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 thread *td); 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 /* 182 * If low >= size, just return low. Otherwise find the first zero bit in the 183 * given bitmap, starting at low and not exceeding size - 1. Return size if 184 * not found. 185 */ 186 static int 187 fd_first_free(struct filedesc *fdp, int low, int size) 188 { 189 NDSLOTTYPE *map = fdp->fd_map; 190 NDSLOTTYPE mask; 191 int off, maxoff; 192 193 if (low >= size) 194 return (low); 195 196 off = NDSLOT(low); 197 if (low % NDENTRIES) { 198 mask = ~(~(NDSLOTTYPE)0 >> (NDENTRIES - (low % NDENTRIES))); 199 if ((mask &= ~map[off]) != 0UL) 200 return (off * NDENTRIES + ffsl(mask) - 1); 201 ++off; 202 } 203 for (maxoff = NDSLOTS(size); off < maxoff; ++off) 204 if (map[off] != ~0UL) 205 return (off * NDENTRIES + ffsl(~map[off]) - 1); 206 return (size); 207 } 208 209 /* 210 * Find the highest non-zero bit in the given bitmap, starting at 0 and 211 * not exceeding size - 1. Return -1 if not found. 212 */ 213 static int 214 fd_last_used(struct filedesc *fdp, int size) 215 { 216 NDSLOTTYPE *map = fdp->fd_map; 217 NDSLOTTYPE mask; 218 int off, minoff; 219 220 off = NDSLOT(size); 221 if (size % NDENTRIES) { 222 mask = ~(~(NDSLOTTYPE)0 << (size % NDENTRIES)); 223 if ((mask &= map[off]) != 0) 224 return (off * NDENTRIES + flsl(mask) - 1); 225 --off; 226 } 227 for (minoff = NDSLOT(0); off >= minoff; --off) 228 if (map[off] != 0) 229 return (off * NDENTRIES + flsl(map[off]) - 1); 230 return (-1); 231 } 232 233 #ifdef INVARIANTS 234 static int 235 fdisused(struct filedesc *fdp, int fd) 236 { 237 238 KASSERT(fd >= 0 && fd < fdp->fd_nfiles, 239 ("file descriptor %d out of range (0, %d)", fd, fdp->fd_nfiles)); 240 241 return ((fdp->fd_map[NDSLOT(fd)] & NDBIT(fd)) != 0); 242 } 243 #endif 244 245 /* 246 * Mark a file descriptor as used. 247 */ 248 static void 249 fdused_init(struct filedesc *fdp, int fd) 250 { 251 252 KASSERT(!fdisused(fdp, fd), ("fd=%d is already used", fd)); 253 254 fdp->fd_map[NDSLOT(fd)] |= NDBIT(fd); 255 } 256 257 static void 258 fdused(struct filedesc *fdp, int fd) 259 { 260 261 FILEDESC_XLOCK_ASSERT(fdp); 262 263 fdused_init(fdp, fd); 264 if (fd > fdp->fd_lastfile) 265 fdp->fd_lastfile = fd; 266 if (fd == fdp->fd_freefile) 267 fdp->fd_freefile = fd_first_free(fdp, fd, fdp->fd_nfiles); 268 } 269 270 /* 271 * Mark a file descriptor as unused. 272 */ 273 static void 274 fdunused(struct filedesc *fdp, int fd) 275 { 276 277 FILEDESC_XLOCK_ASSERT(fdp); 278 279 KASSERT(fdisused(fdp, fd), ("fd=%d is already unused", fd)); 280 KASSERT(fdp->fd_ofiles[fd].fde_file == NULL, 281 ("fd=%d is still in use", fd)); 282 283 fdp->fd_map[NDSLOT(fd)] &= ~NDBIT(fd); 284 if (fd < fdp->fd_freefile) 285 fdp->fd_freefile = fd; 286 if (fd == fdp->fd_lastfile) 287 fdp->fd_lastfile = fd_last_used(fdp, fd); 288 } 289 290 /* 291 * Free a file descriptor. 292 * 293 * Avoid some work if fdp is about to be destroyed. 294 */ 295 static inline void 296 fdefree_last(struct filedescent *fde) 297 { 298 299 filecaps_free(&fde->fde_caps); 300 } 301 302 static inline void 303 fdfree(struct filedesc *fdp, int fd) 304 { 305 struct filedescent *fde; 306 307 fde = &fdp->fd_ofiles[fd]; 308 #ifdef CAPABILITIES 309 seq_write_begin(&fde->fde_seq); 310 #endif 311 fdefree_last(fde); 312 bzero(fde, fde_change_size); 313 fdunused(fdp, fd); 314 #ifdef CAPABILITIES 315 seq_write_end(&fde->fde_seq); 316 #endif 317 } 318 319 /* 320 * System calls on descriptors. 321 */ 322 #ifndef _SYS_SYSPROTO_H_ 323 struct getdtablesize_args { 324 int dummy; 325 }; 326 #endif 327 /* ARGSUSED */ 328 int 329 sys_getdtablesize(struct thread *td, struct getdtablesize_args *uap) 330 { 331 #ifdef RACCT 332 uint64_t lim; 333 #endif 334 335 td->td_retval[0] = 336 min((int)lim_cur(td, RLIMIT_NOFILE), maxfilesperproc); 337 #ifdef RACCT 338 PROC_LOCK(td->td_proc); 339 lim = racct_get_limit(td->td_proc, RACCT_NOFILE); 340 PROC_UNLOCK(td->td_proc); 341 if (lim < td->td_retval[0]) 342 td->td_retval[0] = lim; 343 #endif 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_fcntl(td, fd, 535 cap_rights_init(&rights, CAP_FCNTL), F_GETFL, &fp); 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_fcntl(td, fd, 544 cap_rights_init(&rights, CAP_FCNTL), F_SETFL, &fp); 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_fcntl(td, fd, 572 cap_rights_init(&rights, CAP_FCNTL), F_GETOWN, &fp); 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_fcntl(td, fd, 583 cap_rights_init(&rights, CAP_FCNTL), F_SETOWN, &fp); 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, &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 error = EOVERFLOW; 621 fdrop(fp, td); 622 break; 623 } 624 flp->l_start += foffset; 625 } 626 627 vp = fp->f_vnode; 628 switch (flp->l_type) { 629 case F_RDLCK: 630 if ((fp->f_flag & FREAD) == 0) { 631 error = EBADF; 632 break; 633 } 634 PROC_LOCK(p->p_leader); 635 p->p_leader->p_flag |= P_ADVLOCK; 636 PROC_UNLOCK(p->p_leader); 637 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_SETLK, 638 flp, flg); 639 break; 640 case F_WRLCK: 641 if ((fp->f_flag & FWRITE) == 0) { 642 error = EBADF; 643 break; 644 } 645 PROC_LOCK(p->p_leader); 646 p->p_leader->p_flag |= P_ADVLOCK; 647 PROC_UNLOCK(p->p_leader); 648 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_SETLK, 649 flp, flg); 650 break; 651 case F_UNLCK: 652 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_UNLCK, 653 flp, flg); 654 break; 655 case F_UNLCKSYS: 656 /* 657 * Temporary api for testing remote lock 658 * infrastructure. 659 */ 660 if (flg != F_REMOTE) { 661 error = EINVAL; 662 break; 663 } 664 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, 665 F_UNLCKSYS, flp, flg); 666 break; 667 default: 668 error = EINVAL; 669 break; 670 } 671 if (error != 0 || flp->l_type == F_UNLCK || 672 flp->l_type == F_UNLCKSYS) { 673 fdrop(fp, td); 674 break; 675 } 676 677 /* 678 * Check for a race with close. 679 * 680 * The vnode is now advisory locked (or unlocked, but this case 681 * is not really important) as the caller requested. 682 * We had to drop the filedesc lock, so we need to recheck if 683 * the descriptor is still valid, because if it was closed 684 * in the meantime we need to remove advisory lock from the 685 * vnode - close on any descriptor leading to an advisory 686 * locked vnode, removes that lock. 687 * We will return 0 on purpose in that case, as the result of 688 * successful advisory lock might have been externally visible 689 * already. This is fine - effectively we pretend to the caller 690 * that the closing thread was a bit slower and that the 691 * advisory lock succeeded before the close. 692 */ 693 error = fget_unlocked(fdp, fd, &rights, &fp2, NULL); 694 if (error != 0) { 695 fdrop(fp, td); 696 break; 697 } 698 if (fp != fp2) { 699 flp->l_whence = SEEK_SET; 700 flp->l_start = 0; 701 flp->l_len = 0; 702 flp->l_type = F_UNLCK; 703 (void) VOP_ADVLOCK(vp, (caddr_t)p->p_leader, 704 F_UNLCK, flp, F_POSIX); 705 } 706 fdrop(fp, td); 707 fdrop(fp2, td); 708 break; 709 710 case F_GETLK: 711 error = fget_unlocked(fdp, fd, 712 cap_rights_init(&rights, CAP_FLOCK), &fp, NULL); 713 if (error != 0) 714 break; 715 if (fp->f_type != DTYPE_VNODE) { 716 error = EBADF; 717 fdrop(fp, td); 718 break; 719 } 720 flp = (struct flock *)arg; 721 if (flp->l_type != F_RDLCK && flp->l_type != F_WRLCK && 722 flp->l_type != F_UNLCK) { 723 error = EINVAL; 724 fdrop(fp, td); 725 break; 726 } 727 if (flp->l_whence == SEEK_CUR) { 728 foffset = foffset_get(fp); 729 if ((flp->l_start > 0 && 730 foffset > OFF_MAX - flp->l_start) || 731 (flp->l_start < 0 && 732 foffset < OFF_MIN - flp->l_start)) { 733 error = EOVERFLOW; 734 fdrop(fp, td); 735 break; 736 } 737 flp->l_start += foffset; 738 } 739 vp = fp->f_vnode; 740 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_GETLK, flp, 741 F_POSIX); 742 fdrop(fp, td); 743 break; 744 745 case F_RDAHEAD: 746 arg = arg ? 128 * 1024: 0; 747 /* FALLTHROUGH */ 748 case F_READAHEAD: 749 error = fget_unlocked(fdp, fd, NULL, &fp, NULL); 750 if (error != 0) 751 break; 752 if (fp->f_type != DTYPE_VNODE) { 753 fdrop(fp, td); 754 error = EBADF; 755 break; 756 } 757 vp = fp->f_vnode; 758 /* 759 * Exclusive lock synchronizes against f_seqcount reads and 760 * writes in sequential_heuristic(). 761 */ 762 error = vn_lock(vp, LK_EXCLUSIVE); 763 if (error != 0) { 764 fdrop(fp, td); 765 break; 766 } 767 if (arg >= 0) { 768 bsize = fp->f_vnode->v_mount->mnt_stat.f_iosize; 769 fp->f_seqcount = (arg + bsize - 1) / bsize; 770 atomic_set_int(&fp->f_flag, FRDAHEAD); 771 } else { 772 atomic_clear_int(&fp->f_flag, FRDAHEAD); 773 } 774 VOP_UNLOCK(vp, 0); 775 fdrop(fp, td); 776 break; 777 778 default: 779 error = EINVAL; 780 break; 781 } 782 return (error); 783 } 784 785 static int 786 getmaxfd(struct thread *td) 787 { 788 789 return (min((int)lim_cur(td, RLIMIT_NOFILE), maxfilesperproc)); 790 } 791 792 /* 793 * Common code for dup, dup2, fcntl(F_DUPFD) and fcntl(F_DUP2FD). 794 */ 795 static int 796 do_dup(struct thread *td, int flags, int old, int new) 797 { 798 struct filedesc *fdp; 799 struct filedescent *oldfde, *newfde; 800 struct proc *p; 801 struct file *fp; 802 struct file *delfp; 803 int error, maxfd; 804 805 p = td->td_proc; 806 fdp = p->p_fd; 807 808 /* 809 * Verify we have a valid descriptor to dup from and possibly to 810 * dup to. Unlike dup() and dup2(), fcntl()'s F_DUPFD should 811 * return EINVAL when the new descriptor is out of bounds. 812 */ 813 if (old < 0) 814 return (EBADF); 815 if (new < 0) 816 return (flags & DUP_FCNTL ? EINVAL : EBADF); 817 maxfd = getmaxfd(td); 818 if (new >= maxfd) 819 return (flags & DUP_FCNTL ? EINVAL : EBADF); 820 821 FILEDESC_XLOCK(fdp); 822 if (fget_locked(fdp, old) == NULL) { 823 FILEDESC_XUNLOCK(fdp); 824 return (EBADF); 825 } 826 oldfde = &fdp->fd_ofiles[old]; 827 if (flags & DUP_FIXED && old == new) { 828 td->td_retval[0] = new; 829 if (flags & DUP_CLOEXEC) 830 fdp->fd_ofiles[new].fde_flags |= UF_EXCLOSE; 831 FILEDESC_XUNLOCK(fdp); 832 return (0); 833 } 834 fp = oldfde->fde_file; 835 fhold(fp); 836 837 /* 838 * If the caller specified a file descriptor, make sure the file 839 * table is large enough to hold it, and grab it. Otherwise, just 840 * allocate a new descriptor the usual way. 841 */ 842 if (flags & DUP_FIXED) { 843 if (new >= fdp->fd_nfiles) { 844 /* 845 * The resource limits are here instead of e.g. 846 * fdalloc(), because the file descriptor table may be 847 * shared between processes, so we can't really use 848 * racct_add()/racct_sub(). Instead of counting the 849 * number of actually allocated descriptors, just put 850 * the limit on the size of the file descriptor table. 851 */ 852 #ifdef RACCT 853 if (racct_enable) { 854 PROC_LOCK(p); 855 error = racct_set(p, RACCT_NOFILE, new + 1); 856 PROC_UNLOCK(p); 857 if (error != 0) { 858 FILEDESC_XUNLOCK(fdp); 859 fdrop(fp, td); 860 return (EMFILE); 861 } 862 } 863 #endif 864 fdgrowtable_exp(fdp, new + 1); 865 oldfde = &fdp->fd_ofiles[old]; 866 } 867 newfde = &fdp->fd_ofiles[new]; 868 if (newfde->fde_file == NULL) 869 fdused(fdp, new); 870 } else { 871 if ((error = fdalloc(td, new, &new)) != 0) { 872 FILEDESC_XUNLOCK(fdp); 873 fdrop(fp, td); 874 return (error); 875 } 876 newfde = &fdp->fd_ofiles[new]; 877 } 878 879 KASSERT(fp == oldfde->fde_file, ("old fd has been modified")); 880 KASSERT(old != new, ("new fd is same as old")); 881 882 delfp = newfde->fde_file; 883 884 /* 885 * Duplicate the source descriptor. 886 */ 887 #ifdef CAPABILITIES 888 seq_write_begin(&newfde->fde_seq); 889 #endif 890 filecaps_free(&newfde->fde_caps); 891 memcpy(newfde, oldfde, fde_change_size); 892 filecaps_copy(&oldfde->fde_caps, &newfde->fde_caps); 893 if ((flags & DUP_CLOEXEC) != 0) 894 newfde->fde_flags = oldfde->fde_flags | UF_EXCLOSE; 895 else 896 newfde->fde_flags = oldfde->fde_flags & ~UF_EXCLOSE; 897 #ifdef CAPABILITIES 898 seq_write_end(&newfde->fde_seq); 899 #endif 900 td->td_retval[0] = new; 901 902 if (delfp != NULL) { 903 (void) closefp(fdp, new, delfp, td, 1); 904 /* closefp() drops the FILEDESC lock for us. */ 905 } else { 906 FILEDESC_XUNLOCK(fdp); 907 } 908 909 return (0); 910 } 911 912 /* 913 * If sigio is on the list associated with a process or process group, 914 * disable signalling from the device, remove sigio from the list and 915 * free sigio. 916 */ 917 void 918 funsetown(struct sigio **sigiop) 919 { 920 struct sigio *sigio; 921 922 SIGIO_LOCK(); 923 sigio = *sigiop; 924 if (sigio == NULL) { 925 SIGIO_UNLOCK(); 926 return; 927 } 928 *(sigio->sio_myref) = NULL; 929 if ((sigio)->sio_pgid < 0) { 930 struct pgrp *pg = (sigio)->sio_pgrp; 931 PGRP_LOCK(pg); 932 SLIST_REMOVE(&sigio->sio_pgrp->pg_sigiolst, sigio, 933 sigio, sio_pgsigio); 934 PGRP_UNLOCK(pg); 935 } else { 936 struct proc *p = (sigio)->sio_proc; 937 PROC_LOCK(p); 938 SLIST_REMOVE(&sigio->sio_proc->p_sigiolst, sigio, 939 sigio, sio_pgsigio); 940 PROC_UNLOCK(p); 941 } 942 SIGIO_UNLOCK(); 943 crfree(sigio->sio_ucred); 944 free(sigio, M_SIGIO); 945 } 946 947 /* 948 * Free a list of sigio structures. 949 * We only need to lock the SIGIO_LOCK because we have made ourselves 950 * inaccessible to callers of fsetown and therefore do not need to lock 951 * the proc or pgrp struct for the list manipulation. 952 */ 953 void 954 funsetownlst(struct sigiolst *sigiolst) 955 { 956 struct proc *p; 957 struct pgrp *pg; 958 struct sigio *sigio; 959 960 sigio = SLIST_FIRST(sigiolst); 961 if (sigio == NULL) 962 return; 963 p = NULL; 964 pg = NULL; 965 966 /* 967 * Every entry of the list should belong 968 * to a single proc or pgrp. 969 */ 970 if (sigio->sio_pgid < 0) { 971 pg = sigio->sio_pgrp; 972 PGRP_LOCK_ASSERT(pg, MA_NOTOWNED); 973 } else /* if (sigio->sio_pgid > 0) */ { 974 p = sigio->sio_proc; 975 PROC_LOCK_ASSERT(p, MA_NOTOWNED); 976 } 977 978 SIGIO_LOCK(); 979 while ((sigio = SLIST_FIRST(sigiolst)) != NULL) { 980 *(sigio->sio_myref) = NULL; 981 if (pg != NULL) { 982 KASSERT(sigio->sio_pgid < 0, 983 ("Proc sigio in pgrp sigio list")); 984 KASSERT(sigio->sio_pgrp == pg, 985 ("Bogus pgrp in sigio list")); 986 PGRP_LOCK(pg); 987 SLIST_REMOVE(&pg->pg_sigiolst, sigio, sigio, 988 sio_pgsigio); 989 PGRP_UNLOCK(pg); 990 } else /* if (p != NULL) */ { 991 KASSERT(sigio->sio_pgid > 0, 992 ("Pgrp sigio in proc sigio list")); 993 KASSERT(sigio->sio_proc == p, 994 ("Bogus proc in sigio list")); 995 PROC_LOCK(p); 996 SLIST_REMOVE(&p->p_sigiolst, sigio, sigio, 997 sio_pgsigio); 998 PROC_UNLOCK(p); 999 } 1000 SIGIO_UNLOCK(); 1001 crfree(sigio->sio_ucred); 1002 free(sigio, M_SIGIO); 1003 SIGIO_LOCK(); 1004 } 1005 SIGIO_UNLOCK(); 1006 } 1007 1008 /* 1009 * This is common code for FIOSETOWN ioctl called by fcntl(fd, F_SETOWN, arg). 1010 * 1011 * After permission checking, add a sigio structure to the sigio list for 1012 * the process or process group. 1013 */ 1014 int 1015 fsetown(pid_t pgid, struct sigio **sigiop) 1016 { 1017 struct proc *proc; 1018 struct pgrp *pgrp; 1019 struct sigio *sigio; 1020 int ret; 1021 1022 if (pgid == 0) { 1023 funsetown(sigiop); 1024 return (0); 1025 } 1026 1027 ret = 0; 1028 1029 /* Allocate and fill in the new sigio out of locks. */ 1030 sigio = malloc(sizeof(struct sigio), M_SIGIO, M_WAITOK); 1031 sigio->sio_pgid = pgid; 1032 sigio->sio_ucred = crhold(curthread->td_ucred); 1033 sigio->sio_myref = sigiop; 1034 1035 sx_slock(&proctree_lock); 1036 if (pgid > 0) { 1037 proc = pfind(pgid); 1038 if (proc == NULL) { 1039 ret = ESRCH; 1040 goto fail; 1041 } 1042 1043 /* 1044 * Policy - Don't allow a process to FSETOWN a process 1045 * in another session. 1046 * 1047 * Remove this test to allow maximum flexibility or 1048 * restrict FSETOWN to the current process or process 1049 * group for maximum safety. 1050 */ 1051 PROC_UNLOCK(proc); 1052 if (proc->p_session != curthread->td_proc->p_session) { 1053 ret = EPERM; 1054 goto fail; 1055 } 1056 1057 pgrp = NULL; 1058 } else /* if (pgid < 0) */ { 1059 pgrp = pgfind(-pgid); 1060 if (pgrp == NULL) { 1061 ret = ESRCH; 1062 goto fail; 1063 } 1064 PGRP_UNLOCK(pgrp); 1065 1066 /* 1067 * Policy - Don't allow a process to FSETOWN a process 1068 * in another session. 1069 * 1070 * Remove this test to allow maximum flexibility or 1071 * restrict FSETOWN to the current process or process 1072 * group for maximum safety. 1073 */ 1074 if (pgrp->pg_session != curthread->td_proc->p_session) { 1075 ret = EPERM; 1076 goto fail; 1077 } 1078 1079 proc = NULL; 1080 } 1081 funsetown(sigiop); 1082 if (pgid > 0) { 1083 PROC_LOCK(proc); 1084 /* 1085 * Since funsetownlst() is called without the proctree 1086 * locked, we need to check for P_WEXIT. 1087 * XXX: is ESRCH correct? 1088 */ 1089 if ((proc->p_flag & P_WEXIT) != 0) { 1090 PROC_UNLOCK(proc); 1091 ret = ESRCH; 1092 goto fail; 1093 } 1094 SLIST_INSERT_HEAD(&proc->p_sigiolst, sigio, sio_pgsigio); 1095 sigio->sio_proc = proc; 1096 PROC_UNLOCK(proc); 1097 } else { 1098 PGRP_LOCK(pgrp); 1099 SLIST_INSERT_HEAD(&pgrp->pg_sigiolst, sigio, sio_pgsigio); 1100 sigio->sio_pgrp = pgrp; 1101 PGRP_UNLOCK(pgrp); 1102 } 1103 sx_sunlock(&proctree_lock); 1104 SIGIO_LOCK(); 1105 *sigiop = sigio; 1106 SIGIO_UNLOCK(); 1107 return (0); 1108 1109 fail: 1110 sx_sunlock(&proctree_lock); 1111 crfree(sigio->sio_ucred); 1112 free(sigio, M_SIGIO); 1113 return (ret); 1114 } 1115 1116 /* 1117 * This is common code for FIOGETOWN ioctl called by fcntl(fd, F_GETOWN, arg). 1118 */ 1119 pid_t 1120 fgetown(sigiop) 1121 struct sigio **sigiop; 1122 { 1123 pid_t pgid; 1124 1125 SIGIO_LOCK(); 1126 pgid = (*sigiop != NULL) ? (*sigiop)->sio_pgid : 0; 1127 SIGIO_UNLOCK(); 1128 return (pgid); 1129 } 1130 1131 /* 1132 * Function drops the filedesc lock on return. 1133 */ 1134 static int 1135 closefp(struct filedesc *fdp, int fd, struct file *fp, struct thread *td, 1136 int holdleaders) 1137 { 1138 int error; 1139 1140 FILEDESC_XLOCK_ASSERT(fdp); 1141 1142 if (holdleaders) { 1143 if (td->td_proc->p_fdtol != NULL) { 1144 /* 1145 * Ask fdfree() to sleep to ensure that all relevant 1146 * process leaders can be traversed in closef(). 1147 */ 1148 fdp->fd_holdleaderscount++; 1149 } else { 1150 holdleaders = 0; 1151 } 1152 } 1153 1154 /* 1155 * We now hold the fp reference that used to be owned by the 1156 * descriptor array. We have to unlock the FILEDESC *AFTER* 1157 * knote_fdclose to prevent a race of the fd getting opened, a knote 1158 * added, and deleteing a knote for the new fd. 1159 */ 1160 knote_fdclose(td, fd); 1161 1162 /* 1163 * We need to notify mqueue if the object is of type mqueue. 1164 */ 1165 if (fp->f_type == DTYPE_MQUEUE) 1166 mq_fdclose(td, fd, fp); 1167 FILEDESC_XUNLOCK(fdp); 1168 1169 error = closef(fp, td); 1170 if (holdleaders) { 1171 FILEDESC_XLOCK(fdp); 1172 fdp->fd_holdleaderscount--; 1173 if (fdp->fd_holdleaderscount == 0 && 1174 fdp->fd_holdleaderswakeup != 0) { 1175 fdp->fd_holdleaderswakeup = 0; 1176 wakeup(&fdp->fd_holdleaderscount); 1177 } 1178 FILEDESC_XUNLOCK(fdp); 1179 } 1180 return (error); 1181 } 1182 1183 /* 1184 * Close a file descriptor. 1185 */ 1186 #ifndef _SYS_SYSPROTO_H_ 1187 struct close_args { 1188 int fd; 1189 }; 1190 #endif 1191 /* ARGSUSED */ 1192 int 1193 sys_close(td, uap) 1194 struct thread *td; 1195 struct close_args *uap; 1196 { 1197 1198 return (kern_close(td, uap->fd)); 1199 } 1200 1201 int 1202 kern_close(td, fd) 1203 struct thread *td; 1204 int fd; 1205 { 1206 struct filedesc *fdp; 1207 struct file *fp; 1208 1209 fdp = td->td_proc->p_fd; 1210 1211 AUDIT_SYSCLOSE(td, fd); 1212 1213 FILEDESC_XLOCK(fdp); 1214 if ((fp = fget_locked(fdp, fd)) == NULL) { 1215 FILEDESC_XUNLOCK(fdp); 1216 return (EBADF); 1217 } 1218 fdfree(fdp, fd); 1219 1220 /* closefp() drops the FILEDESC lock for us. */ 1221 return (closefp(fdp, fd, fp, td, 1)); 1222 } 1223 1224 /* 1225 * Close open file descriptors. 1226 */ 1227 #ifndef _SYS_SYSPROTO_H_ 1228 struct closefrom_args { 1229 int lowfd; 1230 }; 1231 #endif 1232 /* ARGSUSED */ 1233 int 1234 sys_closefrom(struct thread *td, struct closefrom_args *uap) 1235 { 1236 struct filedesc *fdp; 1237 int fd; 1238 1239 fdp = td->td_proc->p_fd; 1240 AUDIT_ARG_FD(uap->lowfd); 1241 1242 /* 1243 * Treat negative starting file descriptor values identical to 1244 * closefrom(0) which closes all files. 1245 */ 1246 if (uap->lowfd < 0) 1247 uap->lowfd = 0; 1248 FILEDESC_SLOCK(fdp); 1249 for (fd = uap->lowfd; fd <= fdp->fd_lastfile; fd++) { 1250 if (fdp->fd_ofiles[fd].fde_file != NULL) { 1251 FILEDESC_SUNLOCK(fdp); 1252 (void)kern_close(td, fd); 1253 FILEDESC_SLOCK(fdp); 1254 } 1255 } 1256 FILEDESC_SUNLOCK(fdp); 1257 return (0); 1258 } 1259 1260 #if defined(COMPAT_43) 1261 /* 1262 * Return status information about a file descriptor. 1263 */ 1264 #ifndef _SYS_SYSPROTO_H_ 1265 struct ofstat_args { 1266 int fd; 1267 struct ostat *sb; 1268 }; 1269 #endif 1270 /* ARGSUSED */ 1271 int 1272 ofstat(struct thread *td, struct ofstat_args *uap) 1273 { 1274 struct ostat oub; 1275 struct stat ub; 1276 int error; 1277 1278 error = kern_fstat(td, uap->fd, &ub); 1279 if (error == 0) { 1280 cvtstat(&ub, &oub); 1281 error = copyout(&oub, uap->sb, sizeof(oub)); 1282 } 1283 return (error); 1284 } 1285 #endif /* COMPAT_43 */ 1286 1287 /* 1288 * Return status information about a file descriptor. 1289 */ 1290 #ifndef _SYS_SYSPROTO_H_ 1291 struct fstat_args { 1292 int fd; 1293 struct stat *sb; 1294 }; 1295 #endif 1296 /* ARGSUSED */ 1297 int 1298 sys_fstat(struct thread *td, struct fstat_args *uap) 1299 { 1300 struct stat ub; 1301 int error; 1302 1303 error = kern_fstat(td, uap->fd, &ub); 1304 if (error == 0) 1305 error = copyout(&ub, uap->sb, sizeof(ub)); 1306 return (error); 1307 } 1308 1309 int 1310 kern_fstat(struct thread *td, int fd, struct stat *sbp) 1311 { 1312 struct file *fp; 1313 cap_rights_t rights; 1314 int error; 1315 1316 AUDIT_ARG_FD(fd); 1317 1318 error = fget(td, fd, cap_rights_init(&rights, CAP_FSTAT), &fp); 1319 if (error != 0) 1320 return (error); 1321 1322 AUDIT_ARG_FILE(td->td_proc, fp); 1323 1324 error = fo_stat(fp, sbp, td->td_ucred, td); 1325 fdrop(fp, td); 1326 #ifdef KTRACE 1327 if (error == 0 && KTRPOINT(td, KTR_STRUCT)) 1328 ktrstat(sbp); 1329 #endif 1330 return (error); 1331 } 1332 1333 /* 1334 * Return status information about a file descriptor. 1335 */ 1336 #ifndef _SYS_SYSPROTO_H_ 1337 struct nfstat_args { 1338 int fd; 1339 struct nstat *sb; 1340 }; 1341 #endif 1342 /* ARGSUSED */ 1343 int 1344 sys_nfstat(struct thread *td, struct nfstat_args *uap) 1345 { 1346 struct nstat nub; 1347 struct stat ub; 1348 int error; 1349 1350 error = kern_fstat(td, uap->fd, &ub); 1351 if (error == 0) { 1352 cvtnstat(&ub, &nub); 1353 error = copyout(&nub, uap->sb, sizeof(nub)); 1354 } 1355 return (error); 1356 } 1357 1358 /* 1359 * Return pathconf information about a file descriptor. 1360 */ 1361 #ifndef _SYS_SYSPROTO_H_ 1362 struct fpathconf_args { 1363 int fd; 1364 int name; 1365 }; 1366 #endif 1367 /* ARGSUSED */ 1368 int 1369 sys_fpathconf(struct thread *td, struct fpathconf_args *uap) 1370 { 1371 struct file *fp; 1372 struct vnode *vp; 1373 cap_rights_t rights; 1374 int error; 1375 1376 error = fget(td, uap->fd, cap_rights_init(&rights, CAP_FPATHCONF), &fp); 1377 if (error != 0) 1378 return (error); 1379 1380 /* If asynchronous I/O is available, it works for all descriptors. */ 1381 if (uap->name == _PC_ASYNC_IO) { 1382 td->td_retval[0] = async_io_version; 1383 goto out; 1384 } 1385 vp = fp->f_vnode; 1386 if (vp != NULL) { 1387 vn_lock(vp, LK_SHARED | LK_RETRY); 1388 error = VOP_PATHCONF(vp, uap->name, td->td_retval); 1389 VOP_UNLOCK(vp, 0); 1390 } else if (fp->f_type == DTYPE_PIPE || fp->f_type == DTYPE_SOCKET) { 1391 if (uap->name != _PC_PIPE_BUF) { 1392 error = EINVAL; 1393 } else { 1394 td->td_retval[0] = PIPE_BUF; 1395 error = 0; 1396 } 1397 } else { 1398 error = EOPNOTSUPP; 1399 } 1400 out: 1401 fdrop(fp, td); 1402 return (error); 1403 } 1404 1405 /* 1406 * Initialize filecaps structure. 1407 */ 1408 void 1409 filecaps_init(struct filecaps *fcaps) 1410 { 1411 1412 bzero(fcaps, sizeof(*fcaps)); 1413 fcaps->fc_nioctls = -1; 1414 } 1415 1416 /* 1417 * Copy filecaps structure allocating memory for ioctls array if needed. 1418 */ 1419 void 1420 filecaps_copy(const struct filecaps *src, struct filecaps *dst) 1421 { 1422 size_t size; 1423 1424 *dst = *src; 1425 if (src->fc_ioctls != NULL) { 1426 KASSERT(src->fc_nioctls > 0, 1427 ("fc_ioctls != NULL, but fc_nioctls=%hd", src->fc_nioctls)); 1428 1429 size = sizeof(src->fc_ioctls[0]) * src->fc_nioctls; 1430 dst->fc_ioctls = malloc(size, M_FILECAPS, M_WAITOK); 1431 bcopy(src->fc_ioctls, dst->fc_ioctls, size); 1432 } 1433 } 1434 1435 /* 1436 * Move filecaps structure to the new place and clear the old place. 1437 */ 1438 void 1439 filecaps_move(struct filecaps *src, struct filecaps *dst) 1440 { 1441 1442 *dst = *src; 1443 bzero(src, sizeof(*src)); 1444 } 1445 1446 /* 1447 * Fill the given filecaps structure with full rights. 1448 */ 1449 static void 1450 filecaps_fill(struct filecaps *fcaps) 1451 { 1452 1453 CAP_ALL(&fcaps->fc_rights); 1454 fcaps->fc_ioctls = NULL; 1455 fcaps->fc_nioctls = -1; 1456 fcaps->fc_fcntls = CAP_FCNTL_ALL; 1457 } 1458 1459 /* 1460 * Free memory allocated within filecaps structure. 1461 */ 1462 void 1463 filecaps_free(struct filecaps *fcaps) 1464 { 1465 1466 free(fcaps->fc_ioctls, M_FILECAPS); 1467 bzero(fcaps, sizeof(*fcaps)); 1468 } 1469 1470 /* 1471 * Validate the given filecaps structure. 1472 */ 1473 static void 1474 filecaps_validate(const struct filecaps *fcaps, const char *func) 1475 { 1476 1477 KASSERT(cap_rights_is_valid(&fcaps->fc_rights), 1478 ("%s: invalid rights", func)); 1479 KASSERT((fcaps->fc_fcntls & ~CAP_FCNTL_ALL) == 0, 1480 ("%s: invalid fcntls", func)); 1481 KASSERT(fcaps->fc_fcntls == 0 || 1482 cap_rights_is_set(&fcaps->fc_rights, CAP_FCNTL), 1483 ("%s: fcntls without CAP_FCNTL", func)); 1484 KASSERT(fcaps->fc_ioctls != NULL ? fcaps->fc_nioctls > 0 : 1485 (fcaps->fc_nioctls == -1 || fcaps->fc_nioctls == 0), 1486 ("%s: invalid ioctls", func)); 1487 KASSERT(fcaps->fc_nioctls == 0 || 1488 cap_rights_is_set(&fcaps->fc_rights, CAP_IOCTL), 1489 ("%s: ioctls without CAP_IOCTL", func)); 1490 } 1491 1492 static void 1493 fdgrowtable_exp(struct filedesc *fdp, int nfd) 1494 { 1495 int nfd1; 1496 1497 FILEDESC_XLOCK_ASSERT(fdp); 1498 1499 nfd1 = fdp->fd_nfiles * 2; 1500 if (nfd1 < nfd) 1501 nfd1 = nfd; 1502 fdgrowtable(fdp, nfd1); 1503 } 1504 1505 /* 1506 * Grow the file table to accomodate (at least) nfd descriptors. 1507 */ 1508 static void 1509 fdgrowtable(struct filedesc *fdp, int nfd) 1510 { 1511 struct filedesc0 *fdp0; 1512 struct freetable *ft; 1513 struct fdescenttbl *ntable; 1514 struct fdescenttbl *otable; 1515 int nnfiles, onfiles; 1516 NDSLOTTYPE *nmap, *omap; 1517 1518 /* 1519 * If lastfile is -1 this struct filedesc was just allocated and we are 1520 * growing it to accomodate for the one we are going to copy from. There 1521 * is no need to have a lock on this one as it's not visible to anyone. 1522 */ 1523 if (fdp->fd_lastfile != -1) 1524 FILEDESC_XLOCK_ASSERT(fdp); 1525 1526 KASSERT(fdp->fd_nfiles > 0, ("zero-length file table")); 1527 1528 /* save old values */ 1529 onfiles = fdp->fd_nfiles; 1530 otable = fdp->fd_files; 1531 omap = fdp->fd_map; 1532 1533 /* compute the size of the new table */ 1534 nnfiles = NDSLOTS(nfd) * NDENTRIES; /* round up */ 1535 if (nnfiles <= onfiles) 1536 /* the table is already large enough */ 1537 return; 1538 1539 /* 1540 * Allocate a new table. We need enough space for the number of 1541 * entries, file entries themselves and the struct freetable we will use 1542 * when we decommission the table and place it on the freelist. 1543 * We place the struct freetable in the middle so we don't have 1544 * to worry about padding. 1545 */ 1546 ntable = malloc(offsetof(struct fdescenttbl, fdt_ofiles) + 1547 nnfiles * sizeof(ntable->fdt_ofiles[0]) + 1548 sizeof(struct freetable), 1549 M_FILEDESC, M_ZERO | M_WAITOK); 1550 /* copy the old data */ 1551 ntable->fdt_nfiles = nnfiles; 1552 memcpy(ntable->fdt_ofiles, otable->fdt_ofiles, 1553 onfiles * sizeof(ntable->fdt_ofiles[0])); 1554 1555 /* 1556 * Allocate a new map only if the old is not large enough. It will 1557 * grow at a slower rate than the table as it can map more 1558 * entries than the table can hold. 1559 */ 1560 if (NDSLOTS(nnfiles) > NDSLOTS(onfiles)) { 1561 nmap = malloc(NDSLOTS(nnfiles) * NDSLOTSIZE, M_FILEDESC, 1562 M_ZERO | M_WAITOK); 1563 /* copy over the old data and update the pointer */ 1564 memcpy(nmap, omap, NDSLOTS(onfiles) * sizeof(*omap)); 1565 fdp->fd_map = nmap; 1566 } 1567 1568 /* 1569 * Make sure that ntable is correctly initialized before we replace 1570 * fd_files poiner. Otherwise fget_unlocked() may see inconsistent 1571 * data. 1572 */ 1573 atomic_store_rel_ptr((volatile void *)&fdp->fd_files, (uintptr_t)ntable); 1574 1575 /* 1576 * Do not free the old file table, as some threads may still 1577 * reference entries within it. Instead, place it on a freelist 1578 * which will be processed when the struct filedesc is released. 1579 * 1580 * Note that if onfiles == NDFILE, we're dealing with the original 1581 * static allocation contained within (struct filedesc0 *)fdp, 1582 * which must not be freed. 1583 */ 1584 if (onfiles > NDFILE) { 1585 ft = (struct freetable *)&otable->fdt_ofiles[onfiles]; 1586 fdp0 = (struct filedesc0 *)fdp; 1587 ft->ft_table = otable; 1588 SLIST_INSERT_HEAD(&fdp0->fd_free, ft, ft_next); 1589 } 1590 /* 1591 * The map does not have the same possibility of threads still 1592 * holding references to it. So always free it as long as it 1593 * does not reference the original static allocation. 1594 */ 1595 if (NDSLOTS(onfiles) > NDSLOTS(NDFILE)) 1596 free(omap, M_FILEDESC); 1597 } 1598 1599 /* 1600 * Allocate a file descriptor for the process. 1601 */ 1602 int 1603 fdalloc(struct thread *td, int minfd, int *result) 1604 { 1605 struct proc *p = td->td_proc; 1606 struct filedesc *fdp = p->p_fd; 1607 int fd, maxfd, allocfd; 1608 #ifdef RACCT 1609 int error; 1610 #endif 1611 1612 FILEDESC_XLOCK_ASSERT(fdp); 1613 1614 if (fdp->fd_freefile > minfd) 1615 minfd = fdp->fd_freefile; 1616 1617 maxfd = getmaxfd(td); 1618 1619 /* 1620 * Search the bitmap for a free descriptor starting at minfd. 1621 * If none is found, grow the file table. 1622 */ 1623 fd = fd_first_free(fdp, minfd, fdp->fd_nfiles); 1624 if (fd >= maxfd) 1625 return (EMFILE); 1626 if (fd >= fdp->fd_nfiles) { 1627 allocfd = min(fd * 2, maxfd); 1628 #ifdef RACCT 1629 if (racct_enable) { 1630 PROC_LOCK(p); 1631 error = racct_set(p, RACCT_NOFILE, allocfd); 1632 PROC_UNLOCK(p); 1633 if (error != 0) 1634 return (EMFILE); 1635 } 1636 #endif 1637 /* 1638 * fd is already equal to first free descriptor >= minfd, so 1639 * we only need to grow the table and we are done. 1640 */ 1641 fdgrowtable_exp(fdp, allocfd); 1642 } 1643 1644 /* 1645 * Perform some sanity checks, then mark the file descriptor as 1646 * used and return it to the caller. 1647 */ 1648 KASSERT(fd >= 0 && fd < min(maxfd, fdp->fd_nfiles), 1649 ("invalid descriptor %d", fd)); 1650 KASSERT(!fdisused(fdp, fd), 1651 ("fd_first_free() returned non-free descriptor")); 1652 KASSERT(fdp->fd_ofiles[fd].fde_file == NULL, 1653 ("file descriptor isn't free")); 1654 KASSERT(fdp->fd_ofiles[fd].fde_flags == 0, ("file flags are set")); 1655 fdused(fdp, fd); 1656 *result = fd; 1657 return (0); 1658 } 1659 1660 /* 1661 * Allocate n file descriptors for the process. 1662 */ 1663 int 1664 fdallocn(struct thread *td, int minfd, int *fds, int n) 1665 { 1666 struct proc *p = td->td_proc; 1667 struct filedesc *fdp = p->p_fd; 1668 int i; 1669 1670 FILEDESC_XLOCK_ASSERT(fdp); 1671 1672 for (i = 0; i < n; i++) 1673 if (fdalloc(td, 0, &fds[i]) != 0) 1674 break; 1675 1676 if (i < n) { 1677 for (i--; i >= 0; i--) 1678 fdunused(fdp, fds[i]); 1679 return (EMFILE); 1680 } 1681 1682 return (0); 1683 } 1684 1685 /* 1686 * Create a new open file structure and allocate a file decriptor for the 1687 * process that refers to it. We add one reference to the file for the 1688 * descriptor table and one reference for resultfp. This is to prevent us 1689 * being preempted and the entry in the descriptor table closed after we 1690 * release the FILEDESC lock. 1691 */ 1692 int 1693 falloc(struct thread *td, struct file **resultfp, int *resultfd, int flags) 1694 { 1695 struct file *fp; 1696 int error, fd; 1697 1698 error = falloc_noinstall(td, &fp); 1699 if (error) 1700 return (error); /* no reference held on error */ 1701 1702 error = finstall(td, fp, &fd, flags, NULL); 1703 if (error) { 1704 fdrop(fp, td); /* one reference (fp only) */ 1705 return (error); 1706 } 1707 1708 if (resultfp != NULL) 1709 *resultfp = fp; /* copy out result */ 1710 else 1711 fdrop(fp, td); /* release local reference */ 1712 1713 if (resultfd != NULL) 1714 *resultfd = fd; 1715 1716 return (0); 1717 } 1718 1719 /* 1720 * Create a new open file structure without allocating a file descriptor. 1721 */ 1722 int 1723 falloc_noinstall(struct thread *td, struct file **resultfp) 1724 { 1725 struct file *fp; 1726 int maxuserfiles = maxfiles - (maxfiles / 20); 1727 static struct timeval lastfail; 1728 static int curfail; 1729 1730 KASSERT(resultfp != NULL, ("%s: resultfp == NULL", __func__)); 1731 1732 if ((openfiles >= maxuserfiles && 1733 priv_check(td, PRIV_MAXFILES) != 0) || 1734 openfiles >= maxfiles) { 1735 if (ppsratecheck(&lastfail, &curfail, 1)) { 1736 printf("kern.maxfiles limit exceeded by uid %i, " 1737 "please see tuning(7).\n", td->td_ucred->cr_ruid); 1738 } 1739 return (ENFILE); 1740 } 1741 atomic_add_int(&openfiles, 1); 1742 fp = uma_zalloc(file_zone, M_WAITOK | M_ZERO); 1743 refcount_init(&fp->f_count, 1); 1744 fp->f_cred = crhold(td->td_ucred); 1745 fp->f_ops = &badfileops; 1746 *resultfp = fp; 1747 return (0); 1748 } 1749 1750 /* 1751 * Install a file in a file descriptor table. 1752 */ 1753 int 1754 finstall(struct thread *td, struct file *fp, int *fd, int flags, 1755 struct filecaps *fcaps) 1756 { 1757 struct filedesc *fdp = td->td_proc->p_fd; 1758 struct filedescent *fde; 1759 int error; 1760 1761 KASSERT(fd != NULL, ("%s: fd == NULL", __func__)); 1762 KASSERT(fp != NULL, ("%s: fp == NULL", __func__)); 1763 if (fcaps != NULL) 1764 filecaps_validate(fcaps, __func__); 1765 1766 FILEDESC_XLOCK(fdp); 1767 if ((error = fdalloc(td, 0, fd))) { 1768 FILEDESC_XUNLOCK(fdp); 1769 return (error); 1770 } 1771 fhold(fp); 1772 fde = &fdp->fd_ofiles[*fd]; 1773 #ifdef CAPABILITIES 1774 seq_write_begin(&fde->fde_seq); 1775 #endif 1776 fde->fde_file = fp; 1777 if ((flags & O_CLOEXEC) != 0) 1778 fde->fde_flags |= UF_EXCLOSE; 1779 if (fcaps != NULL) 1780 filecaps_move(fcaps, &fde->fde_caps); 1781 else 1782 filecaps_fill(&fde->fde_caps); 1783 #ifdef CAPABILITIES 1784 seq_write_end(&fde->fde_seq); 1785 #endif 1786 FILEDESC_XUNLOCK(fdp); 1787 return (0); 1788 } 1789 1790 /* 1791 * Build a new filedesc structure from another. 1792 * Copy the current, root, and jail root vnode references. 1793 * 1794 * If fdp is not NULL, return with it shared locked. 1795 */ 1796 struct filedesc * 1797 fdinit(struct filedesc *fdp, bool prepfiles) 1798 { 1799 struct filedesc0 *newfdp0; 1800 struct filedesc *newfdp; 1801 1802 newfdp0 = uma_zalloc(filedesc0_zone, M_WAITOK | M_ZERO); 1803 newfdp = &newfdp0->fd_fd; 1804 1805 /* Create the file descriptor table. */ 1806 FILEDESC_LOCK_INIT(newfdp); 1807 refcount_init(&newfdp->fd_refcnt, 1); 1808 refcount_init(&newfdp->fd_holdcnt, 1); 1809 newfdp->fd_cmask = CMASK; 1810 newfdp->fd_map = newfdp0->fd_dmap; 1811 newfdp->fd_lastfile = -1; 1812 newfdp->fd_files = (struct fdescenttbl *)&newfdp0->fd_dfiles; 1813 newfdp->fd_files->fdt_nfiles = NDFILE; 1814 1815 if (fdp == NULL) 1816 return (newfdp); 1817 1818 if (prepfiles && fdp->fd_lastfile >= newfdp->fd_nfiles) 1819 fdgrowtable(newfdp, fdp->fd_lastfile + 1); 1820 1821 FILEDESC_SLOCK(fdp); 1822 newfdp->fd_cdir = fdp->fd_cdir; 1823 if (newfdp->fd_cdir) 1824 VREF(newfdp->fd_cdir); 1825 newfdp->fd_rdir = fdp->fd_rdir; 1826 if (newfdp->fd_rdir) 1827 VREF(newfdp->fd_rdir); 1828 newfdp->fd_jdir = fdp->fd_jdir; 1829 if (newfdp->fd_jdir) 1830 VREF(newfdp->fd_jdir); 1831 1832 if (!prepfiles) { 1833 FILEDESC_SUNLOCK(fdp); 1834 } else { 1835 while (fdp->fd_lastfile >= newfdp->fd_nfiles) { 1836 FILEDESC_SUNLOCK(fdp); 1837 fdgrowtable(newfdp, fdp->fd_lastfile + 1); 1838 FILEDESC_SLOCK(fdp); 1839 } 1840 } 1841 1842 return (newfdp); 1843 } 1844 1845 static struct filedesc * 1846 fdhold(struct proc *p) 1847 { 1848 struct filedesc *fdp; 1849 1850 PROC_LOCK_ASSERT(p, MA_OWNED); 1851 fdp = p->p_fd; 1852 if (fdp != NULL) 1853 refcount_acquire(&fdp->fd_holdcnt); 1854 return (fdp); 1855 } 1856 1857 static void 1858 fddrop(struct filedesc *fdp) 1859 { 1860 1861 if (fdp->fd_holdcnt > 1) { 1862 if (refcount_release(&fdp->fd_holdcnt) == 0) 1863 return; 1864 } 1865 1866 FILEDESC_LOCK_DESTROY(fdp); 1867 uma_zfree(filedesc0_zone, fdp); 1868 } 1869 1870 /* 1871 * Share a filedesc structure. 1872 */ 1873 struct filedesc * 1874 fdshare(struct filedesc *fdp) 1875 { 1876 1877 refcount_acquire(&fdp->fd_refcnt); 1878 return (fdp); 1879 } 1880 1881 /* 1882 * Unshare a filedesc structure, if necessary by making a copy 1883 */ 1884 void 1885 fdunshare(struct thread *td) 1886 { 1887 struct filedesc *tmp; 1888 struct proc *p = td->td_proc; 1889 1890 if (p->p_fd->fd_refcnt == 1) 1891 return; 1892 1893 tmp = fdcopy(p->p_fd); 1894 fdescfree(td); 1895 p->p_fd = tmp; 1896 } 1897 1898 /* 1899 * Copy a filedesc structure. A NULL pointer in returns a NULL reference, 1900 * this is to ease callers, not catch errors. 1901 */ 1902 struct filedesc * 1903 fdcopy(struct filedesc *fdp) 1904 { 1905 struct filedesc *newfdp; 1906 struct filedescent *nfde, *ofde; 1907 int i; 1908 1909 MPASS(fdp != NULL); 1910 1911 newfdp = fdinit(fdp, true); 1912 /* copy all passable descriptors (i.e. not kqueue) */ 1913 newfdp->fd_freefile = -1; 1914 for (i = 0; i <= fdp->fd_lastfile; ++i) { 1915 ofde = &fdp->fd_ofiles[i]; 1916 if (ofde->fde_file == NULL || 1917 (ofde->fde_file->f_ops->fo_flags & DFLAG_PASSABLE) == 0) { 1918 if (newfdp->fd_freefile == -1) 1919 newfdp->fd_freefile = i; 1920 continue; 1921 } 1922 nfde = &newfdp->fd_ofiles[i]; 1923 *nfde = *ofde; 1924 filecaps_copy(&ofde->fde_caps, &nfde->fde_caps); 1925 fhold(nfde->fde_file); 1926 fdused_init(newfdp, i); 1927 newfdp->fd_lastfile = i; 1928 } 1929 if (newfdp->fd_freefile == -1) 1930 newfdp->fd_freefile = i; 1931 newfdp->fd_cmask = fdp->fd_cmask; 1932 FILEDESC_SUNLOCK(fdp); 1933 return (newfdp); 1934 } 1935 1936 /* 1937 * Clear POSIX style locks. This is only used when fdp looses a reference (i.e. 1938 * one of processes using it exits) and the table used to be shared. 1939 */ 1940 static void 1941 fdclearlocks(struct thread *td) 1942 { 1943 struct filedesc *fdp; 1944 struct filedesc_to_leader *fdtol; 1945 struct flock lf; 1946 struct file *fp; 1947 struct proc *p; 1948 struct vnode *vp; 1949 int i; 1950 1951 p = td->td_proc; 1952 fdp = p->p_fd; 1953 fdtol = p->p_fdtol; 1954 MPASS(fdtol != NULL); 1955 1956 FILEDESC_XLOCK(fdp); 1957 KASSERT(fdtol->fdl_refcount > 0, 1958 ("filedesc_to_refcount botch: fdl_refcount=%d", 1959 fdtol->fdl_refcount)); 1960 if (fdtol->fdl_refcount == 1 && 1961 (p->p_leader->p_flag & P_ADVLOCK) != 0) { 1962 for (i = 0; i <= fdp->fd_lastfile; i++) { 1963 fp = fdp->fd_ofiles[i].fde_file; 1964 if (fp == NULL || fp->f_type != DTYPE_VNODE) 1965 continue; 1966 fhold(fp); 1967 FILEDESC_XUNLOCK(fdp); 1968 lf.l_whence = SEEK_SET; 1969 lf.l_start = 0; 1970 lf.l_len = 0; 1971 lf.l_type = F_UNLCK; 1972 vp = fp->f_vnode; 1973 (void) VOP_ADVLOCK(vp, 1974 (caddr_t)p->p_leader, F_UNLCK, 1975 &lf, F_POSIX); 1976 FILEDESC_XLOCK(fdp); 1977 fdrop(fp, td); 1978 } 1979 } 1980 retry: 1981 if (fdtol->fdl_refcount == 1) { 1982 if (fdp->fd_holdleaderscount > 0 && 1983 (p->p_leader->p_flag & P_ADVLOCK) != 0) { 1984 /* 1985 * close() or do_dup() has cleared a reference 1986 * in a shared file descriptor table. 1987 */ 1988 fdp->fd_holdleaderswakeup = 1; 1989 sx_sleep(&fdp->fd_holdleaderscount, 1990 FILEDESC_LOCK(fdp), PLOCK, "fdlhold", 0); 1991 goto retry; 1992 } 1993 if (fdtol->fdl_holdcount > 0) { 1994 /* 1995 * Ensure that fdtol->fdl_leader remains 1996 * valid in closef(). 1997 */ 1998 fdtol->fdl_wakeup = 1; 1999 sx_sleep(fdtol, FILEDESC_LOCK(fdp), PLOCK, 2000 "fdlhold", 0); 2001 goto retry; 2002 } 2003 } 2004 fdtol->fdl_refcount--; 2005 if (fdtol->fdl_refcount == 0 && 2006 fdtol->fdl_holdcount == 0) { 2007 fdtol->fdl_next->fdl_prev = fdtol->fdl_prev; 2008 fdtol->fdl_prev->fdl_next = fdtol->fdl_next; 2009 } else 2010 fdtol = NULL; 2011 p->p_fdtol = NULL; 2012 FILEDESC_XUNLOCK(fdp); 2013 if (fdtol != NULL) 2014 free(fdtol, M_FILEDESC_TO_LEADER); 2015 } 2016 2017 /* 2018 * Release a filedesc structure. 2019 */ 2020 void 2021 fdescfree(struct thread *td) 2022 { 2023 struct proc *p; 2024 struct filedesc0 *fdp0; 2025 struct filedesc *fdp; 2026 struct freetable *ft, *tft; 2027 struct filedescent *fde; 2028 struct file *fp; 2029 struct vnode *cdir, *jdir, *rdir; 2030 int i; 2031 2032 p = td->td_proc; 2033 fdp = p->p_fd; 2034 MPASS(fdp != NULL); 2035 2036 #ifdef RACCT 2037 if (racct_enable) { 2038 PROC_LOCK(p); 2039 racct_set(p, RACCT_NOFILE, 0); 2040 PROC_UNLOCK(p); 2041 } 2042 #endif 2043 2044 if (td->td_proc->p_fdtol != NULL) 2045 fdclearlocks(td); 2046 2047 PROC_LOCK(p); 2048 p->p_fd = NULL; 2049 PROC_UNLOCK(p); 2050 2051 if (refcount_release(&fdp->fd_refcnt) == 0) 2052 return; 2053 2054 FILEDESC_XLOCK(fdp); 2055 cdir = fdp->fd_cdir; 2056 fdp->fd_cdir = NULL; 2057 rdir = fdp->fd_rdir; 2058 fdp->fd_rdir = NULL; 2059 jdir = fdp->fd_jdir; 2060 fdp->fd_jdir = NULL; 2061 FILEDESC_XUNLOCK(fdp); 2062 2063 for (i = 0; i <= fdp->fd_lastfile; i++) { 2064 fde = &fdp->fd_ofiles[i]; 2065 fp = fde->fde_file; 2066 if (fp != NULL) { 2067 fdefree_last(fde); 2068 (void) closef(fp, td); 2069 } 2070 } 2071 2072 if (NDSLOTS(fdp->fd_nfiles) > NDSLOTS(NDFILE)) 2073 free(fdp->fd_map, M_FILEDESC); 2074 if (fdp->fd_nfiles > NDFILE) 2075 free(fdp->fd_files, M_FILEDESC); 2076 2077 fdp0 = (struct filedesc0 *)fdp; 2078 SLIST_FOREACH_SAFE(ft, &fdp0->fd_free, ft_next, tft) 2079 free(ft->ft_table, M_FILEDESC); 2080 2081 if (cdir != NULL) 2082 vrele(cdir); 2083 if (rdir != NULL) 2084 vrele(rdir); 2085 if (jdir != NULL) 2086 vrele(jdir); 2087 2088 fddrop(fdp); 2089 } 2090 2091 /* 2092 * For setugid programs, we don't want to people to use that setugidness 2093 * to generate error messages which write to a file which otherwise would 2094 * otherwise be off-limits to the process. We check for filesystems where 2095 * the vnode can change out from under us after execve (like [lin]procfs). 2096 * 2097 * Since fdsetugidsafety calls this only for fd 0, 1 and 2, this check is 2098 * sufficient. We also don't check for setugidness since we know we are. 2099 */ 2100 static bool 2101 is_unsafe(struct file *fp) 2102 { 2103 struct vnode *vp; 2104 2105 if (fp->f_type != DTYPE_VNODE) 2106 return (false); 2107 2108 vp = fp->f_vnode; 2109 return ((vp->v_vflag & VV_PROCDEP) != 0); 2110 } 2111 2112 /* 2113 * Make this setguid thing safe, if at all possible. 2114 */ 2115 void 2116 fdsetugidsafety(struct thread *td) 2117 { 2118 struct filedesc *fdp; 2119 struct file *fp; 2120 int i; 2121 2122 fdp = td->td_proc->p_fd; 2123 KASSERT(fdp->fd_refcnt == 1, ("the fdtable should not be shared")); 2124 MPASS(fdp->fd_nfiles >= 3); 2125 for (i = 0; i <= 2; i++) { 2126 fp = fdp->fd_ofiles[i].fde_file; 2127 if (fp != NULL && is_unsafe(fp)) { 2128 FILEDESC_XLOCK(fdp); 2129 knote_fdclose(td, i); 2130 /* 2131 * NULL-out descriptor prior to close to avoid 2132 * a race while close blocks. 2133 */ 2134 fdfree(fdp, i); 2135 FILEDESC_XUNLOCK(fdp); 2136 (void) closef(fp, td); 2137 } 2138 } 2139 } 2140 2141 /* 2142 * If a specific file object occupies a specific file descriptor, close the 2143 * file descriptor entry and drop a reference on the file object. This is a 2144 * convenience function to handle a subsequent error in a function that calls 2145 * falloc() that handles the race that another thread might have closed the 2146 * file descriptor out from under the thread creating the file object. 2147 */ 2148 void 2149 fdclose(struct thread *td, struct file *fp, int idx) 2150 { 2151 struct filedesc *fdp = td->td_proc->p_fd; 2152 2153 FILEDESC_XLOCK(fdp); 2154 if (fdp->fd_ofiles[idx].fde_file == fp) { 2155 fdfree(fdp, idx); 2156 FILEDESC_XUNLOCK(fdp); 2157 fdrop(fp, td); 2158 } else 2159 FILEDESC_XUNLOCK(fdp); 2160 } 2161 2162 /* 2163 * Close any files on exec? 2164 */ 2165 void 2166 fdcloseexec(struct thread *td) 2167 { 2168 struct filedesc *fdp; 2169 struct filedescent *fde; 2170 struct file *fp; 2171 int i; 2172 2173 fdp = td->td_proc->p_fd; 2174 KASSERT(fdp->fd_refcnt == 1, ("the fdtable should not be shared")); 2175 for (i = 0; i <= fdp->fd_lastfile; i++) { 2176 fde = &fdp->fd_ofiles[i]; 2177 fp = fde->fde_file; 2178 if (fp != NULL && (fp->f_type == DTYPE_MQUEUE || 2179 (fde->fde_flags & UF_EXCLOSE))) { 2180 FILEDESC_XLOCK(fdp); 2181 fdfree(fdp, i); 2182 (void) closefp(fdp, i, fp, td, 0); 2183 /* closefp() drops the FILEDESC lock. */ 2184 } 2185 } 2186 } 2187 2188 /* 2189 * It is unsafe for set[ug]id processes to be started with file 2190 * descriptors 0..2 closed, as these descriptors are given implicit 2191 * significance in the Standard C library. fdcheckstd() will create a 2192 * descriptor referencing /dev/null for each of stdin, stdout, and 2193 * stderr that is not already open. 2194 */ 2195 int 2196 fdcheckstd(struct thread *td) 2197 { 2198 struct filedesc *fdp; 2199 register_t save; 2200 int i, error, devnull; 2201 2202 fdp = td->td_proc->p_fd; 2203 KASSERT(fdp->fd_refcnt == 1, ("the fdtable should not be shared")); 2204 MPASS(fdp->fd_nfiles >= 3); 2205 devnull = -1; 2206 for (i = 0; i <= 2; i++) { 2207 if (fdp->fd_ofiles[i].fde_file != NULL) 2208 continue; 2209 2210 save = td->td_retval[0]; 2211 if (devnull != -1) { 2212 error = do_dup(td, DUP_FIXED, devnull, i); 2213 } else { 2214 error = kern_openat(td, AT_FDCWD, "/dev/null", 2215 UIO_SYSSPACE, O_RDWR, 0); 2216 if (error == 0) { 2217 devnull = td->td_retval[0]; 2218 KASSERT(devnull == i, ("we didn't get our fd")); 2219 } 2220 } 2221 td->td_retval[0] = save; 2222 if (error != 0) 2223 return (error); 2224 } 2225 return (0); 2226 } 2227 2228 /* 2229 * Internal form of close. Decrement reference count on file structure. 2230 * Note: td may be NULL when closing a file that was being passed in a 2231 * message. 2232 * 2233 * XXXRW: Giant is not required for the caller, but often will be held; this 2234 * makes it moderately likely the Giant will be recursed in the VFS case. 2235 */ 2236 int 2237 closef(struct file *fp, struct thread *td) 2238 { 2239 struct vnode *vp; 2240 struct flock lf; 2241 struct filedesc_to_leader *fdtol; 2242 struct filedesc *fdp; 2243 2244 /* 2245 * POSIX record locking dictates that any close releases ALL 2246 * locks owned by this process. This is handled by setting 2247 * a flag in the unlock to free ONLY locks obeying POSIX 2248 * semantics, and not to free BSD-style file locks. 2249 * If the descriptor was in a message, POSIX-style locks 2250 * aren't passed with the descriptor, and the thread pointer 2251 * will be NULL. Callers should be careful only to pass a 2252 * NULL thread pointer when there really is no owning 2253 * context that might have locks, or the locks will be 2254 * leaked. 2255 */ 2256 if (fp->f_type == DTYPE_VNODE && td != NULL) { 2257 vp = fp->f_vnode; 2258 if ((td->td_proc->p_leader->p_flag & P_ADVLOCK) != 0) { 2259 lf.l_whence = SEEK_SET; 2260 lf.l_start = 0; 2261 lf.l_len = 0; 2262 lf.l_type = F_UNLCK; 2263 (void) VOP_ADVLOCK(vp, (caddr_t)td->td_proc->p_leader, 2264 F_UNLCK, &lf, F_POSIX); 2265 } 2266 fdtol = td->td_proc->p_fdtol; 2267 if (fdtol != NULL) { 2268 /* 2269 * Handle special case where file descriptor table is 2270 * shared between multiple process leaders. 2271 */ 2272 fdp = td->td_proc->p_fd; 2273 FILEDESC_XLOCK(fdp); 2274 for (fdtol = fdtol->fdl_next; 2275 fdtol != td->td_proc->p_fdtol; 2276 fdtol = fdtol->fdl_next) { 2277 if ((fdtol->fdl_leader->p_flag & 2278 P_ADVLOCK) == 0) 2279 continue; 2280 fdtol->fdl_holdcount++; 2281 FILEDESC_XUNLOCK(fdp); 2282 lf.l_whence = SEEK_SET; 2283 lf.l_start = 0; 2284 lf.l_len = 0; 2285 lf.l_type = F_UNLCK; 2286 vp = fp->f_vnode; 2287 (void) VOP_ADVLOCK(vp, 2288 (caddr_t)fdtol->fdl_leader, F_UNLCK, &lf, 2289 F_POSIX); 2290 FILEDESC_XLOCK(fdp); 2291 fdtol->fdl_holdcount--; 2292 if (fdtol->fdl_holdcount == 0 && 2293 fdtol->fdl_wakeup != 0) { 2294 fdtol->fdl_wakeup = 0; 2295 wakeup(fdtol); 2296 } 2297 } 2298 FILEDESC_XUNLOCK(fdp); 2299 } 2300 } 2301 return (fdrop(fp, td)); 2302 } 2303 2304 /* 2305 * Initialize the file pointer with the specified properties. 2306 * 2307 * The ops are set with release semantics to be certain that the flags, type, 2308 * and data are visible when ops is. This is to prevent ops methods from being 2309 * called with bad data. 2310 */ 2311 void 2312 finit(struct file *fp, u_int flag, short type, void *data, struct fileops *ops) 2313 { 2314 fp->f_data = data; 2315 fp->f_flag = flag; 2316 fp->f_type = type; 2317 atomic_store_rel_ptr((volatile uintptr_t *)&fp->f_ops, (uintptr_t)ops); 2318 } 2319 2320 int 2321 fget_unlocked(struct filedesc *fdp, int fd, cap_rights_t *needrightsp, 2322 struct file **fpp, seq_t *seqp) 2323 { 2324 #ifdef CAPABILITIES 2325 struct filedescent *fde; 2326 #endif 2327 struct fdescenttbl *fdt; 2328 struct file *fp; 2329 u_int count; 2330 #ifdef CAPABILITIES 2331 seq_t seq; 2332 cap_rights_t haverights; 2333 int error; 2334 #endif 2335 2336 fdt = fdp->fd_files; 2337 if ((u_int)fd >= fdt->fdt_nfiles) 2338 return (EBADF); 2339 /* 2340 * Fetch the descriptor locklessly. We avoid fdrop() races by 2341 * never raising a refcount above 0. To accomplish this we have 2342 * to use a cmpset loop rather than an atomic_add. The descriptor 2343 * must be re-verified once we acquire a reference to be certain 2344 * that the identity is still correct and we did not lose a race 2345 * due to preemption. 2346 */ 2347 for (;;) { 2348 #ifdef CAPABILITIES 2349 seq = seq_read(fd_seq(fdt, fd)); 2350 fde = &fdt->fdt_ofiles[fd]; 2351 haverights = *cap_rights_fde(fde); 2352 fp = fde->fde_file; 2353 if (!seq_consistent(fd_seq(fdt, fd), seq)) { 2354 cpu_spinwait(); 2355 continue; 2356 } 2357 #else 2358 fp = fdt->fdt_ofiles[fd].fde_file; 2359 #endif 2360 if (fp == NULL) 2361 return (EBADF); 2362 #ifdef CAPABILITIES 2363 if (needrightsp != NULL) { 2364 error = cap_check(&haverights, needrightsp); 2365 if (error != 0) 2366 return (error); 2367 } 2368 #endif 2369 retry: 2370 count = fp->f_count; 2371 if (count == 0) { 2372 /* 2373 * Force a reload. Other thread could reallocate the 2374 * table before this fd was closed, so it possible that 2375 * there is a stale fp pointer in cached version. 2376 */ 2377 fdt = *(struct fdescenttbl * volatile *)&(fdp->fd_files); 2378 continue; 2379 } 2380 /* 2381 * Use an acquire barrier to force re-reading of fdt so it is 2382 * refreshed for verification. 2383 */ 2384 if (atomic_cmpset_acq_int(&fp->f_count, count, count + 1) == 0) 2385 goto retry; 2386 fdt = fdp->fd_files; 2387 #ifdef CAPABILITIES 2388 if (seq_consistent_nomb(fd_seq(fdt, fd), seq)) 2389 #else 2390 if (fp == fdt->fdt_ofiles[fd].fde_file) 2391 #endif 2392 break; 2393 fdrop(fp, curthread); 2394 } 2395 *fpp = fp; 2396 if (seqp != NULL) { 2397 #ifdef CAPABILITIES 2398 *seqp = seq; 2399 #endif 2400 } 2401 return (0); 2402 } 2403 2404 /* 2405 * Extract the file pointer associated with the specified descriptor for the 2406 * current user process. 2407 * 2408 * If the descriptor doesn't exist or doesn't match 'flags', EBADF is 2409 * returned. 2410 * 2411 * File's rights will be checked against the capability rights mask. 2412 * 2413 * If an error occured the non-zero error is returned and *fpp is set to 2414 * NULL. Otherwise *fpp is held and set and zero is returned. Caller is 2415 * responsible for fdrop(). 2416 */ 2417 static __inline int 2418 _fget(struct thread *td, int fd, struct file **fpp, int flags, 2419 cap_rights_t *needrightsp, seq_t *seqp) 2420 { 2421 struct filedesc *fdp; 2422 struct file *fp; 2423 cap_rights_t needrights; 2424 int error; 2425 2426 *fpp = NULL; 2427 fdp = td->td_proc->p_fd; 2428 if (needrightsp != NULL) 2429 needrights = *needrightsp; 2430 else 2431 cap_rights_init(&needrights); 2432 error = fget_unlocked(fdp, fd, &needrights, &fp, seqp); 2433 if (error != 0) 2434 return (error); 2435 if (fp->f_ops == &badfileops) { 2436 fdrop(fp, td); 2437 return (EBADF); 2438 } 2439 2440 /* 2441 * FREAD and FWRITE failure return EBADF as per POSIX. 2442 */ 2443 error = 0; 2444 switch (flags) { 2445 case FREAD: 2446 case FWRITE: 2447 if ((fp->f_flag & flags) == 0) 2448 error = EBADF; 2449 break; 2450 case FEXEC: 2451 if ((fp->f_flag & (FREAD | FEXEC)) == 0 || 2452 ((fp->f_flag & FWRITE) != 0)) 2453 error = EBADF; 2454 break; 2455 case 0: 2456 break; 2457 default: 2458 KASSERT(0, ("wrong flags")); 2459 } 2460 2461 if (error != 0) { 2462 fdrop(fp, td); 2463 return (error); 2464 } 2465 2466 *fpp = fp; 2467 return (0); 2468 } 2469 2470 int 2471 fget(struct thread *td, int fd, cap_rights_t *rightsp, struct file **fpp) 2472 { 2473 2474 return (_fget(td, fd, fpp, 0, rightsp, NULL)); 2475 } 2476 2477 int 2478 fget_mmap(struct thread *td, int fd, cap_rights_t *rightsp, u_char *maxprotp, 2479 struct file **fpp) 2480 { 2481 int error; 2482 #ifndef CAPABILITIES 2483 error = _fget(td, fd, fpp, 0, rightsp, NULL); 2484 if (maxprotp != NULL) 2485 *maxprotp = VM_PROT_ALL; 2486 #else 2487 struct filedesc *fdp = td->td_proc->p_fd; 2488 seq_t seq; 2489 2490 MPASS(cap_rights_is_set(rightsp, CAP_MMAP)); 2491 for (;;) { 2492 error = _fget(td, fd, fpp, 0, rightsp, &seq); 2493 if (error != 0) 2494 return (error); 2495 /* 2496 * If requested, convert capability rights to access flags. 2497 */ 2498 if (maxprotp != NULL) 2499 *maxprotp = cap_rights_to_vmprot(cap_rights(fdp, fd)); 2500 if (!fd_modified(fdp, fd, seq)) 2501 break; 2502 fdrop(*fpp, td); 2503 } 2504 #endif 2505 return (error); 2506 } 2507 2508 int 2509 fget_read(struct thread *td, int fd, cap_rights_t *rightsp, struct file **fpp) 2510 { 2511 2512 return (_fget(td, fd, fpp, FREAD, rightsp, NULL)); 2513 } 2514 2515 int 2516 fget_write(struct thread *td, int fd, cap_rights_t *rightsp, struct file **fpp) 2517 { 2518 2519 return (_fget(td, fd, fpp, FWRITE, rightsp, NULL)); 2520 } 2521 2522 int 2523 fget_fcntl(struct thread *td, int fd, cap_rights_t *rightsp, int needfcntl, 2524 struct file **fpp) 2525 { 2526 struct filedesc *fdp = td->td_proc->p_fd; 2527 #ifndef CAPABILITIES 2528 return (fget_unlocked(fdp, fd, rightsp, fpp, NULL)); 2529 #else 2530 int error; 2531 seq_t seq; 2532 2533 MPASS(cap_rights_is_set(rightsp, CAP_FCNTL)); 2534 for (;;) { 2535 error = fget_unlocked(fdp, fd, rightsp, fpp, &seq); 2536 if (error != 0) 2537 return (error); 2538 error = cap_fcntl_check(fdp, fd, needfcntl); 2539 if (!fd_modified(fdp, fd, seq)) 2540 break; 2541 fdrop(*fpp, td); 2542 } 2543 if (error != 0) { 2544 fdrop(*fpp, td); 2545 *fpp = NULL; 2546 } 2547 return (error); 2548 #endif 2549 } 2550 2551 /* 2552 * Like fget() but loads the underlying vnode, or returns an error if the 2553 * descriptor does not represent a vnode. Note that pipes use vnodes but 2554 * never have VM objects. The returned vnode will be vref()'d. 2555 * 2556 * XXX: what about the unused flags ? 2557 */ 2558 static __inline int 2559 _fgetvp(struct thread *td, int fd, int flags, cap_rights_t *needrightsp, 2560 struct vnode **vpp) 2561 { 2562 struct file *fp; 2563 int error; 2564 2565 *vpp = NULL; 2566 error = _fget(td, fd, &fp, flags, needrightsp, NULL); 2567 if (error != 0) 2568 return (error); 2569 if (fp->f_vnode == NULL) { 2570 error = EINVAL; 2571 } else { 2572 *vpp = fp->f_vnode; 2573 vref(*vpp); 2574 } 2575 fdrop(fp, td); 2576 2577 return (error); 2578 } 2579 2580 int 2581 fgetvp(struct thread *td, int fd, cap_rights_t *rightsp, struct vnode **vpp) 2582 { 2583 2584 return (_fgetvp(td, fd, 0, rightsp, vpp)); 2585 } 2586 2587 int 2588 fgetvp_rights(struct thread *td, int fd, cap_rights_t *needrightsp, 2589 struct filecaps *havecaps, struct vnode **vpp) 2590 { 2591 struct filedesc *fdp; 2592 struct file *fp; 2593 #ifdef CAPABILITIES 2594 int error; 2595 #endif 2596 2597 fdp = td->td_proc->p_fd; 2598 fp = fget_locked(fdp, fd); 2599 if (fp == NULL || fp->f_ops == &badfileops) 2600 return (EBADF); 2601 2602 #ifdef CAPABILITIES 2603 if (needrightsp != NULL) { 2604 error = cap_check(cap_rights(fdp, fd), needrightsp); 2605 if (error != 0) 2606 return (error); 2607 } 2608 #endif 2609 2610 if (fp->f_vnode == NULL) 2611 return (EINVAL); 2612 2613 *vpp = fp->f_vnode; 2614 vref(*vpp); 2615 filecaps_copy(&fdp->fd_ofiles[fd].fde_caps, havecaps); 2616 2617 return (0); 2618 } 2619 2620 int 2621 fgetvp_read(struct thread *td, int fd, cap_rights_t *rightsp, struct vnode **vpp) 2622 { 2623 2624 return (_fgetvp(td, fd, FREAD, rightsp, vpp)); 2625 } 2626 2627 int 2628 fgetvp_exec(struct thread *td, int fd, cap_rights_t *rightsp, struct vnode **vpp) 2629 { 2630 2631 return (_fgetvp(td, fd, FEXEC, rightsp, vpp)); 2632 } 2633 2634 #ifdef notyet 2635 int 2636 fgetvp_write(struct thread *td, int fd, cap_rights_t *rightsp, 2637 struct vnode **vpp) 2638 { 2639 2640 return (_fgetvp(td, fd, FWRITE, rightsp, vpp)); 2641 } 2642 #endif 2643 2644 /* 2645 * Like fget() but loads the underlying socket, or returns an error if the 2646 * descriptor does not represent a socket. 2647 * 2648 * We bump the ref count on the returned socket. XXX Also obtain the SX lock 2649 * in the future. 2650 * 2651 * Note: fgetsock() and fputsock() are deprecated, as consumers should rely 2652 * on their file descriptor reference to prevent the socket from being free'd 2653 * during use. 2654 */ 2655 int 2656 fgetsock(struct thread *td, int fd, cap_rights_t *rightsp, struct socket **spp, 2657 u_int *fflagp) 2658 { 2659 struct file *fp; 2660 int error; 2661 2662 *spp = NULL; 2663 if (fflagp != NULL) 2664 *fflagp = 0; 2665 if ((error = _fget(td, fd, &fp, 0, rightsp, NULL)) != 0) 2666 return (error); 2667 if (fp->f_type != DTYPE_SOCKET) { 2668 error = ENOTSOCK; 2669 } else { 2670 *spp = fp->f_data; 2671 if (fflagp) 2672 *fflagp = fp->f_flag; 2673 SOCK_LOCK(*spp); 2674 soref(*spp); 2675 SOCK_UNLOCK(*spp); 2676 } 2677 fdrop(fp, td); 2678 2679 return (error); 2680 } 2681 2682 /* 2683 * Drop the reference count on the socket and XXX release the SX lock in the 2684 * future. The last reference closes the socket. 2685 * 2686 * Note: fputsock() is deprecated, see comment for fgetsock(). 2687 */ 2688 void 2689 fputsock(struct socket *so) 2690 { 2691 2692 ACCEPT_LOCK(); 2693 SOCK_LOCK(so); 2694 CURVNET_SET(so->so_vnet); 2695 sorele(so); 2696 CURVNET_RESTORE(); 2697 } 2698 2699 /* 2700 * Handle the last reference to a file being closed. 2701 */ 2702 int 2703 _fdrop(struct file *fp, struct thread *td) 2704 { 2705 int error; 2706 2707 if (fp->f_count != 0) 2708 panic("fdrop: count %d", fp->f_count); 2709 error = fo_close(fp, td); 2710 atomic_subtract_int(&openfiles, 1); 2711 crfree(fp->f_cred); 2712 free(fp->f_advice, M_FADVISE); 2713 uma_zfree(file_zone, fp); 2714 2715 return (error); 2716 } 2717 2718 /* 2719 * Apply an advisory lock on a file descriptor. 2720 * 2721 * Just attempt to get a record lock of the requested type on the entire file 2722 * (l_whence = SEEK_SET, l_start = 0, l_len = 0). 2723 */ 2724 #ifndef _SYS_SYSPROTO_H_ 2725 struct flock_args { 2726 int fd; 2727 int how; 2728 }; 2729 #endif 2730 /* ARGSUSED */ 2731 int 2732 sys_flock(struct thread *td, struct flock_args *uap) 2733 { 2734 struct file *fp; 2735 struct vnode *vp; 2736 struct flock lf; 2737 cap_rights_t rights; 2738 int error; 2739 2740 error = fget(td, uap->fd, cap_rights_init(&rights, CAP_FLOCK), &fp); 2741 if (error != 0) 2742 return (error); 2743 if (fp->f_type != DTYPE_VNODE) { 2744 fdrop(fp, td); 2745 return (EOPNOTSUPP); 2746 } 2747 2748 vp = fp->f_vnode; 2749 lf.l_whence = SEEK_SET; 2750 lf.l_start = 0; 2751 lf.l_len = 0; 2752 if (uap->how & LOCK_UN) { 2753 lf.l_type = F_UNLCK; 2754 atomic_clear_int(&fp->f_flag, FHASLOCK); 2755 error = VOP_ADVLOCK(vp, (caddr_t)fp, F_UNLCK, &lf, F_FLOCK); 2756 goto done2; 2757 } 2758 if (uap->how & LOCK_EX) 2759 lf.l_type = F_WRLCK; 2760 else if (uap->how & LOCK_SH) 2761 lf.l_type = F_RDLCK; 2762 else { 2763 error = EBADF; 2764 goto done2; 2765 } 2766 atomic_set_int(&fp->f_flag, FHASLOCK); 2767 error = VOP_ADVLOCK(vp, (caddr_t)fp, F_SETLK, &lf, 2768 (uap->how & LOCK_NB) ? F_FLOCK : F_FLOCK | F_WAIT); 2769 done2: 2770 fdrop(fp, td); 2771 return (error); 2772 } 2773 /* 2774 * Duplicate the specified descriptor to a free descriptor. 2775 */ 2776 int 2777 dupfdopen(struct thread *td, struct filedesc *fdp, int dfd, int mode, 2778 int openerror, int *indxp) 2779 { 2780 struct filedescent *newfde, *oldfde; 2781 struct file *fp; 2782 int error, indx; 2783 2784 KASSERT(openerror == ENODEV || openerror == ENXIO, 2785 ("unexpected error %d in %s", openerror, __func__)); 2786 2787 /* 2788 * If the to-be-dup'd fd number is greater than the allowed number 2789 * of file descriptors, or the fd to be dup'd has already been 2790 * closed, then reject. 2791 */ 2792 FILEDESC_XLOCK(fdp); 2793 if ((fp = fget_locked(fdp, dfd)) == NULL) { 2794 FILEDESC_XUNLOCK(fdp); 2795 return (EBADF); 2796 } 2797 2798 error = fdalloc(td, 0, &indx); 2799 if (error != 0) { 2800 FILEDESC_XUNLOCK(fdp); 2801 return (error); 2802 } 2803 2804 /* 2805 * There are two cases of interest here. 2806 * 2807 * For ENODEV simply dup (dfd) to file descriptor (indx) and return. 2808 * 2809 * For ENXIO steal away the file structure from (dfd) and store it in 2810 * (indx). (dfd) is effectively closed by this operation. 2811 */ 2812 switch (openerror) { 2813 case ENODEV: 2814 /* 2815 * Check that the mode the file is being opened for is a 2816 * subset of the mode of the existing descriptor. 2817 */ 2818 if (((mode & (FREAD|FWRITE)) | fp->f_flag) != fp->f_flag) { 2819 fdunused(fdp, indx); 2820 FILEDESC_XUNLOCK(fdp); 2821 return (EACCES); 2822 } 2823 fhold(fp); 2824 newfde = &fdp->fd_ofiles[indx]; 2825 oldfde = &fdp->fd_ofiles[dfd]; 2826 #ifdef CAPABILITIES 2827 seq_write_begin(&newfde->fde_seq); 2828 #endif 2829 memcpy(newfde, oldfde, fde_change_size); 2830 filecaps_copy(&oldfde->fde_caps, &newfde->fde_caps); 2831 #ifdef CAPABILITIES 2832 seq_write_end(&newfde->fde_seq); 2833 #endif 2834 break; 2835 case ENXIO: 2836 /* 2837 * Steal away the file pointer from dfd and stuff it into indx. 2838 */ 2839 newfde = &fdp->fd_ofiles[indx]; 2840 oldfde = &fdp->fd_ofiles[dfd]; 2841 #ifdef CAPABILITIES 2842 seq_write_begin(&newfde->fde_seq); 2843 #endif 2844 memcpy(newfde, oldfde, fde_change_size); 2845 bzero(oldfde, fde_change_size); 2846 fdunused(fdp, dfd); 2847 #ifdef CAPABILITIES 2848 seq_write_end(&newfde->fde_seq); 2849 #endif 2850 break; 2851 } 2852 FILEDESC_XUNLOCK(fdp); 2853 *indxp = indx; 2854 return (0); 2855 } 2856 2857 /* 2858 * Scan all active processes and prisons to see if any of them have a current 2859 * or root directory of `olddp'. If so, replace them with the new mount point. 2860 */ 2861 void 2862 mountcheckdirs(struct vnode *olddp, struct vnode *newdp) 2863 { 2864 struct filedesc *fdp; 2865 struct prison *pr; 2866 struct proc *p; 2867 int nrele; 2868 2869 if (vrefcnt(olddp) == 1) 2870 return; 2871 nrele = 0; 2872 sx_slock(&allproc_lock); 2873 FOREACH_PROC_IN_SYSTEM(p) { 2874 PROC_LOCK(p); 2875 fdp = fdhold(p); 2876 PROC_UNLOCK(p); 2877 if (fdp == NULL) 2878 continue; 2879 FILEDESC_XLOCK(fdp); 2880 if (fdp->fd_cdir == olddp) { 2881 vref(newdp); 2882 fdp->fd_cdir = newdp; 2883 nrele++; 2884 } 2885 if (fdp->fd_rdir == olddp) { 2886 vref(newdp); 2887 fdp->fd_rdir = newdp; 2888 nrele++; 2889 } 2890 if (fdp->fd_jdir == olddp) { 2891 vref(newdp); 2892 fdp->fd_jdir = newdp; 2893 nrele++; 2894 } 2895 FILEDESC_XUNLOCK(fdp); 2896 fddrop(fdp); 2897 } 2898 sx_sunlock(&allproc_lock); 2899 if (rootvnode == olddp) { 2900 vref(newdp); 2901 rootvnode = newdp; 2902 nrele++; 2903 } 2904 mtx_lock(&prison0.pr_mtx); 2905 if (prison0.pr_root == olddp) { 2906 vref(newdp); 2907 prison0.pr_root = newdp; 2908 nrele++; 2909 } 2910 mtx_unlock(&prison0.pr_mtx); 2911 sx_slock(&allprison_lock); 2912 TAILQ_FOREACH(pr, &allprison, pr_list) { 2913 mtx_lock(&pr->pr_mtx); 2914 if (pr->pr_root == olddp) { 2915 vref(newdp); 2916 pr->pr_root = newdp; 2917 nrele++; 2918 } 2919 mtx_unlock(&pr->pr_mtx); 2920 } 2921 sx_sunlock(&allprison_lock); 2922 while (nrele--) 2923 vrele(olddp); 2924 } 2925 2926 struct filedesc_to_leader * 2927 filedesc_to_leader_alloc(struct filedesc_to_leader *old, struct filedesc *fdp, struct proc *leader) 2928 { 2929 struct filedesc_to_leader *fdtol; 2930 2931 fdtol = malloc(sizeof(struct filedesc_to_leader), 2932 M_FILEDESC_TO_LEADER, 2933 M_WAITOK); 2934 fdtol->fdl_refcount = 1; 2935 fdtol->fdl_holdcount = 0; 2936 fdtol->fdl_wakeup = 0; 2937 fdtol->fdl_leader = leader; 2938 if (old != NULL) { 2939 FILEDESC_XLOCK(fdp); 2940 fdtol->fdl_next = old->fdl_next; 2941 fdtol->fdl_prev = old; 2942 old->fdl_next = fdtol; 2943 fdtol->fdl_next->fdl_prev = fdtol; 2944 FILEDESC_XUNLOCK(fdp); 2945 } else { 2946 fdtol->fdl_next = fdtol; 2947 fdtol->fdl_prev = fdtol; 2948 } 2949 return (fdtol); 2950 } 2951 2952 /* 2953 * Get file structures globally. 2954 */ 2955 static int 2956 sysctl_kern_file(SYSCTL_HANDLER_ARGS) 2957 { 2958 struct xfile xf; 2959 struct filedesc *fdp; 2960 struct file *fp; 2961 struct proc *p; 2962 int error, n; 2963 2964 error = sysctl_wire_old_buffer(req, 0); 2965 if (error != 0) 2966 return (error); 2967 if (req->oldptr == NULL) { 2968 n = 0; 2969 sx_slock(&allproc_lock); 2970 FOREACH_PROC_IN_SYSTEM(p) { 2971 PROC_LOCK(p); 2972 if (p->p_state == PRS_NEW) { 2973 PROC_UNLOCK(p); 2974 continue; 2975 } 2976 fdp = fdhold(p); 2977 PROC_UNLOCK(p); 2978 if (fdp == NULL) 2979 continue; 2980 /* overestimates sparse tables. */ 2981 if (fdp->fd_lastfile > 0) 2982 n += fdp->fd_lastfile; 2983 fddrop(fdp); 2984 } 2985 sx_sunlock(&allproc_lock); 2986 return (SYSCTL_OUT(req, 0, n * sizeof(xf))); 2987 } 2988 error = 0; 2989 bzero(&xf, sizeof(xf)); 2990 xf.xf_size = sizeof(xf); 2991 sx_slock(&allproc_lock); 2992 FOREACH_PROC_IN_SYSTEM(p) { 2993 PROC_LOCK(p); 2994 if (p->p_state == PRS_NEW) { 2995 PROC_UNLOCK(p); 2996 continue; 2997 } 2998 if (p_cansee(req->td, p) != 0) { 2999 PROC_UNLOCK(p); 3000 continue; 3001 } 3002 xf.xf_pid = p->p_pid; 3003 xf.xf_uid = p->p_ucred->cr_uid; 3004 fdp = fdhold(p); 3005 PROC_UNLOCK(p); 3006 if (fdp == NULL) 3007 continue; 3008 FILEDESC_SLOCK(fdp); 3009 for (n = 0; fdp->fd_refcnt > 0 && n <= fdp->fd_lastfile; ++n) { 3010 if ((fp = fdp->fd_ofiles[n].fde_file) == NULL) 3011 continue; 3012 xf.xf_fd = n; 3013 xf.xf_file = fp; 3014 xf.xf_data = fp->f_data; 3015 xf.xf_vnode = fp->f_vnode; 3016 xf.xf_type = fp->f_type; 3017 xf.xf_count = fp->f_count; 3018 xf.xf_msgcount = 0; 3019 xf.xf_offset = foffset_get(fp); 3020 xf.xf_flag = fp->f_flag; 3021 error = SYSCTL_OUT(req, &xf, sizeof(xf)); 3022 if (error) 3023 break; 3024 } 3025 FILEDESC_SUNLOCK(fdp); 3026 fddrop(fdp); 3027 if (error) 3028 break; 3029 } 3030 sx_sunlock(&allproc_lock); 3031 return (error); 3032 } 3033 3034 SYSCTL_PROC(_kern, KERN_FILE, file, CTLTYPE_OPAQUE|CTLFLAG_RD|CTLFLAG_MPSAFE, 3035 0, 0, sysctl_kern_file, "S,xfile", "Entire file table"); 3036 3037 #ifdef KINFO_FILE_SIZE 3038 CTASSERT(sizeof(struct kinfo_file) == KINFO_FILE_SIZE); 3039 #endif 3040 3041 static int 3042 xlate_fflags(int fflags) 3043 { 3044 static const struct { 3045 int fflag; 3046 int kf_fflag; 3047 } fflags_table[] = { 3048 { FAPPEND, KF_FLAG_APPEND }, 3049 { FASYNC, KF_FLAG_ASYNC }, 3050 { FFSYNC, KF_FLAG_FSYNC }, 3051 { FHASLOCK, KF_FLAG_HASLOCK }, 3052 { FNONBLOCK, KF_FLAG_NONBLOCK }, 3053 { FREAD, KF_FLAG_READ }, 3054 { FWRITE, KF_FLAG_WRITE }, 3055 { O_CREAT, KF_FLAG_CREAT }, 3056 { O_DIRECT, KF_FLAG_DIRECT }, 3057 { O_EXCL, KF_FLAG_EXCL }, 3058 { O_EXEC, KF_FLAG_EXEC }, 3059 { O_EXLOCK, KF_FLAG_EXLOCK }, 3060 { O_NOFOLLOW, KF_FLAG_NOFOLLOW }, 3061 { O_SHLOCK, KF_FLAG_SHLOCK }, 3062 { O_TRUNC, KF_FLAG_TRUNC } 3063 }; 3064 unsigned int i; 3065 int kflags; 3066 3067 kflags = 0; 3068 for (i = 0; i < nitems(fflags_table); i++) 3069 if (fflags & fflags_table[i].fflag) 3070 kflags |= fflags_table[i].kf_fflag; 3071 return (kflags); 3072 } 3073 3074 /* Trim unused data from kf_path by truncating the structure size. */ 3075 static void 3076 pack_kinfo(struct kinfo_file *kif) 3077 { 3078 3079 kif->kf_structsize = offsetof(struct kinfo_file, kf_path) + 3080 strlen(kif->kf_path) + 1; 3081 kif->kf_structsize = roundup(kif->kf_structsize, sizeof(uint64_t)); 3082 } 3083 3084 static void 3085 export_file_to_kinfo(struct file *fp, int fd, cap_rights_t *rightsp, 3086 struct kinfo_file *kif, struct filedesc *fdp) 3087 { 3088 int error; 3089 3090 bzero(kif, sizeof(*kif)); 3091 3092 /* Set a default type to allow for empty fill_kinfo() methods. */ 3093 kif->kf_type = KF_TYPE_UNKNOWN; 3094 kif->kf_flags = xlate_fflags(fp->f_flag); 3095 if (rightsp != NULL) 3096 kif->kf_cap_rights = *rightsp; 3097 else 3098 cap_rights_init(&kif->kf_cap_rights); 3099 kif->kf_fd = fd; 3100 kif->kf_ref_count = fp->f_count; 3101 kif->kf_offset = foffset_get(fp); 3102 3103 /* 3104 * This may drop the filedesc lock, so the 'fp' cannot be 3105 * accessed after this call. 3106 */ 3107 error = fo_fill_kinfo(fp, kif, fdp); 3108 if (error == 0) 3109 kif->kf_status |= KF_ATTR_VALID; 3110 pack_kinfo(kif); 3111 } 3112 3113 static void 3114 export_vnode_to_kinfo(struct vnode *vp, int fd, int fflags, 3115 struct kinfo_file *kif) 3116 { 3117 int error; 3118 3119 bzero(kif, sizeof(*kif)); 3120 3121 kif->kf_type = KF_TYPE_VNODE; 3122 error = vn_fill_kinfo_vnode(vp, kif); 3123 if (error == 0) 3124 kif->kf_status |= KF_ATTR_VALID; 3125 kif->kf_flags = xlate_fflags(fflags); 3126 cap_rights_init(&kif->kf_cap_rights); 3127 kif->kf_fd = fd; 3128 kif->kf_ref_count = -1; 3129 kif->kf_offset = -1; 3130 pack_kinfo(kif); 3131 vrele(vp); 3132 } 3133 3134 struct export_fd_buf { 3135 struct filedesc *fdp; 3136 struct sbuf *sb; 3137 ssize_t remainder; 3138 struct kinfo_file kif; 3139 }; 3140 3141 static int 3142 export_kinfo_to_sb(struct export_fd_buf *efbuf) 3143 { 3144 struct kinfo_file *kif; 3145 3146 kif = &efbuf->kif; 3147 if (efbuf->remainder != -1) { 3148 if (efbuf->remainder < kif->kf_structsize) { 3149 /* Terminate export. */ 3150 efbuf->remainder = 0; 3151 return (0); 3152 } 3153 efbuf->remainder -= kif->kf_structsize; 3154 } 3155 return (sbuf_bcat(efbuf->sb, kif, kif->kf_structsize) == 0 ? 0 : ENOMEM); 3156 } 3157 3158 static int 3159 export_file_to_sb(struct file *fp, int fd, cap_rights_t *rightsp, 3160 struct export_fd_buf *efbuf) 3161 { 3162 int error; 3163 3164 if (efbuf->remainder == 0) 3165 return (0); 3166 export_file_to_kinfo(fp, fd, rightsp, &efbuf->kif, efbuf->fdp); 3167 FILEDESC_SUNLOCK(efbuf->fdp); 3168 error = export_kinfo_to_sb(efbuf); 3169 FILEDESC_SLOCK(efbuf->fdp); 3170 return (error); 3171 } 3172 3173 static int 3174 export_vnode_to_sb(struct vnode *vp, int fd, int fflags, 3175 struct export_fd_buf *efbuf) 3176 { 3177 int error; 3178 3179 if (efbuf->remainder == 0) 3180 return (0); 3181 if (efbuf->fdp != NULL) 3182 FILEDESC_SUNLOCK(efbuf->fdp); 3183 export_vnode_to_kinfo(vp, fd, fflags, &efbuf->kif); 3184 error = export_kinfo_to_sb(efbuf); 3185 if (efbuf->fdp != NULL) 3186 FILEDESC_SLOCK(efbuf->fdp); 3187 return (error); 3188 } 3189 3190 /* 3191 * Store a process file descriptor information to sbuf. 3192 * 3193 * Takes a locked proc as argument, and returns with the proc unlocked. 3194 */ 3195 int 3196 kern_proc_filedesc_out(struct proc *p, struct sbuf *sb, ssize_t maxlen) 3197 { 3198 struct file *fp; 3199 struct filedesc *fdp; 3200 struct export_fd_buf *efbuf; 3201 struct vnode *cttyvp, *textvp, *tracevp; 3202 int error, i; 3203 cap_rights_t rights; 3204 3205 PROC_LOCK_ASSERT(p, MA_OWNED); 3206 3207 /* ktrace vnode */ 3208 tracevp = p->p_tracevp; 3209 if (tracevp != NULL) 3210 vref(tracevp); 3211 /* text vnode */ 3212 textvp = p->p_textvp; 3213 if (textvp != NULL) 3214 vref(textvp); 3215 /* Controlling tty. */ 3216 cttyvp = NULL; 3217 if (p->p_pgrp != NULL && p->p_pgrp->pg_session != NULL) { 3218 cttyvp = p->p_pgrp->pg_session->s_ttyvp; 3219 if (cttyvp != NULL) 3220 vref(cttyvp); 3221 } 3222 fdp = fdhold(p); 3223 PROC_UNLOCK(p); 3224 efbuf = malloc(sizeof(*efbuf), M_TEMP, M_WAITOK); 3225 efbuf->fdp = NULL; 3226 efbuf->sb = sb; 3227 efbuf->remainder = maxlen; 3228 if (tracevp != NULL) 3229 export_vnode_to_sb(tracevp, KF_FD_TYPE_TRACE, FREAD | FWRITE, 3230 efbuf); 3231 if (textvp != NULL) 3232 export_vnode_to_sb(textvp, KF_FD_TYPE_TEXT, FREAD, efbuf); 3233 if (cttyvp != NULL) 3234 export_vnode_to_sb(cttyvp, KF_FD_TYPE_CTTY, FREAD | FWRITE, 3235 efbuf); 3236 error = 0; 3237 if (fdp == NULL) 3238 goto fail; 3239 efbuf->fdp = fdp; 3240 FILEDESC_SLOCK(fdp); 3241 /* working directory */ 3242 if (fdp->fd_cdir != NULL) { 3243 vref(fdp->fd_cdir); 3244 export_vnode_to_sb(fdp->fd_cdir, KF_FD_TYPE_CWD, FREAD, efbuf); 3245 } 3246 /* root directory */ 3247 if (fdp->fd_rdir != NULL) { 3248 vref(fdp->fd_rdir); 3249 export_vnode_to_sb(fdp->fd_rdir, KF_FD_TYPE_ROOT, FREAD, efbuf); 3250 } 3251 /* jail directory */ 3252 if (fdp->fd_jdir != NULL) { 3253 vref(fdp->fd_jdir); 3254 export_vnode_to_sb(fdp->fd_jdir, KF_FD_TYPE_JAIL, FREAD, efbuf); 3255 } 3256 for (i = 0; fdp->fd_refcnt > 0 && i <= fdp->fd_lastfile; i++) { 3257 if ((fp = fdp->fd_ofiles[i].fde_file) == NULL) 3258 continue; 3259 #ifdef CAPABILITIES 3260 rights = *cap_rights(fdp, i); 3261 #else /* !CAPABILITIES */ 3262 cap_rights_init(&rights); 3263 #endif 3264 /* 3265 * Create sysctl entry. It is OK to drop the filedesc 3266 * lock inside of export_file_to_sb() as we will 3267 * re-validate and re-evaluate its properties when the 3268 * loop continues. 3269 */ 3270 error = export_file_to_sb(fp, i, &rights, efbuf); 3271 if (error != 0 || efbuf->remainder == 0) 3272 break; 3273 } 3274 FILEDESC_SUNLOCK(fdp); 3275 fddrop(fdp); 3276 fail: 3277 free(efbuf, M_TEMP); 3278 return (error); 3279 } 3280 3281 #define FILEDESC_SBUF_SIZE (sizeof(struct kinfo_file) * 5) 3282 3283 /* 3284 * Get per-process file descriptors for use by procstat(1), et al. 3285 */ 3286 static int 3287 sysctl_kern_proc_filedesc(SYSCTL_HANDLER_ARGS) 3288 { 3289 struct sbuf sb; 3290 struct proc *p; 3291 ssize_t maxlen; 3292 int error, error2, *name; 3293 3294 name = (int *)arg1; 3295 3296 sbuf_new_for_sysctl(&sb, NULL, FILEDESC_SBUF_SIZE, req); 3297 sbuf_clear_flags(&sb, SBUF_INCLUDENUL); 3298 error = pget((pid_t)name[0], PGET_CANDEBUG | PGET_NOTWEXIT, &p); 3299 if (error != 0) { 3300 sbuf_delete(&sb); 3301 return (error); 3302 } 3303 maxlen = req->oldptr != NULL ? req->oldlen : -1; 3304 error = kern_proc_filedesc_out(p, &sb, maxlen); 3305 error2 = sbuf_finish(&sb); 3306 sbuf_delete(&sb); 3307 return (error != 0 ? error : error2); 3308 } 3309 3310 #ifdef KINFO_OFILE_SIZE 3311 CTASSERT(sizeof(struct kinfo_ofile) == KINFO_OFILE_SIZE); 3312 #endif 3313 3314 #ifdef COMPAT_FREEBSD7 3315 static void 3316 kinfo_to_okinfo(struct kinfo_file *kif, struct kinfo_ofile *okif) 3317 { 3318 3319 okif->kf_structsize = sizeof(*okif); 3320 okif->kf_type = kif->kf_type; 3321 okif->kf_fd = kif->kf_fd; 3322 okif->kf_ref_count = kif->kf_ref_count; 3323 okif->kf_flags = kif->kf_flags & (KF_FLAG_READ | KF_FLAG_WRITE | 3324 KF_FLAG_APPEND | KF_FLAG_ASYNC | KF_FLAG_FSYNC | KF_FLAG_NONBLOCK | 3325 KF_FLAG_DIRECT | KF_FLAG_HASLOCK); 3326 okif->kf_offset = kif->kf_offset; 3327 okif->kf_vnode_type = kif->kf_vnode_type; 3328 okif->kf_sock_domain = kif->kf_sock_domain; 3329 okif->kf_sock_type = kif->kf_sock_type; 3330 okif->kf_sock_protocol = kif->kf_sock_protocol; 3331 strlcpy(okif->kf_path, kif->kf_path, sizeof(okif->kf_path)); 3332 okif->kf_sa_local = kif->kf_sa_local; 3333 okif->kf_sa_peer = kif->kf_sa_peer; 3334 } 3335 3336 static int 3337 export_vnode_for_osysctl(struct vnode *vp, int type, struct kinfo_file *kif, 3338 struct kinfo_ofile *okif, struct filedesc *fdp, struct sysctl_req *req) 3339 { 3340 int error; 3341 3342 vref(vp); 3343 FILEDESC_SUNLOCK(fdp); 3344 export_vnode_to_kinfo(vp, type, 0, kif); 3345 kinfo_to_okinfo(kif, okif); 3346 error = SYSCTL_OUT(req, okif, sizeof(*okif)); 3347 FILEDESC_SLOCK(fdp); 3348 return (error); 3349 } 3350 3351 /* 3352 * Get per-process file descriptors for use by procstat(1), et al. 3353 */ 3354 static int 3355 sysctl_kern_proc_ofiledesc(SYSCTL_HANDLER_ARGS) 3356 { 3357 struct kinfo_ofile *okif; 3358 struct kinfo_file *kif; 3359 struct filedesc *fdp; 3360 int error, i, *name; 3361 struct file *fp; 3362 struct proc *p; 3363 3364 name = (int *)arg1; 3365 error = pget((pid_t)name[0], PGET_CANDEBUG | PGET_NOTWEXIT, &p); 3366 if (error != 0) 3367 return (error); 3368 fdp = fdhold(p); 3369 PROC_UNLOCK(p); 3370 if (fdp == NULL) 3371 return (ENOENT); 3372 kif = malloc(sizeof(*kif), M_TEMP, M_WAITOK); 3373 okif = malloc(sizeof(*okif), M_TEMP, M_WAITOK); 3374 FILEDESC_SLOCK(fdp); 3375 if (fdp->fd_cdir != NULL) 3376 export_vnode_for_osysctl(fdp->fd_cdir, KF_FD_TYPE_CWD, kif, 3377 okif, fdp, req); 3378 if (fdp->fd_rdir != NULL) 3379 export_vnode_for_osysctl(fdp->fd_rdir, KF_FD_TYPE_ROOT, kif, 3380 okif, fdp, req); 3381 if (fdp->fd_jdir != NULL) 3382 export_vnode_for_osysctl(fdp->fd_jdir, KF_FD_TYPE_JAIL, kif, 3383 okif, fdp, req); 3384 for (i = 0; fdp->fd_refcnt > 0 && i <= fdp->fd_lastfile; i++) { 3385 if ((fp = fdp->fd_ofiles[i].fde_file) == NULL) 3386 continue; 3387 export_file_to_kinfo(fp, i, NULL, kif, fdp); 3388 FILEDESC_SUNLOCK(fdp); 3389 kinfo_to_okinfo(kif, okif); 3390 error = SYSCTL_OUT(req, okif, sizeof(*okif)); 3391 FILEDESC_SLOCK(fdp); 3392 if (error) 3393 break; 3394 } 3395 FILEDESC_SUNLOCK(fdp); 3396 fddrop(fdp); 3397 free(kif, M_TEMP); 3398 free(okif, M_TEMP); 3399 return (0); 3400 } 3401 3402 static SYSCTL_NODE(_kern_proc, KERN_PROC_OFILEDESC, ofiledesc, 3403 CTLFLAG_RD|CTLFLAG_MPSAFE, sysctl_kern_proc_ofiledesc, 3404 "Process ofiledesc entries"); 3405 #endif /* COMPAT_FREEBSD7 */ 3406 3407 int 3408 vntype_to_kinfo(int vtype) 3409 { 3410 struct { 3411 int vtype; 3412 int kf_vtype; 3413 } vtypes_table[] = { 3414 { VBAD, KF_VTYPE_VBAD }, 3415 { VBLK, KF_VTYPE_VBLK }, 3416 { VCHR, KF_VTYPE_VCHR }, 3417 { VDIR, KF_VTYPE_VDIR }, 3418 { VFIFO, KF_VTYPE_VFIFO }, 3419 { VLNK, KF_VTYPE_VLNK }, 3420 { VNON, KF_VTYPE_VNON }, 3421 { VREG, KF_VTYPE_VREG }, 3422 { VSOCK, KF_VTYPE_VSOCK } 3423 }; 3424 unsigned int i; 3425 3426 /* 3427 * Perform vtype translation. 3428 */ 3429 for (i = 0; i < nitems(vtypes_table); i++) 3430 if (vtypes_table[i].vtype == vtype) 3431 return (vtypes_table[i].kf_vtype); 3432 3433 return (KF_VTYPE_UNKNOWN); 3434 } 3435 3436 static SYSCTL_NODE(_kern_proc, KERN_PROC_FILEDESC, filedesc, 3437 CTLFLAG_RD|CTLFLAG_MPSAFE, sysctl_kern_proc_filedesc, 3438 "Process filedesc entries"); 3439 3440 /* 3441 * Store a process current working directory information to sbuf. 3442 * 3443 * Takes a locked proc as argument, and returns with the proc unlocked. 3444 */ 3445 int 3446 kern_proc_cwd_out(struct proc *p, struct sbuf *sb, ssize_t maxlen) 3447 { 3448 struct filedesc *fdp; 3449 struct export_fd_buf *efbuf; 3450 int error; 3451 3452 PROC_LOCK_ASSERT(p, MA_OWNED); 3453 3454 fdp = fdhold(p); 3455 PROC_UNLOCK(p); 3456 if (fdp == NULL) 3457 return (EINVAL); 3458 3459 efbuf = malloc(sizeof(*efbuf), M_TEMP, M_WAITOK); 3460 efbuf->fdp = fdp; 3461 efbuf->sb = sb; 3462 efbuf->remainder = maxlen; 3463 3464 FILEDESC_SLOCK(fdp); 3465 if (fdp->fd_cdir == NULL) 3466 error = EINVAL; 3467 else { 3468 vref(fdp->fd_cdir); 3469 error = export_vnode_to_sb(fdp->fd_cdir, KF_FD_TYPE_CWD, 3470 FREAD, efbuf); 3471 } 3472 FILEDESC_SUNLOCK(fdp); 3473 fddrop(fdp); 3474 free(efbuf, M_TEMP); 3475 return (error); 3476 } 3477 3478 /* 3479 * Get per-process current working directory. 3480 */ 3481 static int 3482 sysctl_kern_proc_cwd(SYSCTL_HANDLER_ARGS) 3483 { 3484 struct sbuf sb; 3485 struct proc *p; 3486 ssize_t maxlen; 3487 int error, error2, *name; 3488 3489 name = (int *)arg1; 3490 3491 sbuf_new_for_sysctl(&sb, NULL, sizeof(struct kinfo_file), req); 3492 sbuf_clear_flags(&sb, SBUF_INCLUDENUL); 3493 error = pget((pid_t)name[0], PGET_CANDEBUG | PGET_NOTWEXIT, &p); 3494 if (error != 0) { 3495 sbuf_delete(&sb); 3496 return (error); 3497 } 3498 maxlen = req->oldptr != NULL ? req->oldlen : -1; 3499 error = kern_proc_cwd_out(p, &sb, maxlen); 3500 error2 = sbuf_finish(&sb); 3501 sbuf_delete(&sb); 3502 return (error != 0 ? error : error2); 3503 } 3504 3505 static SYSCTL_NODE(_kern_proc, KERN_PROC_CWD, cwd, CTLFLAG_RD|CTLFLAG_MPSAFE, 3506 sysctl_kern_proc_cwd, "Process current working directory"); 3507 3508 #ifdef DDB 3509 /* 3510 * For the purposes of debugging, generate a human-readable string for the 3511 * file type. 3512 */ 3513 static const char * 3514 file_type_to_name(short type) 3515 { 3516 3517 switch (type) { 3518 case 0: 3519 return ("zero"); 3520 case DTYPE_VNODE: 3521 return ("vnod"); 3522 case DTYPE_SOCKET: 3523 return ("sock"); 3524 case DTYPE_PIPE: 3525 return ("pipe"); 3526 case DTYPE_FIFO: 3527 return ("fifo"); 3528 case DTYPE_KQUEUE: 3529 return ("kque"); 3530 case DTYPE_CRYPTO: 3531 return ("crpt"); 3532 case DTYPE_MQUEUE: 3533 return ("mque"); 3534 case DTYPE_SHM: 3535 return ("shm"); 3536 case DTYPE_SEM: 3537 return ("ksem"); 3538 default: 3539 return ("unkn"); 3540 } 3541 } 3542 3543 /* 3544 * For the purposes of debugging, identify a process (if any, perhaps one of 3545 * many) that references the passed file in its file descriptor array. Return 3546 * NULL if none. 3547 */ 3548 static struct proc * 3549 file_to_first_proc(struct file *fp) 3550 { 3551 struct filedesc *fdp; 3552 struct proc *p; 3553 int n; 3554 3555 FOREACH_PROC_IN_SYSTEM(p) { 3556 if (p->p_state == PRS_NEW) 3557 continue; 3558 fdp = p->p_fd; 3559 if (fdp == NULL) 3560 continue; 3561 for (n = 0; n <= fdp->fd_lastfile; n++) { 3562 if (fp == fdp->fd_ofiles[n].fde_file) 3563 return (p); 3564 } 3565 } 3566 return (NULL); 3567 } 3568 3569 static void 3570 db_print_file(struct file *fp, int header) 3571 { 3572 struct proc *p; 3573 3574 if (header) 3575 db_printf("%8s %4s %8s %8s %4s %5s %6s %8s %5s %12s\n", 3576 "File", "Type", "Data", "Flag", "GCFl", "Count", 3577 "MCount", "Vnode", "FPID", "FCmd"); 3578 p = file_to_first_proc(fp); 3579 db_printf("%8p %4s %8p %08x %04x %5d %6d %8p %5d %12s\n", fp, 3580 file_type_to_name(fp->f_type), fp->f_data, fp->f_flag, 3581 0, fp->f_count, 0, fp->f_vnode, 3582 p != NULL ? p->p_pid : -1, p != NULL ? p->p_comm : "-"); 3583 } 3584 3585 DB_SHOW_COMMAND(file, db_show_file) 3586 { 3587 struct file *fp; 3588 3589 if (!have_addr) { 3590 db_printf("usage: show file <addr>\n"); 3591 return; 3592 } 3593 fp = (struct file *)addr; 3594 db_print_file(fp, 1); 3595 } 3596 3597 DB_SHOW_COMMAND(files, db_show_files) 3598 { 3599 struct filedesc *fdp; 3600 struct file *fp; 3601 struct proc *p; 3602 int header; 3603 int n; 3604 3605 header = 1; 3606 FOREACH_PROC_IN_SYSTEM(p) { 3607 if (p->p_state == PRS_NEW) 3608 continue; 3609 if ((fdp = p->p_fd) == NULL) 3610 continue; 3611 for (n = 0; n <= fdp->fd_lastfile; ++n) { 3612 if ((fp = fdp->fd_ofiles[n].fde_file) == NULL) 3613 continue; 3614 db_print_file(fp, header); 3615 header = 0; 3616 } 3617 } 3618 } 3619 #endif 3620 3621 SYSCTL_INT(_kern, KERN_MAXFILESPERPROC, maxfilesperproc, CTLFLAG_RW, 3622 &maxfilesperproc, 0, "Maximum files allowed open per process"); 3623 3624 SYSCTL_INT(_kern, KERN_MAXFILES, maxfiles, CTLFLAG_RW, 3625 &maxfiles, 0, "Maximum number of files"); 3626 3627 SYSCTL_INT(_kern, OID_AUTO, openfiles, CTLFLAG_RD, 3628 __DEVOLATILE(int *, &openfiles), 0, "System-wide number of open files"); 3629 3630 /* ARGSUSED*/ 3631 static void 3632 filelistinit(void *dummy) 3633 { 3634 3635 file_zone = uma_zcreate("Files", sizeof(struct file), NULL, NULL, 3636 NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE); 3637 filedesc0_zone = uma_zcreate("filedesc0", sizeof(struct filedesc0), 3638 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0); 3639 mtx_init(&sigio_lock, "sigio lock", NULL, MTX_DEF); 3640 } 3641 SYSINIT(select, SI_SUB_LOCK, SI_ORDER_FIRST, filelistinit, NULL); 3642 3643 /*-------------------------------------------------------------------*/ 3644 3645 static int 3646 badfo_readwrite(struct file *fp, struct uio *uio, struct ucred *active_cred, 3647 int flags, struct thread *td) 3648 { 3649 3650 return (EBADF); 3651 } 3652 3653 static int 3654 badfo_truncate(struct file *fp, off_t length, struct ucred *active_cred, 3655 struct thread *td) 3656 { 3657 3658 return (EINVAL); 3659 } 3660 3661 static int 3662 badfo_ioctl(struct file *fp, u_long com, void *data, struct ucred *active_cred, 3663 struct thread *td) 3664 { 3665 3666 return (EBADF); 3667 } 3668 3669 static int 3670 badfo_poll(struct file *fp, int events, struct ucred *active_cred, 3671 struct thread *td) 3672 { 3673 3674 return (0); 3675 } 3676 3677 static int 3678 badfo_kqfilter(struct file *fp, struct knote *kn) 3679 { 3680 3681 return (EBADF); 3682 } 3683 3684 static int 3685 badfo_stat(struct file *fp, struct stat *sb, struct ucred *active_cred, 3686 struct thread *td) 3687 { 3688 3689 return (EBADF); 3690 } 3691 3692 static int 3693 badfo_close(struct file *fp, struct thread *td) 3694 { 3695 3696 return (0); 3697 } 3698 3699 static int 3700 badfo_chmod(struct file *fp, mode_t mode, struct ucred *active_cred, 3701 struct thread *td) 3702 { 3703 3704 return (EBADF); 3705 } 3706 3707 static int 3708 badfo_chown(struct file *fp, uid_t uid, gid_t gid, struct ucred *active_cred, 3709 struct thread *td) 3710 { 3711 3712 return (EBADF); 3713 } 3714 3715 static int 3716 badfo_sendfile(struct file *fp, int sockfd, struct uio *hdr_uio, 3717 struct uio *trl_uio, off_t offset, size_t nbytes, off_t *sent, int flags, 3718 int kflags, struct thread *td) 3719 { 3720 3721 return (EBADF); 3722 } 3723 3724 static int 3725 badfo_fill_kinfo(struct file *fp, struct kinfo_file *kif, struct filedesc *fdp) 3726 { 3727 3728 return (0); 3729 } 3730 3731 struct fileops badfileops = { 3732 .fo_read = badfo_readwrite, 3733 .fo_write = badfo_readwrite, 3734 .fo_truncate = badfo_truncate, 3735 .fo_ioctl = badfo_ioctl, 3736 .fo_poll = badfo_poll, 3737 .fo_kqfilter = badfo_kqfilter, 3738 .fo_stat = badfo_stat, 3739 .fo_close = badfo_close, 3740 .fo_chmod = badfo_chmod, 3741 .fo_chown = badfo_chown, 3742 .fo_sendfile = badfo_sendfile, 3743 .fo_fill_kinfo = badfo_fill_kinfo, 3744 }; 3745 3746 int 3747 invfo_rdwr(struct file *fp, struct uio *uio, struct ucred *active_cred, 3748 int flags, struct thread *td) 3749 { 3750 3751 return (EOPNOTSUPP); 3752 } 3753 3754 int 3755 invfo_truncate(struct file *fp, off_t length, struct ucred *active_cred, 3756 struct thread *td) 3757 { 3758 3759 return (EINVAL); 3760 } 3761 3762 int 3763 invfo_ioctl(struct file *fp, u_long com, void *data, 3764 struct ucred *active_cred, struct thread *td) 3765 { 3766 3767 return (ENOTTY); 3768 } 3769 3770 int 3771 invfo_poll(struct file *fp, int events, struct ucred *active_cred, 3772 struct thread *td) 3773 { 3774 3775 return (poll_no_poll(events)); 3776 } 3777 3778 int 3779 invfo_kqfilter(struct file *fp, struct knote *kn) 3780 { 3781 3782 return (EINVAL); 3783 } 3784 3785 int 3786 invfo_chmod(struct file *fp, mode_t mode, struct ucred *active_cred, 3787 struct thread *td) 3788 { 3789 3790 return (EINVAL); 3791 } 3792 3793 int 3794 invfo_chown(struct file *fp, uid_t uid, gid_t gid, struct ucred *active_cred, 3795 struct thread *td) 3796 { 3797 3798 return (EINVAL); 3799 } 3800 3801 int 3802 invfo_sendfile(struct file *fp, int sockfd, struct uio *hdr_uio, 3803 struct uio *trl_uio, off_t offset, size_t nbytes, off_t *sent, int flags, 3804 int kflags, struct thread *td) 3805 { 3806 3807 return (EINVAL); 3808 } 3809 3810 /*-------------------------------------------------------------------*/ 3811 3812 /* 3813 * File Descriptor pseudo-device driver (/dev/fd/). 3814 * 3815 * Opening minor device N dup()s the file (if any) connected to file 3816 * descriptor N belonging to the calling process. Note that this driver 3817 * consists of only the ``open()'' routine, because all subsequent 3818 * references to this file will be direct to the other driver. 3819 * 3820 * XXX: we could give this one a cloning event handler if necessary. 3821 */ 3822 3823 /* ARGSUSED */ 3824 static int 3825 fdopen(struct cdev *dev, int mode, int type, struct thread *td) 3826 { 3827 3828 /* 3829 * XXX Kludge: set curthread->td_dupfd to contain the value of the 3830 * the file descriptor being sought for duplication. The error 3831 * return ensures that the vnode for this device will be released 3832 * by vn_open. Open will detect this special error and take the 3833 * actions in dupfdopen below. Other callers of vn_open or VOP_OPEN 3834 * will simply report the error. 3835 */ 3836 td->td_dupfd = dev2unit(dev); 3837 return (ENODEV); 3838 } 3839 3840 static struct cdevsw fildesc_cdevsw = { 3841 .d_version = D_VERSION, 3842 .d_open = fdopen, 3843 .d_name = "FD", 3844 }; 3845 3846 static void 3847 fildesc_drvinit(void *unused) 3848 { 3849 struct cdev *dev; 3850 3851 dev = make_dev_credf(MAKEDEV_ETERNAL, &fildesc_cdevsw, 0, NULL, 3852 UID_ROOT, GID_WHEEL, 0666, "fd/0"); 3853 make_dev_alias(dev, "stdin"); 3854 dev = make_dev_credf(MAKEDEV_ETERNAL, &fildesc_cdevsw, 1, NULL, 3855 UID_ROOT, GID_WHEEL, 0666, "fd/1"); 3856 make_dev_alias(dev, "stdout"); 3857 dev = make_dev_credf(MAKEDEV_ETERNAL, &fildesc_cdevsw, 2, NULL, 3858 UID_ROOT, GID_WHEEL, 0666, "fd/2"); 3859 make_dev_alias(dev, "stderr"); 3860 } 3861 3862 SYSINIT(fildescdev, SI_SUB_DRIVERS, SI_ORDER_MIDDLE, fildesc_drvinit, NULL); 3863