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/smr.h> 73 #include <sys/stat.h> 74 #include <sys/sx.h> 75 #include <sys/syscallsubr.h> 76 #include <sys/sysctl.h> 77 #include <sys/sysproto.h> 78 #include <sys/unistd.h> 79 #include <sys/user.h> 80 #include <sys/vnode.h> 81 #ifdef KTRACE 82 #include <sys/ktrace.h> 83 #endif 84 85 #include <net/vnet.h> 86 87 #include <security/audit/audit.h> 88 89 #include <vm/uma.h> 90 #include <vm/vm.h> 91 92 #include <ddb/ddb.h> 93 94 static MALLOC_DEFINE(M_FILEDESC, "filedesc", "Open file descriptor table"); 95 static MALLOC_DEFINE(M_PWD, "pwd", "Descriptor table vnodes"); 96 static MALLOC_DEFINE(M_FILEDESC_TO_LEADER, "filedesc_to_leader", 97 "file desc to leader structures"); 98 static MALLOC_DEFINE(M_SIGIO, "sigio", "sigio structures"); 99 MALLOC_DEFINE(M_FILECAPS, "filecaps", "descriptor capabilities"); 100 101 MALLOC_DECLARE(M_FADVISE); 102 103 static __read_mostly uma_zone_t file_zone; 104 static __read_mostly uma_zone_t filedesc0_zone; 105 static __read_mostly uma_zone_t pwd_zone; 106 static __read_mostly smr_t pwd_smr; 107 108 static int closefp(struct filedesc *fdp, int fd, struct file *fp, 109 struct thread *td, int holdleaders); 110 static int fd_first_free(struct filedesc *fdp, int low, int size); 111 static int fd_last_used(struct filedesc *fdp, int size); 112 static void fdgrowtable(struct filedesc *fdp, int nfd); 113 static void fdgrowtable_exp(struct filedesc *fdp, int nfd); 114 static void fdunused(struct filedesc *fdp, int fd); 115 static void fdused(struct filedesc *fdp, int fd); 116 static int getmaxfd(struct thread *td); 117 static u_long *filecaps_copy_prep(const struct filecaps *src); 118 static void filecaps_copy_finish(const struct filecaps *src, 119 struct filecaps *dst, u_long *ioctls); 120 static u_long *filecaps_free_prep(struct filecaps *fcaps); 121 static void filecaps_free_finish(u_long *ioctls); 122 123 static struct pwd *pwd_alloc(void); 124 125 /* 126 * Each process has: 127 * 128 * - An array of open file descriptors (fd_ofiles) 129 * - An array of file flags (fd_ofileflags) 130 * - A bitmap recording which descriptors are in use (fd_map) 131 * 132 * A process starts out with NDFILE descriptors. The value of NDFILE has 133 * been selected based the historical limit of 20 open files, and an 134 * assumption that the majority of processes, especially short-lived 135 * processes like shells, will never need more. 136 * 137 * If this initial allocation is exhausted, a larger descriptor table and 138 * map are allocated dynamically, and the pointers in the process's struct 139 * filedesc are updated to point to those. This is repeated every time 140 * the process runs out of file descriptors (provided it hasn't hit its 141 * resource limit). 142 * 143 * Since threads may hold references to individual descriptor table 144 * entries, the tables are never freed. Instead, they are placed on a 145 * linked list and freed only when the struct filedesc is released. 146 */ 147 #define NDFILE 20 148 #define NDSLOTSIZE sizeof(NDSLOTTYPE) 149 #define NDENTRIES (NDSLOTSIZE * __CHAR_BIT) 150 #define NDSLOT(x) ((x) / NDENTRIES) 151 #define NDBIT(x) ((NDSLOTTYPE)1 << ((x) % NDENTRIES)) 152 #define NDSLOTS(x) (((x) + NDENTRIES - 1) / NDENTRIES) 153 154 /* 155 * SLIST entry used to keep track of ofiles which must be reclaimed when 156 * the process exits. 157 */ 158 struct freetable { 159 struct fdescenttbl *ft_table; 160 SLIST_ENTRY(freetable) ft_next; 161 }; 162 163 /* 164 * Initial allocation: a filedesc structure + the head of SLIST used to 165 * keep track of old ofiles + enough space for NDFILE descriptors. 166 */ 167 168 struct fdescenttbl0 { 169 int fdt_nfiles; 170 struct filedescent fdt_ofiles[NDFILE]; 171 }; 172 173 struct filedesc0 { 174 struct filedesc fd_fd; 175 SLIST_HEAD(, freetable) fd_free; 176 struct fdescenttbl0 fd_dfiles; 177 NDSLOTTYPE fd_dmap[NDSLOTS(NDFILE)]; 178 }; 179 180 /* 181 * Descriptor management. 182 */ 183 static int __exclusive_cache_line openfiles; /* actual number of open files */ 184 struct mtx sigio_lock; /* mtx to protect pointers to sigio */ 185 void __read_mostly (*mq_fdclose)(struct thread *td, int fd, struct file *fp); 186 187 /* 188 * If low >= size, just return low. Otherwise find the first zero bit in the 189 * given bitmap, starting at low and not exceeding size - 1. Return size if 190 * not found. 191 */ 192 static int 193 fd_first_free(struct filedesc *fdp, int low, int size) 194 { 195 NDSLOTTYPE *map = fdp->fd_map; 196 NDSLOTTYPE mask; 197 int off, maxoff; 198 199 if (low >= size) 200 return (low); 201 202 off = NDSLOT(low); 203 if (low % NDENTRIES) { 204 mask = ~(~(NDSLOTTYPE)0 >> (NDENTRIES - (low % NDENTRIES))); 205 if ((mask &= ~map[off]) != 0UL) 206 return (off * NDENTRIES + ffsl(mask) - 1); 207 ++off; 208 } 209 for (maxoff = NDSLOTS(size); off < maxoff; ++off) 210 if (map[off] != ~0UL) 211 return (off * NDENTRIES + ffsl(~map[off]) - 1); 212 return (size); 213 } 214 215 /* 216 * Find the highest non-zero bit in the given bitmap, starting at 0 and 217 * not exceeding size - 1. Return -1 if not found. 218 */ 219 static int 220 fd_last_used(struct filedesc *fdp, int size) 221 { 222 NDSLOTTYPE *map = fdp->fd_map; 223 NDSLOTTYPE mask; 224 int off, minoff; 225 226 off = NDSLOT(size); 227 if (size % NDENTRIES) { 228 mask = ~(~(NDSLOTTYPE)0 << (size % NDENTRIES)); 229 if ((mask &= map[off]) != 0) 230 return (off * NDENTRIES + flsl(mask) - 1); 231 --off; 232 } 233 for (minoff = NDSLOT(0); off >= minoff; --off) 234 if (map[off] != 0) 235 return (off * NDENTRIES + flsl(map[off]) - 1); 236 return (-1); 237 } 238 239 static int 240 fdisused(struct filedesc *fdp, int fd) 241 { 242 243 KASSERT(fd >= 0 && fd < fdp->fd_nfiles, 244 ("file descriptor %d out of range (0, %d)", fd, fdp->fd_nfiles)); 245 246 return ((fdp->fd_map[NDSLOT(fd)] & NDBIT(fd)) != 0); 247 } 248 249 /* 250 * Mark a file descriptor as used. 251 */ 252 static void 253 fdused_init(struct filedesc *fdp, int fd) 254 { 255 256 KASSERT(!fdisused(fdp, fd), ("fd=%d is already used", fd)); 257 258 fdp->fd_map[NDSLOT(fd)] |= NDBIT(fd); 259 } 260 261 static void 262 fdused(struct filedesc *fdp, int fd) 263 { 264 265 FILEDESC_XLOCK_ASSERT(fdp); 266 267 fdused_init(fdp, fd); 268 if (fd > fdp->fd_lastfile) 269 fdp->fd_lastfile = fd; 270 if (fd == fdp->fd_freefile) 271 fdp->fd_freefile++; 272 } 273 274 /* 275 * Mark a file descriptor as unused. 276 */ 277 static void 278 fdunused(struct filedesc *fdp, int fd) 279 { 280 281 FILEDESC_XLOCK_ASSERT(fdp); 282 283 KASSERT(fdisused(fdp, fd), ("fd=%d is already unused", fd)); 284 KASSERT(fdp->fd_ofiles[fd].fde_file == NULL, 285 ("fd=%d is still in use", fd)); 286 287 fdp->fd_map[NDSLOT(fd)] &= ~NDBIT(fd); 288 if (fd < fdp->fd_freefile) 289 fdp->fd_freefile = fd; 290 if (fd == fdp->fd_lastfile) 291 fdp->fd_lastfile = fd_last_used(fdp, fd); 292 } 293 294 /* 295 * Free a file descriptor. 296 * 297 * Avoid some work if fdp is about to be destroyed. 298 */ 299 static inline void 300 fdefree_last(struct filedescent *fde) 301 { 302 303 filecaps_free(&fde->fde_caps); 304 } 305 306 static inline void 307 fdfree(struct filedesc *fdp, int fd) 308 { 309 struct filedescent *fde; 310 311 fde = &fdp->fd_ofiles[fd]; 312 #ifdef CAPABILITIES 313 seqc_write_begin(&fde->fde_seqc); 314 #endif 315 fde->fde_file = NULL; 316 #ifdef CAPABILITIES 317 seqc_write_end(&fde->fde_seqc); 318 #endif 319 fdefree_last(fde); 320 fdunused(fdp, fd); 321 } 322 323 /* 324 * System calls on descriptors. 325 */ 326 #ifndef _SYS_SYSPROTO_H_ 327 struct getdtablesize_args { 328 int dummy; 329 }; 330 #endif 331 /* ARGSUSED */ 332 int 333 sys_getdtablesize(struct thread *td, struct getdtablesize_args *uap) 334 { 335 #ifdef RACCT 336 uint64_t lim; 337 #endif 338 339 td->td_retval[0] = getmaxfd(td); 340 #ifdef RACCT 341 PROC_LOCK(td->td_proc); 342 lim = racct_get_limit(td->td_proc, RACCT_NOFILE); 343 PROC_UNLOCK(td->td_proc); 344 if (lim < td->td_retval[0]) 345 td->td_retval[0] = lim; 346 #endif 347 return (0); 348 } 349 350 /* 351 * Duplicate a file descriptor to a particular value. 352 * 353 * Note: keep in mind that a potential race condition exists when closing 354 * descriptors from a shared descriptor table (via rfork). 355 */ 356 #ifndef _SYS_SYSPROTO_H_ 357 struct dup2_args { 358 u_int from; 359 u_int to; 360 }; 361 #endif 362 /* ARGSUSED */ 363 int 364 sys_dup2(struct thread *td, struct dup2_args *uap) 365 { 366 367 return (kern_dup(td, FDDUP_FIXED, 0, (int)uap->from, (int)uap->to)); 368 } 369 370 /* 371 * Duplicate a file descriptor. 372 */ 373 #ifndef _SYS_SYSPROTO_H_ 374 struct dup_args { 375 u_int fd; 376 }; 377 #endif 378 /* ARGSUSED */ 379 int 380 sys_dup(struct thread *td, struct dup_args *uap) 381 { 382 383 return (kern_dup(td, FDDUP_NORMAL, 0, (int)uap->fd, 0)); 384 } 385 386 /* 387 * The file control system call. 388 */ 389 #ifndef _SYS_SYSPROTO_H_ 390 struct fcntl_args { 391 int fd; 392 int cmd; 393 long arg; 394 }; 395 #endif 396 /* ARGSUSED */ 397 int 398 sys_fcntl(struct thread *td, struct fcntl_args *uap) 399 { 400 401 return (kern_fcntl_freebsd(td, uap->fd, uap->cmd, uap->arg)); 402 } 403 404 int 405 kern_fcntl_freebsd(struct thread *td, int fd, int cmd, long arg) 406 { 407 struct flock fl; 408 struct __oflock ofl; 409 intptr_t arg1; 410 int error, newcmd; 411 412 error = 0; 413 newcmd = cmd; 414 switch (cmd) { 415 case F_OGETLK: 416 case F_OSETLK: 417 case F_OSETLKW: 418 /* 419 * Convert old flock structure to new. 420 */ 421 error = copyin((void *)(intptr_t)arg, &ofl, sizeof(ofl)); 422 fl.l_start = ofl.l_start; 423 fl.l_len = ofl.l_len; 424 fl.l_pid = ofl.l_pid; 425 fl.l_type = ofl.l_type; 426 fl.l_whence = ofl.l_whence; 427 fl.l_sysid = 0; 428 429 switch (cmd) { 430 case F_OGETLK: 431 newcmd = F_GETLK; 432 break; 433 case F_OSETLK: 434 newcmd = F_SETLK; 435 break; 436 case F_OSETLKW: 437 newcmd = F_SETLKW; 438 break; 439 } 440 arg1 = (intptr_t)&fl; 441 break; 442 case F_GETLK: 443 case F_SETLK: 444 case F_SETLKW: 445 case F_SETLK_REMOTE: 446 error = copyin((void *)(intptr_t)arg, &fl, sizeof(fl)); 447 arg1 = (intptr_t)&fl; 448 break; 449 default: 450 arg1 = arg; 451 break; 452 } 453 if (error) 454 return (error); 455 error = kern_fcntl(td, fd, newcmd, arg1); 456 if (error) 457 return (error); 458 if (cmd == F_OGETLK) { 459 ofl.l_start = fl.l_start; 460 ofl.l_len = fl.l_len; 461 ofl.l_pid = fl.l_pid; 462 ofl.l_type = fl.l_type; 463 ofl.l_whence = fl.l_whence; 464 error = copyout(&ofl, (void *)(intptr_t)arg, sizeof(ofl)); 465 } else if (cmd == F_GETLK) { 466 error = copyout(&fl, (void *)(intptr_t)arg, sizeof(fl)); 467 } 468 return (error); 469 } 470 471 int 472 kern_fcntl(struct thread *td, int fd, int cmd, intptr_t arg) 473 { 474 struct filedesc *fdp; 475 struct flock *flp; 476 struct file *fp, *fp2; 477 struct filedescent *fde; 478 struct proc *p; 479 struct vnode *vp; 480 struct mount *mp; 481 int error, flg, seals, tmp; 482 uint64_t bsize; 483 off_t foffset; 484 485 error = 0; 486 flg = F_POSIX; 487 p = td->td_proc; 488 fdp = p->p_fd; 489 490 AUDIT_ARG_FD(cmd); 491 AUDIT_ARG_CMD(cmd); 492 switch (cmd) { 493 case F_DUPFD: 494 tmp = arg; 495 error = kern_dup(td, FDDUP_FCNTL, 0, fd, tmp); 496 break; 497 498 case F_DUPFD_CLOEXEC: 499 tmp = arg; 500 error = kern_dup(td, FDDUP_FCNTL, FDDUP_FLAG_CLOEXEC, fd, tmp); 501 break; 502 503 case F_DUP2FD: 504 tmp = arg; 505 error = kern_dup(td, FDDUP_FIXED, 0, fd, tmp); 506 break; 507 508 case F_DUP2FD_CLOEXEC: 509 tmp = arg; 510 error = kern_dup(td, FDDUP_FIXED, FDDUP_FLAG_CLOEXEC, fd, tmp); 511 break; 512 513 case F_GETFD: 514 error = EBADF; 515 FILEDESC_SLOCK(fdp); 516 fde = fdeget_locked(fdp, fd); 517 if (fde != NULL) { 518 td->td_retval[0] = 519 (fde->fde_flags & UF_EXCLOSE) ? FD_CLOEXEC : 0; 520 error = 0; 521 } 522 FILEDESC_SUNLOCK(fdp); 523 break; 524 525 case F_SETFD: 526 error = EBADF; 527 FILEDESC_XLOCK(fdp); 528 fde = fdeget_locked(fdp, fd); 529 if (fde != NULL) { 530 fde->fde_flags = (fde->fde_flags & ~UF_EXCLOSE) | 531 (arg & FD_CLOEXEC ? UF_EXCLOSE : 0); 532 error = 0; 533 } 534 FILEDESC_XUNLOCK(fdp); 535 break; 536 537 case F_GETFL: 538 error = fget_fcntl(td, fd, &cap_fcntl_rights, F_GETFL, &fp); 539 if (error != 0) 540 break; 541 td->td_retval[0] = OFLAGS(fp->f_flag); 542 fdrop(fp, td); 543 break; 544 545 case F_SETFL: 546 error = fget_fcntl(td, fd, &cap_fcntl_rights, F_SETFL, &fp); 547 if (error != 0) 548 break; 549 do { 550 tmp = flg = fp->f_flag; 551 tmp &= ~FCNTLFLAGS; 552 tmp |= FFLAGS(arg & ~O_ACCMODE) & FCNTLFLAGS; 553 } while(atomic_cmpset_int(&fp->f_flag, flg, tmp) == 0); 554 tmp = fp->f_flag & FNONBLOCK; 555 error = fo_ioctl(fp, FIONBIO, &tmp, td->td_ucred, td); 556 if (error != 0) { 557 fdrop(fp, td); 558 break; 559 } 560 tmp = fp->f_flag & FASYNC; 561 error = fo_ioctl(fp, FIOASYNC, &tmp, td->td_ucred, td); 562 if (error == 0) { 563 fdrop(fp, td); 564 break; 565 } 566 atomic_clear_int(&fp->f_flag, FNONBLOCK); 567 tmp = 0; 568 (void)fo_ioctl(fp, FIONBIO, &tmp, td->td_ucred, td); 569 fdrop(fp, td); 570 break; 571 572 case F_GETOWN: 573 error = fget_fcntl(td, fd, &cap_fcntl_rights, F_GETOWN, &fp); 574 if (error != 0) 575 break; 576 error = fo_ioctl(fp, FIOGETOWN, &tmp, td->td_ucred, td); 577 if (error == 0) 578 td->td_retval[0] = tmp; 579 fdrop(fp, td); 580 break; 581 582 case F_SETOWN: 583 error = fget_fcntl(td, fd, &cap_fcntl_rights, F_SETOWN, &fp); 584 if (error != 0) 585 break; 586 tmp = arg; 587 error = fo_ioctl(fp, FIOSETOWN, &tmp, td->td_ucred, td); 588 fdrop(fp, td); 589 break; 590 591 case F_SETLK_REMOTE: 592 error = priv_check(td, PRIV_NFS_LOCKD); 593 if (error != 0) 594 return (error); 595 flg = F_REMOTE; 596 goto do_setlk; 597 598 case F_SETLKW: 599 flg |= F_WAIT; 600 /* FALLTHROUGH F_SETLK */ 601 602 case F_SETLK: 603 do_setlk: 604 flp = (struct flock *)arg; 605 if ((flg & F_REMOTE) != 0 && flp->l_sysid == 0) { 606 error = EINVAL; 607 break; 608 } 609 610 error = fget_unlocked(fdp, fd, &cap_flock_rights, &fp); 611 if (error != 0) 612 break; 613 if (fp->f_type != DTYPE_VNODE) { 614 error = EBADF; 615 fdrop(fp, td); 616 break; 617 } 618 619 if (flp->l_whence == SEEK_CUR) { 620 foffset = foffset_get(fp); 621 if (foffset < 0 || 622 (flp->l_start > 0 && 623 foffset > OFF_MAX - flp->l_start)) { 624 error = EOVERFLOW; 625 fdrop(fp, td); 626 break; 627 } 628 flp->l_start += foffset; 629 } 630 631 vp = fp->f_vnode; 632 switch (flp->l_type) { 633 case F_RDLCK: 634 if ((fp->f_flag & FREAD) == 0) { 635 error = EBADF; 636 break; 637 } 638 if ((p->p_leader->p_flag & P_ADVLOCK) == 0) { 639 PROC_LOCK(p->p_leader); 640 p->p_leader->p_flag |= P_ADVLOCK; 641 PROC_UNLOCK(p->p_leader); 642 } 643 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_SETLK, 644 flp, flg); 645 break; 646 case F_WRLCK: 647 if ((fp->f_flag & FWRITE) == 0) { 648 error = EBADF; 649 break; 650 } 651 if ((p->p_leader->p_flag & P_ADVLOCK) == 0) { 652 PROC_LOCK(p->p_leader); 653 p->p_leader->p_flag |= P_ADVLOCK; 654 PROC_UNLOCK(p->p_leader); 655 } 656 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_SETLK, 657 flp, flg); 658 break; 659 case F_UNLCK: 660 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_UNLCK, 661 flp, flg); 662 break; 663 case F_UNLCKSYS: 664 if (flg != F_REMOTE) { 665 error = EINVAL; 666 break; 667 } 668 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, 669 F_UNLCKSYS, flp, flg); 670 break; 671 default: 672 error = EINVAL; 673 break; 674 } 675 if (error != 0 || flp->l_type == F_UNLCK || 676 flp->l_type == F_UNLCKSYS) { 677 fdrop(fp, td); 678 break; 679 } 680 681 /* 682 * Check for a race with close. 683 * 684 * The vnode is now advisory locked (or unlocked, but this case 685 * is not really important) as the caller requested. 686 * We had to drop the filedesc lock, so we need to recheck if 687 * the descriptor is still valid, because if it was closed 688 * in the meantime we need to remove advisory lock from the 689 * vnode - close on any descriptor leading to an advisory 690 * locked vnode, removes that lock. 691 * We will return 0 on purpose in that case, as the result of 692 * successful advisory lock might have been externally visible 693 * already. This is fine - effectively we pretend to the caller 694 * that the closing thread was a bit slower and that the 695 * advisory lock succeeded before the close. 696 */ 697 error = fget_unlocked(fdp, fd, &cap_no_rights, &fp2); 698 if (error != 0) { 699 fdrop(fp, td); 700 break; 701 } 702 if (fp != fp2) { 703 flp->l_whence = SEEK_SET; 704 flp->l_start = 0; 705 flp->l_len = 0; 706 flp->l_type = F_UNLCK; 707 (void) VOP_ADVLOCK(vp, (caddr_t)p->p_leader, 708 F_UNLCK, flp, F_POSIX); 709 } 710 fdrop(fp, td); 711 fdrop(fp2, td); 712 break; 713 714 case F_GETLK: 715 error = fget_unlocked(fdp, fd, &cap_flock_rights, &fp); 716 if (error != 0) 717 break; 718 if (fp->f_type != DTYPE_VNODE) { 719 error = EBADF; 720 fdrop(fp, td); 721 break; 722 } 723 flp = (struct flock *)arg; 724 if (flp->l_type != F_RDLCK && flp->l_type != F_WRLCK && 725 flp->l_type != F_UNLCK) { 726 error = EINVAL; 727 fdrop(fp, td); 728 break; 729 } 730 if (flp->l_whence == SEEK_CUR) { 731 foffset = foffset_get(fp); 732 if ((flp->l_start > 0 && 733 foffset > OFF_MAX - flp->l_start) || 734 (flp->l_start < 0 && 735 foffset < OFF_MIN - flp->l_start)) { 736 error = EOVERFLOW; 737 fdrop(fp, td); 738 break; 739 } 740 flp->l_start += foffset; 741 } 742 vp = fp->f_vnode; 743 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_GETLK, flp, 744 F_POSIX); 745 fdrop(fp, td); 746 break; 747 748 case F_ADD_SEALS: 749 error = fget_unlocked(fdp, fd, &cap_no_rights, &fp); 750 if (error != 0) 751 break; 752 error = fo_add_seals(fp, arg); 753 fdrop(fp, td); 754 break; 755 756 case F_GET_SEALS: 757 error = fget_unlocked(fdp, fd, &cap_no_rights, &fp); 758 if (error != 0) 759 break; 760 if (fo_get_seals(fp, &seals) == 0) 761 td->td_retval[0] = seals; 762 else 763 error = EINVAL; 764 fdrop(fp, td); 765 break; 766 767 case F_RDAHEAD: 768 arg = arg ? 128 * 1024: 0; 769 /* FALLTHROUGH */ 770 case F_READAHEAD: 771 error = fget_unlocked(fdp, fd, &cap_no_rights, &fp); 772 if (error != 0) 773 break; 774 if (fp->f_type != DTYPE_VNODE) { 775 fdrop(fp, td); 776 error = EBADF; 777 break; 778 } 779 vp = fp->f_vnode; 780 if (vp->v_type != VREG) { 781 fdrop(fp, td); 782 error = ENOTTY; 783 break; 784 } 785 786 /* 787 * Exclusive lock synchronizes against f_seqcount reads and 788 * writes in sequential_heuristic(). 789 */ 790 error = vn_lock(vp, LK_EXCLUSIVE); 791 if (error != 0) { 792 fdrop(fp, td); 793 break; 794 } 795 if (arg >= 0) { 796 bsize = fp->f_vnode->v_mount->mnt_stat.f_iosize; 797 arg = MIN(arg, INT_MAX - bsize + 1); 798 fp->f_seqcount = MIN(IO_SEQMAX, 799 (arg + bsize - 1) / bsize); 800 atomic_set_int(&fp->f_flag, FRDAHEAD); 801 } else { 802 atomic_clear_int(&fp->f_flag, FRDAHEAD); 803 } 804 VOP_UNLOCK(vp); 805 fdrop(fp, td); 806 break; 807 808 case F_ISUNIONSTACK: 809 /* 810 * Check if the vnode is part of a union stack (either the 811 * "union" flag from mount(2) or unionfs). 812 * 813 * Prior to introduction of this op libc's readdir would call 814 * fstatfs(2), in effect unnecessarily copying kilobytes of 815 * data just to check fs name and a mount flag. 816 * 817 * Fixing the code to handle everything in the kernel instead 818 * is a non-trivial endeavor and has low priority, thus this 819 * horrible kludge facilitates the current behavior in a much 820 * cheaper manner until someone(tm) sorts this out. 821 */ 822 error = fget_unlocked(fdp, fd, &cap_no_rights, &fp); 823 if (error != 0) 824 break; 825 if (fp->f_type != DTYPE_VNODE) { 826 fdrop(fp, td); 827 error = EBADF; 828 break; 829 } 830 vp = fp->f_vnode; 831 /* 832 * Since we don't prevent dooming the vnode even non-null mp 833 * found can become immediately stale. This is tolerable since 834 * mount points are type-stable (providing safe memory access) 835 * and any vfs op on this vnode going forward will return an 836 * error (meaning return value in this case is meaningless). 837 */ 838 mp = atomic_load_ptr(&vp->v_mount); 839 if (__predict_false(mp == NULL)) { 840 fdrop(fp, td); 841 error = EBADF; 842 break; 843 } 844 td->td_retval[0] = 0; 845 if (mp->mnt_kern_flag & MNTK_UNIONFS || 846 mp->mnt_flag & MNT_UNION) 847 td->td_retval[0] = 1; 848 fdrop(fp, td); 849 break; 850 851 default: 852 error = EINVAL; 853 break; 854 } 855 return (error); 856 } 857 858 static int 859 getmaxfd(struct thread *td) 860 { 861 862 return (min((int)lim_cur(td, RLIMIT_NOFILE), maxfilesperproc)); 863 } 864 865 /* 866 * Common code for dup, dup2, fcntl(F_DUPFD) and fcntl(F_DUP2FD). 867 */ 868 int 869 kern_dup(struct thread *td, u_int mode, int flags, int old, int new) 870 { 871 struct filedesc *fdp; 872 struct filedescent *oldfde, *newfde; 873 struct proc *p; 874 struct file *delfp; 875 u_long *oioctls, *nioctls; 876 int error, maxfd; 877 878 p = td->td_proc; 879 fdp = p->p_fd; 880 oioctls = NULL; 881 882 MPASS((flags & ~(FDDUP_FLAG_CLOEXEC)) == 0); 883 MPASS(mode < FDDUP_LASTMODE); 884 885 AUDIT_ARG_FD(old); 886 /* XXXRW: if (flags & FDDUP_FIXED) AUDIT_ARG_FD2(new); */ 887 888 /* 889 * Verify we have a valid descriptor to dup from and possibly to 890 * dup to. Unlike dup() and dup2(), fcntl()'s F_DUPFD should 891 * return EINVAL when the new descriptor is out of bounds. 892 */ 893 if (old < 0) 894 return (EBADF); 895 if (new < 0) 896 return (mode == FDDUP_FCNTL ? EINVAL : EBADF); 897 maxfd = getmaxfd(td); 898 if (new >= maxfd) 899 return (mode == FDDUP_FCNTL ? EINVAL : EBADF); 900 901 error = EBADF; 902 FILEDESC_XLOCK(fdp); 903 if (fget_locked(fdp, old) == NULL) 904 goto unlock; 905 if ((mode == FDDUP_FIXED || mode == FDDUP_MUSTREPLACE) && old == new) { 906 td->td_retval[0] = new; 907 if (flags & FDDUP_FLAG_CLOEXEC) 908 fdp->fd_ofiles[new].fde_flags |= UF_EXCLOSE; 909 error = 0; 910 goto unlock; 911 } 912 913 oldfde = &fdp->fd_ofiles[old]; 914 if (!fhold(oldfde->fde_file)) 915 goto unlock; 916 917 /* 918 * If the caller specified a file descriptor, make sure the file 919 * table is large enough to hold it, and grab it. Otherwise, just 920 * allocate a new descriptor the usual way. 921 */ 922 switch (mode) { 923 case FDDUP_NORMAL: 924 case FDDUP_FCNTL: 925 if ((error = fdalloc(td, new, &new)) != 0) { 926 fdrop(oldfde->fde_file, td); 927 goto unlock; 928 } 929 break; 930 case FDDUP_MUSTREPLACE: 931 /* Target file descriptor must exist. */ 932 if (fget_locked(fdp, new) == NULL) { 933 fdrop(oldfde->fde_file, td); 934 goto unlock; 935 } 936 break; 937 case FDDUP_FIXED: 938 if (new >= fdp->fd_nfiles) { 939 /* 940 * The resource limits are here instead of e.g. 941 * fdalloc(), because the file descriptor table may be 942 * shared between processes, so we can't really use 943 * racct_add()/racct_sub(). Instead of counting the 944 * number of actually allocated descriptors, just put 945 * the limit on the size of the file descriptor table. 946 */ 947 #ifdef RACCT 948 if (RACCT_ENABLED()) { 949 error = racct_set_unlocked(p, RACCT_NOFILE, new + 1); 950 if (error != 0) { 951 error = EMFILE; 952 fdrop(oldfde->fde_file, td); 953 goto unlock; 954 } 955 } 956 #endif 957 fdgrowtable_exp(fdp, new + 1); 958 } 959 if (!fdisused(fdp, new)) 960 fdused(fdp, new); 961 break; 962 default: 963 KASSERT(0, ("%s unsupported mode %d", __func__, mode)); 964 } 965 966 KASSERT(old != new, ("new fd is same as old")); 967 968 newfde = &fdp->fd_ofiles[new]; 969 delfp = newfde->fde_file; 970 971 nioctls = filecaps_copy_prep(&oldfde->fde_caps); 972 973 /* 974 * Duplicate the source descriptor. 975 */ 976 #ifdef CAPABILITIES 977 seqc_write_begin(&newfde->fde_seqc); 978 #endif 979 oioctls = filecaps_free_prep(&newfde->fde_caps); 980 memcpy(newfde, oldfde, fde_change_size); 981 filecaps_copy_finish(&oldfde->fde_caps, &newfde->fde_caps, 982 nioctls); 983 if ((flags & FDDUP_FLAG_CLOEXEC) != 0) 984 newfde->fde_flags = oldfde->fde_flags | UF_EXCLOSE; 985 else 986 newfde->fde_flags = oldfde->fde_flags & ~UF_EXCLOSE; 987 #ifdef CAPABILITIES 988 seqc_write_end(&newfde->fde_seqc); 989 #endif 990 td->td_retval[0] = new; 991 992 error = 0; 993 994 if (delfp != NULL) { 995 (void) closefp(fdp, new, delfp, td, 1); 996 FILEDESC_UNLOCK_ASSERT(fdp); 997 } else { 998 unlock: 999 FILEDESC_XUNLOCK(fdp); 1000 } 1001 1002 filecaps_free_finish(oioctls); 1003 return (error); 1004 } 1005 1006 /* 1007 * If sigio is on the list associated with a process or process group, 1008 * disable signalling from the device, remove sigio from the list and 1009 * free sigio. 1010 */ 1011 void 1012 funsetown(struct sigio **sigiop) 1013 { 1014 struct sigio *sigio; 1015 1016 if (*sigiop == NULL) 1017 return; 1018 SIGIO_LOCK(); 1019 sigio = *sigiop; 1020 if (sigio == NULL) { 1021 SIGIO_UNLOCK(); 1022 return; 1023 } 1024 *(sigio->sio_myref) = NULL; 1025 if ((sigio)->sio_pgid < 0) { 1026 struct pgrp *pg = (sigio)->sio_pgrp; 1027 PGRP_LOCK(pg); 1028 SLIST_REMOVE(&sigio->sio_pgrp->pg_sigiolst, sigio, 1029 sigio, sio_pgsigio); 1030 PGRP_UNLOCK(pg); 1031 } else { 1032 struct proc *p = (sigio)->sio_proc; 1033 PROC_LOCK(p); 1034 SLIST_REMOVE(&sigio->sio_proc->p_sigiolst, sigio, 1035 sigio, sio_pgsigio); 1036 PROC_UNLOCK(p); 1037 } 1038 SIGIO_UNLOCK(); 1039 crfree(sigio->sio_ucred); 1040 free(sigio, M_SIGIO); 1041 } 1042 1043 /* 1044 * Free a list of sigio structures. 1045 * We only need to lock the SIGIO_LOCK because we have made ourselves 1046 * inaccessible to callers of fsetown and therefore do not need to lock 1047 * the proc or pgrp struct for the list manipulation. 1048 */ 1049 void 1050 funsetownlst(struct sigiolst *sigiolst) 1051 { 1052 struct proc *p; 1053 struct pgrp *pg; 1054 struct sigio *sigio; 1055 1056 sigio = SLIST_FIRST(sigiolst); 1057 if (sigio == NULL) 1058 return; 1059 p = NULL; 1060 pg = NULL; 1061 1062 /* 1063 * Every entry of the list should belong 1064 * to a single proc or pgrp. 1065 */ 1066 if (sigio->sio_pgid < 0) { 1067 pg = sigio->sio_pgrp; 1068 PGRP_LOCK_ASSERT(pg, MA_NOTOWNED); 1069 } else /* if (sigio->sio_pgid > 0) */ { 1070 p = sigio->sio_proc; 1071 PROC_LOCK_ASSERT(p, MA_NOTOWNED); 1072 } 1073 1074 SIGIO_LOCK(); 1075 while ((sigio = SLIST_FIRST(sigiolst)) != NULL) { 1076 *(sigio->sio_myref) = NULL; 1077 if (pg != NULL) { 1078 KASSERT(sigio->sio_pgid < 0, 1079 ("Proc sigio in pgrp sigio list")); 1080 KASSERT(sigio->sio_pgrp == pg, 1081 ("Bogus pgrp in sigio list")); 1082 PGRP_LOCK(pg); 1083 SLIST_REMOVE(&pg->pg_sigiolst, sigio, sigio, 1084 sio_pgsigio); 1085 PGRP_UNLOCK(pg); 1086 } else /* if (p != NULL) */ { 1087 KASSERT(sigio->sio_pgid > 0, 1088 ("Pgrp sigio in proc sigio list")); 1089 KASSERT(sigio->sio_proc == p, 1090 ("Bogus proc in sigio list")); 1091 PROC_LOCK(p); 1092 SLIST_REMOVE(&p->p_sigiolst, sigio, sigio, 1093 sio_pgsigio); 1094 PROC_UNLOCK(p); 1095 } 1096 SIGIO_UNLOCK(); 1097 crfree(sigio->sio_ucred); 1098 free(sigio, M_SIGIO); 1099 SIGIO_LOCK(); 1100 } 1101 SIGIO_UNLOCK(); 1102 } 1103 1104 /* 1105 * This is common code for FIOSETOWN ioctl called by fcntl(fd, F_SETOWN, arg). 1106 * 1107 * After permission checking, add a sigio structure to the sigio list for 1108 * the process or process group. 1109 */ 1110 int 1111 fsetown(pid_t pgid, struct sigio **sigiop) 1112 { 1113 struct proc *proc; 1114 struct pgrp *pgrp; 1115 struct sigio *sigio; 1116 int ret; 1117 1118 if (pgid == 0) { 1119 funsetown(sigiop); 1120 return (0); 1121 } 1122 1123 ret = 0; 1124 1125 /* Allocate and fill in the new sigio out of locks. */ 1126 sigio = malloc(sizeof(struct sigio), M_SIGIO, M_WAITOK); 1127 sigio->sio_pgid = pgid; 1128 sigio->sio_ucred = crhold(curthread->td_ucred); 1129 sigio->sio_myref = sigiop; 1130 1131 sx_slock(&proctree_lock); 1132 if (pgid > 0) { 1133 proc = pfind(pgid); 1134 if (proc == NULL) { 1135 ret = ESRCH; 1136 goto fail; 1137 } 1138 1139 /* 1140 * Policy - Don't allow a process to FSETOWN a process 1141 * in another session. 1142 * 1143 * Remove this test to allow maximum flexibility or 1144 * restrict FSETOWN to the current process or process 1145 * group for maximum safety. 1146 */ 1147 PROC_UNLOCK(proc); 1148 if (proc->p_session != curthread->td_proc->p_session) { 1149 ret = EPERM; 1150 goto fail; 1151 } 1152 1153 pgrp = NULL; 1154 } else /* if (pgid < 0) */ { 1155 pgrp = pgfind(-pgid); 1156 if (pgrp == NULL) { 1157 ret = ESRCH; 1158 goto fail; 1159 } 1160 PGRP_UNLOCK(pgrp); 1161 1162 /* 1163 * Policy - Don't allow a process to FSETOWN a process 1164 * in another session. 1165 * 1166 * Remove this test to allow maximum flexibility or 1167 * restrict FSETOWN to the current process or process 1168 * group for maximum safety. 1169 */ 1170 if (pgrp->pg_session != curthread->td_proc->p_session) { 1171 ret = EPERM; 1172 goto fail; 1173 } 1174 1175 proc = NULL; 1176 } 1177 funsetown(sigiop); 1178 if (pgid > 0) { 1179 PROC_LOCK(proc); 1180 /* 1181 * Since funsetownlst() is called without the proctree 1182 * locked, we need to check for P_WEXIT. 1183 * XXX: is ESRCH correct? 1184 */ 1185 if ((proc->p_flag & P_WEXIT) != 0) { 1186 PROC_UNLOCK(proc); 1187 ret = ESRCH; 1188 goto fail; 1189 } 1190 SLIST_INSERT_HEAD(&proc->p_sigiolst, sigio, sio_pgsigio); 1191 sigio->sio_proc = proc; 1192 PROC_UNLOCK(proc); 1193 } else { 1194 PGRP_LOCK(pgrp); 1195 SLIST_INSERT_HEAD(&pgrp->pg_sigiolst, sigio, sio_pgsigio); 1196 sigio->sio_pgrp = pgrp; 1197 PGRP_UNLOCK(pgrp); 1198 } 1199 sx_sunlock(&proctree_lock); 1200 SIGIO_LOCK(); 1201 *sigiop = sigio; 1202 SIGIO_UNLOCK(); 1203 return (0); 1204 1205 fail: 1206 sx_sunlock(&proctree_lock); 1207 crfree(sigio->sio_ucred); 1208 free(sigio, M_SIGIO); 1209 return (ret); 1210 } 1211 1212 /* 1213 * This is common code for FIOGETOWN ioctl called by fcntl(fd, F_GETOWN, arg). 1214 */ 1215 pid_t 1216 fgetown(struct sigio **sigiop) 1217 { 1218 pid_t pgid; 1219 1220 SIGIO_LOCK(); 1221 pgid = (*sigiop != NULL) ? (*sigiop)->sio_pgid : 0; 1222 SIGIO_UNLOCK(); 1223 return (pgid); 1224 } 1225 1226 /* 1227 * Function drops the filedesc lock on return. 1228 */ 1229 static int 1230 closefp(struct filedesc *fdp, int fd, struct file *fp, struct thread *td, 1231 int holdleaders) 1232 { 1233 int error; 1234 1235 FILEDESC_XLOCK_ASSERT(fdp); 1236 1237 if (holdleaders) { 1238 if (td->td_proc->p_fdtol != NULL) { 1239 /* 1240 * Ask fdfree() to sleep to ensure that all relevant 1241 * process leaders can be traversed in closef(). 1242 */ 1243 fdp->fd_holdleaderscount++; 1244 } else { 1245 holdleaders = 0; 1246 } 1247 } 1248 1249 /* 1250 * We now hold the fp reference that used to be owned by the 1251 * descriptor array. We have to unlock the FILEDESC *AFTER* 1252 * knote_fdclose to prevent a race of the fd getting opened, a knote 1253 * added, and deleteing a knote for the new fd. 1254 */ 1255 if (__predict_false(!TAILQ_EMPTY(&fdp->fd_kqlist))) 1256 knote_fdclose(td, fd); 1257 1258 /* 1259 * We need to notify mqueue if the object is of type mqueue. 1260 */ 1261 if (__predict_false(fp->f_type == DTYPE_MQUEUE)) 1262 mq_fdclose(td, fd, fp); 1263 FILEDESC_XUNLOCK(fdp); 1264 1265 error = closef(fp, td); 1266 if (holdleaders) { 1267 FILEDESC_XLOCK(fdp); 1268 fdp->fd_holdleaderscount--; 1269 if (fdp->fd_holdleaderscount == 0 && 1270 fdp->fd_holdleaderswakeup != 0) { 1271 fdp->fd_holdleaderswakeup = 0; 1272 wakeup(&fdp->fd_holdleaderscount); 1273 } 1274 FILEDESC_XUNLOCK(fdp); 1275 } 1276 return (error); 1277 } 1278 1279 /* 1280 * Close a file descriptor. 1281 */ 1282 #ifndef _SYS_SYSPROTO_H_ 1283 struct close_args { 1284 int fd; 1285 }; 1286 #endif 1287 /* ARGSUSED */ 1288 int 1289 sys_close(struct thread *td, struct close_args *uap) 1290 { 1291 1292 return (kern_close(td, uap->fd)); 1293 } 1294 1295 int 1296 kern_close(struct thread *td, int fd) 1297 { 1298 struct filedesc *fdp; 1299 struct file *fp; 1300 1301 fdp = td->td_proc->p_fd; 1302 1303 AUDIT_SYSCLOSE(td, fd); 1304 1305 FILEDESC_XLOCK(fdp); 1306 if ((fp = fget_locked(fdp, fd)) == NULL) { 1307 FILEDESC_XUNLOCK(fdp); 1308 return (EBADF); 1309 } 1310 fdfree(fdp, fd); 1311 1312 /* closefp() drops the FILEDESC lock for us. */ 1313 return (closefp(fdp, fd, fp, td, 1)); 1314 } 1315 1316 /* 1317 * Close open file descriptors. 1318 */ 1319 #ifndef _SYS_SYSPROTO_H_ 1320 struct closefrom_args { 1321 int lowfd; 1322 }; 1323 #endif 1324 /* ARGSUSED */ 1325 int 1326 sys_closefrom(struct thread *td, struct closefrom_args *uap) 1327 { 1328 struct filedesc *fdp; 1329 int fd; 1330 1331 fdp = td->td_proc->p_fd; 1332 AUDIT_ARG_FD(uap->lowfd); 1333 1334 /* 1335 * Treat negative starting file descriptor values identical to 1336 * closefrom(0) which closes all files. 1337 */ 1338 if (uap->lowfd < 0) 1339 uap->lowfd = 0; 1340 FILEDESC_SLOCK(fdp); 1341 for (fd = uap->lowfd; fd <= fdp->fd_lastfile; fd++) { 1342 if (fdp->fd_ofiles[fd].fde_file != NULL) { 1343 FILEDESC_SUNLOCK(fdp); 1344 (void)kern_close(td, fd); 1345 FILEDESC_SLOCK(fdp); 1346 } 1347 } 1348 FILEDESC_SUNLOCK(fdp); 1349 return (0); 1350 } 1351 1352 #if defined(COMPAT_43) 1353 /* 1354 * Return status information about a file descriptor. 1355 */ 1356 #ifndef _SYS_SYSPROTO_H_ 1357 struct ofstat_args { 1358 int fd; 1359 struct ostat *sb; 1360 }; 1361 #endif 1362 /* ARGSUSED */ 1363 int 1364 ofstat(struct thread *td, struct ofstat_args *uap) 1365 { 1366 struct ostat oub; 1367 struct stat ub; 1368 int error; 1369 1370 error = kern_fstat(td, uap->fd, &ub); 1371 if (error == 0) { 1372 cvtstat(&ub, &oub); 1373 error = copyout(&oub, uap->sb, sizeof(oub)); 1374 } 1375 return (error); 1376 } 1377 #endif /* COMPAT_43 */ 1378 1379 #if defined(COMPAT_FREEBSD11) 1380 int 1381 freebsd11_fstat(struct thread *td, struct freebsd11_fstat_args *uap) 1382 { 1383 struct stat sb; 1384 struct freebsd11_stat osb; 1385 int error; 1386 1387 error = kern_fstat(td, uap->fd, &sb); 1388 if (error != 0) 1389 return (error); 1390 error = freebsd11_cvtstat(&sb, &osb); 1391 if (error == 0) 1392 error = copyout(&osb, uap->sb, sizeof(osb)); 1393 return (error); 1394 } 1395 #endif /* COMPAT_FREEBSD11 */ 1396 1397 /* 1398 * Return status information about a file descriptor. 1399 */ 1400 #ifndef _SYS_SYSPROTO_H_ 1401 struct fstat_args { 1402 int fd; 1403 struct stat *sb; 1404 }; 1405 #endif 1406 /* ARGSUSED */ 1407 int 1408 sys_fstat(struct thread *td, struct fstat_args *uap) 1409 { 1410 struct stat ub; 1411 int error; 1412 1413 error = kern_fstat(td, uap->fd, &ub); 1414 if (error == 0) 1415 error = copyout(&ub, uap->sb, sizeof(ub)); 1416 return (error); 1417 } 1418 1419 int 1420 kern_fstat(struct thread *td, int fd, struct stat *sbp) 1421 { 1422 struct file *fp; 1423 int error; 1424 1425 AUDIT_ARG_FD(fd); 1426 1427 error = fget(td, fd, &cap_fstat_rights, &fp); 1428 if (__predict_false(error != 0)) 1429 return (error); 1430 1431 AUDIT_ARG_FILE(td->td_proc, fp); 1432 1433 error = fo_stat(fp, sbp, td->td_ucred, td); 1434 fdrop(fp, td); 1435 #ifdef __STAT_TIME_T_EXT 1436 sbp->st_atim_ext = 0; 1437 sbp->st_mtim_ext = 0; 1438 sbp->st_ctim_ext = 0; 1439 sbp->st_btim_ext = 0; 1440 #endif 1441 #ifdef KTRACE 1442 if (KTRPOINT(td, KTR_STRUCT)) 1443 ktrstat_error(sbp, error); 1444 #endif 1445 return (error); 1446 } 1447 1448 #if defined(COMPAT_FREEBSD11) 1449 /* 1450 * Return status information about a file descriptor. 1451 */ 1452 #ifndef _SYS_SYSPROTO_H_ 1453 struct freebsd11_nfstat_args { 1454 int fd; 1455 struct nstat *sb; 1456 }; 1457 #endif 1458 /* ARGSUSED */ 1459 int 1460 freebsd11_nfstat(struct thread *td, struct freebsd11_nfstat_args *uap) 1461 { 1462 struct nstat nub; 1463 struct stat ub; 1464 int error; 1465 1466 error = kern_fstat(td, uap->fd, &ub); 1467 if (error == 0) { 1468 freebsd11_cvtnstat(&ub, &nub); 1469 error = copyout(&nub, uap->sb, sizeof(nub)); 1470 } 1471 return (error); 1472 } 1473 #endif /* COMPAT_FREEBSD11 */ 1474 1475 /* 1476 * Return pathconf information about a file descriptor. 1477 */ 1478 #ifndef _SYS_SYSPROTO_H_ 1479 struct fpathconf_args { 1480 int fd; 1481 int name; 1482 }; 1483 #endif 1484 /* ARGSUSED */ 1485 int 1486 sys_fpathconf(struct thread *td, struct fpathconf_args *uap) 1487 { 1488 long value; 1489 int error; 1490 1491 error = kern_fpathconf(td, uap->fd, uap->name, &value); 1492 if (error == 0) 1493 td->td_retval[0] = value; 1494 return (error); 1495 } 1496 1497 int 1498 kern_fpathconf(struct thread *td, int fd, int name, long *valuep) 1499 { 1500 struct file *fp; 1501 struct vnode *vp; 1502 int error; 1503 1504 error = fget(td, fd, &cap_fpathconf_rights, &fp); 1505 if (error != 0) 1506 return (error); 1507 1508 if (name == _PC_ASYNC_IO) { 1509 *valuep = _POSIX_ASYNCHRONOUS_IO; 1510 goto out; 1511 } 1512 vp = fp->f_vnode; 1513 if (vp != NULL) { 1514 vn_lock(vp, LK_SHARED | LK_RETRY); 1515 error = VOP_PATHCONF(vp, name, valuep); 1516 VOP_UNLOCK(vp); 1517 } else if (fp->f_type == DTYPE_PIPE || fp->f_type == DTYPE_SOCKET) { 1518 if (name != _PC_PIPE_BUF) { 1519 error = EINVAL; 1520 } else { 1521 *valuep = PIPE_BUF; 1522 error = 0; 1523 } 1524 } else { 1525 error = EOPNOTSUPP; 1526 } 1527 out: 1528 fdrop(fp, td); 1529 return (error); 1530 } 1531 1532 /* 1533 * Copy filecaps structure allocating memory for ioctls array if needed. 1534 * 1535 * The last parameter indicates whether the fdtable is locked. If it is not and 1536 * ioctls are encountered, copying fails and the caller must lock the table. 1537 * 1538 * Note that if the table was not locked, the caller has to check the relevant 1539 * sequence counter to determine whether the operation was successful. 1540 */ 1541 bool 1542 filecaps_copy(const struct filecaps *src, struct filecaps *dst, bool locked) 1543 { 1544 size_t size; 1545 1546 if (src->fc_ioctls != NULL && !locked) 1547 return (false); 1548 memcpy(dst, src, sizeof(*src)); 1549 if (src->fc_ioctls == NULL) 1550 return (true); 1551 1552 KASSERT(src->fc_nioctls > 0, 1553 ("fc_ioctls != NULL, but fc_nioctls=%hd", src->fc_nioctls)); 1554 1555 size = sizeof(src->fc_ioctls[0]) * src->fc_nioctls; 1556 dst->fc_ioctls = malloc(size, M_FILECAPS, M_WAITOK); 1557 memcpy(dst->fc_ioctls, src->fc_ioctls, size); 1558 return (true); 1559 } 1560 1561 static u_long * 1562 filecaps_copy_prep(const struct filecaps *src) 1563 { 1564 u_long *ioctls; 1565 size_t size; 1566 1567 if (__predict_true(src->fc_ioctls == NULL)) 1568 return (NULL); 1569 1570 KASSERT(src->fc_nioctls > 0, 1571 ("fc_ioctls != NULL, but fc_nioctls=%hd", src->fc_nioctls)); 1572 1573 size = sizeof(src->fc_ioctls[0]) * src->fc_nioctls; 1574 ioctls = malloc(size, M_FILECAPS, M_WAITOK); 1575 return (ioctls); 1576 } 1577 1578 static void 1579 filecaps_copy_finish(const struct filecaps *src, struct filecaps *dst, 1580 u_long *ioctls) 1581 { 1582 size_t size; 1583 1584 *dst = *src; 1585 if (__predict_true(src->fc_ioctls == NULL)) { 1586 MPASS(ioctls == NULL); 1587 return; 1588 } 1589 1590 size = sizeof(src->fc_ioctls[0]) * src->fc_nioctls; 1591 dst->fc_ioctls = ioctls; 1592 bcopy(src->fc_ioctls, dst->fc_ioctls, size); 1593 } 1594 1595 /* 1596 * Move filecaps structure to the new place and clear the old place. 1597 */ 1598 void 1599 filecaps_move(struct filecaps *src, struct filecaps *dst) 1600 { 1601 1602 *dst = *src; 1603 bzero(src, sizeof(*src)); 1604 } 1605 1606 /* 1607 * Fill the given filecaps structure with full rights. 1608 */ 1609 static void 1610 filecaps_fill(struct filecaps *fcaps) 1611 { 1612 1613 CAP_ALL(&fcaps->fc_rights); 1614 fcaps->fc_ioctls = NULL; 1615 fcaps->fc_nioctls = -1; 1616 fcaps->fc_fcntls = CAP_FCNTL_ALL; 1617 } 1618 1619 /* 1620 * Free memory allocated within filecaps structure. 1621 */ 1622 void 1623 filecaps_free(struct filecaps *fcaps) 1624 { 1625 1626 free(fcaps->fc_ioctls, M_FILECAPS); 1627 bzero(fcaps, sizeof(*fcaps)); 1628 } 1629 1630 static u_long * 1631 filecaps_free_prep(struct filecaps *fcaps) 1632 { 1633 u_long *ioctls; 1634 1635 ioctls = fcaps->fc_ioctls; 1636 bzero(fcaps, sizeof(*fcaps)); 1637 return (ioctls); 1638 } 1639 1640 static void 1641 filecaps_free_finish(u_long *ioctls) 1642 { 1643 1644 free(ioctls, M_FILECAPS); 1645 } 1646 1647 /* 1648 * Validate the given filecaps structure. 1649 */ 1650 static void 1651 filecaps_validate(const struct filecaps *fcaps, const char *func) 1652 { 1653 1654 KASSERT(cap_rights_is_valid(&fcaps->fc_rights), 1655 ("%s: invalid rights", func)); 1656 KASSERT((fcaps->fc_fcntls & ~CAP_FCNTL_ALL) == 0, 1657 ("%s: invalid fcntls", func)); 1658 KASSERT(fcaps->fc_fcntls == 0 || 1659 cap_rights_is_set(&fcaps->fc_rights, CAP_FCNTL), 1660 ("%s: fcntls without CAP_FCNTL", func)); 1661 KASSERT(fcaps->fc_ioctls != NULL ? fcaps->fc_nioctls > 0 : 1662 (fcaps->fc_nioctls == -1 || fcaps->fc_nioctls == 0), 1663 ("%s: invalid ioctls", func)); 1664 KASSERT(fcaps->fc_nioctls == 0 || 1665 cap_rights_is_set(&fcaps->fc_rights, CAP_IOCTL), 1666 ("%s: ioctls without CAP_IOCTL", func)); 1667 } 1668 1669 static void 1670 fdgrowtable_exp(struct filedesc *fdp, int nfd) 1671 { 1672 int nfd1; 1673 1674 FILEDESC_XLOCK_ASSERT(fdp); 1675 1676 nfd1 = fdp->fd_nfiles * 2; 1677 if (nfd1 < nfd) 1678 nfd1 = nfd; 1679 fdgrowtable(fdp, nfd1); 1680 } 1681 1682 /* 1683 * Grow the file table to accommodate (at least) nfd descriptors. 1684 */ 1685 static void 1686 fdgrowtable(struct filedesc *fdp, int nfd) 1687 { 1688 struct filedesc0 *fdp0; 1689 struct freetable *ft; 1690 struct fdescenttbl *ntable; 1691 struct fdescenttbl *otable; 1692 int nnfiles, onfiles; 1693 NDSLOTTYPE *nmap, *omap; 1694 1695 /* 1696 * If lastfile is -1 this struct filedesc was just allocated and we are 1697 * growing it to accommodate for the one we are going to copy from. There 1698 * is no need to have a lock on this one as it's not visible to anyone. 1699 */ 1700 if (fdp->fd_lastfile != -1) 1701 FILEDESC_XLOCK_ASSERT(fdp); 1702 1703 KASSERT(fdp->fd_nfiles > 0, ("zero-length file table")); 1704 1705 /* save old values */ 1706 onfiles = fdp->fd_nfiles; 1707 otable = fdp->fd_files; 1708 omap = fdp->fd_map; 1709 1710 /* compute the size of the new table */ 1711 nnfiles = NDSLOTS(nfd) * NDENTRIES; /* round up */ 1712 if (nnfiles <= onfiles) 1713 /* the table is already large enough */ 1714 return; 1715 1716 /* 1717 * Allocate a new table. We need enough space for the number of 1718 * entries, file entries themselves and the struct freetable we will use 1719 * when we decommission the table and place it on the freelist. 1720 * We place the struct freetable in the middle so we don't have 1721 * to worry about padding. 1722 */ 1723 ntable = malloc(offsetof(struct fdescenttbl, fdt_ofiles) + 1724 nnfiles * sizeof(ntable->fdt_ofiles[0]) + 1725 sizeof(struct freetable), 1726 M_FILEDESC, M_ZERO | M_WAITOK); 1727 /* copy the old data */ 1728 ntable->fdt_nfiles = nnfiles; 1729 memcpy(ntable->fdt_ofiles, otable->fdt_ofiles, 1730 onfiles * sizeof(ntable->fdt_ofiles[0])); 1731 1732 /* 1733 * Allocate a new map only if the old is not large enough. It will 1734 * grow at a slower rate than the table as it can map more 1735 * entries than the table can hold. 1736 */ 1737 if (NDSLOTS(nnfiles) > NDSLOTS(onfiles)) { 1738 nmap = malloc(NDSLOTS(nnfiles) * NDSLOTSIZE, M_FILEDESC, 1739 M_ZERO | M_WAITOK); 1740 /* copy over the old data and update the pointer */ 1741 memcpy(nmap, omap, NDSLOTS(onfiles) * sizeof(*omap)); 1742 fdp->fd_map = nmap; 1743 } 1744 1745 /* 1746 * Make sure that ntable is correctly initialized before we replace 1747 * fd_files poiner. Otherwise fget_unlocked() may see inconsistent 1748 * data. 1749 */ 1750 atomic_store_rel_ptr((volatile void *)&fdp->fd_files, (uintptr_t)ntable); 1751 1752 /* 1753 * Do not free the old file table, as some threads may still 1754 * reference entries within it. Instead, place it on a freelist 1755 * which will be processed when the struct filedesc is released. 1756 * 1757 * Note that if onfiles == NDFILE, we're dealing with the original 1758 * static allocation contained within (struct filedesc0 *)fdp, 1759 * which must not be freed. 1760 */ 1761 if (onfiles > NDFILE) { 1762 ft = (struct freetable *)&otable->fdt_ofiles[onfiles]; 1763 fdp0 = (struct filedesc0 *)fdp; 1764 ft->ft_table = otable; 1765 SLIST_INSERT_HEAD(&fdp0->fd_free, ft, ft_next); 1766 } 1767 /* 1768 * The map does not have the same possibility of threads still 1769 * holding references to it. So always free it as long as it 1770 * does not reference the original static allocation. 1771 */ 1772 if (NDSLOTS(onfiles) > NDSLOTS(NDFILE)) 1773 free(omap, M_FILEDESC); 1774 } 1775 1776 /* 1777 * Allocate a file descriptor for the process. 1778 */ 1779 int 1780 fdalloc(struct thread *td, int minfd, int *result) 1781 { 1782 struct proc *p = td->td_proc; 1783 struct filedesc *fdp = p->p_fd; 1784 int fd, maxfd, allocfd; 1785 #ifdef RACCT 1786 int error; 1787 #endif 1788 1789 FILEDESC_XLOCK_ASSERT(fdp); 1790 1791 if (fdp->fd_freefile > minfd) 1792 minfd = fdp->fd_freefile; 1793 1794 maxfd = getmaxfd(td); 1795 1796 /* 1797 * Search the bitmap for a free descriptor starting at minfd. 1798 * If none is found, grow the file table. 1799 */ 1800 fd = fd_first_free(fdp, minfd, fdp->fd_nfiles); 1801 if (fd >= maxfd) 1802 return (EMFILE); 1803 if (fd >= fdp->fd_nfiles) { 1804 allocfd = min(fd * 2, maxfd); 1805 #ifdef RACCT 1806 if (RACCT_ENABLED()) { 1807 error = racct_set_unlocked(p, RACCT_NOFILE, allocfd); 1808 if (error != 0) 1809 return (EMFILE); 1810 } 1811 #endif 1812 /* 1813 * fd is already equal to first free descriptor >= minfd, so 1814 * we only need to grow the table and we are done. 1815 */ 1816 fdgrowtable_exp(fdp, allocfd); 1817 } 1818 1819 /* 1820 * Perform some sanity checks, then mark the file descriptor as 1821 * used and return it to the caller. 1822 */ 1823 KASSERT(fd >= 0 && fd < min(maxfd, fdp->fd_nfiles), 1824 ("invalid descriptor %d", fd)); 1825 KASSERT(!fdisused(fdp, fd), 1826 ("fd_first_free() returned non-free descriptor")); 1827 KASSERT(fdp->fd_ofiles[fd].fde_file == NULL, 1828 ("file descriptor isn't free")); 1829 fdused(fdp, fd); 1830 *result = fd; 1831 return (0); 1832 } 1833 1834 /* 1835 * Allocate n file descriptors for the process. 1836 */ 1837 int 1838 fdallocn(struct thread *td, int minfd, int *fds, int n) 1839 { 1840 struct proc *p = td->td_proc; 1841 struct filedesc *fdp = p->p_fd; 1842 int i; 1843 1844 FILEDESC_XLOCK_ASSERT(fdp); 1845 1846 for (i = 0; i < n; i++) 1847 if (fdalloc(td, 0, &fds[i]) != 0) 1848 break; 1849 1850 if (i < n) { 1851 for (i--; i >= 0; i--) 1852 fdunused(fdp, fds[i]); 1853 return (EMFILE); 1854 } 1855 1856 return (0); 1857 } 1858 1859 /* 1860 * Create a new open file structure and allocate a file descriptor for the 1861 * process that refers to it. We add one reference to the file for the 1862 * descriptor table and one reference for resultfp. This is to prevent us 1863 * being preempted and the entry in the descriptor table closed after we 1864 * release the FILEDESC lock. 1865 */ 1866 int 1867 falloc_caps(struct thread *td, struct file **resultfp, int *resultfd, int flags, 1868 struct filecaps *fcaps) 1869 { 1870 struct file *fp; 1871 int error, fd; 1872 1873 error = falloc_noinstall(td, &fp); 1874 if (error) 1875 return (error); /* no reference held on error */ 1876 1877 error = finstall(td, fp, &fd, flags, fcaps); 1878 if (error) { 1879 fdrop(fp, td); /* one reference (fp only) */ 1880 return (error); 1881 } 1882 1883 if (resultfp != NULL) 1884 *resultfp = fp; /* copy out result */ 1885 else 1886 fdrop(fp, td); /* release local reference */ 1887 1888 if (resultfd != NULL) 1889 *resultfd = fd; 1890 1891 return (0); 1892 } 1893 1894 /* 1895 * Create a new open file structure without allocating a file descriptor. 1896 */ 1897 int 1898 falloc_noinstall(struct thread *td, struct file **resultfp) 1899 { 1900 struct file *fp; 1901 int maxuserfiles = maxfiles - (maxfiles / 20); 1902 int openfiles_new; 1903 static struct timeval lastfail; 1904 static int curfail; 1905 1906 KASSERT(resultfp != NULL, ("%s: resultfp == NULL", __func__)); 1907 1908 openfiles_new = atomic_fetchadd_int(&openfiles, 1) + 1; 1909 if ((openfiles_new >= maxuserfiles && 1910 priv_check(td, PRIV_MAXFILES) != 0) || 1911 openfiles_new >= maxfiles) { 1912 atomic_subtract_int(&openfiles, 1); 1913 if (ppsratecheck(&lastfail, &curfail, 1)) { 1914 printf("kern.maxfiles limit exceeded by uid %i, (%s) " 1915 "please see tuning(7).\n", td->td_ucred->cr_ruid, td->td_proc->p_comm); 1916 } 1917 return (ENFILE); 1918 } 1919 fp = uma_zalloc(file_zone, M_WAITOK); 1920 bzero(fp, sizeof(*fp)); 1921 refcount_init(&fp->f_count, 1); 1922 fp->f_cred = crhold(td->td_ucred); 1923 fp->f_ops = &badfileops; 1924 *resultfp = fp; 1925 return (0); 1926 } 1927 1928 /* 1929 * Install a file in a file descriptor table. 1930 */ 1931 void 1932 _finstall(struct filedesc *fdp, struct file *fp, int fd, int flags, 1933 struct filecaps *fcaps) 1934 { 1935 struct filedescent *fde; 1936 1937 MPASS(fp != NULL); 1938 if (fcaps != NULL) 1939 filecaps_validate(fcaps, __func__); 1940 FILEDESC_XLOCK_ASSERT(fdp); 1941 1942 fde = &fdp->fd_ofiles[fd]; 1943 #ifdef CAPABILITIES 1944 seqc_write_begin(&fde->fde_seqc); 1945 #endif 1946 fde->fde_file = fp; 1947 fde->fde_flags = (flags & O_CLOEXEC) != 0 ? UF_EXCLOSE : 0; 1948 if (fcaps != NULL) 1949 filecaps_move(fcaps, &fde->fde_caps); 1950 else 1951 filecaps_fill(&fde->fde_caps); 1952 #ifdef CAPABILITIES 1953 seqc_write_end(&fde->fde_seqc); 1954 #endif 1955 } 1956 1957 int 1958 finstall(struct thread *td, struct file *fp, int *fd, int flags, 1959 struct filecaps *fcaps) 1960 { 1961 struct filedesc *fdp = td->td_proc->p_fd; 1962 int error; 1963 1964 MPASS(fd != NULL); 1965 1966 if (!fhold(fp)) 1967 return (EBADF); 1968 FILEDESC_XLOCK(fdp); 1969 error = fdalloc(td, 0, fd); 1970 if (__predict_false(error != 0)) { 1971 FILEDESC_XUNLOCK(fdp); 1972 fdrop(fp, td); 1973 return (error); 1974 } 1975 _finstall(fdp, fp, *fd, flags, fcaps); 1976 FILEDESC_XUNLOCK(fdp); 1977 return (0); 1978 } 1979 1980 /* 1981 * Build a new filedesc structure from another. 1982 * Copy the current, root, and jail root vnode references. 1983 * 1984 * If fdp is not NULL, return with it shared locked. 1985 */ 1986 struct filedesc * 1987 fdinit(struct filedesc *fdp, bool prepfiles) 1988 { 1989 struct filedesc0 *newfdp0; 1990 struct filedesc *newfdp; 1991 struct pwd *newpwd; 1992 1993 newfdp0 = uma_zalloc(filedesc0_zone, M_WAITOK | M_ZERO); 1994 newfdp = &newfdp0->fd_fd; 1995 1996 /* Create the file descriptor table. */ 1997 FILEDESC_LOCK_INIT(newfdp); 1998 refcount_init(&newfdp->fd_refcnt, 1); 1999 refcount_init(&newfdp->fd_holdcnt, 1); 2000 newfdp->fd_cmask = CMASK; 2001 newfdp->fd_map = newfdp0->fd_dmap; 2002 newfdp->fd_lastfile = -1; 2003 newfdp->fd_files = (struct fdescenttbl *)&newfdp0->fd_dfiles; 2004 newfdp->fd_files->fdt_nfiles = NDFILE; 2005 2006 if (fdp == NULL) { 2007 newpwd = pwd_alloc(); 2008 smr_serialized_store(&newfdp->fd_pwd, newpwd, true); 2009 return (newfdp); 2010 } 2011 2012 if (prepfiles && fdp->fd_lastfile >= newfdp->fd_nfiles) 2013 fdgrowtable(newfdp, fdp->fd_lastfile + 1); 2014 2015 FILEDESC_SLOCK(fdp); 2016 newpwd = pwd_hold_filedesc(fdp); 2017 smr_serialized_store(&newfdp->fd_pwd, newpwd, true); 2018 2019 if (!prepfiles) { 2020 FILEDESC_SUNLOCK(fdp); 2021 } else { 2022 while (fdp->fd_lastfile >= newfdp->fd_nfiles) { 2023 FILEDESC_SUNLOCK(fdp); 2024 fdgrowtable(newfdp, fdp->fd_lastfile + 1); 2025 FILEDESC_SLOCK(fdp); 2026 } 2027 } 2028 2029 return (newfdp); 2030 } 2031 2032 static struct filedesc * 2033 fdhold(struct proc *p) 2034 { 2035 struct filedesc *fdp; 2036 2037 PROC_LOCK_ASSERT(p, MA_OWNED); 2038 fdp = p->p_fd; 2039 if (fdp != NULL) 2040 refcount_acquire(&fdp->fd_holdcnt); 2041 return (fdp); 2042 } 2043 2044 static void 2045 fddrop(struct filedesc *fdp) 2046 { 2047 2048 if (fdp->fd_holdcnt > 1) { 2049 if (refcount_release(&fdp->fd_holdcnt) == 0) 2050 return; 2051 } 2052 2053 FILEDESC_LOCK_DESTROY(fdp); 2054 uma_zfree(filedesc0_zone, fdp); 2055 } 2056 2057 /* 2058 * Share a filedesc structure. 2059 */ 2060 struct filedesc * 2061 fdshare(struct filedesc *fdp) 2062 { 2063 2064 refcount_acquire(&fdp->fd_refcnt); 2065 return (fdp); 2066 } 2067 2068 /* 2069 * Unshare a filedesc structure, if necessary by making a copy 2070 */ 2071 void 2072 fdunshare(struct thread *td) 2073 { 2074 struct filedesc *tmp; 2075 struct proc *p = td->td_proc; 2076 2077 if (p->p_fd->fd_refcnt == 1) 2078 return; 2079 2080 tmp = fdcopy(p->p_fd); 2081 fdescfree(td); 2082 p->p_fd = tmp; 2083 } 2084 2085 void 2086 fdinstall_remapped(struct thread *td, struct filedesc *fdp) 2087 { 2088 2089 fdescfree(td); 2090 td->td_proc->p_fd = fdp; 2091 } 2092 2093 /* 2094 * Copy a filedesc structure. A NULL pointer in returns a NULL reference, 2095 * this is to ease callers, not catch errors. 2096 */ 2097 struct filedesc * 2098 fdcopy(struct filedesc *fdp) 2099 { 2100 struct filedesc *newfdp; 2101 struct filedescent *nfde, *ofde; 2102 int i; 2103 2104 MPASS(fdp != NULL); 2105 2106 newfdp = fdinit(fdp, true); 2107 /* copy all passable descriptors (i.e. not kqueue) */ 2108 newfdp->fd_freefile = -1; 2109 for (i = 0; i <= fdp->fd_lastfile; ++i) { 2110 ofde = &fdp->fd_ofiles[i]; 2111 if (ofde->fde_file == NULL || 2112 (ofde->fde_file->f_ops->fo_flags & DFLAG_PASSABLE) == 0 || 2113 !fhold(ofde->fde_file)) { 2114 if (newfdp->fd_freefile == -1) 2115 newfdp->fd_freefile = i; 2116 continue; 2117 } 2118 nfde = &newfdp->fd_ofiles[i]; 2119 *nfde = *ofde; 2120 filecaps_copy(&ofde->fde_caps, &nfde->fde_caps, true); 2121 fdused_init(newfdp, i); 2122 newfdp->fd_lastfile = i; 2123 } 2124 if (newfdp->fd_freefile == -1) 2125 newfdp->fd_freefile = i; 2126 newfdp->fd_cmask = fdp->fd_cmask; 2127 FILEDESC_SUNLOCK(fdp); 2128 return (newfdp); 2129 } 2130 2131 /* 2132 * Copies a filedesc structure, while remapping all file descriptors 2133 * stored inside using a translation table. 2134 * 2135 * File descriptors are copied over to the new file descriptor table, 2136 * regardless of whether the close-on-exec flag is set. 2137 */ 2138 int 2139 fdcopy_remapped(struct filedesc *fdp, const int *fds, size_t nfds, 2140 struct filedesc **ret) 2141 { 2142 struct filedesc *newfdp; 2143 struct filedescent *nfde, *ofde; 2144 int error, i; 2145 2146 MPASS(fdp != NULL); 2147 2148 newfdp = fdinit(fdp, true); 2149 if (nfds > fdp->fd_lastfile + 1) { 2150 /* New table cannot be larger than the old one. */ 2151 error = E2BIG; 2152 goto bad; 2153 } 2154 /* Copy all passable descriptors (i.e. not kqueue). */ 2155 newfdp->fd_freefile = nfds; 2156 for (i = 0; i < nfds; ++i) { 2157 if (fds[i] < 0 || fds[i] > fdp->fd_lastfile) { 2158 /* File descriptor out of bounds. */ 2159 error = EBADF; 2160 goto bad; 2161 } 2162 ofde = &fdp->fd_ofiles[fds[i]]; 2163 if (ofde->fde_file == NULL) { 2164 /* Unused file descriptor. */ 2165 error = EBADF; 2166 goto bad; 2167 } 2168 if ((ofde->fde_file->f_ops->fo_flags & DFLAG_PASSABLE) == 0) { 2169 /* File descriptor cannot be passed. */ 2170 error = EINVAL; 2171 goto bad; 2172 } 2173 if (!fhold(nfde->fde_file)) { 2174 error = EBADF; 2175 goto bad; 2176 } 2177 nfde = &newfdp->fd_ofiles[i]; 2178 *nfde = *ofde; 2179 filecaps_copy(&ofde->fde_caps, &nfde->fde_caps, true); 2180 fdused_init(newfdp, i); 2181 newfdp->fd_lastfile = i; 2182 } 2183 newfdp->fd_cmask = fdp->fd_cmask; 2184 FILEDESC_SUNLOCK(fdp); 2185 *ret = newfdp; 2186 return (0); 2187 bad: 2188 FILEDESC_SUNLOCK(fdp); 2189 fdescfree_remapped(newfdp); 2190 return (error); 2191 } 2192 2193 /* 2194 * Clear POSIX style locks. This is only used when fdp looses a reference (i.e. 2195 * one of processes using it exits) and the table used to be shared. 2196 */ 2197 static void 2198 fdclearlocks(struct thread *td) 2199 { 2200 struct filedesc *fdp; 2201 struct filedesc_to_leader *fdtol; 2202 struct flock lf; 2203 struct file *fp; 2204 struct proc *p; 2205 struct vnode *vp; 2206 int i; 2207 2208 p = td->td_proc; 2209 fdp = p->p_fd; 2210 fdtol = p->p_fdtol; 2211 MPASS(fdtol != NULL); 2212 2213 FILEDESC_XLOCK(fdp); 2214 KASSERT(fdtol->fdl_refcount > 0, 2215 ("filedesc_to_refcount botch: fdl_refcount=%d", 2216 fdtol->fdl_refcount)); 2217 if (fdtol->fdl_refcount == 1 && 2218 (p->p_leader->p_flag & P_ADVLOCK) != 0) { 2219 for (i = 0; i <= fdp->fd_lastfile; i++) { 2220 fp = fdp->fd_ofiles[i].fde_file; 2221 if (fp == NULL || fp->f_type != DTYPE_VNODE || 2222 !fhold(fp)) 2223 continue; 2224 FILEDESC_XUNLOCK(fdp); 2225 lf.l_whence = SEEK_SET; 2226 lf.l_start = 0; 2227 lf.l_len = 0; 2228 lf.l_type = F_UNLCK; 2229 vp = fp->f_vnode; 2230 (void) VOP_ADVLOCK(vp, 2231 (caddr_t)p->p_leader, F_UNLCK, 2232 &lf, F_POSIX); 2233 FILEDESC_XLOCK(fdp); 2234 fdrop(fp, td); 2235 } 2236 } 2237 retry: 2238 if (fdtol->fdl_refcount == 1) { 2239 if (fdp->fd_holdleaderscount > 0 && 2240 (p->p_leader->p_flag & P_ADVLOCK) != 0) { 2241 /* 2242 * close() or kern_dup() has cleared a reference 2243 * in a shared file descriptor table. 2244 */ 2245 fdp->fd_holdleaderswakeup = 1; 2246 sx_sleep(&fdp->fd_holdleaderscount, 2247 FILEDESC_LOCK(fdp), PLOCK, "fdlhold", 0); 2248 goto retry; 2249 } 2250 if (fdtol->fdl_holdcount > 0) { 2251 /* 2252 * Ensure that fdtol->fdl_leader remains 2253 * valid in closef(). 2254 */ 2255 fdtol->fdl_wakeup = 1; 2256 sx_sleep(fdtol, FILEDESC_LOCK(fdp), PLOCK, 2257 "fdlhold", 0); 2258 goto retry; 2259 } 2260 } 2261 fdtol->fdl_refcount--; 2262 if (fdtol->fdl_refcount == 0 && 2263 fdtol->fdl_holdcount == 0) { 2264 fdtol->fdl_next->fdl_prev = fdtol->fdl_prev; 2265 fdtol->fdl_prev->fdl_next = fdtol->fdl_next; 2266 } else 2267 fdtol = NULL; 2268 p->p_fdtol = NULL; 2269 FILEDESC_XUNLOCK(fdp); 2270 if (fdtol != NULL) 2271 free(fdtol, M_FILEDESC_TO_LEADER); 2272 } 2273 2274 /* 2275 * Release a filedesc structure. 2276 */ 2277 static void 2278 fdescfree_fds(struct thread *td, struct filedesc *fdp, bool needclose) 2279 { 2280 struct filedesc0 *fdp0; 2281 struct freetable *ft, *tft; 2282 struct filedescent *fde; 2283 struct file *fp; 2284 int i; 2285 2286 for (i = 0; i <= fdp->fd_lastfile; i++) { 2287 fde = &fdp->fd_ofiles[i]; 2288 fp = fde->fde_file; 2289 if (fp != NULL) { 2290 fdefree_last(fde); 2291 if (needclose) 2292 (void) closef(fp, td); 2293 else 2294 fdrop(fp, td); 2295 } 2296 } 2297 2298 if (NDSLOTS(fdp->fd_nfiles) > NDSLOTS(NDFILE)) 2299 free(fdp->fd_map, M_FILEDESC); 2300 if (fdp->fd_nfiles > NDFILE) 2301 free(fdp->fd_files, M_FILEDESC); 2302 2303 fdp0 = (struct filedesc0 *)fdp; 2304 SLIST_FOREACH_SAFE(ft, &fdp0->fd_free, ft_next, tft) 2305 free(ft->ft_table, M_FILEDESC); 2306 2307 fddrop(fdp); 2308 } 2309 2310 void 2311 fdescfree(struct thread *td) 2312 { 2313 struct proc *p; 2314 struct filedesc *fdp; 2315 struct pwd *pwd; 2316 2317 p = td->td_proc; 2318 fdp = p->p_fd; 2319 MPASS(fdp != NULL); 2320 2321 #ifdef RACCT 2322 if (RACCT_ENABLED()) 2323 racct_set_unlocked(p, RACCT_NOFILE, 0); 2324 #endif 2325 2326 if (p->p_fdtol != NULL) 2327 fdclearlocks(td); 2328 2329 PROC_LOCK(p); 2330 p->p_fd = NULL; 2331 PROC_UNLOCK(p); 2332 2333 if (refcount_release(&fdp->fd_refcnt) == 0) 2334 return; 2335 2336 FILEDESC_XLOCK(fdp); 2337 pwd = FILEDESC_XLOCKED_LOAD_PWD(fdp); 2338 pwd_set(fdp, NULL); 2339 FILEDESC_XUNLOCK(fdp); 2340 2341 pwd_drop(pwd); 2342 2343 fdescfree_fds(td, fdp, 1); 2344 } 2345 2346 void 2347 fdescfree_remapped(struct filedesc *fdp) 2348 { 2349 2350 pwd_drop(smr_serialized_load(&fdp->fd_pwd, true)); 2351 fdescfree_fds(curthread, fdp, 0); 2352 } 2353 2354 /* 2355 * For setugid programs, we don't want to people to use that setugidness 2356 * to generate error messages which write to a file which otherwise would 2357 * otherwise be off-limits to the process. We check for filesystems where 2358 * the vnode can change out from under us after execve (like [lin]procfs). 2359 * 2360 * Since fdsetugidsafety calls this only for fd 0, 1 and 2, this check is 2361 * sufficient. We also don't check for setugidness since we know we are. 2362 */ 2363 static bool 2364 is_unsafe(struct file *fp) 2365 { 2366 struct vnode *vp; 2367 2368 if (fp->f_type != DTYPE_VNODE) 2369 return (false); 2370 2371 vp = fp->f_vnode; 2372 return ((vp->v_vflag & VV_PROCDEP) != 0); 2373 } 2374 2375 /* 2376 * Make this setguid thing safe, if at all possible. 2377 */ 2378 void 2379 fdsetugidsafety(struct thread *td) 2380 { 2381 struct filedesc *fdp; 2382 struct file *fp; 2383 int i; 2384 2385 fdp = td->td_proc->p_fd; 2386 KASSERT(fdp->fd_refcnt == 1, ("the fdtable should not be shared")); 2387 MPASS(fdp->fd_nfiles >= 3); 2388 for (i = 0; i <= 2; i++) { 2389 fp = fdp->fd_ofiles[i].fde_file; 2390 if (fp != NULL && is_unsafe(fp)) { 2391 FILEDESC_XLOCK(fdp); 2392 knote_fdclose(td, i); 2393 /* 2394 * NULL-out descriptor prior to close to avoid 2395 * a race while close blocks. 2396 */ 2397 fdfree(fdp, i); 2398 FILEDESC_XUNLOCK(fdp); 2399 (void) closef(fp, td); 2400 } 2401 } 2402 } 2403 2404 /* 2405 * If a specific file object occupies a specific file descriptor, close the 2406 * file descriptor entry and drop a reference on the file object. This is a 2407 * convenience function to handle a subsequent error in a function that calls 2408 * falloc() that handles the race that another thread might have closed the 2409 * file descriptor out from under the thread creating the file object. 2410 */ 2411 void 2412 fdclose(struct thread *td, struct file *fp, int idx) 2413 { 2414 struct filedesc *fdp = td->td_proc->p_fd; 2415 2416 FILEDESC_XLOCK(fdp); 2417 if (fdp->fd_ofiles[idx].fde_file == fp) { 2418 fdfree(fdp, idx); 2419 FILEDESC_XUNLOCK(fdp); 2420 fdrop(fp, td); 2421 } else 2422 FILEDESC_XUNLOCK(fdp); 2423 } 2424 2425 /* 2426 * Close any files on exec? 2427 */ 2428 void 2429 fdcloseexec(struct thread *td) 2430 { 2431 struct filedesc *fdp; 2432 struct filedescent *fde; 2433 struct file *fp; 2434 int i; 2435 2436 fdp = td->td_proc->p_fd; 2437 KASSERT(fdp->fd_refcnt == 1, ("the fdtable should not be shared")); 2438 for (i = 0; i <= fdp->fd_lastfile; i++) { 2439 fde = &fdp->fd_ofiles[i]; 2440 fp = fde->fde_file; 2441 if (fp != NULL && (fp->f_type == DTYPE_MQUEUE || 2442 (fde->fde_flags & UF_EXCLOSE))) { 2443 FILEDESC_XLOCK(fdp); 2444 fdfree(fdp, i); 2445 (void) closefp(fdp, i, fp, td, 0); 2446 FILEDESC_UNLOCK_ASSERT(fdp); 2447 } 2448 } 2449 } 2450 2451 /* 2452 * It is unsafe for set[ug]id processes to be started with file 2453 * descriptors 0..2 closed, as these descriptors are given implicit 2454 * significance in the Standard C library. fdcheckstd() will create a 2455 * descriptor referencing /dev/null for each of stdin, stdout, and 2456 * stderr that is not already open. 2457 */ 2458 int 2459 fdcheckstd(struct thread *td) 2460 { 2461 struct filedesc *fdp; 2462 register_t save; 2463 int i, error, devnull; 2464 2465 fdp = td->td_proc->p_fd; 2466 KASSERT(fdp->fd_refcnt == 1, ("the fdtable should not be shared")); 2467 MPASS(fdp->fd_nfiles >= 3); 2468 devnull = -1; 2469 for (i = 0; i <= 2; i++) { 2470 if (fdp->fd_ofiles[i].fde_file != NULL) 2471 continue; 2472 2473 save = td->td_retval[0]; 2474 if (devnull != -1) { 2475 error = kern_dup(td, FDDUP_FIXED, 0, devnull, i); 2476 } else { 2477 error = kern_openat(td, AT_FDCWD, "/dev/null", 2478 UIO_SYSSPACE, O_RDWR, 0); 2479 if (error == 0) { 2480 devnull = td->td_retval[0]; 2481 KASSERT(devnull == i, ("we didn't get our fd")); 2482 } 2483 } 2484 td->td_retval[0] = save; 2485 if (error != 0) 2486 return (error); 2487 } 2488 return (0); 2489 } 2490 2491 /* 2492 * Internal form of close. Decrement reference count on file structure. 2493 * Note: td may be NULL when closing a file that was being passed in a 2494 * message. 2495 */ 2496 int 2497 closef(struct file *fp, struct thread *td) 2498 { 2499 struct vnode *vp; 2500 struct flock lf; 2501 struct filedesc_to_leader *fdtol; 2502 struct filedesc *fdp; 2503 2504 /* 2505 * POSIX record locking dictates that any close releases ALL 2506 * locks owned by this process. This is handled by setting 2507 * a flag in the unlock to free ONLY locks obeying POSIX 2508 * semantics, and not to free BSD-style file locks. 2509 * If the descriptor was in a message, POSIX-style locks 2510 * aren't passed with the descriptor, and the thread pointer 2511 * will be NULL. Callers should be careful only to pass a 2512 * NULL thread pointer when there really is no owning 2513 * context that might have locks, or the locks will be 2514 * leaked. 2515 */ 2516 if (fp->f_type == DTYPE_VNODE && td != NULL) { 2517 vp = fp->f_vnode; 2518 if ((td->td_proc->p_leader->p_flag & P_ADVLOCK) != 0) { 2519 lf.l_whence = SEEK_SET; 2520 lf.l_start = 0; 2521 lf.l_len = 0; 2522 lf.l_type = F_UNLCK; 2523 (void) VOP_ADVLOCK(vp, (caddr_t)td->td_proc->p_leader, 2524 F_UNLCK, &lf, F_POSIX); 2525 } 2526 fdtol = td->td_proc->p_fdtol; 2527 if (fdtol != NULL) { 2528 /* 2529 * Handle special case where file descriptor table is 2530 * shared between multiple process leaders. 2531 */ 2532 fdp = td->td_proc->p_fd; 2533 FILEDESC_XLOCK(fdp); 2534 for (fdtol = fdtol->fdl_next; 2535 fdtol != td->td_proc->p_fdtol; 2536 fdtol = fdtol->fdl_next) { 2537 if ((fdtol->fdl_leader->p_flag & 2538 P_ADVLOCK) == 0) 2539 continue; 2540 fdtol->fdl_holdcount++; 2541 FILEDESC_XUNLOCK(fdp); 2542 lf.l_whence = SEEK_SET; 2543 lf.l_start = 0; 2544 lf.l_len = 0; 2545 lf.l_type = F_UNLCK; 2546 vp = fp->f_vnode; 2547 (void) VOP_ADVLOCK(vp, 2548 (caddr_t)fdtol->fdl_leader, F_UNLCK, &lf, 2549 F_POSIX); 2550 FILEDESC_XLOCK(fdp); 2551 fdtol->fdl_holdcount--; 2552 if (fdtol->fdl_holdcount == 0 && 2553 fdtol->fdl_wakeup != 0) { 2554 fdtol->fdl_wakeup = 0; 2555 wakeup(fdtol); 2556 } 2557 } 2558 FILEDESC_XUNLOCK(fdp); 2559 } 2560 } 2561 return (fdrop(fp, td)); 2562 } 2563 2564 /* 2565 * Initialize the file pointer with the specified properties. 2566 * 2567 * The ops are set with release semantics to be certain that the flags, type, 2568 * and data are visible when ops is. This is to prevent ops methods from being 2569 * called with bad data. 2570 */ 2571 void 2572 finit(struct file *fp, u_int flag, short type, void *data, struct fileops *ops) 2573 { 2574 fp->f_data = data; 2575 fp->f_flag = flag; 2576 fp->f_type = type; 2577 atomic_store_rel_ptr((volatile uintptr_t *)&fp->f_ops, (uintptr_t)ops); 2578 } 2579 2580 int 2581 fget_cap_locked(struct filedesc *fdp, int fd, cap_rights_t *needrightsp, 2582 struct file **fpp, struct filecaps *havecapsp) 2583 { 2584 struct filedescent *fde; 2585 int error; 2586 2587 FILEDESC_LOCK_ASSERT(fdp); 2588 2589 fde = fdeget_locked(fdp, fd); 2590 if (fde == NULL) { 2591 error = EBADF; 2592 goto out; 2593 } 2594 2595 #ifdef CAPABILITIES 2596 error = cap_check(cap_rights_fde_inline(fde), needrightsp); 2597 if (error != 0) 2598 goto out; 2599 #endif 2600 2601 if (havecapsp != NULL) 2602 filecaps_copy(&fde->fde_caps, havecapsp, true); 2603 2604 *fpp = fde->fde_file; 2605 2606 error = 0; 2607 out: 2608 return (error); 2609 } 2610 2611 int 2612 fget_cap(struct thread *td, int fd, cap_rights_t *needrightsp, 2613 struct file **fpp, struct filecaps *havecapsp) 2614 { 2615 struct filedesc *fdp = td->td_proc->p_fd; 2616 int error; 2617 #ifndef CAPABILITIES 2618 error = fget_unlocked(fdp, fd, needrightsp, fpp); 2619 if (havecapsp != NULL && error == 0) 2620 filecaps_fill(havecapsp); 2621 #else 2622 struct file *fp; 2623 seqc_t seq; 2624 2625 *fpp = NULL; 2626 for (;;) { 2627 error = fget_unlocked_seq(fdp, fd, needrightsp, &fp, &seq); 2628 if (error != 0) 2629 return (error); 2630 2631 if (havecapsp != NULL) { 2632 if (!filecaps_copy(&fdp->fd_ofiles[fd].fde_caps, 2633 havecapsp, false)) { 2634 fdrop(fp, td); 2635 goto get_locked; 2636 } 2637 } 2638 2639 if (!fd_modified(fdp, fd, seq)) 2640 break; 2641 fdrop(fp, td); 2642 } 2643 2644 *fpp = fp; 2645 return (0); 2646 2647 get_locked: 2648 FILEDESC_SLOCK(fdp); 2649 error = fget_cap_locked(fdp, fd, needrightsp, fpp, havecapsp); 2650 if (error == 0 && !fhold(*fpp)) 2651 error = EBADF; 2652 FILEDESC_SUNLOCK(fdp); 2653 #endif 2654 return (error); 2655 } 2656 2657 int 2658 fget_unlocked_seq(struct filedesc *fdp, int fd, cap_rights_t *needrightsp, 2659 struct file **fpp, seqc_t *seqp) 2660 { 2661 #ifdef CAPABILITIES 2662 const struct filedescent *fde; 2663 #endif 2664 const struct fdescenttbl *fdt; 2665 struct file *fp; 2666 #ifdef CAPABILITIES 2667 seqc_t seq; 2668 cap_rights_t haverights; 2669 int error; 2670 #endif 2671 2672 fdt = fdp->fd_files; 2673 if (__predict_false((u_int)fd >= fdt->fdt_nfiles)) 2674 return (EBADF); 2675 /* 2676 * Fetch the descriptor locklessly. We avoid fdrop() races by 2677 * never raising a refcount above 0. To accomplish this we have 2678 * to use a cmpset loop rather than an atomic_add. The descriptor 2679 * must be re-verified once we acquire a reference to be certain 2680 * that the identity is still correct and we did not lose a race 2681 * due to preemption. 2682 */ 2683 for (;;) { 2684 #ifdef CAPABILITIES 2685 seq = seqc_read(fd_seqc(fdt, fd)); 2686 fde = &fdt->fdt_ofiles[fd]; 2687 haverights = *cap_rights_fde_inline(fde); 2688 fp = fde->fde_file; 2689 if (!seqc_consistent(fd_seqc(fdt, fd), seq)) 2690 continue; 2691 #else 2692 fp = fdt->fdt_ofiles[fd].fde_file; 2693 #endif 2694 if (fp == NULL) 2695 return (EBADF); 2696 #ifdef CAPABILITIES 2697 error = cap_check_inline(&haverights, needrightsp); 2698 if (error != 0) 2699 return (error); 2700 #endif 2701 if (__predict_false(!refcount_acquire_if_not_zero(&fp->f_count))) { 2702 /* 2703 * The count was found either saturated or zero. 2704 * This re-read is not any more racy than using the 2705 * return value from fcmpset. 2706 */ 2707 if (fp->f_count != 0) 2708 return (EBADF); 2709 /* 2710 * Force a reload. Other thread could reallocate the 2711 * table before this fd was closed, so it is possible 2712 * that there is a stale fp pointer in cached version. 2713 */ 2714 fdt = atomic_load_ptr(&fdp->fd_files); 2715 continue; 2716 } 2717 /* 2718 * Use an acquire barrier to force re-reading of fdt so it is 2719 * refreshed for verification. 2720 */ 2721 atomic_thread_fence_acq(); 2722 fdt = fdp->fd_files; 2723 #ifdef CAPABILITIES 2724 if (seqc_consistent_nomb(fd_seqc(fdt, fd), seq)) 2725 #else 2726 if (fp == fdt->fdt_ofiles[fd].fde_file) 2727 #endif 2728 break; 2729 fdrop(fp, curthread); 2730 } 2731 *fpp = fp; 2732 if (seqp != NULL) { 2733 #ifdef CAPABILITIES 2734 *seqp = seq; 2735 #endif 2736 } 2737 return (0); 2738 } 2739 2740 /* 2741 * See the comments in fget_unlocked_seq for an explanation of how this works. 2742 * 2743 * This is a simplified variant which bails out to the aforementioned routine 2744 * if anything goes wrong. In practice this only happens when userspace is 2745 * racing with itself. 2746 */ 2747 int 2748 fget_unlocked(struct filedesc *fdp, int fd, cap_rights_t *needrightsp, 2749 struct file **fpp) 2750 { 2751 #ifdef CAPABILITIES 2752 const struct filedescent *fde; 2753 #endif 2754 const struct fdescenttbl *fdt; 2755 struct file *fp; 2756 #ifdef CAPABILITIES 2757 seqc_t seq; 2758 const cap_rights_t *haverights; 2759 #endif 2760 2761 fdt = fdp->fd_files; 2762 if (__predict_false((u_int)fd >= fdt->fdt_nfiles)) 2763 return (EBADF); 2764 #ifdef CAPABILITIES 2765 seq = seqc_read_any(fd_seqc(fdt, fd)); 2766 if (__predict_false(seqc_in_modify(seq))) 2767 goto out_fallback; 2768 fde = &fdt->fdt_ofiles[fd]; 2769 haverights = cap_rights_fde_inline(fde); 2770 fp = fde->fde_file; 2771 #else 2772 fp = fdt->fdt_ofiles[fd].fde_file; 2773 #endif 2774 if (__predict_false(fp == NULL)) 2775 goto out_fallback; 2776 #ifdef CAPABILITIES 2777 if (__predict_false(cap_check_inline_transient(haverights, needrightsp))) 2778 goto out_fallback; 2779 #endif 2780 if (__predict_false(!refcount_acquire_if_not_zero(&fp->f_count))) 2781 goto out_fallback; 2782 2783 /* 2784 * Use an acquire barrier to force re-reading of fdt so it is 2785 * refreshed for verification. 2786 */ 2787 atomic_thread_fence_acq(); 2788 fdt = fdp->fd_files; 2789 #ifdef CAPABILITIES 2790 if (__predict_false(!seqc_consistent_nomb(fd_seqc(fdt, fd), seq))) 2791 #else 2792 if (__predict_false(fp != fdt->fdt_ofiles[fd].fde_file)) 2793 #endif 2794 goto out_fdrop; 2795 *fpp = fp; 2796 return (0); 2797 out_fdrop: 2798 fdrop(fp, curthread); 2799 out_fallback: 2800 return (fget_unlocked_seq(fdp, fd, needrightsp, fpp, NULL)); 2801 } 2802 2803 /* 2804 * Extract the file pointer associated with the specified descriptor for the 2805 * current user process. 2806 * 2807 * If the descriptor doesn't exist or doesn't match 'flags', EBADF is 2808 * returned. 2809 * 2810 * File's rights will be checked against the capability rights mask. 2811 * 2812 * If an error occurred the non-zero error is returned and *fpp is set to 2813 * NULL. Otherwise *fpp is held and set and zero is returned. Caller is 2814 * responsible for fdrop(). 2815 */ 2816 static __inline int 2817 _fget(struct thread *td, int fd, struct file **fpp, int flags, 2818 cap_rights_t *needrightsp) 2819 { 2820 struct filedesc *fdp; 2821 struct file *fp; 2822 int error; 2823 2824 *fpp = NULL; 2825 fdp = td->td_proc->p_fd; 2826 error = fget_unlocked(fdp, fd, needrightsp, &fp); 2827 if (__predict_false(error != 0)) 2828 return (error); 2829 if (__predict_false(fp->f_ops == &badfileops)) { 2830 fdrop(fp, td); 2831 return (EBADF); 2832 } 2833 2834 /* 2835 * FREAD and FWRITE failure return EBADF as per POSIX. 2836 */ 2837 error = 0; 2838 switch (flags) { 2839 case FREAD: 2840 case FWRITE: 2841 if ((fp->f_flag & flags) == 0) 2842 error = EBADF; 2843 break; 2844 case FEXEC: 2845 if ((fp->f_flag & (FREAD | FEXEC)) == 0 || 2846 ((fp->f_flag & FWRITE) != 0)) 2847 error = EBADF; 2848 break; 2849 case 0: 2850 break; 2851 default: 2852 KASSERT(0, ("wrong flags")); 2853 } 2854 2855 if (error != 0) { 2856 fdrop(fp, td); 2857 return (error); 2858 } 2859 2860 *fpp = fp; 2861 return (0); 2862 } 2863 2864 int 2865 fget(struct thread *td, int fd, cap_rights_t *rightsp, struct file **fpp) 2866 { 2867 2868 return (_fget(td, fd, fpp, 0, rightsp)); 2869 } 2870 2871 int 2872 fget_mmap(struct thread *td, int fd, cap_rights_t *rightsp, vm_prot_t *maxprotp, 2873 struct file **fpp) 2874 { 2875 int error; 2876 #ifndef CAPABILITIES 2877 error = _fget(td, fd, fpp, 0, rightsp); 2878 if (maxprotp != NULL) 2879 *maxprotp = VM_PROT_ALL; 2880 return (error); 2881 #else 2882 cap_rights_t fdrights; 2883 struct filedesc *fdp; 2884 struct file *fp; 2885 seqc_t seq; 2886 2887 *fpp = NULL; 2888 fdp = td->td_proc->p_fd; 2889 MPASS(cap_rights_is_set(rightsp, CAP_MMAP)); 2890 for (;;) { 2891 error = fget_unlocked_seq(fdp, fd, rightsp, &fp, &seq); 2892 if (__predict_false(error != 0)) 2893 return (error); 2894 if (__predict_false(fp->f_ops == &badfileops)) { 2895 fdrop(fp, td); 2896 return (EBADF); 2897 } 2898 if (maxprotp != NULL) 2899 fdrights = *cap_rights(fdp, fd); 2900 if (!fd_modified(fdp, fd, seq)) 2901 break; 2902 fdrop(fp, td); 2903 } 2904 2905 /* 2906 * If requested, convert capability rights to access flags. 2907 */ 2908 if (maxprotp != NULL) 2909 *maxprotp = cap_rights_to_vmprot(&fdrights); 2910 *fpp = fp; 2911 return (0); 2912 #endif 2913 } 2914 2915 int 2916 fget_read(struct thread *td, int fd, cap_rights_t *rightsp, struct file **fpp) 2917 { 2918 2919 return (_fget(td, fd, fpp, FREAD, rightsp)); 2920 } 2921 2922 int 2923 fget_write(struct thread *td, int fd, cap_rights_t *rightsp, struct file **fpp) 2924 { 2925 2926 return (_fget(td, fd, fpp, FWRITE, rightsp)); 2927 } 2928 2929 int 2930 fget_fcntl(struct thread *td, int fd, cap_rights_t *rightsp, int needfcntl, 2931 struct file **fpp) 2932 { 2933 struct filedesc *fdp = td->td_proc->p_fd; 2934 #ifndef CAPABILITIES 2935 return (fget_unlocked(fdp, fd, rightsp, fpp)); 2936 #else 2937 struct file *fp; 2938 int error; 2939 seqc_t seq; 2940 2941 *fpp = NULL; 2942 MPASS(cap_rights_is_set(rightsp, CAP_FCNTL)); 2943 for (;;) { 2944 error = fget_unlocked_seq(fdp, fd, rightsp, &fp, &seq); 2945 if (error != 0) 2946 return (error); 2947 error = cap_fcntl_check(fdp, fd, needfcntl); 2948 if (!fd_modified(fdp, fd, seq)) 2949 break; 2950 fdrop(fp, td); 2951 } 2952 if (error != 0) { 2953 fdrop(fp, td); 2954 return (error); 2955 } 2956 *fpp = fp; 2957 return (0); 2958 #endif 2959 } 2960 2961 /* 2962 * Like fget() but loads the underlying vnode, or returns an error if the 2963 * descriptor does not represent a vnode. Note that pipes use vnodes but 2964 * never have VM objects. The returned vnode will be vref()'d. 2965 * 2966 * XXX: what about the unused flags ? 2967 */ 2968 static __inline int 2969 _fgetvp(struct thread *td, int fd, int flags, cap_rights_t *needrightsp, 2970 struct vnode **vpp) 2971 { 2972 struct file *fp; 2973 int error; 2974 2975 *vpp = NULL; 2976 error = _fget(td, fd, &fp, flags, needrightsp); 2977 if (error != 0) 2978 return (error); 2979 if (fp->f_vnode == NULL) { 2980 error = EINVAL; 2981 } else { 2982 *vpp = fp->f_vnode; 2983 vrefact(*vpp); 2984 } 2985 fdrop(fp, td); 2986 2987 return (error); 2988 } 2989 2990 int 2991 fgetvp(struct thread *td, int fd, cap_rights_t *rightsp, struct vnode **vpp) 2992 { 2993 2994 return (_fgetvp(td, fd, 0, rightsp, vpp)); 2995 } 2996 2997 int 2998 fgetvp_rights(struct thread *td, int fd, cap_rights_t *needrightsp, 2999 struct filecaps *havecaps, struct vnode **vpp) 3000 { 3001 struct filecaps caps; 3002 struct file *fp; 3003 int error; 3004 3005 error = fget_cap(td, fd, needrightsp, &fp, &caps); 3006 if (error != 0) 3007 return (error); 3008 if (fp->f_ops == &badfileops) { 3009 error = EBADF; 3010 goto out; 3011 } 3012 if (fp->f_vnode == NULL) { 3013 error = EINVAL; 3014 goto out; 3015 } 3016 3017 *havecaps = caps; 3018 *vpp = fp->f_vnode; 3019 vrefact(*vpp); 3020 fdrop(fp, td); 3021 3022 return (0); 3023 out: 3024 filecaps_free(&caps); 3025 fdrop(fp, td); 3026 return (error); 3027 } 3028 3029 int 3030 fgetvp_read(struct thread *td, int fd, cap_rights_t *rightsp, struct vnode **vpp) 3031 { 3032 3033 return (_fgetvp(td, fd, FREAD, rightsp, vpp)); 3034 } 3035 3036 int 3037 fgetvp_exec(struct thread *td, int fd, cap_rights_t *rightsp, struct vnode **vpp) 3038 { 3039 3040 return (_fgetvp(td, fd, FEXEC, rightsp, vpp)); 3041 } 3042 3043 #ifdef notyet 3044 int 3045 fgetvp_write(struct thread *td, int fd, cap_rights_t *rightsp, 3046 struct vnode **vpp) 3047 { 3048 3049 return (_fgetvp(td, fd, FWRITE, rightsp, vpp)); 3050 } 3051 #endif 3052 3053 /* 3054 * Handle the last reference to a file being closed. 3055 * 3056 * Without the noinline attribute clang keeps inlining the func thorough this 3057 * file when fdrop is used. 3058 */ 3059 int __noinline 3060 _fdrop(struct file *fp, struct thread *td) 3061 { 3062 int error; 3063 3064 if (fp->f_count != 0) 3065 panic("fdrop: count %d", fp->f_count); 3066 error = fo_close(fp, td); 3067 atomic_subtract_int(&openfiles, 1); 3068 crfree(fp->f_cred); 3069 free(fp->f_advice, M_FADVISE); 3070 uma_zfree(file_zone, fp); 3071 3072 return (error); 3073 } 3074 3075 /* 3076 * Apply an advisory lock on a file descriptor. 3077 * 3078 * Just attempt to get a record lock of the requested type on the entire file 3079 * (l_whence = SEEK_SET, l_start = 0, l_len = 0). 3080 */ 3081 #ifndef _SYS_SYSPROTO_H_ 3082 struct flock_args { 3083 int fd; 3084 int how; 3085 }; 3086 #endif 3087 /* ARGSUSED */ 3088 int 3089 sys_flock(struct thread *td, struct flock_args *uap) 3090 { 3091 struct file *fp; 3092 struct vnode *vp; 3093 struct flock lf; 3094 int error; 3095 3096 error = fget(td, uap->fd, &cap_flock_rights, &fp); 3097 if (error != 0) 3098 return (error); 3099 if (fp->f_type != DTYPE_VNODE) { 3100 fdrop(fp, td); 3101 return (EOPNOTSUPP); 3102 } 3103 3104 vp = fp->f_vnode; 3105 lf.l_whence = SEEK_SET; 3106 lf.l_start = 0; 3107 lf.l_len = 0; 3108 if (uap->how & LOCK_UN) { 3109 lf.l_type = F_UNLCK; 3110 atomic_clear_int(&fp->f_flag, FHASLOCK); 3111 error = VOP_ADVLOCK(vp, (caddr_t)fp, F_UNLCK, &lf, F_FLOCK); 3112 goto done2; 3113 } 3114 if (uap->how & LOCK_EX) 3115 lf.l_type = F_WRLCK; 3116 else if (uap->how & LOCK_SH) 3117 lf.l_type = F_RDLCK; 3118 else { 3119 error = EBADF; 3120 goto done2; 3121 } 3122 atomic_set_int(&fp->f_flag, FHASLOCK); 3123 error = VOP_ADVLOCK(vp, (caddr_t)fp, F_SETLK, &lf, 3124 (uap->how & LOCK_NB) ? F_FLOCK : F_FLOCK | F_WAIT); 3125 done2: 3126 fdrop(fp, td); 3127 return (error); 3128 } 3129 /* 3130 * Duplicate the specified descriptor to a free descriptor. 3131 */ 3132 int 3133 dupfdopen(struct thread *td, struct filedesc *fdp, int dfd, int mode, 3134 int openerror, int *indxp) 3135 { 3136 struct filedescent *newfde, *oldfde; 3137 struct file *fp; 3138 u_long *ioctls; 3139 int error, indx; 3140 3141 KASSERT(openerror == ENODEV || openerror == ENXIO, 3142 ("unexpected error %d in %s", openerror, __func__)); 3143 3144 /* 3145 * If the to-be-dup'd fd number is greater than the allowed number 3146 * of file descriptors, or the fd to be dup'd has already been 3147 * closed, then reject. 3148 */ 3149 FILEDESC_XLOCK(fdp); 3150 if ((fp = fget_locked(fdp, dfd)) == NULL) { 3151 FILEDESC_XUNLOCK(fdp); 3152 return (EBADF); 3153 } 3154 3155 error = fdalloc(td, 0, &indx); 3156 if (error != 0) { 3157 FILEDESC_XUNLOCK(fdp); 3158 return (error); 3159 } 3160 3161 /* 3162 * There are two cases of interest here. 3163 * 3164 * For ENODEV simply dup (dfd) to file descriptor (indx) and return. 3165 * 3166 * For ENXIO steal away the file structure from (dfd) and store it in 3167 * (indx). (dfd) is effectively closed by this operation. 3168 */ 3169 switch (openerror) { 3170 case ENODEV: 3171 /* 3172 * Check that the mode the file is being opened for is a 3173 * subset of the mode of the existing descriptor. 3174 */ 3175 if (((mode & (FREAD|FWRITE)) | fp->f_flag) != fp->f_flag) { 3176 fdunused(fdp, indx); 3177 FILEDESC_XUNLOCK(fdp); 3178 return (EACCES); 3179 } 3180 if (!fhold(fp)) { 3181 fdunused(fdp, indx); 3182 FILEDESC_XUNLOCK(fdp); 3183 return (EBADF); 3184 } 3185 newfde = &fdp->fd_ofiles[indx]; 3186 oldfde = &fdp->fd_ofiles[dfd]; 3187 ioctls = filecaps_copy_prep(&oldfde->fde_caps); 3188 #ifdef CAPABILITIES 3189 seqc_write_begin(&newfde->fde_seqc); 3190 #endif 3191 memcpy(newfde, oldfde, fde_change_size); 3192 filecaps_copy_finish(&oldfde->fde_caps, &newfde->fde_caps, 3193 ioctls); 3194 #ifdef CAPABILITIES 3195 seqc_write_end(&newfde->fde_seqc); 3196 #endif 3197 break; 3198 case ENXIO: 3199 /* 3200 * Steal away the file pointer from dfd and stuff it into indx. 3201 */ 3202 newfde = &fdp->fd_ofiles[indx]; 3203 oldfde = &fdp->fd_ofiles[dfd]; 3204 #ifdef CAPABILITIES 3205 seqc_write_begin(&newfde->fde_seqc); 3206 #endif 3207 memcpy(newfde, oldfde, fde_change_size); 3208 oldfde->fde_file = NULL; 3209 fdunused(fdp, dfd); 3210 #ifdef CAPABILITIES 3211 seqc_write_end(&newfde->fde_seqc); 3212 #endif 3213 break; 3214 } 3215 FILEDESC_XUNLOCK(fdp); 3216 *indxp = indx; 3217 return (0); 3218 } 3219 3220 /* 3221 * This sysctl determines if we will allow a process to chroot(2) if it 3222 * has a directory open: 3223 * 0: disallowed for all processes. 3224 * 1: allowed for processes that were not already chroot(2)'ed. 3225 * 2: allowed for all processes. 3226 */ 3227 3228 static int chroot_allow_open_directories = 1; 3229 3230 SYSCTL_INT(_kern, OID_AUTO, chroot_allow_open_directories, CTLFLAG_RW, 3231 &chroot_allow_open_directories, 0, 3232 "Allow a process to chroot(2) if it has a directory open"); 3233 3234 /* 3235 * Helper function for raised chroot(2) security function: Refuse if 3236 * any filedescriptors are open directories. 3237 */ 3238 static int 3239 chroot_refuse_vdir_fds(struct filedesc *fdp) 3240 { 3241 struct vnode *vp; 3242 struct file *fp; 3243 int fd; 3244 3245 FILEDESC_LOCK_ASSERT(fdp); 3246 3247 for (fd = 0; fd <= fdp->fd_lastfile; fd++) { 3248 fp = fget_locked(fdp, fd); 3249 if (fp == NULL) 3250 continue; 3251 if (fp->f_type == DTYPE_VNODE) { 3252 vp = fp->f_vnode; 3253 if (vp->v_type == VDIR) 3254 return (EPERM); 3255 } 3256 } 3257 return (0); 3258 } 3259 3260 static void 3261 pwd_fill(struct pwd *oldpwd, struct pwd *newpwd) 3262 { 3263 3264 if (newpwd->pwd_cdir == NULL && oldpwd->pwd_cdir != NULL) { 3265 vrefact(oldpwd->pwd_cdir); 3266 newpwd->pwd_cdir = oldpwd->pwd_cdir; 3267 } 3268 3269 if (newpwd->pwd_rdir == NULL && oldpwd->pwd_rdir != NULL) { 3270 vrefact(oldpwd->pwd_rdir); 3271 newpwd->pwd_rdir = oldpwd->pwd_rdir; 3272 } 3273 3274 if (newpwd->pwd_jdir == NULL && oldpwd->pwd_jdir != NULL) { 3275 vrefact(oldpwd->pwd_jdir); 3276 newpwd->pwd_jdir = oldpwd->pwd_jdir; 3277 } 3278 } 3279 3280 struct pwd * 3281 pwd_hold_filedesc(struct filedesc *fdp) 3282 { 3283 struct pwd *pwd; 3284 3285 FILEDESC_LOCK_ASSERT(fdp); 3286 pwd = FILEDESC_LOCKED_LOAD_PWD(fdp); 3287 if (pwd != NULL) 3288 refcount_acquire(&pwd->pwd_refcount); 3289 return (pwd); 3290 } 3291 3292 struct pwd * 3293 pwd_hold(struct thread *td) 3294 { 3295 struct filedesc *fdp; 3296 struct pwd *pwd; 3297 3298 fdp = td->td_proc->p_fd; 3299 3300 smr_enter(pwd_smr); 3301 for (;;) { 3302 pwd = smr_entered_load(&fdp->fd_pwd, pwd_smr); 3303 MPASS(pwd != NULL); 3304 if (refcount_acquire_if_not_zero(&pwd->pwd_refcount)) 3305 break; 3306 } 3307 smr_exit(pwd_smr); 3308 return (pwd); 3309 } 3310 3311 static struct pwd * 3312 pwd_alloc(void) 3313 { 3314 struct pwd *pwd; 3315 3316 pwd = uma_zalloc_smr(pwd_zone, M_WAITOK); 3317 bzero(pwd, sizeof(*pwd)); 3318 refcount_init(&pwd->pwd_refcount, 1); 3319 return (pwd); 3320 } 3321 3322 void 3323 pwd_drop(struct pwd *pwd) 3324 { 3325 3326 if (!refcount_release(&pwd->pwd_refcount)) 3327 return; 3328 3329 if (pwd->pwd_cdir != NULL) 3330 vrele(pwd->pwd_cdir); 3331 if (pwd->pwd_rdir != NULL) 3332 vrele(pwd->pwd_rdir); 3333 if (pwd->pwd_jdir != NULL) 3334 vrele(pwd->pwd_jdir); 3335 uma_zfree_smr(pwd_zone, pwd); 3336 } 3337 3338 /* 3339 * Common routine for kern_chroot() and jail_attach(). The caller is 3340 * responsible for invoking priv_check() and mac_vnode_check_chroot() to 3341 * authorize this operation. 3342 */ 3343 int 3344 pwd_chroot(struct thread *td, struct vnode *vp) 3345 { 3346 struct filedesc *fdp; 3347 struct pwd *newpwd, *oldpwd; 3348 int error; 3349 3350 fdp = td->td_proc->p_fd; 3351 newpwd = pwd_alloc(); 3352 FILEDESC_XLOCK(fdp); 3353 oldpwd = FILEDESC_XLOCKED_LOAD_PWD(fdp); 3354 if (chroot_allow_open_directories == 0 || 3355 (chroot_allow_open_directories == 1 && 3356 oldpwd->pwd_rdir != rootvnode)) { 3357 error = chroot_refuse_vdir_fds(fdp); 3358 if (error != 0) { 3359 FILEDESC_XUNLOCK(fdp); 3360 pwd_drop(newpwd); 3361 return (error); 3362 } 3363 } 3364 3365 vrefact(vp); 3366 newpwd->pwd_rdir = vp; 3367 if (oldpwd->pwd_jdir == NULL) { 3368 vrefact(vp); 3369 newpwd->pwd_jdir = vp; 3370 } 3371 pwd_fill(oldpwd, newpwd); 3372 pwd_set(fdp, newpwd); 3373 FILEDESC_XUNLOCK(fdp); 3374 pwd_drop(oldpwd); 3375 return (0); 3376 } 3377 3378 void 3379 pwd_chdir(struct thread *td, struct vnode *vp) 3380 { 3381 struct filedesc *fdp; 3382 struct pwd *newpwd, *oldpwd; 3383 3384 VNPASS(vp->v_usecount > 0, vp); 3385 3386 newpwd = pwd_alloc(); 3387 fdp = td->td_proc->p_fd; 3388 FILEDESC_XLOCK(fdp); 3389 oldpwd = FILEDESC_XLOCKED_LOAD_PWD(fdp); 3390 newpwd->pwd_cdir = vp; 3391 pwd_fill(oldpwd, newpwd); 3392 pwd_set(fdp, newpwd); 3393 FILEDESC_XUNLOCK(fdp); 3394 pwd_drop(oldpwd); 3395 } 3396 3397 void 3398 pwd_ensure_dirs(void) 3399 { 3400 struct filedesc *fdp; 3401 struct pwd *oldpwd, *newpwd; 3402 3403 fdp = curproc->p_fd; 3404 FILEDESC_XLOCK(fdp); 3405 oldpwd = FILEDESC_XLOCKED_LOAD_PWD(fdp); 3406 if (oldpwd->pwd_cdir != NULL && oldpwd->pwd_rdir != NULL) { 3407 FILEDESC_XUNLOCK(fdp); 3408 return; 3409 } 3410 FILEDESC_XUNLOCK(fdp); 3411 3412 newpwd = pwd_alloc(); 3413 FILEDESC_XLOCK(fdp); 3414 oldpwd = FILEDESC_XLOCKED_LOAD_PWD(fdp); 3415 pwd_fill(oldpwd, newpwd); 3416 if (newpwd->pwd_cdir == NULL) { 3417 vrefact(rootvnode); 3418 newpwd->pwd_cdir = rootvnode; 3419 } 3420 if (newpwd->pwd_rdir == NULL) { 3421 vrefact(rootvnode); 3422 newpwd->pwd_rdir = rootvnode; 3423 } 3424 pwd_set(fdp, newpwd); 3425 FILEDESC_XUNLOCK(fdp); 3426 pwd_drop(oldpwd); 3427 } 3428 3429 /* 3430 * Scan all active processes and prisons to see if any of them have a current 3431 * or root directory of `olddp'. If so, replace them with the new mount point. 3432 */ 3433 void 3434 mountcheckdirs(struct vnode *olddp, struct vnode *newdp) 3435 { 3436 struct filedesc *fdp; 3437 struct pwd *newpwd, *oldpwd; 3438 struct prison *pr; 3439 struct proc *p; 3440 int nrele; 3441 3442 if (vrefcnt(olddp) == 1) 3443 return; 3444 nrele = 0; 3445 newpwd = pwd_alloc(); 3446 sx_slock(&allproc_lock); 3447 FOREACH_PROC_IN_SYSTEM(p) { 3448 PROC_LOCK(p); 3449 fdp = fdhold(p); 3450 PROC_UNLOCK(p); 3451 if (fdp == NULL) 3452 continue; 3453 FILEDESC_XLOCK(fdp); 3454 oldpwd = FILEDESC_XLOCKED_LOAD_PWD(fdp); 3455 if (oldpwd == NULL || 3456 (oldpwd->pwd_cdir != olddp && 3457 oldpwd->pwd_rdir != olddp && 3458 oldpwd->pwd_jdir != olddp)) { 3459 FILEDESC_XUNLOCK(fdp); 3460 fddrop(fdp); 3461 continue; 3462 } 3463 if (oldpwd->pwd_cdir == olddp) { 3464 vrefact(newdp); 3465 newpwd->pwd_cdir = newdp; 3466 } 3467 if (oldpwd->pwd_rdir == olddp) { 3468 vrefact(newdp); 3469 newpwd->pwd_rdir = newdp; 3470 } 3471 if (oldpwd->pwd_jdir == olddp) { 3472 vrefact(newdp); 3473 newpwd->pwd_jdir = newdp; 3474 } 3475 pwd_fill(oldpwd, newpwd); 3476 pwd_set(fdp, newpwd); 3477 FILEDESC_XUNLOCK(fdp); 3478 pwd_drop(oldpwd); 3479 fddrop(fdp); 3480 newpwd = pwd_alloc(); 3481 } 3482 sx_sunlock(&allproc_lock); 3483 pwd_drop(newpwd); 3484 if (rootvnode == olddp) { 3485 vrefact(newdp); 3486 rootvnode = newdp; 3487 nrele++; 3488 } 3489 mtx_lock(&prison0.pr_mtx); 3490 if (prison0.pr_root == olddp) { 3491 vrefact(newdp); 3492 prison0.pr_root = newdp; 3493 nrele++; 3494 } 3495 mtx_unlock(&prison0.pr_mtx); 3496 sx_slock(&allprison_lock); 3497 TAILQ_FOREACH(pr, &allprison, pr_list) { 3498 mtx_lock(&pr->pr_mtx); 3499 if (pr->pr_root == olddp) { 3500 vrefact(newdp); 3501 pr->pr_root = newdp; 3502 nrele++; 3503 } 3504 mtx_unlock(&pr->pr_mtx); 3505 } 3506 sx_sunlock(&allprison_lock); 3507 while (nrele--) 3508 vrele(olddp); 3509 } 3510 3511 struct filedesc_to_leader * 3512 filedesc_to_leader_alloc(struct filedesc_to_leader *old, struct filedesc *fdp, struct proc *leader) 3513 { 3514 struct filedesc_to_leader *fdtol; 3515 3516 fdtol = malloc(sizeof(struct filedesc_to_leader), 3517 M_FILEDESC_TO_LEADER, M_WAITOK); 3518 fdtol->fdl_refcount = 1; 3519 fdtol->fdl_holdcount = 0; 3520 fdtol->fdl_wakeup = 0; 3521 fdtol->fdl_leader = leader; 3522 if (old != NULL) { 3523 FILEDESC_XLOCK(fdp); 3524 fdtol->fdl_next = old->fdl_next; 3525 fdtol->fdl_prev = old; 3526 old->fdl_next = fdtol; 3527 fdtol->fdl_next->fdl_prev = fdtol; 3528 FILEDESC_XUNLOCK(fdp); 3529 } else { 3530 fdtol->fdl_next = fdtol; 3531 fdtol->fdl_prev = fdtol; 3532 } 3533 return (fdtol); 3534 } 3535 3536 static int 3537 sysctl_kern_proc_nfds(SYSCTL_HANDLER_ARGS) 3538 { 3539 struct filedesc *fdp; 3540 int i, count, slots; 3541 3542 if (*(int *)arg1 != 0) 3543 return (EINVAL); 3544 3545 fdp = curproc->p_fd; 3546 count = 0; 3547 FILEDESC_SLOCK(fdp); 3548 slots = NDSLOTS(fdp->fd_lastfile + 1); 3549 for (i = 0; i < slots; i++) 3550 count += bitcountl(fdp->fd_map[i]); 3551 FILEDESC_SUNLOCK(fdp); 3552 3553 return (SYSCTL_OUT(req, &count, sizeof(count))); 3554 } 3555 3556 static SYSCTL_NODE(_kern_proc, KERN_PROC_NFDS, nfds, 3557 CTLFLAG_RD|CTLFLAG_CAPRD|CTLFLAG_MPSAFE, sysctl_kern_proc_nfds, 3558 "Number of open file descriptors"); 3559 3560 /* 3561 * Get file structures globally. 3562 */ 3563 static int 3564 sysctl_kern_file(SYSCTL_HANDLER_ARGS) 3565 { 3566 struct xfile xf; 3567 struct filedesc *fdp; 3568 struct file *fp; 3569 struct proc *p; 3570 int error, n; 3571 3572 error = sysctl_wire_old_buffer(req, 0); 3573 if (error != 0) 3574 return (error); 3575 if (req->oldptr == NULL) { 3576 n = 0; 3577 sx_slock(&allproc_lock); 3578 FOREACH_PROC_IN_SYSTEM(p) { 3579 PROC_LOCK(p); 3580 if (p->p_state == PRS_NEW) { 3581 PROC_UNLOCK(p); 3582 continue; 3583 } 3584 fdp = fdhold(p); 3585 PROC_UNLOCK(p); 3586 if (fdp == NULL) 3587 continue; 3588 /* overestimates sparse tables. */ 3589 if (fdp->fd_lastfile > 0) 3590 n += fdp->fd_lastfile; 3591 fddrop(fdp); 3592 } 3593 sx_sunlock(&allproc_lock); 3594 return (SYSCTL_OUT(req, 0, n * sizeof(xf))); 3595 } 3596 error = 0; 3597 bzero(&xf, sizeof(xf)); 3598 xf.xf_size = sizeof(xf); 3599 sx_slock(&allproc_lock); 3600 FOREACH_PROC_IN_SYSTEM(p) { 3601 PROC_LOCK(p); 3602 if (p->p_state == PRS_NEW) { 3603 PROC_UNLOCK(p); 3604 continue; 3605 } 3606 if (p_cansee(req->td, p) != 0) { 3607 PROC_UNLOCK(p); 3608 continue; 3609 } 3610 xf.xf_pid = p->p_pid; 3611 xf.xf_uid = p->p_ucred->cr_uid; 3612 fdp = fdhold(p); 3613 PROC_UNLOCK(p); 3614 if (fdp == NULL) 3615 continue; 3616 FILEDESC_SLOCK(fdp); 3617 for (n = 0; fdp->fd_refcnt > 0 && n <= fdp->fd_lastfile; ++n) { 3618 if ((fp = fdp->fd_ofiles[n].fde_file) == NULL) 3619 continue; 3620 xf.xf_fd = n; 3621 xf.xf_file = (uintptr_t)fp; 3622 xf.xf_data = (uintptr_t)fp->f_data; 3623 xf.xf_vnode = (uintptr_t)fp->f_vnode; 3624 xf.xf_type = (uintptr_t)fp->f_type; 3625 xf.xf_count = fp->f_count; 3626 xf.xf_msgcount = 0; 3627 xf.xf_offset = foffset_get(fp); 3628 xf.xf_flag = fp->f_flag; 3629 error = SYSCTL_OUT(req, &xf, sizeof(xf)); 3630 if (error) 3631 break; 3632 } 3633 FILEDESC_SUNLOCK(fdp); 3634 fddrop(fdp); 3635 if (error) 3636 break; 3637 } 3638 sx_sunlock(&allproc_lock); 3639 return (error); 3640 } 3641 3642 SYSCTL_PROC(_kern, KERN_FILE, file, CTLTYPE_OPAQUE|CTLFLAG_RD|CTLFLAG_MPSAFE, 3643 0, 0, sysctl_kern_file, "S,xfile", "Entire file table"); 3644 3645 #ifdef KINFO_FILE_SIZE 3646 CTASSERT(sizeof(struct kinfo_file) == KINFO_FILE_SIZE); 3647 #endif 3648 3649 static int 3650 xlate_fflags(int fflags) 3651 { 3652 static const struct { 3653 int fflag; 3654 int kf_fflag; 3655 } fflags_table[] = { 3656 { FAPPEND, KF_FLAG_APPEND }, 3657 { FASYNC, KF_FLAG_ASYNC }, 3658 { FFSYNC, KF_FLAG_FSYNC }, 3659 { FHASLOCK, KF_FLAG_HASLOCK }, 3660 { FNONBLOCK, KF_FLAG_NONBLOCK }, 3661 { FREAD, KF_FLAG_READ }, 3662 { FWRITE, KF_FLAG_WRITE }, 3663 { O_CREAT, KF_FLAG_CREAT }, 3664 { O_DIRECT, KF_FLAG_DIRECT }, 3665 { O_EXCL, KF_FLAG_EXCL }, 3666 { O_EXEC, KF_FLAG_EXEC }, 3667 { O_EXLOCK, KF_FLAG_EXLOCK }, 3668 { O_NOFOLLOW, KF_FLAG_NOFOLLOW }, 3669 { O_SHLOCK, KF_FLAG_SHLOCK }, 3670 { O_TRUNC, KF_FLAG_TRUNC } 3671 }; 3672 unsigned int i; 3673 int kflags; 3674 3675 kflags = 0; 3676 for (i = 0; i < nitems(fflags_table); i++) 3677 if (fflags & fflags_table[i].fflag) 3678 kflags |= fflags_table[i].kf_fflag; 3679 return (kflags); 3680 } 3681 3682 /* Trim unused data from kf_path by truncating the structure size. */ 3683 void 3684 pack_kinfo(struct kinfo_file *kif) 3685 { 3686 3687 kif->kf_structsize = offsetof(struct kinfo_file, kf_path) + 3688 strlen(kif->kf_path) + 1; 3689 kif->kf_structsize = roundup(kif->kf_structsize, sizeof(uint64_t)); 3690 } 3691 3692 static void 3693 export_file_to_kinfo(struct file *fp, int fd, cap_rights_t *rightsp, 3694 struct kinfo_file *kif, struct filedesc *fdp, int flags) 3695 { 3696 int error; 3697 3698 bzero(kif, sizeof(*kif)); 3699 3700 /* Set a default type to allow for empty fill_kinfo() methods. */ 3701 kif->kf_type = KF_TYPE_UNKNOWN; 3702 kif->kf_flags = xlate_fflags(fp->f_flag); 3703 if (rightsp != NULL) 3704 kif->kf_cap_rights = *rightsp; 3705 else 3706 cap_rights_init_zero(&kif->kf_cap_rights); 3707 kif->kf_fd = fd; 3708 kif->kf_ref_count = fp->f_count; 3709 kif->kf_offset = foffset_get(fp); 3710 3711 /* 3712 * This may drop the filedesc lock, so the 'fp' cannot be 3713 * accessed after this call. 3714 */ 3715 error = fo_fill_kinfo(fp, kif, fdp); 3716 if (error == 0) 3717 kif->kf_status |= KF_ATTR_VALID; 3718 if ((flags & KERN_FILEDESC_PACK_KINFO) != 0) 3719 pack_kinfo(kif); 3720 else 3721 kif->kf_structsize = roundup2(sizeof(*kif), sizeof(uint64_t)); 3722 } 3723 3724 static void 3725 export_vnode_to_kinfo(struct vnode *vp, int fd, int fflags, 3726 struct kinfo_file *kif, int flags) 3727 { 3728 int error; 3729 3730 bzero(kif, sizeof(*kif)); 3731 3732 kif->kf_type = KF_TYPE_VNODE; 3733 error = vn_fill_kinfo_vnode(vp, kif); 3734 if (error == 0) 3735 kif->kf_status |= KF_ATTR_VALID; 3736 kif->kf_flags = xlate_fflags(fflags); 3737 cap_rights_init_zero(&kif->kf_cap_rights); 3738 kif->kf_fd = fd; 3739 kif->kf_ref_count = -1; 3740 kif->kf_offset = -1; 3741 if ((flags & KERN_FILEDESC_PACK_KINFO) != 0) 3742 pack_kinfo(kif); 3743 else 3744 kif->kf_structsize = roundup2(sizeof(*kif), sizeof(uint64_t)); 3745 vrele(vp); 3746 } 3747 3748 struct export_fd_buf { 3749 struct filedesc *fdp; 3750 struct sbuf *sb; 3751 ssize_t remainder; 3752 struct kinfo_file kif; 3753 int flags; 3754 }; 3755 3756 static int 3757 export_kinfo_to_sb(struct export_fd_buf *efbuf) 3758 { 3759 struct kinfo_file *kif; 3760 3761 kif = &efbuf->kif; 3762 if (efbuf->remainder != -1) { 3763 if (efbuf->remainder < kif->kf_structsize) { 3764 /* Terminate export. */ 3765 efbuf->remainder = 0; 3766 return (0); 3767 } 3768 efbuf->remainder -= kif->kf_structsize; 3769 } 3770 return (sbuf_bcat(efbuf->sb, kif, kif->kf_structsize) == 0 ? 0 : ENOMEM); 3771 } 3772 3773 static int 3774 export_file_to_sb(struct file *fp, int fd, cap_rights_t *rightsp, 3775 struct export_fd_buf *efbuf) 3776 { 3777 int error; 3778 3779 if (efbuf->remainder == 0) 3780 return (0); 3781 export_file_to_kinfo(fp, fd, rightsp, &efbuf->kif, efbuf->fdp, 3782 efbuf->flags); 3783 FILEDESC_SUNLOCK(efbuf->fdp); 3784 error = export_kinfo_to_sb(efbuf); 3785 FILEDESC_SLOCK(efbuf->fdp); 3786 return (error); 3787 } 3788 3789 static int 3790 export_vnode_to_sb(struct vnode *vp, int fd, int fflags, 3791 struct export_fd_buf *efbuf) 3792 { 3793 int error; 3794 3795 if (efbuf->remainder == 0) 3796 return (0); 3797 if (efbuf->fdp != NULL) 3798 FILEDESC_SUNLOCK(efbuf->fdp); 3799 export_vnode_to_kinfo(vp, fd, fflags, &efbuf->kif, efbuf->flags); 3800 error = export_kinfo_to_sb(efbuf); 3801 if (efbuf->fdp != NULL) 3802 FILEDESC_SLOCK(efbuf->fdp); 3803 return (error); 3804 } 3805 3806 /* 3807 * Store a process file descriptor information to sbuf. 3808 * 3809 * Takes a locked proc as argument, and returns with the proc unlocked. 3810 */ 3811 int 3812 kern_proc_filedesc_out(struct proc *p, struct sbuf *sb, ssize_t maxlen, 3813 int flags) 3814 { 3815 struct file *fp; 3816 struct filedesc *fdp; 3817 struct export_fd_buf *efbuf; 3818 struct vnode *cttyvp, *textvp, *tracevp; 3819 struct pwd *pwd; 3820 int error, i; 3821 cap_rights_t rights; 3822 3823 PROC_LOCK_ASSERT(p, MA_OWNED); 3824 3825 /* ktrace vnode */ 3826 tracevp = p->p_tracevp; 3827 if (tracevp != NULL) 3828 vrefact(tracevp); 3829 /* text vnode */ 3830 textvp = p->p_textvp; 3831 if (textvp != NULL) 3832 vrefact(textvp); 3833 /* Controlling tty. */ 3834 cttyvp = NULL; 3835 if (p->p_pgrp != NULL && p->p_pgrp->pg_session != NULL) { 3836 cttyvp = p->p_pgrp->pg_session->s_ttyvp; 3837 if (cttyvp != NULL) 3838 vrefact(cttyvp); 3839 } 3840 fdp = fdhold(p); 3841 PROC_UNLOCK(p); 3842 efbuf = malloc(sizeof(*efbuf), M_TEMP, M_WAITOK); 3843 efbuf->fdp = NULL; 3844 efbuf->sb = sb; 3845 efbuf->remainder = maxlen; 3846 efbuf->flags = flags; 3847 if (tracevp != NULL) 3848 export_vnode_to_sb(tracevp, KF_FD_TYPE_TRACE, FREAD | FWRITE, 3849 efbuf); 3850 if (textvp != NULL) 3851 export_vnode_to_sb(textvp, KF_FD_TYPE_TEXT, FREAD, efbuf); 3852 if (cttyvp != NULL) 3853 export_vnode_to_sb(cttyvp, KF_FD_TYPE_CTTY, FREAD | FWRITE, 3854 efbuf); 3855 error = 0; 3856 if (fdp == NULL) 3857 goto fail; 3858 efbuf->fdp = fdp; 3859 FILEDESC_SLOCK(fdp); 3860 pwd = pwd_hold_filedesc(fdp); 3861 if (pwd != NULL) { 3862 /* working directory */ 3863 if (pwd->pwd_cdir != NULL) { 3864 vrefact(pwd->pwd_cdir); 3865 export_vnode_to_sb(pwd->pwd_cdir, KF_FD_TYPE_CWD, FREAD, efbuf); 3866 } 3867 /* root directory */ 3868 if (pwd->pwd_rdir != NULL) { 3869 vrefact(pwd->pwd_rdir); 3870 export_vnode_to_sb(pwd->pwd_rdir, KF_FD_TYPE_ROOT, FREAD, efbuf); 3871 } 3872 /* jail directory */ 3873 if (pwd->pwd_jdir != NULL) { 3874 vrefact(pwd->pwd_jdir); 3875 export_vnode_to_sb(pwd->pwd_jdir, KF_FD_TYPE_JAIL, FREAD, efbuf); 3876 } 3877 pwd_drop(pwd); 3878 } 3879 for (i = 0; fdp->fd_refcnt > 0 && i <= fdp->fd_lastfile; i++) { 3880 if ((fp = fdp->fd_ofiles[i].fde_file) == NULL) 3881 continue; 3882 #ifdef CAPABILITIES 3883 rights = *cap_rights(fdp, i); 3884 #else /* !CAPABILITIES */ 3885 rights = cap_no_rights; 3886 #endif 3887 /* 3888 * Create sysctl entry. It is OK to drop the filedesc 3889 * lock inside of export_file_to_sb() as we will 3890 * re-validate and re-evaluate its properties when the 3891 * loop continues. 3892 */ 3893 error = export_file_to_sb(fp, i, &rights, efbuf); 3894 if (error != 0 || efbuf->remainder == 0) 3895 break; 3896 } 3897 FILEDESC_SUNLOCK(fdp); 3898 fddrop(fdp); 3899 fail: 3900 free(efbuf, M_TEMP); 3901 return (error); 3902 } 3903 3904 #define FILEDESC_SBUF_SIZE (sizeof(struct kinfo_file) * 5) 3905 3906 /* 3907 * Get per-process file descriptors for use by procstat(1), et al. 3908 */ 3909 static int 3910 sysctl_kern_proc_filedesc(SYSCTL_HANDLER_ARGS) 3911 { 3912 struct sbuf sb; 3913 struct proc *p; 3914 ssize_t maxlen; 3915 int error, error2, *name; 3916 3917 name = (int *)arg1; 3918 3919 sbuf_new_for_sysctl(&sb, NULL, FILEDESC_SBUF_SIZE, req); 3920 sbuf_clear_flags(&sb, SBUF_INCLUDENUL); 3921 error = pget((pid_t)name[0], PGET_CANDEBUG | PGET_NOTWEXIT, &p); 3922 if (error != 0) { 3923 sbuf_delete(&sb); 3924 return (error); 3925 } 3926 maxlen = req->oldptr != NULL ? req->oldlen : -1; 3927 error = kern_proc_filedesc_out(p, &sb, maxlen, 3928 KERN_FILEDESC_PACK_KINFO); 3929 error2 = sbuf_finish(&sb); 3930 sbuf_delete(&sb); 3931 return (error != 0 ? error : error2); 3932 } 3933 3934 #ifdef COMPAT_FREEBSD7 3935 #ifdef KINFO_OFILE_SIZE 3936 CTASSERT(sizeof(struct kinfo_ofile) == KINFO_OFILE_SIZE); 3937 #endif 3938 3939 static void 3940 kinfo_to_okinfo(struct kinfo_file *kif, struct kinfo_ofile *okif) 3941 { 3942 3943 okif->kf_structsize = sizeof(*okif); 3944 okif->kf_type = kif->kf_type; 3945 okif->kf_fd = kif->kf_fd; 3946 okif->kf_ref_count = kif->kf_ref_count; 3947 okif->kf_flags = kif->kf_flags & (KF_FLAG_READ | KF_FLAG_WRITE | 3948 KF_FLAG_APPEND | KF_FLAG_ASYNC | KF_FLAG_FSYNC | KF_FLAG_NONBLOCK | 3949 KF_FLAG_DIRECT | KF_FLAG_HASLOCK); 3950 okif->kf_offset = kif->kf_offset; 3951 if (kif->kf_type == KF_TYPE_VNODE) 3952 okif->kf_vnode_type = kif->kf_un.kf_file.kf_file_type; 3953 else 3954 okif->kf_vnode_type = KF_VTYPE_VNON; 3955 strlcpy(okif->kf_path, kif->kf_path, sizeof(okif->kf_path)); 3956 if (kif->kf_type == KF_TYPE_SOCKET) { 3957 okif->kf_sock_domain = kif->kf_un.kf_sock.kf_sock_domain0; 3958 okif->kf_sock_type = kif->kf_un.kf_sock.kf_sock_type0; 3959 okif->kf_sock_protocol = kif->kf_un.kf_sock.kf_sock_protocol0; 3960 okif->kf_sa_local = kif->kf_un.kf_sock.kf_sa_local; 3961 okif->kf_sa_peer = kif->kf_un.kf_sock.kf_sa_peer; 3962 } else { 3963 okif->kf_sa_local.ss_family = AF_UNSPEC; 3964 okif->kf_sa_peer.ss_family = AF_UNSPEC; 3965 } 3966 } 3967 3968 static int 3969 export_vnode_for_osysctl(struct vnode *vp, int type, struct kinfo_file *kif, 3970 struct kinfo_ofile *okif, struct filedesc *fdp, struct sysctl_req *req) 3971 { 3972 int error; 3973 3974 vrefact(vp); 3975 FILEDESC_SUNLOCK(fdp); 3976 export_vnode_to_kinfo(vp, type, 0, kif, KERN_FILEDESC_PACK_KINFO); 3977 kinfo_to_okinfo(kif, okif); 3978 error = SYSCTL_OUT(req, okif, sizeof(*okif)); 3979 FILEDESC_SLOCK(fdp); 3980 return (error); 3981 } 3982 3983 /* 3984 * Get per-process file descriptors for use by procstat(1), et al. 3985 */ 3986 static int 3987 sysctl_kern_proc_ofiledesc(SYSCTL_HANDLER_ARGS) 3988 { 3989 struct kinfo_ofile *okif; 3990 struct kinfo_file *kif; 3991 struct filedesc *fdp; 3992 struct pwd *pwd; 3993 int error, i, *name; 3994 struct file *fp; 3995 struct proc *p; 3996 3997 name = (int *)arg1; 3998 error = pget((pid_t)name[0], PGET_CANDEBUG | PGET_NOTWEXIT, &p); 3999 if (error != 0) 4000 return (error); 4001 fdp = fdhold(p); 4002 PROC_UNLOCK(p); 4003 if (fdp == NULL) 4004 return (ENOENT); 4005 kif = malloc(sizeof(*kif), M_TEMP, M_WAITOK); 4006 okif = malloc(sizeof(*okif), M_TEMP, M_WAITOK); 4007 FILEDESC_SLOCK(fdp); 4008 pwd = pwd_hold_filedesc(fdp); 4009 if (pwd != NULL) { 4010 if (pwd->pwd_cdir != NULL) 4011 export_vnode_for_osysctl(pwd->pwd_cdir, KF_FD_TYPE_CWD, kif, 4012 okif, fdp, req); 4013 if (pwd->pwd_rdir != NULL) 4014 export_vnode_for_osysctl(pwd->pwd_rdir, KF_FD_TYPE_ROOT, kif, 4015 okif, fdp, req); 4016 if (pwd->pwd_jdir != NULL) 4017 export_vnode_for_osysctl(pwd->pwd_jdir, KF_FD_TYPE_JAIL, kif, 4018 okif, fdp, req); 4019 pwd_drop(pwd); 4020 } 4021 for (i = 0; fdp->fd_refcnt > 0 && i <= fdp->fd_lastfile; i++) { 4022 if ((fp = fdp->fd_ofiles[i].fde_file) == NULL) 4023 continue; 4024 export_file_to_kinfo(fp, i, NULL, kif, fdp, 4025 KERN_FILEDESC_PACK_KINFO); 4026 FILEDESC_SUNLOCK(fdp); 4027 kinfo_to_okinfo(kif, okif); 4028 error = SYSCTL_OUT(req, okif, sizeof(*okif)); 4029 FILEDESC_SLOCK(fdp); 4030 if (error) 4031 break; 4032 } 4033 FILEDESC_SUNLOCK(fdp); 4034 fddrop(fdp); 4035 free(kif, M_TEMP); 4036 free(okif, M_TEMP); 4037 return (0); 4038 } 4039 4040 static SYSCTL_NODE(_kern_proc, KERN_PROC_OFILEDESC, ofiledesc, 4041 CTLFLAG_RD|CTLFLAG_MPSAFE, sysctl_kern_proc_ofiledesc, 4042 "Process ofiledesc entries"); 4043 #endif /* COMPAT_FREEBSD7 */ 4044 4045 int 4046 vntype_to_kinfo(int vtype) 4047 { 4048 struct { 4049 int vtype; 4050 int kf_vtype; 4051 } vtypes_table[] = { 4052 { VBAD, KF_VTYPE_VBAD }, 4053 { VBLK, KF_VTYPE_VBLK }, 4054 { VCHR, KF_VTYPE_VCHR }, 4055 { VDIR, KF_VTYPE_VDIR }, 4056 { VFIFO, KF_VTYPE_VFIFO }, 4057 { VLNK, KF_VTYPE_VLNK }, 4058 { VNON, KF_VTYPE_VNON }, 4059 { VREG, KF_VTYPE_VREG }, 4060 { VSOCK, KF_VTYPE_VSOCK } 4061 }; 4062 unsigned int i; 4063 4064 /* 4065 * Perform vtype translation. 4066 */ 4067 for (i = 0; i < nitems(vtypes_table); i++) 4068 if (vtypes_table[i].vtype == vtype) 4069 return (vtypes_table[i].kf_vtype); 4070 4071 return (KF_VTYPE_UNKNOWN); 4072 } 4073 4074 static SYSCTL_NODE(_kern_proc, KERN_PROC_FILEDESC, filedesc, 4075 CTLFLAG_RD|CTLFLAG_MPSAFE, sysctl_kern_proc_filedesc, 4076 "Process filedesc entries"); 4077 4078 /* 4079 * Store a process current working directory information to sbuf. 4080 * 4081 * Takes a locked proc as argument, and returns with the proc unlocked. 4082 */ 4083 int 4084 kern_proc_cwd_out(struct proc *p, struct sbuf *sb, ssize_t maxlen) 4085 { 4086 struct filedesc *fdp; 4087 struct pwd *pwd; 4088 struct export_fd_buf *efbuf; 4089 struct vnode *cdir; 4090 int error; 4091 4092 PROC_LOCK_ASSERT(p, MA_OWNED); 4093 4094 fdp = fdhold(p); 4095 PROC_UNLOCK(p); 4096 if (fdp == NULL) 4097 return (EINVAL); 4098 4099 efbuf = malloc(sizeof(*efbuf), M_TEMP, M_WAITOK); 4100 efbuf->fdp = fdp; 4101 efbuf->sb = sb; 4102 efbuf->remainder = maxlen; 4103 4104 FILEDESC_SLOCK(fdp); 4105 pwd = FILEDESC_LOCKED_LOAD_PWD(fdp); 4106 cdir = pwd->pwd_cdir; 4107 if (cdir == NULL) { 4108 error = EINVAL; 4109 } else { 4110 vrefact(cdir); 4111 error = export_vnode_to_sb(cdir, KF_FD_TYPE_CWD, FREAD, efbuf); 4112 } 4113 FILEDESC_SUNLOCK(fdp); 4114 fddrop(fdp); 4115 free(efbuf, M_TEMP); 4116 return (error); 4117 } 4118 4119 /* 4120 * Get per-process current working directory. 4121 */ 4122 static int 4123 sysctl_kern_proc_cwd(SYSCTL_HANDLER_ARGS) 4124 { 4125 struct sbuf sb; 4126 struct proc *p; 4127 ssize_t maxlen; 4128 int error, error2, *name; 4129 4130 name = (int *)arg1; 4131 4132 sbuf_new_for_sysctl(&sb, NULL, sizeof(struct kinfo_file), req); 4133 sbuf_clear_flags(&sb, SBUF_INCLUDENUL); 4134 error = pget((pid_t)name[0], PGET_CANDEBUG | PGET_NOTWEXIT, &p); 4135 if (error != 0) { 4136 sbuf_delete(&sb); 4137 return (error); 4138 } 4139 maxlen = req->oldptr != NULL ? req->oldlen : -1; 4140 error = kern_proc_cwd_out(p, &sb, maxlen); 4141 error2 = sbuf_finish(&sb); 4142 sbuf_delete(&sb); 4143 return (error != 0 ? error : error2); 4144 } 4145 4146 static SYSCTL_NODE(_kern_proc, KERN_PROC_CWD, cwd, CTLFLAG_RD|CTLFLAG_MPSAFE, 4147 sysctl_kern_proc_cwd, "Process current working directory"); 4148 4149 #ifdef DDB 4150 /* 4151 * For the purposes of debugging, generate a human-readable string for the 4152 * file type. 4153 */ 4154 static const char * 4155 file_type_to_name(short type) 4156 { 4157 4158 switch (type) { 4159 case 0: 4160 return ("zero"); 4161 case DTYPE_VNODE: 4162 return ("vnode"); 4163 case DTYPE_SOCKET: 4164 return ("socket"); 4165 case DTYPE_PIPE: 4166 return ("pipe"); 4167 case DTYPE_FIFO: 4168 return ("fifo"); 4169 case DTYPE_KQUEUE: 4170 return ("kqueue"); 4171 case DTYPE_CRYPTO: 4172 return ("crypto"); 4173 case DTYPE_MQUEUE: 4174 return ("mqueue"); 4175 case DTYPE_SHM: 4176 return ("shm"); 4177 case DTYPE_SEM: 4178 return ("ksem"); 4179 case DTYPE_PTS: 4180 return ("pts"); 4181 case DTYPE_DEV: 4182 return ("dev"); 4183 case DTYPE_PROCDESC: 4184 return ("proc"); 4185 case DTYPE_LINUXEFD: 4186 return ("levent"); 4187 case DTYPE_LINUXTFD: 4188 return ("ltimer"); 4189 default: 4190 return ("unkn"); 4191 } 4192 } 4193 4194 /* 4195 * For the purposes of debugging, identify a process (if any, perhaps one of 4196 * many) that references the passed file in its file descriptor array. Return 4197 * NULL if none. 4198 */ 4199 static struct proc * 4200 file_to_first_proc(struct file *fp) 4201 { 4202 struct filedesc *fdp; 4203 struct proc *p; 4204 int n; 4205 4206 FOREACH_PROC_IN_SYSTEM(p) { 4207 if (p->p_state == PRS_NEW) 4208 continue; 4209 fdp = p->p_fd; 4210 if (fdp == NULL) 4211 continue; 4212 for (n = 0; n <= fdp->fd_lastfile; n++) { 4213 if (fp == fdp->fd_ofiles[n].fde_file) 4214 return (p); 4215 } 4216 } 4217 return (NULL); 4218 } 4219 4220 static void 4221 db_print_file(struct file *fp, int header) 4222 { 4223 #define XPTRWIDTH ((int)howmany(sizeof(void *) * NBBY, 4)) 4224 struct proc *p; 4225 4226 if (header) 4227 db_printf("%*s %6s %*s %8s %4s %5s %6s %*s %5s %s\n", 4228 XPTRWIDTH, "File", "Type", XPTRWIDTH, "Data", "Flag", 4229 "GCFl", "Count", "MCount", XPTRWIDTH, "Vnode", "FPID", 4230 "FCmd"); 4231 p = file_to_first_proc(fp); 4232 db_printf("%*p %6s %*p %08x %04x %5d %6d %*p %5d %s\n", XPTRWIDTH, 4233 fp, file_type_to_name(fp->f_type), XPTRWIDTH, fp->f_data, 4234 fp->f_flag, 0, fp->f_count, 0, XPTRWIDTH, fp->f_vnode, 4235 p != NULL ? p->p_pid : -1, p != NULL ? p->p_comm : "-"); 4236 4237 #undef XPTRWIDTH 4238 } 4239 4240 DB_SHOW_COMMAND(file, db_show_file) 4241 { 4242 struct file *fp; 4243 4244 if (!have_addr) { 4245 db_printf("usage: show file <addr>\n"); 4246 return; 4247 } 4248 fp = (struct file *)addr; 4249 db_print_file(fp, 1); 4250 } 4251 4252 DB_SHOW_COMMAND(files, db_show_files) 4253 { 4254 struct filedesc *fdp; 4255 struct file *fp; 4256 struct proc *p; 4257 int header; 4258 int n; 4259 4260 header = 1; 4261 FOREACH_PROC_IN_SYSTEM(p) { 4262 if (p->p_state == PRS_NEW) 4263 continue; 4264 if ((fdp = p->p_fd) == NULL) 4265 continue; 4266 for (n = 0; n <= fdp->fd_lastfile; ++n) { 4267 if ((fp = fdp->fd_ofiles[n].fde_file) == NULL) 4268 continue; 4269 db_print_file(fp, header); 4270 header = 0; 4271 } 4272 } 4273 } 4274 #endif 4275 4276 SYSCTL_INT(_kern, KERN_MAXFILESPERPROC, maxfilesperproc, CTLFLAG_RW, 4277 &maxfilesperproc, 0, "Maximum files allowed open per process"); 4278 4279 SYSCTL_INT(_kern, KERN_MAXFILES, maxfiles, CTLFLAG_RW, 4280 &maxfiles, 0, "Maximum number of files"); 4281 4282 SYSCTL_INT(_kern, OID_AUTO, openfiles, CTLFLAG_RD, 4283 &openfiles, 0, "System-wide number of open files"); 4284 4285 /* ARGSUSED*/ 4286 static void 4287 filelistinit(void *dummy) 4288 { 4289 4290 file_zone = uma_zcreate("Files", sizeof(struct file), NULL, NULL, 4291 NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE); 4292 filedesc0_zone = uma_zcreate("filedesc0", sizeof(struct filedesc0), 4293 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0); 4294 pwd_zone = uma_zcreate("PWD", sizeof(struct pwd), NULL, NULL, 4295 NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_SMR); 4296 pwd_smr = uma_zone_get_smr(pwd_zone); 4297 mtx_init(&sigio_lock, "sigio lock", NULL, MTX_DEF); 4298 } 4299 SYSINIT(select, SI_SUB_LOCK, SI_ORDER_FIRST, filelistinit, NULL); 4300 4301 /*-------------------------------------------------------------------*/ 4302 4303 static int 4304 badfo_readwrite(struct file *fp, struct uio *uio, struct ucred *active_cred, 4305 int flags, struct thread *td) 4306 { 4307 4308 return (EBADF); 4309 } 4310 4311 static int 4312 badfo_truncate(struct file *fp, off_t length, struct ucred *active_cred, 4313 struct thread *td) 4314 { 4315 4316 return (EINVAL); 4317 } 4318 4319 static int 4320 badfo_ioctl(struct file *fp, u_long com, void *data, struct ucred *active_cred, 4321 struct thread *td) 4322 { 4323 4324 return (EBADF); 4325 } 4326 4327 static int 4328 badfo_poll(struct file *fp, int events, struct ucred *active_cred, 4329 struct thread *td) 4330 { 4331 4332 return (0); 4333 } 4334 4335 static int 4336 badfo_kqfilter(struct file *fp, struct knote *kn) 4337 { 4338 4339 return (EBADF); 4340 } 4341 4342 static int 4343 badfo_stat(struct file *fp, struct stat *sb, struct ucred *active_cred, 4344 struct thread *td) 4345 { 4346 4347 return (EBADF); 4348 } 4349 4350 static int 4351 badfo_close(struct file *fp, struct thread *td) 4352 { 4353 4354 return (0); 4355 } 4356 4357 static int 4358 badfo_chmod(struct file *fp, mode_t mode, struct ucred *active_cred, 4359 struct thread *td) 4360 { 4361 4362 return (EBADF); 4363 } 4364 4365 static int 4366 badfo_chown(struct file *fp, uid_t uid, gid_t gid, struct ucred *active_cred, 4367 struct thread *td) 4368 { 4369 4370 return (EBADF); 4371 } 4372 4373 static int 4374 badfo_sendfile(struct file *fp, int sockfd, struct uio *hdr_uio, 4375 struct uio *trl_uio, off_t offset, size_t nbytes, off_t *sent, int flags, 4376 struct thread *td) 4377 { 4378 4379 return (EBADF); 4380 } 4381 4382 static int 4383 badfo_fill_kinfo(struct file *fp, struct kinfo_file *kif, struct filedesc *fdp) 4384 { 4385 4386 return (0); 4387 } 4388 4389 struct fileops badfileops = { 4390 .fo_read = badfo_readwrite, 4391 .fo_write = badfo_readwrite, 4392 .fo_truncate = badfo_truncate, 4393 .fo_ioctl = badfo_ioctl, 4394 .fo_poll = badfo_poll, 4395 .fo_kqfilter = badfo_kqfilter, 4396 .fo_stat = badfo_stat, 4397 .fo_close = badfo_close, 4398 .fo_chmod = badfo_chmod, 4399 .fo_chown = badfo_chown, 4400 .fo_sendfile = badfo_sendfile, 4401 .fo_fill_kinfo = badfo_fill_kinfo, 4402 }; 4403 4404 int 4405 invfo_rdwr(struct file *fp, struct uio *uio, struct ucred *active_cred, 4406 int flags, struct thread *td) 4407 { 4408 4409 return (EOPNOTSUPP); 4410 } 4411 4412 int 4413 invfo_truncate(struct file *fp, off_t length, struct ucred *active_cred, 4414 struct thread *td) 4415 { 4416 4417 return (EINVAL); 4418 } 4419 4420 int 4421 invfo_ioctl(struct file *fp, u_long com, void *data, 4422 struct ucred *active_cred, struct thread *td) 4423 { 4424 4425 return (ENOTTY); 4426 } 4427 4428 int 4429 invfo_poll(struct file *fp, int events, struct ucred *active_cred, 4430 struct thread *td) 4431 { 4432 4433 return (poll_no_poll(events)); 4434 } 4435 4436 int 4437 invfo_kqfilter(struct file *fp, struct knote *kn) 4438 { 4439 4440 return (EINVAL); 4441 } 4442 4443 int 4444 invfo_chmod(struct file *fp, mode_t mode, struct ucred *active_cred, 4445 struct thread *td) 4446 { 4447 4448 return (EINVAL); 4449 } 4450 4451 int 4452 invfo_chown(struct file *fp, uid_t uid, gid_t gid, struct ucred *active_cred, 4453 struct thread *td) 4454 { 4455 4456 return (EINVAL); 4457 } 4458 4459 int 4460 invfo_sendfile(struct file *fp, int sockfd, struct uio *hdr_uio, 4461 struct uio *trl_uio, off_t offset, size_t nbytes, off_t *sent, int flags, 4462 struct thread *td) 4463 { 4464 4465 return (EINVAL); 4466 } 4467 4468 /*-------------------------------------------------------------------*/ 4469 4470 /* 4471 * File Descriptor pseudo-device driver (/dev/fd/). 4472 * 4473 * Opening minor device N dup()s the file (if any) connected to file 4474 * descriptor N belonging to the calling process. Note that this driver 4475 * consists of only the ``open()'' routine, because all subsequent 4476 * references to this file will be direct to the other driver. 4477 * 4478 * XXX: we could give this one a cloning event handler if necessary. 4479 */ 4480 4481 /* ARGSUSED */ 4482 static int 4483 fdopen(struct cdev *dev, int mode, int type, struct thread *td) 4484 { 4485 4486 /* 4487 * XXX Kludge: set curthread->td_dupfd to contain the value of the 4488 * the file descriptor being sought for duplication. The error 4489 * return ensures that the vnode for this device will be released 4490 * by vn_open. Open will detect this special error and take the 4491 * actions in dupfdopen below. Other callers of vn_open or VOP_OPEN 4492 * will simply report the error. 4493 */ 4494 td->td_dupfd = dev2unit(dev); 4495 return (ENODEV); 4496 } 4497 4498 static struct cdevsw fildesc_cdevsw = { 4499 .d_version = D_VERSION, 4500 .d_open = fdopen, 4501 .d_name = "FD", 4502 }; 4503 4504 static void 4505 fildesc_drvinit(void *unused) 4506 { 4507 struct cdev *dev; 4508 4509 dev = make_dev_credf(MAKEDEV_ETERNAL, &fildesc_cdevsw, 0, NULL, 4510 UID_ROOT, GID_WHEEL, 0666, "fd/0"); 4511 make_dev_alias(dev, "stdin"); 4512 dev = make_dev_credf(MAKEDEV_ETERNAL, &fildesc_cdevsw, 1, NULL, 4513 UID_ROOT, GID_WHEEL, 0666, "fd/1"); 4514 make_dev_alias(dev, "stdout"); 4515 dev = make_dev_credf(MAKEDEV_ETERNAL, &fildesc_cdevsw, 2, NULL, 4516 UID_ROOT, GID_WHEEL, 0666, "fd/2"); 4517 make_dev_alias(dev, "stderr"); 4518 } 4519 4520 SYSINIT(fildescdev, SI_SUB_DRIVERS, SI_ORDER_MIDDLE, fildesc_drvinit, NULL); 4521