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; 408 409 error = 0; 410 switch (cmd) { 411 case F_OGETLK: 412 case F_OSETLK: 413 case F_OSETLKW: 414 /* 415 * Convert old flock structure to new. 416 */ 417 error = copyin((void *)(intptr_t)arg, &ofl, sizeof(ofl)); 418 fl.l_start = ofl.l_start; 419 fl.l_len = ofl.l_len; 420 fl.l_pid = ofl.l_pid; 421 fl.l_type = ofl.l_type; 422 fl.l_whence = ofl.l_whence; 423 fl.l_sysid = 0; 424 425 switch (cmd) { 426 case F_OGETLK: 427 cmd = F_GETLK; 428 break; 429 case F_OSETLK: 430 cmd = F_SETLK; 431 break; 432 case F_OSETLKW: 433 cmd = F_SETLKW; 434 break; 435 } 436 arg1 = (intptr_t)&fl; 437 break; 438 case F_GETLK: 439 case F_SETLK: 440 case F_SETLKW: 441 case F_SETLK_REMOTE: 442 error = copyin((void *)(intptr_t)arg, &fl, sizeof(fl)); 443 arg1 = (intptr_t)&fl; 444 break; 445 default: 446 arg1 = arg; 447 break; 448 } 449 if (error) 450 return (error); 451 error = kern_fcntl(td, fd, cmd, arg1); 452 if (error) 453 return (error); 454 if (cmd == F_OGETLK) { 455 ofl.l_start = fl.l_start; 456 ofl.l_len = fl.l_len; 457 ofl.l_pid = fl.l_pid; 458 ofl.l_type = fl.l_type; 459 ofl.l_whence = fl.l_whence; 460 error = copyout(&ofl, (void *)(intptr_t)arg, sizeof(ofl)); 461 } else if (cmd == F_GETLK) { 462 error = copyout(&fl, (void *)(intptr_t)arg, sizeof(fl)); 463 } 464 return (error); 465 } 466 467 int 468 kern_fcntl(struct thread *td, int fd, int cmd, intptr_t arg) 469 { 470 struct filedesc *fdp; 471 struct flock *flp; 472 struct file *fp, *fp2; 473 struct filedescent *fde; 474 struct proc *p; 475 struct vnode *vp; 476 cap_rights_t rights; 477 int error, flg, tmp; 478 uint64_t bsize; 479 off_t foffset; 480 481 error = 0; 482 flg = F_POSIX; 483 p = td->td_proc; 484 fdp = p->p_fd; 485 486 switch (cmd) { 487 case F_DUPFD: 488 tmp = arg; 489 error = do_dup(td, DUP_FCNTL, fd, tmp); 490 break; 491 492 case F_DUPFD_CLOEXEC: 493 tmp = arg; 494 error = do_dup(td, DUP_FCNTL | DUP_CLOEXEC, fd, tmp); 495 break; 496 497 case F_DUP2FD: 498 tmp = arg; 499 error = do_dup(td, DUP_FIXED, fd, tmp); 500 break; 501 502 case F_DUP2FD_CLOEXEC: 503 tmp = arg; 504 error = do_dup(td, DUP_FIXED | DUP_CLOEXEC, fd, tmp); 505 break; 506 507 case F_GETFD: 508 FILEDESC_SLOCK(fdp); 509 if (fget_locked(fdp, fd) == NULL) { 510 FILEDESC_SUNLOCK(fdp); 511 error = EBADF; 512 break; 513 } 514 fde = &fdp->fd_ofiles[fd]; 515 td->td_retval[0] = 516 (fde->fde_flags & UF_EXCLOSE) ? FD_CLOEXEC : 0; 517 FILEDESC_SUNLOCK(fdp); 518 break; 519 520 case F_SETFD: 521 FILEDESC_XLOCK(fdp); 522 if (fget_locked(fdp, fd) == NULL) { 523 FILEDESC_XUNLOCK(fdp); 524 error = EBADF; 525 break; 526 } 527 fde = &fdp->fd_ofiles[fd]; 528 fde->fde_flags = (fde->fde_flags & ~UF_EXCLOSE) | 529 (arg & FD_CLOEXEC ? UF_EXCLOSE : 0); 530 FILEDESC_XUNLOCK(fdp); 531 break; 532 533 case F_GETFL: 534 error = fget_fcntl(td, fd, 535 cap_rights_init(&rights, CAP_FCNTL), F_GETFL, &fp); 536 if (error != 0) 537 break; 538 td->td_retval[0] = OFLAGS(fp->f_flag); 539 fdrop(fp, td); 540 break; 541 542 case F_SETFL: 543 error = fget_fcntl(td, fd, 544 cap_rights_init(&rights, CAP_FCNTL), F_SETFL, &fp); 545 if (error != 0) 546 break; 547 do { 548 tmp = flg = fp->f_flag; 549 tmp &= ~FCNTLFLAGS; 550 tmp |= FFLAGS(arg & ~O_ACCMODE) & FCNTLFLAGS; 551 } while(atomic_cmpset_int(&fp->f_flag, flg, tmp) == 0); 552 tmp = fp->f_flag & FNONBLOCK; 553 error = fo_ioctl(fp, FIONBIO, &tmp, td->td_ucred, td); 554 if (error != 0) { 555 fdrop(fp, td); 556 break; 557 } 558 tmp = fp->f_flag & FASYNC; 559 error = fo_ioctl(fp, FIOASYNC, &tmp, td->td_ucred, td); 560 if (error == 0) { 561 fdrop(fp, td); 562 break; 563 } 564 atomic_clear_int(&fp->f_flag, FNONBLOCK); 565 tmp = 0; 566 (void)fo_ioctl(fp, FIONBIO, &tmp, td->td_ucred, td); 567 fdrop(fp, td); 568 break; 569 570 case F_GETOWN: 571 error = fget_fcntl(td, fd, 572 cap_rights_init(&rights, CAP_FCNTL), F_GETOWN, &fp); 573 if (error != 0) 574 break; 575 error = fo_ioctl(fp, FIOGETOWN, &tmp, td->td_ucred, td); 576 if (error == 0) 577 td->td_retval[0] = tmp; 578 fdrop(fp, td); 579 break; 580 581 case F_SETOWN: 582 error = fget_fcntl(td, fd, 583 cap_rights_init(&rights, CAP_FCNTL), F_SETOWN, &fp); 584 if (error != 0) 585 break; 586 tmp = arg; 587 error = fo_ioctl(fp, FIOSETOWN, &tmp, td->td_ucred, td); 588 fdrop(fp, td); 589 break; 590 591 case F_SETLK_REMOTE: 592 error = priv_check(td, PRIV_NFS_LOCKD); 593 if (error) 594 return (error); 595 flg = F_REMOTE; 596 goto do_setlk; 597 598 case F_SETLKW: 599 flg |= F_WAIT; 600 /* FALLTHROUGH F_SETLK */ 601 602 case F_SETLK: 603 do_setlk: 604 cap_rights_init(&rights, CAP_FLOCK); 605 error = fget_unlocked(fdp, fd, &rights, &fp, NULL); 606 if (error != 0) 607 break; 608 if (fp->f_type != DTYPE_VNODE) { 609 error = EBADF; 610 fdrop(fp, td); 611 break; 612 } 613 614 flp = (struct flock *)arg; 615 if (flp->l_whence == SEEK_CUR) { 616 foffset = foffset_get(fp); 617 if (foffset < 0 || 618 (flp->l_start > 0 && 619 foffset > OFF_MAX - flp->l_start)) { 620 error = EOVERFLOW; 621 fdrop(fp, td); 622 break; 623 } 624 flp->l_start += foffset; 625 } 626 627 vp = fp->f_vnode; 628 switch (flp->l_type) { 629 case F_RDLCK: 630 if ((fp->f_flag & FREAD) == 0) { 631 error = EBADF; 632 break; 633 } 634 PROC_LOCK(p->p_leader); 635 p->p_leader->p_flag |= P_ADVLOCK; 636 PROC_UNLOCK(p->p_leader); 637 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_SETLK, 638 flp, flg); 639 break; 640 case F_WRLCK: 641 if ((fp->f_flag & FWRITE) == 0) { 642 error = EBADF; 643 break; 644 } 645 PROC_LOCK(p->p_leader); 646 p->p_leader->p_flag |= P_ADVLOCK; 647 PROC_UNLOCK(p->p_leader); 648 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_SETLK, 649 flp, flg); 650 break; 651 case F_UNLCK: 652 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_UNLCK, 653 flp, flg); 654 break; 655 case F_UNLCKSYS: 656 /* 657 * Temporary api for testing remote lock 658 * infrastructure. 659 */ 660 if (flg != F_REMOTE) { 661 error = EINVAL; 662 break; 663 } 664 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, 665 F_UNLCKSYS, flp, flg); 666 break; 667 default: 668 error = EINVAL; 669 break; 670 } 671 if (error != 0 || flp->l_type == F_UNLCK || 672 flp->l_type == F_UNLCKSYS) { 673 fdrop(fp, td); 674 break; 675 } 676 677 /* 678 * Check for a race with close. 679 * 680 * The vnode is now advisory locked (or unlocked, but this case 681 * is not really important) as the caller requested. 682 * We had to drop the filedesc lock, so we need to recheck if 683 * the descriptor is still valid, because if it was closed 684 * in the meantime we need to remove advisory lock from the 685 * vnode - close on any descriptor leading to an advisory 686 * locked vnode, removes that lock. 687 * We will return 0 on purpose in that case, as the result of 688 * successful advisory lock might have been externally visible 689 * already. This is fine - effectively we pretend to the caller 690 * that the closing thread was a bit slower and that the 691 * advisory lock succeeded before the close. 692 */ 693 error = fget_unlocked(fdp, fd, &rights, &fp2, NULL); 694 if (error != 0) { 695 fdrop(fp, td); 696 break; 697 } 698 if (fp != fp2) { 699 flp->l_whence = SEEK_SET; 700 flp->l_start = 0; 701 flp->l_len = 0; 702 flp->l_type = F_UNLCK; 703 (void) VOP_ADVLOCK(vp, (caddr_t)p->p_leader, 704 F_UNLCK, flp, F_POSIX); 705 } 706 fdrop(fp, td); 707 fdrop(fp2, td); 708 break; 709 710 case F_GETLK: 711 error = fget_unlocked(fdp, fd, 712 cap_rights_init(&rights, CAP_FLOCK), &fp, NULL); 713 if (error != 0) 714 break; 715 if (fp->f_type != DTYPE_VNODE) { 716 error = EBADF; 717 fdrop(fp, td); 718 break; 719 } 720 flp = (struct flock *)arg; 721 if (flp->l_type != F_RDLCK && flp->l_type != F_WRLCK && 722 flp->l_type != F_UNLCK) { 723 error = EINVAL; 724 fdrop(fp, td); 725 break; 726 } 727 if (flp->l_whence == SEEK_CUR) { 728 foffset = foffset_get(fp); 729 if ((flp->l_start > 0 && 730 foffset > OFF_MAX - flp->l_start) || 731 (flp->l_start < 0 && 732 foffset < OFF_MIN - flp->l_start)) { 733 error = EOVERFLOW; 734 fdrop(fp, td); 735 break; 736 } 737 flp->l_start += foffset; 738 } 739 vp = fp->f_vnode; 740 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_GETLK, flp, 741 F_POSIX); 742 fdrop(fp, td); 743 break; 744 745 case F_RDAHEAD: 746 arg = arg ? 128 * 1024: 0; 747 /* FALLTHROUGH */ 748 case F_READAHEAD: 749 error = fget_unlocked(fdp, fd, 750 cap_rights_init(&rights), &fp, NULL); 751 if (error != 0) 752 break; 753 if (fp->f_type != DTYPE_VNODE) { 754 fdrop(fp, td); 755 error = EBADF; 756 break; 757 } 758 vp = fp->f_vnode; 759 /* 760 * Exclusive lock synchronizes against f_seqcount reads and 761 * writes in sequential_heuristic(). 762 */ 763 error = vn_lock(vp, LK_EXCLUSIVE); 764 if (error != 0) { 765 fdrop(fp, td); 766 break; 767 } 768 if (arg >= 0) { 769 bsize = fp->f_vnode->v_mount->mnt_stat.f_iosize; 770 fp->f_seqcount = (arg + bsize - 1) / bsize; 771 atomic_set_int(&fp->f_flag, FRDAHEAD); 772 } else { 773 atomic_clear_int(&fp->f_flag, FRDAHEAD); 774 } 775 VOP_UNLOCK(vp, 0); 776 fdrop(fp, td); 777 break; 778 779 default: 780 error = EINVAL; 781 break; 782 } 783 return (error); 784 } 785 786 static int 787 getmaxfd(struct thread *td) 788 { 789 790 return (min((int)lim_cur(td, RLIMIT_NOFILE), maxfilesperproc)); 791 } 792 793 /* 794 * Common code for dup, dup2, fcntl(F_DUPFD) and fcntl(F_DUP2FD). 795 */ 796 static int 797 do_dup(struct thread *td, int flags, int old, int new) 798 { 799 struct filedesc *fdp; 800 struct filedescent *oldfde, *newfde; 801 struct proc *p; 802 struct file *fp; 803 struct file *delfp; 804 int error, maxfd; 805 806 p = td->td_proc; 807 fdp = p->p_fd; 808 809 /* 810 * Verify we have a valid descriptor to dup from and possibly to 811 * dup to. Unlike dup() and dup2(), fcntl()'s F_DUPFD should 812 * return EINVAL when the new descriptor is out of bounds. 813 */ 814 if (old < 0) 815 return (EBADF); 816 if (new < 0) 817 return (flags & DUP_FCNTL ? EINVAL : EBADF); 818 maxfd = getmaxfd(td); 819 if (new >= maxfd) 820 return (flags & DUP_FCNTL ? EINVAL : EBADF); 821 822 FILEDESC_XLOCK(fdp); 823 if (fget_locked(fdp, old) == NULL) { 824 FILEDESC_XUNLOCK(fdp); 825 return (EBADF); 826 } 827 oldfde = &fdp->fd_ofiles[old]; 828 if (flags & DUP_FIXED && old == new) { 829 td->td_retval[0] = new; 830 if (flags & DUP_CLOEXEC) 831 fdp->fd_ofiles[new].fde_flags |= UF_EXCLOSE; 832 FILEDESC_XUNLOCK(fdp); 833 return (0); 834 } 835 fp = oldfde->fde_file; 836 fhold(fp); 837 838 /* 839 * If the caller specified a file descriptor, make sure the file 840 * table is large enough to hold it, and grab it. Otherwise, just 841 * allocate a new descriptor the usual way. 842 */ 843 if (flags & DUP_FIXED) { 844 if (new >= fdp->fd_nfiles) { 845 /* 846 * The resource limits are here instead of e.g. 847 * fdalloc(), because the file descriptor table may be 848 * shared between processes, so we can't really use 849 * racct_add()/racct_sub(). Instead of counting the 850 * number of actually allocated descriptors, just put 851 * the limit on the size of the file descriptor table. 852 */ 853 #ifdef RACCT 854 if (racct_enable) { 855 PROC_LOCK(p); 856 error = racct_set(p, RACCT_NOFILE, new + 1); 857 PROC_UNLOCK(p); 858 if (error != 0) { 859 FILEDESC_XUNLOCK(fdp); 860 fdrop(fp, td); 861 return (EMFILE); 862 } 863 } 864 #endif 865 fdgrowtable_exp(fdp, new + 1); 866 oldfde = &fdp->fd_ofiles[old]; 867 } 868 newfde = &fdp->fd_ofiles[new]; 869 if (newfde->fde_file == NULL) 870 fdused(fdp, new); 871 } else { 872 if ((error = fdalloc(td, new, &new)) != 0) { 873 FILEDESC_XUNLOCK(fdp); 874 fdrop(fp, td); 875 return (error); 876 } 877 newfde = &fdp->fd_ofiles[new]; 878 } 879 880 KASSERT(fp == oldfde->fde_file, ("old fd has been modified")); 881 KASSERT(old != new, ("new fd is same as old")); 882 883 delfp = newfde->fde_file; 884 885 /* 886 * Duplicate the source descriptor. 887 */ 888 #ifdef CAPABILITIES 889 seq_write_begin(&newfde->fde_seq); 890 #endif 891 filecaps_free(&newfde->fde_caps); 892 memcpy(newfde, oldfde, fde_change_size); 893 filecaps_copy(&oldfde->fde_caps, &newfde->fde_caps); 894 if ((flags & DUP_CLOEXEC) != 0) 895 newfde->fde_flags = oldfde->fde_flags | UF_EXCLOSE; 896 else 897 newfde->fde_flags = oldfde->fde_flags & ~UF_EXCLOSE; 898 #ifdef CAPABILITIES 899 seq_write_end(&newfde->fde_seq); 900 #endif 901 td->td_retval[0] = new; 902 903 if (delfp != NULL) { 904 (void) closefp(fdp, new, delfp, td, 1); 905 /* closefp() drops the FILEDESC lock for us. */ 906 } else { 907 FILEDESC_XUNLOCK(fdp); 908 } 909 910 return (0); 911 } 912 913 /* 914 * If sigio is on the list associated with a process or process group, 915 * disable signalling from the device, remove sigio from the list and 916 * free sigio. 917 */ 918 void 919 funsetown(struct sigio **sigiop) 920 { 921 struct sigio *sigio; 922 923 SIGIO_LOCK(); 924 sigio = *sigiop; 925 if (sigio == NULL) { 926 SIGIO_UNLOCK(); 927 return; 928 } 929 *(sigio->sio_myref) = NULL; 930 if ((sigio)->sio_pgid < 0) { 931 struct pgrp *pg = (sigio)->sio_pgrp; 932 PGRP_LOCK(pg); 933 SLIST_REMOVE(&sigio->sio_pgrp->pg_sigiolst, sigio, 934 sigio, sio_pgsigio); 935 PGRP_UNLOCK(pg); 936 } else { 937 struct proc *p = (sigio)->sio_proc; 938 PROC_LOCK(p); 939 SLIST_REMOVE(&sigio->sio_proc->p_sigiolst, sigio, 940 sigio, sio_pgsigio); 941 PROC_UNLOCK(p); 942 } 943 SIGIO_UNLOCK(); 944 crfree(sigio->sio_ucred); 945 free(sigio, M_SIGIO); 946 } 947 948 /* 949 * Free a list of sigio structures. 950 * We only need to lock the SIGIO_LOCK because we have made ourselves 951 * inaccessible to callers of fsetown and therefore do not need to lock 952 * the proc or pgrp struct for the list manipulation. 953 */ 954 void 955 funsetownlst(struct sigiolst *sigiolst) 956 { 957 struct proc *p; 958 struct pgrp *pg; 959 struct sigio *sigio; 960 961 sigio = SLIST_FIRST(sigiolst); 962 if (sigio == NULL) 963 return; 964 p = NULL; 965 pg = NULL; 966 967 /* 968 * Every entry of the list should belong 969 * to a single proc or pgrp. 970 */ 971 if (sigio->sio_pgid < 0) { 972 pg = sigio->sio_pgrp; 973 PGRP_LOCK_ASSERT(pg, MA_NOTOWNED); 974 } else /* if (sigio->sio_pgid > 0) */ { 975 p = sigio->sio_proc; 976 PROC_LOCK_ASSERT(p, MA_NOTOWNED); 977 } 978 979 SIGIO_LOCK(); 980 while ((sigio = SLIST_FIRST(sigiolst)) != NULL) { 981 *(sigio->sio_myref) = NULL; 982 if (pg != NULL) { 983 KASSERT(sigio->sio_pgid < 0, 984 ("Proc sigio in pgrp sigio list")); 985 KASSERT(sigio->sio_pgrp == pg, 986 ("Bogus pgrp in sigio list")); 987 PGRP_LOCK(pg); 988 SLIST_REMOVE(&pg->pg_sigiolst, sigio, sigio, 989 sio_pgsigio); 990 PGRP_UNLOCK(pg); 991 } else /* if (p != NULL) */ { 992 KASSERT(sigio->sio_pgid > 0, 993 ("Pgrp sigio in proc sigio list")); 994 KASSERT(sigio->sio_proc == p, 995 ("Bogus proc in sigio list")); 996 PROC_LOCK(p); 997 SLIST_REMOVE(&p->p_sigiolst, sigio, sigio, 998 sio_pgsigio); 999 PROC_UNLOCK(p); 1000 } 1001 SIGIO_UNLOCK(); 1002 crfree(sigio->sio_ucred); 1003 free(sigio, M_SIGIO); 1004 SIGIO_LOCK(); 1005 } 1006 SIGIO_UNLOCK(); 1007 } 1008 1009 /* 1010 * This is common code for FIOSETOWN ioctl called by fcntl(fd, F_SETOWN, arg). 1011 * 1012 * After permission checking, add a sigio structure to the sigio list for 1013 * the process or process group. 1014 */ 1015 int 1016 fsetown(pid_t pgid, struct sigio **sigiop) 1017 { 1018 struct proc *proc; 1019 struct pgrp *pgrp; 1020 struct sigio *sigio; 1021 int ret; 1022 1023 if (pgid == 0) { 1024 funsetown(sigiop); 1025 return (0); 1026 } 1027 1028 ret = 0; 1029 1030 /* Allocate and fill in the new sigio out of locks. */ 1031 sigio = malloc(sizeof(struct sigio), M_SIGIO, M_WAITOK); 1032 sigio->sio_pgid = pgid; 1033 sigio->sio_ucred = crhold(curthread->td_ucred); 1034 sigio->sio_myref = sigiop; 1035 1036 sx_slock(&proctree_lock); 1037 if (pgid > 0) { 1038 proc = pfind(pgid); 1039 if (proc == NULL) { 1040 ret = ESRCH; 1041 goto fail; 1042 } 1043 1044 /* 1045 * Policy - Don't allow a process to FSETOWN a process 1046 * in another session. 1047 * 1048 * Remove this test to allow maximum flexibility or 1049 * restrict FSETOWN to the current process or process 1050 * group for maximum safety. 1051 */ 1052 PROC_UNLOCK(proc); 1053 if (proc->p_session != curthread->td_proc->p_session) { 1054 ret = EPERM; 1055 goto fail; 1056 } 1057 1058 pgrp = NULL; 1059 } else /* if (pgid < 0) */ { 1060 pgrp = pgfind(-pgid); 1061 if (pgrp == NULL) { 1062 ret = ESRCH; 1063 goto fail; 1064 } 1065 PGRP_UNLOCK(pgrp); 1066 1067 /* 1068 * Policy - Don't allow a process to FSETOWN a process 1069 * in another session. 1070 * 1071 * Remove this test to allow maximum flexibility or 1072 * restrict FSETOWN to the current process or process 1073 * group for maximum safety. 1074 */ 1075 if (pgrp->pg_session != curthread->td_proc->p_session) { 1076 ret = EPERM; 1077 goto fail; 1078 } 1079 1080 proc = NULL; 1081 } 1082 funsetown(sigiop); 1083 if (pgid > 0) { 1084 PROC_LOCK(proc); 1085 /* 1086 * Since funsetownlst() is called without the proctree 1087 * locked, we need to check for P_WEXIT. 1088 * XXX: is ESRCH correct? 1089 */ 1090 if ((proc->p_flag & P_WEXIT) != 0) { 1091 PROC_UNLOCK(proc); 1092 ret = ESRCH; 1093 goto fail; 1094 } 1095 SLIST_INSERT_HEAD(&proc->p_sigiolst, sigio, sio_pgsigio); 1096 sigio->sio_proc = proc; 1097 PROC_UNLOCK(proc); 1098 } else { 1099 PGRP_LOCK(pgrp); 1100 SLIST_INSERT_HEAD(&pgrp->pg_sigiolst, sigio, sio_pgsigio); 1101 sigio->sio_pgrp = pgrp; 1102 PGRP_UNLOCK(pgrp); 1103 } 1104 sx_sunlock(&proctree_lock); 1105 SIGIO_LOCK(); 1106 *sigiop = sigio; 1107 SIGIO_UNLOCK(); 1108 return (0); 1109 1110 fail: 1111 sx_sunlock(&proctree_lock); 1112 crfree(sigio->sio_ucred); 1113 free(sigio, M_SIGIO); 1114 return (ret); 1115 } 1116 1117 /* 1118 * This is common code for FIOGETOWN ioctl called by fcntl(fd, F_GETOWN, arg). 1119 */ 1120 pid_t 1121 fgetown(sigiop) 1122 struct sigio **sigiop; 1123 { 1124 pid_t pgid; 1125 1126 SIGIO_LOCK(); 1127 pgid = (*sigiop != NULL) ? (*sigiop)->sio_pgid : 0; 1128 SIGIO_UNLOCK(); 1129 return (pgid); 1130 } 1131 1132 /* 1133 * Function drops the filedesc lock on return. 1134 */ 1135 static int 1136 closefp(struct filedesc *fdp, int fd, struct file *fp, struct thread *td, 1137 int holdleaders) 1138 { 1139 int error; 1140 1141 FILEDESC_XLOCK_ASSERT(fdp); 1142 1143 if (holdleaders) { 1144 if (td->td_proc->p_fdtol != NULL) { 1145 /* 1146 * Ask fdfree() to sleep to ensure that all relevant 1147 * process leaders can be traversed in closef(). 1148 */ 1149 fdp->fd_holdleaderscount++; 1150 } else { 1151 holdleaders = 0; 1152 } 1153 } 1154 1155 /* 1156 * We now hold the fp reference that used to be owned by the 1157 * descriptor array. We have to unlock the FILEDESC *AFTER* 1158 * knote_fdclose to prevent a race of the fd getting opened, a knote 1159 * added, and deleteing a knote for the new fd. 1160 */ 1161 knote_fdclose(td, fd); 1162 1163 /* 1164 * We need to notify mqueue if the object is of type mqueue. 1165 */ 1166 if (fp->f_type == DTYPE_MQUEUE) 1167 mq_fdclose(td, fd, fp); 1168 FILEDESC_XUNLOCK(fdp); 1169 1170 error = closef(fp, td); 1171 if (holdleaders) { 1172 FILEDESC_XLOCK(fdp); 1173 fdp->fd_holdleaderscount--; 1174 if (fdp->fd_holdleaderscount == 0 && 1175 fdp->fd_holdleaderswakeup != 0) { 1176 fdp->fd_holdleaderswakeup = 0; 1177 wakeup(&fdp->fd_holdleaderscount); 1178 } 1179 FILEDESC_XUNLOCK(fdp); 1180 } 1181 return (error); 1182 } 1183 1184 /* 1185 * Close a file descriptor. 1186 */ 1187 #ifndef _SYS_SYSPROTO_H_ 1188 struct close_args { 1189 int fd; 1190 }; 1191 #endif 1192 /* ARGSUSED */ 1193 int 1194 sys_close(td, uap) 1195 struct thread *td; 1196 struct close_args *uap; 1197 { 1198 1199 return (kern_close(td, uap->fd)); 1200 } 1201 1202 int 1203 kern_close(td, fd) 1204 struct thread *td; 1205 int fd; 1206 { 1207 struct filedesc *fdp; 1208 struct file *fp; 1209 1210 fdp = td->td_proc->p_fd; 1211 1212 AUDIT_SYSCLOSE(td, fd); 1213 1214 FILEDESC_XLOCK(fdp); 1215 if ((fp = fget_locked(fdp, fd)) == NULL) { 1216 FILEDESC_XUNLOCK(fdp); 1217 return (EBADF); 1218 } 1219 fdfree(fdp, fd); 1220 1221 /* closefp() drops the FILEDESC lock for us. */ 1222 return (closefp(fdp, fd, fp, td, 1)); 1223 } 1224 1225 /* 1226 * Close open file descriptors. 1227 */ 1228 #ifndef _SYS_SYSPROTO_H_ 1229 struct closefrom_args { 1230 int lowfd; 1231 }; 1232 #endif 1233 /* ARGSUSED */ 1234 int 1235 sys_closefrom(struct thread *td, struct closefrom_args *uap) 1236 { 1237 struct filedesc *fdp; 1238 int fd; 1239 1240 fdp = td->td_proc->p_fd; 1241 AUDIT_ARG_FD(uap->lowfd); 1242 1243 /* 1244 * Treat negative starting file descriptor values identical to 1245 * closefrom(0) which closes all files. 1246 */ 1247 if (uap->lowfd < 0) 1248 uap->lowfd = 0; 1249 FILEDESC_SLOCK(fdp); 1250 for (fd = uap->lowfd; fd <= fdp->fd_lastfile; fd++) { 1251 if (fdp->fd_ofiles[fd].fde_file != NULL) { 1252 FILEDESC_SUNLOCK(fdp); 1253 (void)kern_close(td, fd); 1254 FILEDESC_SLOCK(fdp); 1255 } 1256 } 1257 FILEDESC_SUNLOCK(fdp); 1258 return (0); 1259 } 1260 1261 #if defined(COMPAT_43) 1262 /* 1263 * Return status information about a file descriptor. 1264 */ 1265 #ifndef _SYS_SYSPROTO_H_ 1266 struct ofstat_args { 1267 int fd; 1268 struct ostat *sb; 1269 }; 1270 #endif 1271 /* ARGSUSED */ 1272 int 1273 ofstat(struct thread *td, struct ofstat_args *uap) 1274 { 1275 struct ostat oub; 1276 struct stat ub; 1277 int error; 1278 1279 error = kern_fstat(td, uap->fd, &ub); 1280 if (error == 0) { 1281 cvtstat(&ub, &oub); 1282 error = copyout(&oub, uap->sb, sizeof(oub)); 1283 } 1284 return (error); 1285 } 1286 #endif /* COMPAT_43 */ 1287 1288 /* 1289 * Return status information about a file descriptor. 1290 */ 1291 #ifndef _SYS_SYSPROTO_H_ 1292 struct fstat_args { 1293 int fd; 1294 struct stat *sb; 1295 }; 1296 #endif 1297 /* ARGSUSED */ 1298 int 1299 sys_fstat(struct thread *td, struct fstat_args *uap) 1300 { 1301 struct stat ub; 1302 int error; 1303 1304 error = kern_fstat(td, uap->fd, &ub); 1305 if (error == 0) 1306 error = copyout(&ub, uap->sb, sizeof(ub)); 1307 return (error); 1308 } 1309 1310 int 1311 kern_fstat(struct thread *td, int fd, struct stat *sbp) 1312 { 1313 struct file *fp; 1314 cap_rights_t rights; 1315 int error; 1316 1317 AUDIT_ARG_FD(fd); 1318 1319 error = fget(td, fd, cap_rights_init(&rights, CAP_FSTAT), &fp); 1320 if (error != 0) 1321 return (error); 1322 1323 AUDIT_ARG_FILE(td->td_proc, fp); 1324 1325 error = fo_stat(fp, sbp, td->td_ucred, td); 1326 fdrop(fp, td); 1327 #ifdef KTRACE 1328 if (error == 0 && KTRPOINT(td, KTR_STRUCT)) 1329 ktrstat(sbp); 1330 #endif 1331 return (error); 1332 } 1333 1334 /* 1335 * Return status information about a file descriptor. 1336 */ 1337 #ifndef _SYS_SYSPROTO_H_ 1338 struct nfstat_args { 1339 int fd; 1340 struct nstat *sb; 1341 }; 1342 #endif 1343 /* ARGSUSED */ 1344 int 1345 sys_nfstat(struct thread *td, struct nfstat_args *uap) 1346 { 1347 struct nstat nub; 1348 struct stat ub; 1349 int error; 1350 1351 error = kern_fstat(td, uap->fd, &ub); 1352 if (error == 0) { 1353 cvtnstat(&ub, &nub); 1354 error = copyout(&nub, uap->sb, sizeof(nub)); 1355 } 1356 return (error); 1357 } 1358 1359 /* 1360 * Return pathconf information about a file descriptor. 1361 */ 1362 #ifndef _SYS_SYSPROTO_H_ 1363 struct fpathconf_args { 1364 int fd; 1365 int name; 1366 }; 1367 #endif 1368 /* ARGSUSED */ 1369 int 1370 sys_fpathconf(struct thread *td, struct fpathconf_args *uap) 1371 { 1372 struct file *fp; 1373 struct vnode *vp; 1374 cap_rights_t rights; 1375 int error; 1376 1377 error = fget(td, uap->fd, cap_rights_init(&rights, CAP_FPATHCONF), &fp); 1378 if (error != 0) 1379 return (error); 1380 1381 /* If asynchronous I/O is available, it works for all descriptors. */ 1382 if (uap->name == _PC_ASYNC_IO) { 1383 td->td_retval[0] = async_io_version; 1384 goto out; 1385 } 1386 vp = fp->f_vnode; 1387 if (vp != NULL) { 1388 vn_lock(vp, LK_SHARED | LK_RETRY); 1389 error = VOP_PATHCONF(vp, uap->name, td->td_retval); 1390 VOP_UNLOCK(vp, 0); 1391 } else if (fp->f_type == DTYPE_PIPE || fp->f_type == DTYPE_SOCKET) { 1392 if (uap->name != _PC_PIPE_BUF) { 1393 error = EINVAL; 1394 } else { 1395 td->td_retval[0] = PIPE_BUF; 1396 error = 0; 1397 } 1398 } else { 1399 error = EOPNOTSUPP; 1400 } 1401 out: 1402 fdrop(fp, td); 1403 return (error); 1404 } 1405 1406 /* 1407 * Initialize filecaps structure. 1408 */ 1409 void 1410 filecaps_init(struct filecaps *fcaps) 1411 { 1412 1413 bzero(fcaps, sizeof(*fcaps)); 1414 fcaps->fc_nioctls = -1; 1415 } 1416 1417 /* 1418 * Copy filecaps structure allocating memory for ioctls array if needed. 1419 */ 1420 void 1421 filecaps_copy(const struct filecaps *src, struct filecaps *dst) 1422 { 1423 size_t size; 1424 1425 *dst = *src; 1426 if (src->fc_ioctls != NULL) { 1427 KASSERT(src->fc_nioctls > 0, 1428 ("fc_ioctls != NULL, but fc_nioctls=%hd", src->fc_nioctls)); 1429 1430 size = sizeof(src->fc_ioctls[0]) * src->fc_nioctls; 1431 dst->fc_ioctls = malloc(size, M_FILECAPS, M_WAITOK); 1432 bcopy(src->fc_ioctls, dst->fc_ioctls, size); 1433 } 1434 } 1435 1436 /* 1437 * Move filecaps structure to the new place and clear the old place. 1438 */ 1439 void 1440 filecaps_move(struct filecaps *src, struct filecaps *dst) 1441 { 1442 1443 *dst = *src; 1444 bzero(src, sizeof(*src)); 1445 } 1446 1447 /* 1448 * Fill the given filecaps structure with full rights. 1449 */ 1450 static void 1451 filecaps_fill(struct filecaps *fcaps) 1452 { 1453 1454 CAP_ALL(&fcaps->fc_rights); 1455 fcaps->fc_ioctls = NULL; 1456 fcaps->fc_nioctls = -1; 1457 fcaps->fc_fcntls = CAP_FCNTL_ALL; 1458 } 1459 1460 /* 1461 * Free memory allocated within filecaps structure. 1462 */ 1463 void 1464 filecaps_free(struct filecaps *fcaps) 1465 { 1466 1467 free(fcaps->fc_ioctls, M_FILECAPS); 1468 bzero(fcaps, sizeof(*fcaps)); 1469 } 1470 1471 /* 1472 * Validate the given filecaps structure. 1473 */ 1474 static void 1475 filecaps_validate(const struct filecaps *fcaps, const char *func) 1476 { 1477 1478 KASSERT(cap_rights_is_valid(&fcaps->fc_rights), 1479 ("%s: invalid rights", func)); 1480 KASSERT((fcaps->fc_fcntls & ~CAP_FCNTL_ALL) == 0, 1481 ("%s: invalid fcntls", func)); 1482 KASSERT(fcaps->fc_fcntls == 0 || 1483 cap_rights_is_set(&fcaps->fc_rights, CAP_FCNTL), 1484 ("%s: fcntls without CAP_FCNTL", func)); 1485 KASSERT(fcaps->fc_ioctls != NULL ? fcaps->fc_nioctls > 0 : 1486 (fcaps->fc_nioctls == -1 || fcaps->fc_nioctls == 0), 1487 ("%s: invalid ioctls", func)); 1488 KASSERT(fcaps->fc_nioctls == 0 || 1489 cap_rights_is_set(&fcaps->fc_rights, CAP_IOCTL), 1490 ("%s: ioctls without CAP_IOCTL", func)); 1491 } 1492 1493 static void 1494 fdgrowtable_exp(struct filedesc *fdp, int nfd) 1495 { 1496 int nfd1; 1497 1498 FILEDESC_XLOCK_ASSERT(fdp); 1499 1500 nfd1 = fdp->fd_nfiles * 2; 1501 if (nfd1 < nfd) 1502 nfd1 = nfd; 1503 fdgrowtable(fdp, nfd1); 1504 } 1505 1506 /* 1507 * Grow the file table to accomodate (at least) nfd descriptors. 1508 */ 1509 static void 1510 fdgrowtable(struct filedesc *fdp, int nfd) 1511 { 1512 struct filedesc0 *fdp0; 1513 struct freetable *ft; 1514 struct fdescenttbl *ntable; 1515 struct fdescenttbl *otable; 1516 int nnfiles, onfiles; 1517 NDSLOTTYPE *nmap, *omap; 1518 1519 /* 1520 * If lastfile is -1 this struct filedesc was just allocated and we are 1521 * growing it to accomodate for the one we are going to copy from. There 1522 * is no need to have a lock on this one as it's not visible to anyone. 1523 */ 1524 if (fdp->fd_lastfile != -1) 1525 FILEDESC_XLOCK_ASSERT(fdp); 1526 1527 KASSERT(fdp->fd_nfiles > 0, ("zero-length file table")); 1528 1529 /* save old values */ 1530 onfiles = fdp->fd_nfiles; 1531 otable = fdp->fd_files; 1532 omap = fdp->fd_map; 1533 1534 /* compute the size of the new table */ 1535 nnfiles = NDSLOTS(nfd) * NDENTRIES; /* round up */ 1536 if (nnfiles <= onfiles) 1537 /* the table is already large enough */ 1538 return; 1539 1540 /* 1541 * Allocate a new table. We need enough space for the number of 1542 * entries, file entries themselves and the struct freetable we will use 1543 * when we decommission the table and place it on the freelist. 1544 * We place the struct freetable in the middle so we don't have 1545 * to worry about padding. 1546 */ 1547 ntable = malloc(offsetof(struct fdescenttbl, fdt_ofiles) + 1548 nnfiles * sizeof(ntable->fdt_ofiles[0]) + 1549 sizeof(struct freetable), 1550 M_FILEDESC, M_ZERO | M_WAITOK); 1551 /* copy the old data */ 1552 ntable->fdt_nfiles = nnfiles; 1553 memcpy(ntable->fdt_ofiles, otable->fdt_ofiles, 1554 onfiles * sizeof(ntable->fdt_ofiles[0])); 1555 1556 /* 1557 * Allocate a new map only if the old is not large enough. It will 1558 * grow at a slower rate than the table as it can map more 1559 * entries than the table can hold. 1560 */ 1561 if (NDSLOTS(nnfiles) > NDSLOTS(onfiles)) { 1562 nmap = malloc(NDSLOTS(nnfiles) * NDSLOTSIZE, M_FILEDESC, 1563 M_ZERO | M_WAITOK); 1564 /* copy over the old data and update the pointer */ 1565 memcpy(nmap, omap, NDSLOTS(onfiles) * sizeof(*omap)); 1566 fdp->fd_map = nmap; 1567 } 1568 1569 /* 1570 * Make sure that ntable is correctly initialized before we replace 1571 * fd_files poiner. Otherwise fget_unlocked() may see inconsistent 1572 * data. 1573 */ 1574 atomic_store_rel_ptr((volatile void *)&fdp->fd_files, (uintptr_t)ntable); 1575 1576 /* 1577 * Do not free the old file table, as some threads may still 1578 * reference entries within it. Instead, place it on a freelist 1579 * which will be processed when the struct filedesc is released. 1580 * 1581 * Note that if onfiles == NDFILE, we're dealing with the original 1582 * static allocation contained within (struct filedesc0 *)fdp, 1583 * which must not be freed. 1584 */ 1585 if (onfiles > NDFILE) { 1586 ft = (struct freetable *)&otable->fdt_ofiles[onfiles]; 1587 fdp0 = (struct filedesc0 *)fdp; 1588 ft->ft_table = otable; 1589 SLIST_INSERT_HEAD(&fdp0->fd_free, ft, ft_next); 1590 } 1591 /* 1592 * The map does not have the same possibility of threads still 1593 * holding references to it. So always free it as long as it 1594 * does not reference the original static allocation. 1595 */ 1596 if (NDSLOTS(onfiles) > NDSLOTS(NDFILE)) 1597 free(omap, M_FILEDESC); 1598 } 1599 1600 /* 1601 * Allocate a file descriptor for the process. 1602 */ 1603 int 1604 fdalloc(struct thread *td, int minfd, int *result) 1605 { 1606 struct proc *p = td->td_proc; 1607 struct filedesc *fdp = p->p_fd; 1608 int fd, maxfd, allocfd; 1609 #ifdef RACCT 1610 int error; 1611 #endif 1612 1613 FILEDESC_XLOCK_ASSERT(fdp); 1614 1615 if (fdp->fd_freefile > minfd) 1616 minfd = fdp->fd_freefile; 1617 1618 maxfd = getmaxfd(td); 1619 1620 /* 1621 * Search the bitmap for a free descriptor starting at minfd. 1622 * If none is found, grow the file table. 1623 */ 1624 fd = fd_first_free(fdp, minfd, fdp->fd_nfiles); 1625 if (fd >= maxfd) 1626 return (EMFILE); 1627 if (fd >= fdp->fd_nfiles) { 1628 allocfd = min(fd * 2, maxfd); 1629 #ifdef RACCT 1630 if (racct_enable) { 1631 PROC_LOCK(p); 1632 error = racct_set(p, RACCT_NOFILE, allocfd); 1633 PROC_UNLOCK(p); 1634 if (error != 0) 1635 return (EMFILE); 1636 } 1637 #endif 1638 /* 1639 * fd is already equal to first free descriptor >= minfd, so 1640 * we only need to grow the table and we are done. 1641 */ 1642 fdgrowtable_exp(fdp, allocfd); 1643 } 1644 1645 /* 1646 * Perform some sanity checks, then mark the file descriptor as 1647 * used and return it to the caller. 1648 */ 1649 KASSERT(fd >= 0 && fd < min(maxfd, fdp->fd_nfiles), 1650 ("invalid descriptor %d", fd)); 1651 KASSERT(!fdisused(fdp, fd), 1652 ("fd_first_free() returned non-free descriptor")); 1653 KASSERT(fdp->fd_ofiles[fd].fde_file == NULL, 1654 ("file descriptor isn't free")); 1655 fdused(fdp, fd); 1656 *result = fd; 1657 return (0); 1658 } 1659 1660 /* 1661 * Allocate n file descriptors for the process. 1662 */ 1663 int 1664 fdallocn(struct thread *td, int minfd, int *fds, int n) 1665 { 1666 struct proc *p = td->td_proc; 1667 struct filedesc *fdp = p->p_fd; 1668 int i; 1669 1670 FILEDESC_XLOCK_ASSERT(fdp); 1671 1672 for (i = 0; i < n; i++) 1673 if (fdalloc(td, 0, &fds[i]) != 0) 1674 break; 1675 1676 if (i < n) { 1677 for (i--; i >= 0; i--) 1678 fdunused(fdp, fds[i]); 1679 return (EMFILE); 1680 } 1681 1682 return (0); 1683 } 1684 1685 /* 1686 * Create a new open file structure and allocate a file decriptor for the 1687 * process that refers to it. We add one reference to the file for the 1688 * descriptor table and one reference for resultfp. This is to prevent us 1689 * being preempted and the entry in the descriptor table closed after we 1690 * release the FILEDESC lock. 1691 */ 1692 int 1693 falloc(struct thread *td, struct file **resultfp, int *resultfd, int flags) 1694 { 1695 struct file *fp; 1696 int error, fd; 1697 1698 error = falloc_noinstall(td, &fp); 1699 if (error) 1700 return (error); /* no reference held on error */ 1701 1702 error = finstall(td, fp, &fd, flags, NULL); 1703 if (error) { 1704 fdrop(fp, td); /* one reference (fp only) */ 1705 return (error); 1706 } 1707 1708 if (resultfp != NULL) 1709 *resultfp = fp; /* copy out result */ 1710 else 1711 fdrop(fp, td); /* release local reference */ 1712 1713 if (resultfd != NULL) 1714 *resultfd = fd; 1715 1716 return (0); 1717 } 1718 1719 /* 1720 * Create a new open file structure without allocating a file descriptor. 1721 */ 1722 int 1723 falloc_noinstall(struct thread *td, struct file **resultfp) 1724 { 1725 struct file *fp; 1726 int maxuserfiles = maxfiles - (maxfiles / 20); 1727 static struct timeval lastfail; 1728 static int curfail; 1729 1730 KASSERT(resultfp != NULL, ("%s: resultfp == NULL", __func__)); 1731 1732 if ((openfiles >= maxuserfiles && 1733 priv_check(td, PRIV_MAXFILES) != 0) || 1734 openfiles >= maxfiles) { 1735 if (ppsratecheck(&lastfail, &curfail, 1)) { 1736 printf("kern.maxfiles limit exceeded by uid %i, " 1737 "please see tuning(7).\n", td->td_ucred->cr_ruid); 1738 } 1739 return (ENFILE); 1740 } 1741 atomic_add_int(&openfiles, 1); 1742 fp = uma_zalloc(file_zone, M_WAITOK | M_ZERO); 1743 refcount_init(&fp->f_count, 1); 1744 fp->f_cred = crhold(td->td_ucred); 1745 fp->f_ops = &badfileops; 1746 *resultfp = fp; 1747 return (0); 1748 } 1749 1750 /* 1751 * Install a file in a file descriptor table. 1752 */ 1753 void 1754 _finstall(struct filedesc *fdp, struct file *fp, int fd, int flags, 1755 struct filecaps *fcaps) 1756 { 1757 struct filedescent *fde; 1758 1759 MPASS(fp != NULL); 1760 if (fcaps != NULL) 1761 filecaps_validate(fcaps, __func__); 1762 FILEDESC_XLOCK_ASSERT(fdp); 1763 1764 fde = &fdp->fd_ofiles[fd]; 1765 #ifdef CAPABILITIES 1766 seq_write_begin(&fde->fde_seq); 1767 #endif 1768 fde->fde_file = fp; 1769 fde->fde_flags = (flags & O_CLOEXEC) != 0 ? UF_EXCLOSE : 0; 1770 if (fcaps != NULL) 1771 filecaps_move(fcaps, &fde->fde_caps); 1772 else 1773 filecaps_fill(&fde->fde_caps); 1774 #ifdef CAPABILITIES 1775 seq_write_end(&fde->fde_seq); 1776 #endif 1777 } 1778 1779 int 1780 finstall(struct thread *td, struct file *fp, int *fd, int flags, 1781 struct filecaps *fcaps) 1782 { 1783 struct filedesc *fdp = td->td_proc->p_fd; 1784 int error; 1785 1786 MPASS(fd != NULL); 1787 1788 FILEDESC_XLOCK(fdp); 1789 if ((error = fdalloc(td, 0, fd))) { 1790 FILEDESC_XUNLOCK(fdp); 1791 return (error); 1792 } 1793 fhold(fp); 1794 _finstall(fdp, fp, *fd, flags, fcaps); 1795 FILEDESC_XUNLOCK(fdp); 1796 return (0); 1797 } 1798 1799 /* 1800 * Build a new filedesc structure from another. 1801 * Copy the current, root, and jail root vnode references. 1802 * 1803 * If fdp is not NULL, return with it shared locked. 1804 */ 1805 struct filedesc * 1806 fdinit(struct filedesc *fdp, bool prepfiles) 1807 { 1808 struct filedesc0 *newfdp0; 1809 struct filedesc *newfdp; 1810 1811 newfdp0 = uma_zalloc(filedesc0_zone, M_WAITOK | M_ZERO); 1812 newfdp = &newfdp0->fd_fd; 1813 1814 /* Create the file descriptor table. */ 1815 FILEDESC_LOCK_INIT(newfdp); 1816 refcount_init(&newfdp->fd_refcnt, 1); 1817 refcount_init(&newfdp->fd_holdcnt, 1); 1818 newfdp->fd_cmask = CMASK; 1819 newfdp->fd_map = newfdp0->fd_dmap; 1820 newfdp->fd_lastfile = -1; 1821 newfdp->fd_files = (struct fdescenttbl *)&newfdp0->fd_dfiles; 1822 newfdp->fd_files->fdt_nfiles = NDFILE; 1823 1824 if (fdp == NULL) 1825 return (newfdp); 1826 1827 if (prepfiles && fdp->fd_lastfile >= newfdp->fd_nfiles) 1828 fdgrowtable(newfdp, fdp->fd_lastfile + 1); 1829 1830 FILEDESC_SLOCK(fdp); 1831 newfdp->fd_cdir = fdp->fd_cdir; 1832 if (newfdp->fd_cdir) 1833 VREF(newfdp->fd_cdir); 1834 newfdp->fd_rdir = fdp->fd_rdir; 1835 if (newfdp->fd_rdir) 1836 VREF(newfdp->fd_rdir); 1837 newfdp->fd_jdir = fdp->fd_jdir; 1838 if (newfdp->fd_jdir) 1839 VREF(newfdp->fd_jdir); 1840 1841 if (!prepfiles) { 1842 FILEDESC_SUNLOCK(fdp); 1843 } else { 1844 while (fdp->fd_lastfile >= newfdp->fd_nfiles) { 1845 FILEDESC_SUNLOCK(fdp); 1846 fdgrowtable(newfdp, fdp->fd_lastfile + 1); 1847 FILEDESC_SLOCK(fdp); 1848 } 1849 } 1850 1851 return (newfdp); 1852 } 1853 1854 static struct filedesc * 1855 fdhold(struct proc *p) 1856 { 1857 struct filedesc *fdp; 1858 1859 PROC_LOCK_ASSERT(p, MA_OWNED); 1860 fdp = p->p_fd; 1861 if (fdp != NULL) 1862 refcount_acquire(&fdp->fd_holdcnt); 1863 return (fdp); 1864 } 1865 1866 static void 1867 fddrop(struct filedesc *fdp) 1868 { 1869 1870 if (fdp->fd_holdcnt > 1) { 1871 if (refcount_release(&fdp->fd_holdcnt) == 0) 1872 return; 1873 } 1874 1875 FILEDESC_LOCK_DESTROY(fdp); 1876 uma_zfree(filedesc0_zone, fdp); 1877 } 1878 1879 /* 1880 * Share a filedesc structure. 1881 */ 1882 struct filedesc * 1883 fdshare(struct filedesc *fdp) 1884 { 1885 1886 refcount_acquire(&fdp->fd_refcnt); 1887 return (fdp); 1888 } 1889 1890 /* 1891 * Unshare a filedesc structure, if necessary by making a copy 1892 */ 1893 void 1894 fdunshare(struct thread *td) 1895 { 1896 struct filedesc *tmp; 1897 struct proc *p = td->td_proc; 1898 1899 if (p->p_fd->fd_refcnt == 1) 1900 return; 1901 1902 tmp = fdcopy(p->p_fd); 1903 fdescfree(td); 1904 p->p_fd = tmp; 1905 } 1906 1907 /* 1908 * Copy a filedesc structure. A NULL pointer in returns a NULL reference, 1909 * this is to ease callers, not catch errors. 1910 */ 1911 struct filedesc * 1912 fdcopy(struct filedesc *fdp) 1913 { 1914 struct filedesc *newfdp; 1915 struct filedescent *nfde, *ofde; 1916 int i; 1917 1918 MPASS(fdp != NULL); 1919 1920 newfdp = fdinit(fdp, true); 1921 /* copy all passable descriptors (i.e. not kqueue) */ 1922 newfdp->fd_freefile = -1; 1923 for (i = 0; i <= fdp->fd_lastfile; ++i) { 1924 ofde = &fdp->fd_ofiles[i]; 1925 if (ofde->fde_file == NULL || 1926 (ofde->fde_file->f_ops->fo_flags & DFLAG_PASSABLE) == 0) { 1927 if (newfdp->fd_freefile == -1) 1928 newfdp->fd_freefile = i; 1929 continue; 1930 } 1931 nfde = &newfdp->fd_ofiles[i]; 1932 *nfde = *ofde; 1933 filecaps_copy(&ofde->fde_caps, &nfde->fde_caps); 1934 fhold(nfde->fde_file); 1935 fdused_init(newfdp, i); 1936 newfdp->fd_lastfile = i; 1937 } 1938 if (newfdp->fd_freefile == -1) 1939 newfdp->fd_freefile = i; 1940 newfdp->fd_cmask = fdp->fd_cmask; 1941 FILEDESC_SUNLOCK(fdp); 1942 return (newfdp); 1943 } 1944 1945 /* 1946 * Clear POSIX style locks. This is only used when fdp looses a reference (i.e. 1947 * one of processes using it exits) and the table used to be shared. 1948 */ 1949 static void 1950 fdclearlocks(struct thread *td) 1951 { 1952 struct filedesc *fdp; 1953 struct filedesc_to_leader *fdtol; 1954 struct flock lf; 1955 struct file *fp; 1956 struct proc *p; 1957 struct vnode *vp; 1958 int i; 1959 1960 p = td->td_proc; 1961 fdp = p->p_fd; 1962 fdtol = p->p_fdtol; 1963 MPASS(fdtol != NULL); 1964 1965 FILEDESC_XLOCK(fdp); 1966 KASSERT(fdtol->fdl_refcount > 0, 1967 ("filedesc_to_refcount botch: fdl_refcount=%d", 1968 fdtol->fdl_refcount)); 1969 if (fdtol->fdl_refcount == 1 && 1970 (p->p_leader->p_flag & P_ADVLOCK) != 0) { 1971 for (i = 0; i <= fdp->fd_lastfile; i++) { 1972 fp = fdp->fd_ofiles[i].fde_file; 1973 if (fp == NULL || fp->f_type != DTYPE_VNODE) 1974 continue; 1975 fhold(fp); 1976 FILEDESC_XUNLOCK(fdp); 1977 lf.l_whence = SEEK_SET; 1978 lf.l_start = 0; 1979 lf.l_len = 0; 1980 lf.l_type = F_UNLCK; 1981 vp = fp->f_vnode; 1982 (void) VOP_ADVLOCK(vp, 1983 (caddr_t)p->p_leader, F_UNLCK, 1984 &lf, F_POSIX); 1985 FILEDESC_XLOCK(fdp); 1986 fdrop(fp, td); 1987 } 1988 } 1989 retry: 1990 if (fdtol->fdl_refcount == 1) { 1991 if (fdp->fd_holdleaderscount > 0 && 1992 (p->p_leader->p_flag & P_ADVLOCK) != 0) { 1993 /* 1994 * close() or do_dup() has cleared a reference 1995 * in a shared file descriptor table. 1996 */ 1997 fdp->fd_holdleaderswakeup = 1; 1998 sx_sleep(&fdp->fd_holdleaderscount, 1999 FILEDESC_LOCK(fdp), PLOCK, "fdlhold", 0); 2000 goto retry; 2001 } 2002 if (fdtol->fdl_holdcount > 0) { 2003 /* 2004 * Ensure that fdtol->fdl_leader remains 2005 * valid in closef(). 2006 */ 2007 fdtol->fdl_wakeup = 1; 2008 sx_sleep(fdtol, FILEDESC_LOCK(fdp), PLOCK, 2009 "fdlhold", 0); 2010 goto retry; 2011 } 2012 } 2013 fdtol->fdl_refcount--; 2014 if (fdtol->fdl_refcount == 0 && 2015 fdtol->fdl_holdcount == 0) { 2016 fdtol->fdl_next->fdl_prev = fdtol->fdl_prev; 2017 fdtol->fdl_prev->fdl_next = fdtol->fdl_next; 2018 } else 2019 fdtol = NULL; 2020 p->p_fdtol = NULL; 2021 FILEDESC_XUNLOCK(fdp); 2022 if (fdtol != NULL) 2023 free(fdtol, M_FILEDESC_TO_LEADER); 2024 } 2025 2026 /* 2027 * Release a filedesc structure. 2028 */ 2029 void 2030 fdescfree(struct thread *td) 2031 { 2032 struct proc *p; 2033 struct filedesc0 *fdp0; 2034 struct filedesc *fdp; 2035 struct freetable *ft, *tft; 2036 struct filedescent *fde; 2037 struct file *fp; 2038 struct vnode *cdir, *jdir, *rdir; 2039 int i; 2040 2041 p = td->td_proc; 2042 fdp = p->p_fd; 2043 MPASS(fdp != NULL); 2044 2045 #ifdef RACCT 2046 if (racct_enable) { 2047 PROC_LOCK(p); 2048 racct_set(p, RACCT_NOFILE, 0); 2049 PROC_UNLOCK(p); 2050 } 2051 #endif 2052 2053 if (td->td_proc->p_fdtol != NULL) 2054 fdclearlocks(td); 2055 2056 PROC_LOCK(p); 2057 p->p_fd = NULL; 2058 PROC_UNLOCK(p); 2059 2060 if (refcount_release(&fdp->fd_refcnt) == 0) 2061 return; 2062 2063 FILEDESC_XLOCK(fdp); 2064 cdir = fdp->fd_cdir; 2065 fdp->fd_cdir = NULL; 2066 rdir = fdp->fd_rdir; 2067 fdp->fd_rdir = NULL; 2068 jdir = fdp->fd_jdir; 2069 fdp->fd_jdir = NULL; 2070 FILEDESC_XUNLOCK(fdp); 2071 2072 for (i = 0; i <= fdp->fd_lastfile; i++) { 2073 fde = &fdp->fd_ofiles[i]; 2074 fp = fde->fde_file; 2075 if (fp != NULL) { 2076 fdefree_last(fde); 2077 (void) closef(fp, td); 2078 } 2079 } 2080 2081 if (NDSLOTS(fdp->fd_nfiles) > NDSLOTS(NDFILE)) 2082 free(fdp->fd_map, M_FILEDESC); 2083 if (fdp->fd_nfiles > NDFILE) 2084 free(fdp->fd_files, M_FILEDESC); 2085 2086 fdp0 = (struct filedesc0 *)fdp; 2087 SLIST_FOREACH_SAFE(ft, &fdp0->fd_free, ft_next, tft) 2088 free(ft->ft_table, M_FILEDESC); 2089 2090 if (cdir != NULL) 2091 vrele(cdir); 2092 if (rdir != NULL) 2093 vrele(rdir); 2094 if (jdir != NULL) 2095 vrele(jdir); 2096 2097 fddrop(fdp); 2098 } 2099 2100 /* 2101 * For setugid programs, we don't want to people to use that setugidness 2102 * to generate error messages which write to a file which otherwise would 2103 * otherwise be off-limits to the process. We check for filesystems where 2104 * the vnode can change out from under us after execve (like [lin]procfs). 2105 * 2106 * Since fdsetugidsafety calls this only for fd 0, 1 and 2, this check is 2107 * sufficient. We also don't check for setugidness since we know we are. 2108 */ 2109 static bool 2110 is_unsafe(struct file *fp) 2111 { 2112 struct vnode *vp; 2113 2114 if (fp->f_type != DTYPE_VNODE) 2115 return (false); 2116 2117 vp = fp->f_vnode; 2118 return ((vp->v_vflag & VV_PROCDEP) != 0); 2119 } 2120 2121 /* 2122 * Make this setguid thing safe, if at all possible. 2123 */ 2124 void 2125 fdsetugidsafety(struct thread *td) 2126 { 2127 struct filedesc *fdp; 2128 struct file *fp; 2129 int i; 2130 2131 fdp = td->td_proc->p_fd; 2132 KASSERT(fdp->fd_refcnt == 1, ("the fdtable should not be shared")); 2133 MPASS(fdp->fd_nfiles >= 3); 2134 for (i = 0; i <= 2; i++) { 2135 fp = fdp->fd_ofiles[i].fde_file; 2136 if (fp != NULL && is_unsafe(fp)) { 2137 FILEDESC_XLOCK(fdp); 2138 knote_fdclose(td, i); 2139 /* 2140 * NULL-out descriptor prior to close to avoid 2141 * a race while close blocks. 2142 */ 2143 fdfree(fdp, i); 2144 FILEDESC_XUNLOCK(fdp); 2145 (void) closef(fp, td); 2146 } 2147 } 2148 } 2149 2150 /* 2151 * If a specific file object occupies a specific file descriptor, close the 2152 * file descriptor entry and drop a reference on the file object. This is a 2153 * convenience function to handle a subsequent error in a function that calls 2154 * falloc() that handles the race that another thread might have closed the 2155 * file descriptor out from under the thread creating the file object. 2156 */ 2157 void 2158 fdclose(struct thread *td, struct file *fp, int idx) 2159 { 2160 struct filedesc *fdp = td->td_proc->p_fd; 2161 2162 FILEDESC_XLOCK(fdp); 2163 if (fdp->fd_ofiles[idx].fde_file == fp) { 2164 fdfree(fdp, idx); 2165 FILEDESC_XUNLOCK(fdp); 2166 fdrop(fp, td); 2167 } else 2168 FILEDESC_XUNLOCK(fdp); 2169 } 2170 2171 /* 2172 * Close any files on exec? 2173 */ 2174 void 2175 fdcloseexec(struct thread *td) 2176 { 2177 struct filedesc *fdp; 2178 struct filedescent *fde; 2179 struct file *fp; 2180 int i; 2181 2182 fdp = td->td_proc->p_fd; 2183 KASSERT(fdp->fd_refcnt == 1, ("the fdtable should not be shared")); 2184 for (i = 0; i <= fdp->fd_lastfile; i++) { 2185 fde = &fdp->fd_ofiles[i]; 2186 fp = fde->fde_file; 2187 if (fp != NULL && (fp->f_type == DTYPE_MQUEUE || 2188 (fde->fde_flags & UF_EXCLOSE))) { 2189 FILEDESC_XLOCK(fdp); 2190 fdfree(fdp, i); 2191 (void) closefp(fdp, i, fp, td, 0); 2192 /* closefp() drops the FILEDESC lock. */ 2193 } 2194 } 2195 } 2196 2197 /* 2198 * It is unsafe for set[ug]id processes to be started with file 2199 * descriptors 0..2 closed, as these descriptors are given implicit 2200 * significance in the Standard C library. fdcheckstd() will create a 2201 * descriptor referencing /dev/null for each of stdin, stdout, and 2202 * stderr that is not already open. 2203 */ 2204 int 2205 fdcheckstd(struct thread *td) 2206 { 2207 struct filedesc *fdp; 2208 register_t save; 2209 int i, error, devnull; 2210 2211 fdp = td->td_proc->p_fd; 2212 KASSERT(fdp->fd_refcnt == 1, ("the fdtable should not be shared")); 2213 MPASS(fdp->fd_nfiles >= 3); 2214 devnull = -1; 2215 for (i = 0; i <= 2; i++) { 2216 if (fdp->fd_ofiles[i].fde_file != NULL) 2217 continue; 2218 2219 save = td->td_retval[0]; 2220 if (devnull != -1) { 2221 error = do_dup(td, DUP_FIXED, devnull, i); 2222 } else { 2223 error = kern_openat(td, AT_FDCWD, "/dev/null", 2224 UIO_SYSSPACE, O_RDWR, 0); 2225 if (error == 0) { 2226 devnull = td->td_retval[0]; 2227 KASSERT(devnull == i, ("we didn't get our fd")); 2228 } 2229 } 2230 td->td_retval[0] = save; 2231 if (error != 0) 2232 return (error); 2233 } 2234 return (0); 2235 } 2236 2237 /* 2238 * Internal form of close. Decrement reference count on file structure. 2239 * Note: td may be NULL when closing a file that was being passed in a 2240 * message. 2241 * 2242 * XXXRW: Giant is not required for the caller, but often will be held; this 2243 * makes it moderately likely the Giant will be recursed in the VFS case. 2244 */ 2245 int 2246 closef(struct file *fp, struct thread *td) 2247 { 2248 struct vnode *vp; 2249 struct flock lf; 2250 struct filedesc_to_leader *fdtol; 2251 struct filedesc *fdp; 2252 2253 /* 2254 * POSIX record locking dictates that any close releases ALL 2255 * locks owned by this process. This is handled by setting 2256 * a flag in the unlock to free ONLY locks obeying POSIX 2257 * semantics, and not to free BSD-style file locks. 2258 * If the descriptor was in a message, POSIX-style locks 2259 * aren't passed with the descriptor, and the thread pointer 2260 * will be NULL. Callers should be careful only to pass a 2261 * NULL thread pointer when there really is no owning 2262 * context that might have locks, or the locks will be 2263 * leaked. 2264 */ 2265 if (fp->f_type == DTYPE_VNODE && td != NULL) { 2266 vp = fp->f_vnode; 2267 if ((td->td_proc->p_leader->p_flag & P_ADVLOCK) != 0) { 2268 lf.l_whence = SEEK_SET; 2269 lf.l_start = 0; 2270 lf.l_len = 0; 2271 lf.l_type = F_UNLCK; 2272 (void) VOP_ADVLOCK(vp, (caddr_t)td->td_proc->p_leader, 2273 F_UNLCK, &lf, F_POSIX); 2274 } 2275 fdtol = td->td_proc->p_fdtol; 2276 if (fdtol != NULL) { 2277 /* 2278 * Handle special case where file descriptor table is 2279 * shared between multiple process leaders. 2280 */ 2281 fdp = td->td_proc->p_fd; 2282 FILEDESC_XLOCK(fdp); 2283 for (fdtol = fdtol->fdl_next; 2284 fdtol != td->td_proc->p_fdtol; 2285 fdtol = fdtol->fdl_next) { 2286 if ((fdtol->fdl_leader->p_flag & 2287 P_ADVLOCK) == 0) 2288 continue; 2289 fdtol->fdl_holdcount++; 2290 FILEDESC_XUNLOCK(fdp); 2291 lf.l_whence = SEEK_SET; 2292 lf.l_start = 0; 2293 lf.l_len = 0; 2294 lf.l_type = F_UNLCK; 2295 vp = fp->f_vnode; 2296 (void) VOP_ADVLOCK(vp, 2297 (caddr_t)fdtol->fdl_leader, F_UNLCK, &lf, 2298 F_POSIX); 2299 FILEDESC_XLOCK(fdp); 2300 fdtol->fdl_holdcount--; 2301 if (fdtol->fdl_holdcount == 0 && 2302 fdtol->fdl_wakeup != 0) { 2303 fdtol->fdl_wakeup = 0; 2304 wakeup(fdtol); 2305 } 2306 } 2307 FILEDESC_XUNLOCK(fdp); 2308 } 2309 } 2310 return (fdrop(fp, td)); 2311 } 2312 2313 /* 2314 * Initialize the file pointer with the specified properties. 2315 * 2316 * The ops are set with release semantics to be certain that the flags, type, 2317 * and data are visible when ops is. This is to prevent ops methods from being 2318 * called with bad data. 2319 */ 2320 void 2321 finit(struct file *fp, u_int flag, short type, void *data, struct fileops *ops) 2322 { 2323 fp->f_data = data; 2324 fp->f_flag = flag; 2325 fp->f_type = type; 2326 atomic_store_rel_ptr((volatile uintptr_t *)&fp->f_ops, (uintptr_t)ops); 2327 } 2328 2329 int 2330 fget_unlocked(struct filedesc *fdp, int fd, cap_rights_t *needrightsp, 2331 struct file **fpp, seq_t *seqp) 2332 { 2333 #ifdef CAPABILITIES 2334 struct filedescent *fde; 2335 #endif 2336 struct fdescenttbl *fdt; 2337 struct file *fp; 2338 u_int count; 2339 #ifdef CAPABILITIES 2340 seq_t seq; 2341 cap_rights_t haverights; 2342 int error; 2343 #endif 2344 2345 fdt = fdp->fd_files; 2346 if ((u_int)fd >= fdt->fdt_nfiles) 2347 return (EBADF); 2348 /* 2349 * Fetch the descriptor locklessly. We avoid fdrop() races by 2350 * never raising a refcount above 0. To accomplish this we have 2351 * to use a cmpset loop rather than an atomic_add. The descriptor 2352 * must be re-verified once we acquire a reference to be certain 2353 * that the identity is still correct and we did not lose a race 2354 * due to preemption. 2355 */ 2356 for (;;) { 2357 #ifdef CAPABILITIES 2358 seq = seq_read(fd_seq(fdt, fd)); 2359 fde = &fdt->fdt_ofiles[fd]; 2360 haverights = *cap_rights_fde(fde); 2361 fp = fde->fde_file; 2362 if (!seq_consistent(fd_seq(fdt, fd), seq)) { 2363 cpu_spinwait(); 2364 continue; 2365 } 2366 #else 2367 fp = fdt->fdt_ofiles[fd].fde_file; 2368 #endif 2369 if (fp == NULL) 2370 return (EBADF); 2371 #ifdef CAPABILITIES 2372 error = cap_check(&haverights, needrightsp); 2373 if (error != 0) 2374 return (error); 2375 #endif 2376 retry: 2377 count = fp->f_count; 2378 if (count == 0) { 2379 /* 2380 * Force a reload. Other thread could reallocate the 2381 * table before this fd was closed, so it possible that 2382 * there is a stale fp pointer in cached version. 2383 */ 2384 fdt = *(struct fdescenttbl * volatile *)&(fdp->fd_files); 2385 continue; 2386 } 2387 /* 2388 * Use an acquire barrier to force re-reading of fdt so it is 2389 * refreshed for verification. 2390 */ 2391 if (atomic_cmpset_acq_int(&fp->f_count, count, count + 1) == 0) 2392 goto retry; 2393 fdt = fdp->fd_files; 2394 #ifdef CAPABILITIES 2395 if (seq_consistent_nomb(fd_seq(fdt, fd), seq)) 2396 #else 2397 if (fp == fdt->fdt_ofiles[fd].fde_file) 2398 #endif 2399 break; 2400 fdrop(fp, curthread); 2401 } 2402 *fpp = fp; 2403 if (seqp != NULL) { 2404 #ifdef CAPABILITIES 2405 *seqp = seq; 2406 #endif 2407 } 2408 return (0); 2409 } 2410 2411 /* 2412 * Extract the file pointer associated with the specified descriptor for the 2413 * current user process. 2414 * 2415 * If the descriptor doesn't exist or doesn't match 'flags', EBADF is 2416 * returned. 2417 * 2418 * File's rights will be checked against the capability rights mask. 2419 * 2420 * If an error occured the non-zero error is returned and *fpp is set to 2421 * NULL. Otherwise *fpp is held and set and zero is returned. Caller is 2422 * responsible for fdrop(). 2423 */ 2424 static __inline int 2425 _fget(struct thread *td, int fd, struct file **fpp, int flags, 2426 cap_rights_t *needrightsp, seq_t *seqp) 2427 { 2428 struct filedesc *fdp; 2429 struct file *fp; 2430 cap_rights_t needrights; 2431 int error; 2432 2433 *fpp = NULL; 2434 fdp = td->td_proc->p_fd; 2435 if (needrightsp == NULL) 2436 needrightsp = cap_rights_init(&needrights); 2437 error = fget_unlocked(fdp, fd, needrightsp, &fp, seqp); 2438 if (error != 0) 2439 return (error); 2440 if (fp->f_ops == &badfileops) { 2441 fdrop(fp, td); 2442 return (EBADF); 2443 } 2444 2445 /* 2446 * FREAD and FWRITE failure return EBADF as per POSIX. 2447 */ 2448 error = 0; 2449 switch (flags) { 2450 case FREAD: 2451 case FWRITE: 2452 if ((fp->f_flag & flags) == 0) 2453 error = EBADF; 2454 break; 2455 case FEXEC: 2456 if ((fp->f_flag & (FREAD | FEXEC)) == 0 || 2457 ((fp->f_flag & FWRITE) != 0)) 2458 error = EBADF; 2459 break; 2460 case 0: 2461 break; 2462 default: 2463 KASSERT(0, ("wrong flags")); 2464 } 2465 2466 if (error != 0) { 2467 fdrop(fp, td); 2468 return (error); 2469 } 2470 2471 *fpp = fp; 2472 return (0); 2473 } 2474 2475 int 2476 fget(struct thread *td, int fd, cap_rights_t *rightsp, struct file **fpp) 2477 { 2478 2479 return (_fget(td, fd, fpp, 0, rightsp, NULL)); 2480 } 2481 2482 int 2483 fget_mmap(struct thread *td, int fd, cap_rights_t *rightsp, u_char *maxprotp, 2484 struct file **fpp) 2485 { 2486 int error; 2487 #ifndef CAPABILITIES 2488 error = _fget(td, fd, fpp, 0, rightsp, NULL); 2489 if (maxprotp != NULL) 2490 *maxprotp = VM_PROT_ALL; 2491 #else 2492 struct filedesc *fdp = td->td_proc->p_fd; 2493 seq_t seq; 2494 2495 MPASS(cap_rights_is_set(rightsp, CAP_MMAP)); 2496 for (;;) { 2497 error = _fget(td, fd, fpp, 0, rightsp, &seq); 2498 if (error != 0) 2499 return (error); 2500 /* 2501 * If requested, convert capability rights to access flags. 2502 */ 2503 if (maxprotp != NULL) 2504 *maxprotp = cap_rights_to_vmprot(cap_rights(fdp, fd)); 2505 if (!fd_modified(fdp, fd, seq)) 2506 break; 2507 fdrop(*fpp, td); 2508 } 2509 #endif 2510 return (error); 2511 } 2512 2513 int 2514 fget_read(struct thread *td, int fd, cap_rights_t *rightsp, struct file **fpp) 2515 { 2516 2517 return (_fget(td, fd, fpp, FREAD, rightsp, NULL)); 2518 } 2519 2520 int 2521 fget_write(struct thread *td, int fd, cap_rights_t *rightsp, struct file **fpp) 2522 { 2523 2524 return (_fget(td, fd, fpp, FWRITE, rightsp, NULL)); 2525 } 2526 2527 int 2528 fget_fcntl(struct thread *td, int fd, cap_rights_t *rightsp, int needfcntl, 2529 struct file **fpp) 2530 { 2531 struct filedesc *fdp = td->td_proc->p_fd; 2532 #ifndef CAPABILITIES 2533 return (fget_unlocked(fdp, fd, rightsp, fpp, NULL)); 2534 #else 2535 int error; 2536 seq_t seq; 2537 2538 MPASS(cap_rights_is_set(rightsp, CAP_FCNTL)); 2539 for (;;) { 2540 error = fget_unlocked(fdp, fd, rightsp, fpp, &seq); 2541 if (error != 0) 2542 return (error); 2543 error = cap_fcntl_check(fdp, fd, needfcntl); 2544 if (!fd_modified(fdp, fd, seq)) 2545 break; 2546 fdrop(*fpp, td); 2547 } 2548 if (error != 0) { 2549 fdrop(*fpp, td); 2550 *fpp = NULL; 2551 } 2552 return (error); 2553 #endif 2554 } 2555 2556 /* 2557 * Like fget() but loads the underlying vnode, or returns an error if the 2558 * descriptor does not represent a vnode. Note that pipes use vnodes but 2559 * never have VM objects. The returned vnode will be vref()'d. 2560 * 2561 * XXX: what about the unused flags ? 2562 */ 2563 static __inline int 2564 _fgetvp(struct thread *td, int fd, int flags, cap_rights_t *needrightsp, 2565 struct vnode **vpp) 2566 { 2567 struct file *fp; 2568 int error; 2569 2570 *vpp = NULL; 2571 error = _fget(td, fd, &fp, flags, needrightsp, NULL); 2572 if (error != 0) 2573 return (error); 2574 if (fp->f_vnode == NULL) { 2575 error = EINVAL; 2576 } else { 2577 *vpp = fp->f_vnode; 2578 vref(*vpp); 2579 } 2580 fdrop(fp, td); 2581 2582 return (error); 2583 } 2584 2585 int 2586 fgetvp(struct thread *td, int fd, cap_rights_t *rightsp, struct vnode **vpp) 2587 { 2588 2589 return (_fgetvp(td, fd, 0, rightsp, vpp)); 2590 } 2591 2592 int 2593 fgetvp_rights(struct thread *td, int fd, cap_rights_t *needrightsp, 2594 struct filecaps *havecaps, struct vnode **vpp) 2595 { 2596 struct filedesc *fdp; 2597 struct file *fp; 2598 #ifdef CAPABILITIES 2599 int error; 2600 #endif 2601 2602 fdp = td->td_proc->p_fd; 2603 fp = fget_locked(fdp, fd); 2604 if (fp == NULL || fp->f_ops == &badfileops) 2605 return (EBADF); 2606 2607 #ifdef CAPABILITIES 2608 if (needrightsp != NULL) { 2609 error = cap_check(cap_rights(fdp, fd), needrightsp); 2610 if (error != 0) 2611 return (error); 2612 } 2613 #endif 2614 2615 if (fp->f_vnode == NULL) 2616 return (EINVAL); 2617 2618 *vpp = fp->f_vnode; 2619 vref(*vpp); 2620 filecaps_copy(&fdp->fd_ofiles[fd].fde_caps, havecaps); 2621 2622 return (0); 2623 } 2624 2625 int 2626 fgetvp_read(struct thread *td, int fd, cap_rights_t *rightsp, struct vnode **vpp) 2627 { 2628 2629 return (_fgetvp(td, fd, FREAD, rightsp, vpp)); 2630 } 2631 2632 int 2633 fgetvp_exec(struct thread *td, int fd, cap_rights_t *rightsp, struct vnode **vpp) 2634 { 2635 2636 return (_fgetvp(td, fd, FEXEC, rightsp, vpp)); 2637 } 2638 2639 #ifdef notyet 2640 int 2641 fgetvp_write(struct thread *td, int fd, cap_rights_t *rightsp, 2642 struct vnode **vpp) 2643 { 2644 2645 return (_fgetvp(td, fd, FWRITE, rightsp, vpp)); 2646 } 2647 #endif 2648 2649 /* 2650 * Like fget() but loads the underlying socket, or returns an error if the 2651 * descriptor does not represent a socket. 2652 * 2653 * We bump the ref count on the returned socket. XXX Also obtain the SX lock 2654 * in the future. 2655 * 2656 * Note: fgetsock() and fputsock() are deprecated, as consumers should rely 2657 * on their file descriptor reference to prevent the socket from being free'd 2658 * during use. 2659 */ 2660 int 2661 fgetsock(struct thread *td, int fd, cap_rights_t *rightsp, struct socket **spp, 2662 u_int *fflagp) 2663 { 2664 struct file *fp; 2665 int error; 2666 2667 *spp = NULL; 2668 if (fflagp != NULL) 2669 *fflagp = 0; 2670 if ((error = _fget(td, fd, &fp, 0, rightsp, NULL)) != 0) 2671 return (error); 2672 if (fp->f_type != DTYPE_SOCKET) { 2673 error = ENOTSOCK; 2674 } else { 2675 *spp = fp->f_data; 2676 if (fflagp) 2677 *fflagp = fp->f_flag; 2678 SOCK_LOCK(*spp); 2679 soref(*spp); 2680 SOCK_UNLOCK(*spp); 2681 } 2682 fdrop(fp, td); 2683 2684 return (error); 2685 } 2686 2687 /* 2688 * Drop the reference count on the socket and XXX release the SX lock in the 2689 * future. The last reference closes the socket. 2690 * 2691 * Note: fputsock() is deprecated, see comment for fgetsock(). 2692 */ 2693 void 2694 fputsock(struct socket *so) 2695 { 2696 2697 ACCEPT_LOCK(); 2698 SOCK_LOCK(so); 2699 CURVNET_SET(so->so_vnet); 2700 sorele(so); 2701 CURVNET_RESTORE(); 2702 } 2703 2704 /* 2705 * Handle the last reference to a file being closed. 2706 */ 2707 int 2708 _fdrop(struct file *fp, struct thread *td) 2709 { 2710 int error; 2711 2712 if (fp->f_count != 0) 2713 panic("fdrop: count %d", fp->f_count); 2714 error = fo_close(fp, td); 2715 atomic_subtract_int(&openfiles, 1); 2716 crfree(fp->f_cred); 2717 free(fp->f_advice, M_FADVISE); 2718 uma_zfree(file_zone, fp); 2719 2720 return (error); 2721 } 2722 2723 /* 2724 * Apply an advisory lock on a file descriptor. 2725 * 2726 * Just attempt to get a record lock of the requested type on the entire file 2727 * (l_whence = SEEK_SET, l_start = 0, l_len = 0). 2728 */ 2729 #ifndef _SYS_SYSPROTO_H_ 2730 struct flock_args { 2731 int fd; 2732 int how; 2733 }; 2734 #endif 2735 /* ARGSUSED */ 2736 int 2737 sys_flock(struct thread *td, struct flock_args *uap) 2738 { 2739 struct file *fp; 2740 struct vnode *vp; 2741 struct flock lf; 2742 cap_rights_t rights; 2743 int error; 2744 2745 error = fget(td, uap->fd, cap_rights_init(&rights, CAP_FLOCK), &fp); 2746 if (error != 0) 2747 return (error); 2748 if (fp->f_type != DTYPE_VNODE) { 2749 fdrop(fp, td); 2750 return (EOPNOTSUPP); 2751 } 2752 2753 vp = fp->f_vnode; 2754 lf.l_whence = SEEK_SET; 2755 lf.l_start = 0; 2756 lf.l_len = 0; 2757 if (uap->how & LOCK_UN) { 2758 lf.l_type = F_UNLCK; 2759 atomic_clear_int(&fp->f_flag, FHASLOCK); 2760 error = VOP_ADVLOCK(vp, (caddr_t)fp, F_UNLCK, &lf, F_FLOCK); 2761 goto done2; 2762 } 2763 if (uap->how & LOCK_EX) 2764 lf.l_type = F_WRLCK; 2765 else if (uap->how & LOCK_SH) 2766 lf.l_type = F_RDLCK; 2767 else { 2768 error = EBADF; 2769 goto done2; 2770 } 2771 atomic_set_int(&fp->f_flag, FHASLOCK); 2772 error = VOP_ADVLOCK(vp, (caddr_t)fp, F_SETLK, &lf, 2773 (uap->how & LOCK_NB) ? F_FLOCK : F_FLOCK | F_WAIT); 2774 done2: 2775 fdrop(fp, td); 2776 return (error); 2777 } 2778 /* 2779 * Duplicate the specified descriptor to a free descriptor. 2780 */ 2781 int 2782 dupfdopen(struct thread *td, struct filedesc *fdp, int dfd, int mode, 2783 int openerror, int *indxp) 2784 { 2785 struct filedescent *newfde, *oldfde; 2786 struct file *fp; 2787 int error, indx; 2788 2789 KASSERT(openerror == ENODEV || openerror == ENXIO, 2790 ("unexpected error %d in %s", openerror, __func__)); 2791 2792 /* 2793 * If the to-be-dup'd fd number is greater than the allowed number 2794 * of file descriptors, or the fd to be dup'd has already been 2795 * closed, then reject. 2796 */ 2797 FILEDESC_XLOCK(fdp); 2798 if ((fp = fget_locked(fdp, dfd)) == NULL) { 2799 FILEDESC_XUNLOCK(fdp); 2800 return (EBADF); 2801 } 2802 2803 error = fdalloc(td, 0, &indx); 2804 if (error != 0) { 2805 FILEDESC_XUNLOCK(fdp); 2806 return (error); 2807 } 2808 2809 /* 2810 * There are two cases of interest here. 2811 * 2812 * For ENODEV simply dup (dfd) to file descriptor (indx) and return. 2813 * 2814 * For ENXIO steal away the file structure from (dfd) and store it in 2815 * (indx). (dfd) is effectively closed by this operation. 2816 */ 2817 switch (openerror) { 2818 case ENODEV: 2819 /* 2820 * Check that the mode the file is being opened for is a 2821 * subset of the mode of the existing descriptor. 2822 */ 2823 if (((mode & (FREAD|FWRITE)) | fp->f_flag) != fp->f_flag) { 2824 fdunused(fdp, indx); 2825 FILEDESC_XUNLOCK(fdp); 2826 return (EACCES); 2827 } 2828 fhold(fp); 2829 newfde = &fdp->fd_ofiles[indx]; 2830 oldfde = &fdp->fd_ofiles[dfd]; 2831 #ifdef CAPABILITIES 2832 seq_write_begin(&newfde->fde_seq); 2833 #endif 2834 memcpy(newfde, oldfde, fde_change_size); 2835 filecaps_copy(&oldfde->fde_caps, &newfde->fde_caps); 2836 #ifdef CAPABILITIES 2837 seq_write_end(&newfde->fde_seq); 2838 #endif 2839 break; 2840 case ENXIO: 2841 /* 2842 * Steal away the file pointer from dfd and stuff it into indx. 2843 */ 2844 newfde = &fdp->fd_ofiles[indx]; 2845 oldfde = &fdp->fd_ofiles[dfd]; 2846 #ifdef CAPABILITIES 2847 seq_write_begin(&newfde->fde_seq); 2848 #endif 2849 memcpy(newfde, oldfde, fde_change_size); 2850 oldfde->fde_file = NULL; 2851 fdunused(fdp, dfd); 2852 #ifdef CAPABILITIES 2853 seq_write_end(&newfde->fde_seq); 2854 #endif 2855 break; 2856 } 2857 FILEDESC_XUNLOCK(fdp); 2858 *indxp = indx; 2859 return (0); 2860 } 2861 2862 /* 2863 * Scan all active processes and prisons to see if any of them have a current 2864 * or root directory of `olddp'. If so, replace them with the new mount point. 2865 */ 2866 void 2867 mountcheckdirs(struct vnode *olddp, struct vnode *newdp) 2868 { 2869 struct filedesc *fdp; 2870 struct prison *pr; 2871 struct proc *p; 2872 int nrele; 2873 2874 if (vrefcnt(olddp) == 1) 2875 return; 2876 nrele = 0; 2877 sx_slock(&allproc_lock); 2878 FOREACH_PROC_IN_SYSTEM(p) { 2879 PROC_LOCK(p); 2880 fdp = fdhold(p); 2881 PROC_UNLOCK(p); 2882 if (fdp == NULL) 2883 continue; 2884 FILEDESC_XLOCK(fdp); 2885 if (fdp->fd_cdir == olddp) { 2886 vref(newdp); 2887 fdp->fd_cdir = newdp; 2888 nrele++; 2889 } 2890 if (fdp->fd_rdir == olddp) { 2891 vref(newdp); 2892 fdp->fd_rdir = newdp; 2893 nrele++; 2894 } 2895 if (fdp->fd_jdir == olddp) { 2896 vref(newdp); 2897 fdp->fd_jdir = newdp; 2898 nrele++; 2899 } 2900 FILEDESC_XUNLOCK(fdp); 2901 fddrop(fdp); 2902 } 2903 sx_sunlock(&allproc_lock); 2904 if (rootvnode == olddp) { 2905 vref(newdp); 2906 rootvnode = newdp; 2907 nrele++; 2908 } 2909 mtx_lock(&prison0.pr_mtx); 2910 if (prison0.pr_root == olddp) { 2911 vref(newdp); 2912 prison0.pr_root = newdp; 2913 nrele++; 2914 } 2915 mtx_unlock(&prison0.pr_mtx); 2916 sx_slock(&allprison_lock); 2917 TAILQ_FOREACH(pr, &allprison, pr_list) { 2918 mtx_lock(&pr->pr_mtx); 2919 if (pr->pr_root == olddp) { 2920 vref(newdp); 2921 pr->pr_root = newdp; 2922 nrele++; 2923 } 2924 mtx_unlock(&pr->pr_mtx); 2925 } 2926 sx_sunlock(&allprison_lock); 2927 while (nrele--) 2928 vrele(olddp); 2929 } 2930 2931 struct filedesc_to_leader * 2932 filedesc_to_leader_alloc(struct filedesc_to_leader *old, struct filedesc *fdp, struct proc *leader) 2933 { 2934 struct filedesc_to_leader *fdtol; 2935 2936 fdtol = malloc(sizeof(struct filedesc_to_leader), 2937 M_FILEDESC_TO_LEADER, 2938 M_WAITOK); 2939 fdtol->fdl_refcount = 1; 2940 fdtol->fdl_holdcount = 0; 2941 fdtol->fdl_wakeup = 0; 2942 fdtol->fdl_leader = leader; 2943 if (old != NULL) { 2944 FILEDESC_XLOCK(fdp); 2945 fdtol->fdl_next = old->fdl_next; 2946 fdtol->fdl_prev = old; 2947 old->fdl_next = fdtol; 2948 fdtol->fdl_next->fdl_prev = fdtol; 2949 FILEDESC_XUNLOCK(fdp); 2950 } else { 2951 fdtol->fdl_next = fdtol; 2952 fdtol->fdl_prev = fdtol; 2953 } 2954 return (fdtol); 2955 } 2956 2957 /* 2958 * Get file structures globally. 2959 */ 2960 static int 2961 sysctl_kern_file(SYSCTL_HANDLER_ARGS) 2962 { 2963 struct xfile xf; 2964 struct filedesc *fdp; 2965 struct file *fp; 2966 struct proc *p; 2967 int error, n; 2968 2969 error = sysctl_wire_old_buffer(req, 0); 2970 if (error != 0) 2971 return (error); 2972 if (req->oldptr == NULL) { 2973 n = 0; 2974 sx_slock(&allproc_lock); 2975 FOREACH_PROC_IN_SYSTEM(p) { 2976 PROC_LOCK(p); 2977 if (p->p_state == PRS_NEW) { 2978 PROC_UNLOCK(p); 2979 continue; 2980 } 2981 fdp = fdhold(p); 2982 PROC_UNLOCK(p); 2983 if (fdp == NULL) 2984 continue; 2985 /* overestimates sparse tables. */ 2986 if (fdp->fd_lastfile > 0) 2987 n += fdp->fd_lastfile; 2988 fddrop(fdp); 2989 } 2990 sx_sunlock(&allproc_lock); 2991 return (SYSCTL_OUT(req, 0, n * sizeof(xf))); 2992 } 2993 error = 0; 2994 bzero(&xf, sizeof(xf)); 2995 xf.xf_size = sizeof(xf); 2996 sx_slock(&allproc_lock); 2997 FOREACH_PROC_IN_SYSTEM(p) { 2998 PROC_LOCK(p); 2999 if (p->p_state == PRS_NEW) { 3000 PROC_UNLOCK(p); 3001 continue; 3002 } 3003 if (p_cansee(req->td, p) != 0) { 3004 PROC_UNLOCK(p); 3005 continue; 3006 } 3007 xf.xf_pid = p->p_pid; 3008 xf.xf_uid = p->p_ucred->cr_uid; 3009 fdp = fdhold(p); 3010 PROC_UNLOCK(p); 3011 if (fdp == NULL) 3012 continue; 3013 FILEDESC_SLOCK(fdp); 3014 for (n = 0; fdp->fd_refcnt > 0 && n <= fdp->fd_lastfile; ++n) { 3015 if ((fp = fdp->fd_ofiles[n].fde_file) == NULL) 3016 continue; 3017 xf.xf_fd = n; 3018 xf.xf_file = fp; 3019 xf.xf_data = fp->f_data; 3020 xf.xf_vnode = fp->f_vnode; 3021 xf.xf_type = fp->f_type; 3022 xf.xf_count = fp->f_count; 3023 xf.xf_msgcount = 0; 3024 xf.xf_offset = foffset_get(fp); 3025 xf.xf_flag = fp->f_flag; 3026 error = SYSCTL_OUT(req, &xf, sizeof(xf)); 3027 if (error) 3028 break; 3029 } 3030 FILEDESC_SUNLOCK(fdp); 3031 fddrop(fdp); 3032 if (error) 3033 break; 3034 } 3035 sx_sunlock(&allproc_lock); 3036 return (error); 3037 } 3038 3039 SYSCTL_PROC(_kern, KERN_FILE, file, CTLTYPE_OPAQUE|CTLFLAG_RD|CTLFLAG_MPSAFE, 3040 0, 0, sysctl_kern_file, "S,xfile", "Entire file table"); 3041 3042 #ifdef KINFO_FILE_SIZE 3043 CTASSERT(sizeof(struct kinfo_file) == KINFO_FILE_SIZE); 3044 #endif 3045 3046 static int 3047 xlate_fflags(int fflags) 3048 { 3049 static const struct { 3050 int fflag; 3051 int kf_fflag; 3052 } fflags_table[] = { 3053 { FAPPEND, KF_FLAG_APPEND }, 3054 { FASYNC, KF_FLAG_ASYNC }, 3055 { FFSYNC, KF_FLAG_FSYNC }, 3056 { FHASLOCK, KF_FLAG_HASLOCK }, 3057 { FNONBLOCK, KF_FLAG_NONBLOCK }, 3058 { FREAD, KF_FLAG_READ }, 3059 { FWRITE, KF_FLAG_WRITE }, 3060 { O_CREAT, KF_FLAG_CREAT }, 3061 { O_DIRECT, KF_FLAG_DIRECT }, 3062 { O_EXCL, KF_FLAG_EXCL }, 3063 { O_EXEC, KF_FLAG_EXEC }, 3064 { O_EXLOCK, KF_FLAG_EXLOCK }, 3065 { O_NOFOLLOW, KF_FLAG_NOFOLLOW }, 3066 { O_SHLOCK, KF_FLAG_SHLOCK }, 3067 { O_TRUNC, KF_FLAG_TRUNC } 3068 }; 3069 unsigned int i; 3070 int kflags; 3071 3072 kflags = 0; 3073 for (i = 0; i < nitems(fflags_table); i++) 3074 if (fflags & fflags_table[i].fflag) 3075 kflags |= fflags_table[i].kf_fflag; 3076 return (kflags); 3077 } 3078 3079 /* Trim unused data from kf_path by truncating the structure size. */ 3080 static void 3081 pack_kinfo(struct kinfo_file *kif) 3082 { 3083 3084 kif->kf_structsize = offsetof(struct kinfo_file, kf_path) + 3085 strlen(kif->kf_path) + 1; 3086 kif->kf_structsize = roundup(kif->kf_structsize, sizeof(uint64_t)); 3087 } 3088 3089 static void 3090 export_file_to_kinfo(struct file *fp, int fd, cap_rights_t *rightsp, 3091 struct kinfo_file *kif, struct filedesc *fdp) 3092 { 3093 int error; 3094 3095 bzero(kif, sizeof(*kif)); 3096 3097 /* Set a default type to allow for empty fill_kinfo() methods. */ 3098 kif->kf_type = KF_TYPE_UNKNOWN; 3099 kif->kf_flags = xlate_fflags(fp->f_flag); 3100 if (rightsp != NULL) 3101 kif->kf_cap_rights = *rightsp; 3102 else 3103 cap_rights_init(&kif->kf_cap_rights); 3104 kif->kf_fd = fd; 3105 kif->kf_ref_count = fp->f_count; 3106 kif->kf_offset = foffset_get(fp); 3107 3108 /* 3109 * This may drop the filedesc lock, so the 'fp' cannot be 3110 * accessed after this call. 3111 */ 3112 error = fo_fill_kinfo(fp, kif, fdp); 3113 if (error == 0) 3114 kif->kf_status |= KF_ATTR_VALID; 3115 pack_kinfo(kif); 3116 } 3117 3118 static void 3119 export_vnode_to_kinfo(struct vnode *vp, int fd, int fflags, 3120 struct kinfo_file *kif) 3121 { 3122 int error; 3123 3124 bzero(kif, sizeof(*kif)); 3125 3126 kif->kf_type = KF_TYPE_VNODE; 3127 error = vn_fill_kinfo_vnode(vp, kif); 3128 if (error == 0) 3129 kif->kf_status |= KF_ATTR_VALID; 3130 kif->kf_flags = xlate_fflags(fflags); 3131 cap_rights_init(&kif->kf_cap_rights); 3132 kif->kf_fd = fd; 3133 kif->kf_ref_count = -1; 3134 kif->kf_offset = -1; 3135 pack_kinfo(kif); 3136 vrele(vp); 3137 } 3138 3139 struct export_fd_buf { 3140 struct filedesc *fdp; 3141 struct sbuf *sb; 3142 ssize_t remainder; 3143 struct kinfo_file kif; 3144 }; 3145 3146 static int 3147 export_kinfo_to_sb(struct export_fd_buf *efbuf) 3148 { 3149 struct kinfo_file *kif; 3150 3151 kif = &efbuf->kif; 3152 if (efbuf->remainder != -1) { 3153 if (efbuf->remainder < kif->kf_structsize) { 3154 /* Terminate export. */ 3155 efbuf->remainder = 0; 3156 return (0); 3157 } 3158 efbuf->remainder -= kif->kf_structsize; 3159 } 3160 return (sbuf_bcat(efbuf->sb, kif, kif->kf_structsize) == 0 ? 0 : ENOMEM); 3161 } 3162 3163 static int 3164 export_file_to_sb(struct file *fp, int fd, cap_rights_t *rightsp, 3165 struct export_fd_buf *efbuf) 3166 { 3167 int error; 3168 3169 if (efbuf->remainder == 0) 3170 return (0); 3171 export_file_to_kinfo(fp, fd, rightsp, &efbuf->kif, efbuf->fdp); 3172 FILEDESC_SUNLOCK(efbuf->fdp); 3173 error = export_kinfo_to_sb(efbuf); 3174 FILEDESC_SLOCK(efbuf->fdp); 3175 return (error); 3176 } 3177 3178 static int 3179 export_vnode_to_sb(struct vnode *vp, int fd, int fflags, 3180 struct export_fd_buf *efbuf) 3181 { 3182 int error; 3183 3184 if (efbuf->remainder == 0) 3185 return (0); 3186 if (efbuf->fdp != NULL) 3187 FILEDESC_SUNLOCK(efbuf->fdp); 3188 export_vnode_to_kinfo(vp, fd, fflags, &efbuf->kif); 3189 error = export_kinfo_to_sb(efbuf); 3190 if (efbuf->fdp != NULL) 3191 FILEDESC_SLOCK(efbuf->fdp); 3192 return (error); 3193 } 3194 3195 /* 3196 * Store a process file descriptor information to sbuf. 3197 * 3198 * Takes a locked proc as argument, and returns with the proc unlocked. 3199 */ 3200 int 3201 kern_proc_filedesc_out(struct proc *p, struct sbuf *sb, ssize_t maxlen) 3202 { 3203 struct file *fp; 3204 struct filedesc *fdp; 3205 struct export_fd_buf *efbuf; 3206 struct vnode *cttyvp, *textvp, *tracevp; 3207 int error, i; 3208 cap_rights_t rights; 3209 3210 PROC_LOCK_ASSERT(p, MA_OWNED); 3211 3212 /* ktrace vnode */ 3213 tracevp = p->p_tracevp; 3214 if (tracevp != NULL) 3215 vref(tracevp); 3216 /* text vnode */ 3217 textvp = p->p_textvp; 3218 if (textvp != NULL) 3219 vref(textvp); 3220 /* Controlling tty. */ 3221 cttyvp = NULL; 3222 if (p->p_pgrp != NULL && p->p_pgrp->pg_session != NULL) { 3223 cttyvp = p->p_pgrp->pg_session->s_ttyvp; 3224 if (cttyvp != NULL) 3225 vref(cttyvp); 3226 } 3227 fdp = fdhold(p); 3228 PROC_UNLOCK(p); 3229 efbuf = malloc(sizeof(*efbuf), M_TEMP, M_WAITOK); 3230 efbuf->fdp = NULL; 3231 efbuf->sb = sb; 3232 efbuf->remainder = maxlen; 3233 if (tracevp != NULL) 3234 export_vnode_to_sb(tracevp, KF_FD_TYPE_TRACE, FREAD | FWRITE, 3235 efbuf); 3236 if (textvp != NULL) 3237 export_vnode_to_sb(textvp, KF_FD_TYPE_TEXT, FREAD, efbuf); 3238 if (cttyvp != NULL) 3239 export_vnode_to_sb(cttyvp, KF_FD_TYPE_CTTY, FREAD | FWRITE, 3240 efbuf); 3241 error = 0; 3242 if (fdp == NULL) 3243 goto fail; 3244 efbuf->fdp = fdp; 3245 FILEDESC_SLOCK(fdp); 3246 /* working directory */ 3247 if (fdp->fd_cdir != NULL) { 3248 vref(fdp->fd_cdir); 3249 export_vnode_to_sb(fdp->fd_cdir, KF_FD_TYPE_CWD, FREAD, efbuf); 3250 } 3251 /* root directory */ 3252 if (fdp->fd_rdir != NULL) { 3253 vref(fdp->fd_rdir); 3254 export_vnode_to_sb(fdp->fd_rdir, KF_FD_TYPE_ROOT, FREAD, efbuf); 3255 } 3256 /* jail directory */ 3257 if (fdp->fd_jdir != NULL) { 3258 vref(fdp->fd_jdir); 3259 export_vnode_to_sb(fdp->fd_jdir, KF_FD_TYPE_JAIL, FREAD, efbuf); 3260 } 3261 for (i = 0; fdp->fd_refcnt > 0 && i <= fdp->fd_lastfile; i++) { 3262 if ((fp = fdp->fd_ofiles[i].fde_file) == NULL) 3263 continue; 3264 #ifdef CAPABILITIES 3265 rights = *cap_rights(fdp, i); 3266 #else /* !CAPABILITIES */ 3267 cap_rights_init(&rights); 3268 #endif 3269 /* 3270 * Create sysctl entry. It is OK to drop the filedesc 3271 * lock inside of export_file_to_sb() as we will 3272 * re-validate and re-evaluate its properties when the 3273 * loop continues. 3274 */ 3275 error = export_file_to_sb(fp, i, &rights, efbuf); 3276 if (error != 0 || efbuf->remainder == 0) 3277 break; 3278 } 3279 FILEDESC_SUNLOCK(fdp); 3280 fddrop(fdp); 3281 fail: 3282 free(efbuf, M_TEMP); 3283 return (error); 3284 } 3285 3286 #define FILEDESC_SBUF_SIZE (sizeof(struct kinfo_file) * 5) 3287 3288 /* 3289 * Get per-process file descriptors for use by procstat(1), et al. 3290 */ 3291 static int 3292 sysctl_kern_proc_filedesc(SYSCTL_HANDLER_ARGS) 3293 { 3294 struct sbuf sb; 3295 struct proc *p; 3296 ssize_t maxlen; 3297 int error, error2, *name; 3298 3299 name = (int *)arg1; 3300 3301 sbuf_new_for_sysctl(&sb, NULL, FILEDESC_SBUF_SIZE, req); 3302 sbuf_clear_flags(&sb, SBUF_INCLUDENUL); 3303 error = pget((pid_t)name[0], PGET_CANDEBUG | PGET_NOTWEXIT, &p); 3304 if (error != 0) { 3305 sbuf_delete(&sb); 3306 return (error); 3307 } 3308 maxlen = req->oldptr != NULL ? req->oldlen : -1; 3309 error = kern_proc_filedesc_out(p, &sb, maxlen); 3310 error2 = sbuf_finish(&sb); 3311 sbuf_delete(&sb); 3312 return (error != 0 ? error : error2); 3313 } 3314 3315 #ifdef KINFO_OFILE_SIZE 3316 CTASSERT(sizeof(struct kinfo_ofile) == KINFO_OFILE_SIZE); 3317 #endif 3318 3319 #ifdef COMPAT_FREEBSD7 3320 static void 3321 kinfo_to_okinfo(struct kinfo_file *kif, struct kinfo_ofile *okif) 3322 { 3323 3324 okif->kf_structsize = sizeof(*okif); 3325 okif->kf_type = kif->kf_type; 3326 okif->kf_fd = kif->kf_fd; 3327 okif->kf_ref_count = kif->kf_ref_count; 3328 okif->kf_flags = kif->kf_flags & (KF_FLAG_READ | KF_FLAG_WRITE | 3329 KF_FLAG_APPEND | KF_FLAG_ASYNC | KF_FLAG_FSYNC | KF_FLAG_NONBLOCK | 3330 KF_FLAG_DIRECT | KF_FLAG_HASLOCK); 3331 okif->kf_offset = kif->kf_offset; 3332 okif->kf_vnode_type = kif->kf_vnode_type; 3333 okif->kf_sock_domain = kif->kf_sock_domain; 3334 okif->kf_sock_type = kif->kf_sock_type; 3335 okif->kf_sock_protocol = kif->kf_sock_protocol; 3336 strlcpy(okif->kf_path, kif->kf_path, sizeof(okif->kf_path)); 3337 okif->kf_sa_local = kif->kf_sa_local; 3338 okif->kf_sa_peer = kif->kf_sa_peer; 3339 } 3340 3341 static int 3342 export_vnode_for_osysctl(struct vnode *vp, int type, struct kinfo_file *kif, 3343 struct kinfo_ofile *okif, struct filedesc *fdp, struct sysctl_req *req) 3344 { 3345 int error; 3346 3347 vref(vp); 3348 FILEDESC_SUNLOCK(fdp); 3349 export_vnode_to_kinfo(vp, type, 0, kif); 3350 kinfo_to_okinfo(kif, okif); 3351 error = SYSCTL_OUT(req, okif, sizeof(*okif)); 3352 FILEDESC_SLOCK(fdp); 3353 return (error); 3354 } 3355 3356 /* 3357 * Get per-process file descriptors for use by procstat(1), et al. 3358 */ 3359 static int 3360 sysctl_kern_proc_ofiledesc(SYSCTL_HANDLER_ARGS) 3361 { 3362 struct kinfo_ofile *okif; 3363 struct kinfo_file *kif; 3364 struct filedesc *fdp; 3365 int error, i, *name; 3366 struct file *fp; 3367 struct proc *p; 3368 3369 name = (int *)arg1; 3370 error = pget((pid_t)name[0], PGET_CANDEBUG | PGET_NOTWEXIT, &p); 3371 if (error != 0) 3372 return (error); 3373 fdp = fdhold(p); 3374 PROC_UNLOCK(p); 3375 if (fdp == NULL) 3376 return (ENOENT); 3377 kif = malloc(sizeof(*kif), M_TEMP, M_WAITOK); 3378 okif = malloc(sizeof(*okif), M_TEMP, M_WAITOK); 3379 FILEDESC_SLOCK(fdp); 3380 if (fdp->fd_cdir != NULL) 3381 export_vnode_for_osysctl(fdp->fd_cdir, KF_FD_TYPE_CWD, kif, 3382 okif, fdp, req); 3383 if (fdp->fd_rdir != NULL) 3384 export_vnode_for_osysctl(fdp->fd_rdir, KF_FD_TYPE_ROOT, kif, 3385 okif, fdp, req); 3386 if (fdp->fd_jdir != NULL) 3387 export_vnode_for_osysctl(fdp->fd_jdir, KF_FD_TYPE_JAIL, kif, 3388 okif, fdp, req); 3389 for (i = 0; fdp->fd_refcnt > 0 && i <= fdp->fd_lastfile; i++) { 3390 if ((fp = fdp->fd_ofiles[i].fde_file) == NULL) 3391 continue; 3392 export_file_to_kinfo(fp, i, NULL, kif, fdp); 3393 FILEDESC_SUNLOCK(fdp); 3394 kinfo_to_okinfo(kif, okif); 3395 error = SYSCTL_OUT(req, okif, sizeof(*okif)); 3396 FILEDESC_SLOCK(fdp); 3397 if (error) 3398 break; 3399 } 3400 FILEDESC_SUNLOCK(fdp); 3401 fddrop(fdp); 3402 free(kif, M_TEMP); 3403 free(okif, M_TEMP); 3404 return (0); 3405 } 3406 3407 static SYSCTL_NODE(_kern_proc, KERN_PROC_OFILEDESC, ofiledesc, 3408 CTLFLAG_RD|CTLFLAG_MPSAFE, sysctl_kern_proc_ofiledesc, 3409 "Process ofiledesc entries"); 3410 #endif /* COMPAT_FREEBSD7 */ 3411 3412 int 3413 vntype_to_kinfo(int vtype) 3414 { 3415 struct { 3416 int vtype; 3417 int kf_vtype; 3418 } vtypes_table[] = { 3419 { VBAD, KF_VTYPE_VBAD }, 3420 { VBLK, KF_VTYPE_VBLK }, 3421 { VCHR, KF_VTYPE_VCHR }, 3422 { VDIR, KF_VTYPE_VDIR }, 3423 { VFIFO, KF_VTYPE_VFIFO }, 3424 { VLNK, KF_VTYPE_VLNK }, 3425 { VNON, KF_VTYPE_VNON }, 3426 { VREG, KF_VTYPE_VREG }, 3427 { VSOCK, KF_VTYPE_VSOCK } 3428 }; 3429 unsigned int i; 3430 3431 /* 3432 * Perform vtype translation. 3433 */ 3434 for (i = 0; i < nitems(vtypes_table); i++) 3435 if (vtypes_table[i].vtype == vtype) 3436 return (vtypes_table[i].kf_vtype); 3437 3438 return (KF_VTYPE_UNKNOWN); 3439 } 3440 3441 static SYSCTL_NODE(_kern_proc, KERN_PROC_FILEDESC, filedesc, 3442 CTLFLAG_RD|CTLFLAG_MPSAFE, sysctl_kern_proc_filedesc, 3443 "Process filedesc entries"); 3444 3445 /* 3446 * Store a process current working directory information to sbuf. 3447 * 3448 * Takes a locked proc as argument, and returns with the proc unlocked. 3449 */ 3450 int 3451 kern_proc_cwd_out(struct proc *p, struct sbuf *sb, ssize_t maxlen) 3452 { 3453 struct filedesc *fdp; 3454 struct export_fd_buf *efbuf; 3455 int error; 3456 3457 PROC_LOCK_ASSERT(p, MA_OWNED); 3458 3459 fdp = fdhold(p); 3460 PROC_UNLOCK(p); 3461 if (fdp == NULL) 3462 return (EINVAL); 3463 3464 efbuf = malloc(sizeof(*efbuf), M_TEMP, M_WAITOK); 3465 efbuf->fdp = fdp; 3466 efbuf->sb = sb; 3467 efbuf->remainder = maxlen; 3468 3469 FILEDESC_SLOCK(fdp); 3470 if (fdp->fd_cdir == NULL) 3471 error = EINVAL; 3472 else { 3473 vref(fdp->fd_cdir); 3474 error = export_vnode_to_sb(fdp->fd_cdir, KF_FD_TYPE_CWD, 3475 FREAD, efbuf); 3476 } 3477 FILEDESC_SUNLOCK(fdp); 3478 fddrop(fdp); 3479 free(efbuf, M_TEMP); 3480 return (error); 3481 } 3482 3483 /* 3484 * Get per-process current working directory. 3485 */ 3486 static int 3487 sysctl_kern_proc_cwd(SYSCTL_HANDLER_ARGS) 3488 { 3489 struct sbuf sb; 3490 struct proc *p; 3491 ssize_t maxlen; 3492 int error, error2, *name; 3493 3494 name = (int *)arg1; 3495 3496 sbuf_new_for_sysctl(&sb, NULL, sizeof(struct kinfo_file), req); 3497 sbuf_clear_flags(&sb, SBUF_INCLUDENUL); 3498 error = pget((pid_t)name[0], PGET_CANDEBUG | PGET_NOTWEXIT, &p); 3499 if (error != 0) { 3500 sbuf_delete(&sb); 3501 return (error); 3502 } 3503 maxlen = req->oldptr != NULL ? req->oldlen : -1; 3504 error = kern_proc_cwd_out(p, &sb, maxlen); 3505 error2 = sbuf_finish(&sb); 3506 sbuf_delete(&sb); 3507 return (error != 0 ? error : error2); 3508 } 3509 3510 static SYSCTL_NODE(_kern_proc, KERN_PROC_CWD, cwd, CTLFLAG_RD|CTLFLAG_MPSAFE, 3511 sysctl_kern_proc_cwd, "Process current working directory"); 3512 3513 #ifdef DDB 3514 /* 3515 * For the purposes of debugging, generate a human-readable string for the 3516 * file type. 3517 */ 3518 static const char * 3519 file_type_to_name(short type) 3520 { 3521 3522 switch (type) { 3523 case 0: 3524 return ("zero"); 3525 case DTYPE_VNODE: 3526 return ("vnod"); 3527 case DTYPE_SOCKET: 3528 return ("sock"); 3529 case DTYPE_PIPE: 3530 return ("pipe"); 3531 case DTYPE_FIFO: 3532 return ("fifo"); 3533 case DTYPE_KQUEUE: 3534 return ("kque"); 3535 case DTYPE_CRYPTO: 3536 return ("crpt"); 3537 case DTYPE_MQUEUE: 3538 return ("mque"); 3539 case DTYPE_SHM: 3540 return ("shm"); 3541 case DTYPE_SEM: 3542 return ("ksem"); 3543 default: 3544 return ("unkn"); 3545 } 3546 } 3547 3548 /* 3549 * For the purposes of debugging, identify a process (if any, perhaps one of 3550 * many) that references the passed file in its file descriptor array. Return 3551 * NULL if none. 3552 */ 3553 static struct proc * 3554 file_to_first_proc(struct file *fp) 3555 { 3556 struct filedesc *fdp; 3557 struct proc *p; 3558 int n; 3559 3560 FOREACH_PROC_IN_SYSTEM(p) { 3561 if (p->p_state == PRS_NEW) 3562 continue; 3563 fdp = p->p_fd; 3564 if (fdp == NULL) 3565 continue; 3566 for (n = 0; n <= fdp->fd_lastfile; n++) { 3567 if (fp == fdp->fd_ofiles[n].fde_file) 3568 return (p); 3569 } 3570 } 3571 return (NULL); 3572 } 3573 3574 static void 3575 db_print_file(struct file *fp, int header) 3576 { 3577 struct proc *p; 3578 3579 if (header) 3580 db_printf("%8s %4s %8s %8s %4s %5s %6s %8s %5s %12s\n", 3581 "File", "Type", "Data", "Flag", "GCFl", "Count", 3582 "MCount", "Vnode", "FPID", "FCmd"); 3583 p = file_to_first_proc(fp); 3584 db_printf("%8p %4s %8p %08x %04x %5d %6d %8p %5d %12s\n", fp, 3585 file_type_to_name(fp->f_type), fp->f_data, fp->f_flag, 3586 0, fp->f_count, 0, fp->f_vnode, 3587 p != NULL ? p->p_pid : -1, p != NULL ? p->p_comm : "-"); 3588 } 3589 3590 DB_SHOW_COMMAND(file, db_show_file) 3591 { 3592 struct file *fp; 3593 3594 if (!have_addr) { 3595 db_printf("usage: show file <addr>\n"); 3596 return; 3597 } 3598 fp = (struct file *)addr; 3599 db_print_file(fp, 1); 3600 } 3601 3602 DB_SHOW_COMMAND(files, db_show_files) 3603 { 3604 struct filedesc *fdp; 3605 struct file *fp; 3606 struct proc *p; 3607 int header; 3608 int n; 3609 3610 header = 1; 3611 FOREACH_PROC_IN_SYSTEM(p) { 3612 if (p->p_state == PRS_NEW) 3613 continue; 3614 if ((fdp = p->p_fd) == NULL) 3615 continue; 3616 for (n = 0; n <= fdp->fd_lastfile; ++n) { 3617 if ((fp = fdp->fd_ofiles[n].fde_file) == NULL) 3618 continue; 3619 db_print_file(fp, header); 3620 header = 0; 3621 } 3622 } 3623 } 3624 #endif 3625 3626 SYSCTL_INT(_kern, KERN_MAXFILESPERPROC, maxfilesperproc, CTLFLAG_RW, 3627 &maxfilesperproc, 0, "Maximum files allowed open per process"); 3628 3629 SYSCTL_INT(_kern, KERN_MAXFILES, maxfiles, CTLFLAG_RW, 3630 &maxfiles, 0, "Maximum number of files"); 3631 3632 SYSCTL_INT(_kern, OID_AUTO, openfiles, CTLFLAG_RD, 3633 __DEVOLATILE(int *, &openfiles), 0, "System-wide number of open files"); 3634 3635 /* ARGSUSED*/ 3636 static void 3637 filelistinit(void *dummy) 3638 { 3639 3640 file_zone = uma_zcreate("Files", sizeof(struct file), NULL, NULL, 3641 NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE); 3642 filedesc0_zone = uma_zcreate("filedesc0", sizeof(struct filedesc0), 3643 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0); 3644 mtx_init(&sigio_lock, "sigio lock", NULL, MTX_DEF); 3645 } 3646 SYSINIT(select, SI_SUB_LOCK, SI_ORDER_FIRST, filelistinit, NULL); 3647 3648 /*-------------------------------------------------------------------*/ 3649 3650 static int 3651 badfo_readwrite(struct file *fp, struct uio *uio, struct ucred *active_cred, 3652 int flags, struct thread *td) 3653 { 3654 3655 return (EBADF); 3656 } 3657 3658 static int 3659 badfo_truncate(struct file *fp, off_t length, struct ucred *active_cred, 3660 struct thread *td) 3661 { 3662 3663 return (EINVAL); 3664 } 3665 3666 static int 3667 badfo_ioctl(struct file *fp, u_long com, void *data, struct ucred *active_cred, 3668 struct thread *td) 3669 { 3670 3671 return (EBADF); 3672 } 3673 3674 static int 3675 badfo_poll(struct file *fp, int events, struct ucred *active_cred, 3676 struct thread *td) 3677 { 3678 3679 return (0); 3680 } 3681 3682 static int 3683 badfo_kqfilter(struct file *fp, struct knote *kn) 3684 { 3685 3686 return (EBADF); 3687 } 3688 3689 static int 3690 badfo_stat(struct file *fp, struct stat *sb, struct ucred *active_cred, 3691 struct thread *td) 3692 { 3693 3694 return (EBADF); 3695 } 3696 3697 static int 3698 badfo_close(struct file *fp, struct thread *td) 3699 { 3700 3701 return (0); 3702 } 3703 3704 static int 3705 badfo_chmod(struct file *fp, mode_t mode, struct ucred *active_cred, 3706 struct thread *td) 3707 { 3708 3709 return (EBADF); 3710 } 3711 3712 static int 3713 badfo_chown(struct file *fp, uid_t uid, gid_t gid, struct ucred *active_cred, 3714 struct thread *td) 3715 { 3716 3717 return (EBADF); 3718 } 3719 3720 static int 3721 badfo_sendfile(struct file *fp, int sockfd, struct uio *hdr_uio, 3722 struct uio *trl_uio, off_t offset, size_t nbytes, off_t *sent, int flags, 3723 int kflags, struct thread *td) 3724 { 3725 3726 return (EBADF); 3727 } 3728 3729 static int 3730 badfo_fill_kinfo(struct file *fp, struct kinfo_file *kif, struct filedesc *fdp) 3731 { 3732 3733 return (0); 3734 } 3735 3736 struct fileops badfileops = { 3737 .fo_read = badfo_readwrite, 3738 .fo_write = badfo_readwrite, 3739 .fo_truncate = badfo_truncate, 3740 .fo_ioctl = badfo_ioctl, 3741 .fo_poll = badfo_poll, 3742 .fo_kqfilter = badfo_kqfilter, 3743 .fo_stat = badfo_stat, 3744 .fo_close = badfo_close, 3745 .fo_chmod = badfo_chmod, 3746 .fo_chown = badfo_chown, 3747 .fo_sendfile = badfo_sendfile, 3748 .fo_fill_kinfo = badfo_fill_kinfo, 3749 }; 3750 3751 int 3752 invfo_rdwr(struct file *fp, struct uio *uio, struct ucred *active_cred, 3753 int flags, struct thread *td) 3754 { 3755 3756 return (EOPNOTSUPP); 3757 } 3758 3759 int 3760 invfo_truncate(struct file *fp, off_t length, struct ucred *active_cred, 3761 struct thread *td) 3762 { 3763 3764 return (EINVAL); 3765 } 3766 3767 int 3768 invfo_ioctl(struct file *fp, u_long com, void *data, 3769 struct ucred *active_cred, struct thread *td) 3770 { 3771 3772 return (ENOTTY); 3773 } 3774 3775 int 3776 invfo_poll(struct file *fp, int events, struct ucred *active_cred, 3777 struct thread *td) 3778 { 3779 3780 return (poll_no_poll(events)); 3781 } 3782 3783 int 3784 invfo_kqfilter(struct file *fp, struct knote *kn) 3785 { 3786 3787 return (EINVAL); 3788 } 3789 3790 int 3791 invfo_chmod(struct file *fp, mode_t mode, struct ucred *active_cred, 3792 struct thread *td) 3793 { 3794 3795 return (EINVAL); 3796 } 3797 3798 int 3799 invfo_chown(struct file *fp, uid_t uid, gid_t gid, struct ucred *active_cred, 3800 struct thread *td) 3801 { 3802 3803 return (EINVAL); 3804 } 3805 3806 int 3807 invfo_sendfile(struct file *fp, int sockfd, struct uio *hdr_uio, 3808 struct uio *trl_uio, off_t offset, size_t nbytes, off_t *sent, int flags, 3809 int kflags, struct thread *td) 3810 { 3811 3812 return (EINVAL); 3813 } 3814 3815 /*-------------------------------------------------------------------*/ 3816 3817 /* 3818 * File Descriptor pseudo-device driver (/dev/fd/). 3819 * 3820 * Opening minor device N dup()s the file (if any) connected to file 3821 * descriptor N belonging to the calling process. Note that this driver 3822 * consists of only the ``open()'' routine, because all subsequent 3823 * references to this file will be direct to the other driver. 3824 * 3825 * XXX: we could give this one a cloning event handler if necessary. 3826 */ 3827 3828 /* ARGSUSED */ 3829 static int 3830 fdopen(struct cdev *dev, int mode, int type, struct thread *td) 3831 { 3832 3833 /* 3834 * XXX Kludge: set curthread->td_dupfd to contain the value of the 3835 * the file descriptor being sought for duplication. The error 3836 * return ensures that the vnode for this device will be released 3837 * by vn_open. Open will detect this special error and take the 3838 * actions in dupfdopen below. Other callers of vn_open or VOP_OPEN 3839 * will simply report the error. 3840 */ 3841 td->td_dupfd = dev2unit(dev); 3842 return (ENODEV); 3843 } 3844 3845 static struct cdevsw fildesc_cdevsw = { 3846 .d_version = D_VERSION, 3847 .d_open = fdopen, 3848 .d_name = "FD", 3849 }; 3850 3851 static void 3852 fildesc_drvinit(void *unused) 3853 { 3854 struct cdev *dev; 3855 3856 dev = make_dev_credf(MAKEDEV_ETERNAL, &fildesc_cdevsw, 0, NULL, 3857 UID_ROOT, GID_WHEEL, 0666, "fd/0"); 3858 make_dev_alias(dev, "stdin"); 3859 dev = make_dev_credf(MAKEDEV_ETERNAL, &fildesc_cdevsw, 1, NULL, 3860 UID_ROOT, GID_WHEEL, 0666, "fd/1"); 3861 make_dev_alias(dev, "stdout"); 3862 dev = make_dev_credf(MAKEDEV_ETERNAL, &fildesc_cdevsw, 2, NULL, 3863 UID_ROOT, GID_WHEEL, 0666, "fd/2"); 3864 make_dev_alias(dev, "stderr"); 3865 } 3866 3867 SYSINIT(fildescdev, SI_SUB_DRIVERS, SI_ORDER_MIDDLE, fildesc_drvinit, NULL); 3868