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 static uma_zone_t filedesc0_zone; 102 103 static int closefp(struct filedesc *fdp, int fd, struct file *fp, 104 struct thread *td, int holdleaders); 105 static int do_dup(struct thread *td, int flags, int old, int new); 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 fdescenttbl *ft_table; 154 SLIST_ENTRY(freetable) ft_next; 155 }; 156 157 /* 158 * Initial allocation: a filedesc structure + the head of SLIST used to 159 * keep track of old ofiles + enough space for NDFILE descriptors. 160 */ 161 162 struct fdescenttbl0 { 163 int fdt_nfiles; 164 struct filedescent fdt_ofiles[NDFILE]; 165 }; 166 167 struct filedesc0 { 168 struct filedesc fd_fd; 169 SLIST_HEAD(, freetable) fd_free; 170 struct fdescenttbl0 fd_dfiles; 171 NDSLOTTYPE fd_dmap[NDSLOTS(NDFILE)]; 172 }; 173 174 /* 175 * Descriptor management. 176 */ 177 volatile int openfiles; /* actual number of open files */ 178 struct mtx sigio_lock; /* mtx to protect pointers to sigio */ 179 void (*mq_fdclose)(struct thread *td, int fd, struct file *fp); 180 181 /* A mutex to protect the association between a proc and filedesc. */ 182 static struct mtx fdesc_mtx; 183 184 /* 185 * If low >= size, just return low. Otherwise find the first zero bit in the 186 * given bitmap, starting at low and not exceeding size - 1. Return size if 187 * not found. 188 */ 189 static int 190 fd_first_free(struct filedesc *fdp, int low, int size) 191 { 192 NDSLOTTYPE *map = fdp->fd_map; 193 NDSLOTTYPE mask; 194 int off, maxoff; 195 196 if (low >= size) 197 return (low); 198 199 off = NDSLOT(low); 200 if (low % NDENTRIES) { 201 mask = ~(~(NDSLOTTYPE)0 >> (NDENTRIES - (low % NDENTRIES))); 202 if ((mask &= ~map[off]) != 0UL) 203 return (off * NDENTRIES + ffsl(mask) - 1); 204 ++off; 205 } 206 for (maxoff = NDSLOTS(size); off < maxoff; ++off) 207 if (map[off] != ~0UL) 208 return (off * NDENTRIES + ffsl(~map[off]) - 1); 209 return (size); 210 } 211 212 /* 213 * Find the highest non-zero bit in the given bitmap, starting at 0 and 214 * not exceeding size - 1. Return -1 if not found. 215 */ 216 static int 217 fd_last_used(struct filedesc *fdp, int size) 218 { 219 NDSLOTTYPE *map = fdp->fd_map; 220 NDSLOTTYPE mask; 221 int off, minoff; 222 223 off = NDSLOT(size); 224 if (size % NDENTRIES) { 225 mask = ~(~(NDSLOTTYPE)0 << (size % NDENTRIES)); 226 if ((mask &= map[off]) != 0) 227 return (off * NDENTRIES + flsl(mask) - 1); 228 --off; 229 } 230 for (minoff = NDSLOT(0); off >= minoff; --off) 231 if (map[off] != 0) 232 return (off * NDENTRIES + flsl(map[off]) - 1); 233 return (-1); 234 } 235 236 #ifdef INVARIANTS 237 static int 238 fdisused(struct filedesc *fdp, int fd) 239 { 240 241 KASSERT(fd >= 0 && fd < fdp->fd_nfiles, 242 ("file descriptor %d out of range (0, %d)", fd, fdp->fd_nfiles)); 243 244 return ((fdp->fd_map[NDSLOT(fd)] & NDBIT(fd)) != 0); 245 } 246 #endif 247 248 /* 249 * Mark a file descriptor as used. 250 */ 251 static void 252 fdused_init(struct filedesc *fdp, int fd) 253 { 254 255 KASSERT(!fdisused(fdp, fd), ("fd=%d is already used", fd)); 256 257 fdp->fd_map[NDSLOT(fd)] |= NDBIT(fd); 258 } 259 260 static void 261 fdused(struct filedesc *fdp, int fd) 262 { 263 264 FILEDESC_XLOCK_ASSERT(fdp); 265 266 fdused_init(fdp, fd); 267 if (fd > fdp->fd_lastfile) 268 fdp->fd_lastfile = fd; 269 if (fd == fdp->fd_freefile) 270 fdp->fd_freefile = fd_first_free(fdp, fd, fdp->fd_nfiles); 271 } 272 273 /* 274 * Mark a file descriptor as unused. 275 */ 276 static void 277 fdunused(struct filedesc *fdp, int fd) 278 { 279 280 FILEDESC_XLOCK_ASSERT(fdp); 281 282 KASSERT(fdisused(fdp, fd), ("fd=%d is already unused", fd)); 283 KASSERT(fdp->fd_ofiles[fd].fde_file == NULL, 284 ("fd=%d is still in use", fd)); 285 286 fdp->fd_map[NDSLOT(fd)] &= ~NDBIT(fd); 287 if (fd < fdp->fd_freefile) 288 fdp->fd_freefile = fd; 289 if (fd == fdp->fd_lastfile) 290 fdp->fd_lastfile = fd_last_used(fdp, fd); 291 } 292 293 /* 294 * Free a file descriptor. 295 * 296 * Avoid some work if fdp is about to be destroyed. 297 */ 298 static inline void 299 fdefree_last(struct filedescent *fde) 300 { 301 302 filecaps_free(&fde->fde_caps); 303 } 304 305 static inline void 306 fdfree(struct filedesc *fdp, int fd) 307 { 308 struct filedescent *fde; 309 310 fde = &fdp->fd_ofiles[fd]; 311 #ifdef CAPABILITIES 312 seq_write_begin(&fde->fde_seq); 313 #endif 314 fdefree_last(fde); 315 bzero(fde, fde_change_size); 316 fdunused(fdp, fd); 317 #ifdef CAPABILITIES 318 seq_write_end(&fde->fde_seq); 319 #endif 320 } 321 322 /* 323 * System calls on descriptors. 324 */ 325 #ifndef _SYS_SYSPROTO_H_ 326 struct getdtablesize_args { 327 int dummy; 328 }; 329 #endif 330 /* ARGSUSED */ 331 int 332 sys_getdtablesize(struct thread *td, struct getdtablesize_args *uap) 333 { 334 struct proc *p = td->td_proc; 335 uint64_t lim; 336 337 PROC_LOCK(p); 338 td->td_retval[0] = 339 min((int)lim_cur(p, RLIMIT_NOFILE), maxfilesperproc); 340 lim = racct_get_limit(td->td_proc, RACCT_NOFILE); 341 PROC_UNLOCK(p); 342 if (lim < td->td_retval[0]) 343 td->td_retval[0] = lim; 344 return (0); 345 } 346 347 /* 348 * Duplicate a file descriptor to a particular value. 349 * 350 * Note: keep in mind that a potential race condition exists when closing 351 * descriptors from a shared descriptor table (via rfork). 352 */ 353 #ifndef _SYS_SYSPROTO_H_ 354 struct dup2_args { 355 u_int from; 356 u_int to; 357 }; 358 #endif 359 /* ARGSUSED */ 360 int 361 sys_dup2(struct thread *td, struct dup2_args *uap) 362 { 363 364 return (do_dup(td, DUP_FIXED, (int)uap->from, (int)uap->to)); 365 } 366 367 /* 368 * Duplicate a file descriptor. 369 */ 370 #ifndef _SYS_SYSPROTO_H_ 371 struct dup_args { 372 u_int fd; 373 }; 374 #endif 375 /* ARGSUSED */ 376 int 377 sys_dup(struct thread *td, struct dup_args *uap) 378 { 379 380 return (do_dup(td, 0, (int)uap->fd, 0)); 381 } 382 383 /* 384 * The file control system call. 385 */ 386 #ifndef _SYS_SYSPROTO_H_ 387 struct fcntl_args { 388 int fd; 389 int cmd; 390 long arg; 391 }; 392 #endif 393 /* ARGSUSED */ 394 int 395 sys_fcntl(struct thread *td, struct fcntl_args *uap) 396 { 397 398 return (kern_fcntl_freebsd(td, uap->fd, uap->cmd, uap->arg)); 399 } 400 401 int 402 kern_fcntl_freebsd(struct thread *td, int fd, int cmd, long arg) 403 { 404 struct flock fl; 405 struct __oflock ofl; 406 intptr_t arg1; 407 int error; 408 409 error = 0; 410 switch (cmd) { 411 case F_OGETLK: 412 case F_OSETLK: 413 case F_OSETLKW: 414 /* 415 * Convert old flock structure to new. 416 */ 417 error = copyin((void *)(intptr_t)arg, &ofl, sizeof(ofl)); 418 fl.l_start = ofl.l_start; 419 fl.l_len = ofl.l_len; 420 fl.l_pid = ofl.l_pid; 421 fl.l_type = ofl.l_type; 422 fl.l_whence = ofl.l_whence; 423 fl.l_sysid = 0; 424 425 switch (cmd) { 426 case F_OGETLK: 427 cmd = F_GETLK; 428 break; 429 case F_OSETLK: 430 cmd = F_SETLK; 431 break; 432 case F_OSETLKW: 433 cmd = F_SETLKW; 434 break; 435 } 436 arg1 = (intptr_t)&fl; 437 break; 438 case F_GETLK: 439 case F_SETLK: 440 case F_SETLKW: 441 case F_SETLK_REMOTE: 442 error = copyin((void *)(intptr_t)arg, &fl, sizeof(fl)); 443 arg1 = (intptr_t)&fl; 444 break; 445 default: 446 arg1 = arg; 447 break; 448 } 449 if (error) 450 return (error); 451 error = kern_fcntl(td, fd, cmd, arg1); 452 if (error) 453 return (error); 454 if (cmd == F_OGETLK) { 455 ofl.l_start = fl.l_start; 456 ofl.l_len = fl.l_len; 457 ofl.l_pid = fl.l_pid; 458 ofl.l_type = fl.l_type; 459 ofl.l_whence = fl.l_whence; 460 error = copyout(&ofl, (void *)(intptr_t)arg, sizeof(ofl)); 461 } else if (cmd == F_GETLK) { 462 error = copyout(&fl, (void *)(intptr_t)arg, sizeof(fl)); 463 } 464 return (error); 465 } 466 467 int 468 kern_fcntl(struct thread *td, int fd, int cmd, intptr_t arg) 469 { 470 struct filedesc *fdp; 471 struct flock *flp; 472 struct file *fp, *fp2; 473 struct filedescent *fde; 474 struct proc *p; 475 struct vnode *vp; 476 cap_rights_t rights; 477 int error, flg, tmp; 478 uint64_t bsize; 479 off_t foffset; 480 481 error = 0; 482 flg = F_POSIX; 483 p = td->td_proc; 484 fdp = p->p_fd; 485 486 switch (cmd) { 487 case F_DUPFD: 488 tmp = arg; 489 error = do_dup(td, DUP_FCNTL, fd, tmp); 490 break; 491 492 case F_DUPFD_CLOEXEC: 493 tmp = arg; 494 error = do_dup(td, DUP_FCNTL | DUP_CLOEXEC, fd, tmp); 495 break; 496 497 case F_DUP2FD: 498 tmp = arg; 499 error = do_dup(td, DUP_FIXED, fd, tmp); 500 break; 501 502 case F_DUP2FD_CLOEXEC: 503 tmp = arg; 504 error = do_dup(td, DUP_FIXED | DUP_CLOEXEC, fd, tmp); 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 { 805 struct filedesc *fdp; 806 struct filedescent *oldfde, *newfde; 807 struct proc *p; 808 struct file *fp; 809 struct file *delfp; 810 int error, maxfd; 811 812 p = td->td_proc; 813 fdp = p->p_fd; 814 815 /* 816 * Verify we have a valid descriptor to dup from and possibly to 817 * dup to. Unlike dup() and dup2(), fcntl()'s F_DUPFD should 818 * return EINVAL when the new descriptor is out of bounds. 819 */ 820 if (old < 0) 821 return (EBADF); 822 if (new < 0) 823 return (flags & DUP_FCNTL ? EINVAL : EBADF); 824 maxfd = getmaxfd(p); 825 if (new >= maxfd) 826 return (flags & DUP_FCNTL ? EINVAL : EBADF); 827 828 FILEDESC_XLOCK(fdp); 829 if (fget_locked(fdp, old) == NULL) { 830 FILEDESC_XUNLOCK(fdp); 831 return (EBADF); 832 } 833 oldfde = &fdp->fd_ofiles[old]; 834 if (flags & DUP_FIXED && old == new) { 835 td->td_retval[0] = new; 836 if (flags & DUP_CLOEXEC) 837 fdp->fd_ofiles[new].fde_flags |= UF_EXCLOSE; 838 FILEDESC_XUNLOCK(fdp); 839 return (0); 840 } 841 fp = oldfde->fde_file; 842 fhold(fp); 843 844 /* 845 * If the caller specified a file descriptor, make sure the file 846 * table is large enough to hold it, and grab it. Otherwise, just 847 * allocate a new descriptor the usual way. 848 */ 849 if (flags & DUP_FIXED) { 850 if (new >= fdp->fd_nfiles) { 851 /* 852 * The resource limits are here instead of e.g. 853 * fdalloc(), because the file descriptor table may be 854 * shared between processes, so we can't really use 855 * racct_add()/racct_sub(). Instead of counting the 856 * number of actually allocated descriptors, just put 857 * the limit on the size of the file descriptor table. 858 */ 859 #ifdef RACCT 860 PROC_LOCK(p); 861 error = racct_set(p, RACCT_NOFILE, new + 1); 862 PROC_UNLOCK(p); 863 if (error != 0) { 864 FILEDESC_XUNLOCK(fdp); 865 fdrop(fp, td); 866 return (EMFILE); 867 } 868 #endif 869 fdgrowtable_exp(fdp, new + 1); 870 oldfde = &fdp->fd_ofiles[old]; 871 } 872 newfde = &fdp->fd_ofiles[new]; 873 if (newfde->fde_file == NULL) 874 fdused(fdp, new); 875 } else { 876 if ((error = fdalloc(td, new, &new)) != 0) { 877 FILEDESC_XUNLOCK(fdp); 878 fdrop(fp, td); 879 return (error); 880 } 881 newfde = &fdp->fd_ofiles[new]; 882 } 883 884 KASSERT(fp == oldfde->fde_file, ("old fd has been modified")); 885 KASSERT(old != new, ("new fd is same as old")); 886 887 delfp = newfde->fde_file; 888 889 /* 890 * Duplicate the source descriptor. 891 */ 892 #ifdef CAPABILITIES 893 seq_write_begin(&newfde->fde_seq); 894 #endif 895 filecaps_free(&newfde->fde_caps); 896 memcpy(newfde, oldfde, fde_change_size); 897 filecaps_copy(&oldfde->fde_caps, &newfde->fde_caps); 898 if ((flags & DUP_CLOEXEC) != 0) 899 newfde->fde_flags = oldfde->fde_flags | UF_EXCLOSE; 900 else 901 newfde->fde_flags = oldfde->fde_flags & ~UF_EXCLOSE; 902 #ifdef CAPABILITIES 903 seq_write_end(&newfde->fde_seq); 904 #endif 905 td->td_retval[0] = new; 906 907 if (delfp != NULL) { 908 (void) closefp(fdp, new, delfp, td, 1); 909 /* closefp() drops the FILEDESC lock for us. */ 910 } else { 911 FILEDESC_XUNLOCK(fdp); 912 } 913 914 return (0); 915 } 916 917 /* 918 * If sigio is on the list associated with a process or process group, 919 * disable signalling from the device, remove sigio from the list and 920 * free sigio. 921 */ 922 void 923 funsetown(struct sigio **sigiop) 924 { 925 struct sigio *sigio; 926 927 SIGIO_LOCK(); 928 sigio = *sigiop; 929 if (sigio == NULL) { 930 SIGIO_UNLOCK(); 931 return; 932 } 933 *(sigio->sio_myref) = NULL; 934 if ((sigio)->sio_pgid < 0) { 935 struct pgrp *pg = (sigio)->sio_pgrp; 936 PGRP_LOCK(pg); 937 SLIST_REMOVE(&sigio->sio_pgrp->pg_sigiolst, sigio, 938 sigio, sio_pgsigio); 939 PGRP_UNLOCK(pg); 940 } else { 941 struct proc *p = (sigio)->sio_proc; 942 PROC_LOCK(p); 943 SLIST_REMOVE(&sigio->sio_proc->p_sigiolst, sigio, 944 sigio, sio_pgsigio); 945 PROC_UNLOCK(p); 946 } 947 SIGIO_UNLOCK(); 948 crfree(sigio->sio_ucred); 949 free(sigio, M_SIGIO); 950 } 951 952 /* 953 * Free a list of sigio structures. 954 * We only need to lock the SIGIO_LOCK because we have made ourselves 955 * inaccessible to callers of fsetown and therefore do not need to lock 956 * the proc or pgrp struct for the list manipulation. 957 */ 958 void 959 funsetownlst(struct sigiolst *sigiolst) 960 { 961 struct proc *p; 962 struct pgrp *pg; 963 struct sigio *sigio; 964 965 sigio = SLIST_FIRST(sigiolst); 966 if (sigio == NULL) 967 return; 968 p = NULL; 969 pg = NULL; 970 971 /* 972 * Every entry of the list should belong 973 * to a single proc or pgrp. 974 */ 975 if (sigio->sio_pgid < 0) { 976 pg = sigio->sio_pgrp; 977 PGRP_LOCK_ASSERT(pg, MA_NOTOWNED); 978 } else /* if (sigio->sio_pgid > 0) */ { 979 p = sigio->sio_proc; 980 PROC_LOCK_ASSERT(p, MA_NOTOWNED); 981 } 982 983 SIGIO_LOCK(); 984 while ((sigio = SLIST_FIRST(sigiolst)) != NULL) { 985 *(sigio->sio_myref) = NULL; 986 if (pg != NULL) { 987 KASSERT(sigio->sio_pgid < 0, 988 ("Proc sigio in pgrp sigio list")); 989 KASSERT(sigio->sio_pgrp == pg, 990 ("Bogus pgrp in sigio list")); 991 PGRP_LOCK(pg); 992 SLIST_REMOVE(&pg->pg_sigiolst, sigio, sigio, 993 sio_pgsigio); 994 PGRP_UNLOCK(pg); 995 } else /* if (p != NULL) */ { 996 KASSERT(sigio->sio_pgid > 0, 997 ("Pgrp sigio in proc sigio list")); 998 KASSERT(sigio->sio_proc == p, 999 ("Bogus proc in sigio list")); 1000 PROC_LOCK(p); 1001 SLIST_REMOVE(&p->p_sigiolst, sigio, sigio, 1002 sio_pgsigio); 1003 PROC_UNLOCK(p); 1004 } 1005 SIGIO_UNLOCK(); 1006 crfree(sigio->sio_ucred); 1007 free(sigio, M_SIGIO); 1008 SIGIO_LOCK(); 1009 } 1010 SIGIO_UNLOCK(); 1011 } 1012 1013 /* 1014 * This is common code for FIOSETOWN ioctl called by fcntl(fd, F_SETOWN, arg). 1015 * 1016 * After permission checking, add a sigio structure to the sigio list for 1017 * the process or process group. 1018 */ 1019 int 1020 fsetown(pid_t pgid, struct sigio **sigiop) 1021 { 1022 struct proc *proc; 1023 struct pgrp *pgrp; 1024 struct sigio *sigio; 1025 int ret; 1026 1027 if (pgid == 0) { 1028 funsetown(sigiop); 1029 return (0); 1030 } 1031 1032 ret = 0; 1033 1034 /* Allocate and fill in the new sigio out of locks. */ 1035 sigio = malloc(sizeof(struct sigio), M_SIGIO, M_WAITOK); 1036 sigio->sio_pgid = pgid; 1037 sigio->sio_ucred = crhold(curthread->td_ucred); 1038 sigio->sio_myref = sigiop; 1039 1040 sx_slock(&proctree_lock); 1041 if (pgid > 0) { 1042 proc = pfind(pgid); 1043 if (proc == NULL) { 1044 ret = ESRCH; 1045 goto fail; 1046 } 1047 1048 /* 1049 * Policy - Don't allow a process to FSETOWN a process 1050 * in another session. 1051 * 1052 * Remove this test to allow maximum flexibility or 1053 * restrict FSETOWN to the current process or process 1054 * group for maximum safety. 1055 */ 1056 PROC_UNLOCK(proc); 1057 if (proc->p_session != curthread->td_proc->p_session) { 1058 ret = EPERM; 1059 goto fail; 1060 } 1061 1062 pgrp = NULL; 1063 } else /* if (pgid < 0) */ { 1064 pgrp = pgfind(-pgid); 1065 if (pgrp == NULL) { 1066 ret = ESRCH; 1067 goto fail; 1068 } 1069 PGRP_UNLOCK(pgrp); 1070 1071 /* 1072 * Policy - Don't allow a process to FSETOWN a process 1073 * in another session. 1074 * 1075 * Remove this test to allow maximum flexibility or 1076 * restrict FSETOWN to the current process or process 1077 * group for maximum safety. 1078 */ 1079 if (pgrp->pg_session != curthread->td_proc->p_session) { 1080 ret = EPERM; 1081 goto fail; 1082 } 1083 1084 proc = NULL; 1085 } 1086 funsetown(sigiop); 1087 if (pgid > 0) { 1088 PROC_LOCK(proc); 1089 /* 1090 * Since funsetownlst() is called without the proctree 1091 * locked, we need to check for P_WEXIT. 1092 * XXX: is ESRCH correct? 1093 */ 1094 if ((proc->p_flag & P_WEXIT) != 0) { 1095 PROC_UNLOCK(proc); 1096 ret = ESRCH; 1097 goto fail; 1098 } 1099 SLIST_INSERT_HEAD(&proc->p_sigiolst, sigio, sio_pgsigio); 1100 sigio->sio_proc = proc; 1101 PROC_UNLOCK(proc); 1102 } else { 1103 PGRP_LOCK(pgrp); 1104 SLIST_INSERT_HEAD(&pgrp->pg_sigiolst, sigio, sio_pgsigio); 1105 sigio->sio_pgrp = pgrp; 1106 PGRP_UNLOCK(pgrp); 1107 } 1108 sx_sunlock(&proctree_lock); 1109 SIGIO_LOCK(); 1110 *sigiop = sigio; 1111 SIGIO_UNLOCK(); 1112 return (0); 1113 1114 fail: 1115 sx_sunlock(&proctree_lock); 1116 crfree(sigio->sio_ucred); 1117 free(sigio, M_SIGIO); 1118 return (ret); 1119 } 1120 1121 /* 1122 * This is common code for FIOGETOWN ioctl called by fcntl(fd, F_GETOWN, arg). 1123 */ 1124 pid_t 1125 fgetown(sigiop) 1126 struct sigio **sigiop; 1127 { 1128 pid_t pgid; 1129 1130 SIGIO_LOCK(); 1131 pgid = (*sigiop != NULL) ? (*sigiop)->sio_pgid : 0; 1132 SIGIO_UNLOCK(); 1133 return (pgid); 1134 } 1135 1136 /* 1137 * Function drops the filedesc lock on return. 1138 */ 1139 static int 1140 closefp(struct filedesc *fdp, int fd, struct file *fp, struct thread *td, 1141 int holdleaders) 1142 { 1143 int error; 1144 1145 FILEDESC_XLOCK_ASSERT(fdp); 1146 1147 if (holdleaders) { 1148 if (td->td_proc->p_fdtol != NULL) { 1149 /* 1150 * Ask fdfree() to sleep to ensure that all relevant 1151 * process leaders can be traversed in closef(). 1152 */ 1153 fdp->fd_holdleaderscount++; 1154 } else { 1155 holdleaders = 0; 1156 } 1157 } 1158 1159 /* 1160 * We now hold the fp reference that used to be owned by the 1161 * descriptor array. We have to unlock the FILEDESC *AFTER* 1162 * knote_fdclose to prevent a race of the fd getting opened, a knote 1163 * added, and deleteing a knote for the new fd. 1164 */ 1165 knote_fdclose(td, fd); 1166 1167 /* 1168 * We need to notify mqueue if the object is of type mqueue. 1169 */ 1170 if (fp->f_type == DTYPE_MQUEUE) 1171 mq_fdclose(td, fd, fp); 1172 FILEDESC_XUNLOCK(fdp); 1173 1174 error = closef(fp, td); 1175 if (holdleaders) { 1176 FILEDESC_XLOCK(fdp); 1177 fdp->fd_holdleaderscount--; 1178 if (fdp->fd_holdleaderscount == 0 && 1179 fdp->fd_holdleaderswakeup != 0) { 1180 fdp->fd_holdleaderswakeup = 0; 1181 wakeup(&fdp->fd_holdleaderscount); 1182 } 1183 FILEDESC_XUNLOCK(fdp); 1184 } 1185 return (error); 1186 } 1187 1188 /* 1189 * Close a file descriptor. 1190 */ 1191 #ifndef _SYS_SYSPROTO_H_ 1192 struct close_args { 1193 int fd; 1194 }; 1195 #endif 1196 /* ARGSUSED */ 1197 int 1198 sys_close(td, uap) 1199 struct thread *td; 1200 struct close_args *uap; 1201 { 1202 1203 return (kern_close(td, uap->fd)); 1204 } 1205 1206 int 1207 kern_close(td, fd) 1208 struct thread *td; 1209 int fd; 1210 { 1211 struct filedesc *fdp; 1212 struct file *fp; 1213 1214 fdp = td->td_proc->p_fd; 1215 1216 AUDIT_SYSCLOSE(td, fd); 1217 1218 FILEDESC_XLOCK(fdp); 1219 if ((fp = fget_locked(fdp, fd)) == NULL) { 1220 FILEDESC_XUNLOCK(fdp); 1221 return (EBADF); 1222 } 1223 fdfree(fdp, fd); 1224 1225 /* closefp() drops the FILEDESC lock for us. */ 1226 return (closefp(fdp, fd, fp, td, 1)); 1227 } 1228 1229 /* 1230 * Close open file descriptors. 1231 */ 1232 #ifndef _SYS_SYSPROTO_H_ 1233 struct closefrom_args { 1234 int lowfd; 1235 }; 1236 #endif 1237 /* ARGSUSED */ 1238 int 1239 sys_closefrom(struct thread *td, struct closefrom_args *uap) 1240 { 1241 struct filedesc *fdp; 1242 int fd; 1243 1244 fdp = td->td_proc->p_fd; 1245 AUDIT_ARG_FD(uap->lowfd); 1246 1247 /* 1248 * Treat negative starting file descriptor values identical to 1249 * closefrom(0) which closes all files. 1250 */ 1251 if (uap->lowfd < 0) 1252 uap->lowfd = 0; 1253 FILEDESC_SLOCK(fdp); 1254 for (fd = uap->lowfd; fd <= fdp->fd_lastfile; fd++) { 1255 if (fdp->fd_ofiles[fd].fde_file != NULL) { 1256 FILEDESC_SUNLOCK(fdp); 1257 (void)kern_close(td, fd); 1258 FILEDESC_SLOCK(fdp); 1259 } 1260 } 1261 FILEDESC_SUNLOCK(fdp); 1262 return (0); 1263 } 1264 1265 #if defined(COMPAT_43) 1266 /* 1267 * Return status information about a file descriptor. 1268 */ 1269 #ifndef _SYS_SYSPROTO_H_ 1270 struct ofstat_args { 1271 int fd; 1272 struct ostat *sb; 1273 }; 1274 #endif 1275 /* ARGSUSED */ 1276 int 1277 ofstat(struct thread *td, struct ofstat_args *uap) 1278 { 1279 struct ostat oub; 1280 struct stat ub; 1281 int error; 1282 1283 error = kern_fstat(td, uap->fd, &ub); 1284 if (error == 0) { 1285 cvtstat(&ub, &oub); 1286 error = copyout(&oub, uap->sb, sizeof(oub)); 1287 } 1288 return (error); 1289 } 1290 #endif /* COMPAT_43 */ 1291 1292 /* 1293 * Return status information about a file descriptor. 1294 */ 1295 #ifndef _SYS_SYSPROTO_H_ 1296 struct fstat_args { 1297 int fd; 1298 struct stat *sb; 1299 }; 1300 #endif 1301 /* ARGSUSED */ 1302 int 1303 sys_fstat(struct thread *td, struct fstat_args *uap) 1304 { 1305 struct stat ub; 1306 int error; 1307 1308 error = kern_fstat(td, uap->fd, &ub); 1309 if (error == 0) 1310 error = copyout(&ub, uap->sb, sizeof(ub)); 1311 return (error); 1312 } 1313 1314 int 1315 kern_fstat(struct thread *td, int fd, struct stat *sbp) 1316 { 1317 struct file *fp; 1318 cap_rights_t rights; 1319 int error; 1320 1321 AUDIT_ARG_FD(fd); 1322 1323 error = fget(td, fd, cap_rights_init(&rights, CAP_FSTAT), &fp); 1324 if (error != 0) 1325 return (error); 1326 1327 AUDIT_ARG_FILE(td->td_proc, fp); 1328 1329 error = fo_stat(fp, sbp, td->td_ucred, td); 1330 fdrop(fp, td); 1331 #ifdef KTRACE 1332 if (error == 0 && KTRPOINT(td, KTR_STRUCT)) 1333 ktrstat(sbp); 1334 #endif 1335 return (error); 1336 } 1337 1338 /* 1339 * Return status information about a file descriptor. 1340 */ 1341 #ifndef _SYS_SYSPROTO_H_ 1342 struct nfstat_args { 1343 int fd; 1344 struct nstat *sb; 1345 }; 1346 #endif 1347 /* ARGSUSED */ 1348 int 1349 sys_nfstat(struct thread *td, struct nfstat_args *uap) 1350 { 1351 struct nstat nub; 1352 struct stat ub; 1353 int error; 1354 1355 error = kern_fstat(td, uap->fd, &ub); 1356 if (error == 0) { 1357 cvtnstat(&ub, &nub); 1358 error = copyout(&nub, uap->sb, sizeof(nub)); 1359 } 1360 return (error); 1361 } 1362 1363 /* 1364 * Return pathconf information about a file descriptor. 1365 */ 1366 #ifndef _SYS_SYSPROTO_H_ 1367 struct fpathconf_args { 1368 int fd; 1369 int name; 1370 }; 1371 #endif 1372 /* ARGSUSED */ 1373 int 1374 sys_fpathconf(struct thread *td, struct fpathconf_args *uap) 1375 { 1376 struct file *fp; 1377 struct vnode *vp; 1378 cap_rights_t rights; 1379 int error; 1380 1381 error = fget(td, uap->fd, cap_rights_init(&rights, CAP_FPATHCONF), &fp); 1382 if (error != 0) 1383 return (error); 1384 1385 /* If asynchronous I/O is available, it works for all descriptors. */ 1386 if (uap->name == _PC_ASYNC_IO) { 1387 td->td_retval[0] = async_io_version; 1388 goto out; 1389 } 1390 vp = fp->f_vnode; 1391 if (vp != NULL) { 1392 vn_lock(vp, LK_SHARED | LK_RETRY); 1393 error = VOP_PATHCONF(vp, uap->name, td->td_retval); 1394 VOP_UNLOCK(vp, 0); 1395 } else if (fp->f_type == DTYPE_PIPE || fp->f_type == DTYPE_SOCKET) { 1396 if (uap->name != _PC_PIPE_BUF) { 1397 error = EINVAL; 1398 } else { 1399 td->td_retval[0] = PIPE_BUF; 1400 error = 0; 1401 } 1402 } else { 1403 error = EOPNOTSUPP; 1404 } 1405 out: 1406 fdrop(fp, td); 1407 return (error); 1408 } 1409 1410 /* 1411 * Initialize filecaps structure. 1412 */ 1413 void 1414 filecaps_init(struct filecaps *fcaps) 1415 { 1416 1417 bzero(fcaps, sizeof(*fcaps)); 1418 fcaps->fc_nioctls = -1; 1419 } 1420 1421 /* 1422 * Copy filecaps structure allocating memory for ioctls array if needed. 1423 */ 1424 void 1425 filecaps_copy(const struct filecaps *src, struct filecaps *dst) 1426 { 1427 size_t size; 1428 1429 *dst = *src; 1430 if (src->fc_ioctls != NULL) { 1431 KASSERT(src->fc_nioctls > 0, 1432 ("fc_ioctls != NULL, but fc_nioctls=%hd", src->fc_nioctls)); 1433 1434 size = sizeof(src->fc_ioctls[0]) * src->fc_nioctls; 1435 dst->fc_ioctls = malloc(size, M_FILECAPS, M_WAITOK); 1436 bcopy(src->fc_ioctls, dst->fc_ioctls, size); 1437 } 1438 } 1439 1440 /* 1441 * Move filecaps structure to the new place and clear the old place. 1442 */ 1443 void 1444 filecaps_move(struct filecaps *src, struct filecaps *dst) 1445 { 1446 1447 *dst = *src; 1448 bzero(src, sizeof(*src)); 1449 } 1450 1451 /* 1452 * Fill the given filecaps structure with full rights. 1453 */ 1454 static void 1455 filecaps_fill(struct filecaps *fcaps) 1456 { 1457 1458 CAP_ALL(&fcaps->fc_rights); 1459 fcaps->fc_ioctls = NULL; 1460 fcaps->fc_nioctls = -1; 1461 fcaps->fc_fcntls = CAP_FCNTL_ALL; 1462 } 1463 1464 /* 1465 * Free memory allocated within filecaps structure. 1466 */ 1467 void 1468 filecaps_free(struct filecaps *fcaps) 1469 { 1470 1471 free(fcaps->fc_ioctls, M_FILECAPS); 1472 bzero(fcaps, sizeof(*fcaps)); 1473 } 1474 1475 /* 1476 * Validate the given filecaps structure. 1477 */ 1478 static void 1479 filecaps_validate(const struct filecaps *fcaps, const char *func) 1480 { 1481 1482 KASSERT(cap_rights_is_valid(&fcaps->fc_rights), 1483 ("%s: invalid rights", func)); 1484 KASSERT((fcaps->fc_fcntls & ~CAP_FCNTL_ALL) == 0, 1485 ("%s: invalid fcntls", func)); 1486 KASSERT(fcaps->fc_fcntls == 0 || 1487 cap_rights_is_set(&fcaps->fc_rights, CAP_FCNTL), 1488 ("%s: fcntls without CAP_FCNTL", func)); 1489 KASSERT(fcaps->fc_ioctls != NULL ? fcaps->fc_nioctls > 0 : 1490 (fcaps->fc_nioctls == -1 || fcaps->fc_nioctls == 0), 1491 ("%s: invalid ioctls", func)); 1492 KASSERT(fcaps->fc_nioctls == 0 || 1493 cap_rights_is_set(&fcaps->fc_rights, CAP_IOCTL), 1494 ("%s: ioctls without CAP_IOCTL", func)); 1495 } 1496 1497 static void 1498 fdgrowtable_exp(struct filedesc *fdp, int nfd) 1499 { 1500 int nfd1; 1501 1502 FILEDESC_XLOCK_ASSERT(fdp); 1503 1504 nfd1 = fdp->fd_nfiles * 2; 1505 if (nfd1 < nfd) 1506 nfd1 = nfd; 1507 fdgrowtable(fdp, nfd1); 1508 } 1509 1510 /* 1511 * Grow the file table to accomodate (at least) nfd descriptors. 1512 */ 1513 static void 1514 fdgrowtable(struct filedesc *fdp, int nfd) 1515 { 1516 struct filedesc0 *fdp0; 1517 struct freetable *ft; 1518 struct fdescenttbl *ntable; 1519 struct fdescenttbl *otable; 1520 int nnfiles, onfiles; 1521 NDSLOTTYPE *nmap, *omap; 1522 1523 /* 1524 * If lastfile is -1 this struct filedesc was just allocated and we are 1525 * growing it to accomodate for the one we are going to copy from. There 1526 * is no need to have a lock on this one as it's not visible to anyone. 1527 */ 1528 if (fdp->fd_lastfile != -1) 1529 FILEDESC_XLOCK_ASSERT(fdp); 1530 1531 KASSERT(fdp->fd_nfiles > 0, ("zero-length file table")); 1532 1533 /* save old values */ 1534 onfiles = fdp->fd_nfiles; 1535 otable = fdp->fd_files; 1536 omap = fdp->fd_map; 1537 1538 /* compute the size of the new table */ 1539 nnfiles = NDSLOTS(nfd) * NDENTRIES; /* round up */ 1540 if (nnfiles <= onfiles) 1541 /* the table is already large enough */ 1542 return; 1543 1544 /* 1545 * Allocate a new table. We need enough space for the number of 1546 * entries, file entries themselves and the struct freetable we will use 1547 * when we decommission the table and place it on the freelist. 1548 * We place the struct freetable in the middle so we don't have 1549 * to worry about padding. 1550 */ 1551 ntable = malloc(offsetof(struct fdescenttbl, fdt_ofiles) + 1552 nnfiles * sizeof(ntable->fdt_ofiles[0]) + 1553 sizeof(struct freetable), 1554 M_FILEDESC, M_ZERO | M_WAITOK); 1555 /* copy the old data */ 1556 ntable->fdt_nfiles = nnfiles; 1557 memcpy(ntable->fdt_ofiles, otable->fdt_ofiles, 1558 onfiles * sizeof(ntable->fdt_ofiles[0])); 1559 1560 /* 1561 * Allocate a new map only if the old is not large enough. It will 1562 * grow at a slower rate than the table as it can map more 1563 * entries than the table can hold. 1564 */ 1565 if (NDSLOTS(nnfiles) > NDSLOTS(onfiles)) { 1566 nmap = malloc(NDSLOTS(nnfiles) * NDSLOTSIZE, M_FILEDESC, 1567 M_ZERO | M_WAITOK); 1568 /* copy over the old data and update the pointer */ 1569 memcpy(nmap, omap, NDSLOTS(onfiles) * sizeof(*omap)); 1570 fdp->fd_map = nmap; 1571 } 1572 1573 /* 1574 * Make sure that ntable is correctly initialized before we replace 1575 * fd_files poiner. Otherwise fget_unlocked() may see inconsistent 1576 * data. 1577 */ 1578 atomic_store_rel_ptr((volatile void *)&fdp->fd_files, (uintptr_t)ntable); 1579 1580 /* 1581 * Do not free the old file table, as some threads may still 1582 * reference entries within it. Instead, place it on a freelist 1583 * which will be processed when the struct filedesc is released. 1584 * 1585 * Note that if onfiles == NDFILE, we're dealing with the original 1586 * static allocation contained within (struct filedesc0 *)fdp, 1587 * which must not be freed. 1588 */ 1589 if (onfiles > NDFILE) { 1590 ft = (struct freetable *)&otable->fdt_ofiles[onfiles]; 1591 fdp0 = (struct filedesc0 *)fdp; 1592 ft->ft_table = otable; 1593 SLIST_INSERT_HEAD(&fdp0->fd_free, ft, ft_next); 1594 } 1595 /* 1596 * The map does not have the same possibility of threads still 1597 * holding references to it. So always free it as long as it 1598 * does not reference the original static allocation. 1599 */ 1600 if (NDSLOTS(onfiles) > NDSLOTS(NDFILE)) 1601 free(omap, M_FILEDESC); 1602 } 1603 1604 /* 1605 * Allocate a file descriptor for the process. 1606 */ 1607 int 1608 fdalloc(struct thread *td, int minfd, int *result) 1609 { 1610 struct proc *p = td->td_proc; 1611 struct filedesc *fdp = p->p_fd; 1612 int fd = -1, maxfd, allocfd; 1613 #ifdef RACCT 1614 int error; 1615 #endif 1616 1617 FILEDESC_XLOCK_ASSERT(fdp); 1618 1619 if (fdp->fd_freefile > minfd) 1620 minfd = fdp->fd_freefile; 1621 1622 maxfd = getmaxfd(p); 1623 1624 /* 1625 * Search the bitmap for a free descriptor starting at minfd. 1626 * If none is found, grow the file table. 1627 */ 1628 fd = fd_first_free(fdp, minfd, fdp->fd_nfiles); 1629 if (fd >= maxfd) 1630 return (EMFILE); 1631 if (fd >= fdp->fd_nfiles) { 1632 allocfd = min(fd * 2, maxfd); 1633 #ifdef RACCT 1634 PROC_LOCK(p); 1635 error = racct_set(p, RACCT_NOFILE, allocfd); 1636 PROC_UNLOCK(p); 1637 if (error != 0) 1638 return (EMFILE); 1639 #endif 1640 /* 1641 * fd is already equal to first free descriptor >= minfd, so 1642 * we only need to grow the table and we are done. 1643 */ 1644 fdgrowtable_exp(fdp, allocfd); 1645 } 1646 1647 /* 1648 * Perform some sanity checks, then mark the file descriptor as 1649 * used and return it to the caller. 1650 */ 1651 KASSERT(fd >= 0 && fd < min(maxfd, fdp->fd_nfiles), 1652 ("invalid descriptor %d", fd)); 1653 KASSERT(!fdisused(fdp, fd), 1654 ("fd_first_free() returned non-free descriptor")); 1655 KASSERT(fdp->fd_ofiles[fd].fde_file == NULL, 1656 ("file descriptor isn't free")); 1657 KASSERT(fdp->fd_ofiles[fd].fde_flags == 0, ("file flags are set")); 1658 fdused(fdp, fd); 1659 *result = fd; 1660 return (0); 1661 } 1662 1663 /* 1664 * Allocate n file descriptors for the process. 1665 */ 1666 int 1667 fdallocn(struct thread *td, int minfd, int *fds, int n) 1668 { 1669 struct proc *p = td->td_proc; 1670 struct filedesc *fdp = p->p_fd; 1671 int i; 1672 1673 FILEDESC_XLOCK_ASSERT(fdp); 1674 1675 for (i = 0; i < n; i++) 1676 if (fdalloc(td, 0, &fds[i]) != 0) 1677 break; 1678 1679 if (i < n) { 1680 for (i--; i >= 0; i--) 1681 fdunused(fdp, fds[i]); 1682 return (EMFILE); 1683 } 1684 1685 return (0); 1686 } 1687 1688 /* 1689 * Create a new open file structure and allocate a file decriptor for the 1690 * process that refers to it. We add one reference to the file for the 1691 * descriptor table and one reference for resultfp. This is to prevent us 1692 * being preempted and the entry in the descriptor table closed after we 1693 * release the FILEDESC lock. 1694 */ 1695 int 1696 falloc(struct thread *td, struct file **resultfp, int *resultfd, int flags) 1697 { 1698 struct file *fp; 1699 int error, fd; 1700 1701 error = falloc_noinstall(td, &fp); 1702 if (error) 1703 return (error); /* no reference held on error */ 1704 1705 error = finstall(td, fp, &fd, flags, NULL); 1706 if (error) { 1707 fdrop(fp, td); /* one reference (fp only) */ 1708 return (error); 1709 } 1710 1711 if (resultfp != NULL) 1712 *resultfp = fp; /* copy out result */ 1713 else 1714 fdrop(fp, td); /* release local reference */ 1715 1716 if (resultfd != NULL) 1717 *resultfd = fd; 1718 1719 return (0); 1720 } 1721 1722 /* 1723 * Create a new open file structure without allocating a file descriptor. 1724 */ 1725 int 1726 falloc_noinstall(struct thread *td, struct file **resultfp) 1727 { 1728 struct file *fp; 1729 int maxuserfiles = maxfiles - (maxfiles / 20); 1730 static struct timeval lastfail; 1731 static int curfail; 1732 1733 KASSERT(resultfp != NULL, ("%s: resultfp == NULL", __func__)); 1734 1735 if ((openfiles >= maxuserfiles && 1736 priv_check(td, PRIV_MAXFILES) != 0) || 1737 openfiles >= maxfiles) { 1738 if (ppsratecheck(&lastfail, &curfail, 1)) { 1739 printf("kern.maxfiles limit exceeded by uid %i, " 1740 "please see tuning(7).\n", td->td_ucred->cr_ruid); 1741 } 1742 return (ENFILE); 1743 } 1744 atomic_add_int(&openfiles, 1); 1745 fp = uma_zalloc(file_zone, M_WAITOK | M_ZERO); 1746 refcount_init(&fp->f_count, 1); 1747 fp->f_cred = crhold(td->td_ucred); 1748 fp->f_ops = &badfileops; 1749 *resultfp = fp; 1750 return (0); 1751 } 1752 1753 /* 1754 * Install a file in a file descriptor table. 1755 */ 1756 int 1757 finstall(struct thread *td, struct file *fp, int *fd, int flags, 1758 struct filecaps *fcaps) 1759 { 1760 struct filedesc *fdp = td->td_proc->p_fd; 1761 struct filedescent *fde; 1762 int error; 1763 1764 KASSERT(fd != NULL, ("%s: fd == NULL", __func__)); 1765 KASSERT(fp != NULL, ("%s: fp == NULL", __func__)); 1766 if (fcaps != NULL) 1767 filecaps_validate(fcaps, __func__); 1768 1769 FILEDESC_XLOCK(fdp); 1770 if ((error = fdalloc(td, 0, fd))) { 1771 FILEDESC_XUNLOCK(fdp); 1772 return (error); 1773 } 1774 fhold(fp); 1775 fde = &fdp->fd_ofiles[*fd]; 1776 #ifdef CAPABILITIES 1777 seq_write_begin(&fde->fde_seq); 1778 #endif 1779 fde->fde_file = fp; 1780 if ((flags & O_CLOEXEC) != 0) 1781 fde->fde_flags |= UF_EXCLOSE; 1782 if (fcaps != NULL) 1783 filecaps_move(fcaps, &fde->fde_caps); 1784 else 1785 filecaps_fill(&fde->fde_caps); 1786 #ifdef CAPABILITIES 1787 seq_write_end(&fde->fde_seq); 1788 #endif 1789 FILEDESC_XUNLOCK(fdp); 1790 return (0); 1791 } 1792 1793 /* 1794 * Build a new filedesc structure from another. 1795 * Copy the current, root, and jail root vnode references. 1796 * 1797 * If fdp is not NULL, return with it shared locked. 1798 */ 1799 struct filedesc * 1800 fdinit(struct filedesc *fdp, bool prepfiles) 1801 { 1802 struct filedesc0 *newfdp0; 1803 struct filedesc *newfdp; 1804 1805 newfdp0 = uma_zalloc(filedesc0_zone, M_WAITOK | M_ZERO); 1806 newfdp = &newfdp0->fd_fd; 1807 1808 /* Create the file descriptor table. */ 1809 FILEDESC_LOCK_INIT(newfdp); 1810 newfdp->fd_refcnt = 1; 1811 newfdp->fd_holdcnt = 1; 1812 newfdp->fd_cmask = CMASK; 1813 newfdp->fd_map = newfdp0->fd_dmap; 1814 newfdp->fd_lastfile = -1; 1815 newfdp->fd_files = (struct fdescenttbl *)&newfdp0->fd_dfiles; 1816 newfdp->fd_files->fdt_nfiles = NDFILE; 1817 1818 if (fdp == NULL) 1819 return (newfdp); 1820 1821 if (prepfiles && fdp->fd_lastfile >= newfdp->fd_nfiles) 1822 fdgrowtable(newfdp, fdp->fd_lastfile + 1); 1823 1824 FILEDESC_SLOCK(fdp); 1825 newfdp->fd_cdir = fdp->fd_cdir; 1826 if (newfdp->fd_cdir) 1827 VREF(newfdp->fd_cdir); 1828 newfdp->fd_rdir = fdp->fd_rdir; 1829 if (newfdp->fd_rdir) 1830 VREF(newfdp->fd_rdir); 1831 newfdp->fd_jdir = fdp->fd_jdir; 1832 if (newfdp->fd_jdir) 1833 VREF(newfdp->fd_jdir); 1834 1835 if (!prepfiles) { 1836 FILEDESC_SUNLOCK(fdp); 1837 } else { 1838 while (fdp->fd_lastfile >= newfdp->fd_nfiles) { 1839 FILEDESC_SUNLOCK(fdp); 1840 fdgrowtable(newfdp, fdp->fd_lastfile + 1); 1841 FILEDESC_SLOCK(fdp); 1842 } 1843 } 1844 1845 return (newfdp); 1846 } 1847 1848 static struct filedesc * 1849 fdhold(struct proc *p) 1850 { 1851 struct filedesc *fdp; 1852 1853 mtx_lock(&fdesc_mtx); 1854 fdp = p->p_fd; 1855 if (fdp != NULL) 1856 fdp->fd_holdcnt++; 1857 mtx_unlock(&fdesc_mtx); 1858 return (fdp); 1859 } 1860 1861 static void 1862 fddrop(struct filedesc *fdp) 1863 { 1864 int i; 1865 1866 if (fdp->fd_holdcnt > 1) { 1867 mtx_lock(&fdesc_mtx); 1868 i = --fdp->fd_holdcnt; 1869 mtx_unlock(&fdesc_mtx); 1870 if (i > 0) 1871 return; 1872 } 1873 1874 FILEDESC_LOCK_DESTROY(fdp); 1875 uma_zfree(filedesc0_zone, fdp); 1876 } 1877 1878 /* 1879 * Share a filedesc structure. 1880 */ 1881 struct filedesc * 1882 fdshare(struct filedesc *fdp) 1883 { 1884 1885 FILEDESC_XLOCK(fdp); 1886 fdp->fd_refcnt++; 1887 FILEDESC_XUNLOCK(fdp); 1888 return (fdp); 1889 } 1890 1891 /* 1892 * Unshare a filedesc structure, if necessary by making a copy 1893 */ 1894 void 1895 fdunshare(struct thread *td) 1896 { 1897 struct filedesc *tmp; 1898 struct proc *p = td->td_proc; 1899 1900 if (p->p_fd->fd_refcnt == 1) 1901 return; 1902 1903 tmp = fdcopy(p->p_fd); 1904 fdescfree(td); 1905 p->p_fd = tmp; 1906 } 1907 1908 /* 1909 * Copy a filedesc structure. A NULL pointer in returns a NULL reference, 1910 * this is to ease callers, not catch errors. 1911 */ 1912 struct filedesc * 1913 fdcopy(struct filedesc *fdp) 1914 { 1915 struct filedesc *newfdp; 1916 struct filedescent *nfde, *ofde; 1917 int i; 1918 1919 MPASS(fdp != NULL); 1920 1921 newfdp = fdinit(fdp, true); 1922 /* copy all passable descriptors (i.e. not kqueue) */ 1923 newfdp->fd_freefile = -1; 1924 for (i = 0; i <= fdp->fd_lastfile; ++i) { 1925 ofde = &fdp->fd_ofiles[i]; 1926 if (ofde->fde_file == NULL || 1927 (ofde->fde_file->f_ops->fo_flags & DFLAG_PASSABLE) == 0) { 1928 if (newfdp->fd_freefile == -1) 1929 newfdp->fd_freefile = i; 1930 continue; 1931 } 1932 nfde = &newfdp->fd_ofiles[i]; 1933 *nfde = *ofde; 1934 filecaps_copy(&ofde->fde_caps, &nfde->fde_caps); 1935 fhold(nfde->fde_file); 1936 fdused_init(newfdp, i); 1937 newfdp->fd_lastfile = i; 1938 } 1939 if (newfdp->fd_freefile == -1) 1940 newfdp->fd_freefile = i; 1941 newfdp->fd_cmask = fdp->fd_cmask; 1942 FILEDESC_SUNLOCK(fdp); 1943 return (newfdp); 1944 } 1945 1946 /* 1947 * Clear POSIX style locks. This is only used when fdp looses a reference (i.e. 1948 * one of processes using it exits) and the table used to be shared. 1949 */ 1950 static void 1951 fdclearlocks(struct thread *td) 1952 { 1953 struct filedesc *fdp; 1954 struct filedesc_to_leader *fdtol; 1955 struct flock lf; 1956 struct file *fp; 1957 struct proc *p; 1958 struct vnode *vp; 1959 int i; 1960 1961 p = td->td_proc; 1962 fdp = p->p_fd; 1963 fdtol = p->p_fdtol; 1964 MPASS(fdtol != NULL); 1965 1966 FILEDESC_XLOCK(fdp); 1967 KASSERT(fdtol->fdl_refcount > 0, 1968 ("filedesc_to_refcount botch: fdl_refcount=%d", 1969 fdtol->fdl_refcount)); 1970 if (fdtol->fdl_refcount == 1 && 1971 (p->p_leader->p_flag & P_ADVLOCK) != 0) { 1972 for (i = 0; i <= fdp->fd_lastfile; i++) { 1973 fp = fdp->fd_ofiles[i].fde_file; 1974 if (fp == NULL || fp->f_type != DTYPE_VNODE) 1975 continue; 1976 fhold(fp); 1977 FILEDESC_XUNLOCK(fdp); 1978 lf.l_whence = SEEK_SET; 1979 lf.l_start = 0; 1980 lf.l_len = 0; 1981 lf.l_type = F_UNLCK; 1982 vp = fp->f_vnode; 1983 (void) VOP_ADVLOCK(vp, 1984 (caddr_t)p->p_leader, F_UNLCK, 1985 &lf, F_POSIX); 1986 FILEDESC_XLOCK(fdp); 1987 fdrop(fp, td); 1988 } 1989 } 1990 retry: 1991 if (fdtol->fdl_refcount == 1) { 1992 if (fdp->fd_holdleaderscount > 0 && 1993 (p->p_leader->p_flag & P_ADVLOCK) != 0) { 1994 /* 1995 * close() or do_dup() has cleared a reference 1996 * in a shared file descriptor table. 1997 */ 1998 fdp->fd_holdleaderswakeup = 1; 1999 sx_sleep(&fdp->fd_holdleaderscount, 2000 FILEDESC_LOCK(fdp), PLOCK, "fdlhold", 0); 2001 goto retry; 2002 } 2003 if (fdtol->fdl_holdcount > 0) { 2004 /* 2005 * Ensure that fdtol->fdl_leader remains 2006 * valid in closef(). 2007 */ 2008 fdtol->fdl_wakeup = 1; 2009 sx_sleep(fdtol, FILEDESC_LOCK(fdp), PLOCK, 2010 "fdlhold", 0); 2011 goto retry; 2012 } 2013 } 2014 fdtol->fdl_refcount--; 2015 if (fdtol->fdl_refcount == 0 && 2016 fdtol->fdl_holdcount == 0) { 2017 fdtol->fdl_next->fdl_prev = fdtol->fdl_prev; 2018 fdtol->fdl_prev->fdl_next = fdtol->fdl_next; 2019 } else 2020 fdtol = NULL; 2021 p->p_fdtol = NULL; 2022 FILEDESC_XUNLOCK(fdp); 2023 if (fdtol != NULL) 2024 free(fdtol, M_FILEDESC_TO_LEADER); 2025 } 2026 2027 /* 2028 * Release a filedesc structure. 2029 */ 2030 void 2031 fdescfree(struct thread *td) 2032 { 2033 struct filedesc0 *fdp0; 2034 struct filedesc *fdp; 2035 struct freetable *ft, *tft; 2036 struct filedescent *fde; 2037 struct file *fp; 2038 struct vnode *cdir, *jdir, *rdir; 2039 int i; 2040 2041 fdp = td->td_proc->p_fd; 2042 MPASS(fdp != NULL); 2043 2044 #ifdef RACCT 2045 PROC_LOCK(td->td_proc); 2046 racct_set(td->td_proc, RACCT_NOFILE, 0); 2047 PROC_UNLOCK(td->td_proc); 2048 #endif 2049 2050 if (td->td_proc->p_fdtol != NULL) 2051 fdclearlocks(td); 2052 2053 mtx_lock(&fdesc_mtx); 2054 td->td_proc->p_fd = NULL; 2055 mtx_unlock(&fdesc_mtx); 2056 2057 FILEDESC_XLOCK(fdp); 2058 i = --fdp->fd_refcnt; 2059 if (i > 0) { 2060 FILEDESC_XUNLOCK(fdp); 2061 return; 2062 } 2063 2064 cdir = fdp->fd_cdir; 2065 fdp->fd_cdir = NULL; 2066 rdir = fdp->fd_rdir; 2067 fdp->fd_rdir = NULL; 2068 jdir = fdp->fd_jdir; 2069 fdp->fd_jdir = NULL; 2070 FILEDESC_XUNLOCK(fdp); 2071 2072 for (i = 0; i <= fdp->fd_lastfile; i++) { 2073 fde = &fdp->fd_ofiles[i]; 2074 fp = fde->fde_file; 2075 if (fp != NULL) { 2076 fdefree_last(fde); 2077 (void) closef(fp, td); 2078 } 2079 } 2080 2081 if (NDSLOTS(fdp->fd_nfiles) > NDSLOTS(NDFILE)) 2082 free(fdp->fd_map, M_FILEDESC); 2083 if (fdp->fd_nfiles > NDFILE) 2084 free(fdp->fd_files, M_FILEDESC); 2085 2086 fdp0 = (struct filedesc0 *)fdp; 2087 SLIST_FOREACH_SAFE(ft, &fdp0->fd_free, ft_next, tft) 2088 free(ft->ft_table, M_FILEDESC); 2089 2090 if (cdir != NULL) 2091 vrele(cdir); 2092 if (rdir != NULL) 2093 vrele(rdir); 2094 if (jdir != NULL) 2095 vrele(jdir); 2096 2097 fddrop(fdp); 2098 } 2099 2100 /* 2101 * For setugid programs, we don't want to people to use that setugidness 2102 * to generate error messages which write to a file which otherwise would 2103 * otherwise be off-limits to the process. We check for filesystems where 2104 * the vnode can change out from under us after execve (like [lin]procfs). 2105 * 2106 * Since fdsetugidsafety calls this only for fd 0, 1 and 2, this check is 2107 * sufficient. We also don't check for setugidness since we know we are. 2108 */ 2109 static bool 2110 is_unsafe(struct file *fp) 2111 { 2112 struct vnode *vp; 2113 2114 if (fp->f_type != DTYPE_VNODE) 2115 return (false); 2116 2117 vp = fp->f_vnode; 2118 return ((vp->v_vflag & VV_PROCDEP) != 0); 2119 } 2120 2121 /* 2122 * Make this setguid thing safe, if at all possible. 2123 */ 2124 void 2125 fdsetugidsafety(struct thread *td) 2126 { 2127 struct filedesc *fdp; 2128 struct file *fp; 2129 int i; 2130 2131 fdp = td->td_proc->p_fd; 2132 KASSERT(fdp->fd_refcnt == 1, ("the fdtable should not be shared")); 2133 MPASS(fdp->fd_nfiles >= 3); 2134 for (i = 0; i <= 2; i++) { 2135 fp = fdp->fd_ofiles[i].fde_file; 2136 if (fp != NULL && is_unsafe(fp)) { 2137 FILEDESC_XLOCK(fdp); 2138 knote_fdclose(td, i); 2139 /* 2140 * NULL-out descriptor prior to close to avoid 2141 * a race while close blocks. 2142 */ 2143 fdfree(fdp, i); 2144 FILEDESC_XUNLOCK(fdp); 2145 (void) closef(fp, td); 2146 } 2147 } 2148 } 2149 2150 /* 2151 * If a specific file object occupies a specific file descriptor, close the 2152 * file descriptor entry and drop a reference on the file object. This is a 2153 * convenience function to handle a subsequent error in a function that calls 2154 * falloc() that handles the race that another thread might have closed the 2155 * file descriptor out from under the thread creating the file object. 2156 */ 2157 void 2158 fdclose(struct filedesc *fdp, struct file *fp, int idx, struct thread *td) 2159 { 2160 2161 FILEDESC_XLOCK(fdp); 2162 if (fdp->fd_ofiles[idx].fde_file == fp) { 2163 fdfree(fdp, idx); 2164 FILEDESC_XUNLOCK(fdp); 2165 fdrop(fp, td); 2166 } else 2167 FILEDESC_XUNLOCK(fdp); 2168 } 2169 2170 /* 2171 * Close any files on exec? 2172 */ 2173 void 2174 fdcloseexec(struct thread *td) 2175 { 2176 struct filedesc *fdp; 2177 struct filedescent *fde; 2178 struct file *fp; 2179 int i; 2180 2181 fdp = td->td_proc->p_fd; 2182 KASSERT(fdp->fd_refcnt == 1, ("the fdtable should not be shared")); 2183 for (i = 0; i <= fdp->fd_lastfile; i++) { 2184 fde = &fdp->fd_ofiles[i]; 2185 fp = fde->fde_file; 2186 if (fp != NULL && (fp->f_type == DTYPE_MQUEUE || 2187 (fde->fde_flags & UF_EXCLOSE))) { 2188 FILEDESC_XLOCK(fdp); 2189 fdfree(fdp, i); 2190 (void) closefp(fdp, i, fp, td, 0); 2191 /* closefp() drops the FILEDESC lock. */ 2192 } 2193 } 2194 } 2195 2196 /* 2197 * It is unsafe for set[ug]id processes to be started with file 2198 * descriptors 0..2 closed, as these descriptors are given implicit 2199 * significance in the Standard C library. fdcheckstd() will create a 2200 * descriptor referencing /dev/null for each of stdin, stdout, and 2201 * stderr that is not already open. 2202 */ 2203 int 2204 fdcheckstd(struct thread *td) 2205 { 2206 struct filedesc *fdp; 2207 register_t save; 2208 int i, error, devnull; 2209 2210 fdp = td->td_proc->p_fd; 2211 KASSERT(fdp->fd_refcnt == 1, ("the fdtable should not be shared")); 2212 MPASS(fdp->fd_nfiles >= 3); 2213 devnull = -1; 2214 for (i = 0; i <= 2; i++) { 2215 if (fdp->fd_ofiles[i].fde_file != NULL) 2216 continue; 2217 2218 save = td->td_retval[0]; 2219 if (devnull != -1) { 2220 error = do_dup(td, DUP_FIXED, devnull, i); 2221 } else { 2222 error = kern_openat(td, AT_FDCWD, "/dev/null", 2223 UIO_SYSSPACE, O_RDWR, 0); 2224 if (error == 0) { 2225 devnull = td->td_retval[0]; 2226 KASSERT(devnull == i, ("we didn't get our fd")); 2227 } 2228 } 2229 td->td_retval[0] = save; 2230 if (error != 0) 2231 return (error); 2232 } 2233 return (0); 2234 } 2235 2236 /* 2237 * Internal form of close. Decrement reference count on file structure. 2238 * Note: td may be NULL when closing a file that was being passed in a 2239 * message. 2240 * 2241 * XXXRW: Giant is not required for the caller, but often will be held; this 2242 * makes it moderately likely the Giant will be recursed in the VFS case. 2243 */ 2244 int 2245 closef(struct file *fp, struct thread *td) 2246 { 2247 struct vnode *vp; 2248 struct flock lf; 2249 struct filedesc_to_leader *fdtol; 2250 struct filedesc *fdp; 2251 2252 /* 2253 * POSIX record locking dictates that any close releases ALL 2254 * locks owned by this process. This is handled by setting 2255 * a flag in the unlock to free ONLY locks obeying POSIX 2256 * semantics, and not to free BSD-style file locks. 2257 * If the descriptor was in a message, POSIX-style locks 2258 * aren't passed with the descriptor, and the thread pointer 2259 * will be NULL. Callers should be careful only to pass a 2260 * NULL thread pointer when there really is no owning 2261 * context that might have locks, or the locks will be 2262 * leaked. 2263 */ 2264 if (fp->f_type == DTYPE_VNODE && td != NULL) { 2265 vp = fp->f_vnode; 2266 if ((td->td_proc->p_leader->p_flag & P_ADVLOCK) != 0) { 2267 lf.l_whence = SEEK_SET; 2268 lf.l_start = 0; 2269 lf.l_len = 0; 2270 lf.l_type = F_UNLCK; 2271 (void) VOP_ADVLOCK(vp, (caddr_t)td->td_proc->p_leader, 2272 F_UNLCK, &lf, F_POSIX); 2273 } 2274 fdtol = td->td_proc->p_fdtol; 2275 if (fdtol != NULL) { 2276 /* 2277 * Handle special case where file descriptor table is 2278 * shared between multiple process leaders. 2279 */ 2280 fdp = td->td_proc->p_fd; 2281 FILEDESC_XLOCK(fdp); 2282 for (fdtol = fdtol->fdl_next; 2283 fdtol != td->td_proc->p_fdtol; 2284 fdtol = fdtol->fdl_next) { 2285 if ((fdtol->fdl_leader->p_flag & 2286 P_ADVLOCK) == 0) 2287 continue; 2288 fdtol->fdl_holdcount++; 2289 FILEDESC_XUNLOCK(fdp); 2290 lf.l_whence = SEEK_SET; 2291 lf.l_start = 0; 2292 lf.l_len = 0; 2293 lf.l_type = F_UNLCK; 2294 vp = fp->f_vnode; 2295 (void) VOP_ADVLOCK(vp, 2296 (caddr_t)fdtol->fdl_leader, F_UNLCK, &lf, 2297 F_POSIX); 2298 FILEDESC_XLOCK(fdp); 2299 fdtol->fdl_holdcount--; 2300 if (fdtol->fdl_holdcount == 0 && 2301 fdtol->fdl_wakeup != 0) { 2302 fdtol->fdl_wakeup = 0; 2303 wakeup(fdtol); 2304 } 2305 } 2306 FILEDESC_XUNLOCK(fdp); 2307 } 2308 } 2309 return (fdrop(fp, td)); 2310 } 2311 2312 /* 2313 * Initialize the file pointer with the specified properties. 2314 * 2315 * The ops are set with release semantics to be certain that the flags, type, 2316 * and data are visible when ops is. This is to prevent ops methods from being 2317 * called with bad data. 2318 */ 2319 void 2320 finit(struct file *fp, u_int flag, short type, void *data, struct fileops *ops) 2321 { 2322 fp->f_data = data; 2323 fp->f_flag = flag; 2324 fp->f_type = type; 2325 atomic_store_rel_ptr((volatile uintptr_t *)&fp->f_ops, (uintptr_t)ops); 2326 } 2327 2328 int 2329 fget_unlocked(struct filedesc *fdp, int fd, cap_rights_t *needrightsp, 2330 int needfcntl, struct file **fpp, cap_rights_t *haverightsp) 2331 { 2332 #ifdef CAPABILITIES 2333 struct filedescent fde; 2334 #endif 2335 struct fdescenttbl *fdt; 2336 struct file *fp; 2337 u_int count; 2338 #ifdef CAPABILITIES 2339 seq_t seq; 2340 cap_rights_t haverights; 2341 int error; 2342 #endif 2343 2344 fdt = fdp->fd_files; 2345 if (fd < 0 || fd >= fdt->fdt_nfiles) 2346 return (EBADF); 2347 /* 2348 * Fetch the descriptor locklessly. We avoid fdrop() races by 2349 * never raising a refcount above 0. To accomplish this we have 2350 * to use a cmpset loop rather than an atomic_add. The descriptor 2351 * must be re-verified once we acquire a reference to be certain 2352 * that the identity is still correct and we did not lose a race 2353 * due to preemption. 2354 */ 2355 for (;;) { 2356 #ifdef CAPABILITIES 2357 seq = seq_read(fd_seq(fdt, fd)); 2358 fde = fdt->fdt_ofiles[fd]; 2359 if (!seq_consistent(fd_seq(fdt, fd), seq)) { 2360 cpu_spinwait(); 2361 continue; 2362 } 2363 fp = fde.fde_file; 2364 #else 2365 fp = fdt->fdt_ofiles[fd].fde_file; 2366 #endif 2367 if (fp == NULL) 2368 return (EBADF); 2369 #ifdef CAPABILITIES 2370 haverights = *cap_rights_fde(&fde); 2371 if (needrightsp != NULL) { 2372 error = cap_check(&haverights, needrightsp); 2373 if (error != 0) 2374 return (error); 2375 if (cap_rights_is_set(needrightsp, CAP_FCNTL)) { 2376 error = cap_fcntl_check_fde(&fde, needfcntl); 2377 if (error != 0) 2378 return (error); 2379 } 2380 } 2381 #endif 2382 retry: 2383 count = fp->f_count; 2384 if (count == 0) { 2385 /* 2386 * Force a reload. Other thread could reallocate the 2387 * table before this fd was closed, so it possible that 2388 * there is a stale fp pointer in cached version. 2389 */ 2390 fdt = *(struct fdescenttbl * volatile *)&(fdp->fd_files); 2391 continue; 2392 } 2393 /* 2394 * Use an acquire barrier to force re-reading of fdt so it is 2395 * refreshed for verification. 2396 */ 2397 if (atomic_cmpset_acq_int(&fp->f_count, count, count + 1) == 0) 2398 goto retry; 2399 fdt = fdp->fd_files; 2400 #ifdef CAPABILITIES 2401 if (seq_consistent_nomb(fd_seq(fdt, fd), seq)) 2402 #else 2403 if (fp == fdt->fdt_ofiles[fd].fde_file) 2404 #endif 2405 break; 2406 fdrop(fp, curthread); 2407 } 2408 *fpp = fp; 2409 if (haverightsp != NULL) { 2410 #ifdef CAPABILITIES 2411 *haverightsp = haverights; 2412 #else 2413 CAP_ALL(haverightsp); 2414 #endif 2415 } 2416 return (0); 2417 } 2418 2419 /* 2420 * Extract the file pointer associated with the specified descriptor for the 2421 * current user process. 2422 * 2423 * If the descriptor doesn't exist or doesn't match 'flags', EBADF is 2424 * returned. 2425 * 2426 * File's rights will be checked against the capability rights mask. 2427 * 2428 * If an error occured the non-zero error is returned and *fpp is set to 2429 * NULL. Otherwise *fpp is held and set and zero is returned. Caller is 2430 * responsible for fdrop(). 2431 */ 2432 static __inline int 2433 _fget(struct thread *td, int fd, struct file **fpp, int flags, 2434 cap_rights_t *needrightsp, u_char *maxprotp) 2435 { 2436 struct filedesc *fdp; 2437 struct file *fp; 2438 cap_rights_t haverights, needrights; 2439 int error; 2440 2441 *fpp = NULL; 2442 if (td == NULL || (fdp = td->td_proc->p_fd) == NULL) 2443 return (EBADF); 2444 if (needrightsp != NULL) 2445 needrights = *needrightsp; 2446 else 2447 cap_rights_init(&needrights); 2448 if (maxprotp != NULL) 2449 cap_rights_set(&needrights, CAP_MMAP); 2450 error = fget_unlocked(fdp, fd, &needrights, 0, &fp, &haverights); 2451 if (error != 0) 2452 return (error); 2453 if (fp->f_ops == &badfileops) { 2454 fdrop(fp, td); 2455 return (EBADF); 2456 } 2457 2458 #ifdef CAPABILITIES 2459 /* 2460 * If requested, convert capability rights to access flags. 2461 */ 2462 if (maxprotp != NULL) 2463 *maxprotp = cap_rights_to_vmprot(&haverights); 2464 #else /* !CAPABILITIES */ 2465 if (maxprotp != NULL) 2466 *maxprotp = VM_PROT_ALL; 2467 #endif /* CAPABILITIES */ 2468 2469 /* 2470 * FREAD and FWRITE failure return EBADF as per POSIX. 2471 */ 2472 error = 0; 2473 switch (flags) { 2474 case FREAD: 2475 case FWRITE: 2476 if ((fp->f_flag & flags) == 0) 2477 error = EBADF; 2478 break; 2479 case FEXEC: 2480 if ((fp->f_flag & (FREAD | FEXEC)) == 0 || 2481 ((fp->f_flag & FWRITE) != 0)) 2482 error = EBADF; 2483 break; 2484 case 0: 2485 break; 2486 default: 2487 KASSERT(0, ("wrong flags")); 2488 } 2489 2490 if (error != 0) { 2491 fdrop(fp, td); 2492 return (error); 2493 } 2494 2495 *fpp = fp; 2496 return (0); 2497 } 2498 2499 int 2500 fget(struct thread *td, int fd, cap_rights_t *rightsp, struct file **fpp) 2501 { 2502 2503 return(_fget(td, fd, fpp, 0, rightsp, NULL)); 2504 } 2505 2506 int 2507 fget_mmap(struct thread *td, int fd, cap_rights_t *rightsp, u_char *maxprotp, 2508 struct file **fpp) 2509 { 2510 2511 return (_fget(td, fd, fpp, 0, rightsp, maxprotp)); 2512 } 2513 2514 int 2515 fget_read(struct thread *td, int fd, cap_rights_t *rightsp, struct file **fpp) 2516 { 2517 2518 return(_fget(td, fd, fpp, FREAD, rightsp, NULL)); 2519 } 2520 2521 int 2522 fget_write(struct thread *td, int fd, cap_rights_t *rightsp, struct file **fpp) 2523 { 2524 2525 return (_fget(td, fd, fpp, FWRITE, rightsp, NULL)); 2526 } 2527 2528 /* 2529 * Like fget() but loads the underlying vnode, or returns an error if the 2530 * descriptor does not represent a vnode. Note that pipes use vnodes but 2531 * never have VM objects. The returned vnode will be vref()'d. 2532 * 2533 * XXX: what about the unused flags ? 2534 */ 2535 static __inline int 2536 _fgetvp(struct thread *td, int fd, int flags, cap_rights_t *needrightsp, 2537 struct vnode **vpp) 2538 { 2539 struct file *fp; 2540 int error; 2541 2542 *vpp = NULL; 2543 error = _fget(td, fd, &fp, flags, needrightsp, NULL); 2544 if (error != 0) 2545 return (error); 2546 if (fp->f_vnode == NULL) { 2547 error = EINVAL; 2548 } else { 2549 *vpp = fp->f_vnode; 2550 vref(*vpp); 2551 } 2552 fdrop(fp, td); 2553 2554 return (error); 2555 } 2556 2557 int 2558 fgetvp(struct thread *td, int fd, cap_rights_t *rightsp, struct vnode **vpp) 2559 { 2560 2561 return (_fgetvp(td, fd, 0, rightsp, vpp)); 2562 } 2563 2564 int 2565 fgetvp_rights(struct thread *td, int fd, cap_rights_t *needrightsp, 2566 struct filecaps *havecaps, struct vnode **vpp) 2567 { 2568 struct filedesc *fdp; 2569 struct file *fp; 2570 #ifdef CAPABILITIES 2571 int error; 2572 #endif 2573 2574 fdp = td->td_proc->p_fd; 2575 fp = fget_locked(fdp, fd); 2576 if (fp == NULL || fp->f_ops == &badfileops) 2577 return (EBADF); 2578 2579 #ifdef CAPABILITIES 2580 if (needrightsp != NULL) { 2581 error = cap_check(cap_rights(fdp, fd), needrightsp); 2582 if (error != 0) 2583 return (error); 2584 } 2585 #endif 2586 2587 if (fp->f_vnode == NULL) 2588 return (EINVAL); 2589 2590 *vpp = fp->f_vnode; 2591 vref(*vpp); 2592 filecaps_copy(&fdp->fd_ofiles[fd].fde_caps, havecaps); 2593 2594 return (0); 2595 } 2596 2597 int 2598 fgetvp_read(struct thread *td, int fd, cap_rights_t *rightsp, struct vnode **vpp) 2599 { 2600 2601 return (_fgetvp(td, fd, FREAD, rightsp, vpp)); 2602 } 2603 2604 int 2605 fgetvp_exec(struct thread *td, int fd, cap_rights_t *rightsp, struct vnode **vpp) 2606 { 2607 2608 return (_fgetvp(td, fd, FEXEC, rightsp, vpp)); 2609 } 2610 2611 #ifdef notyet 2612 int 2613 fgetvp_write(struct thread *td, int fd, cap_rights_t *rightsp, 2614 struct vnode **vpp) 2615 { 2616 2617 return (_fgetvp(td, fd, FWRITE, rightsp, vpp)); 2618 } 2619 #endif 2620 2621 /* 2622 * Like fget() but loads the underlying socket, or returns an error if the 2623 * descriptor does not represent a socket. 2624 * 2625 * We bump the ref count on the returned socket. XXX Also obtain the SX lock 2626 * in the future. 2627 * 2628 * Note: fgetsock() and fputsock() are deprecated, as consumers should rely 2629 * on their file descriptor reference to prevent the socket from being free'd 2630 * during use. 2631 */ 2632 int 2633 fgetsock(struct thread *td, int fd, cap_rights_t *rightsp, struct socket **spp, 2634 u_int *fflagp) 2635 { 2636 struct file *fp; 2637 int error; 2638 2639 *spp = NULL; 2640 if (fflagp != NULL) 2641 *fflagp = 0; 2642 if ((error = _fget(td, fd, &fp, 0, rightsp, NULL)) != 0) 2643 return (error); 2644 if (fp->f_type != DTYPE_SOCKET) { 2645 error = ENOTSOCK; 2646 } else { 2647 *spp = fp->f_data; 2648 if (fflagp) 2649 *fflagp = fp->f_flag; 2650 SOCK_LOCK(*spp); 2651 soref(*spp); 2652 SOCK_UNLOCK(*spp); 2653 } 2654 fdrop(fp, td); 2655 2656 return (error); 2657 } 2658 2659 /* 2660 * Drop the reference count on the socket and XXX release the SX lock in the 2661 * future. The last reference closes the socket. 2662 * 2663 * Note: fputsock() is deprecated, see comment for fgetsock(). 2664 */ 2665 void 2666 fputsock(struct socket *so) 2667 { 2668 2669 ACCEPT_LOCK(); 2670 SOCK_LOCK(so); 2671 CURVNET_SET(so->so_vnet); 2672 sorele(so); 2673 CURVNET_RESTORE(); 2674 } 2675 2676 /* 2677 * Handle the last reference to a file being closed. 2678 */ 2679 int 2680 _fdrop(struct file *fp, struct thread *td) 2681 { 2682 int error; 2683 2684 error = 0; 2685 if (fp->f_count != 0) 2686 panic("fdrop: count %d", fp->f_count); 2687 if (fp->f_ops != &badfileops) 2688 error = fo_close(fp, td); 2689 atomic_subtract_int(&openfiles, 1); 2690 crfree(fp->f_cred); 2691 free(fp->f_advice, M_FADVISE); 2692 uma_zfree(file_zone, fp); 2693 2694 return (error); 2695 } 2696 2697 /* 2698 * Apply an advisory lock on a file descriptor. 2699 * 2700 * Just attempt to get a record lock of the requested type on the entire file 2701 * (l_whence = SEEK_SET, l_start = 0, l_len = 0). 2702 */ 2703 #ifndef _SYS_SYSPROTO_H_ 2704 struct flock_args { 2705 int fd; 2706 int how; 2707 }; 2708 #endif 2709 /* ARGSUSED */ 2710 int 2711 sys_flock(struct thread *td, struct flock_args *uap) 2712 { 2713 struct file *fp; 2714 struct vnode *vp; 2715 struct flock lf; 2716 cap_rights_t rights; 2717 int error; 2718 2719 error = fget(td, uap->fd, cap_rights_init(&rights, CAP_FLOCK), &fp); 2720 if (error != 0) 2721 return (error); 2722 if (fp->f_type != DTYPE_VNODE) { 2723 fdrop(fp, td); 2724 return (EOPNOTSUPP); 2725 } 2726 2727 vp = fp->f_vnode; 2728 lf.l_whence = SEEK_SET; 2729 lf.l_start = 0; 2730 lf.l_len = 0; 2731 if (uap->how & LOCK_UN) { 2732 lf.l_type = F_UNLCK; 2733 atomic_clear_int(&fp->f_flag, FHASLOCK); 2734 error = VOP_ADVLOCK(vp, (caddr_t)fp, F_UNLCK, &lf, F_FLOCK); 2735 goto done2; 2736 } 2737 if (uap->how & LOCK_EX) 2738 lf.l_type = F_WRLCK; 2739 else if (uap->how & LOCK_SH) 2740 lf.l_type = F_RDLCK; 2741 else { 2742 error = EBADF; 2743 goto done2; 2744 } 2745 atomic_set_int(&fp->f_flag, FHASLOCK); 2746 error = VOP_ADVLOCK(vp, (caddr_t)fp, F_SETLK, &lf, 2747 (uap->how & LOCK_NB) ? F_FLOCK : F_FLOCK | F_WAIT); 2748 done2: 2749 fdrop(fp, td); 2750 return (error); 2751 } 2752 /* 2753 * Duplicate the specified descriptor to a free descriptor. 2754 */ 2755 int 2756 dupfdopen(struct thread *td, struct filedesc *fdp, int dfd, int mode, 2757 int openerror, int *indxp) 2758 { 2759 struct filedescent *newfde, *oldfde; 2760 struct file *fp; 2761 int error, indx; 2762 2763 KASSERT(openerror == ENODEV || openerror == ENXIO, 2764 ("unexpected error %d in %s", openerror, __func__)); 2765 2766 /* 2767 * If the to-be-dup'd fd number is greater than the allowed number 2768 * of file descriptors, or the fd to be dup'd has already been 2769 * closed, then reject. 2770 */ 2771 FILEDESC_XLOCK(fdp); 2772 if ((fp = fget_locked(fdp, dfd)) == NULL) { 2773 FILEDESC_XUNLOCK(fdp); 2774 return (EBADF); 2775 } 2776 2777 error = fdalloc(td, 0, &indx); 2778 if (error != 0) { 2779 FILEDESC_XUNLOCK(fdp); 2780 return (error); 2781 } 2782 2783 /* 2784 * There are two cases of interest here. 2785 * 2786 * For ENODEV simply dup (dfd) to file descriptor (indx) and return. 2787 * 2788 * For ENXIO steal away the file structure from (dfd) and store it in 2789 * (indx). (dfd) is effectively closed by this operation. 2790 */ 2791 switch (openerror) { 2792 case ENODEV: 2793 /* 2794 * Check that the mode the file is being opened for is a 2795 * subset of the mode of the existing descriptor. 2796 */ 2797 if (((mode & (FREAD|FWRITE)) | fp->f_flag) != fp->f_flag) { 2798 fdunused(fdp, indx); 2799 FILEDESC_XUNLOCK(fdp); 2800 return (EACCES); 2801 } 2802 fhold(fp); 2803 newfde = &fdp->fd_ofiles[indx]; 2804 oldfde = &fdp->fd_ofiles[dfd]; 2805 #ifdef CAPABILITIES 2806 seq_write_begin(&newfde->fde_seq); 2807 #endif 2808 memcpy(newfde, oldfde, fde_change_size); 2809 filecaps_copy(&oldfde->fde_caps, &newfde->fde_caps); 2810 #ifdef CAPABILITIES 2811 seq_write_end(&newfde->fde_seq); 2812 #endif 2813 break; 2814 case ENXIO: 2815 /* 2816 * Steal away the file pointer from dfd and stuff it into indx. 2817 */ 2818 newfde = &fdp->fd_ofiles[indx]; 2819 oldfde = &fdp->fd_ofiles[dfd]; 2820 #ifdef CAPABILITIES 2821 seq_write_begin(&newfde->fde_seq); 2822 #endif 2823 memcpy(newfde, oldfde, fde_change_size); 2824 bzero(oldfde, fde_change_size); 2825 fdunused(fdp, dfd); 2826 #ifdef CAPABILITIES 2827 seq_write_end(&newfde->fde_seq); 2828 #endif 2829 break; 2830 } 2831 FILEDESC_XUNLOCK(fdp); 2832 *indxp = indx; 2833 return (0); 2834 } 2835 2836 /* 2837 * Scan all active processes and prisons to see if any of them have a current 2838 * or root directory of `olddp'. If so, replace them with the new mount point. 2839 */ 2840 void 2841 mountcheckdirs(struct vnode *olddp, struct vnode *newdp) 2842 { 2843 struct filedesc *fdp; 2844 struct prison *pr; 2845 struct proc *p; 2846 int nrele; 2847 2848 if (vrefcnt(olddp) == 1) 2849 return; 2850 nrele = 0; 2851 sx_slock(&allproc_lock); 2852 FOREACH_PROC_IN_SYSTEM(p) { 2853 fdp = fdhold(p); 2854 if (fdp == NULL) 2855 continue; 2856 FILEDESC_XLOCK(fdp); 2857 if (fdp->fd_cdir == olddp) { 2858 vref(newdp); 2859 fdp->fd_cdir = newdp; 2860 nrele++; 2861 } 2862 if (fdp->fd_rdir == olddp) { 2863 vref(newdp); 2864 fdp->fd_rdir = newdp; 2865 nrele++; 2866 } 2867 if (fdp->fd_jdir == olddp) { 2868 vref(newdp); 2869 fdp->fd_jdir = newdp; 2870 nrele++; 2871 } 2872 FILEDESC_XUNLOCK(fdp); 2873 fddrop(fdp); 2874 } 2875 sx_sunlock(&allproc_lock); 2876 if (rootvnode == olddp) { 2877 vref(newdp); 2878 rootvnode = newdp; 2879 nrele++; 2880 } 2881 mtx_lock(&prison0.pr_mtx); 2882 if (prison0.pr_root == olddp) { 2883 vref(newdp); 2884 prison0.pr_root = newdp; 2885 nrele++; 2886 } 2887 mtx_unlock(&prison0.pr_mtx); 2888 sx_slock(&allprison_lock); 2889 TAILQ_FOREACH(pr, &allprison, pr_list) { 2890 mtx_lock(&pr->pr_mtx); 2891 if (pr->pr_root == olddp) { 2892 vref(newdp); 2893 pr->pr_root = newdp; 2894 nrele++; 2895 } 2896 mtx_unlock(&pr->pr_mtx); 2897 } 2898 sx_sunlock(&allprison_lock); 2899 while (nrele--) 2900 vrele(olddp); 2901 } 2902 2903 struct filedesc_to_leader * 2904 filedesc_to_leader_alloc(struct filedesc_to_leader *old, struct filedesc *fdp, struct proc *leader) 2905 { 2906 struct filedesc_to_leader *fdtol; 2907 2908 fdtol = malloc(sizeof(struct filedesc_to_leader), 2909 M_FILEDESC_TO_LEADER, 2910 M_WAITOK); 2911 fdtol->fdl_refcount = 1; 2912 fdtol->fdl_holdcount = 0; 2913 fdtol->fdl_wakeup = 0; 2914 fdtol->fdl_leader = leader; 2915 if (old != NULL) { 2916 FILEDESC_XLOCK(fdp); 2917 fdtol->fdl_next = old->fdl_next; 2918 fdtol->fdl_prev = old; 2919 old->fdl_next = fdtol; 2920 fdtol->fdl_next->fdl_prev = fdtol; 2921 FILEDESC_XUNLOCK(fdp); 2922 } else { 2923 fdtol->fdl_next = fdtol; 2924 fdtol->fdl_prev = fdtol; 2925 } 2926 return (fdtol); 2927 } 2928 2929 /* 2930 * Get file structures globally. 2931 */ 2932 static int 2933 sysctl_kern_file(SYSCTL_HANDLER_ARGS) 2934 { 2935 struct xfile xf; 2936 struct filedesc *fdp; 2937 struct file *fp; 2938 struct proc *p; 2939 int error, n; 2940 2941 error = sysctl_wire_old_buffer(req, 0); 2942 if (error != 0) 2943 return (error); 2944 if (req->oldptr == NULL) { 2945 n = 0; 2946 sx_slock(&allproc_lock); 2947 FOREACH_PROC_IN_SYSTEM(p) { 2948 if (p->p_state == PRS_NEW) 2949 continue; 2950 fdp = fdhold(p); 2951 if (fdp == NULL) 2952 continue; 2953 /* overestimates sparse tables. */ 2954 if (fdp->fd_lastfile > 0) 2955 n += fdp->fd_lastfile; 2956 fddrop(fdp); 2957 } 2958 sx_sunlock(&allproc_lock); 2959 return (SYSCTL_OUT(req, 0, n * sizeof(xf))); 2960 } 2961 error = 0; 2962 bzero(&xf, sizeof(xf)); 2963 xf.xf_size = sizeof(xf); 2964 sx_slock(&allproc_lock); 2965 FOREACH_PROC_IN_SYSTEM(p) { 2966 PROC_LOCK(p); 2967 if (p->p_state == PRS_NEW) { 2968 PROC_UNLOCK(p); 2969 continue; 2970 } 2971 if (p_cansee(req->td, p) != 0) { 2972 PROC_UNLOCK(p); 2973 continue; 2974 } 2975 xf.xf_pid = p->p_pid; 2976 xf.xf_uid = p->p_ucred->cr_uid; 2977 PROC_UNLOCK(p); 2978 fdp = fdhold(p); 2979 if (fdp == NULL) 2980 continue; 2981 FILEDESC_SLOCK(fdp); 2982 for (n = 0; fdp->fd_refcnt > 0 && n <= fdp->fd_lastfile; ++n) { 2983 if ((fp = fdp->fd_ofiles[n].fde_file) == NULL) 2984 continue; 2985 xf.xf_fd = n; 2986 xf.xf_file = fp; 2987 xf.xf_data = fp->f_data; 2988 xf.xf_vnode = fp->f_vnode; 2989 xf.xf_type = fp->f_type; 2990 xf.xf_count = fp->f_count; 2991 xf.xf_msgcount = 0; 2992 xf.xf_offset = foffset_get(fp); 2993 xf.xf_flag = fp->f_flag; 2994 error = SYSCTL_OUT(req, &xf, sizeof(xf)); 2995 if (error) 2996 break; 2997 } 2998 FILEDESC_SUNLOCK(fdp); 2999 fddrop(fdp); 3000 if (error) 3001 break; 3002 } 3003 sx_sunlock(&allproc_lock); 3004 return (error); 3005 } 3006 3007 SYSCTL_PROC(_kern, KERN_FILE, file, CTLTYPE_OPAQUE|CTLFLAG_RD|CTLFLAG_MPSAFE, 3008 0, 0, sysctl_kern_file, "S,xfile", "Entire file table"); 3009 3010 #ifdef KINFO_FILE_SIZE 3011 CTASSERT(sizeof(struct kinfo_file) == KINFO_FILE_SIZE); 3012 #endif 3013 3014 static int 3015 xlate_fflags(int fflags) 3016 { 3017 static const struct { 3018 int fflag; 3019 int kf_fflag; 3020 } fflags_table[] = { 3021 { FAPPEND, KF_FLAG_APPEND }, 3022 { FASYNC, KF_FLAG_ASYNC }, 3023 { FFSYNC, KF_FLAG_FSYNC }, 3024 { FHASLOCK, KF_FLAG_HASLOCK }, 3025 { FNONBLOCK, KF_FLAG_NONBLOCK }, 3026 { FREAD, KF_FLAG_READ }, 3027 { FWRITE, KF_FLAG_WRITE }, 3028 { O_CREAT, KF_FLAG_CREAT }, 3029 { O_DIRECT, KF_FLAG_DIRECT }, 3030 { O_EXCL, KF_FLAG_EXCL }, 3031 { O_EXEC, KF_FLAG_EXEC }, 3032 { O_EXLOCK, KF_FLAG_EXLOCK }, 3033 { O_NOFOLLOW, KF_FLAG_NOFOLLOW }, 3034 { O_SHLOCK, KF_FLAG_SHLOCK }, 3035 { O_TRUNC, KF_FLAG_TRUNC } 3036 }; 3037 unsigned int i; 3038 int kflags; 3039 3040 kflags = 0; 3041 for (i = 0; i < nitems(fflags_table); i++) 3042 if (fflags & fflags_table[i].fflag) 3043 kflags |= fflags_table[i].kf_fflag; 3044 return (kflags); 3045 } 3046 3047 /* Trim unused data from kf_path by truncating the structure size. */ 3048 static void 3049 pack_kinfo(struct kinfo_file *kif) 3050 { 3051 3052 kif->kf_structsize = offsetof(struct kinfo_file, kf_path) + 3053 strlen(kif->kf_path) + 1; 3054 kif->kf_structsize = roundup(kif->kf_structsize, sizeof(uint64_t)); 3055 } 3056 3057 static void 3058 export_file_to_kinfo(struct file *fp, int fd, cap_rights_t *rightsp, 3059 struct kinfo_file *kif, struct filedesc *fdp) 3060 { 3061 int error; 3062 3063 bzero(kif, sizeof(*kif)); 3064 3065 /* Set a default type to allow for empty fill_kinfo() methods. */ 3066 kif->kf_type = KF_TYPE_UNKNOWN; 3067 kif->kf_flags = xlate_fflags(fp->f_flag); 3068 if (rightsp != NULL) 3069 kif->kf_cap_rights = *rightsp; 3070 else 3071 cap_rights_init(&kif->kf_cap_rights); 3072 kif->kf_fd = fd; 3073 kif->kf_ref_count = fp->f_count; 3074 kif->kf_offset = foffset_get(fp); 3075 3076 /* 3077 * This may drop the filedesc lock, so the 'fp' cannot be 3078 * accessed after this call. 3079 */ 3080 error = fo_fill_kinfo(fp, kif, fdp); 3081 if (error == 0) 3082 kif->kf_status |= KF_ATTR_VALID; 3083 pack_kinfo(kif); 3084 } 3085 3086 static void 3087 export_vnode_to_kinfo(struct vnode *vp, int fd, int fflags, 3088 struct kinfo_file *kif) 3089 { 3090 int error; 3091 3092 bzero(kif, sizeof(*kif)); 3093 3094 kif->kf_type = KF_TYPE_VNODE; 3095 error = vn_fill_kinfo_vnode(vp, kif); 3096 if (error == 0) 3097 kif->kf_status |= KF_ATTR_VALID; 3098 kif->kf_flags = xlate_fflags(fflags); 3099 cap_rights_init(&kif->kf_cap_rights); 3100 kif->kf_fd = fd; 3101 kif->kf_ref_count = -1; 3102 kif->kf_offset = -1; 3103 pack_kinfo(kif); 3104 vrele(vp); 3105 } 3106 3107 struct export_fd_buf { 3108 struct filedesc *fdp; 3109 struct sbuf *sb; 3110 ssize_t remainder; 3111 struct kinfo_file kif; 3112 }; 3113 3114 static int 3115 export_kinfo_to_sb(struct export_fd_buf *efbuf) 3116 { 3117 struct kinfo_file *kif; 3118 3119 kif = &efbuf->kif; 3120 if (efbuf->remainder != -1) { 3121 if (efbuf->remainder < kif->kf_structsize) { 3122 /* Terminate export. */ 3123 efbuf->remainder = 0; 3124 return (0); 3125 } 3126 efbuf->remainder -= kif->kf_structsize; 3127 } 3128 return (sbuf_bcat(efbuf->sb, kif, kif->kf_structsize) == 0 ? 0 : ENOMEM); 3129 } 3130 3131 static int 3132 export_file_to_sb(struct file *fp, int fd, cap_rights_t *rightsp, 3133 struct export_fd_buf *efbuf) 3134 { 3135 int error; 3136 3137 if (efbuf->remainder == 0) 3138 return (0); 3139 export_file_to_kinfo(fp, fd, rightsp, &efbuf->kif, efbuf->fdp); 3140 FILEDESC_SUNLOCK(efbuf->fdp); 3141 error = export_kinfo_to_sb(efbuf); 3142 FILEDESC_SLOCK(efbuf->fdp); 3143 return (error); 3144 } 3145 3146 static int 3147 export_vnode_to_sb(struct vnode *vp, int fd, int fflags, 3148 struct export_fd_buf *efbuf) 3149 { 3150 int error; 3151 3152 if (efbuf->remainder == 0) 3153 return (0); 3154 if (efbuf->fdp != NULL) 3155 FILEDESC_SUNLOCK(efbuf->fdp); 3156 export_vnode_to_kinfo(vp, fd, fflags, &efbuf->kif); 3157 error = export_kinfo_to_sb(efbuf); 3158 if (efbuf->fdp != NULL) 3159 FILEDESC_SLOCK(efbuf->fdp); 3160 return (error); 3161 } 3162 3163 /* 3164 * Store a process file descriptor information to sbuf. 3165 * 3166 * Takes a locked proc as argument, and returns with the proc unlocked. 3167 */ 3168 int 3169 kern_proc_filedesc_out(struct proc *p, struct sbuf *sb, ssize_t maxlen) 3170 { 3171 struct file *fp; 3172 struct filedesc *fdp; 3173 struct export_fd_buf *efbuf; 3174 struct vnode *cttyvp, *textvp, *tracevp; 3175 int error, i; 3176 cap_rights_t rights; 3177 3178 PROC_LOCK_ASSERT(p, MA_OWNED); 3179 3180 /* ktrace vnode */ 3181 tracevp = p->p_tracevp; 3182 if (tracevp != NULL) 3183 vref(tracevp); 3184 /* text vnode */ 3185 textvp = p->p_textvp; 3186 if (textvp != NULL) 3187 vref(textvp); 3188 /* Controlling tty. */ 3189 cttyvp = NULL; 3190 if (p->p_pgrp != NULL && p->p_pgrp->pg_session != NULL) { 3191 cttyvp = p->p_pgrp->pg_session->s_ttyvp; 3192 if (cttyvp != NULL) 3193 vref(cttyvp); 3194 } 3195 fdp = fdhold(p); 3196 PROC_UNLOCK(p); 3197 efbuf = malloc(sizeof(*efbuf), M_TEMP, M_WAITOK); 3198 efbuf->fdp = NULL; 3199 efbuf->sb = sb; 3200 efbuf->remainder = maxlen; 3201 if (tracevp != NULL) 3202 export_vnode_to_sb(tracevp, KF_FD_TYPE_TRACE, FREAD | FWRITE, 3203 efbuf); 3204 if (textvp != NULL) 3205 export_vnode_to_sb(textvp, KF_FD_TYPE_TEXT, FREAD, efbuf); 3206 if (cttyvp != NULL) 3207 export_vnode_to_sb(cttyvp, KF_FD_TYPE_CTTY, FREAD | FWRITE, 3208 efbuf); 3209 error = 0; 3210 if (fdp == NULL) 3211 goto fail; 3212 efbuf->fdp = fdp; 3213 FILEDESC_SLOCK(fdp); 3214 /* working directory */ 3215 if (fdp->fd_cdir != NULL) { 3216 vref(fdp->fd_cdir); 3217 export_vnode_to_sb(fdp->fd_cdir, KF_FD_TYPE_CWD, FREAD, efbuf); 3218 } 3219 /* root directory */ 3220 if (fdp->fd_rdir != NULL) { 3221 vref(fdp->fd_rdir); 3222 export_vnode_to_sb(fdp->fd_rdir, KF_FD_TYPE_ROOT, FREAD, efbuf); 3223 } 3224 /* jail directory */ 3225 if (fdp->fd_jdir != NULL) { 3226 vref(fdp->fd_jdir); 3227 export_vnode_to_sb(fdp->fd_jdir, KF_FD_TYPE_JAIL, FREAD, efbuf); 3228 } 3229 for (i = 0; fdp->fd_refcnt > 0 && i <= fdp->fd_lastfile; i++) { 3230 if ((fp = fdp->fd_ofiles[i].fde_file) == NULL) 3231 continue; 3232 #ifdef CAPABILITIES 3233 rights = *cap_rights(fdp, i); 3234 #else /* !CAPABILITIES */ 3235 cap_rights_init(&rights); 3236 #endif 3237 /* 3238 * Create sysctl entry. It is OK to drop the filedesc 3239 * lock inside of export_file_to_sb() as we will 3240 * re-validate and re-evaluate its properties when the 3241 * loop continues. 3242 */ 3243 error = export_file_to_sb(fp, i, &rights, efbuf); 3244 if (error != 0 || efbuf->remainder == 0) 3245 break; 3246 } 3247 FILEDESC_SUNLOCK(fdp); 3248 fddrop(fdp); 3249 fail: 3250 free(efbuf, M_TEMP); 3251 return (error); 3252 } 3253 3254 #define FILEDESC_SBUF_SIZE (sizeof(struct kinfo_file) * 5) 3255 3256 /* 3257 * Get per-process file descriptors for use by procstat(1), et al. 3258 */ 3259 static int 3260 sysctl_kern_proc_filedesc(SYSCTL_HANDLER_ARGS) 3261 { 3262 struct sbuf sb; 3263 struct proc *p; 3264 ssize_t maxlen; 3265 int error, error2, *name; 3266 3267 name = (int *)arg1; 3268 3269 sbuf_new_for_sysctl(&sb, NULL, FILEDESC_SBUF_SIZE, req); 3270 error = pget((pid_t)name[0], PGET_CANDEBUG | PGET_NOTWEXIT, &p); 3271 if (error != 0) { 3272 sbuf_delete(&sb); 3273 return (error); 3274 } 3275 maxlen = req->oldptr != NULL ? req->oldlen : -1; 3276 error = kern_proc_filedesc_out(p, &sb, maxlen); 3277 error2 = sbuf_finish(&sb); 3278 sbuf_delete(&sb); 3279 return (error != 0 ? error : error2); 3280 } 3281 3282 #ifdef KINFO_OFILE_SIZE 3283 CTASSERT(sizeof(struct kinfo_ofile) == KINFO_OFILE_SIZE); 3284 #endif 3285 3286 #ifdef COMPAT_FREEBSD7 3287 static void 3288 kinfo_to_okinfo(struct kinfo_file *kif, struct kinfo_ofile *okif) 3289 { 3290 3291 okif->kf_structsize = sizeof(*okif); 3292 okif->kf_type = kif->kf_type; 3293 okif->kf_fd = kif->kf_fd; 3294 okif->kf_ref_count = kif->kf_ref_count; 3295 okif->kf_flags = kif->kf_flags & (KF_FLAG_READ | KF_FLAG_WRITE | 3296 KF_FLAG_APPEND | KF_FLAG_ASYNC | KF_FLAG_FSYNC | KF_FLAG_NONBLOCK | 3297 KF_FLAG_DIRECT | KF_FLAG_HASLOCK); 3298 okif->kf_offset = kif->kf_offset; 3299 okif->kf_vnode_type = kif->kf_vnode_type; 3300 okif->kf_sock_domain = kif->kf_sock_domain; 3301 okif->kf_sock_type = kif->kf_sock_type; 3302 okif->kf_sock_protocol = kif->kf_sock_protocol; 3303 strlcpy(okif->kf_path, kif->kf_path, sizeof(okif->kf_path)); 3304 okif->kf_sa_local = kif->kf_sa_local; 3305 okif->kf_sa_peer = kif->kf_sa_peer; 3306 } 3307 3308 static int 3309 export_vnode_for_osysctl(struct vnode *vp, int type, struct kinfo_file *kif, 3310 struct kinfo_ofile *okif, struct filedesc *fdp, struct sysctl_req *req) 3311 { 3312 int error; 3313 3314 vref(vp); 3315 FILEDESC_SUNLOCK(fdp); 3316 export_vnode_to_kinfo(vp, type, 0, kif); 3317 kinfo_to_okinfo(kif, okif); 3318 error = SYSCTL_OUT(req, okif, sizeof(*okif)); 3319 FILEDESC_SLOCK(fdp); 3320 return (error); 3321 } 3322 3323 /* 3324 * Get per-process file descriptors for use by procstat(1), et al. 3325 */ 3326 static int 3327 sysctl_kern_proc_ofiledesc(SYSCTL_HANDLER_ARGS) 3328 { 3329 struct kinfo_ofile *okif; 3330 struct kinfo_file *kif; 3331 struct filedesc *fdp; 3332 int error, i, *name; 3333 struct file *fp; 3334 struct proc *p; 3335 3336 name = (int *)arg1; 3337 error = pget((pid_t)name[0], PGET_CANDEBUG | PGET_NOTWEXIT, &p); 3338 if (error != 0) 3339 return (error); 3340 fdp = fdhold(p); 3341 PROC_UNLOCK(p); 3342 if (fdp == NULL) 3343 return (ENOENT); 3344 kif = malloc(sizeof(*kif), M_TEMP, M_WAITOK); 3345 okif = malloc(sizeof(*okif), M_TEMP, M_WAITOK); 3346 FILEDESC_SLOCK(fdp); 3347 if (fdp->fd_cdir != NULL) 3348 export_vnode_for_osysctl(fdp->fd_cdir, KF_FD_TYPE_CWD, kif, 3349 okif, fdp, req); 3350 if (fdp->fd_rdir != NULL) 3351 export_vnode_for_osysctl(fdp->fd_rdir, KF_FD_TYPE_ROOT, kif, 3352 okif, fdp, req); 3353 if (fdp->fd_jdir != NULL) 3354 export_vnode_for_osysctl(fdp->fd_jdir, KF_FD_TYPE_JAIL, kif, 3355 okif, fdp, req); 3356 for (i = 0; fdp->fd_refcnt > 0 && i <= fdp->fd_lastfile; i++) { 3357 if ((fp = fdp->fd_ofiles[i].fde_file) == NULL) 3358 continue; 3359 export_file_to_kinfo(fp, i, NULL, kif, fdp); 3360 FILEDESC_SUNLOCK(fdp); 3361 kinfo_to_okinfo(kif, okif); 3362 error = SYSCTL_OUT(req, okif, sizeof(*okif)); 3363 FILEDESC_SLOCK(fdp); 3364 if (error) 3365 break; 3366 } 3367 FILEDESC_SUNLOCK(fdp); 3368 fddrop(fdp); 3369 free(kif, M_TEMP); 3370 free(okif, M_TEMP); 3371 return (0); 3372 } 3373 3374 static SYSCTL_NODE(_kern_proc, KERN_PROC_OFILEDESC, ofiledesc, 3375 CTLFLAG_RD|CTLFLAG_MPSAFE, sysctl_kern_proc_ofiledesc, 3376 "Process ofiledesc entries"); 3377 #endif /* COMPAT_FREEBSD7 */ 3378 3379 int 3380 vntype_to_kinfo(int vtype) 3381 { 3382 struct { 3383 int vtype; 3384 int kf_vtype; 3385 } vtypes_table[] = { 3386 { VBAD, KF_VTYPE_VBAD }, 3387 { VBLK, KF_VTYPE_VBLK }, 3388 { VCHR, KF_VTYPE_VCHR }, 3389 { VDIR, KF_VTYPE_VDIR }, 3390 { VFIFO, KF_VTYPE_VFIFO }, 3391 { VLNK, KF_VTYPE_VLNK }, 3392 { VNON, KF_VTYPE_VNON }, 3393 { VREG, KF_VTYPE_VREG }, 3394 { VSOCK, KF_VTYPE_VSOCK } 3395 }; 3396 unsigned int i; 3397 3398 /* 3399 * Perform vtype translation. 3400 */ 3401 for (i = 0; i < nitems(vtypes_table); i++) 3402 if (vtypes_table[i].vtype == vtype) 3403 return (vtypes_table[i].kf_vtype); 3404 3405 return (KF_VTYPE_UNKNOWN); 3406 } 3407 3408 static SYSCTL_NODE(_kern_proc, KERN_PROC_FILEDESC, filedesc, 3409 CTLFLAG_RD|CTLFLAG_MPSAFE, sysctl_kern_proc_filedesc, 3410 "Process filedesc entries"); 3411 3412 /* 3413 * Store a process current working directory information to sbuf. 3414 * 3415 * Takes a locked proc as argument, and returns with the proc unlocked. 3416 */ 3417 int 3418 kern_proc_cwd_out(struct proc *p, struct sbuf *sb, ssize_t maxlen) 3419 { 3420 struct filedesc *fdp; 3421 struct export_fd_buf *efbuf; 3422 int error; 3423 3424 PROC_LOCK_ASSERT(p, MA_OWNED); 3425 3426 fdp = fdhold(p); 3427 PROC_UNLOCK(p); 3428 if (fdp == NULL) 3429 return (EINVAL); 3430 3431 efbuf = malloc(sizeof(*efbuf), M_TEMP, M_WAITOK); 3432 efbuf->fdp = fdp; 3433 efbuf->sb = sb; 3434 efbuf->remainder = maxlen; 3435 3436 FILEDESC_SLOCK(fdp); 3437 if (fdp->fd_cdir == NULL) 3438 error = EINVAL; 3439 else { 3440 vref(fdp->fd_cdir); 3441 error = export_vnode_to_sb(fdp->fd_cdir, KF_FD_TYPE_CWD, 3442 FREAD, efbuf); 3443 } 3444 FILEDESC_SUNLOCK(fdp); 3445 fddrop(fdp); 3446 free(efbuf, M_TEMP); 3447 return (error); 3448 } 3449 3450 /* 3451 * Get per-process current working directory. 3452 */ 3453 static int 3454 sysctl_kern_proc_cwd(SYSCTL_HANDLER_ARGS) 3455 { 3456 struct sbuf sb; 3457 struct proc *p; 3458 ssize_t maxlen; 3459 int error, error2, *name; 3460 3461 name = (int *)arg1; 3462 3463 sbuf_new_for_sysctl(&sb, NULL, sizeof(struct kinfo_file), req); 3464 error = pget((pid_t)name[0], PGET_CANDEBUG | PGET_NOTWEXIT, &p); 3465 if (error != 0) { 3466 sbuf_delete(&sb); 3467 return (error); 3468 } 3469 maxlen = req->oldptr != NULL ? req->oldlen : -1; 3470 error = kern_proc_cwd_out(p, &sb, maxlen); 3471 error2 = sbuf_finish(&sb); 3472 sbuf_delete(&sb); 3473 return (error != 0 ? error : error2); 3474 } 3475 3476 static SYSCTL_NODE(_kern_proc, KERN_PROC_CWD, cwd, CTLFLAG_RD|CTLFLAG_MPSAFE, 3477 sysctl_kern_proc_cwd, "Process current working directory"); 3478 3479 #ifdef DDB 3480 /* 3481 * For the purposes of debugging, generate a human-readable string for the 3482 * file type. 3483 */ 3484 static const char * 3485 file_type_to_name(short type) 3486 { 3487 3488 switch (type) { 3489 case 0: 3490 return ("zero"); 3491 case DTYPE_VNODE: 3492 return ("vnod"); 3493 case DTYPE_SOCKET: 3494 return ("sock"); 3495 case DTYPE_PIPE: 3496 return ("pipe"); 3497 case DTYPE_FIFO: 3498 return ("fifo"); 3499 case DTYPE_KQUEUE: 3500 return ("kque"); 3501 case DTYPE_CRYPTO: 3502 return ("crpt"); 3503 case DTYPE_MQUEUE: 3504 return ("mque"); 3505 case DTYPE_SHM: 3506 return ("shm"); 3507 case DTYPE_SEM: 3508 return ("ksem"); 3509 default: 3510 return ("unkn"); 3511 } 3512 } 3513 3514 /* 3515 * For the purposes of debugging, identify a process (if any, perhaps one of 3516 * many) that references the passed file in its file descriptor array. Return 3517 * NULL if none. 3518 */ 3519 static struct proc * 3520 file_to_first_proc(struct file *fp) 3521 { 3522 struct filedesc *fdp; 3523 struct proc *p; 3524 int n; 3525 3526 FOREACH_PROC_IN_SYSTEM(p) { 3527 if (p->p_state == PRS_NEW) 3528 continue; 3529 fdp = p->p_fd; 3530 if (fdp == NULL) 3531 continue; 3532 for (n = 0; n <= fdp->fd_lastfile; n++) { 3533 if (fp == fdp->fd_ofiles[n].fde_file) 3534 return (p); 3535 } 3536 } 3537 return (NULL); 3538 } 3539 3540 static void 3541 db_print_file(struct file *fp, int header) 3542 { 3543 struct proc *p; 3544 3545 if (header) 3546 db_printf("%8s %4s %8s %8s %4s %5s %6s %8s %5s %12s\n", 3547 "File", "Type", "Data", "Flag", "GCFl", "Count", 3548 "MCount", "Vnode", "FPID", "FCmd"); 3549 p = file_to_first_proc(fp); 3550 db_printf("%8p %4s %8p %08x %04x %5d %6d %8p %5d %12s\n", fp, 3551 file_type_to_name(fp->f_type), fp->f_data, fp->f_flag, 3552 0, fp->f_count, 0, fp->f_vnode, 3553 p != NULL ? p->p_pid : -1, p != NULL ? p->p_comm : "-"); 3554 } 3555 3556 DB_SHOW_COMMAND(file, db_show_file) 3557 { 3558 struct file *fp; 3559 3560 if (!have_addr) { 3561 db_printf("usage: show file <addr>\n"); 3562 return; 3563 } 3564 fp = (struct file *)addr; 3565 db_print_file(fp, 1); 3566 } 3567 3568 DB_SHOW_COMMAND(files, db_show_files) 3569 { 3570 struct filedesc *fdp; 3571 struct file *fp; 3572 struct proc *p; 3573 int header; 3574 int n; 3575 3576 header = 1; 3577 FOREACH_PROC_IN_SYSTEM(p) { 3578 if (p->p_state == PRS_NEW) 3579 continue; 3580 if ((fdp = p->p_fd) == NULL) 3581 continue; 3582 for (n = 0; n <= fdp->fd_lastfile; ++n) { 3583 if ((fp = fdp->fd_ofiles[n].fde_file) == NULL) 3584 continue; 3585 db_print_file(fp, header); 3586 header = 0; 3587 } 3588 } 3589 } 3590 #endif 3591 3592 SYSCTL_INT(_kern, KERN_MAXFILESPERPROC, maxfilesperproc, CTLFLAG_RW, 3593 &maxfilesperproc, 0, "Maximum files allowed open per process"); 3594 3595 SYSCTL_INT(_kern, KERN_MAXFILES, maxfiles, CTLFLAG_RW, 3596 &maxfiles, 0, "Maximum number of files"); 3597 3598 SYSCTL_INT(_kern, OID_AUTO, openfiles, CTLFLAG_RD, 3599 __DEVOLATILE(int *, &openfiles), 0, "System-wide number of open files"); 3600 3601 /* ARGSUSED*/ 3602 static void 3603 filelistinit(void *dummy) 3604 { 3605 3606 file_zone = uma_zcreate("Files", sizeof(struct file), NULL, NULL, 3607 NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE); 3608 filedesc0_zone = uma_zcreate("filedesc0", sizeof(struct filedesc0), 3609 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0); 3610 mtx_init(&sigio_lock, "sigio lock", NULL, MTX_DEF); 3611 mtx_init(&fdesc_mtx, "fdesc", NULL, MTX_DEF); 3612 } 3613 SYSINIT(select, SI_SUB_LOCK, SI_ORDER_FIRST, filelistinit, NULL); 3614 3615 /*-------------------------------------------------------------------*/ 3616 3617 static int 3618 badfo_readwrite(struct file *fp, struct uio *uio, struct ucred *active_cred, 3619 int flags, struct thread *td) 3620 { 3621 3622 return (EBADF); 3623 } 3624 3625 static int 3626 badfo_truncate(struct file *fp, off_t length, struct ucred *active_cred, 3627 struct thread *td) 3628 { 3629 3630 return (EINVAL); 3631 } 3632 3633 static int 3634 badfo_ioctl(struct file *fp, u_long com, void *data, struct ucred *active_cred, 3635 struct thread *td) 3636 { 3637 3638 return (EBADF); 3639 } 3640 3641 static int 3642 badfo_poll(struct file *fp, int events, struct ucred *active_cred, 3643 struct thread *td) 3644 { 3645 3646 return (0); 3647 } 3648 3649 static int 3650 badfo_kqfilter(struct file *fp, struct knote *kn) 3651 { 3652 3653 return (EBADF); 3654 } 3655 3656 static int 3657 badfo_stat(struct file *fp, struct stat *sb, struct ucred *active_cred, 3658 struct thread *td) 3659 { 3660 3661 return (EBADF); 3662 } 3663 3664 static int 3665 badfo_close(struct file *fp, struct thread *td) 3666 { 3667 3668 return (EBADF); 3669 } 3670 3671 static int 3672 badfo_chmod(struct file *fp, mode_t mode, struct ucred *active_cred, 3673 struct thread *td) 3674 { 3675 3676 return (EBADF); 3677 } 3678 3679 static int 3680 badfo_chown(struct file *fp, uid_t uid, gid_t gid, struct ucred *active_cred, 3681 struct thread *td) 3682 { 3683 3684 return (EBADF); 3685 } 3686 3687 static int 3688 badfo_sendfile(struct file *fp, int sockfd, struct uio *hdr_uio, 3689 struct uio *trl_uio, off_t offset, size_t nbytes, off_t *sent, int flags, 3690 int kflags, struct thread *td) 3691 { 3692 3693 return (EBADF); 3694 } 3695 3696 static int 3697 badfo_fill_kinfo(struct file *fp, struct kinfo_file *kif, struct filedesc *fdp) 3698 { 3699 3700 return (0); 3701 } 3702 3703 struct fileops badfileops = { 3704 .fo_read = badfo_readwrite, 3705 .fo_write = badfo_readwrite, 3706 .fo_truncate = badfo_truncate, 3707 .fo_ioctl = badfo_ioctl, 3708 .fo_poll = badfo_poll, 3709 .fo_kqfilter = badfo_kqfilter, 3710 .fo_stat = badfo_stat, 3711 .fo_close = badfo_close, 3712 .fo_chmod = badfo_chmod, 3713 .fo_chown = badfo_chown, 3714 .fo_sendfile = badfo_sendfile, 3715 .fo_fill_kinfo = badfo_fill_kinfo, 3716 }; 3717 3718 int 3719 invfo_rdwr(struct file *fp, struct uio *uio, struct ucred *active_cred, 3720 int flags, struct thread *td) 3721 { 3722 3723 return (EOPNOTSUPP); 3724 } 3725 3726 int 3727 invfo_truncate(struct file *fp, off_t length, struct ucred *active_cred, 3728 struct thread *td) 3729 { 3730 3731 return (EINVAL); 3732 } 3733 3734 int 3735 invfo_ioctl(struct file *fp, u_long com, void *data, 3736 struct ucred *active_cred, struct thread *td) 3737 { 3738 3739 return (ENOTTY); 3740 } 3741 3742 int 3743 invfo_poll(struct file *fp, int events, struct ucred *active_cred, 3744 struct thread *td) 3745 { 3746 3747 return (poll_no_poll(events)); 3748 } 3749 3750 int 3751 invfo_kqfilter(struct file *fp, struct knote *kn) 3752 { 3753 3754 return (EINVAL); 3755 } 3756 3757 int 3758 invfo_chmod(struct file *fp, mode_t mode, struct ucred *active_cred, 3759 struct thread *td) 3760 { 3761 3762 return (EINVAL); 3763 } 3764 3765 int 3766 invfo_chown(struct file *fp, uid_t uid, gid_t gid, struct ucred *active_cred, 3767 struct thread *td) 3768 { 3769 3770 return (EINVAL); 3771 } 3772 3773 int 3774 invfo_sendfile(struct file *fp, int sockfd, struct uio *hdr_uio, 3775 struct uio *trl_uio, off_t offset, size_t nbytes, off_t *sent, int flags, 3776 int kflags, struct thread *td) 3777 { 3778 3779 return (EINVAL); 3780 } 3781 3782 /*-------------------------------------------------------------------*/ 3783 3784 /* 3785 * File Descriptor pseudo-device driver (/dev/fd/). 3786 * 3787 * Opening minor device N dup()s the file (if any) connected to file 3788 * descriptor N belonging to the calling process. Note that this driver 3789 * consists of only the ``open()'' routine, because all subsequent 3790 * references to this file will be direct to the other driver. 3791 * 3792 * XXX: we could give this one a cloning event handler if necessary. 3793 */ 3794 3795 /* ARGSUSED */ 3796 static int 3797 fdopen(struct cdev *dev, int mode, int type, struct thread *td) 3798 { 3799 3800 /* 3801 * XXX Kludge: set curthread->td_dupfd to contain the value of the 3802 * the file descriptor being sought for duplication. The error 3803 * return ensures that the vnode for this device will be released 3804 * by vn_open. Open will detect this special error and take the 3805 * actions in dupfdopen below. Other callers of vn_open or VOP_OPEN 3806 * will simply report the error. 3807 */ 3808 td->td_dupfd = dev2unit(dev); 3809 return (ENODEV); 3810 } 3811 3812 static struct cdevsw fildesc_cdevsw = { 3813 .d_version = D_VERSION, 3814 .d_open = fdopen, 3815 .d_name = "FD", 3816 }; 3817 3818 static void 3819 fildesc_drvinit(void *unused) 3820 { 3821 struct cdev *dev; 3822 3823 dev = make_dev_credf(MAKEDEV_ETERNAL, &fildesc_cdevsw, 0, NULL, 3824 UID_ROOT, GID_WHEEL, 0666, "fd/0"); 3825 make_dev_alias(dev, "stdin"); 3826 dev = make_dev_credf(MAKEDEV_ETERNAL, &fildesc_cdevsw, 1, NULL, 3827 UID_ROOT, GID_WHEEL, 0666, "fd/1"); 3828 make_dev_alias(dev, "stdout"); 3829 dev = make_dev_credf(MAKEDEV_ETERNAL, &fildesc_cdevsw, 2, NULL, 3830 UID_ROOT, GID_WHEEL, 0666, "fd/2"); 3831 make_dev_alias(dev, "stderr"); 3832 } 3833 3834 SYSINIT(fildescdev, SI_SUB_DRIVERS, SI_ORDER_MIDDLE, fildesc_drvinit, NULL); 3835