1 /*- 2 * Copyright (c) 1982, 1986, 1989, 1991, 1993 3 * The Regents of the University of California. All rights reserved. 4 * (c) UNIX System Laboratories, Inc. 5 * All or some portions of this file are derived from material licensed 6 * to the University of California by American Telephone and Telegraph 7 * Co. or Unix System Laboratories, Inc. and are reproduced herein with 8 * the permission of UNIX System Laboratories, Inc. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 4. Neither the name of the University nor the names of its contributors 19 * may be used to endorse or promote products derived from this software 20 * without specific prior written permission. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32 * SUCH DAMAGE. 33 * 34 * @(#)kern_descrip.c 8.6 (Berkeley) 4/19/94 35 */ 36 37 #include <sys/cdefs.h> 38 __FBSDID("$FreeBSD$"); 39 40 #include "opt_capsicum.h" 41 #include "opt_compat.h" 42 #include "opt_ddb.h" 43 #include "opt_ktrace.h" 44 45 #include <sys/param.h> 46 #include <sys/systm.h> 47 48 #include <sys/capsicum.h> 49 #include <sys/conf.h> 50 #include <sys/fcntl.h> 51 #include <sys/file.h> 52 #include <sys/filedesc.h> 53 #include <sys/filio.h> 54 #include <sys/jail.h> 55 #include <sys/kernel.h> 56 #include <sys/limits.h> 57 #include <sys/lock.h> 58 #include <sys/malloc.h> 59 #include <sys/mount.h> 60 #include <sys/mutex.h> 61 #include <sys/namei.h> 62 #include <sys/selinfo.h> 63 #include <sys/priv.h> 64 #include <sys/proc.h> 65 #include <sys/protosw.h> 66 #include <sys/racct.h> 67 #include <sys/resourcevar.h> 68 #include <sys/sbuf.h> 69 #include <sys/signalvar.h> 70 #include <sys/socketvar.h> 71 #include <sys/stat.h> 72 #include <sys/sx.h> 73 #include <sys/syscallsubr.h> 74 #include <sys/sysctl.h> 75 #include <sys/sysproto.h> 76 #include <sys/unistd.h> 77 #include <sys/user.h> 78 #include <sys/vnode.h> 79 #ifdef KTRACE 80 #include <sys/ktrace.h> 81 #endif 82 83 #include <net/vnet.h> 84 85 #include <security/audit/audit.h> 86 87 #include <vm/uma.h> 88 #include <vm/vm.h> 89 90 #include <ddb/ddb.h> 91 92 static MALLOC_DEFINE(M_FILEDESC, "filedesc", "Open file descriptor table"); 93 static MALLOC_DEFINE(M_FILEDESC_TO_LEADER, "filedesc_to_leader", 94 "file desc to leader structures"); 95 static MALLOC_DEFINE(M_SIGIO, "sigio", "sigio structures"); 96 MALLOC_DEFINE(M_FILECAPS, "filecaps", "descriptor capabilities"); 97 98 MALLOC_DECLARE(M_FADVISE); 99 100 static uma_zone_t file_zone; 101 102 static int closefp(struct filedesc *fdp, int fd, struct file *fp, 103 struct thread *td, int holdleaders); 104 static int do_dup(struct thread *td, int flags, int old, int new); 105 static int fd_first_free(struct filedesc *fdp, int low, int size); 106 static int fd_last_used(struct filedesc *fdp, int size); 107 static void fdgrowtable(struct filedesc *fdp, int nfd); 108 static void fdgrowtable_exp(struct filedesc *fdp, int nfd); 109 static void fdunused(struct filedesc *fdp, int fd); 110 static void fdused(struct filedesc *fdp, int fd); 111 static int getmaxfd(struct proc *p); 112 113 /* Flags for do_dup() */ 114 #define DUP_FIXED 0x1 /* Force fixed allocation. */ 115 #define DUP_FCNTL 0x2 /* fcntl()-style errors. */ 116 #define DUP_CLOEXEC 0x4 /* Atomically set FD_CLOEXEC. */ 117 118 /* 119 * Each process has: 120 * 121 * - An array of open file descriptors (fd_ofiles) 122 * - An array of file flags (fd_ofileflags) 123 * - A bitmap recording which descriptors are in use (fd_map) 124 * 125 * A process starts out with NDFILE descriptors. The value of NDFILE has 126 * been selected based the historical limit of 20 open files, and an 127 * assumption that the majority of processes, especially short-lived 128 * processes like shells, will never need more. 129 * 130 * If this initial allocation is exhausted, a larger descriptor table and 131 * map are allocated dynamically, and the pointers in the process's struct 132 * filedesc are updated to point to those. This is repeated every time 133 * the process runs out of file descriptors (provided it hasn't hit its 134 * resource limit). 135 * 136 * Since threads may hold references to individual descriptor table 137 * entries, the tables are never freed. Instead, they are placed on a 138 * linked list and freed only when the struct filedesc is released. 139 */ 140 #define NDFILE 20 141 #define NDSLOTSIZE sizeof(NDSLOTTYPE) 142 #define NDENTRIES (NDSLOTSIZE * __CHAR_BIT) 143 #define NDSLOT(x) ((x) / NDENTRIES) 144 #define NDBIT(x) ((NDSLOTTYPE)1 << ((x) % NDENTRIES)) 145 #define NDSLOTS(x) (((x) + NDENTRIES - 1) / NDENTRIES) 146 147 /* 148 * SLIST entry used to keep track of ofiles which must be reclaimed when 149 * the process exits. 150 */ 151 struct freetable { 152 struct fdescenttbl *ft_table; 153 SLIST_ENTRY(freetable) ft_next; 154 }; 155 156 /* 157 * Initial allocation: a filedesc structure + the head of SLIST used to 158 * keep track of old ofiles + enough space for NDFILE descriptors. 159 */ 160 161 struct fdescenttbl0 { 162 int fdt_nfiles; 163 struct filedescent fdt_ofiles[NDFILE]; 164 }; 165 166 struct filedesc0 { 167 struct filedesc fd_fd; 168 SLIST_HEAD(, freetable) fd_free; 169 struct fdescenttbl0 fd_dfiles; 170 NDSLOTTYPE fd_dmap[NDSLOTS(NDFILE)]; 171 }; 172 173 /* 174 * Descriptor management. 175 */ 176 volatile int openfiles; /* actual number of open files */ 177 struct mtx sigio_lock; /* mtx to protect pointers to sigio */ 178 void (*mq_fdclose)(struct thread *td, int fd, struct file *fp); 179 180 /* A mutex to protect the association between a proc and filedesc. */ 181 static struct mtx fdesc_mtx; 182 183 /* 184 * If low >= size, just return low. Otherwise find the first zero bit in the 185 * given bitmap, starting at low and not exceeding size - 1. Return size if 186 * not found. 187 */ 188 static int 189 fd_first_free(struct filedesc *fdp, int low, int size) 190 { 191 NDSLOTTYPE *map = fdp->fd_map; 192 NDSLOTTYPE mask; 193 int off, maxoff; 194 195 if (low >= size) 196 return (low); 197 198 off = NDSLOT(low); 199 if (low % NDENTRIES) { 200 mask = ~(~(NDSLOTTYPE)0 >> (NDENTRIES - (low % NDENTRIES))); 201 if ((mask &= ~map[off]) != 0UL) 202 return (off * NDENTRIES + ffsl(mask) - 1); 203 ++off; 204 } 205 for (maxoff = NDSLOTS(size); off < maxoff; ++off) 206 if (map[off] != ~0UL) 207 return (off * NDENTRIES + ffsl(~map[off]) - 1); 208 return (size); 209 } 210 211 /* 212 * Find the highest non-zero bit in the given bitmap, starting at 0 and 213 * not exceeding size - 1. Return -1 if not found. 214 */ 215 static int 216 fd_last_used(struct filedesc *fdp, int size) 217 { 218 NDSLOTTYPE *map = fdp->fd_map; 219 NDSLOTTYPE mask; 220 int off, minoff; 221 222 off = NDSLOT(size); 223 if (size % NDENTRIES) { 224 mask = ~(~(NDSLOTTYPE)0 << (size % NDENTRIES)); 225 if ((mask &= map[off]) != 0) 226 return (off * NDENTRIES + flsl(mask) - 1); 227 --off; 228 } 229 for (minoff = NDSLOT(0); off >= minoff; --off) 230 if (map[off] != 0) 231 return (off * NDENTRIES + flsl(map[off]) - 1); 232 return (-1); 233 } 234 235 #ifdef INVARIANTS 236 static int 237 fdisused(struct filedesc *fdp, int fd) 238 { 239 240 KASSERT(fd >= 0 && fd < fdp->fd_nfiles, 241 ("file descriptor %d out of range (0, %d)", fd, fdp->fd_nfiles)); 242 243 return ((fdp->fd_map[NDSLOT(fd)] & NDBIT(fd)) != 0); 244 } 245 #endif 246 247 /* 248 * Mark a file descriptor as used. 249 */ 250 static void 251 fdused_init(struct filedesc *fdp, int fd) 252 { 253 254 KASSERT(!fdisused(fdp, fd), ("fd=%d is already used", fd)); 255 256 fdp->fd_map[NDSLOT(fd)] |= NDBIT(fd); 257 } 258 259 static void 260 fdused(struct filedesc *fdp, int fd) 261 { 262 263 FILEDESC_XLOCK_ASSERT(fdp); 264 265 fdused_init(fdp, fd); 266 if (fd > fdp->fd_lastfile) 267 fdp->fd_lastfile = fd; 268 if (fd == fdp->fd_freefile) 269 fdp->fd_freefile = fd_first_free(fdp, fd, fdp->fd_nfiles); 270 } 271 272 /* 273 * Mark a file descriptor as unused. 274 */ 275 static void 276 fdunused(struct filedesc *fdp, int fd) 277 { 278 279 FILEDESC_XLOCK_ASSERT(fdp); 280 281 KASSERT(fdisused(fdp, fd), ("fd=%d is already unused", fd)); 282 KASSERT(fdp->fd_ofiles[fd].fde_file == NULL, 283 ("fd=%d is still in use", fd)); 284 285 fdp->fd_map[NDSLOT(fd)] &= ~NDBIT(fd); 286 if (fd < fdp->fd_freefile) 287 fdp->fd_freefile = fd; 288 if (fd == fdp->fd_lastfile) 289 fdp->fd_lastfile = fd_last_used(fdp, fd); 290 } 291 292 /* 293 * Free a file descriptor. 294 * 295 * Avoid some work if fdp is about to be destroyed. 296 */ 297 static inline void 298 fdefree_last(struct filedescent *fde) 299 { 300 301 filecaps_free(&fde->fde_caps); 302 } 303 304 static inline void 305 fdfree(struct filedesc *fdp, int fd) 306 { 307 struct filedescent *fde; 308 309 fde = &fdp->fd_ofiles[fd]; 310 #ifdef CAPABILITIES 311 seq_write_begin(&fde->fde_seq); 312 #endif 313 fdefree_last(fde); 314 bzero(fde, fde_change_size); 315 fdunused(fdp, fd); 316 #ifdef CAPABILITIES 317 seq_write_end(&fde->fde_seq); 318 #endif 319 } 320 321 /* 322 * System calls on descriptors. 323 */ 324 #ifndef _SYS_SYSPROTO_H_ 325 struct getdtablesize_args { 326 int dummy; 327 }; 328 #endif 329 /* ARGSUSED */ 330 int 331 sys_getdtablesize(struct thread *td, struct getdtablesize_args *uap) 332 { 333 struct proc *p = td->td_proc; 334 uint64_t lim; 335 336 PROC_LOCK(p); 337 td->td_retval[0] = 338 min((int)lim_cur(p, RLIMIT_NOFILE), maxfilesperproc); 339 lim = racct_get_limit(td->td_proc, RACCT_NOFILE); 340 PROC_UNLOCK(p); 341 if (lim < td->td_retval[0]) 342 td->td_retval[0] = lim; 343 return (0); 344 } 345 346 /* 347 * Duplicate a file descriptor to a particular value. 348 * 349 * Note: keep in mind that a potential race condition exists when closing 350 * descriptors from a shared descriptor table (via rfork). 351 */ 352 #ifndef _SYS_SYSPROTO_H_ 353 struct dup2_args { 354 u_int from; 355 u_int to; 356 }; 357 #endif 358 /* ARGSUSED */ 359 int 360 sys_dup2(struct thread *td, struct dup2_args *uap) 361 { 362 363 return (do_dup(td, DUP_FIXED, (int)uap->from, (int)uap->to)); 364 } 365 366 /* 367 * Duplicate a file descriptor. 368 */ 369 #ifndef _SYS_SYSPROTO_H_ 370 struct dup_args { 371 u_int fd; 372 }; 373 #endif 374 /* ARGSUSED */ 375 int 376 sys_dup(struct thread *td, struct dup_args *uap) 377 { 378 379 return (do_dup(td, 0, (int)uap->fd, 0)); 380 } 381 382 /* 383 * The file control system call. 384 */ 385 #ifndef _SYS_SYSPROTO_H_ 386 struct fcntl_args { 387 int fd; 388 int cmd; 389 long arg; 390 }; 391 #endif 392 /* ARGSUSED */ 393 int 394 sys_fcntl(struct thread *td, struct fcntl_args *uap) 395 { 396 397 return (kern_fcntl_freebsd(td, uap->fd, uap->cmd, uap->arg)); 398 } 399 400 int 401 kern_fcntl_freebsd(struct thread *td, int fd, int cmd, long arg) 402 { 403 struct flock fl; 404 struct __oflock ofl; 405 intptr_t arg1; 406 int error; 407 408 error = 0; 409 switch (cmd) { 410 case F_OGETLK: 411 case F_OSETLK: 412 case F_OSETLKW: 413 /* 414 * Convert old flock structure to new. 415 */ 416 error = copyin((void *)(intptr_t)arg, &ofl, sizeof(ofl)); 417 fl.l_start = ofl.l_start; 418 fl.l_len = ofl.l_len; 419 fl.l_pid = ofl.l_pid; 420 fl.l_type = ofl.l_type; 421 fl.l_whence = ofl.l_whence; 422 fl.l_sysid = 0; 423 424 switch (cmd) { 425 case F_OGETLK: 426 cmd = F_GETLK; 427 break; 428 case F_OSETLK: 429 cmd = F_SETLK; 430 break; 431 case F_OSETLKW: 432 cmd = F_SETLKW; 433 break; 434 } 435 arg1 = (intptr_t)&fl; 436 break; 437 case F_GETLK: 438 case F_SETLK: 439 case F_SETLKW: 440 case F_SETLK_REMOTE: 441 error = copyin((void *)(intptr_t)arg, &fl, sizeof(fl)); 442 arg1 = (intptr_t)&fl; 443 break; 444 default: 445 arg1 = arg; 446 break; 447 } 448 if (error) 449 return (error); 450 error = kern_fcntl(td, fd, cmd, arg1); 451 if (error) 452 return (error); 453 if (cmd == F_OGETLK) { 454 ofl.l_start = fl.l_start; 455 ofl.l_len = fl.l_len; 456 ofl.l_pid = fl.l_pid; 457 ofl.l_type = fl.l_type; 458 ofl.l_whence = fl.l_whence; 459 error = copyout(&ofl, (void *)(intptr_t)arg, sizeof(ofl)); 460 } else if (cmd == F_GETLK) { 461 error = copyout(&fl, (void *)(intptr_t)arg, sizeof(fl)); 462 } 463 return (error); 464 } 465 466 int 467 kern_fcntl(struct thread *td, int fd, int cmd, intptr_t arg) 468 { 469 struct filedesc *fdp; 470 struct flock *flp; 471 struct file *fp, *fp2; 472 struct filedescent *fde; 473 struct proc *p; 474 struct vnode *vp; 475 cap_rights_t rights; 476 int error, flg, tmp; 477 uint64_t bsize; 478 off_t foffset; 479 480 error = 0; 481 flg = F_POSIX; 482 p = td->td_proc; 483 fdp = p->p_fd; 484 485 switch (cmd) { 486 case F_DUPFD: 487 tmp = arg; 488 error = do_dup(td, DUP_FCNTL, fd, tmp); 489 break; 490 491 case F_DUPFD_CLOEXEC: 492 tmp = arg; 493 error = do_dup(td, DUP_FCNTL | DUP_CLOEXEC, fd, tmp); 494 break; 495 496 case F_DUP2FD: 497 tmp = arg; 498 error = do_dup(td, DUP_FIXED, fd, tmp); 499 break; 500 501 case F_DUP2FD_CLOEXEC: 502 tmp = arg; 503 error = do_dup(td, DUP_FIXED | DUP_CLOEXEC, fd, tmp); 504 break; 505 506 case F_GETFD: 507 FILEDESC_SLOCK(fdp); 508 if (fget_locked(fdp, fd) == NULL) { 509 FILEDESC_SUNLOCK(fdp); 510 error = EBADF; 511 break; 512 } 513 fde = &fdp->fd_ofiles[fd]; 514 td->td_retval[0] = 515 (fde->fde_flags & UF_EXCLOSE) ? FD_CLOEXEC : 0; 516 FILEDESC_SUNLOCK(fdp); 517 break; 518 519 case F_SETFD: 520 FILEDESC_XLOCK(fdp); 521 if (fget_locked(fdp, fd) == NULL) { 522 FILEDESC_XUNLOCK(fdp); 523 error = EBADF; 524 break; 525 } 526 fde = &fdp->fd_ofiles[fd]; 527 fde->fde_flags = (fde->fde_flags & ~UF_EXCLOSE) | 528 (arg & FD_CLOEXEC ? UF_EXCLOSE : 0); 529 FILEDESC_XUNLOCK(fdp); 530 break; 531 532 case F_GETFL: 533 error = fget_unlocked(fdp, fd, 534 cap_rights_init(&rights, CAP_FCNTL), F_GETFL, &fp, NULL); 535 if (error != 0) 536 break; 537 td->td_retval[0] = OFLAGS(fp->f_flag); 538 fdrop(fp, td); 539 break; 540 541 case F_SETFL: 542 error = fget_unlocked(fdp, fd, 543 cap_rights_init(&rights, CAP_FCNTL), F_SETFL, &fp, NULL); 544 if (error != 0) 545 break; 546 do { 547 tmp = flg = fp->f_flag; 548 tmp &= ~FCNTLFLAGS; 549 tmp |= FFLAGS(arg & ~O_ACCMODE) & FCNTLFLAGS; 550 } while(atomic_cmpset_int(&fp->f_flag, flg, tmp) == 0); 551 tmp = fp->f_flag & FNONBLOCK; 552 error = fo_ioctl(fp, FIONBIO, &tmp, td->td_ucred, td); 553 if (error != 0) { 554 fdrop(fp, td); 555 break; 556 } 557 tmp = fp->f_flag & FASYNC; 558 error = fo_ioctl(fp, FIOASYNC, &tmp, td->td_ucred, td); 559 if (error == 0) { 560 fdrop(fp, td); 561 break; 562 } 563 atomic_clear_int(&fp->f_flag, FNONBLOCK); 564 tmp = 0; 565 (void)fo_ioctl(fp, FIONBIO, &tmp, td->td_ucred, td); 566 fdrop(fp, td); 567 break; 568 569 case F_GETOWN: 570 error = fget_unlocked(fdp, fd, 571 cap_rights_init(&rights, CAP_FCNTL), F_GETOWN, &fp, NULL); 572 if (error != 0) 573 break; 574 error = fo_ioctl(fp, FIOGETOWN, &tmp, td->td_ucred, td); 575 if (error == 0) 576 td->td_retval[0] = tmp; 577 fdrop(fp, td); 578 break; 579 580 case F_SETOWN: 581 error = fget_unlocked(fdp, fd, 582 cap_rights_init(&rights, CAP_FCNTL), F_SETOWN, &fp, NULL); 583 if (error != 0) 584 break; 585 tmp = arg; 586 error = fo_ioctl(fp, FIOSETOWN, &tmp, td->td_ucred, td); 587 fdrop(fp, td); 588 break; 589 590 case F_SETLK_REMOTE: 591 error = priv_check(td, PRIV_NFS_LOCKD); 592 if (error) 593 return (error); 594 flg = F_REMOTE; 595 goto do_setlk; 596 597 case F_SETLKW: 598 flg |= F_WAIT; 599 /* FALLTHROUGH F_SETLK */ 600 601 case F_SETLK: 602 do_setlk: 603 cap_rights_init(&rights, CAP_FLOCK); 604 error = fget_unlocked(fdp, fd, &rights, 0, &fp, NULL); 605 if (error != 0) 606 break; 607 if (fp->f_type != DTYPE_VNODE) { 608 error = EBADF; 609 fdrop(fp, td); 610 break; 611 } 612 613 flp = (struct flock *)arg; 614 if (flp->l_whence == SEEK_CUR) { 615 foffset = foffset_get(fp); 616 if (foffset < 0 || 617 (flp->l_start > 0 && 618 foffset > OFF_MAX - flp->l_start)) { 619 FILEDESC_SUNLOCK(fdp); 620 error = EOVERFLOW; 621 fdrop(fp, td); 622 break; 623 } 624 flp->l_start += foffset; 625 } 626 627 vp = fp->f_vnode; 628 switch (flp->l_type) { 629 case F_RDLCK: 630 if ((fp->f_flag & FREAD) == 0) { 631 error = EBADF; 632 break; 633 } 634 PROC_LOCK(p->p_leader); 635 p->p_leader->p_flag |= P_ADVLOCK; 636 PROC_UNLOCK(p->p_leader); 637 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_SETLK, 638 flp, flg); 639 break; 640 case F_WRLCK: 641 if ((fp->f_flag & FWRITE) == 0) { 642 error = EBADF; 643 break; 644 } 645 PROC_LOCK(p->p_leader); 646 p->p_leader->p_flag |= P_ADVLOCK; 647 PROC_UNLOCK(p->p_leader); 648 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_SETLK, 649 flp, flg); 650 break; 651 case F_UNLCK: 652 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_UNLCK, 653 flp, flg); 654 break; 655 case F_UNLCKSYS: 656 /* 657 * Temporary api for testing remote lock 658 * infrastructure. 659 */ 660 if (flg != F_REMOTE) { 661 error = EINVAL; 662 break; 663 } 664 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, 665 F_UNLCKSYS, flp, flg); 666 break; 667 default: 668 error = EINVAL; 669 break; 670 } 671 if (error != 0 || flp->l_type == F_UNLCK || 672 flp->l_type == F_UNLCKSYS) { 673 fdrop(fp, td); 674 break; 675 } 676 677 /* 678 * Check for a race with close. 679 * 680 * The vnode is now advisory locked (or unlocked, but this case 681 * is not really important) as the caller requested. 682 * We had to drop the filedesc lock, so we need to recheck if 683 * the descriptor is still valid, because if it was closed 684 * in the meantime we need to remove advisory lock from the 685 * vnode - close on any descriptor leading to an advisory 686 * locked vnode, removes that lock. 687 * We will return 0 on purpose in that case, as the result of 688 * successful advisory lock might have been externally visible 689 * already. This is fine - effectively we pretend to the caller 690 * that the closing thread was a bit slower and that the 691 * advisory lock succeeded before the close. 692 */ 693 error = fget_unlocked(fdp, fd, &rights, 0, &fp2, NULL); 694 if (error != 0) { 695 fdrop(fp, td); 696 break; 697 } 698 if (fp != fp2) { 699 flp->l_whence = SEEK_SET; 700 flp->l_start = 0; 701 flp->l_len = 0; 702 flp->l_type = F_UNLCK; 703 (void) VOP_ADVLOCK(vp, (caddr_t)p->p_leader, 704 F_UNLCK, flp, F_POSIX); 705 } 706 fdrop(fp, td); 707 fdrop(fp2, td); 708 break; 709 710 case F_GETLK: 711 error = fget_unlocked(fdp, fd, 712 cap_rights_init(&rights, CAP_FLOCK), 0, &fp, NULL); 713 if (error != 0) 714 break; 715 if (fp->f_type != DTYPE_VNODE) { 716 error = EBADF; 717 fdrop(fp, td); 718 break; 719 } 720 flp = (struct flock *)arg; 721 if (flp->l_type != F_RDLCK && flp->l_type != F_WRLCK && 722 flp->l_type != F_UNLCK) { 723 error = EINVAL; 724 fdrop(fp, td); 725 break; 726 } 727 if (flp->l_whence == SEEK_CUR) { 728 foffset = foffset_get(fp); 729 if ((flp->l_start > 0 && 730 foffset > OFF_MAX - flp->l_start) || 731 (flp->l_start < 0 && 732 foffset < OFF_MIN - flp->l_start)) { 733 FILEDESC_SUNLOCK(fdp); 734 error = EOVERFLOW; 735 fdrop(fp, td); 736 break; 737 } 738 flp->l_start += foffset; 739 } 740 vp = fp->f_vnode; 741 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_GETLK, flp, 742 F_POSIX); 743 fdrop(fp, td); 744 break; 745 746 case F_RDAHEAD: 747 arg = arg ? 128 * 1024: 0; 748 /* FALLTHROUGH */ 749 case F_READAHEAD: 750 error = fget_unlocked(fdp, fd, NULL, 0, &fp, NULL); 751 if (error != 0) 752 break; 753 if (fp->f_type != DTYPE_VNODE) { 754 fdrop(fp, td); 755 error = EBADF; 756 break; 757 } 758 vp = fp->f_vnode; 759 /* 760 * Exclusive lock synchronizes against f_seqcount reads and 761 * writes in sequential_heuristic(). 762 */ 763 error = vn_lock(vp, LK_EXCLUSIVE); 764 if (error != 0) { 765 fdrop(fp, td); 766 break; 767 } 768 if (arg >= 0) { 769 bsize = fp->f_vnode->v_mount->mnt_stat.f_iosize; 770 fp->f_seqcount = (arg + bsize - 1) / bsize; 771 atomic_set_int(&fp->f_flag, FRDAHEAD); 772 } else { 773 atomic_clear_int(&fp->f_flag, FRDAHEAD); 774 } 775 VOP_UNLOCK(vp, 0); 776 fdrop(fp, td); 777 break; 778 779 default: 780 error = EINVAL; 781 break; 782 } 783 return (error); 784 } 785 786 static int 787 getmaxfd(struct proc *p) 788 { 789 int maxfd; 790 791 PROC_LOCK(p); 792 maxfd = min((int)lim_cur(p, RLIMIT_NOFILE), maxfilesperproc); 793 PROC_UNLOCK(p); 794 795 return (maxfd); 796 } 797 798 /* 799 * Common code for dup, dup2, fcntl(F_DUPFD) and fcntl(F_DUP2FD). 800 */ 801 static int 802 do_dup(struct thread *td, int flags, int old, int new) 803 { 804 struct filedesc *fdp; 805 struct filedescent *oldfde, *newfde; 806 struct proc *p; 807 struct file *fp; 808 struct file *delfp; 809 int error, maxfd; 810 811 p = td->td_proc; 812 fdp = p->p_fd; 813 814 /* 815 * Verify we have a valid descriptor to dup from and possibly to 816 * dup to. Unlike dup() and dup2(), fcntl()'s F_DUPFD should 817 * return EINVAL when the new descriptor is out of bounds. 818 */ 819 if (old < 0) 820 return (EBADF); 821 if (new < 0) 822 return (flags & DUP_FCNTL ? EINVAL : EBADF); 823 maxfd = getmaxfd(p); 824 if (new >= maxfd) 825 return (flags & DUP_FCNTL ? EINVAL : EBADF); 826 827 FILEDESC_XLOCK(fdp); 828 if (fget_locked(fdp, old) == NULL) { 829 FILEDESC_XUNLOCK(fdp); 830 return (EBADF); 831 } 832 oldfde = &fdp->fd_ofiles[old]; 833 if (flags & DUP_FIXED && old == new) { 834 td->td_retval[0] = new; 835 if (flags & DUP_CLOEXEC) 836 fdp->fd_ofiles[new].fde_flags |= UF_EXCLOSE; 837 FILEDESC_XUNLOCK(fdp); 838 return (0); 839 } 840 fp = oldfde->fde_file; 841 fhold(fp); 842 843 /* 844 * If the caller specified a file descriptor, make sure the file 845 * table is large enough to hold it, and grab it. Otherwise, just 846 * allocate a new descriptor the usual way. 847 */ 848 if (flags & DUP_FIXED) { 849 if (new >= fdp->fd_nfiles) { 850 /* 851 * The resource limits are here instead of e.g. 852 * fdalloc(), because the file descriptor table may be 853 * shared between processes, so we can't really use 854 * racct_add()/racct_sub(). Instead of counting the 855 * number of actually allocated descriptors, just put 856 * the limit on the size of the file descriptor table. 857 */ 858 #ifdef RACCT 859 PROC_LOCK(p); 860 error = racct_set(p, RACCT_NOFILE, new + 1); 861 PROC_UNLOCK(p); 862 if (error != 0) { 863 FILEDESC_XUNLOCK(fdp); 864 fdrop(fp, td); 865 return (EMFILE); 866 } 867 #endif 868 fdgrowtable_exp(fdp, new + 1); 869 oldfde = &fdp->fd_ofiles[old]; 870 } 871 newfde = &fdp->fd_ofiles[new]; 872 if (newfde->fde_file == NULL) 873 fdused(fdp, new); 874 } else { 875 if ((error = fdalloc(td, new, &new)) != 0) { 876 FILEDESC_XUNLOCK(fdp); 877 fdrop(fp, td); 878 return (error); 879 } 880 newfde = &fdp->fd_ofiles[new]; 881 } 882 883 KASSERT(fp == oldfde->fde_file, ("old fd has been modified")); 884 KASSERT(old != new, ("new fd is same as old")); 885 886 delfp = newfde->fde_file; 887 888 /* 889 * Duplicate the source descriptor. 890 */ 891 #ifdef CAPABILITIES 892 seq_write_begin(&newfde->fde_seq); 893 #endif 894 filecaps_free(&newfde->fde_caps); 895 memcpy(newfde, oldfde, fde_change_size); 896 filecaps_copy(&oldfde->fde_caps, &newfde->fde_caps); 897 if ((flags & DUP_CLOEXEC) != 0) 898 newfde->fde_flags = oldfde->fde_flags | UF_EXCLOSE; 899 else 900 newfde->fde_flags = oldfde->fde_flags & ~UF_EXCLOSE; 901 #ifdef CAPABILITIES 902 seq_write_end(&newfde->fde_seq); 903 #endif 904 td->td_retval[0] = new; 905 906 if (delfp != NULL) { 907 (void) closefp(fdp, new, delfp, td, 1); 908 /* closefp() drops the FILEDESC lock for us. */ 909 } else { 910 FILEDESC_XUNLOCK(fdp); 911 } 912 913 return (0); 914 } 915 916 /* 917 * If sigio is on the list associated with a process or process group, 918 * disable signalling from the device, remove sigio from the list and 919 * free sigio. 920 */ 921 void 922 funsetown(struct sigio **sigiop) 923 { 924 struct sigio *sigio; 925 926 SIGIO_LOCK(); 927 sigio = *sigiop; 928 if (sigio == NULL) { 929 SIGIO_UNLOCK(); 930 return; 931 } 932 *(sigio->sio_myref) = NULL; 933 if ((sigio)->sio_pgid < 0) { 934 struct pgrp *pg = (sigio)->sio_pgrp; 935 PGRP_LOCK(pg); 936 SLIST_REMOVE(&sigio->sio_pgrp->pg_sigiolst, sigio, 937 sigio, sio_pgsigio); 938 PGRP_UNLOCK(pg); 939 } else { 940 struct proc *p = (sigio)->sio_proc; 941 PROC_LOCK(p); 942 SLIST_REMOVE(&sigio->sio_proc->p_sigiolst, sigio, 943 sigio, sio_pgsigio); 944 PROC_UNLOCK(p); 945 } 946 SIGIO_UNLOCK(); 947 crfree(sigio->sio_ucred); 948 free(sigio, M_SIGIO); 949 } 950 951 /* 952 * Free a list of sigio structures. 953 * We only need to lock the SIGIO_LOCK because we have made ourselves 954 * inaccessible to callers of fsetown and therefore do not need to lock 955 * the proc or pgrp struct for the list manipulation. 956 */ 957 void 958 funsetownlst(struct sigiolst *sigiolst) 959 { 960 struct proc *p; 961 struct pgrp *pg; 962 struct sigio *sigio; 963 964 sigio = SLIST_FIRST(sigiolst); 965 if (sigio == NULL) 966 return; 967 p = NULL; 968 pg = NULL; 969 970 /* 971 * Every entry of the list should belong 972 * to a single proc or pgrp. 973 */ 974 if (sigio->sio_pgid < 0) { 975 pg = sigio->sio_pgrp; 976 PGRP_LOCK_ASSERT(pg, MA_NOTOWNED); 977 } else /* if (sigio->sio_pgid > 0) */ { 978 p = sigio->sio_proc; 979 PROC_LOCK_ASSERT(p, MA_NOTOWNED); 980 } 981 982 SIGIO_LOCK(); 983 while ((sigio = SLIST_FIRST(sigiolst)) != NULL) { 984 *(sigio->sio_myref) = NULL; 985 if (pg != NULL) { 986 KASSERT(sigio->sio_pgid < 0, 987 ("Proc sigio in pgrp sigio list")); 988 KASSERT(sigio->sio_pgrp == pg, 989 ("Bogus pgrp in sigio list")); 990 PGRP_LOCK(pg); 991 SLIST_REMOVE(&pg->pg_sigiolst, sigio, sigio, 992 sio_pgsigio); 993 PGRP_UNLOCK(pg); 994 } else /* if (p != NULL) */ { 995 KASSERT(sigio->sio_pgid > 0, 996 ("Pgrp sigio in proc sigio list")); 997 KASSERT(sigio->sio_proc == p, 998 ("Bogus proc in sigio list")); 999 PROC_LOCK(p); 1000 SLIST_REMOVE(&p->p_sigiolst, sigio, sigio, 1001 sio_pgsigio); 1002 PROC_UNLOCK(p); 1003 } 1004 SIGIO_UNLOCK(); 1005 crfree(sigio->sio_ucred); 1006 free(sigio, M_SIGIO); 1007 SIGIO_LOCK(); 1008 } 1009 SIGIO_UNLOCK(); 1010 } 1011 1012 /* 1013 * This is common code for FIOSETOWN ioctl called by fcntl(fd, F_SETOWN, arg). 1014 * 1015 * After permission checking, add a sigio structure to the sigio list for 1016 * the process or process group. 1017 */ 1018 int 1019 fsetown(pid_t pgid, struct sigio **sigiop) 1020 { 1021 struct proc *proc; 1022 struct pgrp *pgrp; 1023 struct sigio *sigio; 1024 int ret; 1025 1026 if (pgid == 0) { 1027 funsetown(sigiop); 1028 return (0); 1029 } 1030 1031 ret = 0; 1032 1033 /* Allocate and fill in the new sigio out of locks. */ 1034 sigio = malloc(sizeof(struct sigio), M_SIGIO, M_WAITOK); 1035 sigio->sio_pgid = pgid; 1036 sigio->sio_ucred = crhold(curthread->td_ucred); 1037 sigio->sio_myref = sigiop; 1038 1039 sx_slock(&proctree_lock); 1040 if (pgid > 0) { 1041 proc = pfind(pgid); 1042 if (proc == NULL) { 1043 ret = ESRCH; 1044 goto fail; 1045 } 1046 1047 /* 1048 * Policy - Don't allow a process to FSETOWN a process 1049 * in another session. 1050 * 1051 * Remove this test to allow maximum flexibility or 1052 * restrict FSETOWN to the current process or process 1053 * group for maximum safety. 1054 */ 1055 PROC_UNLOCK(proc); 1056 if (proc->p_session != curthread->td_proc->p_session) { 1057 ret = EPERM; 1058 goto fail; 1059 } 1060 1061 pgrp = NULL; 1062 } else /* if (pgid < 0) */ { 1063 pgrp = pgfind(-pgid); 1064 if (pgrp == NULL) { 1065 ret = ESRCH; 1066 goto fail; 1067 } 1068 PGRP_UNLOCK(pgrp); 1069 1070 /* 1071 * Policy - Don't allow a process to FSETOWN a process 1072 * in another session. 1073 * 1074 * Remove this test to allow maximum flexibility or 1075 * restrict FSETOWN to the current process or process 1076 * group for maximum safety. 1077 */ 1078 if (pgrp->pg_session != curthread->td_proc->p_session) { 1079 ret = EPERM; 1080 goto fail; 1081 } 1082 1083 proc = NULL; 1084 } 1085 funsetown(sigiop); 1086 if (pgid > 0) { 1087 PROC_LOCK(proc); 1088 /* 1089 * Since funsetownlst() is called without the proctree 1090 * locked, we need to check for P_WEXIT. 1091 * XXX: is ESRCH correct? 1092 */ 1093 if ((proc->p_flag & P_WEXIT) != 0) { 1094 PROC_UNLOCK(proc); 1095 ret = ESRCH; 1096 goto fail; 1097 } 1098 SLIST_INSERT_HEAD(&proc->p_sigiolst, sigio, sio_pgsigio); 1099 sigio->sio_proc = proc; 1100 PROC_UNLOCK(proc); 1101 } else { 1102 PGRP_LOCK(pgrp); 1103 SLIST_INSERT_HEAD(&pgrp->pg_sigiolst, sigio, sio_pgsigio); 1104 sigio->sio_pgrp = pgrp; 1105 PGRP_UNLOCK(pgrp); 1106 } 1107 sx_sunlock(&proctree_lock); 1108 SIGIO_LOCK(); 1109 *sigiop = sigio; 1110 SIGIO_UNLOCK(); 1111 return (0); 1112 1113 fail: 1114 sx_sunlock(&proctree_lock); 1115 crfree(sigio->sio_ucred); 1116 free(sigio, M_SIGIO); 1117 return (ret); 1118 } 1119 1120 /* 1121 * This is common code for FIOGETOWN ioctl called by fcntl(fd, F_GETOWN, arg). 1122 */ 1123 pid_t 1124 fgetown(sigiop) 1125 struct sigio **sigiop; 1126 { 1127 pid_t pgid; 1128 1129 SIGIO_LOCK(); 1130 pgid = (*sigiop != NULL) ? (*sigiop)->sio_pgid : 0; 1131 SIGIO_UNLOCK(); 1132 return (pgid); 1133 } 1134 1135 /* 1136 * Function drops the filedesc lock on return. 1137 */ 1138 static int 1139 closefp(struct filedesc *fdp, int fd, struct file *fp, struct thread *td, 1140 int holdleaders) 1141 { 1142 int error; 1143 1144 FILEDESC_XLOCK_ASSERT(fdp); 1145 1146 if (holdleaders) { 1147 if (td->td_proc->p_fdtol != NULL) { 1148 /* 1149 * Ask fdfree() to sleep to ensure that all relevant 1150 * process leaders can be traversed in closef(). 1151 */ 1152 fdp->fd_holdleaderscount++; 1153 } else { 1154 holdleaders = 0; 1155 } 1156 } 1157 1158 /* 1159 * We now hold the fp reference that used to be owned by the 1160 * descriptor array. We have to unlock the FILEDESC *AFTER* 1161 * knote_fdclose to prevent a race of the fd getting opened, a knote 1162 * added, and deleteing a knote for the new fd. 1163 */ 1164 knote_fdclose(td, fd); 1165 1166 /* 1167 * We need to notify mqueue if the object is of type mqueue. 1168 */ 1169 if (fp->f_type == DTYPE_MQUEUE) 1170 mq_fdclose(td, fd, fp); 1171 FILEDESC_XUNLOCK(fdp); 1172 1173 error = closef(fp, td); 1174 if (holdleaders) { 1175 FILEDESC_XLOCK(fdp); 1176 fdp->fd_holdleaderscount--; 1177 if (fdp->fd_holdleaderscount == 0 && 1178 fdp->fd_holdleaderswakeup != 0) { 1179 fdp->fd_holdleaderswakeup = 0; 1180 wakeup(&fdp->fd_holdleaderscount); 1181 } 1182 FILEDESC_XUNLOCK(fdp); 1183 } 1184 return (error); 1185 } 1186 1187 /* 1188 * Close a file descriptor. 1189 */ 1190 #ifndef _SYS_SYSPROTO_H_ 1191 struct close_args { 1192 int fd; 1193 }; 1194 #endif 1195 /* ARGSUSED */ 1196 int 1197 sys_close(td, uap) 1198 struct thread *td; 1199 struct close_args *uap; 1200 { 1201 1202 return (kern_close(td, uap->fd)); 1203 } 1204 1205 int 1206 kern_close(td, fd) 1207 struct thread *td; 1208 int fd; 1209 { 1210 struct filedesc *fdp; 1211 struct file *fp; 1212 1213 fdp = td->td_proc->p_fd; 1214 1215 AUDIT_SYSCLOSE(td, fd); 1216 1217 FILEDESC_XLOCK(fdp); 1218 if ((fp = fget_locked(fdp, fd)) == NULL) { 1219 FILEDESC_XUNLOCK(fdp); 1220 return (EBADF); 1221 } 1222 fdfree(fdp, fd); 1223 1224 /* closefp() drops the FILEDESC lock for us. */ 1225 return (closefp(fdp, fd, fp, td, 1)); 1226 } 1227 1228 /* 1229 * Close open file descriptors. 1230 */ 1231 #ifndef _SYS_SYSPROTO_H_ 1232 struct closefrom_args { 1233 int lowfd; 1234 }; 1235 #endif 1236 /* ARGSUSED */ 1237 int 1238 sys_closefrom(struct thread *td, struct closefrom_args *uap) 1239 { 1240 struct filedesc *fdp; 1241 int fd; 1242 1243 fdp = td->td_proc->p_fd; 1244 AUDIT_ARG_FD(uap->lowfd); 1245 1246 /* 1247 * Treat negative starting file descriptor values identical to 1248 * closefrom(0) which closes all files. 1249 */ 1250 if (uap->lowfd < 0) 1251 uap->lowfd = 0; 1252 FILEDESC_SLOCK(fdp); 1253 for (fd = uap->lowfd; fd <= fdp->fd_lastfile; fd++) { 1254 if (fdp->fd_ofiles[fd].fde_file != NULL) { 1255 FILEDESC_SUNLOCK(fdp); 1256 (void)kern_close(td, fd); 1257 FILEDESC_SLOCK(fdp); 1258 } 1259 } 1260 FILEDESC_SUNLOCK(fdp); 1261 return (0); 1262 } 1263 1264 #if defined(COMPAT_43) 1265 /* 1266 * Return status information about a file descriptor. 1267 */ 1268 #ifndef _SYS_SYSPROTO_H_ 1269 struct ofstat_args { 1270 int fd; 1271 struct ostat *sb; 1272 }; 1273 #endif 1274 /* ARGSUSED */ 1275 int 1276 ofstat(struct thread *td, struct ofstat_args *uap) 1277 { 1278 struct ostat oub; 1279 struct stat ub; 1280 int error; 1281 1282 error = kern_fstat(td, uap->fd, &ub); 1283 if (error == 0) { 1284 cvtstat(&ub, &oub); 1285 error = copyout(&oub, uap->sb, sizeof(oub)); 1286 } 1287 return (error); 1288 } 1289 #endif /* COMPAT_43 */ 1290 1291 /* 1292 * Return status information about a file descriptor. 1293 */ 1294 #ifndef _SYS_SYSPROTO_H_ 1295 struct fstat_args { 1296 int fd; 1297 struct stat *sb; 1298 }; 1299 #endif 1300 /* ARGSUSED */ 1301 int 1302 sys_fstat(struct thread *td, struct fstat_args *uap) 1303 { 1304 struct stat ub; 1305 int error; 1306 1307 error = kern_fstat(td, uap->fd, &ub); 1308 if (error == 0) 1309 error = copyout(&ub, uap->sb, sizeof(ub)); 1310 return (error); 1311 } 1312 1313 int 1314 kern_fstat(struct thread *td, int fd, struct stat *sbp) 1315 { 1316 struct file *fp; 1317 cap_rights_t rights; 1318 int error; 1319 1320 AUDIT_ARG_FD(fd); 1321 1322 error = fget(td, fd, cap_rights_init(&rights, CAP_FSTAT), &fp); 1323 if (error != 0) 1324 return (error); 1325 1326 AUDIT_ARG_FILE(td->td_proc, fp); 1327 1328 error = fo_stat(fp, sbp, td->td_ucred, td); 1329 fdrop(fp, td); 1330 #ifdef KTRACE 1331 if (error == 0 && KTRPOINT(td, KTR_STRUCT)) 1332 ktrstat(sbp); 1333 #endif 1334 return (error); 1335 } 1336 1337 /* 1338 * Return status information about a file descriptor. 1339 */ 1340 #ifndef _SYS_SYSPROTO_H_ 1341 struct nfstat_args { 1342 int fd; 1343 struct nstat *sb; 1344 }; 1345 #endif 1346 /* ARGSUSED */ 1347 int 1348 sys_nfstat(struct thread *td, struct nfstat_args *uap) 1349 { 1350 struct nstat nub; 1351 struct stat ub; 1352 int error; 1353 1354 error = kern_fstat(td, uap->fd, &ub); 1355 if (error == 0) { 1356 cvtnstat(&ub, &nub); 1357 error = copyout(&nub, uap->sb, sizeof(nub)); 1358 } 1359 return (error); 1360 } 1361 1362 /* 1363 * Return pathconf information about a file descriptor. 1364 */ 1365 #ifndef _SYS_SYSPROTO_H_ 1366 struct fpathconf_args { 1367 int fd; 1368 int name; 1369 }; 1370 #endif 1371 /* ARGSUSED */ 1372 int 1373 sys_fpathconf(struct thread *td, struct fpathconf_args *uap) 1374 { 1375 struct file *fp; 1376 struct vnode *vp; 1377 cap_rights_t rights; 1378 int error; 1379 1380 error = fget(td, uap->fd, cap_rights_init(&rights, CAP_FPATHCONF), &fp); 1381 if (error != 0) 1382 return (error); 1383 1384 /* If asynchronous I/O is available, it works for all descriptors. */ 1385 if (uap->name == _PC_ASYNC_IO) { 1386 td->td_retval[0] = async_io_version; 1387 goto out; 1388 } 1389 vp = fp->f_vnode; 1390 if (vp != NULL) { 1391 vn_lock(vp, LK_SHARED | LK_RETRY); 1392 error = VOP_PATHCONF(vp, uap->name, td->td_retval); 1393 VOP_UNLOCK(vp, 0); 1394 } else if (fp->f_type == DTYPE_PIPE || fp->f_type == DTYPE_SOCKET) { 1395 if (uap->name != _PC_PIPE_BUF) { 1396 error = EINVAL; 1397 } else { 1398 td->td_retval[0] = PIPE_BUF; 1399 error = 0; 1400 } 1401 } else { 1402 error = EOPNOTSUPP; 1403 } 1404 out: 1405 fdrop(fp, td); 1406 return (error); 1407 } 1408 1409 /* 1410 * Initialize filecaps structure. 1411 */ 1412 void 1413 filecaps_init(struct filecaps *fcaps) 1414 { 1415 1416 bzero(fcaps, sizeof(*fcaps)); 1417 fcaps->fc_nioctls = -1; 1418 } 1419 1420 /* 1421 * Copy filecaps structure allocating memory for ioctls array if needed. 1422 */ 1423 void 1424 filecaps_copy(const struct filecaps *src, struct filecaps *dst) 1425 { 1426 size_t size; 1427 1428 *dst = *src; 1429 if (src->fc_ioctls != NULL) { 1430 KASSERT(src->fc_nioctls > 0, 1431 ("fc_ioctls != NULL, but fc_nioctls=%hd", src->fc_nioctls)); 1432 1433 size = sizeof(src->fc_ioctls[0]) * src->fc_nioctls; 1434 dst->fc_ioctls = malloc(size, M_FILECAPS, M_WAITOK); 1435 bcopy(src->fc_ioctls, dst->fc_ioctls, size); 1436 } 1437 } 1438 1439 /* 1440 * Move filecaps structure to the new place and clear the old place. 1441 */ 1442 void 1443 filecaps_move(struct filecaps *src, struct filecaps *dst) 1444 { 1445 1446 *dst = *src; 1447 bzero(src, sizeof(*src)); 1448 } 1449 1450 /* 1451 * Fill the given filecaps structure with full rights. 1452 */ 1453 static void 1454 filecaps_fill(struct filecaps *fcaps) 1455 { 1456 1457 CAP_ALL(&fcaps->fc_rights); 1458 fcaps->fc_ioctls = NULL; 1459 fcaps->fc_nioctls = -1; 1460 fcaps->fc_fcntls = CAP_FCNTL_ALL; 1461 } 1462 1463 /* 1464 * Free memory allocated within filecaps structure. 1465 */ 1466 void 1467 filecaps_free(struct filecaps *fcaps) 1468 { 1469 1470 free(fcaps->fc_ioctls, M_FILECAPS); 1471 bzero(fcaps, sizeof(*fcaps)); 1472 } 1473 1474 /* 1475 * Validate the given filecaps structure. 1476 */ 1477 static void 1478 filecaps_validate(const struct filecaps *fcaps, const char *func) 1479 { 1480 1481 KASSERT(cap_rights_is_valid(&fcaps->fc_rights), 1482 ("%s: invalid rights", func)); 1483 KASSERT((fcaps->fc_fcntls & ~CAP_FCNTL_ALL) == 0, 1484 ("%s: invalid fcntls", func)); 1485 KASSERT(fcaps->fc_fcntls == 0 || 1486 cap_rights_is_set(&fcaps->fc_rights, CAP_FCNTL), 1487 ("%s: fcntls without CAP_FCNTL", func)); 1488 KASSERT(fcaps->fc_ioctls != NULL ? fcaps->fc_nioctls > 0 : 1489 (fcaps->fc_nioctls == -1 || fcaps->fc_nioctls == 0), 1490 ("%s: invalid ioctls", func)); 1491 KASSERT(fcaps->fc_nioctls == 0 || 1492 cap_rights_is_set(&fcaps->fc_rights, CAP_IOCTL), 1493 ("%s: ioctls without CAP_IOCTL", func)); 1494 } 1495 1496 static void 1497 fdgrowtable_exp(struct filedesc *fdp, int nfd) 1498 { 1499 int nfd1; 1500 1501 FILEDESC_XLOCK_ASSERT(fdp); 1502 1503 nfd1 = fdp->fd_nfiles * 2; 1504 if (nfd1 < nfd) 1505 nfd1 = nfd; 1506 fdgrowtable(fdp, nfd1); 1507 } 1508 1509 /* 1510 * Grow the file table to accomodate (at least) nfd descriptors. 1511 */ 1512 static void 1513 fdgrowtable(struct filedesc *fdp, int nfd) 1514 { 1515 struct filedesc0 *fdp0; 1516 struct freetable *ft; 1517 struct fdescenttbl *ntable; 1518 struct fdescenttbl *otable; 1519 int nnfiles, onfiles; 1520 NDSLOTTYPE *nmap, *omap; 1521 1522 /* 1523 * If lastfile is -1 this struct filedesc was just allocated and we are 1524 * growing it to accomodate for the one we are going to copy from. There 1525 * is no need to have a lock on this one as it's not visible to anyone. 1526 */ 1527 if (fdp->fd_lastfile != -1) 1528 FILEDESC_XLOCK_ASSERT(fdp); 1529 1530 KASSERT(fdp->fd_nfiles > 0, ("zero-length file table")); 1531 1532 /* save old values */ 1533 onfiles = fdp->fd_nfiles; 1534 otable = fdp->fd_files; 1535 omap = fdp->fd_map; 1536 1537 /* compute the size of the new table */ 1538 nnfiles = NDSLOTS(nfd) * NDENTRIES; /* round up */ 1539 if (nnfiles <= onfiles) 1540 /* the table is already large enough */ 1541 return; 1542 1543 /* 1544 * Allocate a new table. We need enough space for the number of 1545 * entries, file entries themselves and the struct freetable we will use 1546 * when we decommission the table and place it on the freelist. 1547 * We place the struct freetable in the middle so we don't have 1548 * to worry about padding. 1549 */ 1550 ntable = malloc(offsetof(struct fdescenttbl, fdt_ofiles) + 1551 nnfiles * sizeof(ntable->fdt_ofiles[0]) + 1552 sizeof(struct freetable), 1553 M_FILEDESC, M_ZERO | M_WAITOK); 1554 /* copy the old data */ 1555 ntable->fdt_nfiles = nnfiles; 1556 memcpy(ntable->fdt_ofiles, otable->fdt_ofiles, 1557 onfiles * sizeof(ntable->fdt_ofiles[0])); 1558 1559 /* 1560 * Allocate a new map only if the old is not large enough. It will 1561 * grow at a slower rate than the table as it can map more 1562 * entries than the table can hold. 1563 */ 1564 if (NDSLOTS(nnfiles) > NDSLOTS(onfiles)) { 1565 nmap = malloc(NDSLOTS(nnfiles) * NDSLOTSIZE, M_FILEDESC, 1566 M_ZERO | M_WAITOK); 1567 /* copy over the old data and update the pointer */ 1568 memcpy(nmap, omap, NDSLOTS(onfiles) * sizeof(*omap)); 1569 fdp->fd_map = nmap; 1570 } 1571 1572 /* 1573 * Make sure that ntable is correctly initialized before we replace 1574 * fd_files poiner. Otherwise fget_unlocked() may see inconsistent 1575 * data. 1576 */ 1577 atomic_store_rel_ptr((volatile void *)&fdp->fd_files, (uintptr_t)ntable); 1578 1579 /* 1580 * Do not free the old file table, as some threads may still 1581 * reference entries within it. Instead, place it on a freelist 1582 * which will be processed when the struct filedesc is released. 1583 * 1584 * Note that if onfiles == NDFILE, we're dealing with the original 1585 * static allocation contained within (struct filedesc0 *)fdp, 1586 * which must not be freed. 1587 */ 1588 if (onfiles > NDFILE) { 1589 ft = (struct freetable *)&otable->fdt_ofiles[onfiles]; 1590 fdp0 = (struct filedesc0 *)fdp; 1591 ft->ft_table = otable; 1592 SLIST_INSERT_HEAD(&fdp0->fd_free, ft, ft_next); 1593 } 1594 /* 1595 * The map does not have the same possibility of threads still 1596 * holding references to it. So always free it as long as it 1597 * does not reference the original static allocation. 1598 */ 1599 if (NDSLOTS(onfiles) > NDSLOTS(NDFILE)) 1600 free(omap, M_FILEDESC); 1601 } 1602 1603 /* 1604 * Allocate a file descriptor for the process. 1605 */ 1606 int 1607 fdalloc(struct thread *td, int minfd, int *result) 1608 { 1609 struct proc *p = td->td_proc; 1610 struct filedesc *fdp = p->p_fd; 1611 int fd = -1, maxfd, allocfd; 1612 #ifdef RACCT 1613 int error; 1614 #endif 1615 1616 FILEDESC_XLOCK_ASSERT(fdp); 1617 1618 if (fdp->fd_freefile > minfd) 1619 minfd = fdp->fd_freefile; 1620 1621 maxfd = getmaxfd(p); 1622 1623 /* 1624 * Search the bitmap for a free descriptor starting at minfd. 1625 * If none is found, grow the file table. 1626 */ 1627 fd = fd_first_free(fdp, minfd, fdp->fd_nfiles); 1628 if (fd >= maxfd) 1629 return (EMFILE); 1630 if (fd >= fdp->fd_nfiles) { 1631 allocfd = min(fd * 2, maxfd); 1632 #ifdef RACCT 1633 PROC_LOCK(p); 1634 error = racct_set(p, RACCT_NOFILE, allocfd); 1635 PROC_UNLOCK(p); 1636 if (error != 0) 1637 return (EMFILE); 1638 #endif 1639 /* 1640 * fd is already equal to first free descriptor >= minfd, so 1641 * we only need to grow the table and we are done. 1642 */ 1643 fdgrowtable_exp(fdp, allocfd); 1644 } 1645 1646 /* 1647 * Perform some sanity checks, then mark the file descriptor as 1648 * used and return it to the caller. 1649 */ 1650 KASSERT(fd >= 0 && fd < min(maxfd, fdp->fd_nfiles), 1651 ("invalid descriptor %d", fd)); 1652 KASSERT(!fdisused(fdp, fd), 1653 ("fd_first_free() returned non-free descriptor")); 1654 KASSERT(fdp->fd_ofiles[fd].fde_file == NULL, 1655 ("file descriptor isn't free")); 1656 KASSERT(fdp->fd_ofiles[fd].fde_flags == 0, ("file flags are set")); 1657 fdused(fdp, fd); 1658 *result = fd; 1659 return (0); 1660 } 1661 1662 /* 1663 * Allocate n file descriptors for the process. 1664 */ 1665 int 1666 fdallocn(struct thread *td, int minfd, int *fds, int n) 1667 { 1668 struct proc *p = td->td_proc; 1669 struct filedesc *fdp = p->p_fd; 1670 int i; 1671 1672 FILEDESC_XLOCK_ASSERT(fdp); 1673 1674 for (i = 0; i < n; i++) 1675 if (fdalloc(td, 0, &fds[i]) != 0) 1676 break; 1677 1678 if (i < n) { 1679 for (i--; i >= 0; i--) 1680 fdunused(fdp, fds[i]); 1681 return (EMFILE); 1682 } 1683 1684 return (0); 1685 } 1686 1687 /* 1688 * Create a new open file structure and allocate a file decriptor for the 1689 * process that refers to it. We add one reference to the file for the 1690 * descriptor table and one reference for resultfp. This is to prevent us 1691 * being preempted and the entry in the descriptor table closed after we 1692 * release the FILEDESC lock. 1693 */ 1694 int 1695 falloc(struct thread *td, struct file **resultfp, int *resultfd, int flags) 1696 { 1697 struct file *fp; 1698 int error, fd; 1699 1700 error = falloc_noinstall(td, &fp); 1701 if (error) 1702 return (error); /* no reference held on error */ 1703 1704 error = finstall(td, fp, &fd, flags, NULL); 1705 if (error) { 1706 fdrop(fp, td); /* one reference (fp only) */ 1707 return (error); 1708 } 1709 1710 if (resultfp != NULL) 1711 *resultfp = fp; /* copy out result */ 1712 else 1713 fdrop(fp, td); /* release local reference */ 1714 1715 if (resultfd != NULL) 1716 *resultfd = fd; 1717 1718 return (0); 1719 } 1720 1721 /* 1722 * Create a new open file structure without allocating a file descriptor. 1723 */ 1724 int 1725 falloc_noinstall(struct thread *td, struct file **resultfp) 1726 { 1727 struct file *fp; 1728 int maxuserfiles = maxfiles - (maxfiles / 20); 1729 static struct timeval lastfail; 1730 static int curfail; 1731 1732 KASSERT(resultfp != NULL, ("%s: resultfp == NULL", __func__)); 1733 1734 if ((openfiles >= maxuserfiles && 1735 priv_check(td, PRIV_MAXFILES) != 0) || 1736 openfiles >= maxfiles) { 1737 if (ppsratecheck(&lastfail, &curfail, 1)) { 1738 printf("kern.maxfiles limit exceeded by uid %i, " 1739 "please see tuning(7).\n", td->td_ucred->cr_ruid); 1740 } 1741 return (ENFILE); 1742 } 1743 atomic_add_int(&openfiles, 1); 1744 fp = uma_zalloc(file_zone, M_WAITOK | M_ZERO); 1745 refcount_init(&fp->f_count, 1); 1746 fp->f_cred = crhold(td->td_ucred); 1747 fp->f_ops = &badfileops; 1748 *resultfp = fp; 1749 return (0); 1750 } 1751 1752 /* 1753 * Install a file in a file descriptor table. 1754 */ 1755 int 1756 finstall(struct thread *td, struct file *fp, int *fd, int flags, 1757 struct filecaps *fcaps) 1758 { 1759 struct filedesc *fdp = td->td_proc->p_fd; 1760 struct filedescent *fde; 1761 int error; 1762 1763 KASSERT(fd != NULL, ("%s: fd == NULL", __func__)); 1764 KASSERT(fp != NULL, ("%s: fp == NULL", __func__)); 1765 if (fcaps != NULL) 1766 filecaps_validate(fcaps, __func__); 1767 1768 FILEDESC_XLOCK(fdp); 1769 if ((error = fdalloc(td, 0, fd))) { 1770 FILEDESC_XUNLOCK(fdp); 1771 return (error); 1772 } 1773 fhold(fp); 1774 fde = &fdp->fd_ofiles[*fd]; 1775 #ifdef CAPABILITIES 1776 seq_write_begin(&fde->fde_seq); 1777 #endif 1778 fde->fde_file = fp; 1779 if ((flags & O_CLOEXEC) != 0) 1780 fde->fde_flags |= UF_EXCLOSE; 1781 if (fcaps != NULL) 1782 filecaps_move(fcaps, &fde->fde_caps); 1783 else 1784 filecaps_fill(&fde->fde_caps); 1785 #ifdef CAPABILITIES 1786 seq_write_end(&fde->fde_seq); 1787 #endif 1788 FILEDESC_XUNLOCK(fdp); 1789 return (0); 1790 } 1791 1792 /* 1793 * Build a new filedesc structure from another. 1794 * Copy the current, root, and jail root vnode references. 1795 * 1796 * If fdp is not NULL, return with it shared locked. 1797 */ 1798 struct filedesc * 1799 fdinit(struct filedesc *fdp) 1800 { 1801 struct filedesc0 *newfdp0; 1802 struct filedesc *newfdp; 1803 1804 newfdp0 = malloc(sizeof *newfdp0, M_FILEDESC, M_WAITOK | M_ZERO); 1805 newfdp = &newfdp0->fd_fd; 1806 1807 /* Create the file descriptor table. */ 1808 FILEDESC_LOCK_INIT(newfdp); 1809 newfdp->fd_refcnt = 1; 1810 newfdp->fd_holdcnt = 1; 1811 newfdp->fd_cmask = CMASK; 1812 newfdp->fd_map = newfdp0->fd_dmap; 1813 newfdp->fd_lastfile = -1; 1814 newfdp->fd_files = (struct fdescenttbl *)&newfdp0->fd_dfiles; 1815 newfdp->fd_files->fdt_nfiles = NDFILE; 1816 1817 if (fdp == NULL) 1818 return (newfdp); 1819 1820 if (fdp->fd_lastfile >= newfdp->fd_nfiles) 1821 fdgrowtable(newfdp, fdp->fd_lastfile + 1); 1822 1823 FILEDESC_SLOCK(fdp); 1824 newfdp->fd_cdir = fdp->fd_cdir; 1825 if (newfdp->fd_cdir) 1826 VREF(newfdp->fd_cdir); 1827 newfdp->fd_rdir = fdp->fd_rdir; 1828 if (newfdp->fd_rdir) 1829 VREF(newfdp->fd_rdir); 1830 newfdp->fd_jdir = fdp->fd_jdir; 1831 if (newfdp->fd_jdir) 1832 VREF(newfdp->fd_jdir); 1833 1834 while (fdp->fd_lastfile >= newfdp->fd_nfiles) { 1835 FILEDESC_SUNLOCK(fdp); 1836 fdgrowtable(newfdp, fdp->fd_lastfile + 1); 1837 FILEDESC_SLOCK(fdp); 1838 } 1839 1840 return (newfdp); 1841 } 1842 1843 static struct filedesc * 1844 fdhold(struct proc *p) 1845 { 1846 struct filedesc *fdp; 1847 1848 mtx_lock(&fdesc_mtx); 1849 fdp = p->p_fd; 1850 if (fdp != NULL) 1851 fdp->fd_holdcnt++; 1852 mtx_unlock(&fdesc_mtx); 1853 return (fdp); 1854 } 1855 1856 static void 1857 fddrop(struct filedesc *fdp) 1858 { 1859 struct filedesc0 *fdp0; 1860 struct freetable *ft; 1861 int i; 1862 1863 mtx_lock(&fdesc_mtx); 1864 i = --fdp->fd_holdcnt; 1865 mtx_unlock(&fdesc_mtx); 1866 if (i > 0) 1867 return; 1868 1869 FILEDESC_LOCK_DESTROY(fdp); 1870 fdp0 = (struct filedesc0 *)fdp; 1871 while ((ft = SLIST_FIRST(&fdp0->fd_free)) != NULL) { 1872 SLIST_REMOVE_HEAD(&fdp0->fd_free, ft_next); 1873 free(ft->ft_table, M_FILEDESC); 1874 } 1875 free(fdp, M_FILEDESC); 1876 } 1877 1878 /* 1879 * Share a filedesc structure. 1880 */ 1881 struct filedesc * 1882 fdshare(struct filedesc *fdp) 1883 { 1884 1885 FILEDESC_XLOCK(fdp); 1886 fdp->fd_refcnt++; 1887 FILEDESC_XUNLOCK(fdp); 1888 return (fdp); 1889 } 1890 1891 /* 1892 * Unshare a filedesc structure, if necessary by making a copy 1893 */ 1894 void 1895 fdunshare(struct thread *td) 1896 { 1897 struct filedesc *tmp; 1898 struct proc *p = td->td_proc; 1899 1900 if (p->p_fd->fd_refcnt == 1) 1901 return; 1902 1903 tmp = fdcopy(p->p_fd); 1904 fdescfree(td); 1905 p->p_fd = tmp; 1906 } 1907 1908 /* 1909 * Copy a filedesc structure. A NULL pointer in returns a NULL reference, 1910 * this is to ease callers, not catch errors. 1911 */ 1912 struct filedesc * 1913 fdcopy(struct filedesc *fdp) 1914 { 1915 struct filedesc *newfdp; 1916 struct filedescent *nfde, *ofde; 1917 int i; 1918 1919 /* Certain daemons might not have file descriptors. */ 1920 if (fdp == NULL) 1921 return (NULL); 1922 1923 newfdp = fdinit(fdp); 1924 /* copy all passable descriptors (i.e. not kqueue) */ 1925 newfdp->fd_freefile = -1; 1926 for (i = 0; i <= fdp->fd_lastfile; ++i) { 1927 ofde = &fdp->fd_ofiles[i]; 1928 if (ofde->fde_file == NULL || 1929 (ofde->fde_file->f_ops->fo_flags & DFLAG_PASSABLE) == 0) { 1930 if (newfdp->fd_freefile == -1) 1931 newfdp->fd_freefile = i; 1932 continue; 1933 } 1934 nfde = &newfdp->fd_ofiles[i]; 1935 *nfde = *ofde; 1936 filecaps_copy(&ofde->fde_caps, &nfde->fde_caps); 1937 fhold(nfde->fde_file); 1938 fdused_init(newfdp, i); 1939 newfdp->fd_lastfile = i; 1940 } 1941 if (newfdp->fd_freefile == -1) 1942 newfdp->fd_freefile = i; 1943 newfdp->fd_cmask = fdp->fd_cmask; 1944 FILEDESC_SUNLOCK(fdp); 1945 return (newfdp); 1946 } 1947 1948 /* 1949 * Release a filedesc structure. 1950 */ 1951 void 1952 fdescfree(struct thread *td) 1953 { 1954 struct filedesc *fdp; 1955 int i; 1956 struct filedesc_to_leader *fdtol; 1957 struct filedescent *fde; 1958 struct file *fp; 1959 struct vnode *cdir, *jdir, *rdir, *vp; 1960 struct flock lf; 1961 1962 /* Certain daemons might not have file descriptors. */ 1963 fdp = td->td_proc->p_fd; 1964 if (fdp == NULL) 1965 return; 1966 1967 #ifdef RACCT 1968 PROC_LOCK(td->td_proc); 1969 racct_set(td->td_proc, RACCT_NOFILE, 0); 1970 PROC_UNLOCK(td->td_proc); 1971 #endif 1972 1973 /* Check for special need to clear POSIX style locks */ 1974 fdtol = td->td_proc->p_fdtol; 1975 if (fdtol != NULL) { 1976 FILEDESC_XLOCK(fdp); 1977 KASSERT(fdtol->fdl_refcount > 0, 1978 ("filedesc_to_refcount botch: fdl_refcount=%d", 1979 fdtol->fdl_refcount)); 1980 if (fdtol->fdl_refcount == 1 && 1981 (td->td_proc->p_leader->p_flag & P_ADVLOCK) != 0) { 1982 for (i = 0; i <= fdp->fd_lastfile; i++) { 1983 fp = fdp->fd_ofiles[i].fde_file; 1984 if (fp == NULL || fp->f_type != DTYPE_VNODE) 1985 continue; 1986 fhold(fp); 1987 FILEDESC_XUNLOCK(fdp); 1988 lf.l_whence = SEEK_SET; 1989 lf.l_start = 0; 1990 lf.l_len = 0; 1991 lf.l_type = F_UNLCK; 1992 vp = fp->f_vnode; 1993 (void) VOP_ADVLOCK(vp, 1994 (caddr_t)td->td_proc->p_leader, F_UNLCK, 1995 &lf, F_POSIX); 1996 FILEDESC_XLOCK(fdp); 1997 fdrop(fp, td); 1998 } 1999 } 2000 retry: 2001 if (fdtol->fdl_refcount == 1) { 2002 if (fdp->fd_holdleaderscount > 0 && 2003 (td->td_proc->p_leader->p_flag & P_ADVLOCK) != 0) { 2004 /* 2005 * close() or do_dup() has cleared a reference 2006 * in a shared file descriptor table. 2007 */ 2008 fdp->fd_holdleaderswakeup = 1; 2009 sx_sleep(&fdp->fd_holdleaderscount, 2010 FILEDESC_LOCK(fdp), PLOCK, "fdlhold", 0); 2011 goto retry; 2012 } 2013 if (fdtol->fdl_holdcount > 0) { 2014 /* 2015 * Ensure that fdtol->fdl_leader remains 2016 * valid in closef(). 2017 */ 2018 fdtol->fdl_wakeup = 1; 2019 sx_sleep(fdtol, FILEDESC_LOCK(fdp), PLOCK, 2020 "fdlhold", 0); 2021 goto retry; 2022 } 2023 } 2024 fdtol->fdl_refcount--; 2025 if (fdtol->fdl_refcount == 0 && 2026 fdtol->fdl_holdcount == 0) { 2027 fdtol->fdl_next->fdl_prev = fdtol->fdl_prev; 2028 fdtol->fdl_prev->fdl_next = fdtol->fdl_next; 2029 } else 2030 fdtol = NULL; 2031 td->td_proc->p_fdtol = NULL; 2032 FILEDESC_XUNLOCK(fdp); 2033 if (fdtol != NULL) 2034 free(fdtol, M_FILEDESC_TO_LEADER); 2035 } 2036 2037 mtx_lock(&fdesc_mtx); 2038 td->td_proc->p_fd = NULL; 2039 mtx_unlock(&fdesc_mtx); 2040 2041 FILEDESC_XLOCK(fdp); 2042 i = --fdp->fd_refcnt; 2043 if (i > 0) { 2044 FILEDESC_XUNLOCK(fdp); 2045 return; 2046 } 2047 2048 cdir = fdp->fd_cdir; 2049 fdp->fd_cdir = NULL; 2050 rdir = fdp->fd_rdir; 2051 fdp->fd_rdir = NULL; 2052 jdir = fdp->fd_jdir; 2053 fdp->fd_jdir = NULL; 2054 FILEDESC_XUNLOCK(fdp); 2055 2056 for (i = 0; i <= fdp->fd_lastfile; i++) { 2057 fde = &fdp->fd_ofiles[i]; 2058 fp = fde->fde_file; 2059 if (fp != NULL) { 2060 fdefree_last(fde); 2061 (void) closef(fp, td); 2062 } 2063 } 2064 2065 if (NDSLOTS(fdp->fd_nfiles) > NDSLOTS(NDFILE)) 2066 free(fdp->fd_map, M_FILEDESC); 2067 if (fdp->fd_nfiles > NDFILE) 2068 free(fdp->fd_files, M_FILEDESC); 2069 2070 if (cdir != NULL) 2071 vrele(cdir); 2072 if (rdir != NULL) 2073 vrele(rdir); 2074 if (jdir != NULL) 2075 vrele(jdir); 2076 2077 fddrop(fdp); 2078 } 2079 2080 /* 2081 * For setugid programs, we don't want to people to use that setugidness 2082 * to generate error messages which write to a file which otherwise would 2083 * otherwise be off-limits to the process. We check for filesystems where 2084 * the vnode can change out from under us after execve (like [lin]procfs). 2085 * 2086 * Since fdsetugidsafety calls this only for fd 0, 1 and 2, this check is 2087 * sufficient. We also don't check for setugidness since we know we are. 2088 */ 2089 static bool 2090 is_unsafe(struct file *fp) 2091 { 2092 struct vnode *vp; 2093 2094 if (fp->f_type != DTYPE_VNODE) 2095 return (false); 2096 2097 vp = fp->f_vnode; 2098 return ((vp->v_vflag & VV_PROCDEP) != 0); 2099 } 2100 2101 /* 2102 * Make this setguid thing safe, if at all possible. 2103 */ 2104 void 2105 fdsetugidsafety(struct thread *td) 2106 { 2107 struct filedesc *fdp; 2108 struct file *fp; 2109 int i; 2110 2111 fdp = td->td_proc->p_fd; 2112 KASSERT(fdp->fd_refcnt == 1, ("the fdtable should not be shared")); 2113 MPASS(fdp->fd_nfiles >= 3); 2114 for (i = 0; i <= 2; i++) { 2115 fp = fdp->fd_ofiles[i].fde_file; 2116 if (fp != NULL && is_unsafe(fp)) { 2117 FILEDESC_XLOCK(fdp); 2118 knote_fdclose(td, i); 2119 /* 2120 * NULL-out descriptor prior to close to avoid 2121 * a race while close blocks. 2122 */ 2123 fdfree(fdp, i); 2124 FILEDESC_XUNLOCK(fdp); 2125 (void) closef(fp, td); 2126 } 2127 } 2128 } 2129 2130 /* 2131 * If a specific file object occupies a specific file descriptor, close the 2132 * file descriptor entry and drop a reference on the file object. This is a 2133 * convenience function to handle a subsequent error in a function that calls 2134 * falloc() that handles the race that another thread might have closed the 2135 * file descriptor out from under the thread creating the file object. 2136 */ 2137 void 2138 fdclose(struct filedesc *fdp, struct file *fp, int idx, struct thread *td) 2139 { 2140 2141 FILEDESC_XLOCK(fdp); 2142 if (fdp->fd_ofiles[idx].fde_file == fp) { 2143 fdfree(fdp, idx); 2144 FILEDESC_XUNLOCK(fdp); 2145 fdrop(fp, td); 2146 } else 2147 FILEDESC_XUNLOCK(fdp); 2148 } 2149 2150 /* 2151 * Close any files on exec? 2152 */ 2153 void 2154 fdcloseexec(struct thread *td) 2155 { 2156 struct filedesc *fdp; 2157 struct filedescent *fde; 2158 struct file *fp; 2159 int i; 2160 2161 fdp = td->td_proc->p_fd; 2162 KASSERT(fdp->fd_refcnt == 1, ("the fdtable should not be shared")); 2163 FILEDESC_XLOCK(fdp); 2164 for (i = 0; i <= fdp->fd_lastfile; i++) { 2165 fde = &fdp->fd_ofiles[i]; 2166 fp = fde->fde_file; 2167 if (fp != NULL && (fp->f_type == DTYPE_MQUEUE || 2168 (fde->fde_flags & UF_EXCLOSE))) { 2169 fdfree(fdp, i); 2170 (void) closefp(fdp, i, fp, td, 0); 2171 /* closefp() drops the FILEDESC lock. */ 2172 FILEDESC_XLOCK(fdp); 2173 } 2174 } 2175 FILEDESC_XUNLOCK(fdp); 2176 } 2177 2178 /* 2179 * It is unsafe for set[ug]id processes to be started with file 2180 * descriptors 0..2 closed, as these descriptors are given implicit 2181 * significance in the Standard C library. fdcheckstd() will create a 2182 * descriptor referencing /dev/null for each of stdin, stdout, and 2183 * stderr that is not already open. 2184 */ 2185 int 2186 fdcheckstd(struct thread *td) 2187 { 2188 struct filedesc *fdp; 2189 register_t save; 2190 int i, error, devnull; 2191 2192 fdp = td->td_proc->p_fd; 2193 KASSERT(fdp->fd_refcnt == 1, ("the fdtable should not be shared")); 2194 devnull = -1; 2195 error = 0; 2196 for (i = 0; i < 3; i++) { 2197 if (fdp->fd_ofiles[i].fde_file != NULL) 2198 continue; 2199 if (devnull < 0) { 2200 save = td->td_retval[0]; 2201 error = kern_open(td, "/dev/null", UIO_SYSSPACE, 2202 O_RDWR, 0); 2203 devnull = td->td_retval[0]; 2204 td->td_retval[0] = save; 2205 if (error) 2206 break; 2207 KASSERT(devnull == i, ("oof, we didn't get our fd")); 2208 } else { 2209 save = td->td_retval[0]; 2210 error = do_dup(td, DUP_FIXED, devnull, i); 2211 td->td_retval[0] = save; 2212 if (error != 0) 2213 break; 2214 } 2215 } 2216 return (error); 2217 } 2218 2219 /* 2220 * Internal form of close. Decrement reference count on file structure. 2221 * Note: td may be NULL when closing a file that was being passed in a 2222 * message. 2223 * 2224 * XXXRW: Giant is not required for the caller, but often will be held; this 2225 * makes it moderately likely the Giant will be recursed in the VFS case. 2226 */ 2227 int 2228 closef(struct file *fp, struct thread *td) 2229 { 2230 struct vnode *vp; 2231 struct flock lf; 2232 struct filedesc_to_leader *fdtol; 2233 struct filedesc *fdp; 2234 2235 /* 2236 * POSIX record locking dictates that any close releases ALL 2237 * locks owned by this process. This is handled by setting 2238 * a flag in the unlock to free ONLY locks obeying POSIX 2239 * semantics, and not to free BSD-style file locks. 2240 * If the descriptor was in a message, POSIX-style locks 2241 * aren't passed with the descriptor, and the thread pointer 2242 * will be NULL. Callers should be careful only to pass a 2243 * NULL thread pointer when there really is no owning 2244 * context that might have locks, or the locks will be 2245 * leaked. 2246 */ 2247 if (fp->f_type == DTYPE_VNODE && td != NULL) { 2248 vp = fp->f_vnode; 2249 if ((td->td_proc->p_leader->p_flag & P_ADVLOCK) != 0) { 2250 lf.l_whence = SEEK_SET; 2251 lf.l_start = 0; 2252 lf.l_len = 0; 2253 lf.l_type = F_UNLCK; 2254 (void) VOP_ADVLOCK(vp, (caddr_t)td->td_proc->p_leader, 2255 F_UNLCK, &lf, F_POSIX); 2256 } 2257 fdtol = td->td_proc->p_fdtol; 2258 if (fdtol != NULL) { 2259 /* 2260 * Handle special case where file descriptor table is 2261 * shared between multiple process leaders. 2262 */ 2263 fdp = td->td_proc->p_fd; 2264 FILEDESC_XLOCK(fdp); 2265 for (fdtol = fdtol->fdl_next; 2266 fdtol != td->td_proc->p_fdtol; 2267 fdtol = fdtol->fdl_next) { 2268 if ((fdtol->fdl_leader->p_flag & 2269 P_ADVLOCK) == 0) 2270 continue; 2271 fdtol->fdl_holdcount++; 2272 FILEDESC_XUNLOCK(fdp); 2273 lf.l_whence = SEEK_SET; 2274 lf.l_start = 0; 2275 lf.l_len = 0; 2276 lf.l_type = F_UNLCK; 2277 vp = fp->f_vnode; 2278 (void) VOP_ADVLOCK(vp, 2279 (caddr_t)fdtol->fdl_leader, F_UNLCK, &lf, 2280 F_POSIX); 2281 FILEDESC_XLOCK(fdp); 2282 fdtol->fdl_holdcount--; 2283 if (fdtol->fdl_holdcount == 0 && 2284 fdtol->fdl_wakeup != 0) { 2285 fdtol->fdl_wakeup = 0; 2286 wakeup(fdtol); 2287 } 2288 } 2289 FILEDESC_XUNLOCK(fdp); 2290 } 2291 } 2292 return (fdrop(fp, td)); 2293 } 2294 2295 /* 2296 * Initialize the file pointer with the specified properties. 2297 * 2298 * The ops are set with release semantics to be certain that the flags, type, 2299 * and data are visible when ops is. This is to prevent ops methods from being 2300 * called with bad data. 2301 */ 2302 void 2303 finit(struct file *fp, u_int flag, short type, void *data, struct fileops *ops) 2304 { 2305 fp->f_data = data; 2306 fp->f_flag = flag; 2307 fp->f_type = type; 2308 atomic_store_rel_ptr((volatile uintptr_t *)&fp->f_ops, (uintptr_t)ops); 2309 } 2310 2311 int 2312 fget_unlocked(struct filedesc *fdp, int fd, cap_rights_t *needrightsp, 2313 int needfcntl, struct file **fpp, cap_rights_t *haverightsp) 2314 { 2315 #ifdef CAPABILITIES 2316 struct filedescent fde; 2317 #endif 2318 struct fdescenttbl *fdt; 2319 struct file *fp; 2320 u_int count; 2321 #ifdef CAPABILITIES 2322 seq_t seq; 2323 cap_rights_t haverights; 2324 int error; 2325 #endif 2326 2327 fdt = fdp->fd_files; 2328 if (fd < 0 || fd >= fdt->fdt_nfiles) 2329 return (EBADF); 2330 /* 2331 * Fetch the descriptor locklessly. We avoid fdrop() races by 2332 * never raising a refcount above 0. To accomplish this we have 2333 * to use a cmpset loop rather than an atomic_add. The descriptor 2334 * must be re-verified once we acquire a reference to be certain 2335 * that the identity is still correct and we did not lose a race 2336 * due to preemption. 2337 */ 2338 for (;;) { 2339 #ifdef CAPABILITIES 2340 seq = seq_read(fd_seq(fdt, fd)); 2341 fde = fdt->fdt_ofiles[fd]; 2342 if (!seq_consistent(fd_seq(fdt, fd), seq)) { 2343 cpu_spinwait(); 2344 continue; 2345 } 2346 fp = fde.fde_file; 2347 #else 2348 fp = fdt->fdt_ofiles[fd].fde_file; 2349 #endif 2350 if (fp == NULL) 2351 return (EBADF); 2352 #ifdef CAPABILITIES 2353 haverights = *cap_rights_fde(&fde); 2354 if (needrightsp != NULL) { 2355 error = cap_check(&haverights, needrightsp); 2356 if (error != 0) 2357 return (error); 2358 if (cap_rights_is_set(needrightsp, CAP_FCNTL)) { 2359 error = cap_fcntl_check_fde(&fde, needfcntl); 2360 if (error != 0) 2361 return (error); 2362 } 2363 } 2364 #endif 2365 retry: 2366 count = fp->f_count; 2367 if (count == 0) { 2368 /* 2369 * Force a reload. Other thread could reallocate the 2370 * table before this fd was closed, so it possible that 2371 * there is a stale fp pointer in cached version. 2372 */ 2373 fdt = *(struct fdescenttbl * volatile *)&(fdp->fd_files); 2374 continue; 2375 } 2376 /* 2377 * Use an acquire barrier to force re-reading of fdt so it is 2378 * refreshed for verification. 2379 */ 2380 if (atomic_cmpset_acq_int(&fp->f_count, count, count + 1) == 0) 2381 goto retry; 2382 fdt = fdp->fd_files; 2383 #ifdef CAPABILITIES 2384 if (seq_consistent_nomb(fd_seq(fdt, fd), seq)) 2385 #else 2386 if (fp == fdt->fdt_ofiles[fd].fde_file) 2387 #endif 2388 break; 2389 fdrop(fp, curthread); 2390 } 2391 *fpp = fp; 2392 if (haverightsp != NULL) { 2393 #ifdef CAPABILITIES 2394 *haverightsp = haverights; 2395 #else 2396 CAP_ALL(haverightsp); 2397 #endif 2398 } 2399 return (0); 2400 } 2401 2402 /* 2403 * Extract the file pointer associated with the specified descriptor for the 2404 * current user process. 2405 * 2406 * If the descriptor doesn't exist or doesn't match 'flags', EBADF is 2407 * returned. 2408 * 2409 * File's rights will be checked against the capability rights mask. 2410 * 2411 * If an error occured the non-zero error is returned and *fpp is set to 2412 * NULL. Otherwise *fpp is held and set and zero is returned. Caller is 2413 * responsible for fdrop(). 2414 */ 2415 static __inline int 2416 _fget(struct thread *td, int fd, struct file **fpp, int flags, 2417 cap_rights_t *needrightsp, u_char *maxprotp) 2418 { 2419 struct filedesc *fdp; 2420 struct file *fp; 2421 cap_rights_t haverights, needrights; 2422 int error; 2423 2424 *fpp = NULL; 2425 if (td == NULL || (fdp = td->td_proc->p_fd) == NULL) 2426 return (EBADF); 2427 if (needrightsp != NULL) 2428 needrights = *needrightsp; 2429 else 2430 cap_rights_init(&needrights); 2431 if (maxprotp != NULL) 2432 cap_rights_set(&needrights, CAP_MMAP); 2433 error = fget_unlocked(fdp, fd, &needrights, 0, &fp, &haverights); 2434 if (error != 0) 2435 return (error); 2436 if (fp->f_ops == &badfileops) { 2437 fdrop(fp, td); 2438 return (EBADF); 2439 } 2440 2441 #ifdef CAPABILITIES 2442 /* 2443 * If requested, convert capability rights to access flags. 2444 */ 2445 if (maxprotp != NULL) 2446 *maxprotp = cap_rights_to_vmprot(&haverights); 2447 #else /* !CAPABILITIES */ 2448 if (maxprotp != NULL) 2449 *maxprotp = VM_PROT_ALL; 2450 #endif /* CAPABILITIES */ 2451 2452 /* 2453 * FREAD and FWRITE failure return EBADF as per POSIX. 2454 */ 2455 error = 0; 2456 switch (flags) { 2457 case FREAD: 2458 case FWRITE: 2459 if ((fp->f_flag & flags) == 0) 2460 error = EBADF; 2461 break; 2462 case FEXEC: 2463 if ((fp->f_flag & (FREAD | FEXEC)) == 0 || 2464 ((fp->f_flag & FWRITE) != 0)) 2465 error = EBADF; 2466 break; 2467 case 0: 2468 break; 2469 default: 2470 KASSERT(0, ("wrong flags")); 2471 } 2472 2473 if (error != 0) { 2474 fdrop(fp, td); 2475 return (error); 2476 } 2477 2478 *fpp = fp; 2479 return (0); 2480 } 2481 2482 int 2483 fget(struct thread *td, int fd, cap_rights_t *rightsp, struct file **fpp) 2484 { 2485 2486 return(_fget(td, fd, fpp, 0, rightsp, NULL)); 2487 } 2488 2489 int 2490 fget_mmap(struct thread *td, int fd, cap_rights_t *rightsp, u_char *maxprotp, 2491 struct file **fpp) 2492 { 2493 2494 return (_fget(td, fd, fpp, 0, rightsp, maxprotp)); 2495 } 2496 2497 int 2498 fget_read(struct thread *td, int fd, cap_rights_t *rightsp, struct file **fpp) 2499 { 2500 2501 return(_fget(td, fd, fpp, FREAD, rightsp, NULL)); 2502 } 2503 2504 int 2505 fget_write(struct thread *td, int fd, cap_rights_t *rightsp, struct file **fpp) 2506 { 2507 2508 return (_fget(td, fd, fpp, FWRITE, rightsp, NULL)); 2509 } 2510 2511 /* 2512 * Like fget() but loads the underlying vnode, or returns an error if the 2513 * descriptor does not represent a vnode. Note that pipes use vnodes but 2514 * never have VM objects. The returned vnode will be vref()'d. 2515 * 2516 * XXX: what about the unused flags ? 2517 */ 2518 static __inline int 2519 _fgetvp(struct thread *td, int fd, int flags, cap_rights_t *needrightsp, 2520 struct vnode **vpp) 2521 { 2522 struct file *fp; 2523 int error; 2524 2525 *vpp = NULL; 2526 error = _fget(td, fd, &fp, flags, needrightsp, NULL); 2527 if (error != 0) 2528 return (error); 2529 if (fp->f_vnode == NULL) { 2530 error = EINVAL; 2531 } else { 2532 *vpp = fp->f_vnode; 2533 vref(*vpp); 2534 } 2535 fdrop(fp, td); 2536 2537 return (error); 2538 } 2539 2540 int 2541 fgetvp(struct thread *td, int fd, cap_rights_t *rightsp, struct vnode **vpp) 2542 { 2543 2544 return (_fgetvp(td, fd, 0, rightsp, vpp)); 2545 } 2546 2547 int 2548 fgetvp_rights(struct thread *td, int fd, cap_rights_t *needrightsp, 2549 struct filecaps *havecaps, struct vnode **vpp) 2550 { 2551 struct filedesc *fdp; 2552 struct file *fp; 2553 #ifdef CAPABILITIES 2554 int error; 2555 #endif 2556 2557 if (td == NULL || (fdp = td->td_proc->p_fd) == NULL) 2558 return (EBADF); 2559 2560 fp = fget_locked(fdp, fd); 2561 if (fp == NULL || fp->f_ops == &badfileops) 2562 return (EBADF); 2563 2564 #ifdef CAPABILITIES 2565 if (needrightsp != NULL) { 2566 error = cap_check(cap_rights(fdp, fd), needrightsp); 2567 if (error != 0) 2568 return (error); 2569 } 2570 #endif 2571 2572 if (fp->f_vnode == NULL) 2573 return (EINVAL); 2574 2575 *vpp = fp->f_vnode; 2576 vref(*vpp); 2577 filecaps_copy(&fdp->fd_ofiles[fd].fde_caps, havecaps); 2578 2579 return (0); 2580 } 2581 2582 int 2583 fgetvp_read(struct thread *td, int fd, cap_rights_t *rightsp, struct vnode **vpp) 2584 { 2585 2586 return (_fgetvp(td, fd, FREAD, rightsp, vpp)); 2587 } 2588 2589 int 2590 fgetvp_exec(struct thread *td, int fd, cap_rights_t *rightsp, struct vnode **vpp) 2591 { 2592 2593 return (_fgetvp(td, fd, FEXEC, rightsp, vpp)); 2594 } 2595 2596 #ifdef notyet 2597 int 2598 fgetvp_write(struct thread *td, int fd, cap_rights_t *rightsp, 2599 struct vnode **vpp) 2600 { 2601 2602 return (_fgetvp(td, fd, FWRITE, rightsp, vpp)); 2603 } 2604 #endif 2605 2606 /* 2607 * Like fget() but loads the underlying socket, or returns an error if the 2608 * descriptor does not represent a socket. 2609 * 2610 * We bump the ref count on the returned socket. XXX Also obtain the SX lock 2611 * in the future. 2612 * 2613 * Note: fgetsock() and fputsock() are deprecated, as consumers should rely 2614 * on their file descriptor reference to prevent the socket from being free'd 2615 * during use. 2616 */ 2617 int 2618 fgetsock(struct thread *td, int fd, cap_rights_t *rightsp, struct socket **spp, 2619 u_int *fflagp) 2620 { 2621 struct file *fp; 2622 int error; 2623 2624 *spp = NULL; 2625 if (fflagp != NULL) 2626 *fflagp = 0; 2627 if ((error = _fget(td, fd, &fp, 0, rightsp, NULL)) != 0) 2628 return (error); 2629 if (fp->f_type != DTYPE_SOCKET) { 2630 error = ENOTSOCK; 2631 } else { 2632 *spp = fp->f_data; 2633 if (fflagp) 2634 *fflagp = fp->f_flag; 2635 SOCK_LOCK(*spp); 2636 soref(*spp); 2637 SOCK_UNLOCK(*spp); 2638 } 2639 fdrop(fp, td); 2640 2641 return (error); 2642 } 2643 2644 /* 2645 * Drop the reference count on the socket and XXX release the SX lock in the 2646 * future. The last reference closes the socket. 2647 * 2648 * Note: fputsock() is deprecated, see comment for fgetsock(). 2649 */ 2650 void 2651 fputsock(struct socket *so) 2652 { 2653 2654 ACCEPT_LOCK(); 2655 SOCK_LOCK(so); 2656 CURVNET_SET(so->so_vnet); 2657 sorele(so); 2658 CURVNET_RESTORE(); 2659 } 2660 2661 /* 2662 * Handle the last reference to a file being closed. 2663 */ 2664 int 2665 _fdrop(struct file *fp, struct thread *td) 2666 { 2667 int error; 2668 2669 error = 0; 2670 if (fp->f_count != 0) 2671 panic("fdrop: count %d", fp->f_count); 2672 if (fp->f_ops != &badfileops) 2673 error = fo_close(fp, td); 2674 atomic_subtract_int(&openfiles, 1); 2675 crfree(fp->f_cred); 2676 free(fp->f_advice, M_FADVISE); 2677 uma_zfree(file_zone, fp); 2678 2679 return (error); 2680 } 2681 2682 /* 2683 * Apply an advisory lock on a file descriptor. 2684 * 2685 * Just attempt to get a record lock of the requested type on the entire file 2686 * (l_whence = SEEK_SET, l_start = 0, l_len = 0). 2687 */ 2688 #ifndef _SYS_SYSPROTO_H_ 2689 struct flock_args { 2690 int fd; 2691 int how; 2692 }; 2693 #endif 2694 /* ARGSUSED */ 2695 int 2696 sys_flock(struct thread *td, struct flock_args *uap) 2697 { 2698 struct file *fp; 2699 struct vnode *vp; 2700 struct flock lf; 2701 cap_rights_t rights; 2702 int error; 2703 2704 error = fget(td, uap->fd, cap_rights_init(&rights, CAP_FLOCK), &fp); 2705 if (error != 0) 2706 return (error); 2707 if (fp->f_type != DTYPE_VNODE) { 2708 fdrop(fp, td); 2709 return (EOPNOTSUPP); 2710 } 2711 2712 vp = fp->f_vnode; 2713 lf.l_whence = SEEK_SET; 2714 lf.l_start = 0; 2715 lf.l_len = 0; 2716 if (uap->how & LOCK_UN) { 2717 lf.l_type = F_UNLCK; 2718 atomic_clear_int(&fp->f_flag, FHASLOCK); 2719 error = VOP_ADVLOCK(vp, (caddr_t)fp, F_UNLCK, &lf, F_FLOCK); 2720 goto done2; 2721 } 2722 if (uap->how & LOCK_EX) 2723 lf.l_type = F_WRLCK; 2724 else if (uap->how & LOCK_SH) 2725 lf.l_type = F_RDLCK; 2726 else { 2727 error = EBADF; 2728 goto done2; 2729 } 2730 atomic_set_int(&fp->f_flag, FHASLOCK); 2731 error = VOP_ADVLOCK(vp, (caddr_t)fp, F_SETLK, &lf, 2732 (uap->how & LOCK_NB) ? F_FLOCK : F_FLOCK | F_WAIT); 2733 done2: 2734 fdrop(fp, td); 2735 return (error); 2736 } 2737 /* 2738 * Duplicate the specified descriptor to a free descriptor. 2739 */ 2740 int 2741 dupfdopen(struct thread *td, struct filedesc *fdp, int dfd, int mode, 2742 int openerror, int *indxp) 2743 { 2744 struct filedescent *newfde, *oldfde; 2745 struct file *fp; 2746 int error, indx; 2747 2748 KASSERT(openerror == ENODEV || openerror == ENXIO, 2749 ("unexpected error %d in %s", openerror, __func__)); 2750 2751 /* 2752 * If the to-be-dup'd fd number is greater than the allowed number 2753 * of file descriptors, or the fd to be dup'd has already been 2754 * closed, then reject. 2755 */ 2756 FILEDESC_XLOCK(fdp); 2757 if ((fp = fget_locked(fdp, dfd)) == NULL) { 2758 FILEDESC_XUNLOCK(fdp); 2759 return (EBADF); 2760 } 2761 2762 error = fdalloc(td, 0, &indx); 2763 if (error != 0) { 2764 FILEDESC_XUNLOCK(fdp); 2765 return (error); 2766 } 2767 2768 /* 2769 * There are two cases of interest here. 2770 * 2771 * For ENODEV simply dup (dfd) to file descriptor (indx) and return. 2772 * 2773 * For ENXIO steal away the file structure from (dfd) and store it in 2774 * (indx). (dfd) is effectively closed by this operation. 2775 */ 2776 switch (openerror) { 2777 case ENODEV: 2778 /* 2779 * Check that the mode the file is being opened for is a 2780 * subset of the mode of the existing descriptor. 2781 */ 2782 if (((mode & (FREAD|FWRITE)) | fp->f_flag) != fp->f_flag) { 2783 fdunused(fdp, indx); 2784 FILEDESC_XUNLOCK(fdp); 2785 return (EACCES); 2786 } 2787 fhold(fp); 2788 newfde = &fdp->fd_ofiles[indx]; 2789 oldfde = &fdp->fd_ofiles[dfd]; 2790 #ifdef CAPABILITIES 2791 seq_write_begin(&newfde->fde_seq); 2792 #endif 2793 memcpy(newfde, oldfde, fde_change_size); 2794 filecaps_copy(&oldfde->fde_caps, &newfde->fde_caps); 2795 #ifdef CAPABILITIES 2796 seq_write_end(&newfde->fde_seq); 2797 #endif 2798 break; 2799 case ENXIO: 2800 /* 2801 * Steal away the file pointer from dfd and stuff it into indx. 2802 */ 2803 newfde = &fdp->fd_ofiles[indx]; 2804 oldfde = &fdp->fd_ofiles[dfd]; 2805 #ifdef CAPABILITIES 2806 seq_write_begin(&newfde->fde_seq); 2807 #endif 2808 memcpy(newfde, oldfde, fde_change_size); 2809 bzero(oldfde, fde_change_size); 2810 fdunused(fdp, dfd); 2811 #ifdef CAPABILITIES 2812 seq_write_end(&newfde->fde_seq); 2813 #endif 2814 break; 2815 } 2816 FILEDESC_XUNLOCK(fdp); 2817 *indxp = indx; 2818 return (0); 2819 } 2820 2821 /* 2822 * Scan all active processes and prisons to see if any of them have a current 2823 * or root directory of `olddp'. If so, replace them with the new mount point. 2824 */ 2825 void 2826 mountcheckdirs(struct vnode *olddp, struct vnode *newdp) 2827 { 2828 struct filedesc *fdp; 2829 struct prison *pr; 2830 struct proc *p; 2831 int nrele; 2832 2833 if (vrefcnt(olddp) == 1) 2834 return; 2835 nrele = 0; 2836 sx_slock(&allproc_lock); 2837 FOREACH_PROC_IN_SYSTEM(p) { 2838 fdp = fdhold(p); 2839 if (fdp == NULL) 2840 continue; 2841 FILEDESC_XLOCK(fdp); 2842 if (fdp->fd_cdir == olddp) { 2843 vref(newdp); 2844 fdp->fd_cdir = newdp; 2845 nrele++; 2846 } 2847 if (fdp->fd_rdir == olddp) { 2848 vref(newdp); 2849 fdp->fd_rdir = newdp; 2850 nrele++; 2851 } 2852 if (fdp->fd_jdir == olddp) { 2853 vref(newdp); 2854 fdp->fd_jdir = newdp; 2855 nrele++; 2856 } 2857 FILEDESC_XUNLOCK(fdp); 2858 fddrop(fdp); 2859 } 2860 sx_sunlock(&allproc_lock); 2861 if (rootvnode == olddp) { 2862 vref(newdp); 2863 rootvnode = newdp; 2864 nrele++; 2865 } 2866 mtx_lock(&prison0.pr_mtx); 2867 if (prison0.pr_root == olddp) { 2868 vref(newdp); 2869 prison0.pr_root = newdp; 2870 nrele++; 2871 } 2872 mtx_unlock(&prison0.pr_mtx); 2873 sx_slock(&allprison_lock); 2874 TAILQ_FOREACH(pr, &allprison, pr_list) { 2875 mtx_lock(&pr->pr_mtx); 2876 if (pr->pr_root == olddp) { 2877 vref(newdp); 2878 pr->pr_root = newdp; 2879 nrele++; 2880 } 2881 mtx_unlock(&pr->pr_mtx); 2882 } 2883 sx_sunlock(&allprison_lock); 2884 while (nrele--) 2885 vrele(olddp); 2886 } 2887 2888 struct filedesc_to_leader * 2889 filedesc_to_leader_alloc(struct filedesc_to_leader *old, struct filedesc *fdp, struct proc *leader) 2890 { 2891 struct filedesc_to_leader *fdtol; 2892 2893 fdtol = malloc(sizeof(struct filedesc_to_leader), 2894 M_FILEDESC_TO_LEADER, 2895 M_WAITOK); 2896 fdtol->fdl_refcount = 1; 2897 fdtol->fdl_holdcount = 0; 2898 fdtol->fdl_wakeup = 0; 2899 fdtol->fdl_leader = leader; 2900 if (old != NULL) { 2901 FILEDESC_XLOCK(fdp); 2902 fdtol->fdl_next = old->fdl_next; 2903 fdtol->fdl_prev = old; 2904 old->fdl_next = fdtol; 2905 fdtol->fdl_next->fdl_prev = fdtol; 2906 FILEDESC_XUNLOCK(fdp); 2907 } else { 2908 fdtol->fdl_next = fdtol; 2909 fdtol->fdl_prev = fdtol; 2910 } 2911 return (fdtol); 2912 } 2913 2914 /* 2915 * Get file structures globally. 2916 */ 2917 static int 2918 sysctl_kern_file(SYSCTL_HANDLER_ARGS) 2919 { 2920 struct xfile xf; 2921 struct filedesc *fdp; 2922 struct file *fp; 2923 struct proc *p; 2924 int error, n; 2925 2926 error = sysctl_wire_old_buffer(req, 0); 2927 if (error != 0) 2928 return (error); 2929 if (req->oldptr == NULL) { 2930 n = 0; 2931 sx_slock(&allproc_lock); 2932 FOREACH_PROC_IN_SYSTEM(p) { 2933 if (p->p_state == PRS_NEW) 2934 continue; 2935 fdp = fdhold(p); 2936 if (fdp == NULL) 2937 continue; 2938 /* overestimates sparse tables. */ 2939 if (fdp->fd_lastfile > 0) 2940 n += fdp->fd_lastfile; 2941 fddrop(fdp); 2942 } 2943 sx_sunlock(&allproc_lock); 2944 return (SYSCTL_OUT(req, 0, n * sizeof(xf))); 2945 } 2946 error = 0; 2947 bzero(&xf, sizeof(xf)); 2948 xf.xf_size = sizeof(xf); 2949 sx_slock(&allproc_lock); 2950 FOREACH_PROC_IN_SYSTEM(p) { 2951 PROC_LOCK(p); 2952 if (p->p_state == PRS_NEW) { 2953 PROC_UNLOCK(p); 2954 continue; 2955 } 2956 if (p_cansee(req->td, p) != 0) { 2957 PROC_UNLOCK(p); 2958 continue; 2959 } 2960 xf.xf_pid = p->p_pid; 2961 xf.xf_uid = p->p_ucred->cr_uid; 2962 PROC_UNLOCK(p); 2963 fdp = fdhold(p); 2964 if (fdp == NULL) 2965 continue; 2966 FILEDESC_SLOCK(fdp); 2967 for (n = 0; fdp->fd_refcnt > 0 && n <= fdp->fd_lastfile; ++n) { 2968 if ((fp = fdp->fd_ofiles[n].fde_file) == NULL) 2969 continue; 2970 xf.xf_fd = n; 2971 xf.xf_file = fp; 2972 xf.xf_data = fp->f_data; 2973 xf.xf_vnode = fp->f_vnode; 2974 xf.xf_type = fp->f_type; 2975 xf.xf_count = fp->f_count; 2976 xf.xf_msgcount = 0; 2977 xf.xf_offset = foffset_get(fp); 2978 xf.xf_flag = fp->f_flag; 2979 error = SYSCTL_OUT(req, &xf, sizeof(xf)); 2980 if (error) 2981 break; 2982 } 2983 FILEDESC_SUNLOCK(fdp); 2984 fddrop(fdp); 2985 if (error) 2986 break; 2987 } 2988 sx_sunlock(&allproc_lock); 2989 return (error); 2990 } 2991 2992 SYSCTL_PROC(_kern, KERN_FILE, file, CTLTYPE_OPAQUE|CTLFLAG_RD|CTLFLAG_MPSAFE, 2993 0, 0, sysctl_kern_file, "S,xfile", "Entire file table"); 2994 2995 #ifdef KINFO_FILE_SIZE 2996 CTASSERT(sizeof(struct kinfo_file) == KINFO_FILE_SIZE); 2997 #endif 2998 2999 static int 3000 xlate_fflags(int fflags) 3001 { 3002 static const struct { 3003 int fflag; 3004 int kf_fflag; 3005 } fflags_table[] = { 3006 { FAPPEND, KF_FLAG_APPEND }, 3007 { FASYNC, KF_FLAG_ASYNC }, 3008 { FFSYNC, KF_FLAG_FSYNC }, 3009 { FHASLOCK, KF_FLAG_HASLOCK }, 3010 { FNONBLOCK, KF_FLAG_NONBLOCK }, 3011 { FREAD, KF_FLAG_READ }, 3012 { FWRITE, KF_FLAG_WRITE }, 3013 { O_CREAT, KF_FLAG_CREAT }, 3014 { O_DIRECT, KF_FLAG_DIRECT }, 3015 { O_EXCL, KF_FLAG_EXCL }, 3016 { O_EXEC, KF_FLAG_EXEC }, 3017 { O_EXLOCK, KF_FLAG_EXLOCK }, 3018 { O_NOFOLLOW, KF_FLAG_NOFOLLOW }, 3019 { O_SHLOCK, KF_FLAG_SHLOCK }, 3020 { O_TRUNC, KF_FLAG_TRUNC } 3021 }; 3022 unsigned int i; 3023 int kflags; 3024 3025 kflags = 0; 3026 for (i = 0; i < nitems(fflags_table); i++) 3027 if (fflags & fflags_table[i].fflag) 3028 kflags |= fflags_table[i].kf_fflag; 3029 return (kflags); 3030 } 3031 3032 /* Trim unused data from kf_path by truncating the structure size. */ 3033 static void 3034 pack_kinfo(struct kinfo_file *kif) 3035 { 3036 3037 kif->kf_structsize = offsetof(struct kinfo_file, kf_path) + 3038 strlen(kif->kf_path) + 1; 3039 kif->kf_structsize = roundup(kif->kf_structsize, sizeof(uint64_t)); 3040 } 3041 3042 static void 3043 export_file_to_kinfo(struct file *fp, int fd, cap_rights_t *rightsp, 3044 struct kinfo_file *kif, struct filedesc *fdp) 3045 { 3046 int error; 3047 3048 bzero(kif, sizeof(*kif)); 3049 3050 /* Set a default type to allow for empty fill_kinfo() methods. */ 3051 kif->kf_type = KF_TYPE_UNKNOWN; 3052 kif->kf_flags = xlate_fflags(fp->f_flag); 3053 if (rightsp != NULL) 3054 kif->kf_cap_rights = *rightsp; 3055 else 3056 cap_rights_init(&kif->kf_cap_rights); 3057 kif->kf_fd = fd; 3058 kif->kf_ref_count = fp->f_count; 3059 kif->kf_offset = foffset_get(fp); 3060 3061 /* 3062 * This may drop the filedesc lock, so the 'fp' cannot be 3063 * accessed after this call. 3064 */ 3065 error = fo_fill_kinfo(fp, kif, fdp); 3066 if (error == 0) 3067 kif->kf_status |= KF_ATTR_VALID; 3068 pack_kinfo(kif); 3069 } 3070 3071 static void 3072 export_vnode_to_kinfo(struct vnode *vp, int fd, int fflags, 3073 struct kinfo_file *kif) 3074 { 3075 int error; 3076 3077 bzero(kif, sizeof(*kif)); 3078 3079 kif->kf_type = KF_TYPE_VNODE; 3080 error = vn_fill_kinfo_vnode(vp, kif); 3081 if (error == 0) 3082 kif->kf_status |= KF_ATTR_VALID; 3083 kif->kf_flags = xlate_fflags(fflags); 3084 kif->kf_fd = fd; 3085 kif->kf_ref_count = -1; 3086 kif->kf_offset = -1; 3087 pack_kinfo(kif); 3088 vrele(vp); 3089 } 3090 3091 struct export_fd_buf { 3092 struct filedesc *fdp; 3093 struct sbuf *sb; 3094 ssize_t remainder; 3095 struct kinfo_file kif; 3096 }; 3097 3098 static int 3099 export_kinfo_to_sb(struct export_fd_buf *efbuf) 3100 { 3101 struct kinfo_file *kif; 3102 3103 kif = &efbuf->kif; 3104 if (efbuf->remainder != -1) { 3105 if (efbuf->remainder < kif->kf_structsize) { 3106 /* Terminate export. */ 3107 efbuf->remainder = 0; 3108 return (0); 3109 } 3110 efbuf->remainder -= kif->kf_structsize; 3111 } 3112 return (sbuf_bcat(efbuf->sb, kif, kif->kf_structsize) == 0 ? 0 : ENOMEM); 3113 } 3114 3115 static int 3116 export_file_to_sb(struct file *fp, int fd, cap_rights_t *rightsp, 3117 struct export_fd_buf *efbuf) 3118 { 3119 int error; 3120 3121 if (efbuf->remainder == 0) 3122 return (0); 3123 export_file_to_kinfo(fp, fd, rightsp, &efbuf->kif, efbuf->fdp); 3124 FILEDESC_SUNLOCK(efbuf->fdp); 3125 error = export_kinfo_to_sb(efbuf); 3126 FILEDESC_SLOCK(efbuf->fdp); 3127 return (error); 3128 } 3129 3130 static int 3131 export_vnode_to_sb(struct vnode *vp, int fd, int fflags, 3132 struct export_fd_buf *efbuf) 3133 { 3134 int error; 3135 3136 if (efbuf->remainder == 0) 3137 return (0); 3138 if (efbuf->fdp != NULL) 3139 FILEDESC_SUNLOCK(efbuf->fdp); 3140 export_vnode_to_kinfo(vp, fd, fflags, &efbuf->kif); 3141 error = export_kinfo_to_sb(efbuf); 3142 if (efbuf->fdp != NULL) 3143 FILEDESC_SLOCK(efbuf->fdp); 3144 return (error); 3145 } 3146 3147 /* 3148 * Store a process file descriptor information to sbuf. 3149 * 3150 * Takes a locked proc as argument, and returns with the proc unlocked. 3151 */ 3152 int 3153 kern_proc_filedesc_out(struct proc *p, struct sbuf *sb, ssize_t maxlen) 3154 { 3155 struct file *fp; 3156 struct filedesc *fdp; 3157 struct export_fd_buf *efbuf; 3158 struct vnode *cttyvp, *textvp, *tracevp; 3159 int error, i; 3160 cap_rights_t rights; 3161 3162 PROC_LOCK_ASSERT(p, MA_OWNED); 3163 3164 /* ktrace vnode */ 3165 tracevp = p->p_tracevp; 3166 if (tracevp != NULL) 3167 vref(tracevp); 3168 /* text vnode */ 3169 textvp = p->p_textvp; 3170 if (textvp != NULL) 3171 vref(textvp); 3172 /* Controlling tty. */ 3173 cttyvp = NULL; 3174 if (p->p_pgrp != NULL && p->p_pgrp->pg_session != NULL) { 3175 cttyvp = p->p_pgrp->pg_session->s_ttyvp; 3176 if (cttyvp != NULL) 3177 vref(cttyvp); 3178 } 3179 fdp = fdhold(p); 3180 PROC_UNLOCK(p); 3181 efbuf = malloc(sizeof(*efbuf), M_TEMP, M_WAITOK); 3182 efbuf->fdp = NULL; 3183 efbuf->sb = sb; 3184 efbuf->remainder = maxlen; 3185 if (tracevp != NULL) 3186 export_vnode_to_sb(tracevp, KF_FD_TYPE_TRACE, FREAD | FWRITE, 3187 efbuf); 3188 if (textvp != NULL) 3189 export_vnode_to_sb(textvp, KF_FD_TYPE_TEXT, FREAD, efbuf); 3190 if (cttyvp != NULL) 3191 export_vnode_to_sb(cttyvp, KF_FD_TYPE_CTTY, FREAD | FWRITE, 3192 efbuf); 3193 error = 0; 3194 if (fdp == NULL) 3195 goto fail; 3196 efbuf->fdp = fdp; 3197 FILEDESC_SLOCK(fdp); 3198 /* working directory */ 3199 if (fdp->fd_cdir != NULL) { 3200 vref(fdp->fd_cdir); 3201 export_vnode_to_sb(fdp->fd_cdir, KF_FD_TYPE_CWD, FREAD, efbuf); 3202 } 3203 /* root directory */ 3204 if (fdp->fd_rdir != NULL) { 3205 vref(fdp->fd_rdir); 3206 export_vnode_to_sb(fdp->fd_rdir, KF_FD_TYPE_ROOT, FREAD, efbuf); 3207 } 3208 /* jail directory */ 3209 if (fdp->fd_jdir != NULL) { 3210 vref(fdp->fd_jdir); 3211 export_vnode_to_sb(fdp->fd_jdir, KF_FD_TYPE_JAIL, FREAD, efbuf); 3212 } 3213 for (i = 0; fdp->fd_refcnt > 0 && i <= fdp->fd_lastfile; i++) { 3214 if ((fp = fdp->fd_ofiles[i].fde_file) == NULL) 3215 continue; 3216 #ifdef CAPABILITIES 3217 rights = *cap_rights(fdp, i); 3218 #else /* !CAPABILITIES */ 3219 cap_rights_init(&rights); 3220 #endif 3221 /* 3222 * Create sysctl entry. It is OK to drop the filedesc 3223 * lock inside of export_file_to_sb() as we will 3224 * re-validate and re-evaluate its properties when the 3225 * loop continues. 3226 */ 3227 error = export_file_to_sb(fp, i, &rights, efbuf); 3228 if (error != 0 || efbuf->remainder == 0) 3229 break; 3230 } 3231 FILEDESC_SUNLOCK(fdp); 3232 fddrop(fdp); 3233 fail: 3234 free(efbuf, M_TEMP); 3235 return (error); 3236 } 3237 3238 #define FILEDESC_SBUF_SIZE (sizeof(struct kinfo_file) * 5) 3239 3240 /* 3241 * Get per-process file descriptors for use by procstat(1), et al. 3242 */ 3243 static int 3244 sysctl_kern_proc_filedesc(SYSCTL_HANDLER_ARGS) 3245 { 3246 struct sbuf sb; 3247 struct proc *p; 3248 ssize_t maxlen; 3249 int error, error2, *name; 3250 3251 name = (int *)arg1; 3252 3253 sbuf_new_for_sysctl(&sb, NULL, FILEDESC_SBUF_SIZE, req); 3254 error = pget((pid_t)name[0], PGET_CANDEBUG | PGET_NOTWEXIT, &p); 3255 if (error != 0) { 3256 sbuf_delete(&sb); 3257 return (error); 3258 } 3259 maxlen = req->oldptr != NULL ? req->oldlen : -1; 3260 error = kern_proc_filedesc_out(p, &sb, maxlen); 3261 error2 = sbuf_finish(&sb); 3262 sbuf_delete(&sb); 3263 return (error != 0 ? error : error2); 3264 } 3265 3266 #ifdef KINFO_OFILE_SIZE 3267 CTASSERT(sizeof(struct kinfo_ofile) == KINFO_OFILE_SIZE); 3268 #endif 3269 3270 #ifdef COMPAT_FREEBSD7 3271 static void 3272 kinfo_to_okinfo(struct kinfo_file *kif, struct kinfo_ofile *okif) 3273 { 3274 3275 okif->kf_structsize = sizeof(*okif); 3276 okif->kf_type = kif->kf_type; 3277 okif->kf_fd = kif->kf_fd; 3278 okif->kf_ref_count = kif->kf_ref_count; 3279 okif->kf_flags = kif->kf_flags & (KF_FLAG_READ | KF_FLAG_WRITE | 3280 KF_FLAG_APPEND | KF_FLAG_ASYNC | KF_FLAG_FSYNC | KF_FLAG_NONBLOCK | 3281 KF_FLAG_DIRECT | KF_FLAG_HASLOCK); 3282 okif->kf_offset = kif->kf_offset; 3283 okif->kf_vnode_type = kif->kf_vnode_type; 3284 okif->kf_sock_domain = kif->kf_sock_domain; 3285 okif->kf_sock_type = kif->kf_sock_type; 3286 okif->kf_sock_protocol = kif->kf_sock_protocol; 3287 strlcpy(okif->kf_path, kif->kf_path, sizeof(okif->kf_path)); 3288 okif->kf_sa_local = kif->kf_sa_local; 3289 okif->kf_sa_peer = kif->kf_sa_peer; 3290 } 3291 3292 static int 3293 export_vnode_for_osysctl(struct vnode *vp, int type, struct kinfo_file *kif, 3294 struct kinfo_ofile *okif, struct filedesc *fdp, struct sysctl_req *req) 3295 { 3296 int error; 3297 3298 vref(vp); 3299 FILEDESC_SUNLOCK(fdp); 3300 export_vnode_to_kinfo(vp, type, 0, kif); 3301 kinfo_to_okinfo(kif, okif); 3302 error = SYSCTL_OUT(req, okif, sizeof(*okif)); 3303 FILEDESC_SLOCK(fdp); 3304 return (error); 3305 } 3306 3307 /* 3308 * Get per-process file descriptors for use by procstat(1), et al. 3309 */ 3310 static int 3311 sysctl_kern_proc_ofiledesc(SYSCTL_HANDLER_ARGS) 3312 { 3313 struct kinfo_ofile *okif; 3314 struct kinfo_file *kif; 3315 struct filedesc *fdp; 3316 int error, i, *name; 3317 struct file *fp; 3318 struct proc *p; 3319 3320 name = (int *)arg1; 3321 error = pget((pid_t)name[0], PGET_CANDEBUG | PGET_NOTWEXIT, &p); 3322 if (error != 0) 3323 return (error); 3324 fdp = fdhold(p); 3325 PROC_UNLOCK(p); 3326 if (fdp == NULL) 3327 return (ENOENT); 3328 kif = malloc(sizeof(*kif), M_TEMP, M_WAITOK); 3329 okif = malloc(sizeof(*okif), M_TEMP, M_WAITOK); 3330 FILEDESC_SLOCK(fdp); 3331 if (fdp->fd_cdir != NULL) 3332 export_vnode_for_osysctl(fdp->fd_cdir, KF_FD_TYPE_CWD, kif, 3333 okif, fdp, req); 3334 if (fdp->fd_rdir != NULL) 3335 export_vnode_for_osysctl(fdp->fd_rdir, KF_FD_TYPE_ROOT, kif, 3336 okif, fdp, req); 3337 if (fdp->fd_jdir != NULL) 3338 export_vnode_for_osysctl(fdp->fd_jdir, KF_FD_TYPE_JAIL, kif, 3339 okif, fdp, req); 3340 for (i = 0; fdp->fd_refcnt > 0 && i <= fdp->fd_lastfile; i++) { 3341 if ((fp = fdp->fd_ofiles[i].fde_file) == NULL) 3342 continue; 3343 export_file_to_kinfo(fp, i, NULL, kif, fdp); 3344 FILEDESC_SUNLOCK(fdp); 3345 kinfo_to_okinfo(kif, okif); 3346 error = SYSCTL_OUT(req, okif, sizeof(*okif)); 3347 FILEDESC_SLOCK(fdp); 3348 if (error) 3349 break; 3350 } 3351 FILEDESC_SUNLOCK(fdp); 3352 fddrop(fdp); 3353 free(kif, M_TEMP); 3354 free(okif, M_TEMP); 3355 return (0); 3356 } 3357 3358 static SYSCTL_NODE(_kern_proc, KERN_PROC_OFILEDESC, ofiledesc, 3359 CTLFLAG_RD|CTLFLAG_MPSAFE, sysctl_kern_proc_ofiledesc, 3360 "Process ofiledesc entries"); 3361 #endif /* COMPAT_FREEBSD7 */ 3362 3363 int 3364 vntype_to_kinfo(int vtype) 3365 { 3366 struct { 3367 int vtype; 3368 int kf_vtype; 3369 } vtypes_table[] = { 3370 { VBAD, KF_VTYPE_VBAD }, 3371 { VBLK, KF_VTYPE_VBLK }, 3372 { VCHR, KF_VTYPE_VCHR }, 3373 { VDIR, KF_VTYPE_VDIR }, 3374 { VFIFO, KF_VTYPE_VFIFO }, 3375 { VLNK, KF_VTYPE_VLNK }, 3376 { VNON, KF_VTYPE_VNON }, 3377 { VREG, KF_VTYPE_VREG }, 3378 { VSOCK, KF_VTYPE_VSOCK } 3379 }; 3380 unsigned int i; 3381 3382 /* 3383 * Perform vtype translation. 3384 */ 3385 for (i = 0; i < nitems(vtypes_table); i++) 3386 if (vtypes_table[i].vtype == vtype) 3387 return (vtypes_table[i].kf_vtype); 3388 3389 return (KF_VTYPE_UNKNOWN); 3390 } 3391 3392 static SYSCTL_NODE(_kern_proc, KERN_PROC_FILEDESC, filedesc, 3393 CTLFLAG_RD|CTLFLAG_MPSAFE, sysctl_kern_proc_filedesc, 3394 "Process filedesc entries"); 3395 3396 #ifdef DDB 3397 /* 3398 * For the purposes of debugging, generate a human-readable string for the 3399 * file type. 3400 */ 3401 static const char * 3402 file_type_to_name(short type) 3403 { 3404 3405 switch (type) { 3406 case 0: 3407 return ("zero"); 3408 case DTYPE_VNODE: 3409 return ("vnod"); 3410 case DTYPE_SOCKET: 3411 return ("sock"); 3412 case DTYPE_PIPE: 3413 return ("pipe"); 3414 case DTYPE_FIFO: 3415 return ("fifo"); 3416 case DTYPE_KQUEUE: 3417 return ("kque"); 3418 case DTYPE_CRYPTO: 3419 return ("crpt"); 3420 case DTYPE_MQUEUE: 3421 return ("mque"); 3422 case DTYPE_SHM: 3423 return ("shm"); 3424 case DTYPE_SEM: 3425 return ("ksem"); 3426 default: 3427 return ("unkn"); 3428 } 3429 } 3430 3431 /* 3432 * For the purposes of debugging, identify a process (if any, perhaps one of 3433 * many) that references the passed file in its file descriptor array. Return 3434 * NULL if none. 3435 */ 3436 static struct proc * 3437 file_to_first_proc(struct file *fp) 3438 { 3439 struct filedesc *fdp; 3440 struct proc *p; 3441 int n; 3442 3443 FOREACH_PROC_IN_SYSTEM(p) { 3444 if (p->p_state == PRS_NEW) 3445 continue; 3446 fdp = p->p_fd; 3447 if (fdp == NULL) 3448 continue; 3449 for (n = 0; n <= fdp->fd_lastfile; n++) { 3450 if (fp == fdp->fd_ofiles[n].fde_file) 3451 return (p); 3452 } 3453 } 3454 return (NULL); 3455 } 3456 3457 static void 3458 db_print_file(struct file *fp, int header) 3459 { 3460 struct proc *p; 3461 3462 if (header) 3463 db_printf("%8s %4s %8s %8s %4s %5s %6s %8s %5s %12s\n", 3464 "File", "Type", "Data", "Flag", "GCFl", "Count", 3465 "MCount", "Vnode", "FPID", "FCmd"); 3466 p = file_to_first_proc(fp); 3467 db_printf("%8p %4s %8p %08x %04x %5d %6d %8p %5d %12s\n", fp, 3468 file_type_to_name(fp->f_type), fp->f_data, fp->f_flag, 3469 0, fp->f_count, 0, fp->f_vnode, 3470 p != NULL ? p->p_pid : -1, p != NULL ? p->p_comm : "-"); 3471 } 3472 3473 DB_SHOW_COMMAND(file, db_show_file) 3474 { 3475 struct file *fp; 3476 3477 if (!have_addr) { 3478 db_printf("usage: show file <addr>\n"); 3479 return; 3480 } 3481 fp = (struct file *)addr; 3482 db_print_file(fp, 1); 3483 } 3484 3485 DB_SHOW_COMMAND(files, db_show_files) 3486 { 3487 struct filedesc *fdp; 3488 struct file *fp; 3489 struct proc *p; 3490 int header; 3491 int n; 3492 3493 header = 1; 3494 FOREACH_PROC_IN_SYSTEM(p) { 3495 if (p->p_state == PRS_NEW) 3496 continue; 3497 if ((fdp = p->p_fd) == NULL) 3498 continue; 3499 for (n = 0; n <= fdp->fd_lastfile; ++n) { 3500 if ((fp = fdp->fd_ofiles[n].fde_file) == NULL) 3501 continue; 3502 db_print_file(fp, header); 3503 header = 0; 3504 } 3505 } 3506 } 3507 #endif 3508 3509 SYSCTL_INT(_kern, KERN_MAXFILESPERPROC, maxfilesperproc, CTLFLAG_RW, 3510 &maxfilesperproc, 0, "Maximum files allowed open per process"); 3511 3512 SYSCTL_INT(_kern, KERN_MAXFILES, maxfiles, CTLFLAG_RW, 3513 &maxfiles, 0, "Maximum number of files"); 3514 3515 SYSCTL_INT(_kern, OID_AUTO, openfiles, CTLFLAG_RD, 3516 __DEVOLATILE(int *, &openfiles), 0, "System-wide number of open files"); 3517 3518 /* ARGSUSED*/ 3519 static void 3520 filelistinit(void *dummy) 3521 { 3522 3523 file_zone = uma_zcreate("Files", sizeof(struct file), NULL, NULL, 3524 NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE); 3525 mtx_init(&sigio_lock, "sigio lock", NULL, MTX_DEF); 3526 mtx_init(&fdesc_mtx, "fdesc", NULL, MTX_DEF); 3527 } 3528 SYSINIT(select, SI_SUB_LOCK, SI_ORDER_FIRST, filelistinit, NULL); 3529 3530 /*-------------------------------------------------------------------*/ 3531 3532 static int 3533 badfo_readwrite(struct file *fp, struct uio *uio, struct ucred *active_cred, 3534 int flags, struct thread *td) 3535 { 3536 3537 return (EBADF); 3538 } 3539 3540 static int 3541 badfo_truncate(struct file *fp, off_t length, struct ucred *active_cred, 3542 struct thread *td) 3543 { 3544 3545 return (EINVAL); 3546 } 3547 3548 static int 3549 badfo_ioctl(struct file *fp, u_long com, void *data, struct ucred *active_cred, 3550 struct thread *td) 3551 { 3552 3553 return (EBADF); 3554 } 3555 3556 static int 3557 badfo_poll(struct file *fp, int events, struct ucred *active_cred, 3558 struct thread *td) 3559 { 3560 3561 return (0); 3562 } 3563 3564 static int 3565 badfo_kqfilter(struct file *fp, struct knote *kn) 3566 { 3567 3568 return (EBADF); 3569 } 3570 3571 static int 3572 badfo_stat(struct file *fp, struct stat *sb, struct ucred *active_cred, 3573 struct thread *td) 3574 { 3575 3576 return (EBADF); 3577 } 3578 3579 static int 3580 badfo_close(struct file *fp, struct thread *td) 3581 { 3582 3583 return (EBADF); 3584 } 3585 3586 static int 3587 badfo_chmod(struct file *fp, mode_t mode, struct ucred *active_cred, 3588 struct thread *td) 3589 { 3590 3591 return (EBADF); 3592 } 3593 3594 static int 3595 badfo_chown(struct file *fp, uid_t uid, gid_t gid, struct ucred *active_cred, 3596 struct thread *td) 3597 { 3598 3599 return (EBADF); 3600 } 3601 3602 static int 3603 badfo_sendfile(struct file *fp, int sockfd, struct uio *hdr_uio, 3604 struct uio *trl_uio, off_t offset, size_t nbytes, off_t *sent, int flags, 3605 int kflags, struct sendfile_sync *sfs, struct thread *td) 3606 { 3607 3608 return (EBADF); 3609 } 3610 3611 static int 3612 badfo_fill_kinfo(struct file *fp, struct kinfo_file *kif, struct filedesc *fdp) 3613 { 3614 3615 return (0); 3616 } 3617 3618 struct fileops badfileops = { 3619 .fo_read = badfo_readwrite, 3620 .fo_write = badfo_readwrite, 3621 .fo_truncate = badfo_truncate, 3622 .fo_ioctl = badfo_ioctl, 3623 .fo_poll = badfo_poll, 3624 .fo_kqfilter = badfo_kqfilter, 3625 .fo_stat = badfo_stat, 3626 .fo_close = badfo_close, 3627 .fo_chmod = badfo_chmod, 3628 .fo_chown = badfo_chown, 3629 .fo_sendfile = badfo_sendfile, 3630 .fo_fill_kinfo = badfo_fill_kinfo, 3631 }; 3632 3633 int 3634 invfo_rdwr(struct file *fp, struct uio *uio, struct ucred *active_cred, 3635 int flags, struct thread *td) 3636 { 3637 3638 return (EOPNOTSUPP); 3639 } 3640 3641 int 3642 invfo_truncate(struct file *fp, off_t length, struct ucred *active_cred, 3643 struct thread *td) 3644 { 3645 3646 return (EINVAL); 3647 } 3648 3649 int 3650 invfo_ioctl(struct file *fp, u_long com, void *data, 3651 struct ucred *active_cred, struct thread *td) 3652 { 3653 3654 return (ENOTTY); 3655 } 3656 3657 int 3658 invfo_poll(struct file *fp, int events, struct ucred *active_cred, 3659 struct thread *td) 3660 { 3661 3662 return (poll_no_poll(events)); 3663 } 3664 3665 int 3666 invfo_kqfilter(struct file *fp, struct knote *kn) 3667 { 3668 3669 return (EINVAL); 3670 } 3671 3672 int 3673 invfo_chmod(struct file *fp, mode_t mode, struct ucred *active_cred, 3674 struct thread *td) 3675 { 3676 3677 return (EINVAL); 3678 } 3679 3680 int 3681 invfo_chown(struct file *fp, uid_t uid, gid_t gid, struct ucred *active_cred, 3682 struct thread *td) 3683 { 3684 3685 return (EINVAL); 3686 } 3687 3688 int 3689 invfo_sendfile(struct file *fp, int sockfd, struct uio *hdr_uio, 3690 struct uio *trl_uio, off_t offset, size_t nbytes, off_t *sent, int flags, 3691 int kflags, struct sendfile_sync *sfs, struct thread *td) 3692 { 3693 3694 return (EINVAL); 3695 } 3696 3697 /*-------------------------------------------------------------------*/ 3698 3699 /* 3700 * File Descriptor pseudo-device driver (/dev/fd/). 3701 * 3702 * Opening minor device N dup()s the file (if any) connected to file 3703 * descriptor N belonging to the calling process. Note that this driver 3704 * consists of only the ``open()'' routine, because all subsequent 3705 * references to this file will be direct to the other driver. 3706 * 3707 * XXX: we could give this one a cloning event handler if necessary. 3708 */ 3709 3710 /* ARGSUSED */ 3711 static int 3712 fdopen(struct cdev *dev, int mode, int type, struct thread *td) 3713 { 3714 3715 /* 3716 * XXX Kludge: set curthread->td_dupfd to contain the value of the 3717 * the file descriptor being sought for duplication. The error 3718 * return ensures that the vnode for this device will be released 3719 * by vn_open. Open will detect this special error and take the 3720 * actions in dupfdopen below. Other callers of vn_open or VOP_OPEN 3721 * will simply report the error. 3722 */ 3723 td->td_dupfd = dev2unit(dev); 3724 return (ENODEV); 3725 } 3726 3727 static struct cdevsw fildesc_cdevsw = { 3728 .d_version = D_VERSION, 3729 .d_open = fdopen, 3730 .d_name = "FD", 3731 }; 3732 3733 static void 3734 fildesc_drvinit(void *unused) 3735 { 3736 struct cdev *dev; 3737 3738 dev = make_dev_credf(MAKEDEV_ETERNAL, &fildesc_cdevsw, 0, NULL, 3739 UID_ROOT, GID_WHEEL, 0666, "fd/0"); 3740 make_dev_alias(dev, "stdin"); 3741 dev = make_dev_credf(MAKEDEV_ETERNAL, &fildesc_cdevsw, 1, NULL, 3742 UID_ROOT, GID_WHEEL, 0666, "fd/1"); 3743 make_dev_alias(dev, "stdout"); 3744 dev = make_dev_credf(MAKEDEV_ETERNAL, &fildesc_cdevsw, 2, NULL, 3745 UID_ROOT, GID_WHEEL, 0666, "fd/2"); 3746 make_dev_alias(dev, "stderr"); 3747 } 3748 3749 SYSINIT(fildescdev, SI_SUB_DRIVERS, SI_ORDER_MIDDLE, fildesc_drvinit, NULL); 3750