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_PWDDESC, "pwddesc", "Pwd descriptors"); 97 static MALLOC_DEFINE(M_FILEDESC_TO_LEADER, "filedesc_to_leader", 98 "file desc to leader structures"); 99 static MALLOC_DEFINE(M_SIGIO, "sigio", "sigio structures"); 100 MALLOC_DEFINE(M_FILECAPS, "filecaps", "descriptor capabilities"); 101 102 MALLOC_DECLARE(M_FADVISE); 103 104 static __read_mostly uma_zone_t file_zone; 105 static __read_mostly uma_zone_t filedesc0_zone; 106 __read_mostly uma_zone_t pwd_zone; 107 VFS_SMR_DECLARE; 108 109 static int closefp(struct filedesc *fdp, int fd, struct file *fp, 110 struct thread *td, int holdleaders); 111 static int fd_first_free(struct filedesc *fdp, int low, 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 last used fd. 217 * 218 * Call this variant if fdp can't be modified by anyone else (e.g, during exec). 219 * Otherwise use fdlastfile. 220 */ 221 int 222 fdlastfile_single(struct filedesc *fdp) 223 { 224 NDSLOTTYPE *map = fdp->fd_map; 225 int off, minoff; 226 227 off = NDSLOT(fdp->fd_nfiles - 1); 228 for (minoff = NDSLOT(0); off >= minoff; --off) 229 if (map[off] != 0) 230 return (off * NDENTRIES + flsl(map[off]) - 1); 231 return (-1); 232 } 233 234 int 235 fdlastfile(struct filedesc *fdp) 236 { 237 238 FILEDESC_LOCK_ASSERT(fdp); 239 return (fdlastfile_single(fdp)); 240 } 241 242 static int 243 fdisused(struct filedesc *fdp, int fd) 244 { 245 246 KASSERT(fd >= 0 && fd < fdp->fd_nfiles, 247 ("file descriptor %d out of range (0, %d)", fd, fdp->fd_nfiles)); 248 249 return ((fdp->fd_map[NDSLOT(fd)] & NDBIT(fd)) != 0); 250 } 251 252 /* 253 * Mark a file descriptor as used. 254 */ 255 static void 256 fdused_init(struct filedesc *fdp, int fd) 257 { 258 259 KASSERT(!fdisused(fdp, fd), ("fd=%d is already used", fd)); 260 261 fdp->fd_map[NDSLOT(fd)] |= NDBIT(fd); 262 } 263 264 static void 265 fdused(struct filedesc *fdp, int fd) 266 { 267 268 FILEDESC_XLOCK_ASSERT(fdp); 269 270 fdused_init(fdp, fd); 271 if (fd == fdp->fd_freefile) 272 fdp->fd_freefile++; 273 } 274 275 /* 276 * Mark a file descriptor as unused. 277 */ 278 static void 279 fdunused(struct filedesc *fdp, int fd) 280 { 281 282 FILEDESC_XLOCK_ASSERT(fdp); 283 284 KASSERT(fdisused(fdp, fd), ("fd=%d is already unused", fd)); 285 KASSERT(fdp->fd_ofiles[fd].fde_file == NULL, 286 ("fd=%d is still in use", fd)); 287 288 fdp->fd_map[NDSLOT(fd)] &= ~NDBIT(fd); 289 if (fd < fdp->fd_freefile) 290 fdp->fd_freefile = fd; 291 } 292 293 /* 294 * Free a file descriptor. 295 * 296 * Avoid some work if fdp is about to be destroyed. 297 */ 298 static inline void 299 fdefree_last(struct filedescent *fde) 300 { 301 302 filecaps_free(&fde->fde_caps); 303 } 304 305 static inline void 306 fdfree(struct filedesc *fdp, int fd) 307 { 308 struct filedescent *fde; 309 310 fde = &fdp->fd_ofiles[fd]; 311 #ifdef CAPABILITIES 312 seqc_write_begin(&fde->fde_seqc); 313 #endif 314 fde->fde_file = NULL; 315 #ifdef CAPABILITIES 316 seqc_write_end(&fde->fde_seqc); 317 #endif 318 fdefree_last(fde); 319 fdunused(fdp, fd); 320 } 321 322 /* 323 * System calls on descriptors. 324 */ 325 #ifndef _SYS_SYSPROTO_H_ 326 struct getdtablesize_args { 327 int dummy; 328 }; 329 #endif 330 /* ARGSUSED */ 331 int 332 sys_getdtablesize(struct thread *td, struct getdtablesize_args *uap) 333 { 334 #ifdef RACCT 335 uint64_t lim; 336 #endif 337 338 td->td_retval[0] = getmaxfd(td); 339 #ifdef RACCT 340 PROC_LOCK(td->td_proc); 341 lim = racct_get_limit(td->td_proc, RACCT_NOFILE); 342 PROC_UNLOCK(td->td_proc); 343 if (lim < td->td_retval[0]) 344 td->td_retval[0] = lim; 345 #endif 346 return (0); 347 } 348 349 /* 350 * Duplicate a file descriptor to a particular value. 351 * 352 * Note: keep in mind that a potential race condition exists when closing 353 * descriptors from a shared descriptor table (via rfork). 354 */ 355 #ifndef _SYS_SYSPROTO_H_ 356 struct dup2_args { 357 u_int from; 358 u_int to; 359 }; 360 #endif 361 /* ARGSUSED */ 362 int 363 sys_dup2(struct thread *td, struct dup2_args *uap) 364 { 365 366 return (kern_dup(td, FDDUP_FIXED, 0, (int)uap->from, (int)uap->to)); 367 } 368 369 /* 370 * Duplicate a file descriptor. 371 */ 372 #ifndef _SYS_SYSPROTO_H_ 373 struct dup_args { 374 u_int fd; 375 }; 376 #endif 377 /* ARGSUSED */ 378 int 379 sys_dup(struct thread *td, struct dup_args *uap) 380 { 381 382 return (kern_dup(td, FDDUP_NORMAL, 0, (int)uap->fd, 0)); 383 } 384 385 /* 386 * The file control system call. 387 */ 388 #ifndef _SYS_SYSPROTO_H_ 389 struct fcntl_args { 390 int fd; 391 int cmd; 392 long arg; 393 }; 394 #endif 395 /* ARGSUSED */ 396 int 397 sys_fcntl(struct thread *td, struct fcntl_args *uap) 398 { 399 400 return (kern_fcntl_freebsd(td, uap->fd, uap->cmd, uap->arg)); 401 } 402 403 int 404 kern_fcntl_freebsd(struct thread *td, int fd, int cmd, long arg) 405 { 406 struct flock fl; 407 struct __oflock ofl; 408 intptr_t arg1; 409 int error, newcmd; 410 411 error = 0; 412 newcmd = cmd; 413 switch (cmd) { 414 case F_OGETLK: 415 case F_OSETLK: 416 case F_OSETLKW: 417 /* 418 * Convert old flock structure to new. 419 */ 420 error = copyin((void *)(intptr_t)arg, &ofl, sizeof(ofl)); 421 fl.l_start = ofl.l_start; 422 fl.l_len = ofl.l_len; 423 fl.l_pid = ofl.l_pid; 424 fl.l_type = ofl.l_type; 425 fl.l_whence = ofl.l_whence; 426 fl.l_sysid = 0; 427 428 switch (cmd) { 429 case F_OGETLK: 430 newcmd = F_GETLK; 431 break; 432 case F_OSETLK: 433 newcmd = F_SETLK; 434 break; 435 case F_OSETLKW: 436 newcmd = F_SETLKW; 437 break; 438 } 439 arg1 = (intptr_t)&fl; 440 break; 441 case F_GETLK: 442 case F_SETLK: 443 case F_SETLKW: 444 case F_SETLK_REMOTE: 445 error = copyin((void *)(intptr_t)arg, &fl, sizeof(fl)); 446 arg1 = (intptr_t)&fl; 447 break; 448 default: 449 arg1 = arg; 450 break; 451 } 452 if (error) 453 return (error); 454 error = kern_fcntl(td, fd, newcmd, arg1); 455 if (error) 456 return (error); 457 if (cmd == F_OGETLK) { 458 ofl.l_start = fl.l_start; 459 ofl.l_len = fl.l_len; 460 ofl.l_pid = fl.l_pid; 461 ofl.l_type = fl.l_type; 462 ofl.l_whence = fl.l_whence; 463 error = copyout(&ofl, (void *)(intptr_t)arg, sizeof(ofl)); 464 } else if (cmd == F_GETLK) { 465 error = copyout(&fl, (void *)(intptr_t)arg, sizeof(fl)); 466 } 467 return (error); 468 } 469 470 int 471 kern_fcntl(struct thread *td, int fd, int cmd, intptr_t arg) 472 { 473 struct filedesc *fdp; 474 struct flock *flp; 475 struct file *fp, *fp2; 476 struct filedescent *fde; 477 struct proc *p; 478 struct vnode *vp; 479 struct mount *mp; 480 int error, flg, seals, tmp; 481 uint64_t bsize; 482 off_t foffset; 483 484 error = 0; 485 flg = F_POSIX; 486 p = td->td_proc; 487 fdp = p->p_fd; 488 489 AUDIT_ARG_FD(cmd); 490 AUDIT_ARG_CMD(cmd); 491 switch (cmd) { 492 case F_DUPFD: 493 tmp = arg; 494 error = kern_dup(td, FDDUP_FCNTL, 0, fd, tmp); 495 break; 496 497 case F_DUPFD_CLOEXEC: 498 tmp = arg; 499 error = kern_dup(td, FDDUP_FCNTL, FDDUP_FLAG_CLOEXEC, fd, tmp); 500 break; 501 502 case F_DUP2FD: 503 tmp = arg; 504 error = kern_dup(td, FDDUP_FIXED, 0, fd, tmp); 505 break; 506 507 case F_DUP2FD_CLOEXEC: 508 tmp = arg; 509 error = kern_dup(td, FDDUP_FIXED, FDDUP_FLAG_CLOEXEC, fd, tmp); 510 break; 511 512 case F_GETFD: 513 error = EBADF; 514 FILEDESC_SLOCK(fdp); 515 fde = fdeget_locked(fdp, fd); 516 if (fde != NULL) { 517 td->td_retval[0] = 518 (fde->fde_flags & UF_EXCLOSE) ? FD_CLOEXEC : 0; 519 error = 0; 520 } 521 FILEDESC_SUNLOCK(fdp); 522 break; 523 524 case F_SETFD: 525 error = EBADF; 526 FILEDESC_XLOCK(fdp); 527 fde = fdeget_locked(fdp, fd); 528 if (fde != NULL) { 529 fde->fde_flags = (fde->fde_flags & ~UF_EXCLOSE) | 530 (arg & FD_CLOEXEC ? UF_EXCLOSE : 0); 531 error = 0; 532 } 533 FILEDESC_XUNLOCK(fdp); 534 break; 535 536 case F_GETFL: 537 error = fget_fcntl(td, fd, &cap_fcntl_rights, F_GETFL, &fp); 538 if (error != 0) 539 break; 540 td->td_retval[0] = OFLAGS(fp->f_flag); 541 fdrop(fp, td); 542 break; 543 544 case F_SETFL: 545 error = fget_fcntl(td, fd, &cap_fcntl_rights, F_SETFL, &fp); 546 if (error != 0) 547 break; 548 do { 549 tmp = flg = fp->f_flag; 550 tmp &= ~FCNTLFLAGS; 551 tmp |= FFLAGS(arg & ~O_ACCMODE) & FCNTLFLAGS; 552 } while(atomic_cmpset_int(&fp->f_flag, flg, tmp) == 0); 553 tmp = fp->f_flag & FNONBLOCK; 554 error = fo_ioctl(fp, FIONBIO, &tmp, td->td_ucred, td); 555 if (error != 0) { 556 fdrop(fp, td); 557 break; 558 } 559 tmp = fp->f_flag & FASYNC; 560 error = fo_ioctl(fp, FIOASYNC, &tmp, td->td_ucred, td); 561 if (error == 0) { 562 fdrop(fp, td); 563 break; 564 } 565 atomic_clear_int(&fp->f_flag, FNONBLOCK); 566 tmp = 0; 567 (void)fo_ioctl(fp, FIONBIO, &tmp, td->td_ucred, td); 568 fdrop(fp, td); 569 break; 570 571 case F_GETOWN: 572 error = fget_fcntl(td, fd, &cap_fcntl_rights, F_GETOWN, &fp); 573 if (error != 0) 574 break; 575 error = fo_ioctl(fp, FIOGETOWN, &tmp, td->td_ucred, td); 576 if (error == 0) 577 td->td_retval[0] = tmp; 578 fdrop(fp, td); 579 break; 580 581 case F_SETOWN: 582 error = fget_fcntl(td, fd, &cap_fcntl_rights, F_SETOWN, &fp); 583 if (error != 0) 584 break; 585 tmp = arg; 586 error = fo_ioctl(fp, FIOSETOWN, &tmp, td->td_ucred, td); 587 fdrop(fp, td); 588 break; 589 590 case F_SETLK_REMOTE: 591 error = priv_check(td, PRIV_NFS_LOCKD); 592 if (error != 0) 593 return (error); 594 flg = F_REMOTE; 595 goto do_setlk; 596 597 case F_SETLKW: 598 flg |= F_WAIT; 599 /* FALLTHROUGH F_SETLK */ 600 601 case F_SETLK: 602 do_setlk: 603 flp = (struct flock *)arg; 604 if ((flg & F_REMOTE) != 0 && flp->l_sysid == 0) { 605 error = EINVAL; 606 break; 607 } 608 609 error = fget_unlocked(fdp, fd, &cap_flock_rights, &fp); 610 if (error != 0) 611 break; 612 if (fp->f_type != DTYPE_VNODE) { 613 error = EBADF; 614 fdrop(fp, td); 615 break; 616 } 617 618 if (flp->l_whence == SEEK_CUR) { 619 foffset = foffset_get(fp); 620 if (foffset < 0 || 621 (flp->l_start > 0 && 622 foffset > OFF_MAX - flp->l_start)) { 623 error = EOVERFLOW; 624 fdrop(fp, td); 625 break; 626 } 627 flp->l_start += foffset; 628 } 629 630 vp = fp->f_vnode; 631 switch (flp->l_type) { 632 case F_RDLCK: 633 if ((fp->f_flag & FREAD) == 0) { 634 error = EBADF; 635 break; 636 } 637 if ((p->p_leader->p_flag & P_ADVLOCK) == 0) { 638 PROC_LOCK(p->p_leader); 639 p->p_leader->p_flag |= P_ADVLOCK; 640 PROC_UNLOCK(p->p_leader); 641 } 642 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_SETLK, 643 flp, flg); 644 break; 645 case F_WRLCK: 646 if ((fp->f_flag & FWRITE) == 0) { 647 error = EBADF; 648 break; 649 } 650 if ((p->p_leader->p_flag & P_ADVLOCK) == 0) { 651 PROC_LOCK(p->p_leader); 652 p->p_leader->p_flag |= P_ADVLOCK; 653 PROC_UNLOCK(p->p_leader); 654 } 655 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_SETLK, 656 flp, flg); 657 break; 658 case F_UNLCK: 659 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_UNLCK, 660 flp, flg); 661 break; 662 case F_UNLCKSYS: 663 if (flg != F_REMOTE) { 664 error = EINVAL; 665 break; 666 } 667 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, 668 F_UNLCKSYS, flp, flg); 669 break; 670 default: 671 error = EINVAL; 672 break; 673 } 674 if (error != 0 || flp->l_type == F_UNLCK || 675 flp->l_type == F_UNLCKSYS) { 676 fdrop(fp, td); 677 break; 678 } 679 680 /* 681 * Check for a race with close. 682 * 683 * The vnode is now advisory locked (or unlocked, but this case 684 * is not really important) as the caller requested. 685 * We had to drop the filedesc lock, so we need to recheck if 686 * the descriptor is still valid, because if it was closed 687 * in the meantime we need to remove advisory lock from the 688 * vnode - close on any descriptor leading to an advisory 689 * locked vnode, removes that lock. 690 * We will return 0 on purpose in that case, as the result of 691 * successful advisory lock might have been externally visible 692 * already. This is fine - effectively we pretend to the caller 693 * that the closing thread was a bit slower and that the 694 * advisory lock succeeded before the close. 695 */ 696 error = fget_unlocked(fdp, fd, &cap_no_rights, &fp2); 697 if (error != 0) { 698 fdrop(fp, td); 699 break; 700 } 701 if (fp != fp2) { 702 flp->l_whence = SEEK_SET; 703 flp->l_start = 0; 704 flp->l_len = 0; 705 flp->l_type = F_UNLCK; 706 (void) VOP_ADVLOCK(vp, (caddr_t)p->p_leader, 707 F_UNLCK, flp, F_POSIX); 708 } 709 fdrop(fp, td); 710 fdrop(fp2, td); 711 break; 712 713 case F_GETLK: 714 error = fget_unlocked(fdp, fd, &cap_flock_rights, &fp); 715 if (error != 0) 716 break; 717 if (fp->f_type != DTYPE_VNODE) { 718 error = EBADF; 719 fdrop(fp, td); 720 break; 721 } 722 flp = (struct flock *)arg; 723 if (flp->l_type != F_RDLCK && flp->l_type != F_WRLCK && 724 flp->l_type != F_UNLCK) { 725 error = EINVAL; 726 fdrop(fp, td); 727 break; 728 } 729 if (flp->l_whence == SEEK_CUR) { 730 foffset = foffset_get(fp); 731 if ((flp->l_start > 0 && 732 foffset > OFF_MAX - flp->l_start) || 733 (flp->l_start < 0 && 734 foffset < OFF_MIN - flp->l_start)) { 735 error = EOVERFLOW; 736 fdrop(fp, td); 737 break; 738 } 739 flp->l_start += foffset; 740 } 741 vp = fp->f_vnode; 742 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_GETLK, flp, 743 F_POSIX); 744 fdrop(fp, td); 745 break; 746 747 case F_ADD_SEALS: 748 error = fget_unlocked(fdp, fd, &cap_no_rights, &fp); 749 if (error != 0) 750 break; 751 error = fo_add_seals(fp, arg); 752 fdrop(fp, td); 753 break; 754 755 case F_GET_SEALS: 756 error = fget_unlocked(fdp, fd, &cap_no_rights, &fp); 757 if (error != 0) 758 break; 759 if (fo_get_seals(fp, &seals) == 0) 760 td->td_retval[0] = seals; 761 else 762 error = EINVAL; 763 fdrop(fp, td); 764 break; 765 766 case F_RDAHEAD: 767 arg = arg ? 128 * 1024: 0; 768 /* FALLTHROUGH */ 769 case F_READAHEAD: 770 error = fget_unlocked(fdp, fd, &cap_no_rights, &fp); 771 if (error != 0) 772 break; 773 if (fp->f_type != DTYPE_VNODE) { 774 fdrop(fp, td); 775 error = EBADF; 776 break; 777 } 778 vp = fp->f_vnode; 779 if (vp->v_type != VREG) { 780 fdrop(fp, td); 781 error = ENOTTY; 782 break; 783 } 784 785 /* 786 * Exclusive lock synchronizes against f_seqcount reads and 787 * writes in sequential_heuristic(). 788 */ 789 error = vn_lock(vp, LK_EXCLUSIVE); 790 if (error != 0) { 791 fdrop(fp, td); 792 break; 793 } 794 if (arg >= 0) { 795 bsize = fp->f_vnode->v_mount->mnt_stat.f_iosize; 796 arg = MIN(arg, INT_MAX - bsize + 1); 797 fp->f_seqcount[UIO_READ] = MIN(IO_SEQMAX, 798 (arg + bsize - 1) / bsize); 799 atomic_set_int(&fp->f_flag, FRDAHEAD); 800 } else { 801 atomic_clear_int(&fp->f_flag, FRDAHEAD); 802 } 803 VOP_UNLOCK(vp); 804 fdrop(fp, td); 805 break; 806 807 case F_ISUNIONSTACK: 808 /* 809 * Check if the vnode is part of a union stack (either the 810 * "union" flag from mount(2) or unionfs). 811 * 812 * Prior to introduction of this op libc's readdir would call 813 * fstatfs(2), in effect unnecessarily copying kilobytes of 814 * data just to check fs name and a mount flag. 815 * 816 * Fixing the code to handle everything in the kernel instead 817 * is a non-trivial endeavor and has low priority, thus this 818 * horrible kludge facilitates the current behavior in a much 819 * cheaper manner until someone(tm) sorts this out. 820 */ 821 error = fget_unlocked(fdp, fd, &cap_no_rights, &fp); 822 if (error != 0) 823 break; 824 if (fp->f_type != DTYPE_VNODE) { 825 fdrop(fp, td); 826 error = EBADF; 827 break; 828 } 829 vp = fp->f_vnode; 830 /* 831 * Since we don't prevent dooming the vnode even non-null mp 832 * found can become immediately stale. This is tolerable since 833 * mount points are type-stable (providing safe memory access) 834 * and any vfs op on this vnode going forward will return an 835 * error (meaning return value in this case is meaningless). 836 */ 837 mp = atomic_load_ptr(&vp->v_mount); 838 if (__predict_false(mp == NULL)) { 839 fdrop(fp, td); 840 error = EBADF; 841 break; 842 } 843 td->td_retval[0] = 0; 844 if (mp->mnt_kern_flag & MNTK_UNIONFS || 845 mp->mnt_flag & MNT_UNION) 846 td->td_retval[0] = 1; 847 fdrop(fp, td); 848 break; 849 850 default: 851 error = EINVAL; 852 break; 853 } 854 return (error); 855 } 856 857 static int 858 getmaxfd(struct thread *td) 859 { 860 861 return (min((int)lim_cur(td, RLIMIT_NOFILE), maxfilesperproc)); 862 } 863 864 /* 865 * Common code for dup, dup2, fcntl(F_DUPFD) and fcntl(F_DUP2FD). 866 */ 867 int 868 kern_dup(struct thread *td, u_int mode, int flags, int old, int new) 869 { 870 struct filedesc *fdp; 871 struct filedescent *oldfde, *newfde; 872 struct proc *p; 873 struct file *delfp, *oldfp; 874 u_long *oioctls, *nioctls; 875 int error, maxfd; 876 877 p = td->td_proc; 878 fdp = p->p_fd; 879 oioctls = NULL; 880 881 MPASS((flags & ~(FDDUP_FLAG_CLOEXEC)) == 0); 882 MPASS(mode < FDDUP_LASTMODE); 883 884 AUDIT_ARG_FD(old); 885 /* XXXRW: if (flags & FDDUP_FIXED) AUDIT_ARG_FD2(new); */ 886 887 /* 888 * Verify we have a valid descriptor to dup from and possibly to 889 * dup to. Unlike dup() and dup2(), fcntl()'s F_DUPFD should 890 * return EINVAL when the new descriptor is out of bounds. 891 */ 892 if (old < 0) 893 return (EBADF); 894 if (new < 0) 895 return (mode == FDDUP_FCNTL ? EINVAL : EBADF); 896 maxfd = getmaxfd(td); 897 if (new >= maxfd) 898 return (mode == FDDUP_FCNTL ? EINVAL : EBADF); 899 900 error = EBADF; 901 FILEDESC_XLOCK(fdp); 902 if (fget_locked(fdp, old) == NULL) 903 goto unlock; 904 if ((mode == FDDUP_FIXED || mode == FDDUP_MUSTREPLACE) && old == new) { 905 td->td_retval[0] = new; 906 if (flags & FDDUP_FLAG_CLOEXEC) 907 fdp->fd_ofiles[new].fde_flags |= UF_EXCLOSE; 908 error = 0; 909 goto unlock; 910 } 911 912 oldfde = &fdp->fd_ofiles[old]; 913 oldfp = oldfde->fde_file; 914 if (!fhold(oldfp)) 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(oldfp, 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(oldfp, 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(oldfp, 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 /* Refetch oldfde because the table may have grown and old one freed. */ 969 oldfde = &fdp->fd_ofiles[old]; 970 KASSERT(oldfp == oldfde->fde_file, 971 ("fdt_ofiles shift from growth observed at fd %d", 972 old)); 973 974 newfde = &fdp->fd_ofiles[new]; 975 delfp = newfde->fde_file; 976 977 nioctls = filecaps_copy_prep(&oldfde->fde_caps); 978 979 /* 980 * Duplicate the source descriptor. 981 */ 982 #ifdef CAPABILITIES 983 seqc_write_begin(&newfde->fde_seqc); 984 #endif 985 oioctls = filecaps_free_prep(&newfde->fde_caps); 986 memcpy(newfde, oldfde, fde_change_size); 987 filecaps_copy_finish(&oldfde->fde_caps, &newfde->fde_caps, 988 nioctls); 989 if ((flags & FDDUP_FLAG_CLOEXEC) != 0) 990 newfde->fde_flags = oldfde->fde_flags | UF_EXCLOSE; 991 else 992 newfde->fde_flags = oldfde->fde_flags & ~UF_EXCLOSE; 993 #ifdef CAPABILITIES 994 seqc_write_end(&newfde->fde_seqc); 995 #endif 996 td->td_retval[0] = new; 997 998 error = 0; 999 1000 if (delfp != NULL) { 1001 (void) closefp(fdp, new, delfp, td, 1); 1002 FILEDESC_UNLOCK_ASSERT(fdp); 1003 } else { 1004 unlock: 1005 FILEDESC_XUNLOCK(fdp); 1006 } 1007 1008 filecaps_free_finish(oioctls); 1009 return (error); 1010 } 1011 1012 static void 1013 sigiofree(struct sigio *sigio) 1014 { 1015 crfree(sigio->sio_ucred); 1016 free(sigio, M_SIGIO); 1017 } 1018 1019 static struct sigio * 1020 funsetown_locked(struct sigio *sigio) 1021 { 1022 struct proc *p; 1023 struct pgrp *pg; 1024 1025 SIGIO_ASSERT_LOCKED(); 1026 1027 if (sigio == NULL) 1028 return (NULL); 1029 *(sigio->sio_myref) = NULL; 1030 if (sigio->sio_pgid < 0) { 1031 pg = sigio->sio_pgrp; 1032 PGRP_LOCK(pg); 1033 SLIST_REMOVE(&sigio->sio_pgrp->pg_sigiolst, sigio, 1034 sigio, sio_pgsigio); 1035 PGRP_UNLOCK(pg); 1036 } else { 1037 p = sigio->sio_proc; 1038 PROC_LOCK(p); 1039 SLIST_REMOVE(&sigio->sio_proc->p_sigiolst, sigio, 1040 sigio, sio_pgsigio); 1041 PROC_UNLOCK(p); 1042 } 1043 return (sigio); 1044 } 1045 1046 /* 1047 * If sigio is on the list associated with a process or process group, 1048 * disable signalling from the device, remove sigio from the list and 1049 * free sigio. 1050 */ 1051 void 1052 funsetown(struct sigio **sigiop) 1053 { 1054 struct sigio *sigio; 1055 1056 /* Racy check, consumers must provide synchronization. */ 1057 if (*sigiop == NULL) 1058 return; 1059 1060 SIGIO_LOCK(); 1061 sigio = funsetown_locked(*sigiop); 1062 SIGIO_UNLOCK(); 1063 if (sigio != NULL) 1064 sigiofree(sigio); 1065 } 1066 1067 /* 1068 * Free a list of sigio structures. The caller must ensure that new sigio 1069 * structures cannot be added after this point. For process groups this is 1070 * guaranteed using the proctree lock; for processes, the P_WEXIT flag serves 1071 * as an interlock. 1072 */ 1073 void 1074 funsetownlst(struct sigiolst *sigiolst) 1075 { 1076 struct proc *p; 1077 struct pgrp *pg; 1078 struct sigio *sigio, *tmp; 1079 1080 /* Racy check. */ 1081 sigio = SLIST_FIRST(sigiolst); 1082 if (sigio == NULL) 1083 return; 1084 1085 p = NULL; 1086 pg = NULL; 1087 1088 SIGIO_LOCK(); 1089 sigio = SLIST_FIRST(sigiolst); 1090 if (sigio == NULL) { 1091 SIGIO_UNLOCK(); 1092 return; 1093 } 1094 1095 /* 1096 * Every entry of the list should belong to a single proc or pgrp. 1097 */ 1098 if (sigio->sio_pgid < 0) { 1099 pg = sigio->sio_pgrp; 1100 sx_assert(&proctree_lock, SX_XLOCKED); 1101 PGRP_LOCK(pg); 1102 } else /* if (sigio->sio_pgid > 0) */ { 1103 p = sigio->sio_proc; 1104 PROC_LOCK(p); 1105 KASSERT((p->p_flag & P_WEXIT) != 0, 1106 ("%s: process %p is not exiting", __func__, p)); 1107 } 1108 1109 SLIST_FOREACH(sigio, sigiolst, sio_pgsigio) { 1110 *sigio->sio_myref = NULL; 1111 if (pg != NULL) { 1112 KASSERT(sigio->sio_pgid < 0, 1113 ("Proc sigio in pgrp sigio list")); 1114 KASSERT(sigio->sio_pgrp == pg, 1115 ("Bogus pgrp in sigio list")); 1116 } else /* if (p != NULL) */ { 1117 KASSERT(sigio->sio_pgid > 0, 1118 ("Pgrp sigio in proc sigio list")); 1119 KASSERT(sigio->sio_proc == p, 1120 ("Bogus proc in sigio list")); 1121 } 1122 } 1123 1124 if (pg != NULL) 1125 PGRP_UNLOCK(pg); 1126 else 1127 PROC_UNLOCK(p); 1128 SIGIO_UNLOCK(); 1129 1130 SLIST_FOREACH_SAFE(sigio, sigiolst, sio_pgsigio, tmp) 1131 sigiofree(sigio); 1132 } 1133 1134 /* 1135 * This is common code for FIOSETOWN ioctl called by fcntl(fd, F_SETOWN, arg). 1136 * 1137 * After permission checking, add a sigio structure to the sigio list for 1138 * the process or process group. 1139 */ 1140 int 1141 fsetown(pid_t pgid, struct sigio **sigiop) 1142 { 1143 struct proc *proc; 1144 struct pgrp *pgrp; 1145 struct sigio *osigio, *sigio; 1146 int ret; 1147 1148 if (pgid == 0) { 1149 funsetown(sigiop); 1150 return (0); 1151 } 1152 1153 ret = 0; 1154 1155 sigio = malloc(sizeof(struct sigio), M_SIGIO, M_WAITOK); 1156 sigio->sio_pgid = pgid; 1157 sigio->sio_ucred = crhold(curthread->td_ucred); 1158 sigio->sio_myref = sigiop; 1159 1160 sx_slock(&proctree_lock); 1161 SIGIO_LOCK(); 1162 osigio = funsetown_locked(*sigiop); 1163 if (pgid > 0) { 1164 proc = pfind(pgid); 1165 if (proc == NULL) { 1166 ret = ESRCH; 1167 goto fail; 1168 } 1169 1170 /* 1171 * Policy - Don't allow a process to FSETOWN a process 1172 * in another session. 1173 * 1174 * Remove this test to allow maximum flexibility or 1175 * restrict FSETOWN to the current process or process 1176 * group for maximum safety. 1177 */ 1178 if (proc->p_session != curthread->td_proc->p_session) { 1179 PROC_UNLOCK(proc); 1180 ret = EPERM; 1181 goto fail; 1182 } 1183 1184 sigio->sio_proc = proc; 1185 SLIST_INSERT_HEAD(&proc->p_sigiolst, sigio, sio_pgsigio); 1186 PROC_UNLOCK(proc); 1187 } else /* if (pgid < 0) */ { 1188 pgrp = pgfind(-pgid); 1189 if (pgrp == NULL) { 1190 ret = ESRCH; 1191 goto fail; 1192 } 1193 1194 /* 1195 * Policy - Don't allow a process to FSETOWN a process 1196 * in another session. 1197 * 1198 * Remove this test to allow maximum flexibility or 1199 * restrict FSETOWN to the current process or process 1200 * group for maximum safety. 1201 */ 1202 if (pgrp->pg_session != curthread->td_proc->p_session) { 1203 PGRP_UNLOCK(pgrp); 1204 ret = EPERM; 1205 goto fail; 1206 } 1207 1208 SLIST_INSERT_HEAD(&pgrp->pg_sigiolst, sigio, sio_pgsigio); 1209 sigio->sio_pgrp = pgrp; 1210 PGRP_UNLOCK(pgrp); 1211 } 1212 sx_sunlock(&proctree_lock); 1213 *sigiop = sigio; 1214 SIGIO_UNLOCK(); 1215 if (osigio != NULL) 1216 sigiofree(osigio); 1217 return (0); 1218 1219 fail: 1220 SIGIO_UNLOCK(); 1221 sx_sunlock(&proctree_lock); 1222 sigiofree(sigio); 1223 if (osigio != NULL) 1224 sigiofree(osigio); 1225 return (ret); 1226 } 1227 1228 /* 1229 * This is common code for FIOGETOWN ioctl called by fcntl(fd, F_GETOWN, arg). 1230 */ 1231 pid_t 1232 fgetown(struct sigio **sigiop) 1233 { 1234 pid_t pgid; 1235 1236 SIGIO_LOCK(); 1237 pgid = (*sigiop != NULL) ? (*sigiop)->sio_pgid : 0; 1238 SIGIO_UNLOCK(); 1239 return (pgid); 1240 } 1241 1242 /* 1243 * Function drops the filedesc lock on return. 1244 */ 1245 static int 1246 closefp(struct filedesc *fdp, int fd, struct file *fp, struct thread *td, 1247 int holdleaders) 1248 { 1249 int error; 1250 1251 FILEDESC_XLOCK_ASSERT(fdp); 1252 1253 if (holdleaders) { 1254 if (td->td_proc->p_fdtol != NULL) { 1255 /* 1256 * Ask fdfree() to sleep to ensure that all relevant 1257 * process leaders can be traversed in closef(). 1258 */ 1259 fdp->fd_holdleaderscount++; 1260 } else { 1261 holdleaders = 0; 1262 } 1263 } 1264 1265 /* 1266 * We now hold the fp reference that used to be owned by the 1267 * descriptor array. We have to unlock the FILEDESC *AFTER* 1268 * knote_fdclose to prevent a race of the fd getting opened, a knote 1269 * added, and deleteing a knote for the new fd. 1270 */ 1271 if (__predict_false(!TAILQ_EMPTY(&fdp->fd_kqlist))) 1272 knote_fdclose(td, fd); 1273 1274 /* 1275 * We need to notify mqueue if the object is of type mqueue. 1276 */ 1277 if (__predict_false(fp->f_type == DTYPE_MQUEUE)) 1278 mq_fdclose(td, fd, fp); 1279 FILEDESC_XUNLOCK(fdp); 1280 1281 error = closef(fp, td); 1282 1283 /* 1284 * All paths leading up to closefp() will have already removed or 1285 * replaced the fd in the filedesc table, so a restart would not 1286 * operate on the same file. 1287 */ 1288 if (error == ERESTART) 1289 error = EINTR; 1290 1291 if (holdleaders) { 1292 FILEDESC_XLOCK(fdp); 1293 fdp->fd_holdleaderscount--; 1294 if (fdp->fd_holdleaderscount == 0 && 1295 fdp->fd_holdleaderswakeup != 0) { 1296 fdp->fd_holdleaderswakeup = 0; 1297 wakeup(&fdp->fd_holdleaderscount); 1298 } 1299 FILEDESC_XUNLOCK(fdp); 1300 } 1301 return (error); 1302 } 1303 1304 /* 1305 * Close a file descriptor. 1306 */ 1307 #ifndef _SYS_SYSPROTO_H_ 1308 struct close_args { 1309 int fd; 1310 }; 1311 #endif 1312 /* ARGSUSED */ 1313 int 1314 sys_close(struct thread *td, struct close_args *uap) 1315 { 1316 1317 return (kern_close(td, uap->fd)); 1318 } 1319 1320 int 1321 kern_close(struct thread *td, int fd) 1322 { 1323 struct filedesc *fdp; 1324 struct file *fp; 1325 1326 fdp = td->td_proc->p_fd; 1327 1328 AUDIT_SYSCLOSE(td, fd); 1329 1330 FILEDESC_XLOCK(fdp); 1331 if ((fp = fget_locked(fdp, fd)) == NULL) { 1332 FILEDESC_XUNLOCK(fdp); 1333 return (EBADF); 1334 } 1335 fdfree(fdp, fd); 1336 1337 /* closefp() drops the FILEDESC lock for us. */ 1338 return (closefp(fdp, fd, fp, td, 1)); 1339 } 1340 1341 int 1342 kern_close_range(struct thread *td, u_int lowfd, u_int highfd) 1343 { 1344 struct filedesc *fdp; 1345 int fd, ret, lastfile; 1346 1347 ret = 0; 1348 fdp = td->td_proc->p_fd; 1349 FILEDESC_SLOCK(fdp); 1350 1351 /* 1352 * Check this prior to clamping; closefrom(3) with only fd 0, 1, and 2 1353 * open should not be a usage error. From a close_range() perspective, 1354 * close_range(3, ~0U, 0) in the same scenario should also likely not 1355 * be a usage error as all fd above 3 are in-fact already closed. 1356 */ 1357 if (highfd < lowfd) { 1358 ret = EINVAL; 1359 goto out; 1360 } 1361 1362 /* 1363 * If lastfile == -1, we're dealing with either a fresh file 1364 * table or one in which every fd has been closed. Just return 1365 * successful; there's nothing left to do. 1366 */ 1367 lastfile = fdlastfile(fdp); 1368 if (lastfile == -1) 1369 goto out; 1370 /* Clamped to [lowfd, lastfile] */ 1371 highfd = MIN(highfd, lastfile); 1372 for (fd = lowfd; fd <= highfd; fd++) { 1373 if (fdp->fd_ofiles[fd].fde_file != NULL) { 1374 FILEDESC_SUNLOCK(fdp); 1375 (void)kern_close(td, fd); 1376 FILEDESC_SLOCK(fdp); 1377 } 1378 } 1379 out: 1380 FILEDESC_SUNLOCK(fdp); 1381 return (ret); 1382 } 1383 1384 #ifndef _SYS_SYSPROTO_H_ 1385 struct close_range_args { 1386 u_int lowfd; 1387 u_int highfd; 1388 int flags; 1389 }; 1390 #endif 1391 int 1392 sys_close_range(struct thread *td, struct close_range_args *uap) 1393 { 1394 1395 /* No flags currently defined */ 1396 if (uap->flags != 0) 1397 return (EINVAL); 1398 return (kern_close_range(td, uap->lowfd, uap->highfd)); 1399 } 1400 1401 #ifdef COMPAT_FREEBSD12 1402 /* 1403 * Close open file descriptors. 1404 */ 1405 #ifndef _SYS_SYSPROTO_H_ 1406 struct freebsd12_closefrom_args { 1407 int lowfd; 1408 }; 1409 #endif 1410 /* ARGSUSED */ 1411 int 1412 freebsd12_closefrom(struct thread *td, struct freebsd12_closefrom_args *uap) 1413 { 1414 u_int lowfd; 1415 1416 AUDIT_ARG_FD(uap->lowfd); 1417 1418 /* 1419 * Treat negative starting file descriptor values identical to 1420 * closefrom(0) which closes all files. 1421 */ 1422 lowfd = MAX(0, uap->lowfd); 1423 return (kern_close_range(td, lowfd, ~0U)); 1424 } 1425 #endif /* COMPAT_FREEBSD12 */ 1426 1427 #if defined(COMPAT_43) 1428 /* 1429 * Return status information about a file descriptor. 1430 */ 1431 #ifndef _SYS_SYSPROTO_H_ 1432 struct ofstat_args { 1433 int fd; 1434 struct ostat *sb; 1435 }; 1436 #endif 1437 /* ARGSUSED */ 1438 int 1439 ofstat(struct thread *td, struct ofstat_args *uap) 1440 { 1441 struct ostat oub; 1442 struct stat ub; 1443 int error; 1444 1445 error = kern_fstat(td, uap->fd, &ub); 1446 if (error == 0) { 1447 cvtstat(&ub, &oub); 1448 error = copyout(&oub, uap->sb, sizeof(oub)); 1449 } 1450 return (error); 1451 } 1452 #endif /* COMPAT_43 */ 1453 1454 #if defined(COMPAT_FREEBSD11) 1455 int 1456 freebsd11_fstat(struct thread *td, struct freebsd11_fstat_args *uap) 1457 { 1458 struct stat sb; 1459 struct freebsd11_stat osb; 1460 int error; 1461 1462 error = kern_fstat(td, uap->fd, &sb); 1463 if (error != 0) 1464 return (error); 1465 error = freebsd11_cvtstat(&sb, &osb); 1466 if (error == 0) 1467 error = copyout(&osb, uap->sb, sizeof(osb)); 1468 return (error); 1469 } 1470 #endif /* COMPAT_FREEBSD11 */ 1471 1472 /* 1473 * Return status information about a file descriptor. 1474 */ 1475 #ifndef _SYS_SYSPROTO_H_ 1476 struct fstat_args { 1477 int fd; 1478 struct stat *sb; 1479 }; 1480 #endif 1481 /* ARGSUSED */ 1482 int 1483 sys_fstat(struct thread *td, struct fstat_args *uap) 1484 { 1485 struct stat ub; 1486 int error; 1487 1488 error = kern_fstat(td, uap->fd, &ub); 1489 if (error == 0) 1490 error = copyout(&ub, uap->sb, sizeof(ub)); 1491 return (error); 1492 } 1493 1494 int 1495 kern_fstat(struct thread *td, int fd, struct stat *sbp) 1496 { 1497 struct file *fp; 1498 int error; 1499 1500 AUDIT_ARG_FD(fd); 1501 1502 error = fget(td, fd, &cap_fstat_rights, &fp); 1503 if (__predict_false(error != 0)) 1504 return (error); 1505 1506 AUDIT_ARG_FILE(td->td_proc, fp); 1507 1508 error = fo_stat(fp, sbp, td->td_ucred, td); 1509 fdrop(fp, td); 1510 #ifdef __STAT_TIME_T_EXT 1511 sbp->st_atim_ext = 0; 1512 sbp->st_mtim_ext = 0; 1513 sbp->st_ctim_ext = 0; 1514 sbp->st_btim_ext = 0; 1515 #endif 1516 #ifdef KTRACE 1517 if (KTRPOINT(td, KTR_STRUCT)) 1518 ktrstat_error(sbp, error); 1519 #endif 1520 return (error); 1521 } 1522 1523 #if defined(COMPAT_FREEBSD11) 1524 /* 1525 * Return status information about a file descriptor. 1526 */ 1527 #ifndef _SYS_SYSPROTO_H_ 1528 struct freebsd11_nfstat_args { 1529 int fd; 1530 struct nstat *sb; 1531 }; 1532 #endif 1533 /* ARGSUSED */ 1534 int 1535 freebsd11_nfstat(struct thread *td, struct freebsd11_nfstat_args *uap) 1536 { 1537 struct nstat nub; 1538 struct stat ub; 1539 int error; 1540 1541 error = kern_fstat(td, uap->fd, &ub); 1542 if (error == 0) { 1543 freebsd11_cvtnstat(&ub, &nub); 1544 error = copyout(&nub, uap->sb, sizeof(nub)); 1545 } 1546 return (error); 1547 } 1548 #endif /* COMPAT_FREEBSD11 */ 1549 1550 /* 1551 * Return pathconf information about a file descriptor. 1552 */ 1553 #ifndef _SYS_SYSPROTO_H_ 1554 struct fpathconf_args { 1555 int fd; 1556 int name; 1557 }; 1558 #endif 1559 /* ARGSUSED */ 1560 int 1561 sys_fpathconf(struct thread *td, struct fpathconf_args *uap) 1562 { 1563 long value; 1564 int error; 1565 1566 error = kern_fpathconf(td, uap->fd, uap->name, &value); 1567 if (error == 0) 1568 td->td_retval[0] = value; 1569 return (error); 1570 } 1571 1572 int 1573 kern_fpathconf(struct thread *td, int fd, int name, long *valuep) 1574 { 1575 struct file *fp; 1576 struct vnode *vp; 1577 int error; 1578 1579 error = fget(td, fd, &cap_fpathconf_rights, &fp); 1580 if (error != 0) 1581 return (error); 1582 1583 if (name == _PC_ASYNC_IO) { 1584 *valuep = _POSIX_ASYNCHRONOUS_IO; 1585 goto out; 1586 } 1587 vp = fp->f_vnode; 1588 if (vp != NULL) { 1589 vn_lock(vp, LK_SHARED | LK_RETRY); 1590 error = VOP_PATHCONF(vp, name, valuep); 1591 VOP_UNLOCK(vp); 1592 } else if (fp->f_type == DTYPE_PIPE || fp->f_type == DTYPE_SOCKET) { 1593 if (name != _PC_PIPE_BUF) { 1594 error = EINVAL; 1595 } else { 1596 *valuep = PIPE_BUF; 1597 error = 0; 1598 } 1599 } else { 1600 error = EOPNOTSUPP; 1601 } 1602 out: 1603 fdrop(fp, td); 1604 return (error); 1605 } 1606 1607 /* 1608 * Copy filecaps structure allocating memory for ioctls array if needed. 1609 * 1610 * The last parameter indicates whether the fdtable is locked. If it is not and 1611 * ioctls are encountered, copying fails and the caller must lock the table. 1612 * 1613 * Note that if the table was not locked, the caller has to check the relevant 1614 * sequence counter to determine whether the operation was successful. 1615 */ 1616 bool 1617 filecaps_copy(const struct filecaps *src, struct filecaps *dst, bool locked) 1618 { 1619 size_t size; 1620 1621 if (src->fc_ioctls != NULL && !locked) 1622 return (false); 1623 memcpy(dst, src, sizeof(*src)); 1624 if (src->fc_ioctls == NULL) 1625 return (true); 1626 1627 KASSERT(src->fc_nioctls > 0, 1628 ("fc_ioctls != NULL, but fc_nioctls=%hd", src->fc_nioctls)); 1629 1630 size = sizeof(src->fc_ioctls[0]) * src->fc_nioctls; 1631 dst->fc_ioctls = malloc(size, M_FILECAPS, M_WAITOK); 1632 memcpy(dst->fc_ioctls, src->fc_ioctls, size); 1633 return (true); 1634 } 1635 1636 static u_long * 1637 filecaps_copy_prep(const struct filecaps *src) 1638 { 1639 u_long *ioctls; 1640 size_t size; 1641 1642 if (__predict_true(src->fc_ioctls == NULL)) 1643 return (NULL); 1644 1645 KASSERT(src->fc_nioctls > 0, 1646 ("fc_ioctls != NULL, but fc_nioctls=%hd", src->fc_nioctls)); 1647 1648 size = sizeof(src->fc_ioctls[0]) * src->fc_nioctls; 1649 ioctls = malloc(size, M_FILECAPS, M_WAITOK); 1650 return (ioctls); 1651 } 1652 1653 static void 1654 filecaps_copy_finish(const struct filecaps *src, struct filecaps *dst, 1655 u_long *ioctls) 1656 { 1657 size_t size; 1658 1659 *dst = *src; 1660 if (__predict_true(src->fc_ioctls == NULL)) { 1661 MPASS(ioctls == NULL); 1662 return; 1663 } 1664 1665 size = sizeof(src->fc_ioctls[0]) * src->fc_nioctls; 1666 dst->fc_ioctls = ioctls; 1667 bcopy(src->fc_ioctls, dst->fc_ioctls, size); 1668 } 1669 1670 /* 1671 * Move filecaps structure to the new place and clear the old place. 1672 */ 1673 void 1674 filecaps_move(struct filecaps *src, struct filecaps *dst) 1675 { 1676 1677 *dst = *src; 1678 bzero(src, sizeof(*src)); 1679 } 1680 1681 /* 1682 * Fill the given filecaps structure with full rights. 1683 */ 1684 static void 1685 filecaps_fill(struct filecaps *fcaps) 1686 { 1687 1688 CAP_ALL(&fcaps->fc_rights); 1689 fcaps->fc_ioctls = NULL; 1690 fcaps->fc_nioctls = -1; 1691 fcaps->fc_fcntls = CAP_FCNTL_ALL; 1692 } 1693 1694 /* 1695 * Free memory allocated within filecaps structure. 1696 */ 1697 void 1698 filecaps_free(struct filecaps *fcaps) 1699 { 1700 1701 free(fcaps->fc_ioctls, M_FILECAPS); 1702 bzero(fcaps, sizeof(*fcaps)); 1703 } 1704 1705 static u_long * 1706 filecaps_free_prep(struct filecaps *fcaps) 1707 { 1708 u_long *ioctls; 1709 1710 ioctls = fcaps->fc_ioctls; 1711 bzero(fcaps, sizeof(*fcaps)); 1712 return (ioctls); 1713 } 1714 1715 static void 1716 filecaps_free_finish(u_long *ioctls) 1717 { 1718 1719 free(ioctls, M_FILECAPS); 1720 } 1721 1722 /* 1723 * Validate the given filecaps structure. 1724 */ 1725 static void 1726 filecaps_validate(const struct filecaps *fcaps, const char *func) 1727 { 1728 1729 KASSERT(cap_rights_is_valid(&fcaps->fc_rights), 1730 ("%s: invalid rights", func)); 1731 KASSERT((fcaps->fc_fcntls & ~CAP_FCNTL_ALL) == 0, 1732 ("%s: invalid fcntls", func)); 1733 KASSERT(fcaps->fc_fcntls == 0 || 1734 cap_rights_is_set(&fcaps->fc_rights, CAP_FCNTL), 1735 ("%s: fcntls without CAP_FCNTL", func)); 1736 KASSERT(fcaps->fc_ioctls != NULL ? fcaps->fc_nioctls > 0 : 1737 (fcaps->fc_nioctls == -1 || fcaps->fc_nioctls == 0), 1738 ("%s: invalid ioctls", func)); 1739 KASSERT(fcaps->fc_nioctls == 0 || 1740 cap_rights_is_set(&fcaps->fc_rights, CAP_IOCTL), 1741 ("%s: ioctls without CAP_IOCTL", func)); 1742 } 1743 1744 static void 1745 fdgrowtable_exp(struct filedesc *fdp, int nfd) 1746 { 1747 int nfd1; 1748 1749 FILEDESC_XLOCK_ASSERT(fdp); 1750 1751 nfd1 = fdp->fd_nfiles * 2; 1752 if (nfd1 < nfd) 1753 nfd1 = nfd; 1754 fdgrowtable(fdp, nfd1); 1755 } 1756 1757 /* 1758 * Grow the file table to accommodate (at least) nfd descriptors. 1759 */ 1760 static void 1761 fdgrowtable(struct filedesc *fdp, int nfd) 1762 { 1763 struct filedesc0 *fdp0; 1764 struct freetable *ft; 1765 struct fdescenttbl *ntable; 1766 struct fdescenttbl *otable; 1767 int nnfiles, onfiles; 1768 NDSLOTTYPE *nmap, *omap; 1769 1770 KASSERT(fdp->fd_nfiles > 0, ("zero-length file table")); 1771 1772 /* save old values */ 1773 onfiles = fdp->fd_nfiles; 1774 otable = fdp->fd_files; 1775 omap = fdp->fd_map; 1776 1777 /* compute the size of the new table */ 1778 nnfiles = NDSLOTS(nfd) * NDENTRIES; /* round up */ 1779 if (nnfiles <= onfiles) 1780 /* the table is already large enough */ 1781 return; 1782 1783 /* 1784 * Allocate a new table. We need enough space for the number of 1785 * entries, file entries themselves and the struct freetable we will use 1786 * when we decommission the table and place it on the freelist. 1787 * We place the struct freetable in the middle so we don't have 1788 * to worry about padding. 1789 */ 1790 ntable = malloc(offsetof(struct fdescenttbl, fdt_ofiles) + 1791 nnfiles * sizeof(ntable->fdt_ofiles[0]) + 1792 sizeof(struct freetable), 1793 M_FILEDESC, M_ZERO | M_WAITOK); 1794 /* copy the old data */ 1795 ntable->fdt_nfiles = nnfiles; 1796 memcpy(ntable->fdt_ofiles, otable->fdt_ofiles, 1797 onfiles * sizeof(ntable->fdt_ofiles[0])); 1798 1799 /* 1800 * Allocate a new map only if the old is not large enough. It will 1801 * grow at a slower rate than the table as it can map more 1802 * entries than the table can hold. 1803 */ 1804 if (NDSLOTS(nnfiles) > NDSLOTS(onfiles)) { 1805 nmap = malloc(NDSLOTS(nnfiles) * NDSLOTSIZE, M_FILEDESC, 1806 M_ZERO | M_WAITOK); 1807 /* copy over the old data and update the pointer */ 1808 memcpy(nmap, omap, NDSLOTS(onfiles) * sizeof(*omap)); 1809 fdp->fd_map = nmap; 1810 } 1811 1812 /* 1813 * Make sure that ntable is correctly initialized before we replace 1814 * fd_files poiner. Otherwise fget_unlocked() may see inconsistent 1815 * data. 1816 */ 1817 atomic_store_rel_ptr((volatile void *)&fdp->fd_files, (uintptr_t)ntable); 1818 1819 /* 1820 * Free the old file table when not shared by other threads or processes. 1821 * The old file table is considered to be shared when either are true: 1822 * - The process has more than one thread. 1823 * - The file descriptor table has been shared via fdshare(). 1824 * 1825 * When shared, the old file table will be placed on a freelist 1826 * which will be processed when the struct filedesc is released. 1827 * 1828 * Note that if onfiles == NDFILE, we're dealing with the original 1829 * static allocation contained within (struct filedesc0 *)fdp, 1830 * which must not be freed. 1831 */ 1832 if (onfiles > NDFILE) { 1833 if (curproc->p_numthreads == 1 && fdp->fd_refcnt == 1) 1834 free(otable, M_FILEDESC); 1835 else { 1836 ft = (struct freetable *)&otable->fdt_ofiles[onfiles]; 1837 fdp0 = (struct filedesc0 *)fdp; 1838 ft->ft_table = otable; 1839 SLIST_INSERT_HEAD(&fdp0->fd_free, ft, ft_next); 1840 } 1841 } 1842 /* 1843 * The map does not have the same possibility of threads still 1844 * holding references to it. So always free it as long as it 1845 * does not reference the original static allocation. 1846 */ 1847 if (NDSLOTS(onfiles) > NDSLOTS(NDFILE)) 1848 free(omap, M_FILEDESC); 1849 } 1850 1851 /* 1852 * Allocate a file descriptor for the process. 1853 */ 1854 int 1855 fdalloc(struct thread *td, int minfd, int *result) 1856 { 1857 struct proc *p = td->td_proc; 1858 struct filedesc *fdp = p->p_fd; 1859 int fd, maxfd, allocfd; 1860 #ifdef RACCT 1861 int error; 1862 #endif 1863 1864 FILEDESC_XLOCK_ASSERT(fdp); 1865 1866 if (fdp->fd_freefile > minfd) 1867 minfd = fdp->fd_freefile; 1868 1869 maxfd = getmaxfd(td); 1870 1871 /* 1872 * Search the bitmap for a free descriptor starting at minfd. 1873 * If none is found, grow the file table. 1874 */ 1875 fd = fd_first_free(fdp, minfd, fdp->fd_nfiles); 1876 if (__predict_false(fd >= maxfd)) 1877 return (EMFILE); 1878 if (__predict_false(fd >= fdp->fd_nfiles)) { 1879 allocfd = min(fd * 2, maxfd); 1880 #ifdef RACCT 1881 if (RACCT_ENABLED()) { 1882 error = racct_set_unlocked(p, RACCT_NOFILE, allocfd); 1883 if (error != 0) 1884 return (EMFILE); 1885 } 1886 #endif 1887 /* 1888 * fd is already equal to first free descriptor >= minfd, so 1889 * we only need to grow the table and we are done. 1890 */ 1891 fdgrowtable_exp(fdp, allocfd); 1892 } 1893 1894 /* 1895 * Perform some sanity checks, then mark the file descriptor as 1896 * used and return it to the caller. 1897 */ 1898 KASSERT(fd >= 0 && fd < min(maxfd, fdp->fd_nfiles), 1899 ("invalid descriptor %d", fd)); 1900 KASSERT(!fdisused(fdp, fd), 1901 ("fd_first_free() returned non-free descriptor")); 1902 KASSERT(fdp->fd_ofiles[fd].fde_file == NULL, 1903 ("file descriptor isn't free")); 1904 fdused(fdp, fd); 1905 *result = fd; 1906 return (0); 1907 } 1908 1909 /* 1910 * Allocate n file descriptors for the process. 1911 */ 1912 int 1913 fdallocn(struct thread *td, int minfd, int *fds, int n) 1914 { 1915 struct proc *p = td->td_proc; 1916 struct filedesc *fdp = p->p_fd; 1917 int i; 1918 1919 FILEDESC_XLOCK_ASSERT(fdp); 1920 1921 for (i = 0; i < n; i++) 1922 if (fdalloc(td, 0, &fds[i]) != 0) 1923 break; 1924 1925 if (i < n) { 1926 for (i--; i >= 0; i--) 1927 fdunused(fdp, fds[i]); 1928 return (EMFILE); 1929 } 1930 1931 return (0); 1932 } 1933 1934 /* 1935 * Create a new open file structure and allocate a file descriptor for the 1936 * process that refers to it. We add one reference to the file for the 1937 * descriptor table and one reference for resultfp. This is to prevent us 1938 * being preempted and the entry in the descriptor table closed after we 1939 * release the FILEDESC lock. 1940 */ 1941 int 1942 falloc_caps(struct thread *td, struct file **resultfp, int *resultfd, int flags, 1943 struct filecaps *fcaps) 1944 { 1945 struct file *fp; 1946 int error, fd; 1947 1948 error = falloc_noinstall(td, &fp); 1949 if (error) 1950 return (error); /* no reference held on error */ 1951 1952 error = finstall(td, fp, &fd, flags, fcaps); 1953 if (error) { 1954 fdrop(fp, td); /* one reference (fp only) */ 1955 return (error); 1956 } 1957 1958 if (resultfp != NULL) 1959 *resultfp = fp; /* copy out result */ 1960 else 1961 fdrop(fp, td); /* release local reference */ 1962 1963 if (resultfd != NULL) 1964 *resultfd = fd; 1965 1966 return (0); 1967 } 1968 1969 /* 1970 * Create a new open file structure without allocating a file descriptor. 1971 */ 1972 int 1973 falloc_noinstall(struct thread *td, struct file **resultfp) 1974 { 1975 struct file *fp; 1976 int maxuserfiles = maxfiles - (maxfiles / 20); 1977 int openfiles_new; 1978 static struct timeval lastfail; 1979 static int curfail; 1980 1981 KASSERT(resultfp != NULL, ("%s: resultfp == NULL", __func__)); 1982 1983 openfiles_new = atomic_fetchadd_int(&openfiles, 1) + 1; 1984 if ((openfiles_new >= maxuserfiles && 1985 priv_check(td, PRIV_MAXFILES) != 0) || 1986 openfiles_new >= maxfiles) { 1987 atomic_subtract_int(&openfiles, 1); 1988 if (ppsratecheck(&lastfail, &curfail, 1)) { 1989 printf("kern.maxfiles limit exceeded by uid %i, (%s) " 1990 "please see tuning(7).\n", td->td_ucred->cr_ruid, td->td_proc->p_comm); 1991 } 1992 return (ENFILE); 1993 } 1994 fp = uma_zalloc(file_zone, M_WAITOK); 1995 bzero(fp, sizeof(*fp)); 1996 refcount_init(&fp->f_count, 1); 1997 fp->f_cred = crhold(td->td_ucred); 1998 fp->f_ops = &badfileops; 1999 *resultfp = fp; 2000 return (0); 2001 } 2002 2003 /* 2004 * Install a file in a file descriptor table. 2005 */ 2006 void 2007 _finstall(struct filedesc *fdp, struct file *fp, int fd, int flags, 2008 struct filecaps *fcaps) 2009 { 2010 struct filedescent *fde; 2011 2012 MPASS(fp != NULL); 2013 if (fcaps != NULL) 2014 filecaps_validate(fcaps, __func__); 2015 FILEDESC_XLOCK_ASSERT(fdp); 2016 2017 fde = &fdp->fd_ofiles[fd]; 2018 #ifdef CAPABILITIES 2019 seqc_write_begin(&fde->fde_seqc); 2020 #endif 2021 fde->fde_file = fp; 2022 fde->fde_flags = (flags & O_CLOEXEC) != 0 ? UF_EXCLOSE : 0; 2023 if (fcaps != NULL) 2024 filecaps_move(fcaps, &fde->fde_caps); 2025 else 2026 filecaps_fill(&fde->fde_caps); 2027 #ifdef CAPABILITIES 2028 seqc_write_end(&fde->fde_seqc); 2029 #endif 2030 } 2031 2032 int 2033 finstall(struct thread *td, struct file *fp, int *fd, int flags, 2034 struct filecaps *fcaps) 2035 { 2036 struct filedesc *fdp = td->td_proc->p_fd; 2037 int error; 2038 2039 MPASS(fd != NULL); 2040 2041 if (!fhold(fp)) 2042 return (EBADF); 2043 FILEDESC_XLOCK(fdp); 2044 error = fdalloc(td, 0, fd); 2045 if (__predict_false(error != 0)) { 2046 FILEDESC_XUNLOCK(fdp); 2047 fdrop(fp, td); 2048 return (error); 2049 } 2050 _finstall(fdp, fp, *fd, flags, fcaps); 2051 FILEDESC_XUNLOCK(fdp); 2052 return (0); 2053 } 2054 2055 /* 2056 * Build a new filedesc structure from another. 2057 * 2058 * If fdp is not NULL, return with it shared locked. 2059 */ 2060 struct filedesc * 2061 fdinit(struct filedesc *fdp, bool prepfiles, int *lastfile) 2062 { 2063 struct filedesc0 *newfdp0; 2064 struct filedesc *newfdp; 2065 2066 if (prepfiles) 2067 MPASS(lastfile != NULL); 2068 else 2069 MPASS(lastfile == NULL); 2070 2071 newfdp0 = uma_zalloc(filedesc0_zone, M_WAITOK | M_ZERO); 2072 newfdp = &newfdp0->fd_fd; 2073 2074 /* Create the file descriptor table. */ 2075 FILEDESC_LOCK_INIT(newfdp); 2076 refcount_init(&newfdp->fd_refcnt, 1); 2077 refcount_init(&newfdp->fd_holdcnt, 1); 2078 newfdp->fd_map = newfdp0->fd_dmap; 2079 newfdp->fd_files = (struct fdescenttbl *)&newfdp0->fd_dfiles; 2080 newfdp->fd_files->fdt_nfiles = NDFILE; 2081 2082 if (fdp == NULL) 2083 return (newfdp); 2084 2085 FILEDESC_SLOCK(fdp); 2086 if (!prepfiles) { 2087 FILEDESC_SUNLOCK(fdp); 2088 return (newfdp); 2089 } 2090 2091 for (;;) { 2092 *lastfile = fdlastfile(fdp); 2093 if (*lastfile < newfdp->fd_nfiles) 2094 break; 2095 FILEDESC_SUNLOCK(fdp); 2096 fdgrowtable(newfdp, *lastfile + 1); 2097 FILEDESC_SLOCK(fdp); 2098 } 2099 2100 return (newfdp); 2101 } 2102 2103 /* 2104 * Build a pwddesc structure from another. 2105 * Copy the current, root, and jail root vnode references. 2106 * 2107 * If pdp is not NULL, return with it shared locked. 2108 */ 2109 struct pwddesc * 2110 pdinit(struct pwddesc *pdp, bool keeplock) 2111 { 2112 struct pwddesc *newpdp; 2113 struct pwd *newpwd; 2114 2115 newpdp = malloc(sizeof(*newpdp), M_PWDDESC, M_WAITOK | M_ZERO); 2116 2117 PWDDESC_LOCK_INIT(newpdp); 2118 refcount_init(&newpdp->pd_refcount, 1); 2119 newpdp->pd_cmask = CMASK; 2120 2121 if (pdp == NULL) { 2122 newpwd = pwd_alloc(); 2123 smr_serialized_store(&newpdp->pd_pwd, newpwd, true); 2124 return (newpdp); 2125 } 2126 2127 PWDDESC_XLOCK(pdp); 2128 newpwd = pwd_hold_pwddesc(pdp); 2129 smr_serialized_store(&newpdp->pd_pwd, newpwd, true); 2130 if (!keeplock) 2131 PWDDESC_XUNLOCK(pdp); 2132 return (newpdp); 2133 } 2134 2135 static struct filedesc * 2136 fdhold(struct proc *p) 2137 { 2138 struct filedesc *fdp; 2139 2140 PROC_LOCK_ASSERT(p, MA_OWNED); 2141 fdp = p->p_fd; 2142 if (fdp != NULL) 2143 refcount_acquire(&fdp->fd_holdcnt); 2144 return (fdp); 2145 } 2146 2147 static struct pwddesc * 2148 pdhold(struct proc *p) 2149 { 2150 struct pwddesc *pdp; 2151 2152 PROC_LOCK_ASSERT(p, MA_OWNED); 2153 pdp = p->p_pd; 2154 if (pdp != NULL) 2155 refcount_acquire(&pdp->pd_refcount); 2156 return (pdp); 2157 } 2158 2159 static void 2160 fddrop(struct filedesc *fdp) 2161 { 2162 2163 if (fdp->fd_holdcnt > 1) { 2164 if (refcount_release(&fdp->fd_holdcnt) == 0) 2165 return; 2166 } 2167 2168 FILEDESC_LOCK_DESTROY(fdp); 2169 uma_zfree(filedesc0_zone, fdp); 2170 } 2171 2172 static void 2173 pddrop(struct pwddesc *pdp) 2174 { 2175 struct pwd *pwd; 2176 2177 if (refcount_release_if_not_last(&pdp->pd_refcount)) 2178 return; 2179 2180 PWDDESC_XLOCK(pdp); 2181 if (refcount_release(&pdp->pd_refcount) == 0) { 2182 PWDDESC_XUNLOCK(pdp); 2183 return; 2184 } 2185 pwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); 2186 pwd_set(pdp, NULL); 2187 PWDDESC_XUNLOCK(pdp); 2188 pwd_drop(pwd); 2189 2190 PWDDESC_LOCK_DESTROY(pdp); 2191 free(pdp, M_PWDDESC); 2192 } 2193 2194 /* 2195 * Share a filedesc structure. 2196 */ 2197 struct filedesc * 2198 fdshare(struct filedesc *fdp) 2199 { 2200 2201 refcount_acquire(&fdp->fd_refcnt); 2202 return (fdp); 2203 } 2204 2205 /* 2206 * Share a pwddesc structure. 2207 */ 2208 struct pwddesc * 2209 pdshare(struct pwddesc *pdp) 2210 { 2211 refcount_acquire(&pdp->pd_refcount); 2212 return (pdp); 2213 } 2214 2215 /* 2216 * Unshare a filedesc structure, if necessary by making a copy 2217 */ 2218 void 2219 fdunshare(struct thread *td) 2220 { 2221 struct filedesc *tmp; 2222 struct proc *p = td->td_proc; 2223 2224 if (p->p_fd->fd_refcnt == 1) 2225 return; 2226 2227 tmp = fdcopy(p->p_fd); 2228 fdescfree(td); 2229 p->p_fd = tmp; 2230 } 2231 2232 /* 2233 * Unshare a pwddesc structure. 2234 */ 2235 void 2236 pdunshare(struct thread *td) 2237 { 2238 struct pwddesc *pdp; 2239 struct proc *p; 2240 2241 p = td->td_proc; 2242 /* Not shared. */ 2243 if (p->p_pd->pd_refcount == 1) 2244 return; 2245 2246 pdp = pdcopy(p->p_pd); 2247 pdescfree(td); 2248 p->p_pd = pdp; 2249 } 2250 2251 void 2252 fdinstall_remapped(struct thread *td, struct filedesc *fdp) 2253 { 2254 2255 fdescfree(td); 2256 td->td_proc->p_fd = fdp; 2257 } 2258 2259 /* 2260 * Copy a filedesc structure. A NULL pointer in returns a NULL reference, 2261 * this is to ease callers, not catch errors. 2262 */ 2263 struct filedesc * 2264 fdcopy(struct filedesc *fdp) 2265 { 2266 struct filedesc *newfdp; 2267 struct filedescent *nfde, *ofde; 2268 int i, lastfile; 2269 2270 MPASS(fdp != NULL); 2271 2272 newfdp = fdinit(fdp, true, &lastfile); 2273 /* copy all passable descriptors (i.e. not kqueue) */ 2274 newfdp->fd_freefile = -1; 2275 for (i = 0; i <= lastfile; ++i) { 2276 ofde = &fdp->fd_ofiles[i]; 2277 if (ofde->fde_file == NULL || 2278 (ofde->fde_file->f_ops->fo_flags & DFLAG_PASSABLE) == 0 || 2279 !fhold(ofde->fde_file)) { 2280 if (newfdp->fd_freefile == -1) 2281 newfdp->fd_freefile = i; 2282 continue; 2283 } 2284 nfde = &newfdp->fd_ofiles[i]; 2285 *nfde = *ofde; 2286 filecaps_copy(&ofde->fde_caps, &nfde->fde_caps, true); 2287 fdused_init(newfdp, i); 2288 } 2289 if (newfdp->fd_freefile == -1) 2290 newfdp->fd_freefile = i; 2291 FILEDESC_SUNLOCK(fdp); 2292 return (newfdp); 2293 } 2294 2295 /* 2296 * Copy a pwddesc structure. 2297 */ 2298 struct pwddesc * 2299 pdcopy(struct pwddesc *pdp) 2300 { 2301 struct pwddesc *newpdp; 2302 2303 MPASS(pdp != NULL); 2304 2305 newpdp = pdinit(pdp, true); 2306 newpdp->pd_cmask = pdp->pd_cmask; 2307 PWDDESC_XUNLOCK(pdp); 2308 return (newpdp); 2309 } 2310 2311 /* 2312 * Copies a filedesc structure, while remapping all file descriptors 2313 * stored inside using a translation table. 2314 * 2315 * File descriptors are copied over to the new file descriptor table, 2316 * regardless of whether the close-on-exec flag is set. 2317 */ 2318 int 2319 fdcopy_remapped(struct filedesc *fdp, const int *fds, size_t nfds, 2320 struct filedesc **ret) 2321 { 2322 struct filedesc *newfdp; 2323 struct filedescent *nfde, *ofde; 2324 int error, i, lastfile; 2325 2326 MPASS(fdp != NULL); 2327 2328 newfdp = fdinit(fdp, true, &lastfile); 2329 if (nfds > lastfile + 1) { 2330 /* New table cannot be larger than the old one. */ 2331 error = E2BIG; 2332 goto bad; 2333 } 2334 /* Copy all passable descriptors (i.e. not kqueue). */ 2335 newfdp->fd_freefile = nfds; 2336 for (i = 0; i < nfds; ++i) { 2337 if (fds[i] < 0 || fds[i] > lastfile) { 2338 /* File descriptor out of bounds. */ 2339 error = EBADF; 2340 goto bad; 2341 } 2342 ofde = &fdp->fd_ofiles[fds[i]]; 2343 if (ofde->fde_file == NULL) { 2344 /* Unused file descriptor. */ 2345 error = EBADF; 2346 goto bad; 2347 } 2348 if ((ofde->fde_file->f_ops->fo_flags & DFLAG_PASSABLE) == 0) { 2349 /* File descriptor cannot be passed. */ 2350 error = EINVAL; 2351 goto bad; 2352 } 2353 if (!fhold(ofde->fde_file)) { 2354 error = EBADF; 2355 goto bad; 2356 } 2357 nfde = &newfdp->fd_ofiles[i]; 2358 *nfde = *ofde; 2359 filecaps_copy(&ofde->fde_caps, &nfde->fde_caps, true); 2360 fdused_init(newfdp, i); 2361 } 2362 FILEDESC_SUNLOCK(fdp); 2363 *ret = newfdp; 2364 return (0); 2365 bad: 2366 FILEDESC_SUNLOCK(fdp); 2367 fdescfree_remapped(newfdp); 2368 return (error); 2369 } 2370 2371 /* 2372 * Clear POSIX style locks. This is only used when fdp looses a reference (i.e. 2373 * one of processes using it exits) and the table used to be shared. 2374 */ 2375 static void 2376 fdclearlocks(struct thread *td) 2377 { 2378 struct filedesc *fdp; 2379 struct filedesc_to_leader *fdtol; 2380 struct flock lf; 2381 struct file *fp; 2382 struct proc *p; 2383 struct vnode *vp; 2384 int i, lastfile; 2385 2386 p = td->td_proc; 2387 fdp = p->p_fd; 2388 fdtol = p->p_fdtol; 2389 MPASS(fdtol != NULL); 2390 2391 FILEDESC_XLOCK(fdp); 2392 KASSERT(fdtol->fdl_refcount > 0, 2393 ("filedesc_to_refcount botch: fdl_refcount=%d", 2394 fdtol->fdl_refcount)); 2395 if (fdtol->fdl_refcount == 1 && 2396 (p->p_leader->p_flag & P_ADVLOCK) != 0) { 2397 lastfile = fdlastfile(fdp); 2398 for (i = 0; i <= lastfile; i++) { 2399 fp = fdp->fd_ofiles[i].fde_file; 2400 if (fp == NULL || fp->f_type != DTYPE_VNODE || 2401 !fhold(fp)) 2402 continue; 2403 FILEDESC_XUNLOCK(fdp); 2404 lf.l_whence = SEEK_SET; 2405 lf.l_start = 0; 2406 lf.l_len = 0; 2407 lf.l_type = F_UNLCK; 2408 vp = fp->f_vnode; 2409 (void) VOP_ADVLOCK(vp, 2410 (caddr_t)p->p_leader, F_UNLCK, 2411 &lf, F_POSIX); 2412 FILEDESC_XLOCK(fdp); 2413 fdrop(fp, td); 2414 } 2415 } 2416 retry: 2417 if (fdtol->fdl_refcount == 1) { 2418 if (fdp->fd_holdleaderscount > 0 && 2419 (p->p_leader->p_flag & P_ADVLOCK) != 0) { 2420 /* 2421 * close() or kern_dup() has cleared a reference 2422 * in a shared file descriptor table. 2423 */ 2424 fdp->fd_holdleaderswakeup = 1; 2425 sx_sleep(&fdp->fd_holdleaderscount, 2426 FILEDESC_LOCK(fdp), PLOCK, "fdlhold", 0); 2427 goto retry; 2428 } 2429 if (fdtol->fdl_holdcount > 0) { 2430 /* 2431 * Ensure that fdtol->fdl_leader remains 2432 * valid in closef(). 2433 */ 2434 fdtol->fdl_wakeup = 1; 2435 sx_sleep(fdtol, FILEDESC_LOCK(fdp), PLOCK, 2436 "fdlhold", 0); 2437 goto retry; 2438 } 2439 } 2440 fdtol->fdl_refcount--; 2441 if (fdtol->fdl_refcount == 0 && 2442 fdtol->fdl_holdcount == 0) { 2443 fdtol->fdl_next->fdl_prev = fdtol->fdl_prev; 2444 fdtol->fdl_prev->fdl_next = fdtol->fdl_next; 2445 } else 2446 fdtol = NULL; 2447 p->p_fdtol = NULL; 2448 FILEDESC_XUNLOCK(fdp); 2449 if (fdtol != NULL) 2450 free(fdtol, M_FILEDESC_TO_LEADER); 2451 } 2452 2453 /* 2454 * Release a filedesc structure. 2455 */ 2456 static void 2457 fdescfree_fds(struct thread *td, struct filedesc *fdp, bool needclose) 2458 { 2459 struct filedesc0 *fdp0; 2460 struct freetable *ft, *tft; 2461 struct filedescent *fde; 2462 struct file *fp; 2463 int i, lastfile; 2464 2465 lastfile = fdlastfile_single(fdp); 2466 for (i = 0; i <= lastfile; i++) { 2467 fde = &fdp->fd_ofiles[i]; 2468 fp = fde->fde_file; 2469 if (fp != NULL) { 2470 fdefree_last(fde); 2471 if (needclose) 2472 (void) closef(fp, td); 2473 else 2474 fdrop(fp, td); 2475 } 2476 } 2477 2478 if (NDSLOTS(fdp->fd_nfiles) > NDSLOTS(NDFILE)) 2479 free(fdp->fd_map, M_FILEDESC); 2480 if (fdp->fd_nfiles > NDFILE) 2481 free(fdp->fd_files, M_FILEDESC); 2482 2483 fdp0 = (struct filedesc0 *)fdp; 2484 SLIST_FOREACH_SAFE(ft, &fdp0->fd_free, ft_next, tft) 2485 free(ft->ft_table, M_FILEDESC); 2486 2487 fddrop(fdp); 2488 } 2489 2490 void 2491 fdescfree(struct thread *td) 2492 { 2493 struct proc *p; 2494 struct filedesc *fdp; 2495 2496 p = td->td_proc; 2497 fdp = p->p_fd; 2498 MPASS(fdp != NULL); 2499 2500 #ifdef RACCT 2501 if (RACCT_ENABLED()) 2502 racct_set_unlocked(p, RACCT_NOFILE, 0); 2503 #endif 2504 2505 if (p->p_fdtol != NULL) 2506 fdclearlocks(td); 2507 2508 PROC_LOCK(p); 2509 p->p_fd = NULL; 2510 PROC_UNLOCK(p); 2511 2512 if (refcount_release(&fdp->fd_refcnt) == 0) 2513 return; 2514 2515 fdescfree_fds(td, fdp, 1); 2516 } 2517 2518 void 2519 pdescfree(struct thread *td) 2520 { 2521 struct proc *p; 2522 struct pwddesc *pdp; 2523 2524 p = td->td_proc; 2525 pdp = p->p_pd; 2526 MPASS(pdp != NULL); 2527 2528 PROC_LOCK(p); 2529 p->p_pd = NULL; 2530 PROC_UNLOCK(p); 2531 2532 pddrop(pdp); 2533 } 2534 2535 void 2536 fdescfree_remapped(struct filedesc *fdp) 2537 { 2538 fdescfree_fds(curthread, fdp, 0); 2539 } 2540 2541 /* 2542 * For setugid programs, we don't want to people to use that setugidness 2543 * to generate error messages which write to a file which otherwise would 2544 * otherwise be off-limits to the process. We check for filesystems where 2545 * the vnode can change out from under us after execve (like [lin]procfs). 2546 * 2547 * Since fdsetugidsafety calls this only for fd 0, 1 and 2, this check is 2548 * sufficient. We also don't check for setugidness since we know we are. 2549 */ 2550 static bool 2551 is_unsafe(struct file *fp) 2552 { 2553 struct vnode *vp; 2554 2555 if (fp->f_type != DTYPE_VNODE) 2556 return (false); 2557 2558 vp = fp->f_vnode; 2559 return ((vp->v_vflag & VV_PROCDEP) != 0); 2560 } 2561 2562 /* 2563 * Make this setguid thing safe, if at all possible. 2564 */ 2565 void 2566 fdsetugidsafety(struct thread *td) 2567 { 2568 struct filedesc *fdp; 2569 struct file *fp; 2570 int i; 2571 2572 fdp = td->td_proc->p_fd; 2573 KASSERT(fdp->fd_refcnt == 1, ("the fdtable should not be shared")); 2574 MPASS(fdp->fd_nfiles >= 3); 2575 for (i = 0; i <= 2; i++) { 2576 fp = fdp->fd_ofiles[i].fde_file; 2577 if (fp != NULL && is_unsafe(fp)) { 2578 FILEDESC_XLOCK(fdp); 2579 knote_fdclose(td, i); 2580 /* 2581 * NULL-out descriptor prior to close to avoid 2582 * a race while close blocks. 2583 */ 2584 fdfree(fdp, i); 2585 FILEDESC_XUNLOCK(fdp); 2586 (void) closef(fp, td); 2587 } 2588 } 2589 } 2590 2591 /* 2592 * If a specific file object occupies a specific file descriptor, close the 2593 * file descriptor entry and drop a reference on the file object. This is a 2594 * convenience function to handle a subsequent error in a function that calls 2595 * falloc() that handles the race that another thread might have closed the 2596 * file descriptor out from under the thread creating the file object. 2597 */ 2598 void 2599 fdclose(struct thread *td, struct file *fp, int idx) 2600 { 2601 struct filedesc *fdp = td->td_proc->p_fd; 2602 2603 FILEDESC_XLOCK(fdp); 2604 if (fdp->fd_ofiles[idx].fde_file == fp) { 2605 fdfree(fdp, idx); 2606 FILEDESC_XUNLOCK(fdp); 2607 fdrop(fp, td); 2608 } else 2609 FILEDESC_XUNLOCK(fdp); 2610 } 2611 2612 /* 2613 * Close any files on exec? 2614 */ 2615 void 2616 fdcloseexec(struct thread *td) 2617 { 2618 struct filedesc *fdp; 2619 struct filedescent *fde; 2620 struct file *fp; 2621 int i, lastfile; 2622 2623 fdp = td->td_proc->p_fd; 2624 KASSERT(fdp->fd_refcnt == 1, ("the fdtable should not be shared")); 2625 lastfile = fdlastfile_single(fdp); 2626 for (i = 0; i <= lastfile; i++) { 2627 fde = &fdp->fd_ofiles[i]; 2628 fp = fde->fde_file; 2629 if (fp != NULL && (fp->f_type == DTYPE_MQUEUE || 2630 (fde->fde_flags & UF_EXCLOSE))) { 2631 FILEDESC_XLOCK(fdp); 2632 fdfree(fdp, i); 2633 (void) closefp(fdp, i, fp, td, 0); 2634 FILEDESC_UNLOCK_ASSERT(fdp); 2635 } 2636 } 2637 } 2638 2639 /* 2640 * It is unsafe for set[ug]id processes to be started with file 2641 * descriptors 0..2 closed, as these descriptors are given implicit 2642 * significance in the Standard C library. fdcheckstd() will create a 2643 * descriptor referencing /dev/null for each of stdin, stdout, and 2644 * stderr that is not already open. 2645 */ 2646 int 2647 fdcheckstd(struct thread *td) 2648 { 2649 struct filedesc *fdp; 2650 register_t save; 2651 int i, error, devnull; 2652 2653 fdp = td->td_proc->p_fd; 2654 KASSERT(fdp->fd_refcnt == 1, ("the fdtable should not be shared")); 2655 MPASS(fdp->fd_nfiles >= 3); 2656 devnull = -1; 2657 for (i = 0; i <= 2; i++) { 2658 if (fdp->fd_ofiles[i].fde_file != NULL) 2659 continue; 2660 2661 save = td->td_retval[0]; 2662 if (devnull != -1) { 2663 error = kern_dup(td, FDDUP_FIXED, 0, devnull, i); 2664 } else { 2665 error = kern_openat(td, AT_FDCWD, "/dev/null", 2666 UIO_SYSSPACE, O_RDWR, 0); 2667 if (error == 0) { 2668 devnull = td->td_retval[0]; 2669 KASSERT(devnull == i, ("we didn't get our fd")); 2670 } 2671 } 2672 td->td_retval[0] = save; 2673 if (error != 0) 2674 return (error); 2675 } 2676 return (0); 2677 } 2678 2679 /* 2680 * Internal form of close. Decrement reference count on file structure. 2681 * Note: td may be NULL when closing a file that was being passed in a 2682 * message. 2683 */ 2684 int 2685 closef(struct file *fp, struct thread *td) 2686 { 2687 struct vnode *vp; 2688 struct flock lf; 2689 struct filedesc_to_leader *fdtol; 2690 struct filedesc *fdp; 2691 2692 /* 2693 * POSIX record locking dictates that any close releases ALL 2694 * locks owned by this process. This is handled by setting 2695 * a flag in the unlock to free ONLY locks obeying POSIX 2696 * semantics, and not to free BSD-style file locks. 2697 * If the descriptor was in a message, POSIX-style locks 2698 * aren't passed with the descriptor, and the thread pointer 2699 * will be NULL. Callers should be careful only to pass a 2700 * NULL thread pointer when there really is no owning 2701 * context that might have locks, or the locks will be 2702 * leaked. 2703 */ 2704 if (fp->f_type == DTYPE_VNODE && td != NULL) { 2705 vp = fp->f_vnode; 2706 if ((td->td_proc->p_leader->p_flag & P_ADVLOCK) != 0) { 2707 lf.l_whence = SEEK_SET; 2708 lf.l_start = 0; 2709 lf.l_len = 0; 2710 lf.l_type = F_UNLCK; 2711 (void) VOP_ADVLOCK(vp, (caddr_t)td->td_proc->p_leader, 2712 F_UNLCK, &lf, F_POSIX); 2713 } 2714 fdtol = td->td_proc->p_fdtol; 2715 if (fdtol != NULL) { 2716 /* 2717 * Handle special case where file descriptor table is 2718 * shared between multiple process leaders. 2719 */ 2720 fdp = td->td_proc->p_fd; 2721 FILEDESC_XLOCK(fdp); 2722 for (fdtol = fdtol->fdl_next; 2723 fdtol != td->td_proc->p_fdtol; 2724 fdtol = fdtol->fdl_next) { 2725 if ((fdtol->fdl_leader->p_flag & 2726 P_ADVLOCK) == 0) 2727 continue; 2728 fdtol->fdl_holdcount++; 2729 FILEDESC_XUNLOCK(fdp); 2730 lf.l_whence = SEEK_SET; 2731 lf.l_start = 0; 2732 lf.l_len = 0; 2733 lf.l_type = F_UNLCK; 2734 vp = fp->f_vnode; 2735 (void) VOP_ADVLOCK(vp, 2736 (caddr_t)fdtol->fdl_leader, F_UNLCK, &lf, 2737 F_POSIX); 2738 FILEDESC_XLOCK(fdp); 2739 fdtol->fdl_holdcount--; 2740 if (fdtol->fdl_holdcount == 0 && 2741 fdtol->fdl_wakeup != 0) { 2742 fdtol->fdl_wakeup = 0; 2743 wakeup(fdtol); 2744 } 2745 } 2746 FILEDESC_XUNLOCK(fdp); 2747 } 2748 } 2749 return (fdrop(fp, td)); 2750 } 2751 2752 /* 2753 * Initialize the file pointer with the specified properties. 2754 * 2755 * The ops are set with release semantics to be certain that the flags, type, 2756 * and data are visible when ops is. This is to prevent ops methods from being 2757 * called with bad data. 2758 */ 2759 void 2760 finit(struct file *fp, u_int flag, short type, void *data, struct fileops *ops) 2761 { 2762 fp->f_data = data; 2763 fp->f_flag = flag; 2764 fp->f_type = type; 2765 atomic_store_rel_ptr((volatile uintptr_t *)&fp->f_ops, (uintptr_t)ops); 2766 } 2767 2768 void 2769 finit_vnode(struct file *fp, u_int flag, void *data, struct fileops *ops) 2770 { 2771 fp->f_seqcount[UIO_READ] = 1; 2772 fp->f_seqcount[UIO_WRITE] = 1; 2773 finit(fp, (flag & FMASK) | (fp->f_flag & FHASLOCK), DTYPE_VNODE, 2774 data, ops); 2775 } 2776 2777 int 2778 fget_cap_locked(struct filedesc *fdp, int fd, cap_rights_t *needrightsp, 2779 struct file **fpp, struct filecaps *havecapsp) 2780 { 2781 struct filedescent *fde; 2782 int error; 2783 2784 FILEDESC_LOCK_ASSERT(fdp); 2785 2786 fde = fdeget_locked(fdp, fd); 2787 if (fde == NULL) { 2788 error = EBADF; 2789 goto out; 2790 } 2791 2792 #ifdef CAPABILITIES 2793 error = cap_check(cap_rights_fde_inline(fde), needrightsp); 2794 if (error != 0) 2795 goto out; 2796 #endif 2797 2798 if (havecapsp != NULL) 2799 filecaps_copy(&fde->fde_caps, havecapsp, true); 2800 2801 *fpp = fde->fde_file; 2802 2803 error = 0; 2804 out: 2805 return (error); 2806 } 2807 2808 int 2809 fget_cap(struct thread *td, int fd, cap_rights_t *needrightsp, 2810 struct file **fpp, struct filecaps *havecapsp) 2811 { 2812 struct filedesc *fdp = td->td_proc->p_fd; 2813 int error; 2814 #ifndef CAPABILITIES 2815 error = fget_unlocked(fdp, fd, needrightsp, fpp); 2816 if (havecapsp != NULL && error == 0) 2817 filecaps_fill(havecapsp); 2818 #else 2819 struct file *fp; 2820 seqc_t seq; 2821 2822 *fpp = NULL; 2823 for (;;) { 2824 error = fget_unlocked_seq(fdp, fd, needrightsp, &fp, &seq); 2825 if (error != 0) 2826 return (error); 2827 2828 if (havecapsp != NULL) { 2829 if (!filecaps_copy(&fdp->fd_ofiles[fd].fde_caps, 2830 havecapsp, false)) { 2831 fdrop(fp, td); 2832 goto get_locked; 2833 } 2834 } 2835 2836 if (!fd_modified(fdp, fd, seq)) 2837 break; 2838 fdrop(fp, td); 2839 } 2840 2841 *fpp = fp; 2842 return (0); 2843 2844 get_locked: 2845 FILEDESC_SLOCK(fdp); 2846 error = fget_cap_locked(fdp, fd, needrightsp, fpp, havecapsp); 2847 if (error == 0 && !fhold(*fpp)) 2848 error = EBADF; 2849 FILEDESC_SUNLOCK(fdp); 2850 #endif 2851 return (error); 2852 } 2853 2854 #ifdef CAPABILITIES 2855 int 2856 fgetvp_lookup_smr(int fd, struct nameidata *ndp, struct vnode **vpp, bool *fsearch) 2857 { 2858 const struct filedescent *fde; 2859 const struct fdescenttbl *fdt; 2860 struct filedesc *fdp; 2861 struct file *fp; 2862 struct vnode *vp; 2863 const cap_rights_t *haverights; 2864 cap_rights_t rights; 2865 seqc_t seq; 2866 2867 VFS_SMR_ASSERT_ENTERED(); 2868 2869 rights = *ndp->ni_rightsneeded; 2870 cap_rights_set_one(&rights, CAP_LOOKUP); 2871 2872 fdp = curproc->p_fd; 2873 fdt = fdp->fd_files; 2874 if (__predict_false((u_int)fd >= fdt->fdt_nfiles)) 2875 return (EBADF); 2876 seq = seqc_read_any(fd_seqc(fdt, fd)); 2877 if (__predict_false(seqc_in_modify(seq))) 2878 return (EAGAIN); 2879 fde = &fdt->fdt_ofiles[fd]; 2880 haverights = cap_rights_fde_inline(fde); 2881 fp = fde->fde_file; 2882 if (__predict_false(fp == NULL)) 2883 return (EAGAIN); 2884 if (__predict_false(cap_check_inline_transient(haverights, &rights))) 2885 return (EAGAIN); 2886 *fsearch = ((fp->f_flag & FSEARCH) != 0); 2887 vp = fp->f_vnode; 2888 if (__predict_false(vp == NULL || vp->v_type != VDIR)) { 2889 return (EAGAIN); 2890 } 2891 if (!filecaps_copy(&fde->fde_caps, &ndp->ni_filecaps, false)) { 2892 return (EAGAIN); 2893 } 2894 /* 2895 * Use an acquire barrier to force re-reading of fdt so it is 2896 * refreshed for verification. 2897 */ 2898 atomic_thread_fence_acq(); 2899 fdt = fdp->fd_files; 2900 if (__predict_false(!seqc_consistent_nomb(fd_seqc(fdt, fd), seq))) 2901 return (EAGAIN); 2902 /* 2903 * If file descriptor doesn't have all rights, 2904 * all lookups relative to it must also be 2905 * strictly relative. 2906 * 2907 * Not yet supported by fast path. 2908 */ 2909 CAP_ALL(&rights); 2910 if (!cap_rights_contains(&ndp->ni_filecaps.fc_rights, &rights) || 2911 ndp->ni_filecaps.fc_fcntls != CAP_FCNTL_ALL || 2912 ndp->ni_filecaps.fc_nioctls != -1) { 2913 #ifdef notyet 2914 ndp->ni_lcf |= NI_LCF_STRICTRELATIVE; 2915 #else 2916 return (EAGAIN); 2917 #endif 2918 } 2919 *vpp = vp; 2920 return (0); 2921 } 2922 #else 2923 int 2924 fgetvp_lookup_smr(int fd, struct nameidata *ndp, struct vnode **vpp, bool *fsearch) 2925 { 2926 const struct fdescenttbl *fdt; 2927 struct filedesc *fdp; 2928 struct file *fp; 2929 struct vnode *vp; 2930 2931 VFS_SMR_ASSERT_ENTERED(); 2932 2933 fdp = curproc->p_fd; 2934 fdt = fdp->fd_files; 2935 if (__predict_false((u_int)fd >= fdt->fdt_nfiles)) 2936 return (EBADF); 2937 fp = fdt->fdt_ofiles[fd].fde_file; 2938 if (__predict_false(fp == NULL)) 2939 return (EAGAIN); 2940 *fsearch = ((fp->f_flag & FSEARCH) != 0); 2941 vp = fp->f_vnode; 2942 if (__predict_false(vp == NULL || vp->v_type != VDIR)) { 2943 return (EAGAIN); 2944 } 2945 /* 2946 * Use an acquire barrier to force re-reading of fdt so it is 2947 * refreshed for verification. 2948 */ 2949 atomic_thread_fence_acq(); 2950 fdt = fdp->fd_files; 2951 if (__predict_false(fp != fdt->fdt_ofiles[fd].fde_file)) 2952 return (EAGAIN); 2953 filecaps_fill(&ndp->ni_filecaps); 2954 *vpp = vp; 2955 return (0); 2956 } 2957 #endif 2958 2959 int 2960 fget_unlocked_seq(struct filedesc *fdp, int fd, cap_rights_t *needrightsp, 2961 struct file **fpp, seqc_t *seqp) 2962 { 2963 #ifdef CAPABILITIES 2964 const struct filedescent *fde; 2965 #endif 2966 const struct fdescenttbl *fdt; 2967 struct file *fp; 2968 #ifdef CAPABILITIES 2969 seqc_t seq; 2970 cap_rights_t haverights; 2971 int error; 2972 #endif 2973 2974 fdt = fdp->fd_files; 2975 if (__predict_false((u_int)fd >= fdt->fdt_nfiles)) 2976 return (EBADF); 2977 /* 2978 * Fetch the descriptor locklessly. We avoid fdrop() races by 2979 * never raising a refcount above 0. To accomplish this we have 2980 * to use a cmpset loop rather than an atomic_add. The descriptor 2981 * must be re-verified once we acquire a reference to be certain 2982 * that the identity is still correct and we did not lose a race 2983 * due to preemption. 2984 */ 2985 for (;;) { 2986 #ifdef CAPABILITIES 2987 seq = seqc_read(fd_seqc(fdt, fd)); 2988 fde = &fdt->fdt_ofiles[fd]; 2989 haverights = *cap_rights_fde_inline(fde); 2990 fp = fde->fde_file; 2991 if (!seqc_consistent(fd_seqc(fdt, fd), seq)) 2992 continue; 2993 #else 2994 fp = fdt->fdt_ofiles[fd].fde_file; 2995 #endif 2996 if (fp == NULL) 2997 return (EBADF); 2998 #ifdef CAPABILITIES 2999 error = cap_check_inline(&haverights, needrightsp); 3000 if (error != 0) 3001 return (error); 3002 #endif 3003 if (__predict_false(!refcount_acquire_if_not_zero(&fp->f_count))) { 3004 /* 3005 * The count was found either saturated or zero. 3006 * This re-read is not any more racy than using the 3007 * return value from fcmpset. 3008 */ 3009 if (refcount_load(&fp->f_count) != 0) 3010 return (EBADF); 3011 /* 3012 * Force a reload. Other thread could reallocate the 3013 * table before this fd was closed, so it is possible 3014 * that there is a stale fp pointer in cached version. 3015 */ 3016 fdt = atomic_load_ptr(&fdp->fd_files); 3017 continue; 3018 } 3019 /* 3020 * Use an acquire barrier to force re-reading of fdt so it is 3021 * refreshed for verification. 3022 */ 3023 atomic_thread_fence_acq(); 3024 fdt = fdp->fd_files; 3025 #ifdef CAPABILITIES 3026 if (seqc_consistent_nomb(fd_seqc(fdt, fd), seq)) 3027 #else 3028 if (fp == fdt->fdt_ofiles[fd].fde_file) 3029 #endif 3030 break; 3031 fdrop(fp, curthread); 3032 } 3033 *fpp = fp; 3034 if (seqp != NULL) { 3035 #ifdef CAPABILITIES 3036 *seqp = seq; 3037 #endif 3038 } 3039 return (0); 3040 } 3041 3042 /* 3043 * See the comments in fget_unlocked_seq for an explanation of how this works. 3044 * 3045 * This is a simplified variant which bails out to the aforementioned routine 3046 * if anything goes wrong. In practice this only happens when userspace is 3047 * racing with itself. 3048 */ 3049 int 3050 fget_unlocked(struct filedesc *fdp, int fd, cap_rights_t *needrightsp, 3051 struct file **fpp) 3052 { 3053 #ifdef CAPABILITIES 3054 const struct filedescent *fde; 3055 #endif 3056 const struct fdescenttbl *fdt; 3057 struct file *fp; 3058 #ifdef CAPABILITIES 3059 seqc_t seq; 3060 const cap_rights_t *haverights; 3061 #endif 3062 3063 fdt = fdp->fd_files; 3064 if (__predict_false((u_int)fd >= fdt->fdt_nfiles)) 3065 return (EBADF); 3066 #ifdef CAPABILITIES 3067 seq = seqc_read_any(fd_seqc(fdt, fd)); 3068 if (__predict_false(seqc_in_modify(seq))) 3069 goto out_fallback; 3070 fde = &fdt->fdt_ofiles[fd]; 3071 haverights = cap_rights_fde_inline(fde); 3072 fp = fde->fde_file; 3073 #else 3074 fp = fdt->fdt_ofiles[fd].fde_file; 3075 #endif 3076 if (__predict_false(fp == NULL)) 3077 goto out_fallback; 3078 #ifdef CAPABILITIES 3079 if (__predict_false(cap_check_inline_transient(haverights, needrightsp))) 3080 goto out_fallback; 3081 #endif 3082 if (__predict_false(!refcount_acquire_if_not_zero(&fp->f_count))) 3083 goto out_fallback; 3084 3085 /* 3086 * Use an acquire barrier to force re-reading of fdt so it is 3087 * refreshed for verification. 3088 */ 3089 atomic_thread_fence_acq(); 3090 fdt = fdp->fd_files; 3091 #ifdef CAPABILITIES 3092 if (__predict_false(!seqc_consistent_nomb(fd_seqc(fdt, fd), seq))) 3093 #else 3094 if (__predict_false(fp != fdt->fdt_ofiles[fd].fde_file)) 3095 #endif 3096 goto out_fdrop; 3097 *fpp = fp; 3098 return (0); 3099 out_fdrop: 3100 fdrop(fp, curthread); 3101 out_fallback: 3102 return (fget_unlocked_seq(fdp, fd, needrightsp, fpp, NULL)); 3103 } 3104 3105 /* 3106 * Extract the file pointer associated with the specified descriptor for the 3107 * current user process. 3108 * 3109 * If the descriptor doesn't exist or doesn't match 'flags', EBADF is 3110 * returned. 3111 * 3112 * File's rights will be checked against the capability rights mask. 3113 * 3114 * If an error occurred the non-zero error is returned and *fpp is set to 3115 * NULL. Otherwise *fpp is held and set and zero is returned. Caller is 3116 * responsible for fdrop(). 3117 */ 3118 static __inline int 3119 _fget(struct thread *td, int fd, struct file **fpp, int flags, 3120 cap_rights_t *needrightsp) 3121 { 3122 struct filedesc *fdp; 3123 struct file *fp; 3124 int error; 3125 3126 *fpp = NULL; 3127 fdp = td->td_proc->p_fd; 3128 error = fget_unlocked(fdp, fd, needrightsp, &fp); 3129 if (__predict_false(error != 0)) 3130 return (error); 3131 if (__predict_false(fp->f_ops == &badfileops)) { 3132 fdrop(fp, td); 3133 return (EBADF); 3134 } 3135 3136 /* 3137 * FREAD and FWRITE failure return EBADF as per POSIX. 3138 */ 3139 error = 0; 3140 switch (flags) { 3141 case FREAD: 3142 case FWRITE: 3143 if ((fp->f_flag & flags) == 0) 3144 error = EBADF; 3145 break; 3146 case FEXEC: 3147 if ((fp->f_flag & (FREAD | FEXEC)) == 0 || 3148 ((fp->f_flag & FWRITE) != 0)) 3149 error = EBADF; 3150 break; 3151 case 0: 3152 break; 3153 default: 3154 KASSERT(0, ("wrong flags")); 3155 } 3156 3157 if (error != 0) { 3158 fdrop(fp, td); 3159 return (error); 3160 } 3161 3162 *fpp = fp; 3163 return (0); 3164 } 3165 3166 int 3167 fget(struct thread *td, int fd, cap_rights_t *rightsp, struct file **fpp) 3168 { 3169 3170 return (_fget(td, fd, fpp, 0, rightsp)); 3171 } 3172 3173 int 3174 fget_mmap(struct thread *td, int fd, cap_rights_t *rightsp, vm_prot_t *maxprotp, 3175 struct file **fpp) 3176 { 3177 int error; 3178 #ifndef CAPABILITIES 3179 error = _fget(td, fd, fpp, 0, rightsp); 3180 if (maxprotp != NULL) 3181 *maxprotp = VM_PROT_ALL; 3182 return (error); 3183 #else 3184 cap_rights_t fdrights; 3185 struct filedesc *fdp; 3186 struct file *fp; 3187 seqc_t seq; 3188 3189 *fpp = NULL; 3190 fdp = td->td_proc->p_fd; 3191 MPASS(cap_rights_is_set(rightsp, CAP_MMAP)); 3192 for (;;) { 3193 error = fget_unlocked_seq(fdp, fd, rightsp, &fp, &seq); 3194 if (__predict_false(error != 0)) 3195 return (error); 3196 if (__predict_false(fp->f_ops == &badfileops)) { 3197 fdrop(fp, td); 3198 return (EBADF); 3199 } 3200 if (maxprotp != NULL) 3201 fdrights = *cap_rights(fdp, fd); 3202 if (!fd_modified(fdp, fd, seq)) 3203 break; 3204 fdrop(fp, td); 3205 } 3206 3207 /* 3208 * If requested, convert capability rights to access flags. 3209 */ 3210 if (maxprotp != NULL) 3211 *maxprotp = cap_rights_to_vmprot(&fdrights); 3212 *fpp = fp; 3213 return (0); 3214 #endif 3215 } 3216 3217 int 3218 fget_read(struct thread *td, int fd, cap_rights_t *rightsp, struct file **fpp) 3219 { 3220 3221 return (_fget(td, fd, fpp, FREAD, rightsp)); 3222 } 3223 3224 int 3225 fget_write(struct thread *td, int fd, cap_rights_t *rightsp, struct file **fpp) 3226 { 3227 3228 return (_fget(td, fd, fpp, FWRITE, rightsp)); 3229 } 3230 3231 int 3232 fget_fcntl(struct thread *td, int fd, cap_rights_t *rightsp, int needfcntl, 3233 struct file **fpp) 3234 { 3235 struct filedesc *fdp = td->td_proc->p_fd; 3236 #ifndef CAPABILITIES 3237 return (fget_unlocked(fdp, fd, rightsp, fpp)); 3238 #else 3239 struct file *fp; 3240 int error; 3241 seqc_t seq; 3242 3243 *fpp = NULL; 3244 MPASS(cap_rights_is_set(rightsp, CAP_FCNTL)); 3245 for (;;) { 3246 error = fget_unlocked_seq(fdp, fd, rightsp, &fp, &seq); 3247 if (error != 0) 3248 return (error); 3249 error = cap_fcntl_check(fdp, fd, needfcntl); 3250 if (!fd_modified(fdp, fd, seq)) 3251 break; 3252 fdrop(fp, td); 3253 } 3254 if (error != 0) { 3255 fdrop(fp, td); 3256 return (error); 3257 } 3258 *fpp = fp; 3259 return (0); 3260 #endif 3261 } 3262 3263 /* 3264 * Like fget() but loads the underlying vnode, or returns an error if the 3265 * descriptor does not represent a vnode. Note that pipes use vnodes but 3266 * never have VM objects. The returned vnode will be vref()'d. 3267 * 3268 * XXX: what about the unused flags ? 3269 */ 3270 static __inline int 3271 _fgetvp(struct thread *td, int fd, int flags, cap_rights_t *needrightsp, 3272 struct vnode **vpp) 3273 { 3274 struct file *fp; 3275 int error; 3276 3277 *vpp = NULL; 3278 error = _fget(td, fd, &fp, flags, needrightsp); 3279 if (error != 0) 3280 return (error); 3281 if (fp->f_vnode == NULL) { 3282 error = EINVAL; 3283 } else { 3284 *vpp = fp->f_vnode; 3285 vrefact(*vpp); 3286 } 3287 fdrop(fp, td); 3288 3289 return (error); 3290 } 3291 3292 int 3293 fgetvp(struct thread *td, int fd, cap_rights_t *rightsp, struct vnode **vpp) 3294 { 3295 3296 return (_fgetvp(td, fd, 0, rightsp, vpp)); 3297 } 3298 3299 int 3300 fgetvp_rights(struct thread *td, int fd, cap_rights_t *needrightsp, 3301 struct filecaps *havecaps, struct vnode **vpp) 3302 { 3303 struct filecaps caps; 3304 struct file *fp; 3305 int error; 3306 3307 error = fget_cap(td, fd, needrightsp, &fp, &caps); 3308 if (error != 0) 3309 return (error); 3310 if (fp->f_ops == &badfileops) { 3311 error = EBADF; 3312 goto out; 3313 } 3314 if (fp->f_vnode == NULL) { 3315 error = EINVAL; 3316 goto out; 3317 } 3318 3319 *havecaps = caps; 3320 *vpp = fp->f_vnode; 3321 vrefact(*vpp); 3322 fdrop(fp, td); 3323 3324 return (0); 3325 out: 3326 filecaps_free(&caps); 3327 fdrop(fp, td); 3328 return (error); 3329 } 3330 3331 int 3332 fgetvp_read(struct thread *td, int fd, cap_rights_t *rightsp, struct vnode **vpp) 3333 { 3334 3335 return (_fgetvp(td, fd, FREAD, rightsp, vpp)); 3336 } 3337 3338 int 3339 fgetvp_exec(struct thread *td, int fd, cap_rights_t *rightsp, struct vnode **vpp) 3340 { 3341 3342 return (_fgetvp(td, fd, FEXEC, rightsp, vpp)); 3343 } 3344 3345 #ifdef notyet 3346 int 3347 fgetvp_write(struct thread *td, int fd, cap_rights_t *rightsp, 3348 struct vnode **vpp) 3349 { 3350 3351 return (_fgetvp(td, fd, FWRITE, rightsp, vpp)); 3352 } 3353 #endif 3354 3355 /* 3356 * Handle the last reference to a file being closed. 3357 * 3358 * Without the noinline attribute clang keeps inlining the func thorough this 3359 * file when fdrop is used. 3360 */ 3361 int __noinline 3362 _fdrop(struct file *fp, struct thread *td) 3363 { 3364 int error; 3365 #ifdef INVARIANTS 3366 int count; 3367 3368 count = refcount_load(&fp->f_count); 3369 if (count != 0) 3370 panic("fdrop: fp %p count %d", fp, count); 3371 #endif 3372 error = fo_close(fp, td); 3373 atomic_subtract_int(&openfiles, 1); 3374 crfree(fp->f_cred); 3375 free(fp->f_advice, M_FADVISE); 3376 uma_zfree(file_zone, fp); 3377 3378 return (error); 3379 } 3380 3381 /* 3382 * Apply an advisory lock on a file descriptor. 3383 * 3384 * Just attempt to get a record lock of the requested type on the entire file 3385 * (l_whence = SEEK_SET, l_start = 0, l_len = 0). 3386 */ 3387 #ifndef _SYS_SYSPROTO_H_ 3388 struct flock_args { 3389 int fd; 3390 int how; 3391 }; 3392 #endif 3393 /* ARGSUSED */ 3394 int 3395 sys_flock(struct thread *td, struct flock_args *uap) 3396 { 3397 struct file *fp; 3398 struct vnode *vp; 3399 struct flock lf; 3400 int error; 3401 3402 error = fget(td, uap->fd, &cap_flock_rights, &fp); 3403 if (error != 0) 3404 return (error); 3405 if (fp->f_type != DTYPE_VNODE) { 3406 fdrop(fp, td); 3407 return (EOPNOTSUPP); 3408 } 3409 3410 vp = fp->f_vnode; 3411 lf.l_whence = SEEK_SET; 3412 lf.l_start = 0; 3413 lf.l_len = 0; 3414 if (uap->how & LOCK_UN) { 3415 lf.l_type = F_UNLCK; 3416 atomic_clear_int(&fp->f_flag, FHASLOCK); 3417 error = VOP_ADVLOCK(vp, (caddr_t)fp, F_UNLCK, &lf, F_FLOCK); 3418 goto done2; 3419 } 3420 if (uap->how & LOCK_EX) 3421 lf.l_type = F_WRLCK; 3422 else if (uap->how & LOCK_SH) 3423 lf.l_type = F_RDLCK; 3424 else { 3425 error = EBADF; 3426 goto done2; 3427 } 3428 atomic_set_int(&fp->f_flag, FHASLOCK); 3429 error = VOP_ADVLOCK(vp, (caddr_t)fp, F_SETLK, &lf, 3430 (uap->how & LOCK_NB) ? F_FLOCK : F_FLOCK | F_WAIT); 3431 done2: 3432 fdrop(fp, td); 3433 return (error); 3434 } 3435 /* 3436 * Duplicate the specified descriptor to a free descriptor. 3437 */ 3438 int 3439 dupfdopen(struct thread *td, struct filedesc *fdp, int dfd, int mode, 3440 int openerror, int *indxp) 3441 { 3442 struct filedescent *newfde, *oldfde; 3443 struct file *fp; 3444 u_long *ioctls; 3445 int error, indx; 3446 3447 KASSERT(openerror == ENODEV || openerror == ENXIO, 3448 ("unexpected error %d in %s", openerror, __func__)); 3449 3450 /* 3451 * If the to-be-dup'd fd number is greater than the allowed number 3452 * of file descriptors, or the fd to be dup'd has already been 3453 * closed, then reject. 3454 */ 3455 FILEDESC_XLOCK(fdp); 3456 if ((fp = fget_locked(fdp, dfd)) == NULL) { 3457 FILEDESC_XUNLOCK(fdp); 3458 return (EBADF); 3459 } 3460 3461 error = fdalloc(td, 0, &indx); 3462 if (error != 0) { 3463 FILEDESC_XUNLOCK(fdp); 3464 return (error); 3465 } 3466 3467 /* 3468 * There are two cases of interest here. 3469 * 3470 * For ENODEV simply dup (dfd) to file descriptor (indx) and return. 3471 * 3472 * For ENXIO steal away the file structure from (dfd) and store it in 3473 * (indx). (dfd) is effectively closed by this operation. 3474 */ 3475 switch (openerror) { 3476 case ENODEV: 3477 /* 3478 * Check that the mode the file is being opened for is a 3479 * subset of the mode of the existing descriptor. 3480 */ 3481 if (((mode & (FREAD|FWRITE)) | fp->f_flag) != fp->f_flag) { 3482 fdunused(fdp, indx); 3483 FILEDESC_XUNLOCK(fdp); 3484 return (EACCES); 3485 } 3486 if (!fhold(fp)) { 3487 fdunused(fdp, indx); 3488 FILEDESC_XUNLOCK(fdp); 3489 return (EBADF); 3490 } 3491 newfde = &fdp->fd_ofiles[indx]; 3492 oldfde = &fdp->fd_ofiles[dfd]; 3493 ioctls = filecaps_copy_prep(&oldfde->fde_caps); 3494 #ifdef CAPABILITIES 3495 seqc_write_begin(&newfde->fde_seqc); 3496 #endif 3497 memcpy(newfde, oldfde, fde_change_size); 3498 filecaps_copy_finish(&oldfde->fde_caps, &newfde->fde_caps, 3499 ioctls); 3500 #ifdef CAPABILITIES 3501 seqc_write_end(&newfde->fde_seqc); 3502 #endif 3503 break; 3504 case ENXIO: 3505 /* 3506 * Steal away the file pointer from dfd and stuff it into indx. 3507 */ 3508 newfde = &fdp->fd_ofiles[indx]; 3509 oldfde = &fdp->fd_ofiles[dfd]; 3510 #ifdef CAPABILITIES 3511 seqc_write_begin(&newfde->fde_seqc); 3512 #endif 3513 memcpy(newfde, oldfde, fde_change_size); 3514 oldfde->fde_file = NULL; 3515 fdunused(fdp, dfd); 3516 #ifdef CAPABILITIES 3517 seqc_write_end(&newfde->fde_seqc); 3518 #endif 3519 break; 3520 } 3521 FILEDESC_XUNLOCK(fdp); 3522 *indxp = indx; 3523 return (0); 3524 } 3525 3526 /* 3527 * This sysctl determines if we will allow a process to chroot(2) if it 3528 * has a directory open: 3529 * 0: disallowed for all processes. 3530 * 1: allowed for processes that were not already chroot(2)'ed. 3531 * 2: allowed for all processes. 3532 */ 3533 3534 static int chroot_allow_open_directories = 1; 3535 3536 SYSCTL_INT(_kern, OID_AUTO, chroot_allow_open_directories, CTLFLAG_RW, 3537 &chroot_allow_open_directories, 0, 3538 "Allow a process to chroot(2) if it has a directory open"); 3539 3540 /* 3541 * Helper function for raised chroot(2) security function: Refuse if 3542 * any filedescriptors are open directories. 3543 */ 3544 static int 3545 chroot_refuse_vdir_fds(struct filedesc *fdp) 3546 { 3547 struct vnode *vp; 3548 struct file *fp; 3549 int fd, lastfile; 3550 3551 FILEDESC_LOCK_ASSERT(fdp); 3552 3553 lastfile = fdlastfile(fdp); 3554 for (fd = 0; fd <= lastfile; fd++) { 3555 fp = fget_locked(fdp, fd); 3556 if (fp == NULL) 3557 continue; 3558 if (fp->f_type == DTYPE_VNODE) { 3559 vp = fp->f_vnode; 3560 if (vp->v_type == VDIR) 3561 return (EPERM); 3562 } 3563 } 3564 return (0); 3565 } 3566 3567 static void 3568 pwd_fill(struct pwd *oldpwd, struct pwd *newpwd) 3569 { 3570 3571 if (newpwd->pwd_cdir == NULL && oldpwd->pwd_cdir != NULL) { 3572 vrefact(oldpwd->pwd_cdir); 3573 newpwd->pwd_cdir = oldpwd->pwd_cdir; 3574 } 3575 3576 if (newpwd->pwd_rdir == NULL && oldpwd->pwd_rdir != NULL) { 3577 vrefact(oldpwd->pwd_rdir); 3578 newpwd->pwd_rdir = oldpwd->pwd_rdir; 3579 } 3580 3581 if (newpwd->pwd_jdir == NULL && oldpwd->pwd_jdir != NULL) { 3582 vrefact(oldpwd->pwd_jdir); 3583 newpwd->pwd_jdir = oldpwd->pwd_jdir; 3584 } 3585 } 3586 3587 struct pwd * 3588 pwd_hold_pwddesc(struct pwddesc *pdp) 3589 { 3590 struct pwd *pwd; 3591 3592 PWDDESC_ASSERT_XLOCKED(pdp); 3593 pwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); 3594 if (pwd != NULL) 3595 refcount_acquire(&pwd->pwd_refcount); 3596 return (pwd); 3597 } 3598 3599 bool 3600 pwd_hold_smr(struct pwd *pwd) 3601 { 3602 3603 MPASS(pwd != NULL); 3604 if (__predict_true(refcount_acquire_if_not_zero(&pwd->pwd_refcount))) { 3605 return (true); 3606 } 3607 return (false); 3608 } 3609 3610 struct pwd * 3611 pwd_hold(struct thread *td) 3612 { 3613 struct pwddesc *pdp; 3614 struct pwd *pwd; 3615 3616 pdp = td->td_proc->p_pd; 3617 3618 vfs_smr_enter(); 3619 pwd = vfs_smr_entered_load(&pdp->pd_pwd); 3620 if (pwd_hold_smr(pwd)) { 3621 vfs_smr_exit(); 3622 return (pwd); 3623 } 3624 vfs_smr_exit(); 3625 PWDDESC_XLOCK(pdp); 3626 pwd = pwd_hold_pwddesc(pdp); 3627 MPASS(pwd != NULL); 3628 PWDDESC_XUNLOCK(pdp); 3629 return (pwd); 3630 } 3631 3632 struct pwd * 3633 pwd_get_smr(void) 3634 { 3635 struct pwd *pwd; 3636 3637 pwd = vfs_smr_entered_load(&curproc->p_pd->pd_pwd); 3638 MPASS(pwd != NULL); 3639 return (pwd); 3640 } 3641 3642 static struct pwd * 3643 pwd_alloc(void) 3644 { 3645 struct pwd *pwd; 3646 3647 pwd = uma_zalloc_smr(pwd_zone, M_WAITOK); 3648 bzero(pwd, sizeof(*pwd)); 3649 refcount_init(&pwd->pwd_refcount, 1); 3650 return (pwd); 3651 } 3652 3653 void 3654 pwd_drop(struct pwd *pwd) 3655 { 3656 3657 if (!refcount_release(&pwd->pwd_refcount)) 3658 return; 3659 3660 if (pwd->pwd_cdir != NULL) 3661 vrele(pwd->pwd_cdir); 3662 if (pwd->pwd_rdir != NULL) 3663 vrele(pwd->pwd_rdir); 3664 if (pwd->pwd_jdir != NULL) 3665 vrele(pwd->pwd_jdir); 3666 uma_zfree_smr(pwd_zone, pwd); 3667 } 3668 3669 /* 3670 * Common routine for kern_chroot() and jail_attach(). The caller is 3671 * responsible for invoking priv_check() and mac_vnode_check_chroot() to 3672 * authorize this operation. 3673 */ 3674 int 3675 pwd_chroot(struct thread *td, struct vnode *vp) 3676 { 3677 struct pwddesc *pdp; 3678 struct filedesc *fdp; 3679 struct pwd *newpwd, *oldpwd; 3680 int error; 3681 3682 fdp = td->td_proc->p_fd; 3683 pdp = td->td_proc->p_pd; 3684 newpwd = pwd_alloc(); 3685 FILEDESC_SLOCK(fdp); 3686 PWDDESC_XLOCK(pdp); 3687 oldpwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); 3688 if (chroot_allow_open_directories == 0 || 3689 (chroot_allow_open_directories == 1 && 3690 oldpwd->pwd_rdir != rootvnode)) { 3691 error = chroot_refuse_vdir_fds(fdp); 3692 FILEDESC_SUNLOCK(fdp); 3693 if (error != 0) { 3694 PWDDESC_XUNLOCK(pdp); 3695 pwd_drop(newpwd); 3696 return (error); 3697 } 3698 } else { 3699 FILEDESC_SUNLOCK(fdp); 3700 } 3701 3702 vrefact(vp); 3703 newpwd->pwd_rdir = vp; 3704 if (oldpwd->pwd_jdir == NULL) { 3705 vrefact(vp); 3706 newpwd->pwd_jdir = vp; 3707 } 3708 pwd_fill(oldpwd, newpwd); 3709 pwd_set(pdp, newpwd); 3710 PWDDESC_XUNLOCK(pdp); 3711 pwd_drop(oldpwd); 3712 return (0); 3713 } 3714 3715 void 3716 pwd_chdir(struct thread *td, struct vnode *vp) 3717 { 3718 struct pwddesc *pdp; 3719 struct pwd *newpwd, *oldpwd; 3720 3721 VNPASS(vp->v_usecount > 0, vp); 3722 3723 newpwd = pwd_alloc(); 3724 pdp = td->td_proc->p_pd; 3725 PWDDESC_XLOCK(pdp); 3726 oldpwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); 3727 newpwd->pwd_cdir = vp; 3728 pwd_fill(oldpwd, newpwd); 3729 pwd_set(pdp, newpwd); 3730 PWDDESC_XUNLOCK(pdp); 3731 pwd_drop(oldpwd); 3732 } 3733 3734 void 3735 pwd_ensure_dirs(void) 3736 { 3737 struct pwddesc *pdp; 3738 struct pwd *oldpwd, *newpwd; 3739 3740 pdp = curproc->p_pd; 3741 PWDDESC_XLOCK(pdp); 3742 oldpwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); 3743 if (oldpwd->pwd_cdir != NULL && oldpwd->pwd_rdir != NULL) { 3744 PWDDESC_XUNLOCK(pdp); 3745 return; 3746 } 3747 PWDDESC_XUNLOCK(pdp); 3748 3749 newpwd = pwd_alloc(); 3750 PWDDESC_XLOCK(pdp); 3751 oldpwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); 3752 pwd_fill(oldpwd, newpwd); 3753 if (newpwd->pwd_cdir == NULL) { 3754 vrefact(rootvnode); 3755 newpwd->pwd_cdir = rootvnode; 3756 } 3757 if (newpwd->pwd_rdir == NULL) { 3758 vrefact(rootvnode); 3759 newpwd->pwd_rdir = rootvnode; 3760 } 3761 pwd_set(pdp, newpwd); 3762 PWDDESC_XUNLOCK(pdp); 3763 pwd_drop(oldpwd); 3764 } 3765 3766 void 3767 pwd_set_rootvnode(void) 3768 { 3769 struct pwddesc *pdp; 3770 struct pwd *oldpwd, *newpwd; 3771 3772 pdp = curproc->p_pd; 3773 3774 newpwd = pwd_alloc(); 3775 PWDDESC_XLOCK(pdp); 3776 oldpwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); 3777 vrefact(rootvnode); 3778 newpwd->pwd_cdir = rootvnode; 3779 vrefact(rootvnode); 3780 newpwd->pwd_rdir = rootvnode; 3781 pwd_fill(oldpwd, newpwd); 3782 pwd_set(pdp, newpwd); 3783 PWDDESC_XUNLOCK(pdp); 3784 pwd_drop(oldpwd); 3785 } 3786 3787 /* 3788 * Scan all active processes and prisons to see if any of them have a current 3789 * or root directory of `olddp'. If so, replace them with the new mount point. 3790 */ 3791 void 3792 mountcheckdirs(struct vnode *olddp, struct vnode *newdp) 3793 { 3794 struct pwddesc *pdp; 3795 struct pwd *newpwd, *oldpwd; 3796 struct prison *pr; 3797 struct proc *p; 3798 int nrele; 3799 3800 if (vrefcnt(olddp) == 1) 3801 return; 3802 nrele = 0; 3803 newpwd = pwd_alloc(); 3804 sx_slock(&allproc_lock); 3805 FOREACH_PROC_IN_SYSTEM(p) { 3806 PROC_LOCK(p); 3807 pdp = pdhold(p); 3808 PROC_UNLOCK(p); 3809 if (pdp == NULL) 3810 continue; 3811 PWDDESC_XLOCK(pdp); 3812 oldpwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); 3813 if (oldpwd == NULL || 3814 (oldpwd->pwd_cdir != olddp && 3815 oldpwd->pwd_rdir != olddp && 3816 oldpwd->pwd_jdir != olddp)) { 3817 PWDDESC_XUNLOCK(pdp); 3818 pddrop(pdp); 3819 continue; 3820 } 3821 if (oldpwd->pwd_cdir == olddp) { 3822 vrefact(newdp); 3823 newpwd->pwd_cdir = newdp; 3824 } 3825 if (oldpwd->pwd_rdir == olddp) { 3826 vrefact(newdp); 3827 newpwd->pwd_rdir = newdp; 3828 } 3829 if (oldpwd->pwd_jdir == olddp) { 3830 vrefact(newdp); 3831 newpwd->pwd_jdir = newdp; 3832 } 3833 pwd_fill(oldpwd, newpwd); 3834 pwd_set(pdp, newpwd); 3835 PWDDESC_XUNLOCK(pdp); 3836 pwd_drop(oldpwd); 3837 pddrop(pdp); 3838 newpwd = pwd_alloc(); 3839 } 3840 sx_sunlock(&allproc_lock); 3841 pwd_drop(newpwd); 3842 if (rootvnode == olddp) { 3843 vrefact(newdp); 3844 rootvnode = newdp; 3845 nrele++; 3846 } 3847 mtx_lock(&prison0.pr_mtx); 3848 if (prison0.pr_root == olddp) { 3849 vrefact(newdp); 3850 prison0.pr_root = newdp; 3851 nrele++; 3852 } 3853 mtx_unlock(&prison0.pr_mtx); 3854 sx_slock(&allprison_lock); 3855 TAILQ_FOREACH(pr, &allprison, pr_list) { 3856 mtx_lock(&pr->pr_mtx); 3857 if (pr->pr_root == olddp) { 3858 vrefact(newdp); 3859 pr->pr_root = newdp; 3860 nrele++; 3861 } 3862 mtx_unlock(&pr->pr_mtx); 3863 } 3864 sx_sunlock(&allprison_lock); 3865 while (nrele--) 3866 vrele(olddp); 3867 } 3868 3869 struct filedesc_to_leader * 3870 filedesc_to_leader_alloc(struct filedesc_to_leader *old, struct filedesc *fdp, struct proc *leader) 3871 { 3872 struct filedesc_to_leader *fdtol; 3873 3874 fdtol = malloc(sizeof(struct filedesc_to_leader), 3875 M_FILEDESC_TO_LEADER, M_WAITOK); 3876 fdtol->fdl_refcount = 1; 3877 fdtol->fdl_holdcount = 0; 3878 fdtol->fdl_wakeup = 0; 3879 fdtol->fdl_leader = leader; 3880 if (old != NULL) { 3881 FILEDESC_XLOCK(fdp); 3882 fdtol->fdl_next = old->fdl_next; 3883 fdtol->fdl_prev = old; 3884 old->fdl_next = fdtol; 3885 fdtol->fdl_next->fdl_prev = fdtol; 3886 FILEDESC_XUNLOCK(fdp); 3887 } else { 3888 fdtol->fdl_next = fdtol; 3889 fdtol->fdl_prev = fdtol; 3890 } 3891 return (fdtol); 3892 } 3893 3894 static int 3895 sysctl_kern_proc_nfds(SYSCTL_HANDLER_ARGS) 3896 { 3897 NDSLOTTYPE *map; 3898 struct filedesc *fdp; 3899 int count, off, minoff; 3900 3901 if (*(int *)arg1 != 0) 3902 return (EINVAL); 3903 3904 fdp = curproc->p_fd; 3905 count = 0; 3906 FILEDESC_SLOCK(fdp); 3907 map = fdp->fd_map; 3908 off = NDSLOT(fdp->fd_nfiles - 1); 3909 for (minoff = NDSLOT(0); off >= minoff; --off) 3910 count += bitcountl(map[off]); 3911 FILEDESC_SUNLOCK(fdp); 3912 3913 return (SYSCTL_OUT(req, &count, sizeof(count))); 3914 } 3915 3916 static SYSCTL_NODE(_kern_proc, KERN_PROC_NFDS, nfds, 3917 CTLFLAG_RD|CTLFLAG_CAPRD|CTLFLAG_MPSAFE, sysctl_kern_proc_nfds, 3918 "Number of open file descriptors"); 3919 3920 /* 3921 * Get file structures globally. 3922 */ 3923 static int 3924 sysctl_kern_file(SYSCTL_HANDLER_ARGS) 3925 { 3926 struct xfile xf; 3927 struct filedesc *fdp; 3928 struct file *fp; 3929 struct proc *p; 3930 int error, n, lastfile; 3931 3932 error = sysctl_wire_old_buffer(req, 0); 3933 if (error != 0) 3934 return (error); 3935 if (req->oldptr == NULL) { 3936 n = 0; 3937 sx_slock(&allproc_lock); 3938 FOREACH_PROC_IN_SYSTEM(p) { 3939 PROC_LOCK(p); 3940 if (p->p_state == PRS_NEW) { 3941 PROC_UNLOCK(p); 3942 continue; 3943 } 3944 fdp = fdhold(p); 3945 PROC_UNLOCK(p); 3946 if (fdp == NULL) 3947 continue; 3948 /* overestimates sparse tables. */ 3949 n += fdp->fd_nfiles; 3950 fddrop(fdp); 3951 } 3952 sx_sunlock(&allproc_lock); 3953 return (SYSCTL_OUT(req, 0, n * sizeof(xf))); 3954 } 3955 error = 0; 3956 bzero(&xf, sizeof(xf)); 3957 xf.xf_size = sizeof(xf); 3958 sx_slock(&allproc_lock); 3959 FOREACH_PROC_IN_SYSTEM(p) { 3960 PROC_LOCK(p); 3961 if (p->p_state == PRS_NEW) { 3962 PROC_UNLOCK(p); 3963 continue; 3964 } 3965 if (p_cansee(req->td, p) != 0) { 3966 PROC_UNLOCK(p); 3967 continue; 3968 } 3969 xf.xf_pid = p->p_pid; 3970 xf.xf_uid = p->p_ucred->cr_uid; 3971 fdp = fdhold(p); 3972 PROC_UNLOCK(p); 3973 if (fdp == NULL) 3974 continue; 3975 FILEDESC_SLOCK(fdp); 3976 lastfile = fdlastfile(fdp); 3977 for (n = 0; fdp->fd_refcnt > 0 && n <= lastfile; ++n) { 3978 if ((fp = fdp->fd_ofiles[n].fde_file) == NULL) 3979 continue; 3980 xf.xf_fd = n; 3981 xf.xf_file = (uintptr_t)fp; 3982 xf.xf_data = (uintptr_t)fp->f_data; 3983 xf.xf_vnode = (uintptr_t)fp->f_vnode; 3984 xf.xf_type = (uintptr_t)fp->f_type; 3985 xf.xf_count = refcount_load(&fp->f_count); 3986 xf.xf_msgcount = 0; 3987 xf.xf_offset = foffset_get(fp); 3988 xf.xf_flag = fp->f_flag; 3989 error = SYSCTL_OUT(req, &xf, sizeof(xf)); 3990 if (error) 3991 break; 3992 } 3993 FILEDESC_SUNLOCK(fdp); 3994 fddrop(fdp); 3995 if (error) 3996 break; 3997 } 3998 sx_sunlock(&allproc_lock); 3999 return (error); 4000 } 4001 4002 SYSCTL_PROC(_kern, KERN_FILE, file, CTLTYPE_OPAQUE|CTLFLAG_RD|CTLFLAG_MPSAFE, 4003 0, 0, sysctl_kern_file, "S,xfile", "Entire file table"); 4004 4005 #ifdef KINFO_FILE_SIZE 4006 CTASSERT(sizeof(struct kinfo_file) == KINFO_FILE_SIZE); 4007 #endif 4008 4009 static int 4010 xlate_fflags(int fflags) 4011 { 4012 static const struct { 4013 int fflag; 4014 int kf_fflag; 4015 } fflags_table[] = { 4016 { FAPPEND, KF_FLAG_APPEND }, 4017 { FASYNC, KF_FLAG_ASYNC }, 4018 { FFSYNC, KF_FLAG_FSYNC }, 4019 { FHASLOCK, KF_FLAG_HASLOCK }, 4020 { FNONBLOCK, KF_FLAG_NONBLOCK }, 4021 { FREAD, KF_FLAG_READ }, 4022 { FWRITE, KF_FLAG_WRITE }, 4023 { O_CREAT, KF_FLAG_CREAT }, 4024 { O_DIRECT, KF_FLAG_DIRECT }, 4025 { O_EXCL, KF_FLAG_EXCL }, 4026 { O_EXEC, KF_FLAG_EXEC }, 4027 { O_EXLOCK, KF_FLAG_EXLOCK }, 4028 { O_NOFOLLOW, KF_FLAG_NOFOLLOW }, 4029 { O_SHLOCK, KF_FLAG_SHLOCK }, 4030 { O_TRUNC, KF_FLAG_TRUNC } 4031 }; 4032 unsigned int i; 4033 int kflags; 4034 4035 kflags = 0; 4036 for (i = 0; i < nitems(fflags_table); i++) 4037 if (fflags & fflags_table[i].fflag) 4038 kflags |= fflags_table[i].kf_fflag; 4039 return (kflags); 4040 } 4041 4042 /* Trim unused data from kf_path by truncating the structure size. */ 4043 void 4044 pack_kinfo(struct kinfo_file *kif) 4045 { 4046 4047 kif->kf_structsize = offsetof(struct kinfo_file, kf_path) + 4048 strlen(kif->kf_path) + 1; 4049 kif->kf_structsize = roundup(kif->kf_structsize, sizeof(uint64_t)); 4050 } 4051 4052 static void 4053 export_file_to_kinfo(struct file *fp, int fd, cap_rights_t *rightsp, 4054 struct kinfo_file *kif, struct filedesc *fdp, int flags) 4055 { 4056 int error; 4057 4058 bzero(kif, sizeof(*kif)); 4059 4060 /* Set a default type to allow for empty fill_kinfo() methods. */ 4061 kif->kf_type = KF_TYPE_UNKNOWN; 4062 kif->kf_flags = xlate_fflags(fp->f_flag); 4063 if (rightsp != NULL) 4064 kif->kf_cap_rights = *rightsp; 4065 else 4066 cap_rights_init_zero(&kif->kf_cap_rights); 4067 kif->kf_fd = fd; 4068 kif->kf_ref_count = refcount_load(&fp->f_count); 4069 kif->kf_offset = foffset_get(fp); 4070 4071 /* 4072 * This may drop the filedesc lock, so the 'fp' cannot be 4073 * accessed after this call. 4074 */ 4075 error = fo_fill_kinfo(fp, kif, fdp); 4076 if (error == 0) 4077 kif->kf_status |= KF_ATTR_VALID; 4078 if ((flags & KERN_FILEDESC_PACK_KINFO) != 0) 4079 pack_kinfo(kif); 4080 else 4081 kif->kf_structsize = roundup2(sizeof(*kif), sizeof(uint64_t)); 4082 } 4083 4084 static void 4085 export_vnode_to_kinfo(struct vnode *vp, int fd, int fflags, 4086 struct kinfo_file *kif, int flags) 4087 { 4088 int error; 4089 4090 bzero(kif, sizeof(*kif)); 4091 4092 kif->kf_type = KF_TYPE_VNODE; 4093 error = vn_fill_kinfo_vnode(vp, kif); 4094 if (error == 0) 4095 kif->kf_status |= KF_ATTR_VALID; 4096 kif->kf_flags = xlate_fflags(fflags); 4097 cap_rights_init_zero(&kif->kf_cap_rights); 4098 kif->kf_fd = fd; 4099 kif->kf_ref_count = -1; 4100 kif->kf_offset = -1; 4101 if ((flags & KERN_FILEDESC_PACK_KINFO) != 0) 4102 pack_kinfo(kif); 4103 else 4104 kif->kf_structsize = roundup2(sizeof(*kif), sizeof(uint64_t)); 4105 vrele(vp); 4106 } 4107 4108 struct export_fd_buf { 4109 struct filedesc *fdp; 4110 struct pwddesc *pdp; 4111 struct sbuf *sb; 4112 ssize_t remainder; 4113 struct kinfo_file kif; 4114 int flags; 4115 }; 4116 4117 static int 4118 export_kinfo_to_sb(struct export_fd_buf *efbuf) 4119 { 4120 struct kinfo_file *kif; 4121 4122 kif = &efbuf->kif; 4123 if (efbuf->remainder != -1) { 4124 if (efbuf->remainder < kif->kf_structsize) { 4125 /* Terminate export. */ 4126 efbuf->remainder = 0; 4127 return (0); 4128 } 4129 efbuf->remainder -= kif->kf_structsize; 4130 } 4131 return (sbuf_bcat(efbuf->sb, kif, kif->kf_structsize) == 0 ? 0 : ENOMEM); 4132 } 4133 4134 static int 4135 export_file_to_sb(struct file *fp, int fd, cap_rights_t *rightsp, 4136 struct export_fd_buf *efbuf) 4137 { 4138 int error; 4139 4140 if (efbuf->remainder == 0) 4141 return (0); 4142 export_file_to_kinfo(fp, fd, rightsp, &efbuf->kif, efbuf->fdp, 4143 efbuf->flags); 4144 FILEDESC_SUNLOCK(efbuf->fdp); 4145 error = export_kinfo_to_sb(efbuf); 4146 FILEDESC_SLOCK(efbuf->fdp); 4147 return (error); 4148 } 4149 4150 static int 4151 export_vnode_to_sb(struct vnode *vp, int fd, int fflags, 4152 struct export_fd_buf *efbuf) 4153 { 4154 int error; 4155 4156 if (efbuf->remainder == 0) 4157 return (0); 4158 if (efbuf->pdp != NULL) 4159 PWDDESC_XUNLOCK(efbuf->pdp); 4160 export_vnode_to_kinfo(vp, fd, fflags, &efbuf->kif, efbuf->flags); 4161 error = export_kinfo_to_sb(efbuf); 4162 if (efbuf->pdp != NULL) 4163 PWDDESC_XLOCK(efbuf->pdp); 4164 return (error); 4165 } 4166 4167 /* 4168 * Store a process file descriptor information to sbuf. 4169 * 4170 * Takes a locked proc as argument, and returns with the proc unlocked. 4171 */ 4172 int 4173 kern_proc_filedesc_out(struct proc *p, struct sbuf *sb, ssize_t maxlen, 4174 int flags) 4175 { 4176 struct file *fp; 4177 struct filedesc *fdp; 4178 struct pwddesc *pdp; 4179 struct export_fd_buf *efbuf; 4180 struct vnode *cttyvp, *textvp, *tracevp; 4181 struct pwd *pwd; 4182 int error, i, lastfile; 4183 cap_rights_t rights; 4184 4185 PROC_LOCK_ASSERT(p, MA_OWNED); 4186 4187 /* ktrace vnode */ 4188 tracevp = p->p_tracevp; 4189 if (tracevp != NULL) 4190 vrefact(tracevp); 4191 /* text vnode */ 4192 textvp = p->p_textvp; 4193 if (textvp != NULL) 4194 vrefact(textvp); 4195 /* Controlling tty. */ 4196 cttyvp = NULL; 4197 if (p->p_pgrp != NULL && p->p_pgrp->pg_session != NULL) { 4198 cttyvp = p->p_pgrp->pg_session->s_ttyvp; 4199 if (cttyvp != NULL) 4200 vrefact(cttyvp); 4201 } 4202 fdp = fdhold(p); 4203 pdp = pdhold(p); 4204 PROC_UNLOCK(p); 4205 efbuf = malloc(sizeof(*efbuf), M_TEMP, M_WAITOK); 4206 efbuf->fdp = NULL; 4207 efbuf->pdp = NULL; 4208 efbuf->sb = sb; 4209 efbuf->remainder = maxlen; 4210 efbuf->flags = flags; 4211 if (tracevp != NULL) 4212 export_vnode_to_sb(tracevp, KF_FD_TYPE_TRACE, FREAD | FWRITE, 4213 efbuf); 4214 if (textvp != NULL) 4215 export_vnode_to_sb(textvp, KF_FD_TYPE_TEXT, FREAD, efbuf); 4216 if (cttyvp != NULL) 4217 export_vnode_to_sb(cttyvp, KF_FD_TYPE_CTTY, FREAD | FWRITE, 4218 efbuf); 4219 error = 0; 4220 if (pdp == NULL || fdp == NULL) 4221 goto fail; 4222 efbuf->fdp = fdp; 4223 efbuf->pdp = pdp; 4224 PWDDESC_XLOCK(pdp); 4225 pwd = pwd_hold_pwddesc(pdp); 4226 if (pwd != NULL) { 4227 /* working directory */ 4228 if (pwd->pwd_cdir != NULL) { 4229 vrefact(pwd->pwd_cdir); 4230 export_vnode_to_sb(pwd->pwd_cdir, KF_FD_TYPE_CWD, FREAD, efbuf); 4231 } 4232 /* root directory */ 4233 if (pwd->pwd_rdir != NULL) { 4234 vrefact(pwd->pwd_rdir); 4235 export_vnode_to_sb(pwd->pwd_rdir, KF_FD_TYPE_ROOT, FREAD, efbuf); 4236 } 4237 /* jail directory */ 4238 if (pwd->pwd_jdir != NULL) { 4239 vrefact(pwd->pwd_jdir); 4240 export_vnode_to_sb(pwd->pwd_jdir, KF_FD_TYPE_JAIL, FREAD, efbuf); 4241 } 4242 } 4243 PWDDESC_XUNLOCK(pdp); 4244 if (pwd != NULL) 4245 pwd_drop(pwd); 4246 FILEDESC_SLOCK(fdp); 4247 lastfile = fdlastfile(fdp); 4248 for (i = 0; fdp->fd_refcnt > 0 && i <= lastfile; i++) { 4249 if ((fp = fdp->fd_ofiles[i].fde_file) == NULL) 4250 continue; 4251 #ifdef CAPABILITIES 4252 rights = *cap_rights(fdp, i); 4253 #else /* !CAPABILITIES */ 4254 rights = cap_no_rights; 4255 #endif 4256 /* 4257 * Create sysctl entry. It is OK to drop the filedesc 4258 * lock inside of export_file_to_sb() as we will 4259 * re-validate and re-evaluate its properties when the 4260 * loop continues. 4261 */ 4262 error = export_file_to_sb(fp, i, &rights, efbuf); 4263 if (error != 0 || efbuf->remainder == 0) 4264 break; 4265 } 4266 FILEDESC_SUNLOCK(fdp); 4267 fail: 4268 if (fdp != NULL) 4269 fddrop(fdp); 4270 if (pdp != NULL) 4271 pddrop(pdp); 4272 free(efbuf, M_TEMP); 4273 return (error); 4274 } 4275 4276 #define FILEDESC_SBUF_SIZE (sizeof(struct kinfo_file) * 5) 4277 4278 /* 4279 * Get per-process file descriptors for use by procstat(1), et al. 4280 */ 4281 static int 4282 sysctl_kern_proc_filedesc(SYSCTL_HANDLER_ARGS) 4283 { 4284 struct sbuf sb; 4285 struct proc *p; 4286 ssize_t maxlen; 4287 int error, error2, *name; 4288 4289 name = (int *)arg1; 4290 4291 sbuf_new_for_sysctl(&sb, NULL, FILEDESC_SBUF_SIZE, req); 4292 sbuf_clear_flags(&sb, SBUF_INCLUDENUL); 4293 error = pget((pid_t)name[0], PGET_CANDEBUG | PGET_NOTWEXIT, &p); 4294 if (error != 0) { 4295 sbuf_delete(&sb); 4296 return (error); 4297 } 4298 maxlen = req->oldptr != NULL ? req->oldlen : -1; 4299 error = kern_proc_filedesc_out(p, &sb, maxlen, 4300 KERN_FILEDESC_PACK_KINFO); 4301 error2 = sbuf_finish(&sb); 4302 sbuf_delete(&sb); 4303 return (error != 0 ? error : error2); 4304 } 4305 4306 #ifdef COMPAT_FREEBSD7 4307 #ifdef KINFO_OFILE_SIZE 4308 CTASSERT(sizeof(struct kinfo_ofile) == KINFO_OFILE_SIZE); 4309 #endif 4310 4311 static void 4312 kinfo_to_okinfo(struct kinfo_file *kif, struct kinfo_ofile *okif) 4313 { 4314 4315 okif->kf_structsize = sizeof(*okif); 4316 okif->kf_type = kif->kf_type; 4317 okif->kf_fd = kif->kf_fd; 4318 okif->kf_ref_count = kif->kf_ref_count; 4319 okif->kf_flags = kif->kf_flags & (KF_FLAG_READ | KF_FLAG_WRITE | 4320 KF_FLAG_APPEND | KF_FLAG_ASYNC | KF_FLAG_FSYNC | KF_FLAG_NONBLOCK | 4321 KF_FLAG_DIRECT | KF_FLAG_HASLOCK); 4322 okif->kf_offset = kif->kf_offset; 4323 if (kif->kf_type == KF_TYPE_VNODE) 4324 okif->kf_vnode_type = kif->kf_un.kf_file.kf_file_type; 4325 else 4326 okif->kf_vnode_type = KF_VTYPE_VNON; 4327 strlcpy(okif->kf_path, kif->kf_path, sizeof(okif->kf_path)); 4328 if (kif->kf_type == KF_TYPE_SOCKET) { 4329 okif->kf_sock_domain = kif->kf_un.kf_sock.kf_sock_domain0; 4330 okif->kf_sock_type = kif->kf_un.kf_sock.kf_sock_type0; 4331 okif->kf_sock_protocol = kif->kf_un.kf_sock.kf_sock_protocol0; 4332 okif->kf_sa_local = kif->kf_un.kf_sock.kf_sa_local; 4333 okif->kf_sa_peer = kif->kf_un.kf_sock.kf_sa_peer; 4334 } else { 4335 okif->kf_sa_local.ss_family = AF_UNSPEC; 4336 okif->kf_sa_peer.ss_family = AF_UNSPEC; 4337 } 4338 } 4339 4340 static int 4341 export_vnode_for_osysctl(struct vnode *vp, int type, struct kinfo_file *kif, 4342 struct kinfo_ofile *okif, struct pwddesc *pdp, struct sysctl_req *req) 4343 { 4344 int error; 4345 4346 vrefact(vp); 4347 PWDDESC_XUNLOCK(pdp); 4348 export_vnode_to_kinfo(vp, type, 0, kif, KERN_FILEDESC_PACK_KINFO); 4349 kinfo_to_okinfo(kif, okif); 4350 error = SYSCTL_OUT(req, okif, sizeof(*okif)); 4351 PWDDESC_XLOCK(pdp); 4352 return (error); 4353 } 4354 4355 /* 4356 * Get per-process file descriptors for use by procstat(1), et al. 4357 */ 4358 static int 4359 sysctl_kern_proc_ofiledesc(SYSCTL_HANDLER_ARGS) 4360 { 4361 struct kinfo_ofile *okif; 4362 struct kinfo_file *kif; 4363 struct filedesc *fdp; 4364 struct pwddesc *pdp; 4365 struct pwd *pwd; 4366 int error, i, lastfile, *name; 4367 struct file *fp; 4368 struct proc *p; 4369 4370 name = (int *)arg1; 4371 error = pget((pid_t)name[0], PGET_CANDEBUG | PGET_NOTWEXIT, &p); 4372 if (error != 0) 4373 return (error); 4374 fdp = fdhold(p); 4375 if (fdp != NULL) 4376 pdp = pdhold(p); 4377 PROC_UNLOCK(p); 4378 if (fdp == NULL || pdp == NULL) { 4379 if (fdp != NULL) 4380 fddrop(fdp); 4381 return (ENOENT); 4382 } 4383 kif = malloc(sizeof(*kif), M_TEMP, M_WAITOK); 4384 okif = malloc(sizeof(*okif), M_TEMP, M_WAITOK); 4385 PWDDESC_XLOCK(pdp); 4386 pwd = pwd_hold_pwddesc(pdp); 4387 if (pwd != NULL) { 4388 if (pwd->pwd_cdir != NULL) 4389 export_vnode_for_osysctl(pwd->pwd_cdir, KF_FD_TYPE_CWD, kif, 4390 okif, pdp, req); 4391 if (pwd->pwd_rdir != NULL) 4392 export_vnode_for_osysctl(pwd->pwd_rdir, KF_FD_TYPE_ROOT, kif, 4393 okif, pdp, req); 4394 if (pwd->pwd_jdir != NULL) 4395 export_vnode_for_osysctl(pwd->pwd_jdir, KF_FD_TYPE_JAIL, kif, 4396 okif, pdp, req); 4397 } 4398 PWDDESC_XUNLOCK(pdp); 4399 if (pwd != NULL) 4400 pwd_drop(pwd); 4401 FILEDESC_SLOCK(fdp); 4402 lastfile = fdlastfile(fdp); 4403 for (i = 0; fdp->fd_refcnt > 0 && i <= lastfile; i++) { 4404 if ((fp = fdp->fd_ofiles[i].fde_file) == NULL) 4405 continue; 4406 export_file_to_kinfo(fp, i, NULL, kif, fdp, 4407 KERN_FILEDESC_PACK_KINFO); 4408 FILEDESC_SUNLOCK(fdp); 4409 kinfo_to_okinfo(kif, okif); 4410 error = SYSCTL_OUT(req, okif, sizeof(*okif)); 4411 FILEDESC_SLOCK(fdp); 4412 if (error) 4413 break; 4414 } 4415 FILEDESC_SUNLOCK(fdp); 4416 fddrop(fdp); 4417 pddrop(pdp); 4418 free(kif, M_TEMP); 4419 free(okif, M_TEMP); 4420 return (0); 4421 } 4422 4423 static SYSCTL_NODE(_kern_proc, KERN_PROC_OFILEDESC, ofiledesc, 4424 CTLFLAG_RD|CTLFLAG_MPSAFE, sysctl_kern_proc_ofiledesc, 4425 "Process ofiledesc entries"); 4426 #endif /* COMPAT_FREEBSD7 */ 4427 4428 int 4429 vntype_to_kinfo(int vtype) 4430 { 4431 struct { 4432 int vtype; 4433 int kf_vtype; 4434 } vtypes_table[] = { 4435 { VBAD, KF_VTYPE_VBAD }, 4436 { VBLK, KF_VTYPE_VBLK }, 4437 { VCHR, KF_VTYPE_VCHR }, 4438 { VDIR, KF_VTYPE_VDIR }, 4439 { VFIFO, KF_VTYPE_VFIFO }, 4440 { VLNK, KF_VTYPE_VLNK }, 4441 { VNON, KF_VTYPE_VNON }, 4442 { VREG, KF_VTYPE_VREG }, 4443 { VSOCK, KF_VTYPE_VSOCK } 4444 }; 4445 unsigned int i; 4446 4447 /* 4448 * Perform vtype translation. 4449 */ 4450 for (i = 0; i < nitems(vtypes_table); i++) 4451 if (vtypes_table[i].vtype == vtype) 4452 return (vtypes_table[i].kf_vtype); 4453 4454 return (KF_VTYPE_UNKNOWN); 4455 } 4456 4457 static SYSCTL_NODE(_kern_proc, KERN_PROC_FILEDESC, filedesc, 4458 CTLFLAG_RD|CTLFLAG_MPSAFE, sysctl_kern_proc_filedesc, 4459 "Process filedesc entries"); 4460 4461 /* 4462 * Store a process current working directory information to sbuf. 4463 * 4464 * Takes a locked proc as argument, and returns with the proc unlocked. 4465 */ 4466 int 4467 kern_proc_cwd_out(struct proc *p, struct sbuf *sb, ssize_t maxlen) 4468 { 4469 struct pwddesc *pdp; 4470 struct pwd *pwd; 4471 struct export_fd_buf *efbuf; 4472 struct vnode *cdir; 4473 int error; 4474 4475 PROC_LOCK_ASSERT(p, MA_OWNED); 4476 4477 pdp = pdhold(p); 4478 PROC_UNLOCK(p); 4479 if (pdp == NULL) 4480 return (EINVAL); 4481 4482 efbuf = malloc(sizeof(*efbuf), M_TEMP, M_WAITOK); 4483 efbuf->pdp = pdp; 4484 efbuf->sb = sb; 4485 efbuf->remainder = maxlen; 4486 4487 PWDDESC_XLOCK(pdp); 4488 pwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); 4489 cdir = pwd->pwd_cdir; 4490 if (cdir == NULL) { 4491 error = EINVAL; 4492 } else { 4493 vrefact(cdir); 4494 error = export_vnode_to_sb(cdir, KF_FD_TYPE_CWD, FREAD, efbuf); 4495 } 4496 PWDDESC_XUNLOCK(pdp); 4497 pddrop(pdp); 4498 free(efbuf, M_TEMP); 4499 return (error); 4500 } 4501 4502 /* 4503 * Get per-process current working directory. 4504 */ 4505 static int 4506 sysctl_kern_proc_cwd(SYSCTL_HANDLER_ARGS) 4507 { 4508 struct sbuf sb; 4509 struct proc *p; 4510 ssize_t maxlen; 4511 int error, error2, *name; 4512 4513 name = (int *)arg1; 4514 4515 sbuf_new_for_sysctl(&sb, NULL, sizeof(struct kinfo_file), req); 4516 sbuf_clear_flags(&sb, SBUF_INCLUDENUL); 4517 error = pget((pid_t)name[0], PGET_CANDEBUG | PGET_NOTWEXIT, &p); 4518 if (error != 0) { 4519 sbuf_delete(&sb); 4520 return (error); 4521 } 4522 maxlen = req->oldptr != NULL ? req->oldlen : -1; 4523 error = kern_proc_cwd_out(p, &sb, maxlen); 4524 error2 = sbuf_finish(&sb); 4525 sbuf_delete(&sb); 4526 return (error != 0 ? error : error2); 4527 } 4528 4529 static SYSCTL_NODE(_kern_proc, KERN_PROC_CWD, cwd, CTLFLAG_RD|CTLFLAG_MPSAFE, 4530 sysctl_kern_proc_cwd, "Process current working directory"); 4531 4532 #ifdef DDB 4533 /* 4534 * For the purposes of debugging, generate a human-readable string for the 4535 * file type. 4536 */ 4537 static const char * 4538 file_type_to_name(short type) 4539 { 4540 4541 switch (type) { 4542 case 0: 4543 return ("zero"); 4544 case DTYPE_VNODE: 4545 return ("vnode"); 4546 case DTYPE_SOCKET: 4547 return ("socket"); 4548 case DTYPE_PIPE: 4549 return ("pipe"); 4550 case DTYPE_FIFO: 4551 return ("fifo"); 4552 case DTYPE_KQUEUE: 4553 return ("kqueue"); 4554 case DTYPE_CRYPTO: 4555 return ("crypto"); 4556 case DTYPE_MQUEUE: 4557 return ("mqueue"); 4558 case DTYPE_SHM: 4559 return ("shm"); 4560 case DTYPE_SEM: 4561 return ("ksem"); 4562 case DTYPE_PTS: 4563 return ("pts"); 4564 case DTYPE_DEV: 4565 return ("dev"); 4566 case DTYPE_PROCDESC: 4567 return ("proc"); 4568 case DTYPE_LINUXEFD: 4569 return ("levent"); 4570 case DTYPE_LINUXTFD: 4571 return ("ltimer"); 4572 default: 4573 return ("unkn"); 4574 } 4575 } 4576 4577 /* 4578 * For the purposes of debugging, identify a process (if any, perhaps one of 4579 * many) that references the passed file in its file descriptor array. Return 4580 * NULL if none. 4581 */ 4582 static struct proc * 4583 file_to_first_proc(struct file *fp) 4584 { 4585 struct filedesc *fdp; 4586 struct proc *p; 4587 int n; 4588 4589 FOREACH_PROC_IN_SYSTEM(p) { 4590 if (p->p_state == PRS_NEW) 4591 continue; 4592 fdp = p->p_fd; 4593 if (fdp == NULL) 4594 continue; 4595 for (n = 0; n < fdp->fd_nfiles; n++) { 4596 if (fp == fdp->fd_ofiles[n].fde_file) 4597 return (p); 4598 } 4599 } 4600 return (NULL); 4601 } 4602 4603 static void 4604 db_print_file(struct file *fp, int header) 4605 { 4606 #define XPTRWIDTH ((int)howmany(sizeof(void *) * NBBY, 4)) 4607 struct proc *p; 4608 4609 if (header) 4610 db_printf("%*s %6s %*s %8s %4s %5s %6s %*s %5s %s\n", 4611 XPTRWIDTH, "File", "Type", XPTRWIDTH, "Data", "Flag", 4612 "GCFl", "Count", "MCount", XPTRWIDTH, "Vnode", "FPID", 4613 "FCmd"); 4614 p = file_to_first_proc(fp); 4615 db_printf("%*p %6s %*p %08x %04x %5d %6d %*p %5d %s\n", XPTRWIDTH, 4616 fp, file_type_to_name(fp->f_type), XPTRWIDTH, fp->f_data, 4617 fp->f_flag, 0, refcount_load(&fp->f_count), 0, XPTRWIDTH, fp->f_vnode, 4618 p != NULL ? p->p_pid : -1, p != NULL ? p->p_comm : "-"); 4619 4620 #undef XPTRWIDTH 4621 } 4622 4623 DB_SHOW_COMMAND(file, db_show_file) 4624 { 4625 struct file *fp; 4626 4627 if (!have_addr) { 4628 db_printf("usage: show file <addr>\n"); 4629 return; 4630 } 4631 fp = (struct file *)addr; 4632 db_print_file(fp, 1); 4633 } 4634 4635 DB_SHOW_COMMAND(files, db_show_files) 4636 { 4637 struct filedesc *fdp; 4638 struct file *fp; 4639 struct proc *p; 4640 int header; 4641 int n; 4642 4643 header = 1; 4644 FOREACH_PROC_IN_SYSTEM(p) { 4645 if (p->p_state == PRS_NEW) 4646 continue; 4647 if ((fdp = p->p_fd) == NULL) 4648 continue; 4649 for (n = 0; n < fdp->fd_nfiles; ++n) { 4650 if ((fp = fdp->fd_ofiles[n].fde_file) == NULL) 4651 continue; 4652 db_print_file(fp, header); 4653 header = 0; 4654 } 4655 } 4656 } 4657 #endif 4658 4659 SYSCTL_INT(_kern, KERN_MAXFILESPERPROC, maxfilesperproc, CTLFLAG_RW, 4660 &maxfilesperproc, 0, "Maximum files allowed open per process"); 4661 4662 SYSCTL_INT(_kern, KERN_MAXFILES, maxfiles, CTLFLAG_RW, 4663 &maxfiles, 0, "Maximum number of files"); 4664 4665 SYSCTL_INT(_kern, OID_AUTO, openfiles, CTLFLAG_RD, 4666 &openfiles, 0, "System-wide number of open files"); 4667 4668 /* ARGSUSED*/ 4669 static void 4670 filelistinit(void *dummy) 4671 { 4672 4673 file_zone = uma_zcreate("Files", sizeof(struct file), NULL, NULL, 4674 NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE); 4675 filedesc0_zone = uma_zcreate("filedesc0", sizeof(struct filedesc0), 4676 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0); 4677 pwd_zone = uma_zcreate("PWD", sizeof(struct pwd), NULL, NULL, 4678 NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_SMR); 4679 /* 4680 * XXXMJG this is a temporary hack due to boot ordering issues against 4681 * the vnode zone. 4682 */ 4683 vfs_smr = uma_zone_get_smr(pwd_zone); 4684 mtx_init(&sigio_lock, "sigio lock", NULL, MTX_DEF); 4685 } 4686 SYSINIT(select, SI_SUB_LOCK, SI_ORDER_FIRST, filelistinit, NULL); 4687 4688 /*-------------------------------------------------------------------*/ 4689 4690 static int 4691 badfo_readwrite(struct file *fp, struct uio *uio, struct ucred *active_cred, 4692 int flags, struct thread *td) 4693 { 4694 4695 return (EBADF); 4696 } 4697 4698 static int 4699 badfo_truncate(struct file *fp, off_t length, struct ucred *active_cred, 4700 struct thread *td) 4701 { 4702 4703 return (EINVAL); 4704 } 4705 4706 static int 4707 badfo_ioctl(struct file *fp, u_long com, void *data, struct ucred *active_cred, 4708 struct thread *td) 4709 { 4710 4711 return (EBADF); 4712 } 4713 4714 static int 4715 badfo_poll(struct file *fp, int events, struct ucred *active_cred, 4716 struct thread *td) 4717 { 4718 4719 return (0); 4720 } 4721 4722 static int 4723 badfo_kqfilter(struct file *fp, struct knote *kn) 4724 { 4725 4726 return (EBADF); 4727 } 4728 4729 static int 4730 badfo_stat(struct file *fp, struct stat *sb, struct ucred *active_cred, 4731 struct thread *td) 4732 { 4733 4734 return (EBADF); 4735 } 4736 4737 static int 4738 badfo_close(struct file *fp, struct thread *td) 4739 { 4740 4741 return (0); 4742 } 4743 4744 static int 4745 badfo_chmod(struct file *fp, mode_t mode, struct ucred *active_cred, 4746 struct thread *td) 4747 { 4748 4749 return (EBADF); 4750 } 4751 4752 static int 4753 badfo_chown(struct file *fp, uid_t uid, gid_t gid, struct ucred *active_cred, 4754 struct thread *td) 4755 { 4756 4757 return (EBADF); 4758 } 4759 4760 static int 4761 badfo_sendfile(struct file *fp, int sockfd, struct uio *hdr_uio, 4762 struct uio *trl_uio, off_t offset, size_t nbytes, off_t *sent, int flags, 4763 struct thread *td) 4764 { 4765 4766 return (EBADF); 4767 } 4768 4769 static int 4770 badfo_fill_kinfo(struct file *fp, struct kinfo_file *kif, struct filedesc *fdp) 4771 { 4772 4773 return (0); 4774 } 4775 4776 struct fileops badfileops = { 4777 .fo_read = badfo_readwrite, 4778 .fo_write = badfo_readwrite, 4779 .fo_truncate = badfo_truncate, 4780 .fo_ioctl = badfo_ioctl, 4781 .fo_poll = badfo_poll, 4782 .fo_kqfilter = badfo_kqfilter, 4783 .fo_stat = badfo_stat, 4784 .fo_close = badfo_close, 4785 .fo_chmod = badfo_chmod, 4786 .fo_chown = badfo_chown, 4787 .fo_sendfile = badfo_sendfile, 4788 .fo_fill_kinfo = badfo_fill_kinfo, 4789 }; 4790 4791 int 4792 invfo_rdwr(struct file *fp, struct uio *uio, struct ucred *active_cred, 4793 int flags, struct thread *td) 4794 { 4795 4796 return (EOPNOTSUPP); 4797 } 4798 4799 int 4800 invfo_truncate(struct file *fp, off_t length, struct ucred *active_cred, 4801 struct thread *td) 4802 { 4803 4804 return (EINVAL); 4805 } 4806 4807 int 4808 invfo_ioctl(struct file *fp, u_long com, void *data, 4809 struct ucred *active_cred, struct thread *td) 4810 { 4811 4812 return (ENOTTY); 4813 } 4814 4815 int 4816 invfo_poll(struct file *fp, int events, struct ucred *active_cred, 4817 struct thread *td) 4818 { 4819 4820 return (poll_no_poll(events)); 4821 } 4822 4823 int 4824 invfo_kqfilter(struct file *fp, struct knote *kn) 4825 { 4826 4827 return (EINVAL); 4828 } 4829 4830 int 4831 invfo_chmod(struct file *fp, mode_t mode, struct ucred *active_cred, 4832 struct thread *td) 4833 { 4834 4835 return (EINVAL); 4836 } 4837 4838 int 4839 invfo_chown(struct file *fp, uid_t uid, gid_t gid, struct ucred *active_cred, 4840 struct thread *td) 4841 { 4842 4843 return (EINVAL); 4844 } 4845 4846 int 4847 invfo_sendfile(struct file *fp, int sockfd, struct uio *hdr_uio, 4848 struct uio *trl_uio, off_t offset, size_t nbytes, off_t *sent, int flags, 4849 struct thread *td) 4850 { 4851 4852 return (EINVAL); 4853 } 4854 4855 /*-------------------------------------------------------------------*/ 4856 4857 /* 4858 * File Descriptor pseudo-device driver (/dev/fd/). 4859 * 4860 * Opening minor device N dup()s the file (if any) connected to file 4861 * descriptor N belonging to the calling process. Note that this driver 4862 * consists of only the ``open()'' routine, because all subsequent 4863 * references to this file will be direct to the other driver. 4864 * 4865 * XXX: we could give this one a cloning event handler if necessary. 4866 */ 4867 4868 /* ARGSUSED */ 4869 static int 4870 fdopen(struct cdev *dev, int mode, int type, struct thread *td) 4871 { 4872 4873 /* 4874 * XXX Kludge: set curthread->td_dupfd to contain the value of the 4875 * the file descriptor being sought for duplication. The error 4876 * return ensures that the vnode for this device will be released 4877 * by vn_open. Open will detect this special error and take the 4878 * actions in dupfdopen below. Other callers of vn_open or VOP_OPEN 4879 * will simply report the error. 4880 */ 4881 td->td_dupfd = dev2unit(dev); 4882 return (ENODEV); 4883 } 4884 4885 static struct cdevsw fildesc_cdevsw = { 4886 .d_version = D_VERSION, 4887 .d_open = fdopen, 4888 .d_name = "FD", 4889 }; 4890 4891 static void 4892 fildesc_drvinit(void *unused) 4893 { 4894 struct cdev *dev; 4895 4896 dev = make_dev_credf(MAKEDEV_ETERNAL, &fildesc_cdevsw, 0, NULL, 4897 UID_ROOT, GID_WHEEL, 0666, "fd/0"); 4898 make_dev_alias(dev, "stdin"); 4899 dev = make_dev_credf(MAKEDEV_ETERNAL, &fildesc_cdevsw, 1, NULL, 4900 UID_ROOT, GID_WHEEL, 0666, "fd/1"); 4901 make_dev_alias(dev, "stdout"); 4902 dev = make_dev_credf(MAKEDEV_ETERNAL, &fildesc_cdevsw, 2, NULL, 4903 UID_ROOT, GID_WHEEL, 0666, "fd/2"); 4904 make_dev_alias(dev, "stderr"); 4905 } 4906 4907 SYSINIT(fildescdev, SI_SUB_DRIVERS, SI_ORDER_MIDDLE, fildesc_drvinit, NULL); 4908