_directories, CTLFLAG_RW, 3659 &chroot_allow_open_directories, 0, 3660 "Allow a process to chroot(2) if it has a directory open"); 3661 3662 /* 3663 * Helper function for raised chroot(2) security function: Refuse if 3664 * any filedescriptors are open directories. 3665 */ 3666 static int 3667 chroot_refuse_vdir_fds(struct filedesc *fdp) 3668 { 3669 struct vnode *vp; 3670 struct file *fp; 3671 int fd, lastfile; 3672 3673 FILEDESC_LOCK_ASSERT(fdp); 3674 3675 lastfile = fdlastfile(fdp); 3676 for (fd = 0; fd <= lastfile; fd++) { 3677 fp = fget_locked(fdp, fd); 3678 if (fp == NULL) 3679 continue; 3680 if (fp->f_type == DTYPE_VNODE) { 3681 vp = fp->f_vnode; 3682 if (vp->v_type == VDIR) 3683 return (EPERM); 3684 } 3685 } 3686 return (0); 3687 } 3688 3689 static void 3690 pwd_fill(struct pwd *oldpwd, struct pwd *newpwd) 3691 { 3692 3693 if (newpwd->pwd_cdir == NULL && oldpwd->pwd_cdir != NULL) { 3694 vrefact(oldpwd->pwd_cdir); 3695 newpwd->pwd_cdir = oldpwd->pwd_cdir; 3696 } 3697 3698 if (newpwd->pwd_rdir == NULL && oldpwd->pwd_rdir != NULL) { 3699 vrefact(oldpwd->pwd_rdir); 3700 newpwd->pwd_rdir = oldpwd->pwd_rdir; 3701 } 3702 3703 if (newpwd->pwd_jdir == NULL && oldpwd->pwd_jdir != NULL) { 3704 vrefact(oldpwd->pwd_jdir); 3705 newpwd->pwd_jdir = oldpwd->pwd_jdir; 3706 } 3707 } 3708 3709 struct pwd * 3710 pwd_hold_pwddesc(struct pwddesc *pdp) 3711 { 3712 struct pwd *pwd; 3713 3714 PWDDESC_ASSERT_XLOCKED(pdp); 3715 pwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); 3716 if (pwd != NULL) 3717 refcount_acquire(&pwd->pwd_refcount); 3718 return (pwd); 3719 } 3720 3721 bool 3722 pwd_hold_smr(struct pwd *pwd) 3723 { 3724 3725 MPASS(pwd != NULL); 3726 if (__predict_true(refcount_acquire_if_not_zero(&pwd->pwd_refcount))) { 3727 return (true); 3728 } 3729 return (false); 3730 } 3731 3732 struct pwd * 3733 pwd_hold(struct thread *td) 3734 { 3735 struct pwddesc *pdp; 3736 struct pwd *pwd; 3737 3738 pdp = td->td_proc->p_pd; 3739 3740 vfs_smr_enter(); 3741 pwd = vfs_smr_entered_load(&pdp->pd_pwd); 3742 if (pwd_hold_smr(pwd)) { 3743 vfs_smr_exit(); 3744 return (pwd); 3745 } 3746 vfs_smr_exit(); 3747 PWDDESC_XLOCK(pdp); 3748 pwd = pwd_hold_pwddesc(pdp); 3749 MPASS(pwd != NULL); 3750 PWDDESC_XUNLOCK(pdp); 3751 return (pwd); 3752 } 3753 3754 struct pwd * 3755 pwd_hold_proc(struct proc *p) 3756 { 3757 struct pwddesc *pdp; 3758 struct pwd *pwd; 3759 3760 PROC_ASSERT_HELD(p); 3761 PROC_LOCK(p); 3762 pdp = pdhold(p); 3763 MPASS(pdp != NULL); 3764 PROC_UNLOCK(p); 3765 3766 PWDDESC_XLOCK(pdp); 3767 pwd = pwd_hold_pwddesc(pdp); 3768 MPASS(pwd != NULL); 3769 PWDDESC_XUNLOCK(pdp); 3770 pddrop(pdp); 3771 return (pwd); 3772 } 3773 3774 static struct pwd * 3775 pwd_alloc(void) 3776 { 3777 struct pwd *pwd; 3778 3779 pwd = uma_zalloc_smr(pwd_zone, M_WAITOK); 3780 bzero(pwd, sizeof(*pwd)); 3781 refcount_init(&pwd->pwd_refcount, 1); 3782 return (pwd); 3783 } 3784 3785 void 3786 pwd_drop(struct pwd *pwd) 3787 { 3788 3789 if (!refcount_release(&pwd->pwd_refcount)) 3790 return; 3791 3792 if (pwd->pwd_cdir != NULL) 3793 vrele(pwd->pwd_cdir); 3794 if (pwd->pwd_rdir != NULL) 3795 vrele(pwd->pwd_rdir); 3796 if (pwd->pwd_jdir != NULL) 3797 vrele(pwd->pwd_jdir); 3798 uma_zfree_smr(pwd_zone, pwd); 3799 } 3800 3801 /* 3802 * The caller is responsible for invoking priv_check() and 3803 * mac_vnode_check_chroot() to authorize this operation. 3804 */ 3805 int 3806 pwd_chroot(struct thread *td, struct vnode *vp) 3807 { 3808 struct pwddesc *pdp; 3809 struct filedesc *fdp; 3810 struct pwd *newpwd, *oldpwd; 3811 int error; 3812 3813 fdp = td->td_proc->p_fd; 3814 pdp = td->td_proc->p_pd; 3815 newpwd = pwd_alloc(); 3816 FILEDESC_SLOCK(fdp); 3817 PWDDESC_XLOCK(pdp); 3818 oldpwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); 3819 if (chroot_allow_open_directories == 0 || 3820 (chroot_allow_open_directories == 1 && 3821 oldpwd->pwd_rdir != rootvnode)) { 3822 error = chroot_refuse_vdir_fds(fdp); 3823 FILEDESC_SUNLOCK(fdp); 3824 if (error != 0) { 3825 PWDDESC_XUNLOCK(pdp); 3826 pwd_drop(newpwd); 3827 return (error); 3828 } 3829 } else { 3830 FILEDESC_SUNLOCK(fdp); 3831 } 3832 3833 vrefact(vp); 3834 newpwd->pwd_rdir = vp; 3835 if (oldpwd->pwd_jdir == NULL) { 3836 vrefact(vp); 3837 newpwd->pwd_jdir = vp; 3838 } 3839 pwd_fill(oldpwd, newpwd); 3840 pwd_set(pdp, newpwd); 3841 PWDDESC_XUNLOCK(pdp); 3842 pwd_drop(oldpwd); 3843 return (0); 3844 } 3845 3846 void 3847 pwd_chdir(struct thread *td, struct vnode *vp) 3848 { 3849 struct pwddesc *pdp; 3850 struct pwd *newpwd, *oldpwd; 3851 3852 VNPASS(vp->v_usecount > 0, vp); 3853 3854 newpwd = pwd_alloc(); 3855 pdp = td->td_proc->p_pd; 3856 PWDDESC_XLOCK(pdp); 3857 oldpwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); 3858 newpwd->pwd_cdir = vp; 3859 pwd_fill(oldpwd, newpwd); 3860 pwd_set(pdp, newpwd); 3861 PWDDESC_XUNLOCK(pdp); 3862 pwd_drop(oldpwd); 3863 } 3864 3865 /* 3866 * jail_attach(2) changes both root and working directories. 3867 */ 3868 int 3869 pwd_chroot_chdir(struct thread *td, struct vnode *vp) 3870 { 3871 struct pwddesc *pdp; 3872 struct filedesc *fdp; 3873 struct pwd *newpwd, *oldpwd; 3874 int error; 3875 3876 fdp = td->td_proc->p_fd; 3877 pdp = td->td_proc->p_pd; 3878 newpwd = pwd_alloc(); 3879 FILEDESC_SLOCK(fdp); 3880 PWDDESC_XLOCK(pdp); 3881 oldpwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); 3882 error = chroot_refuse_vdir_fds(fdp); 3883 FILEDESC_SUNLOCK(fdp); 3884 if (error != 0) { 3885 PWDDESC_XUNLOCK(pdp); 3886 pwd_drop(newpwd); 3887 return (error); 3888 } 3889 3890 vrefact(vp); 3891 newpwd->pwd_rdir = vp; 3892 vrefact(vp); 3893 newpwd->pwd_cdir = vp; 3894 if (oldpwd->pwd_jdir == NULL) { 3895 vrefact(vp); 3896 newpwd->pwd_jdir = vp; 3897 } 3898 pwd_fill(oldpwd, newpwd); 3899 pwd_set(pdp, newpwd); 3900 PWDDESC_XUNLOCK(pdp); 3901 pwd_drop(oldpwd); 3902 return (0); 3903 } 3904 3905 void 3906 pwd_ensure_dirs(void) 3907 { 3908 struct pwddesc *pdp; 3909 struct pwd *oldpwd, *newpwd; 3910 3911 pdp = curproc->p_pd; 3912 PWDDESC_XLOCK(pdp); 3913 oldpwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); 3914 if (oldpwd->pwd_cdir != NULL && oldpwd->pwd_rdir != NULL) { 3915 PWDDESC_XUNLOCK(pdp); 3916 return; 3917 } 3918 PWDDESC_XUNLOCK(pdp); 3919 3920 newpwd = pwd_alloc(); 3921 PWDDESC_XLOCK(pdp); 3922 oldpwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); 3923 pwd_fill(oldpwd, newpwd); 3924 if (newpwd->pwd_cdir == NULL) { 3925 vrefact(rootvnode); 3926 newpwd->pwd_cdir = rootvnode; 3927 } 3928 if (newpwd->pwd_rdir == NULL) { 3929 vrefact(rootvnode); 3930 newpwd->pwd_rdir = rootvnode; 3931 } 3932 pwd_set(pdp, newpwd); 3933 PWDDESC_XUNLOCK(pdp); 3934 pwd_drop(oldpwd); 3935 } 3936 3937 void 3938 pwd_set_rootvnode(void) 3939 { 3940 struct pwddesc *pdp; 3941 struct pwd *oldpwd, *newpwd; 3942 3943 pdp = curproc->p_pd; 3944 3945 newpwd = pwd_alloc(); 3946 PWDDESC_XLOCK(pdp); 3947 oldpwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); 3948 vrefact(rootvnode); 3949 newpwd->pwd_cdir = rootvnode; 3950 vrefact(rootvnode); 3951 newpwd->pwd_rdir = rootvnode; 3952 pwd_fill(oldpwd, newpwd); 3953 pwd_set(pdp, newpwd); 3954 PWDDESC_XUNLOCK(pdp); 3955 pwd_drop(oldpwd); 3956 } 3957 3958 /* 3959 * Scan all active processes and prisons to see if any of them have a current 3960 * or root directory of `olddp'. If so, replace them with the new mount point. 3961 */ 3962 void 3963 mountcheckdirs(struct vnode *olddp, struct vnode *newdp) 3964 { 3965 struct pwddesc *pdp; 3966 struct pwd *newpwd, *oldpwd; 3967 struct prison *pr; 3968 struct proc *p; 3969 int nrele; 3970 3971 if (vrefcnt(olddp) == 1) 3972 return; 3973 nrele = 0; 3974 newpwd = pwd_alloc(); 3975 sx_slock(&allproc_lock); 3976 FOREACH_PROC_IN_SYSTEM(p) { 3977 PROC_LOCK(p); 3978 pdp = pdhold(p); 3979 PROC_UNLOCK(p); 3980 if (pdp == NULL) 3981 continue; 3982 PWDDESC_XLOCK(pdp); 3983 oldpwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); 3984 if (oldpwd == NULL || 3985 (oldpwd->pwd_cdir != olddp && 3986 oldpwd->pwd_rdir != olddp && 3987 oldpwd->pwd_jdir != olddp)) { 3988 PWDDESC_XUNLOCK(pdp); 3989 pddrop(pdp); 3990 continue; 3991 } 3992 if (oldpwd->pwd_cdir == olddp) { 3993 vrefact(newdp); 3994 newpwd->pwd_cdir = newdp; 3995 } 3996 if (oldpwd->pwd_rdir == olddp) { 3997 vrefact(newdp); 3998 newpwd->pwd_rdir = newdp; 3999 } 4000 if (oldpwd->pwd_jdir == olddp) { 4001 vrefact(newdp); 4002 newpwd->pwd_jdir = newdp; 4003 } 4004 pwd_fill(oldpwd, newpwd); 4005 pwd_set(pdp, newpwd); 4006 PWDDESC_XUNLOCK(pdp); 4007 pwd_drop(oldpwd); 4008 pddrop(pdp); 4009 newpwd = pwd_alloc(); 4010 } 4011 sx_sunlock(&allproc_lock); 4012 pwd_drop(newpwd); 4013 if (rootvnode == olddp) { 4014 vrefact(newdp); 4015 rootvnode = newdp; 4016 nrele++; 4017 } 4018 mtx_lock(&prison0.pr_mtx); 4019 if (prison0.pr_root == olddp) { 4020 vrefact(newdp); 4021 prison0.pr_root = newdp; 4022 nrele++; 4023 } 4024 mtx_unlock(&prison0.pr_mtx); 4025 sx_slock(&allprison_lock); 4026 TAILQ_FOREACH(pr, &allprison, pr_list) { 4027 mtx_lock(&pr->pr_mtx); 4028 if (pr->pr_root == olddp) { 4029 vrefact(newdp); 4030 pr->pr_root = newdp; 4031 nrele++; 4032 } 4033 mtx_unlock(&pr->pr_mtx); 4034 } 4035 sx_sunlock(&allprison_lock); 4036 while (nrele--) 4037 vrele(olddp); 4038 } 4039 4040 struct filedesc_to_leader * 4041 filedesc_to_leader_alloc(struct filedesc_to_leader *old, struct filedesc *fdp, struct proc *leader) 4042 { 4043 struct filedesc_to_leader *fdtol; 4044 4045 fdtol = malloc(sizeof(struct filedesc_to_leader), 4046 M_FILEDESC_TO_LEADER, M_WAITOK); 4047 fdtol->fdl_refcount = 1; 4048 fdtol->fdl_holdcount = 0; 4049 fdtol->fdl_wakeup = 0; 4050 fdtol->fdl_leader = leader; 4051 if (old != NULL) { 4052 FILEDESC_XLOCK(fdp); 4053 fdtol->fdl_next = old->fdl_next; 4054 fdtol->fdl_prev = old; 4055 old->fdl_next = fdtol; 4056 fdtol->fdl_next->fdl_prev = fdtol; 4057 FILEDESC_XUNLOCK(fdp); 4058 } else { 4059 fdtol->fdl_next = fdtol; 4060 fdtol->fdl_prev = fdtol; 4061 } 4062 return (fdtol); 4063 } 4064 4065 static int 4066 sysctl_kern_proc_nfds(SYSCTL_HANDLER_ARGS) 4067 { 4068 NDSLOTTYPE *map; 4069 struct filedesc *fdp; 4070 u_int namelen; 4071 int count, off, minoff; 4072 4073 namelen = arg2; 4074 if (namelen != 1) 4075 return (EINVAL); 4076 4077 if (*(int *)arg1 != 0) 4078 return (EINVAL); 4079 4080 fdp = curproc->p_fd; 4081 count = 0; 4082 FILEDESC_SLOCK(fdp); 4083 map = fdp->fd_map; 4084 off = NDSLOT(fdp->fd_nfiles - 1); 4085 for (minoff = NDSLOT(0); off >= minoff; --off) 4086 count += bitcountl(map[off]); 4087 FILEDESC_SUNLOCK(fdp); 4088 4089 return (SYSCTL_OUT(req, &count, sizeof(count))); 4090 } 4091 4092 static SYSCTL_NODE(_kern_proc, KERN_PROC_NFDS, nfds, 4093 CTLFLAG_RD|CTLFLAG_CAPRD|CTLFLAG_MPSAFE, sysctl_kern_proc_nfds, 4094 "Number of open file descriptors"); 4095 4096 /* 4097 * Get file structures globally. 4098 */ 4099 static int 4100 sysctl_kern_file(SYSCTL_HANDLER_ARGS) 4101 { 4102 struct xfile xf; 4103 struct filedesc *fdp; 4104 struct file *fp; 4105 struct proc *p; 4106 int error, n, lastfile; 4107 4108 error = sysctl_wire_old_buffer(req, 0); 4109 if (error != 0) 4110 return (error); 4111 if (req->oldptr == NULL) { 4112 n = 0; 4113 sx_slock(&allproc_lock); 4114 FOREACH_PROC_IN_SYSTEM(p) { 4115 PROC_LOCK(p); 4116 if (p->p_state == PRS_NEW) { 4117 PROC_UNLOCK(p); 4118 continue; 4119 } 4120 fdp = fdhold(p); 4121 PROC_UNLOCK(p); 4122 if (fdp == NULL) 4123 continue; 4124 /* overestimates sparse tables. */ 4125 n += fdp->fd_nfiles; 4126 fddrop(fdp); 4127 } 4128 sx_sunlock(&allproc_lock); 4129 return (SYSCTL_OUT(req, 0, n * sizeof(xf))); 4130 } 4131 error = 0; 4132 bzero(&xf, sizeof(xf)); 4133 xf.xf_size = sizeof(xf); 4134 sx_slock(&allproc_lock); 4135 FOREACH_PROC_IN_SYSTEM(p) { 4136 PROC_LOCK(p); 4137 if (p->p_state == PRS_NEW) { 4138 PROC_UNLOCK(p); 4139 continue; 4140 } 4141 if (p_cansee(req->td, p) != 0) { 4142 PROC_UNLOCK(p); 4143 continue; 4144 } 4145 xf.xf_pid = p->p_pid; 4146 xf.xf_uid = p->p_ucred->cr_uid; 4147 fdp = fdhold(p); 4148 PROC_UNLOCK(p); 4149 if (fdp == NULL) 4150 continue; 4151 FILEDESC_SLOCK(fdp); 4152 lastfile = fdlastfile(fdp); 4153 for (n = 0; refcount_load(&fdp->fd_refcnt) > 0 && n <= lastfile; 4154 n++) { 4155 if ((fp = fdp->fd_ofiles[n].fde_file) == NULL) 4156 continue; 4157 xf.xf_fd = n; 4158 xf.xf_file = (uintptr_t)fp; 4159 xf.xf_data = (uintptr_t)fp->f_data; 4160 xf.xf_vnode = (uintptr_t)fp->f_vnode; 4161 xf.xf_type = (uintptr_t)fp->f_type; 4162 xf.xf_count = refcount_load(&fp->f_count); 4163 xf.xf_msgcount = 0; 4164 xf.xf_offset = foffset_get(fp); 4165 xf.xf_flag = fp->f_flag; 4166 error = SYSCTL_OUT(req, &xf, sizeof(xf)); 4167 if (error) 4168 break; 4169 } 4170 FILEDESC_SUNLOCK(fdp); 4171 fddrop(fdp); 4172 if (error) 4173 break; 4174 } 4175 sx_sunlock(&allproc_lock); 4176 return (error); 4177 } 4178 4179 SYSCTL_PROC(_kern, KERN_FILE, file, CTLTYPE_OPAQUE|CTLFLAG_RD|CTLFLAG_MPSAFE, 4180 0, 0, sysctl_kern_file, "S,xfile", "Entire file table"); 4181 4182 #ifdef KINFO_FILE_SIZE 4183 CTASSERT(sizeof(struct kinfo_file) == KINFO_FILE_SIZE); 4184 #endif 4185 4186 static int 4187 xlate_fflags(int fflags) 4188 { 4189 static const struct { 4190 int fflag; 4191 int kf_fflag; 4192 } fflags_table[] = { 4193 { FAPPEND, KF_FLAG_APPEND }, 4194 { FASYNC, KF_FLAG_ASYNC }, 4195 { FFSYNC, KF_FLAG_FSYNC }, 4196 { FHASLOCK, KF_FLAG_HASLOCK }, 4197 { FNONBLOCK, KF_FLAG_NONBLOCK }, 4198 { FREAD, KF_FLAG_READ }, 4199 { FWRITE, KF_FLAG_WRITE }, 4200 { O_CREAT, KF_FLAG_CREAT }, 4201 { O_DIRECT, KF_FLAG_DIRECT }, 4202 { O_EXCL, KF_FLAG_EXCL }, 4203 { O_EXEC, KF_FLAG_EXEC }, 4204 { O_EXLOCK, KF_FLAG_EXLOCK }, 4205 { O_NOFOLLOW, KF_FLAG_NOFOLLOW }, 4206 { O_SHLOCK, KF_FLAG_SHLOCK }, 4207 { O_TRUNC, KF_FLAG_TRUNC } 4208 }; 4209 unsigned int i; 4210 int kflags; 4211 4212 kflags = 0; 4213 for (i = 0; i < nitems(fflags_table); i++) 4214 if (fflags & fflags_table[i].fflag) 4215 kflags |= fflags_table[i].kf_fflag; 4216 return (kflags); 4217 } 4218 4219 /* Trim unused data from kf_path by truncating the structure size. */ 4220 void 4221 pack_kinfo(struct kinfo_file *kif) 4222 { 4223 4224 kif->kf_structsize = offsetof(struct kinfo_file, kf_path) + 4225 strlen(kif->kf_path) + 1; 4226 kif->kf_structsize = roundup(kif->kf_structsize, sizeof(uint64_t)); 4227 } 4228 4229 static void 4230 export_file_to_kinfo(struct file *fp, int fd, cap_rights_t *rightsp, 4231 struct kinfo_file *kif, struct filedesc *fdp, int flags) 4232 { 4233 int error; 4234 4235 bzero(kif, sizeof(*kif)); 4236 4237 /* Set a default type to allow for empty fill_kinfo() methods. */ 4238 kif->kf_type = KF_TYPE_UNKNOWN; 4239 kif->kf_flags = xlate_fflags(fp->f_flag); 4240 if (rightsp != NULL) 4241 kif->kf_cap_rights = *rightsp; 4242 else 4243 cap_rights_init_zero(&kif->kf_cap_rights); 4244 kif->kf_fd = fd; 4245 kif->kf_ref_count = refcount_load(&fp->f_count); 4246 kif->kf_offset = foffset_get(fp); 4247 4248 /* 4249 * This may drop the filedesc lock, so the 'fp' cannot be 4250 * accessed after this call. 4251 */ 4252 error = fo_fill_kinfo(fp, kif, fdp); 4253 if (error == 0) 4254 kif->kf_status |= KF_ATTR_VALID; 4255 if ((flags & KERN_FILEDESC_PACK_KINFO) != 0) 4256 pack_kinfo(kif); 4257 else 4258 kif->kf_structsize = roundup2(sizeof(*kif), sizeof(uint64_t)); 4259 } 4260 4261 static void 4262 export_vnode_to_kinfo(struct vnode *vp, int fd, int fflags, 4263 struct kinfo_file *kif, int flags) 4264 { 4265 int error; 4266 4267 bzero(kif, sizeof(*kif)); 4268 4269 kif->kf_type = KF_TYPE_VNODE; 4270 error = vn_fill_kinfo_vnode(vp, kif); 4271 if (error == 0) 4272 kif->kf_status |= KF_ATTR_VALID; 4273 kif->kf_flags = xlate_fflags(fflags); 4274 cap_rights_init_zero(&kif->kf_cap_rights); 4275 kif->kf_fd = fd; 4276 kif->kf_ref_count = -1; 4277 kif->kf_offset = -1; 4278 if ((flags & KERN_FILEDESC_PACK_KINFO) != 0) 4279 pack_kinfo(kif); 4280 else 4281 kif->kf_structsize = roundup2(sizeof(*kif), sizeof(uint64_t)); 4282 vrele(vp); 4283 } 4284 4285 struct export_fd_buf { 4286 struct filedesc *fdp; 4287 struct pwddesc *pdp; 4288 struct sbuf *sb; 4289 ssize_t remainder; 4290 struct kinfo_file kif; 4291 int flags; 4292 }; 4293 4294 static int 4295 export_kinfo_to_sb(struct export_fd_buf *efbuf) 4296 { 4297 struct kinfo_file *kif; 4298 4299 kif = &efbuf->kif; 4300 if (efbuf->remainder != -1) { 4301 if (efbuf->remainder < kif->kf_structsize) 4302 return (ENOMEM); 4303 efbuf->remainder -= kif->kf_structsize; 4304 } 4305 if (sbuf_bcat(efbuf->sb, kif, kif->kf_structsize) != 0) 4306 return (sbuf_error(efbuf->sb)); 4307 return (0); 4308 } 4309 4310 static int 4311 export_file_to_sb(struct file *fp, int fd, cap_rights_t *rightsp, 4312 struct export_fd_buf *efbuf) 4313 { 4314 int error; 4315 4316 if (efbuf->remainder == 0) 4317 return (ENOMEM); 4318 export_file_to_kinfo(fp, fd, rightsp, &efbuf->kif, efbuf->fdp, 4319 efbuf->flags); 4320 FILEDESC_SUNLOCK(efbuf->fdp); 4321 error = export_kinfo_to_sb(efbuf); 4322 FILEDESC_SLOCK(efbuf->fdp); 4323 return (error); 4324 } 4325 4326 static int 4327 export_vnode_to_sb(struct vnode *vp, int fd, int fflags, 4328 struct export_fd_buf *efbuf) 4329 { 4330 int error; 4331 4332 if (efbuf->remainder == 0) 4333 return (ENOMEM); 4334 if (efbuf->pdp != NULL) 4335 PWDDESC_XUNLOCK(efbuf->pdp); 4336 export_vnode_to_kinfo(vp, fd, fflags, &efbuf->kif, efbuf->flags); 4337 error = export_kinfo_to_sb(efbuf); 4338 if (efbuf->pdp != NULL) 4339 PWDDESC_XLOCK(efbuf->pdp); 4340 return (error); 4341 } 4342 4343 /* 4344 * Store a process file descriptor information to sbuf. 4345 * 4346 * Takes a locked proc as argument, and returns with the proc unlocked. 4347 */ 4348 int 4349 kern_proc_filedesc_out(struct proc *p, struct sbuf *sb, ssize_t maxlen, 4350 int flags) 4351 { 4352 struct file *fp; 4353 struct filedesc *fdp; 4354 struct pwddesc *pdp; 4355 struct export_fd_buf *efbuf; 4356 struct vnode *cttyvp, *textvp, *tracevp; 4357 struct pwd *pwd; 4358 int error, i, lastfile; 4359 cap_rights_t rights; 4360 4361 PROC_LOCK_ASSERT(p, MA_OWNED); 4362 4363 /* ktrace vnode */ 4364 tracevp = ktr_get_tracevp(p, true); 4365 /* text vnode */ 4366 textvp = p->p_textvp; 4367 if (textvp != NULL) 4368 vrefact(textvp); 4369 /* Controlling tty. */ 4370 cttyvp = NULL; 4371 if (p->p_pgrp != NULL && p->p_pgrp->pg_session != NULL) { 4372 cttyvp = p->p_pgrp->pg_session->s_ttyvp; 4373 if (cttyvp != NULL) 4374 vrefact(cttyvp); 4375 } 4376 fdp = fdhold(p); 4377 pdp = pdhold(p); 4378 PROC_UNLOCK(p); 4379 4380 efbuf = malloc(sizeof(*efbuf), M_TEMP, M_WAITOK); 4381 efbuf->fdp = NULL; 4382 efbuf->pdp = NULL; 4383 efbuf->sb = sb; 4384 efbuf->remainder = maxlen; 4385 efbuf->flags = flags; 4386 4387 error = 0; 4388 if (tracevp != NULL) 4389 error = export_vnode_to_sb(tracevp, KF_FD_TYPE_TRACE, 4390 FREAD | FWRITE, efbuf); 4391 if (error == 0 && textvp != NULL) 4392 error = export_vnode_to_sb(textvp, KF_FD_TYPE_TEXT, FREAD, 4393 efbuf); 4394 if (error == 0 && cttyvp != NULL) 4395 error = export_vnode_to_sb(cttyvp, KF_FD_TYPE_CTTY, 4396 FREAD | FWRITE, efbuf); 4397 if (error != 0 || pdp == NULL || fdp == NULL) 4398 goto fail; 4399 efbuf->fdp = fdp; 4400 efbuf->pdp = pdp; 4401 PWDDESC_XLOCK(pdp); 4402 pwd = pwd_hold_pwddesc(pdp); 4403 if (pwd != NULL) { 4404 /* working directory */ 4405 if (pwd->pwd_cdir != NULL) { 4406 vrefact(pwd->pwd_cdir); 4407 error = export_vnode_to_sb(pwd->pwd_cdir, 4408 KF_FD_TYPE_CWD, FREAD, efbuf); 4409 } 4410 /* root directory */ 4411 if (error == 0 && pwd->pwd_rdir != NULL) { 4412 vrefact(pwd->pwd_rdir); 4413 error = export_vnode_to_sb(pwd->pwd_rdir, 4414 KF_FD_TYPE_ROOT, FREAD, efbuf); 4415 } 4416 /* jail directory */ 4417 if (error == 0 && pwd->pwd_jdir != NULL) { 4418 vrefact(pwd->pwd_jdir); 4419 error = export_vnode_to_sb(pwd->pwd_jdir, 4420 KF_FD_TYPE_JAIL, FREAD, efbuf); 4421 } 4422 } 4423 PWDDESC_XUNLOCK(pdp); 4424 if (error != 0) 4425 goto fail; 4426 if (pwd != NULL) 4427 pwd_drop(pwd); 4428 FILEDESC_SLOCK(fdp); 4429 lastfile = fdlastfile(fdp); 4430 for (i = 0; refcount_load(&fdp->fd_refcnt) > 0 && i <= lastfile; i++) { 4431 if ((fp = fdp->fd_ofiles[i].fde_file) == NULL) 4432 continue; 4433 #ifdef CAPABILITIES 4434 rights = *cap_rights(fdp, i); 4435 #else /* !CAPABILITIES */ 4436 rights = cap_no_rights; 4437 #endif 4438 /* 4439 * Create sysctl entry. It is OK to drop the filedesc 4440 * lock inside of export_file_to_sb() as we will 4441 * re-validate and re-evaluate its properties when the 4442 * loop continues. 4443 */ 4444 error = export_file_to_sb(fp, i, &rights, efbuf); 4445 if (error != 0) 4446 break; 4447 } 4448 FILEDESC_SUNLOCK(fdp); 4449 fail: 4450 if (fdp != NULL) 4451 fddrop(fdp); 4452 if (pdp != NULL) 4453 pddrop(pdp); 4454 free(efbuf, M_TEMP); 4455 return (error); 4456 } 4457 4458 #define FILEDESC_SBUF_SIZE (sizeof(struct kinfo_file) * 5) 4459 4460 /* 4461 * Get per-process file descriptors for use by procstat(1), et al. 4462 */ 4463 static int 4464 sysctl_kern_proc_filedesc(SYSCTL_HANDLER_ARGS) 4465 { 4466 struct sbuf sb; 4467 struct proc *p; 4468 ssize_t maxlen; 4469 u_int namelen; 4470 int error, error2, *name; 4471 4472 namelen = arg2; 4473 if (namelen != 1) 4474 return (EINVAL); 4475 4476 name = (int *)arg1; 4477 4478 sbuf_new_for_sysctl(&sb, NULL, FILEDESC_SBUF_SIZE, req); 4479 sbuf_clear_flags(&sb, SBUF_INCLUDENUL); 4480 error = pget((pid_t)name[0], PGET_CANDEBUG | PGET_NOTWEXIT, &p); 4481 if (error != 0) { 4482 sbuf_delete(&sb); 4483 return (error); 4484 } 4485 maxlen = req->oldptr != NULL ? req->oldlen : -1; 4486 error = kern_proc_filedesc_out(p, &sb, maxlen, 4487 KERN_FILEDESC_PACK_KINFO); 4488 error2 = sbuf_finish(&sb); 4489 sbuf_delete(&sb); 4490 return (error != 0 ? error : error2); 4491 } 4492 4493 #ifdef COMPAT_FREEBSD7 4494 #ifdef KINFO_OFILE_SIZE 4495 CTASSERT(sizeof(struct kinfo_ofile) == KINFO_OFILE_SIZE); 4496 #endif 4497 4498 static void 4499 kinfo_to_okinfo(struct kinfo_file *kif, struct kinfo_ofile *okif) 4500 { 4501 4502 okif->kf_structsize = sizeof(*okif); 4503 okif->kf_type = kif->kf_type; 4504 okif->kf_fd = kif->kf_fd; 4505 okif->kf_ref_count = kif->kf_ref_count; 4506 okif->kf_flags = kif->kf_flags & (KF_FLAG_READ | KF_FLAG_WRITE | 4507 KF_FLAG_APPEND | KF_FLAG_ASYNC | KF_FLAG_FSYNC | KF_FLAG_NONBLOCK | 4508 KF_FLAG_DIRECT | KF_FLAG_HASLOCK); 4509 okif->kf_offset = kif->kf_offset; 4510 if (kif->kf_type == KF_TYPE_VNODE) 4511 okif->kf_vnode_type = kif->kf_un.kf_file.kf_file_type; 4512 else 4513 okif->kf_vnode_type = KF_VTYPE_VNON; 4514 strlcpy(okif->kf_path, kif->kf_path, sizeof(okif->kf_path)); 4515 if (kif->kf_type == KF_TYPE_SOCKET) { 4516 okif->kf_sock_domain = kif->kf_un.kf_sock.kf_sock_domain0; 4517 okif->kf_sock_type = kif->kf_un.kf_sock.kf_sock_type0; 4518 okif->kf_sock_protocol = kif->kf_un.kf_sock.kf_sock_protocol0; 4519 okif->kf_sa_local = kif->kf_un.kf_sock.kf_sa_local; 4520 okif->kf_sa_peer = kif->kf_un.kf_sock.kf_sa_peer; 4521 } else { 4522 okif->kf_sa_local.ss_family = AF_UNSPEC; 4523 okif->kf_sa_peer.ss_family = AF_UNSPEC; 4524 } 4525 } 4526 4527 static int 4528 export_vnode_for_osysctl(struct vnode *vp, int type, struct kinfo_file *kif, 4529 struct kinfo_ofile *okif, struct pwddesc *pdp, struct sysctl_req *req) 4530 { 4531 int error; 4532 4533 vrefact(vp); 4534 PWDDESC_XUNLOCK(pdp); 4535 export_vnode_to_kinfo(vp, type, 0, kif, KERN_FILEDESC_PACK_KINFO); 4536 kinfo_to_okinfo(kif, okif); 4537 error = SYSCTL_OUT(req, okif, sizeof(*okif)); 4538 PWDDESC_XLOCK(pdp); 4539 return (error); 4540 } 4541 4542 /* 4543 * Get per-process file descriptors for use by procstat(1), et al. 4544 */ 4545 static int 4546 sysctl_kern_proc_ofiledesc(SYSCTL_HANDLER_ARGS) 4547 { 4548 struct kinfo_ofile *okif; 4549 struct kinfo_file *kif; 4550 struct filedesc *fdp; 4551 struct pwddesc *pdp; 4552 struct pwd *pwd; 4553 u_int namelen; 4554 int error, i, lastfile, *name; 4555 struct file *fp; 4556 struct proc *p; 4557 4558 namelen = arg2; 4559 if (namelen != 1) 4560 return (EINVAL); 4561 4562 name = (int *)arg1; 4563 error = pget((pid_t)name[0], PGET_CANDEBUG | PGET_NOTWEXIT, &p); 4564 if (error != 0) 4565 return (error); 4566 fdp = fdhold(p); 4567 if (fdp != NULL) 4568 pdp = pdhold(p); 4569 PROC_UNLOCK(p); 4570 if (fdp == NULL || pdp == NULL) { 4571 if (fdp != NULL) 4572 fddrop(fdp); 4573 return (ENOENT); 4574 } 4575 kif = malloc(sizeof(*kif), M_TEMP, M_WAITOK); 4576 okif = malloc(sizeof(*okif), M_TEMP, M_WAITOK); 4577 PWDDESC_XLOCK(pdp); 4578 pwd = pwd_hold_pwddesc(pdp); 4579 if (pwd != NULL) { 4580 if (pwd->pwd_cdir != NULL) 4581 export_vnode_for_osysctl(pwd->pwd_cdir, KF_FD_TYPE_CWD, kif, 4582 okif, pdp, req); 4583 if (pwd->pwd_rdir != NULL) 4584 export_vnode_for_osysctl(pwd->pwd_rdir, KF_FD_TYPE_ROOT, kif, 4585 okif, pdp, req); 4586 if (pwd->pwd_jdir != NULL) 4587 export_vnode_for_osysctl(pwd->pwd_jdir, KF_FD_TYPE_JAIL, kif, 4588 okif, pdp, req); 4589 } 4590 PWDDESC_XUNLOCK(pdp); 4591 if (pwd != NULL) 4592 pwd_drop(pwd); 4593 FILEDESC_SLOCK(fdp); 4594 lastfile = fdlastfile(fdp); 4595 for (i = 0; refcount_load(&fdp->fd_refcnt) > 0 && i <= lastfile; i++) { 4596 if ((fp = fdp->fd_ofiles[i].fde_file) == NULL) 4597 continue; 4598 export_file_to_kinfo(fp, i, NULL, kif, fdp, 4599 KERN_FILEDESC_PACK_KINFO); 4600 FILEDESC_SUNLOCK(fdp); 4601 kinfo_to_okinfo(kif, okif); 4602 error = SYSCTL_OUT(req, okif, sizeof(*okif)); 4603 FILEDESC_SLOCK(fdp); 4604 if (error) 4605 break; 4606 } 4607 FILEDESC_SUNLOCK(fdp); 4608 fddrop(fdp); 4609 pddrop(pdp); 4610 free(kif, M_TEMP); 4611 free(okif, M_TEMP); 4612 return (0); 4613 } 4614 4615 static SYSCTL_NODE(_kern_proc, KERN_PROC_OFILEDESC, ofiledesc, 4616 CTLFLAG_RD|CTLFLAG_MPSAFE, sysctl_kern_proc_ofiledesc, 4617 "Process ofiledesc entries"); 4618 #endif /* COMPAT_FREEBSD7 */ 4619 4620 int 4621 vntype_to_kinfo(int vtype) 4622 { 4623 struct { 4624 int vtype; 4625 int kf_vtype; 4626 } vtypes_table[] = { 4627 { VBAD, KF_VTYPE_VBAD }, 4628 { VBLK, KF_VTYPE_VBLK }, 4629 { VCHR, KF_VTYPE_VCHR }, 4630 { VDIR, KF_VTYPE_VDIR }, 4631 { VFIFO, KF_VTYPE_VFIFO }, 4632 { VLNK, KF_VTYPE_VLNK }, 4633 { VNON, KF_VTYPE_VNON }, 4634 { VREG, KF_VTYPE_VREG }, 4635 { VSOCK, KF_VTYPE_VSOCK } 4636 }; 4637 unsigned int i; 4638 4639 /* 4640 * Perform vtype translation. 4641 */ 4642 for (i = 0; i < nitems(vtypes_table); i++) 4643 if (vtypes_table[i].vtype == vtype) 4644 return (vtypes_table[i].kf_vtype); 4645 4646 return (KF_VTYPE_UNKNOWN); 4647 } 4648 4649 static SYSCTL_NODE(_kern_proc, KERN_PROC_FILEDESC, filedesc, 4650 CTLFLAG_RD|CTLFLAG_MPSAFE, sysctl_kern_proc_filedesc, 4651 "Process filedesc entries"); 4652 4653 /* 4654 * Store a process current working directory information to sbuf. 4655 * 4656 * Takes a locked proc as argument, and returns with the proc unlocked. 4657 */ 4658 int 4659 kern_proc_cwd_out(struct proc *p, struct sbuf *sb, ssize_t maxlen) 4660 { 4661 struct pwddesc *pdp; 4662 struct pwd *pwd; 4663 struct export_fd_buf *efbuf; 4664 struct vnode *cdir; 4665 int error; 4666 4667 PROC_LOCK_ASSERT(p, MA_OWNED); 4668 4669 pdp = pdhold(p); 4670 PROC_UNLOCK(p); 4671 if (pdp == NULL) 4672 return (EINVAL); 4673 4674 efbuf = malloc(sizeof(*efbuf), M_TEMP, M_WAITOK); 4675 efbuf->fdp = NULL; 4676 efbuf->pdp = pdp; 4677 efbuf->sb = sb; 4678 efbuf->remainder = maxlen; 4679 efbuf->flags = 0; 4680 4681 PWDDESC_XLOCK(pdp); 4682 pwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); 4683 cdir = pwd->pwd_cdir; 4684 if (cdir == NULL) { 4685 error = EINVAL; 4686 } else { 4687 vrefact(cdir); 4688 error = export_vnode_to_sb(cdir, KF_FD_TYPE_CWD, FREAD, efbuf); 4689 } 4690 PWDDESC_XUNLOCK(pdp); 4691 pddrop(pdp); 4692 free(efbuf, M_TEMP); 4693 return (error); 4694 } 4695 4696 /* 4697 * Get per-process current working directory. 4698 */ 4699 static int 4700 sysctl_kern_proc_cwd(SYSCTL_HANDLER_ARGS) 4701 { 4702 struct sbuf sb; 4703 struct proc *p; 4704 ssize_t maxlen; 4705 u_int namelen; 4706 int error, error2, *name; 4707 4708 namelen = arg2; 4709 if (namelen != 1) 4710 return (EINVAL); 4711 4712 name = (int *)arg1; 4713 4714 sbuf_new_for_sysctl(&sb, NULL, sizeof(struct kinfo_file), req); 4715 sbuf_clear_flags(&sb, SBUF_INCLUDENUL); 4716 error = pget((pid_t)name[0], PGET_CANDEBUG | PGET_NOTWEXIT, &p); 4717 if (error != 0) { 4718 sbuf_delete(&sb); 4719 return (error); 4720 } 4721 maxlen = req->oldptr != NULL ? req->oldlen : -1; 4722 error = kern_proc_cwd_out(p, &sb, maxlen); 4723 error2 = sbuf_finish(&sb); 4724 sbuf_delete(&sb); 4725 return (error != 0 ? error : error2); 4726 } 4727 4728 static SYSCTL_NODE(_kern_proc, KERN_PROC_CWD, cwd, CTLFLAG_RD|CTLFLAG_MPSAFE, 4729 sysctl_kern_proc_cwd, "Process current working directory"); 4730 4731 #ifdef DDB 4732 /* 4733 * For the purposes of debugging, generate a human-readable string for the 4734 * file type. 4735 */ 4736 static const char * 4737 file_type_to_name(short type) 4738 { 4739 4740 switch (type) { 4741 case 0: 4742 return ("zero"); 4743 case DTYPE_VNODE: 4744 return ("vnode"); 4745 case DTYPE_SOCKET: 4746 return ("socket"); 4747 case DTYPE_PIPE: 4748 return ("pipe"); 4749 case DTYPE_FIFO: 4750 return ("fifo"); 4751 case DTYPE_KQUEUE: 4752 return ("kqueue"); 4753 case DTYPE_CRYPTO: 4754 return ("crypto"); 4755 case DTYPE_MQUEUE: 4756 return ("mqueue"); 4757 case DTYPE_SHM: 4758 return ("shm"); 4759 case DTYPE_SEM: 4760 return ("ksem"); 4761 case DTYPE_PTS: 4762 return ("pts"); 4763 case DTYPE_DEV: 4764 return ("dev"); 4765 case DTYPE_PROCDESC: 4766 return ("proc"); 4767 case DTYPE_EVENTFD: 4768 return ("eventfd"); 4769 case DTYPE_LINUXTFD: 4770 return ("ltimer"); 4771 default: 4772 return ("unkn"); 4773 } 4774 } 4775 4776 /* 4777 * For the purposes of debugging, identify a process (if any, perhaps one of 4778 * many) that references the passed file in its file descriptor array. Return 4779 * NULL if none. 4780 */ 4781 static struct proc * 4782 file_to_first_proc(struct file *fp) 4783 { 4784 struct filedesc *fdp; 4785 struct proc *p; 4786 int n; 4787 4788 FOREACH_PROC_IN_SYSTEM(p) { 4789 if (p->p_state == PRS_NEW) 4790 continue; 4791 fdp = p->p_fd; 4792 if (fdp == NULL) 4793 continue; 4794 for (n = 0; n < fdp->fd_nfiles; n++) { 4795 if (fp == fdp->fd_ofiles[n].fde_file) 4796 return (p); 4797 } 4798 } 4799 return (NULL); 4800 } 4801 4802 static void 4803 db_print_file(struct file *fp, int header) 4804 { 4805 #define XPTRWIDTH ((int)howmany(sizeof(void *) * NBBY, 4)) 4806 struct proc *p; 4807 4808 if (header) 4809 db_printf("%*s %6s %*s %8s %4s %5s %6s %*s %5s %s\n", 4810 XPTRWIDTH, "File", "Type", XPTRWIDTH, "Data", "Flag", 4811 "GCFl", "Count", "MCount", XPTRWIDTH, "Vnode", "FPID", 4812 "FCmd"); 4813 p = file_to_first_proc(fp); 4814 db_printf("%*p %6s %*p %08x %04x %5d %6d %*p %5d %s\n", XPTRWIDTH, 4815 fp, file_type_to_name(fp->f_type), XPTRWIDTH, fp->f_data, 4816 fp->f_flag, 0, refcount_load(&fp->f_count), 0, XPTRWIDTH, fp->f_vnode, 4817 p != NULL ? p->p_pid : -1, p != NULL ? p->p_comm : "-"); 4818 4819 #undef XPTRWIDTH 4820 } 4821 4822 DB_SHOW_COMMAND(file, db_show_file) 4823 { 4824 struct file *fp; 4825 4826 if (!have_addr) { 4827 db_printf("usage: show file <addr>\n"); 4828 return; 4829 } 4830 fp = (struct file *)addr; 4831 db_print_file(fp, 1); 4832 } 4833 4834 DB_SHOW_COMMAND(files, db_show_files) 4835 { 4836 struct filedesc *fdp; 4837 struct file *fp; 4838 struct proc *p; 4839 int header; 4840 int n; 4841 4842 header = 1; 4843 FOREACH_PROC_IN_SYSTEM(p) { 4844 if (p->p_state == PRS_NEW) 4845 continue; 4846 if ((fdp = p->p_fd) == NULL) 4847 continue; 4848 for (n = 0; n < fdp->fd_nfiles; ++n) { 4849 if ((fp = fdp->fd_ofiles[n].fde_file) == NULL) 4850 continue; 4851 db_print_file(fp, header); 4852 header = 0; 4853 } 4854 } 4855 } 4856 #endif 4857 4858 SYSCTL_INT(_kern, KERN_MAXFILESPERPROC, maxfilesperproc, CTLFLAG_RW, 4859 &maxfilesperproc, 0, "Maximum files allowed open per process"); 4860 4861 SYSCTL_INT(_kern, KERN_MAXFILES, maxfiles, CTLFLAG_RW, 4862 &maxfiles, 0, "Maximum number of files"); 4863 4864 SYSCTL_INT(_kern, OID_AUTO, openfiles, CTLFLAG_RD, 4865 &openfiles, 0, "System-wide number of open files"); 4866 4867 /* ARGSUSED*/ 4868 static void 4869 filelistinit(void *dummy) 4870 { 4871 4872 file_zone = uma_zcreate("Files", sizeof(struct file), NULL, NULL, 4873 NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE); 4874 filedesc0_zone = uma_zcreate("filedesc0", sizeof(struct filedesc0), 4875 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0); 4876 pwd_zone = uma_zcreate("PWD", sizeof(struct pwd), NULL, NULL, 4877 NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_SMR); 4878 /* 4879 * XXXMJG this is a temporary hack due to boot ordering issues against 4880 * the vnode zone. 4881 */ 4882 vfs_smr = uma_zone_get_smr(pwd_zone); 4883 mtx_init(&sigio_lock, "sigio lock", NULL, MTX_DEF); 4884 } 4885 SYSINIT(select, SI_SUB_LOCK, SI_ORDER_FIRST, filelistinit, NULL); 4886 4887 /*-------------------------------------------------------------------*/ 4888 4889 static int 4890 badfo_readwrite(struct file *fp, struct uio *uio, struct ucred *active_cred, 4891 int flags, struct thread *td) 4892 { 4893 4894 return (EBADF); 4895 } 4896 4897 static int 4898 badfo_truncate(struct file *fp, off_t length, struct ucred *active_cred, 4899 struct thread *td) 4900 { 4901 4902 return (EINVAL); 4903 } 4904 4905 static int 4906 badfo_ioctl(struct file *fp, u_long com, void *data, struct ucred *active_cred, 4907 struct thread *td) 4908 { 4909 4910 return (EBADF); 4911 } 4912 4913 static int 4914 badfo_poll(struct file *fp, int events, struct ucred *active_cred, 4915 struct thread *td) 4916 { 4917 4918 return (0); 4919 } 4920 4921 static int 4922 badfo_kqfilter(struct file *fp, struct knote *kn) 4923 { 4924 4925 return (EBADF); 4926 } 4927 4928 static int 4929 badfo_stat(struct file *fp, struct stat *sb, struct ucred *active_cred) 4930 { 4931 4932 return (EBADF); 4933 } 4934 4935 static int 4936 badfo_close(struct file *fp, struct thread *td) 4937 { 4938 4939 return (0); 4940 } 4941 4942 static int 4943 badfo_chmod(struct file *fp, mode_t mode, struct ucred *active_cred, 4944 struct thread *td) 4945 { 4946 4947 return (EBADF); 4948 } 4949 4950 static int 4951 badfo_chown(struct file *fp, uid_t uid, gid_t gid, struct ucred *active_cred, 4952 struct thread *td) 4953 { 4954 4955 return (EBADF); 4956 } 4957 4958 static int 4959 badfo_sendfile(struct file *fp, int sockfd, struct uio *hdr_uio, 4960 struct uio *trl_uio, off_t offset, size_t nbytes, off_t *sent, int flags, 4961 struct thread *td) 4962 { 4963 4964 return (EBADF); 4965 } 4966 4967 static int 4968 badfo_fill_kinfo(struct file *fp, struct kinfo_file *kif, struct filedesc *fdp) 4969 { 4970 4971 return (0); 4972 } 4973 4974 struct fileops badfileops = { 4975 .fo_read = badfo_readwrite, 4976 .fo_write = badfo_readwrite, 4977 .fo_truncate = badfo_truncate, 4978 .fo_ioctl = badfo_ioctl, 4979 .fo_poll = badfo_poll, 4980 .fo_kqfilter = badfo_kqfilter, 4981 .fo_stat = badfo_stat, 4982 .fo_close = badfo_close, 4983 .fo_chmod = badfo_chmod, 4984 .fo_chown = badfo_chown, 4985 .fo_sendfile = badfo_sendfile, 4986 .fo_fill_kinfo = badfo_fill_kinfo, 4987 }; 4988 4989 static int 4990 path_poll(struct file *fp, int events, struct ucred *active_cred, 4991 struct thread *td) 4992 { 4993 return (POLLNVAL); 4994 } 4995 4996 static int 4997 path_close(struct file *fp, struct thread *td) 4998 { 4999 MPASS(fp->f_type == DTYPE_VNODE); 5000 fp->f_ops = &badfileops; 5001 vdrop(fp->f_vnode); 5002 return (0); 5003 } 5004 5005 struct fileops path_fileops = { 5006 .fo_read = badfo_readwrite, 5007 .fo_write = badfo_readwrite, 5008 .fo_truncate = badfo_truncate, 5009 .fo_ioctl = badfo_ioctl, 5010 .fo_poll = path_poll, 5011 .fo_kqfilter = vn_kqfilter_opath, 5012 .fo_stat = vn_statfile, 5013 .fo_close = path_close, 5014 .fo_chmod = badfo_chmod, 5015 .fo_chown = badfo_chown, 5016 .fo_sendfile = badfo_sendfile, 5017 .fo_fill_kinfo = vn_fill_kinfo, 5018 .fo_flags = DFLAG_PASSABLE, 5019 }; 5020 5021 int 5022 invfo_rdwr(struct file *fp, struct uio *uio, struct ucred *active_cred, 5023 int flags, struct thread *td) 5024 { 5025 5026 return (EOPNOTSUPP); 5027 } 5028 5029 int 5030 invfo_truncate(struct file *fp, off_t length, struct ucred *active_cred, 5031 struct thread *td) 5032 { 5033 5034 return (EINVAL); 5035 } 5036 5037 int 5038 invfo_ioctl(struct file *fp, u_long com, void *data, 5039 struct ucred *active_cred, struct thread *td) 5040 { 5041 5042 return (ENOTTY); 5043 } 5044 5045 int 5046 invfo_poll(struct file *fp, int events, struct ucred *active_cred, 5047 struct thread *td) 5048 { 5049 5050 return (poll_no_poll(events)); 5051 } 5052 5053 int 5054 invfo_kqfilter(struct file *fp, struct knote *kn) 5055 { 5056 5057 return (EINVAL); 5058 } 5059 5060 int 5061 invfo_chmod(struct file *fp, mode_t mode, struct ucred *active_cred, 5062 struct thread *td) 5063 { 5064 5065 return (EINVAL); 5066 } 5067 5068 int 5069 invfo_chown(struct file *fp, uid_t uid, gid_t gid, struct ucred *active_cred, 5070 struct thread *td) 5071 { 5072 5073 return (EINVAL); 5074 } 5075 5076 int 5077 invfo_sendfile(struct file *fp, int sockfd, struct uio *hdr_uio, 5078 struct uio *trl_uio, off_t offset, size_t nbytes, off_t *sent, int flags, 5079 struct thread *td) 5080 { 5081 5082 return (EINVAL); 5083 } 5084 5085 /*-------------------------------------------------------------------*/ 5086 5087 /* 5088 * File Descriptor pseudo-device driver (/dev/fd/). 5089 * 5090 * Opening minor device N dup()s the file (if any) connected to file 5091 * descriptor N belonging to the calling process. Note that this driver 5092 * consists of only the ``open()'' routine, because all subsequent 5093 * references to this file will be direct to the other driver. 5094 * 5095 * XXX: we could give this one a cloning event handler if necessary. 5096 */ 5097 5098 /* ARGSUSED */ 5099 static int 5100 fdopen(struct cdev *dev, int mode, int type, struct thread *td) 5101 { 5102 5103 /* 5104 * XXX Kludge: set curthread->td_dupfd to contain the value of the 5105 * the file descriptor being sought for duplication. The error 5106 * return ensures that the vnode for this device will be released 5107 * by vn_open. Open will detect this special error and take the 5108 * actions in dupfdopen below. Other callers of vn_open or VOP_OPEN 5109 * will simply report the error. 5110 */ 5111 td->td_dupfd = dev2unit(dev); 5112 return (ENODEV); 5113 } 5114 5115 static struct cdevsw fildesc_cdevsw = { 5116 .d_version = D_VERSION, 5117 .d_open = fdopen, 5118 .d_name = "FD", 5119 }; 5120 5121 static void 5122 fildesc_drvinit(void *unused) 5123 { 5124 struct cdev *dev; 5125 5126 dev = make_dev_credf(MAKEDEV_ETERNAL, &fildesc_cdevsw, 0, NULL, 5127 UID_ROOT, GID_WHEEL, 0666, "fd/0"); 5128 make_dev_alias(dev, "stdin"); 5129 dev = make_dev_credf(MAKEDEV_ETERNAL, &fildesc_cdevsw, 1, NULL, 5130 UID_ROOT, GID_WHEEL, 0666, "fd/1"); 5131 make_dev_alias(dev, "stdout"); 5132 dev = make_dev_credf(MAKEDEV_ETERNAL, &fildesc_cdevsw, 2, NULL, 5133 UID_ROOT, GID_WHEEL, 0666, "fd/2"); 5134 make_dev_alias(dev, "stderr"); 5135 } 5136 5137 SYSINIT(fildescdev, SI_SUB_DRIVERS, SI_ORDER_MIDDLE, fildesc_drvinit, NULL); 5138