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