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 fde->fde_file = NULL; 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, newcmd; 408 409 error = 0; 410 newcmd = cmd; 411 switch (cmd) { 412 case F_OGETLK: 413 case F_OSETLK: 414 case F_OSETLKW: 415 /* 416 * Convert old flock structure to new. 417 */ 418 error = copyin((void *)(intptr_t)arg, &ofl, sizeof(ofl)); 419 fl.l_start = ofl.l_start; 420 fl.l_len = ofl.l_len; 421 fl.l_pid = ofl.l_pid; 422 fl.l_type = ofl.l_type; 423 fl.l_whence = ofl.l_whence; 424 fl.l_sysid = 0; 425 426 switch (cmd) { 427 case F_OGETLK: 428 newcmd = F_GETLK; 429 break; 430 case F_OSETLK: 431 newcmd = F_SETLK; 432 break; 433 case F_OSETLKW: 434 newcmd = F_SETLKW; 435 break; 436 } 437 arg1 = (intptr_t)&fl; 438 break; 439 case F_GETLK: 440 case F_SETLK: 441 case F_SETLKW: 442 case F_SETLK_REMOTE: 443 error = copyin((void *)(intptr_t)arg, &fl, sizeof(fl)); 444 arg1 = (intptr_t)&fl; 445 break; 446 default: 447 arg1 = arg; 448 break; 449 } 450 if (error) 451 return (error); 452 error = kern_fcntl(td, fd, newcmd, arg1); 453 if (error) 454 return (error); 455 if (cmd == F_OGETLK) { 456 ofl.l_start = fl.l_start; 457 ofl.l_len = fl.l_len; 458 ofl.l_pid = fl.l_pid; 459 ofl.l_type = fl.l_type; 460 ofl.l_whence = fl.l_whence; 461 error = copyout(&ofl, (void *)(intptr_t)arg, sizeof(ofl)); 462 } else if (cmd == F_GETLK) { 463 error = copyout(&fl, (void *)(intptr_t)arg, sizeof(fl)); 464 } 465 return (error); 466 } 467 468 int 469 kern_fcntl(struct thread *td, int fd, int cmd, intptr_t arg) 470 { 471 struct filedesc *fdp; 472 struct flock *flp; 473 struct file *fp, *fp2; 474 struct filedescent *fde; 475 struct proc *p; 476 struct vnode *vp; 477 cap_rights_t rights; 478 int error, flg, tmp; 479 uint64_t bsize; 480 off_t foffset; 481 482 error = 0; 483 flg = F_POSIX; 484 p = td->td_proc; 485 fdp = p->p_fd; 486 487 switch (cmd) { 488 case F_DUPFD: 489 tmp = arg; 490 error = do_dup(td, DUP_FCNTL, fd, tmp); 491 break; 492 493 case F_DUPFD_CLOEXEC: 494 tmp = arg; 495 error = do_dup(td, DUP_FCNTL | DUP_CLOEXEC, fd, tmp); 496 break; 497 498 case F_DUP2FD: 499 tmp = arg; 500 error = do_dup(td, DUP_FIXED, fd, tmp); 501 break; 502 503 case F_DUP2FD_CLOEXEC: 504 tmp = arg; 505 error = do_dup(td, DUP_FIXED | DUP_CLOEXEC, fd, tmp); 506 break; 507 508 case F_GETFD: 509 FILEDESC_SLOCK(fdp); 510 if (fget_locked(fdp, fd) == NULL) { 511 FILEDESC_SUNLOCK(fdp); 512 error = EBADF; 513 break; 514 } 515 fde = &fdp->fd_ofiles[fd]; 516 td->td_retval[0] = 517 (fde->fde_flags & UF_EXCLOSE) ? FD_CLOEXEC : 0; 518 FILEDESC_SUNLOCK(fdp); 519 break; 520 521 case F_SETFD: 522 FILEDESC_XLOCK(fdp); 523 if (fget_locked(fdp, fd) == NULL) { 524 FILEDESC_XUNLOCK(fdp); 525 error = EBADF; 526 break; 527 } 528 fde = &fdp->fd_ofiles[fd]; 529 fde->fde_flags = (fde->fde_flags & ~UF_EXCLOSE) | 530 (arg & FD_CLOEXEC ? UF_EXCLOSE : 0); 531 FILEDESC_XUNLOCK(fdp); 532 break; 533 534 case F_GETFL: 535 error = fget_fcntl(td, fd, 536 cap_rights_init(&rights, CAP_FCNTL), F_GETFL, &fp); 537 if (error != 0) 538 break; 539 td->td_retval[0] = OFLAGS(fp->f_flag); 540 fdrop(fp, td); 541 break; 542 543 case F_SETFL: 544 error = fget_fcntl(td, fd, 545 cap_rights_init(&rights, CAP_FCNTL), F_SETFL, &fp); 546 if (error != 0) 547 break; 548 do { 549 tmp = flg = fp->f_flag; 550 tmp &= ~FCNTLFLAGS; 551 tmp |= FFLAGS(arg & ~O_ACCMODE) & FCNTLFLAGS; 552 } while(atomic_cmpset_int(&fp->f_flag, flg, tmp) == 0); 553 tmp = fp->f_flag & FNONBLOCK; 554 error = fo_ioctl(fp, FIONBIO, &tmp, td->td_ucred, td); 555 if (error != 0) { 556 fdrop(fp, td); 557 break; 558 } 559 tmp = fp->f_flag & FASYNC; 560 error = fo_ioctl(fp, FIOASYNC, &tmp, td->td_ucred, td); 561 if (error == 0) { 562 fdrop(fp, td); 563 break; 564 } 565 atomic_clear_int(&fp->f_flag, FNONBLOCK); 566 tmp = 0; 567 (void)fo_ioctl(fp, FIONBIO, &tmp, td->td_ucred, td); 568 fdrop(fp, td); 569 break; 570 571 case F_GETOWN: 572 error = fget_fcntl(td, fd, 573 cap_rights_init(&rights, CAP_FCNTL), F_GETOWN, &fp); 574 if (error != 0) 575 break; 576 error = fo_ioctl(fp, FIOGETOWN, &tmp, td->td_ucred, td); 577 if (error == 0) 578 td->td_retval[0] = tmp; 579 fdrop(fp, td); 580 break; 581 582 case F_SETOWN: 583 error = fget_fcntl(td, fd, 584 cap_rights_init(&rights, CAP_FCNTL), F_SETOWN, &fp); 585 if (error != 0) 586 break; 587 tmp = arg; 588 error = fo_ioctl(fp, FIOSETOWN, &tmp, td->td_ucred, td); 589 fdrop(fp, td); 590 break; 591 592 case F_SETLK_REMOTE: 593 error = priv_check(td, PRIV_NFS_LOCKD); 594 if (error) 595 return (error); 596 flg = F_REMOTE; 597 goto do_setlk; 598 599 case F_SETLKW: 600 flg |= F_WAIT; 601 /* FALLTHROUGH F_SETLK */ 602 603 case F_SETLK: 604 do_setlk: 605 cap_rights_init(&rights, CAP_FLOCK); 606 error = fget_unlocked(fdp, fd, &rights, &fp, NULL); 607 if (error != 0) 608 break; 609 if (fp->f_type != DTYPE_VNODE) { 610 error = EBADF; 611 fdrop(fp, td); 612 break; 613 } 614 615 flp = (struct flock *)arg; 616 if (flp->l_whence == SEEK_CUR) { 617 foffset = foffset_get(fp); 618 if (foffset < 0 || 619 (flp->l_start > 0 && 620 foffset > OFF_MAX - flp->l_start)) { 621 error = EOVERFLOW; 622 fdrop(fp, td); 623 break; 624 } 625 flp->l_start += foffset; 626 } 627 628 vp = fp->f_vnode; 629 switch (flp->l_type) { 630 case F_RDLCK: 631 if ((fp->f_flag & FREAD) == 0) { 632 error = EBADF; 633 break; 634 } 635 PROC_LOCK(p->p_leader); 636 p->p_leader->p_flag |= P_ADVLOCK; 637 PROC_UNLOCK(p->p_leader); 638 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_SETLK, 639 flp, flg); 640 break; 641 case F_WRLCK: 642 if ((fp->f_flag & FWRITE) == 0) { 643 error = EBADF; 644 break; 645 } 646 PROC_LOCK(p->p_leader); 647 p->p_leader->p_flag |= P_ADVLOCK; 648 PROC_UNLOCK(p->p_leader); 649 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_SETLK, 650 flp, flg); 651 break; 652 case F_UNLCK: 653 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_UNLCK, 654 flp, flg); 655 break; 656 case F_UNLCKSYS: 657 /* 658 * Temporary api for testing remote lock 659 * infrastructure. 660 */ 661 if (flg != F_REMOTE) { 662 error = EINVAL; 663 break; 664 } 665 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, 666 F_UNLCKSYS, flp, flg); 667 break; 668 default: 669 error = EINVAL; 670 break; 671 } 672 if (error != 0 || flp->l_type == F_UNLCK || 673 flp->l_type == F_UNLCKSYS) { 674 fdrop(fp, td); 675 break; 676 } 677 678 /* 679 * Check for a race with close. 680 * 681 * The vnode is now advisory locked (or unlocked, but this case 682 * is not really important) as the caller requested. 683 * We had to drop the filedesc lock, so we need to recheck if 684 * the descriptor is still valid, because if it was closed 685 * in the meantime we need to remove advisory lock from the 686 * vnode - close on any descriptor leading to an advisory 687 * locked vnode, removes that lock. 688 * We will return 0 on purpose in that case, as the result of 689 * successful advisory lock might have been externally visible 690 * already. This is fine - effectively we pretend to the caller 691 * that the closing thread was a bit slower and that the 692 * advisory lock succeeded before the close. 693 */ 694 error = fget_unlocked(fdp, fd, &rights, &fp2, NULL); 695 if (error != 0) { 696 fdrop(fp, td); 697 break; 698 } 699 if (fp != fp2) { 700 flp->l_whence = SEEK_SET; 701 flp->l_start = 0; 702 flp->l_len = 0; 703 flp->l_type = F_UNLCK; 704 (void) VOP_ADVLOCK(vp, (caddr_t)p->p_leader, 705 F_UNLCK, flp, F_POSIX); 706 } 707 fdrop(fp, td); 708 fdrop(fp2, td); 709 break; 710 711 case F_GETLK: 712 error = fget_unlocked(fdp, fd, 713 cap_rights_init(&rights, CAP_FLOCK), &fp, NULL); 714 if (error != 0) 715 break; 716 if (fp->f_type != DTYPE_VNODE) { 717 error = EBADF; 718 fdrop(fp, td); 719 break; 720 } 721 flp = (struct flock *)arg; 722 if (flp->l_type != F_RDLCK && flp->l_type != F_WRLCK && 723 flp->l_type != F_UNLCK) { 724 error = EINVAL; 725 fdrop(fp, td); 726 break; 727 } 728 if (flp->l_whence == SEEK_CUR) { 729 foffset = foffset_get(fp); 730 if ((flp->l_start > 0 && 731 foffset > OFF_MAX - flp->l_start) || 732 (flp->l_start < 0 && 733 foffset < OFF_MIN - flp->l_start)) { 734 error = EOVERFLOW; 735 fdrop(fp, td); 736 break; 737 } 738 flp->l_start += foffset; 739 } 740 vp = fp->f_vnode; 741 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_GETLK, flp, 742 F_POSIX); 743 fdrop(fp, td); 744 break; 745 746 case F_RDAHEAD: 747 arg = arg ? 128 * 1024: 0; 748 /* FALLTHROUGH */ 749 case F_READAHEAD: 750 error = fget_unlocked(fdp, fd, 751 cap_rights_init(&rights), &fp, NULL); 752 if (error != 0) 753 break; 754 if (fp->f_type != DTYPE_VNODE) { 755 fdrop(fp, td); 756 error = EBADF; 757 break; 758 } 759 vp = fp->f_vnode; 760 /* 761 * Exclusive lock synchronizes against f_seqcount reads and 762 * writes in sequential_heuristic(). 763 */ 764 error = vn_lock(vp, LK_EXCLUSIVE); 765 if (error != 0) { 766 fdrop(fp, td); 767 break; 768 } 769 if (arg >= 0) { 770 bsize = fp->f_vnode->v_mount->mnt_stat.f_iosize; 771 fp->f_seqcount = (arg + bsize - 1) / bsize; 772 atomic_set_int(&fp->f_flag, FRDAHEAD); 773 } else { 774 atomic_clear_int(&fp->f_flag, FRDAHEAD); 775 } 776 VOP_UNLOCK(vp, 0); 777 fdrop(fp, td); 778 break; 779 780 default: 781 error = EINVAL; 782 break; 783 } 784 return (error); 785 } 786 787 static int 788 getmaxfd(struct thread *td) 789 { 790 791 return (min((int)lim_cur(td, RLIMIT_NOFILE), maxfilesperproc)); 792 } 793 794 /* 795 * Common code for dup, dup2, fcntl(F_DUPFD) and fcntl(F_DUP2FD). 796 */ 797 static int 798 do_dup(struct thread *td, int flags, int old, int new) 799 { 800 struct filedesc *fdp; 801 struct filedescent *oldfde, *newfde; 802 struct proc *p; 803 struct file *fp; 804 struct file *delfp; 805 int error, maxfd; 806 807 p = td->td_proc; 808 fdp = p->p_fd; 809 810 /* 811 * Verify we have a valid descriptor to dup from and possibly to 812 * dup to. Unlike dup() and dup2(), fcntl()'s F_DUPFD should 813 * return EINVAL when the new descriptor is out of bounds. 814 */ 815 if (old < 0) 816 return (EBADF); 817 if (new < 0) 818 return (flags & DUP_FCNTL ? EINVAL : EBADF); 819 maxfd = getmaxfd(td); 820 if (new >= maxfd) 821 return (flags & DUP_FCNTL ? EINVAL : EBADF); 822 823 FILEDESC_XLOCK(fdp); 824 if (fget_locked(fdp, old) == NULL) { 825 FILEDESC_XUNLOCK(fdp); 826 return (EBADF); 827 } 828 oldfde = &fdp->fd_ofiles[old]; 829 if (flags & DUP_FIXED && old == new) { 830 td->td_retval[0] = new; 831 if (flags & DUP_CLOEXEC) 832 fdp->fd_ofiles[new].fde_flags |= UF_EXCLOSE; 833 FILEDESC_XUNLOCK(fdp); 834 return (0); 835 } 836 fp = oldfde->fde_file; 837 fhold(fp); 838 839 /* 840 * If the caller specified a file descriptor, make sure the file 841 * table is large enough to hold it, and grab it. Otherwise, just 842 * allocate a new descriptor the usual way. 843 */ 844 if (flags & DUP_FIXED) { 845 if (new >= fdp->fd_nfiles) { 846 /* 847 * The resource limits are here instead of e.g. 848 * fdalloc(), because the file descriptor table may be 849 * shared between processes, so we can't really use 850 * racct_add()/racct_sub(). Instead of counting the 851 * number of actually allocated descriptors, just put 852 * the limit on the size of the file descriptor table. 853 */ 854 #ifdef RACCT 855 if (racct_enable) { 856 PROC_LOCK(p); 857 error = racct_set(p, RACCT_NOFILE, new + 1); 858 PROC_UNLOCK(p); 859 if (error != 0) { 860 FILEDESC_XUNLOCK(fdp); 861 fdrop(fp, td); 862 return (EMFILE); 863 } 864 } 865 #endif 866 fdgrowtable_exp(fdp, new + 1); 867 oldfde = &fdp->fd_ofiles[old]; 868 } 869 newfde = &fdp->fd_ofiles[new]; 870 if (newfde->fde_file == NULL) 871 fdused(fdp, new); 872 } else { 873 if ((error = fdalloc(td, new, &new)) != 0) { 874 FILEDESC_XUNLOCK(fdp); 875 fdrop(fp, td); 876 return (error); 877 } 878 newfde = &fdp->fd_ofiles[new]; 879 } 880 881 KASSERT(fp == oldfde->fde_file, ("old fd has been modified")); 882 KASSERT(old != new, ("new fd is same as old")); 883 884 delfp = newfde->fde_file; 885 886 /* 887 * Duplicate the source descriptor. 888 */ 889 #ifdef CAPABILITIES 890 seq_write_begin(&newfde->fde_seq); 891 #endif 892 filecaps_free(&newfde->fde_caps); 893 memcpy(newfde, oldfde, fde_change_size); 894 filecaps_copy(&oldfde->fde_caps, &newfde->fde_caps); 895 if ((flags & DUP_CLOEXEC) != 0) 896 newfde->fde_flags = oldfde->fde_flags | UF_EXCLOSE; 897 else 898 newfde->fde_flags = oldfde->fde_flags & ~UF_EXCLOSE; 899 #ifdef CAPABILITIES 900 seq_write_end(&newfde->fde_seq); 901 #endif 902 td->td_retval[0] = new; 903 904 if (delfp != NULL) { 905 (void) closefp(fdp, new, delfp, td, 1); 906 /* closefp() drops the FILEDESC lock for us. */ 907 } else { 908 FILEDESC_XUNLOCK(fdp); 909 } 910 911 return (0); 912 } 913 914 /* 915 * If sigio is on the list associated with a process or process group, 916 * disable signalling from the device, remove sigio from the list and 917 * free sigio. 918 */ 919 void 920 funsetown(struct sigio **sigiop) 921 { 922 struct sigio *sigio; 923 924 SIGIO_LOCK(); 925 sigio = *sigiop; 926 if (sigio == NULL) { 927 SIGIO_UNLOCK(); 928 return; 929 } 930 *(sigio->sio_myref) = NULL; 931 if ((sigio)->sio_pgid < 0) { 932 struct pgrp *pg = (sigio)->sio_pgrp; 933 PGRP_LOCK(pg); 934 SLIST_REMOVE(&sigio->sio_pgrp->pg_sigiolst, sigio, 935 sigio, sio_pgsigio); 936 PGRP_UNLOCK(pg); 937 } else { 938 struct proc *p = (sigio)->sio_proc; 939 PROC_LOCK(p); 940 SLIST_REMOVE(&sigio->sio_proc->p_sigiolst, sigio, 941 sigio, sio_pgsigio); 942 PROC_UNLOCK(p); 943 } 944 SIGIO_UNLOCK(); 945 crfree(sigio->sio_ucred); 946 free(sigio, M_SIGIO); 947 } 948 949 /* 950 * Free a list of sigio structures. 951 * We only need to lock the SIGIO_LOCK because we have made ourselves 952 * inaccessible to callers of fsetown and therefore do not need to lock 953 * the proc or pgrp struct for the list manipulation. 954 */ 955 void 956 funsetownlst(struct sigiolst *sigiolst) 957 { 958 struct proc *p; 959 struct pgrp *pg; 960 struct sigio *sigio; 961 962 sigio = SLIST_FIRST(sigiolst); 963 if (sigio == NULL) 964 return; 965 p = NULL; 966 pg = NULL; 967 968 /* 969 * Every entry of the list should belong 970 * to a single proc or pgrp. 971 */ 972 if (sigio->sio_pgid < 0) { 973 pg = sigio->sio_pgrp; 974 PGRP_LOCK_ASSERT(pg, MA_NOTOWNED); 975 } else /* if (sigio->sio_pgid > 0) */ { 976 p = sigio->sio_proc; 977 PROC_LOCK_ASSERT(p, MA_NOTOWNED); 978 } 979 980 SIGIO_LOCK(); 981 while ((sigio = SLIST_FIRST(sigiolst)) != NULL) { 982 *(sigio->sio_myref) = NULL; 983 if (pg != NULL) { 984 KASSERT(sigio->sio_pgid < 0, 985 ("Proc sigio in pgrp sigio list")); 986 KASSERT(sigio->sio_pgrp == pg, 987 ("Bogus pgrp in sigio list")); 988 PGRP_LOCK(pg); 989 SLIST_REMOVE(&pg->pg_sigiolst, sigio, sigio, 990 sio_pgsigio); 991 PGRP_UNLOCK(pg); 992 } else /* if (p != NULL) */ { 993 KASSERT(sigio->sio_pgid > 0, 994 ("Pgrp sigio in proc sigio list")); 995 KASSERT(sigio->sio_proc == p, 996 ("Bogus proc in sigio list")); 997 PROC_LOCK(p); 998 SLIST_REMOVE(&p->p_sigiolst, sigio, sigio, 999 sio_pgsigio); 1000 PROC_UNLOCK(p); 1001 } 1002 SIGIO_UNLOCK(); 1003 crfree(sigio->sio_ucred); 1004 free(sigio, M_SIGIO); 1005 SIGIO_LOCK(); 1006 } 1007 SIGIO_UNLOCK(); 1008 } 1009 1010 /* 1011 * This is common code for FIOSETOWN ioctl called by fcntl(fd, F_SETOWN, arg). 1012 * 1013 * After permission checking, add a sigio structure to the sigio list for 1014 * the process or process group. 1015 */ 1016 int 1017 fsetown(pid_t pgid, struct sigio **sigiop) 1018 { 1019 struct proc *proc; 1020 struct pgrp *pgrp; 1021 struct sigio *sigio; 1022 int ret; 1023 1024 if (pgid == 0) { 1025 funsetown(sigiop); 1026 return (0); 1027 } 1028 1029 ret = 0; 1030 1031 /* Allocate and fill in the new sigio out of locks. */ 1032 sigio = malloc(sizeof(struct sigio), M_SIGIO, M_WAITOK); 1033 sigio->sio_pgid = pgid; 1034 sigio->sio_ucred = crhold(curthread->td_ucred); 1035 sigio->sio_myref = sigiop; 1036 1037 sx_slock(&proctree_lock); 1038 if (pgid > 0) { 1039 proc = pfind(pgid); 1040 if (proc == NULL) { 1041 ret = ESRCH; 1042 goto fail; 1043 } 1044 1045 /* 1046 * Policy - Don't allow a process to FSETOWN a process 1047 * in another session. 1048 * 1049 * Remove this test to allow maximum flexibility or 1050 * restrict FSETOWN to the current process or process 1051 * group for maximum safety. 1052 */ 1053 PROC_UNLOCK(proc); 1054 if (proc->p_session != curthread->td_proc->p_session) { 1055 ret = EPERM; 1056 goto fail; 1057 } 1058 1059 pgrp = NULL; 1060 } else /* if (pgid < 0) */ { 1061 pgrp = pgfind(-pgid); 1062 if (pgrp == NULL) { 1063 ret = ESRCH; 1064 goto fail; 1065 } 1066 PGRP_UNLOCK(pgrp); 1067 1068 /* 1069 * Policy - Don't allow a process to FSETOWN a process 1070 * in another session. 1071 * 1072 * Remove this test to allow maximum flexibility or 1073 * restrict FSETOWN to the current process or process 1074 * group for maximum safety. 1075 */ 1076 if (pgrp->pg_session != curthread->td_proc->p_session) { 1077 ret = EPERM; 1078 goto fail; 1079 } 1080 1081 proc = NULL; 1082 } 1083 funsetown(sigiop); 1084 if (pgid > 0) { 1085 PROC_LOCK(proc); 1086 /* 1087 * Since funsetownlst() is called without the proctree 1088 * locked, we need to check for P_WEXIT. 1089 * XXX: is ESRCH correct? 1090 */ 1091 if ((proc->p_flag & P_WEXIT) != 0) { 1092 PROC_UNLOCK(proc); 1093 ret = ESRCH; 1094 goto fail; 1095 } 1096 SLIST_INSERT_HEAD(&proc->p_sigiolst, sigio, sio_pgsigio); 1097 sigio->sio_proc = proc; 1098 PROC_UNLOCK(proc); 1099 } else { 1100 PGRP_LOCK(pgrp); 1101 SLIST_INSERT_HEAD(&pgrp->pg_sigiolst, sigio, sio_pgsigio); 1102 sigio->sio_pgrp = pgrp; 1103 PGRP_UNLOCK(pgrp); 1104 } 1105 sx_sunlock(&proctree_lock); 1106 SIGIO_LOCK(); 1107 *sigiop = sigio; 1108 SIGIO_UNLOCK(); 1109 return (0); 1110 1111 fail: 1112 sx_sunlock(&proctree_lock); 1113 crfree(sigio->sio_ucred); 1114 free(sigio, M_SIGIO); 1115 return (ret); 1116 } 1117 1118 /* 1119 * This is common code for FIOGETOWN ioctl called by fcntl(fd, F_GETOWN, arg). 1120 */ 1121 pid_t 1122 fgetown(sigiop) 1123 struct sigio **sigiop; 1124 { 1125 pid_t pgid; 1126 1127 SIGIO_LOCK(); 1128 pgid = (*sigiop != NULL) ? (*sigiop)->sio_pgid : 0; 1129 SIGIO_UNLOCK(); 1130 return (pgid); 1131 } 1132 1133 /* 1134 * Function drops the filedesc lock on return. 1135 */ 1136 static int 1137 closefp(struct filedesc *fdp, int fd, struct file *fp, struct thread *td, 1138 int holdleaders) 1139 { 1140 int error; 1141 1142 FILEDESC_XLOCK_ASSERT(fdp); 1143 1144 if (holdleaders) { 1145 if (td->td_proc->p_fdtol != NULL) { 1146 /* 1147 * Ask fdfree() to sleep to ensure that all relevant 1148 * process leaders can be traversed in closef(). 1149 */ 1150 fdp->fd_holdleaderscount++; 1151 } else { 1152 holdleaders = 0; 1153 } 1154 } 1155 1156 /* 1157 * We now hold the fp reference that used to be owned by the 1158 * descriptor array. We have to unlock the FILEDESC *AFTER* 1159 * knote_fdclose to prevent a race of the fd getting opened, a knote 1160 * added, and deleteing a knote for the new fd. 1161 */ 1162 knote_fdclose(td, fd); 1163 1164 /* 1165 * We need to notify mqueue if the object is of type mqueue. 1166 */ 1167 if (fp->f_type == DTYPE_MQUEUE) 1168 mq_fdclose(td, fd, fp); 1169 FILEDESC_XUNLOCK(fdp); 1170 1171 error = closef(fp, td); 1172 if (holdleaders) { 1173 FILEDESC_XLOCK(fdp); 1174 fdp->fd_holdleaderscount--; 1175 if (fdp->fd_holdleaderscount == 0 && 1176 fdp->fd_holdleaderswakeup != 0) { 1177 fdp->fd_holdleaderswakeup = 0; 1178 wakeup(&fdp->fd_holdleaderscount); 1179 } 1180 FILEDESC_XUNLOCK(fdp); 1181 } 1182 return (error); 1183 } 1184 1185 /* 1186 * Close a file descriptor. 1187 */ 1188 #ifndef _SYS_SYSPROTO_H_ 1189 struct close_args { 1190 int fd; 1191 }; 1192 #endif 1193 /* ARGSUSED */ 1194 int 1195 sys_close(struct thread *td, struct close_args *uap) 1196 { 1197 1198 return (kern_close(td, uap->fd)); 1199 } 1200 1201 int 1202 kern_close(struct thread *td, int fd) 1203 { 1204 struct filedesc *fdp; 1205 struct file *fp; 1206 1207 fdp = td->td_proc->p_fd; 1208 1209 AUDIT_SYSCLOSE(td, fd); 1210 1211 FILEDESC_XLOCK(fdp); 1212 if ((fp = fget_locked(fdp, fd)) == NULL) { 1213 FILEDESC_XUNLOCK(fdp); 1214 return (EBADF); 1215 } 1216 fdfree(fdp, fd); 1217 1218 /* closefp() drops the FILEDESC lock for us. */ 1219 return (closefp(fdp, fd, fp, td, 1)); 1220 } 1221 1222 /* 1223 * Close open file descriptors. 1224 */ 1225 #ifndef _SYS_SYSPROTO_H_ 1226 struct closefrom_args { 1227 int lowfd; 1228 }; 1229 #endif 1230 /* ARGSUSED */ 1231 int 1232 sys_closefrom(struct thread *td, struct closefrom_args *uap) 1233 { 1234 struct filedesc *fdp; 1235 int fd; 1236 1237 fdp = td->td_proc->p_fd; 1238 AUDIT_ARG_FD(uap->lowfd); 1239 1240 /* 1241 * Treat negative starting file descriptor values identical to 1242 * closefrom(0) which closes all files. 1243 */ 1244 if (uap->lowfd < 0) 1245 uap->lowfd = 0; 1246 FILEDESC_SLOCK(fdp); 1247 for (fd = uap->lowfd; fd <= fdp->fd_lastfile; fd++) { 1248 if (fdp->fd_ofiles[fd].fde_file != NULL) { 1249 FILEDESC_SUNLOCK(fdp); 1250 (void)kern_close(td, fd); 1251 FILEDESC_SLOCK(fdp); 1252 } 1253 } 1254 FILEDESC_SUNLOCK(fdp); 1255 return (0); 1256 } 1257 1258 #if defined(COMPAT_43) 1259 /* 1260 * Return status information about a file descriptor. 1261 */ 1262 #ifndef _SYS_SYSPROTO_H_ 1263 struct ofstat_args { 1264 int fd; 1265 struct ostat *sb; 1266 }; 1267 #endif 1268 /* ARGSUSED */ 1269 int 1270 ofstat(struct thread *td, struct ofstat_args *uap) 1271 { 1272 struct ostat oub; 1273 struct stat ub; 1274 int error; 1275 1276 error = kern_fstat(td, uap->fd, &ub); 1277 if (error == 0) { 1278 cvtstat(&ub, &oub); 1279 error = copyout(&oub, uap->sb, sizeof(oub)); 1280 } 1281 return (error); 1282 } 1283 #endif /* COMPAT_43 */ 1284 1285 /* 1286 * Return status information about a file descriptor. 1287 */ 1288 #ifndef _SYS_SYSPROTO_H_ 1289 struct fstat_args { 1290 int fd; 1291 struct stat *sb; 1292 }; 1293 #endif 1294 /* ARGSUSED */ 1295 int 1296 sys_fstat(struct thread *td, struct fstat_args *uap) 1297 { 1298 struct stat ub; 1299 int error; 1300 1301 error = kern_fstat(td, uap->fd, &ub); 1302 if (error == 0) 1303 error = copyout(&ub, uap->sb, sizeof(ub)); 1304 return (error); 1305 } 1306 1307 int 1308 kern_fstat(struct thread *td, int fd, struct stat *sbp) 1309 { 1310 struct file *fp; 1311 cap_rights_t rights; 1312 int error; 1313 1314 AUDIT_ARG_FD(fd); 1315 1316 error = fget(td, fd, cap_rights_init(&rights, CAP_FSTAT), &fp); 1317 if (error != 0) 1318 return (error); 1319 1320 AUDIT_ARG_FILE(td->td_proc, fp); 1321 1322 error = fo_stat(fp, sbp, td->td_ucred, td); 1323 fdrop(fp, td); 1324 #ifdef KTRACE 1325 if (error == 0 && KTRPOINT(td, KTR_STRUCT)) 1326 ktrstat(sbp); 1327 #endif 1328 return (error); 1329 } 1330 1331 /* 1332 * Return status information about a file descriptor. 1333 */ 1334 #ifndef _SYS_SYSPROTO_H_ 1335 struct nfstat_args { 1336 int fd; 1337 struct nstat *sb; 1338 }; 1339 #endif 1340 /* ARGSUSED */ 1341 int 1342 sys_nfstat(struct thread *td, struct nfstat_args *uap) 1343 { 1344 struct nstat nub; 1345 struct stat ub; 1346 int error; 1347 1348 error = kern_fstat(td, uap->fd, &ub); 1349 if (error == 0) { 1350 cvtnstat(&ub, &nub); 1351 error = copyout(&nub, uap->sb, sizeof(nub)); 1352 } 1353 return (error); 1354 } 1355 1356 /* 1357 * Return pathconf information about a file descriptor. 1358 */ 1359 #ifndef _SYS_SYSPROTO_H_ 1360 struct fpathconf_args { 1361 int fd; 1362 int name; 1363 }; 1364 #endif 1365 /* ARGSUSED */ 1366 int 1367 sys_fpathconf(struct thread *td, struct fpathconf_args *uap) 1368 { 1369 struct file *fp; 1370 struct vnode *vp; 1371 cap_rights_t rights; 1372 int error; 1373 1374 error = fget(td, uap->fd, cap_rights_init(&rights, CAP_FPATHCONF), &fp); 1375 if (error != 0) 1376 return (error); 1377 1378 /* If asynchronous I/O is available, it works for all descriptors. */ 1379 if (uap->name == _PC_ASYNC_IO) { 1380 td->td_retval[0] = async_io_version; 1381 goto out; 1382 } 1383 vp = fp->f_vnode; 1384 if (vp != NULL) { 1385 vn_lock(vp, LK_SHARED | LK_RETRY); 1386 error = VOP_PATHCONF(vp, uap->name, td->td_retval); 1387 VOP_UNLOCK(vp, 0); 1388 } else if (fp->f_type == DTYPE_PIPE || fp->f_type == DTYPE_SOCKET) { 1389 if (uap->name != _PC_PIPE_BUF) { 1390 error = EINVAL; 1391 } else { 1392 td->td_retval[0] = PIPE_BUF; 1393 error = 0; 1394 } 1395 } else { 1396 error = EOPNOTSUPP; 1397 } 1398 out: 1399 fdrop(fp, td); 1400 return (error); 1401 } 1402 1403 /* 1404 * Initialize filecaps structure. 1405 */ 1406 void 1407 filecaps_init(struct filecaps *fcaps) 1408 { 1409 1410 bzero(fcaps, sizeof(*fcaps)); 1411 fcaps->fc_nioctls = -1; 1412 } 1413 1414 /* 1415 * Copy filecaps structure allocating memory for ioctls array if needed. 1416 */ 1417 void 1418 filecaps_copy(const struct filecaps *src, struct filecaps *dst) 1419 { 1420 size_t size; 1421 1422 *dst = *src; 1423 if (src->fc_ioctls != NULL) { 1424 KASSERT(src->fc_nioctls > 0, 1425 ("fc_ioctls != NULL, but fc_nioctls=%hd", src->fc_nioctls)); 1426 1427 size = sizeof(src->fc_ioctls[0]) * src->fc_nioctls; 1428 dst->fc_ioctls = malloc(size, M_FILECAPS, M_WAITOK); 1429 bcopy(src->fc_ioctls, dst->fc_ioctls, size); 1430 } 1431 } 1432 1433 /* 1434 * Move filecaps structure to the new place and clear the old place. 1435 */ 1436 void 1437 filecaps_move(struct filecaps *src, struct filecaps *dst) 1438 { 1439 1440 *dst = *src; 1441 bzero(src, sizeof(*src)); 1442 } 1443 1444 /* 1445 * Fill the given filecaps structure with full rights. 1446 */ 1447 static void 1448 filecaps_fill(struct filecaps *fcaps) 1449 { 1450 1451 CAP_ALL(&fcaps->fc_rights); 1452 fcaps->fc_ioctls = NULL; 1453 fcaps->fc_nioctls = -1; 1454 fcaps->fc_fcntls = CAP_FCNTL_ALL; 1455 } 1456 1457 /* 1458 * Free memory allocated within filecaps structure. 1459 */ 1460 void 1461 filecaps_free(struct filecaps *fcaps) 1462 { 1463 1464 free(fcaps->fc_ioctls, M_FILECAPS); 1465 bzero(fcaps, sizeof(*fcaps)); 1466 } 1467 1468 /* 1469 * Validate the given filecaps structure. 1470 */ 1471 static void 1472 filecaps_validate(const struct filecaps *fcaps, const char *func) 1473 { 1474 1475 KASSERT(cap_rights_is_valid(&fcaps->fc_rights), 1476 ("%s: invalid rights", func)); 1477 KASSERT((fcaps->fc_fcntls & ~CAP_FCNTL_ALL) == 0, 1478 ("%s: invalid fcntls", func)); 1479 KASSERT(fcaps->fc_fcntls == 0 || 1480 cap_rights_is_set(&fcaps->fc_rights, CAP_FCNTL), 1481 ("%s: fcntls without CAP_FCNTL", func)); 1482 KASSERT(fcaps->fc_ioctls != NULL ? fcaps->fc_nioctls > 0 : 1483 (fcaps->fc_nioctls == -1 || fcaps->fc_nioctls == 0), 1484 ("%s: invalid ioctls", func)); 1485 KASSERT(fcaps->fc_nioctls == 0 || 1486 cap_rights_is_set(&fcaps->fc_rights, CAP_IOCTL), 1487 ("%s: ioctls without CAP_IOCTL", func)); 1488 } 1489 1490 static void 1491 fdgrowtable_exp(struct filedesc *fdp, int nfd) 1492 { 1493 int nfd1; 1494 1495 FILEDESC_XLOCK_ASSERT(fdp); 1496 1497 nfd1 = fdp->fd_nfiles * 2; 1498 if (nfd1 < nfd) 1499 nfd1 = nfd; 1500 fdgrowtable(fdp, nfd1); 1501 } 1502 1503 /* 1504 * Grow the file table to accomodate (at least) nfd descriptors. 1505 */ 1506 static void 1507 fdgrowtable(struct filedesc *fdp, int nfd) 1508 { 1509 struct filedesc0 *fdp0; 1510 struct freetable *ft; 1511 struct fdescenttbl *ntable; 1512 struct fdescenttbl *otable; 1513 int nnfiles, onfiles; 1514 NDSLOTTYPE *nmap, *omap; 1515 1516 /* 1517 * If lastfile is -1 this struct filedesc was just allocated and we are 1518 * growing it to accomodate for the one we are going to copy from. There 1519 * is no need to have a lock on this one as it's not visible to anyone. 1520 */ 1521 if (fdp->fd_lastfile != -1) 1522 FILEDESC_XLOCK_ASSERT(fdp); 1523 1524 KASSERT(fdp->fd_nfiles > 0, ("zero-length file table")); 1525 1526 /* save old values */ 1527 onfiles = fdp->fd_nfiles; 1528 otable = fdp->fd_files; 1529 omap = fdp->fd_map; 1530 1531 /* compute the size of the new table */ 1532 nnfiles = NDSLOTS(nfd) * NDENTRIES; /* round up */ 1533 if (nnfiles <= onfiles) 1534 /* the table is already large enough */ 1535 return; 1536 1537 /* 1538 * Allocate a new table. We need enough space for the number of 1539 * entries, file entries themselves and the struct freetable we will use 1540 * when we decommission the table and place it on the freelist. 1541 * We place the struct freetable in the middle so we don't have 1542 * to worry about padding. 1543 */ 1544 ntable = malloc(offsetof(struct fdescenttbl, fdt_ofiles) + 1545 nnfiles * sizeof(ntable->fdt_ofiles[0]) + 1546 sizeof(struct freetable), 1547 M_FILEDESC, M_ZERO | M_WAITOK); 1548 /* copy the old data */ 1549 ntable->fdt_nfiles = nnfiles; 1550 memcpy(ntable->fdt_ofiles, otable->fdt_ofiles, 1551 onfiles * sizeof(ntable->fdt_ofiles[0])); 1552 1553 /* 1554 * Allocate a new map only if the old is not large enough. It will 1555 * grow at a slower rate than the table as it can map more 1556 * entries than the table can hold. 1557 */ 1558 if (NDSLOTS(nnfiles) > NDSLOTS(onfiles)) { 1559 nmap = malloc(NDSLOTS(nnfiles) * NDSLOTSIZE, M_FILEDESC, 1560 M_ZERO | M_WAITOK); 1561 /* copy over the old data and update the pointer */ 1562 memcpy(nmap, omap, NDSLOTS(onfiles) * sizeof(*omap)); 1563 fdp->fd_map = nmap; 1564 } 1565 1566 /* 1567 * Make sure that ntable is correctly initialized before we replace 1568 * fd_files poiner. Otherwise fget_unlocked() may see inconsistent 1569 * data. 1570 */ 1571 atomic_store_rel_ptr((volatile void *)&fdp->fd_files, (uintptr_t)ntable); 1572 1573 /* 1574 * Do not free the old file table, as some threads may still 1575 * reference entries within it. Instead, place it on a freelist 1576 * which will be processed when the struct filedesc is released. 1577 * 1578 * Note that if onfiles == NDFILE, we're dealing with the original 1579 * static allocation contained within (struct filedesc0 *)fdp, 1580 * which must not be freed. 1581 */ 1582 if (onfiles > NDFILE) { 1583 ft = (struct freetable *)&otable->fdt_ofiles[onfiles]; 1584 fdp0 = (struct filedesc0 *)fdp; 1585 ft->ft_table = otable; 1586 SLIST_INSERT_HEAD(&fdp0->fd_free, ft, ft_next); 1587 } 1588 /* 1589 * The map does not have the same possibility of threads still 1590 * holding references to it. So always free it as long as it 1591 * does not reference the original static allocation. 1592 */ 1593 if (NDSLOTS(onfiles) > NDSLOTS(NDFILE)) 1594 free(omap, M_FILEDESC); 1595 } 1596 1597 /* 1598 * Allocate a file descriptor for the process. 1599 */ 1600 int 1601 fdalloc(struct thread *td, int minfd, int *result) 1602 { 1603 struct proc *p = td->td_proc; 1604 struct filedesc *fdp = p->p_fd; 1605 int fd, maxfd, allocfd; 1606 #ifdef RACCT 1607 int error; 1608 #endif 1609 1610 FILEDESC_XLOCK_ASSERT(fdp); 1611 1612 if (fdp->fd_freefile > minfd) 1613 minfd = fdp->fd_freefile; 1614 1615 maxfd = getmaxfd(td); 1616 1617 /* 1618 * Search the bitmap for a free descriptor starting at minfd. 1619 * If none is found, grow the file table. 1620 */ 1621 fd = fd_first_free(fdp, minfd, fdp->fd_nfiles); 1622 if (fd >= maxfd) 1623 return (EMFILE); 1624 if (fd >= fdp->fd_nfiles) { 1625 allocfd = min(fd * 2, maxfd); 1626 #ifdef RACCT 1627 if (racct_enable) { 1628 PROC_LOCK(p); 1629 error = racct_set(p, RACCT_NOFILE, allocfd); 1630 PROC_UNLOCK(p); 1631 if (error != 0) 1632 return (EMFILE); 1633 } 1634 #endif 1635 /* 1636 * fd is already equal to first free descriptor >= minfd, so 1637 * we only need to grow the table and we are done. 1638 */ 1639 fdgrowtable_exp(fdp, allocfd); 1640 } 1641 1642 /* 1643 * Perform some sanity checks, then mark the file descriptor as 1644 * used and return it to the caller. 1645 */ 1646 KASSERT(fd >= 0 && fd < min(maxfd, fdp->fd_nfiles), 1647 ("invalid descriptor %d", fd)); 1648 KASSERT(!fdisused(fdp, fd), 1649 ("fd_first_free() returned non-free descriptor")); 1650 KASSERT(fdp->fd_ofiles[fd].fde_file == NULL, 1651 ("file descriptor isn't free")); 1652 fdused(fdp, fd); 1653 *result = fd; 1654 return (0); 1655 } 1656 1657 /* 1658 * Allocate n file descriptors for the process. 1659 */ 1660 int 1661 fdallocn(struct thread *td, int minfd, int *fds, int n) 1662 { 1663 struct proc *p = td->td_proc; 1664 struct filedesc *fdp = p->p_fd; 1665 int i; 1666 1667 FILEDESC_XLOCK_ASSERT(fdp); 1668 1669 for (i = 0; i < n; i++) 1670 if (fdalloc(td, 0, &fds[i]) != 0) 1671 break; 1672 1673 if (i < n) { 1674 for (i--; i >= 0; i--) 1675 fdunused(fdp, fds[i]); 1676 return (EMFILE); 1677 } 1678 1679 return (0); 1680 } 1681 1682 /* 1683 * Create a new open file structure and allocate a file decriptor for the 1684 * process that refers to it. We add one reference to the file for the 1685 * descriptor table and one reference for resultfp. This is to prevent us 1686 * being preempted and the entry in the descriptor table closed after we 1687 * release the FILEDESC lock. 1688 */ 1689 int 1690 falloc(struct thread *td, struct file **resultfp, int *resultfd, int flags) 1691 { 1692 struct file *fp; 1693 int error, fd; 1694 1695 error = falloc_noinstall(td, &fp); 1696 if (error) 1697 return (error); /* no reference held on error */ 1698 1699 error = finstall(td, fp, &fd, flags, NULL); 1700 if (error) { 1701 fdrop(fp, td); /* one reference (fp only) */ 1702 return (error); 1703 } 1704 1705 if (resultfp != NULL) 1706 *resultfp = fp; /* copy out result */ 1707 else 1708 fdrop(fp, td); /* release local reference */ 1709 1710 if (resultfd != NULL) 1711 *resultfd = fd; 1712 1713 return (0); 1714 } 1715 1716 /* 1717 * Create a new open file structure without allocating a file descriptor. 1718 */ 1719 int 1720 falloc_noinstall(struct thread *td, struct file **resultfp) 1721 { 1722 struct file *fp; 1723 int maxuserfiles = maxfiles - (maxfiles / 20); 1724 static struct timeval lastfail; 1725 static int curfail; 1726 1727 KASSERT(resultfp != NULL, ("%s: resultfp == NULL", __func__)); 1728 1729 if ((openfiles >= maxuserfiles && 1730 priv_check(td, PRIV_MAXFILES) != 0) || 1731 openfiles >= maxfiles) { 1732 if (ppsratecheck(&lastfail, &curfail, 1)) { 1733 printf("kern.maxfiles limit exceeded by uid %i, " 1734 "please see tuning(7).\n", td->td_ucred->cr_ruid); 1735 } 1736 return (ENFILE); 1737 } 1738 atomic_add_int(&openfiles, 1); 1739 fp = uma_zalloc(file_zone, M_WAITOK | M_ZERO); 1740 refcount_init(&fp->f_count, 1); 1741 fp->f_cred = crhold(td->td_ucred); 1742 fp->f_ops = &badfileops; 1743 *resultfp = fp; 1744 return (0); 1745 } 1746 1747 /* 1748 * Install a file in a file descriptor table. 1749 */ 1750 void 1751 _finstall(struct filedesc *fdp, struct file *fp, int fd, int flags, 1752 struct filecaps *fcaps) 1753 { 1754 struct filedescent *fde; 1755 1756 MPASS(fp != NULL); 1757 if (fcaps != NULL) 1758 filecaps_validate(fcaps, __func__); 1759 FILEDESC_XLOCK_ASSERT(fdp); 1760 1761 fde = &fdp->fd_ofiles[fd]; 1762 #ifdef CAPABILITIES 1763 seq_write_begin(&fde->fde_seq); 1764 #endif 1765 fde->fde_file = fp; 1766 fde->fde_flags = (flags & O_CLOEXEC) != 0 ? UF_EXCLOSE : 0; 1767 if (fcaps != NULL) 1768 filecaps_move(fcaps, &fde->fde_caps); 1769 else 1770 filecaps_fill(&fde->fde_caps); 1771 #ifdef CAPABILITIES 1772 seq_write_end(&fde->fde_seq); 1773 #endif 1774 } 1775 1776 int 1777 finstall(struct thread *td, struct file *fp, int *fd, int flags, 1778 struct filecaps *fcaps) 1779 { 1780 struct filedesc *fdp = td->td_proc->p_fd; 1781 int error; 1782 1783 MPASS(fd != NULL); 1784 1785 FILEDESC_XLOCK(fdp); 1786 if ((error = fdalloc(td, 0, fd))) { 1787 FILEDESC_XUNLOCK(fdp); 1788 return (error); 1789 } 1790 fhold(fp); 1791 _finstall(fdp, fp, *fd, flags, fcaps); 1792 FILEDESC_XUNLOCK(fdp); 1793 return (0); 1794 } 1795 1796 /* 1797 * Build a new filedesc structure from another. 1798 * Copy the current, root, and jail root vnode references. 1799 * 1800 * If fdp is not NULL, return with it shared locked. 1801 */ 1802 struct filedesc * 1803 fdinit(struct filedesc *fdp, bool prepfiles) 1804 { 1805 struct filedesc0 *newfdp0; 1806 struct filedesc *newfdp; 1807 1808 newfdp0 = uma_zalloc(filedesc0_zone, M_WAITOK | M_ZERO); 1809 newfdp = &newfdp0->fd_fd; 1810 1811 /* Create the file descriptor table. */ 1812 FILEDESC_LOCK_INIT(newfdp); 1813 refcount_init(&newfdp->fd_refcnt, 1); 1814 refcount_init(&newfdp->fd_holdcnt, 1); 1815 newfdp->fd_cmask = CMASK; 1816 newfdp->fd_map = newfdp0->fd_dmap; 1817 newfdp->fd_lastfile = -1; 1818 newfdp->fd_files = (struct fdescenttbl *)&newfdp0->fd_dfiles; 1819 newfdp->fd_files->fdt_nfiles = NDFILE; 1820 1821 if (fdp == NULL) 1822 return (newfdp); 1823 1824 if (prepfiles && fdp->fd_lastfile >= newfdp->fd_nfiles) 1825 fdgrowtable(newfdp, fdp->fd_lastfile + 1); 1826 1827 FILEDESC_SLOCK(fdp); 1828 newfdp->fd_cdir = fdp->fd_cdir; 1829 if (newfdp->fd_cdir) 1830 VREF(newfdp->fd_cdir); 1831 newfdp->fd_rdir = fdp->fd_rdir; 1832 if (newfdp->fd_rdir) 1833 VREF(newfdp->fd_rdir); 1834 newfdp->fd_jdir = fdp->fd_jdir; 1835 if (newfdp->fd_jdir) 1836 VREF(newfdp->fd_jdir); 1837 1838 if (!prepfiles) { 1839 FILEDESC_SUNLOCK(fdp); 1840 } else { 1841 while (fdp->fd_lastfile >= newfdp->fd_nfiles) { 1842 FILEDESC_SUNLOCK(fdp); 1843 fdgrowtable(newfdp, fdp->fd_lastfile + 1); 1844 FILEDESC_SLOCK(fdp); 1845 } 1846 } 1847 1848 return (newfdp); 1849 } 1850 1851 static struct filedesc * 1852 fdhold(struct proc *p) 1853 { 1854 struct filedesc *fdp; 1855 1856 PROC_LOCK_ASSERT(p, MA_OWNED); 1857 fdp = p->p_fd; 1858 if (fdp != NULL) 1859 refcount_acquire(&fdp->fd_holdcnt); 1860 return (fdp); 1861 } 1862 1863 static void 1864 fddrop(struct filedesc *fdp) 1865 { 1866 1867 if (fdp->fd_holdcnt > 1) { 1868 if (refcount_release(&fdp->fd_holdcnt) == 0) 1869 return; 1870 } 1871 1872 FILEDESC_LOCK_DESTROY(fdp); 1873 uma_zfree(filedesc0_zone, fdp); 1874 } 1875 1876 /* 1877 * Share a filedesc structure. 1878 */ 1879 struct filedesc * 1880 fdshare(struct filedesc *fdp) 1881 { 1882 1883 refcount_acquire(&fdp->fd_refcnt); 1884 return (fdp); 1885 } 1886 1887 /* 1888 * Unshare a filedesc structure, if necessary by making a copy 1889 */ 1890 void 1891 fdunshare(struct thread *td) 1892 { 1893 struct filedesc *tmp; 1894 struct proc *p = td->td_proc; 1895 1896 if (p->p_fd->fd_refcnt == 1) 1897 return; 1898 1899 tmp = fdcopy(p->p_fd); 1900 fdescfree(td); 1901 p->p_fd = tmp; 1902 } 1903 1904 /* 1905 * Copy a filedesc structure. A NULL pointer in returns a NULL reference, 1906 * this is to ease callers, not catch errors. 1907 */ 1908 struct filedesc * 1909 fdcopy(struct filedesc *fdp) 1910 { 1911 struct filedesc *newfdp; 1912 struct filedescent *nfde, *ofde; 1913 int i; 1914 1915 MPASS(fdp != NULL); 1916 1917 newfdp = fdinit(fdp, true); 1918 /* copy all passable descriptors (i.e. not kqueue) */ 1919 newfdp->fd_freefile = -1; 1920 for (i = 0; i <= fdp->fd_lastfile; ++i) { 1921 ofde = &fdp->fd_ofiles[i]; 1922 if (ofde->fde_file == NULL || 1923 (ofde->fde_file->f_ops->fo_flags & DFLAG_PASSABLE) == 0) { 1924 if (newfdp->fd_freefile == -1) 1925 newfdp->fd_freefile = i; 1926 continue; 1927 } 1928 nfde = &newfdp->fd_ofiles[i]; 1929 *nfde = *ofde; 1930 filecaps_copy(&ofde->fde_caps, &nfde->fde_caps); 1931 fhold(nfde->fde_file); 1932 fdused_init(newfdp, i); 1933 newfdp->fd_lastfile = i; 1934 } 1935 if (newfdp->fd_freefile == -1) 1936 newfdp->fd_freefile = i; 1937 newfdp->fd_cmask = fdp->fd_cmask; 1938 FILEDESC_SUNLOCK(fdp); 1939 return (newfdp); 1940 } 1941 1942 /* 1943 * Clear POSIX style locks. This is only used when fdp looses a reference (i.e. 1944 * one of processes using it exits) and the table used to be shared. 1945 */ 1946 static void 1947 fdclearlocks(struct thread *td) 1948 { 1949 struct filedesc *fdp; 1950 struct filedesc_to_leader *fdtol; 1951 struct flock lf; 1952 struct file *fp; 1953 struct proc *p; 1954 struct vnode *vp; 1955 int i; 1956 1957 p = td->td_proc; 1958 fdp = p->p_fd; 1959 fdtol = p->p_fdtol; 1960 MPASS(fdtol != NULL); 1961 1962 FILEDESC_XLOCK(fdp); 1963 KASSERT(fdtol->fdl_refcount > 0, 1964 ("filedesc_to_refcount botch: fdl_refcount=%d", 1965 fdtol->fdl_refcount)); 1966 if (fdtol->fdl_refcount == 1 && 1967 (p->p_leader->p_flag & P_ADVLOCK) != 0) { 1968 for (i = 0; i <= fdp->fd_lastfile; i++) { 1969 fp = fdp->fd_ofiles[i].fde_file; 1970 if (fp == NULL || fp->f_type != DTYPE_VNODE) 1971 continue; 1972 fhold(fp); 1973 FILEDESC_XUNLOCK(fdp); 1974 lf.l_whence = SEEK_SET; 1975 lf.l_start = 0; 1976 lf.l_len = 0; 1977 lf.l_type = F_UNLCK; 1978 vp = fp->f_vnode; 1979 (void) VOP_ADVLOCK(vp, 1980 (caddr_t)p->p_leader, F_UNLCK, 1981 &lf, F_POSIX); 1982 FILEDESC_XLOCK(fdp); 1983 fdrop(fp, td); 1984 } 1985 } 1986 retry: 1987 if (fdtol->fdl_refcount == 1) { 1988 if (fdp->fd_holdleaderscount > 0 && 1989 (p->p_leader->p_flag & P_ADVLOCK) != 0) { 1990 /* 1991 * close() or do_dup() has cleared a reference 1992 * in a shared file descriptor table. 1993 */ 1994 fdp->fd_holdleaderswakeup = 1; 1995 sx_sleep(&fdp->fd_holdleaderscount, 1996 FILEDESC_LOCK(fdp), PLOCK, "fdlhold", 0); 1997 goto retry; 1998 } 1999 if (fdtol->fdl_holdcount > 0) { 2000 /* 2001 * Ensure that fdtol->fdl_leader remains 2002 * valid in closef(). 2003 */ 2004 fdtol->fdl_wakeup = 1; 2005 sx_sleep(fdtol, FILEDESC_LOCK(fdp), PLOCK, 2006 "fdlhold", 0); 2007 goto retry; 2008 } 2009 } 2010 fdtol->fdl_refcount--; 2011 if (fdtol->fdl_refcount == 0 && 2012 fdtol->fdl_holdcount == 0) { 2013 fdtol->fdl_next->fdl_prev = fdtol->fdl_prev; 2014 fdtol->fdl_prev->fdl_next = fdtol->fdl_next; 2015 } else 2016 fdtol = NULL; 2017 p->p_fdtol = NULL; 2018 FILEDESC_XUNLOCK(fdp); 2019 if (fdtol != NULL) 2020 free(fdtol, M_FILEDESC_TO_LEADER); 2021 } 2022 2023 /* 2024 * Release a filedesc structure. 2025 */ 2026 void 2027 fdescfree(struct thread *td) 2028 { 2029 struct proc *p; 2030 struct filedesc0 *fdp0; 2031 struct filedesc *fdp; 2032 struct freetable *ft, *tft; 2033 struct filedescent *fde; 2034 struct file *fp; 2035 struct vnode *cdir, *jdir, *rdir; 2036 int i; 2037 2038 p = td->td_proc; 2039 fdp = p->p_fd; 2040 MPASS(fdp != NULL); 2041 2042 #ifdef RACCT 2043 if (racct_enable) { 2044 PROC_LOCK(p); 2045 racct_set(p, RACCT_NOFILE, 0); 2046 PROC_UNLOCK(p); 2047 } 2048 #endif 2049 2050 if (td->td_proc->p_fdtol != NULL) 2051 fdclearlocks(td); 2052 2053 PROC_LOCK(p); 2054 p->p_fd = NULL; 2055 PROC_UNLOCK(p); 2056 2057 if (refcount_release(&fdp->fd_refcnt) == 0) 2058 return; 2059 2060 FILEDESC_XLOCK(fdp); 2061 cdir = fdp->fd_cdir; 2062 fdp->fd_cdir = NULL; 2063 rdir = fdp->fd_rdir; 2064 fdp->fd_rdir = NULL; 2065 jdir = fdp->fd_jdir; 2066 fdp->fd_jdir = NULL; 2067 FILEDESC_XUNLOCK(fdp); 2068 2069 for (i = 0; i <= fdp->fd_lastfile; i++) { 2070 fde = &fdp->fd_ofiles[i]; 2071 fp = fde->fde_file; 2072 if (fp != NULL) { 2073 fdefree_last(fde); 2074 (void) closef(fp, td); 2075 } 2076 } 2077 2078 if (NDSLOTS(fdp->fd_nfiles) > NDSLOTS(NDFILE)) 2079 free(fdp->fd_map, M_FILEDESC); 2080 if (fdp->fd_nfiles > NDFILE) 2081 free(fdp->fd_files, M_FILEDESC); 2082 2083 fdp0 = (struct filedesc0 *)fdp; 2084 SLIST_FOREACH_SAFE(ft, &fdp0->fd_free, ft_next, tft) 2085 free(ft->ft_table, M_FILEDESC); 2086 2087 if (cdir != NULL) 2088 vrele(cdir); 2089 if (rdir != NULL) 2090 vrele(rdir); 2091 if (jdir != NULL) 2092 vrele(jdir); 2093 2094 fddrop(fdp); 2095 } 2096 2097 /* 2098 * For setugid programs, we don't want to people to use that setugidness 2099 * to generate error messages which write to a file which otherwise would 2100 * otherwise be off-limits to the process. We check for filesystems where 2101 * the vnode can change out from under us after execve (like [lin]procfs). 2102 * 2103 * Since fdsetugidsafety calls this only for fd 0, 1 and 2, this check is 2104 * sufficient. We also don't check for setugidness since we know we are. 2105 */ 2106 static bool 2107 is_unsafe(struct file *fp) 2108 { 2109 struct vnode *vp; 2110 2111 if (fp->f_type != DTYPE_VNODE) 2112 return (false); 2113 2114 vp = fp->f_vnode; 2115 return ((vp->v_vflag & VV_PROCDEP) != 0); 2116 } 2117 2118 /* 2119 * Make this setguid thing safe, if at all possible. 2120 */ 2121 void 2122 fdsetugidsafety(struct thread *td) 2123 { 2124 struct filedesc *fdp; 2125 struct file *fp; 2126 int i; 2127 2128 fdp = td->td_proc->p_fd; 2129 KASSERT(fdp->fd_refcnt == 1, ("the fdtable should not be shared")); 2130 MPASS(fdp->fd_nfiles >= 3); 2131 for (i = 0; i <= 2; i++) { 2132 fp = fdp->fd_ofiles[i].fde_file; 2133 if (fp != NULL && is_unsafe(fp)) { 2134 FILEDESC_XLOCK(fdp); 2135 knote_fdclose(td, i); 2136 /* 2137 * NULL-out descriptor prior to close to avoid 2138 * a race while close blocks. 2139 */ 2140 fdfree(fdp, i); 2141 FILEDESC_XUNLOCK(fdp); 2142 (void) closef(fp, td); 2143 } 2144 } 2145 } 2146 2147 /* 2148 * If a specific file object occupies a specific file descriptor, close the 2149 * file descriptor entry and drop a reference on the file object. This is a 2150 * convenience function to handle a subsequent error in a function that calls 2151 * falloc() that handles the race that another thread might have closed the 2152 * file descriptor out from under the thread creating the file object. 2153 */ 2154 void 2155 fdclose(struct thread *td, struct file *fp, int idx) 2156 { 2157 struct filedesc *fdp = td->td_proc->p_fd; 2158 2159 FILEDESC_XLOCK(fdp); 2160 if (fdp->fd_ofiles[idx].fde_file == fp) { 2161 fdfree(fdp, idx); 2162 FILEDESC_XUNLOCK(fdp); 2163 fdrop(fp, td); 2164 } else 2165 FILEDESC_XUNLOCK(fdp); 2166 } 2167 2168 /* 2169 * Close any files on exec? 2170 */ 2171 void 2172 fdcloseexec(struct thread *td) 2173 { 2174 struct filedesc *fdp; 2175 struct filedescent *fde; 2176 struct file *fp; 2177 int i; 2178 2179 fdp = td->td_proc->p_fd; 2180 KASSERT(fdp->fd_refcnt == 1, ("the fdtable should not be shared")); 2181 for (i = 0; i <= fdp->fd_lastfile; i++) { 2182 fde = &fdp->fd_ofiles[i]; 2183 fp = fde->fde_file; 2184 if (fp != NULL && (fp->f_type == DTYPE_MQUEUE || 2185 (fde->fde_flags & UF_EXCLOSE))) { 2186 FILEDESC_XLOCK(fdp); 2187 fdfree(fdp, i); 2188 (void) closefp(fdp, i, fp, td, 0); 2189 /* closefp() drops the FILEDESC lock. */ 2190 } 2191 } 2192 } 2193 2194 /* 2195 * It is unsafe for set[ug]id processes to be started with file 2196 * descriptors 0..2 closed, as these descriptors are given implicit 2197 * significance in the Standard C library. fdcheckstd() will create a 2198 * descriptor referencing /dev/null for each of stdin, stdout, and 2199 * stderr that is not already open. 2200 */ 2201 int 2202 fdcheckstd(struct thread *td) 2203 { 2204 struct filedesc *fdp; 2205 register_t save; 2206 int i, error, devnull; 2207 2208 fdp = td->td_proc->p_fd; 2209 KASSERT(fdp->fd_refcnt == 1, ("the fdtable should not be shared")); 2210 MPASS(fdp->fd_nfiles >= 3); 2211 devnull = -1; 2212 for (i = 0; i <= 2; i++) { 2213 if (fdp->fd_ofiles[i].fde_file != NULL) 2214 continue; 2215 2216 save = td->td_retval[0]; 2217 if (devnull != -1) { 2218 error = do_dup(td, DUP_FIXED, devnull, i); 2219 } else { 2220 error = kern_openat(td, AT_FDCWD, "/dev/null", 2221 UIO_SYSSPACE, O_RDWR, 0); 2222 if (error == 0) { 2223 devnull = td->td_retval[0]; 2224 KASSERT(devnull == i, ("we didn't get our fd")); 2225 } 2226 } 2227 td->td_retval[0] = save; 2228 if (error != 0) 2229 return (error); 2230 } 2231 return (0); 2232 } 2233 2234 /* 2235 * Internal form of close. Decrement reference count on file structure. 2236 * Note: td may be NULL when closing a file that was being passed in a 2237 * message. 2238 * 2239 * XXXRW: Giant is not required for the caller, but often will be held; this 2240 * makes it moderately likely the Giant will be recursed in the VFS case. 2241 */ 2242 int 2243 closef(struct file *fp, struct thread *td) 2244 { 2245 struct vnode *vp; 2246 struct flock lf; 2247 struct filedesc_to_leader *fdtol; 2248 struct filedesc *fdp; 2249 2250 /* 2251 * POSIX record locking dictates that any close releases ALL 2252 * locks owned by this process. This is handled by setting 2253 * a flag in the unlock to free ONLY locks obeying POSIX 2254 * semantics, and not to free BSD-style file locks. 2255 * If the descriptor was in a message, POSIX-style locks 2256 * aren't passed with the descriptor, and the thread pointer 2257 * will be NULL. Callers should be careful only to pass a 2258 * NULL thread pointer when there really is no owning 2259 * context that might have locks, or the locks will be 2260 * leaked. 2261 */ 2262 if (fp->f_type == DTYPE_VNODE && td != NULL) { 2263 vp = fp->f_vnode; 2264 if ((td->td_proc->p_leader->p_flag & P_ADVLOCK) != 0) { 2265 lf.l_whence = SEEK_SET; 2266 lf.l_start = 0; 2267 lf.l_len = 0; 2268 lf.l_type = F_UNLCK; 2269 (void) VOP_ADVLOCK(vp, (caddr_t)td->td_proc->p_leader, 2270 F_UNLCK, &lf, F_POSIX); 2271 } 2272 fdtol = td->td_proc->p_fdtol; 2273 if (fdtol != NULL) { 2274 /* 2275 * Handle special case where file descriptor table is 2276 * shared between multiple process leaders. 2277 */ 2278 fdp = td->td_proc->p_fd; 2279 FILEDESC_XLOCK(fdp); 2280 for (fdtol = fdtol->fdl_next; 2281 fdtol != td->td_proc->p_fdtol; 2282 fdtol = fdtol->fdl_next) { 2283 if ((fdtol->fdl_leader->p_flag & 2284 P_ADVLOCK) == 0) 2285 continue; 2286 fdtol->fdl_holdcount++; 2287 FILEDESC_XUNLOCK(fdp); 2288 lf.l_whence = SEEK_SET; 2289 lf.l_start = 0; 2290 lf.l_len = 0; 2291 lf.l_type = F_UNLCK; 2292 vp = fp->f_vnode; 2293 (void) VOP_ADVLOCK(vp, 2294 (caddr_t)fdtol->fdl_leader, F_UNLCK, &lf, 2295 F_POSIX); 2296 FILEDESC_XLOCK(fdp); 2297 fdtol->fdl_holdcount--; 2298 if (fdtol->fdl_holdcount == 0 && 2299 fdtol->fdl_wakeup != 0) { 2300 fdtol->fdl_wakeup = 0; 2301 wakeup(fdtol); 2302 } 2303 } 2304 FILEDESC_XUNLOCK(fdp); 2305 } 2306 } 2307 return (fdrop(fp, td)); 2308 } 2309 2310 /* 2311 * Initialize the file pointer with the specified properties. 2312 * 2313 * The ops are set with release semantics to be certain that the flags, type, 2314 * and data are visible when ops is. This is to prevent ops methods from being 2315 * called with bad data. 2316 */ 2317 void 2318 finit(struct file *fp, u_int flag, short type, void *data, struct fileops *ops) 2319 { 2320 fp->f_data = data; 2321 fp->f_flag = flag; 2322 fp->f_type = type; 2323 atomic_store_rel_ptr((volatile uintptr_t *)&fp->f_ops, (uintptr_t)ops); 2324 } 2325 2326 int 2327 fget_unlocked(struct filedesc *fdp, int fd, cap_rights_t *needrightsp, 2328 struct file **fpp, seq_t *seqp) 2329 { 2330 #ifdef CAPABILITIES 2331 struct filedescent *fde; 2332 #endif 2333 struct fdescenttbl *fdt; 2334 struct file *fp; 2335 u_int count; 2336 #ifdef CAPABILITIES 2337 seq_t seq; 2338 cap_rights_t haverights; 2339 int error; 2340 #endif 2341 2342 fdt = fdp->fd_files; 2343 if ((u_int)fd >= fdt->fdt_nfiles) 2344 return (EBADF); 2345 /* 2346 * Fetch the descriptor locklessly. We avoid fdrop() races by 2347 * never raising a refcount above 0. To accomplish this we have 2348 * to use a cmpset loop rather than an atomic_add. The descriptor 2349 * must be re-verified once we acquire a reference to be certain 2350 * that the identity is still correct and we did not lose a race 2351 * due to preemption. 2352 */ 2353 for (;;) { 2354 #ifdef CAPABILITIES 2355 seq = seq_read(fd_seq(fdt, fd)); 2356 fde = &fdt->fdt_ofiles[fd]; 2357 haverights = *cap_rights_fde(fde); 2358 fp = fde->fde_file; 2359 if (!seq_consistent(fd_seq(fdt, fd), seq)) { 2360 cpu_spinwait(); 2361 continue; 2362 } 2363 #else 2364 fp = fdt->fdt_ofiles[fd].fde_file; 2365 #endif 2366 if (fp == NULL) 2367 return (EBADF); 2368 #ifdef CAPABILITIES 2369 error = cap_check(&haverights, needrightsp); 2370 if (error != 0) 2371 return (error); 2372 #endif 2373 retry: 2374 count = fp->f_count; 2375 if (count == 0) { 2376 /* 2377 * Force a reload. Other thread could reallocate the 2378 * table before this fd was closed, so it possible that 2379 * there is a stale fp pointer in cached version. 2380 */ 2381 fdt = *(struct fdescenttbl * volatile *)&(fdp->fd_files); 2382 continue; 2383 } 2384 /* 2385 * Use an acquire barrier to force re-reading of fdt so it is 2386 * refreshed for verification. 2387 */ 2388 if (atomic_cmpset_acq_int(&fp->f_count, count, count + 1) == 0) 2389 goto retry; 2390 fdt = fdp->fd_files; 2391 #ifdef CAPABILITIES 2392 if (seq_consistent_nomb(fd_seq(fdt, fd), seq)) 2393 #else 2394 if (fp == fdt->fdt_ofiles[fd].fde_file) 2395 #endif 2396 break; 2397 fdrop(fp, curthread); 2398 } 2399 *fpp = fp; 2400 if (seqp != NULL) { 2401 #ifdef CAPABILITIES 2402 *seqp = seq; 2403 #endif 2404 } 2405 return (0); 2406 } 2407 2408 /* 2409 * Extract the file pointer associated with the specified descriptor for the 2410 * current user process. 2411 * 2412 * If the descriptor doesn't exist or doesn't match 'flags', EBADF is 2413 * returned. 2414 * 2415 * File's rights will be checked against the capability rights mask. 2416 * 2417 * If an error occured the non-zero error is returned and *fpp is set to 2418 * NULL. Otherwise *fpp is held and set and zero is returned. Caller is 2419 * responsible for fdrop(). 2420 */ 2421 static __inline int 2422 _fget(struct thread *td, int fd, struct file **fpp, int flags, 2423 cap_rights_t *needrightsp, seq_t *seqp) 2424 { 2425 struct filedesc *fdp; 2426 struct file *fp; 2427 int error; 2428 2429 *fpp = NULL; 2430 fdp = td->td_proc->p_fd; 2431 error = fget_unlocked(fdp, fd, needrightsp, &fp, seqp); 2432 if (error != 0) 2433 return (error); 2434 if (fp->f_ops == &badfileops) { 2435 fdrop(fp, td); 2436 return (EBADF); 2437 } 2438 2439 /* 2440 * FREAD and FWRITE failure return EBADF as per POSIX. 2441 */ 2442 error = 0; 2443 switch (flags) { 2444 case FREAD: 2445 case FWRITE: 2446 if ((fp->f_flag & flags) == 0) 2447 error = EBADF; 2448 break; 2449 case FEXEC: 2450 if ((fp->f_flag & (FREAD | FEXEC)) == 0 || 2451 ((fp->f_flag & FWRITE) != 0)) 2452 error = EBADF; 2453 break; 2454 case 0: 2455 break; 2456 default: 2457 KASSERT(0, ("wrong flags")); 2458 } 2459 2460 if (error != 0) { 2461 fdrop(fp, td); 2462 return (error); 2463 } 2464 2465 *fpp = fp; 2466 return (0); 2467 } 2468 2469 int 2470 fget(struct thread *td, int fd, cap_rights_t *rightsp, struct file **fpp) 2471 { 2472 2473 return (_fget(td, fd, fpp, 0, rightsp, NULL)); 2474 } 2475 2476 int 2477 fget_mmap(struct thread *td, int fd, cap_rights_t *rightsp, u_char *maxprotp, 2478 struct file **fpp) 2479 { 2480 int error; 2481 #ifndef CAPABILITIES 2482 error = _fget(td, fd, fpp, 0, rightsp, NULL); 2483 if (maxprotp != NULL) 2484 *maxprotp = VM_PROT_ALL; 2485 #else 2486 struct filedesc *fdp = td->td_proc->p_fd; 2487 seq_t seq; 2488 2489 MPASS(cap_rights_is_set(rightsp, CAP_MMAP)); 2490 for (;;) { 2491 error = _fget(td, fd, fpp, 0, rightsp, &seq); 2492 if (error != 0) 2493 return (error); 2494 /* 2495 * If requested, convert capability rights to access flags. 2496 */ 2497 if (maxprotp != NULL) 2498 *maxprotp = cap_rights_to_vmprot(cap_rights(fdp, fd)); 2499 if (!fd_modified(fdp, fd, seq)) 2500 break; 2501 fdrop(*fpp, td); 2502 } 2503 #endif 2504 return (error); 2505 } 2506 2507 int 2508 fget_read(struct thread *td, int fd, cap_rights_t *rightsp, struct file **fpp) 2509 { 2510 2511 return (_fget(td, fd, fpp, FREAD, rightsp, NULL)); 2512 } 2513 2514 int 2515 fget_write(struct thread *td, int fd, cap_rights_t *rightsp, struct file **fpp) 2516 { 2517 2518 return (_fget(td, fd, fpp, FWRITE, rightsp, NULL)); 2519 } 2520 2521 int 2522 fget_fcntl(struct thread *td, int fd, cap_rights_t *rightsp, int needfcntl, 2523 struct file **fpp) 2524 { 2525 struct filedesc *fdp = td->td_proc->p_fd; 2526 #ifndef CAPABILITIES 2527 return (fget_unlocked(fdp, fd, rightsp, fpp, NULL)); 2528 #else 2529 int error; 2530 seq_t seq; 2531 2532 MPASS(cap_rights_is_set(rightsp, CAP_FCNTL)); 2533 for (;;) { 2534 error = fget_unlocked(fdp, fd, rightsp, fpp, &seq); 2535 if (error != 0) 2536 return (error); 2537 error = cap_fcntl_check(fdp, fd, needfcntl); 2538 if (!fd_modified(fdp, fd, seq)) 2539 break; 2540 fdrop(*fpp, td); 2541 } 2542 if (error != 0) { 2543 fdrop(*fpp, td); 2544 *fpp = NULL; 2545 } 2546 return (error); 2547 #endif 2548 } 2549 2550 /* 2551 * Like fget() but loads the underlying vnode, or returns an error if the 2552 * descriptor does not represent a vnode. Note that pipes use vnodes but 2553 * never have VM objects. The returned vnode will be vref()'d. 2554 * 2555 * XXX: what about the unused flags ? 2556 */ 2557 static __inline int 2558 _fgetvp(struct thread *td, int fd, int flags, cap_rights_t *needrightsp, 2559 struct vnode **vpp) 2560 { 2561 struct file *fp; 2562 int error; 2563 2564 *vpp = NULL; 2565 error = _fget(td, fd, &fp, flags, needrightsp, NULL); 2566 if (error != 0) 2567 return (error); 2568 if (fp->f_vnode == NULL) { 2569 error = EINVAL; 2570 } else { 2571 *vpp = fp->f_vnode; 2572 vref(*vpp); 2573 } 2574 fdrop(fp, td); 2575 2576 return (error); 2577 } 2578 2579 int 2580 fgetvp(struct thread *td, int fd, cap_rights_t *rightsp, struct vnode **vpp) 2581 { 2582 2583 return (_fgetvp(td, fd, 0, rightsp, vpp)); 2584 } 2585 2586 int 2587 fgetvp_rights(struct thread *td, int fd, cap_rights_t *needrightsp, 2588 struct filecaps *havecaps, struct vnode **vpp) 2589 { 2590 struct filedesc *fdp; 2591 struct file *fp; 2592 #ifdef CAPABILITIES 2593 int error; 2594 #endif 2595 2596 fdp = td->td_proc->p_fd; 2597 fp = fget_locked(fdp, fd); 2598 if (fp == NULL || fp->f_ops == &badfileops) 2599 return (EBADF); 2600 2601 #ifdef CAPABILITIES 2602 if (needrightsp != NULL) { 2603 error = cap_check(cap_rights(fdp, fd), needrightsp); 2604 if (error != 0) 2605 return (error); 2606 } 2607 #endif 2608 2609 if (fp->f_vnode == NULL) 2610 return (EINVAL); 2611 2612 *vpp = fp->f_vnode; 2613 vref(*vpp); 2614 filecaps_copy(&fdp->fd_ofiles[fd].fde_caps, havecaps); 2615 2616 return (0); 2617 } 2618 2619 int 2620 fgetvp_read(struct thread *td, int fd, cap_rights_t *rightsp, struct vnode **vpp) 2621 { 2622 2623 return (_fgetvp(td, fd, FREAD, rightsp, vpp)); 2624 } 2625 2626 int 2627 fgetvp_exec(struct thread *td, int fd, cap_rights_t *rightsp, struct vnode **vpp) 2628 { 2629 2630 return (_fgetvp(td, fd, FEXEC, rightsp, vpp)); 2631 } 2632 2633 #ifdef notyet 2634 int 2635 fgetvp_write(struct thread *td, int fd, cap_rights_t *rightsp, 2636 struct vnode **vpp) 2637 { 2638 2639 return (_fgetvp(td, fd, FWRITE, rightsp, vpp)); 2640 } 2641 #endif 2642 2643 /* 2644 * Like fget() but loads the underlying socket, or returns an error if the 2645 * descriptor does not represent a socket. 2646 * 2647 * We bump the ref count on the returned socket. XXX Also obtain the SX lock 2648 * in the future. 2649 * 2650 * Note: fgetsock() and fputsock() are deprecated, as consumers should rely 2651 * on their file descriptor reference to prevent the socket from being free'd 2652 * during use. 2653 */ 2654 int 2655 fgetsock(struct thread *td, int fd, cap_rights_t *rightsp, struct socket **spp, 2656 u_int *fflagp) 2657 { 2658 struct file *fp; 2659 int error; 2660 2661 *spp = NULL; 2662 if (fflagp != NULL) 2663 *fflagp = 0; 2664 if ((error = _fget(td, fd, &fp, 0, rightsp, NULL)) != 0) 2665 return (error); 2666 if (fp->f_type != DTYPE_SOCKET) { 2667 error = ENOTSOCK; 2668 } else { 2669 *spp = fp->f_data; 2670 if (fflagp) 2671 *fflagp = fp->f_flag; 2672 SOCK_LOCK(*spp); 2673 soref(*spp); 2674 SOCK_UNLOCK(*spp); 2675 } 2676 fdrop(fp, td); 2677 2678 return (error); 2679 } 2680 2681 /* 2682 * Drop the reference count on the socket and XXX release the SX lock in the 2683 * future. The last reference closes the socket. 2684 * 2685 * Note: fputsock() is deprecated, see comment for fgetsock(). 2686 */ 2687 void 2688 fputsock(struct socket *so) 2689 { 2690 2691 ACCEPT_LOCK(); 2692 SOCK_LOCK(so); 2693 CURVNET_SET(so->so_vnet); 2694 sorele(so); 2695 CURVNET_RESTORE(); 2696 } 2697 2698 /* 2699 * Handle the last reference to a file being closed. 2700 */ 2701 int 2702 _fdrop(struct file *fp, struct thread *td) 2703 { 2704 int error; 2705 2706 if (fp->f_count != 0) 2707 panic("fdrop: count %d", fp->f_count); 2708 error = fo_close(fp, td); 2709 atomic_subtract_int(&openfiles, 1); 2710 crfree(fp->f_cred); 2711 free(fp->f_advice, M_FADVISE); 2712 uma_zfree(file_zone, fp); 2713 2714 return (error); 2715 } 2716 2717 /* 2718 * Apply an advisory lock on a file descriptor. 2719 * 2720 * Just attempt to get a record lock of the requested type on the entire file 2721 * (l_whence = SEEK_SET, l_start = 0, l_len = 0). 2722 */ 2723 #ifndef _SYS_SYSPROTO_H_ 2724 struct flock_args { 2725 int fd; 2726 int how; 2727 }; 2728 #endif 2729 /* ARGSUSED */ 2730 int 2731 sys_flock(struct thread *td, struct flock_args *uap) 2732 { 2733 struct file *fp; 2734 struct vnode *vp; 2735 struct flock lf; 2736 cap_rights_t rights; 2737 int error; 2738 2739 error = fget(td, uap->fd, cap_rights_init(&rights, CAP_FLOCK), &fp); 2740 if (error != 0) 2741 return (error); 2742 if (fp->f_type != DTYPE_VNODE) { 2743 fdrop(fp, td); 2744 return (EOPNOTSUPP); 2745 } 2746 2747 vp = fp->f_vnode; 2748 lf.l_whence = SEEK_SET; 2749 lf.l_start = 0; 2750 lf.l_len = 0; 2751 if (uap->how & LOCK_UN) { 2752 lf.l_type = F_UNLCK; 2753 atomic_clear_int(&fp->f_flag, FHASLOCK); 2754 error = VOP_ADVLOCK(vp, (caddr_t)fp, F_UNLCK, &lf, F_FLOCK); 2755 goto done2; 2756 } 2757 if (uap->how & LOCK_EX) 2758 lf.l_type = F_WRLCK; 2759 else if (uap->how & LOCK_SH) 2760 lf.l_type = F_RDLCK; 2761 else { 2762 error = EBADF; 2763 goto done2; 2764 } 2765 atomic_set_int(&fp->f_flag, FHASLOCK); 2766 error = VOP_ADVLOCK(vp, (caddr_t)fp, F_SETLK, &lf, 2767 (uap->how & LOCK_NB) ? F_FLOCK : F_FLOCK | F_WAIT); 2768 done2: 2769 fdrop(fp, td); 2770 return (error); 2771 } 2772 /* 2773 * Duplicate the specified descriptor to a free descriptor. 2774 */ 2775 int 2776 dupfdopen(struct thread *td, struct filedesc *fdp, int dfd, int mode, 2777 int openerror, int *indxp) 2778 { 2779 struct filedescent *newfde, *oldfde; 2780 struct file *fp; 2781 int error, indx; 2782 2783 KASSERT(openerror == ENODEV || openerror == ENXIO, 2784 ("unexpected error %d in %s", openerror, __func__)); 2785 2786 /* 2787 * If the to-be-dup'd fd number is greater than the allowed number 2788 * of file descriptors, or the fd to be dup'd has already been 2789 * closed, then reject. 2790 */ 2791 FILEDESC_XLOCK(fdp); 2792 if ((fp = fget_locked(fdp, dfd)) == NULL) { 2793 FILEDESC_XUNLOCK(fdp); 2794 return (EBADF); 2795 } 2796 2797 error = fdalloc(td, 0, &indx); 2798 if (error != 0) { 2799 FILEDESC_XUNLOCK(fdp); 2800 return (error); 2801 } 2802 2803 /* 2804 * There are two cases of interest here. 2805 * 2806 * For ENODEV simply dup (dfd) to file descriptor (indx) and return. 2807 * 2808 * For ENXIO steal away the file structure from (dfd) and store it in 2809 * (indx). (dfd) is effectively closed by this operation. 2810 */ 2811 switch (openerror) { 2812 case ENODEV: 2813 /* 2814 * Check that the mode the file is being opened for is a 2815 * subset of the mode of the existing descriptor. 2816 */ 2817 if (((mode & (FREAD|FWRITE)) | fp->f_flag) != fp->f_flag) { 2818 fdunused(fdp, indx); 2819 FILEDESC_XUNLOCK(fdp); 2820 return (EACCES); 2821 } 2822 fhold(fp); 2823 newfde = &fdp->fd_ofiles[indx]; 2824 oldfde = &fdp->fd_ofiles[dfd]; 2825 #ifdef CAPABILITIES 2826 seq_write_begin(&newfde->fde_seq); 2827 #endif 2828 memcpy(newfde, oldfde, fde_change_size); 2829 filecaps_copy(&oldfde->fde_caps, &newfde->fde_caps); 2830 #ifdef CAPABILITIES 2831 seq_write_end(&newfde->fde_seq); 2832 #endif 2833 break; 2834 case ENXIO: 2835 /* 2836 * Steal away the file pointer from dfd and stuff it into indx. 2837 */ 2838 newfde = &fdp->fd_ofiles[indx]; 2839 oldfde = &fdp->fd_ofiles[dfd]; 2840 #ifdef CAPABILITIES 2841 seq_write_begin(&newfde->fde_seq); 2842 #endif 2843 memcpy(newfde, oldfde, fde_change_size); 2844 oldfde->fde_file = NULL; 2845 fdunused(fdp, dfd); 2846 #ifdef CAPABILITIES 2847 seq_write_end(&newfde->fde_seq); 2848 #endif 2849 break; 2850 } 2851 FILEDESC_XUNLOCK(fdp); 2852 *indxp = indx; 2853 return (0); 2854 } 2855 2856 /* 2857 * Scan all active processes and prisons to see if any of them have a current 2858 * or root directory of `olddp'. If so, replace them with the new mount point. 2859 */ 2860 void 2861 mountcheckdirs(struct vnode *olddp, struct vnode *newdp) 2862 { 2863 struct filedesc *fdp; 2864 struct prison *pr; 2865 struct proc *p; 2866 int nrele; 2867 2868 if (vrefcnt(olddp) == 1) 2869 return; 2870 nrele = 0; 2871 sx_slock(&allproc_lock); 2872 FOREACH_PROC_IN_SYSTEM(p) { 2873 PROC_LOCK(p); 2874 fdp = fdhold(p); 2875 PROC_UNLOCK(p); 2876 if (fdp == NULL) 2877 continue; 2878 FILEDESC_XLOCK(fdp); 2879 if (fdp->fd_cdir == olddp) { 2880 vref(newdp); 2881 fdp->fd_cdir = newdp; 2882 nrele++; 2883 } 2884 if (fdp->fd_rdir == olddp) { 2885 vref(newdp); 2886 fdp->fd_rdir = newdp; 2887 nrele++; 2888 } 2889 if (fdp->fd_jdir == olddp) { 2890 vref(newdp); 2891 fdp->fd_jdir = newdp; 2892 nrele++; 2893 } 2894 FILEDESC_XUNLOCK(fdp); 2895 fddrop(fdp); 2896 } 2897 sx_sunlock(&allproc_lock); 2898 if (rootvnode == olddp) { 2899 vref(newdp); 2900 rootvnode = newdp; 2901 nrele++; 2902 } 2903 mtx_lock(&prison0.pr_mtx); 2904 if (prison0.pr_root == olddp) { 2905 vref(newdp); 2906 prison0.pr_root = newdp; 2907 nrele++; 2908 } 2909 mtx_unlock(&prison0.pr_mtx); 2910 sx_slock(&allprison_lock); 2911 TAILQ_FOREACH(pr, &allprison, pr_list) { 2912 mtx_lock(&pr->pr_mtx); 2913 if (pr->pr_root == olddp) { 2914 vref(newdp); 2915 pr->pr_root = newdp; 2916 nrele++; 2917 } 2918 mtx_unlock(&pr->pr_mtx); 2919 } 2920 sx_sunlock(&allprison_lock); 2921 while (nrele--) 2922 vrele(olddp); 2923 } 2924 2925 struct filedesc_to_leader * 2926 filedesc_to_leader_alloc(struct filedesc_to_leader *old, struct filedesc *fdp, struct proc *leader) 2927 { 2928 struct filedesc_to_leader *fdtol; 2929 2930 fdtol = malloc(sizeof(struct filedesc_to_leader), 2931 M_FILEDESC_TO_LEADER, M_WAITOK); 2932 fdtol->fdl_refcount = 1; 2933 fdtol->fdl_holdcount = 0; 2934 fdtol->fdl_wakeup = 0; 2935 fdtol->fdl_leader = leader; 2936 if (old != NULL) { 2937 FILEDESC_XLOCK(fdp); 2938 fdtol->fdl_next = old->fdl_next; 2939 fdtol->fdl_prev = old; 2940 old->fdl_next = fdtol; 2941 fdtol->fdl_next->fdl_prev = fdtol; 2942 FILEDESC_XUNLOCK(fdp); 2943 } else { 2944 fdtol->fdl_next = fdtol; 2945 fdtol->fdl_prev = fdtol; 2946 } 2947 return (fdtol); 2948 } 2949 2950 /* 2951 * Get file structures globally. 2952 */ 2953 static int 2954 sysctl_kern_file(SYSCTL_HANDLER_ARGS) 2955 { 2956 struct xfile xf; 2957 struct filedesc *fdp; 2958 struct file *fp; 2959 struct proc *p; 2960 int error, n; 2961 2962 error = sysctl_wire_old_buffer(req, 0); 2963 if (error != 0) 2964 return (error); 2965 if (req->oldptr == NULL) { 2966 n = 0; 2967 sx_slock(&allproc_lock); 2968 FOREACH_PROC_IN_SYSTEM(p) { 2969 PROC_LOCK(p); 2970 if (p->p_state == PRS_NEW) { 2971 PROC_UNLOCK(p); 2972 continue; 2973 } 2974 fdp = fdhold(p); 2975 PROC_UNLOCK(p); 2976 if (fdp == NULL) 2977 continue; 2978 /* overestimates sparse tables. */ 2979 if (fdp->fd_lastfile > 0) 2980 n += fdp->fd_lastfile; 2981 fddrop(fdp); 2982 } 2983 sx_sunlock(&allproc_lock); 2984 return (SYSCTL_OUT(req, 0, n * sizeof(xf))); 2985 } 2986 error = 0; 2987 bzero(&xf, sizeof(xf)); 2988 xf.xf_size = sizeof(xf); 2989 sx_slock(&allproc_lock); 2990 FOREACH_PROC_IN_SYSTEM(p) { 2991 PROC_LOCK(p); 2992 if (p->p_state == PRS_NEW) { 2993 PROC_UNLOCK(p); 2994 continue; 2995 } 2996 if (p_cansee(req->td, p) != 0) { 2997 PROC_UNLOCK(p); 2998 continue; 2999 } 3000 xf.xf_pid = p->p_pid; 3001 xf.xf_uid = p->p_ucred->cr_uid; 3002 fdp = fdhold(p); 3003 PROC_UNLOCK(p); 3004 if (fdp == NULL) 3005 continue; 3006 FILEDESC_SLOCK(fdp); 3007 for (n = 0; fdp->fd_refcnt > 0 && n <= fdp->fd_lastfile; ++n) { 3008 if ((fp = fdp->fd_ofiles[n].fde_file) == NULL) 3009 continue; 3010 xf.xf_fd = n; 3011 xf.xf_file = fp; 3012 xf.xf_data = fp->f_data; 3013 xf.xf_vnode = fp->f_vnode; 3014 xf.xf_type = fp->f_type; 3015 xf.xf_count = fp->f_count; 3016 xf.xf_msgcount = 0; 3017 xf.xf_offset = foffset_get(fp); 3018 xf.xf_flag = fp->f_flag; 3019 error = SYSCTL_OUT(req, &xf, sizeof(xf)); 3020 if (error) 3021 break; 3022 } 3023 FILEDESC_SUNLOCK(fdp); 3024 fddrop(fdp); 3025 if (error) 3026 break; 3027 } 3028 sx_sunlock(&allproc_lock); 3029 return (error); 3030 } 3031 3032 SYSCTL_PROC(_kern, KERN_FILE, file, CTLTYPE_OPAQUE|CTLFLAG_RD|CTLFLAG_MPSAFE, 3033 0, 0, sysctl_kern_file, "S,xfile", "Entire file table"); 3034 3035 #ifdef KINFO_FILE_SIZE 3036 CTASSERT(sizeof(struct kinfo_file) == KINFO_FILE_SIZE); 3037 #endif 3038 3039 static int 3040 xlate_fflags(int fflags) 3041 { 3042 static const struct { 3043 int fflag; 3044 int kf_fflag; 3045 } fflags_table[] = { 3046 { FAPPEND, KF_FLAG_APPEND }, 3047 { FASYNC, KF_FLAG_ASYNC }, 3048 { FFSYNC, KF_FLAG_FSYNC }, 3049 { FHASLOCK, KF_FLAG_HASLOCK }, 3050 { FNONBLOCK, KF_FLAG_NONBLOCK }, 3051 { FREAD, KF_FLAG_READ }, 3052 { FWRITE, KF_FLAG_WRITE }, 3053 { O_CREAT, KF_FLAG_CREAT }, 3054 { O_DIRECT, KF_FLAG_DIRECT }, 3055 { O_EXCL, KF_FLAG_EXCL }, 3056 { O_EXEC, KF_FLAG_EXEC }, 3057 { O_EXLOCK, KF_FLAG_EXLOCK }, 3058 { O_NOFOLLOW, KF_FLAG_NOFOLLOW }, 3059 { O_SHLOCK, KF_FLAG_SHLOCK }, 3060 { O_TRUNC, KF_FLAG_TRUNC } 3061 }; 3062 unsigned int i; 3063 int kflags; 3064 3065 kflags = 0; 3066 for (i = 0; i < nitems(fflags_table); i++) 3067 if (fflags & fflags_table[i].fflag) 3068 kflags |= fflags_table[i].kf_fflag; 3069 return (kflags); 3070 } 3071 3072 /* Trim unused data from kf_path by truncating the structure size. */ 3073 static void 3074 pack_kinfo(struct kinfo_file *kif) 3075 { 3076 3077 kif->kf_structsize = offsetof(struct kinfo_file, kf_path) + 3078 strlen(kif->kf_path) + 1; 3079 kif->kf_structsize = roundup(kif->kf_structsize, sizeof(uint64_t)); 3080 } 3081 3082 static void 3083 export_file_to_kinfo(struct file *fp, int fd, cap_rights_t *rightsp, 3084 struct kinfo_file *kif, struct filedesc *fdp) 3085 { 3086 int error; 3087 3088 bzero(kif, sizeof(*kif)); 3089 3090 /* Set a default type to allow for empty fill_kinfo() methods. */ 3091 kif->kf_type = KF_TYPE_UNKNOWN; 3092 kif->kf_flags = xlate_fflags(fp->f_flag); 3093 if (rightsp != NULL) 3094 kif->kf_cap_rights = *rightsp; 3095 else 3096 cap_rights_init(&kif->kf_cap_rights); 3097 kif->kf_fd = fd; 3098 kif->kf_ref_count = fp->f_count; 3099 kif->kf_offset = foffset_get(fp); 3100 3101 /* 3102 * This may drop the filedesc lock, so the 'fp' cannot be 3103 * accessed after this call. 3104 */ 3105 error = fo_fill_kinfo(fp, kif, fdp); 3106 if (error == 0) 3107 kif->kf_status |= KF_ATTR_VALID; 3108 pack_kinfo(kif); 3109 } 3110 3111 static void 3112 export_vnode_to_kinfo(struct vnode *vp, int fd, int fflags, 3113 struct kinfo_file *kif) 3114 { 3115 int error; 3116 3117 bzero(kif, sizeof(*kif)); 3118 3119 kif->kf_type = KF_TYPE_VNODE; 3120 error = vn_fill_kinfo_vnode(vp, kif); 3121 if (error == 0) 3122 kif->kf_status |= KF_ATTR_VALID; 3123 kif->kf_flags = xlate_fflags(fflags); 3124 cap_rights_init(&kif->kf_cap_rights); 3125 kif->kf_fd = fd; 3126 kif->kf_ref_count = -1; 3127 kif->kf_offset = -1; 3128 pack_kinfo(kif); 3129 vrele(vp); 3130 } 3131 3132 struct export_fd_buf { 3133 struct filedesc *fdp; 3134 struct sbuf *sb; 3135 ssize_t remainder; 3136 struct kinfo_file kif; 3137 }; 3138 3139 static int 3140 export_kinfo_to_sb(struct export_fd_buf *efbuf) 3141 { 3142 struct kinfo_file *kif; 3143 3144 kif = &efbuf->kif; 3145 if (efbuf->remainder != -1) { 3146 if (efbuf->remainder < kif->kf_structsize) { 3147 /* Terminate export. */ 3148 efbuf->remainder = 0; 3149 return (0); 3150 } 3151 efbuf->remainder -= kif->kf_structsize; 3152 } 3153 return (sbuf_bcat(efbuf->sb, kif, kif->kf_structsize) == 0 ? 0 : ENOMEM); 3154 } 3155 3156 static int 3157 export_file_to_sb(struct file *fp, int fd, cap_rights_t *rightsp, 3158 struct export_fd_buf *efbuf) 3159 { 3160 int error; 3161 3162 if (efbuf->remainder == 0) 3163 return (0); 3164 export_file_to_kinfo(fp, fd, rightsp, &efbuf->kif, efbuf->fdp); 3165 FILEDESC_SUNLOCK(efbuf->fdp); 3166 error = export_kinfo_to_sb(efbuf); 3167 FILEDESC_SLOCK(efbuf->fdp); 3168 return (error); 3169 } 3170 3171 static int 3172 export_vnode_to_sb(struct vnode *vp, int fd, int fflags, 3173 struct export_fd_buf *efbuf) 3174 { 3175 int error; 3176 3177 if (efbuf->remainder == 0) 3178 return (0); 3179 if (efbuf->fdp != NULL) 3180 FILEDESC_SUNLOCK(efbuf->fdp); 3181 export_vnode_to_kinfo(vp, fd, fflags, &efbuf->kif); 3182 error = export_kinfo_to_sb(efbuf); 3183 if (efbuf->fdp != NULL) 3184 FILEDESC_SLOCK(efbuf->fdp); 3185 return (error); 3186 } 3187 3188 /* 3189 * Store a process file descriptor information to sbuf. 3190 * 3191 * Takes a locked proc as argument, and returns with the proc unlocked. 3192 */ 3193 int 3194 kern_proc_filedesc_out(struct proc *p, struct sbuf *sb, ssize_t maxlen) 3195 { 3196 struct file *fp; 3197 struct filedesc *fdp; 3198 struct export_fd_buf *efbuf; 3199 struct vnode *cttyvp, *textvp, *tracevp; 3200 int error, i; 3201 cap_rights_t rights; 3202 3203 PROC_LOCK_ASSERT(p, MA_OWNED); 3204 3205 /* ktrace vnode */ 3206 tracevp = p->p_tracevp; 3207 if (tracevp != NULL) 3208 vref(tracevp); 3209 /* text vnode */ 3210 textvp = p->p_textvp; 3211 if (textvp != NULL) 3212 vref(textvp); 3213 /* Controlling tty. */ 3214 cttyvp = NULL; 3215 if (p->p_pgrp != NULL && p->p_pgrp->pg_session != NULL) { 3216 cttyvp = p->p_pgrp->pg_session->s_ttyvp; 3217 if (cttyvp != NULL) 3218 vref(cttyvp); 3219 } 3220 fdp = fdhold(p); 3221 PROC_UNLOCK(p); 3222 efbuf = malloc(sizeof(*efbuf), M_TEMP, M_WAITOK); 3223 efbuf->fdp = NULL; 3224 efbuf->sb = sb; 3225 efbuf->remainder = maxlen; 3226 if (tracevp != NULL) 3227 export_vnode_to_sb(tracevp, KF_FD_TYPE_TRACE, FREAD | FWRITE, 3228 efbuf); 3229 if (textvp != NULL) 3230 export_vnode_to_sb(textvp, KF_FD_TYPE_TEXT, FREAD, efbuf); 3231 if (cttyvp != NULL) 3232 export_vnode_to_sb(cttyvp, KF_FD_TYPE_CTTY, FREAD | FWRITE, 3233 efbuf); 3234 error = 0; 3235 if (fdp == NULL) 3236 goto fail; 3237 efbuf->fdp = fdp; 3238 FILEDESC_SLOCK(fdp); 3239 /* working directory */ 3240 if (fdp->fd_cdir != NULL) { 3241 vref(fdp->fd_cdir); 3242 export_vnode_to_sb(fdp->fd_cdir, KF_FD_TYPE_CWD, FREAD, efbuf); 3243 } 3244 /* root directory */ 3245 if (fdp->fd_rdir != NULL) { 3246 vref(fdp->fd_rdir); 3247 export_vnode_to_sb(fdp->fd_rdir, KF_FD_TYPE_ROOT, FREAD, efbuf); 3248 } 3249 /* jail directory */ 3250 if (fdp->fd_jdir != NULL) { 3251 vref(fdp->fd_jdir); 3252 export_vnode_to_sb(fdp->fd_jdir, KF_FD_TYPE_JAIL, FREAD, efbuf); 3253 } 3254 for (i = 0; fdp->fd_refcnt > 0 && i <= fdp->fd_lastfile; i++) { 3255 if ((fp = fdp->fd_ofiles[i].fde_file) == NULL) 3256 continue; 3257 #ifdef CAPABILITIES 3258 rights = *cap_rights(fdp, i); 3259 #else /* !CAPABILITIES */ 3260 cap_rights_init(&rights); 3261 #endif 3262 /* 3263 * Create sysctl entry. It is OK to drop the filedesc 3264 * lock inside of export_file_to_sb() as we will 3265 * re-validate and re-evaluate its properties when the 3266 * loop continues. 3267 */ 3268 error = export_file_to_sb(fp, i, &rights, efbuf); 3269 if (error != 0 || efbuf->remainder == 0) 3270 break; 3271 } 3272 FILEDESC_SUNLOCK(fdp); 3273 fddrop(fdp); 3274 fail: 3275 free(efbuf, M_TEMP); 3276 return (error); 3277 } 3278 3279 #define FILEDESC_SBUF_SIZE (sizeof(struct kinfo_file) * 5) 3280 3281 /* 3282 * Get per-process file descriptors for use by procstat(1), et al. 3283 */ 3284 static int 3285 sysctl_kern_proc_filedesc(SYSCTL_HANDLER_ARGS) 3286 { 3287 struct sbuf sb; 3288 struct proc *p; 3289 ssize_t maxlen; 3290 int error, error2, *name; 3291 3292 name = (int *)arg1; 3293 3294 sbuf_new_for_sysctl(&sb, NULL, FILEDESC_SBUF_SIZE, req); 3295 sbuf_clear_flags(&sb, SBUF_INCLUDENUL); 3296 error = pget((pid_t)name[0], PGET_CANDEBUG | PGET_NOTWEXIT, &p); 3297 if (error != 0) { 3298 sbuf_delete(&sb); 3299 return (error); 3300 } 3301 maxlen = req->oldptr != NULL ? req->oldlen : -1; 3302 error = kern_proc_filedesc_out(p, &sb, maxlen); 3303 error2 = sbuf_finish(&sb); 3304 sbuf_delete(&sb); 3305 return (error != 0 ? error : error2); 3306 } 3307 3308 #ifdef KINFO_OFILE_SIZE 3309 CTASSERT(sizeof(struct kinfo_ofile) == KINFO_OFILE_SIZE); 3310 #endif 3311 3312 #ifdef COMPAT_FREEBSD7 3313 static void 3314 kinfo_to_okinfo(struct kinfo_file *kif, struct kinfo_ofile *okif) 3315 { 3316 3317 okif->kf_structsize = sizeof(*okif); 3318 okif->kf_type = kif->kf_type; 3319 okif->kf_fd = kif->kf_fd; 3320 okif->kf_ref_count = kif->kf_ref_count; 3321 okif->kf_flags = kif->kf_flags & (KF_FLAG_READ | KF_FLAG_WRITE | 3322 KF_FLAG_APPEND | KF_FLAG_ASYNC | KF_FLAG_FSYNC | KF_FLAG_NONBLOCK | 3323 KF_FLAG_DIRECT | KF_FLAG_HASLOCK); 3324 okif->kf_offset = kif->kf_offset; 3325 okif->kf_vnode_type = kif->kf_vnode_type; 3326 okif->kf_sock_domain = kif->kf_sock_domain; 3327 okif->kf_sock_type = kif->kf_sock_type; 3328 okif->kf_sock_protocol = kif->kf_sock_protocol; 3329 strlcpy(okif->kf_path, kif->kf_path, sizeof(okif->kf_path)); 3330 okif->kf_sa_local = kif->kf_sa_local; 3331 okif->kf_sa_peer = kif->kf_sa_peer; 3332 } 3333 3334 static int 3335 export_vnode_for_osysctl(struct vnode *vp, int type, struct kinfo_file *kif, 3336 struct kinfo_ofile *okif, struct filedesc *fdp, struct sysctl_req *req) 3337 { 3338 int error; 3339 3340 vref(vp); 3341 FILEDESC_SUNLOCK(fdp); 3342 export_vnode_to_kinfo(vp, type, 0, kif); 3343 kinfo_to_okinfo(kif, okif); 3344 error = SYSCTL_OUT(req, okif, sizeof(*okif)); 3345 FILEDESC_SLOCK(fdp); 3346 return (error); 3347 } 3348 3349 /* 3350 * Get per-process file descriptors for use by procstat(1), et al. 3351 */ 3352 static int 3353 sysctl_kern_proc_ofiledesc(SYSCTL_HANDLER_ARGS) 3354 { 3355 struct kinfo_ofile *okif; 3356 struct kinfo_file *kif; 3357 struct filedesc *fdp; 3358 int error, i, *name; 3359 struct file *fp; 3360 struct proc *p; 3361 3362 name = (int *)arg1; 3363 error = pget((pid_t)name[0], PGET_CANDEBUG | PGET_NOTWEXIT, &p); 3364 if (error != 0) 3365 return (error); 3366 fdp = fdhold(p); 3367 PROC_UNLOCK(p); 3368 if (fdp == NULL) 3369 return (ENOENT); 3370 kif = malloc(sizeof(*kif), M_TEMP, M_WAITOK); 3371 okif = malloc(sizeof(*okif), M_TEMP, M_WAITOK); 3372 FILEDESC_SLOCK(fdp); 3373 if (fdp->fd_cdir != NULL) 3374 export_vnode_for_osysctl(fdp->fd_cdir, KF_FD_TYPE_CWD, kif, 3375 okif, fdp, req); 3376 if (fdp->fd_rdir != NULL) 3377 export_vnode_for_osysctl(fdp->fd_rdir, KF_FD_TYPE_ROOT, kif, 3378 okif, fdp, req); 3379 if (fdp->fd_jdir != NULL) 3380 export_vnode_for_osysctl(fdp->fd_jdir, KF_FD_TYPE_JAIL, kif, 3381 okif, fdp, req); 3382 for (i = 0; fdp->fd_refcnt > 0 && i <= fdp->fd_lastfile; i++) { 3383 if ((fp = fdp->fd_ofiles[i].fde_file) == NULL) 3384 continue; 3385 export_file_to_kinfo(fp, i, NULL, kif, fdp); 3386 FILEDESC_SUNLOCK(fdp); 3387 kinfo_to_okinfo(kif, okif); 3388 error = SYSCTL_OUT(req, okif, sizeof(*okif)); 3389 FILEDESC_SLOCK(fdp); 3390 if (error) 3391 break; 3392 } 3393 FILEDESC_SUNLOCK(fdp); 3394 fddrop(fdp); 3395 free(kif, M_TEMP); 3396 free(okif, M_TEMP); 3397 return (0); 3398 } 3399 3400 static SYSCTL_NODE(_kern_proc, KERN_PROC_OFILEDESC, ofiledesc, 3401 CTLFLAG_RD|CTLFLAG_MPSAFE, sysctl_kern_proc_ofiledesc, 3402 "Process ofiledesc entries"); 3403 #endif /* COMPAT_FREEBSD7 */ 3404 3405 int 3406 vntype_to_kinfo(int vtype) 3407 { 3408 struct { 3409 int vtype; 3410 int kf_vtype; 3411 } vtypes_table[] = { 3412 { VBAD, KF_VTYPE_VBAD }, 3413 { VBLK, KF_VTYPE_VBLK }, 3414 { VCHR, KF_VTYPE_VCHR }, 3415 { VDIR, KF_VTYPE_VDIR }, 3416 { VFIFO, KF_VTYPE_VFIFO }, 3417 { VLNK, KF_VTYPE_VLNK }, 3418 { VNON, KF_VTYPE_VNON }, 3419 { VREG, KF_VTYPE_VREG }, 3420 { VSOCK, KF_VTYPE_VSOCK } 3421 }; 3422 unsigned int i; 3423 3424 /* 3425 * Perform vtype translation. 3426 */ 3427 for (i = 0; i < nitems(vtypes_table); i++) 3428 if (vtypes_table[i].vtype == vtype) 3429 return (vtypes_table[i].kf_vtype); 3430 3431 return (KF_VTYPE_UNKNOWN); 3432 } 3433 3434 static SYSCTL_NODE(_kern_proc, KERN_PROC_FILEDESC, filedesc, 3435 CTLFLAG_RD|CTLFLAG_MPSAFE, sysctl_kern_proc_filedesc, 3436 "Process filedesc entries"); 3437 3438 /* 3439 * Store a process current working directory information to sbuf. 3440 * 3441 * Takes a locked proc as argument, and returns with the proc unlocked. 3442 */ 3443 int 3444 kern_proc_cwd_out(struct proc *p, struct sbuf *sb, ssize_t maxlen) 3445 { 3446 struct filedesc *fdp; 3447 struct export_fd_buf *efbuf; 3448 int error; 3449 3450 PROC_LOCK_ASSERT(p, MA_OWNED); 3451 3452 fdp = fdhold(p); 3453 PROC_UNLOCK(p); 3454 if (fdp == NULL) 3455 return (EINVAL); 3456 3457 efbuf = malloc(sizeof(*efbuf), M_TEMP, M_WAITOK); 3458 efbuf->fdp = fdp; 3459 efbuf->sb = sb; 3460 efbuf->remainder = maxlen; 3461 3462 FILEDESC_SLOCK(fdp); 3463 if (fdp->fd_cdir == NULL) 3464 error = EINVAL; 3465 else { 3466 vref(fdp->fd_cdir); 3467 error = export_vnode_to_sb(fdp->fd_cdir, KF_FD_TYPE_CWD, 3468 FREAD, efbuf); 3469 } 3470 FILEDESC_SUNLOCK(fdp); 3471 fddrop(fdp); 3472 free(efbuf, M_TEMP); 3473 return (error); 3474 } 3475 3476 /* 3477 * Get per-process current working directory. 3478 */ 3479 static int 3480 sysctl_kern_proc_cwd(SYSCTL_HANDLER_ARGS) 3481 { 3482 struct sbuf sb; 3483 struct proc *p; 3484 ssize_t maxlen; 3485 int error, error2, *name; 3486 3487 name = (int *)arg1; 3488 3489 sbuf_new_for_sysctl(&sb, NULL, sizeof(struct kinfo_file), req); 3490 sbuf_clear_flags(&sb, SBUF_INCLUDENUL); 3491 error = pget((pid_t)name[0], PGET_CANDEBUG | PGET_NOTWEXIT, &p); 3492 if (error != 0) { 3493 sbuf_delete(&sb); 3494 return (error); 3495 } 3496 maxlen = req->oldptr != NULL ? req->oldlen : -1; 3497 error = kern_proc_cwd_out(p, &sb, maxlen); 3498 error2 = sbuf_finish(&sb); 3499 sbuf_delete(&sb); 3500 return (error != 0 ? error : error2); 3501 } 3502 3503 static SYSCTL_NODE(_kern_proc, KERN_PROC_CWD, cwd, CTLFLAG_RD|CTLFLAG_MPSAFE, 3504 sysctl_kern_proc_cwd, "Process current working directory"); 3505 3506 #ifdef DDB 3507 /* 3508 * For the purposes of debugging, generate a human-readable string for the 3509 * file type. 3510 */ 3511 static const char * 3512 file_type_to_name(short type) 3513 { 3514 3515 switch (type) { 3516 case 0: 3517 return ("zero"); 3518 case DTYPE_VNODE: 3519 return ("vnod"); 3520 case DTYPE_SOCKET: 3521 return ("sock"); 3522 case DTYPE_PIPE: 3523 return ("pipe"); 3524 case DTYPE_FIFO: 3525 return ("fifo"); 3526 case DTYPE_KQUEUE: 3527 return ("kque"); 3528 case DTYPE_CRYPTO: 3529 return ("crpt"); 3530 case DTYPE_MQUEUE: 3531 return ("mque"); 3532 case DTYPE_SHM: 3533 return ("shm"); 3534 case DTYPE_SEM: 3535 return ("ksem"); 3536 default: 3537 return ("unkn"); 3538 } 3539 } 3540 3541 /* 3542 * For the purposes of debugging, identify a process (if any, perhaps one of 3543 * many) that references the passed file in its file descriptor array. Return 3544 * NULL if none. 3545 */ 3546 static struct proc * 3547 file_to_first_proc(struct file *fp) 3548 { 3549 struct filedesc *fdp; 3550 struct proc *p; 3551 int n; 3552 3553 FOREACH_PROC_IN_SYSTEM(p) { 3554 if (p->p_state == PRS_NEW) 3555 continue; 3556 fdp = p->p_fd; 3557 if (fdp == NULL) 3558 continue; 3559 for (n = 0; n <= fdp->fd_lastfile; n++) { 3560 if (fp == fdp->fd_ofiles[n].fde_file) 3561 return (p); 3562 } 3563 } 3564 return (NULL); 3565 } 3566 3567 static void 3568 db_print_file(struct file *fp, int header) 3569 { 3570 struct proc *p; 3571 3572 if (header) 3573 db_printf("%8s %4s %8s %8s %4s %5s %6s %8s %5s %12s\n", 3574 "File", "Type", "Data", "Flag", "GCFl", "Count", 3575 "MCount", "Vnode", "FPID", "FCmd"); 3576 p = file_to_first_proc(fp); 3577 db_printf("%8p %4s %8p %08x %04x %5d %6d %8p %5d %12s\n", fp, 3578 file_type_to_name(fp->f_type), fp->f_data, fp->f_flag, 3579 0, fp->f_count, 0, fp->f_vnode, 3580 p != NULL ? p->p_pid : -1, p != NULL ? p->p_comm : "-"); 3581 } 3582 3583 DB_SHOW_COMMAND(file, db_show_file) 3584 { 3585 struct file *fp; 3586 3587 if (!have_addr) { 3588 db_printf("usage: show file <addr>\n"); 3589 return; 3590 } 3591 fp = (struct file *)addr; 3592 db_print_file(fp, 1); 3593 } 3594 3595 DB_SHOW_COMMAND(files, db_show_files) 3596 { 3597 struct filedesc *fdp; 3598 struct file *fp; 3599 struct proc *p; 3600 int header; 3601 int n; 3602 3603 header = 1; 3604 FOREACH_PROC_IN_SYSTEM(p) { 3605 if (p->p_state == PRS_NEW) 3606 continue; 3607 if ((fdp = p->p_fd) == NULL) 3608 continue; 3609 for (n = 0; n <= fdp->fd_lastfile; ++n) { 3610 if ((fp = fdp->fd_ofiles[n].fde_file) == NULL) 3611 continue; 3612 db_print_file(fp, header); 3613 header = 0; 3614 } 3615 } 3616 } 3617 #endif 3618 3619 SYSCTL_INT(_kern, KERN_MAXFILESPERPROC, maxfilesperproc, CTLFLAG_RW, 3620 &maxfilesperproc, 0, "Maximum files allowed open per process"); 3621 3622 SYSCTL_INT(_kern, KERN_MAXFILES, maxfiles, CTLFLAG_RW, 3623 &maxfiles, 0, "Maximum number of files"); 3624 3625 SYSCTL_INT(_kern, OID_AUTO, openfiles, CTLFLAG_RD, 3626 __DEVOLATILE(int *, &openfiles), 0, "System-wide number of open files"); 3627 3628 /* ARGSUSED*/ 3629 static void 3630 filelistinit(void *dummy) 3631 { 3632 3633 file_zone = uma_zcreate("Files", sizeof(struct file), NULL, NULL, 3634 NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE); 3635 filedesc0_zone = uma_zcreate("filedesc0", sizeof(struct filedesc0), 3636 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0); 3637 mtx_init(&sigio_lock, "sigio lock", NULL, MTX_DEF); 3638 } 3639 SYSINIT(select, SI_SUB_LOCK, SI_ORDER_FIRST, filelistinit, NULL); 3640 3641 /*-------------------------------------------------------------------*/ 3642 3643 static int 3644 badfo_readwrite(struct file *fp, struct uio *uio, struct ucred *active_cred, 3645 int flags, struct thread *td) 3646 { 3647 3648 return (EBADF); 3649 } 3650 3651 static int 3652 badfo_truncate(struct file *fp, off_t length, struct ucred *active_cred, 3653 struct thread *td) 3654 { 3655 3656 return (EINVAL); 3657 } 3658 3659 static int 3660 badfo_ioctl(struct file *fp, u_long com, void *data, struct ucred *active_cred, 3661 struct thread *td) 3662 { 3663 3664 return (EBADF); 3665 } 3666 3667 static int 3668 badfo_poll(struct file *fp, int events, struct ucred *active_cred, 3669 struct thread *td) 3670 { 3671 3672 return (0); 3673 } 3674 3675 static int 3676 badfo_kqfilter(struct file *fp, struct knote *kn) 3677 { 3678 3679 return (EBADF); 3680 } 3681 3682 static int 3683 badfo_stat(struct file *fp, struct stat *sb, struct ucred *active_cred, 3684 struct thread *td) 3685 { 3686 3687 return (EBADF); 3688 } 3689 3690 static int 3691 badfo_close(struct file *fp, struct thread *td) 3692 { 3693 3694 return (0); 3695 } 3696 3697 static int 3698 badfo_chmod(struct file *fp, mode_t mode, struct ucred *active_cred, 3699 struct thread *td) 3700 { 3701 3702 return (EBADF); 3703 } 3704 3705 static int 3706 badfo_chown(struct file *fp, uid_t uid, gid_t gid, struct ucred *active_cred, 3707 struct thread *td) 3708 { 3709 3710 return (EBADF); 3711 } 3712 3713 static int 3714 badfo_sendfile(struct file *fp, int sockfd, struct uio *hdr_uio, 3715 struct uio *trl_uio, off_t offset, size_t nbytes, off_t *sent, int flags, 3716 int kflags, struct thread *td) 3717 { 3718 3719 return (EBADF); 3720 } 3721 3722 static int 3723 badfo_fill_kinfo(struct file *fp, struct kinfo_file *kif, struct filedesc *fdp) 3724 { 3725 3726 return (0); 3727 } 3728 3729 struct fileops badfileops = { 3730 .fo_read = badfo_readwrite, 3731 .fo_write = badfo_readwrite, 3732 .fo_truncate = badfo_truncate, 3733 .fo_ioctl = badfo_ioctl, 3734 .fo_poll = badfo_poll, 3735 .fo_kqfilter = badfo_kqfilter, 3736 .fo_stat = badfo_stat, 3737 .fo_close = badfo_close, 3738 .fo_chmod = badfo_chmod, 3739 .fo_chown = badfo_chown, 3740 .fo_sendfile = badfo_sendfile, 3741 .fo_fill_kinfo = badfo_fill_kinfo, 3742 }; 3743 3744 int 3745 invfo_rdwr(struct file *fp, struct uio *uio, struct ucred *active_cred, 3746 int flags, struct thread *td) 3747 { 3748 3749 return (EOPNOTSUPP); 3750 } 3751 3752 int 3753 invfo_truncate(struct file *fp, off_t length, struct ucred *active_cred, 3754 struct thread *td) 3755 { 3756 3757 return (EINVAL); 3758 } 3759 3760 int 3761 invfo_ioctl(struct file *fp, u_long com, void *data, 3762 struct ucred *active_cred, struct thread *td) 3763 { 3764 3765 return (ENOTTY); 3766 } 3767 3768 int 3769 invfo_poll(struct file *fp, int events, struct ucred *active_cred, 3770 struct thread *td) 3771 { 3772 3773 return (poll_no_poll(events)); 3774 } 3775 3776 int 3777 invfo_kqfilter(struct file *fp, struct knote *kn) 3778 { 3779 3780 return (EINVAL); 3781 } 3782 3783 int 3784 invfo_chmod(struct file *fp, mode_t mode, struct ucred *active_cred, 3785 struct thread *td) 3786 { 3787 3788 return (EINVAL); 3789 } 3790 3791 int 3792 invfo_chown(struct file *fp, uid_t uid, gid_t gid, struct ucred *active_cred, 3793 struct thread *td) 3794 { 3795 3796 return (EINVAL); 3797 } 3798 3799 int 3800 invfo_sendfile(struct file *fp, int sockfd, struct uio *hdr_uio, 3801 struct uio *trl_uio, off_t offset, size_t nbytes, off_t *sent, int flags, 3802 int kflags, struct thread *td) 3803 { 3804 3805 return (EINVAL); 3806 } 3807 3808 /*-------------------------------------------------------------------*/ 3809 3810 /* 3811 * File Descriptor pseudo-device driver (/dev/fd/). 3812 * 3813 * Opening minor device N dup()s the file (if any) connected to file 3814 * descriptor N belonging to the calling process. Note that this driver 3815 * consists of only the ``open()'' routine, because all subsequent 3816 * references to this file will be direct to the other driver. 3817 * 3818 * XXX: we could give this one a cloning event handler if necessary. 3819 */ 3820 3821 /* ARGSUSED */ 3822 static int 3823 fdopen(struct cdev *dev, int mode, int type, struct thread *td) 3824 { 3825 3826 /* 3827 * XXX Kludge: set curthread->td_dupfd to contain the value of the 3828 * the file descriptor being sought for duplication. The error 3829 * return ensures that the vnode for this device will be released 3830 * by vn_open. Open will detect this special error and take the 3831 * actions in dupfdopen below. Other callers of vn_open or VOP_OPEN 3832 * will simply report the error. 3833 */ 3834 td->td_dupfd = dev2unit(dev); 3835 return (ENODEV); 3836 } 3837 3838 static struct cdevsw fildesc_cdevsw = { 3839 .d_version = D_VERSION, 3840 .d_open = fdopen, 3841 .d_name = "FD", 3842 }; 3843 3844 static void 3845 fildesc_drvinit(void *unused) 3846 { 3847 struct cdev *dev; 3848 3849 dev = make_dev_credf(MAKEDEV_ETERNAL, &fildesc_cdevsw, 0, NULL, 3850 UID_ROOT, GID_WHEEL, 0666, "fd/0"); 3851 make_dev_alias(dev, "stdin"); 3852 dev = make_dev_credf(MAKEDEV_ETERNAL, &fildesc_cdevsw, 1, NULL, 3853 UID_ROOT, GID_WHEEL, 0666, "fd/1"); 3854 make_dev_alias(dev, "stdout"); 3855 dev = make_dev_credf(MAKEDEV_ETERNAL, &fildesc_cdevsw, 2, NULL, 3856 UID_ROOT, GID_WHEEL, 0666, "fd/2"); 3857 make_dev_alias(dev, "stderr"); 3858 } 3859 3860 SYSINIT(fildescdev, SI_SUB_DRIVERS, SI_ORDER_MIDDLE, fildesc_drvinit, NULL); 3861