1 /*- 2 * SPDX-License-Identifier: BSD-3-Clause 3 * 4 * Copyright (c) 1982, 1986, 1989, 1991, 1993 5 * The Regents of the University of California. All rights reserved. 6 * (c) UNIX System Laboratories, Inc. 7 * All or some portions of this file are derived from material licensed 8 * to the University of California by American Telephone and Telegraph 9 * Co. or Unix System Laboratories, Inc. and are reproduced herein with 10 * the permission of UNIX System Laboratories, Inc. 11 * 12 * Redistribution and use in source and binary forms, with or without 13 * modification, are permitted provided that the following conditions 14 * are met: 15 * 1. Redistributions of source code must retain the above copyright 16 * notice, this list of conditions and the following disclaimer. 17 * 2. Redistributions in binary form must reproduce the above copyright 18 * notice, this list of conditions and the following disclaimer in the 19 * documentation and/or other materials provided with the distribution. 20 * 3. Neither the name of the University nor the names of its contributors 21 * may be used to endorse or promote products derived from this software 22 * without specific prior written permission. 23 * 24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34 * SUCH DAMAGE. 35 * 36 * @(#)kern_descrip.c 8.6 (Berkeley) 4/19/94 37 */ 38 39 #include <sys/cdefs.h> 40 __FBSDID("$FreeBSD$"); 41 42 #include "opt_capsicum.h" 43 #include "opt_ddb.h" 44 #include "opt_ktrace.h" 45 46 #include <sys/param.h> 47 #include <sys/systm.h> 48 49 #include <sys/capsicum.h> 50 #include <sys/conf.h> 51 #include <sys/fcntl.h> 52 #include <sys/file.h> 53 #include <sys/filedesc.h> 54 #include <sys/filio.h> 55 #include <sys/jail.h> 56 #include <sys/kernel.h> 57 #include <sys/limits.h> 58 #include <sys/lock.h> 59 #include <sys/malloc.h> 60 #include <sys/mount.h> 61 #include <sys/mutex.h> 62 #include <sys/namei.h> 63 #include <sys/selinfo.h> 64 #include <sys/priv.h> 65 #include <sys/proc.h> 66 #include <sys/protosw.h> 67 #include <sys/racct.h> 68 #include <sys/resourcevar.h> 69 #include <sys/sbuf.h> 70 #include <sys/signalvar.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_PWD, "pwd", "Descriptor table vnodes"); 95 static MALLOC_DEFINE(M_FILEDESC_TO_LEADER, "filedesc_to_leader", 96 "file desc to leader structures"); 97 static MALLOC_DEFINE(M_SIGIO, "sigio", "sigio structures"); 98 MALLOC_DEFINE(M_FILECAPS, "filecaps", "descriptor capabilities"); 99 100 MALLOC_DECLARE(M_FADVISE); 101 102 static __read_mostly uma_zone_t file_zone; 103 static __read_mostly uma_zone_t filedesc0_zone; 104 105 static int closefp(struct filedesc *fdp, int fd, struct file *fp, 106 struct thread *td, int holdleaders); 107 static int fd_first_free(struct filedesc *fdp, int low, int size); 108 static int fd_last_used(struct filedesc *fdp, int size); 109 static void fdgrowtable(struct filedesc *fdp, int nfd); 110 static void fdgrowtable_exp(struct filedesc *fdp, int nfd); 111 static void fdunused(struct filedesc *fdp, int fd); 112 static void fdused(struct filedesc *fdp, int fd); 113 static int getmaxfd(struct thread *td); 114 static u_long *filecaps_copy_prep(const struct filecaps *src); 115 static void filecaps_copy_finish(const struct filecaps *src, 116 struct filecaps *dst, u_long *ioctls); 117 static u_long *filecaps_free_prep(struct filecaps *fcaps); 118 static void filecaps_free_finish(u_long *ioctls); 119 120 static struct pwd *pwd_alloc(void); 121 122 /* 123 * Each process has: 124 * 125 * - An array of open file descriptors (fd_ofiles) 126 * - An array of file flags (fd_ofileflags) 127 * - A bitmap recording which descriptors are in use (fd_map) 128 * 129 * A process starts out with NDFILE descriptors. The value of NDFILE has 130 * been selected based the historical limit of 20 open files, and an 131 * assumption that the majority of processes, especially short-lived 132 * processes like shells, will never need more. 133 * 134 * If this initial allocation is exhausted, a larger descriptor table and 135 * map are allocated dynamically, and the pointers in the process's struct 136 * filedesc are updated to point to those. This is repeated every time 137 * the process runs out of file descriptors (provided it hasn't hit its 138 * resource limit). 139 * 140 * Since threads may hold references to individual descriptor table 141 * entries, the tables are never freed. Instead, they are placed on a 142 * linked list and freed only when the struct filedesc is released. 143 */ 144 #define NDFILE 20 145 #define NDSLOTSIZE sizeof(NDSLOTTYPE) 146 #define NDENTRIES (NDSLOTSIZE * __CHAR_BIT) 147 #define NDSLOT(x) ((x) / NDENTRIES) 148 #define NDBIT(x) ((NDSLOTTYPE)1 << ((x) % NDENTRIES)) 149 #define NDSLOTS(x) (((x) + NDENTRIES - 1) / NDENTRIES) 150 151 /* 152 * SLIST entry used to keep track of ofiles which must be reclaimed when 153 * the process exits. 154 */ 155 struct freetable { 156 struct fdescenttbl *ft_table; 157 SLIST_ENTRY(freetable) ft_next; 158 }; 159 160 /* 161 * Initial allocation: a filedesc structure + the head of SLIST used to 162 * keep track of old ofiles + enough space for NDFILE descriptors. 163 */ 164 165 struct fdescenttbl0 { 166 int fdt_nfiles; 167 struct filedescent fdt_ofiles[NDFILE]; 168 }; 169 170 struct filedesc0 { 171 struct filedesc fd_fd; 172 SLIST_HEAD(, freetable) fd_free; 173 struct fdescenttbl0 fd_dfiles; 174 NDSLOTTYPE fd_dmap[NDSLOTS(NDFILE)]; 175 }; 176 177 /* 178 * Descriptor management. 179 */ 180 static int __exclusive_cache_line openfiles; /* actual number of open files */ 181 struct mtx sigio_lock; /* mtx to protect pointers to sigio */ 182 void __read_mostly (*mq_fdclose)(struct thread *td, int fd, struct file *fp); 183 184 /* 185 * If low >= size, just return low. Otherwise find the first zero bit in the 186 * given bitmap, starting at low and not exceeding size - 1. Return size if 187 * not found. 188 */ 189 static int 190 fd_first_free(struct filedesc *fdp, int low, int size) 191 { 192 NDSLOTTYPE *map = fdp->fd_map; 193 NDSLOTTYPE mask; 194 int off, maxoff; 195 196 if (low >= size) 197 return (low); 198 199 off = NDSLOT(low); 200 if (low % NDENTRIES) { 201 mask = ~(~(NDSLOTTYPE)0 >> (NDENTRIES - (low % NDENTRIES))); 202 if ((mask &= ~map[off]) != 0UL) 203 return (off * NDENTRIES + ffsl(mask) - 1); 204 ++off; 205 } 206 for (maxoff = NDSLOTS(size); off < maxoff; ++off) 207 if (map[off] != ~0UL) 208 return (off * NDENTRIES + ffsl(~map[off]) - 1); 209 return (size); 210 } 211 212 /* 213 * Find the highest non-zero bit in the given bitmap, starting at 0 and 214 * not exceeding size - 1. Return -1 if not found. 215 */ 216 static int 217 fd_last_used(struct filedesc *fdp, int size) 218 { 219 NDSLOTTYPE *map = fdp->fd_map; 220 NDSLOTTYPE mask; 221 int off, minoff; 222 223 off = NDSLOT(size); 224 if (size % NDENTRIES) { 225 mask = ~(~(NDSLOTTYPE)0 << (size % NDENTRIES)); 226 if ((mask &= map[off]) != 0) 227 return (off * NDENTRIES + flsl(mask) - 1); 228 --off; 229 } 230 for (minoff = NDSLOT(0); off >= minoff; --off) 231 if (map[off] != 0) 232 return (off * NDENTRIES + flsl(map[off]) - 1); 233 return (-1); 234 } 235 236 static int 237 fdisused(struct filedesc *fdp, int fd) 238 { 239 240 KASSERT(fd >= 0 && fd < fdp->fd_nfiles, 241 ("file descriptor %d out of range (0, %d)", fd, fdp->fd_nfiles)); 242 243 return ((fdp->fd_map[NDSLOT(fd)] & NDBIT(fd)) != 0); 244 } 245 246 /* 247 * Mark a file descriptor as used. 248 */ 249 static void 250 fdused_init(struct filedesc *fdp, int fd) 251 { 252 253 KASSERT(!fdisused(fdp, fd), ("fd=%d is already used", fd)); 254 255 fdp->fd_map[NDSLOT(fd)] |= NDBIT(fd); 256 } 257 258 static void 259 fdused(struct filedesc *fdp, int fd) 260 { 261 262 FILEDESC_XLOCK_ASSERT(fdp); 263 264 fdused_init(fdp, fd); 265 if (fd > fdp->fd_lastfile) 266 fdp->fd_lastfile = fd; 267 if (fd == fdp->fd_freefile) 268 fdp->fd_freefile++; 269 } 270 271 /* 272 * Mark a file descriptor as unused. 273 */ 274 static void 275 fdunused(struct filedesc *fdp, int fd) 276 { 277 278 FILEDESC_XLOCK_ASSERT(fdp); 279 280 KASSERT(fdisused(fdp, fd), ("fd=%d is already unused", fd)); 281 KASSERT(fdp->fd_ofiles[fd].fde_file == NULL, 282 ("fd=%d is still in use", fd)); 283 284 fdp->fd_map[NDSLOT(fd)] &= ~NDBIT(fd); 285 if (fd < fdp->fd_freefile) 286 fdp->fd_freefile = fd; 287 if (fd == fdp->fd_lastfile) 288 fdp->fd_lastfile = fd_last_used(fdp, fd); 289 } 290 291 /* 292 * Free a file descriptor. 293 * 294 * Avoid some work if fdp is about to be destroyed. 295 */ 296 static inline void 297 fdefree_last(struct filedescent *fde) 298 { 299 300 filecaps_free(&fde->fde_caps); 301 } 302 303 static inline void 304 fdfree(struct filedesc *fdp, int fd) 305 { 306 struct filedescent *fde; 307 308 fde = &fdp->fd_ofiles[fd]; 309 #ifdef CAPABILITIES 310 seqc_write_begin(&fde->fde_seqc); 311 #endif 312 fde->fde_file = NULL; 313 #ifdef CAPABILITIES 314 seqc_write_end(&fde->fde_seqc); 315 #endif 316 fdefree_last(fde); 317 fdunused(fdp, fd); 318 } 319 320 /* 321 * System calls on descriptors. 322 */ 323 #ifndef _SYS_SYSPROTO_H_ 324 struct getdtablesize_args { 325 int dummy; 326 }; 327 #endif 328 /* ARGSUSED */ 329 int 330 sys_getdtablesize(struct thread *td, struct getdtablesize_args *uap) 331 { 332 #ifdef RACCT 333 uint64_t lim; 334 #endif 335 336 td->td_retval[0] = getmaxfd(td); 337 #ifdef RACCT 338 PROC_LOCK(td->td_proc); 339 lim = racct_get_limit(td->td_proc, RACCT_NOFILE); 340 PROC_UNLOCK(td->td_proc); 341 if (lim < td->td_retval[0]) 342 td->td_retval[0] = lim; 343 #endif 344 return (0); 345 } 346 347 /* 348 * Duplicate a file descriptor to a particular value. 349 * 350 * Note: keep in mind that a potential race condition exists when closing 351 * descriptors from a shared descriptor table (via rfork). 352 */ 353 #ifndef _SYS_SYSPROTO_H_ 354 struct dup2_args { 355 u_int from; 356 u_int to; 357 }; 358 #endif 359 /* ARGSUSED */ 360 int 361 sys_dup2(struct thread *td, struct dup2_args *uap) 362 { 363 364 return (kern_dup(td, FDDUP_FIXED, 0, (int)uap->from, (int)uap->to)); 365 } 366 367 /* 368 * Duplicate a file descriptor. 369 */ 370 #ifndef _SYS_SYSPROTO_H_ 371 struct dup_args { 372 u_int fd; 373 }; 374 #endif 375 /* ARGSUSED */ 376 int 377 sys_dup(struct thread *td, struct dup_args *uap) 378 { 379 380 return (kern_dup(td, FDDUP_NORMAL, 0, (int)uap->fd, 0)); 381 } 382 383 /* 384 * The file control system call. 385 */ 386 #ifndef _SYS_SYSPROTO_H_ 387 struct fcntl_args { 388 int fd; 389 int cmd; 390 long arg; 391 }; 392 #endif 393 /* ARGSUSED */ 394 int 395 sys_fcntl(struct thread *td, struct fcntl_args *uap) 396 { 397 398 return (kern_fcntl_freebsd(td, uap->fd, uap->cmd, uap->arg)); 399 } 400 401 int 402 kern_fcntl_freebsd(struct thread *td, int fd, int cmd, long arg) 403 { 404 struct flock fl; 405 struct __oflock ofl; 406 intptr_t arg1; 407 int error, newcmd; 408 409 error = 0; 410 newcmd = cmd; 411 switch (cmd) { 412 case F_OGETLK: 413 case F_OSETLK: 414 case F_OSETLKW: 415 /* 416 * Convert old flock structure to new. 417 */ 418 error = copyin((void *)(intptr_t)arg, &ofl, sizeof(ofl)); 419 fl.l_start = ofl.l_start; 420 fl.l_len = ofl.l_len; 421 fl.l_pid = ofl.l_pid; 422 fl.l_type = ofl.l_type; 423 fl.l_whence = ofl.l_whence; 424 fl.l_sysid = 0; 425 426 switch (cmd) { 427 case F_OGETLK: 428 newcmd = F_GETLK; 429 break; 430 case F_OSETLK: 431 newcmd = F_SETLK; 432 break; 433 case F_OSETLKW: 434 newcmd = F_SETLKW; 435 break; 436 } 437 arg1 = (intptr_t)&fl; 438 break; 439 case F_GETLK: 440 case F_SETLK: 441 case F_SETLKW: 442 case F_SETLK_REMOTE: 443 error = copyin((void *)(intptr_t)arg, &fl, sizeof(fl)); 444 arg1 = (intptr_t)&fl; 445 break; 446 default: 447 arg1 = arg; 448 break; 449 } 450 if (error) 451 return (error); 452 error = kern_fcntl(td, fd, newcmd, arg1); 453 if (error) 454 return (error); 455 if (cmd == F_OGETLK) { 456 ofl.l_start = fl.l_start; 457 ofl.l_len = fl.l_len; 458 ofl.l_pid = fl.l_pid; 459 ofl.l_type = fl.l_type; 460 ofl.l_whence = fl.l_whence; 461 error = copyout(&ofl, (void *)(intptr_t)arg, sizeof(ofl)); 462 } else if (cmd == F_GETLK) { 463 error = copyout(&fl, (void *)(intptr_t)arg, sizeof(fl)); 464 } 465 return (error); 466 } 467 468 int 469 kern_fcntl(struct thread *td, int fd, int cmd, intptr_t arg) 470 { 471 struct filedesc *fdp; 472 struct flock *flp; 473 struct file *fp, *fp2; 474 struct filedescent *fde; 475 struct proc *p; 476 struct vnode *vp; 477 struct mount *mp; 478 int error, flg, seals, tmp; 479 uint64_t bsize; 480 off_t foffset; 481 482 error = 0; 483 flg = F_POSIX; 484 p = td->td_proc; 485 fdp = p->p_fd; 486 487 AUDIT_ARG_FD(cmd); 488 AUDIT_ARG_CMD(cmd); 489 switch (cmd) { 490 case F_DUPFD: 491 tmp = arg; 492 error = kern_dup(td, FDDUP_FCNTL, 0, fd, tmp); 493 break; 494 495 case F_DUPFD_CLOEXEC: 496 tmp = arg; 497 error = kern_dup(td, FDDUP_FCNTL, FDDUP_FLAG_CLOEXEC, fd, tmp); 498 break; 499 500 case F_DUP2FD: 501 tmp = arg; 502 error = kern_dup(td, FDDUP_FIXED, 0, fd, tmp); 503 break; 504 505 case F_DUP2FD_CLOEXEC: 506 tmp = arg; 507 error = kern_dup(td, FDDUP_FIXED, FDDUP_FLAG_CLOEXEC, fd, tmp); 508 break; 509 510 case F_GETFD: 511 error = EBADF; 512 FILEDESC_SLOCK(fdp); 513 fde = fdeget_locked(fdp, fd); 514 if (fde != NULL) { 515 td->td_retval[0] = 516 (fde->fde_flags & UF_EXCLOSE) ? FD_CLOEXEC : 0; 517 error = 0; 518 } 519 FILEDESC_SUNLOCK(fdp); 520 break; 521 522 case F_SETFD: 523 error = EBADF; 524 FILEDESC_XLOCK(fdp); 525 fde = fdeget_locked(fdp, fd); 526 if (fde != NULL) { 527 fde->fde_flags = (fde->fde_flags & ~UF_EXCLOSE) | 528 (arg & FD_CLOEXEC ? UF_EXCLOSE : 0); 529 error = 0; 530 } 531 FILEDESC_XUNLOCK(fdp); 532 break; 533 534 case F_GETFL: 535 error = fget_fcntl(td, fd, &cap_fcntl_rights, F_GETFL, &fp); 536 if (error != 0) 537 break; 538 td->td_retval[0] = OFLAGS(fp->f_flag); 539 fdrop(fp, td); 540 break; 541 542 case F_SETFL: 543 error = fget_fcntl(td, fd, &cap_fcntl_rights, F_SETFL, &fp); 544 if (error != 0) 545 break; 546 do { 547 tmp = flg = fp->f_flag; 548 tmp &= ~FCNTLFLAGS; 549 tmp |= FFLAGS(arg & ~O_ACCMODE) & FCNTLFLAGS; 550 } while(atomic_cmpset_int(&fp->f_flag, flg, tmp) == 0); 551 tmp = fp->f_flag & FNONBLOCK; 552 error = fo_ioctl(fp, FIONBIO, &tmp, td->td_ucred, td); 553 if (error != 0) { 554 fdrop(fp, td); 555 break; 556 } 557 tmp = fp->f_flag & FASYNC; 558 error = fo_ioctl(fp, FIOASYNC, &tmp, td->td_ucred, td); 559 if (error == 0) { 560 fdrop(fp, td); 561 break; 562 } 563 atomic_clear_int(&fp->f_flag, FNONBLOCK); 564 tmp = 0; 565 (void)fo_ioctl(fp, FIONBIO, &tmp, td->td_ucred, td); 566 fdrop(fp, td); 567 break; 568 569 case F_GETOWN: 570 error = fget_fcntl(td, fd, &cap_fcntl_rights, F_GETOWN, &fp); 571 if (error != 0) 572 break; 573 error = fo_ioctl(fp, FIOGETOWN, &tmp, td->td_ucred, td); 574 if (error == 0) 575 td->td_retval[0] = tmp; 576 fdrop(fp, td); 577 break; 578 579 case F_SETOWN: 580 error = fget_fcntl(td, fd, &cap_fcntl_rights, F_SETOWN, &fp); 581 if (error != 0) 582 break; 583 tmp = arg; 584 error = fo_ioctl(fp, FIOSETOWN, &tmp, td->td_ucred, td); 585 fdrop(fp, td); 586 break; 587 588 case F_SETLK_REMOTE: 589 error = priv_check(td, PRIV_NFS_LOCKD); 590 if (error != 0) 591 return (error); 592 flg = F_REMOTE; 593 goto do_setlk; 594 595 case F_SETLKW: 596 flg |= F_WAIT; 597 /* FALLTHROUGH F_SETLK */ 598 599 case F_SETLK: 600 do_setlk: 601 flp = (struct flock *)arg; 602 if ((flg & F_REMOTE) != 0 && flp->l_sysid == 0) { 603 error = EINVAL; 604 break; 605 } 606 607 error = fget_unlocked(fdp, fd, &cap_flock_rights, &fp); 608 if (error != 0) 609 break; 610 if (fp->f_type != DTYPE_VNODE) { 611 error = EBADF; 612 fdrop(fp, td); 613 break; 614 } 615 616 if (flp->l_whence == SEEK_CUR) { 617 foffset = foffset_get(fp); 618 if (foffset < 0 || 619 (flp->l_start > 0 && 620 foffset > OFF_MAX - flp->l_start)) { 621 error = EOVERFLOW; 622 fdrop(fp, td); 623 break; 624 } 625 flp->l_start += foffset; 626 } 627 628 vp = fp->f_vnode; 629 switch (flp->l_type) { 630 case F_RDLCK: 631 if ((fp->f_flag & FREAD) == 0) { 632 error = EBADF; 633 break; 634 } 635 if ((p->p_leader->p_flag & P_ADVLOCK) == 0) { 636 PROC_LOCK(p->p_leader); 637 p->p_leader->p_flag |= P_ADVLOCK; 638 PROC_UNLOCK(p->p_leader); 639 } 640 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_SETLK, 641 flp, flg); 642 break; 643 case F_WRLCK: 644 if ((fp->f_flag & FWRITE) == 0) { 645 error = EBADF; 646 break; 647 } 648 if ((p->p_leader->p_flag & P_ADVLOCK) == 0) { 649 PROC_LOCK(p->p_leader); 650 p->p_leader->p_flag |= P_ADVLOCK; 651 PROC_UNLOCK(p->p_leader); 652 } 653 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_SETLK, 654 flp, flg); 655 break; 656 case F_UNLCK: 657 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_UNLCK, 658 flp, flg); 659 break; 660 case F_UNLCKSYS: 661 if (flg != F_REMOTE) { 662 error = EINVAL; 663 break; 664 } 665 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, 666 F_UNLCKSYS, flp, flg); 667 break; 668 default: 669 error = EINVAL; 670 break; 671 } 672 if (error != 0 || flp->l_type == F_UNLCK || 673 flp->l_type == F_UNLCKSYS) { 674 fdrop(fp, td); 675 break; 676 } 677 678 /* 679 * Check for a race with close. 680 * 681 * The vnode is now advisory locked (or unlocked, but this case 682 * is not really important) as the caller requested. 683 * We had to drop the filedesc lock, so we need to recheck if 684 * the descriptor is still valid, because if it was closed 685 * in the meantime we need to remove advisory lock from the 686 * vnode - close on any descriptor leading to an advisory 687 * locked vnode, removes that lock. 688 * We will return 0 on purpose in that case, as the result of 689 * successful advisory lock might have been externally visible 690 * already. This is fine - effectively we pretend to the caller 691 * that the closing thread was a bit slower and that the 692 * advisory lock succeeded before the close. 693 */ 694 error = fget_unlocked(fdp, fd, &cap_no_rights, &fp2); 695 if (error != 0) { 696 fdrop(fp, td); 697 break; 698 } 699 if (fp != fp2) { 700 flp->l_whence = SEEK_SET; 701 flp->l_start = 0; 702 flp->l_len = 0; 703 flp->l_type = F_UNLCK; 704 (void) VOP_ADVLOCK(vp, (caddr_t)p->p_leader, 705 F_UNLCK, flp, F_POSIX); 706 } 707 fdrop(fp, td); 708 fdrop(fp2, td); 709 break; 710 711 case F_GETLK: 712 error = fget_unlocked(fdp, fd, &cap_flock_rights, &fp); 713 if (error != 0) 714 break; 715 if (fp->f_type != DTYPE_VNODE) { 716 error = EBADF; 717 fdrop(fp, td); 718 break; 719 } 720 flp = (struct flock *)arg; 721 if (flp->l_type != F_RDLCK && flp->l_type != F_WRLCK && 722 flp->l_type != F_UNLCK) { 723 error = EINVAL; 724 fdrop(fp, td); 725 break; 726 } 727 if (flp->l_whence == SEEK_CUR) { 728 foffset = foffset_get(fp); 729 if ((flp->l_start > 0 && 730 foffset > OFF_MAX - flp->l_start) || 731 (flp->l_start < 0 && 732 foffset < OFF_MIN - flp->l_start)) { 733 error = EOVERFLOW; 734 fdrop(fp, td); 735 break; 736 } 737 flp->l_start += foffset; 738 } 739 vp = fp->f_vnode; 740 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_GETLK, flp, 741 F_POSIX); 742 fdrop(fp, td); 743 break; 744 745 case F_ADD_SEALS: 746 error = fget_unlocked(fdp, fd, &cap_no_rights, &fp); 747 if (error != 0) 748 break; 749 error = fo_add_seals(fp, arg); 750 fdrop(fp, td); 751 break; 752 753 case F_GET_SEALS: 754 error = fget_unlocked(fdp, fd, &cap_no_rights, &fp); 755 if (error != 0) 756 break; 757 if (fo_get_seals(fp, &seals) == 0) 758 td->td_retval[0] = seals; 759 else 760 error = EINVAL; 761 fdrop(fp, td); 762 break; 763 764 case F_RDAHEAD: 765 arg = arg ? 128 * 1024: 0; 766 /* FALLTHROUGH */ 767 case F_READAHEAD: 768 error = fget_unlocked(fdp, fd, &cap_no_rights, &fp); 769 if (error != 0) 770 break; 771 if (fp->f_type != DTYPE_VNODE) { 772 fdrop(fp, td); 773 error = EBADF; 774 break; 775 } 776 vp = fp->f_vnode; 777 if (vp->v_type != VREG) { 778 fdrop(fp, td); 779 error = ENOTTY; 780 break; 781 } 782 783 /* 784 * Exclusive lock synchronizes against f_seqcount reads and 785 * writes in sequential_heuristic(). 786 */ 787 error = vn_lock(vp, LK_EXCLUSIVE); 788 if (error != 0) { 789 fdrop(fp, td); 790 break; 791 } 792 if (arg >= 0) { 793 bsize = fp->f_vnode->v_mount->mnt_stat.f_iosize; 794 arg = MIN(arg, INT_MAX - bsize + 1); 795 fp->f_seqcount = MIN(IO_SEQMAX, 796 (arg + bsize - 1) / bsize); 797 atomic_set_int(&fp->f_flag, FRDAHEAD); 798 } else { 799 atomic_clear_int(&fp->f_flag, FRDAHEAD); 800 } 801 VOP_UNLOCK(vp); 802 fdrop(fp, td); 803 break; 804 805 case F_ISUNIONSTACK: 806 /* 807 * Check if the vnode is part of a union stack (either the 808 * "union" flag from mount(2) or unionfs). 809 * 810 * Prior to introduction of this op libc's readdir would call 811 * fstatfs(2), in effect unnecessarily copying kilobytes of 812 * data just to check fs name and a mount flag. 813 * 814 * Fixing the code to handle everything in the kernel instead 815 * is a non-trivial endeavor and has low priority, thus this 816 * horrible kludge facilitates the current behavior in a much 817 * cheaper manner until someone(tm) sorts this out. 818 */ 819 error = fget_unlocked(fdp, fd, &cap_no_rights, &fp); 820 if (error != 0) 821 break; 822 if (fp->f_type != DTYPE_VNODE) { 823 fdrop(fp, td); 824 error = EBADF; 825 break; 826 } 827 vp = fp->f_vnode; 828 /* 829 * Since we don't prevent dooming the vnode even non-null mp 830 * found can become immediately stale. This is tolerable since 831 * mount points are type-stable (providing safe memory access) 832 * and any vfs op on this vnode going forward will return an 833 * error (meaning return value in this case is meaningless). 834 */ 835 mp = atomic_load_ptr(&vp->v_mount); 836 if (__predict_false(mp == NULL)) { 837 fdrop(fp, td); 838 error = EBADF; 839 break; 840 } 841 td->td_retval[0] = 0; 842 if (mp->mnt_kern_flag & MNTK_UNIONFS || 843 mp->mnt_flag & MNT_UNION) 844 td->td_retval[0] = 1; 845 fdrop(fp, td); 846 break; 847 848 default: 849 error = EINVAL; 850 break; 851 } 852 return (error); 853 } 854 855 static int 856 getmaxfd(struct thread *td) 857 { 858 859 return (min((int)lim_cur(td, RLIMIT_NOFILE), maxfilesperproc)); 860 } 861 862 /* 863 * Common code for dup, dup2, fcntl(F_DUPFD) and fcntl(F_DUP2FD). 864 */ 865 int 866 kern_dup(struct thread *td, u_int mode, int flags, int old, int new) 867 { 868 struct filedesc *fdp; 869 struct filedescent *oldfde, *newfde; 870 struct proc *p; 871 struct file *delfp; 872 u_long *oioctls, *nioctls; 873 int error, maxfd; 874 875 p = td->td_proc; 876 fdp = p->p_fd; 877 oioctls = NULL; 878 879 MPASS((flags & ~(FDDUP_FLAG_CLOEXEC)) == 0); 880 MPASS(mode < FDDUP_LASTMODE); 881 882 AUDIT_ARG_FD(old); 883 /* XXXRW: if (flags & FDDUP_FIXED) AUDIT_ARG_FD2(new); */ 884 885 /* 886 * Verify we have a valid descriptor to dup from and possibly to 887 * dup to. Unlike dup() and dup2(), fcntl()'s F_DUPFD should 888 * return EINVAL when the new descriptor is out of bounds. 889 */ 890 if (old < 0) 891 return (EBADF); 892 if (new < 0) 893 return (mode == FDDUP_FCNTL ? EINVAL : EBADF); 894 maxfd = getmaxfd(td); 895 if (new >= maxfd) 896 return (mode == FDDUP_FCNTL ? EINVAL : EBADF); 897 898 error = EBADF; 899 FILEDESC_XLOCK(fdp); 900 if (fget_locked(fdp, old) == NULL) 901 goto unlock; 902 if ((mode == FDDUP_FIXED || mode == FDDUP_MUSTREPLACE) && old == new) { 903 td->td_retval[0] = new; 904 if (flags & FDDUP_FLAG_CLOEXEC) 905 fdp->fd_ofiles[new].fde_flags |= UF_EXCLOSE; 906 error = 0; 907 goto unlock; 908 } 909 910 oldfde = &fdp->fd_ofiles[old]; 911 if (!fhold(oldfde->fde_file)) 912 goto unlock; 913 914 /* 915 * If the caller specified a file descriptor, make sure the file 916 * table is large enough to hold it, and grab it. Otherwise, just 917 * allocate a new descriptor the usual way. 918 */ 919 switch (mode) { 920 case FDDUP_NORMAL: 921 case FDDUP_FCNTL: 922 if ((error = fdalloc(td, new, &new)) != 0) { 923 fdrop(oldfde->fde_file, td); 924 goto unlock; 925 } 926 break; 927 case FDDUP_MUSTREPLACE: 928 /* Target file descriptor must exist. */ 929 if (fget_locked(fdp, new) == NULL) { 930 fdrop(oldfde->fde_file, td); 931 goto unlock; 932 } 933 break; 934 case FDDUP_FIXED: 935 if (new >= fdp->fd_nfiles) { 936 /* 937 * The resource limits are here instead of e.g. 938 * fdalloc(), because the file descriptor table may be 939 * shared between processes, so we can't really use 940 * racct_add()/racct_sub(). Instead of counting the 941 * number of actually allocated descriptors, just put 942 * the limit on the size of the file descriptor table. 943 */ 944 #ifdef RACCT 945 if (RACCT_ENABLED()) { 946 error = racct_set_unlocked(p, RACCT_NOFILE, new + 1); 947 if (error != 0) { 948 error = EMFILE; 949 fdrop(oldfde->fde_file, td); 950 goto unlock; 951 } 952 } 953 #endif 954 fdgrowtable_exp(fdp, new + 1); 955 } 956 if (!fdisused(fdp, new)) 957 fdused(fdp, new); 958 break; 959 default: 960 KASSERT(0, ("%s unsupported mode %d", __func__, mode)); 961 } 962 963 KASSERT(old != new, ("new fd is same as old")); 964 965 newfde = &fdp->fd_ofiles[new]; 966 delfp = newfde->fde_file; 967 968 oioctls = filecaps_free_prep(&newfde->fde_caps); 969 nioctls = filecaps_copy_prep(&oldfde->fde_caps); 970 971 /* 972 * Duplicate the source descriptor. 973 */ 974 #ifdef CAPABILITIES 975 seqc_write_begin(&newfde->fde_seqc); 976 #endif 977 memcpy(newfde, oldfde, fde_change_size); 978 filecaps_copy_finish(&oldfde->fde_caps, &newfde->fde_caps, 979 nioctls); 980 if ((flags & FDDUP_FLAG_CLOEXEC) != 0) 981 newfde->fde_flags = oldfde->fde_flags | UF_EXCLOSE; 982 else 983 newfde->fde_flags = oldfde->fde_flags & ~UF_EXCLOSE; 984 #ifdef CAPABILITIES 985 seqc_write_end(&newfde->fde_seqc); 986 #endif 987 td->td_retval[0] = new; 988 989 error = 0; 990 991 if (delfp != NULL) { 992 (void) closefp(fdp, new, delfp, td, 1); 993 FILEDESC_UNLOCK_ASSERT(fdp); 994 } else { 995 unlock: 996 FILEDESC_XUNLOCK(fdp); 997 } 998 999 filecaps_free_finish(oioctls); 1000 return (error); 1001 } 1002 1003 /* 1004 * If sigio is on the list associated with a process or process group, 1005 * disable signalling from the device, remove sigio from the list and 1006 * free sigio. 1007 */ 1008 void 1009 funsetown(struct sigio **sigiop) 1010 { 1011 struct sigio *sigio; 1012 1013 if (*sigiop == NULL) 1014 return; 1015 SIGIO_LOCK(); 1016 sigio = *sigiop; 1017 if (sigio == NULL) { 1018 SIGIO_UNLOCK(); 1019 return; 1020 } 1021 *(sigio->sio_myref) = NULL; 1022 if ((sigio)->sio_pgid < 0) { 1023 struct pgrp *pg = (sigio)->sio_pgrp; 1024 PGRP_LOCK(pg); 1025 SLIST_REMOVE(&sigio->sio_pgrp->pg_sigiolst, sigio, 1026 sigio, sio_pgsigio); 1027 PGRP_UNLOCK(pg); 1028 } else { 1029 struct proc *p = (sigio)->sio_proc; 1030 PROC_LOCK(p); 1031 SLIST_REMOVE(&sigio->sio_proc->p_sigiolst, sigio, 1032 sigio, sio_pgsigio); 1033 PROC_UNLOCK(p); 1034 } 1035 SIGIO_UNLOCK(); 1036 crfree(sigio->sio_ucred); 1037 free(sigio, M_SIGIO); 1038 } 1039 1040 /* 1041 * Free a list of sigio structures. 1042 * We only need to lock the SIGIO_LOCK because we have made ourselves 1043 * inaccessible to callers of fsetown and therefore do not need to lock 1044 * the proc or pgrp struct for the list manipulation. 1045 */ 1046 void 1047 funsetownlst(struct sigiolst *sigiolst) 1048 { 1049 struct proc *p; 1050 struct pgrp *pg; 1051 struct sigio *sigio; 1052 1053 sigio = SLIST_FIRST(sigiolst); 1054 if (sigio == NULL) 1055 return; 1056 p = NULL; 1057 pg = NULL; 1058 1059 /* 1060 * Every entry of the list should belong 1061 * to a single proc or pgrp. 1062 */ 1063 if (sigio->sio_pgid < 0) { 1064 pg = sigio->sio_pgrp; 1065 PGRP_LOCK_ASSERT(pg, MA_NOTOWNED); 1066 } else /* if (sigio->sio_pgid > 0) */ { 1067 p = sigio->sio_proc; 1068 PROC_LOCK_ASSERT(p, MA_NOTOWNED); 1069 } 1070 1071 SIGIO_LOCK(); 1072 while ((sigio = SLIST_FIRST(sigiolst)) != NULL) { 1073 *(sigio->sio_myref) = NULL; 1074 if (pg != NULL) { 1075 KASSERT(sigio->sio_pgid < 0, 1076 ("Proc sigio in pgrp sigio list")); 1077 KASSERT(sigio->sio_pgrp == pg, 1078 ("Bogus pgrp in sigio list")); 1079 PGRP_LOCK(pg); 1080 SLIST_REMOVE(&pg->pg_sigiolst, sigio, sigio, 1081 sio_pgsigio); 1082 PGRP_UNLOCK(pg); 1083 } else /* if (p != NULL) */ { 1084 KASSERT(sigio->sio_pgid > 0, 1085 ("Pgrp sigio in proc sigio list")); 1086 KASSERT(sigio->sio_proc == p, 1087 ("Bogus proc in sigio list")); 1088 PROC_LOCK(p); 1089 SLIST_REMOVE(&p->p_sigiolst, sigio, sigio, 1090 sio_pgsigio); 1091 PROC_UNLOCK(p); 1092 } 1093 SIGIO_UNLOCK(); 1094 crfree(sigio->sio_ucred); 1095 free(sigio, M_SIGIO); 1096 SIGIO_LOCK(); 1097 } 1098 SIGIO_UNLOCK(); 1099 } 1100 1101 /* 1102 * This is common code for FIOSETOWN ioctl called by fcntl(fd, F_SETOWN, arg). 1103 * 1104 * After permission checking, add a sigio structure to the sigio list for 1105 * the process or process group. 1106 */ 1107 int 1108 fsetown(pid_t pgid, struct sigio **sigiop) 1109 { 1110 struct proc *proc; 1111 struct pgrp *pgrp; 1112 struct sigio *sigio; 1113 int ret; 1114 1115 if (pgid == 0) { 1116 funsetown(sigiop); 1117 return (0); 1118 } 1119 1120 ret = 0; 1121 1122 /* Allocate and fill in the new sigio out of locks. */ 1123 sigio = malloc(sizeof(struct sigio), M_SIGIO, M_WAITOK); 1124 sigio->sio_pgid = pgid; 1125 sigio->sio_ucred = crhold(curthread->td_ucred); 1126 sigio->sio_myref = sigiop; 1127 1128 sx_slock(&proctree_lock); 1129 if (pgid > 0) { 1130 proc = pfind(pgid); 1131 if (proc == NULL) { 1132 ret = ESRCH; 1133 goto fail; 1134 } 1135 1136 /* 1137 * Policy - Don't allow a process to FSETOWN a process 1138 * in another session. 1139 * 1140 * Remove this test to allow maximum flexibility or 1141 * restrict FSETOWN to the current process or process 1142 * group for maximum safety. 1143 */ 1144 PROC_UNLOCK(proc); 1145 if (proc->p_session != curthread->td_proc->p_session) { 1146 ret = EPERM; 1147 goto fail; 1148 } 1149 1150 pgrp = NULL; 1151 } else /* if (pgid < 0) */ { 1152 pgrp = pgfind(-pgid); 1153 if (pgrp == NULL) { 1154 ret = ESRCH; 1155 goto fail; 1156 } 1157 PGRP_UNLOCK(pgrp); 1158 1159 /* 1160 * Policy - Don't allow a process to FSETOWN a process 1161 * in another session. 1162 * 1163 * Remove this test to allow maximum flexibility or 1164 * restrict FSETOWN to the current process or process 1165 * group for maximum safety. 1166 */ 1167 if (pgrp->pg_session != curthread->td_proc->p_session) { 1168 ret = EPERM; 1169 goto fail; 1170 } 1171 1172 proc = NULL; 1173 } 1174 funsetown(sigiop); 1175 if (pgid > 0) { 1176 PROC_LOCK(proc); 1177 /* 1178 * Since funsetownlst() is called without the proctree 1179 * locked, we need to check for P_WEXIT. 1180 * XXX: is ESRCH correct? 1181 */ 1182 if ((proc->p_flag & P_WEXIT) != 0) { 1183 PROC_UNLOCK(proc); 1184 ret = ESRCH; 1185 goto fail; 1186 } 1187 SLIST_INSERT_HEAD(&proc->p_sigiolst, sigio, sio_pgsigio); 1188 sigio->sio_proc = proc; 1189 PROC_UNLOCK(proc); 1190 } else { 1191 PGRP_LOCK(pgrp); 1192 SLIST_INSERT_HEAD(&pgrp->pg_sigiolst, sigio, sio_pgsigio); 1193 sigio->sio_pgrp = pgrp; 1194 PGRP_UNLOCK(pgrp); 1195 } 1196 sx_sunlock(&proctree_lock); 1197 SIGIO_LOCK(); 1198 *sigiop = sigio; 1199 SIGIO_UNLOCK(); 1200 return (0); 1201 1202 fail: 1203 sx_sunlock(&proctree_lock); 1204 crfree(sigio->sio_ucred); 1205 free(sigio, M_SIGIO); 1206 return (ret); 1207 } 1208 1209 /* 1210 * This is common code for FIOGETOWN ioctl called by fcntl(fd, F_GETOWN, arg). 1211 */ 1212 pid_t 1213 fgetown(struct sigio **sigiop) 1214 { 1215 pid_t pgid; 1216 1217 SIGIO_LOCK(); 1218 pgid = (*sigiop != NULL) ? (*sigiop)->sio_pgid : 0; 1219 SIGIO_UNLOCK(); 1220 return (pgid); 1221 } 1222 1223 /* 1224 * Function drops the filedesc lock on return. 1225 */ 1226 static int 1227 closefp(struct filedesc *fdp, int fd, struct file *fp, struct thread *td, 1228 int holdleaders) 1229 { 1230 int error; 1231 1232 FILEDESC_XLOCK_ASSERT(fdp); 1233 1234 if (holdleaders) { 1235 if (td->td_proc->p_fdtol != NULL) { 1236 /* 1237 * Ask fdfree() to sleep to ensure that all relevant 1238 * process leaders can be traversed in closef(). 1239 */ 1240 fdp->fd_holdleaderscount++; 1241 } else { 1242 holdleaders = 0; 1243 } 1244 } 1245 1246 /* 1247 * We now hold the fp reference that used to be owned by the 1248 * descriptor array. We have to unlock the FILEDESC *AFTER* 1249 * knote_fdclose to prevent a race of the fd getting opened, a knote 1250 * added, and deleteing a knote for the new fd. 1251 */ 1252 if (__predict_false(!TAILQ_EMPTY(&fdp->fd_kqlist))) 1253 knote_fdclose(td, fd); 1254 1255 /* 1256 * We need to notify mqueue if the object is of type mqueue. 1257 */ 1258 if (__predict_false(fp->f_type == DTYPE_MQUEUE)) 1259 mq_fdclose(td, fd, fp); 1260 FILEDESC_XUNLOCK(fdp); 1261 1262 error = closef(fp, td); 1263 if (holdleaders) { 1264 FILEDESC_XLOCK(fdp); 1265 fdp->fd_holdleaderscount--; 1266 if (fdp->fd_holdleaderscount == 0 && 1267 fdp->fd_holdleaderswakeup != 0) { 1268 fdp->fd_holdleaderswakeup = 0; 1269 wakeup(&fdp->fd_holdleaderscount); 1270 } 1271 FILEDESC_XUNLOCK(fdp); 1272 } 1273 return (error); 1274 } 1275 1276 /* 1277 * Close a file descriptor. 1278 */ 1279 #ifndef _SYS_SYSPROTO_H_ 1280 struct close_args { 1281 int fd; 1282 }; 1283 #endif 1284 /* ARGSUSED */ 1285 int 1286 sys_close(struct thread *td, struct close_args *uap) 1287 { 1288 1289 return (kern_close(td, uap->fd)); 1290 } 1291 1292 int 1293 kern_close(struct thread *td, int fd) 1294 { 1295 struct filedesc *fdp; 1296 struct file *fp; 1297 1298 fdp = td->td_proc->p_fd; 1299 1300 AUDIT_SYSCLOSE(td, fd); 1301 1302 FILEDESC_XLOCK(fdp); 1303 if ((fp = fget_locked(fdp, fd)) == NULL) { 1304 FILEDESC_XUNLOCK(fdp); 1305 return (EBADF); 1306 } 1307 fdfree(fdp, fd); 1308 1309 /* closefp() drops the FILEDESC lock for us. */ 1310 return (closefp(fdp, fd, fp, td, 1)); 1311 } 1312 1313 /* 1314 * Close open file descriptors. 1315 */ 1316 #ifndef _SYS_SYSPROTO_H_ 1317 struct closefrom_args { 1318 int lowfd; 1319 }; 1320 #endif 1321 /* ARGSUSED */ 1322 int 1323 sys_closefrom(struct thread *td, struct closefrom_args *uap) 1324 { 1325 struct filedesc *fdp; 1326 int fd; 1327 1328 fdp = td->td_proc->p_fd; 1329 AUDIT_ARG_FD(uap->lowfd); 1330 1331 /* 1332 * Treat negative starting file descriptor values identical to 1333 * closefrom(0) which closes all files. 1334 */ 1335 if (uap->lowfd < 0) 1336 uap->lowfd = 0; 1337 FILEDESC_SLOCK(fdp); 1338 for (fd = uap->lowfd; fd <= fdp->fd_lastfile; fd++) { 1339 if (fdp->fd_ofiles[fd].fde_file != NULL) { 1340 FILEDESC_SUNLOCK(fdp); 1341 (void)kern_close(td, fd); 1342 FILEDESC_SLOCK(fdp); 1343 } 1344 } 1345 FILEDESC_SUNLOCK(fdp); 1346 return (0); 1347 } 1348 1349 #if defined(COMPAT_43) 1350 /* 1351 * Return status information about a file descriptor. 1352 */ 1353 #ifndef _SYS_SYSPROTO_H_ 1354 struct ofstat_args { 1355 int fd; 1356 struct ostat *sb; 1357 }; 1358 #endif 1359 /* ARGSUSED */ 1360 int 1361 ofstat(struct thread *td, struct ofstat_args *uap) 1362 { 1363 struct ostat oub; 1364 struct stat ub; 1365 int error; 1366 1367 error = kern_fstat(td, uap->fd, &ub); 1368 if (error == 0) { 1369 cvtstat(&ub, &oub); 1370 error = copyout(&oub, uap->sb, sizeof(oub)); 1371 } 1372 return (error); 1373 } 1374 #endif /* COMPAT_43 */ 1375 1376 #if defined(COMPAT_FREEBSD11) 1377 int 1378 freebsd11_fstat(struct thread *td, struct freebsd11_fstat_args *uap) 1379 { 1380 struct stat sb; 1381 struct freebsd11_stat osb; 1382 int error; 1383 1384 error = kern_fstat(td, uap->fd, &sb); 1385 if (error != 0) 1386 return (error); 1387 error = freebsd11_cvtstat(&sb, &osb); 1388 if (error == 0) 1389 error = copyout(&osb, uap->sb, sizeof(osb)); 1390 return (error); 1391 } 1392 #endif /* COMPAT_FREEBSD11 */ 1393 1394 /* 1395 * Return status information about a file descriptor. 1396 */ 1397 #ifndef _SYS_SYSPROTO_H_ 1398 struct fstat_args { 1399 int fd; 1400 struct stat *sb; 1401 }; 1402 #endif 1403 /* ARGSUSED */ 1404 int 1405 sys_fstat(struct thread *td, struct fstat_args *uap) 1406 { 1407 struct stat ub; 1408 int error; 1409 1410 error = kern_fstat(td, uap->fd, &ub); 1411 if (error == 0) 1412 error = copyout(&ub, uap->sb, sizeof(ub)); 1413 return (error); 1414 } 1415 1416 int 1417 kern_fstat(struct thread *td, int fd, struct stat *sbp) 1418 { 1419 struct file *fp; 1420 int error; 1421 1422 AUDIT_ARG_FD(fd); 1423 1424 error = fget(td, fd, &cap_fstat_rights, &fp); 1425 if (__predict_false(error != 0)) 1426 return (error); 1427 1428 AUDIT_ARG_FILE(td->td_proc, fp); 1429 1430 error = fo_stat(fp, sbp, td->td_ucred, td); 1431 fdrop(fp, td); 1432 #ifdef __STAT_TIME_T_EXT 1433 sbp->st_atim_ext = 0; 1434 sbp->st_mtim_ext = 0; 1435 sbp->st_ctim_ext = 0; 1436 sbp->st_btim_ext = 0; 1437 #endif 1438 #ifdef KTRACE 1439 if (KTRPOINT(td, KTR_STRUCT)) 1440 ktrstat_error(sbp, error); 1441 #endif 1442 return (error); 1443 } 1444 1445 #if defined(COMPAT_FREEBSD11) 1446 /* 1447 * Return status information about a file descriptor. 1448 */ 1449 #ifndef _SYS_SYSPROTO_H_ 1450 struct freebsd11_nfstat_args { 1451 int fd; 1452 struct nstat *sb; 1453 }; 1454 #endif 1455 /* ARGSUSED */ 1456 int 1457 freebsd11_nfstat(struct thread *td, struct freebsd11_nfstat_args *uap) 1458 { 1459 struct nstat nub; 1460 struct stat ub; 1461 int error; 1462 1463 error = kern_fstat(td, uap->fd, &ub); 1464 if (error == 0) { 1465 freebsd11_cvtnstat(&ub, &nub); 1466 error = copyout(&nub, uap->sb, sizeof(nub)); 1467 } 1468 return (error); 1469 } 1470 #endif /* COMPAT_FREEBSD11 */ 1471 1472 /* 1473 * Return pathconf information about a file descriptor. 1474 */ 1475 #ifndef _SYS_SYSPROTO_H_ 1476 struct fpathconf_args { 1477 int fd; 1478 int name; 1479 }; 1480 #endif 1481 /* ARGSUSED */ 1482 int 1483 sys_fpathconf(struct thread *td, struct fpathconf_args *uap) 1484 { 1485 long value; 1486 int error; 1487 1488 error = kern_fpathconf(td, uap->fd, uap->name, &value); 1489 if (error == 0) 1490 td->td_retval[0] = value; 1491 return (error); 1492 } 1493 1494 int 1495 kern_fpathconf(struct thread *td, int fd, int name, long *valuep) 1496 { 1497 struct file *fp; 1498 struct vnode *vp; 1499 int error; 1500 1501 error = fget(td, fd, &cap_fpathconf_rights, &fp); 1502 if (error != 0) 1503 return (error); 1504 1505 if (name == _PC_ASYNC_IO) { 1506 *valuep = _POSIX_ASYNCHRONOUS_IO; 1507 goto out; 1508 } 1509 vp = fp->f_vnode; 1510 if (vp != NULL) { 1511 vn_lock(vp, LK_SHARED | LK_RETRY); 1512 error = VOP_PATHCONF(vp, name, valuep); 1513 VOP_UNLOCK(vp); 1514 } else if (fp->f_type == DTYPE_PIPE || fp->f_type == DTYPE_SOCKET) { 1515 if (name != _PC_PIPE_BUF) { 1516 error = EINVAL; 1517 } else { 1518 *valuep = PIPE_BUF; 1519 error = 0; 1520 } 1521 } else { 1522 error = EOPNOTSUPP; 1523 } 1524 out: 1525 fdrop(fp, td); 1526 return (error); 1527 } 1528 1529 /* 1530 * Copy filecaps structure allocating memory for ioctls array if needed. 1531 * 1532 * The last parameter indicates whether the fdtable is locked. If it is not and 1533 * ioctls are encountered, copying fails and the caller must lock the table. 1534 * 1535 * Note that if the table was not locked, the caller has to check the relevant 1536 * sequence counter to determine whether the operation was successful. 1537 */ 1538 bool 1539 filecaps_copy(const struct filecaps *src, struct filecaps *dst, bool locked) 1540 { 1541 size_t size; 1542 1543 if (src->fc_ioctls != NULL && !locked) 1544 return (false); 1545 memcpy(dst, src, sizeof(*src)); 1546 if (src->fc_ioctls == NULL) 1547 return (true); 1548 1549 KASSERT(src->fc_nioctls > 0, 1550 ("fc_ioctls != NULL, but fc_nioctls=%hd", src->fc_nioctls)); 1551 1552 size = sizeof(src->fc_ioctls[0]) * src->fc_nioctls; 1553 dst->fc_ioctls = malloc(size, M_FILECAPS, M_WAITOK); 1554 memcpy(dst->fc_ioctls, src->fc_ioctls, size); 1555 return (true); 1556 } 1557 1558 static u_long * 1559 filecaps_copy_prep(const struct filecaps *src) 1560 { 1561 u_long *ioctls; 1562 size_t size; 1563 1564 if (__predict_true(src->fc_ioctls == NULL)) 1565 return (NULL); 1566 1567 KASSERT(src->fc_nioctls > 0, 1568 ("fc_ioctls != NULL, but fc_nioctls=%hd", src->fc_nioctls)); 1569 1570 size = sizeof(src->fc_ioctls[0]) * src->fc_nioctls; 1571 ioctls = malloc(size, M_FILECAPS, M_WAITOK); 1572 return (ioctls); 1573 } 1574 1575 static void 1576 filecaps_copy_finish(const struct filecaps *src, struct filecaps *dst, 1577 u_long *ioctls) 1578 { 1579 size_t size; 1580 1581 *dst = *src; 1582 if (__predict_true(src->fc_ioctls == NULL)) { 1583 MPASS(ioctls == NULL); 1584 return; 1585 } 1586 1587 size = sizeof(src->fc_ioctls[0]) * src->fc_nioctls; 1588 dst->fc_ioctls = ioctls; 1589 bcopy(src->fc_ioctls, dst->fc_ioctls, size); 1590 } 1591 1592 /* 1593 * Move filecaps structure to the new place and clear the old place. 1594 */ 1595 void 1596 filecaps_move(struct filecaps *src, struct filecaps *dst) 1597 { 1598 1599 *dst = *src; 1600 bzero(src, sizeof(*src)); 1601 } 1602 1603 /* 1604 * Fill the given filecaps structure with full rights. 1605 */ 1606 static void 1607 filecaps_fill(struct filecaps *fcaps) 1608 { 1609 1610 CAP_ALL(&fcaps->fc_rights); 1611 fcaps->fc_ioctls = NULL; 1612 fcaps->fc_nioctls = -1; 1613 fcaps->fc_fcntls = CAP_FCNTL_ALL; 1614 } 1615 1616 /* 1617 * Free memory allocated within filecaps structure. 1618 */ 1619 void 1620 filecaps_free(struct filecaps *fcaps) 1621 { 1622 1623 free(fcaps->fc_ioctls, M_FILECAPS); 1624 bzero(fcaps, sizeof(*fcaps)); 1625 } 1626 1627 static u_long * 1628 filecaps_free_prep(struct filecaps *fcaps) 1629 { 1630 u_long *ioctls; 1631 1632 ioctls = fcaps->fc_ioctls; 1633 bzero(fcaps, sizeof(*fcaps)); 1634 return (ioctls); 1635 } 1636 1637 static void 1638 filecaps_free_finish(u_long *ioctls) 1639 { 1640 1641 free(ioctls, M_FILECAPS); 1642 } 1643 1644 /* 1645 * Validate the given filecaps structure. 1646 */ 1647 static void 1648 filecaps_validate(const struct filecaps *fcaps, const char *func) 1649 { 1650 1651 KASSERT(cap_rights_is_valid(&fcaps->fc_rights), 1652 ("%s: invalid rights", func)); 1653 KASSERT((fcaps->fc_fcntls & ~CAP_FCNTL_ALL) == 0, 1654 ("%s: invalid fcntls", func)); 1655 KASSERT(fcaps->fc_fcntls == 0 || 1656 cap_rights_is_set(&fcaps->fc_rights, CAP_FCNTL), 1657 ("%s: fcntls without CAP_FCNTL", func)); 1658 KASSERT(fcaps->fc_ioctls != NULL ? fcaps->fc_nioctls > 0 : 1659 (fcaps->fc_nioctls == -1 || fcaps->fc_nioctls == 0), 1660 ("%s: invalid ioctls", func)); 1661 KASSERT(fcaps->fc_nioctls == 0 || 1662 cap_rights_is_set(&fcaps->fc_rights, CAP_IOCTL), 1663 ("%s: ioctls without CAP_IOCTL", func)); 1664 } 1665 1666 static void 1667 fdgrowtable_exp(struct filedesc *fdp, int nfd) 1668 { 1669 int nfd1; 1670 1671 FILEDESC_XLOCK_ASSERT(fdp); 1672 1673 nfd1 = fdp->fd_nfiles * 2; 1674 if (nfd1 < nfd) 1675 nfd1 = nfd; 1676 fdgrowtable(fdp, nfd1); 1677 } 1678 1679 /* 1680 * Grow the file table to accommodate (at least) nfd descriptors. 1681 */ 1682 static void 1683 fdgrowtable(struct filedesc *fdp, int nfd) 1684 { 1685 struct filedesc0 *fdp0; 1686 struct freetable *ft; 1687 struct fdescenttbl *ntable; 1688 struct fdescenttbl *otable; 1689 int nnfiles, onfiles; 1690 NDSLOTTYPE *nmap, *omap; 1691 1692 /* 1693 * If lastfile is -1 this struct filedesc was just allocated and we are 1694 * growing it to accommodate for the one we are going to copy from. There 1695 * is no need to have a lock on this one as it's not visible to anyone. 1696 */ 1697 if (fdp->fd_lastfile != -1) 1698 FILEDESC_XLOCK_ASSERT(fdp); 1699 1700 KASSERT(fdp->fd_nfiles > 0, ("zero-length file table")); 1701 1702 /* save old values */ 1703 onfiles = fdp->fd_nfiles; 1704 otable = fdp->fd_files; 1705 omap = fdp->fd_map; 1706 1707 /* compute the size of the new table */ 1708 nnfiles = NDSLOTS(nfd) * NDENTRIES; /* round up */ 1709 if (nnfiles <= onfiles) 1710 /* the table is already large enough */ 1711 return; 1712 1713 /* 1714 * Allocate a new table. We need enough space for the number of 1715 * entries, file entries themselves and the struct freetable we will use 1716 * when we decommission the table and place it on the freelist. 1717 * We place the struct freetable in the middle so we don't have 1718 * to worry about padding. 1719 */ 1720 ntable = malloc(offsetof(struct fdescenttbl, fdt_ofiles) + 1721 nnfiles * sizeof(ntable->fdt_ofiles[0]) + 1722 sizeof(struct freetable), 1723 M_FILEDESC, M_ZERO | M_WAITOK); 1724 /* copy the old data */ 1725 ntable->fdt_nfiles = nnfiles; 1726 memcpy(ntable->fdt_ofiles, otable->fdt_ofiles, 1727 onfiles * sizeof(ntable->fdt_ofiles[0])); 1728 1729 /* 1730 * Allocate a new map only if the old is not large enough. It will 1731 * grow at a slower rate than the table as it can map more 1732 * entries than the table can hold. 1733 */ 1734 if (NDSLOTS(nnfiles) > NDSLOTS(onfiles)) { 1735 nmap = malloc(NDSLOTS(nnfiles) * NDSLOTSIZE, M_FILEDESC, 1736 M_ZERO | M_WAITOK); 1737 /* copy over the old data and update the pointer */ 1738 memcpy(nmap, omap, NDSLOTS(onfiles) * sizeof(*omap)); 1739 fdp->fd_map = nmap; 1740 } 1741 1742 /* 1743 * Make sure that ntable is correctly initialized before we replace 1744 * fd_files poiner. Otherwise fget_unlocked() may see inconsistent 1745 * data. 1746 */ 1747 atomic_store_rel_ptr((volatile void *)&fdp->fd_files, (uintptr_t)ntable); 1748 1749 /* 1750 * Do not free the old file table, as some threads may still 1751 * reference entries within it. Instead, place it on a freelist 1752 * which will be processed when the struct filedesc is released. 1753 * 1754 * Note that if onfiles == NDFILE, we're dealing with the original 1755 * static allocation contained within (struct filedesc0 *)fdp, 1756 * which must not be freed. 1757 */ 1758 if (onfiles > NDFILE) { 1759 ft = (struct freetable *)&otable->fdt_ofiles[onfiles]; 1760 fdp0 = (struct filedesc0 *)fdp; 1761 ft->ft_table = otable; 1762 SLIST_INSERT_HEAD(&fdp0->fd_free, ft, ft_next); 1763 } 1764 /* 1765 * The map does not have the same possibility of threads still 1766 * holding references to it. So always free it as long as it 1767 * does not reference the original static allocation. 1768 */ 1769 if (NDSLOTS(onfiles) > NDSLOTS(NDFILE)) 1770 free(omap, M_FILEDESC); 1771 } 1772 1773 /* 1774 * Allocate a file descriptor for the process. 1775 */ 1776 int 1777 fdalloc(struct thread *td, int minfd, int *result) 1778 { 1779 struct proc *p = td->td_proc; 1780 struct filedesc *fdp = p->p_fd; 1781 int fd, maxfd, allocfd; 1782 #ifdef RACCT 1783 int error; 1784 #endif 1785 1786 FILEDESC_XLOCK_ASSERT(fdp); 1787 1788 if (fdp->fd_freefile > minfd) 1789 minfd = fdp->fd_freefile; 1790 1791 maxfd = getmaxfd(td); 1792 1793 /* 1794 * Search the bitmap for a free descriptor starting at minfd. 1795 * If none is found, grow the file table. 1796 */ 1797 fd = fd_first_free(fdp, minfd, fdp->fd_nfiles); 1798 if (fd >= maxfd) 1799 return (EMFILE); 1800 if (fd >= fdp->fd_nfiles) { 1801 allocfd = min(fd * 2, maxfd); 1802 #ifdef RACCT 1803 if (RACCT_ENABLED()) { 1804 error = racct_set_unlocked(p, RACCT_NOFILE, allocfd); 1805 if (error != 0) 1806 return (EMFILE); 1807 } 1808 #endif 1809 /* 1810 * fd is already equal to first free descriptor >= minfd, so 1811 * we only need to grow the table and we are done. 1812 */ 1813 fdgrowtable_exp(fdp, allocfd); 1814 } 1815 1816 /* 1817 * Perform some sanity checks, then mark the file descriptor as 1818 * used and return it to the caller. 1819 */ 1820 KASSERT(fd >= 0 && fd < min(maxfd, fdp->fd_nfiles), 1821 ("invalid descriptor %d", fd)); 1822 KASSERT(!fdisused(fdp, fd), 1823 ("fd_first_free() returned non-free descriptor")); 1824 KASSERT(fdp->fd_ofiles[fd].fde_file == NULL, 1825 ("file descriptor isn't free")); 1826 fdused(fdp, fd); 1827 *result = fd; 1828 return (0); 1829 } 1830 1831 /* 1832 * Allocate n file descriptors for the process. 1833 */ 1834 int 1835 fdallocn(struct thread *td, int minfd, int *fds, int n) 1836 { 1837 struct proc *p = td->td_proc; 1838 struct filedesc *fdp = p->p_fd; 1839 int i; 1840 1841 FILEDESC_XLOCK_ASSERT(fdp); 1842 1843 for (i = 0; i < n; i++) 1844 if (fdalloc(td, 0, &fds[i]) != 0) 1845 break; 1846 1847 if (i < n) { 1848 for (i--; i >= 0; i--) 1849 fdunused(fdp, fds[i]); 1850 return (EMFILE); 1851 } 1852 1853 return (0); 1854 } 1855 1856 /* 1857 * Create a new open file structure and allocate a file descriptor for the 1858 * process that refers to it. We add one reference to the file for the 1859 * descriptor table and one reference for resultfp. This is to prevent us 1860 * being preempted and the entry in the descriptor table closed after we 1861 * release the FILEDESC lock. 1862 */ 1863 int 1864 falloc_caps(struct thread *td, struct file **resultfp, int *resultfd, int flags, 1865 struct filecaps *fcaps) 1866 { 1867 struct file *fp; 1868 int error, fd; 1869 1870 error = falloc_noinstall(td, &fp); 1871 if (error) 1872 return (error); /* no reference held on error */ 1873 1874 error = finstall(td, fp, &fd, flags, fcaps); 1875 if (error) { 1876 fdrop(fp, td); /* one reference (fp only) */ 1877 return (error); 1878 } 1879 1880 if (resultfp != NULL) 1881 *resultfp = fp; /* copy out result */ 1882 else 1883 fdrop(fp, td); /* release local reference */ 1884 1885 if (resultfd != NULL) 1886 *resultfd = fd; 1887 1888 return (0); 1889 } 1890 1891 /* 1892 * Create a new open file structure without allocating a file descriptor. 1893 */ 1894 int 1895 falloc_noinstall(struct thread *td, struct file **resultfp) 1896 { 1897 struct file *fp; 1898 int maxuserfiles = maxfiles - (maxfiles / 20); 1899 int openfiles_new; 1900 static struct timeval lastfail; 1901 static int curfail; 1902 1903 KASSERT(resultfp != NULL, ("%s: resultfp == NULL", __func__)); 1904 1905 openfiles_new = atomic_fetchadd_int(&openfiles, 1) + 1; 1906 if ((openfiles_new >= maxuserfiles && 1907 priv_check(td, PRIV_MAXFILES) != 0) || 1908 openfiles_new >= maxfiles) { 1909 atomic_subtract_int(&openfiles, 1); 1910 if (ppsratecheck(&lastfail, &curfail, 1)) { 1911 printf("kern.maxfiles limit exceeded by uid %i, (%s) " 1912 "please see tuning(7).\n", td->td_ucred->cr_ruid, td->td_proc->p_comm); 1913 } 1914 return (ENFILE); 1915 } 1916 fp = uma_zalloc(file_zone, M_WAITOK); 1917 bzero(fp, sizeof(*fp)); 1918 refcount_init(&fp->f_count, 1); 1919 fp->f_cred = crhold(td->td_ucred); 1920 fp->f_ops = &badfileops; 1921 *resultfp = fp; 1922 return (0); 1923 } 1924 1925 /* 1926 * Install a file in a file descriptor table. 1927 */ 1928 void 1929 _finstall(struct filedesc *fdp, struct file *fp, int fd, int flags, 1930 struct filecaps *fcaps) 1931 { 1932 struct filedescent *fde; 1933 1934 MPASS(fp != NULL); 1935 if (fcaps != NULL) 1936 filecaps_validate(fcaps, __func__); 1937 FILEDESC_XLOCK_ASSERT(fdp); 1938 1939 fde = &fdp->fd_ofiles[fd]; 1940 #ifdef CAPABILITIES 1941 seqc_write_begin(&fde->fde_seqc); 1942 #endif 1943 fde->fde_file = fp; 1944 fde->fde_flags = (flags & O_CLOEXEC) != 0 ? UF_EXCLOSE : 0; 1945 if (fcaps != NULL) 1946 filecaps_move(fcaps, &fde->fde_caps); 1947 else 1948 filecaps_fill(&fde->fde_caps); 1949 #ifdef CAPABILITIES 1950 seqc_write_end(&fde->fde_seqc); 1951 #endif 1952 } 1953 1954 int 1955 finstall(struct thread *td, struct file *fp, int *fd, int flags, 1956 struct filecaps *fcaps) 1957 { 1958 struct filedesc *fdp = td->td_proc->p_fd; 1959 int error; 1960 1961 MPASS(fd != NULL); 1962 1963 if (!fhold(fp)) 1964 return (EBADF); 1965 FILEDESC_XLOCK(fdp); 1966 error = fdalloc(td, 0, fd); 1967 if (__predict_false(error != 0)) { 1968 FILEDESC_XUNLOCK(fdp); 1969 fdrop(fp, td); 1970 return (error); 1971 } 1972 _finstall(fdp, fp, *fd, flags, fcaps); 1973 FILEDESC_XUNLOCK(fdp); 1974 return (0); 1975 } 1976 1977 /* 1978 * Build a new filedesc structure from another. 1979 * Copy the current, root, and jail root vnode references. 1980 * 1981 * If fdp is not NULL, return with it shared locked. 1982 */ 1983 struct filedesc * 1984 fdinit(struct filedesc *fdp, bool prepfiles) 1985 { 1986 struct filedesc0 *newfdp0; 1987 struct filedesc *newfdp; 1988 1989 newfdp0 = uma_zalloc(filedesc0_zone, M_WAITOK | M_ZERO); 1990 newfdp = &newfdp0->fd_fd; 1991 1992 /* Create the file descriptor table. */ 1993 FILEDESC_LOCK_INIT(newfdp); 1994 refcount_init(&newfdp->fd_refcnt, 1); 1995 refcount_init(&newfdp->fd_holdcnt, 1); 1996 newfdp->fd_cmask = CMASK; 1997 newfdp->fd_map = newfdp0->fd_dmap; 1998 newfdp->fd_lastfile = -1; 1999 newfdp->fd_files = (struct fdescenttbl *)&newfdp0->fd_dfiles; 2000 newfdp->fd_files->fdt_nfiles = NDFILE; 2001 2002 if (fdp == NULL) { 2003 newfdp->fd_pwd = pwd_alloc(); 2004 return (newfdp); 2005 } 2006 2007 if (prepfiles && fdp->fd_lastfile >= newfdp->fd_nfiles) 2008 fdgrowtable(newfdp, fdp->fd_lastfile + 1); 2009 2010 FILEDESC_SLOCK(fdp); 2011 newfdp->fd_pwd = pwd_hold_filedesc(fdp); 2012 2013 if (!prepfiles) { 2014 FILEDESC_SUNLOCK(fdp); 2015 } else { 2016 while (fdp->fd_lastfile >= newfdp->fd_nfiles) { 2017 FILEDESC_SUNLOCK(fdp); 2018 fdgrowtable(newfdp, fdp->fd_lastfile + 1); 2019 FILEDESC_SLOCK(fdp); 2020 } 2021 } 2022 2023 return (newfdp); 2024 } 2025 2026 static struct filedesc * 2027 fdhold(struct proc *p) 2028 { 2029 struct filedesc *fdp; 2030 2031 PROC_LOCK_ASSERT(p, MA_OWNED); 2032 fdp = p->p_fd; 2033 if (fdp != NULL) 2034 refcount_acquire(&fdp->fd_holdcnt); 2035 return (fdp); 2036 } 2037 2038 static void 2039 fddrop(struct filedesc *fdp) 2040 { 2041 2042 if (fdp->fd_holdcnt > 1) { 2043 if (refcount_release(&fdp->fd_holdcnt) == 0) 2044 return; 2045 } 2046 2047 FILEDESC_LOCK_DESTROY(fdp); 2048 uma_zfree(filedesc0_zone, fdp); 2049 } 2050 2051 /* 2052 * Share a filedesc structure. 2053 */ 2054 struct filedesc * 2055 fdshare(struct filedesc *fdp) 2056 { 2057 2058 refcount_acquire(&fdp->fd_refcnt); 2059 return (fdp); 2060 } 2061 2062 /* 2063 * Unshare a filedesc structure, if necessary by making a copy 2064 */ 2065 void 2066 fdunshare(struct thread *td) 2067 { 2068 struct filedesc *tmp; 2069 struct proc *p = td->td_proc; 2070 2071 if (p->p_fd->fd_refcnt == 1) 2072 return; 2073 2074 tmp = fdcopy(p->p_fd); 2075 fdescfree(td); 2076 p->p_fd = tmp; 2077 } 2078 2079 void 2080 fdinstall_remapped(struct thread *td, struct filedesc *fdp) 2081 { 2082 2083 fdescfree(td); 2084 td->td_proc->p_fd = fdp; 2085 } 2086 2087 /* 2088 * Copy a filedesc structure. A NULL pointer in returns a NULL reference, 2089 * this is to ease callers, not catch errors. 2090 */ 2091 struct filedesc * 2092 fdcopy(struct filedesc *fdp) 2093 { 2094 struct filedesc *newfdp; 2095 struct filedescent *nfde, *ofde; 2096 int i; 2097 2098 MPASS(fdp != NULL); 2099 2100 newfdp = fdinit(fdp, true); 2101 /* copy all passable descriptors (i.e. not kqueue) */ 2102 newfdp->fd_freefile = -1; 2103 for (i = 0; i <= fdp->fd_lastfile; ++i) { 2104 ofde = &fdp->fd_ofiles[i]; 2105 if (ofde->fde_file == NULL || 2106 (ofde->fde_file->f_ops->fo_flags & DFLAG_PASSABLE) == 0 || 2107 !fhold(ofde->fde_file)) { 2108 if (newfdp->fd_freefile == -1) 2109 newfdp->fd_freefile = i; 2110 continue; 2111 } 2112 nfde = &newfdp->fd_ofiles[i]; 2113 *nfde = *ofde; 2114 filecaps_copy(&ofde->fde_caps, &nfde->fde_caps, true); 2115 fdused_init(newfdp, i); 2116 newfdp->fd_lastfile = i; 2117 } 2118 if (newfdp->fd_freefile == -1) 2119 newfdp->fd_freefile = i; 2120 newfdp->fd_cmask = fdp->fd_cmask; 2121 FILEDESC_SUNLOCK(fdp); 2122 return (newfdp); 2123 } 2124 2125 /* 2126 * Copies a filedesc structure, while remapping all file descriptors 2127 * stored inside using a translation table. 2128 * 2129 * File descriptors are copied over to the new file descriptor table, 2130 * regardless of whether the close-on-exec flag is set. 2131 */ 2132 int 2133 fdcopy_remapped(struct filedesc *fdp, const int *fds, size_t nfds, 2134 struct filedesc **ret) 2135 { 2136 struct filedesc *newfdp; 2137 struct filedescent *nfde, *ofde; 2138 int error, i; 2139 2140 MPASS(fdp != NULL); 2141 2142 newfdp = fdinit(fdp, true); 2143 if (nfds > fdp->fd_lastfile + 1) { 2144 /* New table cannot be larger than the old one. */ 2145 error = E2BIG; 2146 goto bad; 2147 } 2148 /* Copy all passable descriptors (i.e. not kqueue). */ 2149 newfdp->fd_freefile = nfds; 2150 for (i = 0; i < nfds; ++i) { 2151 if (fds[i] < 0 || fds[i] > fdp->fd_lastfile) { 2152 /* File descriptor out of bounds. */ 2153 error = EBADF; 2154 goto bad; 2155 } 2156 ofde = &fdp->fd_ofiles[fds[i]]; 2157 if (ofde->fde_file == NULL) { 2158 /* Unused file descriptor. */ 2159 error = EBADF; 2160 goto bad; 2161 } 2162 if ((ofde->fde_file->f_ops->fo_flags & DFLAG_PASSABLE) == 0) { 2163 /* File descriptor cannot be passed. */ 2164 error = EINVAL; 2165 goto bad; 2166 } 2167 if (!fhold(nfde->fde_file)) { 2168 error = EBADF; 2169 goto bad; 2170 } 2171 nfde = &newfdp->fd_ofiles[i]; 2172 *nfde = *ofde; 2173 filecaps_copy(&ofde->fde_caps, &nfde->fde_caps, true); 2174 fdused_init(newfdp, i); 2175 newfdp->fd_lastfile = i; 2176 } 2177 newfdp->fd_cmask = fdp->fd_cmask; 2178 FILEDESC_SUNLOCK(fdp); 2179 *ret = newfdp; 2180 return (0); 2181 bad: 2182 FILEDESC_SUNLOCK(fdp); 2183 fdescfree_remapped(newfdp); 2184 return (error); 2185 } 2186 2187 /* 2188 * Clear POSIX style locks. This is only used when fdp looses a reference (i.e. 2189 * one of processes using it exits) and the table used to be shared. 2190 */ 2191 static void 2192 fdclearlocks(struct thread *td) 2193 { 2194 struct filedesc *fdp; 2195 struct filedesc_to_leader *fdtol; 2196 struct flock lf; 2197 struct file *fp; 2198 struct proc *p; 2199 struct vnode *vp; 2200 int i; 2201 2202 p = td->td_proc; 2203 fdp = p->p_fd; 2204 fdtol = p->p_fdtol; 2205 MPASS(fdtol != NULL); 2206 2207 FILEDESC_XLOCK(fdp); 2208 KASSERT(fdtol->fdl_refcount > 0, 2209 ("filedesc_to_refcount botch: fdl_refcount=%d", 2210 fdtol->fdl_refcount)); 2211 if (fdtol->fdl_refcount == 1 && 2212 (p->p_leader->p_flag & P_ADVLOCK) != 0) { 2213 for (i = 0; i <= fdp->fd_lastfile; i++) { 2214 fp = fdp->fd_ofiles[i].fde_file; 2215 if (fp == NULL || fp->f_type != DTYPE_VNODE || 2216 !fhold(fp)) 2217 continue; 2218 FILEDESC_XUNLOCK(fdp); 2219 lf.l_whence = SEEK_SET; 2220 lf.l_start = 0; 2221 lf.l_len = 0; 2222 lf.l_type = F_UNLCK; 2223 vp = fp->f_vnode; 2224 (void) VOP_ADVLOCK(vp, 2225 (caddr_t)p->p_leader, F_UNLCK, 2226 &lf, F_POSIX); 2227 FILEDESC_XLOCK(fdp); 2228 fdrop(fp, td); 2229 } 2230 } 2231 retry: 2232 if (fdtol->fdl_refcount == 1) { 2233 if (fdp->fd_holdleaderscount > 0 && 2234 (p->p_leader->p_flag & P_ADVLOCK) != 0) { 2235 /* 2236 * close() or kern_dup() has cleared a reference 2237 * in a shared file descriptor table. 2238 */ 2239 fdp->fd_holdleaderswakeup = 1; 2240 sx_sleep(&fdp->fd_holdleaderscount, 2241 FILEDESC_LOCK(fdp), PLOCK, "fdlhold", 0); 2242 goto retry; 2243 } 2244 if (fdtol->fdl_holdcount > 0) { 2245 /* 2246 * Ensure that fdtol->fdl_leader remains 2247 * valid in closef(). 2248 */ 2249 fdtol->fdl_wakeup = 1; 2250 sx_sleep(fdtol, FILEDESC_LOCK(fdp), PLOCK, 2251 "fdlhold", 0); 2252 goto retry; 2253 } 2254 } 2255 fdtol->fdl_refcount--; 2256 if (fdtol->fdl_refcount == 0 && 2257 fdtol->fdl_holdcount == 0) { 2258 fdtol->fdl_next->fdl_prev = fdtol->fdl_prev; 2259 fdtol->fdl_prev->fdl_next = fdtol->fdl_next; 2260 } else 2261 fdtol = NULL; 2262 p->p_fdtol = NULL; 2263 FILEDESC_XUNLOCK(fdp); 2264 if (fdtol != NULL) 2265 free(fdtol, M_FILEDESC_TO_LEADER); 2266 } 2267 2268 /* 2269 * Release a filedesc structure. 2270 */ 2271 static void 2272 fdescfree_fds(struct thread *td, struct filedesc *fdp, bool needclose) 2273 { 2274 struct filedesc0 *fdp0; 2275 struct freetable *ft, *tft; 2276 struct filedescent *fde; 2277 struct file *fp; 2278 int i; 2279 2280 for (i = 0; i <= fdp->fd_lastfile; i++) { 2281 fde = &fdp->fd_ofiles[i]; 2282 fp = fde->fde_file; 2283 if (fp != NULL) { 2284 fdefree_last(fde); 2285 if (needclose) 2286 (void) closef(fp, td); 2287 else 2288 fdrop(fp, td); 2289 } 2290 } 2291 2292 if (NDSLOTS(fdp->fd_nfiles) > NDSLOTS(NDFILE)) 2293 free(fdp->fd_map, M_FILEDESC); 2294 if (fdp->fd_nfiles > NDFILE) 2295 free(fdp->fd_files, M_FILEDESC); 2296 2297 fdp0 = (struct filedesc0 *)fdp; 2298 SLIST_FOREACH_SAFE(ft, &fdp0->fd_free, ft_next, tft) 2299 free(ft->ft_table, M_FILEDESC); 2300 2301 fddrop(fdp); 2302 } 2303 2304 void 2305 fdescfree(struct thread *td) 2306 { 2307 struct proc *p; 2308 struct filedesc *fdp; 2309 struct pwd *pwd; 2310 2311 p = td->td_proc; 2312 fdp = p->p_fd; 2313 MPASS(fdp != NULL); 2314 2315 #ifdef RACCT 2316 if (RACCT_ENABLED()) 2317 racct_set_unlocked(p, RACCT_NOFILE, 0); 2318 #endif 2319 2320 if (p->p_fdtol != NULL) 2321 fdclearlocks(td); 2322 2323 PROC_LOCK(p); 2324 p->p_fd = NULL; 2325 PROC_UNLOCK(p); 2326 2327 if (refcount_release(&fdp->fd_refcnt) == 0) 2328 return; 2329 2330 FILEDESC_XLOCK(fdp); 2331 pwd = fdp->fd_pwd; 2332 pwd_set(fdp, NULL); 2333 FILEDESC_XUNLOCK(fdp); 2334 2335 pwd_drop(pwd); 2336 2337 fdescfree_fds(td, fdp, 1); 2338 } 2339 2340 void 2341 fdescfree_remapped(struct filedesc *fdp) 2342 { 2343 2344 pwd_drop(fdp->fd_pwd); 2345 fdescfree_fds(curthread, fdp, 0); 2346 } 2347 2348 /* 2349 * For setugid programs, we don't want to people to use that setugidness 2350 * to generate error messages which write to a file which otherwise would 2351 * otherwise be off-limits to the process. We check for filesystems where 2352 * the vnode can change out from under us after execve (like [lin]procfs). 2353 * 2354 * Since fdsetugidsafety calls this only for fd 0, 1 and 2, this check is 2355 * sufficient. We also don't check for setugidness since we know we are. 2356 */ 2357 static bool 2358 is_unsafe(struct file *fp) 2359 { 2360 struct vnode *vp; 2361 2362 if (fp->f_type != DTYPE_VNODE) 2363 return (false); 2364 2365 vp = fp->f_vnode; 2366 return ((vp->v_vflag & VV_PROCDEP) != 0); 2367 } 2368 2369 /* 2370 * Make this setguid thing safe, if at all possible. 2371 */ 2372 void 2373 fdsetugidsafety(struct thread *td) 2374 { 2375 struct filedesc *fdp; 2376 struct file *fp; 2377 int i; 2378 2379 fdp = td->td_proc->p_fd; 2380 KASSERT(fdp->fd_refcnt == 1, ("the fdtable should not be shared")); 2381 MPASS(fdp->fd_nfiles >= 3); 2382 for (i = 0; i <= 2; i++) { 2383 fp = fdp->fd_ofiles[i].fde_file; 2384 if (fp != NULL && is_unsafe(fp)) { 2385 FILEDESC_XLOCK(fdp); 2386 knote_fdclose(td, i); 2387 /* 2388 * NULL-out descriptor prior to close to avoid 2389 * a race while close blocks. 2390 */ 2391 fdfree(fdp, i); 2392 FILEDESC_XUNLOCK(fdp); 2393 (void) closef(fp, td); 2394 } 2395 } 2396 } 2397 2398 /* 2399 * If a specific file object occupies a specific file descriptor, close the 2400 * file descriptor entry and drop a reference on the file object. This is a 2401 * convenience function to handle a subsequent error in a function that calls 2402 * falloc() that handles the race that another thread might have closed the 2403 * file descriptor out from under the thread creating the file object. 2404 */ 2405 void 2406 fdclose(struct thread *td, struct file *fp, int idx) 2407 { 2408 struct filedesc *fdp = td->td_proc->p_fd; 2409 2410 FILEDESC_XLOCK(fdp); 2411 if (fdp->fd_ofiles[idx].fde_file == fp) { 2412 fdfree(fdp, idx); 2413 FILEDESC_XUNLOCK(fdp); 2414 fdrop(fp, td); 2415 } else 2416 FILEDESC_XUNLOCK(fdp); 2417 } 2418 2419 /* 2420 * Close any files on exec? 2421 */ 2422 void 2423 fdcloseexec(struct thread *td) 2424 { 2425 struct filedesc *fdp; 2426 struct filedescent *fde; 2427 struct file *fp; 2428 int i; 2429 2430 fdp = td->td_proc->p_fd; 2431 KASSERT(fdp->fd_refcnt == 1, ("the fdtable should not be shared")); 2432 for (i = 0; i <= fdp->fd_lastfile; i++) { 2433 fde = &fdp->fd_ofiles[i]; 2434 fp = fde->fde_file; 2435 if (fp != NULL && (fp->f_type == DTYPE_MQUEUE || 2436 (fde->fde_flags & UF_EXCLOSE))) { 2437 FILEDESC_XLOCK(fdp); 2438 fdfree(fdp, i); 2439 (void) closefp(fdp, i, fp, td, 0); 2440 FILEDESC_UNLOCK_ASSERT(fdp); 2441 } 2442 } 2443 } 2444 2445 /* 2446 * It is unsafe for set[ug]id processes to be started with file 2447 * descriptors 0..2 closed, as these descriptors are given implicit 2448 * significance in the Standard C library. fdcheckstd() will create a 2449 * descriptor referencing /dev/null for each of stdin, stdout, and 2450 * stderr that is not already open. 2451 */ 2452 int 2453 fdcheckstd(struct thread *td) 2454 { 2455 struct filedesc *fdp; 2456 register_t save; 2457 int i, error, devnull; 2458 2459 fdp = td->td_proc->p_fd; 2460 KASSERT(fdp->fd_refcnt == 1, ("the fdtable should not be shared")); 2461 MPASS(fdp->fd_nfiles >= 3); 2462 devnull = -1; 2463 for (i = 0; i <= 2; i++) { 2464 if (fdp->fd_ofiles[i].fde_file != NULL) 2465 continue; 2466 2467 save = td->td_retval[0]; 2468 if (devnull != -1) { 2469 error = kern_dup(td, FDDUP_FIXED, 0, devnull, i); 2470 } else { 2471 error = kern_openat(td, AT_FDCWD, "/dev/null", 2472 UIO_SYSSPACE, O_RDWR, 0); 2473 if (error == 0) { 2474 devnull = td->td_retval[0]; 2475 KASSERT(devnull == i, ("we didn't get our fd")); 2476 } 2477 } 2478 td->td_retval[0] = save; 2479 if (error != 0) 2480 return (error); 2481 } 2482 return (0); 2483 } 2484 2485 /* 2486 * Internal form of close. Decrement reference count on file structure. 2487 * Note: td may be NULL when closing a file that was being passed in a 2488 * message. 2489 */ 2490 int 2491 closef(struct file *fp, struct thread *td) 2492 { 2493 struct vnode *vp; 2494 struct flock lf; 2495 struct filedesc_to_leader *fdtol; 2496 struct filedesc *fdp; 2497 2498 /* 2499 * POSIX record locking dictates that any close releases ALL 2500 * locks owned by this process. This is handled by setting 2501 * a flag in the unlock to free ONLY locks obeying POSIX 2502 * semantics, and not to free BSD-style file locks. 2503 * If the descriptor was in a message, POSIX-style locks 2504 * aren't passed with the descriptor, and the thread pointer 2505 * will be NULL. Callers should be careful only to pass a 2506 * NULL thread pointer when there really is no owning 2507 * context that might have locks, or the locks will be 2508 * leaked. 2509 */ 2510 if (fp->f_type == DTYPE_VNODE && td != NULL) { 2511 vp = fp->f_vnode; 2512 if ((td->td_proc->p_leader->p_flag & P_ADVLOCK) != 0) { 2513 lf.l_whence = SEEK_SET; 2514 lf.l_start = 0; 2515 lf.l_len = 0; 2516 lf.l_type = F_UNLCK; 2517 (void) VOP_ADVLOCK(vp, (caddr_t)td->td_proc->p_leader, 2518 F_UNLCK, &lf, F_POSIX); 2519 } 2520 fdtol = td->td_proc->p_fdtol; 2521 if (fdtol != NULL) { 2522 /* 2523 * Handle special case where file descriptor table is 2524 * shared between multiple process leaders. 2525 */ 2526 fdp = td->td_proc->p_fd; 2527 FILEDESC_XLOCK(fdp); 2528 for (fdtol = fdtol->fdl_next; 2529 fdtol != td->td_proc->p_fdtol; 2530 fdtol = fdtol->fdl_next) { 2531 if ((fdtol->fdl_leader->p_flag & 2532 P_ADVLOCK) == 0) 2533 continue; 2534 fdtol->fdl_holdcount++; 2535 FILEDESC_XUNLOCK(fdp); 2536 lf.l_whence = SEEK_SET; 2537 lf.l_start = 0; 2538 lf.l_len = 0; 2539 lf.l_type = F_UNLCK; 2540 vp = fp->f_vnode; 2541 (void) VOP_ADVLOCK(vp, 2542 (caddr_t)fdtol->fdl_leader, F_UNLCK, &lf, 2543 F_POSIX); 2544 FILEDESC_XLOCK(fdp); 2545 fdtol->fdl_holdcount--; 2546 if (fdtol->fdl_holdcount == 0 && 2547 fdtol->fdl_wakeup != 0) { 2548 fdtol->fdl_wakeup = 0; 2549 wakeup(fdtol); 2550 } 2551 } 2552 FILEDESC_XUNLOCK(fdp); 2553 } 2554 } 2555 return (fdrop(fp, td)); 2556 } 2557 2558 /* 2559 * Initialize the file pointer with the specified properties. 2560 * 2561 * The ops are set with release semantics to be certain that the flags, type, 2562 * and data are visible when ops is. This is to prevent ops methods from being 2563 * called with bad data. 2564 */ 2565 void 2566 finit(struct file *fp, u_int flag, short type, void *data, struct fileops *ops) 2567 { 2568 fp->f_data = data; 2569 fp->f_flag = flag; 2570 fp->f_type = type; 2571 atomic_store_rel_ptr((volatile uintptr_t *)&fp->f_ops, (uintptr_t)ops); 2572 } 2573 2574 int 2575 fget_cap_locked(struct filedesc *fdp, int fd, cap_rights_t *needrightsp, 2576 struct file **fpp, struct filecaps *havecapsp) 2577 { 2578 struct filedescent *fde; 2579 int error; 2580 2581 FILEDESC_LOCK_ASSERT(fdp); 2582 2583 fde = fdeget_locked(fdp, fd); 2584 if (fde == NULL) { 2585 error = EBADF; 2586 goto out; 2587 } 2588 2589 #ifdef CAPABILITIES 2590 error = cap_check(cap_rights_fde_inline(fde), needrightsp); 2591 if (error != 0) 2592 goto out; 2593 #endif 2594 2595 if (havecapsp != NULL) 2596 filecaps_copy(&fde->fde_caps, havecapsp, true); 2597 2598 *fpp = fde->fde_file; 2599 2600 error = 0; 2601 out: 2602 return (error); 2603 } 2604 2605 int 2606 fget_cap(struct thread *td, int fd, cap_rights_t *needrightsp, 2607 struct file **fpp, struct filecaps *havecapsp) 2608 { 2609 struct filedesc *fdp = td->td_proc->p_fd; 2610 int error; 2611 #ifndef CAPABILITIES 2612 error = fget_unlocked(fdp, fd, needrightsp, fpp); 2613 if (havecapsp != NULL && error == 0) 2614 filecaps_fill(havecapsp); 2615 #else 2616 struct file *fp; 2617 seqc_t seq; 2618 2619 *fpp = NULL; 2620 for (;;) { 2621 error = fget_unlocked_seq(fdp, fd, needrightsp, &fp, &seq); 2622 if (error != 0) 2623 return (error); 2624 2625 if (havecapsp != NULL) { 2626 if (!filecaps_copy(&fdp->fd_ofiles[fd].fde_caps, 2627 havecapsp, false)) { 2628 fdrop(fp, td); 2629 goto get_locked; 2630 } 2631 } 2632 2633 if (!fd_modified(fdp, fd, seq)) 2634 break; 2635 fdrop(fp, td); 2636 } 2637 2638 *fpp = fp; 2639 return (0); 2640 2641 get_locked: 2642 FILEDESC_SLOCK(fdp); 2643 error = fget_cap_locked(fdp, fd, needrightsp, fpp, havecapsp); 2644 if (error == 0 && !fhold(*fpp)) 2645 error = EBADF; 2646 FILEDESC_SUNLOCK(fdp); 2647 #endif 2648 return (error); 2649 } 2650 2651 int 2652 fget_unlocked_seq(struct filedesc *fdp, int fd, cap_rights_t *needrightsp, 2653 struct file **fpp, seqc_t *seqp) 2654 { 2655 #ifdef CAPABILITIES 2656 const struct filedescent *fde; 2657 #endif 2658 const struct fdescenttbl *fdt; 2659 struct file *fp; 2660 #ifdef CAPABILITIES 2661 seqc_t seq; 2662 cap_rights_t haverights; 2663 int error; 2664 #endif 2665 2666 fdt = fdp->fd_files; 2667 if (__predict_false((u_int)fd >= fdt->fdt_nfiles)) 2668 return (EBADF); 2669 /* 2670 * Fetch the descriptor locklessly. We avoid fdrop() races by 2671 * never raising a refcount above 0. To accomplish this we have 2672 * to use a cmpset loop rather than an atomic_add. The descriptor 2673 * must be re-verified once we acquire a reference to be certain 2674 * that the identity is still correct and we did not lose a race 2675 * due to preemption. 2676 */ 2677 for (;;) { 2678 #ifdef CAPABILITIES 2679 seq = seqc_read(fd_seqc(fdt, fd)); 2680 fde = &fdt->fdt_ofiles[fd]; 2681 haverights = *cap_rights_fde_inline(fde); 2682 fp = fde->fde_file; 2683 if (!seqc_consistent(fd_seqc(fdt, fd), seq)) 2684 continue; 2685 #else 2686 fp = fdt->fdt_ofiles[fd].fde_file; 2687 #endif 2688 if (fp == NULL) 2689 return (EBADF); 2690 #ifdef CAPABILITIES 2691 error = cap_check_inline(&haverights, needrightsp); 2692 if (error != 0) 2693 return (error); 2694 #endif 2695 if (__predict_false(!refcount_acquire_if_not_zero(&fp->f_count))) { 2696 /* 2697 * The count was found either saturated or zero. 2698 * This re-read is not any more racy than using the 2699 * return value from fcmpset. 2700 */ 2701 if (fp->f_count != 0) 2702 return (EBADF); 2703 /* 2704 * Force a reload. Other thread could reallocate the 2705 * table before this fd was closed, so it is possible 2706 * that there is a stale fp pointer in cached version. 2707 */ 2708 fdt = atomic_load_ptr(&fdp->fd_files); 2709 continue; 2710 } 2711 /* 2712 * Use an acquire barrier to force re-reading of fdt so it is 2713 * refreshed for verification. 2714 */ 2715 atomic_thread_fence_acq(); 2716 fdt = fdp->fd_files; 2717 #ifdef CAPABILITIES 2718 if (seqc_consistent_nomb(fd_seqc(fdt, fd), seq)) 2719 #else 2720 if (fp == fdt->fdt_ofiles[fd].fde_file) 2721 #endif 2722 break; 2723 fdrop(fp, curthread); 2724 } 2725 *fpp = fp; 2726 if (seqp != NULL) { 2727 #ifdef CAPABILITIES 2728 *seqp = seq; 2729 #endif 2730 } 2731 return (0); 2732 } 2733 2734 /* 2735 * See the comments in fget_unlocked_seq for an explanation of how this works. 2736 * 2737 * This is a simplified variant which bails out to the aforementioned routine 2738 * if anything goes wrong. In practice this only happens when userspace is 2739 * racing with itself. 2740 */ 2741 int 2742 fget_unlocked(struct filedesc *fdp, int fd, cap_rights_t *needrightsp, 2743 struct file **fpp) 2744 { 2745 #ifdef CAPABILITIES 2746 const struct filedescent *fde; 2747 #endif 2748 const struct fdescenttbl *fdt; 2749 struct file *fp; 2750 #ifdef CAPABILITIES 2751 seqc_t seq; 2752 const cap_rights_t *haverights; 2753 #endif 2754 2755 fdt = fdp->fd_files; 2756 if (__predict_false((u_int)fd >= fdt->fdt_nfiles)) 2757 return (EBADF); 2758 #ifdef CAPABILITIES 2759 seq = seqc_read_any(fd_seqc(fdt, fd)); 2760 if (__predict_false(seqc_in_modify(seq))) 2761 goto out_fallback; 2762 fde = &fdt->fdt_ofiles[fd]; 2763 haverights = cap_rights_fde_inline(fde); 2764 fp = fde->fde_file; 2765 #else 2766 fp = fdt->fdt_ofiles[fd].fde_file; 2767 #endif 2768 if (__predict_false(fp == NULL)) 2769 goto out_fallback; 2770 #ifdef CAPABILITIES 2771 if (__predict_false(cap_check_inline_transient(haverights, needrightsp))) 2772 goto out_fallback; 2773 #endif 2774 if (__predict_false(!refcount_acquire_if_not_zero(&fp->f_count))) 2775 goto out_fallback; 2776 2777 /* 2778 * Use an acquire barrier to force re-reading of fdt so it is 2779 * refreshed for verification. 2780 */ 2781 atomic_thread_fence_acq(); 2782 fdt = fdp->fd_files; 2783 #ifdef CAPABILITIES 2784 if (__predict_false(!seqc_consistent_nomb(fd_seqc(fdt, fd), seq))) 2785 #else 2786 if (__predict_false(fp != fdt->fdt_ofiles[fd].fde_file)) 2787 #endif 2788 goto out_fdrop; 2789 *fpp = fp; 2790 return (0); 2791 out_fdrop: 2792 fdrop(fp, curthread); 2793 out_fallback: 2794 return (fget_unlocked_seq(fdp, fd, needrightsp, fpp, NULL)); 2795 } 2796 2797 /* 2798 * Extract the file pointer associated with the specified descriptor for the 2799 * current user process. 2800 * 2801 * If the descriptor doesn't exist or doesn't match 'flags', EBADF is 2802 * returned. 2803 * 2804 * File's rights will be checked against the capability rights mask. 2805 * 2806 * If an error occurred the non-zero error is returned and *fpp is set to 2807 * NULL. Otherwise *fpp is held and set and zero is returned. Caller is 2808 * responsible for fdrop(). 2809 */ 2810 static __inline int 2811 _fget(struct thread *td, int fd, struct file **fpp, int flags, 2812 cap_rights_t *needrightsp) 2813 { 2814 struct filedesc *fdp; 2815 struct file *fp; 2816 int error; 2817 2818 *fpp = NULL; 2819 fdp = td->td_proc->p_fd; 2820 error = fget_unlocked(fdp, fd, needrightsp, &fp); 2821 if (__predict_false(error != 0)) 2822 return (error); 2823 if (__predict_false(fp->f_ops == &badfileops)) { 2824 fdrop(fp, td); 2825 return (EBADF); 2826 } 2827 2828 /* 2829 * FREAD and FWRITE failure return EBADF as per POSIX. 2830 */ 2831 error = 0; 2832 switch (flags) { 2833 case FREAD: 2834 case FWRITE: 2835 if ((fp->f_flag & flags) == 0) 2836 error = EBADF; 2837 break; 2838 case FEXEC: 2839 if ((fp->f_flag & (FREAD | FEXEC)) == 0 || 2840 ((fp->f_flag & FWRITE) != 0)) 2841 error = EBADF; 2842 break; 2843 case 0: 2844 break; 2845 default: 2846 KASSERT(0, ("wrong flags")); 2847 } 2848 2849 if (error != 0) { 2850 fdrop(fp, td); 2851 return (error); 2852 } 2853 2854 *fpp = fp; 2855 return (0); 2856 } 2857 2858 int 2859 fget(struct thread *td, int fd, cap_rights_t *rightsp, struct file **fpp) 2860 { 2861 2862 return (_fget(td, fd, fpp, 0, rightsp)); 2863 } 2864 2865 int 2866 fget_mmap(struct thread *td, int fd, cap_rights_t *rightsp, vm_prot_t *maxprotp, 2867 struct file **fpp) 2868 { 2869 int error; 2870 #ifndef CAPABILITIES 2871 error = _fget(td, fd, fpp, 0, rightsp); 2872 if (maxprotp != NULL) 2873 *maxprotp = VM_PROT_ALL; 2874 return (error); 2875 #else 2876 cap_rights_t fdrights; 2877 struct filedesc *fdp; 2878 struct file *fp; 2879 seqc_t seq; 2880 2881 *fpp = NULL; 2882 fdp = td->td_proc->p_fd; 2883 MPASS(cap_rights_is_set(rightsp, CAP_MMAP)); 2884 for (;;) { 2885 error = fget_unlocked_seq(fdp, fd, rightsp, &fp, &seq); 2886 if (__predict_false(error != 0)) 2887 return (error); 2888 if (__predict_false(fp->f_ops == &badfileops)) { 2889 fdrop(fp, td); 2890 return (EBADF); 2891 } 2892 if (maxprotp != NULL) 2893 fdrights = *cap_rights(fdp, fd); 2894 if (!fd_modified(fdp, fd, seq)) 2895 break; 2896 fdrop(fp, td); 2897 } 2898 2899 /* 2900 * If requested, convert capability rights to access flags. 2901 */ 2902 if (maxprotp != NULL) 2903 *maxprotp = cap_rights_to_vmprot(&fdrights); 2904 *fpp = fp; 2905 return (0); 2906 #endif 2907 } 2908 2909 int 2910 fget_read(struct thread *td, int fd, cap_rights_t *rightsp, struct file **fpp) 2911 { 2912 2913 return (_fget(td, fd, fpp, FREAD, rightsp)); 2914 } 2915 2916 int 2917 fget_write(struct thread *td, int fd, cap_rights_t *rightsp, struct file **fpp) 2918 { 2919 2920 return (_fget(td, fd, fpp, FWRITE, rightsp)); 2921 } 2922 2923 int 2924 fget_fcntl(struct thread *td, int fd, cap_rights_t *rightsp, int needfcntl, 2925 struct file **fpp) 2926 { 2927 struct filedesc *fdp = td->td_proc->p_fd; 2928 #ifndef CAPABILITIES 2929 return (fget_unlocked(fdp, fd, rightsp, fpp)); 2930 #else 2931 struct file *fp; 2932 int error; 2933 seqc_t seq; 2934 2935 *fpp = NULL; 2936 MPASS(cap_rights_is_set(rightsp, CAP_FCNTL)); 2937 for (;;) { 2938 error = fget_unlocked_seq(fdp, fd, rightsp, &fp, &seq); 2939 if (error != 0) 2940 return (error); 2941 error = cap_fcntl_check(fdp, fd, needfcntl); 2942 if (!fd_modified(fdp, fd, seq)) 2943 break; 2944 fdrop(fp, td); 2945 } 2946 if (error != 0) { 2947 fdrop(fp, td); 2948 return (error); 2949 } 2950 *fpp = fp; 2951 return (0); 2952 #endif 2953 } 2954 2955 /* 2956 * Like fget() but loads the underlying vnode, or returns an error if the 2957 * descriptor does not represent a vnode. Note that pipes use vnodes but 2958 * never have VM objects. The returned vnode will be vref()'d. 2959 * 2960 * XXX: what about the unused flags ? 2961 */ 2962 static __inline int 2963 _fgetvp(struct thread *td, int fd, int flags, cap_rights_t *needrightsp, 2964 struct vnode **vpp) 2965 { 2966 struct file *fp; 2967 int error; 2968 2969 *vpp = NULL; 2970 error = _fget(td, fd, &fp, flags, needrightsp); 2971 if (error != 0) 2972 return (error); 2973 if (fp->f_vnode == NULL) { 2974 error = EINVAL; 2975 } else { 2976 *vpp = fp->f_vnode; 2977 vrefact(*vpp); 2978 } 2979 fdrop(fp, td); 2980 2981 return (error); 2982 } 2983 2984 int 2985 fgetvp(struct thread *td, int fd, cap_rights_t *rightsp, struct vnode **vpp) 2986 { 2987 2988 return (_fgetvp(td, fd, 0, rightsp, vpp)); 2989 } 2990 2991 int 2992 fgetvp_rights(struct thread *td, int fd, cap_rights_t *needrightsp, 2993 struct filecaps *havecaps, struct vnode **vpp) 2994 { 2995 struct filecaps caps; 2996 struct file *fp; 2997 int error; 2998 2999 error = fget_cap(td, fd, needrightsp, &fp, &caps); 3000 if (error != 0) 3001 return (error); 3002 if (fp->f_ops == &badfileops) { 3003 error = EBADF; 3004 goto out; 3005 } 3006 if (fp->f_vnode == NULL) { 3007 error = EINVAL; 3008 goto out; 3009 } 3010 3011 *havecaps = caps; 3012 *vpp = fp->f_vnode; 3013 vrefact(*vpp); 3014 fdrop(fp, td); 3015 3016 return (0); 3017 out: 3018 filecaps_free(&caps); 3019 fdrop(fp, td); 3020 return (error); 3021 } 3022 3023 int 3024 fgetvp_read(struct thread *td, int fd, cap_rights_t *rightsp, struct vnode **vpp) 3025 { 3026 3027 return (_fgetvp(td, fd, FREAD, rightsp, vpp)); 3028 } 3029 3030 int 3031 fgetvp_exec(struct thread *td, int fd, cap_rights_t *rightsp, struct vnode **vpp) 3032 { 3033 3034 return (_fgetvp(td, fd, FEXEC, rightsp, vpp)); 3035 } 3036 3037 #ifdef notyet 3038 int 3039 fgetvp_write(struct thread *td, int fd, cap_rights_t *rightsp, 3040 struct vnode **vpp) 3041 { 3042 3043 return (_fgetvp(td, fd, FWRITE, rightsp, vpp)); 3044 } 3045 #endif 3046 3047 /* 3048 * Handle the last reference to a file being closed. 3049 * 3050 * Without the noinline attribute clang keeps inlining the func thorough this 3051 * file when fdrop is used. 3052 */ 3053 int __noinline 3054 _fdrop(struct file *fp, struct thread *td) 3055 { 3056 int error; 3057 3058 if (fp->f_count != 0) 3059 panic("fdrop: count %d", fp->f_count); 3060 error = fo_close(fp, td); 3061 atomic_subtract_int(&openfiles, 1); 3062 crfree(fp->f_cred); 3063 free(fp->f_advice, M_FADVISE); 3064 uma_zfree(file_zone, fp); 3065 3066 return (error); 3067 } 3068 3069 /* 3070 * Apply an advisory lock on a file descriptor. 3071 * 3072 * Just attempt to get a record lock of the requested type on the entire file 3073 * (l_whence = SEEK_SET, l_start = 0, l_len = 0). 3074 */ 3075 #ifndef _SYS_SYSPROTO_H_ 3076 struct flock_args { 3077 int fd; 3078 int how; 3079 }; 3080 #endif 3081 /* ARGSUSED */ 3082 int 3083 sys_flock(struct thread *td, struct flock_args *uap) 3084 { 3085 struct file *fp; 3086 struct vnode *vp; 3087 struct flock lf; 3088 int error; 3089 3090 error = fget(td, uap->fd, &cap_flock_rights, &fp); 3091 if (error != 0) 3092 return (error); 3093 if (fp->f_type != DTYPE_VNODE) { 3094 fdrop(fp, td); 3095 return (EOPNOTSUPP); 3096 } 3097 3098 vp = fp->f_vnode; 3099 lf.l_whence = SEEK_SET; 3100 lf.l_start = 0; 3101 lf.l_len = 0; 3102 if (uap->how & LOCK_UN) { 3103 lf.l_type = F_UNLCK; 3104 atomic_clear_int(&fp->f_flag, FHASLOCK); 3105 error = VOP_ADVLOCK(vp, (caddr_t)fp, F_UNLCK, &lf, F_FLOCK); 3106 goto done2; 3107 } 3108 if (uap->how & LOCK_EX) 3109 lf.l_type = F_WRLCK; 3110 else if (uap->how & LOCK_SH) 3111 lf.l_type = F_RDLCK; 3112 else { 3113 error = EBADF; 3114 goto done2; 3115 } 3116 atomic_set_int(&fp->f_flag, FHASLOCK); 3117 error = VOP_ADVLOCK(vp, (caddr_t)fp, F_SETLK, &lf, 3118 (uap->how & LOCK_NB) ? F_FLOCK : F_FLOCK | F_WAIT); 3119 done2: 3120 fdrop(fp, td); 3121 return (error); 3122 } 3123 /* 3124 * Duplicate the specified descriptor to a free descriptor. 3125 */ 3126 int 3127 dupfdopen(struct thread *td, struct filedesc *fdp, int dfd, int mode, 3128 int openerror, int *indxp) 3129 { 3130 struct filedescent *newfde, *oldfde; 3131 struct file *fp; 3132 u_long *ioctls; 3133 int error, indx; 3134 3135 KASSERT(openerror == ENODEV || openerror == ENXIO, 3136 ("unexpected error %d in %s", openerror, __func__)); 3137 3138 /* 3139 * If the to-be-dup'd fd number is greater than the allowed number 3140 * of file descriptors, or the fd to be dup'd has already been 3141 * closed, then reject. 3142 */ 3143 FILEDESC_XLOCK(fdp); 3144 if ((fp = fget_locked(fdp, dfd)) == NULL) { 3145 FILEDESC_XUNLOCK(fdp); 3146 return (EBADF); 3147 } 3148 3149 error = fdalloc(td, 0, &indx); 3150 if (error != 0) { 3151 FILEDESC_XUNLOCK(fdp); 3152 return (error); 3153 } 3154 3155 /* 3156 * There are two cases of interest here. 3157 * 3158 * For ENODEV simply dup (dfd) to file descriptor (indx) and return. 3159 * 3160 * For ENXIO steal away the file structure from (dfd) and store it in 3161 * (indx). (dfd) is effectively closed by this operation. 3162 */ 3163 switch (openerror) { 3164 case ENODEV: 3165 /* 3166 * Check that the mode the file is being opened for is a 3167 * subset of the mode of the existing descriptor. 3168 */ 3169 if (((mode & (FREAD|FWRITE)) | fp->f_flag) != fp->f_flag) { 3170 fdunused(fdp, indx); 3171 FILEDESC_XUNLOCK(fdp); 3172 return (EACCES); 3173 } 3174 if (!fhold(fp)) { 3175 fdunused(fdp, indx); 3176 FILEDESC_XUNLOCK(fdp); 3177 return (EBADF); 3178 } 3179 newfde = &fdp->fd_ofiles[indx]; 3180 oldfde = &fdp->fd_ofiles[dfd]; 3181 ioctls = filecaps_copy_prep(&oldfde->fde_caps); 3182 #ifdef CAPABILITIES 3183 seqc_write_begin(&newfde->fde_seqc); 3184 #endif 3185 memcpy(newfde, oldfde, fde_change_size); 3186 filecaps_copy_finish(&oldfde->fde_caps, &newfde->fde_caps, 3187 ioctls); 3188 #ifdef CAPABILITIES 3189 seqc_write_end(&newfde->fde_seqc); 3190 #endif 3191 break; 3192 case ENXIO: 3193 /* 3194 * Steal away the file pointer from dfd and stuff it into indx. 3195 */ 3196 newfde = &fdp->fd_ofiles[indx]; 3197 oldfde = &fdp->fd_ofiles[dfd]; 3198 #ifdef CAPABILITIES 3199 seqc_write_begin(&newfde->fde_seqc); 3200 #endif 3201 memcpy(newfde, oldfde, fde_change_size); 3202 oldfde->fde_file = NULL; 3203 fdunused(fdp, dfd); 3204 #ifdef CAPABILITIES 3205 seqc_write_end(&newfde->fde_seqc); 3206 #endif 3207 break; 3208 } 3209 FILEDESC_XUNLOCK(fdp); 3210 *indxp = indx; 3211 return (0); 3212 } 3213 3214 /* 3215 * This sysctl determines if we will allow a process to chroot(2) if it 3216 * has a directory open: 3217 * 0: disallowed for all processes. 3218 * 1: allowed for processes that were not already chroot(2)'ed. 3219 * 2: allowed for all processes. 3220 */ 3221 3222 static int chroot_allow_open_directories = 1; 3223 3224 SYSCTL_INT(_kern, OID_AUTO, chroot_allow_open_directories, CTLFLAG_RW, 3225 &chroot_allow_open_directories, 0, 3226 "Allow a process to chroot(2) if it has a directory open"); 3227 3228 /* 3229 * Helper function for raised chroot(2) security function: Refuse if 3230 * any filedescriptors are open directories. 3231 */ 3232 static int 3233 chroot_refuse_vdir_fds(struct filedesc *fdp) 3234 { 3235 struct vnode *vp; 3236 struct file *fp; 3237 int fd; 3238 3239 FILEDESC_LOCK_ASSERT(fdp); 3240 3241 for (fd = 0; fd <= fdp->fd_lastfile; fd++) { 3242 fp = fget_locked(fdp, fd); 3243 if (fp == NULL) 3244 continue; 3245 if (fp->f_type == DTYPE_VNODE) { 3246 vp = fp->f_vnode; 3247 if (vp->v_type == VDIR) 3248 return (EPERM); 3249 } 3250 } 3251 return (0); 3252 } 3253 3254 static void 3255 pwd_fill(struct pwd *oldpwd, struct pwd *newpwd) 3256 { 3257 3258 if (newpwd->pwd_cdir == NULL && oldpwd->pwd_cdir != NULL) { 3259 vrefact(oldpwd->pwd_cdir); 3260 newpwd->pwd_cdir = oldpwd->pwd_cdir; 3261 } 3262 3263 if (newpwd->pwd_rdir == NULL && oldpwd->pwd_rdir != NULL) { 3264 vrefact(oldpwd->pwd_rdir); 3265 newpwd->pwd_rdir = oldpwd->pwd_rdir; 3266 } 3267 3268 if (newpwd->pwd_jdir == NULL && oldpwd->pwd_jdir != NULL) { 3269 vrefact(oldpwd->pwd_jdir); 3270 newpwd->pwd_jdir = oldpwd->pwd_jdir; 3271 } 3272 } 3273 3274 struct pwd * 3275 pwd_hold_filedesc(struct filedesc *fdp) 3276 { 3277 struct pwd *pwd; 3278 3279 FILEDESC_LOCK_ASSERT(fdp); 3280 pwd = fdp->fd_pwd; 3281 if (pwd != NULL) 3282 refcount_acquire(&pwd->pwd_refcount); 3283 return (pwd); 3284 } 3285 3286 struct pwd * 3287 pwd_hold(struct thread *td) 3288 { 3289 struct filedesc *fdp; 3290 struct pwd *pwd; 3291 3292 fdp = td->td_proc->p_fd; 3293 3294 FILEDESC_SLOCK(fdp); 3295 pwd = fdp->fd_pwd; 3296 MPASS(pwd != NULL); 3297 refcount_acquire(&pwd->pwd_refcount); 3298 FILEDESC_SUNLOCK(fdp); 3299 return (pwd); 3300 } 3301 3302 static struct pwd * 3303 pwd_alloc(void) 3304 { 3305 struct pwd *pwd; 3306 3307 pwd = malloc(sizeof(*pwd), M_PWD, M_WAITOK | M_ZERO); 3308 refcount_init(&pwd->pwd_refcount, 1); 3309 return (pwd); 3310 } 3311 3312 void 3313 pwd_drop(struct pwd *pwd) 3314 { 3315 3316 if (!refcount_release(&pwd->pwd_refcount)) 3317 return; 3318 3319 if (pwd->pwd_cdir != NULL) 3320 vrele(pwd->pwd_cdir); 3321 if (pwd->pwd_rdir != NULL) 3322 vrele(pwd->pwd_rdir); 3323 if (pwd->pwd_jdir != NULL) 3324 vrele(pwd->pwd_jdir); 3325 free(pwd, M_PWD); 3326 } 3327 3328 /* 3329 * Common routine for kern_chroot() and jail_attach(). The caller is 3330 * responsible for invoking priv_check() and mac_vnode_check_chroot() to 3331 * authorize this operation. 3332 */ 3333 int 3334 pwd_chroot(struct thread *td, struct vnode *vp) 3335 { 3336 struct filedesc *fdp; 3337 struct pwd *newpwd, *oldpwd; 3338 int error; 3339 3340 fdp = td->td_proc->p_fd; 3341 newpwd = pwd_alloc(); 3342 FILEDESC_XLOCK(fdp); 3343 oldpwd = fdp->fd_pwd; 3344 if (chroot_allow_open_directories == 0 || 3345 (chroot_allow_open_directories == 1 && 3346 oldpwd->pwd_rdir != rootvnode)) { 3347 error = chroot_refuse_vdir_fds(fdp); 3348 if (error != 0) { 3349 FILEDESC_XUNLOCK(fdp); 3350 pwd_drop(newpwd); 3351 return (error); 3352 } 3353 } 3354 3355 vrefact(vp); 3356 newpwd->pwd_rdir = vp; 3357 if (oldpwd->pwd_jdir == NULL) { 3358 vrefact(vp); 3359 newpwd->pwd_jdir = vp; 3360 } 3361 pwd_fill(oldpwd, newpwd); 3362 pwd_set(fdp, newpwd); 3363 FILEDESC_XUNLOCK(fdp); 3364 pwd_drop(oldpwd); 3365 return (0); 3366 } 3367 3368 void 3369 pwd_chdir(struct thread *td, struct vnode *vp) 3370 { 3371 struct filedesc *fdp; 3372 struct pwd *newpwd, *oldpwd; 3373 3374 VNPASS(vp->v_usecount > 0, vp); 3375 3376 newpwd = pwd_alloc(); 3377 fdp = td->td_proc->p_fd; 3378 FILEDESC_XLOCK(fdp); 3379 oldpwd = fdp->fd_pwd; 3380 newpwd->pwd_cdir = vp; 3381 pwd_fill(oldpwd, newpwd); 3382 pwd_set(fdp, newpwd); 3383 FILEDESC_XUNLOCK(fdp); 3384 pwd_drop(oldpwd); 3385 } 3386 3387 void 3388 pwd_ensure_dirs(void) 3389 { 3390 struct filedesc *fdp; 3391 struct pwd *oldpwd, *newpwd; 3392 3393 fdp = curproc->p_fd; 3394 FILEDESC_XLOCK(fdp); 3395 oldpwd = fdp->fd_pwd; 3396 if (oldpwd->pwd_cdir != NULL && oldpwd->pwd_rdir != NULL) { 3397 FILEDESC_XUNLOCK(fdp); 3398 return; 3399 } 3400 FILEDESC_XUNLOCK(fdp); 3401 3402 newpwd = pwd_alloc(); 3403 FILEDESC_XLOCK(fdp); 3404 oldpwd = fdp->fd_pwd; 3405 pwd_fill(oldpwd, newpwd); 3406 if (newpwd->pwd_cdir == NULL) { 3407 vrefact(rootvnode); 3408 newpwd->pwd_cdir = rootvnode; 3409 } 3410 if (newpwd->pwd_rdir == NULL) { 3411 vrefact(rootvnode); 3412 newpwd->pwd_rdir = rootvnode; 3413 } 3414 pwd_set(fdp, newpwd); 3415 FILEDESC_XUNLOCK(fdp); 3416 pwd_drop(oldpwd); 3417 } 3418 3419 /* 3420 * Scan all active processes and prisons to see if any of them have a current 3421 * or root directory of `olddp'. If so, replace them with the new mount point. 3422 */ 3423 void 3424 mountcheckdirs(struct vnode *olddp, struct vnode *newdp) 3425 { 3426 struct filedesc *fdp; 3427 struct pwd *newpwd, *oldpwd; 3428 struct prison *pr; 3429 struct proc *p; 3430 int nrele; 3431 3432 if (vrefcnt(olddp) == 1) 3433 return; 3434 nrele = 0; 3435 newpwd = pwd_alloc(); 3436 sx_slock(&allproc_lock); 3437 FOREACH_PROC_IN_SYSTEM(p) { 3438 PROC_LOCK(p); 3439 fdp = fdhold(p); 3440 PROC_UNLOCK(p); 3441 if (fdp == NULL) 3442 continue; 3443 FILEDESC_XLOCK(fdp); 3444 oldpwd = fdp->fd_pwd; 3445 if (oldpwd == NULL || 3446 (oldpwd->pwd_cdir != olddp && 3447 oldpwd->pwd_rdir != olddp && 3448 oldpwd->pwd_jdir != olddp)) { 3449 FILEDESC_XUNLOCK(fdp); 3450 fddrop(fdp); 3451 continue; 3452 } 3453 if (oldpwd->pwd_cdir == olddp) { 3454 vrefact(newdp); 3455 newpwd->pwd_cdir = newdp; 3456 } 3457 if (oldpwd->pwd_rdir == olddp) { 3458 vrefact(newdp); 3459 newpwd->pwd_rdir = newdp; 3460 } 3461 if (oldpwd->pwd_jdir == olddp) { 3462 vrefact(newdp); 3463 newpwd->pwd_jdir = newdp; 3464 } 3465 pwd_fill(oldpwd, newpwd); 3466 pwd_set(fdp, newpwd); 3467 FILEDESC_XUNLOCK(fdp); 3468 pwd_drop(oldpwd); 3469 fddrop(fdp); 3470 newpwd = pwd_alloc(); 3471 } 3472 sx_sunlock(&allproc_lock); 3473 pwd_drop(newpwd); 3474 if (rootvnode == olddp) { 3475 vrefact(newdp); 3476 rootvnode = newdp; 3477 nrele++; 3478 } 3479 mtx_lock(&prison0.pr_mtx); 3480 if (prison0.pr_root == olddp) { 3481 vrefact(newdp); 3482 prison0.pr_root = newdp; 3483 nrele++; 3484 } 3485 mtx_unlock(&prison0.pr_mtx); 3486 sx_slock(&allprison_lock); 3487 TAILQ_FOREACH(pr, &allprison, pr_list) { 3488 mtx_lock(&pr->pr_mtx); 3489 if (pr->pr_root == olddp) { 3490 vrefact(newdp); 3491 pr->pr_root = newdp; 3492 nrele++; 3493 } 3494 mtx_unlock(&pr->pr_mtx); 3495 } 3496 sx_sunlock(&allprison_lock); 3497 while (nrele--) 3498 vrele(olddp); 3499 } 3500 3501 struct filedesc_to_leader * 3502 filedesc_to_leader_alloc(struct filedesc_to_leader *old, struct filedesc *fdp, struct proc *leader) 3503 { 3504 struct filedesc_to_leader *fdtol; 3505 3506 fdtol = malloc(sizeof(struct filedesc_to_leader), 3507 M_FILEDESC_TO_LEADER, M_WAITOK); 3508 fdtol->fdl_refcount = 1; 3509 fdtol->fdl_holdcount = 0; 3510 fdtol->fdl_wakeup = 0; 3511 fdtol->fdl_leader = leader; 3512 if (old != NULL) { 3513 FILEDESC_XLOCK(fdp); 3514 fdtol->fdl_next = old->fdl_next; 3515 fdtol->fdl_prev = old; 3516 old->fdl_next = fdtol; 3517 fdtol->fdl_next->fdl_prev = fdtol; 3518 FILEDESC_XUNLOCK(fdp); 3519 } else { 3520 fdtol->fdl_next = fdtol; 3521 fdtol->fdl_prev = fdtol; 3522 } 3523 return (fdtol); 3524 } 3525 3526 static int 3527 sysctl_kern_proc_nfds(SYSCTL_HANDLER_ARGS) 3528 { 3529 struct filedesc *fdp; 3530 int i, count, slots; 3531 3532 if (*(int *)arg1 != 0) 3533 return (EINVAL); 3534 3535 fdp = curproc->p_fd; 3536 count = 0; 3537 FILEDESC_SLOCK(fdp); 3538 slots = NDSLOTS(fdp->fd_lastfile + 1); 3539 for (i = 0; i < slots; i++) 3540 count += bitcountl(fdp->fd_map[i]); 3541 FILEDESC_SUNLOCK(fdp); 3542 3543 return (SYSCTL_OUT(req, &count, sizeof(count))); 3544 } 3545 3546 static SYSCTL_NODE(_kern_proc, KERN_PROC_NFDS, nfds, 3547 CTLFLAG_RD|CTLFLAG_CAPRD|CTLFLAG_MPSAFE, sysctl_kern_proc_nfds, 3548 "Number of open file descriptors"); 3549 3550 /* 3551 * Get file structures globally. 3552 */ 3553 static int 3554 sysctl_kern_file(SYSCTL_HANDLER_ARGS) 3555 { 3556 struct xfile xf; 3557 struct filedesc *fdp; 3558 struct file *fp; 3559 struct proc *p; 3560 int error, n; 3561 3562 error = sysctl_wire_old_buffer(req, 0); 3563 if (error != 0) 3564 return (error); 3565 if (req->oldptr == NULL) { 3566 n = 0; 3567 sx_slock(&allproc_lock); 3568 FOREACH_PROC_IN_SYSTEM(p) { 3569 PROC_LOCK(p); 3570 if (p->p_state == PRS_NEW) { 3571 PROC_UNLOCK(p); 3572 continue; 3573 } 3574 fdp = fdhold(p); 3575 PROC_UNLOCK(p); 3576 if (fdp == NULL) 3577 continue; 3578 /* overestimates sparse tables. */ 3579 if (fdp->fd_lastfile > 0) 3580 n += fdp->fd_lastfile; 3581 fddrop(fdp); 3582 } 3583 sx_sunlock(&allproc_lock); 3584 return (SYSCTL_OUT(req, 0, n * sizeof(xf))); 3585 } 3586 error = 0; 3587 bzero(&xf, sizeof(xf)); 3588 xf.xf_size = sizeof(xf); 3589 sx_slock(&allproc_lock); 3590 FOREACH_PROC_IN_SYSTEM(p) { 3591 PROC_LOCK(p); 3592 if (p->p_state == PRS_NEW) { 3593 PROC_UNLOCK(p); 3594 continue; 3595 } 3596 if (p_cansee(req->td, p) != 0) { 3597 PROC_UNLOCK(p); 3598 continue; 3599 } 3600 xf.xf_pid = p->p_pid; 3601 xf.xf_uid = p->p_ucred->cr_uid; 3602 fdp = fdhold(p); 3603 PROC_UNLOCK(p); 3604 if (fdp == NULL) 3605 continue; 3606 FILEDESC_SLOCK(fdp); 3607 for (n = 0; fdp->fd_refcnt > 0 && n <= fdp->fd_lastfile; ++n) { 3608 if ((fp = fdp->fd_ofiles[n].fde_file) == NULL) 3609 continue; 3610 xf.xf_fd = n; 3611 xf.xf_file = (uintptr_t)fp; 3612 xf.xf_data = (uintptr_t)fp->f_data; 3613 xf.xf_vnode = (uintptr_t)fp->f_vnode; 3614 xf.xf_type = (uintptr_t)fp->f_type; 3615 xf.xf_count = fp->f_count; 3616 xf.xf_msgcount = 0; 3617 xf.xf_offset = foffset_get(fp); 3618 xf.xf_flag = fp->f_flag; 3619 error = SYSCTL_OUT(req, &xf, sizeof(xf)); 3620 if (error) 3621 break; 3622 } 3623 FILEDESC_SUNLOCK(fdp); 3624 fddrop(fdp); 3625 if (error) 3626 break; 3627 } 3628 sx_sunlock(&allproc_lock); 3629 return (error); 3630 } 3631 3632 SYSCTL_PROC(_kern, KERN_FILE, file, CTLTYPE_OPAQUE|CTLFLAG_RD|CTLFLAG_MPSAFE, 3633 0, 0, sysctl_kern_file, "S,xfile", "Entire file table"); 3634 3635 #ifdef KINFO_FILE_SIZE 3636 CTASSERT(sizeof(struct kinfo_file) == KINFO_FILE_SIZE); 3637 #endif 3638 3639 static int 3640 xlate_fflags(int fflags) 3641 { 3642 static const struct { 3643 int fflag; 3644 int kf_fflag; 3645 } fflags_table[] = { 3646 { FAPPEND, KF_FLAG_APPEND }, 3647 { FASYNC, KF_FLAG_ASYNC }, 3648 { FFSYNC, KF_FLAG_FSYNC }, 3649 { FHASLOCK, KF_FLAG_HASLOCK }, 3650 { FNONBLOCK, KF_FLAG_NONBLOCK }, 3651 { FREAD, KF_FLAG_READ }, 3652 { FWRITE, KF_FLAG_WRITE }, 3653 { O_CREAT, KF_FLAG_CREAT }, 3654 { O_DIRECT, KF_FLAG_DIRECT }, 3655 { O_EXCL, KF_FLAG_EXCL }, 3656 { O_EXEC, KF_FLAG_EXEC }, 3657 { O_EXLOCK, KF_FLAG_EXLOCK }, 3658 { O_NOFOLLOW, KF_FLAG_NOFOLLOW }, 3659 { O_SHLOCK, KF_FLAG_SHLOCK }, 3660 { O_TRUNC, KF_FLAG_TRUNC } 3661 }; 3662 unsigned int i; 3663 int kflags; 3664 3665 kflags = 0; 3666 for (i = 0; i < nitems(fflags_table); i++) 3667 if (fflags & fflags_table[i].fflag) 3668 kflags |= fflags_table[i].kf_fflag; 3669 return (kflags); 3670 } 3671 3672 /* Trim unused data from kf_path by truncating the structure size. */ 3673 void 3674 pack_kinfo(struct kinfo_file *kif) 3675 { 3676 3677 kif->kf_structsize = offsetof(struct kinfo_file, kf_path) + 3678 strlen(kif->kf_path) + 1; 3679 kif->kf_structsize = roundup(kif->kf_structsize, sizeof(uint64_t)); 3680 } 3681 3682 static void 3683 export_file_to_kinfo(struct file *fp, int fd, cap_rights_t *rightsp, 3684 struct kinfo_file *kif, struct filedesc *fdp, int flags) 3685 { 3686 int error; 3687 3688 bzero(kif, sizeof(*kif)); 3689 3690 /* Set a default type to allow for empty fill_kinfo() methods. */ 3691 kif->kf_type = KF_TYPE_UNKNOWN; 3692 kif->kf_flags = xlate_fflags(fp->f_flag); 3693 if (rightsp != NULL) 3694 kif->kf_cap_rights = *rightsp; 3695 else 3696 cap_rights_init_zero(&kif->kf_cap_rights); 3697 kif->kf_fd = fd; 3698 kif->kf_ref_count = fp->f_count; 3699 kif->kf_offset = foffset_get(fp); 3700 3701 /* 3702 * This may drop the filedesc lock, so the 'fp' cannot be 3703 * accessed after this call. 3704 */ 3705 error = fo_fill_kinfo(fp, kif, fdp); 3706 if (error == 0) 3707 kif->kf_status |= KF_ATTR_VALID; 3708 if ((flags & KERN_FILEDESC_PACK_KINFO) != 0) 3709 pack_kinfo(kif); 3710 else 3711 kif->kf_structsize = roundup2(sizeof(*kif), sizeof(uint64_t)); 3712 } 3713 3714 static void 3715 export_vnode_to_kinfo(struct vnode *vp, int fd, int fflags, 3716 struct kinfo_file *kif, int flags) 3717 { 3718 int error; 3719 3720 bzero(kif, sizeof(*kif)); 3721 3722 kif->kf_type = KF_TYPE_VNODE; 3723 error = vn_fill_kinfo_vnode(vp, kif); 3724 if (error == 0) 3725 kif->kf_status |= KF_ATTR_VALID; 3726 kif->kf_flags = xlate_fflags(fflags); 3727 cap_rights_init_zero(&kif->kf_cap_rights); 3728 kif->kf_fd = fd; 3729 kif->kf_ref_count = -1; 3730 kif->kf_offset = -1; 3731 if ((flags & KERN_FILEDESC_PACK_KINFO) != 0) 3732 pack_kinfo(kif); 3733 else 3734 kif->kf_structsize = roundup2(sizeof(*kif), sizeof(uint64_t)); 3735 vrele(vp); 3736 } 3737 3738 struct export_fd_buf { 3739 struct filedesc *fdp; 3740 struct sbuf *sb; 3741 ssize_t remainder; 3742 struct kinfo_file kif; 3743 int flags; 3744 }; 3745 3746 static int 3747 export_kinfo_to_sb(struct export_fd_buf *efbuf) 3748 { 3749 struct kinfo_file *kif; 3750 3751 kif = &efbuf->kif; 3752 if (efbuf->remainder != -1) { 3753 if (efbuf->remainder < kif->kf_structsize) { 3754 /* Terminate export. */ 3755 efbuf->remainder = 0; 3756 return (0); 3757 } 3758 efbuf->remainder -= kif->kf_structsize; 3759 } 3760 return (sbuf_bcat(efbuf->sb, kif, kif->kf_structsize) == 0 ? 0 : ENOMEM); 3761 } 3762 3763 static int 3764 export_file_to_sb(struct file *fp, int fd, cap_rights_t *rightsp, 3765 struct export_fd_buf *efbuf) 3766 { 3767 int error; 3768 3769 if (efbuf->remainder == 0) 3770 return (0); 3771 export_file_to_kinfo(fp, fd, rightsp, &efbuf->kif, efbuf->fdp, 3772 efbuf->flags); 3773 FILEDESC_SUNLOCK(efbuf->fdp); 3774 error = export_kinfo_to_sb(efbuf); 3775 FILEDESC_SLOCK(efbuf->fdp); 3776 return (error); 3777 } 3778 3779 static int 3780 export_vnode_to_sb(struct vnode *vp, int fd, int fflags, 3781 struct export_fd_buf *efbuf) 3782 { 3783 int error; 3784 3785 if (efbuf->remainder == 0) 3786 return (0); 3787 if (efbuf->fdp != NULL) 3788 FILEDESC_SUNLOCK(efbuf->fdp); 3789 export_vnode_to_kinfo(vp, fd, fflags, &efbuf->kif, efbuf->flags); 3790 error = export_kinfo_to_sb(efbuf); 3791 if (efbuf->fdp != NULL) 3792 FILEDESC_SLOCK(efbuf->fdp); 3793 return (error); 3794 } 3795 3796 /* 3797 * Store a process file descriptor information to sbuf. 3798 * 3799 * Takes a locked proc as argument, and returns with the proc unlocked. 3800 */ 3801 int 3802 kern_proc_filedesc_out(struct proc *p, struct sbuf *sb, ssize_t maxlen, 3803 int flags) 3804 { 3805 struct file *fp; 3806 struct filedesc *fdp; 3807 struct export_fd_buf *efbuf; 3808 struct vnode *cttyvp, *textvp, *tracevp; 3809 struct pwd *pwd; 3810 int error, i; 3811 cap_rights_t rights; 3812 3813 PROC_LOCK_ASSERT(p, MA_OWNED); 3814 3815 /* ktrace vnode */ 3816 tracevp = p->p_tracevp; 3817 if (tracevp != NULL) 3818 vrefact(tracevp); 3819 /* text vnode */ 3820 textvp = p->p_textvp; 3821 if (textvp != NULL) 3822 vrefact(textvp); 3823 /* Controlling tty. */ 3824 cttyvp = NULL; 3825 if (p->p_pgrp != NULL && p->p_pgrp->pg_session != NULL) { 3826 cttyvp = p->p_pgrp->pg_session->s_ttyvp; 3827 if (cttyvp != NULL) 3828 vrefact(cttyvp); 3829 } 3830 fdp = fdhold(p); 3831 PROC_UNLOCK(p); 3832 efbuf = malloc(sizeof(*efbuf), M_TEMP, M_WAITOK); 3833 efbuf->fdp = NULL; 3834 efbuf->sb = sb; 3835 efbuf->remainder = maxlen; 3836 efbuf->flags = flags; 3837 if (tracevp != NULL) 3838 export_vnode_to_sb(tracevp, KF_FD_TYPE_TRACE, FREAD | FWRITE, 3839 efbuf); 3840 if (textvp != NULL) 3841 export_vnode_to_sb(textvp, KF_FD_TYPE_TEXT, FREAD, efbuf); 3842 if (cttyvp != NULL) 3843 export_vnode_to_sb(cttyvp, KF_FD_TYPE_CTTY, FREAD | FWRITE, 3844 efbuf); 3845 error = 0; 3846 if (fdp == NULL) 3847 goto fail; 3848 efbuf->fdp = fdp; 3849 FILEDESC_SLOCK(fdp); 3850 pwd = pwd_hold_filedesc(fdp); 3851 if (pwd != NULL) { 3852 /* working directory */ 3853 if (pwd->pwd_cdir != NULL) { 3854 vrefact(pwd->pwd_cdir); 3855 export_vnode_to_sb(pwd->pwd_cdir, KF_FD_TYPE_CWD, FREAD, efbuf); 3856 } 3857 /* root directory */ 3858 if (pwd->pwd_rdir != NULL) { 3859 vrefact(pwd->pwd_rdir); 3860 export_vnode_to_sb(pwd->pwd_rdir, KF_FD_TYPE_ROOT, FREAD, efbuf); 3861 } 3862 /* jail directory */ 3863 if (pwd->pwd_jdir != NULL) { 3864 vrefact(pwd->pwd_jdir); 3865 export_vnode_to_sb(pwd->pwd_jdir, KF_FD_TYPE_JAIL, FREAD, efbuf); 3866 } 3867 pwd_drop(pwd); 3868 } 3869 for (i = 0; fdp->fd_refcnt > 0 && i <= fdp->fd_lastfile; i++) { 3870 if ((fp = fdp->fd_ofiles[i].fde_file) == NULL) 3871 continue; 3872 #ifdef CAPABILITIES 3873 rights = *cap_rights(fdp, i); 3874 #else /* !CAPABILITIES */ 3875 rights = cap_no_rights; 3876 #endif 3877 /* 3878 * Create sysctl entry. It is OK to drop the filedesc 3879 * lock inside of export_file_to_sb() as we will 3880 * re-validate and re-evaluate its properties when the 3881 * loop continues. 3882 */ 3883 error = export_file_to_sb(fp, i, &rights, efbuf); 3884 if (error != 0 || efbuf->remainder == 0) 3885 break; 3886 } 3887 FILEDESC_SUNLOCK(fdp); 3888 fddrop(fdp); 3889 fail: 3890 free(efbuf, M_TEMP); 3891 return (error); 3892 } 3893 3894 #define FILEDESC_SBUF_SIZE (sizeof(struct kinfo_file) * 5) 3895 3896 /* 3897 * Get per-process file descriptors for use by procstat(1), et al. 3898 */ 3899 static int 3900 sysctl_kern_proc_filedesc(SYSCTL_HANDLER_ARGS) 3901 { 3902 struct sbuf sb; 3903 struct proc *p; 3904 ssize_t maxlen; 3905 int error, error2, *name; 3906 3907 name = (int *)arg1; 3908 3909 sbuf_new_for_sysctl(&sb, NULL, FILEDESC_SBUF_SIZE, req); 3910 sbuf_clear_flags(&sb, SBUF_INCLUDENUL); 3911 error = pget((pid_t)name[0], PGET_CANDEBUG | PGET_NOTWEXIT, &p); 3912 if (error != 0) { 3913 sbuf_delete(&sb); 3914 return (error); 3915 } 3916 maxlen = req->oldptr != NULL ? req->oldlen : -1; 3917 error = kern_proc_filedesc_out(p, &sb, maxlen, 3918 KERN_FILEDESC_PACK_KINFO); 3919 error2 = sbuf_finish(&sb); 3920 sbuf_delete(&sb); 3921 return (error != 0 ? error : error2); 3922 } 3923 3924 #ifdef COMPAT_FREEBSD7 3925 #ifdef KINFO_OFILE_SIZE 3926 CTASSERT(sizeof(struct kinfo_ofile) == KINFO_OFILE_SIZE); 3927 #endif 3928 3929 static void 3930 kinfo_to_okinfo(struct kinfo_file *kif, struct kinfo_ofile *okif) 3931 { 3932 3933 okif->kf_structsize = sizeof(*okif); 3934 okif->kf_type = kif->kf_type; 3935 okif->kf_fd = kif->kf_fd; 3936 okif->kf_ref_count = kif->kf_ref_count; 3937 okif->kf_flags = kif->kf_flags & (KF_FLAG_READ | KF_FLAG_WRITE | 3938 KF_FLAG_APPEND | KF_FLAG_ASYNC | KF_FLAG_FSYNC | KF_FLAG_NONBLOCK | 3939 KF_FLAG_DIRECT | KF_FLAG_HASLOCK); 3940 okif->kf_offset = kif->kf_offset; 3941 if (kif->kf_type == KF_TYPE_VNODE) 3942 okif->kf_vnode_type = kif->kf_un.kf_file.kf_file_type; 3943 else 3944 okif->kf_vnode_type = KF_VTYPE_VNON; 3945 strlcpy(okif->kf_path, kif->kf_path, sizeof(okif->kf_path)); 3946 if (kif->kf_type == KF_TYPE_SOCKET) { 3947 okif->kf_sock_domain = kif->kf_un.kf_sock.kf_sock_domain0; 3948 okif->kf_sock_type = kif->kf_un.kf_sock.kf_sock_type0; 3949 okif->kf_sock_protocol = kif->kf_un.kf_sock.kf_sock_protocol0; 3950 okif->kf_sa_local = kif->kf_un.kf_sock.kf_sa_local; 3951 okif->kf_sa_peer = kif->kf_un.kf_sock.kf_sa_peer; 3952 } else { 3953 okif->kf_sa_local.ss_family = AF_UNSPEC; 3954 okif->kf_sa_peer.ss_family = AF_UNSPEC; 3955 } 3956 } 3957 3958 static int 3959 export_vnode_for_osysctl(struct vnode *vp, int type, struct kinfo_file *kif, 3960 struct kinfo_ofile *okif, struct filedesc *fdp, struct sysctl_req *req) 3961 { 3962 int error; 3963 3964 vrefact(vp); 3965 FILEDESC_SUNLOCK(fdp); 3966 export_vnode_to_kinfo(vp, type, 0, kif, KERN_FILEDESC_PACK_KINFO); 3967 kinfo_to_okinfo(kif, okif); 3968 error = SYSCTL_OUT(req, okif, sizeof(*okif)); 3969 FILEDESC_SLOCK(fdp); 3970 return (error); 3971 } 3972 3973 /* 3974 * Get per-process file descriptors for use by procstat(1), et al. 3975 */ 3976 static int 3977 sysctl_kern_proc_ofiledesc(SYSCTL_HANDLER_ARGS) 3978 { 3979 struct kinfo_ofile *okif; 3980 struct kinfo_file *kif; 3981 struct filedesc *fdp; 3982 struct pwd *pwd; 3983 int error, i, *name; 3984 struct file *fp; 3985 struct proc *p; 3986 3987 name = (int *)arg1; 3988 error = pget((pid_t)name[0], PGET_CANDEBUG | PGET_NOTWEXIT, &p); 3989 if (error != 0) 3990 return (error); 3991 fdp = fdhold(p); 3992 PROC_UNLOCK(p); 3993 if (fdp == NULL) 3994 return (ENOENT); 3995 kif = malloc(sizeof(*kif), M_TEMP, M_WAITOK); 3996 okif = malloc(sizeof(*okif), M_TEMP, M_WAITOK); 3997 FILEDESC_SLOCK(fdp); 3998 pwd = pwd_hold_filedesc(fdp); 3999 if (pwd != NULL) { 4000 if (pwd->pwd_cdir != NULL) 4001 export_vnode_for_osysctl(pwd->pwd_cdir, KF_FD_TYPE_CWD, kif, 4002 okif, fdp, req); 4003 if (pwd->pwd_rdir != NULL) 4004 export_vnode_for_osysctl(pwd->pwd_rdir, KF_FD_TYPE_ROOT, kif, 4005 okif, fdp, req); 4006 if (pwd->pwd_jdir != NULL) 4007 export_vnode_for_osysctl(pwd->pwd_jdir, KF_FD_TYPE_JAIL, kif, 4008 okif, fdp, req); 4009 pwd_drop(pwd); 4010 } 4011 for (i = 0; fdp->fd_refcnt > 0 && i <= fdp->fd_lastfile; i++) { 4012 if ((fp = fdp->fd_ofiles[i].fde_file) == NULL) 4013 continue; 4014 export_file_to_kinfo(fp, i, NULL, kif, fdp, 4015 KERN_FILEDESC_PACK_KINFO); 4016 FILEDESC_SUNLOCK(fdp); 4017 kinfo_to_okinfo(kif, okif); 4018 error = SYSCTL_OUT(req, okif, sizeof(*okif)); 4019 FILEDESC_SLOCK(fdp); 4020 if (error) 4021 break; 4022 } 4023 FILEDESC_SUNLOCK(fdp); 4024 fddrop(fdp); 4025 free(kif, M_TEMP); 4026 free(okif, M_TEMP); 4027 return (0); 4028 } 4029 4030 static SYSCTL_NODE(_kern_proc, KERN_PROC_OFILEDESC, ofiledesc, 4031 CTLFLAG_RD|CTLFLAG_MPSAFE, sysctl_kern_proc_ofiledesc, 4032 "Process ofiledesc entries"); 4033 #endif /* COMPAT_FREEBSD7 */ 4034 4035 int 4036 vntype_to_kinfo(int vtype) 4037 { 4038 struct { 4039 int vtype; 4040 int kf_vtype; 4041 } vtypes_table[] = { 4042 { VBAD, KF_VTYPE_VBAD }, 4043 { VBLK, KF_VTYPE_VBLK }, 4044 { VCHR, KF_VTYPE_VCHR }, 4045 { VDIR, KF_VTYPE_VDIR }, 4046 { VFIFO, KF_VTYPE_VFIFO }, 4047 { VLNK, KF_VTYPE_VLNK }, 4048 { VNON, KF_VTYPE_VNON }, 4049 { VREG, KF_VTYPE_VREG }, 4050 { VSOCK, KF_VTYPE_VSOCK } 4051 }; 4052 unsigned int i; 4053 4054 /* 4055 * Perform vtype translation. 4056 */ 4057 for (i = 0; i < nitems(vtypes_table); i++) 4058 if (vtypes_table[i].vtype == vtype) 4059 return (vtypes_table[i].kf_vtype); 4060 4061 return (KF_VTYPE_UNKNOWN); 4062 } 4063 4064 static SYSCTL_NODE(_kern_proc, KERN_PROC_FILEDESC, filedesc, 4065 CTLFLAG_RD|CTLFLAG_MPSAFE, sysctl_kern_proc_filedesc, 4066 "Process filedesc entries"); 4067 4068 /* 4069 * Store a process current working directory information to sbuf. 4070 * 4071 * Takes a locked proc as argument, and returns with the proc unlocked. 4072 */ 4073 int 4074 kern_proc_cwd_out(struct proc *p, struct sbuf *sb, ssize_t maxlen) 4075 { 4076 struct filedesc *fdp; 4077 struct export_fd_buf *efbuf; 4078 struct vnode *cdir; 4079 int error; 4080 4081 PROC_LOCK_ASSERT(p, MA_OWNED); 4082 4083 fdp = fdhold(p); 4084 PROC_UNLOCK(p); 4085 if (fdp == NULL) 4086 return (EINVAL); 4087 4088 efbuf = malloc(sizeof(*efbuf), M_TEMP, M_WAITOK); 4089 efbuf->fdp = fdp; 4090 efbuf->sb = sb; 4091 efbuf->remainder = maxlen; 4092 4093 FILEDESC_SLOCK(fdp); 4094 cdir = fdp->fd_pwd->pwd_cdir; 4095 if (cdir == NULL) { 4096 error = EINVAL; 4097 } else { 4098 vrefact(cdir); 4099 error = export_vnode_to_sb(cdir, KF_FD_TYPE_CWD, FREAD, efbuf); 4100 } 4101 FILEDESC_SUNLOCK(fdp); 4102 fddrop(fdp); 4103 free(efbuf, M_TEMP); 4104 return (error); 4105 } 4106 4107 /* 4108 * Get per-process current working directory. 4109 */ 4110 static int 4111 sysctl_kern_proc_cwd(SYSCTL_HANDLER_ARGS) 4112 { 4113 struct sbuf sb; 4114 struct proc *p; 4115 ssize_t maxlen; 4116 int error, error2, *name; 4117 4118 name = (int *)arg1; 4119 4120 sbuf_new_for_sysctl(&sb, NULL, sizeof(struct kinfo_file), req); 4121 sbuf_clear_flags(&sb, SBUF_INCLUDENUL); 4122 error = pget((pid_t)name[0], PGET_CANDEBUG | PGET_NOTWEXIT, &p); 4123 if (error != 0) { 4124 sbuf_delete(&sb); 4125 return (error); 4126 } 4127 maxlen = req->oldptr != NULL ? req->oldlen : -1; 4128 error = kern_proc_cwd_out(p, &sb, maxlen); 4129 error2 = sbuf_finish(&sb); 4130 sbuf_delete(&sb); 4131 return (error != 0 ? error : error2); 4132 } 4133 4134 static SYSCTL_NODE(_kern_proc, KERN_PROC_CWD, cwd, CTLFLAG_RD|CTLFLAG_MPSAFE, 4135 sysctl_kern_proc_cwd, "Process current working directory"); 4136 4137 #ifdef DDB 4138 /* 4139 * For the purposes of debugging, generate a human-readable string for the 4140 * file type. 4141 */ 4142 static const char * 4143 file_type_to_name(short type) 4144 { 4145 4146 switch (type) { 4147 case 0: 4148 return ("zero"); 4149 case DTYPE_VNODE: 4150 return ("vnode"); 4151 case DTYPE_SOCKET: 4152 return ("socket"); 4153 case DTYPE_PIPE: 4154 return ("pipe"); 4155 case DTYPE_FIFO: 4156 return ("fifo"); 4157 case DTYPE_KQUEUE: 4158 return ("kqueue"); 4159 case DTYPE_CRYPTO: 4160 return ("crypto"); 4161 case DTYPE_MQUEUE: 4162 return ("mqueue"); 4163 case DTYPE_SHM: 4164 return ("shm"); 4165 case DTYPE_SEM: 4166 return ("ksem"); 4167 case DTYPE_PTS: 4168 return ("pts"); 4169 case DTYPE_DEV: 4170 return ("dev"); 4171 case DTYPE_PROCDESC: 4172 return ("proc"); 4173 case DTYPE_LINUXEFD: 4174 return ("levent"); 4175 case DTYPE_LINUXTFD: 4176 return ("ltimer"); 4177 default: 4178 return ("unkn"); 4179 } 4180 } 4181 4182 /* 4183 * For the purposes of debugging, identify a process (if any, perhaps one of 4184 * many) that references the passed file in its file descriptor array. Return 4185 * NULL if none. 4186 */ 4187 static struct proc * 4188 file_to_first_proc(struct file *fp) 4189 { 4190 struct filedesc *fdp; 4191 struct proc *p; 4192 int n; 4193 4194 FOREACH_PROC_IN_SYSTEM(p) { 4195 if (p->p_state == PRS_NEW) 4196 continue; 4197 fdp = p->p_fd; 4198 if (fdp == NULL) 4199 continue; 4200 for (n = 0; n <= fdp->fd_lastfile; n++) { 4201 if (fp == fdp->fd_ofiles[n].fde_file) 4202 return (p); 4203 } 4204 } 4205 return (NULL); 4206 } 4207 4208 static void 4209 db_print_file(struct file *fp, int header) 4210 { 4211 #define XPTRWIDTH ((int)howmany(sizeof(void *) * NBBY, 4)) 4212 struct proc *p; 4213 4214 if (header) 4215 db_printf("%*s %6s %*s %8s %4s %5s %6s %*s %5s %s\n", 4216 XPTRWIDTH, "File", "Type", XPTRWIDTH, "Data", "Flag", 4217 "GCFl", "Count", "MCount", XPTRWIDTH, "Vnode", "FPID", 4218 "FCmd"); 4219 p = file_to_first_proc(fp); 4220 db_printf("%*p %6s %*p %08x %04x %5d %6d %*p %5d %s\n", XPTRWIDTH, 4221 fp, file_type_to_name(fp->f_type), XPTRWIDTH, fp->f_data, 4222 fp->f_flag, 0, fp->f_count, 0, XPTRWIDTH, fp->f_vnode, 4223 p != NULL ? p->p_pid : -1, p != NULL ? p->p_comm : "-"); 4224 4225 #undef XPTRWIDTH 4226 } 4227 4228 DB_SHOW_COMMAND(file, db_show_file) 4229 { 4230 struct file *fp; 4231 4232 if (!have_addr) { 4233 db_printf("usage: show file <addr>\n"); 4234 return; 4235 } 4236 fp = (struct file *)addr; 4237 db_print_file(fp, 1); 4238 } 4239 4240 DB_SHOW_COMMAND(files, db_show_files) 4241 { 4242 struct filedesc *fdp; 4243 struct file *fp; 4244 struct proc *p; 4245 int header; 4246 int n; 4247 4248 header = 1; 4249 FOREACH_PROC_IN_SYSTEM(p) { 4250 if (p->p_state == PRS_NEW) 4251 continue; 4252 if ((fdp = p->p_fd) == NULL) 4253 continue; 4254 for (n = 0; n <= fdp->fd_lastfile; ++n) { 4255 if ((fp = fdp->fd_ofiles[n].fde_file) == NULL) 4256 continue; 4257 db_print_file(fp, header); 4258 header = 0; 4259 } 4260 } 4261 } 4262 #endif 4263 4264 SYSCTL_INT(_kern, KERN_MAXFILESPERPROC, maxfilesperproc, CTLFLAG_RW, 4265 &maxfilesperproc, 0, "Maximum files allowed open per process"); 4266 4267 SYSCTL_INT(_kern, KERN_MAXFILES, maxfiles, CTLFLAG_RW, 4268 &maxfiles, 0, "Maximum number of files"); 4269 4270 SYSCTL_INT(_kern, OID_AUTO, openfiles, CTLFLAG_RD, 4271 &openfiles, 0, "System-wide number of open files"); 4272 4273 /* ARGSUSED*/ 4274 static void 4275 filelistinit(void *dummy) 4276 { 4277 4278 file_zone = uma_zcreate("Files", sizeof(struct file), NULL, NULL, 4279 NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE); 4280 filedesc0_zone = uma_zcreate("filedesc0", sizeof(struct filedesc0), 4281 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0); 4282 mtx_init(&sigio_lock, "sigio lock", NULL, MTX_DEF); 4283 } 4284 SYSINIT(select, SI_SUB_LOCK, SI_ORDER_FIRST, filelistinit, NULL); 4285 4286 /*-------------------------------------------------------------------*/ 4287 4288 static int 4289 badfo_readwrite(struct file *fp, struct uio *uio, struct ucred *active_cred, 4290 int flags, struct thread *td) 4291 { 4292 4293 return (EBADF); 4294 } 4295 4296 static int 4297 badfo_truncate(struct file *fp, off_t length, struct ucred *active_cred, 4298 struct thread *td) 4299 { 4300 4301 return (EINVAL); 4302 } 4303 4304 static int 4305 badfo_ioctl(struct file *fp, u_long com, void *data, struct ucred *active_cred, 4306 struct thread *td) 4307 { 4308 4309 return (EBADF); 4310 } 4311 4312 static int 4313 badfo_poll(struct file *fp, int events, struct ucred *active_cred, 4314 struct thread *td) 4315 { 4316 4317 return (0); 4318 } 4319 4320 static int 4321 badfo_kqfilter(struct file *fp, struct knote *kn) 4322 { 4323 4324 return (EBADF); 4325 } 4326 4327 static int 4328 badfo_stat(struct file *fp, struct stat *sb, struct ucred *active_cred, 4329 struct thread *td) 4330 { 4331 4332 return (EBADF); 4333 } 4334 4335 static int 4336 badfo_close(struct file *fp, struct thread *td) 4337 { 4338 4339 return (0); 4340 } 4341 4342 static int 4343 badfo_chmod(struct file *fp, mode_t mode, struct ucred *active_cred, 4344 struct thread *td) 4345 { 4346 4347 return (EBADF); 4348 } 4349 4350 static int 4351 badfo_chown(struct file *fp, uid_t uid, gid_t gid, struct ucred *active_cred, 4352 struct thread *td) 4353 { 4354 4355 return (EBADF); 4356 } 4357 4358 static int 4359 badfo_sendfile(struct file *fp, int sockfd, struct uio *hdr_uio, 4360 struct uio *trl_uio, off_t offset, size_t nbytes, off_t *sent, int flags, 4361 struct thread *td) 4362 { 4363 4364 return (EBADF); 4365 } 4366 4367 static int 4368 badfo_fill_kinfo(struct file *fp, struct kinfo_file *kif, struct filedesc *fdp) 4369 { 4370 4371 return (0); 4372 } 4373 4374 struct fileops badfileops = { 4375 .fo_read = badfo_readwrite, 4376 .fo_write = badfo_readwrite, 4377 .fo_truncate = badfo_truncate, 4378 .fo_ioctl = badfo_ioctl, 4379 .fo_poll = badfo_poll, 4380 .fo_kqfilter = badfo_kqfilter, 4381 .fo_stat = badfo_stat, 4382 .fo_close = badfo_close, 4383 .fo_chmod = badfo_chmod, 4384 .fo_chown = badfo_chown, 4385 .fo_sendfile = badfo_sendfile, 4386 .fo_fill_kinfo = badfo_fill_kinfo, 4387 }; 4388 4389 int 4390 invfo_rdwr(struct file *fp, struct uio *uio, struct ucred *active_cred, 4391 int flags, struct thread *td) 4392 { 4393 4394 return (EOPNOTSUPP); 4395 } 4396 4397 int 4398 invfo_truncate(struct file *fp, off_t length, struct ucred *active_cred, 4399 struct thread *td) 4400 { 4401 4402 return (EINVAL); 4403 } 4404 4405 int 4406 invfo_ioctl(struct file *fp, u_long com, void *data, 4407 struct ucred *active_cred, struct thread *td) 4408 { 4409 4410 return (ENOTTY); 4411 } 4412 4413 int 4414 invfo_poll(struct file *fp, int events, struct ucred *active_cred, 4415 struct thread *td) 4416 { 4417 4418 return (poll_no_poll(events)); 4419 } 4420 4421 int 4422 invfo_kqfilter(struct file *fp, struct knote *kn) 4423 { 4424 4425 return (EINVAL); 4426 } 4427 4428 int 4429 invfo_chmod(struct file *fp, mode_t mode, struct ucred *active_cred, 4430 struct thread *td) 4431 { 4432 4433 return (EINVAL); 4434 } 4435 4436 int 4437 invfo_chown(struct file *fp, uid_t uid, gid_t gid, struct ucred *active_cred, 4438 struct thread *td) 4439 { 4440 4441 return (EINVAL); 4442 } 4443 4444 int 4445 invfo_sendfile(struct file *fp, int sockfd, struct uio *hdr_uio, 4446 struct uio *trl_uio, off_t offset, size_t nbytes, off_t *sent, int flags, 4447 struct thread *td) 4448 { 4449 4450 return (EINVAL); 4451 } 4452 4453 /*-------------------------------------------------------------------*/ 4454 4455 /* 4456 * File Descriptor pseudo-device driver (/dev/fd/). 4457 * 4458 * Opening minor device N dup()s the file (if any) connected to file 4459 * descriptor N belonging to the calling process. Note that this driver 4460 * consists of only the ``open()'' routine, because all subsequent 4461 * references to this file will be direct to the other driver. 4462 * 4463 * XXX: we could give this one a cloning event handler if necessary. 4464 */ 4465 4466 /* ARGSUSED */ 4467 static int 4468 fdopen(struct cdev *dev, int mode, int type, struct thread *td) 4469 { 4470 4471 /* 4472 * XXX Kludge: set curthread->td_dupfd to contain the value of the 4473 * the file descriptor being sought for duplication. The error 4474 * return ensures that the vnode for this device will be released 4475 * by vn_open. Open will detect this special error and take the 4476 * actions in dupfdopen below. Other callers of vn_open or VOP_OPEN 4477 * will simply report the error. 4478 */ 4479 td->td_dupfd = dev2unit(dev); 4480 return (ENODEV); 4481 } 4482 4483 static struct cdevsw fildesc_cdevsw = { 4484 .d_version = D_VERSION, 4485 .d_open = fdopen, 4486 .d_name = "FD", 4487 }; 4488 4489 static void 4490 fildesc_drvinit(void *unused) 4491 { 4492 struct cdev *dev; 4493 4494 dev = make_dev_credf(MAKEDEV_ETERNAL, &fildesc_cdevsw, 0, NULL, 4495 UID_ROOT, GID_WHEEL, 0666, "fd/0"); 4496 make_dev_alias(dev, "stdin"); 4497 dev = make_dev_credf(MAKEDEV_ETERNAL, &fildesc_cdevsw, 1, NULL, 4498 UID_ROOT, GID_WHEEL, 0666, "fd/1"); 4499 make_dev_alias(dev, "stdout"); 4500 dev = make_dev_credf(MAKEDEV_ETERNAL, &fildesc_cdevsw, 2, NULL, 4501 UID_ROOT, GID_WHEEL, 0666, "fd/2"); 4502 make_dev_alias(dev, "stderr"); 4503 } 4504 4505 SYSINIT(fildescdev, SI_SUB_DRIVERS, SI_ORDER_MIDDLE, fildesc_drvinit, NULL); 4506