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/stat.h> 73 #include <sys/sx.h> 74 #include <sys/syscallsubr.h> 75 #include <sys/sysctl.h> 76 #include <sys/sysproto.h> 77 #include <sys/unistd.h> 78 #include <sys/user.h> 79 #include <sys/vnode.h> 80 #ifdef KTRACE 81 #include <sys/ktrace.h> 82 #endif 83 84 #include <net/vnet.h> 85 86 #include <security/audit/audit.h> 87 88 #include <vm/uma.h> 89 #include <vm/vm.h> 90 91 #include <ddb/ddb.h> 92 93 static MALLOC_DEFINE(M_FILEDESC, "filedesc", "Open file descriptor table"); 94 static MALLOC_DEFINE(M_FILEDESC_TO_LEADER, "filedesc_to_leader", 95 "file desc to leader structures"); 96 static MALLOC_DEFINE(M_SIGIO, "sigio", "sigio structures"); 97 MALLOC_DEFINE(M_FILECAPS, "filecaps", "descriptor capabilities"); 98 99 MALLOC_DECLARE(M_FADVISE); 100 101 static __read_mostly uma_zone_t file_zone; 102 static __read_mostly uma_zone_t filedesc0_zone; 103 104 static int closefp(struct filedesc *fdp, int fd, struct file *fp, 105 struct thread *td, int holdleaders); 106 static int fd_first_free(struct filedesc *fdp, int low, int size); 107 static int fd_last_used(struct filedesc *fdp, int size); 108 static void fdgrowtable(struct filedesc *fdp, int nfd); 109 static void fdgrowtable_exp(struct filedesc *fdp, int nfd); 110 static void fdunused(struct filedesc *fdp, int fd); 111 static void fdused(struct filedesc *fdp, int fd); 112 static int getmaxfd(struct thread *td); 113 static u_long *filecaps_copy_prep(const struct filecaps *src); 114 static void filecaps_copy_finish(const struct filecaps *src, 115 struct filecaps *dst, u_long *ioctls); 116 static u_long *filecaps_free_prep(struct filecaps *fcaps); 117 static void filecaps_free_finish(u_long *ioctls); 118 119 /* 120 * Each process has: 121 * 122 * - An array of open file descriptors (fd_ofiles) 123 * - An array of file flags (fd_ofileflags) 124 * - A bitmap recording which descriptors are in use (fd_map) 125 * 126 * A process starts out with NDFILE descriptors. The value of NDFILE has 127 * been selected based the historical limit of 20 open files, and an 128 * assumption that the majority of processes, especially short-lived 129 * processes like shells, will never need more. 130 * 131 * If this initial allocation is exhausted, a larger descriptor table and 132 * map are allocated dynamically, and the pointers in the process's struct 133 * filedesc are updated to point to those. This is repeated every time 134 * the process runs out of file descriptors (provided it hasn't hit its 135 * resource limit). 136 * 137 * Since threads may hold references to individual descriptor table 138 * entries, the tables are never freed. Instead, they are placed on a 139 * linked list and freed only when the struct filedesc is released. 140 */ 141 #define NDFILE 20 142 #define NDSLOTSIZE sizeof(NDSLOTTYPE) 143 #define NDENTRIES (NDSLOTSIZE * __CHAR_BIT) 144 #define NDSLOT(x) ((x) / NDENTRIES) 145 #define NDBIT(x) ((NDSLOTTYPE)1 << ((x) % NDENTRIES)) 146 #define NDSLOTS(x) (((x) + NDENTRIES - 1) / NDENTRIES) 147 148 /* 149 * SLIST entry used to keep track of ofiles which must be reclaimed when 150 * the process exits. 151 */ 152 struct freetable { 153 struct fdescenttbl *ft_table; 154 SLIST_ENTRY(freetable) ft_next; 155 }; 156 157 /* 158 * Initial allocation: a filedesc structure + the head of SLIST used to 159 * keep track of old ofiles + enough space for NDFILE descriptors. 160 */ 161 162 struct fdescenttbl0 { 163 int fdt_nfiles; 164 struct filedescent fdt_ofiles[NDFILE]; 165 }; 166 167 struct filedesc0 { 168 struct filedesc fd_fd; 169 SLIST_HEAD(, freetable) fd_free; 170 struct fdescenttbl0 fd_dfiles; 171 NDSLOTTYPE fd_dmap[NDSLOTS(NDFILE)]; 172 }; 173 174 /* 175 * Descriptor management. 176 */ 177 static int __exclusive_cache_line openfiles; /* actual number of open files */ 178 struct mtx sigio_lock; /* mtx to protect pointers to sigio */ 179 void __read_mostly (*mq_fdclose)(struct thread *td, int fd, struct file *fp); 180 181 /* 182 * If low >= size, just return low. Otherwise find the first zero bit in the 183 * given bitmap, starting at low and not exceeding size - 1. Return size if 184 * not found. 185 */ 186 static int 187 fd_first_free(struct filedesc *fdp, int low, int size) 188 { 189 NDSLOTTYPE *map = fdp->fd_map; 190 NDSLOTTYPE mask; 191 int off, maxoff; 192 193 if (low >= size) 194 return (low); 195 196 off = NDSLOT(low); 197 if (low % NDENTRIES) { 198 mask = ~(~(NDSLOTTYPE)0 >> (NDENTRIES - (low % NDENTRIES))); 199 if ((mask &= ~map[off]) != 0UL) 200 return (off * NDENTRIES + ffsl(mask) - 1); 201 ++off; 202 } 203 for (maxoff = NDSLOTS(size); off < maxoff; ++off) 204 if (map[off] != ~0UL) 205 return (off * NDENTRIES + ffsl(~map[off]) - 1); 206 return (size); 207 } 208 209 /* 210 * Find the highest non-zero bit in the given bitmap, starting at 0 and 211 * not exceeding size - 1. Return -1 if not found. 212 */ 213 static int 214 fd_last_used(struct filedesc *fdp, int size) 215 { 216 NDSLOTTYPE *map = fdp->fd_map; 217 NDSLOTTYPE mask; 218 int off, minoff; 219 220 off = NDSLOT(size); 221 if (size % NDENTRIES) { 222 mask = ~(~(NDSLOTTYPE)0 << (size % NDENTRIES)); 223 if ((mask &= map[off]) != 0) 224 return (off * NDENTRIES + flsl(mask) - 1); 225 --off; 226 } 227 for (minoff = NDSLOT(0); off >= minoff; --off) 228 if (map[off] != 0) 229 return (off * NDENTRIES + flsl(map[off]) - 1); 230 return (-1); 231 } 232 233 static int 234 fdisused(struct filedesc *fdp, int fd) 235 { 236 237 KASSERT(fd >= 0 && fd < fdp->fd_nfiles, 238 ("file descriptor %d out of range (0, %d)", fd, fdp->fd_nfiles)); 239 240 return ((fdp->fd_map[NDSLOT(fd)] & NDBIT(fd)) != 0); 241 } 242 243 /* 244 * Mark a file descriptor as used. 245 */ 246 static void 247 fdused_init(struct filedesc *fdp, int fd) 248 { 249 250 KASSERT(!fdisused(fdp, fd), ("fd=%d is already used", fd)); 251 252 fdp->fd_map[NDSLOT(fd)] |= NDBIT(fd); 253 } 254 255 static void 256 fdused(struct filedesc *fdp, int fd) 257 { 258 259 FILEDESC_XLOCK_ASSERT(fdp); 260 261 fdused_init(fdp, fd); 262 if (fd > fdp->fd_lastfile) 263 fdp->fd_lastfile = fd; 264 if (fd == fdp->fd_freefile) 265 fdp->fd_freefile++; 266 } 267 268 /* 269 * Mark a file descriptor as unused. 270 */ 271 static void 272 fdunused(struct filedesc *fdp, int fd) 273 { 274 275 FILEDESC_XLOCK_ASSERT(fdp); 276 277 KASSERT(fdisused(fdp, fd), ("fd=%d is already unused", fd)); 278 KASSERT(fdp->fd_ofiles[fd].fde_file == NULL, 279 ("fd=%d is still in use", fd)); 280 281 fdp->fd_map[NDSLOT(fd)] &= ~NDBIT(fd); 282 if (fd < fdp->fd_freefile) 283 fdp->fd_freefile = fd; 284 if (fd == fdp->fd_lastfile) 285 fdp->fd_lastfile = fd_last_used(fdp, fd); 286 } 287 288 /* 289 * Free a file descriptor. 290 * 291 * Avoid some work if fdp is about to be destroyed. 292 */ 293 static inline void 294 fdefree_last(struct filedescent *fde) 295 { 296 297 filecaps_free(&fde->fde_caps); 298 } 299 300 static inline void 301 fdfree(struct filedesc *fdp, int fd) 302 { 303 struct filedescent *fde; 304 305 fde = &fdp->fd_ofiles[fd]; 306 #ifdef CAPABILITIES 307 seqc_write_begin(&fde->fde_seqc); 308 #endif 309 fde->fde_file = NULL; 310 #ifdef CAPABILITIES 311 seqc_write_end(&fde->fde_seqc); 312 #endif 313 fdefree_last(fde); 314 fdunused(fdp, fd); 315 } 316 317 void 318 pwd_ensure_dirs(void) 319 { 320 struct filedesc *fdp; 321 322 fdp = curproc->p_fd; 323 FILEDESC_XLOCK(fdp); 324 if (fdp->fd_cdir == NULL) { 325 fdp->fd_cdir = rootvnode; 326 vrefact(rootvnode); 327 } 328 if (fdp->fd_rdir == NULL) { 329 fdp->fd_rdir = rootvnode; 330 vrefact(rootvnode); 331 } 332 FILEDESC_XUNLOCK(fdp); 333 } 334 335 /* 336 * System calls on descriptors. 337 */ 338 #ifndef _SYS_SYSPROTO_H_ 339 struct getdtablesize_args { 340 int dummy; 341 }; 342 #endif 343 /* ARGSUSED */ 344 int 345 sys_getdtablesize(struct thread *td, struct getdtablesize_args *uap) 346 { 347 #ifdef RACCT 348 uint64_t lim; 349 #endif 350 351 td->td_retval[0] = getmaxfd(td); 352 #ifdef RACCT 353 PROC_LOCK(td->td_proc); 354 lim = racct_get_limit(td->td_proc, RACCT_NOFILE); 355 PROC_UNLOCK(td->td_proc); 356 if (lim < td->td_retval[0]) 357 td->td_retval[0] = lim; 358 #endif 359 return (0); 360 } 361 362 /* 363 * Duplicate a file descriptor to a particular value. 364 * 365 * Note: keep in mind that a potential race condition exists when closing 366 * descriptors from a shared descriptor table (via rfork). 367 */ 368 #ifndef _SYS_SYSPROTO_H_ 369 struct dup2_args { 370 u_int from; 371 u_int to; 372 }; 373 #endif 374 /* ARGSUSED */ 375 int 376 sys_dup2(struct thread *td, struct dup2_args *uap) 377 { 378 379 return (kern_dup(td, FDDUP_FIXED, 0, (int)uap->from, (int)uap->to)); 380 } 381 382 /* 383 * Duplicate a file descriptor. 384 */ 385 #ifndef _SYS_SYSPROTO_H_ 386 struct dup_args { 387 u_int fd; 388 }; 389 #endif 390 /* ARGSUSED */ 391 int 392 sys_dup(struct thread *td, struct dup_args *uap) 393 { 394 395 return (kern_dup(td, FDDUP_NORMAL, 0, (int)uap->fd, 0)); 396 } 397 398 /* 399 * The file control system call. 400 */ 401 #ifndef _SYS_SYSPROTO_H_ 402 struct fcntl_args { 403 int fd; 404 int cmd; 405 long arg; 406 }; 407 #endif 408 /* ARGSUSED */ 409 int 410 sys_fcntl(struct thread *td, struct fcntl_args *uap) 411 { 412 413 return (kern_fcntl_freebsd(td, uap->fd, uap->cmd, uap->arg)); 414 } 415 416 int 417 kern_fcntl_freebsd(struct thread *td, int fd, int cmd, long arg) 418 { 419 struct flock fl; 420 struct __oflock ofl; 421 intptr_t arg1; 422 int error, newcmd; 423 424 error = 0; 425 newcmd = cmd; 426 switch (cmd) { 427 case F_OGETLK: 428 case F_OSETLK: 429 case F_OSETLKW: 430 /* 431 * Convert old flock structure to new. 432 */ 433 error = copyin((void *)(intptr_t)arg, &ofl, sizeof(ofl)); 434 fl.l_start = ofl.l_start; 435 fl.l_len = ofl.l_len; 436 fl.l_pid = ofl.l_pid; 437 fl.l_type = ofl.l_type; 438 fl.l_whence = ofl.l_whence; 439 fl.l_sysid = 0; 440 441 switch (cmd) { 442 case F_OGETLK: 443 newcmd = F_GETLK; 444 break; 445 case F_OSETLK: 446 newcmd = F_SETLK; 447 break; 448 case F_OSETLKW: 449 newcmd = F_SETLKW; 450 break; 451 } 452 arg1 = (intptr_t)&fl; 453 break; 454 case F_GETLK: 455 case F_SETLK: 456 case F_SETLKW: 457 case F_SETLK_REMOTE: 458 error = copyin((void *)(intptr_t)arg, &fl, sizeof(fl)); 459 arg1 = (intptr_t)&fl; 460 break; 461 default: 462 arg1 = arg; 463 break; 464 } 465 if (error) 466 return (error); 467 error = kern_fcntl(td, fd, newcmd, arg1); 468 if (error) 469 return (error); 470 if (cmd == F_OGETLK) { 471 ofl.l_start = fl.l_start; 472 ofl.l_len = fl.l_len; 473 ofl.l_pid = fl.l_pid; 474 ofl.l_type = fl.l_type; 475 ofl.l_whence = fl.l_whence; 476 error = copyout(&ofl, (void *)(intptr_t)arg, sizeof(ofl)); 477 } else if (cmd == F_GETLK) { 478 error = copyout(&fl, (void *)(intptr_t)arg, sizeof(fl)); 479 } 480 return (error); 481 } 482 483 int 484 kern_fcntl(struct thread *td, int fd, int cmd, intptr_t arg) 485 { 486 struct filedesc *fdp; 487 struct flock *flp; 488 struct file *fp, *fp2; 489 struct filedescent *fde; 490 struct proc *p; 491 struct vnode *vp; 492 struct mount *mp; 493 int error, flg, seals, tmp; 494 uint64_t bsize; 495 off_t foffset; 496 497 error = 0; 498 flg = F_POSIX; 499 p = td->td_proc; 500 fdp = p->p_fd; 501 502 AUDIT_ARG_FD(cmd); 503 AUDIT_ARG_CMD(cmd); 504 switch (cmd) { 505 case F_DUPFD: 506 tmp = arg; 507 error = kern_dup(td, FDDUP_FCNTL, 0, fd, tmp); 508 break; 509 510 case F_DUPFD_CLOEXEC: 511 tmp = arg; 512 error = kern_dup(td, FDDUP_FCNTL, FDDUP_FLAG_CLOEXEC, fd, tmp); 513 break; 514 515 case F_DUP2FD: 516 tmp = arg; 517 error = kern_dup(td, FDDUP_FIXED, 0, fd, tmp); 518 break; 519 520 case F_DUP2FD_CLOEXEC: 521 tmp = arg; 522 error = kern_dup(td, FDDUP_FIXED, FDDUP_FLAG_CLOEXEC, fd, tmp); 523 break; 524 525 case F_GETFD: 526 error = EBADF; 527 FILEDESC_SLOCK(fdp); 528 fde = fdeget_locked(fdp, fd); 529 if (fde != NULL) { 530 td->td_retval[0] = 531 (fde->fde_flags & UF_EXCLOSE) ? FD_CLOEXEC : 0; 532 error = 0; 533 } 534 FILEDESC_SUNLOCK(fdp); 535 break; 536 537 case F_SETFD: 538 error = EBADF; 539 FILEDESC_XLOCK(fdp); 540 fde = fdeget_locked(fdp, fd); 541 if (fde != NULL) { 542 fde->fde_flags = (fde->fde_flags & ~UF_EXCLOSE) | 543 (arg & FD_CLOEXEC ? UF_EXCLOSE : 0); 544 error = 0; 545 } 546 FILEDESC_XUNLOCK(fdp); 547 break; 548 549 case F_GETFL: 550 error = fget_fcntl(td, fd, &cap_fcntl_rights, F_GETFL, &fp); 551 if (error != 0) 552 break; 553 td->td_retval[0] = OFLAGS(fp->f_flag); 554 fdrop(fp, td); 555 break; 556 557 case F_SETFL: 558 error = fget_fcntl(td, fd, &cap_fcntl_rights, F_SETFL, &fp); 559 if (error != 0) 560 break; 561 do { 562 tmp = flg = fp->f_flag; 563 tmp &= ~FCNTLFLAGS; 564 tmp |= FFLAGS(arg & ~O_ACCMODE) & FCNTLFLAGS; 565 } while(atomic_cmpset_int(&fp->f_flag, flg, tmp) == 0); 566 tmp = fp->f_flag & FNONBLOCK; 567 error = fo_ioctl(fp, FIONBIO, &tmp, td->td_ucred, td); 568 if (error != 0) { 569 fdrop(fp, td); 570 break; 571 } 572 tmp = fp->f_flag & FASYNC; 573 error = fo_ioctl(fp, FIOASYNC, &tmp, td->td_ucred, td); 574 if (error == 0) { 575 fdrop(fp, td); 576 break; 577 } 578 atomic_clear_int(&fp->f_flag, FNONBLOCK); 579 tmp = 0; 580 (void)fo_ioctl(fp, FIONBIO, &tmp, td->td_ucred, td); 581 fdrop(fp, td); 582 break; 583 584 case F_GETOWN: 585 error = fget_fcntl(td, fd, &cap_fcntl_rights, F_GETOWN, &fp); 586 if (error != 0) 587 break; 588 error = fo_ioctl(fp, FIOGETOWN, &tmp, td->td_ucred, td); 589 if (error == 0) 590 td->td_retval[0] = tmp; 591 fdrop(fp, td); 592 break; 593 594 case F_SETOWN: 595 error = fget_fcntl(td, fd, &cap_fcntl_rights, F_SETOWN, &fp); 596 if (error != 0) 597 break; 598 tmp = arg; 599 error = fo_ioctl(fp, FIOSETOWN, &tmp, td->td_ucred, td); 600 fdrop(fp, td); 601 break; 602 603 case F_SETLK_REMOTE: 604 error = priv_check(td, PRIV_NFS_LOCKD); 605 if (error != 0) 606 return (error); 607 flg = F_REMOTE; 608 goto do_setlk; 609 610 case F_SETLKW: 611 flg |= F_WAIT; 612 /* FALLTHROUGH F_SETLK */ 613 614 case F_SETLK: 615 do_setlk: 616 flp = (struct flock *)arg; 617 if ((flg & F_REMOTE) != 0 && flp->l_sysid == 0) { 618 error = EINVAL; 619 break; 620 } 621 622 error = fget_unlocked(fdp, fd, &cap_flock_rights, &fp); 623 if (error != 0) 624 break; 625 if (fp->f_type != DTYPE_VNODE) { 626 error = EBADF; 627 fdrop(fp, td); 628 break; 629 } 630 631 if (flp->l_whence == SEEK_CUR) { 632 foffset = foffset_get(fp); 633 if (foffset < 0 || 634 (flp->l_start > 0 && 635 foffset > OFF_MAX - flp->l_start)) { 636 error = EOVERFLOW; 637 fdrop(fp, td); 638 break; 639 } 640 flp->l_start += foffset; 641 } 642 643 vp = fp->f_vnode; 644 switch (flp->l_type) { 645 case F_RDLCK: 646 if ((fp->f_flag & FREAD) == 0) { 647 error = EBADF; 648 break; 649 } 650 if ((p->p_leader->p_flag & P_ADVLOCK) == 0) { 651 PROC_LOCK(p->p_leader); 652 p->p_leader->p_flag |= P_ADVLOCK; 653 PROC_UNLOCK(p->p_leader); 654 } 655 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_SETLK, 656 flp, flg); 657 break; 658 case F_WRLCK: 659 if ((fp->f_flag & FWRITE) == 0) { 660 error = EBADF; 661 break; 662 } 663 if ((p->p_leader->p_flag & P_ADVLOCK) == 0) { 664 PROC_LOCK(p->p_leader); 665 p->p_leader->p_flag |= P_ADVLOCK; 666 PROC_UNLOCK(p->p_leader); 667 } 668 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_SETLK, 669 flp, flg); 670 break; 671 case F_UNLCK: 672 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_UNLCK, 673 flp, flg); 674 break; 675 case F_UNLCKSYS: 676 if (flg != F_REMOTE) { 677 error = EINVAL; 678 break; 679 } 680 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, 681 F_UNLCKSYS, flp, flg); 682 break; 683 default: 684 error = EINVAL; 685 break; 686 } 687 if (error != 0 || flp->l_type == F_UNLCK || 688 flp->l_type == F_UNLCKSYS) { 689 fdrop(fp, td); 690 break; 691 } 692 693 /* 694 * Check for a race with close. 695 * 696 * The vnode is now advisory locked (or unlocked, but this case 697 * is not really important) as the caller requested. 698 * We had to drop the filedesc lock, so we need to recheck if 699 * the descriptor is still valid, because if it was closed 700 * in the meantime we need to remove advisory lock from the 701 * vnode - close on any descriptor leading to an advisory 702 * locked vnode, removes that lock. 703 * We will return 0 on purpose in that case, as the result of 704 * successful advisory lock might have been externally visible 705 * already. This is fine - effectively we pretend to the caller 706 * that the closing thread was a bit slower and that the 707 * advisory lock succeeded before the close. 708 */ 709 error = fget_unlocked(fdp, fd, &cap_no_rights, &fp2); 710 if (error != 0) { 711 fdrop(fp, td); 712 break; 713 } 714 if (fp != fp2) { 715 flp->l_whence = SEEK_SET; 716 flp->l_start = 0; 717 flp->l_len = 0; 718 flp->l_type = F_UNLCK; 719 (void) VOP_ADVLOCK(vp, (caddr_t)p->p_leader, 720 F_UNLCK, flp, F_POSIX); 721 } 722 fdrop(fp, td); 723 fdrop(fp2, td); 724 break; 725 726 case F_GETLK: 727 error = fget_unlocked(fdp, fd, &cap_flock_rights, &fp); 728 if (error != 0) 729 break; 730 if (fp->f_type != DTYPE_VNODE) { 731 error = EBADF; 732 fdrop(fp, td); 733 break; 734 } 735 flp = (struct flock *)arg; 736 if (flp->l_type != F_RDLCK && flp->l_type != F_WRLCK && 737 flp->l_type != F_UNLCK) { 738 error = EINVAL; 739 fdrop(fp, td); 740 break; 741 } 742 if (flp->l_whence == SEEK_CUR) { 743 foffset = foffset_get(fp); 744 if ((flp->l_start > 0 && 745 foffset > OFF_MAX - flp->l_start) || 746 (flp->l_start < 0 && 747 foffset < OFF_MIN - flp->l_start)) { 748 error = EOVERFLOW; 749 fdrop(fp, td); 750 break; 751 } 752 flp->l_start += foffset; 753 } 754 vp = fp->f_vnode; 755 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_GETLK, flp, 756 F_POSIX); 757 fdrop(fp, td); 758 break; 759 760 case F_ADD_SEALS: 761 error = fget_unlocked(fdp, fd, &cap_no_rights, &fp); 762 if (error != 0) 763 break; 764 error = fo_add_seals(fp, arg); 765 fdrop(fp, td); 766 break; 767 768 case F_GET_SEALS: 769 error = fget_unlocked(fdp, fd, &cap_no_rights, &fp); 770 if (error != 0) 771 break; 772 if (fo_get_seals(fp, &seals) == 0) 773 td->td_retval[0] = seals; 774 else 775 error = EINVAL; 776 fdrop(fp, td); 777 break; 778 779 case F_RDAHEAD: 780 arg = arg ? 128 * 1024: 0; 781 /* FALLTHROUGH */ 782 case F_READAHEAD: 783 error = fget_unlocked(fdp, fd, &cap_no_rights, &fp); 784 if (error != 0) 785 break; 786 if (fp->f_type != DTYPE_VNODE) { 787 fdrop(fp, td); 788 error = EBADF; 789 break; 790 } 791 vp = fp->f_vnode; 792 if (vp->v_type != VREG) { 793 fdrop(fp, td); 794 error = ENOTTY; 795 break; 796 } 797 798 /* 799 * Exclusive lock synchronizes against f_seqcount reads and 800 * writes in sequential_heuristic(). 801 */ 802 error = vn_lock(vp, LK_EXCLUSIVE); 803 if (error != 0) { 804 fdrop(fp, td); 805 break; 806 } 807 if (arg >= 0) { 808 bsize = fp->f_vnode->v_mount->mnt_stat.f_iosize; 809 arg = MIN(arg, INT_MAX - bsize + 1); 810 fp->f_seqcount = MIN(IO_SEQMAX, 811 (arg + bsize - 1) / bsize); 812 atomic_set_int(&fp->f_flag, FRDAHEAD); 813 } else { 814 atomic_clear_int(&fp->f_flag, FRDAHEAD); 815 } 816 VOP_UNLOCK(vp); 817 fdrop(fp, td); 818 break; 819 820 case F_ISUNIONSTACK: 821 /* 822 * Check if the vnode is part of a union stack (either the 823 * "union" flag from mount(2) or unionfs). 824 * 825 * Prior to introduction of this op libc's readdir would call 826 * fstatfs(2), in effect unnecessarily copying kilobytes of 827 * data just to check fs name and a mount flag. 828 * 829 * Fixing the code to handle everything in the kernel instead 830 * is a non-trivial endeavor and has low priority, thus this 831 * horrible kludge facilitates the current behavior in a much 832 * cheaper manner until someone(tm) sorts this out. 833 */ 834 error = fget_unlocked(fdp, fd, &cap_no_rights, &fp); 835 if (error != 0) 836 break; 837 if (fp->f_type != DTYPE_VNODE) { 838 fdrop(fp, td); 839 error = EBADF; 840 break; 841 } 842 vp = fp->f_vnode; 843 /* 844 * Since we don't prevent dooming the vnode even non-null mp 845 * found can become immediately stale. This is tolerable since 846 * mount points are type-stable (providing safe memory access) 847 * and any vfs op on this vnode going forward will return an 848 * error (meaning return value in this case is meaningless). 849 */ 850 mp = (struct mount *)atomic_load_ptr(&vp->v_mount); 851 if (__predict_false(mp == NULL)) { 852 fdrop(fp, td); 853 error = EBADF; 854 break; 855 } 856 td->td_retval[0] = 0; 857 if (mp->mnt_kern_flag & MNTK_UNIONFS || 858 mp->mnt_flag & MNT_UNION) 859 td->td_retval[0] = 1; 860 fdrop(fp, td); 861 break; 862 863 default: 864 error = EINVAL; 865 break; 866 } 867 return (error); 868 } 869 870 static int 871 getmaxfd(struct thread *td) 872 { 873 874 return (min((int)lim_cur(td, RLIMIT_NOFILE), maxfilesperproc)); 875 } 876 877 /* 878 * Common code for dup, dup2, fcntl(F_DUPFD) and fcntl(F_DUP2FD). 879 */ 880 int 881 kern_dup(struct thread *td, u_int mode, int flags, int old, int new) 882 { 883 struct filedesc *fdp; 884 struct filedescent *oldfde, *newfde; 885 struct proc *p; 886 struct file *delfp; 887 u_long *oioctls, *nioctls; 888 int error, maxfd; 889 890 p = td->td_proc; 891 fdp = p->p_fd; 892 oioctls = NULL; 893 894 MPASS((flags & ~(FDDUP_FLAG_CLOEXEC)) == 0); 895 MPASS(mode < FDDUP_LASTMODE); 896 897 AUDIT_ARG_FD(old); 898 /* XXXRW: if (flags & FDDUP_FIXED) AUDIT_ARG_FD2(new); */ 899 900 /* 901 * Verify we have a valid descriptor to dup from and possibly to 902 * dup to. Unlike dup() and dup2(), fcntl()'s F_DUPFD should 903 * return EINVAL when the new descriptor is out of bounds. 904 */ 905 if (old < 0) 906 return (EBADF); 907 if (new < 0) 908 return (mode == FDDUP_FCNTL ? EINVAL : EBADF); 909 maxfd = getmaxfd(td); 910 if (new >= maxfd) 911 return (mode == FDDUP_FCNTL ? EINVAL : EBADF); 912 913 error = EBADF; 914 FILEDESC_XLOCK(fdp); 915 if (fget_locked(fdp, old) == NULL) 916 goto unlock; 917 if ((mode == FDDUP_FIXED || mode == FDDUP_MUSTREPLACE) && old == new) { 918 td->td_retval[0] = new; 919 if (flags & FDDUP_FLAG_CLOEXEC) 920 fdp->fd_ofiles[new].fde_flags |= UF_EXCLOSE; 921 error = 0; 922 goto unlock; 923 } 924 925 oldfde = &fdp->fd_ofiles[old]; 926 if (!fhold(oldfde->fde_file)) 927 goto unlock; 928 929 /* 930 * If the caller specified a file descriptor, make sure the file 931 * table is large enough to hold it, and grab it. Otherwise, just 932 * allocate a new descriptor the usual way. 933 */ 934 switch (mode) { 935 case FDDUP_NORMAL: 936 case FDDUP_FCNTL: 937 if ((error = fdalloc(td, new, &new)) != 0) { 938 fdrop(oldfde->fde_file, td); 939 goto unlock; 940 } 941 break; 942 case FDDUP_MUSTREPLACE: 943 /* Target file descriptor must exist. */ 944 if (fget_locked(fdp, new) == NULL) { 945 fdrop(oldfde->fde_file, td); 946 goto unlock; 947 } 948 break; 949 case FDDUP_FIXED: 950 if (new >= fdp->fd_nfiles) { 951 /* 952 * The resource limits are here instead of e.g. 953 * fdalloc(), because the file descriptor table may be 954 * shared between processes, so we can't really use 955 * racct_add()/racct_sub(). Instead of counting the 956 * number of actually allocated descriptors, just put 957 * the limit on the size of the file descriptor table. 958 */ 959 #ifdef RACCT 960 if (RACCT_ENABLED()) { 961 error = racct_set_unlocked(p, RACCT_NOFILE, new + 1); 962 if (error != 0) { 963 error = EMFILE; 964 fdrop(oldfde->fde_file, td); 965 goto unlock; 966 } 967 } 968 #endif 969 fdgrowtable_exp(fdp, new + 1); 970 } 971 if (!fdisused(fdp, new)) 972 fdused(fdp, new); 973 break; 974 default: 975 KASSERT(0, ("%s unsupported mode %d", __func__, mode)); 976 } 977 978 KASSERT(old != new, ("new fd is same as old")); 979 980 newfde = &fdp->fd_ofiles[new]; 981 delfp = newfde->fde_file; 982 983 oioctls = filecaps_free_prep(&newfde->fde_caps); 984 nioctls = filecaps_copy_prep(&oldfde->fde_caps); 985 986 /* 987 * Duplicate the source descriptor. 988 */ 989 #ifdef CAPABILITIES 990 seqc_write_begin(&newfde->fde_seqc); 991 #endif 992 memcpy(newfde, oldfde, fde_change_size); 993 filecaps_copy_finish(&oldfde->fde_caps, &newfde->fde_caps, 994 nioctls); 995 if ((flags & FDDUP_FLAG_CLOEXEC) != 0) 996 newfde->fde_flags = oldfde->fde_flags | UF_EXCLOSE; 997 else 998 newfde->fde_flags = oldfde->fde_flags & ~UF_EXCLOSE; 999 #ifdef CAPABILITIES 1000 seqc_write_end(&newfde->fde_seqc); 1001 #endif 1002 td->td_retval[0] = new; 1003 1004 error = 0; 1005 1006 if (delfp != NULL) { 1007 (void) closefp(fdp, new, delfp, td, 1); 1008 FILEDESC_UNLOCK_ASSERT(fdp); 1009 } else { 1010 unlock: 1011 FILEDESC_XUNLOCK(fdp); 1012 } 1013 1014 filecaps_free_finish(oioctls); 1015 return (error); 1016 } 1017 1018 /* 1019 * If sigio is on the list associated with a process or process group, 1020 * disable signalling from the device, remove sigio from the list and 1021 * free sigio. 1022 */ 1023 void 1024 funsetown(struct sigio **sigiop) 1025 { 1026 struct sigio *sigio; 1027 1028 if (*sigiop == NULL) 1029 return; 1030 SIGIO_LOCK(); 1031 sigio = *sigiop; 1032 if (sigio == NULL) { 1033 SIGIO_UNLOCK(); 1034 return; 1035 } 1036 *(sigio->sio_myref) = NULL; 1037 if ((sigio)->sio_pgid < 0) { 1038 struct pgrp *pg = (sigio)->sio_pgrp; 1039 PGRP_LOCK(pg); 1040 SLIST_REMOVE(&sigio->sio_pgrp->pg_sigiolst, sigio, 1041 sigio, sio_pgsigio); 1042 PGRP_UNLOCK(pg); 1043 } else { 1044 struct proc *p = (sigio)->sio_proc; 1045 PROC_LOCK(p); 1046 SLIST_REMOVE(&sigio->sio_proc->p_sigiolst, sigio, 1047 sigio, sio_pgsigio); 1048 PROC_UNLOCK(p); 1049 } 1050 SIGIO_UNLOCK(); 1051 crfree(sigio->sio_ucred); 1052 free(sigio, M_SIGIO); 1053 } 1054 1055 /* 1056 * Free a list of sigio structures. 1057 * We only need to lock the SIGIO_LOCK because we have made ourselves 1058 * inaccessible to callers of fsetown and therefore do not need to lock 1059 * the proc or pgrp struct for the list manipulation. 1060 */ 1061 void 1062 funsetownlst(struct sigiolst *sigiolst) 1063 { 1064 struct proc *p; 1065 struct pgrp *pg; 1066 struct sigio *sigio; 1067 1068 sigio = SLIST_FIRST(sigiolst); 1069 if (sigio == NULL) 1070 return; 1071 p = NULL; 1072 pg = NULL; 1073 1074 /* 1075 * Every entry of the list should belong 1076 * to a single proc or pgrp. 1077 */ 1078 if (sigio->sio_pgid < 0) { 1079 pg = sigio->sio_pgrp; 1080 PGRP_LOCK_ASSERT(pg, MA_NOTOWNED); 1081 } else /* if (sigio->sio_pgid > 0) */ { 1082 p = sigio->sio_proc; 1083 PROC_LOCK_ASSERT(p, MA_NOTOWNED); 1084 } 1085 1086 SIGIO_LOCK(); 1087 while ((sigio = SLIST_FIRST(sigiolst)) != NULL) { 1088 *(sigio->sio_myref) = NULL; 1089 if (pg != NULL) { 1090 KASSERT(sigio->sio_pgid < 0, 1091 ("Proc sigio in pgrp sigio list")); 1092 KASSERT(sigio->sio_pgrp == pg, 1093 ("Bogus pgrp in sigio list")); 1094 PGRP_LOCK(pg); 1095 SLIST_REMOVE(&pg->pg_sigiolst, sigio, sigio, 1096 sio_pgsigio); 1097 PGRP_UNLOCK(pg); 1098 } else /* if (p != NULL) */ { 1099 KASSERT(sigio->sio_pgid > 0, 1100 ("Pgrp sigio in proc sigio list")); 1101 KASSERT(sigio->sio_proc == p, 1102 ("Bogus proc in sigio list")); 1103 PROC_LOCK(p); 1104 SLIST_REMOVE(&p->p_sigiolst, sigio, sigio, 1105 sio_pgsigio); 1106 PROC_UNLOCK(p); 1107 } 1108 SIGIO_UNLOCK(); 1109 crfree(sigio->sio_ucred); 1110 free(sigio, M_SIGIO); 1111 SIGIO_LOCK(); 1112 } 1113 SIGIO_UNLOCK(); 1114 } 1115 1116 /* 1117 * This is common code for FIOSETOWN ioctl called by fcntl(fd, F_SETOWN, arg). 1118 * 1119 * After permission checking, add a sigio structure to the sigio list for 1120 * the process or process group. 1121 */ 1122 int 1123 fsetown(pid_t pgid, struct sigio **sigiop) 1124 { 1125 struct proc *proc; 1126 struct pgrp *pgrp; 1127 struct sigio *sigio; 1128 int ret; 1129 1130 if (pgid == 0) { 1131 funsetown(sigiop); 1132 return (0); 1133 } 1134 1135 ret = 0; 1136 1137 /* Allocate and fill in the new sigio out of locks. */ 1138 sigio = malloc(sizeof(struct sigio), M_SIGIO, M_WAITOK); 1139 sigio->sio_pgid = pgid; 1140 sigio->sio_ucred = crhold(curthread->td_ucred); 1141 sigio->sio_myref = sigiop; 1142 1143 sx_slock(&proctree_lock); 1144 if (pgid > 0) { 1145 proc = pfind(pgid); 1146 if (proc == NULL) { 1147 ret = ESRCH; 1148 goto fail; 1149 } 1150 1151 /* 1152 * Policy - Don't allow a process to FSETOWN a process 1153 * in another session. 1154 * 1155 * Remove this test to allow maximum flexibility or 1156 * restrict FSETOWN to the current process or process 1157 * group for maximum safety. 1158 */ 1159 PROC_UNLOCK(proc); 1160 if (proc->p_session != curthread->td_proc->p_session) { 1161 ret = EPERM; 1162 goto fail; 1163 } 1164 1165 pgrp = NULL; 1166 } else /* if (pgid < 0) */ { 1167 pgrp = pgfind(-pgid); 1168 if (pgrp == NULL) { 1169 ret = ESRCH; 1170 goto fail; 1171 } 1172 PGRP_UNLOCK(pgrp); 1173 1174 /* 1175 * Policy - Don't allow a process to FSETOWN a process 1176 * in another session. 1177 * 1178 * Remove this test to allow maximum flexibility or 1179 * restrict FSETOWN to the current process or process 1180 * group for maximum safety. 1181 */ 1182 if (pgrp->pg_session != curthread->td_proc->p_session) { 1183 ret = EPERM; 1184 goto fail; 1185 } 1186 1187 proc = NULL; 1188 } 1189 funsetown(sigiop); 1190 if (pgid > 0) { 1191 PROC_LOCK(proc); 1192 /* 1193 * Since funsetownlst() is called without the proctree 1194 * locked, we need to check for P_WEXIT. 1195 * XXX: is ESRCH correct? 1196 */ 1197 if ((proc->p_flag & P_WEXIT) != 0) { 1198 PROC_UNLOCK(proc); 1199 ret = ESRCH; 1200 goto fail; 1201 } 1202 SLIST_INSERT_HEAD(&proc->p_sigiolst, sigio, sio_pgsigio); 1203 sigio->sio_proc = proc; 1204 PROC_UNLOCK(proc); 1205 } else { 1206 PGRP_LOCK(pgrp); 1207 SLIST_INSERT_HEAD(&pgrp->pg_sigiolst, sigio, sio_pgsigio); 1208 sigio->sio_pgrp = pgrp; 1209 PGRP_UNLOCK(pgrp); 1210 } 1211 sx_sunlock(&proctree_lock); 1212 SIGIO_LOCK(); 1213 *sigiop = sigio; 1214 SIGIO_UNLOCK(); 1215 return (0); 1216 1217 fail: 1218 sx_sunlock(&proctree_lock); 1219 crfree(sigio->sio_ucred); 1220 free(sigio, M_SIGIO); 1221 return (ret); 1222 } 1223 1224 /* 1225 * This is common code for FIOGETOWN ioctl called by fcntl(fd, F_GETOWN, arg). 1226 */ 1227 pid_t 1228 fgetown(struct sigio **sigiop) 1229 { 1230 pid_t pgid; 1231 1232 SIGIO_LOCK(); 1233 pgid = (*sigiop != NULL) ? (*sigiop)->sio_pgid : 0; 1234 SIGIO_UNLOCK(); 1235 return (pgid); 1236 } 1237 1238 /* 1239 * Function drops the filedesc lock on return. 1240 */ 1241 static int 1242 closefp(struct filedesc *fdp, int fd, struct file *fp, struct thread *td, 1243 int holdleaders) 1244 { 1245 int error; 1246 1247 FILEDESC_XLOCK_ASSERT(fdp); 1248 1249 if (holdleaders) { 1250 if (td->td_proc->p_fdtol != NULL) { 1251 /* 1252 * Ask fdfree() to sleep to ensure that all relevant 1253 * process leaders can be traversed in closef(). 1254 */ 1255 fdp->fd_holdleaderscount++; 1256 } else { 1257 holdleaders = 0; 1258 } 1259 } 1260 1261 /* 1262 * We now hold the fp reference that used to be owned by the 1263 * descriptor array. We have to unlock the FILEDESC *AFTER* 1264 * knote_fdclose to prevent a race of the fd getting opened, a knote 1265 * added, and deleteing a knote for the new fd. 1266 */ 1267 if (__predict_false(!TAILQ_EMPTY(&fdp->fd_kqlist))) 1268 knote_fdclose(td, fd); 1269 1270 /* 1271 * We need to notify mqueue if the object is of type mqueue. 1272 */ 1273 if (__predict_false(fp->f_type == DTYPE_MQUEUE)) 1274 mq_fdclose(td, fd, fp); 1275 FILEDESC_XUNLOCK(fdp); 1276 1277 error = closef(fp, td); 1278 if (holdleaders) { 1279 FILEDESC_XLOCK(fdp); 1280 fdp->fd_holdleaderscount--; 1281 if (fdp->fd_holdleaderscount == 0 && 1282 fdp->fd_holdleaderswakeup != 0) { 1283 fdp->fd_holdleaderswakeup = 0; 1284 wakeup(&fdp->fd_holdleaderscount); 1285 } 1286 FILEDESC_XUNLOCK(fdp); 1287 } 1288 return (error); 1289 } 1290 1291 /* 1292 * Close a file descriptor. 1293 */ 1294 #ifndef _SYS_SYSPROTO_H_ 1295 struct close_args { 1296 int fd; 1297 }; 1298 #endif 1299 /* ARGSUSED */ 1300 int 1301 sys_close(struct thread *td, struct close_args *uap) 1302 { 1303 1304 return (kern_close(td, uap->fd)); 1305 } 1306 1307 int 1308 kern_close(struct thread *td, int fd) 1309 { 1310 struct filedesc *fdp; 1311 struct file *fp; 1312 1313 fdp = td->td_proc->p_fd; 1314 1315 AUDIT_SYSCLOSE(td, fd); 1316 1317 FILEDESC_XLOCK(fdp); 1318 if ((fp = fget_locked(fdp, fd)) == NULL) { 1319 FILEDESC_XUNLOCK(fdp); 1320 return (EBADF); 1321 } 1322 fdfree(fdp, fd); 1323 1324 /* closefp() drops the FILEDESC lock for us. */ 1325 return (closefp(fdp, fd, fp, td, 1)); 1326 } 1327 1328 /* 1329 * Close open file descriptors. 1330 */ 1331 #ifndef _SYS_SYSPROTO_H_ 1332 struct closefrom_args { 1333 int lowfd; 1334 }; 1335 #endif 1336 /* ARGSUSED */ 1337 int 1338 sys_closefrom(struct thread *td, struct closefrom_args *uap) 1339 { 1340 struct filedesc *fdp; 1341 int fd; 1342 1343 fdp = td->td_proc->p_fd; 1344 AUDIT_ARG_FD(uap->lowfd); 1345 1346 /* 1347 * Treat negative starting file descriptor values identical to 1348 * closefrom(0) which closes all files. 1349 */ 1350 if (uap->lowfd < 0) 1351 uap->lowfd = 0; 1352 FILEDESC_SLOCK(fdp); 1353 for (fd = uap->lowfd; fd <= fdp->fd_lastfile; fd++) { 1354 if (fdp->fd_ofiles[fd].fde_file != NULL) { 1355 FILEDESC_SUNLOCK(fdp); 1356 (void)kern_close(td, fd); 1357 FILEDESC_SLOCK(fdp); 1358 } 1359 } 1360 FILEDESC_SUNLOCK(fdp); 1361 return (0); 1362 } 1363 1364 #if defined(COMPAT_43) 1365 /* 1366 * Return status information about a file descriptor. 1367 */ 1368 #ifndef _SYS_SYSPROTO_H_ 1369 struct ofstat_args { 1370 int fd; 1371 struct ostat *sb; 1372 }; 1373 #endif 1374 /* ARGSUSED */ 1375 int 1376 ofstat(struct thread *td, struct ofstat_args *uap) 1377 { 1378 struct ostat oub; 1379 struct stat ub; 1380 int error; 1381 1382 error = kern_fstat(td, uap->fd, &ub); 1383 if (error == 0) { 1384 cvtstat(&ub, &oub); 1385 error = copyout(&oub, uap->sb, sizeof(oub)); 1386 } 1387 return (error); 1388 } 1389 #endif /* COMPAT_43 */ 1390 1391 #if defined(COMPAT_FREEBSD11) 1392 int 1393 freebsd11_fstat(struct thread *td, struct freebsd11_fstat_args *uap) 1394 { 1395 struct stat sb; 1396 struct freebsd11_stat osb; 1397 int error; 1398 1399 error = kern_fstat(td, uap->fd, &sb); 1400 if (error != 0) 1401 return (error); 1402 error = freebsd11_cvtstat(&sb, &osb); 1403 if (error == 0) 1404 error = copyout(&osb, uap->sb, sizeof(osb)); 1405 return (error); 1406 } 1407 #endif /* COMPAT_FREEBSD11 */ 1408 1409 /* 1410 * Return status information about a file descriptor. 1411 */ 1412 #ifndef _SYS_SYSPROTO_H_ 1413 struct fstat_args { 1414 int fd; 1415 struct stat *sb; 1416 }; 1417 #endif 1418 /* ARGSUSED */ 1419 int 1420 sys_fstat(struct thread *td, struct fstat_args *uap) 1421 { 1422 struct stat ub; 1423 int error; 1424 1425 error = kern_fstat(td, uap->fd, &ub); 1426 if (error == 0) 1427 error = copyout(&ub, uap->sb, sizeof(ub)); 1428 return (error); 1429 } 1430 1431 int 1432 kern_fstat(struct thread *td, int fd, struct stat *sbp) 1433 { 1434 struct file *fp; 1435 int error; 1436 1437 AUDIT_ARG_FD(fd); 1438 1439 error = fget(td, fd, &cap_fstat_rights, &fp); 1440 if (__predict_false(error != 0)) 1441 return (error); 1442 1443 AUDIT_ARG_FILE(td->td_proc, fp); 1444 1445 error = fo_stat(fp, sbp, td->td_ucred, td); 1446 fdrop(fp, td); 1447 #ifdef __STAT_TIME_T_EXT 1448 sbp->st_atim_ext = 0; 1449 sbp->st_mtim_ext = 0; 1450 sbp->st_ctim_ext = 0; 1451 sbp->st_btim_ext = 0; 1452 #endif 1453 #ifdef KTRACE 1454 if (KTRPOINT(td, KTR_STRUCT)) 1455 ktrstat_error(sbp, error); 1456 #endif 1457 return (error); 1458 } 1459 1460 #if defined(COMPAT_FREEBSD11) 1461 /* 1462 * Return status information about a file descriptor. 1463 */ 1464 #ifndef _SYS_SYSPROTO_H_ 1465 struct freebsd11_nfstat_args { 1466 int fd; 1467 struct nstat *sb; 1468 }; 1469 #endif 1470 /* ARGSUSED */ 1471 int 1472 freebsd11_nfstat(struct thread *td, struct freebsd11_nfstat_args *uap) 1473 { 1474 struct nstat nub; 1475 struct stat ub; 1476 int error; 1477 1478 error = kern_fstat(td, uap->fd, &ub); 1479 if (error == 0) { 1480 freebsd11_cvtnstat(&ub, &nub); 1481 error = copyout(&nub, uap->sb, sizeof(nub)); 1482 } 1483 return (error); 1484 } 1485 #endif /* COMPAT_FREEBSD11 */ 1486 1487 /* 1488 * Return pathconf information about a file descriptor. 1489 */ 1490 #ifndef _SYS_SYSPROTO_H_ 1491 struct fpathconf_args { 1492 int fd; 1493 int name; 1494 }; 1495 #endif 1496 /* ARGSUSED */ 1497 int 1498 sys_fpathconf(struct thread *td, struct fpathconf_args *uap) 1499 { 1500 long value; 1501 int error; 1502 1503 error = kern_fpathconf(td, uap->fd, uap->name, &value); 1504 if (error == 0) 1505 td->td_retval[0] = value; 1506 return (error); 1507 } 1508 1509 int 1510 kern_fpathconf(struct thread *td, int fd, int name, long *valuep) 1511 { 1512 struct file *fp; 1513 struct vnode *vp; 1514 int error; 1515 1516 error = fget(td, fd, &cap_fpathconf_rights, &fp); 1517 if (error != 0) 1518 return (error); 1519 1520 if (name == _PC_ASYNC_IO) { 1521 *valuep = _POSIX_ASYNCHRONOUS_IO; 1522 goto out; 1523 } 1524 vp = fp->f_vnode; 1525 if (vp != NULL) { 1526 vn_lock(vp, LK_SHARED | LK_RETRY); 1527 error = VOP_PATHCONF(vp, name, valuep); 1528 VOP_UNLOCK(vp); 1529 } else if (fp->f_type == DTYPE_PIPE || fp->f_type == DTYPE_SOCKET) { 1530 if (name != _PC_PIPE_BUF) { 1531 error = EINVAL; 1532 } else { 1533 *valuep = PIPE_BUF; 1534 error = 0; 1535 } 1536 } else { 1537 error = EOPNOTSUPP; 1538 } 1539 out: 1540 fdrop(fp, td); 1541 return (error); 1542 } 1543 1544 /* 1545 * Copy filecaps structure allocating memory for ioctls array if needed. 1546 * 1547 * The last parameter indicates whether the fdtable is locked. If it is not and 1548 * ioctls are encountered, copying fails and the caller must lock the table. 1549 * 1550 * Note that if the table was not locked, the caller has to check the relevant 1551 * sequence counter to determine whether the operation was successful. 1552 */ 1553 bool 1554 filecaps_copy(const struct filecaps *src, struct filecaps *dst, bool locked) 1555 { 1556 size_t size; 1557 1558 if (src->fc_ioctls != NULL && !locked) 1559 return (false); 1560 memcpy(dst, src, sizeof(*src)); 1561 if (src->fc_ioctls == NULL) 1562 return (true); 1563 1564 KASSERT(src->fc_nioctls > 0, 1565 ("fc_ioctls != NULL, but fc_nioctls=%hd", src->fc_nioctls)); 1566 1567 size = sizeof(src->fc_ioctls[0]) * src->fc_nioctls; 1568 dst->fc_ioctls = malloc(size, M_FILECAPS, M_WAITOK); 1569 memcpy(dst->fc_ioctls, src->fc_ioctls, size); 1570 return (true); 1571 } 1572 1573 static u_long * 1574 filecaps_copy_prep(const struct filecaps *src) 1575 { 1576 u_long *ioctls; 1577 size_t size; 1578 1579 if (__predict_true(src->fc_ioctls == NULL)) 1580 return (NULL); 1581 1582 KASSERT(src->fc_nioctls > 0, 1583 ("fc_ioctls != NULL, but fc_nioctls=%hd", src->fc_nioctls)); 1584 1585 size = sizeof(src->fc_ioctls[0]) * src->fc_nioctls; 1586 ioctls = malloc(size, M_FILECAPS, M_WAITOK); 1587 return (ioctls); 1588 } 1589 1590 static void 1591 filecaps_copy_finish(const struct filecaps *src, struct filecaps *dst, 1592 u_long *ioctls) 1593 { 1594 size_t size; 1595 1596 *dst = *src; 1597 if (__predict_true(src->fc_ioctls == NULL)) { 1598 MPASS(ioctls == NULL); 1599 return; 1600 } 1601 1602 size = sizeof(src->fc_ioctls[0]) * src->fc_nioctls; 1603 dst->fc_ioctls = ioctls; 1604 bcopy(src->fc_ioctls, dst->fc_ioctls, size); 1605 } 1606 1607 /* 1608 * Move filecaps structure to the new place and clear the old place. 1609 */ 1610 void 1611 filecaps_move(struct filecaps *src, struct filecaps *dst) 1612 { 1613 1614 *dst = *src; 1615 bzero(src, sizeof(*src)); 1616 } 1617 1618 /* 1619 * Fill the given filecaps structure with full rights. 1620 */ 1621 static void 1622 filecaps_fill(struct filecaps *fcaps) 1623 { 1624 1625 CAP_ALL(&fcaps->fc_rights); 1626 fcaps->fc_ioctls = NULL; 1627 fcaps->fc_nioctls = -1; 1628 fcaps->fc_fcntls = CAP_FCNTL_ALL; 1629 } 1630 1631 /* 1632 * Free memory allocated within filecaps structure. 1633 */ 1634 void 1635 filecaps_free(struct filecaps *fcaps) 1636 { 1637 1638 free(fcaps->fc_ioctls, M_FILECAPS); 1639 bzero(fcaps, sizeof(*fcaps)); 1640 } 1641 1642 static u_long * 1643 filecaps_free_prep(struct filecaps *fcaps) 1644 { 1645 u_long *ioctls; 1646 1647 ioctls = fcaps->fc_ioctls; 1648 bzero(fcaps, sizeof(*fcaps)); 1649 return (ioctls); 1650 } 1651 1652 static void 1653 filecaps_free_finish(u_long *ioctls) 1654 { 1655 1656 free(ioctls, M_FILECAPS); 1657 } 1658 1659 /* 1660 * Validate the given filecaps structure. 1661 */ 1662 static void 1663 filecaps_validate(const struct filecaps *fcaps, const char *func) 1664 { 1665 1666 KASSERT(cap_rights_is_valid(&fcaps->fc_rights), 1667 ("%s: invalid rights", func)); 1668 KASSERT((fcaps->fc_fcntls & ~CAP_FCNTL_ALL) == 0, 1669 ("%s: invalid fcntls", func)); 1670 KASSERT(fcaps->fc_fcntls == 0 || 1671 cap_rights_is_set(&fcaps->fc_rights, CAP_FCNTL), 1672 ("%s: fcntls without CAP_FCNTL", func)); 1673 KASSERT(fcaps->fc_ioctls != NULL ? fcaps->fc_nioctls > 0 : 1674 (fcaps->fc_nioctls == -1 || fcaps->fc_nioctls == 0), 1675 ("%s: invalid ioctls", func)); 1676 KASSERT(fcaps->fc_nioctls == 0 || 1677 cap_rights_is_set(&fcaps->fc_rights, CAP_IOCTL), 1678 ("%s: ioctls without CAP_IOCTL", func)); 1679 } 1680 1681 static void 1682 fdgrowtable_exp(struct filedesc *fdp, int nfd) 1683 { 1684 int nfd1; 1685 1686 FILEDESC_XLOCK_ASSERT(fdp); 1687 1688 nfd1 = fdp->fd_nfiles * 2; 1689 if (nfd1 < nfd) 1690 nfd1 = nfd; 1691 fdgrowtable(fdp, nfd1); 1692 } 1693 1694 /* 1695 * Grow the file table to accommodate (at least) nfd descriptors. 1696 */ 1697 static void 1698 fdgrowtable(struct filedesc *fdp, int nfd) 1699 { 1700 struct filedesc0 *fdp0; 1701 struct freetable *ft; 1702 struct fdescenttbl *ntable; 1703 struct fdescenttbl *otable; 1704 int nnfiles, onfiles; 1705 NDSLOTTYPE *nmap, *omap; 1706 1707 /* 1708 * If lastfile is -1 this struct filedesc was just allocated and we are 1709 * growing it to accommodate for the one we are going to copy from. There 1710 * is no need to have a lock on this one as it's not visible to anyone. 1711 */ 1712 if (fdp->fd_lastfile != -1) 1713 FILEDESC_XLOCK_ASSERT(fdp); 1714 1715 KASSERT(fdp->fd_nfiles > 0, ("zero-length file table")); 1716 1717 /* save old values */ 1718 onfiles = fdp->fd_nfiles; 1719 otable = fdp->fd_files; 1720 omap = fdp->fd_map; 1721 1722 /* compute the size of the new table */ 1723 nnfiles = NDSLOTS(nfd) * NDENTRIES; /* round up */ 1724 if (nnfiles <= onfiles) 1725 /* the table is already large enough */ 1726 return; 1727 1728 /* 1729 * Allocate a new table. We need enough space for the number of 1730 * entries, file entries themselves and the struct freetable we will use 1731 * when we decommission the table and place it on the freelist. 1732 * We place the struct freetable in the middle so we don't have 1733 * to worry about padding. 1734 */ 1735 ntable = malloc(offsetof(struct fdescenttbl, fdt_ofiles) + 1736 nnfiles * sizeof(ntable->fdt_ofiles[0]) + 1737 sizeof(struct freetable), 1738 M_FILEDESC, M_ZERO | M_WAITOK); 1739 /* copy the old data */ 1740 ntable->fdt_nfiles = nnfiles; 1741 memcpy(ntable->fdt_ofiles, otable->fdt_ofiles, 1742 onfiles * sizeof(ntable->fdt_ofiles[0])); 1743 1744 /* 1745 * Allocate a new map only if the old is not large enough. It will 1746 * grow at a slower rate than the table as it can map more 1747 * entries than the table can hold. 1748 */ 1749 if (NDSLOTS(nnfiles) > NDSLOTS(onfiles)) { 1750 nmap = malloc(NDSLOTS(nnfiles) * NDSLOTSIZE, M_FILEDESC, 1751 M_ZERO | M_WAITOK); 1752 /* copy over the old data and update the pointer */ 1753 memcpy(nmap, omap, NDSLOTS(onfiles) * sizeof(*omap)); 1754 fdp->fd_map = nmap; 1755 } 1756 1757 /* 1758 * Make sure that ntable is correctly initialized before we replace 1759 * fd_files poiner. Otherwise fget_unlocked() may see inconsistent 1760 * data. 1761 */ 1762 atomic_store_rel_ptr((volatile void *)&fdp->fd_files, (uintptr_t)ntable); 1763 1764 /* 1765 * Do not free the old file table, as some threads may still 1766 * reference entries within it. Instead, place it on a freelist 1767 * which will be processed when the struct filedesc is released. 1768 * 1769 * Note that if onfiles == NDFILE, we're dealing with the original 1770 * static allocation contained within (struct filedesc0 *)fdp, 1771 * which must not be freed. 1772 */ 1773 if (onfiles > NDFILE) { 1774 ft = (struct freetable *)&otable->fdt_ofiles[onfiles]; 1775 fdp0 = (struct filedesc0 *)fdp; 1776 ft->ft_table = otable; 1777 SLIST_INSERT_HEAD(&fdp0->fd_free, ft, ft_next); 1778 } 1779 /* 1780 * The map does not have the same possibility of threads still 1781 * holding references to it. So always free it as long as it 1782 * does not reference the original static allocation. 1783 */ 1784 if (NDSLOTS(onfiles) > NDSLOTS(NDFILE)) 1785 free(omap, M_FILEDESC); 1786 } 1787 1788 /* 1789 * Allocate a file descriptor for the process. 1790 */ 1791 int 1792 fdalloc(struct thread *td, int minfd, int *result) 1793 { 1794 struct proc *p = td->td_proc; 1795 struct filedesc *fdp = p->p_fd; 1796 int fd, maxfd, allocfd; 1797 #ifdef RACCT 1798 int error; 1799 #endif 1800 1801 FILEDESC_XLOCK_ASSERT(fdp); 1802 1803 if (fdp->fd_freefile > minfd) 1804 minfd = fdp->fd_freefile; 1805 1806 maxfd = getmaxfd(td); 1807 1808 /* 1809 * Search the bitmap for a free descriptor starting at minfd. 1810 * If none is found, grow the file table. 1811 */ 1812 fd = fd_first_free(fdp, minfd, fdp->fd_nfiles); 1813 if (fd >= maxfd) 1814 return (EMFILE); 1815 if (fd >= fdp->fd_nfiles) { 1816 allocfd = min(fd * 2, maxfd); 1817 #ifdef RACCT 1818 if (RACCT_ENABLED()) { 1819 error = racct_set_unlocked(p, RACCT_NOFILE, allocfd); 1820 if (error != 0) 1821 return (EMFILE); 1822 } 1823 #endif 1824 /* 1825 * fd is already equal to first free descriptor >= minfd, so 1826 * we only need to grow the table and we are done. 1827 */ 1828 fdgrowtable_exp(fdp, allocfd); 1829 } 1830 1831 /* 1832 * Perform some sanity checks, then mark the file descriptor as 1833 * used and return it to the caller. 1834 */ 1835 KASSERT(fd >= 0 && fd < min(maxfd, fdp->fd_nfiles), 1836 ("invalid descriptor %d", fd)); 1837 KASSERT(!fdisused(fdp, fd), 1838 ("fd_first_free() returned non-free descriptor")); 1839 KASSERT(fdp->fd_ofiles[fd].fde_file == NULL, 1840 ("file descriptor isn't free")); 1841 fdused(fdp, fd); 1842 *result = fd; 1843 return (0); 1844 } 1845 1846 /* 1847 * Allocate n file descriptors for the process. 1848 */ 1849 int 1850 fdallocn(struct thread *td, int minfd, int *fds, int n) 1851 { 1852 struct proc *p = td->td_proc; 1853 struct filedesc *fdp = p->p_fd; 1854 int i; 1855 1856 FILEDESC_XLOCK_ASSERT(fdp); 1857 1858 for (i = 0; i < n; i++) 1859 if (fdalloc(td, 0, &fds[i]) != 0) 1860 break; 1861 1862 if (i < n) { 1863 for (i--; i >= 0; i--) 1864 fdunused(fdp, fds[i]); 1865 return (EMFILE); 1866 } 1867 1868 return (0); 1869 } 1870 1871 /* 1872 * Create a new open file structure and allocate a file descriptor for the 1873 * process that refers to it. We add one reference to the file for the 1874 * descriptor table and one reference for resultfp. This is to prevent us 1875 * being preempted and the entry in the descriptor table closed after we 1876 * release the FILEDESC lock. 1877 */ 1878 int 1879 falloc_caps(struct thread *td, struct file **resultfp, int *resultfd, int flags, 1880 struct filecaps *fcaps) 1881 { 1882 struct file *fp; 1883 int error, fd; 1884 1885 error = falloc_noinstall(td, &fp); 1886 if (error) 1887 return (error); /* no reference held on error */ 1888 1889 error = finstall(td, fp, &fd, flags, fcaps); 1890 if (error) { 1891 fdrop(fp, td); /* one reference (fp only) */ 1892 return (error); 1893 } 1894 1895 if (resultfp != NULL) 1896 *resultfp = fp; /* copy out result */ 1897 else 1898 fdrop(fp, td); /* release local reference */ 1899 1900 if (resultfd != NULL) 1901 *resultfd = fd; 1902 1903 return (0); 1904 } 1905 1906 /* 1907 * Create a new open file structure without allocating a file descriptor. 1908 */ 1909 int 1910 falloc_noinstall(struct thread *td, struct file **resultfp) 1911 { 1912 struct file *fp; 1913 int maxuserfiles = maxfiles - (maxfiles / 20); 1914 int openfiles_new; 1915 static struct timeval lastfail; 1916 static int curfail; 1917 1918 KASSERT(resultfp != NULL, ("%s: resultfp == NULL", __func__)); 1919 1920 openfiles_new = atomic_fetchadd_int(&openfiles, 1) + 1; 1921 if ((openfiles_new >= maxuserfiles && 1922 priv_check(td, PRIV_MAXFILES) != 0) || 1923 openfiles_new >= maxfiles) { 1924 atomic_subtract_int(&openfiles, 1); 1925 if (ppsratecheck(&lastfail, &curfail, 1)) { 1926 printf("kern.maxfiles limit exceeded by uid %i, (%s) " 1927 "please see tuning(7).\n", td->td_ucred->cr_ruid, td->td_proc->p_comm); 1928 } 1929 return (ENFILE); 1930 } 1931 fp = uma_zalloc(file_zone, M_WAITOK); 1932 bzero(fp, sizeof(*fp)); 1933 refcount_init(&fp->f_count, 1); 1934 fp->f_cred = crhold(td->td_ucred); 1935 fp->f_ops = &badfileops; 1936 *resultfp = fp; 1937 return (0); 1938 } 1939 1940 /* 1941 * Install a file in a file descriptor table. 1942 */ 1943 void 1944 _finstall(struct filedesc *fdp, struct file *fp, int fd, int flags, 1945 struct filecaps *fcaps) 1946 { 1947 struct filedescent *fde; 1948 1949 MPASS(fp != NULL); 1950 if (fcaps != NULL) 1951 filecaps_validate(fcaps, __func__); 1952 FILEDESC_XLOCK_ASSERT(fdp); 1953 1954 fde = &fdp->fd_ofiles[fd]; 1955 #ifdef CAPABILITIES 1956 seqc_write_begin(&fde->fde_seqc); 1957 #endif 1958 fde->fde_file = fp; 1959 fde->fde_flags = (flags & O_CLOEXEC) != 0 ? UF_EXCLOSE : 0; 1960 if (fcaps != NULL) 1961 filecaps_move(fcaps, &fde->fde_caps); 1962 else 1963 filecaps_fill(&fde->fde_caps); 1964 #ifdef CAPABILITIES 1965 seqc_write_end(&fde->fde_seqc); 1966 #endif 1967 } 1968 1969 int 1970 finstall(struct thread *td, struct file *fp, int *fd, int flags, 1971 struct filecaps *fcaps) 1972 { 1973 struct filedesc *fdp = td->td_proc->p_fd; 1974 int error; 1975 1976 MPASS(fd != NULL); 1977 1978 if (!fhold(fp)) 1979 return (EBADF); 1980 FILEDESC_XLOCK(fdp); 1981 if ((error = fdalloc(td, 0, fd))) { 1982 FILEDESC_XUNLOCK(fdp); 1983 fdrop(fp, td); 1984 return (error); 1985 } 1986 _finstall(fdp, fp, *fd, flags, fcaps); 1987 FILEDESC_XUNLOCK(fdp); 1988 return (0); 1989 } 1990 1991 /* 1992 * Build a new filedesc structure from another. 1993 * Copy the current, root, and jail root vnode references. 1994 * 1995 * If fdp is not NULL, return with it shared locked. 1996 */ 1997 struct filedesc * 1998 fdinit(struct filedesc *fdp, bool prepfiles) 1999 { 2000 struct filedesc0 *newfdp0; 2001 struct filedesc *newfdp; 2002 2003 newfdp0 = uma_zalloc(filedesc0_zone, M_WAITOK | M_ZERO); 2004 newfdp = &newfdp0->fd_fd; 2005 2006 /* Create the file descriptor table. */ 2007 FILEDESC_LOCK_INIT(newfdp); 2008 refcount_init(&newfdp->fd_refcnt, 1); 2009 refcount_init(&newfdp->fd_holdcnt, 1); 2010 newfdp->fd_cmask = CMASK; 2011 newfdp->fd_map = newfdp0->fd_dmap; 2012 newfdp->fd_lastfile = -1; 2013 newfdp->fd_files = (struct fdescenttbl *)&newfdp0->fd_dfiles; 2014 newfdp->fd_files->fdt_nfiles = NDFILE; 2015 2016 if (fdp == NULL) 2017 return (newfdp); 2018 2019 if (prepfiles && fdp->fd_lastfile >= newfdp->fd_nfiles) 2020 fdgrowtable(newfdp, fdp->fd_lastfile + 1); 2021 2022 FILEDESC_SLOCK(fdp); 2023 newfdp->fd_cdir = fdp->fd_cdir; 2024 if (newfdp->fd_cdir) 2025 vrefact(newfdp->fd_cdir); 2026 newfdp->fd_rdir = fdp->fd_rdir; 2027 if (newfdp->fd_rdir) 2028 vrefact(newfdp->fd_rdir); 2029 newfdp->fd_jdir = fdp->fd_jdir; 2030 if (newfdp->fd_jdir) 2031 vrefact(newfdp->fd_jdir); 2032 2033 if (!prepfiles) { 2034 FILEDESC_SUNLOCK(fdp); 2035 } else { 2036 while (fdp->fd_lastfile >= newfdp->fd_nfiles) { 2037 FILEDESC_SUNLOCK(fdp); 2038 fdgrowtable(newfdp, fdp->fd_lastfile + 1); 2039 FILEDESC_SLOCK(fdp); 2040 } 2041 } 2042 2043 return (newfdp); 2044 } 2045 2046 static struct filedesc * 2047 fdhold(struct proc *p) 2048 { 2049 struct filedesc *fdp; 2050 2051 PROC_LOCK_ASSERT(p, MA_OWNED); 2052 fdp = p->p_fd; 2053 if (fdp != NULL) 2054 refcount_acquire(&fdp->fd_holdcnt); 2055 return (fdp); 2056 } 2057 2058 static void 2059 fddrop(struct filedesc *fdp) 2060 { 2061 2062 if (fdp->fd_holdcnt > 1) { 2063 if (refcount_release(&fdp->fd_holdcnt) == 0) 2064 return; 2065 } 2066 2067 FILEDESC_LOCK_DESTROY(fdp); 2068 uma_zfree(filedesc0_zone, fdp); 2069 } 2070 2071 /* 2072 * Share a filedesc structure. 2073 */ 2074 struct filedesc * 2075 fdshare(struct filedesc *fdp) 2076 { 2077 2078 refcount_acquire(&fdp->fd_refcnt); 2079 return (fdp); 2080 } 2081 2082 /* 2083 * Unshare a filedesc structure, if necessary by making a copy 2084 */ 2085 void 2086 fdunshare(struct thread *td) 2087 { 2088 struct filedesc *tmp; 2089 struct proc *p = td->td_proc; 2090 2091 if (p->p_fd->fd_refcnt == 1) 2092 return; 2093 2094 tmp = fdcopy(p->p_fd); 2095 fdescfree(td); 2096 p->p_fd = tmp; 2097 } 2098 2099 void 2100 fdinstall_remapped(struct thread *td, struct filedesc *fdp) 2101 { 2102 2103 fdescfree(td); 2104 td->td_proc->p_fd = fdp; 2105 } 2106 2107 /* 2108 * Copy a filedesc structure. A NULL pointer in returns a NULL reference, 2109 * this is to ease callers, not catch errors. 2110 */ 2111 struct filedesc * 2112 fdcopy(struct filedesc *fdp) 2113 { 2114 struct filedesc *newfdp; 2115 struct filedescent *nfde, *ofde; 2116 int i; 2117 2118 MPASS(fdp != NULL); 2119 2120 newfdp = fdinit(fdp, true); 2121 /* copy all passable descriptors (i.e. not kqueue) */ 2122 newfdp->fd_freefile = -1; 2123 for (i = 0; i <= fdp->fd_lastfile; ++i) { 2124 ofde = &fdp->fd_ofiles[i]; 2125 if (ofde->fde_file == NULL || 2126 (ofde->fde_file->f_ops->fo_flags & DFLAG_PASSABLE) == 0 || 2127 !fhold(ofde->fde_file)) { 2128 if (newfdp->fd_freefile == -1) 2129 newfdp->fd_freefile = i; 2130 continue; 2131 } 2132 nfde = &newfdp->fd_ofiles[i]; 2133 *nfde = *ofde; 2134 filecaps_copy(&ofde->fde_caps, &nfde->fde_caps, true); 2135 fdused_init(newfdp, i); 2136 newfdp->fd_lastfile = i; 2137 } 2138 if (newfdp->fd_freefile == -1) 2139 newfdp->fd_freefile = i; 2140 newfdp->fd_cmask = fdp->fd_cmask; 2141 FILEDESC_SUNLOCK(fdp); 2142 return (newfdp); 2143 } 2144 2145 /* 2146 * Copies a filedesc structure, while remapping all file descriptors 2147 * stored inside using a translation table. 2148 * 2149 * File descriptors are copied over to the new file descriptor table, 2150 * regardless of whether the close-on-exec flag is set. 2151 */ 2152 int 2153 fdcopy_remapped(struct filedesc *fdp, const int *fds, size_t nfds, 2154 struct filedesc **ret) 2155 { 2156 struct filedesc *newfdp; 2157 struct filedescent *nfde, *ofde; 2158 int error, i; 2159 2160 MPASS(fdp != NULL); 2161 2162 newfdp = fdinit(fdp, true); 2163 if (nfds > fdp->fd_lastfile + 1) { 2164 /* New table cannot be larger than the old one. */ 2165 error = E2BIG; 2166 goto bad; 2167 } 2168 /* Copy all passable descriptors (i.e. not kqueue). */ 2169 newfdp->fd_freefile = nfds; 2170 for (i = 0; i < nfds; ++i) { 2171 if (fds[i] < 0 || fds[i] > fdp->fd_lastfile) { 2172 /* File descriptor out of bounds. */ 2173 error = EBADF; 2174 goto bad; 2175 } 2176 ofde = &fdp->fd_ofiles[fds[i]]; 2177 if (ofde->fde_file == NULL) { 2178 /* Unused file descriptor. */ 2179 error = EBADF; 2180 goto bad; 2181 } 2182 if ((ofde->fde_file->f_ops->fo_flags & DFLAG_PASSABLE) == 0) { 2183 /* File descriptor cannot be passed. */ 2184 error = EINVAL; 2185 goto bad; 2186 } 2187 if (!fhold(nfde->fde_file)) { 2188 error = EBADF; 2189 goto bad; 2190 } 2191 nfde = &newfdp->fd_ofiles[i]; 2192 *nfde = *ofde; 2193 filecaps_copy(&ofde->fde_caps, &nfde->fde_caps, true); 2194 fdused_init(newfdp, i); 2195 newfdp->fd_lastfile = i; 2196 } 2197 newfdp->fd_cmask = fdp->fd_cmask; 2198 FILEDESC_SUNLOCK(fdp); 2199 *ret = newfdp; 2200 return (0); 2201 bad: 2202 FILEDESC_SUNLOCK(fdp); 2203 fdescfree_remapped(newfdp); 2204 return (error); 2205 } 2206 2207 /* 2208 * Clear POSIX style locks. This is only used when fdp looses a reference (i.e. 2209 * one of processes using it exits) and the table used to be shared. 2210 */ 2211 static void 2212 fdclearlocks(struct thread *td) 2213 { 2214 struct filedesc *fdp; 2215 struct filedesc_to_leader *fdtol; 2216 struct flock lf; 2217 struct file *fp; 2218 struct proc *p; 2219 struct vnode *vp; 2220 int i; 2221 2222 p = td->td_proc; 2223 fdp = p->p_fd; 2224 fdtol = p->p_fdtol; 2225 MPASS(fdtol != NULL); 2226 2227 FILEDESC_XLOCK(fdp); 2228 KASSERT(fdtol->fdl_refcount > 0, 2229 ("filedesc_to_refcount botch: fdl_refcount=%d", 2230 fdtol->fdl_refcount)); 2231 if (fdtol->fdl_refcount == 1 && 2232 (p->p_leader->p_flag & P_ADVLOCK) != 0) { 2233 for (i = 0; i <= fdp->fd_lastfile; i++) { 2234 fp = fdp->fd_ofiles[i].fde_file; 2235 if (fp == NULL || fp->f_type != DTYPE_VNODE || 2236 !fhold(fp)) 2237 continue; 2238 FILEDESC_XUNLOCK(fdp); 2239 lf.l_whence = SEEK_SET; 2240 lf.l_start = 0; 2241 lf.l_len = 0; 2242 lf.l_type = F_UNLCK; 2243 vp = fp->f_vnode; 2244 (void) VOP_ADVLOCK(vp, 2245 (caddr_t)p->p_leader, F_UNLCK, 2246 &lf, F_POSIX); 2247 FILEDESC_XLOCK(fdp); 2248 fdrop(fp, td); 2249 } 2250 } 2251 retry: 2252 if (fdtol->fdl_refcount == 1) { 2253 if (fdp->fd_holdleaderscount > 0 && 2254 (p->p_leader->p_flag & P_ADVLOCK) != 0) { 2255 /* 2256 * close() or kern_dup() has cleared a reference 2257 * in a shared file descriptor table. 2258 */ 2259 fdp->fd_holdleaderswakeup = 1; 2260 sx_sleep(&fdp->fd_holdleaderscount, 2261 FILEDESC_LOCK(fdp), PLOCK, "fdlhold", 0); 2262 goto retry; 2263 } 2264 if (fdtol->fdl_holdcount > 0) { 2265 /* 2266 * Ensure that fdtol->fdl_leader remains 2267 * valid in closef(). 2268 */ 2269 fdtol->fdl_wakeup = 1; 2270 sx_sleep(fdtol, FILEDESC_LOCK(fdp), PLOCK, 2271 "fdlhold", 0); 2272 goto retry; 2273 } 2274 } 2275 fdtol->fdl_refcount--; 2276 if (fdtol->fdl_refcount == 0 && 2277 fdtol->fdl_holdcount == 0) { 2278 fdtol->fdl_next->fdl_prev = fdtol->fdl_prev; 2279 fdtol->fdl_prev->fdl_next = fdtol->fdl_next; 2280 } else 2281 fdtol = NULL; 2282 p->p_fdtol = NULL; 2283 FILEDESC_XUNLOCK(fdp); 2284 if (fdtol != NULL) 2285 free(fdtol, M_FILEDESC_TO_LEADER); 2286 } 2287 2288 /* 2289 * Release a filedesc structure. 2290 */ 2291 static void 2292 fdescfree_fds(struct thread *td, struct filedesc *fdp, bool needclose) 2293 { 2294 struct filedesc0 *fdp0; 2295 struct freetable *ft, *tft; 2296 struct filedescent *fde; 2297 struct file *fp; 2298 int i; 2299 2300 for (i = 0; i <= fdp->fd_lastfile; i++) { 2301 fde = &fdp->fd_ofiles[i]; 2302 fp = fde->fde_file; 2303 if (fp != NULL) { 2304 fdefree_last(fde); 2305 if (needclose) 2306 (void) closef(fp, td); 2307 else 2308 fdrop(fp, td); 2309 } 2310 } 2311 2312 if (NDSLOTS(fdp->fd_nfiles) > NDSLOTS(NDFILE)) 2313 free(fdp->fd_map, M_FILEDESC); 2314 if (fdp->fd_nfiles > NDFILE) 2315 free(fdp->fd_files, M_FILEDESC); 2316 2317 fdp0 = (struct filedesc0 *)fdp; 2318 SLIST_FOREACH_SAFE(ft, &fdp0->fd_free, ft_next, tft) 2319 free(ft->ft_table, M_FILEDESC); 2320 2321 fddrop(fdp); 2322 } 2323 2324 void 2325 fdescfree(struct thread *td) 2326 { 2327 struct proc *p; 2328 struct filedesc *fdp; 2329 struct vnode *cdir, *jdir, *rdir; 2330 2331 p = td->td_proc; 2332 fdp = p->p_fd; 2333 MPASS(fdp != NULL); 2334 2335 #ifdef RACCT 2336 if (RACCT_ENABLED()) 2337 racct_set_unlocked(p, RACCT_NOFILE, 0); 2338 #endif 2339 2340 if (p->p_fdtol != NULL) 2341 fdclearlocks(td); 2342 2343 PROC_LOCK(p); 2344 p->p_fd = NULL; 2345 PROC_UNLOCK(p); 2346 2347 if (refcount_release(&fdp->fd_refcnt) == 0) 2348 return; 2349 2350 FILEDESC_XLOCK(fdp); 2351 cdir = fdp->fd_cdir; 2352 fdp->fd_cdir = NULL; 2353 rdir = fdp->fd_rdir; 2354 fdp->fd_rdir = NULL; 2355 jdir = fdp->fd_jdir; 2356 fdp->fd_jdir = NULL; 2357 FILEDESC_XUNLOCK(fdp); 2358 2359 if (cdir != NULL) 2360 vrele(cdir); 2361 if (rdir != NULL) 2362 vrele(rdir); 2363 if (jdir != NULL) 2364 vrele(jdir); 2365 2366 fdescfree_fds(td, fdp, 1); 2367 } 2368 2369 void 2370 fdescfree_remapped(struct filedesc *fdp) 2371 { 2372 2373 if (fdp->fd_cdir != NULL) 2374 vrele(fdp->fd_cdir); 2375 if (fdp->fd_rdir != NULL) 2376 vrele(fdp->fd_rdir); 2377 if (fdp->fd_jdir != NULL) 2378 vrele(fdp->fd_jdir); 2379 2380 fdescfree_fds(curthread, fdp, 0); 2381 } 2382 2383 /* 2384 * For setugid programs, we don't want to people to use that setugidness 2385 * to generate error messages which write to a file which otherwise would 2386 * otherwise be off-limits to the process. We check for filesystems where 2387 * the vnode can change out from under us after execve (like [lin]procfs). 2388 * 2389 * Since fdsetugidsafety calls this only for fd 0, 1 and 2, this check is 2390 * sufficient. We also don't check for setugidness since we know we are. 2391 */ 2392 static bool 2393 is_unsafe(struct file *fp) 2394 { 2395 struct vnode *vp; 2396 2397 if (fp->f_type != DTYPE_VNODE) 2398 return (false); 2399 2400 vp = fp->f_vnode; 2401 return ((vp->v_vflag & VV_PROCDEP) != 0); 2402 } 2403 2404 /* 2405 * Make this setguid thing safe, if at all possible. 2406 */ 2407 void 2408 fdsetugidsafety(struct thread *td) 2409 { 2410 struct filedesc *fdp; 2411 struct file *fp; 2412 int i; 2413 2414 fdp = td->td_proc->p_fd; 2415 KASSERT(fdp->fd_refcnt == 1, ("the fdtable should not be shared")); 2416 MPASS(fdp->fd_nfiles >= 3); 2417 for (i = 0; i <= 2; i++) { 2418 fp = fdp->fd_ofiles[i].fde_file; 2419 if (fp != NULL && is_unsafe(fp)) { 2420 FILEDESC_XLOCK(fdp); 2421 knote_fdclose(td, i); 2422 /* 2423 * NULL-out descriptor prior to close to avoid 2424 * a race while close blocks. 2425 */ 2426 fdfree(fdp, i); 2427 FILEDESC_XUNLOCK(fdp); 2428 (void) closef(fp, td); 2429 } 2430 } 2431 } 2432 2433 /* 2434 * If a specific file object occupies a specific file descriptor, close the 2435 * file descriptor entry and drop a reference on the file object. This is a 2436 * convenience function to handle a subsequent error in a function that calls 2437 * falloc() that handles the race that another thread might have closed the 2438 * file descriptor out from under the thread creating the file object. 2439 */ 2440 void 2441 fdclose(struct thread *td, struct file *fp, int idx) 2442 { 2443 struct filedesc *fdp = td->td_proc->p_fd; 2444 2445 FILEDESC_XLOCK(fdp); 2446 if (fdp->fd_ofiles[idx].fde_file == fp) { 2447 fdfree(fdp, idx); 2448 FILEDESC_XUNLOCK(fdp); 2449 fdrop(fp, td); 2450 } else 2451 FILEDESC_XUNLOCK(fdp); 2452 } 2453 2454 /* 2455 * Close any files on exec? 2456 */ 2457 void 2458 fdcloseexec(struct thread *td) 2459 { 2460 struct filedesc *fdp; 2461 struct filedescent *fde; 2462 struct file *fp; 2463 int i; 2464 2465 fdp = td->td_proc->p_fd; 2466 KASSERT(fdp->fd_refcnt == 1, ("the fdtable should not be shared")); 2467 for (i = 0; i <= fdp->fd_lastfile; i++) { 2468 fde = &fdp->fd_ofiles[i]; 2469 fp = fde->fde_file; 2470 if (fp != NULL && (fp->f_type == DTYPE_MQUEUE || 2471 (fde->fde_flags & UF_EXCLOSE))) { 2472 FILEDESC_XLOCK(fdp); 2473 fdfree(fdp, i); 2474 (void) closefp(fdp, i, fp, td, 0); 2475 FILEDESC_UNLOCK_ASSERT(fdp); 2476 } 2477 } 2478 } 2479 2480 /* 2481 * It is unsafe for set[ug]id processes to be started with file 2482 * descriptors 0..2 closed, as these descriptors are given implicit 2483 * significance in the Standard C library. fdcheckstd() will create a 2484 * descriptor referencing /dev/null for each of stdin, stdout, and 2485 * stderr that is not already open. 2486 */ 2487 int 2488 fdcheckstd(struct thread *td) 2489 { 2490 struct filedesc *fdp; 2491 register_t save; 2492 int i, error, devnull; 2493 2494 fdp = td->td_proc->p_fd; 2495 KASSERT(fdp->fd_refcnt == 1, ("the fdtable should not be shared")); 2496 MPASS(fdp->fd_nfiles >= 3); 2497 devnull = -1; 2498 for (i = 0; i <= 2; i++) { 2499 if (fdp->fd_ofiles[i].fde_file != NULL) 2500 continue; 2501 2502 save = td->td_retval[0]; 2503 if (devnull != -1) { 2504 error = kern_dup(td, FDDUP_FIXED, 0, devnull, i); 2505 } else { 2506 error = kern_openat(td, AT_FDCWD, "/dev/null", 2507 UIO_SYSSPACE, O_RDWR, 0); 2508 if (error == 0) { 2509 devnull = td->td_retval[0]; 2510 KASSERT(devnull == i, ("we didn't get our fd")); 2511 } 2512 } 2513 td->td_retval[0] = save; 2514 if (error != 0) 2515 return (error); 2516 } 2517 return (0); 2518 } 2519 2520 /* 2521 * Internal form of close. Decrement reference count on file structure. 2522 * Note: td may be NULL when closing a file that was being passed in a 2523 * message. 2524 */ 2525 int 2526 closef(struct file *fp, struct thread *td) 2527 { 2528 struct vnode *vp; 2529 struct flock lf; 2530 struct filedesc_to_leader *fdtol; 2531 struct filedesc *fdp; 2532 2533 /* 2534 * POSIX record locking dictates that any close releases ALL 2535 * locks owned by this process. This is handled by setting 2536 * a flag in the unlock to free ONLY locks obeying POSIX 2537 * semantics, and not to free BSD-style file locks. 2538 * If the descriptor was in a message, POSIX-style locks 2539 * aren't passed with the descriptor, and the thread pointer 2540 * will be NULL. Callers should be careful only to pass a 2541 * NULL thread pointer when there really is no owning 2542 * context that might have locks, or the locks will be 2543 * leaked. 2544 */ 2545 if (fp->f_type == DTYPE_VNODE && td != NULL) { 2546 vp = fp->f_vnode; 2547 if ((td->td_proc->p_leader->p_flag & P_ADVLOCK) != 0) { 2548 lf.l_whence = SEEK_SET; 2549 lf.l_start = 0; 2550 lf.l_len = 0; 2551 lf.l_type = F_UNLCK; 2552 (void) VOP_ADVLOCK(vp, (caddr_t)td->td_proc->p_leader, 2553 F_UNLCK, &lf, F_POSIX); 2554 } 2555 fdtol = td->td_proc->p_fdtol; 2556 if (fdtol != NULL) { 2557 /* 2558 * Handle special case where file descriptor table is 2559 * shared between multiple process leaders. 2560 */ 2561 fdp = td->td_proc->p_fd; 2562 FILEDESC_XLOCK(fdp); 2563 for (fdtol = fdtol->fdl_next; 2564 fdtol != td->td_proc->p_fdtol; 2565 fdtol = fdtol->fdl_next) { 2566 if ((fdtol->fdl_leader->p_flag & 2567 P_ADVLOCK) == 0) 2568 continue; 2569 fdtol->fdl_holdcount++; 2570 FILEDESC_XUNLOCK(fdp); 2571 lf.l_whence = SEEK_SET; 2572 lf.l_start = 0; 2573 lf.l_len = 0; 2574 lf.l_type = F_UNLCK; 2575 vp = fp->f_vnode; 2576 (void) VOP_ADVLOCK(vp, 2577 (caddr_t)fdtol->fdl_leader, F_UNLCK, &lf, 2578 F_POSIX); 2579 FILEDESC_XLOCK(fdp); 2580 fdtol->fdl_holdcount--; 2581 if (fdtol->fdl_holdcount == 0 && 2582 fdtol->fdl_wakeup != 0) { 2583 fdtol->fdl_wakeup = 0; 2584 wakeup(fdtol); 2585 } 2586 } 2587 FILEDESC_XUNLOCK(fdp); 2588 } 2589 } 2590 return (fdrop(fp, td)); 2591 } 2592 2593 /* 2594 * Initialize the file pointer with the specified properties. 2595 * 2596 * The ops are set with release semantics to be certain that the flags, type, 2597 * and data are visible when ops is. This is to prevent ops methods from being 2598 * called with bad data. 2599 */ 2600 void 2601 finit(struct file *fp, u_int flag, short type, void *data, struct fileops *ops) 2602 { 2603 fp->f_data = data; 2604 fp->f_flag = flag; 2605 fp->f_type = type; 2606 atomic_store_rel_ptr((volatile uintptr_t *)&fp->f_ops, (uintptr_t)ops); 2607 } 2608 2609 int 2610 fget_cap_locked(struct filedesc *fdp, int fd, cap_rights_t *needrightsp, 2611 struct file **fpp, struct filecaps *havecapsp) 2612 { 2613 struct filedescent *fde; 2614 int error; 2615 2616 FILEDESC_LOCK_ASSERT(fdp); 2617 2618 fde = fdeget_locked(fdp, fd); 2619 if (fde == NULL) { 2620 error = EBADF; 2621 goto out; 2622 } 2623 2624 #ifdef CAPABILITIES 2625 error = cap_check(cap_rights_fde_inline(fde), needrightsp); 2626 if (error != 0) 2627 goto out; 2628 #endif 2629 2630 if (havecapsp != NULL) 2631 filecaps_copy(&fde->fde_caps, havecapsp, true); 2632 2633 *fpp = fde->fde_file; 2634 2635 error = 0; 2636 out: 2637 return (error); 2638 } 2639 2640 int 2641 fget_cap(struct thread *td, int fd, cap_rights_t *needrightsp, 2642 struct file **fpp, struct filecaps *havecapsp) 2643 { 2644 struct filedesc *fdp = td->td_proc->p_fd; 2645 int error; 2646 #ifndef CAPABILITIES 2647 error = fget_unlocked(fdp, fd, needrightsp, fpp); 2648 if (havecapsp != NULL && error == 0) 2649 filecaps_fill(havecapsp); 2650 #else 2651 struct file *fp; 2652 seqc_t seq; 2653 2654 *fpp = NULL; 2655 for (;;) { 2656 error = fget_unlocked_seq(fdp, fd, needrightsp, &fp, &seq); 2657 if (error != 0) 2658 return (error); 2659 2660 if (havecapsp != NULL) { 2661 if (!filecaps_copy(&fdp->fd_ofiles[fd].fde_caps, 2662 havecapsp, false)) { 2663 fdrop(fp, td); 2664 goto get_locked; 2665 } 2666 } 2667 2668 if (!fd_modified(fdp, fd, seq)) 2669 break; 2670 fdrop(fp, td); 2671 } 2672 2673 *fpp = fp; 2674 return (0); 2675 2676 get_locked: 2677 FILEDESC_SLOCK(fdp); 2678 error = fget_cap_locked(fdp, fd, needrightsp, fpp, havecapsp); 2679 if (error == 0 && !fhold(*fpp)) 2680 error = EBADF; 2681 FILEDESC_SUNLOCK(fdp); 2682 #endif 2683 return (error); 2684 } 2685 2686 int 2687 fget_unlocked_seq(struct filedesc *fdp, int fd, cap_rights_t *needrightsp, 2688 struct file **fpp, seqc_t *seqp) 2689 { 2690 #ifdef CAPABILITIES 2691 const struct filedescent *fde; 2692 #endif 2693 const struct fdescenttbl *fdt; 2694 struct file *fp; 2695 #ifdef CAPABILITIES 2696 seqc_t seq; 2697 cap_rights_t haverights; 2698 int error; 2699 #endif 2700 2701 fdt = fdp->fd_files; 2702 if (__predict_false((u_int)fd >= fdt->fdt_nfiles)) 2703 return (EBADF); 2704 /* 2705 * Fetch the descriptor locklessly. We avoid fdrop() races by 2706 * never raising a refcount above 0. To accomplish this we have 2707 * to use a cmpset loop rather than an atomic_add. The descriptor 2708 * must be re-verified once we acquire a reference to be certain 2709 * that the identity is still correct and we did not lose a race 2710 * due to preemption. 2711 */ 2712 for (;;) { 2713 #ifdef CAPABILITIES 2714 seq = seqc_read(fd_seqc(fdt, fd)); 2715 fde = &fdt->fdt_ofiles[fd]; 2716 haverights = *cap_rights_fde_inline(fde); 2717 fp = fde->fde_file; 2718 if (!seqc_consistent(fd_seqc(fdt, fd), seq)) 2719 continue; 2720 #else 2721 fp = fdt->fdt_ofiles[fd].fde_file; 2722 #endif 2723 if (fp == NULL) 2724 return (EBADF); 2725 #ifdef CAPABILITIES 2726 error = cap_check_inline(&haverights, needrightsp); 2727 if (error != 0) 2728 return (error); 2729 #endif 2730 if (__predict_false(!refcount_acquire_if_not_zero(&fp->f_count))) { 2731 /* 2732 * The count was found either saturated or zero. 2733 * This re-read is not any more racy than using the 2734 * return value from fcmpset. 2735 */ 2736 if (fp->f_count != 0) 2737 return (EBADF); 2738 /* 2739 * Force a reload. Other thread could reallocate the 2740 * table before this fd was closed, so it is possible 2741 * that there is a stale fp pointer in cached version. 2742 */ 2743 fdt = (struct fdescenttbl *)atomic_load_ptr(&fdp->fd_files); 2744 continue; 2745 } 2746 /* 2747 * Use an acquire barrier to force re-reading of fdt so it is 2748 * refreshed for verification. 2749 */ 2750 atomic_thread_fence_acq(); 2751 fdt = fdp->fd_files; 2752 #ifdef CAPABILITIES 2753 if (seqc_consistent_nomb(fd_seqc(fdt, fd), seq)) 2754 #else 2755 if (fp == fdt->fdt_ofiles[fd].fde_file) 2756 #endif 2757 break; 2758 fdrop(fp, curthread); 2759 } 2760 *fpp = fp; 2761 if (seqp != NULL) { 2762 #ifdef CAPABILITIES 2763 *seqp = seq; 2764 #endif 2765 } 2766 return (0); 2767 } 2768 2769 /* 2770 * See the comments in fget_unlocked_seq for an explanation of how this works. 2771 * 2772 * This is a simplified variant which bails out to the aforementioned routine 2773 * if anything goes wrong. In practice this only happens when userspace is 2774 * racing with itself. 2775 */ 2776 int 2777 fget_unlocked(struct filedesc *fdp, int fd, cap_rights_t *needrightsp, 2778 struct file **fpp) 2779 { 2780 #ifdef CAPABILITIES 2781 const struct filedescent *fde; 2782 #endif 2783 const struct fdescenttbl *fdt; 2784 struct file *fp; 2785 #ifdef CAPABILITIES 2786 seqc_t seq; 2787 const cap_rights_t *haverights; 2788 #endif 2789 2790 fdt = fdp->fd_files; 2791 if (__predict_false((u_int)fd >= fdt->fdt_nfiles)) 2792 return (EBADF); 2793 #ifdef CAPABILITIES 2794 seq = seqc_read_any(fd_seqc(fdt, fd)); 2795 if (__predict_false(seqc_in_modify(seq))) 2796 goto out_fallback; 2797 fde = &fdt->fdt_ofiles[fd]; 2798 haverights = cap_rights_fde_inline(fde); 2799 fp = fde->fde_file; 2800 #else 2801 fp = fdt->fdt_ofiles[fd].fde_file; 2802 #endif 2803 if (__predict_false(fp == NULL)) 2804 goto out_fallback; 2805 #ifdef CAPABILITIES 2806 if (__predict_false(cap_check_inline_transient(haverights, needrightsp))) 2807 goto out_fallback; 2808 #endif 2809 if (__predict_false(!refcount_acquire_if_not_zero(&fp->f_count))) 2810 goto out_fallback; 2811 2812 /* 2813 * Use an acquire barrier to force re-reading of fdt so it is 2814 * refreshed for verification. 2815 */ 2816 atomic_thread_fence_acq(); 2817 fdt = fdp->fd_files; 2818 #ifdef CAPABILITIES 2819 if (__predict_false(!seqc_consistent_nomb(fd_seqc(fdt, fd), seq))) 2820 #else 2821 if (__predict_false(fp != fdt->fdt_ofiles[fd].fde_file)) 2822 #endif 2823 goto out_fdrop; 2824 *fpp = fp; 2825 return (0); 2826 out_fdrop: 2827 fdrop(fp, curthread); 2828 out_fallback: 2829 return (fget_unlocked_seq(fdp, fd, needrightsp, fpp, NULL)); 2830 } 2831 2832 /* 2833 * Extract the file pointer associated with the specified descriptor for the 2834 * current user process. 2835 * 2836 * If the descriptor doesn't exist or doesn't match 'flags', EBADF is 2837 * returned. 2838 * 2839 * File's rights will be checked against the capability rights mask. 2840 * 2841 * If an error occurred the non-zero error is returned and *fpp is set to 2842 * NULL. Otherwise *fpp is held and set and zero is returned. Caller is 2843 * responsible for fdrop(). 2844 */ 2845 static __inline int 2846 _fget(struct thread *td, int fd, struct file **fpp, int flags, 2847 cap_rights_t *needrightsp) 2848 { 2849 struct filedesc *fdp; 2850 struct file *fp; 2851 int error; 2852 2853 *fpp = NULL; 2854 fdp = td->td_proc->p_fd; 2855 error = fget_unlocked(fdp, fd, needrightsp, &fp); 2856 if (__predict_false(error != 0)) 2857 return (error); 2858 if (__predict_false(fp->f_ops == &badfileops)) { 2859 fdrop(fp, td); 2860 return (EBADF); 2861 } 2862 2863 /* 2864 * FREAD and FWRITE failure return EBADF as per POSIX. 2865 */ 2866 error = 0; 2867 switch (flags) { 2868 case FREAD: 2869 case FWRITE: 2870 if ((fp->f_flag & flags) == 0) 2871 error = EBADF; 2872 break; 2873 case FEXEC: 2874 if ((fp->f_flag & (FREAD | FEXEC)) == 0 || 2875 ((fp->f_flag & FWRITE) != 0)) 2876 error = EBADF; 2877 break; 2878 case 0: 2879 break; 2880 default: 2881 KASSERT(0, ("wrong flags")); 2882 } 2883 2884 if (error != 0) { 2885 fdrop(fp, td); 2886 return (error); 2887 } 2888 2889 *fpp = fp; 2890 return (0); 2891 } 2892 2893 int 2894 fget(struct thread *td, int fd, cap_rights_t *rightsp, struct file **fpp) 2895 { 2896 2897 return (_fget(td, fd, fpp, 0, rightsp)); 2898 } 2899 2900 int 2901 fget_mmap(struct thread *td, int fd, cap_rights_t *rightsp, u_char *maxprotp, 2902 struct file **fpp) 2903 { 2904 int error; 2905 #ifndef CAPABILITIES 2906 error = _fget(td, fd, fpp, 0, rightsp); 2907 if (maxprotp != NULL) 2908 *maxprotp = VM_PROT_ALL; 2909 return (error); 2910 #else 2911 cap_rights_t fdrights; 2912 struct filedesc *fdp; 2913 struct file *fp; 2914 seqc_t seq; 2915 2916 *fpp = NULL; 2917 fdp = td->td_proc->p_fd; 2918 MPASS(cap_rights_is_set(rightsp, CAP_MMAP)); 2919 for (;;) { 2920 error = fget_unlocked_seq(fdp, fd, rightsp, &fp, &seq); 2921 if (__predict_false(error != 0)) 2922 return (error); 2923 if (__predict_false(fp->f_ops == &badfileops)) { 2924 fdrop(fp, td); 2925 return (EBADF); 2926 } 2927 if (maxprotp != NULL) 2928 fdrights = *cap_rights(fdp, fd); 2929 if (!fd_modified(fdp, fd, seq)) 2930 break; 2931 fdrop(fp, td); 2932 } 2933 2934 /* 2935 * If requested, convert capability rights to access flags. 2936 */ 2937 if (maxprotp != NULL) 2938 *maxprotp = cap_rights_to_vmprot(&fdrights); 2939 *fpp = fp; 2940 return (0); 2941 #endif 2942 } 2943 2944 int 2945 fget_read(struct thread *td, int fd, cap_rights_t *rightsp, struct file **fpp) 2946 { 2947 2948 return (_fget(td, fd, fpp, FREAD, rightsp)); 2949 } 2950 2951 int 2952 fget_write(struct thread *td, int fd, cap_rights_t *rightsp, struct file **fpp) 2953 { 2954 2955 return (_fget(td, fd, fpp, FWRITE, rightsp)); 2956 } 2957 2958 int 2959 fget_fcntl(struct thread *td, int fd, cap_rights_t *rightsp, int needfcntl, 2960 struct file **fpp) 2961 { 2962 struct filedesc *fdp = td->td_proc->p_fd; 2963 #ifndef CAPABILITIES 2964 return (fget_unlocked(fdp, fd, rightsp, fpp)); 2965 #else 2966 struct file *fp; 2967 int error; 2968 seqc_t seq; 2969 2970 *fpp = NULL; 2971 MPASS(cap_rights_is_set(rightsp, CAP_FCNTL)); 2972 for (;;) { 2973 error = fget_unlocked_seq(fdp, fd, rightsp, &fp, &seq); 2974 if (error != 0) 2975 return (error); 2976 error = cap_fcntl_check(fdp, fd, needfcntl); 2977 if (!fd_modified(fdp, fd, seq)) 2978 break; 2979 fdrop(fp, td); 2980 } 2981 if (error != 0) { 2982 fdrop(fp, td); 2983 return (error); 2984 } 2985 *fpp = fp; 2986 return (0); 2987 #endif 2988 } 2989 2990 /* 2991 * Like fget() but loads the underlying vnode, or returns an error if the 2992 * descriptor does not represent a vnode. Note that pipes use vnodes but 2993 * never have VM objects. The returned vnode will be vref()'d. 2994 * 2995 * XXX: what about the unused flags ? 2996 */ 2997 static __inline int 2998 _fgetvp(struct thread *td, int fd, int flags, cap_rights_t *needrightsp, 2999 struct vnode **vpp) 3000 { 3001 struct file *fp; 3002 int error; 3003 3004 *vpp = NULL; 3005 error = _fget(td, fd, &fp, flags, needrightsp); 3006 if (error != 0) 3007 return (error); 3008 if (fp->f_vnode == NULL) { 3009 error = EINVAL; 3010 } else { 3011 *vpp = fp->f_vnode; 3012 vrefact(*vpp); 3013 } 3014 fdrop(fp, td); 3015 3016 return (error); 3017 } 3018 3019 int 3020 fgetvp(struct thread *td, int fd, cap_rights_t *rightsp, struct vnode **vpp) 3021 { 3022 3023 return (_fgetvp(td, fd, 0, rightsp, vpp)); 3024 } 3025 3026 int 3027 fgetvp_rights(struct thread *td, int fd, cap_rights_t *needrightsp, 3028 struct filecaps *havecaps, struct vnode **vpp) 3029 { 3030 struct filedesc *fdp; 3031 struct filecaps caps; 3032 struct file *fp; 3033 int error; 3034 3035 fdp = td->td_proc->p_fd; 3036 error = fget_cap_locked(fdp, fd, needrightsp, &fp, &caps); 3037 if (error != 0) 3038 return (error); 3039 if (fp->f_ops == &badfileops) { 3040 error = EBADF; 3041 goto out; 3042 } 3043 if (fp->f_vnode == NULL) { 3044 error = EINVAL; 3045 goto out; 3046 } 3047 3048 *havecaps = caps; 3049 *vpp = fp->f_vnode; 3050 vrefact(*vpp); 3051 3052 return (0); 3053 out: 3054 filecaps_free(&caps); 3055 return (error); 3056 } 3057 3058 int 3059 fgetvp_read(struct thread *td, int fd, cap_rights_t *rightsp, struct vnode **vpp) 3060 { 3061 3062 return (_fgetvp(td, fd, FREAD, rightsp, vpp)); 3063 } 3064 3065 int 3066 fgetvp_exec(struct thread *td, int fd, cap_rights_t *rightsp, struct vnode **vpp) 3067 { 3068 3069 return (_fgetvp(td, fd, FEXEC, rightsp, vpp)); 3070 } 3071 3072 #ifdef notyet 3073 int 3074 fgetvp_write(struct thread *td, int fd, cap_rights_t *rightsp, 3075 struct vnode **vpp) 3076 { 3077 3078 return (_fgetvp(td, fd, FWRITE, rightsp, vpp)); 3079 } 3080 #endif 3081 3082 /* 3083 * Handle the last reference to a file being closed. 3084 * 3085 * Without the noinline attribute clang keeps inlining the func thorough this 3086 * file when fdrop is used. 3087 */ 3088 int __noinline 3089 _fdrop(struct file *fp, struct thread *td) 3090 { 3091 int error; 3092 3093 if (fp->f_count != 0) 3094 panic("fdrop: count %d", fp->f_count); 3095 error = fo_close(fp, td); 3096 atomic_subtract_int(&openfiles, 1); 3097 crfree(fp->f_cred); 3098 free(fp->f_advice, M_FADVISE); 3099 uma_zfree(file_zone, fp); 3100 3101 return (error); 3102 } 3103 3104 /* 3105 * Apply an advisory lock on a file descriptor. 3106 * 3107 * Just attempt to get a record lock of the requested type on the entire file 3108 * (l_whence = SEEK_SET, l_start = 0, l_len = 0). 3109 */ 3110 #ifndef _SYS_SYSPROTO_H_ 3111 struct flock_args { 3112 int fd; 3113 int how; 3114 }; 3115 #endif 3116 /* ARGSUSED */ 3117 int 3118 sys_flock(struct thread *td, struct flock_args *uap) 3119 { 3120 struct file *fp; 3121 struct vnode *vp; 3122 struct flock lf; 3123 int error; 3124 3125 error = fget(td, uap->fd, &cap_flock_rights, &fp); 3126 if (error != 0) 3127 return (error); 3128 if (fp->f_type != DTYPE_VNODE) { 3129 fdrop(fp, td); 3130 return (EOPNOTSUPP); 3131 } 3132 3133 vp = fp->f_vnode; 3134 lf.l_whence = SEEK_SET; 3135 lf.l_start = 0; 3136 lf.l_len = 0; 3137 if (uap->how & LOCK_UN) { 3138 lf.l_type = F_UNLCK; 3139 atomic_clear_int(&fp->f_flag, FHASLOCK); 3140 error = VOP_ADVLOCK(vp, (caddr_t)fp, F_UNLCK, &lf, F_FLOCK); 3141 goto done2; 3142 } 3143 if (uap->how & LOCK_EX) 3144 lf.l_type = F_WRLCK; 3145 else if (uap->how & LOCK_SH) 3146 lf.l_type = F_RDLCK; 3147 else { 3148 error = EBADF; 3149 goto done2; 3150 } 3151 atomic_set_int(&fp->f_flag, FHASLOCK); 3152 error = VOP_ADVLOCK(vp, (caddr_t)fp, F_SETLK, &lf, 3153 (uap->how & LOCK_NB) ? F_FLOCK : F_FLOCK | F_WAIT); 3154 done2: 3155 fdrop(fp, td); 3156 return (error); 3157 } 3158 /* 3159 * Duplicate the specified descriptor to a free descriptor. 3160 */ 3161 int 3162 dupfdopen(struct thread *td, struct filedesc *fdp, int dfd, int mode, 3163 int openerror, int *indxp) 3164 { 3165 struct filedescent *newfde, *oldfde; 3166 struct file *fp; 3167 u_long *ioctls; 3168 int error, indx; 3169 3170 KASSERT(openerror == ENODEV || openerror == ENXIO, 3171 ("unexpected error %d in %s", openerror, __func__)); 3172 3173 /* 3174 * If the to-be-dup'd fd number is greater than the allowed number 3175 * of file descriptors, or the fd to be dup'd has already been 3176 * closed, then reject. 3177 */ 3178 FILEDESC_XLOCK(fdp); 3179 if ((fp = fget_locked(fdp, dfd)) == NULL) { 3180 FILEDESC_XUNLOCK(fdp); 3181 return (EBADF); 3182 } 3183 3184 error = fdalloc(td, 0, &indx); 3185 if (error != 0) { 3186 FILEDESC_XUNLOCK(fdp); 3187 return (error); 3188 } 3189 3190 /* 3191 * There are two cases of interest here. 3192 * 3193 * For ENODEV simply dup (dfd) to file descriptor (indx) and return. 3194 * 3195 * For ENXIO steal away the file structure from (dfd) and store it in 3196 * (indx). (dfd) is effectively closed by this operation. 3197 */ 3198 switch (openerror) { 3199 case ENODEV: 3200 /* 3201 * Check that the mode the file is being opened for is a 3202 * subset of the mode of the existing descriptor. 3203 */ 3204 if (((mode & (FREAD|FWRITE)) | fp->f_flag) != fp->f_flag) { 3205 fdunused(fdp, indx); 3206 FILEDESC_XUNLOCK(fdp); 3207 return (EACCES); 3208 } 3209 if (!fhold(fp)) { 3210 fdunused(fdp, indx); 3211 FILEDESC_XUNLOCK(fdp); 3212 return (EBADF); 3213 } 3214 newfde = &fdp->fd_ofiles[indx]; 3215 oldfde = &fdp->fd_ofiles[dfd]; 3216 ioctls = filecaps_copy_prep(&oldfde->fde_caps); 3217 #ifdef CAPABILITIES 3218 seqc_write_begin(&newfde->fde_seqc); 3219 #endif 3220 memcpy(newfde, oldfde, fde_change_size); 3221 filecaps_copy_finish(&oldfde->fde_caps, &newfde->fde_caps, 3222 ioctls); 3223 #ifdef CAPABILITIES 3224 seqc_write_end(&newfde->fde_seqc); 3225 #endif 3226 break; 3227 case ENXIO: 3228 /* 3229 * Steal away the file pointer from dfd and stuff it into indx. 3230 */ 3231 newfde = &fdp->fd_ofiles[indx]; 3232 oldfde = &fdp->fd_ofiles[dfd]; 3233 #ifdef CAPABILITIES 3234 seqc_write_begin(&newfde->fde_seqc); 3235 #endif 3236 memcpy(newfde, oldfde, fde_change_size); 3237 oldfde->fde_file = NULL; 3238 fdunused(fdp, dfd); 3239 #ifdef CAPABILITIES 3240 seqc_write_end(&newfde->fde_seqc); 3241 #endif 3242 break; 3243 } 3244 FILEDESC_XUNLOCK(fdp); 3245 *indxp = indx; 3246 return (0); 3247 } 3248 3249 /* 3250 * This sysctl determines if we will allow a process to chroot(2) if it 3251 * has a directory open: 3252 * 0: disallowed for all processes. 3253 * 1: allowed for processes that were not already chroot(2)'ed. 3254 * 2: allowed for all processes. 3255 */ 3256 3257 static int chroot_allow_open_directories = 1; 3258 3259 SYSCTL_INT(_kern, OID_AUTO, chroot_allow_open_directories, CTLFLAG_RW, 3260 &chroot_allow_open_directories, 0, 3261 "Allow a process to chroot(2) if it has a directory open"); 3262 3263 /* 3264 * Helper function for raised chroot(2) security function: Refuse if 3265 * any filedescriptors are open directories. 3266 */ 3267 static int 3268 chroot_refuse_vdir_fds(struct filedesc *fdp) 3269 { 3270 struct vnode *vp; 3271 struct file *fp; 3272 int fd; 3273 3274 FILEDESC_LOCK_ASSERT(fdp); 3275 3276 for (fd = 0; fd <= fdp->fd_lastfile; fd++) { 3277 fp = fget_locked(fdp, fd); 3278 if (fp == NULL) 3279 continue; 3280 if (fp->f_type == DTYPE_VNODE) { 3281 vp = fp->f_vnode; 3282 if (vp->v_type == VDIR) 3283 return (EPERM); 3284 } 3285 } 3286 return (0); 3287 } 3288 3289 /* 3290 * Common routine for kern_chroot() and jail_attach(). The caller is 3291 * responsible for invoking priv_check() and mac_vnode_check_chroot() to 3292 * authorize this operation. 3293 */ 3294 int 3295 pwd_chroot(struct thread *td, struct vnode *vp) 3296 { 3297 struct filedesc *fdp; 3298 struct vnode *oldvp; 3299 int error; 3300 3301 fdp = td->td_proc->p_fd; 3302 FILEDESC_XLOCK(fdp); 3303 if (chroot_allow_open_directories == 0 || 3304 (chroot_allow_open_directories == 1 && fdp->fd_rdir != rootvnode)) { 3305 error = chroot_refuse_vdir_fds(fdp); 3306 if (error != 0) { 3307 FILEDESC_XUNLOCK(fdp); 3308 return (error); 3309 } 3310 } 3311 oldvp = fdp->fd_rdir; 3312 vrefact(vp); 3313 fdp->fd_rdir = vp; 3314 if (fdp->fd_jdir == NULL) { 3315 vrefact(vp); 3316 fdp->fd_jdir = vp; 3317 } 3318 FILEDESC_XUNLOCK(fdp); 3319 vrele(oldvp); 3320 return (0); 3321 } 3322 3323 void 3324 pwd_chdir(struct thread *td, struct vnode *vp) 3325 { 3326 struct filedesc *fdp; 3327 struct vnode *oldvp; 3328 3329 fdp = td->td_proc->p_fd; 3330 FILEDESC_XLOCK(fdp); 3331 VNASSERT(vp->v_usecount > 0, vp, 3332 ("chdir to a vnode with zero usecount")); 3333 oldvp = fdp->fd_cdir; 3334 fdp->fd_cdir = vp; 3335 FILEDESC_XUNLOCK(fdp); 3336 vrele(oldvp); 3337 } 3338 3339 /* 3340 * Scan all active processes and prisons to see if any of them have a current 3341 * or root directory of `olddp'. If so, replace them with the new mount point. 3342 */ 3343 void 3344 mountcheckdirs(struct vnode *olddp, struct vnode *newdp) 3345 { 3346 struct filedesc *fdp; 3347 struct prison *pr; 3348 struct proc *p; 3349 int nrele; 3350 3351 if (vrefcnt(olddp) == 1) 3352 return; 3353 nrele = 0; 3354 sx_slock(&allproc_lock); 3355 FOREACH_PROC_IN_SYSTEM(p) { 3356 PROC_LOCK(p); 3357 fdp = fdhold(p); 3358 PROC_UNLOCK(p); 3359 if (fdp == NULL) 3360 continue; 3361 FILEDESC_XLOCK(fdp); 3362 if (fdp->fd_cdir == olddp) { 3363 vrefact(newdp); 3364 fdp->fd_cdir = newdp; 3365 nrele++; 3366 } 3367 if (fdp->fd_rdir == olddp) { 3368 vrefact(newdp); 3369 fdp->fd_rdir = newdp; 3370 nrele++; 3371 } 3372 if (fdp->fd_jdir == olddp) { 3373 vrefact(newdp); 3374 fdp->fd_jdir = newdp; 3375 nrele++; 3376 } 3377 FILEDESC_XUNLOCK(fdp); 3378 fddrop(fdp); 3379 } 3380 sx_sunlock(&allproc_lock); 3381 if (rootvnode == olddp) { 3382 vrefact(newdp); 3383 rootvnode = newdp; 3384 nrele++; 3385 } 3386 mtx_lock(&prison0.pr_mtx); 3387 if (prison0.pr_root == olddp) { 3388 vrefact(newdp); 3389 prison0.pr_root = newdp; 3390 nrele++; 3391 } 3392 mtx_unlock(&prison0.pr_mtx); 3393 sx_slock(&allprison_lock); 3394 TAILQ_FOREACH(pr, &allprison, pr_list) { 3395 mtx_lock(&pr->pr_mtx); 3396 if (pr->pr_root == olddp) { 3397 vrefact(newdp); 3398 pr->pr_root = newdp; 3399 nrele++; 3400 } 3401 mtx_unlock(&pr->pr_mtx); 3402 } 3403 sx_sunlock(&allprison_lock); 3404 while (nrele--) 3405 vrele(olddp); 3406 } 3407 3408 struct filedesc_to_leader * 3409 filedesc_to_leader_alloc(struct filedesc_to_leader *old, struct filedesc *fdp, struct proc *leader) 3410 { 3411 struct filedesc_to_leader *fdtol; 3412 3413 fdtol = malloc(sizeof(struct filedesc_to_leader), 3414 M_FILEDESC_TO_LEADER, M_WAITOK); 3415 fdtol->fdl_refcount = 1; 3416 fdtol->fdl_holdcount = 0; 3417 fdtol->fdl_wakeup = 0; 3418 fdtol->fdl_leader = leader; 3419 if (old != NULL) { 3420 FILEDESC_XLOCK(fdp); 3421 fdtol->fdl_next = old->fdl_next; 3422 fdtol->fdl_prev = old; 3423 old->fdl_next = fdtol; 3424 fdtol->fdl_next->fdl_prev = fdtol; 3425 FILEDESC_XUNLOCK(fdp); 3426 } else { 3427 fdtol->fdl_next = fdtol; 3428 fdtol->fdl_prev = fdtol; 3429 } 3430 return (fdtol); 3431 } 3432 3433 static int 3434 sysctl_kern_proc_nfds(SYSCTL_HANDLER_ARGS) 3435 { 3436 struct filedesc *fdp; 3437 int i, count, slots; 3438 3439 if (*(int *)arg1 != 0) 3440 return (EINVAL); 3441 3442 fdp = curproc->p_fd; 3443 count = 0; 3444 FILEDESC_SLOCK(fdp); 3445 slots = NDSLOTS(fdp->fd_lastfile + 1); 3446 for (i = 0; i < slots; i++) 3447 count += bitcountl(fdp->fd_map[i]); 3448 FILEDESC_SUNLOCK(fdp); 3449 3450 return (SYSCTL_OUT(req, &count, sizeof(count))); 3451 } 3452 3453 static SYSCTL_NODE(_kern_proc, KERN_PROC_NFDS, nfds, 3454 CTLFLAG_RD|CTLFLAG_CAPRD|CTLFLAG_MPSAFE, sysctl_kern_proc_nfds, 3455 "Number of open file descriptors"); 3456 3457 /* 3458 * Get file structures globally. 3459 */ 3460 static int 3461 sysctl_kern_file(SYSCTL_HANDLER_ARGS) 3462 { 3463 struct xfile xf; 3464 struct filedesc *fdp; 3465 struct file *fp; 3466 struct proc *p; 3467 int error, n; 3468 3469 error = sysctl_wire_old_buffer(req, 0); 3470 if (error != 0) 3471 return (error); 3472 if (req->oldptr == NULL) { 3473 n = 0; 3474 sx_slock(&allproc_lock); 3475 FOREACH_PROC_IN_SYSTEM(p) { 3476 PROC_LOCK(p); 3477 if (p->p_state == PRS_NEW) { 3478 PROC_UNLOCK(p); 3479 continue; 3480 } 3481 fdp = fdhold(p); 3482 PROC_UNLOCK(p); 3483 if (fdp == NULL) 3484 continue; 3485 /* overestimates sparse tables. */ 3486 if (fdp->fd_lastfile > 0) 3487 n += fdp->fd_lastfile; 3488 fddrop(fdp); 3489 } 3490 sx_sunlock(&allproc_lock); 3491 return (SYSCTL_OUT(req, 0, n * sizeof(xf))); 3492 } 3493 error = 0; 3494 bzero(&xf, sizeof(xf)); 3495 xf.xf_size = sizeof(xf); 3496 sx_slock(&allproc_lock); 3497 FOREACH_PROC_IN_SYSTEM(p) { 3498 PROC_LOCK(p); 3499 if (p->p_state == PRS_NEW) { 3500 PROC_UNLOCK(p); 3501 continue; 3502 } 3503 if (p_cansee(req->td, p) != 0) { 3504 PROC_UNLOCK(p); 3505 continue; 3506 } 3507 xf.xf_pid = p->p_pid; 3508 xf.xf_uid = p->p_ucred->cr_uid; 3509 fdp = fdhold(p); 3510 PROC_UNLOCK(p); 3511 if (fdp == NULL) 3512 continue; 3513 FILEDESC_SLOCK(fdp); 3514 for (n = 0; fdp->fd_refcnt > 0 && n <= fdp->fd_lastfile; ++n) { 3515 if ((fp = fdp->fd_ofiles[n].fde_file) == NULL) 3516 continue; 3517 xf.xf_fd = n; 3518 xf.xf_file = (uintptr_t)fp; 3519 xf.xf_data = (uintptr_t)fp->f_data; 3520 xf.xf_vnode = (uintptr_t)fp->f_vnode; 3521 xf.xf_type = (uintptr_t)fp->f_type; 3522 xf.xf_count = fp->f_count; 3523 xf.xf_msgcount = 0; 3524 xf.xf_offset = foffset_get(fp); 3525 xf.xf_flag = fp->f_flag; 3526 error = SYSCTL_OUT(req, &xf, sizeof(xf)); 3527 if (error) 3528 break; 3529 } 3530 FILEDESC_SUNLOCK(fdp); 3531 fddrop(fdp); 3532 if (error) 3533 break; 3534 } 3535 sx_sunlock(&allproc_lock); 3536 return (error); 3537 } 3538 3539 SYSCTL_PROC(_kern, KERN_FILE, file, CTLTYPE_OPAQUE|CTLFLAG_RD|CTLFLAG_MPSAFE, 3540 0, 0, sysctl_kern_file, "S,xfile", "Entire file table"); 3541 3542 #ifdef KINFO_FILE_SIZE 3543 CTASSERT(sizeof(struct kinfo_file) == KINFO_FILE_SIZE); 3544 #endif 3545 3546 static int 3547 xlate_fflags(int fflags) 3548 { 3549 static const struct { 3550 int fflag; 3551 int kf_fflag; 3552 } fflags_table[] = { 3553 { FAPPEND, KF_FLAG_APPEND }, 3554 { FASYNC, KF_FLAG_ASYNC }, 3555 { FFSYNC, KF_FLAG_FSYNC }, 3556 { FHASLOCK, KF_FLAG_HASLOCK }, 3557 { FNONBLOCK, KF_FLAG_NONBLOCK }, 3558 { FREAD, KF_FLAG_READ }, 3559 { FWRITE, KF_FLAG_WRITE }, 3560 { O_CREAT, KF_FLAG_CREAT }, 3561 { O_DIRECT, KF_FLAG_DIRECT }, 3562 { O_EXCL, KF_FLAG_EXCL }, 3563 { O_EXEC, KF_FLAG_EXEC }, 3564 { O_EXLOCK, KF_FLAG_EXLOCK }, 3565 { O_NOFOLLOW, KF_FLAG_NOFOLLOW }, 3566 { O_SHLOCK, KF_FLAG_SHLOCK }, 3567 { O_TRUNC, KF_FLAG_TRUNC } 3568 }; 3569 unsigned int i; 3570 int kflags; 3571 3572 kflags = 0; 3573 for (i = 0; i < nitems(fflags_table); i++) 3574 if (fflags & fflags_table[i].fflag) 3575 kflags |= fflags_table[i].kf_fflag; 3576 return (kflags); 3577 } 3578 3579 /* Trim unused data from kf_path by truncating the structure size. */ 3580 void 3581 pack_kinfo(struct kinfo_file *kif) 3582 { 3583 3584 kif->kf_structsize = offsetof(struct kinfo_file, kf_path) + 3585 strlen(kif->kf_path) + 1; 3586 kif->kf_structsize = roundup(kif->kf_structsize, sizeof(uint64_t)); 3587 } 3588 3589 static void 3590 export_file_to_kinfo(struct file *fp, int fd, cap_rights_t *rightsp, 3591 struct kinfo_file *kif, struct filedesc *fdp, int flags) 3592 { 3593 int error; 3594 3595 bzero(kif, sizeof(*kif)); 3596 3597 /* Set a default type to allow for empty fill_kinfo() methods. */ 3598 kif->kf_type = KF_TYPE_UNKNOWN; 3599 kif->kf_flags = xlate_fflags(fp->f_flag); 3600 if (rightsp != NULL) 3601 kif->kf_cap_rights = *rightsp; 3602 else 3603 cap_rights_init(&kif->kf_cap_rights); 3604 kif->kf_fd = fd; 3605 kif->kf_ref_count = fp->f_count; 3606 kif->kf_offset = foffset_get(fp); 3607 3608 /* 3609 * This may drop the filedesc lock, so the 'fp' cannot be 3610 * accessed after this call. 3611 */ 3612 error = fo_fill_kinfo(fp, kif, fdp); 3613 if (error == 0) 3614 kif->kf_status |= KF_ATTR_VALID; 3615 if ((flags & KERN_FILEDESC_PACK_KINFO) != 0) 3616 pack_kinfo(kif); 3617 else 3618 kif->kf_structsize = roundup2(sizeof(*kif), sizeof(uint64_t)); 3619 } 3620 3621 static void 3622 export_vnode_to_kinfo(struct vnode *vp, int fd, int fflags, 3623 struct kinfo_file *kif, int flags) 3624 { 3625 int error; 3626 3627 bzero(kif, sizeof(*kif)); 3628 3629 kif->kf_type = KF_TYPE_VNODE; 3630 error = vn_fill_kinfo_vnode(vp, kif); 3631 if (error == 0) 3632 kif->kf_status |= KF_ATTR_VALID; 3633 kif->kf_flags = xlate_fflags(fflags); 3634 cap_rights_init(&kif->kf_cap_rights); 3635 kif->kf_fd = fd; 3636 kif->kf_ref_count = -1; 3637 kif->kf_offset = -1; 3638 if ((flags & KERN_FILEDESC_PACK_KINFO) != 0) 3639 pack_kinfo(kif); 3640 else 3641 kif->kf_structsize = roundup2(sizeof(*kif), sizeof(uint64_t)); 3642 vrele(vp); 3643 } 3644 3645 struct export_fd_buf { 3646 struct filedesc *fdp; 3647 struct sbuf *sb; 3648 ssize_t remainder; 3649 struct kinfo_file kif; 3650 int flags; 3651 }; 3652 3653 static int 3654 export_kinfo_to_sb(struct export_fd_buf *efbuf) 3655 { 3656 struct kinfo_file *kif; 3657 3658 kif = &efbuf->kif; 3659 if (efbuf->remainder != -1) { 3660 if (efbuf->remainder < kif->kf_structsize) { 3661 /* Terminate export. */ 3662 efbuf->remainder = 0; 3663 return (0); 3664 } 3665 efbuf->remainder -= kif->kf_structsize; 3666 } 3667 return (sbuf_bcat(efbuf->sb, kif, kif->kf_structsize) == 0 ? 0 : ENOMEM); 3668 } 3669 3670 static int 3671 export_file_to_sb(struct file *fp, int fd, cap_rights_t *rightsp, 3672 struct export_fd_buf *efbuf) 3673 { 3674 int error; 3675 3676 if (efbuf->remainder == 0) 3677 return (0); 3678 export_file_to_kinfo(fp, fd, rightsp, &efbuf->kif, efbuf->fdp, 3679 efbuf->flags); 3680 FILEDESC_SUNLOCK(efbuf->fdp); 3681 error = export_kinfo_to_sb(efbuf); 3682 FILEDESC_SLOCK(efbuf->fdp); 3683 return (error); 3684 } 3685 3686 static int 3687 export_vnode_to_sb(struct vnode *vp, int fd, int fflags, 3688 struct export_fd_buf *efbuf) 3689 { 3690 int error; 3691 3692 if (efbuf->remainder == 0) 3693 return (0); 3694 if (efbuf->fdp != NULL) 3695 FILEDESC_SUNLOCK(efbuf->fdp); 3696 export_vnode_to_kinfo(vp, fd, fflags, &efbuf->kif, efbuf->flags); 3697 error = export_kinfo_to_sb(efbuf); 3698 if (efbuf->fdp != NULL) 3699 FILEDESC_SLOCK(efbuf->fdp); 3700 return (error); 3701 } 3702 3703 /* 3704 * Store a process file descriptor information to sbuf. 3705 * 3706 * Takes a locked proc as argument, and returns with the proc unlocked. 3707 */ 3708 int 3709 kern_proc_filedesc_out(struct proc *p, struct sbuf *sb, ssize_t maxlen, 3710 int flags) 3711 { 3712 struct file *fp; 3713 struct filedesc *fdp; 3714 struct export_fd_buf *efbuf; 3715 struct vnode *cttyvp, *textvp, *tracevp; 3716 int error, i; 3717 cap_rights_t rights; 3718 3719 PROC_LOCK_ASSERT(p, MA_OWNED); 3720 3721 /* ktrace vnode */ 3722 tracevp = p->p_tracevp; 3723 if (tracevp != NULL) 3724 vrefact(tracevp); 3725 /* text vnode */ 3726 textvp = p->p_textvp; 3727 if (textvp != NULL) 3728 vrefact(textvp); 3729 /* Controlling tty. */ 3730 cttyvp = NULL; 3731 if (p->p_pgrp != NULL && p->p_pgrp->pg_session != NULL) { 3732 cttyvp = p->p_pgrp->pg_session->s_ttyvp; 3733 if (cttyvp != NULL) 3734 vrefact(cttyvp); 3735 } 3736 fdp = fdhold(p); 3737 PROC_UNLOCK(p); 3738 efbuf = malloc(sizeof(*efbuf), M_TEMP, M_WAITOK); 3739 efbuf->fdp = NULL; 3740 efbuf->sb = sb; 3741 efbuf->remainder = maxlen; 3742 efbuf->flags = flags; 3743 if (tracevp != NULL) 3744 export_vnode_to_sb(tracevp, KF_FD_TYPE_TRACE, FREAD | FWRITE, 3745 efbuf); 3746 if (textvp != NULL) 3747 export_vnode_to_sb(textvp, KF_FD_TYPE_TEXT, FREAD, efbuf); 3748 if (cttyvp != NULL) 3749 export_vnode_to_sb(cttyvp, KF_FD_TYPE_CTTY, FREAD | FWRITE, 3750 efbuf); 3751 error = 0; 3752 if (fdp == NULL) 3753 goto fail; 3754 efbuf->fdp = fdp; 3755 FILEDESC_SLOCK(fdp); 3756 /* working directory */ 3757 if (fdp->fd_cdir != NULL) { 3758 vrefact(fdp->fd_cdir); 3759 export_vnode_to_sb(fdp->fd_cdir, KF_FD_TYPE_CWD, FREAD, efbuf); 3760 } 3761 /* root directory */ 3762 if (fdp->fd_rdir != NULL) { 3763 vrefact(fdp->fd_rdir); 3764 export_vnode_to_sb(fdp->fd_rdir, KF_FD_TYPE_ROOT, FREAD, efbuf); 3765 } 3766 /* jail directory */ 3767 if (fdp->fd_jdir != NULL) { 3768 vrefact(fdp->fd_jdir); 3769 export_vnode_to_sb(fdp->fd_jdir, KF_FD_TYPE_JAIL, FREAD, efbuf); 3770 } 3771 for (i = 0; fdp->fd_refcnt > 0 && i <= fdp->fd_lastfile; i++) { 3772 if ((fp = fdp->fd_ofiles[i].fde_file) == NULL) 3773 continue; 3774 #ifdef CAPABILITIES 3775 rights = *cap_rights(fdp, i); 3776 #else /* !CAPABILITIES */ 3777 rights = cap_no_rights; 3778 #endif 3779 /* 3780 * Create sysctl entry. It is OK to drop the filedesc 3781 * lock inside of export_file_to_sb() as we will 3782 * re-validate and re-evaluate its properties when the 3783 * loop continues. 3784 */ 3785 error = export_file_to_sb(fp, i, &rights, efbuf); 3786 if (error != 0 || efbuf->remainder == 0) 3787 break; 3788 } 3789 FILEDESC_SUNLOCK(fdp); 3790 fddrop(fdp); 3791 fail: 3792 free(efbuf, M_TEMP); 3793 return (error); 3794 } 3795 3796 #define FILEDESC_SBUF_SIZE (sizeof(struct kinfo_file) * 5) 3797 3798 /* 3799 * Get per-process file descriptors for use by procstat(1), et al. 3800 */ 3801 static int 3802 sysctl_kern_proc_filedesc(SYSCTL_HANDLER_ARGS) 3803 { 3804 struct sbuf sb; 3805 struct proc *p; 3806 ssize_t maxlen; 3807 int error, error2, *name; 3808 3809 name = (int *)arg1; 3810 3811 sbuf_new_for_sysctl(&sb, NULL, FILEDESC_SBUF_SIZE, req); 3812 sbuf_clear_flags(&sb, SBUF_INCLUDENUL); 3813 error = pget((pid_t)name[0], PGET_CANDEBUG | PGET_NOTWEXIT, &p); 3814 if (error != 0) { 3815 sbuf_delete(&sb); 3816 return (error); 3817 } 3818 maxlen = req->oldptr != NULL ? req->oldlen : -1; 3819 error = kern_proc_filedesc_out(p, &sb, maxlen, 3820 KERN_FILEDESC_PACK_KINFO); 3821 error2 = sbuf_finish(&sb); 3822 sbuf_delete(&sb); 3823 return (error != 0 ? error : error2); 3824 } 3825 3826 #ifdef COMPAT_FREEBSD7 3827 #ifdef KINFO_OFILE_SIZE 3828 CTASSERT(sizeof(struct kinfo_ofile) == KINFO_OFILE_SIZE); 3829 #endif 3830 3831 static void 3832 kinfo_to_okinfo(struct kinfo_file *kif, struct kinfo_ofile *okif) 3833 { 3834 3835 okif->kf_structsize = sizeof(*okif); 3836 okif->kf_type = kif->kf_type; 3837 okif->kf_fd = kif->kf_fd; 3838 okif->kf_ref_count = kif->kf_ref_count; 3839 okif->kf_flags = kif->kf_flags & (KF_FLAG_READ | KF_FLAG_WRITE | 3840 KF_FLAG_APPEND | KF_FLAG_ASYNC | KF_FLAG_FSYNC | KF_FLAG_NONBLOCK | 3841 KF_FLAG_DIRECT | KF_FLAG_HASLOCK); 3842 okif->kf_offset = kif->kf_offset; 3843 if (kif->kf_type == KF_TYPE_VNODE) 3844 okif->kf_vnode_type = kif->kf_un.kf_file.kf_file_type; 3845 else 3846 okif->kf_vnode_type = KF_VTYPE_VNON; 3847 strlcpy(okif->kf_path, kif->kf_path, sizeof(okif->kf_path)); 3848 if (kif->kf_type == KF_TYPE_SOCKET) { 3849 okif->kf_sock_domain = kif->kf_un.kf_sock.kf_sock_domain0; 3850 okif->kf_sock_type = kif->kf_un.kf_sock.kf_sock_type0; 3851 okif->kf_sock_protocol = kif->kf_un.kf_sock.kf_sock_protocol0; 3852 okif->kf_sa_local = kif->kf_un.kf_sock.kf_sa_local; 3853 okif->kf_sa_peer = kif->kf_un.kf_sock.kf_sa_peer; 3854 } else { 3855 okif->kf_sa_local.ss_family = AF_UNSPEC; 3856 okif->kf_sa_peer.ss_family = AF_UNSPEC; 3857 } 3858 } 3859 3860 static int 3861 export_vnode_for_osysctl(struct vnode *vp, int type, struct kinfo_file *kif, 3862 struct kinfo_ofile *okif, struct filedesc *fdp, struct sysctl_req *req) 3863 { 3864 int error; 3865 3866 vrefact(vp); 3867 FILEDESC_SUNLOCK(fdp); 3868 export_vnode_to_kinfo(vp, type, 0, kif, KERN_FILEDESC_PACK_KINFO); 3869 kinfo_to_okinfo(kif, okif); 3870 error = SYSCTL_OUT(req, okif, sizeof(*okif)); 3871 FILEDESC_SLOCK(fdp); 3872 return (error); 3873 } 3874 3875 /* 3876 * Get per-process file descriptors for use by procstat(1), et al. 3877 */ 3878 static int 3879 sysctl_kern_proc_ofiledesc(SYSCTL_HANDLER_ARGS) 3880 { 3881 struct kinfo_ofile *okif; 3882 struct kinfo_file *kif; 3883 struct filedesc *fdp; 3884 int error, i, *name; 3885 struct file *fp; 3886 struct proc *p; 3887 3888 name = (int *)arg1; 3889 error = pget((pid_t)name[0], PGET_CANDEBUG | PGET_NOTWEXIT, &p); 3890 if (error != 0) 3891 return (error); 3892 fdp = fdhold(p); 3893 PROC_UNLOCK(p); 3894 if (fdp == NULL) 3895 return (ENOENT); 3896 kif = malloc(sizeof(*kif), M_TEMP, M_WAITOK); 3897 okif = malloc(sizeof(*okif), M_TEMP, M_WAITOK); 3898 FILEDESC_SLOCK(fdp); 3899 if (fdp->fd_cdir != NULL) 3900 export_vnode_for_osysctl(fdp->fd_cdir, KF_FD_TYPE_CWD, kif, 3901 okif, fdp, req); 3902 if (fdp->fd_rdir != NULL) 3903 export_vnode_for_osysctl(fdp->fd_rdir, KF_FD_TYPE_ROOT, kif, 3904 okif, fdp, req); 3905 if (fdp->fd_jdir != NULL) 3906 export_vnode_for_osysctl(fdp->fd_jdir, KF_FD_TYPE_JAIL, kif, 3907 okif, fdp, req); 3908 for (i = 0; fdp->fd_refcnt > 0 && i <= fdp->fd_lastfile; i++) { 3909 if ((fp = fdp->fd_ofiles[i].fde_file) == NULL) 3910 continue; 3911 export_file_to_kinfo(fp, i, NULL, kif, fdp, 3912 KERN_FILEDESC_PACK_KINFO); 3913 FILEDESC_SUNLOCK(fdp); 3914 kinfo_to_okinfo(kif, okif); 3915 error = SYSCTL_OUT(req, okif, sizeof(*okif)); 3916 FILEDESC_SLOCK(fdp); 3917 if (error) 3918 break; 3919 } 3920 FILEDESC_SUNLOCK(fdp); 3921 fddrop(fdp); 3922 free(kif, M_TEMP); 3923 free(okif, M_TEMP); 3924 return (0); 3925 } 3926 3927 static SYSCTL_NODE(_kern_proc, KERN_PROC_OFILEDESC, ofiledesc, 3928 CTLFLAG_RD|CTLFLAG_MPSAFE, sysctl_kern_proc_ofiledesc, 3929 "Process ofiledesc entries"); 3930 #endif /* COMPAT_FREEBSD7 */ 3931 3932 int 3933 vntype_to_kinfo(int vtype) 3934 { 3935 struct { 3936 int vtype; 3937 int kf_vtype; 3938 } vtypes_table[] = { 3939 { VBAD, KF_VTYPE_VBAD }, 3940 { VBLK, KF_VTYPE_VBLK }, 3941 { VCHR, KF_VTYPE_VCHR }, 3942 { VDIR, KF_VTYPE_VDIR }, 3943 { VFIFO, KF_VTYPE_VFIFO }, 3944 { VLNK, KF_VTYPE_VLNK }, 3945 { VNON, KF_VTYPE_VNON }, 3946 { VREG, KF_VTYPE_VREG }, 3947 { VSOCK, KF_VTYPE_VSOCK } 3948 }; 3949 unsigned int i; 3950 3951 /* 3952 * Perform vtype translation. 3953 */ 3954 for (i = 0; i < nitems(vtypes_table); i++) 3955 if (vtypes_table[i].vtype == vtype) 3956 return (vtypes_table[i].kf_vtype); 3957 3958 return (KF_VTYPE_UNKNOWN); 3959 } 3960 3961 static SYSCTL_NODE(_kern_proc, KERN_PROC_FILEDESC, filedesc, 3962 CTLFLAG_RD|CTLFLAG_MPSAFE, sysctl_kern_proc_filedesc, 3963 "Process filedesc entries"); 3964 3965 /* 3966 * Store a process current working directory information to sbuf. 3967 * 3968 * Takes a locked proc as argument, and returns with the proc unlocked. 3969 */ 3970 int 3971 kern_proc_cwd_out(struct proc *p, struct sbuf *sb, ssize_t maxlen) 3972 { 3973 struct filedesc *fdp; 3974 struct export_fd_buf *efbuf; 3975 int error; 3976 3977 PROC_LOCK_ASSERT(p, MA_OWNED); 3978 3979 fdp = fdhold(p); 3980 PROC_UNLOCK(p); 3981 if (fdp == NULL) 3982 return (EINVAL); 3983 3984 efbuf = malloc(sizeof(*efbuf), M_TEMP, M_WAITOK); 3985 efbuf->fdp = fdp; 3986 efbuf->sb = sb; 3987 efbuf->remainder = maxlen; 3988 3989 FILEDESC_SLOCK(fdp); 3990 if (fdp->fd_cdir == NULL) 3991 error = EINVAL; 3992 else { 3993 vrefact(fdp->fd_cdir); 3994 error = export_vnode_to_sb(fdp->fd_cdir, KF_FD_TYPE_CWD, 3995 FREAD, efbuf); 3996 } 3997 FILEDESC_SUNLOCK(fdp); 3998 fddrop(fdp); 3999 free(efbuf, M_TEMP); 4000 return (error); 4001 } 4002 4003 /* 4004 * Get per-process current working directory. 4005 */ 4006 static int 4007 sysctl_kern_proc_cwd(SYSCTL_HANDLER_ARGS) 4008 { 4009 struct sbuf sb; 4010 struct proc *p; 4011 ssize_t maxlen; 4012 int error, error2, *name; 4013 4014 name = (int *)arg1; 4015 4016 sbuf_new_for_sysctl(&sb, NULL, sizeof(struct kinfo_file), req); 4017 sbuf_clear_flags(&sb, SBUF_INCLUDENUL); 4018 error = pget((pid_t)name[0], PGET_CANDEBUG | PGET_NOTWEXIT, &p); 4019 if (error != 0) { 4020 sbuf_delete(&sb); 4021 return (error); 4022 } 4023 maxlen = req->oldptr != NULL ? req->oldlen : -1; 4024 error = kern_proc_cwd_out(p, &sb, maxlen); 4025 error2 = sbuf_finish(&sb); 4026 sbuf_delete(&sb); 4027 return (error != 0 ? error : error2); 4028 } 4029 4030 static SYSCTL_NODE(_kern_proc, KERN_PROC_CWD, cwd, CTLFLAG_RD|CTLFLAG_MPSAFE, 4031 sysctl_kern_proc_cwd, "Process current working directory"); 4032 4033 #ifdef DDB 4034 /* 4035 * For the purposes of debugging, generate a human-readable string for the 4036 * file type. 4037 */ 4038 static const char * 4039 file_type_to_name(short type) 4040 { 4041 4042 switch (type) { 4043 case 0: 4044 return ("zero"); 4045 case DTYPE_VNODE: 4046 return ("vnode"); 4047 case DTYPE_SOCKET: 4048 return ("socket"); 4049 case DTYPE_PIPE: 4050 return ("pipe"); 4051 case DTYPE_FIFO: 4052 return ("fifo"); 4053 case DTYPE_KQUEUE: 4054 return ("kqueue"); 4055 case DTYPE_CRYPTO: 4056 return ("crypto"); 4057 case DTYPE_MQUEUE: 4058 return ("mqueue"); 4059 case DTYPE_SHM: 4060 return ("shm"); 4061 case DTYPE_SEM: 4062 return ("ksem"); 4063 case DTYPE_PTS: 4064 return ("pts"); 4065 case DTYPE_DEV: 4066 return ("dev"); 4067 case DTYPE_PROCDESC: 4068 return ("proc"); 4069 case DTYPE_LINUXEFD: 4070 return ("levent"); 4071 case DTYPE_LINUXTFD: 4072 return ("ltimer"); 4073 default: 4074 return ("unkn"); 4075 } 4076 } 4077 4078 /* 4079 * For the purposes of debugging, identify a process (if any, perhaps one of 4080 * many) that references the passed file in its file descriptor array. Return 4081 * NULL if none. 4082 */ 4083 static struct proc * 4084 file_to_first_proc(struct file *fp) 4085 { 4086 struct filedesc *fdp; 4087 struct proc *p; 4088 int n; 4089 4090 FOREACH_PROC_IN_SYSTEM(p) { 4091 if (p->p_state == PRS_NEW) 4092 continue; 4093 fdp = p->p_fd; 4094 if (fdp == NULL) 4095 continue; 4096 for (n = 0; n <= fdp->fd_lastfile; n++) { 4097 if (fp == fdp->fd_ofiles[n].fde_file) 4098 return (p); 4099 } 4100 } 4101 return (NULL); 4102 } 4103 4104 static void 4105 db_print_file(struct file *fp, int header) 4106 { 4107 #define XPTRWIDTH ((int)howmany(sizeof(void *) * NBBY, 4)) 4108 struct proc *p; 4109 4110 if (header) 4111 db_printf("%*s %6s %*s %8s %4s %5s %6s %*s %5s %s\n", 4112 XPTRWIDTH, "File", "Type", XPTRWIDTH, "Data", "Flag", 4113 "GCFl", "Count", "MCount", XPTRWIDTH, "Vnode", "FPID", 4114 "FCmd"); 4115 p = file_to_first_proc(fp); 4116 db_printf("%*p %6s %*p %08x %04x %5d %6d %*p %5d %s\n", XPTRWIDTH, 4117 fp, file_type_to_name(fp->f_type), XPTRWIDTH, fp->f_data, 4118 fp->f_flag, 0, fp->f_count, 0, XPTRWIDTH, fp->f_vnode, 4119 p != NULL ? p->p_pid : -1, p != NULL ? p->p_comm : "-"); 4120 4121 #undef XPTRWIDTH 4122 } 4123 4124 DB_SHOW_COMMAND(file, db_show_file) 4125 { 4126 struct file *fp; 4127 4128 if (!have_addr) { 4129 db_printf("usage: show file <addr>\n"); 4130 return; 4131 } 4132 fp = (struct file *)addr; 4133 db_print_file(fp, 1); 4134 } 4135 4136 DB_SHOW_COMMAND(files, db_show_files) 4137 { 4138 struct filedesc *fdp; 4139 struct file *fp; 4140 struct proc *p; 4141 int header; 4142 int n; 4143 4144 header = 1; 4145 FOREACH_PROC_IN_SYSTEM(p) { 4146 if (p->p_state == PRS_NEW) 4147 continue; 4148 if ((fdp = p->p_fd) == NULL) 4149 continue; 4150 for (n = 0; n <= fdp->fd_lastfile; ++n) { 4151 if ((fp = fdp->fd_ofiles[n].fde_file) == NULL) 4152 continue; 4153 db_print_file(fp, header); 4154 header = 0; 4155 } 4156 } 4157 } 4158 #endif 4159 4160 SYSCTL_INT(_kern, KERN_MAXFILESPERPROC, maxfilesperproc, CTLFLAG_RW, 4161 &maxfilesperproc, 0, "Maximum files allowed open per process"); 4162 4163 SYSCTL_INT(_kern, KERN_MAXFILES, maxfiles, CTLFLAG_RW, 4164 &maxfiles, 0, "Maximum number of files"); 4165 4166 SYSCTL_INT(_kern, OID_AUTO, openfiles, CTLFLAG_RD, 4167 &openfiles, 0, "System-wide number of open files"); 4168 4169 /* ARGSUSED*/ 4170 static void 4171 filelistinit(void *dummy) 4172 { 4173 4174 file_zone = uma_zcreate("Files", sizeof(struct file), NULL, NULL, 4175 NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE); 4176 filedesc0_zone = uma_zcreate("filedesc0", sizeof(struct filedesc0), 4177 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0); 4178 mtx_init(&sigio_lock, "sigio lock", NULL, MTX_DEF); 4179 } 4180 SYSINIT(select, SI_SUB_LOCK, SI_ORDER_FIRST, filelistinit, NULL); 4181 4182 /*-------------------------------------------------------------------*/ 4183 4184 static int 4185 badfo_readwrite(struct file *fp, struct uio *uio, struct ucred *active_cred, 4186 int flags, struct thread *td) 4187 { 4188 4189 return (EBADF); 4190 } 4191 4192 static int 4193 badfo_truncate(struct file *fp, off_t length, struct ucred *active_cred, 4194 struct thread *td) 4195 { 4196 4197 return (EINVAL); 4198 } 4199 4200 static int 4201 badfo_ioctl(struct file *fp, u_long com, void *data, struct ucred *active_cred, 4202 struct thread *td) 4203 { 4204 4205 return (EBADF); 4206 } 4207 4208 static int 4209 badfo_poll(struct file *fp, int events, struct ucred *active_cred, 4210 struct thread *td) 4211 { 4212 4213 return (0); 4214 } 4215 4216 static int 4217 badfo_kqfilter(struct file *fp, struct knote *kn) 4218 { 4219 4220 return (EBADF); 4221 } 4222 4223 static int 4224 badfo_stat(struct file *fp, struct stat *sb, struct ucred *active_cred, 4225 struct thread *td) 4226 { 4227 4228 return (EBADF); 4229 } 4230 4231 static int 4232 badfo_close(struct file *fp, struct thread *td) 4233 { 4234 4235 return (0); 4236 } 4237 4238 static int 4239 badfo_chmod(struct file *fp, mode_t mode, struct ucred *active_cred, 4240 struct thread *td) 4241 { 4242 4243 return (EBADF); 4244 } 4245 4246 static int 4247 badfo_chown(struct file *fp, uid_t uid, gid_t gid, struct ucred *active_cred, 4248 struct thread *td) 4249 { 4250 4251 return (EBADF); 4252 } 4253 4254 static int 4255 badfo_sendfile(struct file *fp, int sockfd, struct uio *hdr_uio, 4256 struct uio *trl_uio, off_t offset, size_t nbytes, off_t *sent, int flags, 4257 struct thread *td) 4258 { 4259 4260 return (EBADF); 4261 } 4262 4263 static int 4264 badfo_fill_kinfo(struct file *fp, struct kinfo_file *kif, struct filedesc *fdp) 4265 { 4266 4267 return (0); 4268 } 4269 4270 struct fileops badfileops = { 4271 .fo_read = badfo_readwrite, 4272 .fo_write = badfo_readwrite, 4273 .fo_truncate = badfo_truncate, 4274 .fo_ioctl = badfo_ioctl, 4275 .fo_poll = badfo_poll, 4276 .fo_kqfilter = badfo_kqfilter, 4277 .fo_stat = badfo_stat, 4278 .fo_close = badfo_close, 4279 .fo_chmod = badfo_chmod, 4280 .fo_chown = badfo_chown, 4281 .fo_sendfile = badfo_sendfile, 4282 .fo_fill_kinfo = badfo_fill_kinfo, 4283 }; 4284 4285 int 4286 invfo_rdwr(struct file *fp, struct uio *uio, struct ucred *active_cred, 4287 int flags, struct thread *td) 4288 { 4289 4290 return (EOPNOTSUPP); 4291 } 4292 4293 int 4294 invfo_truncate(struct file *fp, off_t length, struct ucred *active_cred, 4295 struct thread *td) 4296 { 4297 4298 return (EINVAL); 4299 } 4300 4301 int 4302 invfo_ioctl(struct file *fp, u_long com, void *data, 4303 struct ucred *active_cred, struct thread *td) 4304 { 4305 4306 return (ENOTTY); 4307 } 4308 4309 int 4310 invfo_poll(struct file *fp, int events, struct ucred *active_cred, 4311 struct thread *td) 4312 { 4313 4314 return (poll_no_poll(events)); 4315 } 4316 4317 int 4318 invfo_kqfilter(struct file *fp, struct knote *kn) 4319 { 4320 4321 return (EINVAL); 4322 } 4323 4324 int 4325 invfo_chmod(struct file *fp, mode_t mode, struct ucred *active_cred, 4326 struct thread *td) 4327 { 4328 4329 return (EINVAL); 4330 } 4331 4332 int 4333 invfo_chown(struct file *fp, uid_t uid, gid_t gid, struct ucred *active_cred, 4334 struct thread *td) 4335 { 4336 4337 return (EINVAL); 4338 } 4339 4340 int 4341 invfo_sendfile(struct file *fp, int sockfd, struct uio *hdr_uio, 4342 struct uio *trl_uio, off_t offset, size_t nbytes, off_t *sent, int flags, 4343 struct thread *td) 4344 { 4345 4346 return (EINVAL); 4347 } 4348 4349 /*-------------------------------------------------------------------*/ 4350 4351 /* 4352 * File Descriptor pseudo-device driver (/dev/fd/). 4353 * 4354 * Opening minor device N dup()s the file (if any) connected to file 4355 * descriptor N belonging to the calling process. Note that this driver 4356 * consists of only the ``open()'' routine, because all subsequent 4357 * references to this file will be direct to the other driver. 4358 * 4359 * XXX: we could give this one a cloning event handler if necessary. 4360 */ 4361 4362 /* ARGSUSED */ 4363 static int 4364 fdopen(struct cdev *dev, int mode, int type, struct thread *td) 4365 { 4366 4367 /* 4368 * XXX Kludge: set curthread->td_dupfd to contain the value of the 4369 * the file descriptor being sought for duplication. The error 4370 * return ensures that the vnode for this device will be released 4371 * by vn_open. Open will detect this special error and take the 4372 * actions in dupfdopen below. Other callers of vn_open or VOP_OPEN 4373 * will simply report the error. 4374 */ 4375 td->td_dupfd = dev2unit(dev); 4376 return (ENODEV); 4377 } 4378 4379 static struct cdevsw fildesc_cdevsw = { 4380 .d_version = D_VERSION, 4381 .d_open = fdopen, 4382 .d_name = "FD", 4383 }; 4384 4385 static void 4386 fildesc_drvinit(void *unused) 4387 { 4388 struct cdev *dev; 4389 4390 dev = make_dev_credf(MAKEDEV_ETERNAL, &fildesc_cdevsw, 0, NULL, 4391 UID_ROOT, GID_WHEEL, 0666, "fd/0"); 4392 make_dev_alias(dev, "stdin"); 4393 dev = make_dev_credf(MAKEDEV_ETERNAL, &fildesc_cdevsw, 1, NULL, 4394 UID_ROOT, GID_WHEEL, 0666, "fd/1"); 4395 make_dev_alias(dev, "stdout"); 4396 dev = make_dev_credf(MAKEDEV_ETERNAL, &fildesc_cdevsw, 2, NULL, 4397 UID_ROOT, GID_WHEEL, 0666, "fd/2"); 4398 make_dev_alias(dev, "stderr"); 4399 } 4400 4401 SYSINIT(fildescdev, SI_SUB_DRIVERS, SI_ORDER_MIDDLE, fildesc_drvinit, NULL); 4402