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 bool 2082 is_unsafe(struct file *fp) 2083 { 2084 struct vnode *vp; 2085 2086 if (fp->f_type != DTYPE_VNODE) 2087 return (false); 2088 2089 vp = fp->f_vnode; 2090 return ((vp->v_vflag & VV_PROCDEP) != 0); 2091 } 2092 2093 /* 2094 * Make this setguid thing safe, if at all possible. 2095 */ 2096 void 2097 fdsetugidsafety(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 MPASS(fdp->fd_nfiles >= 3); 2106 for (i = 0; i <= 2; i++) { 2107 fp = fdp->fd_ofiles[i].fde_file; 2108 if (fp != NULL && is_unsafe(fp)) { 2109 FILEDESC_XLOCK(fdp); 2110 knote_fdclose(td, i); 2111 /* 2112 * NULL-out descriptor prior to close to avoid 2113 * a race while close blocks. 2114 */ 2115 fdfree(fdp, i); 2116 FILEDESC_XUNLOCK(fdp); 2117 (void) closef(fp, td); 2118 } 2119 } 2120 } 2121 2122 /* 2123 * If a specific file object occupies a specific file descriptor, close the 2124 * file descriptor entry and drop a reference on the file object. This is a 2125 * convenience function to handle a subsequent error in a function that calls 2126 * falloc() that handles the race that another thread might have closed the 2127 * file descriptor out from under the thread creating the file object. 2128 */ 2129 void 2130 fdclose(struct filedesc *fdp, struct file *fp, int idx, struct thread *td) 2131 { 2132 2133 FILEDESC_XLOCK(fdp); 2134 if (fdp->fd_ofiles[idx].fde_file == fp) { 2135 fdfree(fdp, idx); 2136 FILEDESC_XUNLOCK(fdp); 2137 fdrop(fp, td); 2138 } else 2139 FILEDESC_XUNLOCK(fdp); 2140 } 2141 2142 /* 2143 * Close any files on exec? 2144 */ 2145 void 2146 fdcloseexec(struct thread *td) 2147 { 2148 struct filedesc *fdp; 2149 struct filedescent *fde; 2150 struct file *fp; 2151 int i; 2152 2153 fdp = td->td_proc->p_fd; 2154 KASSERT(fdp->fd_refcnt == 1, ("the fdtable should not be shared")); 2155 FILEDESC_XLOCK(fdp); 2156 for (i = 0; i <= fdp->fd_lastfile; i++) { 2157 fde = &fdp->fd_ofiles[i]; 2158 fp = fde->fde_file; 2159 if (fp != NULL && (fp->f_type == DTYPE_MQUEUE || 2160 (fde->fde_flags & UF_EXCLOSE))) { 2161 fdfree(fdp, i); 2162 (void) closefp(fdp, i, fp, td, 0); 2163 /* closefp() drops the FILEDESC lock. */ 2164 FILEDESC_XLOCK(fdp); 2165 } 2166 } 2167 FILEDESC_XUNLOCK(fdp); 2168 } 2169 2170 /* 2171 * It is unsafe for set[ug]id processes to be started with file 2172 * descriptors 0..2 closed, as these descriptors are given implicit 2173 * significance in the Standard C library. fdcheckstd() will create a 2174 * descriptor referencing /dev/null for each of stdin, stdout, and 2175 * stderr that is not already open. 2176 */ 2177 int 2178 fdcheckstd(struct thread *td) 2179 { 2180 struct filedesc *fdp; 2181 register_t retval, save; 2182 int i, error, devnull; 2183 2184 fdp = td->td_proc->p_fd; 2185 KASSERT(fdp->fd_refcnt == 1, ("the fdtable should not be shared")); 2186 devnull = -1; 2187 error = 0; 2188 for (i = 0; i < 3; i++) { 2189 if (fdp->fd_ofiles[i].fde_file != NULL) 2190 continue; 2191 if (devnull < 0) { 2192 save = td->td_retval[0]; 2193 error = kern_open(td, "/dev/null", UIO_SYSSPACE, 2194 O_RDWR, 0); 2195 devnull = td->td_retval[0]; 2196 td->td_retval[0] = save; 2197 if (error) 2198 break; 2199 KASSERT(devnull == i, ("oof, we didn't get our fd")); 2200 } else { 2201 error = do_dup(td, DUP_FIXED, devnull, i, &retval); 2202 if (error != 0) 2203 break; 2204 } 2205 } 2206 return (error); 2207 } 2208 2209 /* 2210 * Internal form of close. Decrement reference count on file structure. 2211 * Note: td may be NULL when closing a file that was being passed in a 2212 * message. 2213 * 2214 * XXXRW: Giant is not required for the caller, but often will be held; this 2215 * makes it moderately likely the Giant will be recursed in the VFS case. 2216 */ 2217 int 2218 closef(struct file *fp, struct thread *td) 2219 { 2220 struct vnode *vp; 2221 struct flock lf; 2222 struct filedesc_to_leader *fdtol; 2223 struct filedesc *fdp; 2224 2225 /* 2226 * POSIX record locking dictates that any close releases ALL 2227 * locks owned by this process. This is handled by setting 2228 * a flag in the unlock to free ONLY locks obeying POSIX 2229 * semantics, and not to free BSD-style file locks. 2230 * If the descriptor was in a message, POSIX-style locks 2231 * aren't passed with the descriptor, and the thread pointer 2232 * will be NULL. Callers should be careful only to pass a 2233 * NULL thread pointer when there really is no owning 2234 * context that might have locks, or the locks will be 2235 * leaked. 2236 */ 2237 if (fp->f_type == DTYPE_VNODE && td != NULL) { 2238 vp = fp->f_vnode; 2239 if ((td->td_proc->p_leader->p_flag & P_ADVLOCK) != 0) { 2240 lf.l_whence = SEEK_SET; 2241 lf.l_start = 0; 2242 lf.l_len = 0; 2243 lf.l_type = F_UNLCK; 2244 (void) VOP_ADVLOCK(vp, (caddr_t)td->td_proc->p_leader, 2245 F_UNLCK, &lf, F_POSIX); 2246 } 2247 fdtol = td->td_proc->p_fdtol; 2248 if (fdtol != NULL) { 2249 /* 2250 * Handle special case where file descriptor table is 2251 * shared between multiple process leaders. 2252 */ 2253 fdp = td->td_proc->p_fd; 2254 FILEDESC_XLOCK(fdp); 2255 for (fdtol = fdtol->fdl_next; 2256 fdtol != td->td_proc->p_fdtol; 2257 fdtol = fdtol->fdl_next) { 2258 if ((fdtol->fdl_leader->p_flag & 2259 P_ADVLOCK) == 0) 2260 continue; 2261 fdtol->fdl_holdcount++; 2262 FILEDESC_XUNLOCK(fdp); 2263 lf.l_whence = SEEK_SET; 2264 lf.l_start = 0; 2265 lf.l_len = 0; 2266 lf.l_type = F_UNLCK; 2267 vp = fp->f_vnode; 2268 (void) VOP_ADVLOCK(vp, 2269 (caddr_t)fdtol->fdl_leader, F_UNLCK, &lf, 2270 F_POSIX); 2271 FILEDESC_XLOCK(fdp); 2272 fdtol->fdl_holdcount--; 2273 if (fdtol->fdl_holdcount == 0 && 2274 fdtol->fdl_wakeup != 0) { 2275 fdtol->fdl_wakeup = 0; 2276 wakeup(fdtol); 2277 } 2278 } 2279 FILEDESC_XUNLOCK(fdp); 2280 } 2281 } 2282 return (fdrop(fp, td)); 2283 } 2284 2285 /* 2286 * Initialize the file pointer with the specified properties. 2287 * 2288 * The ops are set with release semantics to be certain that the flags, type, 2289 * and data are visible when ops is. This is to prevent ops methods from being 2290 * called with bad data. 2291 */ 2292 void 2293 finit(struct file *fp, u_int flag, short type, void *data, struct fileops *ops) 2294 { 2295 fp->f_data = data; 2296 fp->f_flag = flag; 2297 fp->f_type = type; 2298 atomic_store_rel_ptr((volatile uintptr_t *)&fp->f_ops, (uintptr_t)ops); 2299 } 2300 2301 int 2302 fget_unlocked(struct filedesc *fdp, int fd, cap_rights_t *needrightsp, 2303 int needfcntl, struct file **fpp, cap_rights_t *haverightsp) 2304 { 2305 #ifdef CAPABILITIES 2306 struct filedescent fde; 2307 #endif 2308 struct file *fp; 2309 u_int count; 2310 #ifdef CAPABILITIES 2311 seq_t seq; 2312 cap_rights_t haverights; 2313 int error; 2314 #endif 2315 2316 /* 2317 * Avoid reads reordering and then a first access to the 2318 * fdp->fd_ofiles table which could result in OOB operation. 2319 */ 2320 if (fd < 0 || fd >= atomic_load_acq_int(&fdp->fd_nfiles)) 2321 return (EBADF); 2322 /* 2323 * Fetch the descriptor locklessly. We avoid fdrop() races by 2324 * never raising a refcount above 0. To accomplish this we have 2325 * to use a cmpset loop rather than an atomic_add. The descriptor 2326 * must be re-verified once we acquire a reference to be certain 2327 * that the identity is still correct and we did not lose a race 2328 * due to preemption. 2329 */ 2330 for (;;) { 2331 #ifdef CAPABILITIES 2332 seq = seq_read(fd_seq(fdp, fd)); 2333 fde = fdp->fd_ofiles[fd]; 2334 if (!seq_consistent(fd_seq(fdp, fd), seq)) { 2335 cpu_spinwait(); 2336 continue; 2337 } 2338 fp = fde.fde_file; 2339 #else 2340 fp = fdp->fd_ofiles[fd].fde_file; 2341 #endif 2342 if (fp == NULL) 2343 return (EBADF); 2344 #ifdef CAPABILITIES 2345 haverights = *cap_rights_fde(&fde); 2346 if (needrightsp != NULL) { 2347 error = cap_check(&haverights, needrightsp); 2348 if (error != 0) 2349 return (error); 2350 if (cap_rights_is_set(needrightsp, CAP_FCNTL)) { 2351 error = cap_fcntl_check_fde(&fde, needfcntl); 2352 if (error != 0) 2353 return (error); 2354 } 2355 } 2356 #endif 2357 count = fp->f_count; 2358 if (count == 0) 2359 continue; 2360 /* 2361 * Use an acquire barrier to prevent caching of fd_ofiles 2362 * so it is refreshed for verification. 2363 */ 2364 if (atomic_cmpset_acq_int(&fp->f_count, count, count + 1) != 1) 2365 continue; 2366 #ifdef CAPABILITIES 2367 if (seq_consistent_nomb(fd_seq(fdp, fd), seq)) 2368 #else 2369 if (fp == fdp->fd_ofiles[fd].fde_file) 2370 #endif 2371 break; 2372 fdrop(fp, curthread); 2373 } 2374 *fpp = fp; 2375 if (haverightsp != NULL) { 2376 #ifdef CAPABILITIES 2377 *haverightsp = haverights; 2378 #else 2379 CAP_ALL(haverightsp); 2380 #endif 2381 } 2382 return (0); 2383 } 2384 2385 /* 2386 * Extract the file pointer associated with the specified descriptor for the 2387 * current user process. 2388 * 2389 * If the descriptor doesn't exist or doesn't match 'flags', EBADF is 2390 * returned. 2391 * 2392 * File's rights will be checked against the capability rights mask. 2393 * 2394 * If an error occured the non-zero error is returned and *fpp is set to 2395 * NULL. Otherwise *fpp is held and set and zero is returned. Caller is 2396 * responsible for fdrop(). 2397 */ 2398 static __inline int 2399 _fget(struct thread *td, int fd, struct file **fpp, int flags, 2400 cap_rights_t *needrightsp, u_char *maxprotp) 2401 { 2402 struct filedesc *fdp; 2403 struct file *fp; 2404 cap_rights_t haverights, needrights; 2405 int error; 2406 2407 *fpp = NULL; 2408 if (td == NULL || (fdp = td->td_proc->p_fd) == NULL) 2409 return (EBADF); 2410 if (needrightsp != NULL) 2411 needrights = *needrightsp; 2412 else 2413 cap_rights_init(&needrights); 2414 if (maxprotp != NULL) 2415 cap_rights_set(&needrights, CAP_MMAP); 2416 error = fget_unlocked(fdp, fd, &needrights, 0, &fp, &haverights); 2417 if (error != 0) 2418 return (error); 2419 if (fp->f_ops == &badfileops) { 2420 fdrop(fp, td); 2421 return (EBADF); 2422 } 2423 2424 #ifdef CAPABILITIES 2425 /* 2426 * If requested, convert capability rights to access flags. 2427 */ 2428 if (maxprotp != NULL) 2429 *maxprotp = cap_rights_to_vmprot(&haverights); 2430 #else /* !CAPABILITIES */ 2431 if (maxprotp != NULL) 2432 *maxprotp = VM_PROT_ALL; 2433 #endif /* CAPABILITIES */ 2434 2435 /* 2436 * FREAD and FWRITE failure return EBADF as per POSIX. 2437 */ 2438 error = 0; 2439 switch (flags) { 2440 case FREAD: 2441 case FWRITE: 2442 if ((fp->f_flag & flags) == 0) 2443 error = EBADF; 2444 break; 2445 case FEXEC: 2446 if ((fp->f_flag & (FREAD | FEXEC)) == 0 || 2447 ((fp->f_flag & FWRITE) != 0)) 2448 error = EBADF; 2449 break; 2450 case 0: 2451 break; 2452 default: 2453 KASSERT(0, ("wrong flags")); 2454 } 2455 2456 if (error != 0) { 2457 fdrop(fp, td); 2458 return (error); 2459 } 2460 2461 *fpp = fp; 2462 return (0); 2463 } 2464 2465 int 2466 fget(struct thread *td, int fd, cap_rights_t *rightsp, struct file **fpp) 2467 { 2468 2469 return(_fget(td, fd, fpp, 0, rightsp, NULL)); 2470 } 2471 2472 int 2473 fget_mmap(struct thread *td, int fd, cap_rights_t *rightsp, u_char *maxprotp, 2474 struct file **fpp) 2475 { 2476 2477 return (_fget(td, fd, fpp, 0, rightsp, maxprotp)); 2478 } 2479 2480 int 2481 fget_read(struct thread *td, int fd, cap_rights_t *rightsp, struct file **fpp) 2482 { 2483 2484 return(_fget(td, fd, fpp, FREAD, rightsp, NULL)); 2485 } 2486 2487 int 2488 fget_write(struct thread *td, int fd, cap_rights_t *rightsp, struct file **fpp) 2489 { 2490 2491 return (_fget(td, fd, fpp, FWRITE, rightsp, NULL)); 2492 } 2493 2494 /* 2495 * Like fget() but loads the underlying vnode, or returns an error if the 2496 * descriptor does not represent a vnode. Note that pipes use vnodes but 2497 * never have VM objects. The returned vnode will be vref()'d. 2498 * 2499 * XXX: what about the unused flags ? 2500 */ 2501 static __inline int 2502 _fgetvp(struct thread *td, int fd, int flags, cap_rights_t *needrightsp, 2503 struct vnode **vpp) 2504 { 2505 struct file *fp; 2506 int error; 2507 2508 *vpp = NULL; 2509 error = _fget(td, fd, &fp, flags, needrightsp, NULL); 2510 if (error != 0) 2511 return (error); 2512 if (fp->f_vnode == NULL) { 2513 error = EINVAL; 2514 } else { 2515 *vpp = fp->f_vnode; 2516 vref(*vpp); 2517 } 2518 fdrop(fp, td); 2519 2520 return (error); 2521 } 2522 2523 int 2524 fgetvp(struct thread *td, int fd, cap_rights_t *rightsp, struct vnode **vpp) 2525 { 2526 2527 return (_fgetvp(td, fd, 0, rightsp, vpp)); 2528 } 2529 2530 int 2531 fgetvp_rights(struct thread *td, int fd, cap_rights_t *needrightsp, 2532 struct filecaps *havecaps, struct vnode **vpp) 2533 { 2534 struct filedesc *fdp; 2535 struct file *fp; 2536 #ifdef CAPABILITIES 2537 int error; 2538 #endif 2539 2540 if (td == NULL || (fdp = td->td_proc->p_fd) == NULL) 2541 return (EBADF); 2542 2543 fp = fget_locked(fdp, fd); 2544 if (fp == NULL || fp->f_ops == &badfileops) 2545 return (EBADF); 2546 2547 #ifdef CAPABILITIES 2548 if (needrightsp != NULL) { 2549 error = cap_check(cap_rights(fdp, fd), needrightsp); 2550 if (error != 0) 2551 return (error); 2552 } 2553 #endif 2554 2555 if (fp->f_vnode == NULL) 2556 return (EINVAL); 2557 2558 *vpp = fp->f_vnode; 2559 vref(*vpp); 2560 filecaps_copy(&fdp->fd_ofiles[fd].fde_caps, havecaps); 2561 2562 return (0); 2563 } 2564 2565 int 2566 fgetvp_read(struct thread *td, int fd, cap_rights_t *rightsp, struct vnode **vpp) 2567 { 2568 2569 return (_fgetvp(td, fd, FREAD, rightsp, vpp)); 2570 } 2571 2572 int 2573 fgetvp_exec(struct thread *td, int fd, cap_rights_t *rightsp, struct vnode **vpp) 2574 { 2575 2576 return (_fgetvp(td, fd, FEXEC, rightsp, vpp)); 2577 } 2578 2579 #ifdef notyet 2580 int 2581 fgetvp_write(struct thread *td, int fd, cap_rights_t *rightsp, 2582 struct vnode **vpp) 2583 { 2584 2585 return (_fgetvp(td, fd, FWRITE, rightsp, vpp)); 2586 } 2587 #endif 2588 2589 /* 2590 * Like fget() but loads the underlying socket, or returns an error if the 2591 * descriptor does not represent a socket. 2592 * 2593 * We bump the ref count on the returned socket. XXX Also obtain the SX lock 2594 * in the future. 2595 * 2596 * Note: fgetsock() and fputsock() are deprecated, as consumers should rely 2597 * on their file descriptor reference to prevent the socket from being free'd 2598 * during use. 2599 */ 2600 int 2601 fgetsock(struct thread *td, int fd, cap_rights_t *rightsp, struct socket **spp, 2602 u_int *fflagp) 2603 { 2604 struct file *fp; 2605 int error; 2606 2607 *spp = NULL; 2608 if (fflagp != NULL) 2609 *fflagp = 0; 2610 if ((error = _fget(td, fd, &fp, 0, rightsp, NULL)) != 0) 2611 return (error); 2612 if (fp->f_type != DTYPE_SOCKET) { 2613 error = ENOTSOCK; 2614 } else { 2615 *spp = fp->f_data; 2616 if (fflagp) 2617 *fflagp = fp->f_flag; 2618 SOCK_LOCK(*spp); 2619 soref(*spp); 2620 SOCK_UNLOCK(*spp); 2621 } 2622 fdrop(fp, td); 2623 2624 return (error); 2625 } 2626 2627 /* 2628 * Drop the reference count on the socket and XXX release the SX lock in the 2629 * future. The last reference closes the socket. 2630 * 2631 * Note: fputsock() is deprecated, see comment for fgetsock(). 2632 */ 2633 void 2634 fputsock(struct socket *so) 2635 { 2636 2637 ACCEPT_LOCK(); 2638 SOCK_LOCK(so); 2639 CURVNET_SET(so->so_vnet); 2640 sorele(so); 2641 CURVNET_RESTORE(); 2642 } 2643 2644 /* 2645 * Handle the last reference to a file being closed. 2646 */ 2647 int 2648 _fdrop(struct file *fp, struct thread *td) 2649 { 2650 int error; 2651 2652 error = 0; 2653 if (fp->f_count != 0) 2654 panic("fdrop: count %d", fp->f_count); 2655 if (fp->f_ops != &badfileops) 2656 error = fo_close(fp, td); 2657 atomic_subtract_int(&openfiles, 1); 2658 crfree(fp->f_cred); 2659 free(fp->f_advice, M_FADVISE); 2660 uma_zfree(file_zone, fp); 2661 2662 return (error); 2663 } 2664 2665 /* 2666 * Apply an advisory lock on a file descriptor. 2667 * 2668 * Just attempt to get a record lock of the requested type on the entire file 2669 * (l_whence = SEEK_SET, l_start = 0, l_len = 0). 2670 */ 2671 #ifndef _SYS_SYSPROTO_H_ 2672 struct flock_args { 2673 int fd; 2674 int how; 2675 }; 2676 #endif 2677 /* ARGSUSED */ 2678 int 2679 sys_flock(struct thread *td, struct flock_args *uap) 2680 { 2681 struct file *fp; 2682 struct vnode *vp; 2683 struct flock lf; 2684 cap_rights_t rights; 2685 int error; 2686 2687 error = fget(td, uap->fd, cap_rights_init(&rights, CAP_FLOCK), &fp); 2688 if (error != 0) 2689 return (error); 2690 if (fp->f_type != DTYPE_VNODE) { 2691 fdrop(fp, td); 2692 return (EOPNOTSUPP); 2693 } 2694 2695 vp = fp->f_vnode; 2696 lf.l_whence = SEEK_SET; 2697 lf.l_start = 0; 2698 lf.l_len = 0; 2699 if (uap->how & LOCK_UN) { 2700 lf.l_type = F_UNLCK; 2701 atomic_clear_int(&fp->f_flag, FHASLOCK); 2702 error = VOP_ADVLOCK(vp, (caddr_t)fp, F_UNLCK, &lf, F_FLOCK); 2703 goto done2; 2704 } 2705 if (uap->how & LOCK_EX) 2706 lf.l_type = F_WRLCK; 2707 else if (uap->how & LOCK_SH) 2708 lf.l_type = F_RDLCK; 2709 else { 2710 error = EBADF; 2711 goto done2; 2712 } 2713 atomic_set_int(&fp->f_flag, FHASLOCK); 2714 error = VOP_ADVLOCK(vp, (caddr_t)fp, F_SETLK, &lf, 2715 (uap->how & LOCK_NB) ? F_FLOCK : F_FLOCK | F_WAIT); 2716 done2: 2717 fdrop(fp, td); 2718 return (error); 2719 } 2720 /* 2721 * Duplicate the specified descriptor to a free descriptor. 2722 */ 2723 int 2724 dupfdopen(struct thread *td, struct filedesc *fdp, int dfd, int mode, 2725 int openerror, int *indxp) 2726 { 2727 struct filedescent *newfde, *oldfde; 2728 struct file *fp; 2729 int error, indx; 2730 2731 KASSERT(openerror == ENODEV || openerror == ENXIO, 2732 ("unexpected error %d in %s", openerror, __func__)); 2733 2734 /* 2735 * If the to-be-dup'd fd number is greater than the allowed number 2736 * of file descriptors, or the fd to be dup'd has already been 2737 * closed, then reject. 2738 */ 2739 FILEDESC_XLOCK(fdp); 2740 if ((fp = fget_locked(fdp, dfd)) == NULL) { 2741 FILEDESC_XUNLOCK(fdp); 2742 return (EBADF); 2743 } 2744 2745 error = fdalloc(td, 0, &indx); 2746 if (error != 0) { 2747 FILEDESC_XUNLOCK(fdp); 2748 return (error); 2749 } 2750 2751 /* 2752 * There are two cases of interest here. 2753 * 2754 * For ENODEV simply dup (dfd) to file descriptor (indx) and return. 2755 * 2756 * For ENXIO steal away the file structure from (dfd) and store it in 2757 * (indx). (dfd) is effectively closed by this operation. 2758 */ 2759 switch (openerror) { 2760 case ENODEV: 2761 /* 2762 * Check that the mode the file is being opened for is a 2763 * subset of the mode of the existing descriptor. 2764 */ 2765 if (((mode & (FREAD|FWRITE)) | fp->f_flag) != fp->f_flag) { 2766 fdunused(fdp, indx); 2767 FILEDESC_XUNLOCK(fdp); 2768 return (EACCES); 2769 } 2770 fhold(fp); 2771 newfde = &fdp->fd_ofiles[indx]; 2772 oldfde = &fdp->fd_ofiles[dfd]; 2773 #ifdef CAPABILITIES 2774 seq_write_begin(&newfde->fde_seq); 2775 #endif 2776 memcpy(newfde, oldfde, fde_change_size); 2777 filecaps_copy(&oldfde->fde_caps, &newfde->fde_caps); 2778 #ifdef CAPABILITIES 2779 seq_write_end(&newfde->fde_seq); 2780 #endif 2781 break; 2782 case ENXIO: 2783 /* 2784 * Steal away the file pointer from dfd and stuff it into indx. 2785 */ 2786 newfde = &fdp->fd_ofiles[indx]; 2787 oldfde = &fdp->fd_ofiles[dfd]; 2788 #ifdef CAPABILITIES 2789 seq_write_begin(&newfde->fde_seq); 2790 #endif 2791 memcpy(newfde, oldfde, fde_change_size); 2792 bzero(oldfde, fde_change_size); 2793 fdunused(fdp, dfd); 2794 #ifdef CAPABILITIES 2795 seq_write_end(&newfde->fde_seq); 2796 #endif 2797 break; 2798 } 2799 FILEDESC_XUNLOCK(fdp); 2800 *indxp = indx; 2801 return (0); 2802 } 2803 2804 /* 2805 * Scan all active processes and prisons to see if any of them have a current 2806 * or root directory of `olddp'. If so, replace them with the new mount point. 2807 */ 2808 void 2809 mountcheckdirs(struct vnode *olddp, struct vnode *newdp) 2810 { 2811 struct filedesc *fdp; 2812 struct prison *pr; 2813 struct proc *p; 2814 int nrele; 2815 2816 if (vrefcnt(olddp) == 1) 2817 return; 2818 nrele = 0; 2819 sx_slock(&allproc_lock); 2820 FOREACH_PROC_IN_SYSTEM(p) { 2821 fdp = fdhold(p); 2822 if (fdp == NULL) 2823 continue; 2824 FILEDESC_XLOCK(fdp); 2825 if (fdp->fd_cdir == olddp) { 2826 vref(newdp); 2827 fdp->fd_cdir = newdp; 2828 nrele++; 2829 } 2830 if (fdp->fd_rdir == olddp) { 2831 vref(newdp); 2832 fdp->fd_rdir = newdp; 2833 nrele++; 2834 } 2835 if (fdp->fd_jdir == olddp) { 2836 vref(newdp); 2837 fdp->fd_jdir = newdp; 2838 nrele++; 2839 } 2840 FILEDESC_XUNLOCK(fdp); 2841 fddrop(fdp); 2842 } 2843 sx_sunlock(&allproc_lock); 2844 if (rootvnode == olddp) { 2845 vref(newdp); 2846 rootvnode = newdp; 2847 nrele++; 2848 } 2849 mtx_lock(&prison0.pr_mtx); 2850 if (prison0.pr_root == olddp) { 2851 vref(newdp); 2852 prison0.pr_root = newdp; 2853 nrele++; 2854 } 2855 mtx_unlock(&prison0.pr_mtx); 2856 sx_slock(&allprison_lock); 2857 TAILQ_FOREACH(pr, &allprison, pr_list) { 2858 mtx_lock(&pr->pr_mtx); 2859 if (pr->pr_root == olddp) { 2860 vref(newdp); 2861 pr->pr_root = newdp; 2862 nrele++; 2863 } 2864 mtx_unlock(&pr->pr_mtx); 2865 } 2866 sx_sunlock(&allprison_lock); 2867 while (nrele--) 2868 vrele(olddp); 2869 } 2870 2871 struct filedesc_to_leader * 2872 filedesc_to_leader_alloc(struct filedesc_to_leader *old, struct filedesc *fdp, struct proc *leader) 2873 { 2874 struct filedesc_to_leader *fdtol; 2875 2876 fdtol = malloc(sizeof(struct filedesc_to_leader), 2877 M_FILEDESC_TO_LEADER, 2878 M_WAITOK); 2879 fdtol->fdl_refcount = 1; 2880 fdtol->fdl_holdcount = 0; 2881 fdtol->fdl_wakeup = 0; 2882 fdtol->fdl_leader = leader; 2883 if (old != NULL) { 2884 FILEDESC_XLOCK(fdp); 2885 fdtol->fdl_next = old->fdl_next; 2886 fdtol->fdl_prev = old; 2887 old->fdl_next = fdtol; 2888 fdtol->fdl_next->fdl_prev = fdtol; 2889 FILEDESC_XUNLOCK(fdp); 2890 } else { 2891 fdtol->fdl_next = fdtol; 2892 fdtol->fdl_prev = fdtol; 2893 } 2894 return (fdtol); 2895 } 2896 2897 /* 2898 * Get file structures globally. 2899 */ 2900 static int 2901 sysctl_kern_file(SYSCTL_HANDLER_ARGS) 2902 { 2903 struct xfile xf; 2904 struct filedesc *fdp; 2905 struct file *fp; 2906 struct proc *p; 2907 int error, n; 2908 2909 error = sysctl_wire_old_buffer(req, 0); 2910 if (error != 0) 2911 return (error); 2912 if (req->oldptr == NULL) { 2913 n = 0; 2914 sx_slock(&allproc_lock); 2915 FOREACH_PROC_IN_SYSTEM(p) { 2916 if (p->p_state == PRS_NEW) 2917 continue; 2918 fdp = fdhold(p); 2919 if (fdp == NULL) 2920 continue; 2921 /* overestimates sparse tables. */ 2922 if (fdp->fd_lastfile > 0) 2923 n += fdp->fd_lastfile; 2924 fddrop(fdp); 2925 } 2926 sx_sunlock(&allproc_lock); 2927 return (SYSCTL_OUT(req, 0, n * sizeof(xf))); 2928 } 2929 error = 0; 2930 bzero(&xf, sizeof(xf)); 2931 xf.xf_size = sizeof(xf); 2932 sx_slock(&allproc_lock); 2933 FOREACH_PROC_IN_SYSTEM(p) { 2934 PROC_LOCK(p); 2935 if (p->p_state == PRS_NEW) { 2936 PROC_UNLOCK(p); 2937 continue; 2938 } 2939 if (p_cansee(req->td, p) != 0) { 2940 PROC_UNLOCK(p); 2941 continue; 2942 } 2943 xf.xf_pid = p->p_pid; 2944 xf.xf_uid = p->p_ucred->cr_uid; 2945 PROC_UNLOCK(p); 2946 fdp = fdhold(p); 2947 if (fdp == NULL) 2948 continue; 2949 FILEDESC_SLOCK(fdp); 2950 for (n = 0; fdp->fd_refcnt > 0 && n <= fdp->fd_lastfile; ++n) { 2951 if ((fp = fdp->fd_ofiles[n].fde_file) == NULL) 2952 continue; 2953 xf.xf_fd = n; 2954 xf.xf_file = fp; 2955 xf.xf_data = fp->f_data; 2956 xf.xf_vnode = fp->f_vnode; 2957 xf.xf_type = fp->f_type; 2958 xf.xf_count = fp->f_count; 2959 xf.xf_msgcount = 0; 2960 xf.xf_offset = foffset_get(fp); 2961 xf.xf_flag = fp->f_flag; 2962 error = SYSCTL_OUT(req, &xf, sizeof(xf)); 2963 if (error) 2964 break; 2965 } 2966 FILEDESC_SUNLOCK(fdp); 2967 fddrop(fdp); 2968 if (error) 2969 break; 2970 } 2971 sx_sunlock(&allproc_lock); 2972 return (error); 2973 } 2974 2975 SYSCTL_PROC(_kern, KERN_FILE, file, CTLTYPE_OPAQUE|CTLFLAG_RD|CTLFLAG_MPSAFE, 2976 0, 0, sysctl_kern_file, "S,xfile", "Entire file table"); 2977 2978 #ifdef KINFO_FILE_SIZE 2979 CTASSERT(sizeof(struct kinfo_file) == KINFO_FILE_SIZE); 2980 #endif 2981 2982 static int 2983 xlate_fflags(int fflags) 2984 { 2985 static const struct { 2986 int fflag; 2987 int kf_fflag; 2988 } fflags_table[] = { 2989 { FAPPEND, KF_FLAG_APPEND }, 2990 { FASYNC, KF_FLAG_ASYNC }, 2991 { FFSYNC, KF_FLAG_FSYNC }, 2992 { FHASLOCK, KF_FLAG_HASLOCK }, 2993 { FNONBLOCK, KF_FLAG_NONBLOCK }, 2994 { FREAD, KF_FLAG_READ }, 2995 { FWRITE, KF_FLAG_WRITE }, 2996 { O_CREAT, KF_FLAG_CREAT }, 2997 { O_DIRECT, KF_FLAG_DIRECT }, 2998 { O_EXCL, KF_FLAG_EXCL }, 2999 { O_EXEC, KF_FLAG_EXEC }, 3000 { O_EXLOCK, KF_FLAG_EXLOCK }, 3001 { O_NOFOLLOW, KF_FLAG_NOFOLLOW }, 3002 { O_SHLOCK, KF_FLAG_SHLOCK }, 3003 { O_TRUNC, KF_FLAG_TRUNC } 3004 }; 3005 unsigned int i; 3006 int kflags; 3007 3008 kflags = 0; 3009 for (i = 0; i < nitems(fflags_table); i++) 3010 if (fflags & fflags_table[i].fflag) 3011 kflags |= fflags_table[i].kf_fflag; 3012 return (kflags); 3013 } 3014 3015 /* Trim unused data from kf_path by truncating the structure size. */ 3016 static void 3017 pack_kinfo(struct kinfo_file *kif) 3018 { 3019 3020 kif->kf_structsize = offsetof(struct kinfo_file, kf_path) + 3021 strlen(kif->kf_path) + 1; 3022 kif->kf_structsize = roundup(kif->kf_structsize, sizeof(uint64_t)); 3023 } 3024 3025 static void 3026 export_file_to_kinfo(struct file *fp, int fd, cap_rights_t *rightsp, 3027 struct kinfo_file *kif, struct filedesc *fdp) 3028 { 3029 int error; 3030 3031 bzero(kif, sizeof(*kif)); 3032 3033 /* Set a default type to allow for empty fill_kinfo() methods. */ 3034 kif->kf_type = KF_TYPE_UNKNOWN; 3035 kif->kf_flags = xlate_fflags(fp->f_flag); 3036 if (rightsp != NULL) 3037 kif->kf_cap_rights = *rightsp; 3038 else 3039 cap_rights_init(&kif->kf_cap_rights); 3040 kif->kf_fd = fd; 3041 kif->kf_ref_count = fp->f_count; 3042 kif->kf_offset = foffset_get(fp); 3043 3044 /* 3045 * This may drop the filedesc lock, so the 'fp' cannot be 3046 * accessed after this call. 3047 */ 3048 error = fo_fill_kinfo(fp, kif, fdp); 3049 if (error == 0) 3050 kif->kf_status |= KF_ATTR_VALID; 3051 pack_kinfo(kif); 3052 } 3053 3054 static void 3055 export_vnode_to_kinfo(struct vnode *vp, int fd, int fflags, 3056 struct kinfo_file *kif) 3057 { 3058 int error; 3059 3060 bzero(kif, sizeof(*kif)); 3061 3062 kif->kf_type = KF_TYPE_VNODE; 3063 error = vn_fill_kinfo_vnode(vp, kif); 3064 if (error == 0) 3065 kif->kf_status |= KF_ATTR_VALID; 3066 kif->kf_flags = xlate_fflags(fflags); 3067 kif->kf_fd = fd; 3068 kif->kf_ref_count = -1; 3069 kif->kf_offset = -1; 3070 pack_kinfo(kif); 3071 vrele(vp); 3072 } 3073 3074 struct export_fd_buf { 3075 struct filedesc *fdp; 3076 struct sbuf *sb; 3077 ssize_t remainder; 3078 struct kinfo_file kif; 3079 }; 3080 3081 static int 3082 export_kinfo_to_sb(struct export_fd_buf *efbuf) 3083 { 3084 struct kinfo_file *kif; 3085 3086 kif = &efbuf->kif; 3087 if (efbuf->remainder != -1) { 3088 if (efbuf->remainder < kif->kf_structsize) { 3089 /* Terminate export. */ 3090 efbuf->remainder = 0; 3091 return (0); 3092 } 3093 efbuf->remainder -= kif->kf_structsize; 3094 } 3095 return (sbuf_bcat(efbuf->sb, kif, kif->kf_structsize) == 0 ? 0 : ENOMEM); 3096 } 3097 3098 static int 3099 export_file_to_sb(struct file *fp, int fd, cap_rights_t *rightsp, 3100 struct export_fd_buf *efbuf) 3101 { 3102 int error; 3103 3104 if (efbuf->remainder == 0) 3105 return (0); 3106 export_file_to_kinfo(fp, fd, rightsp, &efbuf->kif, efbuf->fdp); 3107 FILEDESC_SUNLOCK(efbuf->fdp); 3108 error = export_kinfo_to_sb(efbuf); 3109 FILEDESC_SLOCK(efbuf->fdp); 3110 return (error); 3111 } 3112 3113 static int 3114 export_vnode_to_sb(struct vnode *vp, int fd, int fflags, 3115 struct export_fd_buf *efbuf) 3116 { 3117 int error; 3118 3119 if (efbuf->remainder == 0) 3120 return (0); 3121 if (efbuf->fdp != NULL) 3122 FILEDESC_SUNLOCK(efbuf->fdp); 3123 export_vnode_to_kinfo(vp, fd, fflags, &efbuf->kif); 3124 error = export_kinfo_to_sb(efbuf); 3125 if (efbuf->fdp != NULL) 3126 FILEDESC_SLOCK(efbuf->fdp); 3127 return (error); 3128 } 3129 3130 /* 3131 * Store a process file descriptor information to sbuf. 3132 * 3133 * Takes a locked proc as argument, and returns with the proc unlocked. 3134 */ 3135 int 3136 kern_proc_filedesc_out(struct proc *p, struct sbuf *sb, ssize_t maxlen) 3137 { 3138 struct file *fp; 3139 struct filedesc *fdp; 3140 struct export_fd_buf *efbuf; 3141 struct vnode *cttyvp, *textvp, *tracevp; 3142 int error, i; 3143 cap_rights_t rights; 3144 3145 PROC_LOCK_ASSERT(p, MA_OWNED); 3146 3147 /* ktrace vnode */ 3148 tracevp = p->p_tracevp; 3149 if (tracevp != NULL) 3150 vref(tracevp); 3151 /* text vnode */ 3152 textvp = p->p_textvp; 3153 if (textvp != NULL) 3154 vref(textvp); 3155 /* Controlling tty. */ 3156 cttyvp = NULL; 3157 if (p->p_pgrp != NULL && p->p_pgrp->pg_session != NULL) { 3158 cttyvp = p->p_pgrp->pg_session->s_ttyvp; 3159 if (cttyvp != NULL) 3160 vref(cttyvp); 3161 } 3162 fdp = fdhold(p); 3163 PROC_UNLOCK(p); 3164 efbuf = malloc(sizeof(*efbuf), M_TEMP, M_WAITOK); 3165 efbuf->fdp = NULL; 3166 efbuf->sb = sb; 3167 efbuf->remainder = maxlen; 3168 if (tracevp != NULL) 3169 export_vnode_to_sb(tracevp, KF_FD_TYPE_TRACE, FREAD | FWRITE, 3170 efbuf); 3171 if (textvp != NULL) 3172 export_vnode_to_sb(textvp, KF_FD_TYPE_TEXT, FREAD, efbuf); 3173 if (cttyvp != NULL) 3174 export_vnode_to_sb(cttyvp, KF_FD_TYPE_CTTY, FREAD | FWRITE, 3175 efbuf); 3176 error = 0; 3177 if (fdp == NULL) 3178 goto fail; 3179 efbuf->fdp = fdp; 3180 FILEDESC_SLOCK(fdp); 3181 /* working directory */ 3182 if (fdp->fd_cdir != NULL) { 3183 vref(fdp->fd_cdir); 3184 export_vnode_to_sb(fdp->fd_cdir, KF_FD_TYPE_CWD, FREAD, efbuf); 3185 } 3186 /* root directory */ 3187 if (fdp->fd_rdir != NULL) { 3188 vref(fdp->fd_rdir); 3189 export_vnode_to_sb(fdp->fd_rdir, KF_FD_TYPE_ROOT, FREAD, efbuf); 3190 } 3191 /* jail directory */ 3192 if (fdp->fd_jdir != NULL) { 3193 vref(fdp->fd_jdir); 3194 export_vnode_to_sb(fdp->fd_jdir, KF_FD_TYPE_JAIL, FREAD, efbuf); 3195 } 3196 for (i = 0; fdp->fd_refcnt > 0 && i <= fdp->fd_lastfile; i++) { 3197 if ((fp = fdp->fd_ofiles[i].fde_file) == NULL) 3198 continue; 3199 #ifdef CAPABILITIES 3200 rights = *cap_rights(fdp, i); 3201 #else /* !CAPABILITIES */ 3202 cap_rights_init(&rights); 3203 #endif 3204 /* 3205 * Create sysctl entry. It is OK to drop the filedesc 3206 * lock inside of export_file_to_sb() as we will 3207 * re-validate and re-evaluate its properties when the 3208 * loop continues. 3209 */ 3210 error = export_file_to_sb(fp, i, &rights, efbuf); 3211 if (error != 0 || efbuf->remainder == 0) 3212 break; 3213 } 3214 FILEDESC_SUNLOCK(fdp); 3215 fddrop(fdp); 3216 fail: 3217 free(efbuf, M_TEMP); 3218 return (error); 3219 } 3220 3221 #define FILEDESC_SBUF_SIZE (sizeof(struct kinfo_file) * 5) 3222 3223 /* 3224 * Get per-process file descriptors for use by procstat(1), et al. 3225 */ 3226 static int 3227 sysctl_kern_proc_filedesc(SYSCTL_HANDLER_ARGS) 3228 { 3229 struct sbuf sb; 3230 struct proc *p; 3231 ssize_t maxlen; 3232 int error, error2, *name; 3233 3234 name = (int *)arg1; 3235 3236 sbuf_new_for_sysctl(&sb, NULL, FILEDESC_SBUF_SIZE, req); 3237 error = pget((pid_t)name[0], PGET_CANDEBUG | PGET_NOTWEXIT, &p); 3238 if (error != 0) { 3239 sbuf_delete(&sb); 3240 return (error); 3241 } 3242 maxlen = req->oldptr != NULL ? req->oldlen : -1; 3243 error = kern_proc_filedesc_out(p, &sb, maxlen); 3244 error2 = sbuf_finish(&sb); 3245 sbuf_delete(&sb); 3246 return (error != 0 ? error : error2); 3247 } 3248 3249 #ifdef KINFO_OFILE_SIZE 3250 CTASSERT(sizeof(struct kinfo_ofile) == KINFO_OFILE_SIZE); 3251 #endif 3252 3253 #ifdef COMPAT_FREEBSD7 3254 static void 3255 kinfo_to_okinfo(struct kinfo_file *kif, struct kinfo_ofile *okif) 3256 { 3257 3258 okif->kf_structsize = sizeof(*okif); 3259 okif->kf_type = kif->kf_type; 3260 okif->kf_fd = kif->kf_fd; 3261 okif->kf_ref_count = kif->kf_ref_count; 3262 okif->kf_flags = kif->kf_flags & (KF_FLAG_READ | KF_FLAG_WRITE | 3263 KF_FLAG_APPEND | KF_FLAG_ASYNC | KF_FLAG_FSYNC | KF_FLAG_NONBLOCK | 3264 KF_FLAG_DIRECT | KF_FLAG_HASLOCK); 3265 okif->kf_offset = kif->kf_offset; 3266 okif->kf_vnode_type = kif->kf_vnode_type; 3267 okif->kf_sock_domain = kif->kf_sock_domain; 3268 okif->kf_sock_type = kif->kf_sock_type; 3269 okif->kf_sock_protocol = kif->kf_sock_protocol; 3270 strlcpy(okif->kf_path, kif->kf_path, sizeof(okif->kf_path)); 3271 okif->kf_sa_local = kif->kf_sa_local; 3272 okif->kf_sa_peer = kif->kf_sa_peer; 3273 } 3274 3275 static int 3276 export_vnode_for_osysctl(struct vnode *vp, int type, struct kinfo_file *kif, 3277 struct kinfo_ofile *okif, struct filedesc *fdp, struct sysctl_req *req) 3278 { 3279 int error; 3280 3281 vref(vp); 3282 FILEDESC_SUNLOCK(fdp); 3283 export_vnode_to_kinfo(vp, type, 0, kif); 3284 kinfo_to_okinfo(kif, okif); 3285 error = SYSCTL_OUT(req, okif, sizeof(*okif)); 3286 FILEDESC_SLOCK(fdp); 3287 return (error); 3288 } 3289 3290 /* 3291 * Get per-process file descriptors for use by procstat(1), et al. 3292 */ 3293 static int 3294 sysctl_kern_proc_ofiledesc(SYSCTL_HANDLER_ARGS) 3295 { 3296 struct kinfo_ofile *okif; 3297 struct kinfo_file *kif; 3298 struct filedesc *fdp; 3299 int error, i, *name; 3300 struct file *fp; 3301 struct proc *p; 3302 3303 name = (int *)arg1; 3304 error = pget((pid_t)name[0], PGET_CANDEBUG | PGET_NOTWEXIT, &p); 3305 if (error != 0) 3306 return (error); 3307 fdp = fdhold(p); 3308 PROC_UNLOCK(p); 3309 if (fdp == NULL) 3310 return (ENOENT); 3311 kif = malloc(sizeof(*kif), M_TEMP, M_WAITOK); 3312 okif = malloc(sizeof(*okif), M_TEMP, M_WAITOK); 3313 FILEDESC_SLOCK(fdp); 3314 if (fdp->fd_cdir != NULL) 3315 export_vnode_for_osysctl(fdp->fd_cdir, KF_FD_TYPE_CWD, kif, 3316 okif, fdp, req); 3317 if (fdp->fd_rdir != NULL) 3318 export_vnode_for_osysctl(fdp->fd_rdir, KF_FD_TYPE_ROOT, kif, 3319 okif, fdp, req); 3320 if (fdp->fd_jdir != NULL) 3321 export_vnode_for_osysctl(fdp->fd_jdir, KF_FD_TYPE_JAIL, kif, 3322 okif, fdp, req); 3323 for (i = 0; fdp->fd_refcnt > 0 && i <= fdp->fd_lastfile; i++) { 3324 if ((fp = fdp->fd_ofiles[i].fde_file) == NULL) 3325 continue; 3326 export_file_to_kinfo(fp, i, NULL, kif, fdp); 3327 FILEDESC_SUNLOCK(fdp); 3328 kinfo_to_okinfo(kif, okif); 3329 error = SYSCTL_OUT(req, okif, sizeof(*okif)); 3330 FILEDESC_SLOCK(fdp); 3331 if (error) 3332 break; 3333 } 3334 FILEDESC_SUNLOCK(fdp); 3335 fddrop(fdp); 3336 free(kif, M_TEMP); 3337 free(okif, M_TEMP); 3338 return (0); 3339 } 3340 3341 static SYSCTL_NODE(_kern_proc, KERN_PROC_OFILEDESC, ofiledesc, 3342 CTLFLAG_RD|CTLFLAG_MPSAFE, sysctl_kern_proc_ofiledesc, 3343 "Process ofiledesc entries"); 3344 #endif /* COMPAT_FREEBSD7 */ 3345 3346 int 3347 vntype_to_kinfo(int vtype) 3348 { 3349 struct { 3350 int vtype; 3351 int kf_vtype; 3352 } vtypes_table[] = { 3353 { VBAD, KF_VTYPE_VBAD }, 3354 { VBLK, KF_VTYPE_VBLK }, 3355 { VCHR, KF_VTYPE_VCHR }, 3356 { VDIR, KF_VTYPE_VDIR }, 3357 { VFIFO, KF_VTYPE_VFIFO }, 3358 { VLNK, KF_VTYPE_VLNK }, 3359 { VNON, KF_VTYPE_VNON }, 3360 { VREG, KF_VTYPE_VREG }, 3361 { VSOCK, KF_VTYPE_VSOCK } 3362 }; 3363 unsigned int i; 3364 3365 /* 3366 * Perform vtype translation. 3367 */ 3368 for (i = 0; i < nitems(vtypes_table); i++) 3369 if (vtypes_table[i].vtype == vtype) 3370 return (vtypes_table[i].kf_vtype); 3371 3372 return (KF_VTYPE_UNKNOWN); 3373 } 3374 3375 static SYSCTL_NODE(_kern_proc, KERN_PROC_FILEDESC, filedesc, 3376 CTLFLAG_RD|CTLFLAG_MPSAFE, sysctl_kern_proc_filedesc, 3377 "Process filedesc entries"); 3378 3379 #ifdef DDB 3380 /* 3381 * For the purposes of debugging, generate a human-readable string for the 3382 * file type. 3383 */ 3384 static const char * 3385 file_type_to_name(short type) 3386 { 3387 3388 switch (type) { 3389 case 0: 3390 return ("zero"); 3391 case DTYPE_VNODE: 3392 return ("vnod"); 3393 case DTYPE_SOCKET: 3394 return ("sock"); 3395 case DTYPE_PIPE: 3396 return ("pipe"); 3397 case DTYPE_FIFO: 3398 return ("fifo"); 3399 case DTYPE_KQUEUE: 3400 return ("kque"); 3401 case DTYPE_CRYPTO: 3402 return ("crpt"); 3403 case DTYPE_MQUEUE: 3404 return ("mque"); 3405 case DTYPE_SHM: 3406 return ("shm"); 3407 case DTYPE_SEM: 3408 return ("ksem"); 3409 default: 3410 return ("unkn"); 3411 } 3412 } 3413 3414 /* 3415 * For the purposes of debugging, identify a process (if any, perhaps one of 3416 * many) that references the passed file in its file descriptor array. Return 3417 * NULL if none. 3418 */ 3419 static struct proc * 3420 file_to_first_proc(struct file *fp) 3421 { 3422 struct filedesc *fdp; 3423 struct proc *p; 3424 int n; 3425 3426 FOREACH_PROC_IN_SYSTEM(p) { 3427 if (p->p_state == PRS_NEW) 3428 continue; 3429 fdp = p->p_fd; 3430 if (fdp == NULL) 3431 continue; 3432 for (n = 0; n <= fdp->fd_lastfile; n++) { 3433 if (fp == fdp->fd_ofiles[n].fde_file) 3434 return (p); 3435 } 3436 } 3437 return (NULL); 3438 } 3439 3440 static void 3441 db_print_file(struct file *fp, int header) 3442 { 3443 struct proc *p; 3444 3445 if (header) 3446 db_printf("%8s %4s %8s %8s %4s %5s %6s %8s %5s %12s\n", 3447 "File", "Type", "Data", "Flag", "GCFl", "Count", 3448 "MCount", "Vnode", "FPID", "FCmd"); 3449 p = file_to_first_proc(fp); 3450 db_printf("%8p %4s %8p %08x %04x %5d %6d %8p %5d %12s\n", fp, 3451 file_type_to_name(fp->f_type), fp->f_data, fp->f_flag, 3452 0, fp->f_count, 0, fp->f_vnode, 3453 p != NULL ? p->p_pid : -1, p != NULL ? p->p_comm : "-"); 3454 } 3455 3456 DB_SHOW_COMMAND(file, db_show_file) 3457 { 3458 struct file *fp; 3459 3460 if (!have_addr) { 3461 db_printf("usage: show file <addr>\n"); 3462 return; 3463 } 3464 fp = (struct file *)addr; 3465 db_print_file(fp, 1); 3466 } 3467 3468 DB_SHOW_COMMAND(files, db_show_files) 3469 { 3470 struct filedesc *fdp; 3471 struct file *fp; 3472 struct proc *p; 3473 int header; 3474 int n; 3475 3476 header = 1; 3477 FOREACH_PROC_IN_SYSTEM(p) { 3478 if (p->p_state == PRS_NEW) 3479 continue; 3480 if ((fdp = p->p_fd) == NULL) 3481 continue; 3482 for (n = 0; n <= fdp->fd_lastfile; ++n) { 3483 if ((fp = fdp->fd_ofiles[n].fde_file) == NULL) 3484 continue; 3485 db_print_file(fp, header); 3486 header = 0; 3487 } 3488 } 3489 } 3490 #endif 3491 3492 SYSCTL_INT(_kern, KERN_MAXFILESPERPROC, maxfilesperproc, CTLFLAG_RW, 3493 &maxfilesperproc, 0, "Maximum files allowed open per process"); 3494 3495 SYSCTL_INT(_kern, KERN_MAXFILES, maxfiles, CTLFLAG_RW, 3496 &maxfiles, 0, "Maximum number of files"); 3497 3498 SYSCTL_INT(_kern, OID_AUTO, openfiles, CTLFLAG_RD, 3499 __DEVOLATILE(int *, &openfiles), 0, "System-wide number of open files"); 3500 3501 /* ARGSUSED*/ 3502 static void 3503 filelistinit(void *dummy) 3504 { 3505 3506 file_zone = uma_zcreate("Files", sizeof(struct file), NULL, NULL, 3507 NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE); 3508 mtx_init(&sigio_lock, "sigio lock", NULL, MTX_DEF); 3509 mtx_init(&fdesc_mtx, "fdesc", NULL, MTX_DEF); 3510 } 3511 SYSINIT(select, SI_SUB_LOCK, SI_ORDER_FIRST, filelistinit, NULL); 3512 3513 /*-------------------------------------------------------------------*/ 3514 3515 static int 3516 badfo_readwrite(struct file *fp, struct uio *uio, struct ucred *active_cred, 3517 int flags, struct thread *td) 3518 { 3519 3520 return (EBADF); 3521 } 3522 3523 static int 3524 badfo_truncate(struct file *fp, off_t length, struct ucred *active_cred, 3525 struct thread *td) 3526 { 3527 3528 return (EINVAL); 3529 } 3530 3531 static int 3532 badfo_ioctl(struct file *fp, u_long com, void *data, struct ucred *active_cred, 3533 struct thread *td) 3534 { 3535 3536 return (EBADF); 3537 } 3538 3539 static int 3540 badfo_poll(struct file *fp, int events, struct ucred *active_cred, 3541 struct thread *td) 3542 { 3543 3544 return (0); 3545 } 3546 3547 static int 3548 badfo_kqfilter(struct file *fp, struct knote *kn) 3549 { 3550 3551 return (EBADF); 3552 } 3553 3554 static int 3555 badfo_stat(struct file *fp, struct stat *sb, struct ucred *active_cred, 3556 struct thread *td) 3557 { 3558 3559 return (EBADF); 3560 } 3561 3562 static int 3563 badfo_close(struct file *fp, struct thread *td) 3564 { 3565 3566 return (EBADF); 3567 } 3568 3569 static int 3570 badfo_chmod(struct file *fp, mode_t mode, struct ucred *active_cred, 3571 struct thread *td) 3572 { 3573 3574 return (EBADF); 3575 } 3576 3577 static int 3578 badfo_chown(struct file *fp, uid_t uid, gid_t gid, struct ucred *active_cred, 3579 struct thread *td) 3580 { 3581 3582 return (EBADF); 3583 } 3584 3585 static int 3586 badfo_sendfile(struct file *fp, int sockfd, struct uio *hdr_uio, 3587 struct uio *trl_uio, off_t offset, size_t nbytes, off_t *sent, int flags, 3588 int kflags, struct sendfile_sync *sfs, struct thread *td) 3589 { 3590 3591 return (EBADF); 3592 } 3593 3594 static int 3595 badfo_fill_kinfo(struct file *fp, struct kinfo_file *kif, struct filedesc *fdp) 3596 { 3597 3598 return (0); 3599 } 3600 3601 struct fileops badfileops = { 3602 .fo_read = badfo_readwrite, 3603 .fo_write = badfo_readwrite, 3604 .fo_truncate = badfo_truncate, 3605 .fo_ioctl = badfo_ioctl, 3606 .fo_poll = badfo_poll, 3607 .fo_kqfilter = badfo_kqfilter, 3608 .fo_stat = badfo_stat, 3609 .fo_close = badfo_close, 3610 .fo_chmod = badfo_chmod, 3611 .fo_chown = badfo_chown, 3612 .fo_sendfile = badfo_sendfile, 3613 .fo_fill_kinfo = badfo_fill_kinfo, 3614 }; 3615 3616 int 3617 invfo_rdwr(struct file *fp, struct uio *uio, struct ucred *active_cred, 3618 int flags, struct thread *td) 3619 { 3620 3621 return (EOPNOTSUPP); 3622 } 3623 3624 int 3625 invfo_truncate(struct file *fp, off_t length, struct ucred *active_cred, 3626 struct thread *td) 3627 { 3628 3629 return (EINVAL); 3630 } 3631 3632 int 3633 invfo_ioctl(struct file *fp, u_long com, void *data, 3634 struct ucred *active_cred, struct thread *td) 3635 { 3636 3637 return (ENOTTY); 3638 } 3639 3640 int 3641 invfo_poll(struct file *fp, int events, struct ucred *active_cred, 3642 struct thread *td) 3643 { 3644 3645 return (poll_no_poll(events)); 3646 } 3647 3648 int 3649 invfo_kqfilter(struct file *fp, struct knote *kn) 3650 { 3651 3652 return (EINVAL); 3653 } 3654 3655 int 3656 invfo_chmod(struct file *fp, mode_t mode, struct ucred *active_cred, 3657 struct thread *td) 3658 { 3659 3660 return (EINVAL); 3661 } 3662 3663 int 3664 invfo_chown(struct file *fp, uid_t uid, gid_t gid, struct ucred *active_cred, 3665 struct thread *td) 3666 { 3667 3668 return (EINVAL); 3669 } 3670 3671 int 3672 invfo_sendfile(struct file *fp, int sockfd, struct uio *hdr_uio, 3673 struct uio *trl_uio, off_t offset, size_t nbytes, off_t *sent, int flags, 3674 int kflags, struct sendfile_sync *sfs, struct thread *td) 3675 { 3676 3677 return (EINVAL); 3678 } 3679 3680 /*-------------------------------------------------------------------*/ 3681 3682 /* 3683 * File Descriptor pseudo-device driver (/dev/fd/). 3684 * 3685 * Opening minor device N dup()s the file (if any) connected to file 3686 * descriptor N belonging to the calling process. Note that this driver 3687 * consists of only the ``open()'' routine, because all subsequent 3688 * references to this file will be direct to the other driver. 3689 * 3690 * XXX: we could give this one a cloning event handler if necessary. 3691 */ 3692 3693 /* ARGSUSED */ 3694 static int 3695 fdopen(struct cdev *dev, int mode, int type, struct thread *td) 3696 { 3697 3698 /* 3699 * XXX Kludge: set curthread->td_dupfd to contain the value of the 3700 * the file descriptor being sought for duplication. The error 3701 * return ensures that the vnode for this device will be released 3702 * by vn_open. Open will detect this special error and take the 3703 * actions in dupfdopen below. Other callers of vn_open or VOP_OPEN 3704 * will simply report the error. 3705 */ 3706 td->td_dupfd = dev2unit(dev); 3707 return (ENODEV); 3708 } 3709 3710 static struct cdevsw fildesc_cdevsw = { 3711 .d_version = D_VERSION, 3712 .d_open = fdopen, 3713 .d_name = "FD", 3714 }; 3715 3716 static void 3717 fildesc_drvinit(void *unused) 3718 { 3719 struct cdev *dev; 3720 3721 dev = make_dev_credf(MAKEDEV_ETERNAL, &fildesc_cdevsw, 0, NULL, 3722 UID_ROOT, GID_WHEEL, 0666, "fd/0"); 3723 make_dev_alias(dev, "stdin"); 3724 dev = make_dev_credf(MAKEDEV_ETERNAL, &fildesc_cdevsw, 1, NULL, 3725 UID_ROOT, GID_WHEEL, 0666, "fd/1"); 3726 make_dev_alias(dev, "stdout"); 3727 dev = make_dev_credf(MAKEDEV_ETERNAL, &fildesc_cdevsw, 2, NULL, 3728 UID_ROOT, GID_WHEEL, 0666, "fd/2"); 3729 make_dev_alias(dev, "stderr"); 3730 } 3731 3732 SYSINIT(fildescdev, SI_SUB_DRIVERS, SI_ORDER_MIDDLE, fildesc_drvinit, NULL); 3733