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; 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 if (!fhold(oldfde->fde_file)) 914 goto unlock; 915 916 /* 917 * If the caller specified a file descriptor, make sure the file 918 * table is large enough to hold it, and grab it. Otherwise, just 919 * allocate a new descriptor the usual way. 920 */ 921 switch (mode) { 922 case FDDUP_NORMAL: 923 case FDDUP_FCNTL: 924 if ((error = fdalloc(td, new, &new)) != 0) { 925 fdrop(oldfde->fde_file, td); 926 goto unlock; 927 } 928 break; 929 case FDDUP_MUSTREPLACE: 930 /* Target file descriptor must exist. */ 931 if (fget_locked(fdp, new) == NULL) { 932 fdrop(oldfde->fde_file, td); 933 goto unlock; 934 } 935 break; 936 case FDDUP_FIXED: 937 if (new >= fdp->fd_nfiles) { 938 /* 939 * The resource limits are here instead of e.g. 940 * fdalloc(), because the file descriptor table may be 941 * shared between processes, so we can't really use 942 * racct_add()/racct_sub(). Instead of counting the 943 * number of actually allocated descriptors, just put 944 * the limit on the size of the file descriptor table. 945 */ 946 #ifdef RACCT 947 if (RACCT_ENABLED()) { 948 error = racct_set_unlocked(p, RACCT_NOFILE, new + 1); 949 if (error != 0) { 950 error = EMFILE; 951 fdrop(oldfde->fde_file, td); 952 goto unlock; 953 } 954 } 955 #endif 956 fdgrowtable_exp(fdp, new + 1); 957 } 958 if (!fdisused(fdp, new)) 959 fdused(fdp, new); 960 break; 961 default: 962 KASSERT(0, ("%s unsupported mode %d", __func__, mode)); 963 } 964 965 KASSERT(old != new, ("new fd is same as old")); 966 967 newfde = &fdp->fd_ofiles[new]; 968 delfp = newfde->fde_file; 969 970 nioctls = filecaps_copy_prep(&oldfde->fde_caps); 971 972 /* 973 * Duplicate the source descriptor. 974 */ 975 #ifdef CAPABILITIES 976 seqc_write_begin(&newfde->fde_seqc); 977 #endif 978 oioctls = filecaps_free_prep(&newfde->fde_caps); 979 memcpy(newfde, oldfde, fde_change_size); 980 filecaps_copy_finish(&oldfde->fde_caps, &newfde->fde_caps, 981 nioctls); 982 if ((flags & FDDUP_FLAG_CLOEXEC) != 0) 983 newfde->fde_flags = oldfde->fde_flags | UF_EXCLOSE; 984 else 985 newfde->fde_flags = oldfde->fde_flags & ~UF_EXCLOSE; 986 #ifdef CAPABILITIES 987 seqc_write_end(&newfde->fde_seqc); 988 #endif 989 td->td_retval[0] = new; 990 991 error = 0; 992 993 if (delfp != NULL) { 994 (void) closefp(fdp, new, delfp, td, 1); 995 FILEDESC_UNLOCK_ASSERT(fdp); 996 } else { 997 unlock: 998 FILEDESC_XUNLOCK(fdp); 999 } 1000 1001 filecaps_free_finish(oioctls); 1002 return (error); 1003 } 1004 1005 static void 1006 sigiofree(struct sigio *sigio) 1007 { 1008 crfree(sigio->sio_ucred); 1009 free(sigio, M_SIGIO); 1010 } 1011 1012 static struct sigio * 1013 funsetown_locked(struct sigio *sigio) 1014 { 1015 struct proc *p; 1016 struct pgrp *pg; 1017 1018 SIGIO_ASSERT_LOCKED(); 1019 1020 if (sigio == NULL) 1021 return (NULL); 1022 *(sigio->sio_myref) = NULL; 1023 if (sigio->sio_pgid < 0) { 1024 pg = sigio->sio_pgrp; 1025 PGRP_LOCK(pg); 1026 SLIST_REMOVE(&sigio->sio_pgrp->pg_sigiolst, sigio, 1027 sigio, sio_pgsigio); 1028 PGRP_UNLOCK(pg); 1029 } else { 1030 p = sigio->sio_proc; 1031 PROC_LOCK(p); 1032 SLIST_REMOVE(&sigio->sio_proc->p_sigiolst, sigio, 1033 sigio, sio_pgsigio); 1034 PROC_UNLOCK(p); 1035 } 1036 return (sigio); 1037 } 1038 1039 /* 1040 * If sigio is on the list associated with a process or process group, 1041 * disable signalling from the device, remove sigio from the list and 1042 * free sigio. 1043 */ 1044 void 1045 funsetown(struct sigio **sigiop) 1046 { 1047 struct sigio *sigio; 1048 1049 /* Racy check, consumers must provide synchronization. */ 1050 if (*sigiop == NULL) 1051 return; 1052 1053 SIGIO_LOCK(); 1054 sigio = funsetown_locked(*sigiop); 1055 SIGIO_UNLOCK(); 1056 if (sigio != NULL) 1057 sigiofree(sigio); 1058 } 1059 1060 /* 1061 * Free a list of sigio structures. The caller must ensure that new sigio 1062 * structures cannot be added after this point. For process groups this is 1063 * guaranteed using the proctree lock; for processes, the P_WEXIT flag serves 1064 * as an interlock. 1065 */ 1066 void 1067 funsetownlst(struct sigiolst *sigiolst) 1068 { 1069 struct proc *p; 1070 struct pgrp *pg; 1071 struct sigio *sigio, *tmp; 1072 1073 /* Racy check. */ 1074 sigio = SLIST_FIRST(sigiolst); 1075 if (sigio == NULL) 1076 return; 1077 1078 p = NULL; 1079 pg = NULL; 1080 1081 SIGIO_LOCK(); 1082 sigio = SLIST_FIRST(sigiolst); 1083 if (sigio == NULL) { 1084 SIGIO_UNLOCK(); 1085 return; 1086 } 1087 1088 /* 1089 * Every entry of the list should belong to a single proc or pgrp. 1090 */ 1091 if (sigio->sio_pgid < 0) { 1092 pg = sigio->sio_pgrp; 1093 sx_assert(&proctree_lock, SX_XLOCKED); 1094 PGRP_LOCK(pg); 1095 } else /* if (sigio->sio_pgid > 0) */ { 1096 p = sigio->sio_proc; 1097 PROC_LOCK(p); 1098 KASSERT((p->p_flag & P_WEXIT) != 0, 1099 ("%s: process %p is not exiting", __func__, p)); 1100 } 1101 1102 SLIST_FOREACH(sigio, sigiolst, sio_pgsigio) { 1103 *sigio->sio_myref = NULL; 1104 if (pg != NULL) { 1105 KASSERT(sigio->sio_pgid < 0, 1106 ("Proc sigio in pgrp sigio list")); 1107 KASSERT(sigio->sio_pgrp == pg, 1108 ("Bogus pgrp in sigio list")); 1109 } else /* if (p != NULL) */ { 1110 KASSERT(sigio->sio_pgid > 0, 1111 ("Pgrp sigio in proc sigio list")); 1112 KASSERT(sigio->sio_proc == p, 1113 ("Bogus proc in sigio list")); 1114 } 1115 } 1116 1117 if (pg != NULL) 1118 PGRP_UNLOCK(pg); 1119 else 1120 PROC_UNLOCK(p); 1121 SIGIO_UNLOCK(); 1122 1123 SLIST_FOREACH_SAFE(sigio, sigiolst, sio_pgsigio, tmp) 1124 sigiofree(sigio); 1125 } 1126 1127 /* 1128 * This is common code for FIOSETOWN ioctl called by fcntl(fd, F_SETOWN, arg). 1129 * 1130 * After permission checking, add a sigio structure to the sigio list for 1131 * the process or process group. 1132 */ 1133 int 1134 fsetown(pid_t pgid, struct sigio **sigiop) 1135 { 1136 struct proc *proc; 1137 struct pgrp *pgrp; 1138 struct sigio *osigio, *sigio; 1139 int ret; 1140 1141 if (pgid == 0) { 1142 funsetown(sigiop); 1143 return (0); 1144 } 1145 1146 ret = 0; 1147 1148 sigio = malloc(sizeof(struct sigio), M_SIGIO, M_WAITOK); 1149 sigio->sio_pgid = pgid; 1150 sigio->sio_ucred = crhold(curthread->td_ucred); 1151 sigio->sio_myref = sigiop; 1152 1153 sx_slock(&proctree_lock); 1154 SIGIO_LOCK(); 1155 osigio = funsetown_locked(*sigiop); 1156 if (pgid > 0) { 1157 proc = pfind(pgid); 1158 if (proc == NULL) { 1159 ret = ESRCH; 1160 goto fail; 1161 } 1162 1163 /* 1164 * Policy - Don't allow a process to FSETOWN a process 1165 * in another session. 1166 * 1167 * Remove this test to allow maximum flexibility or 1168 * restrict FSETOWN to the current process or process 1169 * group for maximum safety. 1170 */ 1171 if (proc->p_session != curthread->td_proc->p_session) { 1172 PROC_UNLOCK(proc); 1173 ret = EPERM; 1174 goto fail; 1175 } 1176 1177 sigio->sio_proc = proc; 1178 SLIST_INSERT_HEAD(&proc->p_sigiolst, sigio, sio_pgsigio); 1179 PROC_UNLOCK(proc); 1180 } else /* if (pgid < 0) */ { 1181 pgrp = pgfind(-pgid); 1182 if (pgrp == NULL) { 1183 ret = ESRCH; 1184 goto fail; 1185 } 1186 1187 /* 1188 * Policy - Don't allow a process to FSETOWN a process 1189 * in another session. 1190 * 1191 * Remove this test to allow maximum flexibility or 1192 * restrict FSETOWN to the current process or process 1193 * group for maximum safety. 1194 */ 1195 if (pgrp->pg_session != curthread->td_proc->p_session) { 1196 PGRP_UNLOCK(pgrp); 1197 ret = EPERM; 1198 goto fail; 1199 } 1200 1201 SLIST_INSERT_HEAD(&pgrp->pg_sigiolst, sigio, sio_pgsigio); 1202 sigio->sio_pgrp = pgrp; 1203 PGRP_UNLOCK(pgrp); 1204 } 1205 sx_sunlock(&proctree_lock); 1206 *sigiop = sigio; 1207 SIGIO_UNLOCK(); 1208 if (osigio != NULL) 1209 sigiofree(osigio); 1210 return (0); 1211 1212 fail: 1213 SIGIO_UNLOCK(); 1214 sx_sunlock(&proctree_lock); 1215 sigiofree(sigio); 1216 if (osigio != NULL) 1217 sigiofree(osigio); 1218 return (ret); 1219 } 1220 1221 /* 1222 * This is common code for FIOGETOWN ioctl called by fcntl(fd, F_GETOWN, arg). 1223 */ 1224 pid_t 1225 fgetown(struct sigio **sigiop) 1226 { 1227 pid_t pgid; 1228 1229 SIGIO_LOCK(); 1230 pgid = (*sigiop != NULL) ? (*sigiop)->sio_pgid : 0; 1231 SIGIO_UNLOCK(); 1232 return (pgid); 1233 } 1234 1235 /* 1236 * Function drops the filedesc lock on return. 1237 */ 1238 static int 1239 closefp(struct filedesc *fdp, int fd, struct file *fp, struct thread *td, 1240 int holdleaders) 1241 { 1242 int error; 1243 1244 FILEDESC_XLOCK_ASSERT(fdp); 1245 1246 if (holdleaders) { 1247 if (td->td_proc->p_fdtol != NULL) { 1248 /* 1249 * Ask fdfree() to sleep to ensure that all relevant 1250 * process leaders can be traversed in closef(). 1251 */ 1252 fdp->fd_holdleaderscount++; 1253 } else { 1254 holdleaders = 0; 1255 } 1256 } 1257 1258 /* 1259 * We now hold the fp reference that used to be owned by the 1260 * descriptor array. We have to unlock the FILEDESC *AFTER* 1261 * knote_fdclose to prevent a race of the fd getting opened, a knote 1262 * added, and deleteing a knote for the new fd. 1263 */ 1264 if (__predict_false(!TAILQ_EMPTY(&fdp->fd_kqlist))) 1265 knote_fdclose(td, fd); 1266 1267 /* 1268 * We need to notify mqueue if the object is of type mqueue. 1269 */ 1270 if (__predict_false(fp->f_type == DTYPE_MQUEUE)) 1271 mq_fdclose(td, fd, fp); 1272 FILEDESC_XUNLOCK(fdp); 1273 1274 error = closef(fp, td); 1275 if (holdleaders) { 1276 FILEDESC_XLOCK(fdp); 1277 fdp->fd_holdleaderscount--; 1278 if (fdp->fd_holdleaderscount == 0 && 1279 fdp->fd_holdleaderswakeup != 0) { 1280 fdp->fd_holdleaderswakeup = 0; 1281 wakeup(&fdp->fd_holdleaderscount); 1282 } 1283 FILEDESC_XUNLOCK(fdp); 1284 } 1285 return (error); 1286 } 1287 1288 /* 1289 * Close a file descriptor. 1290 */ 1291 #ifndef _SYS_SYSPROTO_H_ 1292 struct close_args { 1293 int fd; 1294 }; 1295 #endif 1296 /* ARGSUSED */ 1297 int 1298 sys_close(struct thread *td, struct close_args *uap) 1299 { 1300 1301 return (kern_close(td, uap->fd)); 1302 } 1303 1304 int 1305 kern_close(struct thread *td, int fd) 1306 { 1307 struct filedesc *fdp; 1308 struct file *fp; 1309 1310 fdp = td->td_proc->p_fd; 1311 1312 AUDIT_SYSCLOSE(td, fd); 1313 1314 FILEDESC_XLOCK(fdp); 1315 if ((fp = fget_locked(fdp, fd)) == NULL) { 1316 FILEDESC_XUNLOCK(fdp); 1317 return (EBADF); 1318 } 1319 fdfree(fdp, fd); 1320 1321 /* closefp() drops the FILEDESC lock for us. */ 1322 return (closefp(fdp, fd, fp, td, 1)); 1323 } 1324 1325 int 1326 kern_close_range(struct thread *td, u_int lowfd, u_int highfd) 1327 { 1328 struct filedesc *fdp; 1329 int fd, ret, lastfile; 1330 1331 ret = 0; 1332 fdp = td->td_proc->p_fd; 1333 FILEDESC_SLOCK(fdp); 1334 1335 /* 1336 * Check this prior to clamping; closefrom(3) with only fd 0, 1, and 2 1337 * open should not be a usage error. From a close_range() perspective, 1338 * close_range(3, ~0U, 0) in the same scenario should also likely not 1339 * be a usage error as all fd above 3 are in-fact already closed. 1340 */ 1341 if (highfd < lowfd) { 1342 ret = EINVAL; 1343 goto out; 1344 } 1345 1346 /* 1347 * If lastfile == -1, we're dealing with either a fresh file 1348 * table or one in which every fd has been closed. Just return 1349 * successful; there's nothing left to do. 1350 */ 1351 lastfile = fdlastfile(fdp); 1352 if (lastfile == -1) 1353 goto out; 1354 /* Clamped to [lowfd, lastfile] */ 1355 highfd = MIN(highfd, lastfile); 1356 for (fd = lowfd; fd <= highfd; fd++) { 1357 if (fdp->fd_ofiles[fd].fde_file != NULL) { 1358 FILEDESC_SUNLOCK(fdp); 1359 (void)kern_close(td, fd); 1360 FILEDESC_SLOCK(fdp); 1361 } 1362 } 1363 out: 1364 FILEDESC_SUNLOCK(fdp); 1365 return (ret); 1366 } 1367 1368 #ifndef _SYS_SYSPROTO_H_ 1369 struct close_range_args { 1370 u_int lowfd; 1371 u_int highfd; 1372 int flags; 1373 }; 1374 #endif 1375 int 1376 sys_close_range(struct thread *td, struct close_range_args *uap) 1377 { 1378 1379 /* No flags currently defined */ 1380 if (uap->flags != 0) 1381 return (EINVAL); 1382 return (kern_close_range(td, uap->lowfd, uap->highfd)); 1383 } 1384 1385 #ifdef COMPAT_FREEBSD12 1386 /* 1387 * Close open file descriptors. 1388 */ 1389 #ifndef _SYS_SYSPROTO_H_ 1390 struct freebsd12_closefrom_args { 1391 int lowfd; 1392 }; 1393 #endif 1394 /* ARGSUSED */ 1395 int 1396 freebsd12_closefrom(struct thread *td, struct freebsd12_closefrom_args *uap) 1397 { 1398 u_int lowfd; 1399 1400 AUDIT_ARG_FD(uap->lowfd); 1401 1402 /* 1403 * Treat negative starting file descriptor values identical to 1404 * closefrom(0) which closes all files. 1405 */ 1406 lowfd = MAX(0, uap->lowfd); 1407 return (kern_close_range(td, lowfd, ~0U)); 1408 } 1409 #endif /* COMPAT_FREEBSD12 */ 1410 1411 #if defined(COMPAT_43) 1412 /* 1413 * Return status information about a file descriptor. 1414 */ 1415 #ifndef _SYS_SYSPROTO_H_ 1416 struct ofstat_args { 1417 int fd; 1418 struct ostat *sb; 1419 }; 1420 #endif 1421 /* ARGSUSED */ 1422 int 1423 ofstat(struct thread *td, struct ofstat_args *uap) 1424 { 1425 struct ostat oub; 1426 struct stat ub; 1427 int error; 1428 1429 error = kern_fstat(td, uap->fd, &ub); 1430 if (error == 0) { 1431 cvtstat(&ub, &oub); 1432 error = copyout(&oub, uap->sb, sizeof(oub)); 1433 } 1434 return (error); 1435 } 1436 #endif /* COMPAT_43 */ 1437 1438 #if defined(COMPAT_FREEBSD11) 1439 int 1440 freebsd11_fstat(struct thread *td, struct freebsd11_fstat_args *uap) 1441 { 1442 struct stat sb; 1443 struct freebsd11_stat osb; 1444 int error; 1445 1446 error = kern_fstat(td, uap->fd, &sb); 1447 if (error != 0) 1448 return (error); 1449 error = freebsd11_cvtstat(&sb, &osb); 1450 if (error == 0) 1451 error = copyout(&osb, uap->sb, sizeof(osb)); 1452 return (error); 1453 } 1454 #endif /* COMPAT_FREEBSD11 */ 1455 1456 /* 1457 * Return status information about a file descriptor. 1458 */ 1459 #ifndef _SYS_SYSPROTO_H_ 1460 struct fstat_args { 1461 int fd; 1462 struct stat *sb; 1463 }; 1464 #endif 1465 /* ARGSUSED */ 1466 int 1467 sys_fstat(struct thread *td, struct fstat_args *uap) 1468 { 1469 struct stat ub; 1470 int error; 1471 1472 error = kern_fstat(td, uap->fd, &ub); 1473 if (error == 0) 1474 error = copyout(&ub, uap->sb, sizeof(ub)); 1475 return (error); 1476 } 1477 1478 int 1479 kern_fstat(struct thread *td, int fd, struct stat *sbp) 1480 { 1481 struct file *fp; 1482 int error; 1483 1484 AUDIT_ARG_FD(fd); 1485 1486 error = fget(td, fd, &cap_fstat_rights, &fp); 1487 if (__predict_false(error != 0)) 1488 return (error); 1489 1490 AUDIT_ARG_FILE(td->td_proc, fp); 1491 1492 error = fo_stat(fp, sbp, td->td_ucred, td); 1493 fdrop(fp, td); 1494 #ifdef __STAT_TIME_T_EXT 1495 sbp->st_atim_ext = 0; 1496 sbp->st_mtim_ext = 0; 1497 sbp->st_ctim_ext = 0; 1498 sbp->st_btim_ext = 0; 1499 #endif 1500 #ifdef KTRACE 1501 if (KTRPOINT(td, KTR_STRUCT)) 1502 ktrstat_error(sbp, error); 1503 #endif 1504 return (error); 1505 } 1506 1507 #if defined(COMPAT_FREEBSD11) 1508 /* 1509 * Return status information about a file descriptor. 1510 */ 1511 #ifndef _SYS_SYSPROTO_H_ 1512 struct freebsd11_nfstat_args { 1513 int fd; 1514 struct nstat *sb; 1515 }; 1516 #endif 1517 /* ARGSUSED */ 1518 int 1519 freebsd11_nfstat(struct thread *td, struct freebsd11_nfstat_args *uap) 1520 { 1521 struct nstat nub; 1522 struct stat ub; 1523 int error; 1524 1525 error = kern_fstat(td, uap->fd, &ub); 1526 if (error == 0) { 1527 freebsd11_cvtnstat(&ub, &nub); 1528 error = copyout(&nub, uap->sb, sizeof(nub)); 1529 } 1530 return (error); 1531 } 1532 #endif /* COMPAT_FREEBSD11 */ 1533 1534 /* 1535 * Return pathconf information about a file descriptor. 1536 */ 1537 #ifndef _SYS_SYSPROTO_H_ 1538 struct fpathconf_args { 1539 int fd; 1540 int name; 1541 }; 1542 #endif 1543 /* ARGSUSED */ 1544 int 1545 sys_fpathconf(struct thread *td, struct fpathconf_args *uap) 1546 { 1547 long value; 1548 int error; 1549 1550 error = kern_fpathconf(td, uap->fd, uap->name, &value); 1551 if (error == 0) 1552 td->td_retval[0] = value; 1553 return (error); 1554 } 1555 1556 int 1557 kern_fpathconf(struct thread *td, int fd, int name, long *valuep) 1558 { 1559 struct file *fp; 1560 struct vnode *vp; 1561 int error; 1562 1563 error = fget(td, fd, &cap_fpathconf_rights, &fp); 1564 if (error != 0) 1565 return (error); 1566 1567 if (name == _PC_ASYNC_IO) { 1568 *valuep = _POSIX_ASYNCHRONOUS_IO; 1569 goto out; 1570 } 1571 vp = fp->f_vnode; 1572 if (vp != NULL) { 1573 vn_lock(vp, LK_SHARED | LK_RETRY); 1574 error = VOP_PATHCONF(vp, name, valuep); 1575 VOP_UNLOCK(vp); 1576 } else if (fp->f_type == DTYPE_PIPE || fp->f_type == DTYPE_SOCKET) { 1577 if (name != _PC_PIPE_BUF) { 1578 error = EINVAL; 1579 } else { 1580 *valuep = PIPE_BUF; 1581 error = 0; 1582 } 1583 } else { 1584 error = EOPNOTSUPP; 1585 } 1586 out: 1587 fdrop(fp, td); 1588 return (error); 1589 } 1590 1591 /* 1592 * Copy filecaps structure allocating memory for ioctls array if needed. 1593 * 1594 * The last parameter indicates whether the fdtable is locked. If it is not and 1595 * ioctls are encountered, copying fails and the caller must lock the table. 1596 * 1597 * Note that if the table was not locked, the caller has to check the relevant 1598 * sequence counter to determine whether the operation was successful. 1599 */ 1600 bool 1601 filecaps_copy(const struct filecaps *src, struct filecaps *dst, bool locked) 1602 { 1603 size_t size; 1604 1605 if (src->fc_ioctls != NULL && !locked) 1606 return (false); 1607 memcpy(dst, src, sizeof(*src)); 1608 if (src->fc_ioctls == NULL) 1609 return (true); 1610 1611 KASSERT(src->fc_nioctls > 0, 1612 ("fc_ioctls != NULL, but fc_nioctls=%hd", src->fc_nioctls)); 1613 1614 size = sizeof(src->fc_ioctls[0]) * src->fc_nioctls; 1615 dst->fc_ioctls = malloc(size, M_FILECAPS, M_WAITOK); 1616 memcpy(dst->fc_ioctls, src->fc_ioctls, size); 1617 return (true); 1618 } 1619 1620 static u_long * 1621 filecaps_copy_prep(const struct filecaps *src) 1622 { 1623 u_long *ioctls; 1624 size_t size; 1625 1626 if (__predict_true(src->fc_ioctls == NULL)) 1627 return (NULL); 1628 1629 KASSERT(src->fc_nioctls > 0, 1630 ("fc_ioctls != NULL, but fc_nioctls=%hd", src->fc_nioctls)); 1631 1632 size = sizeof(src->fc_ioctls[0]) * src->fc_nioctls; 1633 ioctls = malloc(size, M_FILECAPS, M_WAITOK); 1634 return (ioctls); 1635 } 1636 1637 static void 1638 filecaps_copy_finish(const struct filecaps *src, struct filecaps *dst, 1639 u_long *ioctls) 1640 { 1641 size_t size; 1642 1643 *dst = *src; 1644 if (__predict_true(src->fc_ioctls == NULL)) { 1645 MPASS(ioctls == NULL); 1646 return; 1647 } 1648 1649 size = sizeof(src->fc_ioctls[0]) * src->fc_nioctls; 1650 dst->fc_ioctls = ioctls; 1651 bcopy(src->fc_ioctls, dst->fc_ioctls, size); 1652 } 1653 1654 /* 1655 * Move filecaps structure to the new place and clear the old place. 1656 */ 1657 void 1658 filecaps_move(struct filecaps *src, struct filecaps *dst) 1659 { 1660 1661 *dst = *src; 1662 bzero(src, sizeof(*src)); 1663 } 1664 1665 /* 1666 * Fill the given filecaps structure with full rights. 1667 */ 1668 static void 1669 filecaps_fill(struct filecaps *fcaps) 1670 { 1671 1672 CAP_ALL(&fcaps->fc_rights); 1673 fcaps->fc_ioctls = NULL; 1674 fcaps->fc_nioctls = -1; 1675 fcaps->fc_fcntls = CAP_FCNTL_ALL; 1676 } 1677 1678 /* 1679 * Free memory allocated within filecaps structure. 1680 */ 1681 void 1682 filecaps_free(struct filecaps *fcaps) 1683 { 1684 1685 free(fcaps->fc_ioctls, M_FILECAPS); 1686 bzero(fcaps, sizeof(*fcaps)); 1687 } 1688 1689 static u_long * 1690 filecaps_free_prep(struct filecaps *fcaps) 1691 { 1692 u_long *ioctls; 1693 1694 ioctls = fcaps->fc_ioctls; 1695 bzero(fcaps, sizeof(*fcaps)); 1696 return (ioctls); 1697 } 1698 1699 static void 1700 filecaps_free_finish(u_long *ioctls) 1701 { 1702 1703 free(ioctls, M_FILECAPS); 1704 } 1705 1706 /* 1707 * Validate the given filecaps structure. 1708 */ 1709 static void 1710 filecaps_validate(const struct filecaps *fcaps, const char *func) 1711 { 1712 1713 KASSERT(cap_rights_is_valid(&fcaps->fc_rights), 1714 ("%s: invalid rights", func)); 1715 KASSERT((fcaps->fc_fcntls & ~CAP_FCNTL_ALL) == 0, 1716 ("%s: invalid fcntls", func)); 1717 KASSERT(fcaps->fc_fcntls == 0 || 1718 cap_rights_is_set(&fcaps->fc_rights, CAP_FCNTL), 1719 ("%s: fcntls without CAP_FCNTL", func)); 1720 KASSERT(fcaps->fc_ioctls != NULL ? fcaps->fc_nioctls > 0 : 1721 (fcaps->fc_nioctls == -1 || fcaps->fc_nioctls == 0), 1722 ("%s: invalid ioctls", func)); 1723 KASSERT(fcaps->fc_nioctls == 0 || 1724 cap_rights_is_set(&fcaps->fc_rights, CAP_IOCTL), 1725 ("%s: ioctls without CAP_IOCTL", func)); 1726 } 1727 1728 static void 1729 fdgrowtable_exp(struct filedesc *fdp, int nfd) 1730 { 1731 int nfd1; 1732 1733 FILEDESC_XLOCK_ASSERT(fdp); 1734 1735 nfd1 = fdp->fd_nfiles * 2; 1736 if (nfd1 < nfd) 1737 nfd1 = nfd; 1738 fdgrowtable(fdp, nfd1); 1739 } 1740 1741 /* 1742 * Grow the file table to accommodate (at least) nfd descriptors. 1743 */ 1744 static void 1745 fdgrowtable(struct filedesc *fdp, int nfd) 1746 { 1747 struct filedesc0 *fdp0; 1748 struct freetable *ft; 1749 struct fdescenttbl *ntable; 1750 struct fdescenttbl *otable; 1751 int nnfiles, onfiles; 1752 NDSLOTTYPE *nmap, *omap; 1753 1754 KASSERT(fdp->fd_nfiles > 0, ("zero-length file table")); 1755 1756 /* save old values */ 1757 onfiles = fdp->fd_nfiles; 1758 otable = fdp->fd_files; 1759 omap = fdp->fd_map; 1760 1761 /* compute the size of the new table */ 1762 nnfiles = NDSLOTS(nfd) * NDENTRIES; /* round up */ 1763 if (nnfiles <= onfiles) 1764 /* the table is already large enough */ 1765 return; 1766 1767 /* 1768 * Allocate a new table. We need enough space for the number of 1769 * entries, file entries themselves and the struct freetable we will use 1770 * when we decommission the table and place it on the freelist. 1771 * We place the struct freetable in the middle so we don't have 1772 * to worry about padding. 1773 */ 1774 ntable = malloc(offsetof(struct fdescenttbl, fdt_ofiles) + 1775 nnfiles * sizeof(ntable->fdt_ofiles[0]) + 1776 sizeof(struct freetable), 1777 M_FILEDESC, M_ZERO | M_WAITOK); 1778 /* copy the old data */ 1779 ntable->fdt_nfiles = nnfiles; 1780 memcpy(ntable->fdt_ofiles, otable->fdt_ofiles, 1781 onfiles * sizeof(ntable->fdt_ofiles[0])); 1782 1783 /* 1784 * Allocate a new map only if the old is not large enough. It will 1785 * grow at a slower rate than the table as it can map more 1786 * entries than the table can hold. 1787 */ 1788 if (NDSLOTS(nnfiles) > NDSLOTS(onfiles)) { 1789 nmap = malloc(NDSLOTS(nnfiles) * NDSLOTSIZE, M_FILEDESC, 1790 M_ZERO | M_WAITOK); 1791 /* copy over the old data and update the pointer */ 1792 memcpy(nmap, omap, NDSLOTS(onfiles) * sizeof(*omap)); 1793 fdp->fd_map = nmap; 1794 } 1795 1796 /* 1797 * Make sure that ntable is correctly initialized before we replace 1798 * fd_files poiner. Otherwise fget_unlocked() may see inconsistent 1799 * data. 1800 */ 1801 atomic_store_rel_ptr((volatile void *)&fdp->fd_files, (uintptr_t)ntable); 1802 1803 /* 1804 * Do not free the old file table, as some threads may still 1805 * reference entries within it. Instead, place it on a freelist 1806 * which will be processed when the struct filedesc is released. 1807 * 1808 * Note that if onfiles == NDFILE, we're dealing with the original 1809 * static allocation contained within (struct filedesc0 *)fdp, 1810 * which must not be freed. 1811 */ 1812 if (onfiles > NDFILE) { 1813 ft = (struct freetable *)&otable->fdt_ofiles[onfiles]; 1814 fdp0 = (struct filedesc0 *)fdp; 1815 ft->ft_table = otable; 1816 SLIST_INSERT_HEAD(&fdp0->fd_free, ft, ft_next); 1817 } 1818 /* 1819 * The map does not have the same possibility of threads still 1820 * holding references to it. So always free it as long as it 1821 * does not reference the original static allocation. 1822 */ 1823 if (NDSLOTS(onfiles) > NDSLOTS(NDFILE)) 1824 free(omap, M_FILEDESC); 1825 } 1826 1827 /* 1828 * Allocate a file descriptor for the process. 1829 */ 1830 int 1831 fdalloc(struct thread *td, int minfd, int *result) 1832 { 1833 struct proc *p = td->td_proc; 1834 struct filedesc *fdp = p->p_fd; 1835 int fd, maxfd, allocfd; 1836 #ifdef RACCT 1837 int error; 1838 #endif 1839 1840 FILEDESC_XLOCK_ASSERT(fdp); 1841 1842 if (fdp->fd_freefile > minfd) 1843 minfd = fdp->fd_freefile; 1844 1845 maxfd = getmaxfd(td); 1846 1847 /* 1848 * Search the bitmap for a free descriptor starting at minfd. 1849 * If none is found, grow the file table. 1850 */ 1851 fd = fd_first_free(fdp, minfd, fdp->fd_nfiles); 1852 if (__predict_false(fd >= maxfd)) 1853 return (EMFILE); 1854 if (__predict_false(fd >= fdp->fd_nfiles)) { 1855 allocfd = min(fd * 2, maxfd); 1856 #ifdef RACCT 1857 if (RACCT_ENABLED()) { 1858 error = racct_set_unlocked(p, RACCT_NOFILE, allocfd); 1859 if (error != 0) 1860 return (EMFILE); 1861 } 1862 #endif 1863 /* 1864 * fd is already equal to first free descriptor >= minfd, so 1865 * we only need to grow the table and we are done. 1866 */ 1867 fdgrowtable_exp(fdp, allocfd); 1868 } 1869 1870 /* 1871 * Perform some sanity checks, then mark the file descriptor as 1872 * used and return it to the caller. 1873 */ 1874 KASSERT(fd >= 0 && fd < min(maxfd, fdp->fd_nfiles), 1875 ("invalid descriptor %d", fd)); 1876 KASSERT(!fdisused(fdp, fd), 1877 ("fd_first_free() returned non-free descriptor")); 1878 KASSERT(fdp->fd_ofiles[fd].fde_file == NULL, 1879 ("file descriptor isn't free")); 1880 fdused(fdp, fd); 1881 *result = fd; 1882 return (0); 1883 } 1884 1885 /* 1886 * Allocate n file descriptors for the process. 1887 */ 1888 int 1889 fdallocn(struct thread *td, int minfd, int *fds, int n) 1890 { 1891 struct proc *p = td->td_proc; 1892 struct filedesc *fdp = p->p_fd; 1893 int i; 1894 1895 FILEDESC_XLOCK_ASSERT(fdp); 1896 1897 for (i = 0; i < n; i++) 1898 if (fdalloc(td, 0, &fds[i]) != 0) 1899 break; 1900 1901 if (i < n) { 1902 for (i--; i >= 0; i--) 1903 fdunused(fdp, fds[i]); 1904 return (EMFILE); 1905 } 1906 1907 return (0); 1908 } 1909 1910 /* 1911 * Create a new open file structure and allocate a file descriptor for the 1912 * process that refers to it. We add one reference to the file for the 1913 * descriptor table and one reference for resultfp. This is to prevent us 1914 * being preempted and the entry in the descriptor table closed after we 1915 * release the FILEDESC lock. 1916 */ 1917 int 1918 falloc_caps(struct thread *td, struct file **resultfp, int *resultfd, int flags, 1919 struct filecaps *fcaps) 1920 { 1921 struct file *fp; 1922 int error, fd; 1923 1924 error = falloc_noinstall(td, &fp); 1925 if (error) 1926 return (error); /* no reference held on error */ 1927 1928 error = finstall(td, fp, &fd, flags, fcaps); 1929 if (error) { 1930 fdrop(fp, td); /* one reference (fp only) */ 1931 return (error); 1932 } 1933 1934 if (resultfp != NULL) 1935 *resultfp = fp; /* copy out result */ 1936 else 1937 fdrop(fp, td); /* release local reference */ 1938 1939 if (resultfd != NULL) 1940 *resultfd = fd; 1941 1942 return (0); 1943 } 1944 1945 /* 1946 * Create a new open file structure without allocating a file descriptor. 1947 */ 1948 int 1949 falloc_noinstall(struct thread *td, struct file **resultfp) 1950 { 1951 struct file *fp; 1952 int maxuserfiles = maxfiles - (maxfiles / 20); 1953 int openfiles_new; 1954 static struct timeval lastfail; 1955 static int curfail; 1956 1957 KASSERT(resultfp != NULL, ("%s: resultfp == NULL", __func__)); 1958 1959 openfiles_new = atomic_fetchadd_int(&openfiles, 1) + 1; 1960 if ((openfiles_new >= maxuserfiles && 1961 priv_check(td, PRIV_MAXFILES) != 0) || 1962 openfiles_new >= maxfiles) { 1963 atomic_subtract_int(&openfiles, 1); 1964 if (ppsratecheck(&lastfail, &curfail, 1)) { 1965 printf("kern.maxfiles limit exceeded by uid %i, (%s) " 1966 "please see tuning(7).\n", td->td_ucred->cr_ruid, td->td_proc->p_comm); 1967 } 1968 return (ENFILE); 1969 } 1970 fp = uma_zalloc(file_zone, M_WAITOK); 1971 bzero(fp, sizeof(*fp)); 1972 refcount_init(&fp->f_count, 1); 1973 fp->f_cred = crhold(td->td_ucred); 1974 fp->f_ops = &badfileops; 1975 *resultfp = fp; 1976 return (0); 1977 } 1978 1979 /* 1980 * Install a file in a file descriptor table. 1981 */ 1982 void 1983 _finstall(struct filedesc *fdp, struct file *fp, int fd, int flags, 1984 struct filecaps *fcaps) 1985 { 1986 struct filedescent *fde; 1987 1988 MPASS(fp != NULL); 1989 if (fcaps != NULL) 1990 filecaps_validate(fcaps, __func__); 1991 FILEDESC_XLOCK_ASSERT(fdp); 1992 1993 fde = &fdp->fd_ofiles[fd]; 1994 #ifdef CAPABILITIES 1995 seqc_write_begin(&fde->fde_seqc); 1996 #endif 1997 fde->fde_file = fp; 1998 fde->fde_flags = (flags & O_CLOEXEC) != 0 ? UF_EXCLOSE : 0; 1999 if (fcaps != NULL) 2000 filecaps_move(fcaps, &fde->fde_caps); 2001 else 2002 filecaps_fill(&fde->fde_caps); 2003 #ifdef CAPABILITIES 2004 seqc_write_end(&fde->fde_seqc); 2005 #endif 2006 } 2007 2008 int 2009 finstall(struct thread *td, struct file *fp, int *fd, int flags, 2010 struct filecaps *fcaps) 2011 { 2012 struct filedesc *fdp = td->td_proc->p_fd; 2013 int error; 2014 2015 MPASS(fd != NULL); 2016 2017 if (!fhold(fp)) 2018 return (EBADF); 2019 FILEDESC_XLOCK(fdp); 2020 error = fdalloc(td, 0, fd); 2021 if (__predict_false(error != 0)) { 2022 FILEDESC_XUNLOCK(fdp); 2023 fdrop(fp, td); 2024 return (error); 2025 } 2026 _finstall(fdp, fp, *fd, flags, fcaps); 2027 FILEDESC_XUNLOCK(fdp); 2028 return (0); 2029 } 2030 2031 /* 2032 * Build a new filedesc structure from another. 2033 * 2034 * If fdp is not NULL, return with it shared locked. 2035 */ 2036 struct filedesc * 2037 fdinit(struct filedesc *fdp, bool prepfiles, int *lastfile) 2038 { 2039 struct filedesc0 *newfdp0; 2040 struct filedesc *newfdp; 2041 2042 if (prepfiles) 2043 MPASS(lastfile != NULL); 2044 else 2045 MPASS(lastfile == NULL); 2046 2047 newfdp0 = uma_zalloc(filedesc0_zone, M_WAITOK | M_ZERO); 2048 newfdp = &newfdp0->fd_fd; 2049 2050 /* Create the file descriptor table. */ 2051 FILEDESC_LOCK_INIT(newfdp); 2052 refcount_init(&newfdp->fd_refcnt, 1); 2053 refcount_init(&newfdp->fd_holdcnt, 1); 2054 newfdp->fd_map = newfdp0->fd_dmap; 2055 newfdp->fd_files = (struct fdescenttbl *)&newfdp0->fd_dfiles; 2056 newfdp->fd_files->fdt_nfiles = NDFILE; 2057 2058 if (fdp == NULL) 2059 return (newfdp); 2060 2061 FILEDESC_SLOCK(fdp); 2062 if (!prepfiles) { 2063 FILEDESC_SUNLOCK(fdp); 2064 return (newfdp); 2065 } 2066 2067 for (;;) { 2068 *lastfile = fdlastfile(fdp); 2069 if (*lastfile < newfdp->fd_nfiles) 2070 break; 2071 FILEDESC_SUNLOCK(fdp); 2072 fdgrowtable(newfdp, *lastfile + 1); 2073 FILEDESC_SLOCK(fdp); 2074 } 2075 2076 return (newfdp); 2077 } 2078 2079 /* 2080 * Build a pwddesc structure from another. 2081 * Copy the current, root, and jail root vnode references. 2082 * 2083 * If pdp is not NULL, return with it shared locked. 2084 */ 2085 struct pwddesc * 2086 pdinit(struct pwddesc *pdp, bool keeplock) 2087 { 2088 struct pwddesc *newpdp; 2089 struct pwd *newpwd; 2090 2091 newpdp = malloc(sizeof(*newpdp), M_PWDDESC, M_WAITOK | M_ZERO); 2092 2093 PWDDESC_LOCK_INIT(newpdp); 2094 refcount_init(&newpdp->pd_refcount, 1); 2095 newpdp->pd_cmask = CMASK; 2096 2097 if (pdp == NULL) { 2098 newpwd = pwd_alloc(); 2099 smr_serialized_store(&newpdp->pd_pwd, newpwd, true); 2100 return (newpdp); 2101 } 2102 2103 PWDDESC_XLOCK(pdp); 2104 newpwd = pwd_hold_pwddesc(pdp); 2105 smr_serialized_store(&newpdp->pd_pwd, newpwd, true); 2106 if (!keeplock) 2107 PWDDESC_XUNLOCK(pdp); 2108 return (newpdp); 2109 } 2110 2111 static struct filedesc * 2112 fdhold(struct proc *p) 2113 { 2114 struct filedesc *fdp; 2115 2116 PROC_LOCK_ASSERT(p, MA_OWNED); 2117 fdp = p->p_fd; 2118 if (fdp != NULL) 2119 refcount_acquire(&fdp->fd_holdcnt); 2120 return (fdp); 2121 } 2122 2123 static struct pwddesc * 2124 pdhold(struct proc *p) 2125 { 2126 struct pwddesc *pdp; 2127 2128 PROC_LOCK_ASSERT(p, MA_OWNED); 2129 pdp = p->p_pd; 2130 if (pdp != NULL) 2131 refcount_acquire(&pdp->pd_refcount); 2132 return (pdp); 2133 } 2134 2135 static void 2136 fddrop(struct filedesc *fdp) 2137 { 2138 2139 if (fdp->fd_holdcnt > 1) { 2140 if (refcount_release(&fdp->fd_holdcnt) == 0) 2141 return; 2142 } 2143 2144 FILEDESC_LOCK_DESTROY(fdp); 2145 uma_zfree(filedesc0_zone, fdp); 2146 } 2147 2148 static void 2149 pddrop(struct pwddesc *pdp) 2150 { 2151 struct pwd *pwd; 2152 2153 if (refcount_release_if_not_last(&pdp->pd_refcount)) 2154 return; 2155 2156 PWDDESC_XLOCK(pdp); 2157 if (refcount_release(&pdp->pd_refcount) == 0) { 2158 PWDDESC_XUNLOCK(pdp); 2159 return; 2160 } 2161 pwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); 2162 pwd_set(pdp, NULL); 2163 PWDDESC_XUNLOCK(pdp); 2164 pwd_drop(pwd); 2165 2166 PWDDESC_LOCK_DESTROY(pdp); 2167 free(pdp, M_PWDDESC); 2168 } 2169 2170 /* 2171 * Share a filedesc structure. 2172 */ 2173 struct filedesc * 2174 fdshare(struct filedesc *fdp) 2175 { 2176 2177 refcount_acquire(&fdp->fd_refcnt); 2178 return (fdp); 2179 } 2180 2181 /* 2182 * Share a pwddesc structure. 2183 */ 2184 struct pwddesc * 2185 pdshare(struct pwddesc *pdp) 2186 { 2187 refcount_acquire(&pdp->pd_refcount); 2188 return (pdp); 2189 } 2190 2191 /* 2192 * Unshare a filedesc structure, if necessary by making a copy 2193 */ 2194 void 2195 fdunshare(struct thread *td) 2196 { 2197 struct filedesc *tmp; 2198 struct proc *p = td->td_proc; 2199 2200 if (p->p_fd->fd_refcnt == 1) 2201 return; 2202 2203 tmp = fdcopy(p->p_fd); 2204 fdescfree(td); 2205 p->p_fd = tmp; 2206 } 2207 2208 /* 2209 * Unshare a pwddesc structure. 2210 */ 2211 void 2212 pdunshare(struct thread *td) 2213 { 2214 struct pwddesc *pdp; 2215 struct proc *p; 2216 2217 p = td->td_proc; 2218 /* Not shared. */ 2219 if (p->p_pd->pd_refcount == 1) 2220 return; 2221 2222 pdp = pdcopy(p->p_pd); 2223 pdescfree(td); 2224 p->p_pd = pdp; 2225 } 2226 2227 void 2228 fdinstall_remapped(struct thread *td, struct filedesc *fdp) 2229 { 2230 2231 fdescfree(td); 2232 td->td_proc->p_fd = fdp; 2233 } 2234 2235 /* 2236 * Copy a filedesc structure. A NULL pointer in returns a NULL reference, 2237 * this is to ease callers, not catch errors. 2238 */ 2239 struct filedesc * 2240 fdcopy(struct filedesc *fdp) 2241 { 2242 struct filedesc *newfdp; 2243 struct filedescent *nfde, *ofde; 2244 int i, lastfile; 2245 2246 MPASS(fdp != NULL); 2247 2248 newfdp = fdinit(fdp, true, &lastfile); 2249 /* copy all passable descriptors (i.e. not kqueue) */ 2250 newfdp->fd_freefile = -1; 2251 for (i = 0; i <= lastfile; ++i) { 2252 ofde = &fdp->fd_ofiles[i]; 2253 if (ofde->fde_file == NULL || 2254 (ofde->fde_file->f_ops->fo_flags & DFLAG_PASSABLE) == 0 || 2255 !fhold(ofde->fde_file)) { 2256 if (newfdp->fd_freefile == -1) 2257 newfdp->fd_freefile = i; 2258 continue; 2259 } 2260 nfde = &newfdp->fd_ofiles[i]; 2261 *nfde = *ofde; 2262 filecaps_copy(&ofde->fde_caps, &nfde->fde_caps, true); 2263 fdused_init(newfdp, i); 2264 } 2265 if (newfdp->fd_freefile == -1) 2266 newfdp->fd_freefile = i; 2267 FILEDESC_SUNLOCK(fdp); 2268 return (newfdp); 2269 } 2270 2271 /* 2272 * Copy a pwddesc structure. 2273 */ 2274 struct pwddesc * 2275 pdcopy(struct pwddesc *pdp) 2276 { 2277 struct pwddesc *newpdp; 2278 2279 MPASS(pdp != NULL); 2280 2281 newpdp = pdinit(pdp, true); 2282 newpdp->pd_cmask = pdp->pd_cmask; 2283 PWDDESC_XUNLOCK(pdp); 2284 return (newpdp); 2285 } 2286 2287 /* 2288 * Copies a filedesc structure, while remapping all file descriptors 2289 * stored inside using a translation table. 2290 * 2291 * File descriptors are copied over to the new file descriptor table, 2292 * regardless of whether the close-on-exec flag is set. 2293 */ 2294 int 2295 fdcopy_remapped(struct filedesc *fdp, const int *fds, size_t nfds, 2296 struct filedesc **ret) 2297 { 2298 struct filedesc *newfdp; 2299 struct filedescent *nfde, *ofde; 2300 int error, i, lastfile; 2301 2302 MPASS(fdp != NULL); 2303 2304 newfdp = fdinit(fdp, true, &lastfile); 2305 if (nfds > lastfile + 1) { 2306 /* New table cannot be larger than the old one. */ 2307 error = E2BIG; 2308 goto bad; 2309 } 2310 /* Copy all passable descriptors (i.e. not kqueue). */ 2311 newfdp->fd_freefile = nfds; 2312 for (i = 0; i < nfds; ++i) { 2313 if (fds[i] < 0 || fds[i] > lastfile) { 2314 /* File descriptor out of bounds. */ 2315 error = EBADF; 2316 goto bad; 2317 } 2318 ofde = &fdp->fd_ofiles[fds[i]]; 2319 if (ofde->fde_file == NULL) { 2320 /* Unused file descriptor. */ 2321 error = EBADF; 2322 goto bad; 2323 } 2324 if ((ofde->fde_file->f_ops->fo_flags & DFLAG_PASSABLE) == 0) { 2325 /* File descriptor cannot be passed. */ 2326 error = EINVAL; 2327 goto bad; 2328 } 2329 if (!fhold(ofde->fde_file)) { 2330 error = EBADF; 2331 goto bad; 2332 } 2333 nfde = &newfdp->fd_ofiles[i]; 2334 *nfde = *ofde; 2335 filecaps_copy(&ofde->fde_caps, &nfde->fde_caps, true); 2336 fdused_init(newfdp, i); 2337 } 2338 FILEDESC_SUNLOCK(fdp); 2339 *ret = newfdp; 2340 return (0); 2341 bad: 2342 FILEDESC_SUNLOCK(fdp); 2343 fdescfree_remapped(newfdp); 2344 return (error); 2345 } 2346 2347 /* 2348 * Clear POSIX style locks. This is only used when fdp looses a reference (i.e. 2349 * one of processes using it exits) and the table used to be shared. 2350 */ 2351 static void 2352 fdclearlocks(struct thread *td) 2353 { 2354 struct filedesc *fdp; 2355 struct filedesc_to_leader *fdtol; 2356 struct flock lf; 2357 struct file *fp; 2358 struct proc *p; 2359 struct vnode *vp; 2360 int i, lastfile; 2361 2362 p = td->td_proc; 2363 fdp = p->p_fd; 2364 fdtol = p->p_fdtol; 2365 MPASS(fdtol != NULL); 2366 2367 FILEDESC_XLOCK(fdp); 2368 KASSERT(fdtol->fdl_refcount > 0, 2369 ("filedesc_to_refcount botch: fdl_refcount=%d", 2370 fdtol->fdl_refcount)); 2371 if (fdtol->fdl_refcount == 1 && 2372 (p->p_leader->p_flag & P_ADVLOCK) != 0) { 2373 lastfile = fdlastfile(fdp); 2374 for (i = 0; i <= lastfile; i++) { 2375 fp = fdp->fd_ofiles[i].fde_file; 2376 if (fp == NULL || fp->f_type != DTYPE_VNODE || 2377 !fhold(fp)) 2378 continue; 2379 FILEDESC_XUNLOCK(fdp); 2380 lf.l_whence = SEEK_SET; 2381 lf.l_start = 0; 2382 lf.l_len = 0; 2383 lf.l_type = F_UNLCK; 2384 vp = fp->f_vnode; 2385 (void) VOP_ADVLOCK(vp, 2386 (caddr_t)p->p_leader, F_UNLCK, 2387 &lf, F_POSIX); 2388 FILEDESC_XLOCK(fdp); 2389 fdrop(fp, td); 2390 } 2391 } 2392 retry: 2393 if (fdtol->fdl_refcount == 1) { 2394 if (fdp->fd_holdleaderscount > 0 && 2395 (p->p_leader->p_flag & P_ADVLOCK) != 0) { 2396 /* 2397 * close() or kern_dup() has cleared a reference 2398 * in a shared file descriptor table. 2399 */ 2400 fdp->fd_holdleaderswakeup = 1; 2401 sx_sleep(&fdp->fd_holdleaderscount, 2402 FILEDESC_LOCK(fdp), PLOCK, "fdlhold", 0); 2403 goto retry; 2404 } 2405 if (fdtol->fdl_holdcount > 0) { 2406 /* 2407 * Ensure that fdtol->fdl_leader remains 2408 * valid in closef(). 2409 */ 2410 fdtol->fdl_wakeup = 1; 2411 sx_sleep(fdtol, FILEDESC_LOCK(fdp), PLOCK, 2412 "fdlhold", 0); 2413 goto retry; 2414 } 2415 } 2416 fdtol->fdl_refcount--; 2417 if (fdtol->fdl_refcount == 0 && 2418 fdtol->fdl_holdcount == 0) { 2419 fdtol->fdl_next->fdl_prev = fdtol->fdl_prev; 2420 fdtol->fdl_prev->fdl_next = fdtol->fdl_next; 2421 } else 2422 fdtol = NULL; 2423 p->p_fdtol = NULL; 2424 FILEDESC_XUNLOCK(fdp); 2425 if (fdtol != NULL) 2426 free(fdtol, M_FILEDESC_TO_LEADER); 2427 } 2428 2429 /* 2430 * Release a filedesc structure. 2431 */ 2432 static void 2433 fdescfree_fds(struct thread *td, struct filedesc *fdp, bool needclose) 2434 { 2435 struct filedesc0 *fdp0; 2436 struct freetable *ft, *tft; 2437 struct filedescent *fde; 2438 struct file *fp; 2439 int i, lastfile; 2440 2441 lastfile = fdlastfile_single(fdp); 2442 for (i = 0; i <= lastfile; i++) { 2443 fde = &fdp->fd_ofiles[i]; 2444 fp = fde->fde_file; 2445 if (fp != NULL) { 2446 fdefree_last(fde); 2447 if (needclose) 2448 (void) closef(fp, td); 2449 else 2450 fdrop(fp, td); 2451 } 2452 } 2453 2454 if (NDSLOTS(fdp->fd_nfiles) > NDSLOTS(NDFILE)) 2455 free(fdp->fd_map, M_FILEDESC); 2456 if (fdp->fd_nfiles > NDFILE) 2457 free(fdp->fd_files, M_FILEDESC); 2458 2459 fdp0 = (struct filedesc0 *)fdp; 2460 SLIST_FOREACH_SAFE(ft, &fdp0->fd_free, ft_next, tft) 2461 free(ft->ft_table, M_FILEDESC); 2462 2463 fddrop(fdp); 2464 } 2465 2466 void 2467 fdescfree(struct thread *td) 2468 { 2469 struct proc *p; 2470 struct filedesc *fdp; 2471 2472 p = td->td_proc; 2473 fdp = p->p_fd; 2474 MPASS(fdp != NULL); 2475 2476 #ifdef RACCT 2477 if (RACCT_ENABLED()) 2478 racct_set_unlocked(p, RACCT_NOFILE, 0); 2479 #endif 2480 2481 if (p->p_fdtol != NULL) 2482 fdclearlocks(td); 2483 2484 PROC_LOCK(p); 2485 p->p_fd = NULL; 2486 PROC_UNLOCK(p); 2487 2488 if (refcount_release(&fdp->fd_refcnt) == 0) 2489 return; 2490 2491 fdescfree_fds(td, fdp, 1); 2492 } 2493 2494 void 2495 pdescfree(struct thread *td) 2496 { 2497 struct proc *p; 2498 struct pwddesc *pdp; 2499 2500 p = td->td_proc; 2501 pdp = p->p_pd; 2502 MPASS(pdp != NULL); 2503 2504 PROC_LOCK(p); 2505 p->p_pd = NULL; 2506 PROC_UNLOCK(p); 2507 2508 pddrop(pdp); 2509 } 2510 2511 void 2512 fdescfree_remapped(struct filedesc *fdp) 2513 { 2514 fdescfree_fds(curthread, fdp, 0); 2515 } 2516 2517 /* 2518 * For setugid programs, we don't want to people to use that setugidness 2519 * to generate error messages which write to a file which otherwise would 2520 * otherwise be off-limits to the process. We check for filesystems where 2521 * the vnode can change out from under us after execve (like [lin]procfs). 2522 * 2523 * Since fdsetugidsafety calls this only for fd 0, 1 and 2, this check is 2524 * sufficient. We also don't check for setugidness since we know we are. 2525 */ 2526 static bool 2527 is_unsafe(struct file *fp) 2528 { 2529 struct vnode *vp; 2530 2531 if (fp->f_type != DTYPE_VNODE) 2532 return (false); 2533 2534 vp = fp->f_vnode; 2535 return ((vp->v_vflag & VV_PROCDEP) != 0); 2536 } 2537 2538 /* 2539 * Make this setguid thing safe, if at all possible. 2540 */ 2541 void 2542 fdsetugidsafety(struct thread *td) 2543 { 2544 struct filedesc *fdp; 2545 struct file *fp; 2546 int i; 2547 2548 fdp = td->td_proc->p_fd; 2549 KASSERT(fdp->fd_refcnt == 1, ("the fdtable should not be shared")); 2550 MPASS(fdp->fd_nfiles >= 3); 2551 for (i = 0; i <= 2; i++) { 2552 fp = fdp->fd_ofiles[i].fde_file; 2553 if (fp != NULL && is_unsafe(fp)) { 2554 FILEDESC_XLOCK(fdp); 2555 knote_fdclose(td, i); 2556 /* 2557 * NULL-out descriptor prior to close to avoid 2558 * a race while close blocks. 2559 */ 2560 fdfree(fdp, i); 2561 FILEDESC_XUNLOCK(fdp); 2562 (void) closef(fp, td); 2563 } 2564 } 2565 } 2566 2567 /* 2568 * If a specific file object occupies a specific file descriptor, close the 2569 * file descriptor entry and drop a reference on the file object. This is a 2570 * convenience function to handle a subsequent error in a function that calls 2571 * falloc() that handles the race that another thread might have closed the 2572 * file descriptor out from under the thread creating the file object. 2573 */ 2574 void 2575 fdclose(struct thread *td, struct file *fp, int idx) 2576 { 2577 struct filedesc *fdp = td->td_proc->p_fd; 2578 2579 FILEDESC_XLOCK(fdp); 2580 if (fdp->fd_ofiles[idx].fde_file == fp) { 2581 fdfree(fdp, idx); 2582 FILEDESC_XUNLOCK(fdp); 2583 fdrop(fp, td); 2584 } else 2585 FILEDESC_XUNLOCK(fdp); 2586 } 2587 2588 /* 2589 * Close any files on exec? 2590 */ 2591 void 2592 fdcloseexec(struct thread *td) 2593 { 2594 struct filedesc *fdp; 2595 struct filedescent *fde; 2596 struct file *fp; 2597 int i, lastfile; 2598 2599 fdp = td->td_proc->p_fd; 2600 KASSERT(fdp->fd_refcnt == 1, ("the fdtable should not be shared")); 2601 lastfile = fdlastfile_single(fdp); 2602 for (i = 0; i <= lastfile; i++) { 2603 fde = &fdp->fd_ofiles[i]; 2604 fp = fde->fde_file; 2605 if (fp != NULL && (fp->f_type == DTYPE_MQUEUE || 2606 (fde->fde_flags & UF_EXCLOSE))) { 2607 FILEDESC_XLOCK(fdp); 2608 fdfree(fdp, i); 2609 (void) closefp(fdp, i, fp, td, 0); 2610 FILEDESC_UNLOCK_ASSERT(fdp); 2611 } 2612 } 2613 } 2614 2615 /* 2616 * It is unsafe for set[ug]id processes to be started with file 2617 * descriptors 0..2 closed, as these descriptors are given implicit 2618 * significance in the Standard C library. fdcheckstd() will create a 2619 * descriptor referencing /dev/null for each of stdin, stdout, and 2620 * stderr that is not already open. 2621 */ 2622 int 2623 fdcheckstd(struct thread *td) 2624 { 2625 struct filedesc *fdp; 2626 register_t save; 2627 int i, error, devnull; 2628 2629 fdp = td->td_proc->p_fd; 2630 KASSERT(fdp->fd_refcnt == 1, ("the fdtable should not be shared")); 2631 MPASS(fdp->fd_nfiles >= 3); 2632 devnull = -1; 2633 for (i = 0; i <= 2; i++) { 2634 if (fdp->fd_ofiles[i].fde_file != NULL) 2635 continue; 2636 2637 save = td->td_retval[0]; 2638 if (devnull != -1) { 2639 error = kern_dup(td, FDDUP_FIXED, 0, devnull, i); 2640 } else { 2641 error = kern_openat(td, AT_FDCWD, "/dev/null", 2642 UIO_SYSSPACE, O_RDWR, 0); 2643 if (error == 0) { 2644 devnull = td->td_retval[0]; 2645 KASSERT(devnull == i, ("we didn't get our fd")); 2646 } 2647 } 2648 td->td_retval[0] = save; 2649 if (error != 0) 2650 return (error); 2651 } 2652 return (0); 2653 } 2654 2655 /* 2656 * Internal form of close. Decrement reference count on file structure. 2657 * Note: td may be NULL when closing a file that was being passed in a 2658 * message. 2659 */ 2660 int 2661 closef(struct file *fp, struct thread *td) 2662 { 2663 struct vnode *vp; 2664 struct flock lf; 2665 struct filedesc_to_leader *fdtol; 2666 struct filedesc *fdp; 2667 2668 /* 2669 * POSIX record locking dictates that any close releases ALL 2670 * locks owned by this process. This is handled by setting 2671 * a flag in the unlock to free ONLY locks obeying POSIX 2672 * semantics, and not to free BSD-style file locks. 2673 * If the descriptor was in a message, POSIX-style locks 2674 * aren't passed with the descriptor, and the thread pointer 2675 * will be NULL. Callers should be careful only to pass a 2676 * NULL thread pointer when there really is no owning 2677 * context that might have locks, or the locks will be 2678 * leaked. 2679 */ 2680 if (fp->f_type == DTYPE_VNODE && td != NULL) { 2681 vp = fp->f_vnode; 2682 if ((td->td_proc->p_leader->p_flag & P_ADVLOCK) != 0) { 2683 lf.l_whence = SEEK_SET; 2684 lf.l_start = 0; 2685 lf.l_len = 0; 2686 lf.l_type = F_UNLCK; 2687 (void) VOP_ADVLOCK(vp, (caddr_t)td->td_proc->p_leader, 2688 F_UNLCK, &lf, F_POSIX); 2689 } 2690 fdtol = td->td_proc->p_fdtol; 2691 if (fdtol != NULL) { 2692 /* 2693 * Handle special case where file descriptor table is 2694 * shared between multiple process leaders. 2695 */ 2696 fdp = td->td_proc->p_fd; 2697 FILEDESC_XLOCK(fdp); 2698 for (fdtol = fdtol->fdl_next; 2699 fdtol != td->td_proc->p_fdtol; 2700 fdtol = fdtol->fdl_next) { 2701 if ((fdtol->fdl_leader->p_flag & 2702 P_ADVLOCK) == 0) 2703 continue; 2704 fdtol->fdl_holdcount++; 2705 FILEDESC_XUNLOCK(fdp); 2706 lf.l_whence = SEEK_SET; 2707 lf.l_start = 0; 2708 lf.l_len = 0; 2709 lf.l_type = F_UNLCK; 2710 vp = fp->f_vnode; 2711 (void) VOP_ADVLOCK(vp, 2712 (caddr_t)fdtol->fdl_leader, F_UNLCK, &lf, 2713 F_POSIX); 2714 FILEDESC_XLOCK(fdp); 2715 fdtol->fdl_holdcount--; 2716 if (fdtol->fdl_holdcount == 0 && 2717 fdtol->fdl_wakeup != 0) { 2718 fdtol->fdl_wakeup = 0; 2719 wakeup(fdtol); 2720 } 2721 } 2722 FILEDESC_XUNLOCK(fdp); 2723 } 2724 } 2725 return (fdrop(fp, td)); 2726 } 2727 2728 /* 2729 * Initialize the file pointer with the specified properties. 2730 * 2731 * The ops are set with release semantics to be certain that the flags, type, 2732 * and data are visible when ops is. This is to prevent ops methods from being 2733 * called with bad data. 2734 */ 2735 void 2736 finit(struct file *fp, u_int flag, short type, void *data, struct fileops *ops) 2737 { 2738 fp->f_data = data; 2739 fp->f_flag = flag; 2740 fp->f_type = type; 2741 atomic_store_rel_ptr((volatile uintptr_t *)&fp->f_ops, (uintptr_t)ops); 2742 } 2743 2744 void 2745 finit_vnode(struct file *fp, u_int flag, void *data, struct fileops *ops) 2746 { 2747 fp->f_seqcount[UIO_READ] = 1; 2748 fp->f_seqcount[UIO_WRITE] = 1; 2749 finit(fp, (flag & FMASK) | (fp->f_flag & FHASLOCK), DTYPE_VNODE, 2750 data, ops); 2751 } 2752 2753 int 2754 fget_cap_locked(struct filedesc *fdp, int fd, cap_rights_t *needrightsp, 2755 struct file **fpp, struct filecaps *havecapsp) 2756 { 2757 struct filedescent *fde; 2758 int error; 2759 2760 FILEDESC_LOCK_ASSERT(fdp); 2761 2762 fde = fdeget_locked(fdp, fd); 2763 if (fde == NULL) { 2764 error = EBADF; 2765 goto out; 2766 } 2767 2768 #ifdef CAPABILITIES 2769 error = cap_check(cap_rights_fde_inline(fde), needrightsp); 2770 if (error != 0) 2771 goto out; 2772 #endif 2773 2774 if (havecapsp != NULL) 2775 filecaps_copy(&fde->fde_caps, havecapsp, true); 2776 2777 *fpp = fde->fde_file; 2778 2779 error = 0; 2780 out: 2781 return (error); 2782 } 2783 2784 int 2785 fget_cap(struct thread *td, int fd, cap_rights_t *needrightsp, 2786 struct file **fpp, struct filecaps *havecapsp) 2787 { 2788 struct filedesc *fdp = td->td_proc->p_fd; 2789 int error; 2790 #ifndef CAPABILITIES 2791 error = fget_unlocked(fdp, fd, needrightsp, fpp); 2792 if (havecapsp != NULL && error == 0) 2793 filecaps_fill(havecapsp); 2794 #else 2795 struct file *fp; 2796 seqc_t seq; 2797 2798 *fpp = NULL; 2799 for (;;) { 2800 error = fget_unlocked_seq(fdp, fd, needrightsp, &fp, &seq); 2801 if (error != 0) 2802 return (error); 2803 2804 if (havecapsp != NULL) { 2805 if (!filecaps_copy(&fdp->fd_ofiles[fd].fde_caps, 2806 havecapsp, false)) { 2807 fdrop(fp, td); 2808 goto get_locked; 2809 } 2810 } 2811 2812 if (!fd_modified(fdp, fd, seq)) 2813 break; 2814 fdrop(fp, td); 2815 } 2816 2817 *fpp = fp; 2818 return (0); 2819 2820 get_locked: 2821 FILEDESC_SLOCK(fdp); 2822 error = fget_cap_locked(fdp, fd, needrightsp, fpp, havecapsp); 2823 if (error == 0 && !fhold(*fpp)) 2824 error = EBADF; 2825 FILEDESC_SUNLOCK(fdp); 2826 #endif 2827 return (error); 2828 } 2829 2830 #ifdef CAPABILITIES 2831 int 2832 fgetvp_lookup_smr(int fd, struct nameidata *ndp, struct vnode **vpp, bool *fsearch) 2833 { 2834 const struct filedescent *fde; 2835 const struct fdescenttbl *fdt; 2836 struct filedesc *fdp; 2837 struct file *fp; 2838 struct vnode *vp; 2839 const cap_rights_t *haverights; 2840 cap_rights_t rights; 2841 seqc_t seq; 2842 2843 VFS_SMR_ASSERT_ENTERED(); 2844 2845 rights = *ndp->ni_rightsneeded; 2846 cap_rights_set_one(&rights, CAP_LOOKUP); 2847 2848 fdp = curproc->p_fd; 2849 fdt = fdp->fd_files; 2850 if (__predict_false((u_int)fd >= fdt->fdt_nfiles)) 2851 return (EBADF); 2852 seq = seqc_read_any(fd_seqc(fdt, fd)); 2853 if (__predict_false(seqc_in_modify(seq))) 2854 return (EAGAIN); 2855 fde = &fdt->fdt_ofiles[fd]; 2856 haverights = cap_rights_fde_inline(fde); 2857 fp = fde->fde_file; 2858 if (__predict_false(fp == NULL)) 2859 return (EAGAIN); 2860 if (__predict_false(cap_check_inline_transient(haverights, &rights))) 2861 return (EAGAIN); 2862 *fsearch = ((fp->f_flag & FSEARCH) != 0); 2863 vp = fp->f_vnode; 2864 if (__predict_false(vp == NULL || vp->v_type != VDIR)) { 2865 return (EAGAIN); 2866 } 2867 if (!filecaps_copy(&fde->fde_caps, &ndp->ni_filecaps, false)) { 2868 return (EAGAIN); 2869 } 2870 /* 2871 * Use an acquire barrier to force re-reading of fdt so it is 2872 * refreshed for verification. 2873 */ 2874 atomic_thread_fence_acq(); 2875 fdt = fdp->fd_files; 2876 if (__predict_false(!seqc_consistent_nomb(fd_seqc(fdt, fd), seq))) 2877 return (EAGAIN); 2878 /* 2879 * If file descriptor doesn't have all rights, 2880 * all lookups relative to it must also be 2881 * strictly relative. 2882 * 2883 * Not yet supported by fast path. 2884 */ 2885 CAP_ALL(&rights); 2886 if (!cap_rights_contains(&ndp->ni_filecaps.fc_rights, &rights) || 2887 ndp->ni_filecaps.fc_fcntls != CAP_FCNTL_ALL || 2888 ndp->ni_filecaps.fc_nioctls != -1) { 2889 #ifdef notyet 2890 ndp->ni_lcf |= NI_LCF_STRICTRELATIVE; 2891 #else 2892 return (EAGAIN); 2893 #endif 2894 } 2895 *vpp = vp; 2896 return (0); 2897 } 2898 #else 2899 int 2900 fgetvp_lookup_smr(int fd, struct nameidata *ndp, struct vnode **vpp, bool *fsearch) 2901 { 2902 const struct fdescenttbl *fdt; 2903 struct filedesc *fdp; 2904 struct file *fp; 2905 struct vnode *vp; 2906 2907 VFS_SMR_ASSERT_ENTERED(); 2908 2909 fdp = curproc->p_fd; 2910 fdt = fdp->fd_files; 2911 if (__predict_false((u_int)fd >= fdt->fdt_nfiles)) 2912 return (EBADF); 2913 fp = fdt->fdt_ofiles[fd].fde_file; 2914 if (__predict_false(fp == NULL)) 2915 return (EAGAIN); 2916 *fsearch = ((fp->f_flag & FSEARCH) != 0); 2917 vp = fp->f_vnode; 2918 if (__predict_false(vp == NULL || vp->v_type != VDIR)) { 2919 return (EAGAIN); 2920 } 2921 /* 2922 * Use an acquire barrier to force re-reading of fdt so it is 2923 * refreshed for verification. 2924 */ 2925 atomic_thread_fence_acq(); 2926 fdt = fdp->fd_files; 2927 if (__predict_false(fp != fdt->fdt_ofiles[fd].fde_file)) 2928 return (EAGAIN); 2929 filecaps_fill(&ndp->ni_filecaps); 2930 *vpp = vp; 2931 return (0); 2932 } 2933 #endif 2934 2935 int 2936 fget_unlocked_seq(struct filedesc *fdp, int fd, cap_rights_t *needrightsp, 2937 struct file **fpp, seqc_t *seqp) 2938 { 2939 #ifdef CAPABILITIES 2940 const struct filedescent *fde; 2941 #endif 2942 const struct fdescenttbl *fdt; 2943 struct file *fp; 2944 #ifdef CAPABILITIES 2945 seqc_t seq; 2946 cap_rights_t haverights; 2947 int error; 2948 #endif 2949 2950 fdt = fdp->fd_files; 2951 if (__predict_false((u_int)fd >= fdt->fdt_nfiles)) 2952 return (EBADF); 2953 /* 2954 * Fetch the descriptor locklessly. We avoid fdrop() races by 2955 * never raising a refcount above 0. To accomplish this we have 2956 * to use a cmpset loop rather than an atomic_add. The descriptor 2957 * must be re-verified once we acquire a reference to be certain 2958 * that the identity is still correct and we did not lose a race 2959 * due to preemption. 2960 */ 2961 for (;;) { 2962 #ifdef CAPABILITIES 2963 seq = seqc_read(fd_seqc(fdt, fd)); 2964 fde = &fdt->fdt_ofiles[fd]; 2965 haverights = *cap_rights_fde_inline(fde); 2966 fp = fde->fde_file; 2967 if (!seqc_consistent(fd_seqc(fdt, fd), seq)) 2968 continue; 2969 #else 2970 fp = fdt->fdt_ofiles[fd].fde_file; 2971 #endif 2972 if (fp == NULL) 2973 return (EBADF); 2974 #ifdef CAPABILITIES 2975 error = cap_check_inline(&haverights, needrightsp); 2976 if (error != 0) 2977 return (error); 2978 #endif 2979 if (__predict_false(!refcount_acquire_if_not_zero(&fp->f_count))) { 2980 /* 2981 * The count was found either saturated or zero. 2982 * This re-read is not any more racy than using the 2983 * return value from fcmpset. 2984 */ 2985 if (refcount_load(&fp->f_count) != 0) 2986 return (EBADF); 2987 /* 2988 * Force a reload. Other thread could reallocate the 2989 * table before this fd was closed, so it is possible 2990 * that there is a stale fp pointer in cached version. 2991 */ 2992 fdt = atomic_load_ptr(&fdp->fd_files); 2993 continue; 2994 } 2995 /* 2996 * Use an acquire barrier to force re-reading of fdt so it is 2997 * refreshed for verification. 2998 */ 2999 atomic_thread_fence_acq(); 3000 fdt = fdp->fd_files; 3001 #ifdef CAPABILITIES 3002 if (seqc_consistent_nomb(fd_seqc(fdt, fd), seq)) 3003 #else 3004 if (fp == fdt->fdt_ofiles[fd].fde_file) 3005 #endif 3006 break; 3007 fdrop(fp, curthread); 3008 } 3009 *fpp = fp; 3010 if (seqp != NULL) { 3011 #ifdef CAPABILITIES 3012 *seqp = seq; 3013 #endif 3014 } 3015 return (0); 3016 } 3017 3018 /* 3019 * See the comments in fget_unlocked_seq for an explanation of how this works. 3020 * 3021 * This is a simplified variant which bails out to the aforementioned routine 3022 * if anything goes wrong. In practice this only happens when userspace is 3023 * racing with itself. 3024 */ 3025 int 3026 fget_unlocked(struct filedesc *fdp, int fd, cap_rights_t *needrightsp, 3027 struct file **fpp) 3028 { 3029 #ifdef CAPABILITIES 3030 const struct filedescent *fde; 3031 #endif 3032 const struct fdescenttbl *fdt; 3033 struct file *fp; 3034 #ifdef CAPABILITIES 3035 seqc_t seq; 3036 const cap_rights_t *haverights; 3037 #endif 3038 3039 fdt = fdp->fd_files; 3040 if (__predict_false((u_int)fd >= fdt->fdt_nfiles)) 3041 return (EBADF); 3042 #ifdef CAPABILITIES 3043 seq = seqc_read_any(fd_seqc(fdt, fd)); 3044 if (__predict_false(seqc_in_modify(seq))) 3045 goto out_fallback; 3046 fde = &fdt->fdt_ofiles[fd]; 3047 haverights = cap_rights_fde_inline(fde); 3048 fp = fde->fde_file; 3049 #else 3050 fp = fdt->fdt_ofiles[fd].fde_file; 3051 #endif 3052 if (__predict_false(fp == NULL)) 3053 goto out_fallback; 3054 #ifdef CAPABILITIES 3055 if (__predict_false(cap_check_inline_transient(haverights, needrightsp))) 3056 goto out_fallback; 3057 #endif 3058 if (__predict_false(!refcount_acquire_if_not_zero(&fp->f_count))) 3059 goto out_fallback; 3060 3061 /* 3062 * Use an acquire barrier to force re-reading of fdt so it is 3063 * refreshed for verification. 3064 */ 3065 atomic_thread_fence_acq(); 3066 fdt = fdp->fd_files; 3067 #ifdef CAPABILITIES 3068 if (__predict_false(!seqc_consistent_nomb(fd_seqc(fdt, fd), seq))) 3069 #else 3070 if (__predict_false(fp != fdt->fdt_ofiles[fd].fde_file)) 3071 #endif 3072 goto out_fdrop; 3073 *fpp = fp; 3074 return (0); 3075 out_fdrop: 3076 fdrop(fp, curthread); 3077 out_fallback: 3078 return (fget_unlocked_seq(fdp, fd, needrightsp, fpp, NULL)); 3079 } 3080 3081 /* 3082 * Extract the file pointer associated with the specified descriptor for the 3083 * current user process. 3084 * 3085 * If the descriptor doesn't exist or doesn't match 'flags', EBADF is 3086 * returned. 3087 * 3088 * File's rights will be checked against the capability rights mask. 3089 * 3090 * If an error occurred the non-zero error is returned and *fpp is set to 3091 * NULL. Otherwise *fpp is held and set and zero is returned. Caller is 3092 * responsible for fdrop(). 3093 */ 3094 static __inline int 3095 _fget(struct thread *td, int fd, struct file **fpp, int flags, 3096 cap_rights_t *needrightsp) 3097 { 3098 struct filedesc *fdp; 3099 struct file *fp; 3100 int error; 3101 3102 *fpp = NULL; 3103 fdp = td->td_proc->p_fd; 3104 error = fget_unlocked(fdp, fd, needrightsp, &fp); 3105 if (__predict_false(error != 0)) 3106 return (error); 3107 if (__predict_false(fp->f_ops == &badfileops)) { 3108 fdrop(fp, td); 3109 return (EBADF); 3110 } 3111 3112 /* 3113 * FREAD and FWRITE failure return EBADF as per POSIX. 3114 */ 3115 error = 0; 3116 switch (flags) { 3117 case FREAD: 3118 case FWRITE: 3119 if ((fp->f_flag & flags) == 0) 3120 error = EBADF; 3121 break; 3122 case FEXEC: 3123 if ((fp->f_flag & (FREAD | FEXEC)) == 0 || 3124 ((fp->f_flag & FWRITE) != 0)) 3125 error = EBADF; 3126 break; 3127 case 0: 3128 break; 3129 default: 3130 KASSERT(0, ("wrong flags")); 3131 } 3132 3133 if (error != 0) { 3134 fdrop(fp, td); 3135 return (error); 3136 } 3137 3138 *fpp = fp; 3139 return (0); 3140 } 3141 3142 int 3143 fget(struct thread *td, int fd, cap_rights_t *rightsp, struct file **fpp) 3144 { 3145 3146 return (_fget(td, fd, fpp, 0, rightsp)); 3147 } 3148 3149 int 3150 fget_mmap(struct thread *td, int fd, cap_rights_t *rightsp, vm_prot_t *maxprotp, 3151 struct file **fpp) 3152 { 3153 int error; 3154 #ifndef CAPABILITIES 3155 error = _fget(td, fd, fpp, 0, rightsp); 3156 if (maxprotp != NULL) 3157 *maxprotp = VM_PROT_ALL; 3158 return (error); 3159 #else 3160 cap_rights_t fdrights; 3161 struct filedesc *fdp; 3162 struct file *fp; 3163 seqc_t seq; 3164 3165 *fpp = NULL; 3166 fdp = td->td_proc->p_fd; 3167 MPASS(cap_rights_is_set(rightsp, CAP_MMAP)); 3168 for (;;) { 3169 error = fget_unlocked_seq(fdp, fd, rightsp, &fp, &seq); 3170 if (__predict_false(error != 0)) 3171 return (error); 3172 if (__predict_false(fp->f_ops == &badfileops)) { 3173 fdrop(fp, td); 3174 return (EBADF); 3175 } 3176 if (maxprotp != NULL) 3177 fdrights = *cap_rights(fdp, fd); 3178 if (!fd_modified(fdp, fd, seq)) 3179 break; 3180 fdrop(fp, td); 3181 } 3182 3183 /* 3184 * If requested, convert capability rights to access flags. 3185 */ 3186 if (maxprotp != NULL) 3187 *maxprotp = cap_rights_to_vmprot(&fdrights); 3188 *fpp = fp; 3189 return (0); 3190 #endif 3191 } 3192 3193 int 3194 fget_read(struct thread *td, int fd, cap_rights_t *rightsp, struct file **fpp) 3195 { 3196 3197 return (_fget(td, fd, fpp, FREAD, rightsp)); 3198 } 3199 3200 int 3201 fget_write(struct thread *td, int fd, cap_rights_t *rightsp, struct file **fpp) 3202 { 3203 3204 return (_fget(td, fd, fpp, FWRITE, rightsp)); 3205 } 3206 3207 int 3208 fget_fcntl(struct thread *td, int fd, cap_rights_t *rightsp, int needfcntl, 3209 struct file **fpp) 3210 { 3211 struct filedesc *fdp = td->td_proc->p_fd; 3212 #ifndef CAPABILITIES 3213 return (fget_unlocked(fdp, fd, rightsp, fpp)); 3214 #else 3215 struct file *fp; 3216 int error; 3217 seqc_t seq; 3218 3219 *fpp = NULL; 3220 MPASS(cap_rights_is_set(rightsp, CAP_FCNTL)); 3221 for (;;) { 3222 error = fget_unlocked_seq(fdp, fd, rightsp, &fp, &seq); 3223 if (error != 0) 3224 return (error); 3225 error = cap_fcntl_check(fdp, fd, needfcntl); 3226 if (!fd_modified(fdp, fd, seq)) 3227 break; 3228 fdrop(fp, td); 3229 } 3230 if (error != 0) { 3231 fdrop(fp, td); 3232 return (error); 3233 } 3234 *fpp = fp; 3235 return (0); 3236 #endif 3237 } 3238 3239 /* 3240 * Like fget() but loads the underlying vnode, or returns an error if the 3241 * descriptor does not represent a vnode. Note that pipes use vnodes but 3242 * never have VM objects. The returned vnode will be vref()'d. 3243 * 3244 * XXX: what about the unused flags ? 3245 */ 3246 static __inline int 3247 _fgetvp(struct thread *td, int fd, int flags, cap_rights_t *needrightsp, 3248 struct vnode **vpp) 3249 { 3250 struct file *fp; 3251 int error; 3252 3253 *vpp = NULL; 3254 error = _fget(td, fd, &fp, flags, needrightsp); 3255 if (error != 0) 3256 return (error); 3257 if (fp->f_vnode == NULL) { 3258 error = EINVAL; 3259 } else { 3260 *vpp = fp->f_vnode; 3261 vrefact(*vpp); 3262 } 3263 fdrop(fp, td); 3264 3265 return (error); 3266 } 3267 3268 int 3269 fgetvp(struct thread *td, int fd, cap_rights_t *rightsp, struct vnode **vpp) 3270 { 3271 3272 return (_fgetvp(td, fd, 0, rightsp, vpp)); 3273 } 3274 3275 int 3276 fgetvp_rights(struct thread *td, int fd, cap_rights_t *needrightsp, 3277 struct filecaps *havecaps, struct vnode **vpp) 3278 { 3279 struct filecaps caps; 3280 struct file *fp; 3281 int error; 3282 3283 error = fget_cap(td, fd, needrightsp, &fp, &caps); 3284 if (error != 0) 3285 return (error); 3286 if (fp->f_ops == &badfileops) { 3287 error = EBADF; 3288 goto out; 3289 } 3290 if (fp->f_vnode == NULL) { 3291 error = EINVAL; 3292 goto out; 3293 } 3294 3295 *havecaps = caps; 3296 *vpp = fp->f_vnode; 3297 vrefact(*vpp); 3298 fdrop(fp, td); 3299 3300 return (0); 3301 out: 3302 filecaps_free(&caps); 3303 fdrop(fp, td); 3304 return (error); 3305 } 3306 3307 int 3308 fgetvp_read(struct thread *td, int fd, cap_rights_t *rightsp, struct vnode **vpp) 3309 { 3310 3311 return (_fgetvp(td, fd, FREAD, rightsp, vpp)); 3312 } 3313 3314 int 3315 fgetvp_exec(struct thread *td, int fd, cap_rights_t *rightsp, struct vnode **vpp) 3316 { 3317 3318 return (_fgetvp(td, fd, FEXEC, rightsp, vpp)); 3319 } 3320 3321 #ifdef notyet 3322 int 3323 fgetvp_write(struct thread *td, int fd, cap_rights_t *rightsp, 3324 struct vnode **vpp) 3325 { 3326 3327 return (_fgetvp(td, fd, FWRITE, rightsp, vpp)); 3328 } 3329 #endif 3330 3331 /* 3332 * Handle the last reference to a file being closed. 3333 * 3334 * Without the noinline attribute clang keeps inlining the func thorough this 3335 * file when fdrop is used. 3336 */ 3337 int __noinline 3338 _fdrop(struct file *fp, struct thread *td) 3339 { 3340 int error; 3341 #ifdef INVARIANTS 3342 int count; 3343 3344 count = refcount_load(&fp->f_count); 3345 if (count != 0) 3346 panic("fdrop: fp %p count %d", fp, count); 3347 #endif 3348 error = fo_close(fp, td); 3349 atomic_subtract_int(&openfiles, 1); 3350 crfree(fp->f_cred); 3351 free(fp->f_advice, M_FADVISE); 3352 uma_zfree(file_zone, fp); 3353 3354 return (error); 3355 } 3356 3357 /* 3358 * Apply an advisory lock on a file descriptor. 3359 * 3360 * Just attempt to get a record lock of the requested type on the entire file 3361 * (l_whence = SEEK_SET, l_start = 0, l_len = 0). 3362 */ 3363 #ifndef _SYS_SYSPROTO_H_ 3364 struct flock_args { 3365 int fd; 3366 int how; 3367 }; 3368 #endif 3369 /* ARGSUSED */ 3370 int 3371 sys_flock(struct thread *td, struct flock_args *uap) 3372 { 3373 struct file *fp; 3374 struct vnode *vp; 3375 struct flock lf; 3376 int error; 3377 3378 error = fget(td, uap->fd, &cap_flock_rights, &fp); 3379 if (error != 0) 3380 return (error); 3381 if (fp->f_type != DTYPE_VNODE) { 3382 fdrop(fp, td); 3383 return (EOPNOTSUPP); 3384 } 3385 3386 vp = fp->f_vnode; 3387 lf.l_whence = SEEK_SET; 3388 lf.l_start = 0; 3389 lf.l_len = 0; 3390 if (uap->how & LOCK_UN) { 3391 lf.l_type = F_UNLCK; 3392 atomic_clear_int(&fp->f_flag, FHASLOCK); 3393 error = VOP_ADVLOCK(vp, (caddr_t)fp, F_UNLCK, &lf, F_FLOCK); 3394 goto done2; 3395 } 3396 if (uap->how & LOCK_EX) 3397 lf.l_type = F_WRLCK; 3398 else if (uap->how & LOCK_SH) 3399 lf.l_type = F_RDLCK; 3400 else { 3401 error = EBADF; 3402 goto done2; 3403 } 3404 atomic_set_int(&fp->f_flag, FHASLOCK); 3405 error = VOP_ADVLOCK(vp, (caddr_t)fp, F_SETLK, &lf, 3406 (uap->how & LOCK_NB) ? F_FLOCK : F_FLOCK | F_WAIT); 3407 done2: 3408 fdrop(fp, td); 3409 return (error); 3410 } 3411 /* 3412 * Duplicate the specified descriptor to a free descriptor. 3413 */ 3414 int 3415 dupfdopen(struct thread *td, struct filedesc *fdp, int dfd, int mode, 3416 int openerror, int *indxp) 3417 { 3418 struct filedescent *newfde, *oldfde; 3419 struct file *fp; 3420 u_long *ioctls; 3421 int error, indx; 3422 3423 KASSERT(openerror == ENODEV || openerror == ENXIO, 3424 ("unexpected error %d in %s", openerror, __func__)); 3425 3426 /* 3427 * If the to-be-dup'd fd number is greater than the allowed number 3428 * of file descriptors, or the fd to be dup'd has already been 3429 * closed, then reject. 3430 */ 3431 FILEDESC_XLOCK(fdp); 3432 if ((fp = fget_locked(fdp, dfd)) == NULL) { 3433 FILEDESC_XUNLOCK(fdp); 3434 return (EBADF); 3435 } 3436 3437 error = fdalloc(td, 0, &indx); 3438 if (error != 0) { 3439 FILEDESC_XUNLOCK(fdp); 3440 return (error); 3441 } 3442 3443 /* 3444 * There are two cases of interest here. 3445 * 3446 * For ENODEV simply dup (dfd) to file descriptor (indx) and return. 3447 * 3448 * For ENXIO steal away the file structure from (dfd) and store it in 3449 * (indx). (dfd) is effectively closed by this operation. 3450 */ 3451 switch (openerror) { 3452 case ENODEV: 3453 /* 3454 * Check that the mode the file is being opened for is a 3455 * subset of the mode of the existing descriptor. 3456 */ 3457 if (((mode & (FREAD|FWRITE)) | fp->f_flag) != fp->f_flag) { 3458 fdunused(fdp, indx); 3459 FILEDESC_XUNLOCK(fdp); 3460 return (EACCES); 3461 } 3462 if (!fhold(fp)) { 3463 fdunused(fdp, indx); 3464 FILEDESC_XUNLOCK(fdp); 3465 return (EBADF); 3466 } 3467 newfde = &fdp->fd_ofiles[indx]; 3468 oldfde = &fdp->fd_ofiles[dfd]; 3469 ioctls = filecaps_copy_prep(&oldfde->fde_caps); 3470 #ifdef CAPABILITIES 3471 seqc_write_begin(&newfde->fde_seqc); 3472 #endif 3473 memcpy(newfde, oldfde, fde_change_size); 3474 filecaps_copy_finish(&oldfde->fde_caps, &newfde->fde_caps, 3475 ioctls); 3476 #ifdef CAPABILITIES 3477 seqc_write_end(&newfde->fde_seqc); 3478 #endif 3479 break; 3480 case ENXIO: 3481 /* 3482 * Steal away the file pointer from dfd and stuff it into indx. 3483 */ 3484 newfde = &fdp->fd_ofiles[indx]; 3485 oldfde = &fdp->fd_ofiles[dfd]; 3486 #ifdef CAPABILITIES 3487 seqc_write_begin(&newfde->fde_seqc); 3488 #endif 3489 memcpy(newfde, oldfde, fde_change_size); 3490 oldfde->fde_file = NULL; 3491 fdunused(fdp, dfd); 3492 #ifdef CAPABILITIES 3493 seqc_write_end(&newfde->fde_seqc); 3494 #endif 3495 break; 3496 } 3497 FILEDESC_XUNLOCK(fdp); 3498 *indxp = indx; 3499 return (0); 3500 } 3501 3502 /* 3503 * This sysctl determines if we will allow a process to chroot(2) if it 3504 * has a directory open: 3505 * 0: disallowed for all processes. 3506 * 1: allowed for processes that were not already chroot(2)'ed. 3507 * 2: allowed for all processes. 3508 */ 3509 3510 static int chroot_allow_open_directories = 1; 3511 3512 SYSCTL_INT(_kern, OID_AUTO, chroot_allow_open_directories, CTLFLAG_RW, 3513 &chroot_allow_open_directories, 0, 3514 "Allow a process to chroot(2) if it has a directory open"); 3515 3516 /* 3517 * Helper function for raised chroot(2) security function: Refuse if 3518 * any filedescriptors are open directories. 3519 */ 3520 static int 3521 chroot_refuse_vdir_fds(struct filedesc *fdp) 3522 { 3523 struct vnode *vp; 3524 struct file *fp; 3525 int fd, lastfile; 3526 3527 FILEDESC_LOCK_ASSERT(fdp); 3528 3529 lastfile = fdlastfile(fdp); 3530 for (fd = 0; fd <= lastfile; fd++) { 3531 fp = fget_locked(fdp, fd); 3532 if (fp == NULL) 3533 continue; 3534 if (fp->f_type == DTYPE_VNODE) { 3535 vp = fp->f_vnode; 3536 if (vp->v_type == VDIR) 3537 return (EPERM); 3538 } 3539 } 3540 return (0); 3541 } 3542 3543 static void 3544 pwd_fill(struct pwd *oldpwd, struct pwd *newpwd) 3545 { 3546 3547 if (newpwd->pwd_cdir == NULL && oldpwd->pwd_cdir != NULL) { 3548 vrefact(oldpwd->pwd_cdir); 3549 newpwd->pwd_cdir = oldpwd->pwd_cdir; 3550 } 3551 3552 if (newpwd->pwd_rdir == NULL && oldpwd->pwd_rdir != NULL) { 3553 vrefact(oldpwd->pwd_rdir); 3554 newpwd->pwd_rdir = oldpwd->pwd_rdir; 3555 } 3556 3557 if (newpwd->pwd_jdir == NULL && oldpwd->pwd_jdir != NULL) { 3558 vrefact(oldpwd->pwd_jdir); 3559 newpwd->pwd_jdir = oldpwd->pwd_jdir; 3560 } 3561 } 3562 3563 struct pwd * 3564 pwd_hold_pwddesc(struct pwddesc *pdp) 3565 { 3566 struct pwd *pwd; 3567 3568 PWDDESC_ASSERT_XLOCKED(pdp); 3569 pwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); 3570 if (pwd != NULL) 3571 refcount_acquire(&pwd->pwd_refcount); 3572 return (pwd); 3573 } 3574 3575 bool 3576 pwd_hold_smr(struct pwd *pwd) 3577 { 3578 3579 MPASS(pwd != NULL); 3580 if (__predict_true(refcount_acquire_if_not_zero(&pwd->pwd_refcount))) { 3581 return (true); 3582 } 3583 return (false); 3584 } 3585 3586 struct pwd * 3587 pwd_hold(struct thread *td) 3588 { 3589 struct pwddesc *pdp; 3590 struct pwd *pwd; 3591 3592 pdp = td->td_proc->p_pd; 3593 3594 vfs_smr_enter(); 3595 pwd = vfs_smr_entered_load(&pdp->pd_pwd); 3596 if (pwd_hold_smr(pwd)) { 3597 vfs_smr_exit(); 3598 return (pwd); 3599 } 3600 vfs_smr_exit(); 3601 PWDDESC_XLOCK(pdp); 3602 pwd = pwd_hold_pwddesc(pdp); 3603 MPASS(pwd != NULL); 3604 PWDDESC_XUNLOCK(pdp); 3605 return (pwd); 3606 } 3607 3608 struct pwd * 3609 pwd_get_smr(void) 3610 { 3611 struct pwd *pwd; 3612 3613 pwd = vfs_smr_entered_load(&curproc->p_pd->pd_pwd); 3614 MPASS(pwd != NULL); 3615 return (pwd); 3616 } 3617 3618 static struct pwd * 3619 pwd_alloc(void) 3620 { 3621 struct pwd *pwd; 3622 3623 pwd = uma_zalloc_smr(pwd_zone, M_WAITOK); 3624 bzero(pwd, sizeof(*pwd)); 3625 refcount_init(&pwd->pwd_refcount, 1); 3626 return (pwd); 3627 } 3628 3629 void 3630 pwd_drop(struct pwd *pwd) 3631 { 3632 3633 if (!refcount_release(&pwd->pwd_refcount)) 3634 return; 3635 3636 if (pwd->pwd_cdir != NULL) 3637 vrele(pwd->pwd_cdir); 3638 if (pwd->pwd_rdir != NULL) 3639 vrele(pwd->pwd_rdir); 3640 if (pwd->pwd_jdir != NULL) 3641 vrele(pwd->pwd_jdir); 3642 uma_zfree_smr(pwd_zone, pwd); 3643 } 3644 3645 /* 3646 * Common routine for kern_chroot() and jail_attach(). The caller is 3647 * responsible for invoking priv_check() and mac_vnode_check_chroot() to 3648 * authorize this operation. 3649 */ 3650 int 3651 pwd_chroot(struct thread *td, struct vnode *vp) 3652 { 3653 struct pwddesc *pdp; 3654 struct filedesc *fdp; 3655 struct pwd *newpwd, *oldpwd; 3656 int error; 3657 3658 fdp = td->td_proc->p_fd; 3659 pdp = td->td_proc->p_pd; 3660 newpwd = pwd_alloc(); 3661 FILEDESC_SLOCK(fdp); 3662 PWDDESC_XLOCK(pdp); 3663 oldpwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); 3664 if (chroot_allow_open_directories == 0 || 3665 (chroot_allow_open_directories == 1 && 3666 oldpwd->pwd_rdir != rootvnode)) { 3667 error = chroot_refuse_vdir_fds(fdp); 3668 FILEDESC_SUNLOCK(fdp); 3669 if (error != 0) { 3670 PWDDESC_XUNLOCK(pdp); 3671 pwd_drop(newpwd); 3672 return (error); 3673 } 3674 } else { 3675 FILEDESC_SUNLOCK(fdp); 3676 } 3677 3678 vrefact(vp); 3679 newpwd->pwd_rdir = vp; 3680 if (oldpwd->pwd_jdir == NULL) { 3681 vrefact(vp); 3682 newpwd->pwd_jdir = vp; 3683 } 3684 pwd_fill(oldpwd, newpwd); 3685 pwd_set(pdp, newpwd); 3686 PWDDESC_XUNLOCK(pdp); 3687 pwd_drop(oldpwd); 3688 return (0); 3689 } 3690 3691 void 3692 pwd_chdir(struct thread *td, struct vnode *vp) 3693 { 3694 struct pwddesc *pdp; 3695 struct pwd *newpwd, *oldpwd; 3696 3697 VNPASS(vp->v_usecount > 0, vp); 3698 3699 newpwd = pwd_alloc(); 3700 pdp = td->td_proc->p_pd; 3701 PWDDESC_XLOCK(pdp); 3702 oldpwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); 3703 newpwd->pwd_cdir = vp; 3704 pwd_fill(oldpwd, newpwd); 3705 pwd_set(pdp, newpwd); 3706 PWDDESC_XUNLOCK(pdp); 3707 pwd_drop(oldpwd); 3708 } 3709 3710 void 3711 pwd_ensure_dirs(void) 3712 { 3713 struct pwddesc *pdp; 3714 struct pwd *oldpwd, *newpwd; 3715 3716 pdp = curproc->p_pd; 3717 PWDDESC_XLOCK(pdp); 3718 oldpwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); 3719 if (oldpwd->pwd_cdir != NULL && oldpwd->pwd_rdir != NULL) { 3720 PWDDESC_XUNLOCK(pdp); 3721 return; 3722 } 3723 PWDDESC_XUNLOCK(pdp); 3724 3725 newpwd = pwd_alloc(); 3726 PWDDESC_XLOCK(pdp); 3727 oldpwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); 3728 pwd_fill(oldpwd, newpwd); 3729 if (newpwd->pwd_cdir == NULL) { 3730 vrefact(rootvnode); 3731 newpwd->pwd_cdir = rootvnode; 3732 } 3733 if (newpwd->pwd_rdir == NULL) { 3734 vrefact(rootvnode); 3735 newpwd->pwd_rdir = rootvnode; 3736 } 3737 pwd_set(pdp, newpwd); 3738 PWDDESC_XUNLOCK(pdp); 3739 pwd_drop(oldpwd); 3740 } 3741 3742 void 3743 pwd_set_rootvnode(void) 3744 { 3745 struct pwddesc *pdp; 3746 struct pwd *oldpwd, *newpwd; 3747 3748 pdp = curproc->p_pd; 3749 3750 newpwd = pwd_alloc(); 3751 PWDDESC_XLOCK(pdp); 3752 oldpwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); 3753 vrefact(rootvnode); 3754 newpwd->pwd_cdir = rootvnode; 3755 vrefact(rootvnode); 3756 newpwd->pwd_rdir = rootvnode; 3757 pwd_fill(oldpwd, newpwd); 3758 pwd_set(pdp, newpwd); 3759 PWDDESC_XUNLOCK(pdp); 3760 pwd_drop(oldpwd); 3761 } 3762 3763 /* 3764 * Scan all active processes and prisons to see if any of them have a current 3765 * or root directory of `olddp'. If so, replace them with the new mount point. 3766 */ 3767 void 3768 mountcheckdirs(struct vnode *olddp, struct vnode *newdp) 3769 { 3770 struct pwddesc *pdp; 3771 struct pwd *newpwd, *oldpwd; 3772 struct prison *pr; 3773 struct proc *p; 3774 int nrele; 3775 3776 if (vrefcnt(olddp) == 1) 3777 return; 3778 nrele = 0; 3779 newpwd = pwd_alloc(); 3780 sx_slock(&allproc_lock); 3781 FOREACH_PROC_IN_SYSTEM(p) { 3782 PROC_LOCK(p); 3783 pdp = pdhold(p); 3784 PROC_UNLOCK(p); 3785 if (pdp == NULL) 3786 continue; 3787 PWDDESC_XLOCK(pdp); 3788 oldpwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); 3789 if (oldpwd == NULL || 3790 (oldpwd->pwd_cdir != olddp && 3791 oldpwd->pwd_rdir != olddp && 3792 oldpwd->pwd_jdir != olddp)) { 3793 PWDDESC_XUNLOCK(pdp); 3794 pddrop(pdp); 3795 continue; 3796 } 3797 if (oldpwd->pwd_cdir == olddp) { 3798 vrefact(newdp); 3799 newpwd->pwd_cdir = newdp; 3800 } 3801 if (oldpwd->pwd_rdir == olddp) { 3802 vrefact(newdp); 3803 newpwd->pwd_rdir = newdp; 3804 } 3805 if (oldpwd->pwd_jdir == olddp) { 3806 vrefact(newdp); 3807 newpwd->pwd_jdir = newdp; 3808 } 3809 pwd_fill(oldpwd, newpwd); 3810 pwd_set(pdp, newpwd); 3811 PWDDESC_XUNLOCK(pdp); 3812 pwd_drop(oldpwd); 3813 pddrop(pdp); 3814 newpwd = pwd_alloc(); 3815 } 3816 sx_sunlock(&allproc_lock); 3817 pwd_drop(newpwd); 3818 if (rootvnode == olddp) { 3819 vrefact(newdp); 3820 rootvnode = newdp; 3821 nrele++; 3822 } 3823 mtx_lock(&prison0.pr_mtx); 3824 if (prison0.pr_root == olddp) { 3825 vrefact(newdp); 3826 prison0.pr_root = newdp; 3827 nrele++; 3828 } 3829 mtx_unlock(&prison0.pr_mtx); 3830 sx_slock(&allprison_lock); 3831 TAILQ_FOREACH(pr, &allprison, pr_list) { 3832 mtx_lock(&pr->pr_mtx); 3833 if (pr->pr_root == olddp) { 3834 vrefact(newdp); 3835 pr->pr_root = newdp; 3836 nrele++; 3837 } 3838 mtx_unlock(&pr->pr_mtx); 3839 } 3840 sx_sunlock(&allprison_lock); 3841 while (nrele--) 3842 vrele(olddp); 3843 } 3844 3845 struct filedesc_to_leader * 3846 filedesc_to_leader_alloc(struct filedesc_to_leader *old, struct filedesc *fdp, struct proc *leader) 3847 { 3848 struct filedesc_to_leader *fdtol; 3849 3850 fdtol = malloc(sizeof(struct filedesc_to_leader), 3851 M_FILEDESC_TO_LEADER, M_WAITOK); 3852 fdtol->fdl_refcount = 1; 3853 fdtol->fdl_holdcount = 0; 3854 fdtol->fdl_wakeup = 0; 3855 fdtol->fdl_leader = leader; 3856 if (old != NULL) { 3857 FILEDESC_XLOCK(fdp); 3858 fdtol->fdl_next = old->fdl_next; 3859 fdtol->fdl_prev = old; 3860 old->fdl_next = fdtol; 3861 fdtol->fdl_next->fdl_prev = fdtol; 3862 FILEDESC_XUNLOCK(fdp); 3863 } else { 3864 fdtol->fdl_next = fdtol; 3865 fdtol->fdl_prev = fdtol; 3866 } 3867 return (fdtol); 3868 } 3869 3870 static int 3871 sysctl_kern_proc_nfds(SYSCTL_HANDLER_ARGS) 3872 { 3873 NDSLOTTYPE *map; 3874 struct filedesc *fdp; 3875 int count, off, minoff; 3876 3877 if (*(int *)arg1 != 0) 3878 return (EINVAL); 3879 3880 fdp = curproc->p_fd; 3881 count = 0; 3882 FILEDESC_SLOCK(fdp); 3883 map = fdp->fd_map; 3884 off = NDSLOT(fdp->fd_nfiles - 1); 3885 for (minoff = NDSLOT(0); off >= minoff; --off) 3886 count += bitcountl(map[off]); 3887 FILEDESC_SUNLOCK(fdp); 3888 3889 return (SYSCTL_OUT(req, &count, sizeof(count))); 3890 } 3891 3892 static SYSCTL_NODE(_kern_proc, KERN_PROC_NFDS, nfds, 3893 CTLFLAG_RD|CTLFLAG_CAPRD|CTLFLAG_MPSAFE, sysctl_kern_proc_nfds, 3894 "Number of open file descriptors"); 3895 3896 /* 3897 * Get file structures globally. 3898 */ 3899 static int 3900 sysctl_kern_file(SYSCTL_HANDLER_ARGS) 3901 { 3902 struct xfile xf; 3903 struct filedesc *fdp; 3904 struct file *fp; 3905 struct proc *p; 3906 int error, n, lastfile; 3907 3908 error = sysctl_wire_old_buffer(req, 0); 3909 if (error != 0) 3910 return (error); 3911 if (req->oldptr == NULL) { 3912 n = 0; 3913 sx_slock(&allproc_lock); 3914 FOREACH_PROC_IN_SYSTEM(p) { 3915 PROC_LOCK(p); 3916 if (p->p_state == PRS_NEW) { 3917 PROC_UNLOCK(p); 3918 continue; 3919 } 3920 fdp = fdhold(p); 3921 PROC_UNLOCK(p); 3922 if (fdp == NULL) 3923 continue; 3924 /* overestimates sparse tables. */ 3925 n += fdp->fd_nfiles; 3926 fddrop(fdp); 3927 } 3928 sx_sunlock(&allproc_lock); 3929 return (SYSCTL_OUT(req, 0, n * sizeof(xf))); 3930 } 3931 error = 0; 3932 bzero(&xf, sizeof(xf)); 3933 xf.xf_size = sizeof(xf); 3934 sx_slock(&allproc_lock); 3935 FOREACH_PROC_IN_SYSTEM(p) { 3936 PROC_LOCK(p); 3937 if (p->p_state == PRS_NEW) { 3938 PROC_UNLOCK(p); 3939 continue; 3940 } 3941 if (p_cansee(req->td, p) != 0) { 3942 PROC_UNLOCK(p); 3943 continue; 3944 } 3945 xf.xf_pid = p->p_pid; 3946 xf.xf_uid = p->p_ucred->cr_uid; 3947 fdp = fdhold(p); 3948 PROC_UNLOCK(p); 3949 if (fdp == NULL) 3950 continue; 3951 FILEDESC_SLOCK(fdp); 3952 lastfile = fdlastfile(fdp); 3953 for (n = 0; fdp->fd_refcnt > 0 && n <= lastfile; ++n) { 3954 if ((fp = fdp->fd_ofiles[n].fde_file) == NULL) 3955 continue; 3956 xf.xf_fd = n; 3957 xf.xf_file = (uintptr_t)fp; 3958 xf.xf_data = (uintptr_t)fp->f_data; 3959 xf.xf_vnode = (uintptr_t)fp->f_vnode; 3960 xf.xf_type = (uintptr_t)fp->f_type; 3961 xf.xf_count = refcount_load(&fp->f_count); 3962 xf.xf_msgcount = 0; 3963 xf.xf_offset = foffset_get(fp); 3964 xf.xf_flag = fp->f_flag; 3965 error = SYSCTL_OUT(req, &xf, sizeof(xf)); 3966 if (error) 3967 break; 3968 } 3969 FILEDESC_SUNLOCK(fdp); 3970 fddrop(fdp); 3971 if (error) 3972 break; 3973 } 3974 sx_sunlock(&allproc_lock); 3975 return (error); 3976 } 3977 3978 SYSCTL_PROC(_kern, KERN_FILE, file, CTLTYPE_OPAQUE|CTLFLAG_RD|CTLFLAG_MPSAFE, 3979 0, 0, sysctl_kern_file, "S,xfile", "Entire file table"); 3980 3981 #ifdef KINFO_FILE_SIZE 3982 CTASSERT(sizeof(struct kinfo_file) == KINFO_FILE_SIZE); 3983 #endif 3984 3985 static int 3986 xlate_fflags(int fflags) 3987 { 3988 static const struct { 3989 int fflag; 3990 int kf_fflag; 3991 } fflags_table[] = { 3992 { FAPPEND, KF_FLAG_APPEND }, 3993 { FASYNC, KF_FLAG_ASYNC }, 3994 { FFSYNC, KF_FLAG_FSYNC }, 3995 { FHASLOCK, KF_FLAG_HASLOCK }, 3996 { FNONBLOCK, KF_FLAG_NONBLOCK }, 3997 { FREAD, KF_FLAG_READ }, 3998 { FWRITE, KF_FLAG_WRITE }, 3999 { O_CREAT, KF_FLAG_CREAT }, 4000 { O_DIRECT, KF_FLAG_DIRECT }, 4001 { O_EXCL, KF_FLAG_EXCL }, 4002 { O_EXEC, KF_FLAG_EXEC }, 4003 { O_EXLOCK, KF_FLAG_EXLOCK }, 4004 { O_NOFOLLOW, KF_FLAG_NOFOLLOW }, 4005 { O_SHLOCK, KF_FLAG_SHLOCK }, 4006 { O_TRUNC, KF_FLAG_TRUNC } 4007 }; 4008 unsigned int i; 4009 int kflags; 4010 4011 kflags = 0; 4012 for (i = 0; i < nitems(fflags_table); i++) 4013 if (fflags & fflags_table[i].fflag) 4014 kflags |= fflags_table[i].kf_fflag; 4015 return (kflags); 4016 } 4017 4018 /* Trim unused data from kf_path by truncating the structure size. */ 4019 void 4020 pack_kinfo(struct kinfo_file *kif) 4021 { 4022 4023 kif->kf_structsize = offsetof(struct kinfo_file, kf_path) + 4024 strlen(kif->kf_path) + 1; 4025 kif->kf_structsize = roundup(kif->kf_structsize, sizeof(uint64_t)); 4026 } 4027 4028 static void 4029 export_file_to_kinfo(struct file *fp, int fd, cap_rights_t *rightsp, 4030 struct kinfo_file *kif, struct filedesc *fdp, int flags) 4031 { 4032 int error; 4033 4034 bzero(kif, sizeof(*kif)); 4035 4036 /* Set a default type to allow for empty fill_kinfo() methods. */ 4037 kif->kf_type = KF_TYPE_UNKNOWN; 4038 kif->kf_flags = xlate_fflags(fp->f_flag); 4039 if (rightsp != NULL) 4040 kif->kf_cap_rights = *rightsp; 4041 else 4042 cap_rights_init_zero(&kif->kf_cap_rights); 4043 kif->kf_fd = fd; 4044 kif->kf_ref_count = refcount_load(&fp->f_count); 4045 kif->kf_offset = foffset_get(fp); 4046 4047 /* 4048 * This may drop the filedesc lock, so the 'fp' cannot be 4049 * accessed after this call. 4050 */ 4051 error = fo_fill_kinfo(fp, kif, fdp); 4052 if (error == 0) 4053 kif->kf_status |= KF_ATTR_VALID; 4054 if ((flags & KERN_FILEDESC_PACK_KINFO) != 0) 4055 pack_kinfo(kif); 4056 else 4057 kif->kf_structsize = roundup2(sizeof(*kif), sizeof(uint64_t)); 4058 } 4059 4060 static void 4061 export_vnode_to_kinfo(struct vnode *vp, int fd, int fflags, 4062 struct kinfo_file *kif, int flags) 4063 { 4064 int error; 4065 4066 bzero(kif, sizeof(*kif)); 4067 4068 kif->kf_type = KF_TYPE_VNODE; 4069 error = vn_fill_kinfo_vnode(vp, kif); 4070 if (error == 0) 4071 kif->kf_status |= KF_ATTR_VALID; 4072 kif->kf_flags = xlate_fflags(fflags); 4073 cap_rights_init_zero(&kif->kf_cap_rights); 4074 kif->kf_fd = fd; 4075 kif->kf_ref_count = -1; 4076 kif->kf_offset = -1; 4077 if ((flags & KERN_FILEDESC_PACK_KINFO) != 0) 4078 pack_kinfo(kif); 4079 else 4080 kif->kf_structsize = roundup2(sizeof(*kif), sizeof(uint64_t)); 4081 vrele(vp); 4082 } 4083 4084 struct export_fd_buf { 4085 struct filedesc *fdp; 4086 struct pwddesc *pdp; 4087 struct sbuf *sb; 4088 ssize_t remainder; 4089 struct kinfo_file kif; 4090 int flags; 4091 }; 4092 4093 static int 4094 export_kinfo_to_sb(struct export_fd_buf *efbuf) 4095 { 4096 struct kinfo_file *kif; 4097 4098 kif = &efbuf->kif; 4099 if (efbuf->remainder != -1) { 4100 if (efbuf->remainder < kif->kf_structsize) { 4101 /* Terminate export. */ 4102 efbuf->remainder = 0; 4103 return (0); 4104 } 4105 efbuf->remainder -= kif->kf_structsize; 4106 } 4107 return (sbuf_bcat(efbuf->sb, kif, kif->kf_structsize) == 0 ? 0 : ENOMEM); 4108 } 4109 4110 static int 4111 export_file_to_sb(struct file *fp, int fd, cap_rights_t *rightsp, 4112 struct export_fd_buf *efbuf) 4113 { 4114 int error; 4115 4116 if (efbuf->remainder == 0) 4117 return (0); 4118 export_file_to_kinfo(fp, fd, rightsp, &efbuf->kif, efbuf->fdp, 4119 efbuf->flags); 4120 FILEDESC_SUNLOCK(efbuf->fdp); 4121 error = export_kinfo_to_sb(efbuf); 4122 FILEDESC_SLOCK(efbuf->fdp); 4123 return (error); 4124 } 4125 4126 static int 4127 export_vnode_to_sb(struct vnode *vp, int fd, int fflags, 4128 struct export_fd_buf *efbuf) 4129 { 4130 int error; 4131 4132 if (efbuf->remainder == 0) 4133 return (0); 4134 if (efbuf->pdp != NULL) 4135 PWDDESC_XUNLOCK(efbuf->pdp); 4136 export_vnode_to_kinfo(vp, fd, fflags, &efbuf->kif, efbuf->flags); 4137 error = export_kinfo_to_sb(efbuf); 4138 if (efbuf->pdp != NULL) 4139 PWDDESC_XLOCK(efbuf->pdp); 4140 return (error); 4141 } 4142 4143 /* 4144 * Store a process file descriptor information to sbuf. 4145 * 4146 * Takes a locked proc as argument, and returns with the proc unlocked. 4147 */ 4148 int 4149 kern_proc_filedesc_out(struct proc *p, struct sbuf *sb, ssize_t maxlen, 4150 int flags) 4151 { 4152 struct file *fp; 4153 struct filedesc *fdp; 4154 struct pwddesc *pdp; 4155 struct export_fd_buf *efbuf; 4156 struct vnode *cttyvp, *textvp, *tracevp; 4157 struct pwd *pwd; 4158 int error, i, lastfile; 4159 cap_rights_t rights; 4160 4161 PROC_LOCK_ASSERT(p, MA_OWNED); 4162 4163 /* ktrace vnode */ 4164 tracevp = p->p_tracevp; 4165 if (tracevp != NULL) 4166 vrefact(tracevp); 4167 /* text vnode */ 4168 textvp = p->p_textvp; 4169 if (textvp != NULL) 4170 vrefact(textvp); 4171 /* Controlling tty. */ 4172 cttyvp = NULL; 4173 if (p->p_pgrp != NULL && p->p_pgrp->pg_session != NULL) { 4174 cttyvp = p->p_pgrp->pg_session->s_ttyvp; 4175 if (cttyvp != NULL) 4176 vrefact(cttyvp); 4177 } 4178 fdp = fdhold(p); 4179 pdp = pdhold(p); 4180 PROC_UNLOCK(p); 4181 efbuf = malloc(sizeof(*efbuf), M_TEMP, M_WAITOK); 4182 efbuf->fdp = NULL; 4183 efbuf->pdp = NULL; 4184 efbuf->sb = sb; 4185 efbuf->remainder = maxlen; 4186 efbuf->flags = flags; 4187 if (tracevp != NULL) 4188 export_vnode_to_sb(tracevp, KF_FD_TYPE_TRACE, FREAD | FWRITE, 4189 efbuf); 4190 if (textvp != NULL) 4191 export_vnode_to_sb(textvp, KF_FD_TYPE_TEXT, FREAD, efbuf); 4192 if (cttyvp != NULL) 4193 export_vnode_to_sb(cttyvp, KF_FD_TYPE_CTTY, FREAD | FWRITE, 4194 efbuf); 4195 error = 0; 4196 if (pdp == NULL || fdp == NULL) 4197 goto fail; 4198 efbuf->fdp = fdp; 4199 efbuf->pdp = pdp; 4200 PWDDESC_XLOCK(pdp); 4201 pwd = pwd_hold_pwddesc(pdp); 4202 if (pwd != NULL) { 4203 /* working directory */ 4204 if (pwd->pwd_cdir != NULL) { 4205 vrefact(pwd->pwd_cdir); 4206 export_vnode_to_sb(pwd->pwd_cdir, KF_FD_TYPE_CWD, FREAD, efbuf); 4207 } 4208 /* root directory */ 4209 if (pwd->pwd_rdir != NULL) { 4210 vrefact(pwd->pwd_rdir); 4211 export_vnode_to_sb(pwd->pwd_rdir, KF_FD_TYPE_ROOT, FREAD, efbuf); 4212 } 4213 /* jail directory */ 4214 if (pwd->pwd_jdir != NULL) { 4215 vrefact(pwd->pwd_jdir); 4216 export_vnode_to_sb(pwd->pwd_jdir, KF_FD_TYPE_JAIL, FREAD, efbuf); 4217 } 4218 } 4219 PWDDESC_XUNLOCK(pdp); 4220 if (pwd != NULL) 4221 pwd_drop(pwd); 4222 FILEDESC_SLOCK(fdp); 4223 lastfile = fdlastfile(fdp); 4224 for (i = 0; fdp->fd_refcnt > 0 && i <= lastfile; i++) { 4225 if ((fp = fdp->fd_ofiles[i].fde_file) == NULL) 4226 continue; 4227 #ifdef CAPABILITIES 4228 rights = *cap_rights(fdp, i); 4229 #else /* !CAPABILITIES */ 4230 rights = cap_no_rights; 4231 #endif 4232 /* 4233 * Create sysctl entry. It is OK to drop the filedesc 4234 * lock inside of export_file_to_sb() as we will 4235 * re-validate and re-evaluate its properties when the 4236 * loop continues. 4237 */ 4238 error = export_file_to_sb(fp, i, &rights, efbuf); 4239 if (error != 0 || efbuf->remainder == 0) 4240 break; 4241 } 4242 FILEDESC_SUNLOCK(fdp); 4243 fail: 4244 if (fdp != NULL) 4245 fddrop(fdp); 4246 if (pdp != NULL) 4247 pddrop(pdp); 4248 free(efbuf, M_TEMP); 4249 return (error); 4250 } 4251 4252 #define FILEDESC_SBUF_SIZE (sizeof(struct kinfo_file) * 5) 4253 4254 /* 4255 * Get per-process file descriptors for use by procstat(1), et al. 4256 */ 4257 static int 4258 sysctl_kern_proc_filedesc(SYSCTL_HANDLER_ARGS) 4259 { 4260 struct sbuf sb; 4261 struct proc *p; 4262 ssize_t maxlen; 4263 int error, error2, *name; 4264 4265 name = (int *)arg1; 4266 4267 sbuf_new_for_sysctl(&sb, NULL, FILEDESC_SBUF_SIZE, req); 4268 sbuf_clear_flags(&sb, SBUF_INCLUDENUL); 4269 error = pget((pid_t)name[0], PGET_CANDEBUG | PGET_NOTWEXIT, &p); 4270 if (error != 0) { 4271 sbuf_delete(&sb); 4272 return (error); 4273 } 4274 maxlen = req->oldptr != NULL ? req->oldlen : -1; 4275 error = kern_proc_filedesc_out(p, &sb, maxlen, 4276 KERN_FILEDESC_PACK_KINFO); 4277 error2 = sbuf_finish(&sb); 4278 sbuf_delete(&sb); 4279 return (error != 0 ? error : error2); 4280 } 4281 4282 #ifdef COMPAT_FREEBSD7 4283 #ifdef KINFO_OFILE_SIZE 4284 CTASSERT(sizeof(struct kinfo_ofile) == KINFO_OFILE_SIZE); 4285 #endif 4286 4287 static void 4288 kinfo_to_okinfo(struct kinfo_file *kif, struct kinfo_ofile *okif) 4289 { 4290 4291 okif->kf_structsize = sizeof(*okif); 4292 okif->kf_type = kif->kf_type; 4293 okif->kf_fd = kif->kf_fd; 4294 okif->kf_ref_count = kif->kf_ref_count; 4295 okif->kf_flags = kif->kf_flags & (KF_FLAG_READ | KF_FLAG_WRITE | 4296 KF_FLAG_APPEND | KF_FLAG_ASYNC | KF_FLAG_FSYNC | KF_FLAG_NONBLOCK | 4297 KF_FLAG_DIRECT | KF_FLAG_HASLOCK); 4298 okif->kf_offset = kif->kf_offset; 4299 if (kif->kf_type == KF_TYPE_VNODE) 4300 okif->kf_vnode_type = kif->kf_un.kf_file.kf_file_type; 4301 else 4302 okif->kf_vnode_type = KF_VTYPE_VNON; 4303 strlcpy(okif->kf_path, kif->kf_path, sizeof(okif->kf_path)); 4304 if (kif->kf_type == KF_TYPE_SOCKET) { 4305 okif->kf_sock_domain = kif->kf_un.kf_sock.kf_sock_domain0; 4306 okif->kf_sock_type = kif->kf_un.kf_sock.kf_sock_type0; 4307 okif->kf_sock_protocol = kif->kf_un.kf_sock.kf_sock_protocol0; 4308 okif->kf_sa_local = kif->kf_un.kf_sock.kf_sa_local; 4309 okif->kf_sa_peer = kif->kf_un.kf_sock.kf_sa_peer; 4310 } else { 4311 okif->kf_sa_local.ss_family = AF_UNSPEC; 4312 okif->kf_sa_peer.ss_family = AF_UNSPEC; 4313 } 4314 } 4315 4316 static int 4317 export_vnode_for_osysctl(struct vnode *vp, int type, struct kinfo_file *kif, 4318 struct kinfo_ofile *okif, struct pwddesc *pdp, struct sysctl_req *req) 4319 { 4320 int error; 4321 4322 vrefact(vp); 4323 PWDDESC_XUNLOCK(pdp); 4324 export_vnode_to_kinfo(vp, type, 0, kif, KERN_FILEDESC_PACK_KINFO); 4325 kinfo_to_okinfo(kif, okif); 4326 error = SYSCTL_OUT(req, okif, sizeof(*okif)); 4327 PWDDESC_XLOCK(pdp); 4328 return (error); 4329 } 4330 4331 /* 4332 * Get per-process file descriptors for use by procstat(1), et al. 4333 */ 4334 static int 4335 sysctl_kern_proc_ofiledesc(SYSCTL_HANDLER_ARGS) 4336 { 4337 struct kinfo_ofile *okif; 4338 struct kinfo_file *kif; 4339 struct filedesc *fdp; 4340 struct pwddesc *pdp; 4341 struct pwd *pwd; 4342 int error, i, lastfile, *name; 4343 struct file *fp; 4344 struct proc *p; 4345 4346 name = (int *)arg1; 4347 error = pget((pid_t)name[0], PGET_CANDEBUG | PGET_NOTWEXIT, &p); 4348 if (error != 0) 4349 return (error); 4350 fdp = fdhold(p); 4351 if (fdp != NULL) 4352 pdp = pdhold(p); 4353 PROC_UNLOCK(p); 4354 if (fdp == NULL || pdp == NULL) { 4355 if (fdp != NULL) 4356 fddrop(fdp); 4357 return (ENOENT); 4358 } 4359 kif = malloc(sizeof(*kif), M_TEMP, M_WAITOK); 4360 okif = malloc(sizeof(*okif), M_TEMP, M_WAITOK); 4361 PWDDESC_XLOCK(pdp); 4362 pwd = pwd_hold_pwddesc(pdp); 4363 if (pwd != NULL) { 4364 if (pwd->pwd_cdir != NULL) 4365 export_vnode_for_osysctl(pwd->pwd_cdir, KF_FD_TYPE_CWD, kif, 4366 okif, pdp, req); 4367 if (pwd->pwd_rdir != NULL) 4368 export_vnode_for_osysctl(pwd->pwd_rdir, KF_FD_TYPE_ROOT, kif, 4369 okif, pdp, req); 4370 if (pwd->pwd_jdir != NULL) 4371 export_vnode_for_osysctl(pwd->pwd_jdir, KF_FD_TYPE_JAIL, kif, 4372 okif, pdp, req); 4373 } 4374 PWDDESC_XUNLOCK(pdp); 4375 if (pwd != NULL) 4376 pwd_drop(pwd); 4377 FILEDESC_SLOCK(fdp); 4378 lastfile = fdlastfile(fdp); 4379 for (i = 0; fdp->fd_refcnt > 0 && i <= lastfile; i++) { 4380 if ((fp = fdp->fd_ofiles[i].fde_file) == NULL) 4381 continue; 4382 export_file_to_kinfo(fp, i, NULL, kif, fdp, 4383 KERN_FILEDESC_PACK_KINFO); 4384 FILEDESC_SUNLOCK(fdp); 4385 kinfo_to_okinfo(kif, okif); 4386 error = SYSCTL_OUT(req, okif, sizeof(*okif)); 4387 FILEDESC_SLOCK(fdp); 4388 if (error) 4389 break; 4390 } 4391 FILEDESC_SUNLOCK(fdp); 4392 fddrop(fdp); 4393 pddrop(pdp); 4394 free(kif, M_TEMP); 4395 free(okif, M_TEMP); 4396 return (0); 4397 } 4398 4399 static SYSCTL_NODE(_kern_proc, KERN_PROC_OFILEDESC, ofiledesc, 4400 CTLFLAG_RD|CTLFLAG_MPSAFE, sysctl_kern_proc_ofiledesc, 4401 "Process ofiledesc entries"); 4402 #endif /* COMPAT_FREEBSD7 */ 4403 4404 int 4405 vntype_to_kinfo(int vtype) 4406 { 4407 struct { 4408 int vtype; 4409 int kf_vtype; 4410 } vtypes_table[] = { 4411 { VBAD, KF_VTYPE_VBAD }, 4412 { VBLK, KF_VTYPE_VBLK }, 4413 { VCHR, KF_VTYPE_VCHR }, 4414 { VDIR, KF_VTYPE_VDIR }, 4415 { VFIFO, KF_VTYPE_VFIFO }, 4416 { VLNK, KF_VTYPE_VLNK }, 4417 { VNON, KF_VTYPE_VNON }, 4418 { VREG, KF_VTYPE_VREG }, 4419 { VSOCK, KF_VTYPE_VSOCK } 4420 }; 4421 unsigned int i; 4422 4423 /* 4424 * Perform vtype translation. 4425 */ 4426 for (i = 0; i < nitems(vtypes_table); i++) 4427 if (vtypes_table[i].vtype == vtype) 4428 return (vtypes_table[i].kf_vtype); 4429 4430 return (KF_VTYPE_UNKNOWN); 4431 } 4432 4433 static SYSCTL_NODE(_kern_proc, KERN_PROC_FILEDESC, filedesc, 4434 CTLFLAG_RD|CTLFLAG_MPSAFE, sysctl_kern_proc_filedesc, 4435 "Process filedesc entries"); 4436 4437 /* 4438 * Store a process current working directory information to sbuf. 4439 * 4440 * Takes a locked proc as argument, and returns with the proc unlocked. 4441 */ 4442 int 4443 kern_proc_cwd_out(struct proc *p, struct sbuf *sb, ssize_t maxlen) 4444 { 4445 struct pwddesc *pdp; 4446 struct pwd *pwd; 4447 struct export_fd_buf *efbuf; 4448 struct vnode *cdir; 4449 int error; 4450 4451 PROC_LOCK_ASSERT(p, MA_OWNED); 4452 4453 pdp = pdhold(p); 4454 PROC_UNLOCK(p); 4455 if (pdp == NULL) 4456 return (EINVAL); 4457 4458 efbuf = malloc(sizeof(*efbuf), M_TEMP, M_WAITOK); 4459 efbuf->pdp = pdp; 4460 efbuf->sb = sb; 4461 efbuf->remainder = maxlen; 4462 4463 PWDDESC_XLOCK(pdp); 4464 pwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); 4465 cdir = pwd->pwd_cdir; 4466 if (cdir == NULL) { 4467 error = EINVAL; 4468 } else { 4469 vrefact(cdir); 4470 error = export_vnode_to_sb(cdir, KF_FD_TYPE_CWD, FREAD, efbuf); 4471 } 4472 PWDDESC_XUNLOCK(pdp); 4473 pddrop(pdp); 4474 free(efbuf, M_TEMP); 4475 return (error); 4476 } 4477 4478 /* 4479 * Get per-process current working directory. 4480 */ 4481 static int 4482 sysctl_kern_proc_cwd(SYSCTL_HANDLER_ARGS) 4483 { 4484 struct sbuf sb; 4485 struct proc *p; 4486 ssize_t maxlen; 4487 int error, error2, *name; 4488 4489 name = (int *)arg1; 4490 4491 sbuf_new_for_sysctl(&sb, NULL, sizeof(struct kinfo_file), req); 4492 sbuf_clear_flags(&sb, SBUF_INCLUDENUL); 4493 error = pget((pid_t)name[0], PGET_CANDEBUG | PGET_NOTWEXIT, &p); 4494 if (error != 0) { 4495 sbuf_delete(&sb); 4496 return (error); 4497 } 4498 maxlen = req->oldptr != NULL ? req->oldlen : -1; 4499 error = kern_proc_cwd_out(p, &sb, maxlen); 4500 error2 = sbuf_finish(&sb); 4501 sbuf_delete(&sb); 4502 return (error != 0 ? error : error2); 4503 } 4504 4505 static SYSCTL_NODE(_kern_proc, KERN_PROC_CWD, cwd, CTLFLAG_RD|CTLFLAG_MPSAFE, 4506 sysctl_kern_proc_cwd, "Process current working directory"); 4507 4508 #ifdef DDB 4509 /* 4510 * For the purposes of debugging, generate a human-readable string for the 4511 * file type. 4512 */ 4513 static const char * 4514 file_type_to_name(short type) 4515 { 4516 4517 switch (type) { 4518 case 0: 4519 return ("zero"); 4520 case DTYPE_VNODE: 4521 return ("vnode"); 4522 case DTYPE_SOCKET: 4523 return ("socket"); 4524 case DTYPE_PIPE: 4525 return ("pipe"); 4526 case DTYPE_FIFO: 4527 return ("fifo"); 4528 case DTYPE_KQUEUE: 4529 return ("kqueue"); 4530 case DTYPE_CRYPTO: 4531 return ("crypto"); 4532 case DTYPE_MQUEUE: 4533 return ("mqueue"); 4534 case DTYPE_SHM: 4535 return ("shm"); 4536 case DTYPE_SEM: 4537 return ("ksem"); 4538 case DTYPE_PTS: 4539 return ("pts"); 4540 case DTYPE_DEV: 4541 return ("dev"); 4542 case DTYPE_PROCDESC: 4543 return ("proc"); 4544 case DTYPE_LINUXEFD: 4545 return ("levent"); 4546 case DTYPE_LINUXTFD: 4547 return ("ltimer"); 4548 default: 4549 return ("unkn"); 4550 } 4551 } 4552 4553 /* 4554 * For the purposes of debugging, identify a process (if any, perhaps one of 4555 * many) that references the passed file in its file descriptor array. Return 4556 * NULL if none. 4557 */ 4558 static struct proc * 4559 file_to_first_proc(struct file *fp) 4560 { 4561 struct filedesc *fdp; 4562 struct proc *p; 4563 int n; 4564 4565 FOREACH_PROC_IN_SYSTEM(p) { 4566 if (p->p_state == PRS_NEW) 4567 continue; 4568 fdp = p->p_fd; 4569 if (fdp == NULL) 4570 continue; 4571 for (n = 0; n < fdp->fd_nfiles; n++) { 4572 if (fp == fdp->fd_ofiles[n].fde_file) 4573 return (p); 4574 } 4575 } 4576 return (NULL); 4577 } 4578 4579 static void 4580 db_print_file(struct file *fp, int header) 4581 { 4582 #define XPTRWIDTH ((int)howmany(sizeof(void *) * NBBY, 4)) 4583 struct proc *p; 4584 4585 if (header) 4586 db_printf("%*s %6s %*s %8s %4s %5s %6s %*s %5s %s\n", 4587 XPTRWIDTH, "File", "Type", XPTRWIDTH, "Data", "Flag", 4588 "GCFl", "Count", "MCount", XPTRWIDTH, "Vnode", "FPID", 4589 "FCmd"); 4590 p = file_to_first_proc(fp); 4591 db_printf("%*p %6s %*p %08x %04x %5d %6d %*p %5d %s\n", XPTRWIDTH, 4592 fp, file_type_to_name(fp->f_type), XPTRWIDTH, fp->f_data, 4593 fp->f_flag, 0, refcount_load(&fp->f_count), 0, XPTRWIDTH, fp->f_vnode, 4594 p != NULL ? p->p_pid : -1, p != NULL ? p->p_comm : "-"); 4595 4596 #undef XPTRWIDTH 4597 } 4598 4599 DB_SHOW_COMMAND(file, db_show_file) 4600 { 4601 struct file *fp; 4602 4603 if (!have_addr) { 4604 db_printf("usage: show file <addr>\n"); 4605 return; 4606 } 4607 fp = (struct file *)addr; 4608 db_print_file(fp, 1); 4609 } 4610 4611 DB_SHOW_COMMAND(files, db_show_files) 4612 { 4613 struct filedesc *fdp; 4614 struct file *fp; 4615 struct proc *p; 4616 int header; 4617 int n; 4618 4619 header = 1; 4620 FOREACH_PROC_IN_SYSTEM(p) { 4621 if (p->p_state == PRS_NEW) 4622 continue; 4623 if ((fdp = p->p_fd) == NULL) 4624 continue; 4625 for (n = 0; n < fdp->fd_nfiles; ++n) { 4626 if ((fp = fdp->fd_ofiles[n].fde_file) == NULL) 4627 continue; 4628 db_print_file(fp, header); 4629 header = 0; 4630 } 4631 } 4632 } 4633 #endif 4634 4635 SYSCTL_INT(_kern, KERN_MAXFILESPERPROC, maxfilesperproc, CTLFLAG_RW, 4636 &maxfilesperproc, 0, "Maximum files allowed open per process"); 4637 4638 SYSCTL_INT(_kern, KERN_MAXFILES, maxfiles, CTLFLAG_RW, 4639 &maxfiles, 0, "Maximum number of files"); 4640 4641 SYSCTL_INT(_kern, OID_AUTO, openfiles, CTLFLAG_RD, 4642 &openfiles, 0, "System-wide number of open files"); 4643 4644 /* ARGSUSED*/ 4645 static void 4646 filelistinit(void *dummy) 4647 { 4648 4649 file_zone = uma_zcreate("Files", sizeof(struct file), NULL, NULL, 4650 NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE); 4651 filedesc0_zone = uma_zcreate("filedesc0", sizeof(struct filedesc0), 4652 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0); 4653 pwd_zone = uma_zcreate("PWD", sizeof(struct pwd), NULL, NULL, 4654 NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_SMR); 4655 /* 4656 * XXXMJG this is a temporary hack due to boot ordering issues against 4657 * the vnode zone. 4658 */ 4659 vfs_smr = uma_zone_get_smr(pwd_zone); 4660 mtx_init(&sigio_lock, "sigio lock", NULL, MTX_DEF); 4661 } 4662 SYSINIT(select, SI_SUB_LOCK, SI_ORDER_FIRST, filelistinit, NULL); 4663 4664 /*-------------------------------------------------------------------*/ 4665 4666 static int 4667 badfo_readwrite(struct file *fp, struct uio *uio, struct ucred *active_cred, 4668 int flags, struct thread *td) 4669 { 4670 4671 return (EBADF); 4672 } 4673 4674 static int 4675 badfo_truncate(struct file *fp, off_t length, struct ucred *active_cred, 4676 struct thread *td) 4677 { 4678 4679 return (EINVAL); 4680 } 4681 4682 static int 4683 badfo_ioctl(struct file *fp, u_long com, void *data, struct ucred *active_cred, 4684 struct thread *td) 4685 { 4686 4687 return (EBADF); 4688 } 4689 4690 static int 4691 badfo_poll(struct file *fp, int events, struct ucred *active_cred, 4692 struct thread *td) 4693 { 4694 4695 return (0); 4696 } 4697 4698 static int 4699 badfo_kqfilter(struct file *fp, struct knote *kn) 4700 { 4701 4702 return (EBADF); 4703 } 4704 4705 static int 4706 badfo_stat(struct file *fp, struct stat *sb, struct ucred *active_cred, 4707 struct thread *td) 4708 { 4709 4710 return (EBADF); 4711 } 4712 4713 static int 4714 badfo_close(struct file *fp, struct thread *td) 4715 { 4716 4717 return (0); 4718 } 4719 4720 static int 4721 badfo_chmod(struct file *fp, mode_t mode, struct ucred *active_cred, 4722 struct thread *td) 4723 { 4724 4725 return (EBADF); 4726 } 4727 4728 static int 4729 badfo_chown(struct file *fp, uid_t uid, gid_t gid, struct ucred *active_cred, 4730 struct thread *td) 4731 { 4732 4733 return (EBADF); 4734 } 4735 4736 static int 4737 badfo_sendfile(struct file *fp, int sockfd, struct uio *hdr_uio, 4738 struct uio *trl_uio, off_t offset, size_t nbytes, off_t *sent, int flags, 4739 struct thread *td) 4740 { 4741 4742 return (EBADF); 4743 } 4744 4745 static int 4746 badfo_fill_kinfo(struct file *fp, struct kinfo_file *kif, struct filedesc *fdp) 4747 { 4748 4749 return (0); 4750 } 4751 4752 struct fileops badfileops = { 4753 .fo_read = badfo_readwrite, 4754 .fo_write = badfo_readwrite, 4755 .fo_truncate = badfo_truncate, 4756 .fo_ioctl = badfo_ioctl, 4757 .fo_poll = badfo_poll, 4758 .fo_kqfilter = badfo_kqfilter, 4759 .fo_stat = badfo_stat, 4760 .fo_close = badfo_close, 4761 .fo_chmod = badfo_chmod, 4762 .fo_chown = badfo_chown, 4763 .fo_sendfile = badfo_sendfile, 4764 .fo_fill_kinfo = badfo_fill_kinfo, 4765 }; 4766 4767 int 4768 invfo_rdwr(struct file *fp, struct uio *uio, struct ucred *active_cred, 4769 int flags, struct thread *td) 4770 { 4771 4772 return (EOPNOTSUPP); 4773 } 4774 4775 int 4776 invfo_truncate(struct file *fp, off_t length, struct ucred *active_cred, 4777 struct thread *td) 4778 { 4779 4780 return (EINVAL); 4781 } 4782 4783 int 4784 invfo_ioctl(struct file *fp, u_long com, void *data, 4785 struct ucred *active_cred, struct thread *td) 4786 { 4787 4788 return (ENOTTY); 4789 } 4790 4791 int 4792 invfo_poll(struct file *fp, int events, struct ucred *active_cred, 4793 struct thread *td) 4794 { 4795 4796 return (poll_no_poll(events)); 4797 } 4798 4799 int 4800 invfo_kqfilter(struct file *fp, struct knote *kn) 4801 { 4802 4803 return (EINVAL); 4804 } 4805 4806 int 4807 invfo_chmod(struct file *fp, mode_t mode, struct ucred *active_cred, 4808 struct thread *td) 4809 { 4810 4811 return (EINVAL); 4812 } 4813 4814 int 4815 invfo_chown(struct file *fp, uid_t uid, gid_t gid, struct ucred *active_cred, 4816 struct thread *td) 4817 { 4818 4819 return (EINVAL); 4820 } 4821 4822 int 4823 invfo_sendfile(struct file *fp, int sockfd, struct uio *hdr_uio, 4824 struct uio *trl_uio, off_t offset, size_t nbytes, off_t *sent, int flags, 4825 struct thread *td) 4826 { 4827 4828 return (EINVAL); 4829 } 4830 4831 /*-------------------------------------------------------------------*/ 4832 4833 /* 4834 * File Descriptor pseudo-device driver (/dev/fd/). 4835 * 4836 * Opening minor device N dup()s the file (if any) connected to file 4837 * descriptor N belonging to the calling process. Note that this driver 4838 * consists of only the ``open()'' routine, because all subsequent 4839 * references to this file will be direct to the other driver. 4840 * 4841 * XXX: we could give this one a cloning event handler if necessary. 4842 */ 4843 4844 /* ARGSUSED */ 4845 static int 4846 fdopen(struct cdev *dev, int mode, int type, struct thread *td) 4847 { 4848 4849 /* 4850 * XXX Kludge: set curthread->td_dupfd to contain the value of the 4851 * the file descriptor being sought for duplication. The error 4852 * return ensures that the vnode for this device will be released 4853 * by vn_open. Open will detect this special error and take the 4854 * actions in dupfdopen below. Other callers of vn_open or VOP_OPEN 4855 * will simply report the error. 4856 */ 4857 td->td_dupfd = dev2unit(dev); 4858 return (ENODEV); 4859 } 4860 4861 static struct cdevsw fildesc_cdevsw = { 4862 .d_version = D_VERSION, 4863 .d_open = fdopen, 4864 .d_name = "FD", 4865 }; 4866 4867 static void 4868 fildesc_drvinit(void *unused) 4869 { 4870 struct cdev *dev; 4871 4872 dev = make_dev_credf(MAKEDEV_ETERNAL, &fildesc_cdevsw, 0, NULL, 4873 UID_ROOT, GID_WHEEL, 0666, "fd/0"); 4874 make_dev_alias(dev, "stdin"); 4875 dev = make_dev_credf(MAKEDEV_ETERNAL, &fildesc_cdevsw, 1, NULL, 4876 UID_ROOT, GID_WHEEL, 0666, "fd/1"); 4877 make_dev_alias(dev, "stdout"); 4878 dev = make_dev_credf(MAKEDEV_ETERNAL, &fildesc_cdevsw, 2, NULL, 4879 UID_ROOT, GID_WHEEL, 0666, "fd/2"); 4880 make_dev_alias(dev, "stderr"); 4881 } 4882 4883 SYSINIT(fildescdev, SI_SUB_DRIVERS, SI_ORDER_MIDDLE, fildesc_drvinit, NULL); 4884