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/kdb.h> 72 #include <sys/stat.h> 73 #include <sys/sx.h> 74 #include <sys/syscallsubr.h> 75 #include <sys/sysctl.h> 76 #include <sys/sysproto.h> 77 #include <sys/unistd.h> 78 #include <sys/user.h> 79 #include <sys/vnode.h> 80 #ifdef KTRACE 81 #include <sys/ktrace.h> 82 #endif 83 84 #include <net/vnet.h> 85 86 #include <security/audit/audit.h> 87 88 #include <vm/uma.h> 89 #include <vm/vm.h> 90 91 #include <ddb/ddb.h> 92 93 static MALLOC_DEFINE(M_FILEDESC, "filedesc", "Open file descriptor table"); 94 static MALLOC_DEFINE(M_FILEDESC_TO_LEADER, "filedesc_to_leader", 95 "file desc to leader structures"); 96 static MALLOC_DEFINE(M_SIGIO, "sigio", "sigio structures"); 97 MALLOC_DEFINE(M_FILECAPS, "filecaps", "descriptor capabilities"); 98 99 MALLOC_DECLARE(M_FADVISE); 100 101 static uma_zone_t file_zone; 102 static uma_zone_t filedesc0_zone; 103 104 static int closefp(struct filedesc *fdp, int fd, struct file *fp, 105 struct thread *td, int holdleaders); 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 /* 115 * Each process has: 116 * 117 * - An array of open file descriptors (fd_ofiles) 118 * - An array of file flags (fd_ofileflags) 119 * - A bitmap recording which descriptors are in use (fd_map) 120 * 121 * A process starts out with NDFILE descriptors. The value of NDFILE has 122 * been selected based the historical limit of 20 open files, and an 123 * assumption that the majority of processes, especially short-lived 124 * processes like shells, will never need more. 125 * 126 * If this initial allocation is exhausted, a larger descriptor table and 127 * map are allocated dynamically, and the pointers in the process's struct 128 * filedesc are updated to point to those. This is repeated every time 129 * the process runs out of file descriptors (provided it hasn't hit its 130 * resource limit). 131 * 132 * Since threads may hold references to individual descriptor table 133 * entries, the tables are never freed. Instead, they are placed on a 134 * linked list and freed only when the struct filedesc is released. 135 */ 136 #define NDFILE 20 137 #define NDSLOTSIZE sizeof(NDSLOTTYPE) 138 #define NDENTRIES (NDSLOTSIZE * __CHAR_BIT) 139 #define NDSLOT(x) ((x) / NDENTRIES) 140 #define NDBIT(x) ((NDSLOTTYPE)1 << ((x) % NDENTRIES)) 141 #define NDSLOTS(x) (((x) + NDENTRIES - 1) / NDENTRIES) 142 143 /* 144 * SLIST entry used to keep track of ofiles which must be reclaimed when 145 * the process exits. 146 */ 147 struct freetable { 148 struct fdescenttbl *ft_table; 149 SLIST_ENTRY(freetable) ft_next; 150 }; 151 152 /* 153 * Initial allocation: a filedesc structure + the head of SLIST used to 154 * keep track of old ofiles + enough space for NDFILE descriptors. 155 */ 156 157 struct fdescenttbl0 { 158 int fdt_nfiles; 159 struct filedescent fdt_ofiles[NDFILE]; 160 }; 161 162 struct filedesc0 { 163 struct filedesc fd_fd; 164 SLIST_HEAD(, freetable) fd_free; 165 struct fdescenttbl0 fd_dfiles; 166 NDSLOTTYPE fd_dmap[NDSLOTS(NDFILE)]; 167 }; 168 169 /* 170 * Descriptor management. 171 */ 172 volatile int openfiles; /* actual number of open files */ 173 struct mtx sigio_lock; /* mtx to protect pointers to sigio */ 174 void (*mq_fdclose)(struct thread *td, int fd, struct file *fp); 175 176 /* 177 * If low >= size, just return low. Otherwise find the first zero bit in the 178 * given bitmap, starting at low and not exceeding size - 1. Return size if 179 * not found. 180 */ 181 static int 182 fd_first_free(struct filedesc *fdp, int low, int size) 183 { 184 NDSLOTTYPE *map = fdp->fd_map; 185 NDSLOTTYPE mask; 186 int off, maxoff; 187 188 if (low >= size) 189 return (low); 190 191 off = NDSLOT(low); 192 if (low % NDENTRIES) { 193 mask = ~(~(NDSLOTTYPE)0 >> (NDENTRIES - (low % NDENTRIES))); 194 if ((mask &= ~map[off]) != 0UL) 195 return (off * NDENTRIES + ffsl(mask) - 1); 196 ++off; 197 } 198 for (maxoff = NDSLOTS(size); off < maxoff; ++off) 199 if (map[off] != ~0UL) 200 return (off * NDENTRIES + ffsl(~map[off]) - 1); 201 return (size); 202 } 203 204 /* 205 * Find the highest non-zero bit in the given bitmap, starting at 0 and 206 * not exceeding size - 1. Return -1 if not found. 207 */ 208 static int 209 fd_last_used(struct filedesc *fdp, int size) 210 { 211 NDSLOTTYPE *map = fdp->fd_map; 212 NDSLOTTYPE mask; 213 int off, minoff; 214 215 off = NDSLOT(size); 216 if (size % NDENTRIES) { 217 mask = ~(~(NDSLOTTYPE)0 << (size % NDENTRIES)); 218 if ((mask &= map[off]) != 0) 219 return (off * NDENTRIES + flsl(mask) - 1); 220 --off; 221 } 222 for (minoff = NDSLOT(0); off >= minoff; --off) 223 if (map[off] != 0) 224 return (off * NDENTRIES + flsl(map[off]) - 1); 225 return (-1); 226 } 227 228 static int 229 fdisused(struct filedesc *fdp, int fd) 230 { 231 232 KASSERT(fd >= 0 && fd < fdp->fd_nfiles, 233 ("file descriptor %d out of range (0, %d)", fd, fdp->fd_nfiles)); 234 235 return ((fdp->fd_map[NDSLOT(fd)] & NDBIT(fd)) != 0); 236 } 237 238 /* 239 * Mark a file descriptor as used. 240 */ 241 static void 242 fdused_init(struct filedesc *fdp, int fd) 243 { 244 245 KASSERT(!fdisused(fdp, fd), ("fd=%d is already used", fd)); 246 247 fdp->fd_map[NDSLOT(fd)] |= NDBIT(fd); 248 } 249 250 static void 251 fdused(struct filedesc *fdp, int fd) 252 { 253 254 FILEDESC_XLOCK_ASSERT(fdp); 255 256 fdused_init(fdp, fd); 257 if (fd > fdp->fd_lastfile) 258 fdp->fd_lastfile = fd; 259 if (fd == fdp->fd_freefile) 260 fdp->fd_freefile = fd_first_free(fdp, fd, fdp->fd_nfiles); 261 } 262 263 /* 264 * Mark a file descriptor as unused. 265 */ 266 static void 267 fdunused(struct filedesc *fdp, int fd) 268 { 269 270 FILEDESC_XLOCK_ASSERT(fdp); 271 272 KASSERT(fdisused(fdp, fd), ("fd=%d is already unused", fd)); 273 KASSERT(fdp->fd_ofiles[fd].fde_file == NULL, 274 ("fd=%d is still in use", fd)); 275 276 fdp->fd_map[NDSLOT(fd)] &= ~NDBIT(fd); 277 if (fd < fdp->fd_freefile) 278 fdp->fd_freefile = fd; 279 if (fd == fdp->fd_lastfile) 280 fdp->fd_lastfile = fd_last_used(fdp, fd); 281 } 282 283 /* 284 * Free a file descriptor. 285 * 286 * Avoid some work if fdp is about to be destroyed. 287 */ 288 static inline void 289 fdefree_last(struct filedescent *fde) 290 { 291 292 filecaps_free(&fde->fde_caps); 293 } 294 295 static inline void 296 fdfree(struct filedesc *fdp, int fd) 297 { 298 struct filedescent *fde; 299 300 fde = &fdp->fd_ofiles[fd]; 301 #ifdef CAPABILITIES 302 seq_write_begin(&fde->fde_seq); 303 #endif 304 fdefree_last(fde); 305 fde->fde_file = NULL; 306 fdunused(fdp, fd); 307 #ifdef CAPABILITIES 308 seq_write_end(&fde->fde_seq); 309 #endif 310 } 311 312 void 313 pwd_ensure_dirs(void) 314 { 315 struct filedesc *fdp; 316 317 fdp = curproc->p_fd; 318 FILEDESC_XLOCK(fdp); 319 if (fdp->fd_cdir == NULL) { 320 fdp->fd_cdir = rootvnode; 321 VREF(rootvnode); 322 } 323 if (fdp->fd_rdir == NULL) { 324 fdp->fd_rdir = rootvnode; 325 VREF(rootvnode); 326 } 327 FILEDESC_XUNLOCK(fdp); 328 } 329 330 /* 331 * System calls on descriptors. 332 */ 333 #ifndef _SYS_SYSPROTO_H_ 334 struct getdtablesize_args { 335 int dummy; 336 }; 337 #endif 338 /* ARGSUSED */ 339 int 340 sys_getdtablesize(struct thread *td, struct getdtablesize_args *uap) 341 { 342 #ifdef RACCT 343 uint64_t lim; 344 #endif 345 346 td->td_retval[0] = 347 min((int)lim_cur(td, RLIMIT_NOFILE), maxfilesperproc); 348 #ifdef RACCT 349 PROC_LOCK(td->td_proc); 350 lim = racct_get_limit(td->td_proc, RACCT_NOFILE); 351 PROC_UNLOCK(td->td_proc); 352 if (lim < td->td_retval[0]) 353 td->td_retval[0] = lim; 354 #endif 355 return (0); 356 } 357 358 /* 359 * Duplicate a file descriptor to a particular value. 360 * 361 * Note: keep in mind that a potential race condition exists when closing 362 * descriptors from a shared descriptor table (via rfork). 363 */ 364 #ifndef _SYS_SYSPROTO_H_ 365 struct dup2_args { 366 u_int from; 367 u_int to; 368 }; 369 #endif 370 /* ARGSUSED */ 371 int 372 sys_dup2(struct thread *td, struct dup2_args *uap) 373 { 374 375 return (kern_dup(td, FDDUP_FIXED, 0, (int)uap->from, (int)uap->to)); 376 } 377 378 /* 379 * Duplicate a file descriptor. 380 */ 381 #ifndef _SYS_SYSPROTO_H_ 382 struct dup_args { 383 u_int fd; 384 }; 385 #endif 386 /* ARGSUSED */ 387 int 388 sys_dup(struct thread *td, struct dup_args *uap) 389 { 390 391 return (kern_dup(td, FDDUP_NORMAL, 0, (int)uap->fd, 0)); 392 } 393 394 /* 395 * The file control system call. 396 */ 397 #ifndef _SYS_SYSPROTO_H_ 398 struct fcntl_args { 399 int fd; 400 int cmd; 401 long arg; 402 }; 403 #endif 404 /* ARGSUSED */ 405 int 406 sys_fcntl(struct thread *td, struct fcntl_args *uap) 407 { 408 409 return (kern_fcntl_freebsd(td, uap->fd, uap->cmd, uap->arg)); 410 } 411 412 int 413 kern_fcntl_freebsd(struct thread *td, int fd, int cmd, long arg) 414 { 415 struct flock fl; 416 struct __oflock ofl; 417 intptr_t arg1; 418 int error, newcmd; 419 420 error = 0; 421 newcmd = cmd; 422 switch (cmd) { 423 case F_OGETLK: 424 case F_OSETLK: 425 case F_OSETLKW: 426 /* 427 * Convert old flock structure to new. 428 */ 429 error = copyin((void *)(intptr_t)arg, &ofl, sizeof(ofl)); 430 fl.l_start = ofl.l_start; 431 fl.l_len = ofl.l_len; 432 fl.l_pid = ofl.l_pid; 433 fl.l_type = ofl.l_type; 434 fl.l_whence = ofl.l_whence; 435 fl.l_sysid = 0; 436 437 switch (cmd) { 438 case F_OGETLK: 439 newcmd = F_GETLK; 440 break; 441 case F_OSETLK: 442 newcmd = F_SETLK; 443 break; 444 case F_OSETLKW: 445 newcmd = F_SETLKW; 446 break; 447 } 448 arg1 = (intptr_t)&fl; 449 break; 450 case F_GETLK: 451 case F_SETLK: 452 case F_SETLKW: 453 case F_SETLK_REMOTE: 454 error = copyin((void *)(intptr_t)arg, &fl, sizeof(fl)); 455 arg1 = (intptr_t)&fl; 456 break; 457 default: 458 arg1 = arg; 459 break; 460 } 461 if (error) 462 return (error); 463 error = kern_fcntl(td, fd, newcmd, arg1); 464 if (error) 465 return (error); 466 if (cmd == F_OGETLK) { 467 ofl.l_start = fl.l_start; 468 ofl.l_len = fl.l_len; 469 ofl.l_pid = fl.l_pid; 470 ofl.l_type = fl.l_type; 471 ofl.l_whence = fl.l_whence; 472 error = copyout(&ofl, (void *)(intptr_t)arg, sizeof(ofl)); 473 } else if (cmd == F_GETLK) { 474 error = copyout(&fl, (void *)(intptr_t)arg, sizeof(fl)); 475 } 476 return (error); 477 } 478 479 int 480 kern_fcntl(struct thread *td, int fd, int cmd, intptr_t arg) 481 { 482 struct filedesc *fdp; 483 struct flock *flp; 484 struct file *fp, *fp2; 485 struct filedescent *fde; 486 struct proc *p; 487 struct vnode *vp; 488 cap_rights_t rights; 489 int error, flg, tmp; 490 uint64_t bsize; 491 off_t foffset; 492 493 error = 0; 494 flg = F_POSIX; 495 p = td->td_proc; 496 fdp = p->p_fd; 497 498 switch (cmd) { 499 case F_DUPFD: 500 tmp = arg; 501 error = kern_dup(td, FDDUP_FCNTL, 0, fd, tmp); 502 break; 503 504 case F_DUPFD_CLOEXEC: 505 tmp = arg; 506 error = kern_dup(td, FDDUP_FCNTL, FDDUP_FLAG_CLOEXEC, fd, tmp); 507 break; 508 509 case F_DUP2FD: 510 tmp = arg; 511 error = kern_dup(td, FDDUP_FIXED, 0, fd, tmp); 512 break; 513 514 case F_DUP2FD_CLOEXEC: 515 tmp = arg; 516 error = kern_dup(td, FDDUP_FIXED, FDDUP_FLAG_CLOEXEC, fd, tmp); 517 break; 518 519 case F_GETFD: 520 FILEDESC_SLOCK(fdp); 521 if (fget_locked(fdp, fd) == NULL) { 522 FILEDESC_SUNLOCK(fdp); 523 error = EBADF; 524 break; 525 } 526 fde = &fdp->fd_ofiles[fd]; 527 td->td_retval[0] = 528 (fde->fde_flags & UF_EXCLOSE) ? FD_CLOEXEC : 0; 529 FILEDESC_SUNLOCK(fdp); 530 break; 531 532 case F_SETFD: 533 FILEDESC_XLOCK(fdp); 534 if (fget_locked(fdp, fd) == NULL) { 535 FILEDESC_XUNLOCK(fdp); 536 error = EBADF; 537 break; 538 } 539 fde = &fdp->fd_ofiles[fd]; 540 fde->fde_flags = (fde->fde_flags & ~UF_EXCLOSE) | 541 (arg & FD_CLOEXEC ? UF_EXCLOSE : 0); 542 FILEDESC_XUNLOCK(fdp); 543 break; 544 545 case F_GETFL: 546 error = fget_fcntl(td, fd, 547 cap_rights_init(&rights, CAP_FCNTL), F_GETFL, &fp); 548 if (error != 0) 549 break; 550 td->td_retval[0] = OFLAGS(fp->f_flag); 551 fdrop(fp, td); 552 break; 553 554 case F_SETFL: 555 error = fget_fcntl(td, fd, 556 cap_rights_init(&rights, CAP_FCNTL), F_SETFL, &fp); 557 if (error != 0) 558 break; 559 do { 560 tmp = flg = fp->f_flag; 561 tmp &= ~FCNTLFLAGS; 562 tmp |= FFLAGS(arg & ~O_ACCMODE) & FCNTLFLAGS; 563 } while(atomic_cmpset_int(&fp->f_flag, flg, tmp) == 0); 564 tmp = fp->f_flag & FNONBLOCK; 565 error = fo_ioctl(fp, FIONBIO, &tmp, td->td_ucred, td); 566 if (error != 0) { 567 fdrop(fp, td); 568 break; 569 } 570 tmp = fp->f_flag & FASYNC; 571 error = fo_ioctl(fp, FIOASYNC, &tmp, td->td_ucred, td); 572 if (error == 0) { 573 fdrop(fp, td); 574 break; 575 } 576 atomic_clear_int(&fp->f_flag, FNONBLOCK); 577 tmp = 0; 578 (void)fo_ioctl(fp, FIONBIO, &tmp, td->td_ucred, td); 579 fdrop(fp, td); 580 break; 581 582 case F_GETOWN: 583 error = fget_fcntl(td, fd, 584 cap_rights_init(&rights, CAP_FCNTL), F_GETOWN, &fp); 585 if (error != 0) 586 break; 587 error = fo_ioctl(fp, FIOGETOWN, &tmp, td->td_ucred, td); 588 if (error == 0) 589 td->td_retval[0] = tmp; 590 fdrop(fp, td); 591 break; 592 593 case F_SETOWN: 594 error = fget_fcntl(td, fd, 595 cap_rights_init(&rights, CAP_FCNTL), F_SETOWN, &fp); 596 if (error != 0) 597 break; 598 tmp = arg; 599 error = fo_ioctl(fp, FIOSETOWN, &tmp, td->td_ucred, td); 600 fdrop(fp, td); 601 break; 602 603 case F_SETLK_REMOTE: 604 error = priv_check(td, PRIV_NFS_LOCKD); 605 if (error) 606 return (error); 607 flg = F_REMOTE; 608 goto do_setlk; 609 610 case F_SETLKW: 611 flg |= F_WAIT; 612 /* FALLTHROUGH F_SETLK */ 613 614 case F_SETLK: 615 do_setlk: 616 cap_rights_init(&rights, CAP_FLOCK); 617 error = fget_unlocked(fdp, fd, &rights, &fp, NULL); 618 if (error != 0) 619 break; 620 if (fp->f_type != DTYPE_VNODE) { 621 error = EBADF; 622 fdrop(fp, td); 623 break; 624 } 625 626 flp = (struct flock *)arg; 627 if (flp->l_whence == SEEK_CUR) { 628 foffset = foffset_get(fp); 629 if (foffset < 0 || 630 (flp->l_start > 0 && 631 foffset > OFF_MAX - flp->l_start)) { 632 error = EOVERFLOW; 633 fdrop(fp, td); 634 break; 635 } 636 flp->l_start += foffset; 637 } 638 639 vp = fp->f_vnode; 640 switch (flp->l_type) { 641 case F_RDLCK: 642 if ((fp->f_flag & FREAD) == 0) { 643 error = EBADF; 644 break; 645 } 646 PROC_LOCK(p->p_leader); 647 p->p_leader->p_flag |= P_ADVLOCK; 648 PROC_UNLOCK(p->p_leader); 649 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_SETLK, 650 flp, flg); 651 break; 652 case F_WRLCK: 653 if ((fp->f_flag & FWRITE) == 0) { 654 error = EBADF; 655 break; 656 } 657 PROC_LOCK(p->p_leader); 658 p->p_leader->p_flag |= P_ADVLOCK; 659 PROC_UNLOCK(p->p_leader); 660 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_SETLK, 661 flp, flg); 662 break; 663 case F_UNLCK: 664 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_UNLCK, 665 flp, flg); 666 break; 667 case F_UNLCKSYS: 668 /* 669 * Temporary api for testing remote lock 670 * infrastructure. 671 */ 672 if (flg != F_REMOTE) { 673 error = EINVAL; 674 break; 675 } 676 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, 677 F_UNLCKSYS, flp, flg); 678 break; 679 default: 680 error = EINVAL; 681 break; 682 } 683 if (error != 0 || flp->l_type == F_UNLCK || 684 flp->l_type == F_UNLCKSYS) { 685 fdrop(fp, td); 686 break; 687 } 688 689 /* 690 * Check for a race with close. 691 * 692 * The vnode is now advisory locked (or unlocked, but this case 693 * is not really important) as the caller requested. 694 * We had to drop the filedesc lock, so we need to recheck if 695 * the descriptor is still valid, because if it was closed 696 * in the meantime we need to remove advisory lock from the 697 * vnode - close on any descriptor leading to an advisory 698 * locked vnode, removes that lock. 699 * We will return 0 on purpose in that case, as the result of 700 * successful advisory lock might have been externally visible 701 * already. This is fine - effectively we pretend to the caller 702 * that the closing thread was a bit slower and that the 703 * advisory lock succeeded before the close. 704 */ 705 error = fget_unlocked(fdp, fd, &rights, &fp2, NULL); 706 if (error != 0) { 707 fdrop(fp, td); 708 break; 709 } 710 if (fp != fp2) { 711 flp->l_whence = SEEK_SET; 712 flp->l_start = 0; 713 flp->l_len = 0; 714 flp->l_type = F_UNLCK; 715 (void) VOP_ADVLOCK(vp, (caddr_t)p->p_leader, 716 F_UNLCK, flp, F_POSIX); 717 } 718 fdrop(fp, td); 719 fdrop(fp2, td); 720 break; 721 722 case F_GETLK: 723 error = fget_unlocked(fdp, fd, 724 cap_rights_init(&rights, CAP_FLOCK), &fp, NULL); 725 if (error != 0) 726 break; 727 if (fp->f_type != DTYPE_VNODE) { 728 error = EBADF; 729 fdrop(fp, td); 730 break; 731 } 732 flp = (struct flock *)arg; 733 if (flp->l_type != F_RDLCK && flp->l_type != F_WRLCK && 734 flp->l_type != F_UNLCK) { 735 error = EINVAL; 736 fdrop(fp, td); 737 break; 738 } 739 if (flp->l_whence == SEEK_CUR) { 740 foffset = foffset_get(fp); 741 if ((flp->l_start > 0 && 742 foffset > OFF_MAX - flp->l_start) || 743 (flp->l_start < 0 && 744 foffset < OFF_MIN - flp->l_start)) { 745 error = EOVERFLOW; 746 fdrop(fp, td); 747 break; 748 } 749 flp->l_start += foffset; 750 } 751 vp = fp->f_vnode; 752 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_GETLK, flp, 753 F_POSIX); 754 fdrop(fp, td); 755 break; 756 757 case F_RDAHEAD: 758 arg = arg ? 128 * 1024: 0; 759 /* FALLTHROUGH */ 760 case F_READAHEAD: 761 error = fget_unlocked(fdp, fd, 762 cap_rights_init(&rights), &fp, NULL); 763 if (error != 0) 764 break; 765 if (fp->f_type != DTYPE_VNODE) { 766 fdrop(fp, td); 767 error = EBADF; 768 break; 769 } 770 vp = fp->f_vnode; 771 /* 772 * Exclusive lock synchronizes against f_seqcount reads and 773 * writes in sequential_heuristic(). 774 */ 775 error = vn_lock(vp, LK_EXCLUSIVE); 776 if (error != 0) { 777 fdrop(fp, td); 778 break; 779 } 780 if (arg >= 0) { 781 bsize = fp->f_vnode->v_mount->mnt_stat.f_iosize; 782 fp->f_seqcount = (arg + bsize - 1) / bsize; 783 atomic_set_int(&fp->f_flag, FRDAHEAD); 784 } else { 785 atomic_clear_int(&fp->f_flag, FRDAHEAD); 786 } 787 VOP_UNLOCK(vp, 0); 788 fdrop(fp, td); 789 break; 790 791 default: 792 error = EINVAL; 793 break; 794 } 795 return (error); 796 } 797 798 static int 799 getmaxfd(struct thread *td) 800 { 801 802 return (min((int)lim_cur(td, RLIMIT_NOFILE), maxfilesperproc)); 803 } 804 805 /* 806 * Common code for dup, dup2, fcntl(F_DUPFD) and fcntl(F_DUP2FD). 807 */ 808 int 809 kern_dup(struct thread *td, u_int mode, int flags, int old, int new) 810 { 811 struct filedesc *fdp; 812 struct filedescent *oldfde, *newfde; 813 struct proc *p; 814 struct file *delfp; 815 int error, maxfd; 816 817 p = td->td_proc; 818 fdp = p->p_fd; 819 820 MPASS((flags & ~(FDDUP_FLAG_CLOEXEC)) == 0); 821 MPASS(mode < FDDUP_LASTMODE); 822 823 /* 824 * Verify we have a valid descriptor to dup from and possibly to 825 * dup to. Unlike dup() and dup2(), fcntl()'s F_DUPFD should 826 * return EINVAL when the new descriptor is out of bounds. 827 */ 828 if (old < 0) 829 return (EBADF); 830 if (new < 0) 831 return (mode == FDDUP_FCNTL ? EINVAL : EBADF); 832 maxfd = getmaxfd(td); 833 if (new >= maxfd) 834 return (mode == FDDUP_FCNTL ? EINVAL : EBADF); 835 836 FILEDESC_XLOCK(fdp); 837 if (fget_locked(fdp, old) == NULL) { 838 FILEDESC_XUNLOCK(fdp); 839 return (EBADF); 840 } 841 if ((mode == FDDUP_FIXED || mode == FDDUP_MUSTREPLACE) && old == new) { 842 td->td_retval[0] = new; 843 if (flags & FDDUP_FLAG_CLOEXEC) 844 fdp->fd_ofiles[new].fde_flags |= UF_EXCLOSE; 845 FILEDESC_XUNLOCK(fdp); 846 return (0); 847 } 848 849 /* 850 * If the caller specified a file descriptor, make sure the file 851 * table is large enough to hold it, and grab it. Otherwise, just 852 * allocate a new descriptor the usual way. 853 */ 854 switch (mode) { 855 case FDDUP_NORMAL: 856 case FDDUP_FCNTL: 857 if ((error = fdalloc(td, new, &new)) != 0) { 858 FILEDESC_XUNLOCK(fdp); 859 return (error); 860 } 861 break; 862 case FDDUP_MUSTREPLACE: 863 /* Target file descriptor must exist. */ 864 if (fget_locked(fdp, new) == NULL) { 865 FILEDESC_XUNLOCK(fdp); 866 return (EBADF); 867 } 868 break; 869 case FDDUP_FIXED: 870 if (new >= fdp->fd_nfiles) { 871 /* 872 * The resource limits are here instead of e.g. 873 * fdalloc(), because the file descriptor table may be 874 * shared between processes, so we can't really use 875 * racct_add()/racct_sub(). Instead of counting the 876 * number of actually allocated descriptors, just put 877 * the limit on the size of the file descriptor table. 878 */ 879 #ifdef RACCT 880 if (racct_enable) { 881 PROC_LOCK(p); 882 error = racct_set(p, RACCT_NOFILE, new + 1); 883 PROC_UNLOCK(p); 884 if (error != 0) { 885 FILEDESC_XUNLOCK(fdp); 886 return (EMFILE); 887 } 888 } 889 #endif 890 fdgrowtable_exp(fdp, new + 1); 891 } 892 if (!fdisused(fdp, new)) 893 fdused(fdp, new); 894 break; 895 default: 896 KASSERT(0, ("%s unsupported mode %d", __func__, mode)); 897 } 898 899 KASSERT(old != new, ("new fd is same as old")); 900 901 oldfde = &fdp->fd_ofiles[old]; 902 fhold(oldfde->fde_file); 903 newfde = &fdp->fd_ofiles[new]; 904 delfp = newfde->fde_file; 905 906 /* 907 * Duplicate the source descriptor. 908 */ 909 #ifdef CAPABILITIES 910 seq_write_begin(&newfde->fde_seq); 911 #endif 912 filecaps_free(&newfde->fde_caps); 913 memcpy(newfde, oldfde, fde_change_size); 914 filecaps_copy(&oldfde->fde_caps, &newfde->fde_caps); 915 if ((flags & FDDUP_FLAG_CLOEXEC) != 0) 916 newfde->fde_flags = oldfde->fde_flags | UF_EXCLOSE; 917 else 918 newfde->fde_flags = oldfde->fde_flags & ~UF_EXCLOSE; 919 #ifdef CAPABILITIES 920 seq_write_end(&newfde->fde_seq); 921 #endif 922 td->td_retval[0] = new; 923 924 if (delfp != NULL) { 925 (void) closefp(fdp, new, delfp, td, 1); 926 /* closefp() drops the FILEDESC lock for us. */ 927 } else { 928 FILEDESC_XUNLOCK(fdp); 929 } 930 931 return (0); 932 } 933 934 /* 935 * If sigio is on the list associated with a process or process group, 936 * disable signalling from the device, remove sigio from the list and 937 * free sigio. 938 */ 939 void 940 funsetown(struct sigio **sigiop) 941 { 942 struct sigio *sigio; 943 944 SIGIO_LOCK(); 945 sigio = *sigiop; 946 if (sigio == NULL) { 947 SIGIO_UNLOCK(); 948 return; 949 } 950 *(sigio->sio_myref) = NULL; 951 if ((sigio)->sio_pgid < 0) { 952 struct pgrp *pg = (sigio)->sio_pgrp; 953 PGRP_LOCK(pg); 954 SLIST_REMOVE(&sigio->sio_pgrp->pg_sigiolst, sigio, 955 sigio, sio_pgsigio); 956 PGRP_UNLOCK(pg); 957 } else { 958 struct proc *p = (sigio)->sio_proc; 959 PROC_LOCK(p); 960 SLIST_REMOVE(&sigio->sio_proc->p_sigiolst, sigio, 961 sigio, sio_pgsigio); 962 PROC_UNLOCK(p); 963 } 964 SIGIO_UNLOCK(); 965 crfree(sigio->sio_ucred); 966 free(sigio, M_SIGIO); 967 } 968 969 /* 970 * Free a list of sigio structures. 971 * We only need to lock the SIGIO_LOCK because we have made ourselves 972 * inaccessible to callers of fsetown and therefore do not need to lock 973 * the proc or pgrp struct for the list manipulation. 974 */ 975 void 976 funsetownlst(struct sigiolst *sigiolst) 977 { 978 struct proc *p; 979 struct pgrp *pg; 980 struct sigio *sigio; 981 982 sigio = SLIST_FIRST(sigiolst); 983 if (sigio == NULL) 984 return; 985 p = NULL; 986 pg = NULL; 987 988 /* 989 * Every entry of the list should belong 990 * to a single proc or pgrp. 991 */ 992 if (sigio->sio_pgid < 0) { 993 pg = sigio->sio_pgrp; 994 PGRP_LOCK_ASSERT(pg, MA_NOTOWNED); 995 } else /* if (sigio->sio_pgid > 0) */ { 996 p = sigio->sio_proc; 997 PROC_LOCK_ASSERT(p, MA_NOTOWNED); 998 } 999 1000 SIGIO_LOCK(); 1001 while ((sigio = SLIST_FIRST(sigiolst)) != NULL) { 1002 *(sigio->sio_myref) = NULL; 1003 if (pg != NULL) { 1004 KASSERT(sigio->sio_pgid < 0, 1005 ("Proc sigio in pgrp sigio list")); 1006 KASSERT(sigio->sio_pgrp == pg, 1007 ("Bogus pgrp in sigio list")); 1008 PGRP_LOCK(pg); 1009 SLIST_REMOVE(&pg->pg_sigiolst, sigio, sigio, 1010 sio_pgsigio); 1011 PGRP_UNLOCK(pg); 1012 } else /* if (p != NULL) */ { 1013 KASSERT(sigio->sio_pgid > 0, 1014 ("Pgrp sigio in proc sigio list")); 1015 KASSERT(sigio->sio_proc == p, 1016 ("Bogus proc in sigio list")); 1017 PROC_LOCK(p); 1018 SLIST_REMOVE(&p->p_sigiolst, sigio, sigio, 1019 sio_pgsigio); 1020 PROC_UNLOCK(p); 1021 } 1022 SIGIO_UNLOCK(); 1023 crfree(sigio->sio_ucred); 1024 free(sigio, M_SIGIO); 1025 SIGIO_LOCK(); 1026 } 1027 SIGIO_UNLOCK(); 1028 } 1029 1030 /* 1031 * This is common code for FIOSETOWN ioctl called by fcntl(fd, F_SETOWN, arg). 1032 * 1033 * After permission checking, add a sigio structure to the sigio list for 1034 * the process or process group. 1035 */ 1036 int 1037 fsetown(pid_t pgid, struct sigio **sigiop) 1038 { 1039 struct proc *proc; 1040 struct pgrp *pgrp; 1041 struct sigio *sigio; 1042 int ret; 1043 1044 if (pgid == 0) { 1045 funsetown(sigiop); 1046 return (0); 1047 } 1048 1049 ret = 0; 1050 1051 /* Allocate and fill in the new sigio out of locks. */ 1052 sigio = malloc(sizeof(struct sigio), M_SIGIO, M_WAITOK); 1053 sigio->sio_pgid = pgid; 1054 sigio->sio_ucred = crhold(curthread->td_ucred); 1055 sigio->sio_myref = sigiop; 1056 1057 sx_slock(&proctree_lock); 1058 if (pgid > 0) { 1059 proc = pfind(pgid); 1060 if (proc == NULL) { 1061 ret = ESRCH; 1062 goto fail; 1063 } 1064 1065 /* 1066 * Policy - Don't allow a process to FSETOWN a process 1067 * in another session. 1068 * 1069 * Remove this test to allow maximum flexibility or 1070 * restrict FSETOWN to the current process or process 1071 * group for maximum safety. 1072 */ 1073 PROC_UNLOCK(proc); 1074 if (proc->p_session != curthread->td_proc->p_session) { 1075 ret = EPERM; 1076 goto fail; 1077 } 1078 1079 pgrp = NULL; 1080 } else /* if (pgid < 0) */ { 1081 pgrp = pgfind(-pgid); 1082 if (pgrp == NULL) { 1083 ret = ESRCH; 1084 goto fail; 1085 } 1086 PGRP_UNLOCK(pgrp); 1087 1088 /* 1089 * Policy - Don't allow a process to FSETOWN a process 1090 * in another session. 1091 * 1092 * Remove this test to allow maximum flexibility or 1093 * restrict FSETOWN to the current process or process 1094 * group for maximum safety. 1095 */ 1096 if (pgrp->pg_session != curthread->td_proc->p_session) { 1097 ret = EPERM; 1098 goto fail; 1099 } 1100 1101 proc = NULL; 1102 } 1103 funsetown(sigiop); 1104 if (pgid > 0) { 1105 PROC_LOCK(proc); 1106 /* 1107 * Since funsetownlst() is called without the proctree 1108 * locked, we need to check for P_WEXIT. 1109 * XXX: is ESRCH correct? 1110 */ 1111 if ((proc->p_flag & P_WEXIT) != 0) { 1112 PROC_UNLOCK(proc); 1113 ret = ESRCH; 1114 goto fail; 1115 } 1116 SLIST_INSERT_HEAD(&proc->p_sigiolst, sigio, sio_pgsigio); 1117 sigio->sio_proc = proc; 1118 PROC_UNLOCK(proc); 1119 } else { 1120 PGRP_LOCK(pgrp); 1121 SLIST_INSERT_HEAD(&pgrp->pg_sigiolst, sigio, sio_pgsigio); 1122 sigio->sio_pgrp = pgrp; 1123 PGRP_UNLOCK(pgrp); 1124 } 1125 sx_sunlock(&proctree_lock); 1126 SIGIO_LOCK(); 1127 *sigiop = sigio; 1128 SIGIO_UNLOCK(); 1129 return (0); 1130 1131 fail: 1132 sx_sunlock(&proctree_lock); 1133 crfree(sigio->sio_ucred); 1134 free(sigio, M_SIGIO); 1135 return (ret); 1136 } 1137 1138 /* 1139 * This is common code for FIOGETOWN ioctl called by fcntl(fd, F_GETOWN, arg). 1140 */ 1141 pid_t 1142 fgetown(sigiop) 1143 struct sigio **sigiop; 1144 { 1145 pid_t pgid; 1146 1147 SIGIO_LOCK(); 1148 pgid = (*sigiop != NULL) ? (*sigiop)->sio_pgid : 0; 1149 SIGIO_UNLOCK(); 1150 return (pgid); 1151 } 1152 1153 /* 1154 * Function drops the filedesc lock on return. 1155 */ 1156 static int 1157 closefp(struct filedesc *fdp, int fd, struct file *fp, struct thread *td, 1158 int holdleaders) 1159 { 1160 int error; 1161 1162 FILEDESC_XLOCK_ASSERT(fdp); 1163 1164 if (holdleaders) { 1165 if (td->td_proc->p_fdtol != NULL) { 1166 /* 1167 * Ask fdfree() to sleep to ensure that all relevant 1168 * process leaders can be traversed in closef(). 1169 */ 1170 fdp->fd_holdleaderscount++; 1171 } else { 1172 holdleaders = 0; 1173 } 1174 } 1175 1176 /* 1177 * We now hold the fp reference that used to be owned by the 1178 * descriptor array. We have to unlock the FILEDESC *AFTER* 1179 * knote_fdclose to prevent a race of the fd getting opened, a knote 1180 * added, and deleteing a knote for the new fd. 1181 */ 1182 knote_fdclose(td, fd); 1183 1184 /* 1185 * We need to notify mqueue if the object is of type mqueue. 1186 */ 1187 if (fp->f_type == DTYPE_MQUEUE) 1188 mq_fdclose(td, fd, fp); 1189 FILEDESC_XUNLOCK(fdp); 1190 1191 error = closef(fp, td); 1192 if (holdleaders) { 1193 FILEDESC_XLOCK(fdp); 1194 fdp->fd_holdleaderscount--; 1195 if (fdp->fd_holdleaderscount == 0 && 1196 fdp->fd_holdleaderswakeup != 0) { 1197 fdp->fd_holdleaderswakeup = 0; 1198 wakeup(&fdp->fd_holdleaderscount); 1199 } 1200 FILEDESC_XUNLOCK(fdp); 1201 } 1202 return (error); 1203 } 1204 1205 /* 1206 * Close a file descriptor. 1207 */ 1208 #ifndef _SYS_SYSPROTO_H_ 1209 struct close_args { 1210 int fd; 1211 }; 1212 #endif 1213 /* ARGSUSED */ 1214 int 1215 sys_close(struct thread *td, struct close_args *uap) 1216 { 1217 1218 return (kern_close(td, uap->fd)); 1219 } 1220 1221 int 1222 kern_close(struct thread *td, int fd) 1223 { 1224 struct filedesc *fdp; 1225 struct file *fp; 1226 1227 fdp = td->td_proc->p_fd; 1228 1229 AUDIT_SYSCLOSE(td, fd); 1230 1231 FILEDESC_XLOCK(fdp); 1232 if ((fp = fget_locked(fdp, fd)) == NULL) { 1233 FILEDESC_XUNLOCK(fdp); 1234 return (EBADF); 1235 } 1236 fdfree(fdp, fd); 1237 1238 /* closefp() drops the FILEDESC lock for us. */ 1239 return (closefp(fdp, fd, fp, td, 1)); 1240 } 1241 1242 /* 1243 * Close open file descriptors. 1244 */ 1245 #ifndef _SYS_SYSPROTO_H_ 1246 struct closefrom_args { 1247 int lowfd; 1248 }; 1249 #endif 1250 /* ARGSUSED */ 1251 int 1252 sys_closefrom(struct thread *td, struct closefrom_args *uap) 1253 { 1254 struct filedesc *fdp; 1255 int fd; 1256 1257 fdp = td->td_proc->p_fd; 1258 AUDIT_ARG_FD(uap->lowfd); 1259 1260 /* 1261 * Treat negative starting file descriptor values identical to 1262 * closefrom(0) which closes all files. 1263 */ 1264 if (uap->lowfd < 0) 1265 uap->lowfd = 0; 1266 FILEDESC_SLOCK(fdp); 1267 for (fd = uap->lowfd; fd <= fdp->fd_lastfile; fd++) { 1268 if (fdp->fd_ofiles[fd].fde_file != NULL) { 1269 FILEDESC_SUNLOCK(fdp); 1270 (void)kern_close(td, fd); 1271 FILEDESC_SLOCK(fdp); 1272 } 1273 } 1274 FILEDESC_SUNLOCK(fdp); 1275 return (0); 1276 } 1277 1278 #if defined(COMPAT_43) 1279 /* 1280 * Return status information about a file descriptor. 1281 */ 1282 #ifndef _SYS_SYSPROTO_H_ 1283 struct ofstat_args { 1284 int fd; 1285 struct ostat *sb; 1286 }; 1287 #endif 1288 /* ARGSUSED */ 1289 int 1290 ofstat(struct thread *td, struct ofstat_args *uap) 1291 { 1292 struct ostat oub; 1293 struct stat ub; 1294 int error; 1295 1296 error = kern_fstat(td, uap->fd, &ub); 1297 if (error == 0) { 1298 cvtstat(&ub, &oub); 1299 error = copyout(&oub, uap->sb, sizeof(oub)); 1300 } 1301 return (error); 1302 } 1303 #endif /* COMPAT_43 */ 1304 1305 /* 1306 * Return status information about a file descriptor. 1307 */ 1308 #ifndef _SYS_SYSPROTO_H_ 1309 struct fstat_args { 1310 int fd; 1311 struct stat *sb; 1312 }; 1313 #endif 1314 /* ARGSUSED */ 1315 int 1316 sys_fstat(struct thread *td, struct fstat_args *uap) 1317 { 1318 struct stat ub; 1319 int error; 1320 1321 error = kern_fstat(td, uap->fd, &ub); 1322 if (error == 0) 1323 error = copyout(&ub, uap->sb, sizeof(ub)); 1324 return (error); 1325 } 1326 1327 int 1328 kern_fstat(struct thread *td, int fd, struct stat *sbp) 1329 { 1330 struct file *fp; 1331 cap_rights_t rights; 1332 int error; 1333 1334 AUDIT_ARG_FD(fd); 1335 1336 error = fget(td, fd, cap_rights_init(&rights, CAP_FSTAT), &fp); 1337 if (error != 0) 1338 return (error); 1339 1340 AUDIT_ARG_FILE(td->td_proc, fp); 1341 1342 error = fo_stat(fp, sbp, td->td_ucred, td); 1343 fdrop(fp, td); 1344 #ifdef KTRACE 1345 if (error == 0 && KTRPOINT(td, KTR_STRUCT)) 1346 ktrstat(sbp); 1347 #endif 1348 return (error); 1349 } 1350 1351 /* 1352 * Return status information about a file descriptor. 1353 */ 1354 #ifndef _SYS_SYSPROTO_H_ 1355 struct nfstat_args { 1356 int fd; 1357 struct nstat *sb; 1358 }; 1359 #endif 1360 /* ARGSUSED */ 1361 int 1362 sys_nfstat(struct thread *td, struct nfstat_args *uap) 1363 { 1364 struct nstat nub; 1365 struct stat ub; 1366 int error; 1367 1368 error = kern_fstat(td, uap->fd, &ub); 1369 if (error == 0) { 1370 cvtnstat(&ub, &nub); 1371 error = copyout(&nub, uap->sb, sizeof(nub)); 1372 } 1373 return (error); 1374 } 1375 1376 /* 1377 * Return pathconf information about a file descriptor. 1378 */ 1379 #ifndef _SYS_SYSPROTO_H_ 1380 struct fpathconf_args { 1381 int fd; 1382 int name; 1383 }; 1384 #endif 1385 /* ARGSUSED */ 1386 int 1387 sys_fpathconf(struct thread *td, struct fpathconf_args *uap) 1388 { 1389 struct file *fp; 1390 struct vnode *vp; 1391 cap_rights_t rights; 1392 int error; 1393 1394 error = fget(td, uap->fd, cap_rights_init(&rights, CAP_FPATHCONF), &fp); 1395 if (error != 0) 1396 return (error); 1397 1398 /* If asynchronous I/O is available, it works for all descriptors. */ 1399 if (uap->name == _PC_ASYNC_IO) { 1400 td->td_retval[0] = async_io_version; 1401 goto out; 1402 } 1403 vp = fp->f_vnode; 1404 if (vp != NULL) { 1405 vn_lock(vp, LK_SHARED | LK_RETRY); 1406 error = VOP_PATHCONF(vp, uap->name, td->td_retval); 1407 VOP_UNLOCK(vp, 0); 1408 } else if (fp->f_type == DTYPE_PIPE || fp->f_type == DTYPE_SOCKET) { 1409 if (uap->name != _PC_PIPE_BUF) { 1410 error = EINVAL; 1411 } else { 1412 td->td_retval[0] = PIPE_BUF; 1413 error = 0; 1414 } 1415 } else { 1416 error = EOPNOTSUPP; 1417 } 1418 out: 1419 fdrop(fp, td); 1420 return (error); 1421 } 1422 1423 /* 1424 * Initialize filecaps structure. 1425 */ 1426 void 1427 filecaps_init(struct filecaps *fcaps) 1428 { 1429 1430 bzero(fcaps, sizeof(*fcaps)); 1431 fcaps->fc_nioctls = -1; 1432 } 1433 1434 /* 1435 * Copy filecaps structure allocating memory for ioctls array if needed. 1436 */ 1437 void 1438 filecaps_copy(const struct filecaps *src, struct filecaps *dst) 1439 { 1440 size_t size; 1441 1442 *dst = *src; 1443 if (src->fc_ioctls != NULL) { 1444 KASSERT(src->fc_nioctls > 0, 1445 ("fc_ioctls != NULL, but fc_nioctls=%hd", src->fc_nioctls)); 1446 1447 size = sizeof(src->fc_ioctls[0]) * src->fc_nioctls; 1448 dst->fc_ioctls = malloc(size, M_FILECAPS, M_WAITOK); 1449 bcopy(src->fc_ioctls, dst->fc_ioctls, size); 1450 } 1451 } 1452 1453 /* 1454 * Move filecaps structure to the new place and clear the old place. 1455 */ 1456 void 1457 filecaps_move(struct filecaps *src, struct filecaps *dst) 1458 { 1459 1460 *dst = *src; 1461 bzero(src, sizeof(*src)); 1462 } 1463 1464 /* 1465 * Fill the given filecaps structure with full rights. 1466 */ 1467 static void 1468 filecaps_fill(struct filecaps *fcaps) 1469 { 1470 1471 CAP_ALL(&fcaps->fc_rights); 1472 fcaps->fc_ioctls = NULL; 1473 fcaps->fc_nioctls = -1; 1474 fcaps->fc_fcntls = CAP_FCNTL_ALL; 1475 } 1476 1477 /* 1478 * Free memory allocated within filecaps structure. 1479 */ 1480 void 1481 filecaps_free(struct filecaps *fcaps) 1482 { 1483 1484 free(fcaps->fc_ioctls, M_FILECAPS); 1485 bzero(fcaps, sizeof(*fcaps)); 1486 } 1487 1488 /* 1489 * Validate the given filecaps structure. 1490 */ 1491 static void 1492 filecaps_validate(const struct filecaps *fcaps, const char *func) 1493 { 1494 1495 KASSERT(cap_rights_is_valid(&fcaps->fc_rights), 1496 ("%s: invalid rights", func)); 1497 KASSERT((fcaps->fc_fcntls & ~CAP_FCNTL_ALL) == 0, 1498 ("%s: invalid fcntls", func)); 1499 KASSERT(fcaps->fc_fcntls == 0 || 1500 cap_rights_is_set(&fcaps->fc_rights, CAP_FCNTL), 1501 ("%s: fcntls without CAP_FCNTL", func)); 1502 KASSERT(fcaps->fc_ioctls != NULL ? fcaps->fc_nioctls > 0 : 1503 (fcaps->fc_nioctls == -1 || fcaps->fc_nioctls == 0), 1504 ("%s: invalid ioctls", func)); 1505 KASSERT(fcaps->fc_nioctls == 0 || 1506 cap_rights_is_set(&fcaps->fc_rights, CAP_IOCTL), 1507 ("%s: ioctls without CAP_IOCTL", func)); 1508 } 1509 1510 static void 1511 fdgrowtable_exp(struct filedesc *fdp, int nfd) 1512 { 1513 int nfd1; 1514 1515 FILEDESC_XLOCK_ASSERT(fdp); 1516 1517 nfd1 = fdp->fd_nfiles * 2; 1518 if (nfd1 < nfd) 1519 nfd1 = nfd; 1520 fdgrowtable(fdp, nfd1); 1521 } 1522 1523 /* 1524 * Grow the file table to accomodate (at least) nfd descriptors. 1525 */ 1526 static void 1527 fdgrowtable(struct filedesc *fdp, int nfd) 1528 { 1529 struct filedesc0 *fdp0; 1530 struct freetable *ft; 1531 struct fdescenttbl *ntable; 1532 struct fdescenttbl *otable; 1533 int nnfiles, onfiles; 1534 NDSLOTTYPE *nmap, *omap; 1535 1536 /* 1537 * If lastfile is -1 this struct filedesc was just allocated and we are 1538 * growing it to accomodate for the one we are going to copy from. There 1539 * is no need to have a lock on this one as it's not visible to anyone. 1540 */ 1541 if (fdp->fd_lastfile != -1) 1542 FILEDESC_XLOCK_ASSERT(fdp); 1543 1544 KASSERT(fdp->fd_nfiles > 0, ("zero-length file table")); 1545 1546 /* save old values */ 1547 onfiles = fdp->fd_nfiles; 1548 otable = fdp->fd_files; 1549 omap = fdp->fd_map; 1550 1551 /* compute the size of the new table */ 1552 nnfiles = NDSLOTS(nfd) * NDENTRIES; /* round up */ 1553 if (nnfiles <= onfiles) 1554 /* the table is already large enough */ 1555 return; 1556 1557 /* 1558 * Allocate a new table. We need enough space for the number of 1559 * entries, file entries themselves and the struct freetable we will use 1560 * when we decommission the table and place it on the freelist. 1561 * We place the struct freetable in the middle so we don't have 1562 * to worry about padding. 1563 */ 1564 ntable = malloc(offsetof(struct fdescenttbl, fdt_ofiles) + 1565 nnfiles * sizeof(ntable->fdt_ofiles[0]) + 1566 sizeof(struct freetable), 1567 M_FILEDESC, M_ZERO | M_WAITOK); 1568 /* copy the old data */ 1569 ntable->fdt_nfiles = nnfiles; 1570 memcpy(ntable->fdt_ofiles, otable->fdt_ofiles, 1571 onfiles * sizeof(ntable->fdt_ofiles[0])); 1572 1573 /* 1574 * Allocate a new map only if the old is not large enough. It will 1575 * grow at a slower rate than the table as it can map more 1576 * entries than the table can hold. 1577 */ 1578 if (NDSLOTS(nnfiles) > NDSLOTS(onfiles)) { 1579 nmap = malloc(NDSLOTS(nnfiles) * NDSLOTSIZE, M_FILEDESC, 1580 M_ZERO | M_WAITOK); 1581 /* copy over the old data and update the pointer */ 1582 memcpy(nmap, omap, NDSLOTS(onfiles) * sizeof(*omap)); 1583 fdp->fd_map = nmap; 1584 } 1585 1586 /* 1587 * Make sure that ntable is correctly initialized before we replace 1588 * fd_files poiner. Otherwise fget_unlocked() may see inconsistent 1589 * data. 1590 */ 1591 atomic_store_rel_ptr((volatile void *)&fdp->fd_files, (uintptr_t)ntable); 1592 1593 /* 1594 * Do not free the old file table, as some threads may still 1595 * reference entries within it. Instead, place it on a freelist 1596 * which will be processed when the struct filedesc is released. 1597 * 1598 * Note that if onfiles == NDFILE, we're dealing with the original 1599 * static allocation contained within (struct filedesc0 *)fdp, 1600 * which must not be freed. 1601 */ 1602 if (onfiles > NDFILE) { 1603 ft = (struct freetable *)&otable->fdt_ofiles[onfiles]; 1604 fdp0 = (struct filedesc0 *)fdp; 1605 ft->ft_table = otable; 1606 SLIST_INSERT_HEAD(&fdp0->fd_free, ft, ft_next); 1607 } 1608 /* 1609 * The map does not have the same possibility of threads still 1610 * holding references to it. So always free it as long as it 1611 * does not reference the original static allocation. 1612 */ 1613 if (NDSLOTS(onfiles) > NDSLOTS(NDFILE)) 1614 free(omap, M_FILEDESC); 1615 } 1616 1617 /* 1618 * Allocate a file descriptor for the process. 1619 */ 1620 int 1621 fdalloc(struct thread *td, int minfd, int *result) 1622 { 1623 struct proc *p = td->td_proc; 1624 struct filedesc *fdp = p->p_fd; 1625 int fd, maxfd, allocfd; 1626 #ifdef RACCT 1627 int error; 1628 #endif 1629 1630 FILEDESC_XLOCK_ASSERT(fdp); 1631 1632 if (fdp->fd_freefile > minfd) 1633 minfd = fdp->fd_freefile; 1634 1635 maxfd = getmaxfd(td); 1636 1637 /* 1638 * Search the bitmap for a free descriptor starting at minfd. 1639 * If none is found, grow the file table. 1640 */ 1641 fd = fd_first_free(fdp, minfd, fdp->fd_nfiles); 1642 if (fd >= maxfd) 1643 return (EMFILE); 1644 if (fd >= fdp->fd_nfiles) { 1645 allocfd = min(fd * 2, maxfd); 1646 #ifdef RACCT 1647 if (racct_enable) { 1648 PROC_LOCK(p); 1649 error = racct_set(p, RACCT_NOFILE, allocfd); 1650 PROC_UNLOCK(p); 1651 if (error != 0) 1652 return (EMFILE); 1653 } 1654 #endif 1655 /* 1656 * fd is already equal to first free descriptor >= minfd, so 1657 * we only need to grow the table and we are done. 1658 */ 1659 fdgrowtable_exp(fdp, allocfd); 1660 } 1661 1662 /* 1663 * Perform some sanity checks, then mark the file descriptor as 1664 * used and return it to the caller. 1665 */ 1666 KASSERT(fd >= 0 && fd < min(maxfd, fdp->fd_nfiles), 1667 ("invalid descriptor %d", fd)); 1668 KASSERT(!fdisused(fdp, fd), 1669 ("fd_first_free() returned non-free descriptor")); 1670 KASSERT(fdp->fd_ofiles[fd].fde_file == NULL, 1671 ("file descriptor isn't free")); 1672 fdused(fdp, fd); 1673 *result = fd; 1674 return (0); 1675 } 1676 1677 /* 1678 * Allocate n file descriptors for the process. 1679 */ 1680 int 1681 fdallocn(struct thread *td, int minfd, int *fds, int n) 1682 { 1683 struct proc *p = td->td_proc; 1684 struct filedesc *fdp = p->p_fd; 1685 int i; 1686 1687 FILEDESC_XLOCK_ASSERT(fdp); 1688 1689 for (i = 0; i < n; i++) 1690 if (fdalloc(td, 0, &fds[i]) != 0) 1691 break; 1692 1693 if (i < n) { 1694 for (i--; i >= 0; i--) 1695 fdunused(fdp, fds[i]); 1696 return (EMFILE); 1697 } 1698 1699 return (0); 1700 } 1701 1702 /* 1703 * Create a new open file structure and allocate a file decriptor for the 1704 * process that refers to it. We add one reference to the file for the 1705 * descriptor table and one reference for resultfp. This is to prevent us 1706 * being preempted and the entry in the descriptor table closed after we 1707 * release the FILEDESC lock. 1708 */ 1709 int 1710 falloc_caps(struct thread *td, struct file **resultfp, int *resultfd, int flags, 1711 struct filecaps *fcaps) 1712 { 1713 struct file *fp; 1714 int error, fd; 1715 1716 error = falloc_noinstall(td, &fp); 1717 if (error) 1718 return (error); /* no reference held on error */ 1719 1720 error = finstall(td, fp, &fd, flags, fcaps); 1721 if (error) { 1722 fdrop(fp, td); /* one reference (fp only) */ 1723 return (error); 1724 } 1725 1726 if (resultfp != NULL) 1727 *resultfp = fp; /* copy out result */ 1728 else 1729 fdrop(fp, td); /* release local reference */ 1730 1731 if (resultfd != NULL) 1732 *resultfd = fd; 1733 1734 return (0); 1735 } 1736 1737 /* 1738 * Create a new open file structure without allocating a file descriptor. 1739 */ 1740 int 1741 falloc_noinstall(struct thread *td, struct file **resultfp) 1742 { 1743 struct file *fp; 1744 int maxuserfiles = maxfiles - (maxfiles / 20); 1745 static struct timeval lastfail; 1746 static int curfail; 1747 1748 KASSERT(resultfp != NULL, ("%s: resultfp == NULL", __func__)); 1749 1750 if ((openfiles >= maxuserfiles && 1751 priv_check(td, PRIV_MAXFILES) != 0) || 1752 openfiles >= maxfiles) { 1753 if (ppsratecheck(&lastfail, &curfail, 1)) { 1754 printf("kern.maxfiles limit exceeded by uid %i, " 1755 "please see tuning(7).\n", td->td_ucred->cr_ruid); 1756 } 1757 return (ENFILE); 1758 } 1759 atomic_add_int(&openfiles, 1); 1760 fp = uma_zalloc(file_zone, M_WAITOK | M_ZERO); 1761 refcount_init(&fp->f_count, 1); 1762 fp->f_cred = crhold(td->td_ucred); 1763 fp->f_ops = &badfileops; 1764 *resultfp = fp; 1765 return (0); 1766 } 1767 1768 /* 1769 * Install a file in a file descriptor table. 1770 */ 1771 void 1772 _finstall(struct filedesc *fdp, struct file *fp, int fd, int flags, 1773 struct filecaps *fcaps) 1774 { 1775 struct filedescent *fde; 1776 1777 MPASS(fp != NULL); 1778 if (fcaps != NULL) 1779 filecaps_validate(fcaps, __func__); 1780 FILEDESC_XLOCK_ASSERT(fdp); 1781 1782 fde = &fdp->fd_ofiles[fd]; 1783 #ifdef CAPABILITIES 1784 seq_write_begin(&fde->fde_seq); 1785 #endif 1786 fde->fde_file = fp; 1787 fde->fde_flags = (flags & O_CLOEXEC) != 0 ? UF_EXCLOSE : 0; 1788 if (fcaps != NULL) 1789 filecaps_move(fcaps, &fde->fde_caps); 1790 else 1791 filecaps_fill(&fde->fde_caps); 1792 #ifdef CAPABILITIES 1793 seq_write_end(&fde->fde_seq); 1794 #endif 1795 } 1796 1797 int 1798 finstall(struct thread *td, struct file *fp, int *fd, int flags, 1799 struct filecaps *fcaps) 1800 { 1801 struct filedesc *fdp = td->td_proc->p_fd; 1802 int error; 1803 1804 MPASS(fd != NULL); 1805 1806 FILEDESC_XLOCK(fdp); 1807 if ((error = fdalloc(td, 0, fd))) { 1808 FILEDESC_XUNLOCK(fdp); 1809 return (error); 1810 } 1811 fhold(fp); 1812 _finstall(fdp, fp, *fd, flags, fcaps); 1813 FILEDESC_XUNLOCK(fdp); 1814 return (0); 1815 } 1816 1817 /* 1818 * Build a new filedesc structure from another. 1819 * Copy the current, root, and jail root vnode references. 1820 * 1821 * If fdp is not NULL, return with it shared locked. 1822 */ 1823 struct filedesc * 1824 fdinit(struct filedesc *fdp, bool prepfiles) 1825 { 1826 struct filedesc0 *newfdp0; 1827 struct filedesc *newfdp; 1828 1829 newfdp0 = uma_zalloc(filedesc0_zone, M_WAITOK | M_ZERO); 1830 newfdp = &newfdp0->fd_fd; 1831 1832 /* Create the file descriptor table. */ 1833 FILEDESC_LOCK_INIT(newfdp); 1834 refcount_init(&newfdp->fd_refcnt, 1); 1835 refcount_init(&newfdp->fd_holdcnt, 1); 1836 newfdp->fd_cmask = CMASK; 1837 newfdp->fd_map = newfdp0->fd_dmap; 1838 newfdp->fd_lastfile = -1; 1839 newfdp->fd_files = (struct fdescenttbl *)&newfdp0->fd_dfiles; 1840 newfdp->fd_files->fdt_nfiles = NDFILE; 1841 1842 if (fdp == NULL) 1843 return (newfdp); 1844 1845 if (prepfiles && fdp->fd_lastfile >= newfdp->fd_nfiles) 1846 fdgrowtable(newfdp, fdp->fd_lastfile + 1); 1847 1848 FILEDESC_SLOCK(fdp); 1849 newfdp->fd_cdir = fdp->fd_cdir; 1850 if (newfdp->fd_cdir) 1851 VREF(newfdp->fd_cdir); 1852 newfdp->fd_rdir = fdp->fd_rdir; 1853 if (newfdp->fd_rdir) 1854 VREF(newfdp->fd_rdir); 1855 newfdp->fd_jdir = fdp->fd_jdir; 1856 if (newfdp->fd_jdir) 1857 VREF(newfdp->fd_jdir); 1858 1859 if (!prepfiles) { 1860 FILEDESC_SUNLOCK(fdp); 1861 } else { 1862 while (fdp->fd_lastfile >= newfdp->fd_nfiles) { 1863 FILEDESC_SUNLOCK(fdp); 1864 fdgrowtable(newfdp, fdp->fd_lastfile + 1); 1865 FILEDESC_SLOCK(fdp); 1866 } 1867 } 1868 1869 return (newfdp); 1870 } 1871 1872 static struct filedesc * 1873 fdhold(struct proc *p) 1874 { 1875 struct filedesc *fdp; 1876 1877 PROC_LOCK_ASSERT(p, MA_OWNED); 1878 fdp = p->p_fd; 1879 if (fdp != NULL) 1880 refcount_acquire(&fdp->fd_holdcnt); 1881 return (fdp); 1882 } 1883 1884 static void 1885 fddrop(struct filedesc *fdp) 1886 { 1887 1888 if (fdp->fd_holdcnt > 1) { 1889 if (refcount_release(&fdp->fd_holdcnt) == 0) 1890 return; 1891 } 1892 1893 FILEDESC_LOCK_DESTROY(fdp); 1894 uma_zfree(filedesc0_zone, fdp); 1895 } 1896 1897 /* 1898 * Share a filedesc structure. 1899 */ 1900 struct filedesc * 1901 fdshare(struct filedesc *fdp) 1902 { 1903 1904 refcount_acquire(&fdp->fd_refcnt); 1905 return (fdp); 1906 } 1907 1908 /* 1909 * Unshare a filedesc structure, if necessary by making a copy 1910 */ 1911 void 1912 fdunshare(struct thread *td) 1913 { 1914 struct filedesc *tmp; 1915 struct proc *p = td->td_proc; 1916 1917 if (p->p_fd->fd_refcnt == 1) 1918 return; 1919 1920 tmp = fdcopy(p->p_fd); 1921 fdescfree(td); 1922 p->p_fd = tmp; 1923 } 1924 1925 void 1926 fdinstall_remapped(struct thread *td, struct filedesc *fdp) 1927 { 1928 1929 fdescfree(td); 1930 td->td_proc->p_fd = fdp; 1931 } 1932 1933 /* 1934 * Copy a filedesc structure. A NULL pointer in returns a NULL reference, 1935 * this is to ease callers, not catch errors. 1936 */ 1937 struct filedesc * 1938 fdcopy(struct filedesc *fdp) 1939 { 1940 struct filedesc *newfdp; 1941 struct filedescent *nfde, *ofde; 1942 int i; 1943 1944 MPASS(fdp != NULL); 1945 1946 newfdp = fdinit(fdp, true); 1947 /* copy all passable descriptors (i.e. not kqueue) */ 1948 newfdp->fd_freefile = -1; 1949 for (i = 0; i <= fdp->fd_lastfile; ++i) { 1950 ofde = &fdp->fd_ofiles[i]; 1951 if (ofde->fde_file == NULL || 1952 (ofde->fde_file->f_ops->fo_flags & DFLAG_PASSABLE) == 0) { 1953 if (newfdp->fd_freefile == -1) 1954 newfdp->fd_freefile = i; 1955 continue; 1956 } 1957 nfde = &newfdp->fd_ofiles[i]; 1958 *nfde = *ofde; 1959 filecaps_copy(&ofde->fde_caps, &nfde->fde_caps); 1960 fhold(nfde->fde_file); 1961 fdused_init(newfdp, i); 1962 newfdp->fd_lastfile = i; 1963 } 1964 if (newfdp->fd_freefile == -1) 1965 newfdp->fd_freefile = i; 1966 newfdp->fd_cmask = fdp->fd_cmask; 1967 FILEDESC_SUNLOCK(fdp); 1968 return (newfdp); 1969 } 1970 1971 /* 1972 * Copies a filedesc structure, while remapping all file descriptors 1973 * stored inside using a translation table. 1974 * 1975 * File descriptors are copied over to the new file descriptor table, 1976 * regardless of whether the close-on-exec flag is set. 1977 */ 1978 int 1979 fdcopy_remapped(struct filedesc *fdp, const int *fds, size_t nfds, 1980 struct filedesc **ret) 1981 { 1982 struct filedesc *newfdp; 1983 struct filedescent *nfde, *ofde; 1984 int error, i; 1985 1986 MPASS(fdp != NULL); 1987 1988 newfdp = fdinit(fdp, true); 1989 if (nfds > fdp->fd_lastfile + 1) { 1990 /* New table cannot be larger than the old one. */ 1991 error = E2BIG; 1992 goto bad; 1993 } 1994 /* Copy all passable descriptors (i.e. not kqueue). */ 1995 newfdp->fd_freefile = nfds; 1996 for (i = 0; i < nfds; ++i) { 1997 if (fds[i] < 0 || fds[i] > fdp->fd_lastfile) { 1998 /* File descriptor out of bounds. */ 1999 error = EBADF; 2000 goto bad; 2001 } 2002 ofde = &fdp->fd_ofiles[fds[i]]; 2003 if (ofde->fde_file == NULL) { 2004 /* Unused file descriptor. */ 2005 error = EBADF; 2006 goto bad; 2007 } 2008 if ((ofde->fde_file->f_ops->fo_flags & DFLAG_PASSABLE) == 0) { 2009 /* File descriptor cannot be passed. */ 2010 error = EINVAL; 2011 goto bad; 2012 } 2013 nfde = &newfdp->fd_ofiles[i]; 2014 *nfde = *ofde; 2015 filecaps_copy(&ofde->fde_caps, &nfde->fde_caps); 2016 fhold(nfde->fde_file); 2017 fdused_init(newfdp, i); 2018 newfdp->fd_lastfile = i; 2019 } 2020 newfdp->fd_cmask = fdp->fd_cmask; 2021 FILEDESC_SUNLOCK(fdp); 2022 *ret = newfdp; 2023 return (0); 2024 bad: 2025 FILEDESC_SUNLOCK(fdp); 2026 fdescfree_remapped(newfdp); 2027 return (error); 2028 } 2029 2030 /* 2031 * Clear POSIX style locks. This is only used when fdp looses a reference (i.e. 2032 * one of processes using it exits) and the table used to be shared. 2033 */ 2034 static void 2035 fdclearlocks(struct thread *td) 2036 { 2037 struct filedesc *fdp; 2038 struct filedesc_to_leader *fdtol; 2039 struct flock lf; 2040 struct file *fp; 2041 struct proc *p; 2042 struct vnode *vp; 2043 int i; 2044 2045 p = td->td_proc; 2046 fdp = p->p_fd; 2047 fdtol = p->p_fdtol; 2048 MPASS(fdtol != NULL); 2049 2050 FILEDESC_XLOCK(fdp); 2051 KASSERT(fdtol->fdl_refcount > 0, 2052 ("filedesc_to_refcount botch: fdl_refcount=%d", 2053 fdtol->fdl_refcount)); 2054 if (fdtol->fdl_refcount == 1 && 2055 (p->p_leader->p_flag & P_ADVLOCK) != 0) { 2056 for (i = 0; i <= fdp->fd_lastfile; i++) { 2057 fp = fdp->fd_ofiles[i].fde_file; 2058 if (fp == NULL || fp->f_type != DTYPE_VNODE) 2059 continue; 2060 fhold(fp); 2061 FILEDESC_XUNLOCK(fdp); 2062 lf.l_whence = SEEK_SET; 2063 lf.l_start = 0; 2064 lf.l_len = 0; 2065 lf.l_type = F_UNLCK; 2066 vp = fp->f_vnode; 2067 (void) VOP_ADVLOCK(vp, 2068 (caddr_t)p->p_leader, F_UNLCK, 2069 &lf, F_POSIX); 2070 FILEDESC_XLOCK(fdp); 2071 fdrop(fp, td); 2072 } 2073 } 2074 retry: 2075 if (fdtol->fdl_refcount == 1) { 2076 if (fdp->fd_holdleaderscount > 0 && 2077 (p->p_leader->p_flag & P_ADVLOCK) != 0) { 2078 /* 2079 * close() or kern_dup() has cleared a reference 2080 * in a shared file descriptor table. 2081 */ 2082 fdp->fd_holdleaderswakeup = 1; 2083 sx_sleep(&fdp->fd_holdleaderscount, 2084 FILEDESC_LOCK(fdp), PLOCK, "fdlhold", 0); 2085 goto retry; 2086 } 2087 if (fdtol->fdl_holdcount > 0) { 2088 /* 2089 * Ensure that fdtol->fdl_leader remains 2090 * valid in closef(). 2091 */ 2092 fdtol->fdl_wakeup = 1; 2093 sx_sleep(fdtol, FILEDESC_LOCK(fdp), PLOCK, 2094 "fdlhold", 0); 2095 goto retry; 2096 } 2097 } 2098 fdtol->fdl_refcount--; 2099 if (fdtol->fdl_refcount == 0 && 2100 fdtol->fdl_holdcount == 0) { 2101 fdtol->fdl_next->fdl_prev = fdtol->fdl_prev; 2102 fdtol->fdl_prev->fdl_next = fdtol->fdl_next; 2103 } else 2104 fdtol = NULL; 2105 p->p_fdtol = NULL; 2106 FILEDESC_XUNLOCK(fdp); 2107 if (fdtol != NULL) 2108 free(fdtol, M_FILEDESC_TO_LEADER); 2109 } 2110 2111 /* 2112 * Release a filedesc structure. 2113 */ 2114 static void 2115 fdescfree_fds(struct thread *td, struct filedesc *fdp, bool needclose) 2116 { 2117 struct filedesc0 *fdp0; 2118 struct freetable *ft, *tft; 2119 struct filedescent *fde; 2120 struct file *fp; 2121 int i; 2122 2123 for (i = 0; i <= fdp->fd_lastfile; i++) { 2124 fde = &fdp->fd_ofiles[i]; 2125 fp = fde->fde_file; 2126 if (fp != NULL) { 2127 fdefree_last(fde); 2128 if (needclose) 2129 (void) closef(fp, td); 2130 else 2131 fdrop(fp, td); 2132 } 2133 } 2134 2135 if (NDSLOTS(fdp->fd_nfiles) > NDSLOTS(NDFILE)) 2136 free(fdp->fd_map, M_FILEDESC); 2137 if (fdp->fd_nfiles > NDFILE) 2138 free(fdp->fd_files, M_FILEDESC); 2139 2140 fdp0 = (struct filedesc0 *)fdp; 2141 SLIST_FOREACH_SAFE(ft, &fdp0->fd_free, ft_next, tft) 2142 free(ft->ft_table, M_FILEDESC); 2143 2144 fddrop(fdp); 2145 } 2146 2147 void 2148 fdescfree(struct thread *td) 2149 { 2150 struct proc *p; 2151 struct filedesc *fdp; 2152 struct vnode *cdir, *jdir, *rdir; 2153 2154 p = td->td_proc; 2155 fdp = p->p_fd; 2156 MPASS(fdp != NULL); 2157 2158 #ifdef RACCT 2159 if (racct_enable) { 2160 PROC_LOCK(p); 2161 racct_set(p, RACCT_NOFILE, 0); 2162 PROC_UNLOCK(p); 2163 } 2164 #endif 2165 2166 if (p->p_fdtol != NULL) 2167 fdclearlocks(td); 2168 2169 PROC_LOCK(p); 2170 p->p_fd = NULL; 2171 PROC_UNLOCK(p); 2172 2173 if (refcount_release(&fdp->fd_refcnt) == 0) 2174 return; 2175 2176 FILEDESC_XLOCK(fdp); 2177 cdir = fdp->fd_cdir; 2178 fdp->fd_cdir = NULL; 2179 rdir = fdp->fd_rdir; 2180 fdp->fd_rdir = NULL; 2181 jdir = fdp->fd_jdir; 2182 fdp->fd_jdir = NULL; 2183 FILEDESC_XUNLOCK(fdp); 2184 2185 if (cdir != NULL) 2186 vrele(cdir); 2187 if (rdir != NULL) 2188 vrele(rdir); 2189 if (jdir != NULL) 2190 vrele(jdir); 2191 2192 fdescfree_fds(td, fdp, 1); 2193 } 2194 2195 void 2196 fdescfree_remapped(struct filedesc *fdp) 2197 { 2198 2199 if (fdp->fd_cdir != NULL) 2200 vrele(fdp->fd_cdir); 2201 if (fdp->fd_rdir != NULL) 2202 vrele(fdp->fd_rdir); 2203 if (fdp->fd_jdir != NULL) 2204 vrele(fdp->fd_jdir); 2205 2206 fdescfree_fds(curthread, fdp, 0); 2207 } 2208 2209 /* 2210 * For setugid programs, we don't want to people to use that setugidness 2211 * to generate error messages which write to a file which otherwise would 2212 * otherwise be off-limits to the process. We check for filesystems where 2213 * the vnode can change out from under us after execve (like [lin]procfs). 2214 * 2215 * Since fdsetugidsafety calls this only for fd 0, 1 and 2, this check is 2216 * sufficient. We also don't check for setugidness since we know we are. 2217 */ 2218 static bool 2219 is_unsafe(struct file *fp) 2220 { 2221 struct vnode *vp; 2222 2223 if (fp->f_type != DTYPE_VNODE) 2224 return (false); 2225 2226 vp = fp->f_vnode; 2227 return ((vp->v_vflag & VV_PROCDEP) != 0); 2228 } 2229 2230 /* 2231 * Make this setguid thing safe, if at all possible. 2232 */ 2233 void 2234 fdsetugidsafety(struct thread *td) 2235 { 2236 struct filedesc *fdp; 2237 struct file *fp; 2238 int i; 2239 2240 fdp = td->td_proc->p_fd; 2241 KASSERT(fdp->fd_refcnt == 1, ("the fdtable should not be shared")); 2242 MPASS(fdp->fd_nfiles >= 3); 2243 for (i = 0; i <= 2; i++) { 2244 fp = fdp->fd_ofiles[i].fde_file; 2245 if (fp != NULL && is_unsafe(fp)) { 2246 FILEDESC_XLOCK(fdp); 2247 knote_fdclose(td, i); 2248 /* 2249 * NULL-out descriptor prior to close to avoid 2250 * a race while close blocks. 2251 */ 2252 fdfree(fdp, i); 2253 FILEDESC_XUNLOCK(fdp); 2254 (void) closef(fp, td); 2255 } 2256 } 2257 } 2258 2259 /* 2260 * If a specific file object occupies a specific file descriptor, close the 2261 * file descriptor entry and drop a reference on the file object. This is a 2262 * convenience function to handle a subsequent error in a function that calls 2263 * falloc() that handles the race that another thread might have closed the 2264 * file descriptor out from under the thread creating the file object. 2265 */ 2266 void 2267 fdclose(struct thread *td, struct file *fp, int idx) 2268 { 2269 struct filedesc *fdp = td->td_proc->p_fd; 2270 2271 FILEDESC_XLOCK(fdp); 2272 if (fdp->fd_ofiles[idx].fde_file == fp) { 2273 fdfree(fdp, idx); 2274 FILEDESC_XUNLOCK(fdp); 2275 fdrop(fp, td); 2276 } else 2277 FILEDESC_XUNLOCK(fdp); 2278 } 2279 2280 /* 2281 * Close any files on exec? 2282 */ 2283 void 2284 fdcloseexec(struct thread *td) 2285 { 2286 struct filedesc *fdp; 2287 struct filedescent *fde; 2288 struct file *fp; 2289 int i; 2290 2291 fdp = td->td_proc->p_fd; 2292 KASSERT(fdp->fd_refcnt == 1, ("the fdtable should not be shared")); 2293 for (i = 0; i <= fdp->fd_lastfile; i++) { 2294 fde = &fdp->fd_ofiles[i]; 2295 fp = fde->fde_file; 2296 if (fp != NULL && (fp->f_type == DTYPE_MQUEUE || 2297 (fde->fde_flags & UF_EXCLOSE))) { 2298 FILEDESC_XLOCK(fdp); 2299 fdfree(fdp, i); 2300 (void) closefp(fdp, i, fp, td, 0); 2301 /* closefp() drops the FILEDESC lock. */ 2302 } 2303 } 2304 } 2305 2306 /* 2307 * It is unsafe for set[ug]id processes to be started with file 2308 * descriptors 0..2 closed, as these descriptors are given implicit 2309 * significance in the Standard C library. fdcheckstd() will create a 2310 * descriptor referencing /dev/null for each of stdin, stdout, and 2311 * stderr that is not already open. 2312 */ 2313 int 2314 fdcheckstd(struct thread *td) 2315 { 2316 struct filedesc *fdp; 2317 register_t save; 2318 int i, error, devnull; 2319 2320 fdp = td->td_proc->p_fd; 2321 KASSERT(fdp->fd_refcnt == 1, ("the fdtable should not be shared")); 2322 MPASS(fdp->fd_nfiles >= 3); 2323 devnull = -1; 2324 for (i = 0; i <= 2; i++) { 2325 if (fdp->fd_ofiles[i].fde_file != NULL) 2326 continue; 2327 2328 save = td->td_retval[0]; 2329 if (devnull != -1) { 2330 error = kern_dup(td, FDDUP_FIXED, 0, devnull, i); 2331 } else { 2332 error = kern_openat(td, AT_FDCWD, "/dev/null", 2333 UIO_SYSSPACE, O_RDWR, 0); 2334 if (error == 0) { 2335 devnull = td->td_retval[0]; 2336 KASSERT(devnull == i, ("we didn't get our fd")); 2337 } 2338 } 2339 td->td_retval[0] = save; 2340 if (error != 0) 2341 return (error); 2342 } 2343 return (0); 2344 } 2345 2346 /* 2347 * Internal form of close. Decrement reference count on file structure. 2348 * Note: td may be NULL when closing a file that was being passed in a 2349 * message. 2350 * 2351 * XXXRW: Giant is not required for the caller, but often will be held; this 2352 * makes it moderately likely the Giant will be recursed in the VFS case. 2353 */ 2354 int 2355 closef(struct file *fp, struct thread *td) 2356 { 2357 struct vnode *vp; 2358 struct flock lf; 2359 struct filedesc_to_leader *fdtol; 2360 struct filedesc *fdp; 2361 2362 /* 2363 * POSIX record locking dictates that any close releases ALL 2364 * locks owned by this process. This is handled by setting 2365 * a flag in the unlock to free ONLY locks obeying POSIX 2366 * semantics, and not to free BSD-style file locks. 2367 * If the descriptor was in a message, POSIX-style locks 2368 * aren't passed with the descriptor, and the thread pointer 2369 * will be NULL. Callers should be careful only to pass a 2370 * NULL thread pointer when there really is no owning 2371 * context that might have locks, or the locks will be 2372 * leaked. 2373 */ 2374 if (fp->f_type == DTYPE_VNODE && td != NULL) { 2375 vp = fp->f_vnode; 2376 if ((td->td_proc->p_leader->p_flag & P_ADVLOCK) != 0) { 2377 lf.l_whence = SEEK_SET; 2378 lf.l_start = 0; 2379 lf.l_len = 0; 2380 lf.l_type = F_UNLCK; 2381 (void) VOP_ADVLOCK(vp, (caddr_t)td->td_proc->p_leader, 2382 F_UNLCK, &lf, F_POSIX); 2383 } 2384 fdtol = td->td_proc->p_fdtol; 2385 if (fdtol != NULL) { 2386 /* 2387 * Handle special case where file descriptor table is 2388 * shared between multiple process leaders. 2389 */ 2390 fdp = td->td_proc->p_fd; 2391 FILEDESC_XLOCK(fdp); 2392 for (fdtol = fdtol->fdl_next; 2393 fdtol != td->td_proc->p_fdtol; 2394 fdtol = fdtol->fdl_next) { 2395 if ((fdtol->fdl_leader->p_flag & 2396 P_ADVLOCK) == 0) 2397 continue; 2398 fdtol->fdl_holdcount++; 2399 FILEDESC_XUNLOCK(fdp); 2400 lf.l_whence = SEEK_SET; 2401 lf.l_start = 0; 2402 lf.l_len = 0; 2403 lf.l_type = F_UNLCK; 2404 vp = fp->f_vnode; 2405 (void) VOP_ADVLOCK(vp, 2406 (caddr_t)fdtol->fdl_leader, F_UNLCK, &lf, 2407 F_POSIX); 2408 FILEDESC_XLOCK(fdp); 2409 fdtol->fdl_holdcount--; 2410 if (fdtol->fdl_holdcount == 0 && 2411 fdtol->fdl_wakeup != 0) { 2412 fdtol->fdl_wakeup = 0; 2413 wakeup(fdtol); 2414 } 2415 } 2416 FILEDESC_XUNLOCK(fdp); 2417 } 2418 } 2419 return (fdrop(fp, td)); 2420 } 2421 2422 /* 2423 * Initialize the file pointer with the specified properties. 2424 * 2425 * The ops are set with release semantics to be certain that the flags, type, 2426 * and data are visible when ops is. This is to prevent ops methods from being 2427 * called with bad data. 2428 */ 2429 void 2430 finit(struct file *fp, u_int flag, short type, void *data, struct fileops *ops) 2431 { 2432 fp->f_data = data; 2433 fp->f_flag = flag; 2434 fp->f_type = type; 2435 atomic_store_rel_ptr((volatile uintptr_t *)&fp->f_ops, (uintptr_t)ops); 2436 } 2437 2438 int 2439 fget_unlocked(struct filedesc *fdp, int fd, cap_rights_t *needrightsp, 2440 struct file **fpp, seq_t *seqp) 2441 { 2442 #ifdef CAPABILITIES 2443 struct filedescent *fde; 2444 #endif 2445 struct fdescenttbl *fdt; 2446 struct file *fp; 2447 u_int count; 2448 #ifdef CAPABILITIES 2449 seq_t seq; 2450 cap_rights_t haverights; 2451 int error; 2452 #endif 2453 2454 fdt = fdp->fd_files; 2455 if ((u_int)fd >= fdt->fdt_nfiles) 2456 return (EBADF); 2457 /* 2458 * Fetch the descriptor locklessly. We avoid fdrop() races by 2459 * never raising a refcount above 0. To accomplish this we have 2460 * to use a cmpset loop rather than an atomic_add. The descriptor 2461 * must be re-verified once we acquire a reference to be certain 2462 * that the identity is still correct and we did not lose a race 2463 * due to preemption. 2464 */ 2465 for (;;) { 2466 #ifdef CAPABILITIES 2467 seq = seq_read(fd_seq(fdt, fd)); 2468 fde = &fdt->fdt_ofiles[fd]; 2469 haverights = *cap_rights_fde(fde); 2470 fp = fde->fde_file; 2471 if (!seq_consistent(fd_seq(fdt, fd), seq)) { 2472 cpu_spinwait(); 2473 continue; 2474 } 2475 #else 2476 fp = fdt->fdt_ofiles[fd].fde_file; 2477 #endif 2478 if (fp == NULL) 2479 return (EBADF); 2480 #ifdef CAPABILITIES 2481 error = cap_check(&haverights, needrightsp); 2482 if (error != 0) 2483 return (error); 2484 #endif 2485 retry: 2486 count = fp->f_count; 2487 if (count == 0) { 2488 /* 2489 * Force a reload. Other thread could reallocate the 2490 * table before this fd was closed, so it possible that 2491 * there is a stale fp pointer in cached version. 2492 */ 2493 fdt = *(struct fdescenttbl * volatile *)&(fdp->fd_files); 2494 continue; 2495 } 2496 /* 2497 * Use an acquire barrier to force re-reading of fdt so it is 2498 * refreshed for verification. 2499 */ 2500 if (atomic_cmpset_acq_int(&fp->f_count, count, count + 1) == 0) 2501 goto retry; 2502 fdt = fdp->fd_files; 2503 #ifdef CAPABILITIES 2504 if (seq_consistent_nomb(fd_seq(fdt, fd), seq)) 2505 #else 2506 if (fp == fdt->fdt_ofiles[fd].fde_file) 2507 #endif 2508 break; 2509 fdrop(fp, curthread); 2510 } 2511 *fpp = fp; 2512 if (seqp != NULL) { 2513 #ifdef CAPABILITIES 2514 *seqp = seq; 2515 #endif 2516 } 2517 return (0); 2518 } 2519 2520 /* 2521 * Extract the file pointer associated with the specified descriptor for the 2522 * current user process. 2523 * 2524 * If the descriptor doesn't exist or doesn't match 'flags', EBADF is 2525 * returned. 2526 * 2527 * File's rights will be checked against the capability rights mask. 2528 * 2529 * If an error occured the non-zero error is returned and *fpp is set to 2530 * NULL. Otherwise *fpp is held and set and zero is returned. Caller is 2531 * responsible for fdrop(). 2532 */ 2533 static __inline int 2534 _fget(struct thread *td, int fd, struct file **fpp, int flags, 2535 cap_rights_t *needrightsp, seq_t *seqp) 2536 { 2537 struct filedesc *fdp; 2538 struct file *fp; 2539 int error; 2540 2541 *fpp = NULL; 2542 fdp = td->td_proc->p_fd; 2543 error = fget_unlocked(fdp, fd, needrightsp, &fp, seqp); 2544 if (error != 0) 2545 return (error); 2546 if (fp->f_ops == &badfileops) { 2547 fdrop(fp, td); 2548 return (EBADF); 2549 } 2550 2551 /* 2552 * FREAD and FWRITE failure return EBADF as per POSIX. 2553 */ 2554 error = 0; 2555 switch (flags) { 2556 case FREAD: 2557 case FWRITE: 2558 if ((fp->f_flag & flags) == 0) 2559 error = EBADF; 2560 break; 2561 case FEXEC: 2562 if ((fp->f_flag & (FREAD | FEXEC)) == 0 || 2563 ((fp->f_flag & FWRITE) != 0)) 2564 error = EBADF; 2565 break; 2566 case 0: 2567 break; 2568 default: 2569 KASSERT(0, ("wrong flags")); 2570 } 2571 2572 if (error != 0) { 2573 fdrop(fp, td); 2574 return (error); 2575 } 2576 2577 *fpp = fp; 2578 return (0); 2579 } 2580 2581 int 2582 fget(struct thread *td, int fd, cap_rights_t *rightsp, struct file **fpp) 2583 { 2584 2585 return (_fget(td, fd, fpp, 0, rightsp, NULL)); 2586 } 2587 2588 int 2589 fget_mmap(struct thread *td, int fd, cap_rights_t *rightsp, u_char *maxprotp, 2590 struct file **fpp) 2591 { 2592 int error; 2593 #ifndef CAPABILITIES 2594 error = _fget(td, fd, fpp, 0, rightsp, NULL); 2595 if (maxprotp != NULL) 2596 *maxprotp = VM_PROT_ALL; 2597 #else 2598 struct filedesc *fdp = td->td_proc->p_fd; 2599 seq_t seq; 2600 2601 MPASS(cap_rights_is_set(rightsp, CAP_MMAP)); 2602 for (;;) { 2603 error = _fget(td, fd, fpp, 0, rightsp, &seq); 2604 if (error != 0) 2605 return (error); 2606 /* 2607 * If requested, convert capability rights to access flags. 2608 */ 2609 if (maxprotp != NULL) 2610 *maxprotp = cap_rights_to_vmprot(cap_rights(fdp, fd)); 2611 if (!fd_modified(fdp, fd, seq)) 2612 break; 2613 fdrop(*fpp, td); 2614 } 2615 #endif 2616 return (error); 2617 } 2618 2619 int 2620 fget_read(struct thread *td, int fd, cap_rights_t *rightsp, struct file **fpp) 2621 { 2622 2623 return (_fget(td, fd, fpp, FREAD, rightsp, NULL)); 2624 } 2625 2626 int 2627 fget_write(struct thread *td, int fd, cap_rights_t *rightsp, struct file **fpp) 2628 { 2629 2630 return (_fget(td, fd, fpp, FWRITE, rightsp, NULL)); 2631 } 2632 2633 int 2634 fget_fcntl(struct thread *td, int fd, cap_rights_t *rightsp, int needfcntl, 2635 struct file **fpp) 2636 { 2637 struct filedesc *fdp = td->td_proc->p_fd; 2638 #ifndef CAPABILITIES 2639 return (fget_unlocked(fdp, fd, rightsp, fpp, NULL)); 2640 #else 2641 int error; 2642 seq_t seq; 2643 2644 MPASS(cap_rights_is_set(rightsp, CAP_FCNTL)); 2645 for (;;) { 2646 error = fget_unlocked(fdp, fd, rightsp, fpp, &seq); 2647 if (error != 0) 2648 return (error); 2649 error = cap_fcntl_check(fdp, fd, needfcntl); 2650 if (!fd_modified(fdp, fd, seq)) 2651 break; 2652 fdrop(*fpp, td); 2653 } 2654 if (error != 0) { 2655 fdrop(*fpp, td); 2656 *fpp = NULL; 2657 } 2658 return (error); 2659 #endif 2660 } 2661 2662 /* 2663 * Like fget() but loads the underlying vnode, or returns an error if the 2664 * descriptor does not represent a vnode. Note that pipes use vnodes but 2665 * never have VM objects. The returned vnode will be vref()'d. 2666 * 2667 * XXX: what about the unused flags ? 2668 */ 2669 static __inline int 2670 _fgetvp(struct thread *td, int fd, int flags, cap_rights_t *needrightsp, 2671 struct vnode **vpp) 2672 { 2673 struct file *fp; 2674 int error; 2675 2676 *vpp = NULL; 2677 error = _fget(td, fd, &fp, flags, needrightsp, NULL); 2678 if (error != 0) 2679 return (error); 2680 if (fp->f_vnode == NULL) { 2681 error = EINVAL; 2682 } else { 2683 *vpp = fp->f_vnode; 2684 vref(*vpp); 2685 } 2686 fdrop(fp, td); 2687 2688 return (error); 2689 } 2690 2691 int 2692 fgetvp(struct thread *td, int fd, cap_rights_t *rightsp, struct vnode **vpp) 2693 { 2694 2695 return (_fgetvp(td, fd, 0, rightsp, vpp)); 2696 } 2697 2698 int 2699 fgetvp_rights(struct thread *td, int fd, cap_rights_t *needrightsp, 2700 struct filecaps *havecaps, struct vnode **vpp) 2701 { 2702 struct filedesc *fdp; 2703 struct file *fp; 2704 #ifdef CAPABILITIES 2705 int error; 2706 #endif 2707 2708 fdp = td->td_proc->p_fd; 2709 fp = fget_locked(fdp, fd); 2710 if (fp == NULL || fp->f_ops == &badfileops) 2711 return (EBADF); 2712 2713 #ifdef CAPABILITIES 2714 if (needrightsp != NULL) { 2715 error = cap_check(cap_rights(fdp, fd), needrightsp); 2716 if (error != 0) 2717 return (error); 2718 } 2719 #endif 2720 2721 if (fp->f_vnode == NULL) 2722 return (EINVAL); 2723 2724 *vpp = fp->f_vnode; 2725 vref(*vpp); 2726 filecaps_copy(&fdp->fd_ofiles[fd].fde_caps, havecaps); 2727 2728 return (0); 2729 } 2730 2731 int 2732 fgetvp_read(struct thread *td, int fd, cap_rights_t *rightsp, struct vnode **vpp) 2733 { 2734 2735 return (_fgetvp(td, fd, FREAD, rightsp, vpp)); 2736 } 2737 2738 int 2739 fgetvp_exec(struct thread *td, int fd, cap_rights_t *rightsp, struct vnode **vpp) 2740 { 2741 2742 return (_fgetvp(td, fd, FEXEC, rightsp, vpp)); 2743 } 2744 2745 #ifdef notyet 2746 int 2747 fgetvp_write(struct thread *td, int fd, cap_rights_t *rightsp, 2748 struct vnode **vpp) 2749 { 2750 2751 return (_fgetvp(td, fd, FWRITE, rightsp, vpp)); 2752 } 2753 #endif 2754 2755 /* 2756 * Like fget() but loads the underlying socket, or returns an error if the 2757 * descriptor does not represent a socket. 2758 * 2759 * We bump the ref count on the returned socket. XXX Also obtain the SX lock 2760 * in the future. 2761 * 2762 * Note: fgetsock() and fputsock() are deprecated, as consumers should rely 2763 * on their file descriptor reference to prevent the socket from being free'd 2764 * during use. 2765 */ 2766 int 2767 fgetsock(struct thread *td, int fd, cap_rights_t *rightsp, struct socket **spp, 2768 u_int *fflagp) 2769 { 2770 struct file *fp; 2771 int error; 2772 2773 *spp = NULL; 2774 if (fflagp != NULL) 2775 *fflagp = 0; 2776 if ((error = _fget(td, fd, &fp, 0, rightsp, NULL)) != 0) 2777 return (error); 2778 if (fp->f_type != DTYPE_SOCKET) { 2779 error = ENOTSOCK; 2780 } else { 2781 *spp = fp->f_data; 2782 if (fflagp) 2783 *fflagp = fp->f_flag; 2784 SOCK_LOCK(*spp); 2785 soref(*spp); 2786 SOCK_UNLOCK(*spp); 2787 } 2788 fdrop(fp, td); 2789 2790 return (error); 2791 } 2792 2793 /* 2794 * Drop the reference count on the socket and XXX release the SX lock in the 2795 * future. The last reference closes the socket. 2796 * 2797 * Note: fputsock() is deprecated, see comment for fgetsock(). 2798 */ 2799 void 2800 fputsock(struct socket *so) 2801 { 2802 2803 ACCEPT_LOCK(); 2804 SOCK_LOCK(so); 2805 CURVNET_SET(so->so_vnet); 2806 sorele(so); 2807 CURVNET_RESTORE(); 2808 } 2809 2810 /* 2811 * Handle the last reference to a file being closed. 2812 */ 2813 int 2814 _fdrop(struct file *fp, struct thread *td) 2815 { 2816 int error; 2817 2818 if (fp->f_count != 0) 2819 panic("fdrop: count %d", fp->f_count); 2820 error = fo_close(fp, td); 2821 atomic_subtract_int(&openfiles, 1); 2822 crfree(fp->f_cred); 2823 free(fp->f_advice, M_FADVISE); 2824 uma_zfree(file_zone, fp); 2825 2826 return (error); 2827 } 2828 2829 /* 2830 * Apply an advisory lock on a file descriptor. 2831 * 2832 * Just attempt to get a record lock of the requested type on the entire file 2833 * (l_whence = SEEK_SET, l_start = 0, l_len = 0). 2834 */ 2835 #ifndef _SYS_SYSPROTO_H_ 2836 struct flock_args { 2837 int fd; 2838 int how; 2839 }; 2840 #endif 2841 /* ARGSUSED */ 2842 int 2843 sys_flock(struct thread *td, struct flock_args *uap) 2844 { 2845 struct file *fp; 2846 struct vnode *vp; 2847 struct flock lf; 2848 cap_rights_t rights; 2849 int error; 2850 2851 error = fget(td, uap->fd, cap_rights_init(&rights, CAP_FLOCK), &fp); 2852 if (error != 0) 2853 return (error); 2854 if (fp->f_type != DTYPE_VNODE) { 2855 fdrop(fp, td); 2856 return (EOPNOTSUPP); 2857 } 2858 2859 vp = fp->f_vnode; 2860 lf.l_whence = SEEK_SET; 2861 lf.l_start = 0; 2862 lf.l_len = 0; 2863 if (uap->how & LOCK_UN) { 2864 lf.l_type = F_UNLCK; 2865 atomic_clear_int(&fp->f_flag, FHASLOCK); 2866 error = VOP_ADVLOCK(vp, (caddr_t)fp, F_UNLCK, &lf, F_FLOCK); 2867 goto done2; 2868 } 2869 if (uap->how & LOCK_EX) 2870 lf.l_type = F_WRLCK; 2871 else if (uap->how & LOCK_SH) 2872 lf.l_type = F_RDLCK; 2873 else { 2874 error = EBADF; 2875 goto done2; 2876 } 2877 atomic_set_int(&fp->f_flag, FHASLOCK); 2878 error = VOP_ADVLOCK(vp, (caddr_t)fp, F_SETLK, &lf, 2879 (uap->how & LOCK_NB) ? F_FLOCK : F_FLOCK | F_WAIT); 2880 done2: 2881 fdrop(fp, td); 2882 return (error); 2883 } 2884 /* 2885 * Duplicate the specified descriptor to a free descriptor. 2886 */ 2887 int 2888 dupfdopen(struct thread *td, struct filedesc *fdp, int dfd, int mode, 2889 int openerror, int *indxp) 2890 { 2891 struct filedescent *newfde, *oldfde; 2892 struct file *fp; 2893 int error, indx; 2894 2895 KASSERT(openerror == ENODEV || openerror == ENXIO, 2896 ("unexpected error %d in %s", openerror, __func__)); 2897 2898 /* 2899 * If the to-be-dup'd fd number is greater than the allowed number 2900 * of file descriptors, or the fd to be dup'd has already been 2901 * closed, then reject. 2902 */ 2903 FILEDESC_XLOCK(fdp); 2904 if ((fp = fget_locked(fdp, dfd)) == NULL) { 2905 FILEDESC_XUNLOCK(fdp); 2906 return (EBADF); 2907 } 2908 2909 error = fdalloc(td, 0, &indx); 2910 if (error != 0) { 2911 FILEDESC_XUNLOCK(fdp); 2912 return (error); 2913 } 2914 2915 /* 2916 * There are two cases of interest here. 2917 * 2918 * For ENODEV simply dup (dfd) to file descriptor (indx) and return. 2919 * 2920 * For ENXIO steal away the file structure from (dfd) and store it in 2921 * (indx). (dfd) is effectively closed by this operation. 2922 */ 2923 switch (openerror) { 2924 case ENODEV: 2925 /* 2926 * Check that the mode the file is being opened for is a 2927 * subset of the mode of the existing descriptor. 2928 */ 2929 if (((mode & (FREAD|FWRITE)) | fp->f_flag) != fp->f_flag) { 2930 fdunused(fdp, indx); 2931 FILEDESC_XUNLOCK(fdp); 2932 return (EACCES); 2933 } 2934 fhold(fp); 2935 newfde = &fdp->fd_ofiles[indx]; 2936 oldfde = &fdp->fd_ofiles[dfd]; 2937 #ifdef CAPABILITIES 2938 seq_write_begin(&newfde->fde_seq); 2939 #endif 2940 memcpy(newfde, oldfde, fde_change_size); 2941 filecaps_copy(&oldfde->fde_caps, &newfde->fde_caps); 2942 #ifdef CAPABILITIES 2943 seq_write_end(&newfde->fde_seq); 2944 #endif 2945 break; 2946 case ENXIO: 2947 /* 2948 * Steal away the file pointer from dfd and stuff it into indx. 2949 */ 2950 newfde = &fdp->fd_ofiles[indx]; 2951 oldfde = &fdp->fd_ofiles[dfd]; 2952 #ifdef CAPABILITIES 2953 seq_write_begin(&newfde->fde_seq); 2954 #endif 2955 memcpy(newfde, oldfde, fde_change_size); 2956 oldfde->fde_file = NULL; 2957 fdunused(fdp, dfd); 2958 #ifdef CAPABILITIES 2959 seq_write_end(&newfde->fde_seq); 2960 #endif 2961 break; 2962 } 2963 FILEDESC_XUNLOCK(fdp); 2964 *indxp = indx; 2965 return (0); 2966 } 2967 2968 /* 2969 * This sysctl determines if we will allow a process to chroot(2) if it 2970 * has a directory open: 2971 * 0: disallowed for all processes. 2972 * 1: allowed for processes that were not already chroot(2)'ed. 2973 * 2: allowed for all processes. 2974 */ 2975 2976 static int chroot_allow_open_directories = 1; 2977 2978 SYSCTL_INT(_kern, OID_AUTO, chroot_allow_open_directories, CTLFLAG_RW, 2979 &chroot_allow_open_directories, 0, 2980 "Allow a process to chroot(2) if it has a directory open"); 2981 2982 /* 2983 * Helper function for raised chroot(2) security function: Refuse if 2984 * any filedescriptors are open directories. 2985 */ 2986 static int 2987 chroot_refuse_vdir_fds(struct filedesc *fdp) 2988 { 2989 struct vnode *vp; 2990 struct file *fp; 2991 int fd; 2992 2993 FILEDESC_LOCK_ASSERT(fdp); 2994 2995 for (fd = 0; fd <= fdp->fd_lastfile; fd++) { 2996 fp = fget_locked(fdp, fd); 2997 if (fp == NULL) 2998 continue; 2999 if (fp->f_type == DTYPE_VNODE) { 3000 vp = fp->f_vnode; 3001 if (vp->v_type == VDIR) 3002 return (EPERM); 3003 } 3004 } 3005 return (0); 3006 } 3007 3008 /* 3009 * Common routine for kern_chroot() and jail_attach(). The caller is 3010 * responsible for invoking priv_check() and mac_vnode_check_chroot() to 3011 * authorize this operation. 3012 */ 3013 int 3014 pwd_chroot(struct thread *td, struct vnode *vp) 3015 { 3016 struct filedesc *fdp; 3017 struct vnode *oldvp; 3018 int error; 3019 3020 fdp = td->td_proc->p_fd; 3021 FILEDESC_XLOCK(fdp); 3022 if (chroot_allow_open_directories == 0 || 3023 (chroot_allow_open_directories == 1 && fdp->fd_rdir != rootvnode)) { 3024 error = chroot_refuse_vdir_fds(fdp); 3025 if (error != 0) { 3026 FILEDESC_XUNLOCK(fdp); 3027 return (error); 3028 } 3029 } 3030 oldvp = fdp->fd_rdir; 3031 VREF(vp); 3032 fdp->fd_rdir = vp; 3033 if (fdp->fd_jdir == NULL) { 3034 VREF(vp); 3035 fdp->fd_jdir = vp; 3036 } 3037 FILEDESC_XUNLOCK(fdp); 3038 vrele(oldvp); 3039 return (0); 3040 } 3041 3042 void 3043 pwd_chdir(struct thread *td, struct vnode *vp) 3044 { 3045 struct filedesc *fdp; 3046 struct vnode *oldvp; 3047 3048 fdp = td->td_proc->p_fd; 3049 FILEDESC_XLOCK(fdp); 3050 VNASSERT(vp->v_usecount > 0, vp, 3051 ("chdir to a vnode with zero usecount")); 3052 oldvp = fdp->fd_cdir; 3053 fdp->fd_cdir = vp; 3054 FILEDESC_XUNLOCK(fdp); 3055 vrele(oldvp); 3056 } 3057 3058 /* 3059 * Scan all active processes and prisons to see if any of them have a current 3060 * or root directory of `olddp'. If so, replace them with the new mount point. 3061 */ 3062 void 3063 mountcheckdirs(struct vnode *olddp, struct vnode *newdp) 3064 { 3065 struct filedesc *fdp; 3066 struct prison *pr; 3067 struct proc *p; 3068 int nrele; 3069 3070 if (vrefcnt(olddp) == 1) 3071 return; 3072 nrele = 0; 3073 sx_slock(&allproc_lock); 3074 FOREACH_PROC_IN_SYSTEM(p) { 3075 PROC_LOCK(p); 3076 fdp = fdhold(p); 3077 PROC_UNLOCK(p); 3078 if (fdp == NULL) 3079 continue; 3080 FILEDESC_XLOCK(fdp); 3081 if (fdp->fd_cdir == olddp) { 3082 vref(newdp); 3083 fdp->fd_cdir = newdp; 3084 nrele++; 3085 } 3086 if (fdp->fd_rdir == olddp) { 3087 vref(newdp); 3088 fdp->fd_rdir = newdp; 3089 nrele++; 3090 } 3091 if (fdp->fd_jdir == olddp) { 3092 vref(newdp); 3093 fdp->fd_jdir = newdp; 3094 nrele++; 3095 } 3096 FILEDESC_XUNLOCK(fdp); 3097 fddrop(fdp); 3098 } 3099 sx_sunlock(&allproc_lock); 3100 if (rootvnode == olddp) { 3101 vref(newdp); 3102 rootvnode = newdp; 3103 nrele++; 3104 } 3105 mtx_lock(&prison0.pr_mtx); 3106 if (prison0.pr_root == olddp) { 3107 vref(newdp); 3108 prison0.pr_root = newdp; 3109 nrele++; 3110 } 3111 mtx_unlock(&prison0.pr_mtx); 3112 sx_slock(&allprison_lock); 3113 TAILQ_FOREACH(pr, &allprison, pr_list) { 3114 mtx_lock(&pr->pr_mtx); 3115 if (pr->pr_root == olddp) { 3116 vref(newdp); 3117 pr->pr_root = newdp; 3118 nrele++; 3119 } 3120 mtx_unlock(&pr->pr_mtx); 3121 } 3122 sx_sunlock(&allprison_lock); 3123 while (nrele--) 3124 vrele(olddp); 3125 } 3126 3127 struct filedesc_to_leader * 3128 filedesc_to_leader_alloc(struct filedesc_to_leader *old, struct filedesc *fdp, struct proc *leader) 3129 { 3130 struct filedesc_to_leader *fdtol; 3131 3132 fdtol = malloc(sizeof(struct filedesc_to_leader), 3133 M_FILEDESC_TO_LEADER, M_WAITOK); 3134 fdtol->fdl_refcount = 1; 3135 fdtol->fdl_holdcount = 0; 3136 fdtol->fdl_wakeup = 0; 3137 fdtol->fdl_leader = leader; 3138 if (old != NULL) { 3139 FILEDESC_XLOCK(fdp); 3140 fdtol->fdl_next = old->fdl_next; 3141 fdtol->fdl_prev = old; 3142 old->fdl_next = fdtol; 3143 fdtol->fdl_next->fdl_prev = fdtol; 3144 FILEDESC_XUNLOCK(fdp); 3145 } else { 3146 fdtol->fdl_next = fdtol; 3147 fdtol->fdl_prev = fdtol; 3148 } 3149 return (fdtol); 3150 } 3151 3152 /* 3153 * Get file structures globally. 3154 */ 3155 static int 3156 sysctl_kern_file(SYSCTL_HANDLER_ARGS) 3157 { 3158 struct xfile xf; 3159 struct filedesc *fdp; 3160 struct file *fp; 3161 struct proc *p; 3162 int error, n; 3163 3164 error = sysctl_wire_old_buffer(req, 0); 3165 if (error != 0) 3166 return (error); 3167 if (req->oldptr == NULL) { 3168 n = 0; 3169 sx_slock(&allproc_lock); 3170 FOREACH_PROC_IN_SYSTEM(p) { 3171 PROC_LOCK(p); 3172 if (p->p_state == PRS_NEW) { 3173 PROC_UNLOCK(p); 3174 continue; 3175 } 3176 fdp = fdhold(p); 3177 PROC_UNLOCK(p); 3178 if (fdp == NULL) 3179 continue; 3180 /* overestimates sparse tables. */ 3181 if (fdp->fd_lastfile > 0) 3182 n += fdp->fd_lastfile; 3183 fddrop(fdp); 3184 } 3185 sx_sunlock(&allproc_lock); 3186 return (SYSCTL_OUT(req, 0, n * sizeof(xf))); 3187 } 3188 error = 0; 3189 bzero(&xf, sizeof(xf)); 3190 xf.xf_size = sizeof(xf); 3191 sx_slock(&allproc_lock); 3192 FOREACH_PROC_IN_SYSTEM(p) { 3193 PROC_LOCK(p); 3194 if (p->p_state == PRS_NEW) { 3195 PROC_UNLOCK(p); 3196 continue; 3197 } 3198 if (p_cansee(req->td, p) != 0) { 3199 PROC_UNLOCK(p); 3200 continue; 3201 } 3202 xf.xf_pid = p->p_pid; 3203 xf.xf_uid = p->p_ucred->cr_uid; 3204 fdp = fdhold(p); 3205 PROC_UNLOCK(p); 3206 if (fdp == NULL) 3207 continue; 3208 FILEDESC_SLOCK(fdp); 3209 for (n = 0; fdp->fd_refcnt > 0 && n <= fdp->fd_lastfile; ++n) { 3210 if ((fp = fdp->fd_ofiles[n].fde_file) == NULL) 3211 continue; 3212 xf.xf_fd = n; 3213 xf.xf_file = fp; 3214 xf.xf_data = fp->f_data; 3215 xf.xf_vnode = fp->f_vnode; 3216 xf.xf_type = fp->f_type; 3217 xf.xf_count = fp->f_count; 3218 xf.xf_msgcount = 0; 3219 xf.xf_offset = foffset_get(fp); 3220 xf.xf_flag = fp->f_flag; 3221 error = SYSCTL_OUT(req, &xf, sizeof(xf)); 3222 if (error) 3223 break; 3224 } 3225 FILEDESC_SUNLOCK(fdp); 3226 fddrop(fdp); 3227 if (error) 3228 break; 3229 } 3230 sx_sunlock(&allproc_lock); 3231 return (error); 3232 } 3233 3234 SYSCTL_PROC(_kern, KERN_FILE, file, CTLTYPE_OPAQUE|CTLFLAG_RD|CTLFLAG_MPSAFE, 3235 0, 0, sysctl_kern_file, "S,xfile", "Entire file table"); 3236 3237 #ifdef KINFO_FILE_SIZE 3238 CTASSERT(sizeof(struct kinfo_file) == KINFO_FILE_SIZE); 3239 #endif 3240 3241 static int 3242 xlate_fflags(int fflags) 3243 { 3244 static const struct { 3245 int fflag; 3246 int kf_fflag; 3247 } fflags_table[] = { 3248 { FAPPEND, KF_FLAG_APPEND }, 3249 { FASYNC, KF_FLAG_ASYNC }, 3250 { FFSYNC, KF_FLAG_FSYNC }, 3251 { FHASLOCK, KF_FLAG_HASLOCK }, 3252 { FNONBLOCK, KF_FLAG_NONBLOCK }, 3253 { FREAD, KF_FLAG_READ }, 3254 { FWRITE, KF_FLAG_WRITE }, 3255 { O_CREAT, KF_FLAG_CREAT }, 3256 { O_DIRECT, KF_FLAG_DIRECT }, 3257 { O_EXCL, KF_FLAG_EXCL }, 3258 { O_EXEC, KF_FLAG_EXEC }, 3259 { O_EXLOCK, KF_FLAG_EXLOCK }, 3260 { O_NOFOLLOW, KF_FLAG_NOFOLLOW }, 3261 { O_SHLOCK, KF_FLAG_SHLOCK }, 3262 { O_TRUNC, KF_FLAG_TRUNC } 3263 }; 3264 unsigned int i; 3265 int kflags; 3266 3267 kflags = 0; 3268 for (i = 0; i < nitems(fflags_table); i++) 3269 if (fflags & fflags_table[i].fflag) 3270 kflags |= fflags_table[i].kf_fflag; 3271 return (kflags); 3272 } 3273 3274 /* Trim unused data from kf_path by truncating the structure size. */ 3275 static void 3276 pack_kinfo(struct kinfo_file *kif) 3277 { 3278 3279 kif->kf_structsize = offsetof(struct kinfo_file, kf_path) + 3280 strlen(kif->kf_path) + 1; 3281 kif->kf_structsize = roundup(kif->kf_structsize, sizeof(uint64_t)); 3282 } 3283 3284 static void 3285 export_file_to_kinfo(struct file *fp, int fd, cap_rights_t *rightsp, 3286 struct kinfo_file *kif, struct filedesc *fdp) 3287 { 3288 int error; 3289 3290 bzero(kif, sizeof(*kif)); 3291 3292 /* Set a default type to allow for empty fill_kinfo() methods. */ 3293 kif->kf_type = KF_TYPE_UNKNOWN; 3294 kif->kf_flags = xlate_fflags(fp->f_flag); 3295 if (rightsp != NULL) 3296 kif->kf_cap_rights = *rightsp; 3297 else 3298 cap_rights_init(&kif->kf_cap_rights); 3299 kif->kf_fd = fd; 3300 kif->kf_ref_count = fp->f_count; 3301 kif->kf_offset = foffset_get(fp); 3302 3303 /* 3304 * This may drop the filedesc lock, so the 'fp' cannot be 3305 * accessed after this call. 3306 */ 3307 error = fo_fill_kinfo(fp, kif, fdp); 3308 if (error == 0) 3309 kif->kf_status |= KF_ATTR_VALID; 3310 pack_kinfo(kif); 3311 } 3312 3313 static void 3314 export_vnode_to_kinfo(struct vnode *vp, int fd, int fflags, 3315 struct kinfo_file *kif) 3316 { 3317 int error; 3318 3319 bzero(kif, sizeof(*kif)); 3320 3321 kif->kf_type = KF_TYPE_VNODE; 3322 error = vn_fill_kinfo_vnode(vp, kif); 3323 if (error == 0) 3324 kif->kf_status |= KF_ATTR_VALID; 3325 kif->kf_flags = xlate_fflags(fflags); 3326 cap_rights_init(&kif->kf_cap_rights); 3327 kif->kf_fd = fd; 3328 kif->kf_ref_count = -1; 3329 kif->kf_offset = -1; 3330 pack_kinfo(kif); 3331 vrele(vp); 3332 } 3333 3334 struct export_fd_buf { 3335 struct filedesc *fdp; 3336 struct sbuf *sb; 3337 ssize_t remainder; 3338 struct kinfo_file kif; 3339 }; 3340 3341 static int 3342 export_kinfo_to_sb(struct export_fd_buf *efbuf) 3343 { 3344 struct kinfo_file *kif; 3345 3346 kif = &efbuf->kif; 3347 if (efbuf->remainder != -1) { 3348 if (efbuf->remainder < kif->kf_structsize) { 3349 /* Terminate export. */ 3350 efbuf->remainder = 0; 3351 return (0); 3352 } 3353 efbuf->remainder -= kif->kf_structsize; 3354 } 3355 return (sbuf_bcat(efbuf->sb, kif, kif->kf_structsize) == 0 ? 0 : ENOMEM); 3356 } 3357 3358 static int 3359 export_file_to_sb(struct file *fp, int fd, cap_rights_t *rightsp, 3360 struct export_fd_buf *efbuf) 3361 { 3362 int error; 3363 3364 if (efbuf->remainder == 0) 3365 return (0); 3366 export_file_to_kinfo(fp, fd, rightsp, &efbuf->kif, efbuf->fdp); 3367 FILEDESC_SUNLOCK(efbuf->fdp); 3368 error = export_kinfo_to_sb(efbuf); 3369 FILEDESC_SLOCK(efbuf->fdp); 3370 return (error); 3371 } 3372 3373 static int 3374 export_vnode_to_sb(struct vnode *vp, int fd, int fflags, 3375 struct export_fd_buf *efbuf) 3376 { 3377 int error; 3378 3379 if (efbuf->remainder == 0) 3380 return (0); 3381 if (efbuf->fdp != NULL) 3382 FILEDESC_SUNLOCK(efbuf->fdp); 3383 export_vnode_to_kinfo(vp, fd, fflags, &efbuf->kif); 3384 error = export_kinfo_to_sb(efbuf); 3385 if (efbuf->fdp != NULL) 3386 FILEDESC_SLOCK(efbuf->fdp); 3387 return (error); 3388 } 3389 3390 /* 3391 * Store a process file descriptor information to sbuf. 3392 * 3393 * Takes a locked proc as argument, and returns with the proc unlocked. 3394 */ 3395 int 3396 kern_proc_filedesc_out(struct proc *p, struct sbuf *sb, ssize_t maxlen) 3397 { 3398 struct file *fp; 3399 struct filedesc *fdp; 3400 struct export_fd_buf *efbuf; 3401 struct vnode *cttyvp, *textvp, *tracevp; 3402 int error, i; 3403 cap_rights_t rights; 3404 3405 PROC_LOCK_ASSERT(p, MA_OWNED); 3406 3407 /* ktrace vnode */ 3408 tracevp = p->p_tracevp; 3409 if (tracevp != NULL) 3410 vref(tracevp); 3411 /* text vnode */ 3412 textvp = p->p_textvp; 3413 if (textvp != NULL) 3414 vref(textvp); 3415 /* Controlling tty. */ 3416 cttyvp = NULL; 3417 if (p->p_pgrp != NULL && p->p_pgrp->pg_session != NULL) { 3418 cttyvp = p->p_pgrp->pg_session->s_ttyvp; 3419 if (cttyvp != NULL) 3420 vref(cttyvp); 3421 } 3422 fdp = fdhold(p); 3423 PROC_UNLOCK(p); 3424 efbuf = malloc(sizeof(*efbuf), M_TEMP, M_WAITOK); 3425 efbuf->fdp = NULL; 3426 efbuf->sb = sb; 3427 efbuf->remainder = maxlen; 3428 if (tracevp != NULL) 3429 export_vnode_to_sb(tracevp, KF_FD_TYPE_TRACE, FREAD | FWRITE, 3430 efbuf); 3431 if (textvp != NULL) 3432 export_vnode_to_sb(textvp, KF_FD_TYPE_TEXT, FREAD, efbuf); 3433 if (cttyvp != NULL) 3434 export_vnode_to_sb(cttyvp, KF_FD_TYPE_CTTY, FREAD | FWRITE, 3435 efbuf); 3436 error = 0; 3437 if (fdp == NULL) 3438 goto fail; 3439 efbuf->fdp = fdp; 3440 FILEDESC_SLOCK(fdp); 3441 /* working directory */ 3442 if (fdp->fd_cdir != NULL) { 3443 vref(fdp->fd_cdir); 3444 export_vnode_to_sb(fdp->fd_cdir, KF_FD_TYPE_CWD, FREAD, efbuf); 3445 } 3446 /* root directory */ 3447 if (fdp->fd_rdir != NULL) { 3448 vref(fdp->fd_rdir); 3449 export_vnode_to_sb(fdp->fd_rdir, KF_FD_TYPE_ROOT, FREAD, efbuf); 3450 } 3451 /* jail directory */ 3452 if (fdp->fd_jdir != NULL) { 3453 vref(fdp->fd_jdir); 3454 export_vnode_to_sb(fdp->fd_jdir, KF_FD_TYPE_JAIL, FREAD, efbuf); 3455 } 3456 for (i = 0; fdp->fd_refcnt > 0 && i <= fdp->fd_lastfile; i++) { 3457 if ((fp = fdp->fd_ofiles[i].fde_file) == NULL) 3458 continue; 3459 #ifdef CAPABILITIES 3460 rights = *cap_rights(fdp, i); 3461 #else /* !CAPABILITIES */ 3462 cap_rights_init(&rights); 3463 #endif 3464 /* 3465 * Create sysctl entry. It is OK to drop the filedesc 3466 * lock inside of export_file_to_sb() as we will 3467 * re-validate and re-evaluate its properties when the 3468 * loop continues. 3469 */ 3470 error = export_file_to_sb(fp, i, &rights, efbuf); 3471 if (error != 0 || efbuf->remainder == 0) 3472 break; 3473 } 3474 FILEDESC_SUNLOCK(fdp); 3475 fddrop(fdp); 3476 fail: 3477 free(efbuf, M_TEMP); 3478 return (error); 3479 } 3480 3481 #define FILEDESC_SBUF_SIZE (sizeof(struct kinfo_file) * 5) 3482 3483 /* 3484 * Get per-process file descriptors for use by procstat(1), et al. 3485 */ 3486 static int 3487 sysctl_kern_proc_filedesc(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, FILEDESC_SBUF_SIZE, 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_filedesc_out(p, &sb, maxlen); 3505 error2 = sbuf_finish(&sb); 3506 sbuf_delete(&sb); 3507 return (error != 0 ? error : error2); 3508 } 3509 3510 #ifdef KINFO_OFILE_SIZE 3511 CTASSERT(sizeof(struct kinfo_ofile) == KINFO_OFILE_SIZE); 3512 #endif 3513 3514 #ifdef COMPAT_FREEBSD7 3515 static void 3516 kinfo_to_okinfo(struct kinfo_file *kif, struct kinfo_ofile *okif) 3517 { 3518 3519 okif->kf_structsize = sizeof(*okif); 3520 okif->kf_type = kif->kf_type; 3521 okif->kf_fd = kif->kf_fd; 3522 okif->kf_ref_count = kif->kf_ref_count; 3523 okif->kf_flags = kif->kf_flags & (KF_FLAG_READ | KF_FLAG_WRITE | 3524 KF_FLAG_APPEND | KF_FLAG_ASYNC | KF_FLAG_FSYNC | KF_FLAG_NONBLOCK | 3525 KF_FLAG_DIRECT | KF_FLAG_HASLOCK); 3526 okif->kf_offset = kif->kf_offset; 3527 okif->kf_vnode_type = kif->kf_vnode_type; 3528 okif->kf_sock_domain = kif->kf_sock_domain; 3529 okif->kf_sock_type = kif->kf_sock_type; 3530 okif->kf_sock_protocol = kif->kf_sock_protocol; 3531 strlcpy(okif->kf_path, kif->kf_path, sizeof(okif->kf_path)); 3532 okif->kf_sa_local = kif->kf_sa_local; 3533 okif->kf_sa_peer = kif->kf_sa_peer; 3534 } 3535 3536 static int 3537 export_vnode_for_osysctl(struct vnode *vp, int type, struct kinfo_file *kif, 3538 struct kinfo_ofile *okif, struct filedesc *fdp, struct sysctl_req *req) 3539 { 3540 int error; 3541 3542 vref(vp); 3543 FILEDESC_SUNLOCK(fdp); 3544 export_vnode_to_kinfo(vp, type, 0, kif); 3545 kinfo_to_okinfo(kif, okif); 3546 error = SYSCTL_OUT(req, okif, sizeof(*okif)); 3547 FILEDESC_SLOCK(fdp); 3548 return (error); 3549 } 3550 3551 /* 3552 * Get per-process file descriptors for use by procstat(1), et al. 3553 */ 3554 static int 3555 sysctl_kern_proc_ofiledesc(SYSCTL_HANDLER_ARGS) 3556 { 3557 struct kinfo_ofile *okif; 3558 struct kinfo_file *kif; 3559 struct filedesc *fdp; 3560 int error, i, *name; 3561 struct file *fp; 3562 struct proc *p; 3563 3564 name = (int *)arg1; 3565 error = pget((pid_t)name[0], PGET_CANDEBUG | PGET_NOTWEXIT, &p); 3566 if (error != 0) 3567 return (error); 3568 fdp = fdhold(p); 3569 PROC_UNLOCK(p); 3570 if (fdp == NULL) 3571 return (ENOENT); 3572 kif = malloc(sizeof(*kif), M_TEMP, M_WAITOK); 3573 okif = malloc(sizeof(*okif), M_TEMP, M_WAITOK); 3574 FILEDESC_SLOCK(fdp); 3575 if (fdp->fd_cdir != NULL) 3576 export_vnode_for_osysctl(fdp->fd_cdir, KF_FD_TYPE_CWD, kif, 3577 okif, fdp, req); 3578 if (fdp->fd_rdir != NULL) 3579 export_vnode_for_osysctl(fdp->fd_rdir, KF_FD_TYPE_ROOT, kif, 3580 okif, fdp, req); 3581 if (fdp->fd_jdir != NULL) 3582 export_vnode_for_osysctl(fdp->fd_jdir, KF_FD_TYPE_JAIL, kif, 3583 okif, fdp, req); 3584 for (i = 0; fdp->fd_refcnt > 0 && i <= fdp->fd_lastfile; i++) { 3585 if ((fp = fdp->fd_ofiles[i].fde_file) == NULL) 3586 continue; 3587 export_file_to_kinfo(fp, i, NULL, kif, fdp); 3588 FILEDESC_SUNLOCK(fdp); 3589 kinfo_to_okinfo(kif, okif); 3590 error = SYSCTL_OUT(req, okif, sizeof(*okif)); 3591 FILEDESC_SLOCK(fdp); 3592 if (error) 3593 break; 3594 } 3595 FILEDESC_SUNLOCK(fdp); 3596 fddrop(fdp); 3597 free(kif, M_TEMP); 3598 free(okif, M_TEMP); 3599 return (0); 3600 } 3601 3602 static SYSCTL_NODE(_kern_proc, KERN_PROC_OFILEDESC, ofiledesc, 3603 CTLFLAG_RD|CTLFLAG_MPSAFE, sysctl_kern_proc_ofiledesc, 3604 "Process ofiledesc entries"); 3605 #endif /* COMPAT_FREEBSD7 */ 3606 3607 int 3608 vntype_to_kinfo(int vtype) 3609 { 3610 struct { 3611 int vtype; 3612 int kf_vtype; 3613 } vtypes_table[] = { 3614 { VBAD, KF_VTYPE_VBAD }, 3615 { VBLK, KF_VTYPE_VBLK }, 3616 { VCHR, KF_VTYPE_VCHR }, 3617 { VDIR, KF_VTYPE_VDIR }, 3618 { VFIFO, KF_VTYPE_VFIFO }, 3619 { VLNK, KF_VTYPE_VLNK }, 3620 { VNON, KF_VTYPE_VNON }, 3621 { VREG, KF_VTYPE_VREG }, 3622 { VSOCK, KF_VTYPE_VSOCK } 3623 }; 3624 unsigned int i; 3625 3626 /* 3627 * Perform vtype translation. 3628 */ 3629 for (i = 0; i < nitems(vtypes_table); i++) 3630 if (vtypes_table[i].vtype == vtype) 3631 return (vtypes_table[i].kf_vtype); 3632 3633 return (KF_VTYPE_UNKNOWN); 3634 } 3635 3636 static SYSCTL_NODE(_kern_proc, KERN_PROC_FILEDESC, filedesc, 3637 CTLFLAG_RD|CTLFLAG_MPSAFE, sysctl_kern_proc_filedesc, 3638 "Process filedesc entries"); 3639 3640 /* 3641 * Store a process current working directory information to sbuf. 3642 * 3643 * Takes a locked proc as argument, and returns with the proc unlocked. 3644 */ 3645 int 3646 kern_proc_cwd_out(struct proc *p, struct sbuf *sb, ssize_t maxlen) 3647 { 3648 struct filedesc *fdp; 3649 struct export_fd_buf *efbuf; 3650 int error; 3651 3652 PROC_LOCK_ASSERT(p, MA_OWNED); 3653 3654 fdp = fdhold(p); 3655 PROC_UNLOCK(p); 3656 if (fdp == NULL) 3657 return (EINVAL); 3658 3659 efbuf = malloc(sizeof(*efbuf), M_TEMP, M_WAITOK); 3660 efbuf->fdp = fdp; 3661 efbuf->sb = sb; 3662 efbuf->remainder = maxlen; 3663 3664 FILEDESC_SLOCK(fdp); 3665 if (fdp->fd_cdir == NULL) 3666 error = EINVAL; 3667 else { 3668 vref(fdp->fd_cdir); 3669 error = export_vnode_to_sb(fdp->fd_cdir, KF_FD_TYPE_CWD, 3670 FREAD, efbuf); 3671 } 3672 FILEDESC_SUNLOCK(fdp); 3673 fddrop(fdp); 3674 free(efbuf, M_TEMP); 3675 return (error); 3676 } 3677 3678 /* 3679 * Get per-process current working directory. 3680 */ 3681 static int 3682 sysctl_kern_proc_cwd(SYSCTL_HANDLER_ARGS) 3683 { 3684 struct sbuf sb; 3685 struct proc *p; 3686 ssize_t maxlen; 3687 int error, error2, *name; 3688 3689 name = (int *)arg1; 3690 3691 sbuf_new_for_sysctl(&sb, NULL, sizeof(struct kinfo_file), req); 3692 sbuf_clear_flags(&sb, SBUF_INCLUDENUL); 3693 error = pget((pid_t)name[0], PGET_CANDEBUG | PGET_NOTWEXIT, &p); 3694 if (error != 0) { 3695 sbuf_delete(&sb); 3696 return (error); 3697 } 3698 maxlen = req->oldptr != NULL ? req->oldlen : -1; 3699 error = kern_proc_cwd_out(p, &sb, maxlen); 3700 error2 = sbuf_finish(&sb); 3701 sbuf_delete(&sb); 3702 return (error != 0 ? error : error2); 3703 } 3704 3705 static SYSCTL_NODE(_kern_proc, KERN_PROC_CWD, cwd, CTLFLAG_RD|CTLFLAG_MPSAFE, 3706 sysctl_kern_proc_cwd, "Process current working directory"); 3707 3708 #ifdef DDB 3709 /* 3710 * For the purposes of debugging, generate a human-readable string for the 3711 * file type. 3712 */ 3713 static const char * 3714 file_type_to_name(short type) 3715 { 3716 3717 switch (type) { 3718 case 0: 3719 return ("zero"); 3720 case DTYPE_VNODE: 3721 return ("vnod"); 3722 case DTYPE_SOCKET: 3723 return ("sock"); 3724 case DTYPE_PIPE: 3725 return ("pipe"); 3726 case DTYPE_FIFO: 3727 return ("fifo"); 3728 case DTYPE_KQUEUE: 3729 return ("kque"); 3730 case DTYPE_CRYPTO: 3731 return ("crpt"); 3732 case DTYPE_MQUEUE: 3733 return ("mque"); 3734 case DTYPE_SHM: 3735 return ("shm"); 3736 case DTYPE_SEM: 3737 return ("ksem"); 3738 default: 3739 return ("unkn"); 3740 } 3741 } 3742 3743 /* 3744 * For the purposes of debugging, identify a process (if any, perhaps one of 3745 * many) that references the passed file in its file descriptor array. Return 3746 * NULL if none. 3747 */ 3748 static struct proc * 3749 file_to_first_proc(struct file *fp) 3750 { 3751 struct filedesc *fdp; 3752 struct proc *p; 3753 int n; 3754 3755 FOREACH_PROC_IN_SYSTEM(p) { 3756 if (p->p_state == PRS_NEW) 3757 continue; 3758 fdp = p->p_fd; 3759 if (fdp == NULL) 3760 continue; 3761 for (n = 0; n <= fdp->fd_lastfile; n++) { 3762 if (fp == fdp->fd_ofiles[n].fde_file) 3763 return (p); 3764 } 3765 } 3766 return (NULL); 3767 } 3768 3769 static void 3770 db_print_file(struct file *fp, int header) 3771 { 3772 struct proc *p; 3773 3774 if (header) 3775 db_printf("%8s %4s %8s %8s %4s %5s %6s %8s %5s %12s\n", 3776 "File", "Type", "Data", "Flag", "GCFl", "Count", 3777 "MCount", "Vnode", "FPID", "FCmd"); 3778 p = file_to_first_proc(fp); 3779 db_printf("%8p %4s %8p %08x %04x %5d %6d %8p %5d %12s\n", fp, 3780 file_type_to_name(fp->f_type), fp->f_data, fp->f_flag, 3781 0, fp->f_count, 0, fp->f_vnode, 3782 p != NULL ? p->p_pid : -1, p != NULL ? p->p_comm : "-"); 3783 } 3784 3785 DB_SHOW_COMMAND(file, db_show_file) 3786 { 3787 struct file *fp; 3788 3789 if (!have_addr) { 3790 db_printf("usage: show file <addr>\n"); 3791 return; 3792 } 3793 fp = (struct file *)addr; 3794 db_print_file(fp, 1); 3795 } 3796 3797 DB_SHOW_COMMAND(files, db_show_files) 3798 { 3799 struct filedesc *fdp; 3800 struct file *fp; 3801 struct proc *p; 3802 int header; 3803 int n; 3804 3805 header = 1; 3806 FOREACH_PROC_IN_SYSTEM(p) { 3807 if (p->p_state == PRS_NEW) 3808 continue; 3809 if ((fdp = p->p_fd) == NULL) 3810 continue; 3811 for (n = 0; n <= fdp->fd_lastfile; ++n) { 3812 if ((fp = fdp->fd_ofiles[n].fde_file) == NULL) 3813 continue; 3814 db_print_file(fp, header); 3815 header = 0; 3816 } 3817 } 3818 } 3819 #endif 3820 3821 SYSCTL_INT(_kern, KERN_MAXFILESPERPROC, maxfilesperproc, CTLFLAG_RW, 3822 &maxfilesperproc, 0, "Maximum files allowed open per process"); 3823 3824 SYSCTL_INT(_kern, KERN_MAXFILES, maxfiles, CTLFLAG_RW, 3825 &maxfiles, 0, "Maximum number of files"); 3826 3827 SYSCTL_INT(_kern, OID_AUTO, openfiles, CTLFLAG_RD, 3828 __DEVOLATILE(int *, &openfiles), 0, "System-wide number of open files"); 3829 3830 /* ARGSUSED*/ 3831 static void 3832 filelistinit(void *dummy) 3833 { 3834 3835 file_zone = uma_zcreate("Files", sizeof(struct file), NULL, NULL, 3836 NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE); 3837 filedesc0_zone = uma_zcreate("filedesc0", sizeof(struct filedesc0), 3838 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0); 3839 mtx_init(&sigio_lock, "sigio lock", NULL, MTX_DEF); 3840 } 3841 SYSINIT(select, SI_SUB_LOCK, SI_ORDER_FIRST, filelistinit, NULL); 3842 3843 /*-------------------------------------------------------------------*/ 3844 3845 static int 3846 badfo_readwrite(struct file *fp, struct uio *uio, struct ucred *active_cred, 3847 int flags, struct thread *td) 3848 { 3849 3850 return (EBADF); 3851 } 3852 3853 static int 3854 badfo_truncate(struct file *fp, off_t length, struct ucred *active_cred, 3855 struct thread *td) 3856 { 3857 3858 return (EINVAL); 3859 } 3860 3861 static int 3862 badfo_ioctl(struct file *fp, u_long com, void *data, struct ucred *active_cred, 3863 struct thread *td) 3864 { 3865 3866 return (EBADF); 3867 } 3868 3869 static int 3870 badfo_poll(struct file *fp, int events, struct ucred *active_cred, 3871 struct thread *td) 3872 { 3873 3874 return (0); 3875 } 3876 3877 static int 3878 badfo_kqfilter(struct file *fp, struct knote *kn) 3879 { 3880 3881 return (EBADF); 3882 } 3883 3884 static int 3885 badfo_stat(struct file *fp, struct stat *sb, struct ucred *active_cred, 3886 struct thread *td) 3887 { 3888 3889 return (EBADF); 3890 } 3891 3892 static int 3893 badfo_close(struct file *fp, struct thread *td) 3894 { 3895 3896 return (0); 3897 } 3898 3899 static int 3900 badfo_chmod(struct file *fp, mode_t mode, struct ucred *active_cred, 3901 struct thread *td) 3902 { 3903 3904 return (EBADF); 3905 } 3906 3907 static int 3908 badfo_chown(struct file *fp, uid_t uid, gid_t gid, struct ucred *active_cred, 3909 struct thread *td) 3910 { 3911 3912 return (EBADF); 3913 } 3914 3915 static int 3916 badfo_sendfile(struct file *fp, int sockfd, struct uio *hdr_uio, 3917 struct uio *trl_uio, off_t offset, size_t nbytes, off_t *sent, int flags, 3918 int kflags, struct thread *td) 3919 { 3920 3921 return (EBADF); 3922 } 3923 3924 static int 3925 badfo_fill_kinfo(struct file *fp, struct kinfo_file *kif, struct filedesc *fdp) 3926 { 3927 3928 return (0); 3929 } 3930 3931 struct fileops badfileops = { 3932 .fo_read = badfo_readwrite, 3933 .fo_write = badfo_readwrite, 3934 .fo_truncate = badfo_truncate, 3935 .fo_ioctl = badfo_ioctl, 3936 .fo_poll = badfo_poll, 3937 .fo_kqfilter = badfo_kqfilter, 3938 .fo_stat = badfo_stat, 3939 .fo_close = badfo_close, 3940 .fo_chmod = badfo_chmod, 3941 .fo_chown = badfo_chown, 3942 .fo_sendfile = badfo_sendfile, 3943 .fo_fill_kinfo = badfo_fill_kinfo, 3944 }; 3945 3946 int 3947 invfo_rdwr(struct file *fp, struct uio *uio, struct ucred *active_cred, 3948 int flags, struct thread *td) 3949 { 3950 3951 return (EOPNOTSUPP); 3952 } 3953 3954 int 3955 invfo_truncate(struct file *fp, off_t length, struct ucred *active_cred, 3956 struct thread *td) 3957 { 3958 3959 return (EINVAL); 3960 } 3961 3962 int 3963 invfo_ioctl(struct file *fp, u_long com, void *data, 3964 struct ucred *active_cred, struct thread *td) 3965 { 3966 3967 return (ENOTTY); 3968 } 3969 3970 int 3971 invfo_poll(struct file *fp, int events, struct ucred *active_cred, 3972 struct thread *td) 3973 { 3974 3975 return (poll_no_poll(events)); 3976 } 3977 3978 int 3979 invfo_kqfilter(struct file *fp, struct knote *kn) 3980 { 3981 3982 return (EINVAL); 3983 } 3984 3985 int 3986 invfo_chmod(struct file *fp, mode_t mode, struct ucred *active_cred, 3987 struct thread *td) 3988 { 3989 3990 return (EINVAL); 3991 } 3992 3993 int 3994 invfo_chown(struct file *fp, uid_t uid, gid_t gid, struct ucred *active_cred, 3995 struct thread *td) 3996 { 3997 3998 return (EINVAL); 3999 } 4000 4001 int 4002 invfo_sendfile(struct file *fp, int sockfd, struct uio *hdr_uio, 4003 struct uio *trl_uio, off_t offset, size_t nbytes, off_t *sent, int flags, 4004 int kflags, struct thread *td) 4005 { 4006 4007 return (EINVAL); 4008 } 4009 4010 /*-------------------------------------------------------------------*/ 4011 4012 /* 4013 * File Descriptor pseudo-device driver (/dev/fd/). 4014 * 4015 * Opening minor device N dup()s the file (if any) connected to file 4016 * descriptor N belonging to the calling process. Note that this driver 4017 * consists of only the ``open()'' routine, because all subsequent 4018 * references to this file will be direct to the other driver. 4019 * 4020 * XXX: we could give this one a cloning event handler if necessary. 4021 */ 4022 4023 /* ARGSUSED */ 4024 static int 4025 fdopen(struct cdev *dev, int mode, int type, struct thread *td) 4026 { 4027 4028 /* 4029 * XXX Kludge: set curthread->td_dupfd to contain the value of the 4030 * the file descriptor being sought for duplication. The error 4031 * return ensures that the vnode for this device will be released 4032 * by vn_open. Open will detect this special error and take the 4033 * actions in dupfdopen below. Other callers of vn_open or VOP_OPEN 4034 * will simply report the error. 4035 */ 4036 td->td_dupfd = dev2unit(dev); 4037 return (ENODEV); 4038 } 4039 4040 static struct cdevsw fildesc_cdevsw = { 4041 .d_version = D_VERSION, 4042 .d_open = fdopen, 4043 .d_name = "FD", 4044 }; 4045 4046 static void 4047 fildesc_drvinit(void *unused) 4048 { 4049 struct cdev *dev; 4050 4051 dev = make_dev_credf(MAKEDEV_ETERNAL, &fildesc_cdevsw, 0, NULL, 4052 UID_ROOT, GID_WHEEL, 0666, "fd/0"); 4053 make_dev_alias(dev, "stdin"); 4054 dev = make_dev_credf(MAKEDEV_ETERNAL, &fildesc_cdevsw, 1, NULL, 4055 UID_ROOT, GID_WHEEL, 0666, "fd/1"); 4056 make_dev_alias(dev, "stdout"); 4057 dev = make_dev_credf(MAKEDEV_ETERNAL, &fildesc_cdevsw, 2, NULL, 4058 UID_ROOT, GID_WHEEL, 0666, "fd/2"); 4059 make_dev_alias(dev, "stderr"); 4060 } 4061 4062 SYSINIT(fildescdev, SI_SUB_DRIVERS, SI_ORDER_MIDDLE, fildesc_drvinit, NULL); 4063