1 /*- 2 * SPDX-License-Identifier: BSD-3-Clause 3 * 4 * Copyright (c) 1982, 1986, 1989, 1991, 1993 5 * The Regents of the University of California. All rights reserved. 6 * (c) UNIX System Laboratories, Inc. 7 * All or some portions of this file are derived from material licensed 8 * to the University of California by American Telephone and Telegraph 9 * Co. or Unix System Laboratories, Inc. and are reproduced herein with 10 * the permission of UNIX System Laboratories, Inc. 11 * 12 * Redistribution and use in source and binary forms, with or without 13 * modification, are permitted provided that the following conditions 14 * are met: 15 * 1. Redistributions of source code must retain the above copyright 16 * notice, this list of conditions and the following disclaimer. 17 * 2. Redistributions in binary form must reproduce the above copyright 18 * notice, this list of conditions and the following disclaimer in the 19 * documentation and/or other materials provided with the distribution. 20 * 3. Neither the name of the University nor the names of its contributors 21 * may be used to endorse or promote products derived from this software 22 * without specific prior written permission. 23 * 24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34 * SUCH DAMAGE. 35 * 36 * @(#)kern_descrip.c 8.6 (Berkeley) 4/19/94 37 */ 38 39 #include <sys/cdefs.h> 40 __FBSDID("$FreeBSD$"); 41 42 #include "opt_capsicum.h" 43 #include "opt_ddb.h" 44 #include "opt_ktrace.h" 45 46 #include <sys/param.h> 47 #include <sys/systm.h> 48 49 #include <sys/capsicum.h> 50 #include <sys/conf.h> 51 #include <sys/fcntl.h> 52 #include <sys/file.h> 53 #include <sys/filedesc.h> 54 #include <sys/filio.h> 55 #include <sys/jail.h> 56 #include <sys/kernel.h> 57 #include <sys/limits.h> 58 #include <sys/lock.h> 59 #include <sys/malloc.h> 60 #include <sys/mount.h> 61 #include <sys/mutex.h> 62 #include <sys/namei.h> 63 #include <sys/selinfo.h> 64 #include <sys/priv.h> 65 #include <sys/proc.h> 66 #include <sys/protosw.h> 67 #include <sys/racct.h> 68 #include <sys/resourcevar.h> 69 #include <sys/sbuf.h> 70 #include <sys/signalvar.h> 71 #include <sys/kdb.h> 72 #include <sys/smr.h> 73 #include <sys/stat.h> 74 #include <sys/sx.h> 75 #include <sys/syscallsubr.h> 76 #include <sys/sysctl.h> 77 #include <sys/sysproto.h> 78 #include <sys/unistd.h> 79 #include <sys/user.h> 80 #include <sys/vnode.h> 81 #ifdef KTRACE 82 #include <sys/ktrace.h> 83 #endif 84 85 #include <net/vnet.h> 86 87 #include <security/audit/audit.h> 88 89 #include <vm/uma.h> 90 #include <vm/vm.h> 91 92 #include <ddb/ddb.h> 93 94 static MALLOC_DEFINE(M_FILEDESC, "filedesc", "Open file descriptor table"); 95 static MALLOC_DEFINE(M_PWD, "pwd", "Descriptor table vnodes"); 96 static MALLOC_DEFINE(M_PWDDESC, "pwddesc", "Pwd descriptors"); 97 static MALLOC_DEFINE(M_FILEDESC_TO_LEADER, "filedesc_to_leader", 98 "file desc to leader structures"); 99 static MALLOC_DEFINE(M_SIGIO, "sigio", "sigio structures"); 100 MALLOC_DEFINE(M_FILECAPS, "filecaps", "descriptor capabilities"); 101 102 MALLOC_DECLARE(M_FADVISE); 103 104 static __read_mostly uma_zone_t file_zone; 105 static __read_mostly uma_zone_t filedesc0_zone; 106 __read_mostly uma_zone_t pwd_zone; 107 VFS_SMR_DECLARE; 108 109 static int closefp(struct filedesc *fdp, int fd, struct file *fp, 110 struct thread *td, bool holdleaders, bool audit); 111 static int fd_first_free(struct filedesc *fdp, int low, int size); 112 static void fdgrowtable(struct filedesc *fdp, int nfd); 113 static void fdgrowtable_exp(struct filedesc *fdp, int nfd); 114 static void fdunused(struct filedesc *fdp, int fd); 115 static void fdused(struct filedesc *fdp, int fd); 116 static int getmaxfd(struct thread *td); 117 static u_long *filecaps_copy_prep(const struct filecaps *src); 118 static void filecaps_copy_finish(const struct filecaps *src, 119 struct filecaps *dst, u_long *ioctls); 120 static u_long *filecaps_free_prep(struct filecaps *fcaps); 121 static void filecaps_free_finish(u_long *ioctls); 122 123 static struct pwd *pwd_alloc(void); 124 125 /* 126 * Each process has: 127 * 128 * - An array of open file descriptors (fd_ofiles) 129 * - An array of file flags (fd_ofileflags) 130 * - A bitmap recording which descriptors are in use (fd_map) 131 * 132 * A process starts out with NDFILE descriptors. The value of NDFILE has 133 * been selected based the historical limit of 20 open files, and an 134 * assumption that the majority of processes, especially short-lived 135 * processes like shells, will never need more. 136 * 137 * If this initial allocation is exhausted, a larger descriptor table and 138 * map are allocated dynamically, and the pointers in the process's struct 139 * filedesc are updated to point to those. This is repeated every time 140 * the process runs out of file descriptors (provided it hasn't hit its 141 * resource limit). 142 * 143 * Since threads may hold references to individual descriptor table 144 * entries, the tables are never freed. Instead, they are placed on a 145 * linked list and freed only when the struct filedesc is released. 146 */ 147 #define NDFILE 20 148 #define NDSLOTSIZE sizeof(NDSLOTTYPE) 149 #define NDENTRIES (NDSLOTSIZE * __CHAR_BIT) 150 #define NDSLOT(x) ((x) / NDENTRIES) 151 #define NDBIT(x) ((NDSLOTTYPE)1 << ((x) % NDENTRIES)) 152 #define NDSLOTS(x) (((x) + NDENTRIES - 1) / NDENTRIES) 153 154 /* 155 * SLIST entry used to keep track of ofiles which must be reclaimed when 156 * the process exits. 157 */ 158 struct freetable { 159 struct fdescenttbl *ft_table; 160 SLIST_ENTRY(freetable) ft_next; 161 }; 162 163 /* 164 * Initial allocation: a filedesc structure + the head of SLIST used to 165 * keep track of old ofiles + enough space for NDFILE descriptors. 166 */ 167 168 struct fdescenttbl0 { 169 int fdt_nfiles; 170 struct filedescent fdt_ofiles[NDFILE]; 171 }; 172 173 struct filedesc0 { 174 struct filedesc fd_fd; 175 SLIST_HEAD(, freetable) fd_free; 176 struct fdescenttbl0 fd_dfiles; 177 NDSLOTTYPE fd_dmap[NDSLOTS(NDFILE)]; 178 }; 179 180 /* 181 * Descriptor management. 182 */ 183 static int __exclusive_cache_line openfiles; /* actual number of open files */ 184 struct mtx sigio_lock; /* mtx to protect pointers to sigio */ 185 void __read_mostly (*mq_fdclose)(struct thread *td, int fd, struct file *fp); 186 187 /* 188 * If low >= size, just return low. Otherwise find the first zero bit in the 189 * given bitmap, starting at low and not exceeding size - 1. Return size if 190 * not found. 191 */ 192 static int 193 fd_first_free(struct filedesc *fdp, int low, int size) 194 { 195 NDSLOTTYPE *map = fdp->fd_map; 196 NDSLOTTYPE mask; 197 int off, maxoff; 198 199 if (low >= size) 200 return (low); 201 202 off = NDSLOT(low); 203 if (low % NDENTRIES) { 204 mask = ~(~(NDSLOTTYPE)0 >> (NDENTRIES - (low % NDENTRIES))); 205 if ((mask &= ~map[off]) != 0UL) 206 return (off * NDENTRIES + ffsl(mask) - 1); 207 ++off; 208 } 209 for (maxoff = NDSLOTS(size); off < maxoff; ++off) 210 if (map[off] != ~0UL) 211 return (off * NDENTRIES + ffsl(~map[off]) - 1); 212 return (size); 213 } 214 215 /* 216 * Find the last used fd. 217 * 218 * Call this variant if fdp can't be modified by anyone else (e.g, during exec). 219 * Otherwise use fdlastfile. 220 */ 221 int 222 fdlastfile_single(struct filedesc *fdp) 223 { 224 NDSLOTTYPE *map = fdp->fd_map; 225 int off, minoff; 226 227 off = NDSLOT(fdp->fd_nfiles - 1); 228 for (minoff = NDSLOT(0); off >= minoff; --off) 229 if (map[off] != 0) 230 return (off * NDENTRIES + flsl(map[off]) - 1); 231 return (-1); 232 } 233 234 int 235 fdlastfile(struct filedesc *fdp) 236 { 237 238 FILEDESC_LOCK_ASSERT(fdp); 239 return (fdlastfile_single(fdp)); 240 } 241 242 static int 243 fdisused(struct filedesc *fdp, int fd) 244 { 245 246 KASSERT(fd >= 0 && fd < fdp->fd_nfiles, 247 ("file descriptor %d out of range (0, %d)", fd, fdp->fd_nfiles)); 248 249 return ((fdp->fd_map[NDSLOT(fd)] & NDBIT(fd)) != 0); 250 } 251 252 /* 253 * Mark a file descriptor as used. 254 */ 255 static void 256 fdused_init(struct filedesc *fdp, int fd) 257 { 258 259 KASSERT(!fdisused(fdp, fd), ("fd=%d is already used", fd)); 260 261 fdp->fd_map[NDSLOT(fd)] |= NDBIT(fd); 262 } 263 264 static void 265 fdused(struct filedesc *fdp, int fd) 266 { 267 268 FILEDESC_XLOCK_ASSERT(fdp); 269 270 fdused_init(fdp, fd); 271 if (fd == fdp->fd_freefile) 272 fdp->fd_freefile++; 273 } 274 275 /* 276 * Mark a file descriptor as unused. 277 */ 278 static void 279 fdunused(struct filedesc *fdp, int fd) 280 { 281 282 FILEDESC_XLOCK_ASSERT(fdp); 283 284 KASSERT(fdisused(fdp, fd), ("fd=%d is already unused", fd)); 285 KASSERT(fdp->fd_ofiles[fd].fde_file == NULL, 286 ("fd=%d is still in use", fd)); 287 288 fdp->fd_map[NDSLOT(fd)] &= ~NDBIT(fd); 289 if (fd < fdp->fd_freefile) 290 fdp->fd_freefile = fd; 291 } 292 293 /* 294 * Free a file descriptor. 295 * 296 * Avoid some work if fdp is about to be destroyed. 297 */ 298 static inline void 299 fdefree_last(struct filedescent *fde) 300 { 301 302 filecaps_free(&fde->fde_caps); 303 } 304 305 static inline void 306 fdfree(struct filedesc *fdp, int fd) 307 { 308 struct filedescent *fde; 309 310 FILEDESC_XLOCK_ASSERT(fdp); 311 fde = &fdp->fd_ofiles[fd]; 312 #ifdef CAPABILITIES 313 seqc_write_begin(&fde->fde_seqc); 314 #endif 315 fde->fde_file = NULL; 316 #ifdef CAPABILITIES 317 seqc_write_end(&fde->fde_seqc); 318 #endif 319 fdefree_last(fde); 320 fdunused(fdp, fd); 321 } 322 323 /* 324 * System calls on descriptors. 325 */ 326 #ifndef _SYS_SYSPROTO_H_ 327 struct getdtablesize_args { 328 int dummy; 329 }; 330 #endif 331 /* ARGSUSED */ 332 int 333 sys_getdtablesize(struct thread *td, struct getdtablesize_args *uap) 334 { 335 #ifdef RACCT 336 uint64_t lim; 337 #endif 338 339 td->td_retval[0] = getmaxfd(td); 340 #ifdef RACCT 341 PROC_LOCK(td->td_proc); 342 lim = racct_get_limit(td->td_proc, RACCT_NOFILE); 343 PROC_UNLOCK(td->td_proc); 344 if (lim < td->td_retval[0]) 345 td->td_retval[0] = lim; 346 #endif 347 return (0); 348 } 349 350 /* 351 * Duplicate a file descriptor to a particular value. 352 * 353 * Note: keep in mind that a potential race condition exists when closing 354 * descriptors from a shared descriptor table (via rfork). 355 */ 356 #ifndef _SYS_SYSPROTO_H_ 357 struct dup2_args { 358 u_int from; 359 u_int to; 360 }; 361 #endif 362 /* ARGSUSED */ 363 int 364 sys_dup2(struct thread *td, struct dup2_args *uap) 365 { 366 367 return (kern_dup(td, FDDUP_FIXED, 0, (int)uap->from, (int)uap->to)); 368 } 369 370 /* 371 * Duplicate a file descriptor. 372 */ 373 #ifndef _SYS_SYSPROTO_H_ 374 struct dup_args { 375 u_int fd; 376 }; 377 #endif 378 /* ARGSUSED */ 379 int 380 sys_dup(struct thread *td, struct dup_args *uap) 381 { 382 383 return (kern_dup(td, FDDUP_NORMAL, 0, (int)uap->fd, 0)); 384 } 385 386 /* 387 * The file control system call. 388 */ 389 #ifndef _SYS_SYSPROTO_H_ 390 struct fcntl_args { 391 int fd; 392 int cmd; 393 long arg; 394 }; 395 #endif 396 /* ARGSUSED */ 397 int 398 sys_fcntl(struct thread *td, struct fcntl_args *uap) 399 { 400 401 return (kern_fcntl_freebsd(td, uap->fd, uap->cmd, uap->arg)); 402 } 403 404 int 405 kern_fcntl_freebsd(struct thread *td, int fd, int cmd, long arg) 406 { 407 struct flock fl; 408 struct __oflock ofl; 409 intptr_t arg1; 410 int error, newcmd; 411 412 error = 0; 413 newcmd = cmd; 414 switch (cmd) { 415 case F_OGETLK: 416 case F_OSETLK: 417 case F_OSETLKW: 418 /* 419 * Convert old flock structure to new. 420 */ 421 error = copyin((void *)(intptr_t)arg, &ofl, sizeof(ofl)); 422 fl.l_start = ofl.l_start; 423 fl.l_len = ofl.l_len; 424 fl.l_pid = ofl.l_pid; 425 fl.l_type = ofl.l_type; 426 fl.l_whence = ofl.l_whence; 427 fl.l_sysid = 0; 428 429 switch (cmd) { 430 case F_OGETLK: 431 newcmd = F_GETLK; 432 break; 433 case F_OSETLK: 434 newcmd = F_SETLK; 435 break; 436 case F_OSETLKW: 437 newcmd = F_SETLKW; 438 break; 439 } 440 arg1 = (intptr_t)&fl; 441 break; 442 case F_GETLK: 443 case F_SETLK: 444 case F_SETLKW: 445 case F_SETLK_REMOTE: 446 error = copyin((void *)(intptr_t)arg, &fl, sizeof(fl)); 447 arg1 = (intptr_t)&fl; 448 break; 449 default: 450 arg1 = arg; 451 break; 452 } 453 if (error) 454 return (error); 455 error = kern_fcntl(td, fd, newcmd, arg1); 456 if (error) 457 return (error); 458 if (cmd == F_OGETLK) { 459 ofl.l_start = fl.l_start; 460 ofl.l_len = fl.l_len; 461 ofl.l_pid = fl.l_pid; 462 ofl.l_type = fl.l_type; 463 ofl.l_whence = fl.l_whence; 464 error = copyout(&ofl, (void *)(intptr_t)arg, sizeof(ofl)); 465 } else if (cmd == F_GETLK) { 466 error = copyout(&fl, (void *)(intptr_t)arg, sizeof(fl)); 467 } 468 return (error); 469 } 470 471 int 472 kern_fcntl(struct thread *td, int fd, int cmd, intptr_t arg) 473 { 474 struct filedesc *fdp; 475 struct flock *flp; 476 struct file *fp, *fp2; 477 struct filedescent *fde; 478 struct proc *p; 479 struct vnode *vp; 480 struct mount *mp; 481 int error, flg, seals, tmp; 482 uint64_t bsize; 483 off_t foffset; 484 485 error = 0; 486 flg = F_POSIX; 487 p = td->td_proc; 488 fdp = p->p_fd; 489 490 AUDIT_ARG_FD(cmd); 491 AUDIT_ARG_CMD(cmd); 492 switch (cmd) { 493 case F_DUPFD: 494 tmp = arg; 495 error = kern_dup(td, FDDUP_FCNTL, 0, fd, tmp); 496 break; 497 498 case F_DUPFD_CLOEXEC: 499 tmp = arg; 500 error = kern_dup(td, FDDUP_FCNTL, FDDUP_FLAG_CLOEXEC, fd, tmp); 501 break; 502 503 case F_DUP2FD: 504 tmp = arg; 505 error = kern_dup(td, FDDUP_FIXED, 0, fd, tmp); 506 break; 507 508 case F_DUP2FD_CLOEXEC: 509 tmp = arg; 510 error = kern_dup(td, FDDUP_FIXED, FDDUP_FLAG_CLOEXEC, fd, tmp); 511 break; 512 513 case F_GETFD: 514 error = EBADF; 515 FILEDESC_SLOCK(fdp); 516 fde = fdeget_locked(fdp, fd); 517 if (fde != NULL) { 518 td->td_retval[0] = 519 (fde->fde_flags & UF_EXCLOSE) ? FD_CLOEXEC : 0; 520 error = 0; 521 } 522 FILEDESC_SUNLOCK(fdp); 523 break; 524 525 case F_SETFD: 526 error = EBADF; 527 FILEDESC_XLOCK(fdp); 528 fde = fdeget_locked(fdp, fd); 529 if (fde != NULL) { 530 fde->fde_flags = (fde->fde_flags & ~UF_EXCLOSE) | 531 (arg & FD_CLOEXEC ? UF_EXCLOSE : 0); 532 error = 0; 533 } 534 FILEDESC_XUNLOCK(fdp); 535 break; 536 537 case F_GETFL: 538 error = fget_fcntl(td, fd, &cap_fcntl_rights, F_GETFL, &fp); 539 if (error != 0) 540 break; 541 td->td_retval[0] = OFLAGS(fp->f_flag); 542 fdrop(fp, td); 543 break; 544 545 case F_SETFL: 546 error = fget_fcntl(td, fd, &cap_fcntl_rights, F_SETFL, &fp); 547 if (error != 0) 548 break; 549 do { 550 tmp = flg = fp->f_flag; 551 tmp &= ~FCNTLFLAGS; 552 tmp |= FFLAGS(arg & ~O_ACCMODE) & FCNTLFLAGS; 553 } while(atomic_cmpset_int(&fp->f_flag, flg, tmp) == 0); 554 tmp = fp->f_flag & FNONBLOCK; 555 error = fo_ioctl(fp, FIONBIO, &tmp, td->td_ucred, td); 556 if (error != 0) { 557 fdrop(fp, td); 558 break; 559 } 560 tmp = fp->f_flag & FASYNC; 561 error = fo_ioctl(fp, FIOASYNC, &tmp, td->td_ucred, td); 562 if (error == 0) { 563 fdrop(fp, td); 564 break; 565 } 566 atomic_clear_int(&fp->f_flag, FNONBLOCK); 567 tmp = 0; 568 (void)fo_ioctl(fp, FIONBIO, &tmp, td->td_ucred, td); 569 fdrop(fp, td); 570 break; 571 572 case F_GETOWN: 573 error = fget_fcntl(td, fd, &cap_fcntl_rights, F_GETOWN, &fp); 574 if (error != 0) 575 break; 576 error = fo_ioctl(fp, FIOGETOWN, &tmp, td->td_ucred, td); 577 if (error == 0) 578 td->td_retval[0] = tmp; 579 fdrop(fp, td); 580 break; 581 582 case F_SETOWN: 583 error = fget_fcntl(td, fd, &cap_fcntl_rights, F_SETOWN, &fp); 584 if (error != 0) 585 break; 586 tmp = arg; 587 error = fo_ioctl(fp, FIOSETOWN, &tmp, td->td_ucred, td); 588 fdrop(fp, td); 589 break; 590 591 case F_SETLK_REMOTE: 592 error = priv_check(td, PRIV_NFS_LOCKD); 593 if (error != 0) 594 return (error); 595 flg = F_REMOTE; 596 goto do_setlk; 597 598 case F_SETLKW: 599 flg |= F_WAIT; 600 /* FALLTHROUGH F_SETLK */ 601 602 case F_SETLK: 603 do_setlk: 604 flp = (struct flock *)arg; 605 if ((flg & F_REMOTE) != 0 && flp->l_sysid == 0) { 606 error = EINVAL; 607 break; 608 } 609 610 error = fget_unlocked(fdp, fd, &cap_flock_rights, &fp); 611 if (error != 0) 612 break; 613 if (fp->f_type != DTYPE_VNODE) { 614 error = EBADF; 615 fdrop(fp, td); 616 break; 617 } 618 619 if (flp->l_whence == SEEK_CUR) { 620 foffset = foffset_get(fp); 621 if (foffset < 0 || 622 (flp->l_start > 0 && 623 foffset > OFF_MAX - flp->l_start)) { 624 error = EOVERFLOW; 625 fdrop(fp, td); 626 break; 627 } 628 flp->l_start += foffset; 629 } 630 631 vp = fp->f_vnode; 632 switch (flp->l_type) { 633 case F_RDLCK: 634 if ((fp->f_flag & FREAD) == 0) { 635 error = EBADF; 636 break; 637 } 638 if ((p->p_leader->p_flag & P_ADVLOCK) == 0) { 639 PROC_LOCK(p->p_leader); 640 p->p_leader->p_flag |= P_ADVLOCK; 641 PROC_UNLOCK(p->p_leader); 642 } 643 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_SETLK, 644 flp, flg); 645 break; 646 case F_WRLCK: 647 if ((fp->f_flag & FWRITE) == 0) { 648 error = EBADF; 649 break; 650 } 651 if ((p->p_leader->p_flag & P_ADVLOCK) == 0) { 652 PROC_LOCK(p->p_leader); 653 p->p_leader->p_flag |= P_ADVLOCK; 654 PROC_UNLOCK(p->p_leader); 655 } 656 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_SETLK, 657 flp, flg); 658 break; 659 case F_UNLCK: 660 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_UNLCK, 661 flp, flg); 662 break; 663 case F_UNLCKSYS: 664 if (flg != F_REMOTE) { 665 error = EINVAL; 666 break; 667 } 668 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, 669 F_UNLCKSYS, flp, flg); 670 break; 671 default: 672 error = EINVAL; 673 break; 674 } 675 if (error != 0 || flp->l_type == F_UNLCK || 676 flp->l_type == F_UNLCKSYS) { 677 fdrop(fp, td); 678 break; 679 } 680 681 /* 682 * Check for a race with close. 683 * 684 * The vnode is now advisory locked (or unlocked, but this case 685 * is not really important) as the caller requested. 686 * We had to drop the filedesc lock, so we need to recheck if 687 * the descriptor is still valid, because if it was closed 688 * in the meantime we need to remove advisory lock from the 689 * vnode - close on any descriptor leading to an advisory 690 * locked vnode, removes that lock. 691 * We will return 0 on purpose in that case, as the result of 692 * successful advisory lock might have been externally visible 693 * already. This is fine - effectively we pretend to the caller 694 * that the closing thread was a bit slower and that the 695 * advisory lock succeeded before the close. 696 */ 697 error = fget_unlocked(fdp, fd, &cap_no_rights, &fp2); 698 if (error != 0) { 699 fdrop(fp, td); 700 break; 701 } 702 if (fp != fp2) { 703 flp->l_whence = SEEK_SET; 704 flp->l_start = 0; 705 flp->l_len = 0; 706 flp->l_type = F_UNLCK; 707 (void) VOP_ADVLOCK(vp, (caddr_t)p->p_leader, 708 F_UNLCK, flp, F_POSIX); 709 } 710 fdrop(fp, td); 711 fdrop(fp2, td); 712 break; 713 714 case F_GETLK: 715 error = fget_unlocked(fdp, fd, &cap_flock_rights, &fp); 716 if (error != 0) 717 break; 718 if (fp->f_type != DTYPE_VNODE) { 719 error = EBADF; 720 fdrop(fp, td); 721 break; 722 } 723 flp = (struct flock *)arg; 724 if (flp->l_type != F_RDLCK && flp->l_type != F_WRLCK && 725 flp->l_type != F_UNLCK) { 726 error = EINVAL; 727 fdrop(fp, td); 728 break; 729 } 730 if (flp->l_whence == SEEK_CUR) { 731 foffset = foffset_get(fp); 732 if ((flp->l_start > 0 && 733 foffset > OFF_MAX - flp->l_start) || 734 (flp->l_start < 0 && 735 foffset < OFF_MIN - flp->l_start)) { 736 error = EOVERFLOW; 737 fdrop(fp, td); 738 break; 739 } 740 flp->l_start += foffset; 741 } 742 vp = fp->f_vnode; 743 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_GETLK, flp, 744 F_POSIX); 745 fdrop(fp, td); 746 break; 747 748 case F_ADD_SEALS: 749 error = fget_unlocked(fdp, fd, &cap_no_rights, &fp); 750 if (error != 0) 751 break; 752 error = fo_add_seals(fp, arg); 753 fdrop(fp, td); 754 break; 755 756 case F_GET_SEALS: 757 error = fget_unlocked(fdp, fd, &cap_no_rights, &fp); 758 if (error != 0) 759 break; 760 if (fo_get_seals(fp, &seals) == 0) 761 td->td_retval[0] = seals; 762 else 763 error = EINVAL; 764 fdrop(fp, td); 765 break; 766 767 case F_RDAHEAD: 768 arg = arg ? 128 * 1024: 0; 769 /* FALLTHROUGH */ 770 case F_READAHEAD: 771 error = fget_unlocked(fdp, fd, &cap_no_rights, &fp); 772 if (error != 0) 773 break; 774 if (fp->f_type != DTYPE_VNODE) { 775 fdrop(fp, td); 776 error = EBADF; 777 break; 778 } 779 vp = fp->f_vnode; 780 if (vp->v_type != VREG) { 781 fdrop(fp, td); 782 error = ENOTTY; 783 break; 784 } 785 786 /* 787 * Exclusive lock synchronizes against f_seqcount reads and 788 * writes in sequential_heuristic(). 789 */ 790 error = vn_lock(vp, LK_EXCLUSIVE); 791 if (error != 0) { 792 fdrop(fp, td); 793 break; 794 } 795 if (arg >= 0) { 796 bsize = fp->f_vnode->v_mount->mnt_stat.f_iosize; 797 arg = MIN(arg, INT_MAX - bsize + 1); 798 fp->f_seqcount[UIO_READ] = MIN(IO_SEQMAX, 799 (arg + bsize - 1) / bsize); 800 atomic_set_int(&fp->f_flag, FRDAHEAD); 801 } else { 802 atomic_clear_int(&fp->f_flag, FRDAHEAD); 803 } 804 VOP_UNLOCK(vp); 805 fdrop(fp, td); 806 break; 807 808 case F_ISUNIONSTACK: 809 /* 810 * Check if the vnode is part of a union stack (either the 811 * "union" flag from mount(2) or unionfs). 812 * 813 * Prior to introduction of this op libc's readdir would call 814 * fstatfs(2), in effect unnecessarily copying kilobytes of 815 * data just to check fs name and a mount flag. 816 * 817 * Fixing the code to handle everything in the kernel instead 818 * is a non-trivial endeavor and has low priority, thus this 819 * horrible kludge facilitates the current behavior in a much 820 * cheaper manner until someone(tm) sorts this out. 821 */ 822 error = fget_unlocked(fdp, fd, &cap_no_rights, &fp); 823 if (error != 0) 824 break; 825 if (fp->f_type != DTYPE_VNODE) { 826 fdrop(fp, td); 827 error = EBADF; 828 break; 829 } 830 vp = fp->f_vnode; 831 /* 832 * Since we don't prevent dooming the vnode even non-null mp 833 * found can become immediately stale. This is tolerable since 834 * mount points are type-stable (providing safe memory access) 835 * and any vfs op on this vnode going forward will return an 836 * error (meaning return value in this case is meaningless). 837 */ 838 mp = atomic_load_ptr(&vp->v_mount); 839 if (__predict_false(mp == NULL)) { 840 fdrop(fp, td); 841 error = EBADF; 842 break; 843 } 844 td->td_retval[0] = 0; 845 if (mp->mnt_kern_flag & MNTK_UNIONFS || 846 mp->mnt_flag & MNT_UNION) 847 td->td_retval[0] = 1; 848 fdrop(fp, td); 849 break; 850 851 default: 852 error = EINVAL; 853 break; 854 } 855 return (error); 856 } 857 858 static int 859 getmaxfd(struct thread *td) 860 { 861 862 return (min((int)lim_cur(td, RLIMIT_NOFILE), maxfilesperproc)); 863 } 864 865 /* 866 * Common code for dup, dup2, fcntl(F_DUPFD) and fcntl(F_DUP2FD). 867 */ 868 int 869 kern_dup(struct thread *td, u_int mode, int flags, int old, int new) 870 { 871 struct filedesc *fdp; 872 struct filedescent *oldfde, *newfde; 873 struct proc *p; 874 struct file *delfp, *oldfp; 875 u_long *oioctls, *nioctls; 876 int error, maxfd; 877 878 p = td->td_proc; 879 fdp = p->p_fd; 880 oioctls = NULL; 881 882 MPASS((flags & ~(FDDUP_FLAG_CLOEXEC)) == 0); 883 MPASS(mode < FDDUP_LASTMODE); 884 885 AUDIT_ARG_FD(old); 886 /* XXXRW: if (flags & FDDUP_FIXED) AUDIT_ARG_FD2(new); */ 887 888 /* 889 * Verify we have a valid descriptor to dup from and possibly to 890 * dup to. Unlike dup() and dup2(), fcntl()'s F_DUPFD should 891 * return EINVAL when the new descriptor is out of bounds. 892 */ 893 if (old < 0) 894 return (EBADF); 895 if (new < 0) 896 return (mode == FDDUP_FCNTL ? EINVAL : EBADF); 897 maxfd = getmaxfd(td); 898 if (new >= maxfd) 899 return (mode == FDDUP_FCNTL ? EINVAL : EBADF); 900 901 error = EBADF; 902 FILEDESC_XLOCK(fdp); 903 if (fget_locked(fdp, old) == NULL) 904 goto unlock; 905 if ((mode == FDDUP_FIXED || mode == FDDUP_MUSTREPLACE) && old == new) { 906 td->td_retval[0] = new; 907 if (flags & FDDUP_FLAG_CLOEXEC) 908 fdp->fd_ofiles[new].fde_flags |= UF_EXCLOSE; 909 error = 0; 910 goto unlock; 911 } 912 913 oldfde = &fdp->fd_ofiles[old]; 914 oldfp = oldfde->fde_file; 915 if (!fhold(oldfp)) 916 goto unlock; 917 918 /* 919 * If the caller specified a file descriptor, make sure the file 920 * table is large enough to hold it, and grab it. Otherwise, just 921 * allocate a new descriptor the usual way. 922 */ 923 switch (mode) { 924 case FDDUP_NORMAL: 925 case FDDUP_FCNTL: 926 if ((error = fdalloc(td, new, &new)) != 0) { 927 fdrop(oldfp, td); 928 goto unlock; 929 } 930 break; 931 case FDDUP_MUSTREPLACE: 932 /* Target file descriptor must exist. */ 933 if (fget_locked(fdp, new) == NULL) { 934 fdrop(oldfp, td); 935 goto unlock; 936 } 937 break; 938 case FDDUP_FIXED: 939 if (new >= fdp->fd_nfiles) { 940 /* 941 * The resource limits are here instead of e.g. 942 * fdalloc(), because the file descriptor table may be 943 * shared between processes, so we can't really use 944 * racct_add()/racct_sub(). Instead of counting the 945 * number of actually allocated descriptors, just put 946 * the limit on the size of the file descriptor table. 947 */ 948 #ifdef RACCT 949 if (RACCT_ENABLED()) { 950 error = racct_set_unlocked(p, RACCT_NOFILE, new + 1); 951 if (error != 0) { 952 error = EMFILE; 953 fdrop(oldfp, td); 954 goto unlock; 955 } 956 } 957 #endif 958 fdgrowtable_exp(fdp, new + 1); 959 } 960 if (!fdisused(fdp, new)) 961 fdused(fdp, new); 962 break; 963 default: 964 KASSERT(0, ("%s unsupported mode %d", __func__, mode)); 965 } 966 967 KASSERT(old != new, ("new fd is same as old")); 968 969 /* Refetch oldfde because the table may have grown and old one freed. */ 970 oldfde = &fdp->fd_ofiles[old]; 971 KASSERT(oldfp == oldfde->fde_file, 972 ("fdt_ofiles shift from growth observed at fd %d", 973 old)); 974 975 newfde = &fdp->fd_ofiles[new]; 976 delfp = newfde->fde_file; 977 978 nioctls = filecaps_copy_prep(&oldfde->fde_caps); 979 980 /* 981 * Duplicate the source descriptor. 982 */ 983 #ifdef CAPABILITIES 984 seqc_write_begin(&newfde->fde_seqc); 985 #endif 986 oioctls = filecaps_free_prep(&newfde->fde_caps); 987 memcpy(newfde, oldfde, fde_change_size); 988 filecaps_copy_finish(&oldfde->fde_caps, &newfde->fde_caps, 989 nioctls); 990 if ((flags & FDDUP_FLAG_CLOEXEC) != 0) 991 newfde->fde_flags = oldfde->fde_flags | UF_EXCLOSE; 992 else 993 newfde->fde_flags = oldfde->fde_flags & ~UF_EXCLOSE; 994 #ifdef CAPABILITIES 995 seqc_write_end(&newfde->fde_seqc); 996 #endif 997 td->td_retval[0] = new; 998 999 error = 0; 1000 1001 if (delfp != NULL) { 1002 (void) closefp(fdp, new, delfp, td, true, false); 1003 FILEDESC_UNLOCK_ASSERT(fdp); 1004 } else { 1005 unlock: 1006 FILEDESC_XUNLOCK(fdp); 1007 } 1008 1009 filecaps_free_finish(oioctls); 1010 return (error); 1011 } 1012 1013 static void 1014 sigiofree(struct sigio *sigio) 1015 { 1016 crfree(sigio->sio_ucred); 1017 free(sigio, M_SIGIO); 1018 } 1019 1020 static struct sigio * 1021 funsetown_locked(struct sigio *sigio) 1022 { 1023 struct proc *p; 1024 struct pgrp *pg; 1025 1026 SIGIO_ASSERT_LOCKED(); 1027 1028 if (sigio == NULL) 1029 return (NULL); 1030 *(sigio->sio_myref) = NULL; 1031 if (sigio->sio_pgid < 0) { 1032 pg = sigio->sio_pgrp; 1033 PGRP_LOCK(pg); 1034 SLIST_REMOVE(&sigio->sio_pgrp->pg_sigiolst, sigio, 1035 sigio, sio_pgsigio); 1036 PGRP_UNLOCK(pg); 1037 } else { 1038 p = sigio->sio_proc; 1039 PROC_LOCK(p); 1040 SLIST_REMOVE(&sigio->sio_proc->p_sigiolst, sigio, 1041 sigio, sio_pgsigio); 1042 PROC_UNLOCK(p); 1043 } 1044 return (sigio); 1045 } 1046 1047 /* 1048 * If sigio is on the list associated with a process or process group, 1049 * disable signalling from the device, remove sigio from the list and 1050 * free sigio. 1051 */ 1052 void 1053 funsetown(struct sigio **sigiop) 1054 { 1055 struct sigio *sigio; 1056 1057 /* Racy check, consumers must provide synchronization. */ 1058 if (*sigiop == NULL) 1059 return; 1060 1061 SIGIO_LOCK(); 1062 sigio = funsetown_locked(*sigiop); 1063 SIGIO_UNLOCK(); 1064 if (sigio != NULL) 1065 sigiofree(sigio); 1066 } 1067 1068 /* 1069 * Free a list of sigio structures. The caller must ensure that new sigio 1070 * structures cannot be added after this point. For process groups this is 1071 * guaranteed using the proctree lock; for processes, the P_WEXIT flag serves 1072 * as an interlock. 1073 */ 1074 void 1075 funsetownlst(struct sigiolst *sigiolst) 1076 { 1077 struct proc *p; 1078 struct pgrp *pg; 1079 struct sigio *sigio, *tmp; 1080 1081 /* Racy check. */ 1082 sigio = SLIST_FIRST(sigiolst); 1083 if (sigio == NULL) 1084 return; 1085 1086 p = NULL; 1087 pg = NULL; 1088 1089 SIGIO_LOCK(); 1090 sigio = SLIST_FIRST(sigiolst); 1091 if (sigio == NULL) { 1092 SIGIO_UNLOCK(); 1093 return; 1094 } 1095 1096 /* 1097 * Every entry of the list should belong to a single proc or pgrp. 1098 */ 1099 if (sigio->sio_pgid < 0) { 1100 pg = sigio->sio_pgrp; 1101 sx_assert(&proctree_lock, SX_XLOCKED); 1102 PGRP_LOCK(pg); 1103 } else /* if (sigio->sio_pgid > 0) */ { 1104 p = sigio->sio_proc; 1105 PROC_LOCK(p); 1106 KASSERT((p->p_flag & P_WEXIT) != 0, 1107 ("%s: process %p is not exiting", __func__, p)); 1108 } 1109 1110 SLIST_FOREACH(sigio, sigiolst, sio_pgsigio) { 1111 *sigio->sio_myref = NULL; 1112 if (pg != NULL) { 1113 KASSERT(sigio->sio_pgid < 0, 1114 ("Proc sigio in pgrp sigio list")); 1115 KASSERT(sigio->sio_pgrp == pg, 1116 ("Bogus pgrp in sigio list")); 1117 } else /* if (p != NULL) */ { 1118 KASSERT(sigio->sio_pgid > 0, 1119 ("Pgrp sigio in proc sigio list")); 1120 KASSERT(sigio->sio_proc == p, 1121 ("Bogus proc in sigio list")); 1122 } 1123 } 1124 1125 if (pg != NULL) 1126 PGRP_UNLOCK(pg); 1127 else 1128 PROC_UNLOCK(p); 1129 SIGIO_UNLOCK(); 1130 1131 SLIST_FOREACH_SAFE(sigio, sigiolst, sio_pgsigio, tmp) 1132 sigiofree(sigio); 1133 } 1134 1135 /* 1136 * This is common code for FIOSETOWN ioctl called by fcntl(fd, F_SETOWN, arg). 1137 * 1138 * After permission checking, add a sigio structure to the sigio list for 1139 * the process or process group. 1140 */ 1141 int 1142 fsetown(pid_t pgid, struct sigio **sigiop) 1143 { 1144 struct proc *proc; 1145 struct pgrp *pgrp; 1146 struct sigio *osigio, *sigio; 1147 int ret; 1148 1149 if (pgid == 0) { 1150 funsetown(sigiop); 1151 return (0); 1152 } 1153 1154 ret = 0; 1155 1156 sigio = malloc(sizeof(struct sigio), M_SIGIO, M_WAITOK); 1157 sigio->sio_pgid = pgid; 1158 sigio->sio_ucred = crhold(curthread->td_ucred); 1159 sigio->sio_myref = sigiop; 1160 1161 sx_slock(&proctree_lock); 1162 SIGIO_LOCK(); 1163 osigio = funsetown_locked(*sigiop); 1164 if (pgid > 0) { 1165 proc = pfind(pgid); 1166 if (proc == NULL) { 1167 ret = ESRCH; 1168 goto fail; 1169 } 1170 1171 /* 1172 * Policy - Don't allow a process to FSETOWN a process 1173 * in another session. 1174 * 1175 * Remove this test to allow maximum flexibility or 1176 * restrict FSETOWN to the current process or process 1177 * group for maximum safety. 1178 */ 1179 if (proc->p_session != curthread->td_proc->p_session) { 1180 PROC_UNLOCK(proc); 1181 ret = EPERM; 1182 goto fail; 1183 } 1184 1185 sigio->sio_proc = proc; 1186 SLIST_INSERT_HEAD(&proc->p_sigiolst, sigio, sio_pgsigio); 1187 PROC_UNLOCK(proc); 1188 } else /* if (pgid < 0) */ { 1189 pgrp = pgfind(-pgid); 1190 if (pgrp == NULL) { 1191 ret = ESRCH; 1192 goto fail; 1193 } 1194 1195 /* 1196 * Policy - Don't allow a process to FSETOWN a process 1197 * in another session. 1198 * 1199 * Remove this test to allow maximum flexibility or 1200 * restrict FSETOWN to the current process or process 1201 * group for maximum safety. 1202 */ 1203 if (pgrp->pg_session != curthread->td_proc->p_session) { 1204 PGRP_UNLOCK(pgrp); 1205 ret = EPERM; 1206 goto fail; 1207 } 1208 1209 SLIST_INSERT_HEAD(&pgrp->pg_sigiolst, sigio, sio_pgsigio); 1210 sigio->sio_pgrp = pgrp; 1211 PGRP_UNLOCK(pgrp); 1212 } 1213 sx_sunlock(&proctree_lock); 1214 *sigiop = sigio; 1215 SIGIO_UNLOCK(); 1216 if (osigio != NULL) 1217 sigiofree(osigio); 1218 return (0); 1219 1220 fail: 1221 SIGIO_UNLOCK(); 1222 sx_sunlock(&proctree_lock); 1223 sigiofree(sigio); 1224 if (osigio != NULL) 1225 sigiofree(osigio); 1226 return (ret); 1227 } 1228 1229 /* 1230 * This is common code for FIOGETOWN ioctl called by fcntl(fd, F_GETOWN, arg). 1231 */ 1232 pid_t 1233 fgetown(struct sigio **sigiop) 1234 { 1235 pid_t pgid; 1236 1237 SIGIO_LOCK(); 1238 pgid = (*sigiop != NULL) ? (*sigiop)->sio_pgid : 0; 1239 SIGIO_UNLOCK(); 1240 return (pgid); 1241 } 1242 1243 static int 1244 closefp_impl(struct filedesc *fdp, int fd, struct file *fp, struct thread *td, 1245 bool audit) 1246 { 1247 int error; 1248 1249 FILEDESC_XLOCK_ASSERT(fdp); 1250 1251 /* 1252 * We now hold the fp reference that used to be owned by the 1253 * descriptor array. We have to unlock the FILEDESC *AFTER* 1254 * knote_fdclose to prevent a race of the fd getting opened, a knote 1255 * added, and deleteing a knote for the new fd. 1256 */ 1257 if (__predict_false(!TAILQ_EMPTY(&fdp->fd_kqlist))) 1258 knote_fdclose(td, fd); 1259 1260 /* 1261 * We need to notify mqueue if the object is of type mqueue. 1262 */ 1263 if (__predict_false(fp->f_type == DTYPE_MQUEUE)) 1264 mq_fdclose(td, fd, fp); 1265 FILEDESC_XUNLOCK(fdp); 1266 1267 #ifdef AUDIT 1268 if (AUDITING_TD(td) && audit) 1269 audit_sysclose(td, fd, fp); 1270 #endif 1271 error = closef(fp, td); 1272 1273 /* 1274 * All paths leading up to closefp() will have already removed or 1275 * replaced the fd in the filedesc table, so a restart would not 1276 * operate on the same file. 1277 */ 1278 if (error == ERESTART) 1279 error = EINTR; 1280 1281 return (error); 1282 } 1283 1284 static int 1285 closefp_hl(struct filedesc *fdp, int fd, struct file *fp, struct thread *td, 1286 bool holdleaders, bool audit) 1287 { 1288 int error; 1289 1290 FILEDESC_XLOCK_ASSERT(fdp); 1291 1292 if (holdleaders) { 1293 if (td->td_proc->p_fdtol != NULL) { 1294 /* 1295 * Ask fdfree() to sleep to ensure that all relevant 1296 * process leaders can be traversed in closef(). 1297 */ 1298 fdp->fd_holdleaderscount++; 1299 } else { 1300 holdleaders = false; 1301 } 1302 } 1303 1304 error = closefp_impl(fdp, fd, fp, td, audit); 1305 if (holdleaders) { 1306 FILEDESC_XLOCK(fdp); 1307 fdp->fd_holdleaderscount--; 1308 if (fdp->fd_holdleaderscount == 0 && 1309 fdp->fd_holdleaderswakeup != 0) { 1310 fdp->fd_holdleaderswakeup = 0; 1311 wakeup(&fdp->fd_holdleaderscount); 1312 } 1313 FILEDESC_XUNLOCK(fdp); 1314 } 1315 return (error); 1316 } 1317 1318 static int 1319 closefp(struct filedesc *fdp, int fd, struct file *fp, struct thread *td, 1320 bool holdleaders, bool audit) 1321 { 1322 1323 FILEDESC_XLOCK_ASSERT(fdp); 1324 1325 if (__predict_false(td->td_proc->p_fdtol != NULL)) { 1326 return (closefp_hl(fdp, fd, fp, td, holdleaders, audit)); 1327 } else { 1328 return (closefp_impl(fdp, fd, fp, td, audit)); 1329 } 1330 } 1331 1332 /* 1333 * Close a file descriptor. 1334 */ 1335 #ifndef _SYS_SYSPROTO_H_ 1336 struct close_args { 1337 int fd; 1338 }; 1339 #endif 1340 /* ARGSUSED */ 1341 int 1342 sys_close(struct thread *td, struct close_args *uap) 1343 { 1344 1345 return (kern_close(td, uap->fd)); 1346 } 1347 1348 int 1349 kern_close(struct thread *td, int fd) 1350 { 1351 struct filedesc *fdp; 1352 struct file *fp; 1353 1354 fdp = td->td_proc->p_fd; 1355 1356 FILEDESC_XLOCK(fdp); 1357 if ((fp = fget_locked(fdp, fd)) == NULL) { 1358 FILEDESC_XUNLOCK(fdp); 1359 return (EBADF); 1360 } 1361 fdfree(fdp, fd); 1362 1363 /* closefp() drops the FILEDESC lock for us. */ 1364 return (closefp(fdp, fd, fp, td, true, true)); 1365 } 1366 1367 int 1368 kern_close_range(struct thread *td, u_int lowfd, u_int highfd) 1369 { 1370 struct filedesc *fdp; 1371 const struct fdescenttbl *fdt; 1372 struct file *fp; 1373 int fd; 1374 1375 /* 1376 * Check this prior to clamping; closefrom(3) with only fd 0, 1, and 2 1377 * open should not be a usage error. From a close_range() perspective, 1378 * close_range(3, ~0U, 0) in the same scenario should also likely not 1379 * be a usage error as all fd above 3 are in-fact already closed. 1380 */ 1381 if (highfd < lowfd) { 1382 return (EINVAL); 1383 } 1384 1385 fdp = td->td_proc->p_fd; 1386 FILEDESC_XLOCK(fdp); 1387 fdt = atomic_load_ptr(&fdp->fd_files); 1388 highfd = MIN(highfd, fdt->fdt_nfiles - 1); 1389 fd = lowfd; 1390 if (__predict_false(fd > highfd)) { 1391 goto out_locked; 1392 } 1393 for (;;) { 1394 fp = fdt->fdt_ofiles[fd].fde_file; 1395 if (fp == NULL) { 1396 if (fd == highfd) 1397 goto out_locked; 1398 } else { 1399 fdfree(fdp, fd); 1400 (void) closefp(fdp, fd, fp, td, true, true); 1401 if (fd == highfd) 1402 goto out_unlocked; 1403 FILEDESC_XLOCK(fdp); 1404 fdt = atomic_load_ptr(&fdp->fd_files); 1405 } 1406 fd++; 1407 } 1408 out_locked: 1409 FILEDESC_XUNLOCK(fdp); 1410 out_unlocked: 1411 return (0); 1412 } 1413 1414 #ifndef _SYS_SYSPROTO_H_ 1415 struct close_range_args { 1416 u_int lowfd; 1417 u_int highfd; 1418 int flags; 1419 }; 1420 #endif 1421 int 1422 sys_close_range(struct thread *td, struct close_range_args *uap) 1423 { 1424 1425 AUDIT_ARG_FD(uap->lowfd); 1426 AUDIT_ARG_CMD(uap->highfd); 1427 AUDIT_ARG_FFLAGS(uap->flags); 1428 1429 /* No flags currently defined */ 1430 if (uap->flags != 0) 1431 return (EINVAL); 1432 return (kern_close_range(td, uap->lowfd, uap->highfd)); 1433 } 1434 1435 #ifdef COMPAT_FREEBSD12 1436 /* 1437 * Close open file descriptors. 1438 */ 1439 #ifndef _SYS_SYSPROTO_H_ 1440 struct freebsd12_closefrom_args { 1441 int lowfd; 1442 }; 1443 #endif 1444 /* ARGSUSED */ 1445 int 1446 freebsd12_closefrom(struct thread *td, struct freebsd12_closefrom_args *uap) 1447 { 1448 u_int lowfd; 1449 1450 AUDIT_ARG_FD(uap->lowfd); 1451 1452 /* 1453 * Treat negative starting file descriptor values identical to 1454 * closefrom(0) which closes all files. 1455 */ 1456 lowfd = MAX(0, uap->lowfd); 1457 return (kern_close_range(td, lowfd, ~0U)); 1458 } 1459 #endif /* COMPAT_FREEBSD12 */ 1460 1461 #if defined(COMPAT_43) 1462 /* 1463 * Return status information about a file descriptor. 1464 */ 1465 #ifndef _SYS_SYSPROTO_H_ 1466 struct ofstat_args { 1467 int fd; 1468 struct ostat *sb; 1469 }; 1470 #endif 1471 /* ARGSUSED */ 1472 int 1473 ofstat(struct thread *td, struct ofstat_args *uap) 1474 { 1475 struct ostat oub; 1476 struct stat ub; 1477 int error; 1478 1479 error = kern_fstat(td, uap->fd, &ub); 1480 if (error == 0) { 1481 cvtstat(&ub, &oub); 1482 error = copyout(&oub, uap->sb, sizeof(oub)); 1483 } 1484 return (error); 1485 } 1486 #endif /* COMPAT_43 */ 1487 1488 #if defined(COMPAT_FREEBSD11) 1489 int 1490 freebsd11_fstat(struct thread *td, struct freebsd11_fstat_args *uap) 1491 { 1492 struct stat sb; 1493 struct freebsd11_stat osb; 1494 int error; 1495 1496 error = kern_fstat(td, uap->fd, &sb); 1497 if (error != 0) 1498 return (error); 1499 error = freebsd11_cvtstat(&sb, &osb); 1500 if (error == 0) 1501 error = copyout(&osb, uap->sb, sizeof(osb)); 1502 return (error); 1503 } 1504 #endif /* COMPAT_FREEBSD11 */ 1505 1506 /* 1507 * Return status information about a file descriptor. 1508 */ 1509 #ifndef _SYS_SYSPROTO_H_ 1510 struct fstat_args { 1511 int fd; 1512 struct stat *sb; 1513 }; 1514 #endif 1515 /* ARGSUSED */ 1516 int 1517 sys_fstat(struct thread *td, struct fstat_args *uap) 1518 { 1519 struct stat ub; 1520 int error; 1521 1522 error = kern_fstat(td, uap->fd, &ub); 1523 if (error == 0) 1524 error = copyout(&ub, uap->sb, sizeof(ub)); 1525 return (error); 1526 } 1527 1528 int 1529 kern_fstat(struct thread *td, int fd, struct stat *sbp) 1530 { 1531 struct file *fp; 1532 int error; 1533 1534 AUDIT_ARG_FD(fd); 1535 1536 error = fget(td, fd, &cap_fstat_rights, &fp); 1537 if (__predict_false(error != 0)) 1538 return (error); 1539 1540 AUDIT_ARG_FILE(td->td_proc, fp); 1541 1542 error = fo_stat(fp, sbp, td->td_ucred, td); 1543 fdrop(fp, td); 1544 #ifdef __STAT_TIME_T_EXT 1545 sbp->st_atim_ext = 0; 1546 sbp->st_mtim_ext = 0; 1547 sbp->st_ctim_ext = 0; 1548 sbp->st_btim_ext = 0; 1549 #endif 1550 #ifdef KTRACE 1551 if (KTRPOINT(td, KTR_STRUCT)) 1552 ktrstat_error(sbp, error); 1553 #endif 1554 return (error); 1555 } 1556 1557 #if defined(COMPAT_FREEBSD11) 1558 /* 1559 * Return status information about a file descriptor. 1560 */ 1561 #ifndef _SYS_SYSPROTO_H_ 1562 struct freebsd11_nfstat_args { 1563 int fd; 1564 struct nstat *sb; 1565 }; 1566 #endif 1567 /* ARGSUSED */ 1568 int 1569 freebsd11_nfstat(struct thread *td, struct freebsd11_nfstat_args *uap) 1570 { 1571 struct nstat nub; 1572 struct stat ub; 1573 int error; 1574 1575 error = kern_fstat(td, uap->fd, &ub); 1576 if (error == 0) { 1577 freebsd11_cvtnstat(&ub, &nub); 1578 error = copyout(&nub, uap->sb, sizeof(nub)); 1579 } 1580 return (error); 1581 } 1582 #endif /* COMPAT_FREEBSD11 */ 1583 1584 /* 1585 * Return pathconf information about a file descriptor. 1586 */ 1587 #ifndef _SYS_SYSPROTO_H_ 1588 struct fpathconf_args { 1589 int fd; 1590 int name; 1591 }; 1592 #endif 1593 /* ARGSUSED */ 1594 int 1595 sys_fpathconf(struct thread *td, struct fpathconf_args *uap) 1596 { 1597 long value; 1598 int error; 1599 1600 error = kern_fpathconf(td, uap->fd, uap->name, &value); 1601 if (error == 0) 1602 td->td_retval[0] = value; 1603 return (error); 1604 } 1605 1606 int 1607 kern_fpathconf(struct thread *td, int fd, int name, long *valuep) 1608 { 1609 struct file *fp; 1610 struct vnode *vp; 1611 int error; 1612 1613 error = fget(td, fd, &cap_fpathconf_rights, &fp); 1614 if (error != 0) 1615 return (error); 1616 1617 if (name == _PC_ASYNC_IO) { 1618 *valuep = _POSIX_ASYNCHRONOUS_IO; 1619 goto out; 1620 } 1621 vp = fp->f_vnode; 1622 if (vp != NULL) { 1623 vn_lock(vp, LK_SHARED | LK_RETRY); 1624 error = VOP_PATHCONF(vp, name, valuep); 1625 VOP_UNLOCK(vp); 1626 } else if (fp->f_type == DTYPE_PIPE || fp->f_type == DTYPE_SOCKET) { 1627 if (name != _PC_PIPE_BUF) { 1628 error = EINVAL; 1629 } else { 1630 *valuep = PIPE_BUF; 1631 error = 0; 1632 } 1633 } else { 1634 error = EOPNOTSUPP; 1635 } 1636 out: 1637 fdrop(fp, td); 1638 return (error); 1639 } 1640 1641 /* 1642 * Copy filecaps structure allocating memory for ioctls array if needed. 1643 * 1644 * The last parameter indicates whether the fdtable is locked. If it is not and 1645 * ioctls are encountered, copying fails and the caller must lock the table. 1646 * 1647 * Note that if the table was not locked, the caller has to check the relevant 1648 * sequence counter to determine whether the operation was successful. 1649 */ 1650 bool 1651 filecaps_copy(const struct filecaps *src, struct filecaps *dst, bool locked) 1652 { 1653 size_t size; 1654 1655 if (src->fc_ioctls != NULL && !locked) 1656 return (false); 1657 memcpy(dst, src, sizeof(*src)); 1658 if (src->fc_ioctls == NULL) 1659 return (true); 1660 1661 KASSERT(src->fc_nioctls > 0, 1662 ("fc_ioctls != NULL, but fc_nioctls=%hd", src->fc_nioctls)); 1663 1664 size = sizeof(src->fc_ioctls[0]) * src->fc_nioctls; 1665 dst->fc_ioctls = malloc(size, M_FILECAPS, M_WAITOK); 1666 memcpy(dst->fc_ioctls, src->fc_ioctls, size); 1667 return (true); 1668 } 1669 1670 static u_long * 1671 filecaps_copy_prep(const struct filecaps *src) 1672 { 1673 u_long *ioctls; 1674 size_t size; 1675 1676 if (__predict_true(src->fc_ioctls == NULL)) 1677 return (NULL); 1678 1679 KASSERT(src->fc_nioctls > 0, 1680 ("fc_ioctls != NULL, but fc_nioctls=%hd", src->fc_nioctls)); 1681 1682 size = sizeof(src->fc_ioctls[0]) * src->fc_nioctls; 1683 ioctls = malloc(size, M_FILECAPS, M_WAITOK); 1684 return (ioctls); 1685 } 1686 1687 static void 1688 filecaps_copy_finish(const struct filecaps *src, struct filecaps *dst, 1689 u_long *ioctls) 1690 { 1691 size_t size; 1692 1693 *dst = *src; 1694 if (__predict_true(src->fc_ioctls == NULL)) { 1695 MPASS(ioctls == NULL); 1696 return; 1697 } 1698 1699 size = sizeof(src->fc_ioctls[0]) * src->fc_nioctls; 1700 dst->fc_ioctls = ioctls; 1701 bcopy(src->fc_ioctls, dst->fc_ioctls, size); 1702 } 1703 1704 /* 1705 * Move filecaps structure to the new place and clear the old place. 1706 */ 1707 void 1708 filecaps_move(struct filecaps *src, struct filecaps *dst) 1709 { 1710 1711 *dst = *src; 1712 bzero(src, sizeof(*src)); 1713 } 1714 1715 /* 1716 * Fill the given filecaps structure with full rights. 1717 */ 1718 static void 1719 filecaps_fill(struct filecaps *fcaps) 1720 { 1721 1722 CAP_ALL(&fcaps->fc_rights); 1723 fcaps->fc_ioctls = NULL; 1724 fcaps->fc_nioctls = -1; 1725 fcaps->fc_fcntls = CAP_FCNTL_ALL; 1726 } 1727 1728 /* 1729 * Free memory allocated within filecaps structure. 1730 */ 1731 void 1732 filecaps_free(struct filecaps *fcaps) 1733 { 1734 1735 free(fcaps->fc_ioctls, M_FILECAPS); 1736 bzero(fcaps, sizeof(*fcaps)); 1737 } 1738 1739 static u_long * 1740 filecaps_free_prep(struct filecaps *fcaps) 1741 { 1742 u_long *ioctls; 1743 1744 ioctls = fcaps->fc_ioctls; 1745 bzero(fcaps, sizeof(*fcaps)); 1746 return (ioctls); 1747 } 1748 1749 static void 1750 filecaps_free_finish(u_long *ioctls) 1751 { 1752 1753 free(ioctls, M_FILECAPS); 1754 } 1755 1756 /* 1757 * Validate the given filecaps structure. 1758 */ 1759 static void 1760 filecaps_validate(const struct filecaps *fcaps, const char *func) 1761 { 1762 1763 KASSERT(cap_rights_is_valid(&fcaps->fc_rights), 1764 ("%s: invalid rights", func)); 1765 KASSERT((fcaps->fc_fcntls & ~CAP_FCNTL_ALL) == 0, 1766 ("%s: invalid fcntls", func)); 1767 KASSERT(fcaps->fc_fcntls == 0 || 1768 cap_rights_is_set(&fcaps->fc_rights, CAP_FCNTL), 1769 ("%s: fcntls without CAP_FCNTL", func)); 1770 KASSERT(fcaps->fc_ioctls != NULL ? fcaps->fc_nioctls > 0 : 1771 (fcaps->fc_nioctls == -1 || fcaps->fc_nioctls == 0), 1772 ("%s: invalid ioctls", func)); 1773 KASSERT(fcaps->fc_nioctls == 0 || 1774 cap_rights_is_set(&fcaps->fc_rights, CAP_IOCTL), 1775 ("%s: ioctls without CAP_IOCTL", func)); 1776 } 1777 1778 static void 1779 fdgrowtable_exp(struct filedesc *fdp, int nfd) 1780 { 1781 int nfd1; 1782 1783 FILEDESC_XLOCK_ASSERT(fdp); 1784 1785 nfd1 = fdp->fd_nfiles * 2; 1786 if (nfd1 < nfd) 1787 nfd1 = nfd; 1788 fdgrowtable(fdp, nfd1); 1789 } 1790 1791 /* 1792 * Grow the file table to accommodate (at least) nfd descriptors. 1793 */ 1794 static void 1795 fdgrowtable(struct filedesc *fdp, int nfd) 1796 { 1797 struct filedesc0 *fdp0; 1798 struct freetable *ft; 1799 struct fdescenttbl *ntable; 1800 struct fdescenttbl *otable; 1801 int nnfiles, onfiles; 1802 NDSLOTTYPE *nmap, *omap; 1803 1804 KASSERT(fdp->fd_nfiles > 0, ("zero-length file table")); 1805 1806 /* save old values */ 1807 onfiles = fdp->fd_nfiles; 1808 otable = fdp->fd_files; 1809 omap = fdp->fd_map; 1810 1811 /* compute the size of the new table */ 1812 nnfiles = NDSLOTS(nfd) * NDENTRIES; /* round up */ 1813 if (nnfiles <= onfiles) 1814 /* the table is already large enough */ 1815 return; 1816 1817 /* 1818 * Allocate a new table. We need enough space for the number of 1819 * entries, file entries themselves and the struct freetable we will use 1820 * when we decommission the table and place it on the freelist. 1821 * We place the struct freetable in the middle so we don't have 1822 * to worry about padding. 1823 */ 1824 ntable = malloc(offsetof(struct fdescenttbl, fdt_ofiles) + 1825 nnfiles * sizeof(ntable->fdt_ofiles[0]) + 1826 sizeof(struct freetable), 1827 M_FILEDESC, M_ZERO | M_WAITOK); 1828 /* copy the old data */ 1829 ntable->fdt_nfiles = nnfiles; 1830 memcpy(ntable->fdt_ofiles, otable->fdt_ofiles, 1831 onfiles * sizeof(ntable->fdt_ofiles[0])); 1832 1833 /* 1834 * Allocate a new map only if the old is not large enough. It will 1835 * grow at a slower rate than the table as it can map more 1836 * entries than the table can hold. 1837 */ 1838 if (NDSLOTS(nnfiles) > NDSLOTS(onfiles)) { 1839 nmap = malloc(NDSLOTS(nnfiles) * NDSLOTSIZE, M_FILEDESC, 1840 M_ZERO | M_WAITOK); 1841 /* copy over the old data and update the pointer */ 1842 memcpy(nmap, omap, NDSLOTS(onfiles) * sizeof(*omap)); 1843 fdp->fd_map = nmap; 1844 } 1845 1846 /* 1847 * Make sure that ntable is correctly initialized before we replace 1848 * fd_files poiner. Otherwise fget_unlocked() may see inconsistent 1849 * data. 1850 */ 1851 atomic_store_rel_ptr((volatile void *)&fdp->fd_files, (uintptr_t)ntable); 1852 1853 /* 1854 * Free the old file table when not shared by other threads or processes. 1855 * The old file table is considered to be shared when either are true: 1856 * - The process has more than one thread. 1857 * - The file descriptor table has been shared via fdshare(). 1858 * 1859 * When shared, the old file table will be placed on a freelist 1860 * which will be processed when the struct filedesc is released. 1861 * 1862 * Note that if onfiles == NDFILE, we're dealing with the original 1863 * static allocation contained within (struct filedesc0 *)fdp, 1864 * which must not be freed. 1865 */ 1866 if (onfiles > NDFILE) { 1867 /* 1868 * Note we may be called here from fdinit while allocating a 1869 * table for a new process in which case ->p_fd points 1870 * elsewhere. 1871 */ 1872 if (curproc->p_fd != fdp || FILEDESC_IS_ONLY_USER(fdp)) { 1873 free(otable, M_FILEDESC); 1874 } else { 1875 ft = (struct freetable *)&otable->fdt_ofiles[onfiles]; 1876 fdp0 = (struct filedesc0 *)fdp; 1877 ft->ft_table = otable; 1878 SLIST_INSERT_HEAD(&fdp0->fd_free, ft, ft_next); 1879 } 1880 } 1881 /* 1882 * The map does not have the same possibility of threads still 1883 * holding references to it. So always free it as long as it 1884 * does not reference the original static allocation. 1885 */ 1886 if (NDSLOTS(onfiles) > NDSLOTS(NDFILE)) 1887 free(omap, M_FILEDESC); 1888 } 1889 1890 /* 1891 * Allocate a file descriptor for the process. 1892 */ 1893 int 1894 fdalloc(struct thread *td, int minfd, int *result) 1895 { 1896 struct proc *p = td->td_proc; 1897 struct filedesc *fdp = p->p_fd; 1898 int fd, maxfd, allocfd; 1899 #ifdef RACCT 1900 int error; 1901 #endif 1902 1903 FILEDESC_XLOCK_ASSERT(fdp); 1904 1905 if (fdp->fd_freefile > minfd) 1906 minfd = fdp->fd_freefile; 1907 1908 maxfd = getmaxfd(td); 1909 1910 /* 1911 * Search the bitmap for a free descriptor starting at minfd. 1912 * If none is found, grow the file table. 1913 */ 1914 fd = fd_first_free(fdp, minfd, fdp->fd_nfiles); 1915 if (__predict_false(fd >= maxfd)) 1916 return (EMFILE); 1917 if (__predict_false(fd >= fdp->fd_nfiles)) { 1918 allocfd = min(fd * 2, maxfd); 1919 #ifdef RACCT 1920 if (RACCT_ENABLED()) { 1921 error = racct_set_unlocked(p, RACCT_NOFILE, allocfd); 1922 if (error != 0) 1923 return (EMFILE); 1924 } 1925 #endif 1926 /* 1927 * fd is already equal to first free descriptor >= minfd, so 1928 * we only need to grow the table and we are done. 1929 */ 1930 fdgrowtable_exp(fdp, allocfd); 1931 } 1932 1933 /* 1934 * Perform some sanity checks, then mark the file descriptor as 1935 * used and return it to the caller. 1936 */ 1937 KASSERT(fd >= 0 && fd < min(maxfd, fdp->fd_nfiles), 1938 ("invalid descriptor %d", fd)); 1939 KASSERT(!fdisused(fdp, fd), 1940 ("fd_first_free() returned non-free descriptor")); 1941 KASSERT(fdp->fd_ofiles[fd].fde_file == NULL, 1942 ("file descriptor isn't free")); 1943 fdused(fdp, fd); 1944 *result = fd; 1945 return (0); 1946 } 1947 1948 /* 1949 * Allocate n file descriptors for the process. 1950 */ 1951 int 1952 fdallocn(struct thread *td, int minfd, int *fds, int n) 1953 { 1954 struct proc *p = td->td_proc; 1955 struct filedesc *fdp = p->p_fd; 1956 int i; 1957 1958 FILEDESC_XLOCK_ASSERT(fdp); 1959 1960 for (i = 0; i < n; i++) 1961 if (fdalloc(td, 0, &fds[i]) != 0) 1962 break; 1963 1964 if (i < n) { 1965 for (i--; i >= 0; i--) 1966 fdunused(fdp, fds[i]); 1967 return (EMFILE); 1968 } 1969 1970 return (0); 1971 } 1972 1973 /* 1974 * Create a new open file structure and allocate a file descriptor for the 1975 * process that refers to it. We add one reference to the file for the 1976 * descriptor table and one reference for resultfp. This is to prevent us 1977 * being preempted and the entry in the descriptor table closed after we 1978 * release the FILEDESC lock. 1979 */ 1980 int 1981 falloc_caps(struct thread *td, struct file **resultfp, int *resultfd, int flags, 1982 struct filecaps *fcaps) 1983 { 1984 struct file *fp; 1985 int error, fd; 1986 1987 MPASS(resultfp != NULL); 1988 MPASS(resultfd != NULL); 1989 1990 error = _falloc_noinstall(td, &fp, 2); 1991 if (__predict_false(error != 0)) { 1992 return (error); 1993 } 1994 1995 error = finstall_refed(td, fp, &fd, flags, fcaps); 1996 if (__predict_false(error != 0)) { 1997 falloc_abort(td, fp); 1998 return (error); 1999 } 2000 2001 *resultfp = fp; 2002 *resultfd = fd; 2003 2004 return (0); 2005 } 2006 2007 /* 2008 * Create a new open file structure without allocating a file descriptor. 2009 */ 2010 int 2011 _falloc_noinstall(struct thread *td, struct file **resultfp, u_int n) 2012 { 2013 struct file *fp; 2014 int maxuserfiles = maxfiles - (maxfiles / 20); 2015 int openfiles_new; 2016 static struct timeval lastfail; 2017 static int curfail; 2018 2019 KASSERT(resultfp != NULL, ("%s: resultfp == NULL", __func__)); 2020 MPASS(n > 0); 2021 2022 openfiles_new = atomic_fetchadd_int(&openfiles, 1) + 1; 2023 if ((openfiles_new >= maxuserfiles && 2024 priv_check(td, PRIV_MAXFILES) != 0) || 2025 openfiles_new >= maxfiles) { 2026 atomic_subtract_int(&openfiles, 1); 2027 if (ppsratecheck(&lastfail, &curfail, 1)) { 2028 printf("kern.maxfiles limit exceeded by uid %i, (%s) " 2029 "please see tuning(7).\n", td->td_ucred->cr_ruid, td->td_proc->p_comm); 2030 } 2031 return (ENFILE); 2032 } 2033 fp = uma_zalloc(file_zone, M_WAITOK); 2034 bzero(fp, sizeof(*fp)); 2035 refcount_init(&fp->f_count, n); 2036 fp->f_cred = crhold(td->td_ucred); 2037 fp->f_ops = &badfileops; 2038 *resultfp = fp; 2039 return (0); 2040 } 2041 2042 void 2043 falloc_abort(struct thread *td, struct file *fp) 2044 { 2045 2046 /* 2047 * For assertion purposes. 2048 */ 2049 refcount_init(&fp->f_count, 0); 2050 _fdrop(fp, td); 2051 } 2052 2053 /* 2054 * Install a file in a file descriptor table. 2055 */ 2056 void 2057 _finstall(struct filedesc *fdp, struct file *fp, int fd, int flags, 2058 struct filecaps *fcaps) 2059 { 2060 struct filedescent *fde; 2061 2062 MPASS(fp != NULL); 2063 if (fcaps != NULL) 2064 filecaps_validate(fcaps, __func__); 2065 FILEDESC_XLOCK_ASSERT(fdp); 2066 2067 fde = &fdp->fd_ofiles[fd]; 2068 #ifdef CAPABILITIES 2069 seqc_write_begin(&fde->fde_seqc); 2070 #endif 2071 fde->fde_file = fp; 2072 fde->fde_flags = (flags & O_CLOEXEC) != 0 ? UF_EXCLOSE : 0; 2073 if (fcaps != NULL) 2074 filecaps_move(fcaps, &fde->fde_caps); 2075 else 2076 filecaps_fill(&fde->fde_caps); 2077 #ifdef CAPABILITIES 2078 seqc_write_end(&fde->fde_seqc); 2079 #endif 2080 } 2081 2082 int 2083 finstall_refed(struct thread *td, struct file *fp, int *fd, int flags, 2084 struct filecaps *fcaps) 2085 { 2086 struct filedesc *fdp = td->td_proc->p_fd; 2087 int error; 2088 2089 MPASS(fd != NULL); 2090 2091 FILEDESC_XLOCK(fdp); 2092 error = fdalloc(td, 0, fd); 2093 if (__predict_true(error == 0)) { 2094 _finstall(fdp, fp, *fd, flags, fcaps); 2095 } 2096 FILEDESC_XUNLOCK(fdp); 2097 return (error); 2098 } 2099 2100 int 2101 finstall(struct thread *td, struct file *fp, int *fd, int flags, 2102 struct filecaps *fcaps) 2103 { 2104 int error; 2105 2106 MPASS(fd != NULL); 2107 2108 if (!fhold(fp)) 2109 return (EBADF); 2110 error = finstall_refed(td, fp, fd, flags, fcaps); 2111 if (__predict_false(error != 0)) { 2112 fdrop(fp, td); 2113 } 2114 return (error); 2115 } 2116 2117 /* 2118 * Build a new filedesc structure from another. 2119 * 2120 * If fdp is not NULL, return with it shared locked. 2121 */ 2122 struct filedesc * 2123 fdinit(struct filedesc *fdp, bool prepfiles, int *lastfile) 2124 { 2125 struct filedesc0 *newfdp0; 2126 struct filedesc *newfdp; 2127 2128 if (prepfiles) 2129 MPASS(lastfile != NULL); 2130 else 2131 MPASS(lastfile == NULL); 2132 2133 newfdp0 = uma_zalloc(filedesc0_zone, M_WAITOK | M_ZERO); 2134 newfdp = &newfdp0->fd_fd; 2135 2136 /* Create the file descriptor table. */ 2137 FILEDESC_LOCK_INIT(newfdp); 2138 refcount_init(&newfdp->fd_refcnt, 1); 2139 refcount_init(&newfdp->fd_holdcnt, 1); 2140 newfdp->fd_map = newfdp0->fd_dmap; 2141 newfdp->fd_files = (struct fdescenttbl *)&newfdp0->fd_dfiles; 2142 newfdp->fd_files->fdt_nfiles = NDFILE; 2143 2144 if (fdp == NULL) 2145 return (newfdp); 2146 2147 FILEDESC_SLOCK(fdp); 2148 if (!prepfiles) { 2149 FILEDESC_SUNLOCK(fdp); 2150 return (newfdp); 2151 } 2152 2153 for (;;) { 2154 *lastfile = fdlastfile(fdp); 2155 if (*lastfile < newfdp->fd_nfiles) 2156 break; 2157 FILEDESC_SUNLOCK(fdp); 2158 fdgrowtable(newfdp, *lastfile + 1); 2159 FILEDESC_SLOCK(fdp); 2160 } 2161 2162 return (newfdp); 2163 } 2164 2165 /* 2166 * Build a pwddesc structure from another. 2167 * Copy the current, root, and jail root vnode references. 2168 * 2169 * If pdp is not NULL, return with it shared locked. 2170 */ 2171 struct pwddesc * 2172 pdinit(struct pwddesc *pdp, bool keeplock) 2173 { 2174 struct pwddesc *newpdp; 2175 struct pwd *newpwd; 2176 2177 newpdp = malloc(sizeof(*newpdp), M_PWDDESC, M_WAITOK | M_ZERO); 2178 2179 PWDDESC_LOCK_INIT(newpdp); 2180 refcount_init(&newpdp->pd_refcount, 1); 2181 newpdp->pd_cmask = CMASK; 2182 2183 if (pdp == NULL) { 2184 newpwd = pwd_alloc(); 2185 smr_serialized_store(&newpdp->pd_pwd, newpwd, true); 2186 return (newpdp); 2187 } 2188 2189 PWDDESC_XLOCK(pdp); 2190 newpwd = pwd_hold_pwddesc(pdp); 2191 smr_serialized_store(&newpdp->pd_pwd, newpwd, true); 2192 if (!keeplock) 2193 PWDDESC_XUNLOCK(pdp); 2194 return (newpdp); 2195 } 2196 2197 static struct filedesc * 2198 fdhold(struct proc *p) 2199 { 2200 struct filedesc *fdp; 2201 2202 PROC_LOCK_ASSERT(p, MA_OWNED); 2203 fdp = p->p_fd; 2204 if (fdp != NULL) 2205 refcount_acquire(&fdp->fd_holdcnt); 2206 return (fdp); 2207 } 2208 2209 static struct pwddesc * 2210 pdhold(struct proc *p) 2211 { 2212 struct pwddesc *pdp; 2213 2214 PROC_LOCK_ASSERT(p, MA_OWNED); 2215 pdp = p->p_pd; 2216 if (pdp != NULL) 2217 refcount_acquire(&pdp->pd_refcount); 2218 return (pdp); 2219 } 2220 2221 static void 2222 fddrop(struct filedesc *fdp) 2223 { 2224 2225 if (refcount_load(&fdp->fd_holdcnt) > 1) { 2226 if (refcount_release(&fdp->fd_holdcnt) == 0) 2227 return; 2228 } 2229 2230 FILEDESC_LOCK_DESTROY(fdp); 2231 uma_zfree(filedesc0_zone, fdp); 2232 } 2233 2234 static void 2235 pddrop(struct pwddesc *pdp) 2236 { 2237 struct pwd *pwd; 2238 2239 if (refcount_release_if_not_last(&pdp->pd_refcount)) 2240 return; 2241 2242 PWDDESC_XLOCK(pdp); 2243 if (refcount_release(&pdp->pd_refcount) == 0) { 2244 PWDDESC_XUNLOCK(pdp); 2245 return; 2246 } 2247 pwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); 2248 pwd_set(pdp, NULL); 2249 PWDDESC_XUNLOCK(pdp); 2250 pwd_drop(pwd); 2251 2252 PWDDESC_LOCK_DESTROY(pdp); 2253 free(pdp, M_PWDDESC); 2254 } 2255 2256 /* 2257 * Share a filedesc structure. 2258 */ 2259 struct filedesc * 2260 fdshare(struct filedesc *fdp) 2261 { 2262 2263 refcount_acquire(&fdp->fd_refcnt); 2264 return (fdp); 2265 } 2266 2267 /* 2268 * Share a pwddesc structure. 2269 */ 2270 struct pwddesc * 2271 pdshare(struct pwddesc *pdp) 2272 { 2273 refcount_acquire(&pdp->pd_refcount); 2274 return (pdp); 2275 } 2276 2277 /* 2278 * Unshare a filedesc structure, if necessary by making a copy 2279 */ 2280 void 2281 fdunshare(struct thread *td) 2282 { 2283 struct filedesc *tmp; 2284 struct proc *p = td->td_proc; 2285 2286 if (refcount_load(&p->p_fd->fd_refcnt) == 1) 2287 return; 2288 2289 tmp = fdcopy(p->p_fd); 2290 fdescfree(td); 2291 p->p_fd = tmp; 2292 } 2293 2294 /* 2295 * Unshare a pwddesc structure. 2296 */ 2297 void 2298 pdunshare(struct thread *td) 2299 { 2300 struct pwddesc *pdp; 2301 struct proc *p; 2302 2303 p = td->td_proc; 2304 /* Not shared. */ 2305 if (p->p_pd->pd_refcount == 1) 2306 return; 2307 2308 pdp = pdcopy(p->p_pd); 2309 pdescfree(td); 2310 p->p_pd = pdp; 2311 } 2312 2313 void 2314 fdinstall_remapped(struct thread *td, struct filedesc *fdp) 2315 { 2316 2317 fdescfree(td); 2318 td->td_proc->p_fd = fdp; 2319 } 2320 2321 /* 2322 * Copy a filedesc structure. A NULL pointer in returns a NULL reference, 2323 * this is to ease callers, not catch errors. 2324 */ 2325 struct filedesc * 2326 fdcopy(struct filedesc *fdp) 2327 { 2328 struct filedesc *newfdp; 2329 struct filedescent *nfde, *ofde; 2330 int i, lastfile; 2331 2332 MPASS(fdp != NULL); 2333 2334 newfdp = fdinit(fdp, true, &lastfile); 2335 /* copy all passable descriptors (i.e. not kqueue) */ 2336 newfdp->fd_freefile = -1; 2337 for (i = 0; i <= lastfile; ++i) { 2338 ofde = &fdp->fd_ofiles[i]; 2339 if (ofde->fde_file == NULL || 2340 (ofde->fde_file->f_ops->fo_flags & DFLAG_PASSABLE) == 0 || 2341 !fhold(ofde->fde_file)) { 2342 if (newfdp->fd_freefile == -1) 2343 newfdp->fd_freefile = i; 2344 continue; 2345 } 2346 nfde = &newfdp->fd_ofiles[i]; 2347 *nfde = *ofde; 2348 filecaps_copy(&ofde->fde_caps, &nfde->fde_caps, true); 2349 fdused_init(newfdp, i); 2350 } 2351 if (newfdp->fd_freefile == -1) 2352 newfdp->fd_freefile = i; 2353 FILEDESC_SUNLOCK(fdp); 2354 return (newfdp); 2355 } 2356 2357 /* 2358 * Copy a pwddesc structure. 2359 */ 2360 struct pwddesc * 2361 pdcopy(struct pwddesc *pdp) 2362 { 2363 struct pwddesc *newpdp; 2364 2365 MPASS(pdp != NULL); 2366 2367 newpdp = pdinit(pdp, true); 2368 newpdp->pd_cmask = pdp->pd_cmask; 2369 PWDDESC_XUNLOCK(pdp); 2370 return (newpdp); 2371 } 2372 2373 /* 2374 * Copies a filedesc structure, while remapping all file descriptors 2375 * stored inside using a translation table. 2376 * 2377 * File descriptors are copied over to the new file descriptor table, 2378 * regardless of whether the close-on-exec flag is set. 2379 */ 2380 int 2381 fdcopy_remapped(struct filedesc *fdp, const int *fds, size_t nfds, 2382 struct filedesc **ret) 2383 { 2384 struct filedesc *newfdp; 2385 struct filedescent *nfde, *ofde; 2386 int error, i, lastfile; 2387 2388 MPASS(fdp != NULL); 2389 2390 newfdp = fdinit(fdp, true, &lastfile); 2391 if (nfds > lastfile + 1) { 2392 /* New table cannot be larger than the old one. */ 2393 error = E2BIG; 2394 goto bad; 2395 } 2396 /* Copy all passable descriptors (i.e. not kqueue). */ 2397 newfdp->fd_freefile = nfds; 2398 for (i = 0; i < nfds; ++i) { 2399 if (fds[i] < 0 || fds[i] > lastfile) { 2400 /* File descriptor out of bounds. */ 2401 error = EBADF; 2402 goto bad; 2403 } 2404 ofde = &fdp->fd_ofiles[fds[i]]; 2405 if (ofde->fde_file == NULL) { 2406 /* Unused file descriptor. */ 2407 error = EBADF; 2408 goto bad; 2409 } 2410 if ((ofde->fde_file->f_ops->fo_flags & DFLAG_PASSABLE) == 0) { 2411 /* File descriptor cannot be passed. */ 2412 error = EINVAL; 2413 goto bad; 2414 } 2415 if (!fhold(ofde->fde_file)) { 2416 error = EBADF; 2417 goto bad; 2418 } 2419 nfde = &newfdp->fd_ofiles[i]; 2420 *nfde = *ofde; 2421 filecaps_copy(&ofde->fde_caps, &nfde->fde_caps, true); 2422 fdused_init(newfdp, i); 2423 } 2424 FILEDESC_SUNLOCK(fdp); 2425 *ret = newfdp; 2426 return (0); 2427 bad: 2428 FILEDESC_SUNLOCK(fdp); 2429 fdescfree_remapped(newfdp); 2430 return (error); 2431 } 2432 2433 /* 2434 * Clear POSIX style locks. This is only used when fdp looses a reference (i.e. 2435 * one of processes using it exits) and the table used to be shared. 2436 */ 2437 static void 2438 fdclearlocks(struct thread *td) 2439 { 2440 struct filedesc *fdp; 2441 struct filedesc_to_leader *fdtol; 2442 struct flock lf; 2443 struct file *fp; 2444 struct proc *p; 2445 struct vnode *vp; 2446 int i, lastfile; 2447 2448 p = td->td_proc; 2449 fdp = p->p_fd; 2450 fdtol = p->p_fdtol; 2451 MPASS(fdtol != NULL); 2452 2453 FILEDESC_XLOCK(fdp); 2454 KASSERT(fdtol->fdl_refcount > 0, 2455 ("filedesc_to_refcount botch: fdl_refcount=%d", 2456 fdtol->fdl_refcount)); 2457 if (fdtol->fdl_refcount == 1 && 2458 (p->p_leader->p_flag & P_ADVLOCK) != 0) { 2459 lastfile = fdlastfile(fdp); 2460 for (i = 0; i <= lastfile; i++) { 2461 fp = fdp->fd_ofiles[i].fde_file; 2462 if (fp == NULL || fp->f_type != DTYPE_VNODE || 2463 !fhold(fp)) 2464 continue; 2465 FILEDESC_XUNLOCK(fdp); 2466 lf.l_whence = SEEK_SET; 2467 lf.l_start = 0; 2468 lf.l_len = 0; 2469 lf.l_type = F_UNLCK; 2470 vp = fp->f_vnode; 2471 (void) VOP_ADVLOCK(vp, 2472 (caddr_t)p->p_leader, F_UNLCK, 2473 &lf, F_POSIX); 2474 FILEDESC_XLOCK(fdp); 2475 fdrop(fp, td); 2476 } 2477 } 2478 retry: 2479 if (fdtol->fdl_refcount == 1) { 2480 if (fdp->fd_holdleaderscount > 0 && 2481 (p->p_leader->p_flag & P_ADVLOCK) != 0) { 2482 /* 2483 * close() or kern_dup() has cleared a reference 2484 * in a shared file descriptor table. 2485 */ 2486 fdp->fd_holdleaderswakeup = 1; 2487 sx_sleep(&fdp->fd_holdleaderscount, 2488 FILEDESC_LOCK(fdp), PLOCK, "fdlhold", 0); 2489 goto retry; 2490 } 2491 if (fdtol->fdl_holdcount > 0) { 2492 /* 2493 * Ensure that fdtol->fdl_leader remains 2494 * valid in closef(). 2495 */ 2496 fdtol->fdl_wakeup = 1; 2497 sx_sleep(fdtol, FILEDESC_LOCK(fdp), PLOCK, 2498 "fdlhold", 0); 2499 goto retry; 2500 } 2501 } 2502 fdtol->fdl_refcount--; 2503 if (fdtol->fdl_refcount == 0 && 2504 fdtol->fdl_holdcount == 0) { 2505 fdtol->fdl_next->fdl_prev = fdtol->fdl_prev; 2506 fdtol->fdl_prev->fdl_next = fdtol->fdl_next; 2507 } else 2508 fdtol = NULL; 2509 p->p_fdtol = NULL; 2510 FILEDESC_XUNLOCK(fdp); 2511 if (fdtol != NULL) 2512 free(fdtol, M_FILEDESC_TO_LEADER); 2513 } 2514 2515 /* 2516 * Release a filedesc structure. 2517 */ 2518 static void 2519 fdescfree_fds(struct thread *td, struct filedesc *fdp, bool needclose) 2520 { 2521 struct filedesc0 *fdp0; 2522 struct freetable *ft, *tft; 2523 struct filedescent *fde; 2524 struct file *fp; 2525 int i, lastfile; 2526 2527 KASSERT(refcount_load(&fdp->fd_refcnt) == 0, 2528 ("%s: fd table %p carries references", __func__, fdp)); 2529 2530 /* 2531 * Serialize with threads iterating over the table, if any. 2532 */ 2533 if (refcount_load(&fdp->fd_holdcnt) > 1) { 2534 FILEDESC_XLOCK(fdp); 2535 FILEDESC_XUNLOCK(fdp); 2536 } 2537 2538 lastfile = fdlastfile_single(fdp); 2539 for (i = 0; i <= lastfile; i++) { 2540 fde = &fdp->fd_ofiles[i]; 2541 fp = fde->fde_file; 2542 if (fp != NULL) { 2543 fdefree_last(fde); 2544 if (needclose) 2545 (void) closef(fp, td); 2546 else 2547 fdrop(fp, td); 2548 } 2549 } 2550 2551 if (NDSLOTS(fdp->fd_nfiles) > NDSLOTS(NDFILE)) 2552 free(fdp->fd_map, M_FILEDESC); 2553 if (fdp->fd_nfiles > NDFILE) 2554 free(fdp->fd_files, M_FILEDESC); 2555 2556 fdp0 = (struct filedesc0 *)fdp; 2557 SLIST_FOREACH_SAFE(ft, &fdp0->fd_free, ft_next, tft) 2558 free(ft->ft_table, M_FILEDESC); 2559 2560 fddrop(fdp); 2561 } 2562 2563 void 2564 fdescfree(struct thread *td) 2565 { 2566 struct proc *p; 2567 struct filedesc *fdp; 2568 2569 p = td->td_proc; 2570 fdp = p->p_fd; 2571 MPASS(fdp != NULL); 2572 2573 #ifdef RACCT 2574 if (RACCT_ENABLED()) 2575 racct_set_unlocked(p, RACCT_NOFILE, 0); 2576 #endif 2577 2578 if (p->p_fdtol != NULL) 2579 fdclearlocks(td); 2580 2581 PROC_LOCK(p); 2582 p->p_fd = NULL; 2583 PROC_UNLOCK(p); 2584 2585 if (refcount_release(&fdp->fd_refcnt) == 0) 2586 return; 2587 2588 fdescfree_fds(td, fdp, 1); 2589 } 2590 2591 void 2592 pdescfree(struct thread *td) 2593 { 2594 struct proc *p; 2595 struct pwddesc *pdp; 2596 2597 p = td->td_proc; 2598 pdp = p->p_pd; 2599 MPASS(pdp != NULL); 2600 2601 PROC_LOCK(p); 2602 p->p_pd = NULL; 2603 PROC_UNLOCK(p); 2604 2605 pddrop(pdp); 2606 } 2607 2608 void 2609 fdescfree_remapped(struct filedesc *fdp) 2610 { 2611 #ifdef INVARIANTS 2612 /* fdescfree_fds() asserts that fd_refcnt == 0. */ 2613 if (!refcount_release(&fdp->fd_refcnt)) 2614 panic("%s: fd table %p has extra references", __func__, fdp); 2615 #endif 2616 fdescfree_fds(curthread, fdp, 0); 2617 } 2618 2619 /* 2620 * For setugid programs, we don't want to people to use that setugidness 2621 * to generate error messages which write to a file which otherwise would 2622 * otherwise be off-limits to the process. We check for filesystems where 2623 * the vnode can change out from under us after execve (like [lin]procfs). 2624 * 2625 * Since fdsetugidsafety calls this only for fd 0, 1 and 2, this check is 2626 * sufficient. We also don't check for setugidness since we know we are. 2627 */ 2628 static bool 2629 is_unsafe(struct file *fp) 2630 { 2631 struct vnode *vp; 2632 2633 if (fp->f_type != DTYPE_VNODE) 2634 return (false); 2635 2636 vp = fp->f_vnode; 2637 return ((vp->v_vflag & VV_PROCDEP) != 0); 2638 } 2639 2640 /* 2641 * Make this setguid thing safe, if at all possible. 2642 */ 2643 void 2644 fdsetugidsafety(struct thread *td) 2645 { 2646 struct filedesc *fdp; 2647 struct file *fp; 2648 int i; 2649 2650 fdp = td->td_proc->p_fd; 2651 KASSERT(refcount_load(&fdp->fd_refcnt) == 1, 2652 ("the fdtable should not be shared")); 2653 MPASS(fdp->fd_nfiles >= 3); 2654 for (i = 0; i <= 2; i++) { 2655 fp = fdp->fd_ofiles[i].fde_file; 2656 if (fp != NULL && is_unsafe(fp)) { 2657 FILEDESC_XLOCK(fdp); 2658 knote_fdclose(td, i); 2659 /* 2660 * NULL-out descriptor prior to close to avoid 2661 * a race while close blocks. 2662 */ 2663 fdfree(fdp, i); 2664 FILEDESC_XUNLOCK(fdp); 2665 (void) closef(fp, td); 2666 } 2667 } 2668 } 2669 2670 /* 2671 * If a specific file object occupies a specific file descriptor, close the 2672 * file descriptor entry and drop a reference on the file object. This is a 2673 * convenience function to handle a subsequent error in a function that calls 2674 * falloc() that handles the race that another thread might have closed the 2675 * file descriptor out from under the thread creating the file object. 2676 */ 2677 void 2678 fdclose(struct thread *td, struct file *fp, int idx) 2679 { 2680 struct filedesc *fdp = td->td_proc->p_fd; 2681 2682 FILEDESC_XLOCK(fdp); 2683 if (fdp->fd_ofiles[idx].fde_file == fp) { 2684 fdfree(fdp, idx); 2685 FILEDESC_XUNLOCK(fdp); 2686 fdrop(fp, td); 2687 } else 2688 FILEDESC_XUNLOCK(fdp); 2689 } 2690 2691 /* 2692 * Close any files on exec? 2693 */ 2694 void 2695 fdcloseexec(struct thread *td) 2696 { 2697 struct filedesc *fdp; 2698 struct filedescent *fde; 2699 struct file *fp; 2700 int i, lastfile; 2701 2702 fdp = td->td_proc->p_fd; 2703 KASSERT(refcount_load(&fdp->fd_refcnt) == 1, 2704 ("the fdtable should not be shared")); 2705 lastfile = fdlastfile_single(fdp); 2706 for (i = 0; i <= lastfile; i++) { 2707 fde = &fdp->fd_ofiles[i]; 2708 fp = fde->fde_file; 2709 if (fp != NULL && (fp->f_type == DTYPE_MQUEUE || 2710 (fde->fde_flags & UF_EXCLOSE))) { 2711 FILEDESC_XLOCK(fdp); 2712 fdfree(fdp, i); 2713 (void) closefp(fdp, i, fp, td, false, false); 2714 FILEDESC_UNLOCK_ASSERT(fdp); 2715 } 2716 } 2717 } 2718 2719 /* 2720 * It is unsafe for set[ug]id processes to be started with file 2721 * descriptors 0..2 closed, as these descriptors are given implicit 2722 * significance in the Standard C library. fdcheckstd() will create a 2723 * descriptor referencing /dev/null for each of stdin, stdout, and 2724 * stderr that is not already open. 2725 */ 2726 int 2727 fdcheckstd(struct thread *td) 2728 { 2729 struct filedesc *fdp; 2730 register_t save; 2731 int i, error, devnull; 2732 2733 fdp = td->td_proc->p_fd; 2734 KASSERT(refcount_load(&fdp->fd_refcnt) == 1, 2735 ("the fdtable should not be shared")); 2736 MPASS(fdp->fd_nfiles >= 3); 2737 devnull = -1; 2738 for (i = 0; i <= 2; i++) { 2739 if (fdp->fd_ofiles[i].fde_file != NULL) 2740 continue; 2741 2742 save = td->td_retval[0]; 2743 if (devnull != -1) { 2744 error = kern_dup(td, FDDUP_FIXED, 0, devnull, i); 2745 } else { 2746 error = kern_openat(td, AT_FDCWD, "/dev/null", 2747 UIO_SYSSPACE, O_RDWR, 0); 2748 if (error == 0) { 2749 devnull = td->td_retval[0]; 2750 KASSERT(devnull == i, ("we didn't get our fd")); 2751 } 2752 } 2753 td->td_retval[0] = save; 2754 if (error != 0) 2755 return (error); 2756 } 2757 return (0); 2758 } 2759 2760 /* 2761 * Internal form of close. Decrement reference count on file structure. 2762 * Note: td may be NULL when closing a file that was being passed in a 2763 * message. 2764 */ 2765 int 2766 closef(struct file *fp, struct thread *td) 2767 { 2768 struct vnode *vp; 2769 struct flock lf; 2770 struct filedesc_to_leader *fdtol; 2771 struct filedesc *fdp; 2772 2773 MPASS(td != NULL); 2774 2775 /* 2776 * POSIX record locking dictates that any close releases ALL 2777 * locks owned by this process. This is handled by setting 2778 * a flag in the unlock to free ONLY locks obeying POSIX 2779 * semantics, and not to free BSD-style file locks. 2780 * If the descriptor was in a message, POSIX-style locks 2781 * aren't passed with the descriptor, and the thread pointer 2782 * will be NULL. Callers should be careful only to pass a 2783 * NULL thread pointer when there really is no owning 2784 * context that might have locks, or the locks will be 2785 * leaked. 2786 */ 2787 if (fp->f_type == DTYPE_VNODE) { 2788 vp = fp->f_vnode; 2789 if ((td->td_proc->p_leader->p_flag & P_ADVLOCK) != 0) { 2790 lf.l_whence = SEEK_SET; 2791 lf.l_start = 0; 2792 lf.l_len = 0; 2793 lf.l_type = F_UNLCK; 2794 (void) VOP_ADVLOCK(vp, (caddr_t)td->td_proc->p_leader, 2795 F_UNLCK, &lf, F_POSIX); 2796 } 2797 fdtol = td->td_proc->p_fdtol; 2798 if (fdtol != NULL) { 2799 /* 2800 * Handle special case where file descriptor table is 2801 * shared between multiple process leaders. 2802 */ 2803 fdp = td->td_proc->p_fd; 2804 FILEDESC_XLOCK(fdp); 2805 for (fdtol = fdtol->fdl_next; 2806 fdtol != td->td_proc->p_fdtol; 2807 fdtol = fdtol->fdl_next) { 2808 if ((fdtol->fdl_leader->p_flag & 2809 P_ADVLOCK) == 0) 2810 continue; 2811 fdtol->fdl_holdcount++; 2812 FILEDESC_XUNLOCK(fdp); 2813 lf.l_whence = SEEK_SET; 2814 lf.l_start = 0; 2815 lf.l_len = 0; 2816 lf.l_type = F_UNLCK; 2817 vp = fp->f_vnode; 2818 (void) VOP_ADVLOCK(vp, 2819 (caddr_t)fdtol->fdl_leader, F_UNLCK, &lf, 2820 F_POSIX); 2821 FILEDESC_XLOCK(fdp); 2822 fdtol->fdl_holdcount--; 2823 if (fdtol->fdl_holdcount == 0 && 2824 fdtol->fdl_wakeup != 0) { 2825 fdtol->fdl_wakeup = 0; 2826 wakeup(fdtol); 2827 } 2828 } 2829 FILEDESC_XUNLOCK(fdp); 2830 } 2831 } 2832 return (fdrop_close(fp, td)); 2833 } 2834 2835 /* 2836 * Hack for file descriptor passing code. 2837 */ 2838 void 2839 closef_nothread(struct file *fp) 2840 { 2841 2842 fdrop(fp, NULL); 2843 } 2844 2845 /* 2846 * Initialize the file pointer with the specified properties. 2847 * 2848 * The ops are set with release semantics to be certain that the flags, type, 2849 * and data are visible when ops is. This is to prevent ops methods from being 2850 * called with bad data. 2851 */ 2852 void 2853 finit(struct file *fp, u_int flag, short type, void *data, struct fileops *ops) 2854 { 2855 fp->f_data = data; 2856 fp->f_flag = flag; 2857 fp->f_type = type; 2858 atomic_store_rel_ptr((volatile uintptr_t *)&fp->f_ops, (uintptr_t)ops); 2859 } 2860 2861 void 2862 finit_vnode(struct file *fp, u_int flag, void *data, struct fileops *ops) 2863 { 2864 fp->f_seqcount[UIO_READ] = 1; 2865 fp->f_seqcount[UIO_WRITE] = 1; 2866 finit(fp, (flag & FMASK) | (fp->f_flag & FHASLOCK), DTYPE_VNODE, 2867 data, ops); 2868 } 2869 2870 int 2871 fget_cap_locked(struct filedesc *fdp, int fd, cap_rights_t *needrightsp, 2872 struct file **fpp, struct filecaps *havecapsp) 2873 { 2874 struct filedescent *fde; 2875 int error; 2876 2877 FILEDESC_LOCK_ASSERT(fdp); 2878 2879 fde = fdeget_locked(fdp, fd); 2880 if (fde == NULL) { 2881 error = EBADF; 2882 goto out; 2883 } 2884 2885 #ifdef CAPABILITIES 2886 error = cap_check(cap_rights_fde_inline(fde), needrightsp); 2887 if (error != 0) 2888 goto out; 2889 #endif 2890 2891 if (havecapsp != NULL) 2892 filecaps_copy(&fde->fde_caps, havecapsp, true); 2893 2894 *fpp = fde->fde_file; 2895 2896 error = 0; 2897 out: 2898 return (error); 2899 } 2900 2901 int 2902 fget_cap(struct thread *td, int fd, cap_rights_t *needrightsp, 2903 struct file **fpp, struct filecaps *havecapsp) 2904 { 2905 struct filedesc *fdp = td->td_proc->p_fd; 2906 int error; 2907 #ifndef CAPABILITIES 2908 error = fget_unlocked(fdp, fd, needrightsp, fpp); 2909 if (havecapsp != NULL && error == 0) 2910 filecaps_fill(havecapsp); 2911 #else 2912 struct file *fp; 2913 seqc_t seq; 2914 2915 *fpp = NULL; 2916 for (;;) { 2917 error = fget_unlocked_seq(fdp, fd, needrightsp, &fp, &seq); 2918 if (error != 0) 2919 return (error); 2920 2921 if (havecapsp != NULL) { 2922 if (!filecaps_copy(&fdp->fd_ofiles[fd].fde_caps, 2923 havecapsp, false)) { 2924 fdrop(fp, td); 2925 goto get_locked; 2926 } 2927 } 2928 2929 if (!fd_modified(fdp, fd, seq)) 2930 break; 2931 fdrop(fp, td); 2932 } 2933 2934 *fpp = fp; 2935 return (0); 2936 2937 get_locked: 2938 FILEDESC_SLOCK(fdp); 2939 error = fget_cap_locked(fdp, fd, needrightsp, fpp, havecapsp); 2940 if (error == 0 && !fhold(*fpp)) 2941 error = EBADF; 2942 FILEDESC_SUNLOCK(fdp); 2943 #endif 2944 return (error); 2945 } 2946 2947 #ifdef CAPABILITIES 2948 int 2949 fgetvp_lookup_smr(int fd, struct nameidata *ndp, struct vnode **vpp, bool *fsearch) 2950 { 2951 const struct filedescent *fde; 2952 const struct fdescenttbl *fdt; 2953 struct filedesc *fdp; 2954 struct file *fp; 2955 struct vnode *vp; 2956 const cap_rights_t *haverights; 2957 cap_rights_t rights; 2958 seqc_t seq; 2959 2960 VFS_SMR_ASSERT_ENTERED(); 2961 2962 rights = *ndp->ni_rightsneeded; 2963 cap_rights_set_one(&rights, CAP_LOOKUP); 2964 2965 fdp = curproc->p_fd; 2966 fdt = fdp->fd_files; 2967 if (__predict_false((u_int)fd >= fdt->fdt_nfiles)) 2968 return (EBADF); 2969 seq = seqc_read_notmodify(fd_seqc(fdt, fd)); 2970 fde = &fdt->fdt_ofiles[fd]; 2971 haverights = cap_rights_fde_inline(fde); 2972 fp = fde->fde_file; 2973 if (__predict_false(fp == NULL)) 2974 return (EAGAIN); 2975 if (__predict_false(cap_check_inline_transient(haverights, &rights))) 2976 return (EAGAIN); 2977 *fsearch = ((fp->f_flag & FSEARCH) != 0); 2978 vp = fp->f_vnode; 2979 if (__predict_false(vp == NULL || vp->v_type != VDIR)) { 2980 return (EAGAIN); 2981 } 2982 if (!filecaps_copy(&fde->fde_caps, &ndp->ni_filecaps, false)) { 2983 return (EAGAIN); 2984 } 2985 /* 2986 * Use an acquire barrier to force re-reading of fdt so it is 2987 * refreshed for verification. 2988 */ 2989 atomic_thread_fence_acq(); 2990 fdt = fdp->fd_files; 2991 if (__predict_false(!seqc_consistent_nomb(fd_seqc(fdt, fd), seq))) 2992 return (EAGAIN); 2993 /* 2994 * If file descriptor doesn't have all rights, 2995 * all lookups relative to it must also be 2996 * strictly relative. 2997 * 2998 * Not yet supported by fast path. 2999 */ 3000 CAP_ALL(&rights); 3001 if (!cap_rights_contains(&ndp->ni_filecaps.fc_rights, &rights) || 3002 ndp->ni_filecaps.fc_fcntls != CAP_FCNTL_ALL || 3003 ndp->ni_filecaps.fc_nioctls != -1) { 3004 #ifdef notyet 3005 ndp->ni_lcf |= NI_LCF_STRICTRELATIVE; 3006 #else 3007 return (EAGAIN); 3008 #endif 3009 } 3010 *vpp = vp; 3011 return (0); 3012 } 3013 #else 3014 int 3015 fgetvp_lookup_smr(int fd, struct nameidata *ndp, struct vnode **vpp, bool *fsearch) 3016 { 3017 const struct fdescenttbl *fdt; 3018 struct filedesc *fdp; 3019 struct file *fp; 3020 struct vnode *vp; 3021 3022 VFS_SMR_ASSERT_ENTERED(); 3023 3024 fdp = curproc->p_fd; 3025 fdt = fdp->fd_files; 3026 if (__predict_false((u_int)fd >= fdt->fdt_nfiles)) 3027 return (EBADF); 3028 fp = fdt->fdt_ofiles[fd].fde_file; 3029 if (__predict_false(fp == NULL)) 3030 return (EAGAIN); 3031 *fsearch = ((fp->f_flag & FSEARCH) != 0); 3032 vp = fp->f_vnode; 3033 if (__predict_false(vp == NULL || vp->v_type != VDIR)) { 3034 return (EAGAIN); 3035 } 3036 /* 3037 * Use an acquire barrier to force re-reading of fdt so it is 3038 * refreshed for verification. 3039 */ 3040 atomic_thread_fence_acq(); 3041 fdt = fdp->fd_files; 3042 if (__predict_false(fp != fdt->fdt_ofiles[fd].fde_file)) 3043 return (EAGAIN); 3044 filecaps_fill(&ndp->ni_filecaps); 3045 *vpp = vp; 3046 return (0); 3047 } 3048 #endif 3049 3050 int 3051 fget_unlocked_seq(struct filedesc *fdp, int fd, cap_rights_t *needrightsp, 3052 struct file **fpp, seqc_t *seqp) 3053 { 3054 #ifdef CAPABILITIES 3055 const struct filedescent *fde; 3056 #endif 3057 const struct fdescenttbl *fdt; 3058 struct file *fp; 3059 #ifdef CAPABILITIES 3060 seqc_t seq; 3061 cap_rights_t haverights; 3062 int error; 3063 #endif 3064 3065 fdt = fdp->fd_files; 3066 if (__predict_false((u_int)fd >= fdt->fdt_nfiles)) 3067 return (EBADF); 3068 /* 3069 * Fetch the descriptor locklessly. We avoid fdrop() races by 3070 * never raising a refcount above 0. To accomplish this we have 3071 * to use a cmpset loop rather than an atomic_add. The descriptor 3072 * must be re-verified once we acquire a reference to be certain 3073 * that the identity is still correct and we did not lose a race 3074 * due to preemption. 3075 */ 3076 for (;;) { 3077 #ifdef CAPABILITIES 3078 seq = seqc_read_notmodify(fd_seqc(fdt, fd)); 3079 fde = &fdt->fdt_ofiles[fd]; 3080 haverights = *cap_rights_fde_inline(fde); 3081 fp = fde->fde_file; 3082 if (!seqc_consistent(fd_seqc(fdt, fd), seq)) 3083 continue; 3084 #else 3085 fp = fdt->fdt_ofiles[fd].fde_file; 3086 #endif 3087 if (fp == NULL) 3088 return (EBADF); 3089 #ifdef CAPABILITIES 3090 error = cap_check_inline(&haverights, needrightsp); 3091 if (error != 0) 3092 return (error); 3093 #endif 3094 if (__predict_false(!refcount_acquire_if_not_zero(&fp->f_count))) { 3095 /* 3096 * Force a reload. Other thread could reallocate the 3097 * table before this fd was closed, so it is possible 3098 * that there is a stale fp pointer in cached version. 3099 */ 3100 fdt = atomic_load_ptr(&fdp->fd_files); 3101 continue; 3102 } 3103 /* 3104 * Use an acquire barrier to force re-reading of fdt so it is 3105 * refreshed for verification. 3106 */ 3107 atomic_thread_fence_acq(); 3108 fdt = fdp->fd_files; 3109 #ifdef CAPABILITIES 3110 if (seqc_consistent_nomb(fd_seqc(fdt, fd), seq)) 3111 #else 3112 if (fp == fdt->fdt_ofiles[fd].fde_file) 3113 #endif 3114 break; 3115 fdrop(fp, curthread); 3116 } 3117 *fpp = fp; 3118 if (seqp != NULL) { 3119 #ifdef CAPABILITIES 3120 *seqp = seq; 3121 #endif 3122 } 3123 return (0); 3124 } 3125 3126 /* 3127 * See the comments in fget_unlocked_seq for an explanation of how this works. 3128 * 3129 * This is a simplified variant which bails out to the aforementioned routine 3130 * if anything goes wrong. In practice this only happens when userspace is 3131 * racing with itself. 3132 */ 3133 int 3134 fget_unlocked(struct filedesc *fdp, int fd, cap_rights_t *needrightsp, 3135 struct file **fpp) 3136 { 3137 #ifdef CAPABILITIES 3138 const struct filedescent *fde; 3139 #endif 3140 const struct fdescenttbl *fdt; 3141 struct file *fp; 3142 #ifdef CAPABILITIES 3143 seqc_t seq; 3144 const cap_rights_t *haverights; 3145 #endif 3146 3147 fdt = fdp->fd_files; 3148 if (__predict_false((u_int)fd >= fdt->fdt_nfiles)) 3149 return (EBADF); 3150 #ifdef CAPABILITIES 3151 seq = seqc_read_notmodify(fd_seqc(fdt, fd)); 3152 fde = &fdt->fdt_ofiles[fd]; 3153 haverights = cap_rights_fde_inline(fde); 3154 fp = fde->fde_file; 3155 #else 3156 fp = fdt->fdt_ofiles[fd].fde_file; 3157 #endif 3158 if (__predict_false(fp == NULL)) 3159 goto out_fallback; 3160 #ifdef CAPABILITIES 3161 if (__predict_false(cap_check_inline_transient(haverights, needrightsp))) 3162 goto out_fallback; 3163 #endif 3164 if (__predict_false(!refcount_acquire_if_not_zero(&fp->f_count))) 3165 goto out_fallback; 3166 3167 /* 3168 * Use an acquire barrier to force re-reading of fdt so it is 3169 * refreshed for verification. 3170 */ 3171 atomic_thread_fence_acq(); 3172 fdt = fdp->fd_files; 3173 #ifdef CAPABILITIES 3174 if (__predict_false(!seqc_consistent_nomb(fd_seqc(fdt, fd), seq))) 3175 #else 3176 if (__predict_false(fp != fdt->fdt_ofiles[fd].fde_file)) 3177 #endif 3178 goto out_fdrop; 3179 *fpp = fp; 3180 return (0); 3181 out_fdrop: 3182 fdrop(fp, curthread); 3183 out_fallback: 3184 return (fget_unlocked_seq(fdp, fd, needrightsp, fpp, NULL)); 3185 } 3186 3187 /* 3188 * Translate fd -> file when the caller guarantees the file descriptor table 3189 * can't be changed by others. 3190 * 3191 * Note this does not mean the file object itself is only visible to the caller, 3192 * merely that it wont disappear without having to be referenced. 3193 * 3194 * Must be paired with fput_only_user. 3195 */ 3196 #ifdef CAPABILITIES 3197 int 3198 fget_only_user(struct filedesc *fdp, int fd, cap_rights_t *needrightsp, 3199 struct file **fpp) 3200 { 3201 const struct filedescent *fde; 3202 const struct fdescenttbl *fdt; 3203 const cap_rights_t *haverights; 3204 struct file *fp; 3205 int error; 3206 3207 MPASS(FILEDESC_IS_ONLY_USER(fdp)); 3208 3209 if (__predict_false(fd >= fdp->fd_nfiles)) 3210 return (EBADF); 3211 3212 fdt = fdp->fd_files; 3213 fde = &fdt->fdt_ofiles[fd]; 3214 fp = fde->fde_file; 3215 if (__predict_false(fp == NULL)) 3216 return (EBADF); 3217 MPASS(refcount_load(&fp->f_count) > 0); 3218 haverights = cap_rights_fde_inline(fde); 3219 error = cap_check_inline(haverights, needrightsp); 3220 if (__predict_false(error != 0)) 3221 return (error); 3222 *fpp = fp; 3223 return (0); 3224 } 3225 #else 3226 int 3227 fget_only_user(struct filedesc *fdp, int fd, cap_rights_t *needrightsp, 3228 struct file **fpp) 3229 { 3230 struct file *fp; 3231 3232 MPASS(FILEDESC_IS_ONLY_USER(fdp)); 3233 3234 if (__predict_false(fd >= fdp->fd_nfiles)) 3235 return (EBADF); 3236 3237 fp = fdp->fd_ofiles[fd].fde_file; 3238 if (__predict_false(fp == NULL)) 3239 return (EBADF); 3240 3241 MPASS(refcount_load(&fp->f_count) > 0); 3242 *fpp = fp; 3243 return (0); 3244 } 3245 #endif 3246 3247 /* 3248 * Extract the file pointer associated with the specified descriptor for the 3249 * current user process. 3250 * 3251 * If the descriptor doesn't exist or doesn't match 'flags', EBADF is 3252 * returned. 3253 * 3254 * File's rights will be checked against the capability rights mask. 3255 * 3256 * If an error occurred the non-zero error is returned and *fpp is set to 3257 * NULL. Otherwise *fpp is held and set and zero is returned. Caller is 3258 * responsible for fdrop(). 3259 */ 3260 static __inline int 3261 _fget(struct thread *td, int fd, struct file **fpp, int flags, 3262 cap_rights_t *needrightsp) 3263 { 3264 struct filedesc *fdp; 3265 struct file *fp; 3266 int error; 3267 3268 *fpp = NULL; 3269 fdp = td->td_proc->p_fd; 3270 error = fget_unlocked(fdp, fd, needrightsp, &fp); 3271 if (__predict_false(error != 0)) 3272 return (error); 3273 if (__predict_false(fp->f_ops == &badfileops)) { 3274 fdrop(fp, td); 3275 return (EBADF); 3276 } 3277 3278 /* 3279 * FREAD and FWRITE failure return EBADF as per POSIX. 3280 */ 3281 error = 0; 3282 switch (flags) { 3283 case FREAD: 3284 case FWRITE: 3285 if ((fp->f_flag & flags) == 0) 3286 error = EBADF; 3287 break; 3288 case FEXEC: 3289 if ((fp->f_flag & (FREAD | FEXEC)) == 0 || 3290 ((fp->f_flag & FWRITE) != 0)) 3291 error = EBADF; 3292 break; 3293 case 0: 3294 break; 3295 default: 3296 KASSERT(0, ("wrong flags")); 3297 } 3298 3299 if (error != 0) { 3300 fdrop(fp, td); 3301 return (error); 3302 } 3303 3304 *fpp = fp; 3305 return (0); 3306 } 3307 3308 int 3309 fget(struct thread *td, int fd, cap_rights_t *rightsp, struct file **fpp) 3310 { 3311 3312 return (_fget(td, fd, fpp, 0, rightsp)); 3313 } 3314 3315 int 3316 fget_mmap(struct thread *td, int fd, cap_rights_t *rightsp, vm_prot_t *maxprotp, 3317 struct file **fpp) 3318 { 3319 int error; 3320 #ifndef CAPABILITIES 3321 error = _fget(td, fd, fpp, 0, rightsp); 3322 if (maxprotp != NULL) 3323 *maxprotp = VM_PROT_ALL; 3324 return (error); 3325 #else 3326 cap_rights_t fdrights; 3327 struct filedesc *fdp; 3328 struct file *fp; 3329 seqc_t seq; 3330 3331 *fpp = NULL; 3332 fdp = td->td_proc->p_fd; 3333 MPASS(cap_rights_is_set(rightsp, CAP_MMAP)); 3334 for (;;) { 3335 error = fget_unlocked_seq(fdp, fd, rightsp, &fp, &seq); 3336 if (__predict_false(error != 0)) 3337 return (error); 3338 if (__predict_false(fp->f_ops == &badfileops)) { 3339 fdrop(fp, td); 3340 return (EBADF); 3341 } 3342 if (maxprotp != NULL) 3343 fdrights = *cap_rights(fdp, fd); 3344 if (!fd_modified(fdp, fd, seq)) 3345 break; 3346 fdrop(fp, td); 3347 } 3348 3349 /* 3350 * If requested, convert capability rights to access flags. 3351 */ 3352 if (maxprotp != NULL) 3353 *maxprotp = cap_rights_to_vmprot(&fdrights); 3354 *fpp = fp; 3355 return (0); 3356 #endif 3357 } 3358 3359 int 3360 fget_read(struct thread *td, int fd, cap_rights_t *rightsp, struct file **fpp) 3361 { 3362 3363 return (_fget(td, fd, fpp, FREAD, rightsp)); 3364 } 3365 3366 int 3367 fget_write(struct thread *td, int fd, cap_rights_t *rightsp, struct file **fpp) 3368 { 3369 3370 return (_fget(td, fd, fpp, FWRITE, rightsp)); 3371 } 3372 3373 int 3374 fget_fcntl(struct thread *td, int fd, cap_rights_t *rightsp, int needfcntl, 3375 struct file **fpp) 3376 { 3377 struct filedesc *fdp = td->td_proc->p_fd; 3378 #ifndef CAPABILITIES 3379 return (fget_unlocked(fdp, fd, rightsp, fpp)); 3380 #else 3381 struct file *fp; 3382 int error; 3383 seqc_t seq; 3384 3385 *fpp = NULL; 3386 MPASS(cap_rights_is_set(rightsp, CAP_FCNTL)); 3387 for (;;) { 3388 error = fget_unlocked_seq(fdp, fd, rightsp, &fp, &seq); 3389 if (error != 0) 3390 return (error); 3391 error = cap_fcntl_check(fdp, fd, needfcntl); 3392 if (!fd_modified(fdp, fd, seq)) 3393 break; 3394 fdrop(fp, td); 3395 } 3396 if (error != 0) { 3397 fdrop(fp, td); 3398 return (error); 3399 } 3400 *fpp = fp; 3401 return (0); 3402 #endif 3403 } 3404 3405 /* 3406 * Like fget() but loads the underlying vnode, or returns an error if the 3407 * descriptor does not represent a vnode. Note that pipes use vnodes but 3408 * never have VM objects. The returned vnode will be vref()'d. 3409 * 3410 * XXX: what about the unused flags ? 3411 */ 3412 static __inline int 3413 _fgetvp(struct thread *td, int fd, int flags, cap_rights_t *needrightsp, 3414 struct vnode **vpp) 3415 { 3416 struct file *fp; 3417 int error; 3418 3419 *vpp = NULL; 3420 error = _fget(td, fd, &fp, flags, needrightsp); 3421 if (error != 0) 3422 return (error); 3423 if (fp->f_vnode == NULL) { 3424 error = EINVAL; 3425 } else { 3426 *vpp = fp->f_vnode; 3427 vrefact(*vpp); 3428 } 3429 fdrop(fp, td); 3430 3431 return (error); 3432 } 3433 3434 int 3435 fgetvp(struct thread *td, int fd, cap_rights_t *rightsp, struct vnode **vpp) 3436 { 3437 3438 return (_fgetvp(td, fd, 0, rightsp, vpp)); 3439 } 3440 3441 int 3442 fgetvp_rights(struct thread *td, int fd, cap_rights_t *needrightsp, 3443 struct filecaps *havecaps, struct vnode **vpp) 3444 { 3445 struct filecaps caps; 3446 struct file *fp; 3447 int error; 3448 3449 error = fget_cap(td, fd, needrightsp, &fp, &caps); 3450 if (error != 0) 3451 return (error); 3452 if (fp->f_ops == &badfileops) { 3453 error = EBADF; 3454 goto out; 3455 } 3456 if (fp->f_vnode == NULL) { 3457 error = EINVAL; 3458 goto out; 3459 } 3460 3461 *havecaps = caps; 3462 *vpp = fp->f_vnode; 3463 vrefact(*vpp); 3464 fdrop(fp, td); 3465 3466 return (0); 3467 out: 3468 filecaps_free(&caps); 3469 fdrop(fp, td); 3470 return (error); 3471 } 3472 3473 int 3474 fgetvp_read(struct thread *td, int fd, cap_rights_t *rightsp, struct vnode **vpp) 3475 { 3476 3477 return (_fgetvp(td, fd, FREAD, rightsp, vpp)); 3478 } 3479 3480 int 3481 fgetvp_exec(struct thread *td, int fd, cap_rights_t *rightsp, struct vnode **vpp) 3482 { 3483 3484 return (_fgetvp(td, fd, FEXEC, rightsp, vpp)); 3485 } 3486 3487 #ifdef notyet 3488 int 3489 fgetvp_write(struct thread *td, int fd, cap_rights_t *rightsp, 3490 struct vnode **vpp) 3491 { 3492 3493 return (_fgetvp(td, fd, FWRITE, rightsp, vpp)); 3494 } 3495 #endif 3496 3497 /* 3498 * Handle the last reference to a file being closed. 3499 * 3500 * Without the noinline attribute clang keeps inlining the func thorough this 3501 * file when fdrop is used. 3502 */ 3503 int __noinline 3504 _fdrop(struct file *fp, struct thread *td) 3505 { 3506 int error; 3507 #ifdef INVARIANTS 3508 int count; 3509 3510 count = refcount_load(&fp->f_count); 3511 if (count != 0) 3512 panic("fdrop: fp %p count %d", fp, count); 3513 #endif 3514 error = fo_close(fp, td); 3515 atomic_subtract_int(&openfiles, 1); 3516 crfree(fp->f_cred); 3517 free(fp->f_advice, M_FADVISE); 3518 uma_zfree(file_zone, fp); 3519 3520 return (error); 3521 } 3522 3523 /* 3524 * Apply an advisory lock on a file descriptor. 3525 * 3526 * Just attempt to get a record lock of the requested type on the entire file 3527 * (l_whence = SEEK_SET, l_start = 0, l_len = 0). 3528 */ 3529 #ifndef _SYS_SYSPROTO_H_ 3530 struct flock_args { 3531 int fd; 3532 int how; 3533 }; 3534 #endif 3535 /* ARGSUSED */ 3536 int 3537 sys_flock(struct thread *td, struct flock_args *uap) 3538 { 3539 struct file *fp; 3540 struct vnode *vp; 3541 struct flock lf; 3542 int error; 3543 3544 error = fget(td, uap->fd, &cap_flock_rights, &fp); 3545 if (error != 0) 3546 return (error); 3547 if (fp->f_type != DTYPE_VNODE) { 3548 fdrop(fp, td); 3549 return (EOPNOTSUPP); 3550 } 3551 3552 vp = fp->f_vnode; 3553 lf.l_whence = SEEK_SET; 3554 lf.l_start = 0; 3555 lf.l_len = 0; 3556 if (uap->how & LOCK_UN) { 3557 lf.l_type = F_UNLCK; 3558 atomic_clear_int(&fp->f_flag, FHASLOCK); 3559 error = VOP_ADVLOCK(vp, (caddr_t)fp, F_UNLCK, &lf, F_FLOCK); 3560 goto done2; 3561 } 3562 if (uap->how & LOCK_EX) 3563 lf.l_type = F_WRLCK; 3564 else if (uap->how & LOCK_SH) 3565 lf.l_type = F_RDLCK; 3566 else { 3567 error = EBADF; 3568 goto done2; 3569 } 3570 atomic_set_int(&fp->f_flag, FHASLOCK); 3571 error = VOP_ADVLOCK(vp, (caddr_t)fp, F_SETLK, &lf, 3572 (uap->how & LOCK_NB) ? F_FLOCK : F_FLOCK | F_WAIT); 3573 done2: 3574 fdrop(fp, td); 3575 return (error); 3576 } 3577 /* 3578 * Duplicate the specified descriptor to a free descriptor. 3579 */ 3580 int 3581 dupfdopen(struct thread *td, struct filedesc *fdp, int dfd, int mode, 3582 int openerror, int *indxp) 3583 { 3584 struct filedescent *newfde, *oldfde; 3585 struct file *fp; 3586 u_long *ioctls; 3587 int error, indx; 3588 3589 KASSERT(openerror == ENODEV || openerror == ENXIO, 3590 ("unexpected error %d in %s", openerror, __func__)); 3591 3592 /* 3593 * If the to-be-dup'd fd number is greater than the allowed number 3594 * of file descriptors, or the fd to be dup'd has already been 3595 * closed, then reject. 3596 */ 3597 FILEDESC_XLOCK(fdp); 3598 if ((fp = fget_locked(fdp, dfd)) == NULL) { 3599 FILEDESC_XUNLOCK(fdp); 3600 return (EBADF); 3601 } 3602 3603 error = fdalloc(td, 0, &indx); 3604 if (error != 0) { 3605 FILEDESC_XUNLOCK(fdp); 3606 return (error); 3607 } 3608 3609 /* 3610 * There are two cases of interest here. 3611 * 3612 * For ENODEV simply dup (dfd) to file descriptor (indx) and return. 3613 * 3614 * For ENXIO steal away the file structure from (dfd) and store it in 3615 * (indx). (dfd) is effectively closed by this operation. 3616 */ 3617 switch (openerror) { 3618 case ENODEV: 3619 /* 3620 * Check that the mode the file is being opened for is a 3621 * subset of the mode of the existing descriptor. 3622 */ 3623 if (((mode & (FREAD|FWRITE)) | fp->f_flag) != fp->f_flag) { 3624 fdunused(fdp, indx); 3625 FILEDESC_XUNLOCK(fdp); 3626 return (EACCES); 3627 } 3628 if (!fhold(fp)) { 3629 fdunused(fdp, indx); 3630 FILEDESC_XUNLOCK(fdp); 3631 return (EBADF); 3632 } 3633 newfde = &fdp->fd_ofiles[indx]; 3634 oldfde = &fdp->fd_ofiles[dfd]; 3635 ioctls = filecaps_copy_prep(&oldfde->fde_caps); 3636 #ifdef CAPABILITIES 3637 seqc_write_begin(&newfde->fde_seqc); 3638 #endif 3639 memcpy(newfde, oldfde, fde_change_size); 3640 filecaps_copy_finish(&oldfde->fde_caps, &newfde->fde_caps, 3641 ioctls); 3642 #ifdef CAPABILITIES 3643 seqc_write_end(&newfde->fde_seqc); 3644 #endif 3645 break; 3646 case ENXIO: 3647 /* 3648 * Steal away the file pointer from dfd and stuff it into indx. 3649 */ 3650 newfde = &fdp->fd_ofiles[indx]; 3651 oldfde = &fdp->fd_ofiles[dfd]; 3652 #ifdef CAPABILITIES 3653 seqc_write_begin(&newfde->fde_seqc); 3654 #endif 3655 memcpy(newfde, oldfde, fde_change_size); 3656 oldfde->fde_file = NULL; 3657 fdunused(fdp, dfd); 3658 #ifdef CAPABILITIES 3659 seqc_write_end(&newfde->fde_seqc); 3660 #endif 3661 break; 3662 } 3663 FILEDESC_XUNLOCK(fdp); 3664 *indxp = indx; 3665 return (0); 3666 } 3667 3668 /* 3669 * This sysctl determines if we will allow a process to chroot(2) if it 3670 * has a directory open: 3671 * 0: disallowed for all processes. 3672 * 1: allowed for processes that were not already chroot(2)'ed. 3673 * 2: allowed for all processes. 3674 */ 3675 3676 static int chroot_allow_open_directories = 1; 3677 3678 SYSCTL_INT(_kern, OID_AUTO, chroot_allow_open_directories, CTLFLAG_RW, 3679 &chroot_allow_open_directories, 0, 3680 "Allow a process to chroot(2) if it has a directory open"); 3681 3682 /* 3683 * Helper function for raised chroot(2) security function: Refuse if 3684 * any filedescriptors are open directories. 3685 */ 3686 static int 3687 chroot_refuse_vdir_fds(struct filedesc *fdp) 3688 { 3689 struct vnode *vp; 3690 struct file *fp; 3691 int fd, lastfile; 3692 3693 FILEDESC_LOCK_ASSERT(fdp); 3694 3695 lastfile = fdlastfile(fdp); 3696 for (fd = 0; fd <= lastfile; fd++) { 3697 fp = fget_locked(fdp, fd); 3698 if (fp == NULL) 3699 continue; 3700 if (fp->f_type == DTYPE_VNODE) { 3701 vp = fp->f_vnode; 3702 if (vp->v_type == VDIR) 3703 return (EPERM); 3704 } 3705 } 3706 return (0); 3707 } 3708 3709 static void 3710 pwd_fill(struct pwd *oldpwd, struct pwd *newpwd) 3711 { 3712 3713 if (newpwd->pwd_cdir == NULL && oldpwd->pwd_cdir != NULL) { 3714 vrefact(oldpwd->pwd_cdir); 3715 newpwd->pwd_cdir = oldpwd->pwd_cdir; 3716 } 3717 3718 if (newpwd->pwd_rdir == NULL && oldpwd->pwd_rdir != NULL) { 3719 vrefact(oldpwd->pwd_rdir); 3720 newpwd->pwd_rdir = oldpwd->pwd_rdir; 3721 } 3722 3723 if (newpwd->pwd_jdir == NULL && oldpwd->pwd_jdir != NULL) { 3724 vrefact(oldpwd->pwd_jdir); 3725 newpwd->pwd_jdir = oldpwd->pwd_jdir; 3726 } 3727 } 3728 3729 struct pwd * 3730 pwd_hold_pwddesc(struct pwddesc *pdp) 3731 { 3732 struct pwd *pwd; 3733 3734 PWDDESC_ASSERT_XLOCKED(pdp); 3735 pwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); 3736 if (pwd != NULL) 3737 refcount_acquire(&pwd->pwd_refcount); 3738 return (pwd); 3739 } 3740 3741 bool 3742 pwd_hold_smr(struct pwd *pwd) 3743 { 3744 3745 MPASS(pwd != NULL); 3746 if (__predict_true(refcount_acquire_if_not_zero(&pwd->pwd_refcount))) { 3747 return (true); 3748 } 3749 return (false); 3750 } 3751 3752 struct pwd * 3753 pwd_hold(struct thread *td) 3754 { 3755 struct pwddesc *pdp; 3756 struct pwd *pwd; 3757 3758 pdp = td->td_proc->p_pd; 3759 3760 vfs_smr_enter(); 3761 pwd = vfs_smr_entered_load(&pdp->pd_pwd); 3762 if (pwd_hold_smr(pwd)) { 3763 vfs_smr_exit(); 3764 return (pwd); 3765 } 3766 vfs_smr_exit(); 3767 PWDDESC_XLOCK(pdp); 3768 pwd = pwd_hold_pwddesc(pdp); 3769 MPASS(pwd != NULL); 3770 PWDDESC_XUNLOCK(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 int count, off, minoff; 4071 4072 if (*(int *)arg1 != 0) 4073 return (EINVAL); 4074 4075 fdp = curproc->p_fd; 4076 count = 0; 4077 FILEDESC_SLOCK(fdp); 4078 map = fdp->fd_map; 4079 off = NDSLOT(fdp->fd_nfiles - 1); 4080 for (minoff = NDSLOT(0); off >= minoff; --off) 4081 count += bitcountl(map[off]); 4082 FILEDESC_SUNLOCK(fdp); 4083 4084 return (SYSCTL_OUT(req, &count, sizeof(count))); 4085 } 4086 4087 static SYSCTL_NODE(_kern_proc, KERN_PROC_NFDS, nfds, 4088 CTLFLAG_RD|CTLFLAG_CAPRD|CTLFLAG_MPSAFE, sysctl_kern_proc_nfds, 4089 "Number of open file descriptors"); 4090 4091 /* 4092 * Get file structures globally. 4093 */ 4094 static int 4095 sysctl_kern_file(SYSCTL_HANDLER_ARGS) 4096 { 4097 struct xfile xf; 4098 struct filedesc *fdp; 4099 struct file *fp; 4100 struct proc *p; 4101 int error, n, lastfile; 4102 4103 error = sysctl_wire_old_buffer(req, 0); 4104 if (error != 0) 4105 return (error); 4106 if (req->oldptr == NULL) { 4107 n = 0; 4108 sx_slock(&allproc_lock); 4109 FOREACH_PROC_IN_SYSTEM(p) { 4110 PROC_LOCK(p); 4111 if (p->p_state == PRS_NEW) { 4112 PROC_UNLOCK(p); 4113 continue; 4114 } 4115 fdp = fdhold(p); 4116 PROC_UNLOCK(p); 4117 if (fdp == NULL) 4118 continue; 4119 /* overestimates sparse tables. */ 4120 n += fdp->fd_nfiles; 4121 fddrop(fdp); 4122 } 4123 sx_sunlock(&allproc_lock); 4124 return (SYSCTL_OUT(req, 0, n * sizeof(xf))); 4125 } 4126 error = 0; 4127 bzero(&xf, sizeof(xf)); 4128 xf.xf_size = sizeof(xf); 4129 sx_slock(&allproc_lock); 4130 FOREACH_PROC_IN_SYSTEM(p) { 4131 PROC_LOCK(p); 4132 if (p->p_state == PRS_NEW) { 4133 PROC_UNLOCK(p); 4134 continue; 4135 } 4136 if (p_cansee(req->td, p) != 0) { 4137 PROC_UNLOCK(p); 4138 continue; 4139 } 4140 xf.xf_pid = p->p_pid; 4141 xf.xf_uid = p->p_ucred->cr_uid; 4142 fdp = fdhold(p); 4143 PROC_UNLOCK(p); 4144 if (fdp == NULL) 4145 continue; 4146 FILEDESC_SLOCK(fdp); 4147 lastfile = fdlastfile(fdp); 4148 for (n = 0; refcount_load(&fdp->fd_refcnt) > 0 && n <= lastfile; 4149 n++) { 4150 if ((fp = fdp->fd_ofiles[n].fde_file) == NULL) 4151 continue; 4152 xf.xf_fd = n; 4153 xf.xf_file = (uintptr_t)fp; 4154 xf.xf_data = (uintptr_t)fp->f_data; 4155 xf.xf_vnode = (uintptr_t)fp->f_vnode; 4156 xf.xf_type = (uintptr_t)fp->f_type; 4157 xf.xf_count = refcount_load(&fp->f_count); 4158 xf.xf_msgcount = 0; 4159 xf.xf_offset = foffset_get(fp); 4160 xf.xf_flag = fp->f_flag; 4161 error = SYSCTL_OUT(req, &xf, sizeof(xf)); 4162 if (error) 4163 break; 4164 } 4165 FILEDESC_SUNLOCK(fdp); 4166 fddrop(fdp); 4167 if (error) 4168 break; 4169 } 4170 sx_sunlock(&allproc_lock); 4171 return (error); 4172 } 4173 4174 SYSCTL_PROC(_kern, KERN_FILE, file, CTLTYPE_OPAQUE|CTLFLAG_RD|CTLFLAG_MPSAFE, 4175 0, 0, sysctl_kern_file, "S,xfile", "Entire file table"); 4176 4177 #ifdef KINFO_FILE_SIZE 4178 CTASSERT(sizeof(struct kinfo_file) == KINFO_FILE_SIZE); 4179 #endif 4180 4181 static int 4182 xlate_fflags(int fflags) 4183 { 4184 static const struct { 4185 int fflag; 4186 int kf_fflag; 4187 } fflags_table[] = { 4188 { FAPPEND, KF_FLAG_APPEND }, 4189 { FASYNC, KF_FLAG_ASYNC }, 4190 { FFSYNC, KF_FLAG_FSYNC }, 4191 { FHASLOCK, KF_FLAG_HASLOCK }, 4192 { FNONBLOCK, KF_FLAG_NONBLOCK }, 4193 { FREAD, KF_FLAG_READ }, 4194 { FWRITE, KF_FLAG_WRITE }, 4195 { O_CREAT, KF_FLAG_CREAT }, 4196 { O_DIRECT, KF_FLAG_DIRECT }, 4197 { O_EXCL, KF_FLAG_EXCL }, 4198 { O_EXEC, KF_FLAG_EXEC }, 4199 { O_EXLOCK, KF_FLAG_EXLOCK }, 4200 { O_NOFOLLOW, KF_FLAG_NOFOLLOW }, 4201 { O_SHLOCK, KF_FLAG_SHLOCK }, 4202 { O_TRUNC, KF_FLAG_TRUNC } 4203 }; 4204 unsigned int i; 4205 int kflags; 4206 4207 kflags = 0; 4208 for (i = 0; i < nitems(fflags_table); i++) 4209 if (fflags & fflags_table[i].fflag) 4210 kflags |= fflags_table[i].kf_fflag; 4211 return (kflags); 4212 } 4213 4214 /* Trim unused data from kf_path by truncating the structure size. */ 4215 void 4216 pack_kinfo(struct kinfo_file *kif) 4217 { 4218 4219 kif->kf_structsize = offsetof(struct kinfo_file, kf_path) + 4220 strlen(kif->kf_path) + 1; 4221 kif->kf_structsize = roundup(kif->kf_structsize, sizeof(uint64_t)); 4222 } 4223 4224 static void 4225 export_file_to_kinfo(struct file *fp, int fd, cap_rights_t *rightsp, 4226 struct kinfo_file *kif, struct filedesc *fdp, int flags) 4227 { 4228 int error; 4229 4230 bzero(kif, sizeof(*kif)); 4231 4232 /* Set a default type to allow for empty fill_kinfo() methods. */ 4233 kif->kf_type = KF_TYPE_UNKNOWN; 4234 kif->kf_flags = xlate_fflags(fp->f_flag); 4235 if (rightsp != NULL) 4236 kif->kf_cap_rights = *rightsp; 4237 else 4238 cap_rights_init_zero(&kif->kf_cap_rights); 4239 kif->kf_fd = fd; 4240 kif->kf_ref_count = refcount_load(&fp->f_count); 4241 kif->kf_offset = foffset_get(fp); 4242 4243 /* 4244 * This may drop the filedesc lock, so the 'fp' cannot be 4245 * accessed after this call. 4246 */ 4247 error = fo_fill_kinfo(fp, kif, fdp); 4248 if (error == 0) 4249 kif->kf_status |= KF_ATTR_VALID; 4250 if ((flags & KERN_FILEDESC_PACK_KINFO) != 0) 4251 pack_kinfo(kif); 4252 else 4253 kif->kf_structsize = roundup2(sizeof(*kif), sizeof(uint64_t)); 4254 } 4255 4256 static void 4257 export_vnode_to_kinfo(struct vnode *vp, int fd, int fflags, 4258 struct kinfo_file *kif, int flags) 4259 { 4260 int error; 4261 4262 bzero(kif, sizeof(*kif)); 4263 4264 kif->kf_type = KF_TYPE_VNODE; 4265 error = vn_fill_kinfo_vnode(vp, kif); 4266 if (error == 0) 4267 kif->kf_status |= KF_ATTR_VALID; 4268 kif->kf_flags = xlate_fflags(fflags); 4269 cap_rights_init_zero(&kif->kf_cap_rights); 4270 kif->kf_fd = fd; 4271 kif->kf_ref_count = -1; 4272 kif->kf_offset = -1; 4273 if ((flags & KERN_FILEDESC_PACK_KINFO) != 0) 4274 pack_kinfo(kif); 4275 else 4276 kif->kf_structsize = roundup2(sizeof(*kif), sizeof(uint64_t)); 4277 vrele(vp); 4278 } 4279 4280 struct export_fd_buf { 4281 struct filedesc *fdp; 4282 struct pwddesc *pdp; 4283 struct sbuf *sb; 4284 ssize_t remainder; 4285 struct kinfo_file kif; 4286 int flags; 4287 }; 4288 4289 static int 4290 export_kinfo_to_sb(struct export_fd_buf *efbuf) 4291 { 4292 struct kinfo_file *kif; 4293 4294 kif = &efbuf->kif; 4295 if (efbuf->remainder != -1) { 4296 if (efbuf->remainder < kif->kf_structsize) { 4297 /* Terminate export. */ 4298 efbuf->remainder = 0; 4299 return (0); 4300 } 4301 efbuf->remainder -= kif->kf_structsize; 4302 } 4303 return (sbuf_bcat(efbuf->sb, kif, kif->kf_structsize) == 0 ? 0 : ENOMEM); 4304 } 4305 4306 static int 4307 export_file_to_sb(struct file *fp, int fd, cap_rights_t *rightsp, 4308 struct export_fd_buf *efbuf) 4309 { 4310 int error; 4311 4312 if (efbuf->remainder == 0) 4313 return (0); 4314 export_file_to_kinfo(fp, fd, rightsp, &efbuf->kif, efbuf->fdp, 4315 efbuf->flags); 4316 FILEDESC_SUNLOCK(efbuf->fdp); 4317 error = export_kinfo_to_sb(efbuf); 4318 FILEDESC_SLOCK(efbuf->fdp); 4319 return (error); 4320 } 4321 4322 static int 4323 export_vnode_to_sb(struct vnode *vp, int fd, int fflags, 4324 struct export_fd_buf *efbuf) 4325 { 4326 int error; 4327 4328 if (efbuf->remainder == 0) 4329 return (0); 4330 if (efbuf->pdp != NULL) 4331 PWDDESC_XUNLOCK(efbuf->pdp); 4332 export_vnode_to_kinfo(vp, fd, fflags, &efbuf->kif, efbuf->flags); 4333 error = export_kinfo_to_sb(efbuf); 4334 if (efbuf->pdp != NULL) 4335 PWDDESC_XLOCK(efbuf->pdp); 4336 return (error); 4337 } 4338 4339 /* 4340 * Store a process file descriptor information to sbuf. 4341 * 4342 * Takes a locked proc as argument, and returns with the proc unlocked. 4343 */ 4344 int 4345 kern_proc_filedesc_out(struct proc *p, struct sbuf *sb, ssize_t maxlen, 4346 int flags) 4347 { 4348 struct file *fp; 4349 struct filedesc *fdp; 4350 struct pwddesc *pdp; 4351 struct export_fd_buf *efbuf; 4352 struct vnode *cttyvp, *textvp, *tracevp; 4353 struct pwd *pwd; 4354 int error, i, lastfile; 4355 cap_rights_t rights; 4356 4357 PROC_LOCK_ASSERT(p, MA_OWNED); 4358 4359 /* ktrace vnode */ 4360 tracevp = p->p_tracevp; 4361 if (tracevp != NULL) 4362 vrefact(tracevp); 4363 /* text vnode */ 4364 textvp = p->p_textvp; 4365 if (textvp != NULL) 4366 vrefact(textvp); 4367 /* Controlling tty. */ 4368 cttyvp = NULL; 4369 if (p->p_pgrp != NULL && p->p_pgrp->pg_session != NULL) { 4370 cttyvp = p->p_pgrp->pg_session->s_ttyvp; 4371 if (cttyvp != NULL) 4372 vrefact(cttyvp); 4373 } 4374 fdp = fdhold(p); 4375 pdp = pdhold(p); 4376 PROC_UNLOCK(p); 4377 efbuf = malloc(sizeof(*efbuf), M_TEMP, M_WAITOK); 4378 efbuf->fdp = NULL; 4379 efbuf->pdp = NULL; 4380 efbuf->sb = sb; 4381 efbuf->remainder = maxlen; 4382 efbuf->flags = flags; 4383 if (tracevp != NULL) 4384 export_vnode_to_sb(tracevp, KF_FD_TYPE_TRACE, FREAD | FWRITE, 4385 efbuf); 4386 if (textvp != NULL) 4387 export_vnode_to_sb(textvp, KF_FD_TYPE_TEXT, FREAD, efbuf); 4388 if (cttyvp != NULL) 4389 export_vnode_to_sb(cttyvp, KF_FD_TYPE_CTTY, FREAD | FWRITE, 4390 efbuf); 4391 error = 0; 4392 if (pdp == NULL || fdp == NULL) 4393 goto fail; 4394 efbuf->fdp = fdp; 4395 efbuf->pdp = pdp; 4396 PWDDESC_XLOCK(pdp); 4397 pwd = pwd_hold_pwddesc(pdp); 4398 if (pwd != NULL) { 4399 /* working directory */ 4400 if (pwd->pwd_cdir != NULL) { 4401 vrefact(pwd->pwd_cdir); 4402 export_vnode_to_sb(pwd->pwd_cdir, KF_FD_TYPE_CWD, FREAD, efbuf); 4403 } 4404 /* root directory */ 4405 if (pwd->pwd_rdir != NULL) { 4406 vrefact(pwd->pwd_rdir); 4407 export_vnode_to_sb(pwd->pwd_rdir, KF_FD_TYPE_ROOT, FREAD, efbuf); 4408 } 4409 /* jail directory */ 4410 if (pwd->pwd_jdir != NULL) { 4411 vrefact(pwd->pwd_jdir); 4412 export_vnode_to_sb(pwd->pwd_jdir, KF_FD_TYPE_JAIL, FREAD, efbuf); 4413 } 4414 } 4415 PWDDESC_XUNLOCK(pdp); 4416 if (pwd != NULL) 4417 pwd_drop(pwd); 4418 FILEDESC_SLOCK(fdp); 4419 lastfile = fdlastfile(fdp); 4420 for (i = 0; refcount_load(&fdp->fd_refcnt) > 0 && i <= lastfile; i++) { 4421 if ((fp = fdp->fd_ofiles[i].fde_file) == NULL) 4422 continue; 4423 #ifdef CAPABILITIES 4424 rights = *cap_rights(fdp, i); 4425 #else /* !CAPABILITIES */ 4426 rights = cap_no_rights; 4427 #endif 4428 /* 4429 * Create sysctl entry. It is OK to drop the filedesc 4430 * lock inside of export_file_to_sb() as we will 4431 * re-validate and re-evaluate its properties when the 4432 * loop continues. 4433 */ 4434 error = export_file_to_sb(fp, i, &rights, efbuf); 4435 if (error != 0 || efbuf->remainder == 0) 4436 break; 4437 } 4438 FILEDESC_SUNLOCK(fdp); 4439 fail: 4440 if (fdp != NULL) 4441 fddrop(fdp); 4442 if (pdp != NULL) 4443 pddrop(pdp); 4444 free(efbuf, M_TEMP); 4445 return (error); 4446 } 4447 4448 #define FILEDESC_SBUF_SIZE (sizeof(struct kinfo_file) * 5) 4449 4450 /* 4451 * Get per-process file descriptors for use by procstat(1), et al. 4452 */ 4453 static int 4454 sysctl_kern_proc_filedesc(SYSCTL_HANDLER_ARGS) 4455 { 4456 struct sbuf sb; 4457 struct proc *p; 4458 ssize_t maxlen; 4459 int error, error2, *name; 4460 4461 name = (int *)arg1; 4462 4463 sbuf_new_for_sysctl(&sb, NULL, FILEDESC_SBUF_SIZE, req); 4464 sbuf_clear_flags(&sb, SBUF_INCLUDENUL); 4465 error = pget((pid_t)name[0], PGET_CANDEBUG | PGET_NOTWEXIT, &p); 4466 if (error != 0) { 4467 sbuf_delete(&sb); 4468 return (error); 4469 } 4470 maxlen = req->oldptr != NULL ? req->oldlen : -1; 4471 error = kern_proc_filedesc_out(p, &sb, maxlen, 4472 KERN_FILEDESC_PACK_KINFO); 4473 error2 = sbuf_finish(&sb); 4474 sbuf_delete(&sb); 4475 return (error != 0 ? error : error2); 4476 } 4477 4478 #ifdef COMPAT_FREEBSD7 4479 #ifdef KINFO_OFILE_SIZE 4480 CTASSERT(sizeof(struct kinfo_ofile) == KINFO_OFILE_SIZE); 4481 #endif 4482 4483 static void 4484 kinfo_to_okinfo(struct kinfo_file *kif, struct kinfo_ofile *okif) 4485 { 4486 4487 okif->kf_structsize = sizeof(*okif); 4488 okif->kf_type = kif->kf_type; 4489 okif->kf_fd = kif->kf_fd; 4490 okif->kf_ref_count = kif->kf_ref_count; 4491 okif->kf_flags = kif->kf_flags & (KF_FLAG_READ | KF_FLAG_WRITE | 4492 KF_FLAG_APPEND | KF_FLAG_ASYNC | KF_FLAG_FSYNC | KF_FLAG_NONBLOCK | 4493 KF_FLAG_DIRECT | KF_FLAG_HASLOCK); 4494 okif->kf_offset = kif->kf_offset; 4495 if (kif->kf_type == KF_TYPE_VNODE) 4496 okif->kf_vnode_type = kif->kf_un.kf_file.kf_file_type; 4497 else 4498 okif->kf_vnode_type = KF_VTYPE_VNON; 4499 strlcpy(okif->kf_path, kif->kf_path, sizeof(okif->kf_path)); 4500 if (kif->kf_type == KF_TYPE_SOCKET) { 4501 okif->kf_sock_domain = kif->kf_un.kf_sock.kf_sock_domain0; 4502 okif->kf_sock_type = kif->kf_un.kf_sock.kf_sock_type0; 4503 okif->kf_sock_protocol = kif->kf_un.kf_sock.kf_sock_protocol0; 4504 okif->kf_sa_local = kif->kf_un.kf_sock.kf_sa_local; 4505 okif->kf_sa_peer = kif->kf_un.kf_sock.kf_sa_peer; 4506 } else { 4507 okif->kf_sa_local.ss_family = AF_UNSPEC; 4508 okif->kf_sa_peer.ss_family = AF_UNSPEC; 4509 } 4510 } 4511 4512 static int 4513 export_vnode_for_osysctl(struct vnode *vp, int type, struct kinfo_file *kif, 4514 struct kinfo_ofile *okif, struct pwddesc *pdp, struct sysctl_req *req) 4515 { 4516 int error; 4517 4518 vrefact(vp); 4519 PWDDESC_XUNLOCK(pdp); 4520 export_vnode_to_kinfo(vp, type, 0, kif, KERN_FILEDESC_PACK_KINFO); 4521 kinfo_to_okinfo(kif, okif); 4522 error = SYSCTL_OUT(req, okif, sizeof(*okif)); 4523 PWDDESC_XLOCK(pdp); 4524 return (error); 4525 } 4526 4527 /* 4528 * Get per-process file descriptors for use by procstat(1), et al. 4529 */ 4530 static int 4531 sysctl_kern_proc_ofiledesc(SYSCTL_HANDLER_ARGS) 4532 { 4533 struct kinfo_ofile *okif; 4534 struct kinfo_file *kif; 4535 struct filedesc *fdp; 4536 struct pwddesc *pdp; 4537 struct pwd *pwd; 4538 int error, i, lastfile, *name; 4539 struct file *fp; 4540 struct proc *p; 4541 4542 name = (int *)arg1; 4543 error = pget((pid_t)name[0], PGET_CANDEBUG | PGET_NOTWEXIT, &p); 4544 if (error != 0) 4545 return (error); 4546 fdp = fdhold(p); 4547 if (fdp != NULL) 4548 pdp = pdhold(p); 4549 PROC_UNLOCK(p); 4550 if (fdp == NULL || pdp == NULL) { 4551 if (fdp != NULL) 4552 fddrop(fdp); 4553 return (ENOENT); 4554 } 4555 kif = malloc(sizeof(*kif), M_TEMP, M_WAITOK); 4556 okif = malloc(sizeof(*okif), M_TEMP, M_WAITOK); 4557 PWDDESC_XLOCK(pdp); 4558 pwd = pwd_hold_pwddesc(pdp); 4559 if (pwd != NULL) { 4560 if (pwd->pwd_cdir != NULL) 4561 export_vnode_for_osysctl(pwd->pwd_cdir, KF_FD_TYPE_CWD, kif, 4562 okif, pdp, req); 4563 if (pwd->pwd_rdir != NULL) 4564 export_vnode_for_osysctl(pwd->pwd_rdir, KF_FD_TYPE_ROOT, kif, 4565 okif, pdp, req); 4566 if (pwd->pwd_jdir != NULL) 4567 export_vnode_for_osysctl(pwd->pwd_jdir, KF_FD_TYPE_JAIL, kif, 4568 okif, pdp, req); 4569 } 4570 PWDDESC_XUNLOCK(pdp); 4571 if (pwd != NULL) 4572 pwd_drop(pwd); 4573 FILEDESC_SLOCK(fdp); 4574 lastfile = fdlastfile(fdp); 4575 for (i = 0; refcount_load(&fdp->fd_refcnt) > 0 && i <= lastfile; i++) { 4576 if ((fp = fdp->fd_ofiles[i].fde_file) == NULL) 4577 continue; 4578 export_file_to_kinfo(fp, i, NULL, kif, fdp, 4579 KERN_FILEDESC_PACK_KINFO); 4580 FILEDESC_SUNLOCK(fdp); 4581 kinfo_to_okinfo(kif, okif); 4582 error = SYSCTL_OUT(req, okif, sizeof(*okif)); 4583 FILEDESC_SLOCK(fdp); 4584 if (error) 4585 break; 4586 } 4587 FILEDESC_SUNLOCK(fdp); 4588 fddrop(fdp); 4589 pddrop(pdp); 4590 free(kif, M_TEMP); 4591 free(okif, M_TEMP); 4592 return (0); 4593 } 4594 4595 static SYSCTL_NODE(_kern_proc, KERN_PROC_OFILEDESC, ofiledesc, 4596 CTLFLAG_RD|CTLFLAG_MPSAFE, sysctl_kern_proc_ofiledesc, 4597 "Process ofiledesc entries"); 4598 #endif /* COMPAT_FREEBSD7 */ 4599 4600 int 4601 vntype_to_kinfo(int vtype) 4602 { 4603 struct { 4604 int vtype; 4605 int kf_vtype; 4606 } vtypes_table[] = { 4607 { VBAD, KF_VTYPE_VBAD }, 4608 { VBLK, KF_VTYPE_VBLK }, 4609 { VCHR, KF_VTYPE_VCHR }, 4610 { VDIR, KF_VTYPE_VDIR }, 4611 { VFIFO, KF_VTYPE_VFIFO }, 4612 { VLNK, KF_VTYPE_VLNK }, 4613 { VNON, KF_VTYPE_VNON }, 4614 { VREG, KF_VTYPE_VREG }, 4615 { VSOCK, KF_VTYPE_VSOCK } 4616 }; 4617 unsigned int i; 4618 4619 /* 4620 * Perform vtype translation. 4621 */ 4622 for (i = 0; i < nitems(vtypes_table); i++) 4623 if (vtypes_table[i].vtype == vtype) 4624 return (vtypes_table[i].kf_vtype); 4625 4626 return (KF_VTYPE_UNKNOWN); 4627 } 4628 4629 static SYSCTL_NODE(_kern_proc, KERN_PROC_FILEDESC, filedesc, 4630 CTLFLAG_RD|CTLFLAG_MPSAFE, sysctl_kern_proc_filedesc, 4631 "Process filedesc entries"); 4632 4633 /* 4634 * Store a process current working directory information to sbuf. 4635 * 4636 * Takes a locked proc as argument, and returns with the proc unlocked. 4637 */ 4638 int 4639 kern_proc_cwd_out(struct proc *p, struct sbuf *sb, ssize_t maxlen) 4640 { 4641 struct pwddesc *pdp; 4642 struct pwd *pwd; 4643 struct export_fd_buf *efbuf; 4644 struct vnode *cdir; 4645 int error; 4646 4647 PROC_LOCK_ASSERT(p, MA_OWNED); 4648 4649 pdp = pdhold(p); 4650 PROC_UNLOCK(p); 4651 if (pdp == NULL) 4652 return (EINVAL); 4653 4654 efbuf = malloc(sizeof(*efbuf), M_TEMP, M_WAITOK); 4655 efbuf->pdp = pdp; 4656 efbuf->sb = sb; 4657 efbuf->remainder = maxlen; 4658 4659 PWDDESC_XLOCK(pdp); 4660 pwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); 4661 cdir = pwd->pwd_cdir; 4662 if (cdir == NULL) { 4663 error = EINVAL; 4664 } else { 4665 vrefact(cdir); 4666 error = export_vnode_to_sb(cdir, KF_FD_TYPE_CWD, FREAD, efbuf); 4667 } 4668 PWDDESC_XUNLOCK(pdp); 4669 pddrop(pdp); 4670 free(efbuf, M_TEMP); 4671 return (error); 4672 } 4673 4674 /* 4675 * Get per-process current working directory. 4676 */ 4677 static int 4678 sysctl_kern_proc_cwd(SYSCTL_HANDLER_ARGS) 4679 { 4680 struct sbuf sb; 4681 struct proc *p; 4682 ssize_t maxlen; 4683 int error, error2, *name; 4684 4685 name = (int *)arg1; 4686 4687 sbuf_new_for_sysctl(&sb, NULL, sizeof(struct kinfo_file), req); 4688 sbuf_clear_flags(&sb, SBUF_INCLUDENUL); 4689 error = pget((pid_t)name[0], PGET_CANDEBUG | PGET_NOTWEXIT, &p); 4690 if (error != 0) { 4691 sbuf_delete(&sb); 4692 return (error); 4693 } 4694 maxlen = req->oldptr != NULL ? req->oldlen : -1; 4695 error = kern_proc_cwd_out(p, &sb, maxlen); 4696 error2 = sbuf_finish(&sb); 4697 sbuf_delete(&sb); 4698 return (error != 0 ? error : error2); 4699 } 4700 4701 static SYSCTL_NODE(_kern_proc, KERN_PROC_CWD, cwd, CTLFLAG_RD|CTLFLAG_MPSAFE, 4702 sysctl_kern_proc_cwd, "Process current working directory"); 4703 4704 #ifdef DDB 4705 /* 4706 * For the purposes of debugging, generate a human-readable string for the 4707 * file type. 4708 */ 4709 static const char * 4710 file_type_to_name(short type) 4711 { 4712 4713 switch (type) { 4714 case 0: 4715 return ("zero"); 4716 case DTYPE_VNODE: 4717 return ("vnode"); 4718 case DTYPE_SOCKET: 4719 return ("socket"); 4720 case DTYPE_PIPE: 4721 return ("pipe"); 4722 case DTYPE_FIFO: 4723 return ("fifo"); 4724 case DTYPE_KQUEUE: 4725 return ("kqueue"); 4726 case DTYPE_CRYPTO: 4727 return ("crypto"); 4728 case DTYPE_MQUEUE: 4729 return ("mqueue"); 4730 case DTYPE_SHM: 4731 return ("shm"); 4732 case DTYPE_SEM: 4733 return ("ksem"); 4734 case DTYPE_PTS: 4735 return ("pts"); 4736 case DTYPE_DEV: 4737 return ("dev"); 4738 case DTYPE_PROCDESC: 4739 return ("proc"); 4740 case DTYPE_EVENTFD: 4741 return ("eventfd"); 4742 case DTYPE_LINUXTFD: 4743 return ("ltimer"); 4744 default: 4745 return ("unkn"); 4746 } 4747 } 4748 4749 /* 4750 * For the purposes of debugging, identify a process (if any, perhaps one of 4751 * many) that references the passed file in its file descriptor array. Return 4752 * NULL if none. 4753 */ 4754 static struct proc * 4755 file_to_first_proc(struct file *fp) 4756 { 4757 struct filedesc *fdp; 4758 struct proc *p; 4759 int n; 4760 4761 FOREACH_PROC_IN_SYSTEM(p) { 4762 if (p->p_state == PRS_NEW) 4763 continue; 4764 fdp = p->p_fd; 4765 if (fdp == NULL) 4766 continue; 4767 for (n = 0; n < fdp->fd_nfiles; n++) { 4768 if (fp == fdp->fd_ofiles[n].fde_file) 4769 return (p); 4770 } 4771 } 4772 return (NULL); 4773 } 4774 4775 static void 4776 db_print_file(struct file *fp, int header) 4777 { 4778 #define XPTRWIDTH ((int)howmany(sizeof(void *) * NBBY, 4)) 4779 struct proc *p; 4780 4781 if (header) 4782 db_printf("%*s %6s %*s %8s %4s %5s %6s %*s %5s %s\n", 4783 XPTRWIDTH, "File", "Type", XPTRWIDTH, "Data", "Flag", 4784 "GCFl", "Count", "MCount", XPTRWIDTH, "Vnode", "FPID", 4785 "FCmd"); 4786 p = file_to_first_proc(fp); 4787 db_printf("%*p %6s %*p %08x %04x %5d %6d %*p %5d %s\n", XPTRWIDTH, 4788 fp, file_type_to_name(fp->f_type), XPTRWIDTH, fp->f_data, 4789 fp->f_flag, 0, refcount_load(&fp->f_count), 0, XPTRWIDTH, fp->f_vnode, 4790 p != NULL ? p->p_pid : -1, p != NULL ? p->p_comm : "-"); 4791 4792 #undef XPTRWIDTH 4793 } 4794 4795 DB_SHOW_COMMAND(file, db_show_file) 4796 { 4797 struct file *fp; 4798 4799 if (!have_addr) { 4800 db_printf("usage: show file <addr>\n"); 4801 return; 4802 } 4803 fp = (struct file *)addr; 4804 db_print_file(fp, 1); 4805 } 4806 4807 DB_SHOW_COMMAND(files, db_show_files) 4808 { 4809 struct filedesc *fdp; 4810 struct file *fp; 4811 struct proc *p; 4812 int header; 4813 int n; 4814 4815 header = 1; 4816 FOREACH_PROC_IN_SYSTEM(p) { 4817 if (p->p_state == PRS_NEW) 4818 continue; 4819 if ((fdp = p->p_fd) == NULL) 4820 continue; 4821 for (n = 0; n < fdp->fd_nfiles; ++n) { 4822 if ((fp = fdp->fd_ofiles[n].fde_file) == NULL) 4823 continue; 4824 db_print_file(fp, header); 4825 header = 0; 4826 } 4827 } 4828 } 4829 #endif 4830 4831 SYSCTL_INT(_kern, KERN_MAXFILESPERPROC, maxfilesperproc, CTLFLAG_RW, 4832 &maxfilesperproc, 0, "Maximum files allowed open per process"); 4833 4834 SYSCTL_INT(_kern, KERN_MAXFILES, maxfiles, CTLFLAG_RW, 4835 &maxfiles, 0, "Maximum number of files"); 4836 4837 SYSCTL_INT(_kern, OID_AUTO, openfiles, CTLFLAG_RD, 4838 &openfiles, 0, "System-wide number of open files"); 4839 4840 /* ARGSUSED*/ 4841 static void 4842 filelistinit(void *dummy) 4843 { 4844 4845 file_zone = uma_zcreate("Files", sizeof(struct file), NULL, NULL, 4846 NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE); 4847 filedesc0_zone = uma_zcreate("filedesc0", sizeof(struct filedesc0), 4848 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0); 4849 pwd_zone = uma_zcreate("PWD", sizeof(struct pwd), NULL, NULL, 4850 NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_SMR); 4851 /* 4852 * XXXMJG this is a temporary hack due to boot ordering issues against 4853 * the vnode zone. 4854 */ 4855 vfs_smr = uma_zone_get_smr(pwd_zone); 4856 mtx_init(&sigio_lock, "sigio lock", NULL, MTX_DEF); 4857 } 4858 SYSINIT(select, SI_SUB_LOCK, SI_ORDER_FIRST, filelistinit, NULL); 4859 4860 /*-------------------------------------------------------------------*/ 4861 4862 static int 4863 badfo_readwrite(struct file *fp, struct uio *uio, struct ucred *active_cred, 4864 int flags, struct thread *td) 4865 { 4866 4867 return (EBADF); 4868 } 4869 4870 static int 4871 badfo_truncate(struct file *fp, off_t length, struct ucred *active_cred, 4872 struct thread *td) 4873 { 4874 4875 return (EINVAL); 4876 } 4877 4878 static int 4879 badfo_ioctl(struct file *fp, u_long com, void *data, struct ucred *active_cred, 4880 struct thread *td) 4881 { 4882 4883 return (EBADF); 4884 } 4885 4886 static int 4887 badfo_poll(struct file *fp, int events, struct ucred *active_cred, 4888 struct thread *td) 4889 { 4890 4891 return (0); 4892 } 4893 4894 static int 4895 badfo_kqfilter(struct file *fp, struct knote *kn) 4896 { 4897 4898 return (EBADF); 4899 } 4900 4901 static int 4902 badfo_stat(struct file *fp, struct stat *sb, struct ucred *active_cred, 4903 struct thread *td) 4904 { 4905 4906 return (EBADF); 4907 } 4908 4909 static int 4910 badfo_close(struct file *fp, struct thread *td) 4911 { 4912 4913 return (0); 4914 } 4915 4916 static int 4917 badfo_chmod(struct file *fp, mode_t mode, struct ucred *active_cred, 4918 struct thread *td) 4919 { 4920 4921 return (EBADF); 4922 } 4923 4924 static int 4925 badfo_chown(struct file *fp, uid_t uid, gid_t gid, struct ucred *active_cred, 4926 struct thread *td) 4927 { 4928 4929 return (EBADF); 4930 } 4931 4932 static int 4933 badfo_sendfile(struct file *fp, int sockfd, struct uio *hdr_uio, 4934 struct uio *trl_uio, off_t offset, size_t nbytes, off_t *sent, int flags, 4935 struct thread *td) 4936 { 4937 4938 return (EBADF); 4939 } 4940 4941 static int 4942 badfo_fill_kinfo(struct file *fp, struct kinfo_file *kif, struct filedesc *fdp) 4943 { 4944 4945 return (0); 4946 } 4947 4948 struct fileops badfileops = { 4949 .fo_read = badfo_readwrite, 4950 .fo_write = badfo_readwrite, 4951 .fo_truncate = badfo_truncate, 4952 .fo_ioctl = badfo_ioctl, 4953 .fo_poll = badfo_poll, 4954 .fo_kqfilter = badfo_kqfilter, 4955 .fo_stat = badfo_stat, 4956 .fo_close = badfo_close, 4957 .fo_chmod = badfo_chmod, 4958 .fo_chown = badfo_chown, 4959 .fo_sendfile = badfo_sendfile, 4960 .fo_fill_kinfo = badfo_fill_kinfo, 4961 }; 4962 4963 int 4964 invfo_rdwr(struct file *fp, struct uio *uio, struct ucred *active_cred, 4965 int flags, struct thread *td) 4966 { 4967 4968 return (EOPNOTSUPP); 4969 } 4970 4971 int 4972 invfo_truncate(struct file *fp, off_t length, struct ucred *active_cred, 4973 struct thread *td) 4974 { 4975 4976 return (EINVAL); 4977 } 4978 4979 int 4980 invfo_ioctl(struct file *fp, u_long com, void *data, 4981 struct ucred *active_cred, struct thread *td) 4982 { 4983 4984 return (ENOTTY); 4985 } 4986 4987 int 4988 invfo_poll(struct file *fp, int events, struct ucred *active_cred, 4989 struct thread *td) 4990 { 4991 4992 return (poll_no_poll(events)); 4993 } 4994 4995 int 4996 invfo_kqfilter(struct file *fp, struct knote *kn) 4997 { 4998 4999 return (EINVAL); 5000 } 5001 5002 int 5003 invfo_chmod(struct file *fp, mode_t mode, struct ucred *active_cred, 5004 struct thread *td) 5005 { 5006 5007 return (EINVAL); 5008 } 5009 5010 int 5011 invfo_chown(struct file *fp, uid_t uid, gid_t gid, struct ucred *active_cred, 5012 struct thread *td) 5013 { 5014 5015 return (EINVAL); 5016 } 5017 5018 int 5019 invfo_sendfile(struct file *fp, int sockfd, struct uio *hdr_uio, 5020 struct uio *trl_uio, off_t offset, size_t nbytes, off_t *sent, int flags, 5021 struct thread *td) 5022 { 5023 5024 return (EINVAL); 5025 } 5026 5027 /*-------------------------------------------------------------------*/ 5028 5029 /* 5030 * File Descriptor pseudo-device driver (/dev/fd/). 5031 * 5032 * Opening minor device N dup()s the file (if any) connected to file 5033 * descriptor N belonging to the calling process. Note that this driver 5034 * consists of only the ``open()'' routine, because all subsequent 5035 * references to this file will be direct to the other driver. 5036 * 5037 * XXX: we could give this one a cloning event handler if necessary. 5038 */ 5039 5040 /* ARGSUSED */ 5041 static int 5042 fdopen(struct cdev *dev, int mode, int type, struct thread *td) 5043 { 5044 5045 /* 5046 * XXX Kludge: set curthread->td_dupfd to contain the value of the 5047 * the file descriptor being sought for duplication. The error 5048 * return ensures that the vnode for this device will be released 5049 * by vn_open. Open will detect this special error and take the 5050 * actions in dupfdopen below. Other callers of vn_open or VOP_OPEN 5051 * will simply report the error. 5052 */ 5053 td->td_dupfd = dev2unit(dev); 5054 return (ENODEV); 5055 } 5056 5057 static struct cdevsw fildesc_cdevsw = { 5058 .d_version = D_VERSION, 5059 .d_open = fdopen, 5060 .d_name = "FD", 5061 }; 5062 5063 static void 5064 fildesc_drvinit(void *unused) 5065 { 5066 struct cdev *dev; 5067 5068 dev = make_dev_credf(MAKEDEV_ETERNAL, &fildesc_cdevsw, 0, NULL, 5069 UID_ROOT, GID_WHEEL, 0666, "fd/0"); 5070 make_dev_alias(dev, "stdin"); 5071 dev = make_dev_credf(MAKEDEV_ETERNAL, &fildesc_cdevsw, 1, NULL, 5072 UID_ROOT, GID_WHEEL, 0666, "fd/1"); 5073 make_dev_alias(dev, "stdout"); 5074 dev = make_dev_credf(MAKEDEV_ETERNAL, &fildesc_cdevsw, 2, NULL, 5075 UID_ROOT, GID_WHEEL, 0666, "fd/2"); 5076 make_dev_alias(dev, "stderr"); 5077 } 5078 5079 SYSINIT(fildescdev, SI_SUB_DRIVERS, SI_ORDER_MIDDLE, fildesc_drvinit, NULL); 5080