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_compat.h" 41 #include "opt_ddb.h" 42 #include "opt_ktrace.h" 43 44 #include <sys/param.h> 45 #include <sys/systm.h> 46 47 #include <sys/conf.h> 48 #include <sys/domain.h> 49 #include <sys/fcntl.h> 50 #include <sys/file.h> 51 #include <sys/filedesc.h> 52 #include <sys/filio.h> 53 #include <sys/jail.h> 54 #include <sys/kernel.h> 55 #include <sys/limits.h> 56 #include <sys/lock.h> 57 #include <sys/malloc.h> 58 #include <sys/mount.h> 59 #include <sys/mqueue.h> 60 #include <sys/mutex.h> 61 #include <sys/namei.h> 62 #include <sys/priv.h> 63 #include <sys/proc.h> 64 #include <sys/protosw.h> 65 #include <sys/resourcevar.h> 66 #include <sys/signalvar.h> 67 #include <sys/socketvar.h> 68 #include <sys/stat.h> 69 #include <sys/sx.h> 70 #include <sys/syscallsubr.h> 71 #include <sys/sysctl.h> 72 #include <sys/sysproto.h> 73 #include <sys/unistd.h> 74 #include <sys/user.h> 75 #include <sys/vnode.h> 76 #ifdef KTRACE 77 #include <sys/ktrace.h> 78 #endif 79 80 #include <security/audit/audit.h> 81 82 #include <vm/uma.h> 83 84 #include <ddb/ddb.h> 85 86 static MALLOC_DEFINE(M_FILEDESC, "filedesc", "Open file descriptor table"); 87 static MALLOC_DEFINE(M_FILEDESC_TO_LEADER, "filedesc_to_leader", 88 "file desc to leader structures"); 89 static MALLOC_DEFINE(M_SIGIO, "sigio", "sigio structures"); 90 91 static uma_zone_t file_zone; 92 93 94 /* How to treat 'new' parameter when allocating a fd for do_dup(). */ 95 enum dup_type { DUP_VARIABLE, DUP_FIXED }; 96 97 static int do_dup(struct thread *td, enum dup_type type, int old, int new, 98 register_t *retval); 99 static int fd_first_free(struct filedesc *, int, int); 100 static int fd_last_used(struct filedesc *, int, int); 101 static void fdgrowtable(struct filedesc *, int); 102 static void fdunused(struct filedesc *fdp, int fd); 103 static void fdused(struct filedesc *fdp, int fd); 104 105 /* 106 * A process is initially started out with NDFILE descriptors stored within 107 * this structure, selected to be enough for typical applications based on 108 * the historical limit of 20 open files (and the usage of descriptors by 109 * shells). If these descriptors are exhausted, a larger descriptor table 110 * may be allocated, up to a process' resource limit; the internal arrays 111 * are then unused. 112 */ 113 #define NDFILE 20 114 #define NDSLOTSIZE sizeof(NDSLOTTYPE) 115 #define NDENTRIES (NDSLOTSIZE * __CHAR_BIT) 116 #define NDSLOT(x) ((x) / NDENTRIES) 117 #define NDBIT(x) ((NDSLOTTYPE)1 << ((x) % NDENTRIES)) 118 #define NDSLOTS(x) (((x) + NDENTRIES - 1) / NDENTRIES) 119 120 /* 121 * Storage required per open file descriptor. 122 */ 123 #define OFILESIZE (sizeof(struct file *) + sizeof(char)) 124 125 /* 126 * Basic allocation of descriptors: 127 * one of the above, plus arrays for NDFILE descriptors. 128 */ 129 struct filedesc0 { 130 struct filedesc fd_fd; 131 /* 132 * These arrays are used when the number of open files is 133 * <= NDFILE, and are then pointed to by the pointers above. 134 */ 135 struct file *fd_dfiles[NDFILE]; 136 char fd_dfileflags[NDFILE]; 137 NDSLOTTYPE fd_dmap[NDSLOTS(NDFILE)]; 138 }; 139 140 /* 141 * Descriptor management. 142 */ 143 volatile int openfiles; /* actual number of open files */ 144 struct mtx sigio_lock; /* mtx to protect pointers to sigio */ 145 void (*mq_fdclose)(struct thread *td, int fd, struct file *fp); 146 147 /* A mutex to protect the association between a proc and filedesc. */ 148 static struct mtx fdesc_mtx; 149 150 /* 151 * Find the first zero bit in the given bitmap, starting at low and not 152 * exceeding size - 1. 153 */ 154 static int 155 fd_first_free(struct filedesc *fdp, int low, int size) 156 { 157 NDSLOTTYPE *map = fdp->fd_map; 158 NDSLOTTYPE mask; 159 int off, maxoff; 160 161 if (low >= size) 162 return (low); 163 164 off = NDSLOT(low); 165 if (low % NDENTRIES) { 166 mask = ~(~(NDSLOTTYPE)0 >> (NDENTRIES - (low % NDENTRIES))); 167 if ((mask &= ~map[off]) != 0UL) 168 return (off * NDENTRIES + ffsl(mask) - 1); 169 ++off; 170 } 171 for (maxoff = NDSLOTS(size); off < maxoff; ++off) 172 if (map[off] != ~0UL) 173 return (off * NDENTRIES + ffsl(~map[off]) - 1); 174 return (size); 175 } 176 177 /* 178 * Find the highest non-zero bit in the given bitmap, starting at low and 179 * not exceeding size - 1. 180 */ 181 static int 182 fd_last_used(struct filedesc *fdp, int low, int size) 183 { 184 NDSLOTTYPE *map = fdp->fd_map; 185 NDSLOTTYPE mask; 186 int off, minoff; 187 188 if (low >= size) 189 return (-1); 190 191 off = NDSLOT(size); 192 if (size % NDENTRIES) { 193 mask = ~(~(NDSLOTTYPE)0 << (size % NDENTRIES)); 194 if ((mask &= map[off]) != 0) 195 return (off * NDENTRIES + flsl(mask) - 1); 196 --off; 197 } 198 for (minoff = NDSLOT(low); off >= minoff; --off) 199 if (map[off] != 0) 200 return (off * NDENTRIES + flsl(map[off]) - 1); 201 return (low - 1); 202 } 203 204 static int 205 fdisused(struct filedesc *fdp, int fd) 206 { 207 KASSERT(fd >= 0 && fd < fdp->fd_nfiles, 208 ("file descriptor %d out of range (0, %d)", fd, fdp->fd_nfiles)); 209 return ((fdp->fd_map[NDSLOT(fd)] & NDBIT(fd)) != 0); 210 } 211 212 /* 213 * Mark a file descriptor as used. 214 */ 215 static void 216 fdused(struct filedesc *fdp, int fd) 217 { 218 219 FILEDESC_XLOCK_ASSERT(fdp); 220 KASSERT(!fdisused(fdp, fd), 221 ("fd already used")); 222 223 fdp->fd_map[NDSLOT(fd)] |= NDBIT(fd); 224 if (fd > fdp->fd_lastfile) 225 fdp->fd_lastfile = fd; 226 if (fd == fdp->fd_freefile) 227 fdp->fd_freefile = fd_first_free(fdp, fd, fdp->fd_nfiles); 228 } 229 230 /* 231 * Mark a file descriptor as unused. 232 */ 233 static void 234 fdunused(struct filedesc *fdp, int fd) 235 { 236 237 FILEDESC_XLOCK_ASSERT(fdp); 238 KASSERT(fdisused(fdp, fd), 239 ("fd is already unused")); 240 KASSERT(fdp->fd_ofiles[fd] == NULL, 241 ("fd is still in use")); 242 243 fdp->fd_map[NDSLOT(fd)] &= ~NDBIT(fd); 244 if (fd < fdp->fd_freefile) 245 fdp->fd_freefile = fd; 246 if (fd == fdp->fd_lastfile) 247 fdp->fd_lastfile = fd_last_used(fdp, 0, fd); 248 } 249 250 /* 251 * System calls on descriptors. 252 */ 253 #ifndef _SYS_SYSPROTO_H_ 254 struct getdtablesize_args { 255 int dummy; 256 }; 257 #endif 258 /* ARGSUSED */ 259 int 260 getdtablesize(struct thread *td, struct getdtablesize_args *uap) 261 { 262 struct proc *p = td->td_proc; 263 264 PROC_LOCK(p); 265 td->td_retval[0] = 266 min((int)lim_cur(p, RLIMIT_NOFILE), maxfilesperproc); 267 PROC_UNLOCK(p); 268 return (0); 269 } 270 271 /* 272 * Duplicate a file descriptor to a particular value. 273 * 274 * Note: keep in mind that a potential race condition exists when closing 275 * descriptors from a shared descriptor table (via rfork). 276 */ 277 #ifndef _SYS_SYSPROTO_H_ 278 struct dup2_args { 279 u_int from; 280 u_int to; 281 }; 282 #endif 283 /* ARGSUSED */ 284 int 285 dup2(struct thread *td, struct dup2_args *uap) 286 { 287 288 return (do_dup(td, DUP_FIXED, (int)uap->from, (int)uap->to, 289 td->td_retval)); 290 } 291 292 /* 293 * Duplicate a file descriptor. 294 */ 295 #ifndef _SYS_SYSPROTO_H_ 296 struct dup_args { 297 u_int fd; 298 }; 299 #endif 300 /* ARGSUSED */ 301 int 302 dup(struct thread *td, struct dup_args *uap) 303 { 304 305 return (do_dup(td, DUP_VARIABLE, (int)uap->fd, 0, td->td_retval)); 306 } 307 308 /* 309 * The file control system call. 310 */ 311 #ifndef _SYS_SYSPROTO_H_ 312 struct fcntl_args { 313 int fd; 314 int cmd; 315 long arg; 316 }; 317 #endif 318 /* ARGSUSED */ 319 int 320 fcntl(struct thread *td, struct fcntl_args *uap) 321 { 322 struct flock fl; 323 struct oflock ofl; 324 intptr_t arg; 325 int error; 326 int cmd; 327 328 error = 0; 329 cmd = uap->cmd; 330 switch (uap->cmd) { 331 case F_OGETLK: 332 case F_OSETLK: 333 case F_OSETLKW: 334 /* 335 * Convert old flock structure to new. 336 */ 337 error = copyin((void *)(intptr_t)uap->arg, &ofl, sizeof(ofl)); 338 fl.l_start = ofl.l_start; 339 fl.l_len = ofl.l_len; 340 fl.l_pid = ofl.l_pid; 341 fl.l_type = ofl.l_type; 342 fl.l_whence = ofl.l_whence; 343 fl.l_sysid = 0; 344 345 switch (uap->cmd) { 346 case F_OGETLK: 347 cmd = F_GETLK; 348 break; 349 case F_OSETLK: 350 cmd = F_SETLK; 351 break; 352 case F_OSETLKW: 353 cmd = F_SETLKW; 354 break; 355 } 356 arg = (intptr_t)&fl; 357 break; 358 case F_GETLK: 359 case F_SETLK: 360 case F_SETLKW: 361 case F_SETLK_REMOTE: 362 error = copyin((void *)(intptr_t)uap->arg, &fl, sizeof(fl)); 363 arg = (intptr_t)&fl; 364 break; 365 default: 366 arg = uap->arg; 367 break; 368 } 369 if (error) 370 return (error); 371 error = kern_fcntl(td, uap->fd, cmd, arg); 372 if (error) 373 return (error); 374 if (uap->cmd == F_OGETLK) { 375 ofl.l_start = fl.l_start; 376 ofl.l_len = fl.l_len; 377 ofl.l_pid = fl.l_pid; 378 ofl.l_type = fl.l_type; 379 ofl.l_whence = fl.l_whence; 380 error = copyout(&ofl, (void *)(intptr_t)uap->arg, sizeof(ofl)); 381 } else if (uap->cmd == F_GETLK) { 382 error = copyout(&fl, (void *)(intptr_t)uap->arg, sizeof(fl)); 383 } 384 return (error); 385 } 386 387 static inline struct file * 388 fdtofp(int fd, struct filedesc *fdp) 389 { 390 struct file *fp; 391 392 FILEDESC_LOCK_ASSERT(fdp); 393 if ((unsigned)fd >= fdp->fd_nfiles || 394 (fp = fdp->fd_ofiles[fd]) == NULL) 395 return (NULL); 396 return (fp); 397 } 398 399 int 400 kern_fcntl(struct thread *td, int fd, int cmd, intptr_t arg) 401 { 402 struct filedesc *fdp; 403 struct flock *flp; 404 struct file *fp; 405 struct proc *p; 406 char *pop; 407 struct vnode *vp; 408 u_int newmin; 409 int error, flg, tmp; 410 int vfslocked; 411 412 vfslocked = 0; 413 error = 0; 414 flg = F_POSIX; 415 p = td->td_proc; 416 fdp = p->p_fd; 417 418 switch (cmd) { 419 case F_DUPFD: 420 FILEDESC_SLOCK(fdp); 421 if ((fp = fdtofp(fd, fdp)) == NULL) { 422 FILEDESC_SUNLOCK(fdp); 423 error = EBADF; 424 break; 425 } 426 FILEDESC_SUNLOCK(fdp); 427 newmin = arg; 428 PROC_LOCK(p); 429 if (newmin >= lim_cur(p, RLIMIT_NOFILE) || 430 newmin >= maxfilesperproc) { 431 PROC_UNLOCK(p); 432 error = EINVAL; 433 break; 434 } 435 PROC_UNLOCK(p); 436 error = do_dup(td, DUP_VARIABLE, fd, newmin, td->td_retval); 437 break; 438 439 case F_DUP2FD: 440 tmp = arg; 441 error = do_dup(td, DUP_FIXED, fd, tmp, td->td_retval); 442 break; 443 444 case F_GETFD: 445 FILEDESC_SLOCK(fdp); 446 if ((fp = fdtofp(fd, fdp)) == NULL) { 447 FILEDESC_SUNLOCK(fdp); 448 error = EBADF; 449 break; 450 } 451 pop = &fdp->fd_ofileflags[fd]; 452 td->td_retval[0] = (*pop & UF_EXCLOSE) ? FD_CLOEXEC : 0; 453 FILEDESC_SUNLOCK(fdp); 454 break; 455 456 case F_SETFD: 457 FILEDESC_XLOCK(fdp); 458 if ((fp = fdtofp(fd, fdp)) == NULL) { 459 FILEDESC_XUNLOCK(fdp); 460 error = EBADF; 461 break; 462 } 463 pop = &fdp->fd_ofileflags[fd]; 464 *pop = (*pop &~ UF_EXCLOSE) | 465 (arg & FD_CLOEXEC ? UF_EXCLOSE : 0); 466 FILEDESC_XUNLOCK(fdp); 467 break; 468 469 case F_GETFL: 470 FILEDESC_SLOCK(fdp); 471 if ((fp = fdtofp(fd, fdp)) == NULL) { 472 FILEDESC_SUNLOCK(fdp); 473 error = EBADF; 474 break; 475 } 476 td->td_retval[0] = OFLAGS(fp->f_flag); 477 FILEDESC_SUNLOCK(fdp); 478 break; 479 480 case F_SETFL: 481 FILEDESC_SLOCK(fdp); 482 if ((fp = fdtofp(fd, fdp)) == NULL) { 483 FILEDESC_SUNLOCK(fdp); 484 error = EBADF; 485 break; 486 } 487 fhold(fp); 488 FILEDESC_SUNLOCK(fdp); 489 do { 490 tmp = flg = fp->f_flag; 491 tmp &= ~FCNTLFLAGS; 492 tmp |= FFLAGS(arg & ~O_ACCMODE) & FCNTLFLAGS; 493 } while(atomic_cmpset_int(&fp->f_flag, flg, tmp) == 0); 494 tmp = fp->f_flag & FNONBLOCK; 495 error = fo_ioctl(fp, FIONBIO, &tmp, td->td_ucred, td); 496 if (error) { 497 fdrop(fp, td); 498 break; 499 } 500 tmp = fp->f_flag & FASYNC; 501 error = fo_ioctl(fp, FIOASYNC, &tmp, td->td_ucred, td); 502 if (error == 0) { 503 fdrop(fp, td); 504 break; 505 } 506 atomic_clear_int(&fp->f_flag, FNONBLOCK); 507 tmp = 0; 508 (void)fo_ioctl(fp, FIONBIO, &tmp, td->td_ucred, td); 509 fdrop(fp, td); 510 break; 511 512 case F_GETOWN: 513 FILEDESC_SLOCK(fdp); 514 if ((fp = fdtofp(fd, fdp)) == NULL) { 515 FILEDESC_SUNLOCK(fdp); 516 error = EBADF; 517 break; 518 } 519 fhold(fp); 520 FILEDESC_SUNLOCK(fdp); 521 error = fo_ioctl(fp, FIOGETOWN, &tmp, td->td_ucred, td); 522 if (error == 0) 523 td->td_retval[0] = tmp; 524 fdrop(fp, td); 525 break; 526 527 case F_SETOWN: 528 FILEDESC_SLOCK(fdp); 529 if ((fp = fdtofp(fd, fdp)) == NULL) { 530 FILEDESC_SUNLOCK(fdp); 531 error = EBADF; 532 break; 533 } 534 fhold(fp); 535 FILEDESC_SUNLOCK(fdp); 536 tmp = arg; 537 error = fo_ioctl(fp, FIOSETOWN, &tmp, td->td_ucred, td); 538 fdrop(fp, td); 539 break; 540 541 case F_SETLK_REMOTE: 542 error = priv_check(td, PRIV_NFS_LOCKD); 543 if (error) 544 return (error); 545 flg = F_REMOTE; 546 goto do_setlk; 547 548 case F_SETLKW: 549 flg |= F_WAIT; 550 /* FALLTHROUGH F_SETLK */ 551 552 case F_SETLK: 553 do_setlk: 554 FILEDESC_SLOCK(fdp); 555 if ((fp = fdtofp(fd, fdp)) == NULL) { 556 FILEDESC_SUNLOCK(fdp); 557 error = EBADF; 558 break; 559 } 560 if (fp->f_type != DTYPE_VNODE) { 561 FILEDESC_SUNLOCK(fdp); 562 error = EBADF; 563 break; 564 } 565 flp = (struct flock *)arg; 566 if (flp->l_whence == SEEK_CUR) { 567 if (fp->f_offset < 0 || 568 (flp->l_start > 0 && 569 fp->f_offset > OFF_MAX - flp->l_start)) { 570 FILEDESC_SUNLOCK(fdp); 571 error = EOVERFLOW; 572 break; 573 } 574 flp->l_start += fp->f_offset; 575 } 576 577 /* 578 * VOP_ADVLOCK() may block. 579 */ 580 fhold(fp); 581 FILEDESC_SUNLOCK(fdp); 582 vp = fp->f_vnode; 583 vfslocked = VFS_LOCK_GIANT(vp->v_mount); 584 switch (flp->l_type) { 585 case F_RDLCK: 586 if ((fp->f_flag & FREAD) == 0) { 587 error = EBADF; 588 break; 589 } 590 PROC_LOCK(p->p_leader); 591 p->p_leader->p_flag |= P_ADVLOCK; 592 PROC_UNLOCK(p->p_leader); 593 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_SETLK, 594 flp, flg); 595 break; 596 case F_WRLCK: 597 if ((fp->f_flag & FWRITE) == 0) { 598 error = EBADF; 599 break; 600 } 601 PROC_LOCK(p->p_leader); 602 p->p_leader->p_flag |= P_ADVLOCK; 603 PROC_UNLOCK(p->p_leader); 604 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_SETLK, 605 flp, flg); 606 break; 607 case F_UNLCK: 608 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_UNLCK, 609 flp, flg); 610 break; 611 case F_UNLCKSYS: 612 /* 613 * Temporary api for testing remote lock 614 * infrastructure. 615 */ 616 if (flg != F_REMOTE) { 617 error = EINVAL; 618 break; 619 } 620 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, 621 F_UNLCKSYS, flp, flg); 622 break; 623 default: 624 error = EINVAL; 625 break; 626 } 627 VFS_UNLOCK_GIANT(vfslocked); 628 vfslocked = 0; 629 /* Check for race with close */ 630 FILEDESC_SLOCK(fdp); 631 if ((unsigned) fd >= fdp->fd_nfiles || 632 fp != fdp->fd_ofiles[fd]) { 633 FILEDESC_SUNLOCK(fdp); 634 flp->l_whence = SEEK_SET; 635 flp->l_start = 0; 636 flp->l_len = 0; 637 flp->l_type = F_UNLCK; 638 vfslocked = VFS_LOCK_GIANT(vp->v_mount); 639 (void) VOP_ADVLOCK(vp, (caddr_t)p->p_leader, 640 F_UNLCK, flp, F_POSIX); 641 VFS_UNLOCK_GIANT(vfslocked); 642 vfslocked = 0; 643 } else 644 FILEDESC_SUNLOCK(fdp); 645 fdrop(fp, td); 646 break; 647 648 case F_GETLK: 649 FILEDESC_SLOCK(fdp); 650 if ((fp = fdtofp(fd, fdp)) == NULL) { 651 FILEDESC_SUNLOCK(fdp); 652 error = EBADF; 653 break; 654 } 655 if (fp->f_type != DTYPE_VNODE) { 656 FILEDESC_SUNLOCK(fdp); 657 error = EBADF; 658 break; 659 } 660 flp = (struct flock *)arg; 661 if (flp->l_type != F_RDLCK && flp->l_type != F_WRLCK && 662 flp->l_type != F_UNLCK) { 663 FILEDESC_SUNLOCK(fdp); 664 error = EINVAL; 665 break; 666 } 667 if (flp->l_whence == SEEK_CUR) { 668 if ((flp->l_start > 0 && 669 fp->f_offset > OFF_MAX - flp->l_start) || 670 (flp->l_start < 0 && 671 fp->f_offset < OFF_MIN - flp->l_start)) { 672 FILEDESC_SUNLOCK(fdp); 673 error = EOVERFLOW; 674 break; 675 } 676 flp->l_start += fp->f_offset; 677 } 678 /* 679 * VOP_ADVLOCK() may block. 680 */ 681 fhold(fp); 682 FILEDESC_SUNLOCK(fdp); 683 vp = fp->f_vnode; 684 vfslocked = VFS_LOCK_GIANT(vp->v_mount); 685 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_GETLK, flp, 686 F_POSIX); 687 VFS_UNLOCK_GIANT(vfslocked); 688 vfslocked = 0; 689 fdrop(fp, td); 690 break; 691 default: 692 error = EINVAL; 693 break; 694 } 695 VFS_UNLOCK_GIANT(vfslocked); 696 return (error); 697 } 698 699 /* 700 * Common code for dup, dup2, fcntl(F_DUPFD) and fcntl(F_DUP2FD). 701 */ 702 static int 703 do_dup(struct thread *td, enum dup_type type, int old, int new, 704 register_t *retval) 705 { 706 struct filedesc *fdp; 707 struct proc *p; 708 struct file *fp; 709 struct file *delfp; 710 int error, holdleaders, maxfd; 711 712 KASSERT((type == DUP_VARIABLE || type == DUP_FIXED), 713 ("invalid dup type %d", type)); 714 715 p = td->td_proc; 716 fdp = p->p_fd; 717 718 /* 719 * Verify we have a valid descriptor to dup from and possibly to 720 * dup to. 721 */ 722 if (old < 0 || new < 0) 723 return (EBADF); 724 PROC_LOCK(p); 725 maxfd = min((int)lim_cur(p, RLIMIT_NOFILE), maxfilesperproc); 726 PROC_UNLOCK(p); 727 if (new >= maxfd) 728 return (EMFILE); 729 730 FILEDESC_XLOCK(fdp); 731 if (old >= fdp->fd_nfiles || fdp->fd_ofiles[old] == NULL) { 732 FILEDESC_XUNLOCK(fdp); 733 return (EBADF); 734 } 735 if (type == DUP_FIXED && old == new) { 736 *retval = new; 737 FILEDESC_XUNLOCK(fdp); 738 return (0); 739 } 740 fp = fdp->fd_ofiles[old]; 741 fhold(fp); 742 743 /* 744 * If the caller specified a file descriptor, make sure the file 745 * table is large enough to hold it, and grab it. Otherwise, just 746 * allocate a new descriptor the usual way. Since the filedesc 747 * lock may be temporarily dropped in the process, we have to look 748 * out for a race. 749 */ 750 if (type == DUP_FIXED) { 751 if (new >= fdp->fd_nfiles) 752 fdgrowtable(fdp, new + 1); 753 if (fdp->fd_ofiles[new] == NULL) 754 fdused(fdp, new); 755 } else { 756 if ((error = fdalloc(td, new, &new)) != 0) { 757 FILEDESC_XUNLOCK(fdp); 758 fdrop(fp, td); 759 return (error); 760 } 761 } 762 763 /* 764 * If the old file changed out from under us then treat it as a 765 * bad file descriptor. Userland should do its own locking to 766 * avoid this case. 767 */ 768 if (fdp->fd_ofiles[old] != fp) { 769 /* we've allocated a descriptor which we won't use */ 770 if (fdp->fd_ofiles[new] == NULL) 771 fdunused(fdp, new); 772 FILEDESC_XUNLOCK(fdp); 773 fdrop(fp, td); 774 return (EBADF); 775 } 776 KASSERT(old != new, 777 ("new fd is same as old")); 778 779 /* 780 * Save info on the descriptor being overwritten. We cannot close 781 * it without introducing an ownership race for the slot, since we 782 * need to drop the filedesc lock to call closef(). 783 * 784 * XXX this duplicates parts of close(). 785 */ 786 delfp = fdp->fd_ofiles[new]; 787 holdleaders = 0; 788 if (delfp != NULL) { 789 if (td->td_proc->p_fdtol != NULL) { 790 /* 791 * Ask fdfree() to sleep to ensure that all relevant 792 * process leaders can be traversed in closef(). 793 */ 794 fdp->fd_holdleaderscount++; 795 holdleaders = 1; 796 } 797 } 798 799 /* 800 * Duplicate the source descriptor 801 */ 802 fdp->fd_ofiles[new] = fp; 803 fdp->fd_ofileflags[new] = fdp->fd_ofileflags[old] &~ UF_EXCLOSE; 804 if (new > fdp->fd_lastfile) 805 fdp->fd_lastfile = new; 806 *retval = new; 807 808 /* 809 * If we dup'd over a valid file, we now own the reference to it 810 * and must dispose of it using closef() semantics (as if a 811 * close() were performed on it). 812 * 813 * XXX this duplicates parts of close(). 814 */ 815 if (delfp != NULL) { 816 knote_fdclose(td, new); 817 if (delfp->f_type == DTYPE_MQUEUE) 818 mq_fdclose(td, new, delfp); 819 FILEDESC_XUNLOCK(fdp); 820 (void) closef(delfp, td); 821 if (holdleaders) { 822 FILEDESC_XLOCK(fdp); 823 fdp->fd_holdleaderscount--; 824 if (fdp->fd_holdleaderscount == 0 && 825 fdp->fd_holdleaderswakeup != 0) { 826 fdp->fd_holdleaderswakeup = 0; 827 wakeup(&fdp->fd_holdleaderscount); 828 } 829 FILEDESC_XUNLOCK(fdp); 830 } 831 } else { 832 FILEDESC_XUNLOCK(fdp); 833 } 834 return (0); 835 } 836 837 /* 838 * If sigio is on the list associated with a process or process group, 839 * disable signalling from the device, remove sigio from the list and 840 * free sigio. 841 */ 842 void 843 funsetown(struct sigio **sigiop) 844 { 845 struct sigio *sigio; 846 847 SIGIO_LOCK(); 848 sigio = *sigiop; 849 if (sigio == NULL) { 850 SIGIO_UNLOCK(); 851 return; 852 } 853 *(sigio->sio_myref) = NULL; 854 if ((sigio)->sio_pgid < 0) { 855 struct pgrp *pg = (sigio)->sio_pgrp; 856 PGRP_LOCK(pg); 857 SLIST_REMOVE(&sigio->sio_pgrp->pg_sigiolst, sigio, 858 sigio, sio_pgsigio); 859 PGRP_UNLOCK(pg); 860 } else { 861 struct proc *p = (sigio)->sio_proc; 862 PROC_LOCK(p); 863 SLIST_REMOVE(&sigio->sio_proc->p_sigiolst, sigio, 864 sigio, sio_pgsigio); 865 PROC_UNLOCK(p); 866 } 867 SIGIO_UNLOCK(); 868 crfree(sigio->sio_ucred); 869 FREE(sigio, M_SIGIO); 870 } 871 872 /* 873 * Free a list of sigio structures. 874 * We only need to lock the SIGIO_LOCK because we have made ourselves 875 * inaccessible to callers of fsetown and therefore do not need to lock 876 * the proc or pgrp struct for the list manipulation. 877 */ 878 void 879 funsetownlst(struct sigiolst *sigiolst) 880 { 881 struct proc *p; 882 struct pgrp *pg; 883 struct sigio *sigio; 884 885 sigio = SLIST_FIRST(sigiolst); 886 if (sigio == NULL) 887 return; 888 p = NULL; 889 pg = NULL; 890 891 /* 892 * Every entry of the list should belong 893 * to a single proc or pgrp. 894 */ 895 if (sigio->sio_pgid < 0) { 896 pg = sigio->sio_pgrp; 897 PGRP_LOCK_ASSERT(pg, MA_NOTOWNED); 898 } else /* if (sigio->sio_pgid > 0) */ { 899 p = sigio->sio_proc; 900 PROC_LOCK_ASSERT(p, MA_NOTOWNED); 901 } 902 903 SIGIO_LOCK(); 904 while ((sigio = SLIST_FIRST(sigiolst)) != NULL) { 905 *(sigio->sio_myref) = NULL; 906 if (pg != NULL) { 907 KASSERT(sigio->sio_pgid < 0, 908 ("Proc sigio in pgrp sigio list")); 909 KASSERT(sigio->sio_pgrp == pg, 910 ("Bogus pgrp in sigio list")); 911 PGRP_LOCK(pg); 912 SLIST_REMOVE(&pg->pg_sigiolst, sigio, sigio, 913 sio_pgsigio); 914 PGRP_UNLOCK(pg); 915 } else /* if (p != NULL) */ { 916 KASSERT(sigio->sio_pgid > 0, 917 ("Pgrp sigio in proc sigio list")); 918 KASSERT(sigio->sio_proc == p, 919 ("Bogus proc in sigio list")); 920 PROC_LOCK(p); 921 SLIST_REMOVE(&p->p_sigiolst, sigio, sigio, 922 sio_pgsigio); 923 PROC_UNLOCK(p); 924 } 925 SIGIO_UNLOCK(); 926 crfree(sigio->sio_ucred); 927 FREE(sigio, M_SIGIO); 928 SIGIO_LOCK(); 929 } 930 SIGIO_UNLOCK(); 931 } 932 933 /* 934 * This is common code for FIOSETOWN ioctl called by fcntl(fd, F_SETOWN, arg). 935 * 936 * After permission checking, add a sigio structure to the sigio list for 937 * the process or process group. 938 */ 939 int 940 fsetown(pid_t pgid, struct sigio **sigiop) 941 { 942 struct proc *proc; 943 struct pgrp *pgrp; 944 struct sigio *sigio; 945 int ret; 946 947 if (pgid == 0) { 948 funsetown(sigiop); 949 return (0); 950 } 951 952 ret = 0; 953 954 /* Allocate and fill in the new sigio out of locks. */ 955 MALLOC(sigio, struct sigio *, sizeof(struct sigio), M_SIGIO, M_WAITOK); 956 sigio->sio_pgid = pgid; 957 sigio->sio_ucred = crhold(curthread->td_ucred); 958 sigio->sio_myref = sigiop; 959 960 sx_slock(&proctree_lock); 961 if (pgid > 0) { 962 proc = pfind(pgid); 963 if (proc == NULL) { 964 ret = ESRCH; 965 goto fail; 966 } 967 968 /* 969 * Policy - Don't allow a process to FSETOWN a process 970 * in another session. 971 * 972 * Remove this test to allow maximum flexibility or 973 * restrict FSETOWN to the current process or process 974 * group for maximum safety. 975 */ 976 PROC_UNLOCK(proc); 977 if (proc->p_session != curthread->td_proc->p_session) { 978 ret = EPERM; 979 goto fail; 980 } 981 982 pgrp = NULL; 983 } else /* if (pgid < 0) */ { 984 pgrp = pgfind(-pgid); 985 if (pgrp == NULL) { 986 ret = ESRCH; 987 goto fail; 988 } 989 PGRP_UNLOCK(pgrp); 990 991 /* 992 * Policy - Don't allow a process to FSETOWN a process 993 * in another session. 994 * 995 * Remove this test to allow maximum flexibility or 996 * restrict FSETOWN to the current process or process 997 * group for maximum safety. 998 */ 999 if (pgrp->pg_session != curthread->td_proc->p_session) { 1000 ret = EPERM; 1001 goto fail; 1002 } 1003 1004 proc = NULL; 1005 } 1006 funsetown(sigiop); 1007 if (pgid > 0) { 1008 PROC_LOCK(proc); 1009 /* 1010 * Since funsetownlst() is called without the proctree 1011 * locked, we need to check for P_WEXIT. 1012 * XXX: is ESRCH correct? 1013 */ 1014 if ((proc->p_flag & P_WEXIT) != 0) { 1015 PROC_UNLOCK(proc); 1016 ret = ESRCH; 1017 goto fail; 1018 } 1019 SLIST_INSERT_HEAD(&proc->p_sigiolst, sigio, sio_pgsigio); 1020 sigio->sio_proc = proc; 1021 PROC_UNLOCK(proc); 1022 } else { 1023 PGRP_LOCK(pgrp); 1024 SLIST_INSERT_HEAD(&pgrp->pg_sigiolst, sigio, sio_pgsigio); 1025 sigio->sio_pgrp = pgrp; 1026 PGRP_UNLOCK(pgrp); 1027 } 1028 sx_sunlock(&proctree_lock); 1029 SIGIO_LOCK(); 1030 *sigiop = sigio; 1031 SIGIO_UNLOCK(); 1032 return (0); 1033 1034 fail: 1035 sx_sunlock(&proctree_lock); 1036 crfree(sigio->sio_ucred); 1037 FREE(sigio, M_SIGIO); 1038 return (ret); 1039 } 1040 1041 /* 1042 * This is common code for FIOGETOWN ioctl called by fcntl(fd, F_GETOWN, arg). 1043 */ 1044 pid_t 1045 fgetown(sigiop) 1046 struct sigio **sigiop; 1047 { 1048 pid_t pgid; 1049 1050 SIGIO_LOCK(); 1051 pgid = (*sigiop != NULL) ? (*sigiop)->sio_pgid : 0; 1052 SIGIO_UNLOCK(); 1053 return (pgid); 1054 } 1055 1056 /* 1057 * Close a file descriptor. 1058 */ 1059 #ifndef _SYS_SYSPROTO_H_ 1060 struct close_args { 1061 int fd; 1062 }; 1063 #endif 1064 /* ARGSUSED */ 1065 int 1066 close(td, uap) 1067 struct thread *td; 1068 struct close_args *uap; 1069 { 1070 1071 return (kern_close(td, uap->fd)); 1072 } 1073 1074 int 1075 kern_close(td, fd) 1076 struct thread *td; 1077 int fd; 1078 { 1079 struct filedesc *fdp; 1080 struct file *fp; 1081 int error; 1082 int holdleaders; 1083 1084 error = 0; 1085 holdleaders = 0; 1086 fdp = td->td_proc->p_fd; 1087 1088 AUDIT_SYSCLOSE(td, fd); 1089 1090 FILEDESC_XLOCK(fdp); 1091 if ((unsigned)fd >= fdp->fd_nfiles || 1092 (fp = fdp->fd_ofiles[fd]) == NULL) { 1093 FILEDESC_XUNLOCK(fdp); 1094 return (EBADF); 1095 } 1096 fdp->fd_ofiles[fd] = NULL; 1097 fdp->fd_ofileflags[fd] = 0; 1098 fdunused(fdp, fd); 1099 if (td->td_proc->p_fdtol != NULL) { 1100 /* 1101 * Ask fdfree() to sleep to ensure that all relevant 1102 * process leaders can be traversed in closef(). 1103 */ 1104 fdp->fd_holdleaderscount++; 1105 holdleaders = 1; 1106 } 1107 1108 /* 1109 * We now hold the fp reference that used to be owned by the 1110 * descriptor array. We have to unlock the FILEDESC *AFTER* 1111 * knote_fdclose to prevent a race of the fd getting opened, a knote 1112 * added, and deleteing a knote for the new fd. 1113 */ 1114 knote_fdclose(td, fd); 1115 if (fp->f_type == DTYPE_MQUEUE) 1116 mq_fdclose(td, fd, fp); 1117 FILEDESC_XUNLOCK(fdp); 1118 1119 error = closef(fp, td); 1120 if (holdleaders) { 1121 FILEDESC_XLOCK(fdp); 1122 fdp->fd_holdleaderscount--; 1123 if (fdp->fd_holdleaderscount == 0 && 1124 fdp->fd_holdleaderswakeup != 0) { 1125 fdp->fd_holdleaderswakeup = 0; 1126 wakeup(&fdp->fd_holdleaderscount); 1127 } 1128 FILEDESC_XUNLOCK(fdp); 1129 } 1130 return (error); 1131 } 1132 1133 #if defined(COMPAT_43) 1134 /* 1135 * Return status information about a file descriptor. 1136 */ 1137 #ifndef _SYS_SYSPROTO_H_ 1138 struct ofstat_args { 1139 int fd; 1140 struct ostat *sb; 1141 }; 1142 #endif 1143 /* ARGSUSED */ 1144 int 1145 ofstat(struct thread *td, struct ofstat_args *uap) 1146 { 1147 struct ostat oub; 1148 struct stat ub; 1149 int error; 1150 1151 error = kern_fstat(td, uap->fd, &ub); 1152 if (error == 0) { 1153 cvtstat(&ub, &oub); 1154 error = copyout(&oub, uap->sb, sizeof(oub)); 1155 } 1156 return (error); 1157 } 1158 #endif /* COMPAT_43 */ 1159 1160 /* 1161 * Return status information about a file descriptor. 1162 */ 1163 #ifndef _SYS_SYSPROTO_H_ 1164 struct fstat_args { 1165 int fd; 1166 struct stat *sb; 1167 }; 1168 #endif 1169 /* ARGSUSED */ 1170 int 1171 fstat(struct thread *td, struct fstat_args *uap) 1172 { 1173 struct stat ub; 1174 int error; 1175 1176 error = kern_fstat(td, uap->fd, &ub); 1177 if (error == 0) 1178 error = copyout(&ub, uap->sb, sizeof(ub)); 1179 return (error); 1180 } 1181 1182 int 1183 kern_fstat(struct thread *td, int fd, struct stat *sbp) 1184 { 1185 struct file *fp; 1186 int error; 1187 1188 AUDIT_ARG(fd, fd); 1189 1190 if ((error = fget(td, fd, &fp)) != 0) 1191 return (error); 1192 1193 AUDIT_ARG(file, td->td_proc, fp); 1194 1195 error = fo_stat(fp, sbp, td->td_ucred, td); 1196 fdrop(fp, td); 1197 #ifdef KTRACE 1198 if (error == 0 && KTRPOINT(td, KTR_STRUCT)) 1199 ktrstat(sbp); 1200 #endif 1201 return (error); 1202 } 1203 1204 /* 1205 * Return status information about a file descriptor. 1206 */ 1207 #ifndef _SYS_SYSPROTO_H_ 1208 struct nfstat_args { 1209 int fd; 1210 struct nstat *sb; 1211 }; 1212 #endif 1213 /* ARGSUSED */ 1214 int 1215 nfstat(struct thread *td, struct nfstat_args *uap) 1216 { 1217 struct nstat nub; 1218 struct stat ub; 1219 int error; 1220 1221 error = kern_fstat(td, uap->fd, &ub); 1222 if (error == 0) { 1223 cvtnstat(&ub, &nub); 1224 error = copyout(&nub, uap->sb, sizeof(nub)); 1225 } 1226 return (error); 1227 } 1228 1229 /* 1230 * Return pathconf information about a file descriptor. 1231 */ 1232 #ifndef _SYS_SYSPROTO_H_ 1233 struct fpathconf_args { 1234 int fd; 1235 int name; 1236 }; 1237 #endif 1238 /* ARGSUSED */ 1239 int 1240 fpathconf(struct thread *td, struct fpathconf_args *uap) 1241 { 1242 struct file *fp; 1243 struct vnode *vp; 1244 int error; 1245 1246 if ((error = fget(td, uap->fd, &fp)) != 0) 1247 return (error); 1248 1249 /* If asynchronous I/O is available, it works for all descriptors. */ 1250 if (uap->name == _PC_ASYNC_IO) { 1251 td->td_retval[0] = async_io_version; 1252 goto out; 1253 } 1254 vp = fp->f_vnode; 1255 if (vp != NULL) { 1256 int vfslocked; 1257 vfslocked = VFS_LOCK_GIANT(vp->v_mount); 1258 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 1259 error = VOP_PATHCONF(vp, uap->name, td->td_retval); 1260 VOP_UNLOCK(vp, 0); 1261 VFS_UNLOCK_GIANT(vfslocked); 1262 } else if (fp->f_type == DTYPE_PIPE || fp->f_type == DTYPE_SOCKET) { 1263 if (uap->name != _PC_PIPE_BUF) { 1264 error = EINVAL; 1265 } else { 1266 td->td_retval[0] = PIPE_BUF; 1267 error = 0; 1268 } 1269 } else { 1270 error = EOPNOTSUPP; 1271 } 1272 out: 1273 fdrop(fp, td); 1274 return (error); 1275 } 1276 1277 /* 1278 * Grow the file table to accomodate (at least) nfd descriptors. This may 1279 * block and drop the filedesc lock, but it will reacquire it before 1280 * returning. 1281 */ 1282 static void 1283 fdgrowtable(struct filedesc *fdp, int nfd) 1284 { 1285 struct file **ntable; 1286 char *nfileflags; 1287 int nnfiles, onfiles; 1288 NDSLOTTYPE *nmap; 1289 1290 FILEDESC_XLOCK_ASSERT(fdp); 1291 1292 KASSERT(fdp->fd_nfiles > 0, 1293 ("zero-length file table")); 1294 1295 /* compute the size of the new table */ 1296 onfiles = fdp->fd_nfiles; 1297 nnfiles = NDSLOTS(nfd) * NDENTRIES; /* round up */ 1298 if (nnfiles <= onfiles) 1299 /* the table is already large enough */ 1300 return; 1301 1302 /* allocate a new table and (if required) new bitmaps */ 1303 FILEDESC_XUNLOCK(fdp); 1304 MALLOC(ntable, struct file **, nnfiles * OFILESIZE, 1305 M_FILEDESC, M_ZERO | M_WAITOK); 1306 nfileflags = (char *)&ntable[nnfiles]; 1307 if (NDSLOTS(nnfiles) > NDSLOTS(onfiles)) 1308 MALLOC(nmap, NDSLOTTYPE *, NDSLOTS(nnfiles) * NDSLOTSIZE, 1309 M_FILEDESC, M_ZERO | M_WAITOK); 1310 else 1311 nmap = NULL; 1312 FILEDESC_XLOCK(fdp); 1313 1314 /* 1315 * We now have new tables ready to go. Since we dropped the 1316 * filedesc lock to call malloc(), watch out for a race. 1317 */ 1318 onfiles = fdp->fd_nfiles; 1319 if (onfiles >= nnfiles) { 1320 /* we lost the race, but that's OK */ 1321 free(ntable, M_FILEDESC); 1322 if (nmap != NULL) 1323 free(nmap, M_FILEDESC); 1324 return; 1325 } 1326 bcopy(fdp->fd_ofiles, ntable, onfiles * sizeof(*ntable)); 1327 bcopy(fdp->fd_ofileflags, nfileflags, onfiles); 1328 if (onfiles > NDFILE) 1329 free(fdp->fd_ofiles, M_FILEDESC); 1330 fdp->fd_ofiles = ntable; 1331 fdp->fd_ofileflags = nfileflags; 1332 if (NDSLOTS(nnfiles) > NDSLOTS(onfiles)) { 1333 bcopy(fdp->fd_map, nmap, NDSLOTS(onfiles) * sizeof(*nmap)); 1334 if (NDSLOTS(onfiles) > NDSLOTS(NDFILE)) 1335 free(fdp->fd_map, M_FILEDESC); 1336 fdp->fd_map = nmap; 1337 } 1338 fdp->fd_nfiles = nnfiles; 1339 } 1340 1341 /* 1342 * Allocate a file descriptor for the process. 1343 */ 1344 int 1345 fdalloc(struct thread *td, int minfd, int *result) 1346 { 1347 struct proc *p = td->td_proc; 1348 struct filedesc *fdp = p->p_fd; 1349 int fd = -1, maxfd; 1350 1351 FILEDESC_XLOCK_ASSERT(fdp); 1352 1353 if (fdp->fd_freefile > minfd) 1354 minfd = fdp->fd_freefile; 1355 1356 PROC_LOCK(p); 1357 maxfd = min((int)lim_cur(p, RLIMIT_NOFILE), maxfilesperproc); 1358 PROC_UNLOCK(p); 1359 1360 /* 1361 * Search the bitmap for a free descriptor. If none is found, try 1362 * to grow the file table. Keep at it until we either get a file 1363 * descriptor or run into process or system limits; fdgrowtable() 1364 * may drop the filedesc lock, so we're in a race. 1365 */ 1366 for (;;) { 1367 fd = fd_first_free(fdp, minfd, fdp->fd_nfiles); 1368 if (fd >= maxfd) 1369 return (EMFILE); 1370 if (fd < fdp->fd_nfiles) 1371 break; 1372 fdgrowtable(fdp, min(fdp->fd_nfiles * 2, maxfd)); 1373 } 1374 1375 /* 1376 * Perform some sanity checks, then mark the file descriptor as 1377 * used and return it to the caller. 1378 */ 1379 KASSERT(!fdisused(fdp, fd), 1380 ("fd_first_free() returned non-free descriptor")); 1381 KASSERT(fdp->fd_ofiles[fd] == NULL, 1382 ("free descriptor isn't")); 1383 fdp->fd_ofileflags[fd] = 0; /* XXX needed? */ 1384 fdused(fdp, fd); 1385 *result = fd; 1386 return (0); 1387 } 1388 1389 /* 1390 * Check to see whether n user file descriptors are available to the process 1391 * p. 1392 */ 1393 int 1394 fdavail(struct thread *td, int n) 1395 { 1396 struct proc *p = td->td_proc; 1397 struct filedesc *fdp = td->td_proc->p_fd; 1398 struct file **fpp; 1399 int i, lim, last; 1400 1401 FILEDESC_LOCK_ASSERT(fdp); 1402 1403 PROC_LOCK(p); 1404 lim = min((int)lim_cur(p, RLIMIT_NOFILE), maxfilesperproc); 1405 PROC_UNLOCK(p); 1406 if ((i = lim - fdp->fd_nfiles) > 0 && (n -= i) <= 0) 1407 return (1); 1408 last = min(fdp->fd_nfiles, lim); 1409 fpp = &fdp->fd_ofiles[fdp->fd_freefile]; 1410 for (i = last - fdp->fd_freefile; --i >= 0; fpp++) { 1411 if (*fpp == NULL && --n <= 0) 1412 return (1); 1413 } 1414 return (0); 1415 } 1416 1417 /* 1418 * Create a new open file structure and allocate a file decriptor for the 1419 * process that refers to it. We add one reference to the file for the 1420 * descriptor table and one reference for resultfp. This is to prevent us 1421 * being preempted and the entry in the descriptor table closed after we 1422 * release the FILEDESC lock. 1423 */ 1424 int 1425 falloc(struct thread *td, struct file **resultfp, int *resultfd) 1426 { 1427 struct proc *p = td->td_proc; 1428 struct file *fp; 1429 int error, i; 1430 int maxuserfiles = maxfiles - (maxfiles / 20); 1431 static struct timeval lastfail; 1432 static int curfail; 1433 1434 fp = uma_zalloc(file_zone, M_WAITOK | M_ZERO); 1435 if ((openfiles >= maxuserfiles && 1436 priv_check(td, PRIV_MAXFILES) != 0) || 1437 openfiles >= maxfiles) { 1438 if (ppsratecheck(&lastfail, &curfail, 1)) { 1439 printf("kern.maxfiles limit exceeded by uid %i, please see tuning(7).\n", 1440 td->td_ucred->cr_ruid); 1441 } 1442 uma_zfree(file_zone, fp); 1443 return (ENFILE); 1444 } 1445 atomic_add_int(&openfiles, 1); 1446 1447 /* 1448 * If the process has file descriptor zero open, add the new file 1449 * descriptor to the list of open files at that point, otherwise 1450 * put it at the front of the list of open files. 1451 */ 1452 fp->f_count = 1; 1453 if (resultfp) 1454 fp->f_count++; 1455 fp->f_cred = crhold(td->td_ucred); 1456 fp->f_ops = &badfileops; 1457 fp->f_data = NULL; 1458 fp->f_vnode = NULL; 1459 FILEDESC_XLOCK(p->p_fd); 1460 if ((error = fdalloc(td, 0, &i))) { 1461 FILEDESC_XUNLOCK(p->p_fd); 1462 fdrop(fp, td); 1463 if (resultfp) 1464 fdrop(fp, td); 1465 return (error); 1466 } 1467 p->p_fd->fd_ofiles[i] = fp; 1468 FILEDESC_XUNLOCK(p->p_fd); 1469 if (resultfp) 1470 *resultfp = fp; 1471 if (resultfd) 1472 *resultfd = i; 1473 return (0); 1474 } 1475 1476 /* 1477 * Build a new filedesc structure from another. 1478 * Copy the current, root, and jail root vnode references. 1479 */ 1480 struct filedesc * 1481 fdinit(struct filedesc *fdp) 1482 { 1483 struct filedesc0 *newfdp; 1484 1485 newfdp = malloc(sizeof *newfdp, M_FILEDESC, M_WAITOK | M_ZERO); 1486 FILEDESC_LOCK_INIT(&newfdp->fd_fd); 1487 if (fdp != NULL) { 1488 FILEDESC_XLOCK(fdp); 1489 newfdp->fd_fd.fd_cdir = fdp->fd_cdir; 1490 if (newfdp->fd_fd.fd_cdir) 1491 VREF(newfdp->fd_fd.fd_cdir); 1492 newfdp->fd_fd.fd_rdir = fdp->fd_rdir; 1493 if (newfdp->fd_fd.fd_rdir) 1494 VREF(newfdp->fd_fd.fd_rdir); 1495 newfdp->fd_fd.fd_jdir = fdp->fd_jdir; 1496 if (newfdp->fd_fd.fd_jdir) 1497 VREF(newfdp->fd_fd.fd_jdir); 1498 FILEDESC_XUNLOCK(fdp); 1499 } 1500 1501 /* Create the file descriptor table. */ 1502 newfdp->fd_fd.fd_refcnt = 1; 1503 newfdp->fd_fd.fd_holdcnt = 1; 1504 newfdp->fd_fd.fd_cmask = CMASK; 1505 newfdp->fd_fd.fd_ofiles = newfdp->fd_dfiles; 1506 newfdp->fd_fd.fd_ofileflags = newfdp->fd_dfileflags; 1507 newfdp->fd_fd.fd_nfiles = NDFILE; 1508 newfdp->fd_fd.fd_map = newfdp->fd_dmap; 1509 newfdp->fd_fd.fd_lastfile = -1; 1510 return (&newfdp->fd_fd); 1511 } 1512 1513 static struct filedesc * 1514 fdhold(struct proc *p) 1515 { 1516 struct filedesc *fdp; 1517 1518 mtx_lock(&fdesc_mtx); 1519 fdp = p->p_fd; 1520 if (fdp != NULL) 1521 fdp->fd_holdcnt++; 1522 mtx_unlock(&fdesc_mtx); 1523 return (fdp); 1524 } 1525 1526 static void 1527 fddrop(struct filedesc *fdp) 1528 { 1529 int i; 1530 1531 mtx_lock(&fdesc_mtx); 1532 i = --fdp->fd_holdcnt; 1533 mtx_unlock(&fdesc_mtx); 1534 if (i > 0) 1535 return; 1536 1537 FILEDESC_LOCK_DESTROY(fdp); 1538 FREE(fdp, M_FILEDESC); 1539 } 1540 1541 /* 1542 * Share a filedesc structure. 1543 */ 1544 struct filedesc * 1545 fdshare(struct filedesc *fdp) 1546 { 1547 1548 FILEDESC_XLOCK(fdp); 1549 fdp->fd_refcnt++; 1550 FILEDESC_XUNLOCK(fdp); 1551 return (fdp); 1552 } 1553 1554 /* 1555 * Unshare a filedesc structure, if necessary by making a copy 1556 */ 1557 void 1558 fdunshare(struct proc *p, struct thread *td) 1559 { 1560 1561 FILEDESC_XLOCK(p->p_fd); 1562 if (p->p_fd->fd_refcnt > 1) { 1563 struct filedesc *tmp; 1564 1565 FILEDESC_XUNLOCK(p->p_fd); 1566 tmp = fdcopy(p->p_fd); 1567 fdfree(td); 1568 p->p_fd = tmp; 1569 } else 1570 FILEDESC_XUNLOCK(p->p_fd); 1571 } 1572 1573 /* 1574 * Copy a filedesc structure. A NULL pointer in returns a NULL reference, 1575 * this is to ease callers, not catch errors. 1576 */ 1577 struct filedesc * 1578 fdcopy(struct filedesc *fdp) 1579 { 1580 struct filedesc *newfdp; 1581 int i; 1582 1583 /* Certain daemons might not have file descriptors. */ 1584 if (fdp == NULL) 1585 return (NULL); 1586 1587 newfdp = fdinit(fdp); 1588 FILEDESC_SLOCK(fdp); 1589 while (fdp->fd_lastfile >= newfdp->fd_nfiles) { 1590 FILEDESC_SUNLOCK(fdp); 1591 FILEDESC_XLOCK(newfdp); 1592 fdgrowtable(newfdp, fdp->fd_lastfile + 1); 1593 FILEDESC_XUNLOCK(newfdp); 1594 FILEDESC_SLOCK(fdp); 1595 } 1596 /* copy everything except kqueue descriptors */ 1597 newfdp->fd_freefile = -1; 1598 for (i = 0; i <= fdp->fd_lastfile; ++i) { 1599 if (fdisused(fdp, i) && 1600 fdp->fd_ofiles[i]->f_type != DTYPE_KQUEUE) { 1601 newfdp->fd_ofiles[i] = fdp->fd_ofiles[i]; 1602 newfdp->fd_ofileflags[i] = fdp->fd_ofileflags[i]; 1603 fhold(newfdp->fd_ofiles[i]); 1604 newfdp->fd_lastfile = i; 1605 } else { 1606 if (newfdp->fd_freefile == -1) 1607 newfdp->fd_freefile = i; 1608 } 1609 } 1610 FILEDESC_SUNLOCK(fdp); 1611 FILEDESC_XLOCK(newfdp); 1612 for (i = 0; i <= newfdp->fd_lastfile; ++i) 1613 if (newfdp->fd_ofiles[i] != NULL) 1614 fdused(newfdp, i); 1615 FILEDESC_XUNLOCK(newfdp); 1616 FILEDESC_SLOCK(fdp); 1617 if (newfdp->fd_freefile == -1) 1618 newfdp->fd_freefile = i; 1619 newfdp->fd_cmask = fdp->fd_cmask; 1620 FILEDESC_SUNLOCK(fdp); 1621 return (newfdp); 1622 } 1623 1624 /* 1625 * Release a filedesc structure. 1626 */ 1627 void 1628 fdfree(struct thread *td) 1629 { 1630 struct filedesc *fdp; 1631 struct file **fpp; 1632 int i, locked; 1633 struct filedesc_to_leader *fdtol; 1634 struct file *fp; 1635 struct vnode *cdir, *jdir, *rdir, *vp; 1636 struct flock lf; 1637 1638 /* Certain daemons might not have file descriptors. */ 1639 fdp = td->td_proc->p_fd; 1640 if (fdp == NULL) 1641 return; 1642 1643 /* Check for special need to clear POSIX style locks */ 1644 fdtol = td->td_proc->p_fdtol; 1645 if (fdtol != NULL) { 1646 FILEDESC_XLOCK(fdp); 1647 KASSERT(fdtol->fdl_refcount > 0, 1648 ("filedesc_to_refcount botch: fdl_refcount=%d", 1649 fdtol->fdl_refcount)); 1650 if (fdtol->fdl_refcount == 1 && 1651 (td->td_proc->p_leader->p_flag & P_ADVLOCK) != 0) { 1652 for (i = 0, fpp = fdp->fd_ofiles; 1653 i <= fdp->fd_lastfile; 1654 i++, fpp++) { 1655 if (*fpp == NULL || 1656 (*fpp)->f_type != DTYPE_VNODE) 1657 continue; 1658 fp = *fpp; 1659 fhold(fp); 1660 FILEDESC_XUNLOCK(fdp); 1661 lf.l_whence = SEEK_SET; 1662 lf.l_start = 0; 1663 lf.l_len = 0; 1664 lf.l_type = F_UNLCK; 1665 vp = fp->f_vnode; 1666 locked = VFS_LOCK_GIANT(vp->v_mount); 1667 (void) VOP_ADVLOCK(vp, 1668 (caddr_t)td->td_proc-> 1669 p_leader, 1670 F_UNLCK, 1671 &lf, 1672 F_POSIX); 1673 VFS_UNLOCK_GIANT(locked); 1674 FILEDESC_XLOCK(fdp); 1675 fdrop(fp, td); 1676 fpp = fdp->fd_ofiles + i; 1677 } 1678 } 1679 retry: 1680 if (fdtol->fdl_refcount == 1) { 1681 if (fdp->fd_holdleaderscount > 0 && 1682 (td->td_proc->p_leader->p_flag & P_ADVLOCK) != 0) { 1683 /* 1684 * close() or do_dup() has cleared a reference 1685 * in a shared file descriptor table. 1686 */ 1687 fdp->fd_holdleaderswakeup = 1; 1688 sx_sleep(&fdp->fd_holdleaderscount, 1689 FILEDESC_LOCK(fdp), PLOCK, "fdlhold", 0); 1690 goto retry; 1691 } 1692 if (fdtol->fdl_holdcount > 0) { 1693 /* 1694 * Ensure that fdtol->fdl_leader remains 1695 * valid in closef(). 1696 */ 1697 fdtol->fdl_wakeup = 1; 1698 sx_sleep(fdtol, FILEDESC_LOCK(fdp), PLOCK, 1699 "fdlhold", 0); 1700 goto retry; 1701 } 1702 } 1703 fdtol->fdl_refcount--; 1704 if (fdtol->fdl_refcount == 0 && 1705 fdtol->fdl_holdcount == 0) { 1706 fdtol->fdl_next->fdl_prev = fdtol->fdl_prev; 1707 fdtol->fdl_prev->fdl_next = fdtol->fdl_next; 1708 } else 1709 fdtol = NULL; 1710 td->td_proc->p_fdtol = NULL; 1711 FILEDESC_XUNLOCK(fdp); 1712 if (fdtol != NULL) 1713 FREE(fdtol, M_FILEDESC_TO_LEADER); 1714 } 1715 FILEDESC_XLOCK(fdp); 1716 i = --fdp->fd_refcnt; 1717 FILEDESC_XUNLOCK(fdp); 1718 if (i > 0) 1719 return; 1720 /* 1721 * We are the last reference to the structure, so we can 1722 * safely assume it will not change out from under us. 1723 */ 1724 fpp = fdp->fd_ofiles; 1725 for (i = fdp->fd_lastfile; i-- >= 0; fpp++) { 1726 if (*fpp) 1727 (void) closef(*fpp, td); 1728 } 1729 FILEDESC_XLOCK(fdp); 1730 1731 /* XXX This should happen earlier. */ 1732 mtx_lock(&fdesc_mtx); 1733 td->td_proc->p_fd = NULL; 1734 mtx_unlock(&fdesc_mtx); 1735 1736 if (fdp->fd_nfiles > NDFILE) 1737 FREE(fdp->fd_ofiles, M_FILEDESC); 1738 if (NDSLOTS(fdp->fd_nfiles) > NDSLOTS(NDFILE)) 1739 FREE(fdp->fd_map, M_FILEDESC); 1740 1741 fdp->fd_nfiles = 0; 1742 1743 cdir = fdp->fd_cdir; 1744 fdp->fd_cdir = NULL; 1745 rdir = fdp->fd_rdir; 1746 fdp->fd_rdir = NULL; 1747 jdir = fdp->fd_jdir; 1748 fdp->fd_jdir = NULL; 1749 FILEDESC_XUNLOCK(fdp); 1750 1751 if (cdir) { 1752 locked = VFS_LOCK_GIANT(cdir->v_mount); 1753 vrele(cdir); 1754 VFS_UNLOCK_GIANT(locked); 1755 } 1756 if (rdir) { 1757 locked = VFS_LOCK_GIANT(rdir->v_mount); 1758 vrele(rdir); 1759 VFS_UNLOCK_GIANT(locked); 1760 } 1761 if (jdir) { 1762 locked = VFS_LOCK_GIANT(jdir->v_mount); 1763 vrele(jdir); 1764 VFS_UNLOCK_GIANT(locked); 1765 } 1766 1767 fddrop(fdp); 1768 } 1769 1770 /* 1771 * For setugid programs, we don't want to people to use that setugidness 1772 * to generate error messages which write to a file which otherwise would 1773 * otherwise be off-limits to the process. We check for filesystems where 1774 * the vnode can change out from under us after execve (like [lin]procfs). 1775 * 1776 * Since setugidsafety calls this only for fd 0, 1 and 2, this check is 1777 * sufficient. We also don't check for setugidness since we know we are. 1778 */ 1779 static int 1780 is_unsafe(struct file *fp) 1781 { 1782 if (fp->f_type == DTYPE_VNODE) { 1783 struct vnode *vp = fp->f_vnode; 1784 1785 if ((vp->v_vflag & VV_PROCDEP) != 0) 1786 return (1); 1787 } 1788 return (0); 1789 } 1790 1791 /* 1792 * Make this setguid thing safe, if at all possible. 1793 */ 1794 void 1795 setugidsafety(struct thread *td) 1796 { 1797 struct filedesc *fdp; 1798 int i; 1799 1800 /* Certain daemons might not have file descriptors. */ 1801 fdp = td->td_proc->p_fd; 1802 if (fdp == NULL) 1803 return; 1804 1805 /* 1806 * Note: fdp->fd_ofiles may be reallocated out from under us while 1807 * we are blocked in a close. Be careful! 1808 */ 1809 FILEDESC_XLOCK(fdp); 1810 for (i = 0; i <= fdp->fd_lastfile; i++) { 1811 if (i > 2) 1812 break; 1813 if (fdp->fd_ofiles[i] && is_unsafe(fdp->fd_ofiles[i])) { 1814 struct file *fp; 1815 1816 knote_fdclose(td, i); 1817 /* 1818 * NULL-out descriptor prior to close to avoid 1819 * a race while close blocks. 1820 */ 1821 fp = fdp->fd_ofiles[i]; 1822 fdp->fd_ofiles[i] = NULL; 1823 fdp->fd_ofileflags[i] = 0; 1824 fdunused(fdp, i); 1825 FILEDESC_XUNLOCK(fdp); 1826 (void) closef(fp, td); 1827 FILEDESC_XLOCK(fdp); 1828 } 1829 } 1830 FILEDESC_XUNLOCK(fdp); 1831 } 1832 1833 /* 1834 * If a specific file object occupies a specific file descriptor, close the 1835 * file descriptor entry and drop a reference on the file object. This is a 1836 * convenience function to handle a subsequent error in a function that calls 1837 * falloc() that handles the race that another thread might have closed the 1838 * file descriptor out from under the thread creating the file object. 1839 */ 1840 void 1841 fdclose(struct filedesc *fdp, struct file *fp, int idx, struct thread *td) 1842 { 1843 1844 FILEDESC_XLOCK(fdp); 1845 if (fdp->fd_ofiles[idx] == fp) { 1846 fdp->fd_ofiles[idx] = NULL; 1847 fdunused(fdp, idx); 1848 FILEDESC_XUNLOCK(fdp); 1849 fdrop(fp, td); 1850 } else 1851 FILEDESC_XUNLOCK(fdp); 1852 } 1853 1854 /* 1855 * Close any files on exec? 1856 */ 1857 void 1858 fdcloseexec(struct thread *td) 1859 { 1860 struct filedesc *fdp; 1861 int i; 1862 1863 /* Certain daemons might not have file descriptors. */ 1864 fdp = td->td_proc->p_fd; 1865 if (fdp == NULL) 1866 return; 1867 1868 FILEDESC_XLOCK(fdp); 1869 1870 /* 1871 * We cannot cache fd_ofiles or fd_ofileflags since operations 1872 * may block and rip them out from under us. 1873 */ 1874 for (i = 0; i <= fdp->fd_lastfile; i++) { 1875 if (fdp->fd_ofiles[i] != NULL && 1876 (fdp->fd_ofiles[i]->f_type == DTYPE_MQUEUE || 1877 (fdp->fd_ofileflags[i] & UF_EXCLOSE))) { 1878 struct file *fp; 1879 1880 knote_fdclose(td, i); 1881 /* 1882 * NULL-out descriptor prior to close to avoid 1883 * a race while close blocks. 1884 */ 1885 fp = fdp->fd_ofiles[i]; 1886 fdp->fd_ofiles[i] = NULL; 1887 fdp->fd_ofileflags[i] = 0; 1888 fdunused(fdp, i); 1889 if (fp->f_type == DTYPE_MQUEUE) 1890 mq_fdclose(td, i, fp); 1891 FILEDESC_XUNLOCK(fdp); 1892 (void) closef(fp, td); 1893 FILEDESC_XLOCK(fdp); 1894 } 1895 } 1896 FILEDESC_XUNLOCK(fdp); 1897 } 1898 1899 /* 1900 * It is unsafe for set[ug]id processes to be started with file 1901 * descriptors 0..2 closed, as these descriptors are given implicit 1902 * significance in the Standard C library. fdcheckstd() will create a 1903 * descriptor referencing /dev/null for each of stdin, stdout, and 1904 * stderr that is not already open. 1905 */ 1906 int 1907 fdcheckstd(struct thread *td) 1908 { 1909 struct filedesc *fdp; 1910 register_t retval, save; 1911 int i, error, devnull; 1912 1913 fdp = td->td_proc->p_fd; 1914 if (fdp == NULL) 1915 return (0); 1916 KASSERT(fdp->fd_refcnt == 1, ("the fdtable should not be shared")); 1917 devnull = -1; 1918 error = 0; 1919 for (i = 0; i < 3; i++) { 1920 if (fdp->fd_ofiles[i] != NULL) 1921 continue; 1922 if (devnull < 0) { 1923 save = td->td_retval[0]; 1924 error = kern_open(td, "/dev/null", UIO_SYSSPACE, 1925 O_RDWR, 0); 1926 devnull = td->td_retval[0]; 1927 KASSERT(devnull == i, ("oof, we didn't get our fd")); 1928 td->td_retval[0] = save; 1929 if (error) 1930 break; 1931 } else { 1932 error = do_dup(td, DUP_FIXED, devnull, i, &retval); 1933 if (error != 0) 1934 break; 1935 } 1936 } 1937 return (error); 1938 } 1939 1940 /* 1941 * Internal form of close. Decrement reference count on file structure. 1942 * Note: td may be NULL when closing a file that was being passed in a 1943 * message. 1944 * 1945 * XXXRW: Giant is not required for the caller, but often will be held; this 1946 * makes it moderately likely the Giant will be recursed in the VFS case. 1947 */ 1948 int 1949 closef(struct file *fp, struct thread *td) 1950 { 1951 struct vnode *vp; 1952 struct flock lf; 1953 struct filedesc_to_leader *fdtol; 1954 struct filedesc *fdp; 1955 1956 /* 1957 * POSIX record locking dictates that any close releases ALL 1958 * locks owned by this process. This is handled by setting 1959 * a flag in the unlock to free ONLY locks obeying POSIX 1960 * semantics, and not to free BSD-style file locks. 1961 * If the descriptor was in a message, POSIX-style locks 1962 * aren't passed with the descriptor, and the thread pointer 1963 * will be NULL. Callers should be careful only to pass a 1964 * NULL thread pointer when there really is no owning 1965 * context that might have locks, or the locks will be 1966 * leaked. 1967 */ 1968 if (fp->f_type == DTYPE_VNODE && td != NULL) { 1969 int vfslocked; 1970 1971 vp = fp->f_vnode; 1972 vfslocked = VFS_LOCK_GIANT(vp->v_mount); 1973 if ((td->td_proc->p_leader->p_flag & P_ADVLOCK) != 0) { 1974 lf.l_whence = SEEK_SET; 1975 lf.l_start = 0; 1976 lf.l_len = 0; 1977 lf.l_type = F_UNLCK; 1978 (void) VOP_ADVLOCK(vp, (caddr_t)td->td_proc->p_leader, 1979 F_UNLCK, &lf, F_POSIX); 1980 } 1981 fdtol = td->td_proc->p_fdtol; 1982 if (fdtol != NULL) { 1983 /* 1984 * Handle special case where file descriptor table is 1985 * shared between multiple process leaders. 1986 */ 1987 fdp = td->td_proc->p_fd; 1988 FILEDESC_XLOCK(fdp); 1989 for (fdtol = fdtol->fdl_next; 1990 fdtol != td->td_proc->p_fdtol; 1991 fdtol = fdtol->fdl_next) { 1992 if ((fdtol->fdl_leader->p_flag & 1993 P_ADVLOCK) == 0) 1994 continue; 1995 fdtol->fdl_holdcount++; 1996 FILEDESC_XUNLOCK(fdp); 1997 lf.l_whence = SEEK_SET; 1998 lf.l_start = 0; 1999 lf.l_len = 0; 2000 lf.l_type = F_UNLCK; 2001 vp = fp->f_vnode; 2002 (void) VOP_ADVLOCK(vp, 2003 (caddr_t)fdtol->fdl_leader, 2004 F_UNLCK, &lf, F_POSIX); 2005 FILEDESC_XLOCK(fdp); 2006 fdtol->fdl_holdcount--; 2007 if (fdtol->fdl_holdcount == 0 && 2008 fdtol->fdl_wakeup != 0) { 2009 fdtol->fdl_wakeup = 0; 2010 wakeup(fdtol); 2011 } 2012 } 2013 FILEDESC_XUNLOCK(fdp); 2014 } 2015 VFS_UNLOCK_GIANT(vfslocked); 2016 } 2017 return (fdrop(fp, td)); 2018 } 2019 2020 /* 2021 * Initialize the file pointer with the specified properties. 2022 * 2023 * The ops are set with release semantics to be certain that the flags, type, 2024 * and data are visible when ops is. This is to prevent ops methods from being 2025 * called with bad data. 2026 */ 2027 void 2028 finit(struct file *fp, u_int flag, short type, void *data, struct fileops *ops) 2029 { 2030 fp->f_data = data; 2031 fp->f_flag = flag; 2032 fp->f_type = type; 2033 atomic_store_rel_ptr((volatile uintptr_t *)&fp->f_ops, (uintptr_t)ops); 2034 } 2035 2036 2037 /* 2038 * Extract the file pointer associated with the specified descriptor for the 2039 * current user process. 2040 * 2041 * If the descriptor doesn't exist, EBADF is returned. 2042 * 2043 * If the descriptor exists but doesn't match 'flags' then return EBADF for 2044 * read attempts and EINVAL for write attempts. 2045 * 2046 * If 'hold' is set (non-zero) the file's refcount will be bumped on return. 2047 * It should be dropped with fdrop(). If it is not set, then the refcount 2048 * will not be bumped however the thread's filedesc struct will be returned 2049 * locked (for fgetsock). 2050 * 2051 * If an error occured the non-zero error is returned and *fpp is set to 2052 * NULL. Otherwise *fpp is set and zero is returned. 2053 */ 2054 static __inline int 2055 _fget(struct thread *td, int fd, struct file **fpp, int flags, int hold) 2056 { 2057 struct filedesc *fdp; 2058 struct file *fp; 2059 2060 *fpp = NULL; 2061 if (td == NULL || (fdp = td->td_proc->p_fd) == NULL) 2062 return (EBADF); 2063 FILEDESC_SLOCK(fdp); 2064 if ((fp = fget_locked(fdp, fd)) == NULL || fp->f_ops == &badfileops) { 2065 FILEDESC_SUNLOCK(fdp); 2066 return (EBADF); 2067 } 2068 2069 /* 2070 * FREAD and FWRITE failure return EBADF as per POSIX. 2071 * 2072 * Only one flag, or 0, may be specified. 2073 */ 2074 if (flags == FREAD && (fp->f_flag & FREAD) == 0) { 2075 FILEDESC_SUNLOCK(fdp); 2076 return (EBADF); 2077 } 2078 if (flags == FWRITE && (fp->f_flag & FWRITE) == 0) { 2079 FILEDESC_SUNLOCK(fdp); 2080 return (EBADF); 2081 } 2082 if (hold) { 2083 fhold(fp); 2084 FILEDESC_SUNLOCK(fdp); 2085 } 2086 *fpp = fp; 2087 return (0); 2088 } 2089 2090 int 2091 fget(struct thread *td, int fd, struct file **fpp) 2092 { 2093 2094 return(_fget(td, fd, fpp, 0, 1)); 2095 } 2096 2097 int 2098 fget_read(struct thread *td, int fd, struct file **fpp) 2099 { 2100 2101 return(_fget(td, fd, fpp, FREAD, 1)); 2102 } 2103 2104 int 2105 fget_write(struct thread *td, int fd, struct file **fpp) 2106 { 2107 2108 return(_fget(td, fd, fpp, FWRITE, 1)); 2109 } 2110 2111 /* 2112 * Like fget() but loads the underlying vnode, or returns an error if the 2113 * descriptor does not represent a vnode. Note that pipes use vnodes but 2114 * never have VM objects. The returned vnode will be vref()'d. 2115 * 2116 * XXX: what about the unused flags ? 2117 */ 2118 static __inline int 2119 _fgetvp(struct thread *td, int fd, struct vnode **vpp, int flags) 2120 { 2121 struct file *fp; 2122 int error; 2123 2124 *vpp = NULL; 2125 if ((error = _fget(td, fd, &fp, flags, 0)) != 0) 2126 return (error); 2127 if (fp->f_vnode == NULL) { 2128 error = EINVAL; 2129 } else { 2130 *vpp = fp->f_vnode; 2131 vref(*vpp); 2132 } 2133 FILEDESC_SUNLOCK(td->td_proc->p_fd); 2134 return (error); 2135 } 2136 2137 int 2138 fgetvp(struct thread *td, int fd, struct vnode **vpp) 2139 { 2140 2141 return (_fgetvp(td, fd, vpp, 0)); 2142 } 2143 2144 int 2145 fgetvp_read(struct thread *td, int fd, struct vnode **vpp) 2146 { 2147 2148 return (_fgetvp(td, fd, vpp, FREAD)); 2149 } 2150 2151 #ifdef notyet 2152 int 2153 fgetvp_write(struct thread *td, int fd, struct vnode **vpp) 2154 { 2155 2156 return (_fgetvp(td, fd, vpp, FWRITE)); 2157 } 2158 #endif 2159 2160 /* 2161 * Like fget() but loads the underlying socket, or returns an error if the 2162 * descriptor does not represent a socket. 2163 * 2164 * We bump the ref count on the returned socket. XXX Also obtain the SX lock 2165 * in the future. 2166 * 2167 * XXXRW: fgetsock() and fputsock() are deprecated, as consumers should rely 2168 * on their file descriptor reference to prevent the socket from being free'd 2169 * during use. 2170 */ 2171 int 2172 fgetsock(struct thread *td, int fd, struct socket **spp, u_int *fflagp) 2173 { 2174 struct file *fp; 2175 int error; 2176 2177 *spp = NULL; 2178 if (fflagp != NULL) 2179 *fflagp = 0; 2180 if ((error = _fget(td, fd, &fp, 0, 0)) != 0) 2181 return (error); 2182 if (fp->f_type != DTYPE_SOCKET) { 2183 error = ENOTSOCK; 2184 } else { 2185 *spp = fp->f_data; 2186 if (fflagp) 2187 *fflagp = fp->f_flag; 2188 SOCK_LOCK(*spp); 2189 soref(*spp); 2190 SOCK_UNLOCK(*spp); 2191 } 2192 FILEDESC_SUNLOCK(td->td_proc->p_fd); 2193 return (error); 2194 } 2195 2196 /* 2197 * Drop the reference count on the socket and XXX release the SX lock in the 2198 * future. The last reference closes the socket. 2199 * 2200 * XXXRW: fputsock() is deprecated, see comment for fgetsock(). 2201 */ 2202 void 2203 fputsock(struct socket *so) 2204 { 2205 2206 ACCEPT_LOCK(); 2207 SOCK_LOCK(so); 2208 sorele(so); 2209 } 2210 2211 /* 2212 * Handle the last reference to a file being closed. 2213 */ 2214 int 2215 _fdrop(struct file *fp, struct thread *td) 2216 { 2217 int error; 2218 2219 error = 0; 2220 if (fp->f_count != 0) 2221 panic("fdrop: count %d", fp->f_count); 2222 if (fp->f_ops != &badfileops) 2223 error = fo_close(fp, td); 2224 atomic_subtract_int(&openfiles, 1); 2225 crfree(fp->f_cred); 2226 uma_zfree(file_zone, fp); 2227 2228 return (error); 2229 } 2230 2231 /* 2232 * Apply an advisory lock on a file descriptor. 2233 * 2234 * Just attempt to get a record lock of the requested type on the entire file 2235 * (l_whence = SEEK_SET, l_start = 0, l_len = 0). 2236 */ 2237 #ifndef _SYS_SYSPROTO_H_ 2238 struct flock_args { 2239 int fd; 2240 int how; 2241 }; 2242 #endif 2243 /* ARGSUSED */ 2244 int 2245 flock(struct thread *td, struct flock_args *uap) 2246 { 2247 struct file *fp; 2248 struct vnode *vp; 2249 struct flock lf; 2250 int vfslocked; 2251 int error; 2252 2253 if ((error = fget(td, uap->fd, &fp)) != 0) 2254 return (error); 2255 if (fp->f_type != DTYPE_VNODE) { 2256 fdrop(fp, td); 2257 return (EOPNOTSUPP); 2258 } 2259 2260 vp = fp->f_vnode; 2261 vfslocked = VFS_LOCK_GIANT(vp->v_mount); 2262 lf.l_whence = SEEK_SET; 2263 lf.l_start = 0; 2264 lf.l_len = 0; 2265 if (uap->how & LOCK_UN) { 2266 lf.l_type = F_UNLCK; 2267 atomic_clear_int(&fp->f_flag, FHASLOCK); 2268 error = VOP_ADVLOCK(vp, (caddr_t)fp, F_UNLCK, &lf, F_FLOCK); 2269 goto done2; 2270 } 2271 if (uap->how & LOCK_EX) 2272 lf.l_type = F_WRLCK; 2273 else if (uap->how & LOCK_SH) 2274 lf.l_type = F_RDLCK; 2275 else { 2276 error = EBADF; 2277 goto done2; 2278 } 2279 atomic_set_int(&fp->f_flag, FHASLOCK); 2280 error = VOP_ADVLOCK(vp, (caddr_t)fp, F_SETLK, &lf, 2281 (uap->how & LOCK_NB) ? F_FLOCK : F_FLOCK | F_WAIT); 2282 done2: 2283 fdrop(fp, td); 2284 VFS_UNLOCK_GIANT(vfslocked); 2285 return (error); 2286 } 2287 /* 2288 * Duplicate the specified descriptor to a free descriptor. 2289 */ 2290 int 2291 dupfdopen(struct thread *td, struct filedesc *fdp, int indx, int dfd, int mode, int error) 2292 { 2293 struct file *wfp; 2294 struct file *fp; 2295 2296 /* 2297 * If the to-be-dup'd fd number is greater than the allowed number 2298 * of file descriptors, or the fd to be dup'd has already been 2299 * closed, then reject. 2300 */ 2301 FILEDESC_XLOCK(fdp); 2302 if (dfd < 0 || dfd >= fdp->fd_nfiles || 2303 (wfp = fdp->fd_ofiles[dfd]) == NULL) { 2304 FILEDESC_XUNLOCK(fdp); 2305 return (EBADF); 2306 } 2307 2308 /* 2309 * There are two cases of interest here. 2310 * 2311 * For ENODEV simply dup (dfd) to file descriptor (indx) and return. 2312 * 2313 * For ENXIO steal away the file structure from (dfd) and store it in 2314 * (indx). (dfd) is effectively closed by this operation. 2315 * 2316 * Any other error code is just returned. 2317 */ 2318 switch (error) { 2319 case ENODEV: 2320 /* 2321 * Check that the mode the file is being opened for is a 2322 * subset of the mode of the existing descriptor. 2323 */ 2324 if (((mode & (FREAD|FWRITE)) | wfp->f_flag) != wfp->f_flag) { 2325 FILEDESC_XUNLOCK(fdp); 2326 return (EACCES); 2327 } 2328 fp = fdp->fd_ofiles[indx]; 2329 fdp->fd_ofiles[indx] = wfp; 2330 fdp->fd_ofileflags[indx] = fdp->fd_ofileflags[dfd]; 2331 if (fp == NULL) 2332 fdused(fdp, indx); 2333 fhold(wfp); 2334 FILEDESC_XUNLOCK(fdp); 2335 if (fp != NULL) 2336 /* 2337 * We now own the reference to fp that the ofiles[] 2338 * array used to own. Release it. 2339 */ 2340 fdrop(fp, td); 2341 return (0); 2342 2343 case ENXIO: 2344 /* 2345 * Steal away the file pointer from dfd and stuff it into indx. 2346 */ 2347 fp = fdp->fd_ofiles[indx]; 2348 fdp->fd_ofiles[indx] = fdp->fd_ofiles[dfd]; 2349 fdp->fd_ofiles[dfd] = NULL; 2350 fdp->fd_ofileflags[indx] = fdp->fd_ofileflags[dfd]; 2351 fdp->fd_ofileflags[dfd] = 0; 2352 fdunused(fdp, dfd); 2353 if (fp == NULL) 2354 fdused(fdp, indx); 2355 FILEDESC_XUNLOCK(fdp); 2356 2357 /* 2358 * We now own the reference to fp that the ofiles[] array 2359 * used to own. Release it. 2360 */ 2361 if (fp != NULL) 2362 fdrop(fp, td); 2363 return (0); 2364 2365 default: 2366 FILEDESC_XUNLOCK(fdp); 2367 return (error); 2368 } 2369 /* NOTREACHED */ 2370 } 2371 2372 /* 2373 * Scan all active processes to see if any of them have a current or root 2374 * directory of `olddp'. If so, replace them with the new mount point. 2375 */ 2376 void 2377 mountcheckdirs(struct vnode *olddp, struct vnode *newdp) 2378 { 2379 struct filedesc *fdp; 2380 struct proc *p; 2381 int nrele; 2382 2383 if (vrefcnt(olddp) == 1) 2384 return; 2385 sx_slock(&allproc_lock); 2386 FOREACH_PROC_IN_SYSTEM(p) { 2387 fdp = fdhold(p); 2388 if (fdp == NULL) 2389 continue; 2390 nrele = 0; 2391 FILEDESC_XLOCK(fdp); 2392 if (fdp->fd_cdir == olddp) { 2393 vref(newdp); 2394 fdp->fd_cdir = newdp; 2395 nrele++; 2396 } 2397 if (fdp->fd_rdir == olddp) { 2398 vref(newdp); 2399 fdp->fd_rdir = newdp; 2400 nrele++; 2401 } 2402 FILEDESC_XUNLOCK(fdp); 2403 fddrop(fdp); 2404 while (nrele--) 2405 vrele(olddp); 2406 } 2407 sx_sunlock(&allproc_lock); 2408 if (rootvnode == olddp) { 2409 vrele(rootvnode); 2410 vref(newdp); 2411 rootvnode = newdp; 2412 } 2413 } 2414 2415 struct filedesc_to_leader * 2416 filedesc_to_leader_alloc(struct filedesc_to_leader *old, struct filedesc *fdp, struct proc *leader) 2417 { 2418 struct filedesc_to_leader *fdtol; 2419 2420 MALLOC(fdtol, struct filedesc_to_leader *, 2421 sizeof(struct filedesc_to_leader), 2422 M_FILEDESC_TO_LEADER, 2423 M_WAITOK); 2424 fdtol->fdl_refcount = 1; 2425 fdtol->fdl_holdcount = 0; 2426 fdtol->fdl_wakeup = 0; 2427 fdtol->fdl_leader = leader; 2428 if (old != NULL) { 2429 FILEDESC_XLOCK(fdp); 2430 fdtol->fdl_next = old->fdl_next; 2431 fdtol->fdl_prev = old; 2432 old->fdl_next = fdtol; 2433 fdtol->fdl_next->fdl_prev = fdtol; 2434 FILEDESC_XUNLOCK(fdp); 2435 } else { 2436 fdtol->fdl_next = fdtol; 2437 fdtol->fdl_prev = fdtol; 2438 } 2439 return (fdtol); 2440 } 2441 2442 /* 2443 * Get file structures globally. 2444 */ 2445 static int 2446 sysctl_kern_file(SYSCTL_HANDLER_ARGS) 2447 { 2448 struct xfile xf; 2449 struct filedesc *fdp; 2450 struct file *fp; 2451 struct proc *p; 2452 int error, n; 2453 2454 error = sysctl_wire_old_buffer(req, 0); 2455 if (error != 0) 2456 return (error); 2457 if (req->oldptr == NULL) { 2458 n = 0; 2459 sx_slock(&allproc_lock); 2460 FOREACH_PROC_IN_SYSTEM(p) { 2461 if (p->p_state == PRS_NEW) 2462 continue; 2463 fdp = fdhold(p); 2464 if (fdp == NULL) 2465 continue; 2466 /* overestimates sparse tables. */ 2467 if (fdp->fd_lastfile > 0) 2468 n += fdp->fd_lastfile; 2469 fddrop(fdp); 2470 } 2471 sx_sunlock(&allproc_lock); 2472 return (SYSCTL_OUT(req, 0, n * sizeof(xf))); 2473 } 2474 error = 0; 2475 bzero(&xf, sizeof(xf)); 2476 xf.xf_size = sizeof(xf); 2477 sx_slock(&allproc_lock); 2478 FOREACH_PROC_IN_SYSTEM(p) { 2479 if (p->p_state == PRS_NEW) 2480 continue; 2481 PROC_LOCK(p); 2482 if (p_cansee(req->td, p) != 0) { 2483 PROC_UNLOCK(p); 2484 continue; 2485 } 2486 xf.xf_pid = p->p_pid; 2487 xf.xf_uid = p->p_ucred->cr_uid; 2488 PROC_UNLOCK(p); 2489 fdp = fdhold(p); 2490 if (fdp == NULL) 2491 continue; 2492 FILEDESC_SLOCK(fdp); 2493 for (n = 0; fdp->fd_refcnt > 0 && n < fdp->fd_nfiles; ++n) { 2494 if ((fp = fdp->fd_ofiles[n]) == NULL) 2495 continue; 2496 xf.xf_fd = n; 2497 xf.xf_file = fp; 2498 xf.xf_data = fp->f_data; 2499 xf.xf_vnode = fp->f_vnode; 2500 xf.xf_type = fp->f_type; 2501 xf.xf_count = fp->f_count; 2502 xf.xf_msgcount = 0; 2503 xf.xf_offset = fp->f_offset; 2504 xf.xf_flag = fp->f_flag; 2505 error = SYSCTL_OUT(req, &xf, sizeof(xf)); 2506 if (error) 2507 break; 2508 } 2509 FILEDESC_SUNLOCK(fdp); 2510 fddrop(fdp); 2511 if (error) 2512 break; 2513 } 2514 sx_sunlock(&allproc_lock); 2515 return (error); 2516 } 2517 2518 SYSCTL_PROC(_kern, KERN_FILE, file, CTLTYPE_OPAQUE|CTLFLAG_RD, 2519 0, 0, sysctl_kern_file, "S,xfile", "Entire file table"); 2520 2521 static int 2522 export_vnode_for_sysctl(struct vnode *vp, int type, 2523 struct kinfo_file *kif, struct filedesc *fdp, struct sysctl_req *req) 2524 { 2525 int error; 2526 char *fullpath, *freepath; 2527 int vfslocked; 2528 2529 bzero(kif, sizeof(*kif)); 2530 kif->kf_structsize = sizeof(*kif); 2531 2532 vref(vp); 2533 kif->kf_fd = type; 2534 kif->kf_type = KF_TYPE_VNODE; 2535 /* This function only handles directories. */ 2536 KASSERT(vp->v_type == VDIR, ("export_vnode_for_sysctl: vnode not directory")); 2537 kif->kf_vnode_type = KF_VTYPE_VDIR; 2538 2539 /* 2540 * This is not a true file descriptor, so we set a bogus refcount 2541 * and offset to indicate these fields should be ignored. 2542 */ 2543 kif->kf_ref_count = -1; 2544 kif->kf_offset = -1; 2545 2546 freepath = NULL; 2547 fullpath = "-"; 2548 FILEDESC_SUNLOCK(fdp); 2549 vfslocked = VFS_LOCK_GIANT(vp->v_mount); 2550 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 2551 vn_fullpath(curthread, vp, &fullpath, &freepath); 2552 vput(vp); 2553 VFS_UNLOCK_GIANT(vfslocked); 2554 strlcpy(kif->kf_path, fullpath, sizeof(kif->kf_path)); 2555 if (freepath != NULL) 2556 free(freepath, M_TEMP); 2557 error = SYSCTL_OUT(req, kif, sizeof(*kif)); 2558 FILEDESC_SLOCK(fdp); 2559 return (error); 2560 } 2561 2562 /* 2563 * Get per-process file descriptors for use by procstat(1), et al. 2564 */ 2565 static int 2566 sysctl_kern_proc_filedesc(SYSCTL_HANDLER_ARGS) 2567 { 2568 char *fullpath, *freepath; 2569 struct kinfo_file *kif; 2570 struct filedesc *fdp; 2571 int error, i, *name; 2572 struct socket *so; 2573 struct vnode *vp; 2574 struct file *fp; 2575 struct proc *p; 2576 int vfslocked; 2577 2578 name = (int *)arg1; 2579 if ((p = pfind((pid_t)name[0])) == NULL) 2580 return (ESRCH); 2581 if ((error = p_candebug(curthread, p))) { 2582 PROC_UNLOCK(p); 2583 return (error); 2584 } 2585 fdp = fdhold(p); 2586 PROC_UNLOCK(p); 2587 kif = malloc(sizeof(*kif), M_TEMP, M_WAITOK); 2588 FILEDESC_SLOCK(fdp); 2589 if (fdp->fd_cdir != NULL) 2590 export_vnode_for_sysctl(fdp->fd_cdir, KF_FD_TYPE_CWD, kif, 2591 fdp, req); 2592 if (fdp->fd_rdir != NULL) 2593 export_vnode_for_sysctl(fdp->fd_rdir, KF_FD_TYPE_ROOT, kif, 2594 fdp, req); 2595 if (fdp->fd_jdir != NULL) 2596 export_vnode_for_sysctl(fdp->fd_jdir, KF_FD_TYPE_JAIL, kif, 2597 fdp, req); 2598 for (i = 0; i < fdp->fd_nfiles; i++) { 2599 if ((fp = fdp->fd_ofiles[i]) == NULL) 2600 continue; 2601 bzero(kif, sizeof(*kif)); 2602 kif->kf_structsize = sizeof(*kif); 2603 vp = NULL; 2604 so = NULL; 2605 kif->kf_fd = i; 2606 switch (fp->f_type) { 2607 case DTYPE_VNODE: 2608 kif->kf_type = KF_TYPE_VNODE; 2609 vp = fp->f_vnode; 2610 break; 2611 2612 case DTYPE_SOCKET: 2613 kif->kf_type = KF_TYPE_SOCKET; 2614 so = fp->f_data; 2615 break; 2616 2617 case DTYPE_PIPE: 2618 kif->kf_type = KF_TYPE_PIPE; 2619 break; 2620 2621 case DTYPE_FIFO: 2622 kif->kf_type = KF_TYPE_FIFO; 2623 vp = fp->f_vnode; 2624 vref(vp); 2625 break; 2626 2627 case DTYPE_KQUEUE: 2628 kif->kf_type = KF_TYPE_KQUEUE; 2629 break; 2630 2631 case DTYPE_CRYPTO: 2632 kif->kf_type = KF_TYPE_CRYPTO; 2633 break; 2634 2635 case DTYPE_MQUEUE: 2636 kif->kf_type = KF_TYPE_MQUEUE; 2637 break; 2638 2639 case DTYPE_SHM: 2640 kif->kf_type = KF_TYPE_SHM; 2641 break; 2642 2643 default: 2644 kif->kf_type = KF_TYPE_UNKNOWN; 2645 break; 2646 } 2647 kif->kf_ref_count = fp->f_count; 2648 if (fp->f_flag & FREAD) 2649 kif->kf_flags |= KF_FLAG_READ; 2650 if (fp->f_flag & FWRITE) 2651 kif->kf_flags |= KF_FLAG_WRITE; 2652 if (fp->f_flag & FAPPEND) 2653 kif->kf_flags |= KF_FLAG_APPEND; 2654 if (fp->f_flag & FASYNC) 2655 kif->kf_flags |= KF_FLAG_ASYNC; 2656 if (fp->f_flag & FFSYNC) 2657 kif->kf_flags |= KF_FLAG_FSYNC; 2658 if (fp->f_flag & FNONBLOCK) 2659 kif->kf_flags |= KF_FLAG_NONBLOCK; 2660 if (fp->f_flag & O_DIRECT) 2661 kif->kf_flags |= KF_FLAG_DIRECT; 2662 if (fp->f_flag & FHASLOCK) 2663 kif->kf_flags |= KF_FLAG_HASLOCK; 2664 kif->kf_offset = fp->f_offset; 2665 if (vp != NULL) { 2666 vref(vp); 2667 switch (vp->v_type) { 2668 case VNON: 2669 kif->kf_vnode_type = KF_VTYPE_VNON; 2670 break; 2671 case VREG: 2672 kif->kf_vnode_type = KF_VTYPE_VREG; 2673 break; 2674 case VDIR: 2675 kif->kf_vnode_type = KF_VTYPE_VDIR; 2676 break; 2677 case VBLK: 2678 kif->kf_vnode_type = KF_VTYPE_VBLK; 2679 break; 2680 case VCHR: 2681 kif->kf_vnode_type = KF_VTYPE_VCHR; 2682 break; 2683 case VLNK: 2684 kif->kf_vnode_type = KF_VTYPE_VLNK; 2685 break; 2686 case VSOCK: 2687 kif->kf_vnode_type = KF_VTYPE_VSOCK; 2688 break; 2689 case VFIFO: 2690 kif->kf_vnode_type = KF_VTYPE_VFIFO; 2691 break; 2692 case VBAD: 2693 kif->kf_vnode_type = KF_VTYPE_VBAD; 2694 break; 2695 default: 2696 kif->kf_vnode_type = KF_VTYPE_UNKNOWN; 2697 break; 2698 } 2699 /* 2700 * It is OK to drop the filedesc lock here as we will 2701 * re-validate and re-evaluate its properties when 2702 * the loop continues. 2703 */ 2704 freepath = NULL; 2705 fullpath = "-"; 2706 FILEDESC_SUNLOCK(fdp); 2707 vfslocked = VFS_LOCK_GIANT(vp->v_mount); 2708 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 2709 vn_fullpath(curthread, vp, &fullpath, &freepath); 2710 vput(vp); 2711 VFS_UNLOCK_GIANT(vfslocked); 2712 strlcpy(kif->kf_path, fullpath, 2713 sizeof(kif->kf_path)); 2714 if (freepath != NULL) 2715 free(freepath, M_TEMP); 2716 FILEDESC_SLOCK(fdp); 2717 } 2718 if (so != NULL) { 2719 struct sockaddr *sa; 2720 2721 if (so->so_proto->pr_usrreqs->pru_sockaddr(so, &sa) 2722 == 0 && sa->sa_len <= sizeof(kif->kf_sa_local)) { 2723 bcopy(sa, &kif->kf_sa_local, sa->sa_len); 2724 free(sa, M_SONAME); 2725 } 2726 if (so->so_proto->pr_usrreqs->pru_peeraddr(so, &sa) 2727 == 00 && sa->sa_len <= sizeof(kif->kf_sa_peer)) { 2728 bcopy(sa, &kif->kf_sa_peer, sa->sa_len); 2729 free(sa, M_SONAME); 2730 } 2731 kif->kf_sock_domain = 2732 so->so_proto->pr_domain->dom_family; 2733 kif->kf_sock_type = so->so_type; 2734 kif->kf_sock_protocol = so->so_proto->pr_protocol; 2735 } 2736 error = SYSCTL_OUT(req, kif, sizeof(*kif)); 2737 if (error) 2738 break; 2739 } 2740 FILEDESC_SUNLOCK(fdp); 2741 fddrop(fdp); 2742 free(kif, M_TEMP); 2743 return (0); 2744 } 2745 2746 static SYSCTL_NODE(_kern_proc, KERN_PROC_FILEDESC, filedesc, CTLFLAG_RD, 2747 sysctl_kern_proc_filedesc, "Process filedesc entries"); 2748 2749 #ifdef DDB 2750 /* 2751 * For the purposes of debugging, generate a human-readable string for the 2752 * file type. 2753 */ 2754 static const char * 2755 file_type_to_name(short type) 2756 { 2757 2758 switch (type) { 2759 case 0: 2760 return ("zero"); 2761 case DTYPE_VNODE: 2762 return ("vnod"); 2763 case DTYPE_SOCKET: 2764 return ("sock"); 2765 case DTYPE_PIPE: 2766 return ("pipe"); 2767 case DTYPE_FIFO: 2768 return ("fifo"); 2769 case DTYPE_KQUEUE: 2770 return ("kque"); 2771 case DTYPE_CRYPTO: 2772 return ("crpt"); 2773 case DTYPE_MQUEUE: 2774 return ("mque"); 2775 case DTYPE_SHM: 2776 return ("shm"); 2777 default: 2778 return ("unkn"); 2779 } 2780 } 2781 2782 /* 2783 * For the purposes of debugging, identify a process (if any, perhaps one of 2784 * many) that references the passed file in its file descriptor array. Return 2785 * NULL if none. 2786 */ 2787 static struct proc * 2788 file_to_first_proc(struct file *fp) 2789 { 2790 struct filedesc *fdp; 2791 struct proc *p; 2792 int n; 2793 2794 FOREACH_PROC_IN_SYSTEM(p) { 2795 if (p->p_state == PRS_NEW) 2796 continue; 2797 fdp = p->p_fd; 2798 if (fdp == NULL) 2799 continue; 2800 for (n = 0; n < fdp->fd_nfiles; n++) { 2801 if (fp == fdp->fd_ofiles[n]) 2802 return (p); 2803 } 2804 } 2805 return (NULL); 2806 } 2807 2808 static void 2809 db_print_file(struct file *fp, int header) 2810 { 2811 struct proc *p; 2812 2813 if (header) 2814 db_printf("%8s %4s %8s %8s %4s %5s %6s %8s %5s %12s\n", 2815 "File", "Type", "Data", "Flag", "GCFl", "Count", 2816 "MCount", "Vnode", "FPID", "FCmd"); 2817 p = file_to_first_proc(fp); 2818 db_printf("%8p %4s %8p %08x %04x %5d %6d %8p %5d %12s\n", fp, 2819 file_type_to_name(fp->f_type), fp->f_data, fp->f_flag, 2820 0, fp->f_count, 0, fp->f_vnode, 2821 p != NULL ? p->p_pid : -1, p != NULL ? p->p_comm : "-"); 2822 } 2823 2824 DB_SHOW_COMMAND(file, db_show_file) 2825 { 2826 struct file *fp; 2827 2828 if (!have_addr) { 2829 db_printf("usage: show file <addr>\n"); 2830 return; 2831 } 2832 fp = (struct file *)addr; 2833 db_print_file(fp, 1); 2834 } 2835 2836 DB_SHOW_COMMAND(files, db_show_files) 2837 { 2838 struct filedesc *fdp; 2839 struct file *fp; 2840 struct proc *p; 2841 int header; 2842 int n; 2843 2844 header = 1; 2845 FOREACH_PROC_IN_SYSTEM(p) { 2846 if (p->p_state == PRS_NEW) 2847 continue; 2848 if ((fdp = p->p_fd) == NULL) 2849 continue; 2850 for (n = 0; n < fdp->fd_nfiles; ++n) { 2851 if ((fp = fdp->fd_ofiles[n]) == NULL) 2852 continue; 2853 db_print_file(fp, header); 2854 header = 0; 2855 } 2856 } 2857 } 2858 #endif 2859 2860 SYSCTL_INT(_kern, KERN_MAXFILESPERPROC, maxfilesperproc, CTLFLAG_RW, 2861 &maxfilesperproc, 0, "Maximum files allowed open per process"); 2862 2863 SYSCTL_INT(_kern, KERN_MAXFILES, maxfiles, CTLFLAG_RW, 2864 &maxfiles, 0, "Maximum number of files"); 2865 2866 SYSCTL_INT(_kern, OID_AUTO, openfiles, CTLFLAG_RD, 2867 __DEVOLATILE(int *, &openfiles), 0, "System-wide number of open files"); 2868 2869 /* ARGSUSED*/ 2870 static void 2871 filelistinit(void *dummy) 2872 { 2873 2874 file_zone = uma_zcreate("Files", sizeof(struct file), NULL, NULL, 2875 NULL, NULL, UMA_ALIGN_PTR, 0); 2876 mtx_init(&sigio_lock, "sigio lock", NULL, MTX_DEF); 2877 mtx_init(&fdesc_mtx, "fdesc", NULL, MTX_DEF); 2878 } 2879 SYSINIT(select, SI_SUB_LOCK, SI_ORDER_FIRST, filelistinit, NULL); 2880 2881 /*-------------------------------------------------------------------*/ 2882 2883 static int 2884 badfo_readwrite(struct file *fp, struct uio *uio, struct ucred *active_cred, int flags, struct thread *td) 2885 { 2886 2887 return (EBADF); 2888 } 2889 2890 static int 2891 badfo_truncate(struct file *fp, off_t length, struct ucred *active_cred, struct thread *td) 2892 { 2893 2894 return (EINVAL); 2895 } 2896 2897 static int 2898 badfo_ioctl(struct file *fp, u_long com, void *data, struct ucred *active_cred, struct thread *td) 2899 { 2900 2901 return (EBADF); 2902 } 2903 2904 static int 2905 badfo_poll(struct file *fp, int events, struct ucred *active_cred, struct thread *td) 2906 { 2907 2908 return (0); 2909 } 2910 2911 static int 2912 badfo_kqfilter(struct file *fp, struct knote *kn) 2913 { 2914 2915 return (EBADF); 2916 } 2917 2918 static int 2919 badfo_stat(struct file *fp, struct stat *sb, struct ucred *active_cred, struct thread *td) 2920 { 2921 2922 return (EBADF); 2923 } 2924 2925 static int 2926 badfo_close(struct file *fp, struct thread *td) 2927 { 2928 2929 return (EBADF); 2930 } 2931 2932 struct fileops badfileops = { 2933 .fo_read = badfo_readwrite, 2934 .fo_write = badfo_readwrite, 2935 .fo_truncate = badfo_truncate, 2936 .fo_ioctl = badfo_ioctl, 2937 .fo_poll = badfo_poll, 2938 .fo_kqfilter = badfo_kqfilter, 2939 .fo_stat = badfo_stat, 2940 .fo_close = badfo_close, 2941 }; 2942 2943 2944 /*-------------------------------------------------------------------*/ 2945 2946 /* 2947 * File Descriptor pseudo-device driver (/dev/fd/). 2948 * 2949 * Opening minor device N dup()s the file (if any) connected to file 2950 * descriptor N belonging to the calling process. Note that this driver 2951 * consists of only the ``open()'' routine, because all subsequent 2952 * references to this file will be direct to the other driver. 2953 * 2954 * XXX: we could give this one a cloning event handler if necessary. 2955 */ 2956 2957 /* ARGSUSED */ 2958 static int 2959 fdopen(struct cdev *dev, int mode, int type, struct thread *td) 2960 { 2961 2962 /* 2963 * XXX Kludge: set curthread->td_dupfd to contain the value of the 2964 * the file descriptor being sought for duplication. The error 2965 * return ensures that the vnode for this device will be released 2966 * by vn_open. Open will detect this special error and take the 2967 * actions in dupfdopen below. Other callers of vn_open or VOP_OPEN 2968 * will simply report the error. 2969 */ 2970 td->td_dupfd = dev2unit(dev); 2971 return (ENODEV); 2972 } 2973 2974 static struct cdevsw fildesc_cdevsw = { 2975 .d_version = D_VERSION, 2976 .d_flags = D_NEEDGIANT, 2977 .d_open = fdopen, 2978 .d_name = "FD", 2979 }; 2980 2981 static void 2982 fildesc_drvinit(void *unused) 2983 { 2984 struct cdev *dev; 2985 2986 dev = make_dev(&fildesc_cdevsw, 0, UID_ROOT, GID_WHEEL, 0666, "fd/0"); 2987 make_dev_alias(dev, "stdin"); 2988 dev = make_dev(&fildesc_cdevsw, 1, UID_ROOT, GID_WHEEL, 0666, "fd/1"); 2989 make_dev_alias(dev, "stdout"); 2990 dev = make_dev(&fildesc_cdevsw, 2, UID_ROOT, GID_WHEEL, 0666, "fd/2"); 2991 make_dev_alias(dev, "stderr"); 2992 } 2993 2994 SYSINIT(fildescdev, SI_SUB_DRIVERS, SI_ORDER_MIDDLE, fildesc_drvinit, NULL); 2995