1 /*- 2 * SPDX-License-Identifier: BSD-3-Clause 3 * 4 * Copyright (c) 1982, 1986, 1989, 1991, 1993 5 * The Regents of the University of California. All rights reserved. 6 * (c) UNIX System Laboratories, Inc. 7 * All or some portions of this file are derived from material licensed 8 * to the University of California by American Telephone and Telegraph 9 * Co. or Unix System Laboratories, Inc. and are reproduced herein with 10 * the permission of UNIX System Laboratories, Inc. 11 * 12 * Redistribution and use in source and binary forms, with or without 13 * modification, are permitted provided that the following conditions 14 * are met: 15 * 1. Redistributions of source code must retain the above copyright 16 * notice, this list of conditions and the following disclaimer. 17 * 2. Redistributions in binary form must reproduce the above copyright 18 * notice, this list of conditions and the following disclaimer in the 19 * documentation and/or other materials provided with the distribution. 20 * 3. Neither the name of the University nor the names of its contributors 21 * may be used to endorse or promote products derived from this software 22 * without specific prior written permission. 23 * 24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34 * SUCH DAMAGE. 35 * 36 * @(#)kern_descrip.c 8.6 (Berkeley) 4/19/94 37 */ 38 39 #include <sys/cdefs.h> 40 __FBSDID("$FreeBSD$"); 41 42 #include "opt_capsicum.h" 43 #include "opt_ddb.h" 44 #include "opt_ktrace.h" 45 46 #include <sys/param.h> 47 #include <sys/systm.h> 48 49 #include <sys/capsicum.h> 50 #include <sys/conf.h> 51 #include <sys/fcntl.h> 52 #include <sys/file.h> 53 #include <sys/filedesc.h> 54 #include <sys/filio.h> 55 #include <sys/jail.h> 56 #include <sys/kernel.h> 57 #include <sys/limits.h> 58 #include <sys/lock.h> 59 #include <sys/malloc.h> 60 #include <sys/mount.h> 61 #include <sys/mutex.h> 62 #include <sys/namei.h> 63 #include <sys/selinfo.h> 64 #include <sys/priv.h> 65 #include <sys/proc.h> 66 #include <sys/protosw.h> 67 #include <sys/racct.h> 68 #include <sys/resourcevar.h> 69 #include <sys/sbuf.h> 70 #include <sys/signalvar.h> 71 #include <sys/kdb.h> 72 #include <sys/smr.h> 73 #include <sys/stat.h> 74 #include <sys/sx.h> 75 #include <sys/syscallsubr.h> 76 #include <sys/sysctl.h> 77 #include <sys/sysproto.h> 78 #include <sys/unistd.h> 79 #include <sys/user.h> 80 #include <sys/vnode.h> 81 #ifdef KTRACE 82 #include <sys/ktrace.h> 83 #endif 84 85 #include <net/vnet.h> 86 87 #include <security/audit/audit.h> 88 89 #include <vm/uma.h> 90 #include <vm/vm.h> 91 92 #include <ddb/ddb.h> 93 94 static MALLOC_DEFINE(M_FILEDESC, "filedesc", "Open file descriptor table"); 95 static MALLOC_DEFINE(M_PWD, "pwd", "Descriptor table vnodes"); 96 static MALLOC_DEFINE(M_FILEDESC_TO_LEADER, "filedesc_to_leader", 97 "file desc to leader structures"); 98 static MALLOC_DEFINE(M_SIGIO, "sigio", "sigio structures"); 99 MALLOC_DEFINE(M_FILECAPS, "filecaps", "descriptor capabilities"); 100 101 MALLOC_DECLARE(M_FADVISE); 102 103 static __read_mostly uma_zone_t file_zone; 104 static __read_mostly uma_zone_t filedesc0_zone; 105 __read_mostly uma_zone_t pwd_zone; 106 VFS_SMR_DECLARE; 107 108 static int closefp(struct filedesc *fdp, int fd, struct file *fp, 109 struct thread *td, int holdleaders); 110 static int fd_first_free(struct filedesc *fdp, int low, int size); 111 static void fdgrowtable(struct filedesc *fdp, int nfd); 112 static void fdgrowtable_exp(struct filedesc *fdp, int nfd); 113 static void fdunused(struct filedesc *fdp, int fd); 114 static void fdused(struct filedesc *fdp, int fd); 115 static int getmaxfd(struct thread *td); 116 static u_long *filecaps_copy_prep(const struct filecaps *src); 117 static void filecaps_copy_finish(const struct filecaps *src, 118 struct filecaps *dst, u_long *ioctls); 119 static u_long *filecaps_free_prep(struct filecaps *fcaps); 120 static void filecaps_free_finish(u_long *ioctls); 121 122 static struct pwd *pwd_alloc(void); 123 124 /* 125 * Each process has: 126 * 127 * - An array of open file descriptors (fd_ofiles) 128 * - An array of file flags (fd_ofileflags) 129 * - A bitmap recording which descriptors are in use (fd_map) 130 * 131 * A process starts out with NDFILE descriptors. The value of NDFILE has 132 * been selected based the historical limit of 20 open files, and an 133 * assumption that the majority of processes, especially short-lived 134 * processes like shells, will never need more. 135 * 136 * If this initial allocation is exhausted, a larger descriptor table and 137 * map are allocated dynamically, and the pointers in the process's struct 138 * filedesc are updated to point to those. This is repeated every time 139 * the process runs out of file descriptors (provided it hasn't hit its 140 * resource limit). 141 * 142 * Since threads may hold references to individual descriptor table 143 * entries, the tables are never freed. Instead, they are placed on a 144 * linked list and freed only when the struct filedesc is released. 145 */ 146 #define NDFILE 20 147 #define NDSLOTSIZE sizeof(NDSLOTTYPE) 148 #define NDENTRIES (NDSLOTSIZE * __CHAR_BIT) 149 #define NDSLOT(x) ((x) / NDENTRIES) 150 #define NDBIT(x) ((NDSLOTTYPE)1 << ((x) % NDENTRIES)) 151 #define NDSLOTS(x) (((x) + NDENTRIES - 1) / NDENTRIES) 152 153 /* 154 * SLIST entry used to keep track of ofiles which must be reclaimed when 155 * the process exits. 156 */ 157 struct freetable { 158 struct fdescenttbl *ft_table; 159 SLIST_ENTRY(freetable) ft_next; 160 }; 161 162 /* 163 * Initial allocation: a filedesc structure + the head of SLIST used to 164 * keep track of old ofiles + enough space for NDFILE descriptors. 165 */ 166 167 struct fdescenttbl0 { 168 int fdt_nfiles; 169 struct filedescent fdt_ofiles[NDFILE]; 170 }; 171 172 struct filedesc0 { 173 struct filedesc fd_fd; 174 SLIST_HEAD(, freetable) fd_free; 175 struct fdescenttbl0 fd_dfiles; 176 NDSLOTTYPE fd_dmap[NDSLOTS(NDFILE)]; 177 }; 178 179 /* 180 * Descriptor management. 181 */ 182 static int __exclusive_cache_line openfiles; /* actual number of open files */ 183 struct mtx sigio_lock; /* mtx to protect pointers to sigio */ 184 void __read_mostly (*mq_fdclose)(struct thread *td, int fd, struct file *fp); 185 186 /* 187 * If low >= size, just return low. Otherwise find the first zero bit in the 188 * given bitmap, starting at low and not exceeding size - 1. Return size if 189 * not found. 190 */ 191 static int 192 fd_first_free(struct filedesc *fdp, int low, int size) 193 { 194 NDSLOTTYPE *map = fdp->fd_map; 195 NDSLOTTYPE mask; 196 int off, maxoff; 197 198 if (low >= size) 199 return (low); 200 201 off = NDSLOT(low); 202 if (low % NDENTRIES) { 203 mask = ~(~(NDSLOTTYPE)0 >> (NDENTRIES - (low % NDENTRIES))); 204 if ((mask &= ~map[off]) != 0UL) 205 return (off * NDENTRIES + ffsl(mask) - 1); 206 ++off; 207 } 208 for (maxoff = NDSLOTS(size); off < maxoff; ++off) 209 if (map[off] != ~0UL) 210 return (off * NDENTRIES + ffsl(~map[off]) - 1); 211 return (size); 212 } 213 214 /* 215 * Find the last used fd. 216 * 217 * Call this variant if fdp can't be modified by anyone else (e.g, during exec). 218 * Otherwise use fdlastfile. 219 */ 220 int 221 fdlastfile_single(struct filedesc *fdp) 222 { 223 NDSLOTTYPE *map = fdp->fd_map; 224 int off, minoff; 225 226 off = NDSLOT(fdp->fd_nfiles - 1); 227 for (minoff = NDSLOT(0); off >= minoff; --off) 228 if (map[off] != 0) 229 return (off * NDENTRIES + flsl(map[off]) - 1); 230 return (-1); 231 } 232 233 int 234 fdlastfile(struct filedesc *fdp) 235 { 236 237 FILEDESC_LOCK_ASSERT(fdp); 238 return (fdlastfile_single(fdp)); 239 } 240 241 static int 242 fdisused(struct filedesc *fdp, int fd) 243 { 244 245 KASSERT(fd >= 0 && fd < fdp->fd_nfiles, 246 ("file descriptor %d out of range (0, %d)", fd, fdp->fd_nfiles)); 247 248 return ((fdp->fd_map[NDSLOT(fd)] & NDBIT(fd)) != 0); 249 } 250 251 /* 252 * Mark a file descriptor as used. 253 */ 254 static void 255 fdused_init(struct filedesc *fdp, int fd) 256 { 257 258 KASSERT(!fdisused(fdp, fd), ("fd=%d is already used", fd)); 259 260 fdp->fd_map[NDSLOT(fd)] |= NDBIT(fd); 261 } 262 263 static void 264 fdused(struct filedesc *fdp, int fd) 265 { 266 267 FILEDESC_XLOCK_ASSERT(fdp); 268 269 fdused_init(fdp, fd); 270 if (fd == fdp->fd_freefile) 271 fdp->fd_freefile++; 272 } 273 274 /* 275 * Mark a file descriptor as unused. 276 */ 277 static void 278 fdunused(struct filedesc *fdp, int fd) 279 { 280 281 FILEDESC_XLOCK_ASSERT(fdp); 282 283 KASSERT(fdisused(fdp, fd), ("fd=%d is already unused", fd)); 284 KASSERT(fdp->fd_ofiles[fd].fde_file == NULL, 285 ("fd=%d is still in use", fd)); 286 287 fdp->fd_map[NDSLOT(fd)] &= ~NDBIT(fd); 288 if (fd < fdp->fd_freefile) 289 fdp->fd_freefile = fd; 290 } 291 292 /* 293 * Free a file descriptor. 294 * 295 * Avoid some work if fdp is about to be destroyed. 296 */ 297 static inline void 298 fdefree_last(struct filedescent *fde) 299 { 300 301 filecaps_free(&fde->fde_caps); 302 } 303 304 static inline void 305 fdfree(struct filedesc *fdp, int fd) 306 { 307 struct filedescent *fde; 308 309 fde = &fdp->fd_ofiles[fd]; 310 #ifdef CAPABILITIES 311 seqc_write_begin(&fde->fde_seqc); 312 #endif 313 fde->fde_file = NULL; 314 #ifdef CAPABILITIES 315 seqc_write_end(&fde->fde_seqc); 316 #endif 317 fdefree_last(fde); 318 fdunused(fdp, fd); 319 } 320 321 /* 322 * System calls on descriptors. 323 */ 324 #ifndef _SYS_SYSPROTO_H_ 325 struct getdtablesize_args { 326 int dummy; 327 }; 328 #endif 329 /* ARGSUSED */ 330 int 331 sys_getdtablesize(struct thread *td, struct getdtablesize_args *uap) 332 { 333 #ifdef RACCT 334 uint64_t lim; 335 #endif 336 337 td->td_retval[0] = getmaxfd(td); 338 #ifdef RACCT 339 PROC_LOCK(td->td_proc); 340 lim = racct_get_limit(td->td_proc, RACCT_NOFILE); 341 PROC_UNLOCK(td->td_proc); 342 if (lim < td->td_retval[0]) 343 td->td_retval[0] = lim; 344 #endif 345 return (0); 346 } 347 348 /* 349 * Duplicate a file descriptor to a particular value. 350 * 351 * Note: keep in mind that a potential race condition exists when closing 352 * descriptors from a shared descriptor table (via rfork). 353 */ 354 #ifndef _SYS_SYSPROTO_H_ 355 struct dup2_args { 356 u_int from; 357 u_int to; 358 }; 359 #endif 360 /* ARGSUSED */ 361 int 362 sys_dup2(struct thread *td, struct dup2_args *uap) 363 { 364 365 return (kern_dup(td, FDDUP_FIXED, 0, (int)uap->from, (int)uap->to)); 366 } 367 368 /* 369 * Duplicate a file descriptor. 370 */ 371 #ifndef _SYS_SYSPROTO_H_ 372 struct dup_args { 373 u_int fd; 374 }; 375 #endif 376 /* ARGSUSED */ 377 int 378 sys_dup(struct thread *td, struct dup_args *uap) 379 { 380 381 return (kern_dup(td, FDDUP_NORMAL, 0, (int)uap->fd, 0)); 382 } 383 384 /* 385 * The file control system call. 386 */ 387 #ifndef _SYS_SYSPROTO_H_ 388 struct fcntl_args { 389 int fd; 390 int cmd; 391 long arg; 392 }; 393 #endif 394 /* ARGSUSED */ 395 int 396 sys_fcntl(struct thread *td, struct fcntl_args *uap) 397 { 398 399 return (kern_fcntl_freebsd(td, uap->fd, uap->cmd, uap->arg)); 400 } 401 402 int 403 kern_fcntl_freebsd(struct thread *td, int fd, int cmd, long arg) 404 { 405 struct flock fl; 406 struct __oflock ofl; 407 intptr_t arg1; 408 int error, newcmd; 409 410 error = 0; 411 newcmd = cmd; 412 switch (cmd) { 413 case F_OGETLK: 414 case F_OSETLK: 415 case F_OSETLKW: 416 /* 417 * Convert old flock structure to new. 418 */ 419 error = copyin((void *)(intptr_t)arg, &ofl, sizeof(ofl)); 420 fl.l_start = ofl.l_start; 421 fl.l_len = ofl.l_len; 422 fl.l_pid = ofl.l_pid; 423 fl.l_type = ofl.l_type; 424 fl.l_whence = ofl.l_whence; 425 fl.l_sysid = 0; 426 427 switch (cmd) { 428 case F_OGETLK: 429 newcmd = F_GETLK; 430 break; 431 case F_OSETLK: 432 newcmd = F_SETLK; 433 break; 434 case F_OSETLKW: 435 newcmd = F_SETLKW; 436 break; 437 } 438 arg1 = (intptr_t)&fl; 439 break; 440 case F_GETLK: 441 case F_SETLK: 442 case F_SETLKW: 443 case F_SETLK_REMOTE: 444 error = copyin((void *)(intptr_t)arg, &fl, sizeof(fl)); 445 arg1 = (intptr_t)&fl; 446 break; 447 default: 448 arg1 = arg; 449 break; 450 } 451 if (error) 452 return (error); 453 error = kern_fcntl(td, fd, newcmd, arg1); 454 if (error) 455 return (error); 456 if (cmd == F_OGETLK) { 457 ofl.l_start = fl.l_start; 458 ofl.l_len = fl.l_len; 459 ofl.l_pid = fl.l_pid; 460 ofl.l_type = fl.l_type; 461 ofl.l_whence = fl.l_whence; 462 error = copyout(&ofl, (void *)(intptr_t)arg, sizeof(ofl)); 463 } else if (cmd == F_GETLK) { 464 error = copyout(&fl, (void *)(intptr_t)arg, sizeof(fl)); 465 } 466 return (error); 467 } 468 469 int 470 kern_fcntl(struct thread *td, int fd, int cmd, intptr_t arg) 471 { 472 struct filedesc *fdp; 473 struct flock *flp; 474 struct file *fp, *fp2; 475 struct filedescent *fde; 476 struct proc *p; 477 struct vnode *vp; 478 struct mount *mp; 479 int error, flg, seals, tmp; 480 uint64_t bsize; 481 off_t foffset; 482 483 error = 0; 484 flg = F_POSIX; 485 p = td->td_proc; 486 fdp = p->p_fd; 487 488 AUDIT_ARG_FD(cmd); 489 AUDIT_ARG_CMD(cmd); 490 switch (cmd) { 491 case F_DUPFD: 492 tmp = arg; 493 error = kern_dup(td, FDDUP_FCNTL, 0, fd, tmp); 494 break; 495 496 case F_DUPFD_CLOEXEC: 497 tmp = arg; 498 error = kern_dup(td, FDDUP_FCNTL, FDDUP_FLAG_CLOEXEC, fd, tmp); 499 break; 500 501 case F_DUP2FD: 502 tmp = arg; 503 error = kern_dup(td, FDDUP_FIXED, 0, fd, tmp); 504 break; 505 506 case F_DUP2FD_CLOEXEC: 507 tmp = arg; 508 error = kern_dup(td, FDDUP_FIXED, FDDUP_FLAG_CLOEXEC, fd, tmp); 509 break; 510 511 case F_GETFD: 512 error = EBADF; 513 FILEDESC_SLOCK(fdp); 514 fde = fdeget_locked(fdp, fd); 515 if (fde != NULL) { 516 td->td_retval[0] = 517 (fde->fde_flags & UF_EXCLOSE) ? FD_CLOEXEC : 0; 518 error = 0; 519 } 520 FILEDESC_SUNLOCK(fdp); 521 break; 522 523 case F_SETFD: 524 error = EBADF; 525 FILEDESC_XLOCK(fdp); 526 fde = fdeget_locked(fdp, fd); 527 if (fde != NULL) { 528 fde->fde_flags = (fde->fde_flags & ~UF_EXCLOSE) | 529 (arg & FD_CLOEXEC ? UF_EXCLOSE : 0); 530 error = 0; 531 } 532 FILEDESC_XUNLOCK(fdp); 533 break; 534 535 case F_GETFL: 536 error = fget_fcntl(td, fd, &cap_fcntl_rights, F_GETFL, &fp); 537 if (error != 0) 538 break; 539 td->td_retval[0] = OFLAGS(fp->f_flag); 540 fdrop(fp, td); 541 break; 542 543 case F_SETFL: 544 error = fget_fcntl(td, fd, &cap_fcntl_rights, F_SETFL, &fp); 545 if (error != 0) 546 break; 547 do { 548 tmp = flg = fp->f_flag; 549 tmp &= ~FCNTLFLAGS; 550 tmp |= FFLAGS(arg & ~O_ACCMODE) & FCNTLFLAGS; 551 } while(atomic_cmpset_int(&fp->f_flag, flg, tmp) == 0); 552 tmp = fp->f_flag & FNONBLOCK; 553 error = fo_ioctl(fp, FIONBIO, &tmp, td->td_ucred, td); 554 if (error != 0) { 555 fdrop(fp, td); 556 break; 557 } 558 tmp = fp->f_flag & FASYNC; 559 error = fo_ioctl(fp, FIOASYNC, &tmp, td->td_ucred, td); 560 if (error == 0) { 561 fdrop(fp, td); 562 break; 563 } 564 atomic_clear_int(&fp->f_flag, FNONBLOCK); 565 tmp = 0; 566 (void)fo_ioctl(fp, FIONBIO, &tmp, td->td_ucred, td); 567 fdrop(fp, td); 568 break; 569 570 case F_GETOWN: 571 error = fget_fcntl(td, fd, &cap_fcntl_rights, F_GETOWN, &fp); 572 if (error != 0) 573 break; 574 error = fo_ioctl(fp, FIOGETOWN, &tmp, td->td_ucred, td); 575 if (error == 0) 576 td->td_retval[0] = tmp; 577 fdrop(fp, td); 578 break; 579 580 case F_SETOWN: 581 error = fget_fcntl(td, fd, &cap_fcntl_rights, F_SETOWN, &fp); 582 if (error != 0) 583 break; 584 tmp = arg; 585 error = fo_ioctl(fp, FIOSETOWN, &tmp, td->td_ucred, td); 586 fdrop(fp, td); 587 break; 588 589 case F_SETLK_REMOTE: 590 error = priv_check(td, PRIV_NFS_LOCKD); 591 if (error != 0) 592 return (error); 593 flg = F_REMOTE; 594 goto do_setlk; 595 596 case F_SETLKW: 597 flg |= F_WAIT; 598 /* FALLTHROUGH F_SETLK */ 599 600 case F_SETLK: 601 do_setlk: 602 flp = (struct flock *)arg; 603 if ((flg & F_REMOTE) != 0 && flp->l_sysid == 0) { 604 error = EINVAL; 605 break; 606 } 607 608 error = fget_unlocked(fdp, fd, &cap_flock_rights, &fp); 609 if (error != 0) 610 break; 611 if (fp->f_type != DTYPE_VNODE) { 612 error = EBADF; 613 fdrop(fp, td); 614 break; 615 } 616 617 if (flp->l_whence == SEEK_CUR) { 618 foffset = foffset_get(fp); 619 if (foffset < 0 || 620 (flp->l_start > 0 && 621 foffset > OFF_MAX - flp->l_start)) { 622 error = EOVERFLOW; 623 fdrop(fp, td); 624 break; 625 } 626 flp->l_start += foffset; 627 } 628 629 vp = fp->f_vnode; 630 switch (flp->l_type) { 631 case F_RDLCK: 632 if ((fp->f_flag & FREAD) == 0) { 633 error = EBADF; 634 break; 635 } 636 if ((p->p_leader->p_flag & P_ADVLOCK) == 0) { 637 PROC_LOCK(p->p_leader); 638 p->p_leader->p_flag |= P_ADVLOCK; 639 PROC_UNLOCK(p->p_leader); 640 } 641 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_SETLK, 642 flp, flg); 643 break; 644 case F_WRLCK: 645 if ((fp->f_flag & FWRITE) == 0) { 646 error = EBADF; 647 break; 648 } 649 if ((p->p_leader->p_flag & P_ADVLOCK) == 0) { 650 PROC_LOCK(p->p_leader); 651 p->p_leader->p_flag |= P_ADVLOCK; 652 PROC_UNLOCK(p->p_leader); 653 } 654 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_SETLK, 655 flp, flg); 656 break; 657 case F_UNLCK: 658 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_UNLCK, 659 flp, flg); 660 break; 661 case F_UNLCKSYS: 662 if (flg != F_REMOTE) { 663 error = EINVAL; 664 break; 665 } 666 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, 667 F_UNLCKSYS, flp, flg); 668 break; 669 default: 670 error = EINVAL; 671 break; 672 } 673 if (error != 0 || flp->l_type == F_UNLCK || 674 flp->l_type == F_UNLCKSYS) { 675 fdrop(fp, td); 676 break; 677 } 678 679 /* 680 * Check for a race with close. 681 * 682 * The vnode is now advisory locked (or unlocked, but this case 683 * is not really important) as the caller requested. 684 * We had to drop the filedesc lock, so we need to recheck if 685 * the descriptor is still valid, because if it was closed 686 * in the meantime we need to remove advisory lock from the 687 * vnode - close on any descriptor leading to an advisory 688 * locked vnode, removes that lock. 689 * We will return 0 on purpose in that case, as the result of 690 * successful advisory lock might have been externally visible 691 * already. This is fine - effectively we pretend to the caller 692 * that the closing thread was a bit slower and that the 693 * advisory lock succeeded before the close. 694 */ 695 error = fget_unlocked(fdp, fd, &cap_no_rights, &fp2); 696 if (error != 0) { 697 fdrop(fp, td); 698 break; 699 } 700 if (fp != fp2) { 701 flp->l_whence = SEEK_SET; 702 flp->l_start = 0; 703 flp->l_len = 0; 704 flp->l_type = F_UNLCK; 705 (void) VOP_ADVLOCK(vp, (caddr_t)p->p_leader, 706 F_UNLCK, flp, F_POSIX); 707 } 708 fdrop(fp, td); 709 fdrop(fp2, td); 710 break; 711 712 case F_GETLK: 713 error = fget_unlocked(fdp, fd, &cap_flock_rights, &fp); 714 if (error != 0) 715 break; 716 if (fp->f_type != DTYPE_VNODE) { 717 error = EBADF; 718 fdrop(fp, td); 719 break; 720 } 721 flp = (struct flock *)arg; 722 if (flp->l_type != F_RDLCK && flp->l_type != F_WRLCK && 723 flp->l_type != F_UNLCK) { 724 error = EINVAL; 725 fdrop(fp, td); 726 break; 727 } 728 if (flp->l_whence == SEEK_CUR) { 729 foffset = foffset_get(fp); 730 if ((flp->l_start > 0 && 731 foffset > OFF_MAX - flp->l_start) || 732 (flp->l_start < 0 && 733 foffset < OFF_MIN - flp->l_start)) { 734 error = EOVERFLOW; 735 fdrop(fp, td); 736 break; 737 } 738 flp->l_start += foffset; 739 } 740 vp = fp->f_vnode; 741 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_GETLK, flp, 742 F_POSIX); 743 fdrop(fp, td); 744 break; 745 746 case F_ADD_SEALS: 747 error = fget_unlocked(fdp, fd, &cap_no_rights, &fp); 748 if (error != 0) 749 break; 750 error = fo_add_seals(fp, arg); 751 fdrop(fp, td); 752 break; 753 754 case F_GET_SEALS: 755 error = fget_unlocked(fdp, fd, &cap_no_rights, &fp); 756 if (error != 0) 757 break; 758 if (fo_get_seals(fp, &seals) == 0) 759 td->td_retval[0] = seals; 760 else 761 error = EINVAL; 762 fdrop(fp, td); 763 break; 764 765 case F_RDAHEAD: 766 arg = arg ? 128 * 1024: 0; 767 /* FALLTHROUGH */ 768 case F_READAHEAD: 769 error = fget_unlocked(fdp, fd, &cap_no_rights, &fp); 770 if (error != 0) 771 break; 772 if (fp->f_type != DTYPE_VNODE) { 773 fdrop(fp, td); 774 error = EBADF; 775 break; 776 } 777 vp = fp->f_vnode; 778 if (vp->v_type != VREG) { 779 fdrop(fp, td); 780 error = ENOTTY; 781 break; 782 } 783 784 /* 785 * Exclusive lock synchronizes against f_seqcount reads and 786 * writes in sequential_heuristic(). 787 */ 788 error = vn_lock(vp, LK_EXCLUSIVE); 789 if (error != 0) { 790 fdrop(fp, td); 791 break; 792 } 793 if (arg >= 0) { 794 bsize = fp->f_vnode->v_mount->mnt_stat.f_iosize; 795 arg = MIN(arg, INT_MAX - bsize + 1); 796 fp->f_seqcount[UIO_READ] = MIN(IO_SEQMAX, 797 (arg + bsize - 1) / bsize); 798 atomic_set_int(&fp->f_flag, FRDAHEAD); 799 } else { 800 atomic_clear_int(&fp->f_flag, FRDAHEAD); 801 } 802 VOP_UNLOCK(vp); 803 fdrop(fp, td); 804 break; 805 806 case F_ISUNIONSTACK: 807 /* 808 * Check if the vnode is part of a union stack (either the 809 * "union" flag from mount(2) or unionfs). 810 * 811 * Prior to introduction of this op libc's readdir would call 812 * fstatfs(2), in effect unnecessarily copying kilobytes of 813 * data just to check fs name and a mount flag. 814 * 815 * Fixing the code to handle everything in the kernel instead 816 * is a non-trivial endeavor and has low priority, thus this 817 * horrible kludge facilitates the current behavior in a much 818 * cheaper manner until someone(tm) sorts this out. 819 */ 820 error = fget_unlocked(fdp, fd, &cap_no_rights, &fp); 821 if (error != 0) 822 break; 823 if (fp->f_type != DTYPE_VNODE) { 824 fdrop(fp, td); 825 error = EBADF; 826 break; 827 } 828 vp = fp->f_vnode; 829 /* 830 * Since we don't prevent dooming the vnode even non-null mp 831 * found can become immediately stale. This is tolerable since 832 * mount points are type-stable (providing safe memory access) 833 * and any vfs op on this vnode going forward will return an 834 * error (meaning return value in this case is meaningless). 835 */ 836 mp = atomic_load_ptr(&vp->v_mount); 837 if (__predict_false(mp == NULL)) { 838 fdrop(fp, td); 839 error = EBADF; 840 break; 841 } 842 td->td_retval[0] = 0; 843 if (mp->mnt_kern_flag & MNTK_UNIONFS || 844 mp->mnt_flag & MNT_UNION) 845 td->td_retval[0] = 1; 846 fdrop(fp, td); 847 break; 848 849 default: 850 error = EINVAL; 851 break; 852 } 853 return (error); 854 } 855 856 static int 857 getmaxfd(struct thread *td) 858 { 859 860 return (min((int)lim_cur(td, RLIMIT_NOFILE), maxfilesperproc)); 861 } 862 863 /* 864 * Common code for dup, dup2, fcntl(F_DUPFD) and fcntl(F_DUP2FD). 865 */ 866 int 867 kern_dup(struct thread *td, u_int mode, int flags, int old, int new) 868 { 869 struct filedesc *fdp; 870 struct filedescent *oldfde, *newfde; 871 struct proc *p; 872 struct file *delfp; 873 u_long *oioctls, *nioctls; 874 int error, maxfd; 875 876 p = td->td_proc; 877 fdp = p->p_fd; 878 oioctls = NULL; 879 880 MPASS((flags & ~(FDDUP_FLAG_CLOEXEC)) == 0); 881 MPASS(mode < FDDUP_LASTMODE); 882 883 AUDIT_ARG_FD(old); 884 /* XXXRW: if (flags & FDDUP_FIXED) AUDIT_ARG_FD2(new); */ 885 886 /* 887 * Verify we have a valid descriptor to dup from and possibly to 888 * dup to. Unlike dup() and dup2(), fcntl()'s F_DUPFD should 889 * return EINVAL when the new descriptor is out of bounds. 890 */ 891 if (old < 0) 892 return (EBADF); 893 if (new < 0) 894 return (mode == FDDUP_FCNTL ? EINVAL : EBADF); 895 maxfd = getmaxfd(td); 896 if (new >= maxfd) 897 return (mode == FDDUP_FCNTL ? EINVAL : EBADF); 898 899 error = EBADF; 900 FILEDESC_XLOCK(fdp); 901 if (fget_locked(fdp, old) == NULL) 902 goto unlock; 903 if ((mode == FDDUP_FIXED || mode == FDDUP_MUSTREPLACE) && old == new) { 904 td->td_retval[0] = new; 905 if (flags & FDDUP_FLAG_CLOEXEC) 906 fdp->fd_ofiles[new].fde_flags |= UF_EXCLOSE; 907 error = 0; 908 goto unlock; 909 } 910 911 oldfde = &fdp->fd_ofiles[old]; 912 if (!fhold(oldfde->fde_file)) 913 goto unlock; 914 915 /* 916 * If the caller specified a file descriptor, make sure the file 917 * table is large enough to hold it, and grab it. Otherwise, just 918 * allocate a new descriptor the usual way. 919 */ 920 switch (mode) { 921 case FDDUP_NORMAL: 922 case FDDUP_FCNTL: 923 if ((error = fdalloc(td, new, &new)) != 0) { 924 fdrop(oldfde->fde_file, td); 925 goto unlock; 926 } 927 break; 928 case FDDUP_MUSTREPLACE: 929 /* Target file descriptor must exist. */ 930 if (fget_locked(fdp, new) == NULL) { 931 fdrop(oldfde->fde_file, td); 932 goto unlock; 933 } 934 break; 935 case FDDUP_FIXED: 936 if (new >= fdp->fd_nfiles) { 937 /* 938 * The resource limits are here instead of e.g. 939 * fdalloc(), because the file descriptor table may be 940 * shared between processes, so we can't really use 941 * racct_add()/racct_sub(). Instead of counting the 942 * number of actually allocated descriptors, just put 943 * the limit on the size of the file descriptor table. 944 */ 945 #ifdef RACCT 946 if (RACCT_ENABLED()) { 947 error = racct_set_unlocked(p, RACCT_NOFILE, new + 1); 948 if (error != 0) { 949 error = EMFILE; 950 fdrop(oldfde->fde_file, td); 951 goto unlock; 952 } 953 } 954 #endif 955 fdgrowtable_exp(fdp, new + 1); 956 } 957 if (!fdisused(fdp, new)) 958 fdused(fdp, new); 959 break; 960 default: 961 KASSERT(0, ("%s unsupported mode %d", __func__, mode)); 962 } 963 964 KASSERT(old != new, ("new fd is same as old")); 965 966 newfde = &fdp->fd_ofiles[new]; 967 delfp = newfde->fde_file; 968 969 nioctls = filecaps_copy_prep(&oldfde->fde_caps); 970 971 /* 972 * Duplicate the source descriptor. 973 */ 974 #ifdef CAPABILITIES 975 seqc_write_begin(&newfde->fde_seqc); 976 #endif 977 oioctls = filecaps_free_prep(&newfde->fde_caps); 978 memcpy(newfde, oldfde, fde_change_size); 979 filecaps_copy_finish(&oldfde->fde_caps, &newfde->fde_caps, 980 nioctls); 981 if ((flags & FDDUP_FLAG_CLOEXEC) != 0) 982 newfde->fde_flags = oldfde->fde_flags | UF_EXCLOSE; 983 else 984 newfde->fde_flags = oldfde->fde_flags & ~UF_EXCLOSE; 985 #ifdef CAPABILITIES 986 seqc_write_end(&newfde->fde_seqc); 987 #endif 988 td->td_retval[0] = new; 989 990 error = 0; 991 992 if (delfp != NULL) { 993 (void) closefp(fdp, new, delfp, td, 1); 994 FILEDESC_UNLOCK_ASSERT(fdp); 995 } else { 996 unlock: 997 FILEDESC_XUNLOCK(fdp); 998 } 999 1000 filecaps_free_finish(oioctls); 1001 return (error); 1002 } 1003 1004 static void 1005 sigiofree(struct sigio *sigio) 1006 { 1007 crfree(sigio->sio_ucred); 1008 free(sigio, M_SIGIO); 1009 } 1010 1011 static struct sigio * 1012 funsetown_locked(struct sigio *sigio) 1013 { 1014 struct proc *p; 1015 struct pgrp *pg; 1016 1017 SIGIO_ASSERT_LOCKED(); 1018 1019 if (sigio == NULL) 1020 return (NULL); 1021 *(sigio->sio_myref) = NULL; 1022 if (sigio->sio_pgid < 0) { 1023 pg = sigio->sio_pgrp; 1024 PGRP_LOCK(pg); 1025 SLIST_REMOVE(&sigio->sio_pgrp->pg_sigiolst, sigio, 1026 sigio, sio_pgsigio); 1027 PGRP_UNLOCK(pg); 1028 } else { 1029 p = sigio->sio_proc; 1030 PROC_LOCK(p); 1031 SLIST_REMOVE(&sigio->sio_proc->p_sigiolst, sigio, 1032 sigio, sio_pgsigio); 1033 PROC_UNLOCK(p); 1034 } 1035 return (sigio); 1036 } 1037 1038 /* 1039 * If sigio is on the list associated with a process or process group, 1040 * disable signalling from the device, remove sigio from the list and 1041 * free sigio. 1042 */ 1043 void 1044 funsetown(struct sigio **sigiop) 1045 { 1046 struct sigio *sigio; 1047 1048 /* Racy check, consumers must provide synchronization. */ 1049 if (*sigiop == NULL) 1050 return; 1051 1052 SIGIO_LOCK(); 1053 sigio = funsetown_locked(*sigiop); 1054 SIGIO_UNLOCK(); 1055 if (sigio != NULL) 1056 sigiofree(sigio); 1057 } 1058 1059 /* 1060 * Free a list of sigio structures. The caller must ensure that new sigio 1061 * structures cannot be added after this point. For process groups this is 1062 * guaranteed using the proctree lock; for processes, the P_WEXIT flag serves 1063 * as an interlock. 1064 */ 1065 void 1066 funsetownlst(struct sigiolst *sigiolst) 1067 { 1068 struct proc *p; 1069 struct pgrp *pg; 1070 struct sigio *sigio, *tmp; 1071 1072 /* Racy check. */ 1073 sigio = SLIST_FIRST(sigiolst); 1074 if (sigio == NULL) 1075 return; 1076 1077 p = NULL; 1078 pg = NULL; 1079 1080 SIGIO_LOCK(); 1081 sigio = SLIST_FIRST(sigiolst); 1082 if (sigio == NULL) { 1083 SIGIO_UNLOCK(); 1084 return; 1085 } 1086 1087 /* 1088 * Every entry of the list should belong to a single proc or pgrp. 1089 */ 1090 if (sigio->sio_pgid < 0) { 1091 pg = sigio->sio_pgrp; 1092 sx_assert(&proctree_lock, SX_XLOCKED); 1093 PGRP_LOCK(pg); 1094 } else /* if (sigio->sio_pgid > 0) */ { 1095 p = sigio->sio_proc; 1096 PROC_LOCK(p); 1097 KASSERT((p->p_flag & P_WEXIT) != 0, 1098 ("%s: process %p is not exiting", __func__, p)); 1099 } 1100 1101 SLIST_FOREACH(sigio, sigiolst, sio_pgsigio) { 1102 *sigio->sio_myref = NULL; 1103 if (pg != NULL) { 1104 KASSERT(sigio->sio_pgid < 0, 1105 ("Proc sigio in pgrp sigio list")); 1106 KASSERT(sigio->sio_pgrp == pg, 1107 ("Bogus pgrp in sigio list")); 1108 } else /* if (p != NULL) */ { 1109 KASSERT(sigio->sio_pgid > 0, 1110 ("Pgrp sigio in proc sigio list")); 1111 KASSERT(sigio->sio_proc == p, 1112 ("Bogus proc in sigio list")); 1113 } 1114 } 1115 1116 if (pg != NULL) 1117 PGRP_UNLOCK(pg); 1118 else 1119 PROC_UNLOCK(p); 1120 SIGIO_UNLOCK(); 1121 1122 SLIST_FOREACH_SAFE(sigio, sigiolst, sio_pgsigio, tmp) 1123 sigiofree(sigio); 1124 } 1125 1126 /* 1127 * This is common code for FIOSETOWN ioctl called by fcntl(fd, F_SETOWN, arg). 1128 * 1129 * After permission checking, add a sigio structure to the sigio list for 1130 * the process or process group. 1131 */ 1132 int 1133 fsetown(pid_t pgid, struct sigio **sigiop) 1134 { 1135 struct proc *proc; 1136 struct pgrp *pgrp; 1137 struct sigio *osigio, *sigio; 1138 int ret; 1139 1140 if (pgid == 0) { 1141 funsetown(sigiop); 1142 return (0); 1143 } 1144 1145 ret = 0; 1146 1147 sigio = malloc(sizeof(struct sigio), M_SIGIO, M_WAITOK); 1148 sigio->sio_pgid = pgid; 1149 sigio->sio_ucred = crhold(curthread->td_ucred); 1150 sigio->sio_myref = sigiop; 1151 1152 sx_slock(&proctree_lock); 1153 SIGIO_LOCK(); 1154 osigio = funsetown_locked(*sigiop); 1155 if (pgid > 0) { 1156 proc = pfind(pgid); 1157 if (proc == NULL) { 1158 ret = ESRCH; 1159 goto fail; 1160 } 1161 1162 /* 1163 * Policy - Don't allow a process to FSETOWN a process 1164 * in another session. 1165 * 1166 * Remove this test to allow maximum flexibility or 1167 * restrict FSETOWN to the current process or process 1168 * group for maximum safety. 1169 */ 1170 if (proc->p_session != curthread->td_proc->p_session) { 1171 PROC_UNLOCK(proc); 1172 ret = EPERM; 1173 goto fail; 1174 } 1175 1176 sigio->sio_proc = proc; 1177 SLIST_INSERT_HEAD(&proc->p_sigiolst, sigio, sio_pgsigio); 1178 PROC_UNLOCK(proc); 1179 } else /* if (pgid < 0) */ { 1180 pgrp = pgfind(-pgid); 1181 if (pgrp == NULL) { 1182 ret = ESRCH; 1183 goto fail; 1184 } 1185 1186 /* 1187 * Policy - Don't allow a process to FSETOWN a process 1188 * in another session. 1189 * 1190 * Remove this test to allow maximum flexibility or 1191 * restrict FSETOWN to the current process or process 1192 * group for maximum safety. 1193 */ 1194 if (pgrp->pg_session != curthread->td_proc->p_session) { 1195 PGRP_UNLOCK(pgrp); 1196 ret = EPERM; 1197 goto fail; 1198 } 1199 1200 SLIST_INSERT_HEAD(&pgrp->pg_sigiolst, sigio, sio_pgsigio); 1201 sigio->sio_pgrp = pgrp; 1202 PGRP_UNLOCK(pgrp); 1203 } 1204 sx_sunlock(&proctree_lock); 1205 *sigiop = sigio; 1206 SIGIO_UNLOCK(); 1207 if (osigio != NULL) 1208 sigiofree(osigio); 1209 return (0); 1210 1211 fail: 1212 SIGIO_UNLOCK(); 1213 sx_sunlock(&proctree_lock); 1214 sigiofree(sigio); 1215 if (osigio != NULL) 1216 sigiofree(osigio); 1217 return (ret); 1218 } 1219 1220 /* 1221 * This is common code for FIOGETOWN ioctl called by fcntl(fd, F_GETOWN, arg). 1222 */ 1223 pid_t 1224 fgetown(struct sigio **sigiop) 1225 { 1226 pid_t pgid; 1227 1228 SIGIO_LOCK(); 1229 pgid = (*sigiop != NULL) ? (*sigiop)->sio_pgid : 0; 1230 SIGIO_UNLOCK(); 1231 return (pgid); 1232 } 1233 1234 /* 1235 * Function drops the filedesc lock on return. 1236 */ 1237 static int 1238 closefp(struct filedesc *fdp, int fd, struct file *fp, struct thread *td, 1239 int holdleaders) 1240 { 1241 int error; 1242 1243 FILEDESC_XLOCK_ASSERT(fdp); 1244 1245 if (holdleaders) { 1246 if (td->td_proc->p_fdtol != NULL) { 1247 /* 1248 * Ask fdfree() to sleep to ensure that all relevant 1249 * process leaders can be traversed in closef(). 1250 */ 1251 fdp->fd_holdleaderscount++; 1252 } else { 1253 holdleaders = 0; 1254 } 1255 } 1256 1257 /* 1258 * We now hold the fp reference that used to be owned by the 1259 * descriptor array. We have to unlock the FILEDESC *AFTER* 1260 * knote_fdclose to prevent a race of the fd getting opened, a knote 1261 * added, and deleteing a knote for the new fd. 1262 */ 1263 if (__predict_false(!TAILQ_EMPTY(&fdp->fd_kqlist))) 1264 knote_fdclose(td, fd); 1265 1266 /* 1267 * We need to notify mqueue if the object is of type mqueue. 1268 */ 1269 if (__predict_false(fp->f_type == DTYPE_MQUEUE)) 1270 mq_fdclose(td, fd, fp); 1271 FILEDESC_XUNLOCK(fdp); 1272 1273 error = closef(fp, td); 1274 if (holdleaders) { 1275 FILEDESC_XLOCK(fdp); 1276 fdp->fd_holdleaderscount--; 1277 if (fdp->fd_holdleaderscount == 0 && 1278 fdp->fd_holdleaderswakeup != 0) { 1279 fdp->fd_holdleaderswakeup = 0; 1280 wakeup(&fdp->fd_holdleaderscount); 1281 } 1282 FILEDESC_XUNLOCK(fdp); 1283 } 1284 return (error); 1285 } 1286 1287 /* 1288 * Close a file descriptor. 1289 */ 1290 #ifndef _SYS_SYSPROTO_H_ 1291 struct close_args { 1292 int fd; 1293 }; 1294 #endif 1295 /* ARGSUSED */ 1296 int 1297 sys_close(struct thread *td, struct close_args *uap) 1298 { 1299 1300 return (kern_close(td, uap->fd)); 1301 } 1302 1303 int 1304 kern_close(struct thread *td, int fd) 1305 { 1306 struct filedesc *fdp; 1307 struct file *fp; 1308 1309 fdp = td->td_proc->p_fd; 1310 1311 AUDIT_SYSCLOSE(td, fd); 1312 1313 FILEDESC_XLOCK(fdp); 1314 if ((fp = fget_locked(fdp, fd)) == NULL) { 1315 FILEDESC_XUNLOCK(fdp); 1316 return (EBADF); 1317 } 1318 fdfree(fdp, fd); 1319 1320 /* closefp() drops the FILEDESC lock for us. */ 1321 return (closefp(fdp, fd, fp, td, 1)); 1322 } 1323 1324 int 1325 kern_close_range(struct thread *td, u_int lowfd, u_int highfd) 1326 { 1327 struct filedesc *fdp; 1328 int fd, ret, lastfile; 1329 1330 ret = 0; 1331 fdp = td->td_proc->p_fd; 1332 FILEDESC_SLOCK(fdp); 1333 1334 /* 1335 * Check this prior to clamping; closefrom(3) with only fd 0, 1, and 2 1336 * open should not be a usage error. From a close_range() perspective, 1337 * close_range(3, ~0U, 0) in the same scenario should also likely not 1338 * be a usage error as all fd above 3 are in-fact already closed. 1339 */ 1340 if (highfd < lowfd) { 1341 ret = EINVAL; 1342 goto out; 1343 } 1344 1345 /* 1346 * If lastfile == -1, we're dealing with either a fresh file 1347 * table or one in which every fd has been closed. Just return 1348 * successful; there's nothing left to do. 1349 */ 1350 lastfile = fdlastfile(fdp); 1351 if (lastfile == -1) 1352 goto out; 1353 /* Clamped to [lowfd, lastfile] */ 1354 highfd = MIN(highfd, lastfile); 1355 for (fd = lowfd; fd <= highfd; fd++) { 1356 if (fdp->fd_ofiles[fd].fde_file != NULL) { 1357 FILEDESC_SUNLOCK(fdp); 1358 (void)kern_close(td, fd); 1359 FILEDESC_SLOCK(fdp); 1360 } 1361 } 1362 out: 1363 FILEDESC_SUNLOCK(fdp); 1364 return (ret); 1365 } 1366 1367 #ifndef _SYS_SYSPROTO_H_ 1368 struct close_range_args { 1369 u_int lowfd; 1370 u_int highfd; 1371 int flags; 1372 }; 1373 #endif 1374 int 1375 sys_close_range(struct thread *td, struct close_range_args *uap) 1376 { 1377 1378 /* No flags currently defined */ 1379 if (uap->flags != 0) 1380 return (EINVAL); 1381 return (kern_close_range(td, uap->lowfd, uap->highfd)); 1382 } 1383 1384 #ifdef COMPAT_FREEBSD12 1385 /* 1386 * Close open file descriptors. 1387 */ 1388 #ifndef _SYS_SYSPROTO_H_ 1389 struct freebsd12_closefrom_args { 1390 int lowfd; 1391 }; 1392 #endif 1393 /* ARGSUSED */ 1394 int 1395 freebsd12_closefrom(struct thread *td, struct freebsd12_closefrom_args *uap) 1396 { 1397 u_int lowfd; 1398 1399 AUDIT_ARG_FD(uap->lowfd); 1400 1401 /* 1402 * Treat negative starting file descriptor values identical to 1403 * closefrom(0) which closes all files. 1404 */ 1405 lowfd = MAX(0, uap->lowfd); 1406 return (kern_close_range(td, lowfd, ~0U)); 1407 } 1408 #endif /* COMPAT_FREEBSD12 */ 1409 1410 #if defined(COMPAT_43) 1411 /* 1412 * Return status information about a file descriptor. 1413 */ 1414 #ifndef _SYS_SYSPROTO_H_ 1415 struct ofstat_args { 1416 int fd; 1417 struct ostat *sb; 1418 }; 1419 #endif 1420 /* ARGSUSED */ 1421 int 1422 ofstat(struct thread *td, struct ofstat_args *uap) 1423 { 1424 struct ostat oub; 1425 struct stat ub; 1426 int error; 1427 1428 error = kern_fstat(td, uap->fd, &ub); 1429 if (error == 0) { 1430 cvtstat(&ub, &oub); 1431 error = copyout(&oub, uap->sb, sizeof(oub)); 1432 } 1433 return (error); 1434 } 1435 #endif /* COMPAT_43 */ 1436 1437 #if defined(COMPAT_FREEBSD11) 1438 int 1439 freebsd11_fstat(struct thread *td, struct freebsd11_fstat_args *uap) 1440 { 1441 struct stat sb; 1442 struct freebsd11_stat osb; 1443 int error; 1444 1445 error = kern_fstat(td, uap->fd, &sb); 1446 if (error != 0) 1447 return (error); 1448 error = freebsd11_cvtstat(&sb, &osb); 1449 if (error == 0) 1450 error = copyout(&osb, uap->sb, sizeof(osb)); 1451 return (error); 1452 } 1453 #endif /* COMPAT_FREEBSD11 */ 1454 1455 /* 1456 * Return status information about a file descriptor. 1457 */ 1458 #ifndef _SYS_SYSPROTO_H_ 1459 struct fstat_args { 1460 int fd; 1461 struct stat *sb; 1462 }; 1463 #endif 1464 /* ARGSUSED */ 1465 int 1466 sys_fstat(struct thread *td, struct fstat_args *uap) 1467 { 1468 struct stat ub; 1469 int error; 1470 1471 error = kern_fstat(td, uap->fd, &ub); 1472 if (error == 0) 1473 error = copyout(&ub, uap->sb, sizeof(ub)); 1474 return (error); 1475 } 1476 1477 int 1478 kern_fstat(struct thread *td, int fd, struct stat *sbp) 1479 { 1480 struct file *fp; 1481 int error; 1482 1483 AUDIT_ARG_FD(fd); 1484 1485 error = fget(td, fd, &cap_fstat_rights, &fp); 1486 if (__predict_false(error != 0)) 1487 return (error); 1488 1489 AUDIT_ARG_FILE(td->td_proc, fp); 1490 1491 error = fo_stat(fp, sbp, td->td_ucred, td); 1492 fdrop(fp, td); 1493 #ifdef __STAT_TIME_T_EXT 1494 sbp->st_atim_ext = 0; 1495 sbp->st_mtim_ext = 0; 1496 sbp->st_ctim_ext = 0; 1497 sbp->st_btim_ext = 0; 1498 #endif 1499 #ifdef KTRACE 1500 if (KTRPOINT(td, KTR_STRUCT)) 1501 ktrstat_error(sbp, error); 1502 #endif 1503 return (error); 1504 } 1505 1506 #if defined(COMPAT_FREEBSD11) 1507 /* 1508 * Return status information about a file descriptor. 1509 */ 1510 #ifndef _SYS_SYSPROTO_H_ 1511 struct freebsd11_nfstat_args { 1512 int fd; 1513 struct nstat *sb; 1514 }; 1515 #endif 1516 /* ARGSUSED */ 1517 int 1518 freebsd11_nfstat(struct thread *td, struct freebsd11_nfstat_args *uap) 1519 { 1520 struct nstat nub; 1521 struct stat ub; 1522 int error; 1523 1524 error = kern_fstat(td, uap->fd, &ub); 1525 if (error == 0) { 1526 freebsd11_cvtnstat(&ub, &nub); 1527 error = copyout(&nub, uap->sb, sizeof(nub)); 1528 } 1529 return (error); 1530 } 1531 #endif /* COMPAT_FREEBSD11 */ 1532 1533 /* 1534 * Return pathconf information about a file descriptor. 1535 */ 1536 #ifndef _SYS_SYSPROTO_H_ 1537 struct fpathconf_args { 1538 int fd; 1539 int name; 1540 }; 1541 #endif 1542 /* ARGSUSED */ 1543 int 1544 sys_fpathconf(struct thread *td, struct fpathconf_args *uap) 1545 { 1546 long value; 1547 int error; 1548 1549 error = kern_fpathconf(td, uap->fd, uap->name, &value); 1550 if (error == 0) 1551 td->td_retval[0] = value; 1552 return (error); 1553 } 1554 1555 int 1556 kern_fpathconf(struct thread *td, int fd, int name, long *valuep) 1557 { 1558 struct file *fp; 1559 struct vnode *vp; 1560 int error; 1561 1562 error = fget(td, fd, &cap_fpathconf_rights, &fp); 1563 if (error != 0) 1564 return (error); 1565 1566 if (name == _PC_ASYNC_IO) { 1567 *valuep = _POSIX_ASYNCHRONOUS_IO; 1568 goto out; 1569 } 1570 vp = fp->f_vnode; 1571 if (vp != NULL) { 1572 vn_lock(vp, LK_SHARED | LK_RETRY); 1573 error = VOP_PATHCONF(vp, name, valuep); 1574 VOP_UNLOCK(vp); 1575 } else if (fp->f_type == DTYPE_PIPE || fp->f_type == DTYPE_SOCKET) { 1576 if (name != _PC_PIPE_BUF) { 1577 error = EINVAL; 1578 } else { 1579 *valuep = PIPE_BUF; 1580 error = 0; 1581 } 1582 } else { 1583 error = EOPNOTSUPP; 1584 } 1585 out: 1586 fdrop(fp, td); 1587 return (error); 1588 } 1589 1590 /* 1591 * Copy filecaps structure allocating memory for ioctls array if needed. 1592 * 1593 * The last parameter indicates whether the fdtable is locked. If it is not and 1594 * ioctls are encountered, copying fails and the caller must lock the table. 1595 * 1596 * Note that if the table was not locked, the caller has to check the relevant 1597 * sequence counter to determine whether the operation was successful. 1598 */ 1599 bool 1600 filecaps_copy(const struct filecaps *src, struct filecaps *dst, bool locked) 1601 { 1602 size_t size; 1603 1604 if (src->fc_ioctls != NULL && !locked) 1605 return (false); 1606 memcpy(dst, src, sizeof(*src)); 1607 if (src->fc_ioctls == NULL) 1608 return (true); 1609 1610 KASSERT(src->fc_nioctls > 0, 1611 ("fc_ioctls != NULL, but fc_nioctls=%hd", src->fc_nioctls)); 1612 1613 size = sizeof(src->fc_ioctls[0]) * src->fc_nioctls; 1614 dst->fc_ioctls = malloc(size, M_FILECAPS, M_WAITOK); 1615 memcpy(dst->fc_ioctls, src->fc_ioctls, size); 1616 return (true); 1617 } 1618 1619 static u_long * 1620 filecaps_copy_prep(const struct filecaps *src) 1621 { 1622 u_long *ioctls; 1623 size_t size; 1624 1625 if (__predict_true(src->fc_ioctls == NULL)) 1626 return (NULL); 1627 1628 KASSERT(src->fc_nioctls > 0, 1629 ("fc_ioctls != NULL, but fc_nioctls=%hd", src->fc_nioctls)); 1630 1631 size = sizeof(src->fc_ioctls[0]) * src->fc_nioctls; 1632 ioctls = malloc(size, M_FILECAPS, M_WAITOK); 1633 return (ioctls); 1634 } 1635 1636 static void 1637 filecaps_copy_finish(const struct filecaps *src, struct filecaps *dst, 1638 u_long *ioctls) 1639 { 1640 size_t size; 1641 1642 *dst = *src; 1643 if (__predict_true(src->fc_ioctls == NULL)) { 1644 MPASS(ioctls == NULL); 1645 return; 1646 } 1647 1648 size = sizeof(src->fc_ioctls[0]) * src->fc_nioctls; 1649 dst->fc_ioctls = ioctls; 1650 bcopy(src->fc_ioctls, dst->fc_ioctls, size); 1651 } 1652 1653 /* 1654 * Move filecaps structure to the new place and clear the old place. 1655 */ 1656 void 1657 filecaps_move(struct filecaps *src, struct filecaps *dst) 1658 { 1659 1660 *dst = *src; 1661 bzero(src, sizeof(*src)); 1662 } 1663 1664 /* 1665 * Fill the given filecaps structure with full rights. 1666 */ 1667 static void 1668 filecaps_fill(struct filecaps *fcaps) 1669 { 1670 1671 CAP_ALL(&fcaps->fc_rights); 1672 fcaps->fc_ioctls = NULL; 1673 fcaps->fc_nioctls = -1; 1674 fcaps->fc_fcntls = CAP_FCNTL_ALL; 1675 } 1676 1677 /* 1678 * Free memory allocated within filecaps structure. 1679 */ 1680 void 1681 filecaps_free(struct filecaps *fcaps) 1682 { 1683 1684 free(fcaps->fc_ioctls, M_FILECAPS); 1685 bzero(fcaps, sizeof(*fcaps)); 1686 } 1687 1688 static u_long * 1689 filecaps_free_prep(struct filecaps *fcaps) 1690 { 1691 u_long *ioctls; 1692 1693 ioctls = fcaps->fc_ioctls; 1694 bzero(fcaps, sizeof(*fcaps)); 1695 return (ioctls); 1696 } 1697 1698 static void 1699 filecaps_free_finish(u_long *ioctls) 1700 { 1701 1702 free(ioctls, M_FILECAPS); 1703 } 1704 1705 /* 1706 * Validate the given filecaps structure. 1707 */ 1708 static void 1709 filecaps_validate(const struct filecaps *fcaps, const char *func) 1710 { 1711 1712 KASSERT(cap_rights_is_valid(&fcaps->fc_rights), 1713 ("%s: invalid rights", func)); 1714 KASSERT((fcaps->fc_fcntls & ~CAP_FCNTL_ALL) == 0, 1715 ("%s: invalid fcntls", func)); 1716 KASSERT(fcaps->fc_fcntls == 0 || 1717 cap_rights_is_set(&fcaps->fc_rights, CAP_FCNTL), 1718 ("%s: fcntls without CAP_FCNTL", func)); 1719 KASSERT(fcaps->fc_ioctls != NULL ? fcaps->fc_nioctls > 0 : 1720 (fcaps->fc_nioctls == -1 || fcaps->fc_nioctls == 0), 1721 ("%s: invalid ioctls", func)); 1722 KASSERT(fcaps->fc_nioctls == 0 || 1723 cap_rights_is_set(&fcaps->fc_rights, CAP_IOCTL), 1724 ("%s: ioctls without CAP_IOCTL", func)); 1725 } 1726 1727 static void 1728 fdgrowtable_exp(struct filedesc *fdp, int nfd) 1729 { 1730 int nfd1; 1731 1732 FILEDESC_XLOCK_ASSERT(fdp); 1733 1734 nfd1 = fdp->fd_nfiles * 2; 1735 if (nfd1 < nfd) 1736 nfd1 = nfd; 1737 fdgrowtable(fdp, nfd1); 1738 } 1739 1740 /* 1741 * Grow the file table to accommodate (at least) nfd descriptors. 1742 */ 1743 static void 1744 fdgrowtable(struct filedesc *fdp, int nfd) 1745 { 1746 struct filedesc0 *fdp0; 1747 struct freetable *ft; 1748 struct fdescenttbl *ntable; 1749 struct fdescenttbl *otable; 1750 int nnfiles, onfiles; 1751 NDSLOTTYPE *nmap, *omap; 1752 1753 KASSERT(fdp->fd_nfiles > 0, ("zero-length file table")); 1754 1755 /* save old values */ 1756 onfiles = fdp->fd_nfiles; 1757 otable = fdp->fd_files; 1758 omap = fdp->fd_map; 1759 1760 /* compute the size of the new table */ 1761 nnfiles = NDSLOTS(nfd) * NDENTRIES; /* round up */ 1762 if (nnfiles <= onfiles) 1763 /* the table is already large enough */ 1764 return; 1765 1766 /* 1767 * Allocate a new table. We need enough space for the number of 1768 * entries, file entries themselves and the struct freetable we will use 1769 * when we decommission the table and place it on the freelist. 1770 * We place the struct freetable in the middle so we don't have 1771 * to worry about padding. 1772 */ 1773 ntable = malloc(offsetof(struct fdescenttbl, fdt_ofiles) + 1774 nnfiles * sizeof(ntable->fdt_ofiles[0]) + 1775 sizeof(struct freetable), 1776 M_FILEDESC, M_ZERO | M_WAITOK); 1777 /* copy the old data */ 1778 ntable->fdt_nfiles = nnfiles; 1779 memcpy(ntable->fdt_ofiles, otable->fdt_ofiles, 1780 onfiles * sizeof(ntable->fdt_ofiles[0])); 1781 1782 /* 1783 * Allocate a new map only if the old is not large enough. It will 1784 * grow at a slower rate than the table as it can map more 1785 * entries than the table can hold. 1786 */ 1787 if (NDSLOTS(nnfiles) > NDSLOTS(onfiles)) { 1788 nmap = malloc(NDSLOTS(nnfiles) * NDSLOTSIZE, M_FILEDESC, 1789 M_ZERO | M_WAITOK); 1790 /* copy over the old data and update the pointer */ 1791 memcpy(nmap, omap, NDSLOTS(onfiles) * sizeof(*omap)); 1792 fdp->fd_map = nmap; 1793 } 1794 1795 /* 1796 * Make sure that ntable is correctly initialized before we replace 1797 * fd_files poiner. Otherwise fget_unlocked() may see inconsistent 1798 * data. 1799 */ 1800 atomic_store_rel_ptr((volatile void *)&fdp->fd_files, (uintptr_t)ntable); 1801 1802 /* 1803 * Do not free the old file table, as some threads may still 1804 * reference entries within it. Instead, place it on a freelist 1805 * which will be processed when the struct filedesc is released. 1806 * 1807 * Note that if onfiles == NDFILE, we're dealing with the original 1808 * static allocation contained within (struct filedesc0 *)fdp, 1809 * which must not be freed. 1810 */ 1811 if (onfiles > NDFILE) { 1812 ft = (struct freetable *)&otable->fdt_ofiles[onfiles]; 1813 fdp0 = (struct filedesc0 *)fdp; 1814 ft->ft_table = otable; 1815 SLIST_INSERT_HEAD(&fdp0->fd_free, ft, ft_next); 1816 } 1817 /* 1818 * The map does not have the same possibility of threads still 1819 * holding references to it. So always free it as long as it 1820 * does not reference the original static allocation. 1821 */ 1822 if (NDSLOTS(onfiles) > NDSLOTS(NDFILE)) 1823 free(omap, M_FILEDESC); 1824 } 1825 1826 /* 1827 * Allocate a file descriptor for the process. 1828 */ 1829 int 1830 fdalloc(struct thread *td, int minfd, int *result) 1831 { 1832 struct proc *p = td->td_proc; 1833 struct filedesc *fdp = p->p_fd; 1834 int fd, maxfd, allocfd; 1835 #ifdef RACCT 1836 int error; 1837 #endif 1838 1839 FILEDESC_XLOCK_ASSERT(fdp); 1840 1841 if (fdp->fd_freefile > minfd) 1842 minfd = fdp->fd_freefile; 1843 1844 maxfd = getmaxfd(td); 1845 1846 /* 1847 * Search the bitmap for a free descriptor starting at minfd. 1848 * If none is found, grow the file table. 1849 */ 1850 fd = fd_first_free(fdp, minfd, fdp->fd_nfiles); 1851 if (__predict_false(fd >= maxfd)) 1852 return (EMFILE); 1853 if (__predict_false(fd >= fdp->fd_nfiles)) { 1854 allocfd = min(fd * 2, maxfd); 1855 #ifdef RACCT 1856 if (RACCT_ENABLED()) { 1857 error = racct_set_unlocked(p, RACCT_NOFILE, allocfd); 1858 if (error != 0) 1859 return (EMFILE); 1860 } 1861 #endif 1862 /* 1863 * fd is already equal to first free descriptor >= minfd, so 1864 * we only need to grow the table and we are done. 1865 */ 1866 fdgrowtable_exp(fdp, allocfd); 1867 } 1868 1869 /* 1870 * Perform some sanity checks, then mark the file descriptor as 1871 * used and return it to the caller. 1872 */ 1873 KASSERT(fd >= 0 && fd < min(maxfd, fdp->fd_nfiles), 1874 ("invalid descriptor %d", fd)); 1875 KASSERT(!fdisused(fdp, fd), 1876 ("fd_first_free() returned non-free descriptor")); 1877 KASSERT(fdp->fd_ofiles[fd].fde_file == NULL, 1878 ("file descriptor isn't free")); 1879 fdused(fdp, fd); 1880 *result = fd; 1881 return (0); 1882 } 1883 1884 /* 1885 * Allocate n file descriptors for the process. 1886 */ 1887 int 1888 fdallocn(struct thread *td, int minfd, int *fds, int n) 1889 { 1890 struct proc *p = td->td_proc; 1891 struct filedesc *fdp = p->p_fd; 1892 int i; 1893 1894 FILEDESC_XLOCK_ASSERT(fdp); 1895 1896 for (i = 0; i < n; i++) 1897 if (fdalloc(td, 0, &fds[i]) != 0) 1898 break; 1899 1900 if (i < n) { 1901 for (i--; i >= 0; i--) 1902 fdunused(fdp, fds[i]); 1903 return (EMFILE); 1904 } 1905 1906 return (0); 1907 } 1908 1909 /* 1910 * Create a new open file structure and allocate a file descriptor for the 1911 * process that refers to it. We add one reference to the file for the 1912 * descriptor table and one reference for resultfp. This is to prevent us 1913 * being preempted and the entry in the descriptor table closed after we 1914 * release the FILEDESC lock. 1915 */ 1916 int 1917 falloc_caps(struct thread *td, struct file **resultfp, int *resultfd, int flags, 1918 struct filecaps *fcaps) 1919 { 1920 struct file *fp; 1921 int error, fd; 1922 1923 error = falloc_noinstall(td, &fp); 1924 if (error) 1925 return (error); /* no reference held on error */ 1926 1927 error = finstall(td, fp, &fd, flags, fcaps); 1928 if (error) { 1929 fdrop(fp, td); /* one reference (fp only) */ 1930 return (error); 1931 } 1932 1933 if (resultfp != NULL) 1934 *resultfp = fp; /* copy out result */ 1935 else 1936 fdrop(fp, td); /* release local reference */ 1937 1938 if (resultfd != NULL) 1939 *resultfd = fd; 1940 1941 return (0); 1942 } 1943 1944 /* 1945 * Create a new open file structure without allocating a file descriptor. 1946 */ 1947 int 1948 falloc_noinstall(struct thread *td, struct file **resultfp) 1949 { 1950 struct file *fp; 1951 int maxuserfiles = maxfiles - (maxfiles / 20); 1952 int openfiles_new; 1953 static struct timeval lastfail; 1954 static int curfail; 1955 1956 KASSERT(resultfp != NULL, ("%s: resultfp == NULL", __func__)); 1957 1958 openfiles_new = atomic_fetchadd_int(&openfiles, 1) + 1; 1959 if ((openfiles_new >= maxuserfiles && 1960 priv_check(td, PRIV_MAXFILES) != 0) || 1961 openfiles_new >= maxfiles) { 1962 atomic_subtract_int(&openfiles, 1); 1963 if (ppsratecheck(&lastfail, &curfail, 1)) { 1964 printf("kern.maxfiles limit exceeded by uid %i, (%s) " 1965 "please see tuning(7).\n", td->td_ucred->cr_ruid, td->td_proc->p_comm); 1966 } 1967 return (ENFILE); 1968 } 1969 fp = uma_zalloc(file_zone, M_WAITOK); 1970 bzero(fp, sizeof(*fp)); 1971 refcount_init(&fp->f_count, 1); 1972 fp->f_cred = crhold(td->td_ucred); 1973 fp->f_ops = &badfileops; 1974 *resultfp = fp; 1975 return (0); 1976 } 1977 1978 /* 1979 * Install a file in a file descriptor table. 1980 */ 1981 void 1982 _finstall(struct filedesc *fdp, struct file *fp, int fd, int flags, 1983 struct filecaps *fcaps) 1984 { 1985 struct filedescent *fde; 1986 1987 MPASS(fp != NULL); 1988 if (fcaps != NULL) 1989 filecaps_validate(fcaps, __func__); 1990 FILEDESC_XLOCK_ASSERT(fdp); 1991 1992 fde = &fdp->fd_ofiles[fd]; 1993 #ifdef CAPABILITIES 1994 seqc_write_begin(&fde->fde_seqc); 1995 #endif 1996 fde->fde_file = fp; 1997 fde->fde_flags = (flags & O_CLOEXEC) != 0 ? UF_EXCLOSE : 0; 1998 if (fcaps != NULL) 1999 filecaps_move(fcaps, &fde->fde_caps); 2000 else 2001 filecaps_fill(&fde->fde_caps); 2002 #ifdef CAPABILITIES 2003 seqc_write_end(&fde->fde_seqc); 2004 #endif 2005 } 2006 2007 int 2008 finstall(struct thread *td, struct file *fp, int *fd, int flags, 2009 struct filecaps *fcaps) 2010 { 2011 struct filedesc *fdp = td->td_proc->p_fd; 2012 int error; 2013 2014 MPASS(fd != NULL); 2015 2016 if (!fhold(fp)) 2017 return (EBADF); 2018 FILEDESC_XLOCK(fdp); 2019 error = fdalloc(td, 0, fd); 2020 if (__predict_false(error != 0)) { 2021 FILEDESC_XUNLOCK(fdp); 2022 fdrop(fp, td); 2023 return (error); 2024 } 2025 _finstall(fdp, fp, *fd, flags, fcaps); 2026 FILEDESC_XUNLOCK(fdp); 2027 return (0); 2028 } 2029 2030 /* 2031 * Build a new filedesc structure from another. 2032 * Copy the current, root, and jail root vnode references. 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 struct pwd *newpwd; 2042 2043 if (prepfiles) 2044 MPASS(lastfile != NULL); 2045 else 2046 MPASS(lastfile == NULL); 2047 2048 newfdp0 = uma_zalloc(filedesc0_zone, M_WAITOK | M_ZERO); 2049 newfdp = &newfdp0->fd_fd; 2050 2051 /* Create the file descriptor table. */ 2052 FILEDESC_LOCK_INIT(newfdp); 2053 refcount_init(&newfdp->fd_refcnt, 1); 2054 refcount_init(&newfdp->fd_holdcnt, 1); 2055 newfdp->fd_cmask = CMASK; 2056 newfdp->fd_map = newfdp0->fd_dmap; 2057 newfdp->fd_files = (struct fdescenttbl *)&newfdp0->fd_dfiles; 2058 newfdp->fd_files->fdt_nfiles = NDFILE; 2059 2060 if (fdp == NULL) { 2061 newpwd = pwd_alloc(); 2062 smr_serialized_store(&newfdp->fd_pwd, newpwd, true); 2063 return (newfdp); 2064 } 2065 2066 FILEDESC_SLOCK(fdp); 2067 newpwd = pwd_hold_filedesc(fdp); 2068 smr_serialized_store(&newfdp->fd_pwd, newpwd, true); 2069 if (!prepfiles) { 2070 FILEDESC_SUNLOCK(fdp); 2071 return (newfdp); 2072 } 2073 2074 for (;;) { 2075 *lastfile = fdlastfile(fdp); 2076 if (*lastfile < newfdp->fd_nfiles) 2077 break; 2078 FILEDESC_SUNLOCK(fdp); 2079 fdgrowtable(newfdp, *lastfile + 1); 2080 FILEDESC_SLOCK(fdp); 2081 } 2082 2083 return (newfdp); 2084 } 2085 2086 static struct filedesc * 2087 fdhold(struct proc *p) 2088 { 2089 struct filedesc *fdp; 2090 2091 PROC_LOCK_ASSERT(p, MA_OWNED); 2092 fdp = p->p_fd; 2093 if (fdp != NULL) 2094 refcount_acquire(&fdp->fd_holdcnt); 2095 return (fdp); 2096 } 2097 2098 static void 2099 fddrop(struct filedesc *fdp) 2100 { 2101 2102 if (fdp->fd_holdcnt > 1) { 2103 if (refcount_release(&fdp->fd_holdcnt) == 0) 2104 return; 2105 } 2106 2107 FILEDESC_LOCK_DESTROY(fdp); 2108 uma_zfree(filedesc0_zone, fdp); 2109 } 2110 2111 /* 2112 * Share a filedesc structure. 2113 */ 2114 struct filedesc * 2115 fdshare(struct filedesc *fdp) 2116 { 2117 2118 refcount_acquire(&fdp->fd_refcnt); 2119 return (fdp); 2120 } 2121 2122 /* 2123 * Unshare a filedesc structure, if necessary by making a copy 2124 */ 2125 void 2126 fdunshare(struct thread *td) 2127 { 2128 struct filedesc *tmp; 2129 struct proc *p = td->td_proc; 2130 2131 if (p->p_fd->fd_refcnt == 1) 2132 return; 2133 2134 tmp = fdcopy(p->p_fd); 2135 fdescfree(td); 2136 p->p_fd = tmp; 2137 } 2138 2139 void 2140 fdinstall_remapped(struct thread *td, struct filedesc *fdp) 2141 { 2142 2143 fdescfree(td); 2144 td->td_proc->p_fd = fdp; 2145 } 2146 2147 /* 2148 * Copy a filedesc structure. A NULL pointer in returns a NULL reference, 2149 * this is to ease callers, not catch errors. 2150 */ 2151 struct filedesc * 2152 fdcopy(struct filedesc *fdp) 2153 { 2154 struct filedesc *newfdp; 2155 struct filedescent *nfde, *ofde; 2156 int i, lastfile; 2157 2158 MPASS(fdp != NULL); 2159 2160 newfdp = fdinit(fdp, true, &lastfile); 2161 /* copy all passable descriptors (i.e. not kqueue) */ 2162 newfdp->fd_freefile = -1; 2163 for (i = 0; i <= lastfile; ++i) { 2164 ofde = &fdp->fd_ofiles[i]; 2165 if (ofde->fde_file == NULL || 2166 (ofde->fde_file->f_ops->fo_flags & DFLAG_PASSABLE) == 0 || 2167 !fhold(ofde->fde_file)) { 2168 if (newfdp->fd_freefile == -1) 2169 newfdp->fd_freefile = i; 2170 continue; 2171 } 2172 nfde = &newfdp->fd_ofiles[i]; 2173 *nfde = *ofde; 2174 filecaps_copy(&ofde->fde_caps, &nfde->fde_caps, true); 2175 fdused_init(newfdp, i); 2176 } 2177 if (newfdp->fd_freefile == -1) 2178 newfdp->fd_freefile = i; 2179 newfdp->fd_cmask = fdp->fd_cmask; 2180 FILEDESC_SUNLOCK(fdp); 2181 return (newfdp); 2182 } 2183 2184 /* 2185 * Copies a filedesc structure, while remapping all file descriptors 2186 * stored inside using a translation table. 2187 * 2188 * File descriptors are copied over to the new file descriptor table, 2189 * regardless of whether the close-on-exec flag is set. 2190 */ 2191 int 2192 fdcopy_remapped(struct filedesc *fdp, const int *fds, size_t nfds, 2193 struct filedesc **ret) 2194 { 2195 struct filedesc *newfdp; 2196 struct filedescent *nfde, *ofde; 2197 int error, i, lastfile; 2198 2199 MPASS(fdp != NULL); 2200 2201 newfdp = fdinit(fdp, true, &lastfile); 2202 if (nfds > lastfile + 1) { 2203 /* New table cannot be larger than the old one. */ 2204 error = E2BIG; 2205 goto bad; 2206 } 2207 /* Copy all passable descriptors (i.e. not kqueue). */ 2208 newfdp->fd_freefile = nfds; 2209 for (i = 0; i < nfds; ++i) { 2210 if (fds[i] < 0 || fds[i] > lastfile) { 2211 /* File descriptor out of bounds. */ 2212 error = EBADF; 2213 goto bad; 2214 } 2215 ofde = &fdp->fd_ofiles[fds[i]]; 2216 if (ofde->fde_file == NULL) { 2217 /* Unused file descriptor. */ 2218 error = EBADF; 2219 goto bad; 2220 } 2221 if ((ofde->fde_file->f_ops->fo_flags & DFLAG_PASSABLE) == 0) { 2222 /* File descriptor cannot be passed. */ 2223 error = EINVAL; 2224 goto bad; 2225 } 2226 if (!fhold(ofde->fde_file)) { 2227 error = EBADF; 2228 goto bad; 2229 } 2230 nfde = &newfdp->fd_ofiles[i]; 2231 *nfde = *ofde; 2232 filecaps_copy(&ofde->fde_caps, &nfde->fde_caps, true); 2233 fdused_init(newfdp, i); 2234 } 2235 newfdp->fd_cmask = fdp->fd_cmask; 2236 FILEDESC_SUNLOCK(fdp); 2237 *ret = newfdp; 2238 return (0); 2239 bad: 2240 FILEDESC_SUNLOCK(fdp); 2241 fdescfree_remapped(newfdp); 2242 return (error); 2243 } 2244 2245 /* 2246 * Clear POSIX style locks. This is only used when fdp looses a reference (i.e. 2247 * one of processes using it exits) and the table used to be shared. 2248 */ 2249 static void 2250 fdclearlocks(struct thread *td) 2251 { 2252 struct filedesc *fdp; 2253 struct filedesc_to_leader *fdtol; 2254 struct flock lf; 2255 struct file *fp; 2256 struct proc *p; 2257 struct vnode *vp; 2258 int i, lastfile; 2259 2260 p = td->td_proc; 2261 fdp = p->p_fd; 2262 fdtol = p->p_fdtol; 2263 MPASS(fdtol != NULL); 2264 2265 FILEDESC_XLOCK(fdp); 2266 KASSERT(fdtol->fdl_refcount > 0, 2267 ("filedesc_to_refcount botch: fdl_refcount=%d", 2268 fdtol->fdl_refcount)); 2269 if (fdtol->fdl_refcount == 1 && 2270 (p->p_leader->p_flag & P_ADVLOCK) != 0) { 2271 lastfile = fdlastfile(fdp); 2272 for (i = 0; i <= lastfile; i++) { 2273 fp = fdp->fd_ofiles[i].fde_file; 2274 if (fp == NULL || fp->f_type != DTYPE_VNODE || 2275 !fhold(fp)) 2276 continue; 2277 FILEDESC_XUNLOCK(fdp); 2278 lf.l_whence = SEEK_SET; 2279 lf.l_start = 0; 2280 lf.l_len = 0; 2281 lf.l_type = F_UNLCK; 2282 vp = fp->f_vnode; 2283 (void) VOP_ADVLOCK(vp, 2284 (caddr_t)p->p_leader, F_UNLCK, 2285 &lf, F_POSIX); 2286 FILEDESC_XLOCK(fdp); 2287 fdrop(fp, td); 2288 } 2289 } 2290 retry: 2291 if (fdtol->fdl_refcount == 1) { 2292 if (fdp->fd_holdleaderscount > 0 && 2293 (p->p_leader->p_flag & P_ADVLOCK) != 0) { 2294 /* 2295 * close() or kern_dup() has cleared a reference 2296 * in a shared file descriptor table. 2297 */ 2298 fdp->fd_holdleaderswakeup = 1; 2299 sx_sleep(&fdp->fd_holdleaderscount, 2300 FILEDESC_LOCK(fdp), PLOCK, "fdlhold", 0); 2301 goto retry; 2302 } 2303 if (fdtol->fdl_holdcount > 0) { 2304 /* 2305 * Ensure that fdtol->fdl_leader remains 2306 * valid in closef(). 2307 */ 2308 fdtol->fdl_wakeup = 1; 2309 sx_sleep(fdtol, FILEDESC_LOCK(fdp), PLOCK, 2310 "fdlhold", 0); 2311 goto retry; 2312 } 2313 } 2314 fdtol->fdl_refcount--; 2315 if (fdtol->fdl_refcount == 0 && 2316 fdtol->fdl_holdcount == 0) { 2317 fdtol->fdl_next->fdl_prev = fdtol->fdl_prev; 2318 fdtol->fdl_prev->fdl_next = fdtol->fdl_next; 2319 } else 2320 fdtol = NULL; 2321 p->p_fdtol = NULL; 2322 FILEDESC_XUNLOCK(fdp); 2323 if (fdtol != NULL) 2324 free(fdtol, M_FILEDESC_TO_LEADER); 2325 } 2326 2327 /* 2328 * Release a filedesc structure. 2329 */ 2330 static void 2331 fdescfree_fds(struct thread *td, struct filedesc *fdp, bool needclose) 2332 { 2333 struct filedesc0 *fdp0; 2334 struct freetable *ft, *tft; 2335 struct filedescent *fde; 2336 struct file *fp; 2337 int i, lastfile; 2338 2339 lastfile = fdlastfile_single(fdp); 2340 for (i = 0; i <= lastfile; i++) { 2341 fde = &fdp->fd_ofiles[i]; 2342 fp = fde->fde_file; 2343 if (fp != NULL) { 2344 fdefree_last(fde); 2345 if (needclose) 2346 (void) closef(fp, td); 2347 else 2348 fdrop(fp, td); 2349 } 2350 } 2351 2352 if (NDSLOTS(fdp->fd_nfiles) > NDSLOTS(NDFILE)) 2353 free(fdp->fd_map, M_FILEDESC); 2354 if (fdp->fd_nfiles > NDFILE) 2355 free(fdp->fd_files, M_FILEDESC); 2356 2357 fdp0 = (struct filedesc0 *)fdp; 2358 SLIST_FOREACH_SAFE(ft, &fdp0->fd_free, ft_next, tft) 2359 free(ft->ft_table, M_FILEDESC); 2360 2361 fddrop(fdp); 2362 } 2363 2364 void 2365 fdescfree(struct thread *td) 2366 { 2367 struct proc *p; 2368 struct filedesc *fdp; 2369 struct pwd *pwd; 2370 2371 p = td->td_proc; 2372 fdp = p->p_fd; 2373 MPASS(fdp != NULL); 2374 2375 #ifdef RACCT 2376 if (RACCT_ENABLED()) 2377 racct_set_unlocked(p, RACCT_NOFILE, 0); 2378 #endif 2379 2380 if (p->p_fdtol != NULL) 2381 fdclearlocks(td); 2382 2383 PROC_LOCK(p); 2384 p->p_fd = NULL; 2385 PROC_UNLOCK(p); 2386 2387 if (refcount_release(&fdp->fd_refcnt) == 0) 2388 return; 2389 2390 FILEDESC_XLOCK(fdp); 2391 pwd = FILEDESC_XLOCKED_LOAD_PWD(fdp); 2392 pwd_set(fdp, NULL); 2393 FILEDESC_XUNLOCK(fdp); 2394 2395 pwd_drop(pwd); 2396 2397 fdescfree_fds(td, fdp, 1); 2398 } 2399 2400 void 2401 fdescfree_remapped(struct filedesc *fdp) 2402 { 2403 2404 pwd_drop(smr_serialized_load(&fdp->fd_pwd, true)); 2405 fdescfree_fds(curthread, fdp, 0); 2406 } 2407 2408 /* 2409 * For setugid programs, we don't want to people to use that setugidness 2410 * to generate error messages which write to a file which otherwise would 2411 * otherwise be off-limits to the process. We check for filesystems where 2412 * the vnode can change out from under us after execve (like [lin]procfs). 2413 * 2414 * Since fdsetugidsafety calls this only for fd 0, 1 and 2, this check is 2415 * sufficient. We also don't check for setugidness since we know we are. 2416 */ 2417 static bool 2418 is_unsafe(struct file *fp) 2419 { 2420 struct vnode *vp; 2421 2422 if (fp->f_type != DTYPE_VNODE) 2423 return (false); 2424 2425 vp = fp->f_vnode; 2426 return ((vp->v_vflag & VV_PROCDEP) != 0); 2427 } 2428 2429 /* 2430 * Make this setguid thing safe, if at all possible. 2431 */ 2432 void 2433 fdsetugidsafety(struct thread *td) 2434 { 2435 struct filedesc *fdp; 2436 struct file *fp; 2437 int i; 2438 2439 fdp = td->td_proc->p_fd; 2440 KASSERT(fdp->fd_refcnt == 1, ("the fdtable should not be shared")); 2441 MPASS(fdp->fd_nfiles >= 3); 2442 for (i = 0; i <= 2; i++) { 2443 fp = fdp->fd_ofiles[i].fde_file; 2444 if (fp != NULL && is_unsafe(fp)) { 2445 FILEDESC_XLOCK(fdp); 2446 knote_fdclose(td, i); 2447 /* 2448 * NULL-out descriptor prior to close to avoid 2449 * a race while close blocks. 2450 */ 2451 fdfree(fdp, i); 2452 FILEDESC_XUNLOCK(fdp); 2453 (void) closef(fp, td); 2454 } 2455 } 2456 } 2457 2458 /* 2459 * If a specific file object occupies a specific file descriptor, close the 2460 * file descriptor entry and drop a reference on the file object. This is a 2461 * convenience function to handle a subsequent error in a function that calls 2462 * falloc() that handles the race that another thread might have closed the 2463 * file descriptor out from under the thread creating the file object. 2464 */ 2465 void 2466 fdclose(struct thread *td, struct file *fp, int idx) 2467 { 2468 struct filedesc *fdp = td->td_proc->p_fd; 2469 2470 FILEDESC_XLOCK(fdp); 2471 if (fdp->fd_ofiles[idx].fde_file == fp) { 2472 fdfree(fdp, idx); 2473 FILEDESC_XUNLOCK(fdp); 2474 fdrop(fp, td); 2475 } else 2476 FILEDESC_XUNLOCK(fdp); 2477 } 2478 2479 /* 2480 * Close any files on exec? 2481 */ 2482 void 2483 fdcloseexec(struct thread *td) 2484 { 2485 struct filedesc *fdp; 2486 struct filedescent *fde; 2487 struct file *fp; 2488 int i, lastfile; 2489 2490 fdp = td->td_proc->p_fd; 2491 KASSERT(fdp->fd_refcnt == 1, ("the fdtable should not be shared")); 2492 lastfile = fdlastfile_single(fdp); 2493 for (i = 0; i <= lastfile; i++) { 2494 fde = &fdp->fd_ofiles[i]; 2495 fp = fde->fde_file; 2496 if (fp != NULL && (fp->f_type == DTYPE_MQUEUE || 2497 (fde->fde_flags & UF_EXCLOSE))) { 2498 FILEDESC_XLOCK(fdp); 2499 fdfree(fdp, i); 2500 (void) closefp(fdp, i, fp, td, 0); 2501 FILEDESC_UNLOCK_ASSERT(fdp); 2502 } 2503 } 2504 } 2505 2506 /* 2507 * It is unsafe for set[ug]id processes to be started with file 2508 * descriptors 0..2 closed, as these descriptors are given implicit 2509 * significance in the Standard C library. fdcheckstd() will create a 2510 * descriptor referencing /dev/null for each of stdin, stdout, and 2511 * stderr that is not already open. 2512 */ 2513 int 2514 fdcheckstd(struct thread *td) 2515 { 2516 struct filedesc *fdp; 2517 register_t save; 2518 int i, error, devnull; 2519 2520 fdp = td->td_proc->p_fd; 2521 KASSERT(fdp->fd_refcnt == 1, ("the fdtable should not be shared")); 2522 MPASS(fdp->fd_nfiles >= 3); 2523 devnull = -1; 2524 for (i = 0; i <= 2; i++) { 2525 if (fdp->fd_ofiles[i].fde_file != NULL) 2526 continue; 2527 2528 save = td->td_retval[0]; 2529 if (devnull != -1) { 2530 error = kern_dup(td, FDDUP_FIXED, 0, devnull, i); 2531 } else { 2532 error = kern_openat(td, AT_FDCWD, "/dev/null", 2533 UIO_SYSSPACE, O_RDWR, 0); 2534 if (error == 0) { 2535 devnull = td->td_retval[0]; 2536 KASSERT(devnull == i, ("we didn't get our fd")); 2537 } 2538 } 2539 td->td_retval[0] = save; 2540 if (error != 0) 2541 return (error); 2542 } 2543 return (0); 2544 } 2545 2546 /* 2547 * Internal form of close. Decrement reference count on file structure. 2548 * Note: td may be NULL when closing a file that was being passed in a 2549 * message. 2550 */ 2551 int 2552 closef(struct file *fp, struct thread *td) 2553 { 2554 struct vnode *vp; 2555 struct flock lf; 2556 struct filedesc_to_leader *fdtol; 2557 struct filedesc *fdp; 2558 2559 /* 2560 * POSIX record locking dictates that any close releases ALL 2561 * locks owned by this process. This is handled by setting 2562 * a flag in the unlock to free ONLY locks obeying POSIX 2563 * semantics, and not to free BSD-style file locks. 2564 * If the descriptor was in a message, POSIX-style locks 2565 * aren't passed with the descriptor, and the thread pointer 2566 * will be NULL. Callers should be careful only to pass a 2567 * NULL thread pointer when there really is no owning 2568 * context that might have locks, or the locks will be 2569 * leaked. 2570 */ 2571 if (fp->f_type == DTYPE_VNODE && td != NULL) { 2572 vp = fp->f_vnode; 2573 if ((td->td_proc->p_leader->p_flag & P_ADVLOCK) != 0) { 2574 lf.l_whence = SEEK_SET; 2575 lf.l_start = 0; 2576 lf.l_len = 0; 2577 lf.l_type = F_UNLCK; 2578 (void) VOP_ADVLOCK(vp, (caddr_t)td->td_proc->p_leader, 2579 F_UNLCK, &lf, F_POSIX); 2580 } 2581 fdtol = td->td_proc->p_fdtol; 2582 if (fdtol != NULL) { 2583 /* 2584 * Handle special case where file descriptor table is 2585 * shared between multiple process leaders. 2586 */ 2587 fdp = td->td_proc->p_fd; 2588 FILEDESC_XLOCK(fdp); 2589 for (fdtol = fdtol->fdl_next; 2590 fdtol != td->td_proc->p_fdtol; 2591 fdtol = fdtol->fdl_next) { 2592 if ((fdtol->fdl_leader->p_flag & 2593 P_ADVLOCK) == 0) 2594 continue; 2595 fdtol->fdl_holdcount++; 2596 FILEDESC_XUNLOCK(fdp); 2597 lf.l_whence = SEEK_SET; 2598 lf.l_start = 0; 2599 lf.l_len = 0; 2600 lf.l_type = F_UNLCK; 2601 vp = fp->f_vnode; 2602 (void) VOP_ADVLOCK(vp, 2603 (caddr_t)fdtol->fdl_leader, F_UNLCK, &lf, 2604 F_POSIX); 2605 FILEDESC_XLOCK(fdp); 2606 fdtol->fdl_holdcount--; 2607 if (fdtol->fdl_holdcount == 0 && 2608 fdtol->fdl_wakeup != 0) { 2609 fdtol->fdl_wakeup = 0; 2610 wakeup(fdtol); 2611 } 2612 } 2613 FILEDESC_XUNLOCK(fdp); 2614 } 2615 } 2616 return (fdrop(fp, td)); 2617 } 2618 2619 /* 2620 * Initialize the file pointer with the specified properties. 2621 * 2622 * The ops are set with release semantics to be certain that the flags, type, 2623 * and data are visible when ops is. This is to prevent ops methods from being 2624 * called with bad data. 2625 */ 2626 void 2627 finit(struct file *fp, u_int flag, short type, void *data, struct fileops *ops) 2628 { 2629 fp->f_data = data; 2630 fp->f_flag = flag; 2631 fp->f_type = type; 2632 atomic_store_rel_ptr((volatile uintptr_t *)&fp->f_ops, (uintptr_t)ops); 2633 } 2634 2635 void 2636 finit_vnode(struct file *fp, u_int flag, void *data, struct fileops *ops) 2637 { 2638 fp->f_seqcount[UIO_READ] = 1; 2639 fp->f_seqcount[UIO_WRITE] = 1; 2640 finit(fp, (flag & FMASK) | (fp->f_flag & FHASLOCK), DTYPE_VNODE, 2641 data, ops); 2642 } 2643 2644 int 2645 fget_cap_locked(struct filedesc *fdp, int fd, cap_rights_t *needrightsp, 2646 struct file **fpp, struct filecaps *havecapsp) 2647 { 2648 struct filedescent *fde; 2649 int error; 2650 2651 FILEDESC_LOCK_ASSERT(fdp); 2652 2653 fde = fdeget_locked(fdp, fd); 2654 if (fde == NULL) { 2655 error = EBADF; 2656 goto out; 2657 } 2658 2659 #ifdef CAPABILITIES 2660 error = cap_check(cap_rights_fde_inline(fde), needrightsp); 2661 if (error != 0) 2662 goto out; 2663 #endif 2664 2665 if (havecapsp != NULL) 2666 filecaps_copy(&fde->fde_caps, havecapsp, true); 2667 2668 *fpp = fde->fde_file; 2669 2670 error = 0; 2671 out: 2672 return (error); 2673 } 2674 2675 int 2676 fget_cap(struct thread *td, int fd, cap_rights_t *needrightsp, 2677 struct file **fpp, struct filecaps *havecapsp) 2678 { 2679 struct filedesc *fdp = td->td_proc->p_fd; 2680 int error; 2681 #ifndef CAPABILITIES 2682 error = fget_unlocked(fdp, fd, needrightsp, fpp); 2683 if (havecapsp != NULL && error == 0) 2684 filecaps_fill(havecapsp); 2685 #else 2686 struct file *fp; 2687 seqc_t seq; 2688 2689 *fpp = NULL; 2690 for (;;) { 2691 error = fget_unlocked_seq(fdp, fd, needrightsp, &fp, &seq); 2692 if (error != 0) 2693 return (error); 2694 2695 if (havecapsp != NULL) { 2696 if (!filecaps_copy(&fdp->fd_ofiles[fd].fde_caps, 2697 havecapsp, false)) { 2698 fdrop(fp, td); 2699 goto get_locked; 2700 } 2701 } 2702 2703 if (!fd_modified(fdp, fd, seq)) 2704 break; 2705 fdrop(fp, td); 2706 } 2707 2708 *fpp = fp; 2709 return (0); 2710 2711 get_locked: 2712 FILEDESC_SLOCK(fdp); 2713 error = fget_cap_locked(fdp, fd, needrightsp, fpp, havecapsp); 2714 if (error == 0 && !fhold(*fpp)) 2715 error = EBADF; 2716 FILEDESC_SUNLOCK(fdp); 2717 #endif 2718 return (error); 2719 } 2720 2721 #ifdef CAPABILITIES 2722 int 2723 fgetvp_lookup_smr(int fd, struct nameidata *ndp, struct vnode **vpp, bool *fsearch) 2724 { 2725 const struct filedescent *fde; 2726 const struct fdescenttbl *fdt; 2727 struct filedesc *fdp; 2728 struct file *fp; 2729 struct vnode *vp; 2730 const cap_rights_t *haverights; 2731 cap_rights_t rights; 2732 seqc_t seq; 2733 2734 VFS_SMR_ASSERT_ENTERED(); 2735 2736 rights = *ndp->ni_rightsneeded; 2737 cap_rights_set_one(&rights, CAP_LOOKUP); 2738 2739 fdp = curproc->p_fd; 2740 fdt = fdp->fd_files; 2741 if (__predict_false((u_int)fd >= fdt->fdt_nfiles)) 2742 return (EBADF); 2743 seq = seqc_read_any(fd_seqc(fdt, fd)); 2744 if (__predict_false(seqc_in_modify(seq))) 2745 return (EAGAIN); 2746 fde = &fdt->fdt_ofiles[fd]; 2747 haverights = cap_rights_fde_inline(fde); 2748 fp = fde->fde_file; 2749 if (__predict_false(fp == NULL)) 2750 return (EAGAIN); 2751 if (__predict_false(cap_check_inline_transient(haverights, &rights))) 2752 return (EAGAIN); 2753 *fsearch = ((fp->f_flag & FSEARCH) != 0); 2754 vp = fp->f_vnode; 2755 if (__predict_false(vp == NULL || vp->v_type != VDIR)) { 2756 return (EAGAIN); 2757 } 2758 if (!filecaps_copy(&fde->fde_caps, &ndp->ni_filecaps, false)) { 2759 return (EAGAIN); 2760 } 2761 /* 2762 * Use an acquire barrier to force re-reading of fdt so it is 2763 * refreshed for verification. 2764 */ 2765 atomic_thread_fence_acq(); 2766 fdt = fdp->fd_files; 2767 if (__predict_false(!seqc_consistent_nomb(fd_seqc(fdt, fd), seq))) 2768 return (EAGAIN); 2769 /* 2770 * If file descriptor doesn't have all rights, 2771 * all lookups relative to it must also be 2772 * strictly relative. 2773 * 2774 * Not yet supported by fast path. 2775 */ 2776 CAP_ALL(&rights); 2777 if (!cap_rights_contains(&ndp->ni_filecaps.fc_rights, &rights) || 2778 ndp->ni_filecaps.fc_fcntls != CAP_FCNTL_ALL || 2779 ndp->ni_filecaps.fc_nioctls != -1) { 2780 #ifdef notyet 2781 ndp->ni_lcf |= NI_LCF_STRICTRELATIVE; 2782 #else 2783 return (EAGAIN); 2784 #endif 2785 } 2786 *vpp = vp; 2787 return (0); 2788 } 2789 #else 2790 int 2791 fgetvp_lookup_smr(int fd, struct nameidata *ndp, struct vnode **vpp, bool *fsearch) 2792 { 2793 const struct fdescenttbl *fdt; 2794 struct filedesc *fdp; 2795 struct file *fp; 2796 struct vnode *vp; 2797 2798 VFS_SMR_ASSERT_ENTERED(); 2799 2800 fdp = curproc->p_fd; 2801 fdt = fdp->fd_files; 2802 if (__predict_false((u_int)fd >= fdt->fdt_nfiles)) 2803 return (EBADF); 2804 fp = fdt->fdt_ofiles[fd].fde_file; 2805 if (__predict_false(fp == NULL)) 2806 return (EAGAIN); 2807 *fsearch = ((fp->f_flag & FSEARCH) != 0); 2808 vp = fp->f_vnode; 2809 if (__predict_false(vp == NULL || vp->v_type != VDIR)) { 2810 return (EAGAIN); 2811 } 2812 /* 2813 * Use an acquire barrier to force re-reading of fdt so it is 2814 * refreshed for verification. 2815 */ 2816 atomic_thread_fence_acq(); 2817 fdt = fdp->fd_files; 2818 if (__predict_false(fp != fdt->fdt_ofiles[fd].fde_file)) 2819 return (EAGAIN); 2820 filecaps_fill(&ndp->ni_filecaps); 2821 *vpp = vp; 2822 return (0); 2823 } 2824 #endif 2825 2826 int 2827 fget_unlocked_seq(struct filedesc *fdp, int fd, cap_rights_t *needrightsp, 2828 struct file **fpp, seqc_t *seqp) 2829 { 2830 #ifdef CAPABILITIES 2831 const struct filedescent *fde; 2832 #endif 2833 const struct fdescenttbl *fdt; 2834 struct file *fp; 2835 #ifdef CAPABILITIES 2836 seqc_t seq; 2837 cap_rights_t haverights; 2838 int error; 2839 #endif 2840 2841 fdt = fdp->fd_files; 2842 if (__predict_false((u_int)fd >= fdt->fdt_nfiles)) 2843 return (EBADF); 2844 /* 2845 * Fetch the descriptor locklessly. We avoid fdrop() races by 2846 * never raising a refcount above 0. To accomplish this we have 2847 * to use a cmpset loop rather than an atomic_add. The descriptor 2848 * must be re-verified once we acquire a reference to be certain 2849 * that the identity is still correct and we did not lose a race 2850 * due to preemption. 2851 */ 2852 for (;;) { 2853 #ifdef CAPABILITIES 2854 seq = seqc_read(fd_seqc(fdt, fd)); 2855 fde = &fdt->fdt_ofiles[fd]; 2856 haverights = *cap_rights_fde_inline(fde); 2857 fp = fde->fde_file; 2858 if (!seqc_consistent(fd_seqc(fdt, fd), seq)) 2859 continue; 2860 #else 2861 fp = fdt->fdt_ofiles[fd].fde_file; 2862 #endif 2863 if (fp == NULL) 2864 return (EBADF); 2865 #ifdef CAPABILITIES 2866 error = cap_check_inline(&haverights, needrightsp); 2867 if (error != 0) 2868 return (error); 2869 #endif 2870 if (__predict_false(!refcount_acquire_if_not_zero(&fp->f_count))) { 2871 /* 2872 * The count was found either saturated or zero. 2873 * This re-read is not any more racy than using the 2874 * return value from fcmpset. 2875 */ 2876 if (refcount_load(&fp->f_count) != 0) 2877 return (EBADF); 2878 /* 2879 * Force a reload. Other thread could reallocate the 2880 * table before this fd was closed, so it is possible 2881 * that there is a stale fp pointer in cached version. 2882 */ 2883 fdt = atomic_load_ptr(&fdp->fd_files); 2884 continue; 2885 } 2886 /* 2887 * Use an acquire barrier to force re-reading of fdt so it is 2888 * refreshed for verification. 2889 */ 2890 atomic_thread_fence_acq(); 2891 fdt = fdp->fd_files; 2892 #ifdef CAPABILITIES 2893 if (seqc_consistent_nomb(fd_seqc(fdt, fd), seq)) 2894 #else 2895 if (fp == fdt->fdt_ofiles[fd].fde_file) 2896 #endif 2897 break; 2898 fdrop(fp, curthread); 2899 } 2900 *fpp = fp; 2901 if (seqp != NULL) { 2902 #ifdef CAPABILITIES 2903 *seqp = seq; 2904 #endif 2905 } 2906 return (0); 2907 } 2908 2909 /* 2910 * See the comments in fget_unlocked_seq for an explanation of how this works. 2911 * 2912 * This is a simplified variant which bails out to the aforementioned routine 2913 * if anything goes wrong. In practice this only happens when userspace is 2914 * racing with itself. 2915 */ 2916 int 2917 fget_unlocked(struct filedesc *fdp, int fd, cap_rights_t *needrightsp, 2918 struct file **fpp) 2919 { 2920 #ifdef CAPABILITIES 2921 const struct filedescent *fde; 2922 #endif 2923 const struct fdescenttbl *fdt; 2924 struct file *fp; 2925 #ifdef CAPABILITIES 2926 seqc_t seq; 2927 const cap_rights_t *haverights; 2928 #endif 2929 2930 fdt = fdp->fd_files; 2931 if (__predict_false((u_int)fd >= fdt->fdt_nfiles)) 2932 return (EBADF); 2933 #ifdef CAPABILITIES 2934 seq = seqc_read_any(fd_seqc(fdt, fd)); 2935 if (__predict_false(seqc_in_modify(seq))) 2936 goto out_fallback; 2937 fde = &fdt->fdt_ofiles[fd]; 2938 haverights = cap_rights_fde_inline(fde); 2939 fp = fde->fde_file; 2940 #else 2941 fp = fdt->fdt_ofiles[fd].fde_file; 2942 #endif 2943 if (__predict_false(fp == NULL)) 2944 goto out_fallback; 2945 #ifdef CAPABILITIES 2946 if (__predict_false(cap_check_inline_transient(haverights, needrightsp))) 2947 goto out_fallback; 2948 #endif 2949 if (__predict_false(!refcount_acquire_if_not_zero(&fp->f_count))) 2950 goto out_fallback; 2951 2952 /* 2953 * Use an acquire barrier to force re-reading of fdt so it is 2954 * refreshed for verification. 2955 */ 2956 atomic_thread_fence_acq(); 2957 fdt = fdp->fd_files; 2958 #ifdef CAPABILITIES 2959 if (__predict_false(!seqc_consistent_nomb(fd_seqc(fdt, fd), seq))) 2960 #else 2961 if (__predict_false(fp != fdt->fdt_ofiles[fd].fde_file)) 2962 #endif 2963 goto out_fdrop; 2964 *fpp = fp; 2965 return (0); 2966 out_fdrop: 2967 fdrop(fp, curthread); 2968 out_fallback: 2969 return (fget_unlocked_seq(fdp, fd, needrightsp, fpp, NULL)); 2970 } 2971 2972 /* 2973 * Extract the file pointer associated with the specified descriptor for the 2974 * current user process. 2975 * 2976 * If the descriptor doesn't exist or doesn't match 'flags', EBADF is 2977 * returned. 2978 * 2979 * File's rights will be checked against the capability rights mask. 2980 * 2981 * If an error occurred the non-zero error is returned and *fpp is set to 2982 * NULL. Otherwise *fpp is held and set and zero is returned. Caller is 2983 * responsible for fdrop(). 2984 */ 2985 static __inline int 2986 _fget(struct thread *td, int fd, struct file **fpp, int flags, 2987 cap_rights_t *needrightsp) 2988 { 2989 struct filedesc *fdp; 2990 struct file *fp; 2991 int error; 2992 2993 *fpp = NULL; 2994 fdp = td->td_proc->p_fd; 2995 error = fget_unlocked(fdp, fd, needrightsp, &fp); 2996 if (__predict_false(error != 0)) 2997 return (error); 2998 if (__predict_false(fp->f_ops == &badfileops)) { 2999 fdrop(fp, td); 3000 return (EBADF); 3001 } 3002 3003 /* 3004 * FREAD and FWRITE failure return EBADF as per POSIX. 3005 */ 3006 error = 0; 3007 switch (flags) { 3008 case FREAD: 3009 case FWRITE: 3010 if ((fp->f_flag & flags) == 0) 3011 error = EBADF; 3012 break; 3013 case FEXEC: 3014 if ((fp->f_flag & (FREAD | FEXEC)) == 0 || 3015 ((fp->f_flag & FWRITE) != 0)) 3016 error = EBADF; 3017 break; 3018 case 0: 3019 break; 3020 default: 3021 KASSERT(0, ("wrong flags")); 3022 } 3023 3024 if (error != 0) { 3025 fdrop(fp, td); 3026 return (error); 3027 } 3028 3029 *fpp = fp; 3030 return (0); 3031 } 3032 3033 int 3034 fget(struct thread *td, int fd, cap_rights_t *rightsp, struct file **fpp) 3035 { 3036 3037 return (_fget(td, fd, fpp, 0, rightsp)); 3038 } 3039 3040 int 3041 fget_mmap(struct thread *td, int fd, cap_rights_t *rightsp, vm_prot_t *maxprotp, 3042 struct file **fpp) 3043 { 3044 int error; 3045 #ifndef CAPABILITIES 3046 error = _fget(td, fd, fpp, 0, rightsp); 3047 if (maxprotp != NULL) 3048 *maxprotp = VM_PROT_ALL; 3049 return (error); 3050 #else 3051 cap_rights_t fdrights; 3052 struct filedesc *fdp; 3053 struct file *fp; 3054 seqc_t seq; 3055 3056 *fpp = NULL; 3057 fdp = td->td_proc->p_fd; 3058 MPASS(cap_rights_is_set(rightsp, CAP_MMAP)); 3059 for (;;) { 3060 error = fget_unlocked_seq(fdp, fd, rightsp, &fp, &seq); 3061 if (__predict_false(error != 0)) 3062 return (error); 3063 if (__predict_false(fp->f_ops == &badfileops)) { 3064 fdrop(fp, td); 3065 return (EBADF); 3066 } 3067 if (maxprotp != NULL) 3068 fdrights = *cap_rights(fdp, fd); 3069 if (!fd_modified(fdp, fd, seq)) 3070 break; 3071 fdrop(fp, td); 3072 } 3073 3074 /* 3075 * If requested, convert capability rights to access flags. 3076 */ 3077 if (maxprotp != NULL) 3078 *maxprotp = cap_rights_to_vmprot(&fdrights); 3079 *fpp = fp; 3080 return (0); 3081 #endif 3082 } 3083 3084 int 3085 fget_read(struct thread *td, int fd, cap_rights_t *rightsp, struct file **fpp) 3086 { 3087 3088 return (_fget(td, fd, fpp, FREAD, rightsp)); 3089 } 3090 3091 int 3092 fget_write(struct thread *td, int fd, cap_rights_t *rightsp, struct file **fpp) 3093 { 3094 3095 return (_fget(td, fd, fpp, FWRITE, rightsp)); 3096 } 3097 3098 int 3099 fget_fcntl(struct thread *td, int fd, cap_rights_t *rightsp, int needfcntl, 3100 struct file **fpp) 3101 { 3102 struct filedesc *fdp = td->td_proc->p_fd; 3103 #ifndef CAPABILITIES 3104 return (fget_unlocked(fdp, fd, rightsp, fpp)); 3105 #else 3106 struct file *fp; 3107 int error; 3108 seqc_t seq; 3109 3110 *fpp = NULL; 3111 MPASS(cap_rights_is_set(rightsp, CAP_FCNTL)); 3112 for (;;) { 3113 error = fget_unlocked_seq(fdp, fd, rightsp, &fp, &seq); 3114 if (error != 0) 3115 return (error); 3116 error = cap_fcntl_check(fdp, fd, needfcntl); 3117 if (!fd_modified(fdp, fd, seq)) 3118 break; 3119 fdrop(fp, td); 3120 } 3121 if (error != 0) { 3122 fdrop(fp, td); 3123 return (error); 3124 } 3125 *fpp = fp; 3126 return (0); 3127 #endif 3128 } 3129 3130 /* 3131 * Like fget() but loads the underlying vnode, or returns an error if the 3132 * descriptor does not represent a vnode. Note that pipes use vnodes but 3133 * never have VM objects. The returned vnode will be vref()'d. 3134 * 3135 * XXX: what about the unused flags ? 3136 */ 3137 static __inline int 3138 _fgetvp(struct thread *td, int fd, int flags, cap_rights_t *needrightsp, 3139 struct vnode **vpp) 3140 { 3141 struct file *fp; 3142 int error; 3143 3144 *vpp = NULL; 3145 error = _fget(td, fd, &fp, flags, needrightsp); 3146 if (error != 0) 3147 return (error); 3148 if (fp->f_vnode == NULL) { 3149 error = EINVAL; 3150 } else { 3151 *vpp = fp->f_vnode; 3152 vrefact(*vpp); 3153 } 3154 fdrop(fp, td); 3155 3156 return (error); 3157 } 3158 3159 int 3160 fgetvp(struct thread *td, int fd, cap_rights_t *rightsp, struct vnode **vpp) 3161 { 3162 3163 return (_fgetvp(td, fd, 0, rightsp, vpp)); 3164 } 3165 3166 int 3167 fgetvp_rights(struct thread *td, int fd, cap_rights_t *needrightsp, 3168 struct filecaps *havecaps, struct vnode **vpp) 3169 { 3170 struct filecaps caps; 3171 struct file *fp; 3172 int error; 3173 3174 error = fget_cap(td, fd, needrightsp, &fp, &caps); 3175 if (error != 0) 3176 return (error); 3177 if (fp->f_ops == &badfileops) { 3178 error = EBADF; 3179 goto out; 3180 } 3181 if (fp->f_vnode == NULL) { 3182 error = EINVAL; 3183 goto out; 3184 } 3185 3186 *havecaps = caps; 3187 *vpp = fp->f_vnode; 3188 vrefact(*vpp); 3189 fdrop(fp, td); 3190 3191 return (0); 3192 out: 3193 filecaps_free(&caps); 3194 fdrop(fp, td); 3195 return (error); 3196 } 3197 3198 int 3199 fgetvp_read(struct thread *td, int fd, cap_rights_t *rightsp, struct vnode **vpp) 3200 { 3201 3202 return (_fgetvp(td, fd, FREAD, rightsp, vpp)); 3203 } 3204 3205 int 3206 fgetvp_exec(struct thread *td, int fd, cap_rights_t *rightsp, struct vnode **vpp) 3207 { 3208 3209 return (_fgetvp(td, fd, FEXEC, rightsp, vpp)); 3210 } 3211 3212 #ifdef notyet 3213 int 3214 fgetvp_write(struct thread *td, int fd, cap_rights_t *rightsp, 3215 struct vnode **vpp) 3216 { 3217 3218 return (_fgetvp(td, fd, FWRITE, rightsp, vpp)); 3219 } 3220 #endif 3221 3222 /* 3223 * Handle the last reference to a file being closed. 3224 * 3225 * Without the noinline attribute clang keeps inlining the func thorough this 3226 * file when fdrop is used. 3227 */ 3228 int __noinline 3229 _fdrop(struct file *fp, struct thread *td) 3230 { 3231 int error; 3232 #ifdef INVARIANTS 3233 int count; 3234 3235 count = refcount_load(&fp->f_count); 3236 if (count != 0) 3237 panic("fdrop: fp %p count %d", fp, count); 3238 #endif 3239 error = fo_close(fp, td); 3240 atomic_subtract_int(&openfiles, 1); 3241 crfree(fp->f_cred); 3242 free(fp->f_advice, M_FADVISE); 3243 uma_zfree(file_zone, fp); 3244 3245 return (error); 3246 } 3247 3248 /* 3249 * Apply an advisory lock on a file descriptor. 3250 * 3251 * Just attempt to get a record lock of the requested type on the entire file 3252 * (l_whence = SEEK_SET, l_start = 0, l_len = 0). 3253 */ 3254 #ifndef _SYS_SYSPROTO_H_ 3255 struct flock_args { 3256 int fd; 3257 int how; 3258 }; 3259 #endif 3260 /* ARGSUSED */ 3261 int 3262 sys_flock(struct thread *td, struct flock_args *uap) 3263 { 3264 struct file *fp; 3265 struct vnode *vp; 3266 struct flock lf; 3267 int error; 3268 3269 error = fget(td, uap->fd, &cap_flock_rights, &fp); 3270 if (error != 0) 3271 return (error); 3272 if (fp->f_type != DTYPE_VNODE) { 3273 fdrop(fp, td); 3274 return (EOPNOTSUPP); 3275 } 3276 3277 vp = fp->f_vnode; 3278 lf.l_whence = SEEK_SET; 3279 lf.l_start = 0; 3280 lf.l_len = 0; 3281 if (uap->how & LOCK_UN) { 3282 lf.l_type = F_UNLCK; 3283 atomic_clear_int(&fp->f_flag, FHASLOCK); 3284 error = VOP_ADVLOCK(vp, (caddr_t)fp, F_UNLCK, &lf, F_FLOCK); 3285 goto done2; 3286 } 3287 if (uap->how & LOCK_EX) 3288 lf.l_type = F_WRLCK; 3289 else if (uap->how & LOCK_SH) 3290 lf.l_type = F_RDLCK; 3291 else { 3292 error = EBADF; 3293 goto done2; 3294 } 3295 atomic_set_int(&fp->f_flag, FHASLOCK); 3296 error = VOP_ADVLOCK(vp, (caddr_t)fp, F_SETLK, &lf, 3297 (uap->how & LOCK_NB) ? F_FLOCK : F_FLOCK | F_WAIT); 3298 done2: 3299 fdrop(fp, td); 3300 return (error); 3301 } 3302 /* 3303 * Duplicate the specified descriptor to a free descriptor. 3304 */ 3305 int 3306 dupfdopen(struct thread *td, struct filedesc *fdp, int dfd, int mode, 3307 int openerror, int *indxp) 3308 { 3309 struct filedescent *newfde, *oldfde; 3310 struct file *fp; 3311 u_long *ioctls; 3312 int error, indx; 3313 3314 KASSERT(openerror == ENODEV || openerror == ENXIO, 3315 ("unexpected error %d in %s", openerror, __func__)); 3316 3317 /* 3318 * If the to-be-dup'd fd number is greater than the allowed number 3319 * of file descriptors, or the fd to be dup'd has already been 3320 * closed, then reject. 3321 */ 3322 FILEDESC_XLOCK(fdp); 3323 if ((fp = fget_locked(fdp, dfd)) == NULL) { 3324 FILEDESC_XUNLOCK(fdp); 3325 return (EBADF); 3326 } 3327 3328 error = fdalloc(td, 0, &indx); 3329 if (error != 0) { 3330 FILEDESC_XUNLOCK(fdp); 3331 return (error); 3332 } 3333 3334 /* 3335 * There are two cases of interest here. 3336 * 3337 * For ENODEV simply dup (dfd) to file descriptor (indx) and return. 3338 * 3339 * For ENXIO steal away the file structure from (dfd) and store it in 3340 * (indx). (dfd) is effectively closed by this operation. 3341 */ 3342 switch (openerror) { 3343 case ENODEV: 3344 /* 3345 * Check that the mode the file is being opened for is a 3346 * subset of the mode of the existing descriptor. 3347 */ 3348 if (((mode & (FREAD|FWRITE)) | fp->f_flag) != fp->f_flag) { 3349 fdunused(fdp, indx); 3350 FILEDESC_XUNLOCK(fdp); 3351 return (EACCES); 3352 } 3353 if (!fhold(fp)) { 3354 fdunused(fdp, indx); 3355 FILEDESC_XUNLOCK(fdp); 3356 return (EBADF); 3357 } 3358 newfde = &fdp->fd_ofiles[indx]; 3359 oldfde = &fdp->fd_ofiles[dfd]; 3360 ioctls = filecaps_copy_prep(&oldfde->fde_caps); 3361 #ifdef CAPABILITIES 3362 seqc_write_begin(&newfde->fde_seqc); 3363 #endif 3364 memcpy(newfde, oldfde, fde_change_size); 3365 filecaps_copy_finish(&oldfde->fde_caps, &newfde->fde_caps, 3366 ioctls); 3367 #ifdef CAPABILITIES 3368 seqc_write_end(&newfde->fde_seqc); 3369 #endif 3370 break; 3371 case ENXIO: 3372 /* 3373 * Steal away the file pointer from dfd and stuff it into indx. 3374 */ 3375 newfde = &fdp->fd_ofiles[indx]; 3376 oldfde = &fdp->fd_ofiles[dfd]; 3377 #ifdef CAPABILITIES 3378 seqc_write_begin(&newfde->fde_seqc); 3379 #endif 3380 memcpy(newfde, oldfde, fde_change_size); 3381 oldfde->fde_file = NULL; 3382 fdunused(fdp, dfd); 3383 #ifdef CAPABILITIES 3384 seqc_write_end(&newfde->fde_seqc); 3385 #endif 3386 break; 3387 } 3388 FILEDESC_XUNLOCK(fdp); 3389 *indxp = indx; 3390 return (0); 3391 } 3392 3393 /* 3394 * This sysctl determines if we will allow a process to chroot(2) if it 3395 * has a directory open: 3396 * 0: disallowed for all processes. 3397 * 1: allowed for processes that were not already chroot(2)'ed. 3398 * 2: allowed for all processes. 3399 */ 3400 3401 static int chroot_allow_open_directories = 1; 3402 3403 SYSCTL_INT(_kern, OID_AUTO, chroot_allow_open_directories, CTLFLAG_RW, 3404 &chroot_allow_open_directories, 0, 3405 "Allow a process to chroot(2) if it has a directory open"); 3406 3407 /* 3408 * Helper function for raised chroot(2) security function: Refuse if 3409 * any filedescriptors are open directories. 3410 */ 3411 static int 3412 chroot_refuse_vdir_fds(struct filedesc *fdp) 3413 { 3414 struct vnode *vp; 3415 struct file *fp; 3416 int fd, lastfile; 3417 3418 FILEDESC_LOCK_ASSERT(fdp); 3419 3420 lastfile = fdlastfile(fdp); 3421 for (fd = 0; fd <= lastfile; fd++) { 3422 fp = fget_locked(fdp, fd); 3423 if (fp == NULL) 3424 continue; 3425 if (fp->f_type == DTYPE_VNODE) { 3426 vp = fp->f_vnode; 3427 if (vp->v_type == VDIR) 3428 return (EPERM); 3429 } 3430 } 3431 return (0); 3432 } 3433 3434 static void 3435 pwd_fill(struct pwd *oldpwd, struct pwd *newpwd) 3436 { 3437 3438 if (newpwd->pwd_cdir == NULL && oldpwd->pwd_cdir != NULL) { 3439 vrefact(oldpwd->pwd_cdir); 3440 newpwd->pwd_cdir = oldpwd->pwd_cdir; 3441 } 3442 3443 if (newpwd->pwd_rdir == NULL && oldpwd->pwd_rdir != NULL) { 3444 vrefact(oldpwd->pwd_rdir); 3445 newpwd->pwd_rdir = oldpwd->pwd_rdir; 3446 } 3447 3448 if (newpwd->pwd_jdir == NULL && oldpwd->pwd_jdir != NULL) { 3449 vrefact(oldpwd->pwd_jdir); 3450 newpwd->pwd_jdir = oldpwd->pwd_jdir; 3451 } 3452 } 3453 3454 struct pwd * 3455 pwd_hold_filedesc(struct filedesc *fdp) 3456 { 3457 struct pwd *pwd; 3458 3459 FILEDESC_LOCK_ASSERT(fdp); 3460 pwd = FILEDESC_LOCKED_LOAD_PWD(fdp); 3461 if (pwd != NULL) 3462 refcount_acquire(&pwd->pwd_refcount); 3463 return (pwd); 3464 } 3465 3466 bool 3467 pwd_hold_smr(struct pwd *pwd) 3468 { 3469 3470 MPASS(pwd != NULL); 3471 if (__predict_true(refcount_acquire_if_not_zero(&pwd->pwd_refcount))) { 3472 return (true); 3473 } 3474 return (false); 3475 } 3476 3477 struct pwd * 3478 pwd_hold(struct thread *td) 3479 { 3480 struct filedesc *fdp; 3481 struct pwd *pwd; 3482 3483 fdp = td->td_proc->p_fd; 3484 3485 vfs_smr_enter(); 3486 pwd = vfs_smr_entered_load(&fdp->fd_pwd); 3487 if (pwd_hold_smr(pwd)) { 3488 vfs_smr_exit(); 3489 return (pwd); 3490 } 3491 vfs_smr_exit(); 3492 FILEDESC_SLOCK(fdp); 3493 pwd = pwd_hold_filedesc(fdp); 3494 MPASS(pwd != NULL); 3495 FILEDESC_SUNLOCK(fdp); 3496 return (pwd); 3497 } 3498 3499 struct pwd * 3500 pwd_get_smr(void) 3501 { 3502 struct pwd *pwd; 3503 3504 pwd = vfs_smr_entered_load(&curproc->p_fd->fd_pwd); 3505 MPASS(pwd != NULL); 3506 return (pwd); 3507 } 3508 3509 static struct pwd * 3510 pwd_alloc(void) 3511 { 3512 struct pwd *pwd; 3513 3514 pwd = uma_zalloc_smr(pwd_zone, M_WAITOK); 3515 bzero(pwd, sizeof(*pwd)); 3516 refcount_init(&pwd->pwd_refcount, 1); 3517 return (pwd); 3518 } 3519 3520 void 3521 pwd_drop(struct pwd *pwd) 3522 { 3523 3524 if (!refcount_release(&pwd->pwd_refcount)) 3525 return; 3526 3527 if (pwd->pwd_cdir != NULL) 3528 vrele(pwd->pwd_cdir); 3529 if (pwd->pwd_rdir != NULL) 3530 vrele(pwd->pwd_rdir); 3531 if (pwd->pwd_jdir != NULL) 3532 vrele(pwd->pwd_jdir); 3533 uma_zfree_smr(pwd_zone, pwd); 3534 } 3535 3536 /* 3537 * Common routine for kern_chroot() and jail_attach(). The caller is 3538 * responsible for invoking priv_check() and mac_vnode_check_chroot() to 3539 * authorize this operation. 3540 */ 3541 int 3542 pwd_chroot(struct thread *td, struct vnode *vp) 3543 { 3544 struct filedesc *fdp; 3545 struct pwd *newpwd, *oldpwd; 3546 int error; 3547 3548 fdp = td->td_proc->p_fd; 3549 newpwd = pwd_alloc(); 3550 FILEDESC_XLOCK(fdp); 3551 oldpwd = FILEDESC_XLOCKED_LOAD_PWD(fdp); 3552 if (chroot_allow_open_directories == 0 || 3553 (chroot_allow_open_directories == 1 && 3554 oldpwd->pwd_rdir != rootvnode)) { 3555 error = chroot_refuse_vdir_fds(fdp); 3556 if (error != 0) { 3557 FILEDESC_XUNLOCK(fdp); 3558 pwd_drop(newpwd); 3559 return (error); 3560 } 3561 } 3562 3563 vrefact(vp); 3564 newpwd->pwd_rdir = vp; 3565 if (oldpwd->pwd_jdir == NULL) { 3566 vrefact(vp); 3567 newpwd->pwd_jdir = vp; 3568 } 3569 pwd_fill(oldpwd, newpwd); 3570 pwd_set(fdp, newpwd); 3571 FILEDESC_XUNLOCK(fdp); 3572 pwd_drop(oldpwd); 3573 return (0); 3574 } 3575 3576 void 3577 pwd_chdir(struct thread *td, struct vnode *vp) 3578 { 3579 struct filedesc *fdp; 3580 struct pwd *newpwd, *oldpwd; 3581 3582 VNPASS(vp->v_usecount > 0, vp); 3583 3584 newpwd = pwd_alloc(); 3585 fdp = td->td_proc->p_fd; 3586 FILEDESC_XLOCK(fdp); 3587 oldpwd = FILEDESC_XLOCKED_LOAD_PWD(fdp); 3588 newpwd->pwd_cdir = vp; 3589 pwd_fill(oldpwd, newpwd); 3590 pwd_set(fdp, newpwd); 3591 FILEDESC_XUNLOCK(fdp); 3592 pwd_drop(oldpwd); 3593 } 3594 3595 void 3596 pwd_ensure_dirs(void) 3597 { 3598 struct filedesc *fdp; 3599 struct pwd *oldpwd, *newpwd; 3600 3601 fdp = curproc->p_fd; 3602 FILEDESC_XLOCK(fdp); 3603 oldpwd = FILEDESC_XLOCKED_LOAD_PWD(fdp); 3604 if (oldpwd->pwd_cdir != NULL && oldpwd->pwd_rdir != NULL) { 3605 FILEDESC_XUNLOCK(fdp); 3606 return; 3607 } 3608 FILEDESC_XUNLOCK(fdp); 3609 3610 newpwd = pwd_alloc(); 3611 FILEDESC_XLOCK(fdp); 3612 oldpwd = FILEDESC_XLOCKED_LOAD_PWD(fdp); 3613 pwd_fill(oldpwd, newpwd); 3614 if (newpwd->pwd_cdir == NULL) { 3615 vrefact(rootvnode); 3616 newpwd->pwd_cdir = rootvnode; 3617 } 3618 if (newpwd->pwd_rdir == NULL) { 3619 vrefact(rootvnode); 3620 newpwd->pwd_rdir = rootvnode; 3621 } 3622 pwd_set(fdp, newpwd); 3623 FILEDESC_XUNLOCK(fdp); 3624 pwd_drop(oldpwd); 3625 } 3626 3627 void 3628 pwd_set_rootvnode(void) 3629 { 3630 struct filedesc *fdp; 3631 struct pwd *oldpwd, *newpwd; 3632 3633 fdp = curproc->p_fd; 3634 3635 newpwd = pwd_alloc(); 3636 FILEDESC_XLOCK(fdp); 3637 oldpwd = FILEDESC_XLOCKED_LOAD_PWD(fdp); 3638 vrefact(rootvnode); 3639 newpwd->pwd_cdir = rootvnode; 3640 vrefact(rootvnode); 3641 newpwd->pwd_rdir = rootvnode; 3642 pwd_fill(oldpwd, newpwd); 3643 pwd_set(fdp, newpwd); 3644 FILEDESC_XUNLOCK(fdp); 3645 pwd_drop(oldpwd); 3646 } 3647 3648 /* 3649 * Scan all active processes and prisons to see if any of them have a current 3650 * or root directory of `olddp'. If so, replace them with the new mount point. 3651 */ 3652 void 3653 mountcheckdirs(struct vnode *olddp, struct vnode *newdp) 3654 { 3655 struct filedesc *fdp; 3656 struct pwd *newpwd, *oldpwd; 3657 struct prison *pr; 3658 struct proc *p; 3659 int nrele; 3660 3661 if (vrefcnt(olddp) == 1) 3662 return; 3663 nrele = 0; 3664 newpwd = pwd_alloc(); 3665 sx_slock(&allproc_lock); 3666 FOREACH_PROC_IN_SYSTEM(p) { 3667 PROC_LOCK(p); 3668 fdp = fdhold(p); 3669 PROC_UNLOCK(p); 3670 if (fdp == NULL) 3671 continue; 3672 FILEDESC_XLOCK(fdp); 3673 oldpwd = FILEDESC_XLOCKED_LOAD_PWD(fdp); 3674 if (oldpwd == NULL || 3675 (oldpwd->pwd_cdir != olddp && 3676 oldpwd->pwd_rdir != olddp && 3677 oldpwd->pwd_jdir != olddp)) { 3678 FILEDESC_XUNLOCK(fdp); 3679 fddrop(fdp); 3680 continue; 3681 } 3682 if (oldpwd->pwd_cdir == olddp) { 3683 vrefact(newdp); 3684 newpwd->pwd_cdir = newdp; 3685 } 3686 if (oldpwd->pwd_rdir == olddp) { 3687 vrefact(newdp); 3688 newpwd->pwd_rdir = newdp; 3689 } 3690 if (oldpwd->pwd_jdir == olddp) { 3691 vrefact(newdp); 3692 newpwd->pwd_jdir = newdp; 3693 } 3694 pwd_fill(oldpwd, newpwd); 3695 pwd_set(fdp, newpwd); 3696 FILEDESC_XUNLOCK(fdp); 3697 pwd_drop(oldpwd); 3698 fddrop(fdp); 3699 newpwd = pwd_alloc(); 3700 } 3701 sx_sunlock(&allproc_lock); 3702 pwd_drop(newpwd); 3703 if (rootvnode == olddp) { 3704 vrefact(newdp); 3705 rootvnode = newdp; 3706 nrele++; 3707 } 3708 mtx_lock(&prison0.pr_mtx); 3709 if (prison0.pr_root == olddp) { 3710 vrefact(newdp); 3711 prison0.pr_root = newdp; 3712 nrele++; 3713 } 3714 mtx_unlock(&prison0.pr_mtx); 3715 sx_slock(&allprison_lock); 3716 TAILQ_FOREACH(pr, &allprison, pr_list) { 3717 mtx_lock(&pr->pr_mtx); 3718 if (pr->pr_root == olddp) { 3719 vrefact(newdp); 3720 pr->pr_root = newdp; 3721 nrele++; 3722 } 3723 mtx_unlock(&pr->pr_mtx); 3724 } 3725 sx_sunlock(&allprison_lock); 3726 while (nrele--) 3727 vrele(olddp); 3728 } 3729 3730 struct filedesc_to_leader * 3731 filedesc_to_leader_alloc(struct filedesc_to_leader *old, struct filedesc *fdp, struct proc *leader) 3732 { 3733 struct filedesc_to_leader *fdtol; 3734 3735 fdtol = malloc(sizeof(struct filedesc_to_leader), 3736 M_FILEDESC_TO_LEADER, M_WAITOK); 3737 fdtol->fdl_refcount = 1; 3738 fdtol->fdl_holdcount = 0; 3739 fdtol->fdl_wakeup = 0; 3740 fdtol->fdl_leader = leader; 3741 if (old != NULL) { 3742 FILEDESC_XLOCK(fdp); 3743 fdtol->fdl_next = old->fdl_next; 3744 fdtol->fdl_prev = old; 3745 old->fdl_next = fdtol; 3746 fdtol->fdl_next->fdl_prev = fdtol; 3747 FILEDESC_XUNLOCK(fdp); 3748 } else { 3749 fdtol->fdl_next = fdtol; 3750 fdtol->fdl_prev = fdtol; 3751 } 3752 return (fdtol); 3753 } 3754 3755 static int 3756 sysctl_kern_proc_nfds(SYSCTL_HANDLER_ARGS) 3757 { 3758 NDSLOTTYPE *map; 3759 struct filedesc *fdp; 3760 int count, off, minoff; 3761 3762 if (*(int *)arg1 != 0) 3763 return (EINVAL); 3764 3765 fdp = curproc->p_fd; 3766 count = 0; 3767 FILEDESC_SLOCK(fdp); 3768 map = fdp->fd_map; 3769 off = NDSLOT(fdp->fd_nfiles - 1); 3770 for (minoff = NDSLOT(0); off >= minoff; --off) 3771 count += bitcountl(map[off]); 3772 FILEDESC_SUNLOCK(fdp); 3773 3774 return (SYSCTL_OUT(req, &count, sizeof(count))); 3775 } 3776 3777 static SYSCTL_NODE(_kern_proc, KERN_PROC_NFDS, nfds, 3778 CTLFLAG_RD|CTLFLAG_CAPRD|CTLFLAG_MPSAFE, sysctl_kern_proc_nfds, 3779 "Number of open file descriptors"); 3780 3781 /* 3782 * Get file structures globally. 3783 */ 3784 static int 3785 sysctl_kern_file(SYSCTL_HANDLER_ARGS) 3786 { 3787 struct xfile xf; 3788 struct filedesc *fdp; 3789 struct file *fp; 3790 struct proc *p; 3791 int error, n, lastfile; 3792 3793 error = sysctl_wire_old_buffer(req, 0); 3794 if (error != 0) 3795 return (error); 3796 if (req->oldptr == NULL) { 3797 n = 0; 3798 sx_slock(&allproc_lock); 3799 FOREACH_PROC_IN_SYSTEM(p) { 3800 PROC_LOCK(p); 3801 if (p->p_state == PRS_NEW) { 3802 PROC_UNLOCK(p); 3803 continue; 3804 } 3805 fdp = fdhold(p); 3806 PROC_UNLOCK(p); 3807 if (fdp == NULL) 3808 continue; 3809 /* overestimates sparse tables. */ 3810 n += fdp->fd_nfiles; 3811 fddrop(fdp); 3812 } 3813 sx_sunlock(&allproc_lock); 3814 return (SYSCTL_OUT(req, 0, n * sizeof(xf))); 3815 } 3816 error = 0; 3817 bzero(&xf, sizeof(xf)); 3818 xf.xf_size = sizeof(xf); 3819 sx_slock(&allproc_lock); 3820 FOREACH_PROC_IN_SYSTEM(p) { 3821 PROC_LOCK(p); 3822 if (p->p_state == PRS_NEW) { 3823 PROC_UNLOCK(p); 3824 continue; 3825 } 3826 if (p_cansee(req->td, p) != 0) { 3827 PROC_UNLOCK(p); 3828 continue; 3829 } 3830 xf.xf_pid = p->p_pid; 3831 xf.xf_uid = p->p_ucred->cr_uid; 3832 fdp = fdhold(p); 3833 PROC_UNLOCK(p); 3834 if (fdp == NULL) 3835 continue; 3836 FILEDESC_SLOCK(fdp); 3837 lastfile = fdlastfile(fdp); 3838 for (n = 0; fdp->fd_refcnt > 0 && n <= lastfile; ++n) { 3839 if ((fp = fdp->fd_ofiles[n].fde_file) == NULL) 3840 continue; 3841 xf.xf_fd = n; 3842 xf.xf_file = (uintptr_t)fp; 3843 xf.xf_data = (uintptr_t)fp->f_data; 3844 xf.xf_vnode = (uintptr_t)fp->f_vnode; 3845 xf.xf_type = (uintptr_t)fp->f_type; 3846 xf.xf_count = refcount_load(&fp->f_count); 3847 xf.xf_msgcount = 0; 3848 xf.xf_offset = foffset_get(fp); 3849 xf.xf_flag = fp->f_flag; 3850 error = SYSCTL_OUT(req, &xf, sizeof(xf)); 3851 if (error) 3852 break; 3853 } 3854 FILEDESC_SUNLOCK(fdp); 3855 fddrop(fdp); 3856 if (error) 3857 break; 3858 } 3859 sx_sunlock(&allproc_lock); 3860 return (error); 3861 } 3862 3863 SYSCTL_PROC(_kern, KERN_FILE, file, CTLTYPE_OPAQUE|CTLFLAG_RD|CTLFLAG_MPSAFE, 3864 0, 0, sysctl_kern_file, "S,xfile", "Entire file table"); 3865 3866 #ifdef KINFO_FILE_SIZE 3867 CTASSERT(sizeof(struct kinfo_file) == KINFO_FILE_SIZE); 3868 #endif 3869 3870 static int 3871 xlate_fflags(int fflags) 3872 { 3873 static const struct { 3874 int fflag; 3875 int kf_fflag; 3876 } fflags_table[] = { 3877 { FAPPEND, KF_FLAG_APPEND }, 3878 { FASYNC, KF_FLAG_ASYNC }, 3879 { FFSYNC, KF_FLAG_FSYNC }, 3880 { FHASLOCK, KF_FLAG_HASLOCK }, 3881 { FNONBLOCK, KF_FLAG_NONBLOCK }, 3882 { FREAD, KF_FLAG_READ }, 3883 { FWRITE, KF_FLAG_WRITE }, 3884 { O_CREAT, KF_FLAG_CREAT }, 3885 { O_DIRECT, KF_FLAG_DIRECT }, 3886 { O_EXCL, KF_FLAG_EXCL }, 3887 { O_EXEC, KF_FLAG_EXEC }, 3888 { O_EXLOCK, KF_FLAG_EXLOCK }, 3889 { O_NOFOLLOW, KF_FLAG_NOFOLLOW }, 3890 { O_SHLOCK, KF_FLAG_SHLOCK }, 3891 { O_TRUNC, KF_FLAG_TRUNC } 3892 }; 3893 unsigned int i; 3894 int kflags; 3895 3896 kflags = 0; 3897 for (i = 0; i < nitems(fflags_table); i++) 3898 if (fflags & fflags_table[i].fflag) 3899 kflags |= fflags_table[i].kf_fflag; 3900 return (kflags); 3901 } 3902 3903 /* Trim unused data from kf_path by truncating the structure size. */ 3904 void 3905 pack_kinfo(struct kinfo_file *kif) 3906 { 3907 3908 kif->kf_structsize = offsetof(struct kinfo_file, kf_path) + 3909 strlen(kif->kf_path) + 1; 3910 kif->kf_structsize = roundup(kif->kf_structsize, sizeof(uint64_t)); 3911 } 3912 3913 static void 3914 export_file_to_kinfo(struct file *fp, int fd, cap_rights_t *rightsp, 3915 struct kinfo_file *kif, struct filedesc *fdp, int flags) 3916 { 3917 int error; 3918 3919 bzero(kif, sizeof(*kif)); 3920 3921 /* Set a default type to allow for empty fill_kinfo() methods. */ 3922 kif->kf_type = KF_TYPE_UNKNOWN; 3923 kif->kf_flags = xlate_fflags(fp->f_flag); 3924 if (rightsp != NULL) 3925 kif->kf_cap_rights = *rightsp; 3926 else 3927 cap_rights_init_zero(&kif->kf_cap_rights); 3928 kif->kf_fd = fd; 3929 kif->kf_ref_count = refcount_load(&fp->f_count); 3930 kif->kf_offset = foffset_get(fp); 3931 3932 /* 3933 * This may drop the filedesc lock, so the 'fp' cannot be 3934 * accessed after this call. 3935 */ 3936 error = fo_fill_kinfo(fp, kif, fdp); 3937 if (error == 0) 3938 kif->kf_status |= KF_ATTR_VALID; 3939 if ((flags & KERN_FILEDESC_PACK_KINFO) != 0) 3940 pack_kinfo(kif); 3941 else 3942 kif->kf_structsize = roundup2(sizeof(*kif), sizeof(uint64_t)); 3943 } 3944 3945 static void 3946 export_vnode_to_kinfo(struct vnode *vp, int fd, int fflags, 3947 struct kinfo_file *kif, int flags) 3948 { 3949 int error; 3950 3951 bzero(kif, sizeof(*kif)); 3952 3953 kif->kf_type = KF_TYPE_VNODE; 3954 error = vn_fill_kinfo_vnode(vp, kif); 3955 if (error == 0) 3956 kif->kf_status |= KF_ATTR_VALID; 3957 kif->kf_flags = xlate_fflags(fflags); 3958 cap_rights_init_zero(&kif->kf_cap_rights); 3959 kif->kf_fd = fd; 3960 kif->kf_ref_count = -1; 3961 kif->kf_offset = -1; 3962 if ((flags & KERN_FILEDESC_PACK_KINFO) != 0) 3963 pack_kinfo(kif); 3964 else 3965 kif->kf_structsize = roundup2(sizeof(*kif), sizeof(uint64_t)); 3966 vrele(vp); 3967 } 3968 3969 struct export_fd_buf { 3970 struct filedesc *fdp; 3971 struct sbuf *sb; 3972 ssize_t remainder; 3973 struct kinfo_file kif; 3974 int flags; 3975 }; 3976 3977 static int 3978 export_kinfo_to_sb(struct export_fd_buf *efbuf) 3979 { 3980 struct kinfo_file *kif; 3981 3982 kif = &efbuf->kif; 3983 if (efbuf->remainder != -1) { 3984 if (efbuf->remainder < kif->kf_structsize) { 3985 /* Terminate export. */ 3986 efbuf->remainder = 0; 3987 return (0); 3988 } 3989 efbuf->remainder -= kif->kf_structsize; 3990 } 3991 return (sbuf_bcat(efbuf->sb, kif, kif->kf_structsize) == 0 ? 0 : ENOMEM); 3992 } 3993 3994 static int 3995 export_file_to_sb(struct file *fp, int fd, cap_rights_t *rightsp, 3996 struct export_fd_buf *efbuf) 3997 { 3998 int error; 3999 4000 if (efbuf->remainder == 0) 4001 return (0); 4002 export_file_to_kinfo(fp, fd, rightsp, &efbuf->kif, efbuf->fdp, 4003 efbuf->flags); 4004 FILEDESC_SUNLOCK(efbuf->fdp); 4005 error = export_kinfo_to_sb(efbuf); 4006 FILEDESC_SLOCK(efbuf->fdp); 4007 return (error); 4008 } 4009 4010 static int 4011 export_vnode_to_sb(struct vnode *vp, int fd, int fflags, 4012 struct export_fd_buf *efbuf) 4013 { 4014 int error; 4015 4016 if (efbuf->remainder == 0) 4017 return (0); 4018 if (efbuf->fdp != NULL) 4019 FILEDESC_SUNLOCK(efbuf->fdp); 4020 export_vnode_to_kinfo(vp, fd, fflags, &efbuf->kif, efbuf->flags); 4021 error = export_kinfo_to_sb(efbuf); 4022 if (efbuf->fdp != NULL) 4023 FILEDESC_SLOCK(efbuf->fdp); 4024 return (error); 4025 } 4026 4027 /* 4028 * Store a process file descriptor information to sbuf. 4029 * 4030 * Takes a locked proc as argument, and returns with the proc unlocked. 4031 */ 4032 int 4033 kern_proc_filedesc_out(struct proc *p, struct sbuf *sb, ssize_t maxlen, 4034 int flags) 4035 { 4036 struct file *fp; 4037 struct filedesc *fdp; 4038 struct export_fd_buf *efbuf; 4039 struct vnode *cttyvp, *textvp, *tracevp; 4040 struct pwd *pwd; 4041 int error, i, lastfile; 4042 cap_rights_t rights; 4043 4044 PROC_LOCK_ASSERT(p, MA_OWNED); 4045 4046 /* ktrace vnode */ 4047 tracevp = p->p_tracevp; 4048 if (tracevp != NULL) 4049 vrefact(tracevp); 4050 /* text vnode */ 4051 textvp = p->p_textvp; 4052 if (textvp != NULL) 4053 vrefact(textvp); 4054 /* Controlling tty. */ 4055 cttyvp = NULL; 4056 if (p->p_pgrp != NULL && p->p_pgrp->pg_session != NULL) { 4057 cttyvp = p->p_pgrp->pg_session->s_ttyvp; 4058 if (cttyvp != NULL) 4059 vrefact(cttyvp); 4060 } 4061 fdp = fdhold(p); 4062 PROC_UNLOCK(p); 4063 efbuf = malloc(sizeof(*efbuf), M_TEMP, M_WAITOK); 4064 efbuf->fdp = NULL; 4065 efbuf->sb = sb; 4066 efbuf->remainder = maxlen; 4067 efbuf->flags = flags; 4068 if (tracevp != NULL) 4069 export_vnode_to_sb(tracevp, KF_FD_TYPE_TRACE, FREAD | FWRITE, 4070 efbuf); 4071 if (textvp != NULL) 4072 export_vnode_to_sb(textvp, KF_FD_TYPE_TEXT, FREAD, efbuf); 4073 if (cttyvp != NULL) 4074 export_vnode_to_sb(cttyvp, KF_FD_TYPE_CTTY, FREAD | FWRITE, 4075 efbuf); 4076 error = 0; 4077 if (fdp == NULL) 4078 goto fail; 4079 efbuf->fdp = fdp; 4080 FILEDESC_SLOCK(fdp); 4081 pwd = pwd_hold_filedesc(fdp); 4082 if (pwd != NULL) { 4083 /* working directory */ 4084 if (pwd->pwd_cdir != NULL) { 4085 vrefact(pwd->pwd_cdir); 4086 export_vnode_to_sb(pwd->pwd_cdir, KF_FD_TYPE_CWD, FREAD, efbuf); 4087 } 4088 /* root directory */ 4089 if (pwd->pwd_rdir != NULL) { 4090 vrefact(pwd->pwd_rdir); 4091 export_vnode_to_sb(pwd->pwd_rdir, KF_FD_TYPE_ROOT, FREAD, efbuf); 4092 } 4093 /* jail directory */ 4094 if (pwd->pwd_jdir != NULL) { 4095 vrefact(pwd->pwd_jdir); 4096 export_vnode_to_sb(pwd->pwd_jdir, KF_FD_TYPE_JAIL, FREAD, efbuf); 4097 } 4098 } 4099 lastfile = fdlastfile(fdp); 4100 for (i = 0; fdp->fd_refcnt > 0 && i <= lastfile; i++) { 4101 if ((fp = fdp->fd_ofiles[i].fde_file) == NULL) 4102 continue; 4103 #ifdef CAPABILITIES 4104 rights = *cap_rights(fdp, i); 4105 #else /* !CAPABILITIES */ 4106 rights = cap_no_rights; 4107 #endif 4108 /* 4109 * Create sysctl entry. It is OK to drop the filedesc 4110 * lock inside of export_file_to_sb() as we will 4111 * re-validate and re-evaluate its properties when the 4112 * loop continues. 4113 */ 4114 error = export_file_to_sb(fp, i, &rights, efbuf); 4115 if (error != 0 || efbuf->remainder == 0) 4116 break; 4117 } 4118 FILEDESC_SUNLOCK(fdp); 4119 if (pwd != NULL) 4120 pwd_drop(pwd); 4121 fddrop(fdp); 4122 fail: 4123 free(efbuf, M_TEMP); 4124 return (error); 4125 } 4126 4127 #define FILEDESC_SBUF_SIZE (sizeof(struct kinfo_file) * 5) 4128 4129 /* 4130 * Get per-process file descriptors for use by procstat(1), et al. 4131 */ 4132 static int 4133 sysctl_kern_proc_filedesc(SYSCTL_HANDLER_ARGS) 4134 { 4135 struct sbuf sb; 4136 struct proc *p; 4137 ssize_t maxlen; 4138 int error, error2, *name; 4139 4140 name = (int *)arg1; 4141 4142 sbuf_new_for_sysctl(&sb, NULL, FILEDESC_SBUF_SIZE, req); 4143 sbuf_clear_flags(&sb, SBUF_INCLUDENUL); 4144 error = pget((pid_t)name[0], PGET_CANDEBUG | PGET_NOTWEXIT, &p); 4145 if (error != 0) { 4146 sbuf_delete(&sb); 4147 return (error); 4148 } 4149 maxlen = req->oldptr != NULL ? req->oldlen : -1; 4150 error = kern_proc_filedesc_out(p, &sb, maxlen, 4151 KERN_FILEDESC_PACK_KINFO); 4152 error2 = sbuf_finish(&sb); 4153 sbuf_delete(&sb); 4154 return (error != 0 ? error : error2); 4155 } 4156 4157 #ifdef COMPAT_FREEBSD7 4158 #ifdef KINFO_OFILE_SIZE 4159 CTASSERT(sizeof(struct kinfo_ofile) == KINFO_OFILE_SIZE); 4160 #endif 4161 4162 static void 4163 kinfo_to_okinfo(struct kinfo_file *kif, struct kinfo_ofile *okif) 4164 { 4165 4166 okif->kf_structsize = sizeof(*okif); 4167 okif->kf_type = kif->kf_type; 4168 okif->kf_fd = kif->kf_fd; 4169 okif->kf_ref_count = kif->kf_ref_count; 4170 okif->kf_flags = kif->kf_flags & (KF_FLAG_READ | KF_FLAG_WRITE | 4171 KF_FLAG_APPEND | KF_FLAG_ASYNC | KF_FLAG_FSYNC | KF_FLAG_NONBLOCK | 4172 KF_FLAG_DIRECT | KF_FLAG_HASLOCK); 4173 okif->kf_offset = kif->kf_offset; 4174 if (kif->kf_type == KF_TYPE_VNODE) 4175 okif->kf_vnode_type = kif->kf_un.kf_file.kf_file_type; 4176 else 4177 okif->kf_vnode_type = KF_VTYPE_VNON; 4178 strlcpy(okif->kf_path, kif->kf_path, sizeof(okif->kf_path)); 4179 if (kif->kf_type == KF_TYPE_SOCKET) { 4180 okif->kf_sock_domain = kif->kf_un.kf_sock.kf_sock_domain0; 4181 okif->kf_sock_type = kif->kf_un.kf_sock.kf_sock_type0; 4182 okif->kf_sock_protocol = kif->kf_un.kf_sock.kf_sock_protocol0; 4183 okif->kf_sa_local = kif->kf_un.kf_sock.kf_sa_local; 4184 okif->kf_sa_peer = kif->kf_un.kf_sock.kf_sa_peer; 4185 } else { 4186 okif->kf_sa_local.ss_family = AF_UNSPEC; 4187 okif->kf_sa_peer.ss_family = AF_UNSPEC; 4188 } 4189 } 4190 4191 static int 4192 export_vnode_for_osysctl(struct vnode *vp, int type, struct kinfo_file *kif, 4193 struct kinfo_ofile *okif, struct filedesc *fdp, struct sysctl_req *req) 4194 { 4195 int error; 4196 4197 vrefact(vp); 4198 FILEDESC_SUNLOCK(fdp); 4199 export_vnode_to_kinfo(vp, type, 0, kif, KERN_FILEDESC_PACK_KINFO); 4200 kinfo_to_okinfo(kif, okif); 4201 error = SYSCTL_OUT(req, okif, sizeof(*okif)); 4202 FILEDESC_SLOCK(fdp); 4203 return (error); 4204 } 4205 4206 /* 4207 * Get per-process file descriptors for use by procstat(1), et al. 4208 */ 4209 static int 4210 sysctl_kern_proc_ofiledesc(SYSCTL_HANDLER_ARGS) 4211 { 4212 struct kinfo_ofile *okif; 4213 struct kinfo_file *kif; 4214 struct filedesc *fdp; 4215 struct pwd *pwd; 4216 int error, i, lastfile, *name; 4217 struct file *fp; 4218 struct proc *p; 4219 4220 name = (int *)arg1; 4221 error = pget((pid_t)name[0], PGET_CANDEBUG | PGET_NOTWEXIT, &p); 4222 if (error != 0) 4223 return (error); 4224 fdp = fdhold(p); 4225 PROC_UNLOCK(p); 4226 if (fdp == NULL) 4227 return (ENOENT); 4228 kif = malloc(sizeof(*kif), M_TEMP, M_WAITOK); 4229 okif = malloc(sizeof(*okif), M_TEMP, M_WAITOK); 4230 FILEDESC_SLOCK(fdp); 4231 pwd = pwd_hold_filedesc(fdp); 4232 if (pwd != NULL) { 4233 if (pwd->pwd_cdir != NULL) 4234 export_vnode_for_osysctl(pwd->pwd_cdir, KF_FD_TYPE_CWD, kif, 4235 okif, fdp, req); 4236 if (pwd->pwd_rdir != NULL) 4237 export_vnode_for_osysctl(pwd->pwd_rdir, KF_FD_TYPE_ROOT, kif, 4238 okif, fdp, req); 4239 if (pwd->pwd_jdir != NULL) 4240 export_vnode_for_osysctl(pwd->pwd_jdir, KF_FD_TYPE_JAIL, kif, 4241 okif, fdp, req); 4242 } 4243 lastfile = fdlastfile(fdp); 4244 for (i = 0; fdp->fd_refcnt > 0 && i <= lastfile; i++) { 4245 if ((fp = fdp->fd_ofiles[i].fde_file) == NULL) 4246 continue; 4247 export_file_to_kinfo(fp, i, NULL, kif, fdp, 4248 KERN_FILEDESC_PACK_KINFO); 4249 FILEDESC_SUNLOCK(fdp); 4250 kinfo_to_okinfo(kif, okif); 4251 error = SYSCTL_OUT(req, okif, sizeof(*okif)); 4252 FILEDESC_SLOCK(fdp); 4253 if (error) 4254 break; 4255 } 4256 FILEDESC_SUNLOCK(fdp); 4257 if (pwd != NULL) 4258 pwd_drop(pwd); 4259 fddrop(fdp); 4260 free(kif, M_TEMP); 4261 free(okif, M_TEMP); 4262 return (0); 4263 } 4264 4265 static SYSCTL_NODE(_kern_proc, KERN_PROC_OFILEDESC, ofiledesc, 4266 CTLFLAG_RD|CTLFLAG_MPSAFE, sysctl_kern_proc_ofiledesc, 4267 "Process ofiledesc entries"); 4268 #endif /* COMPAT_FREEBSD7 */ 4269 4270 int 4271 vntype_to_kinfo(int vtype) 4272 { 4273 struct { 4274 int vtype; 4275 int kf_vtype; 4276 } vtypes_table[] = { 4277 { VBAD, KF_VTYPE_VBAD }, 4278 { VBLK, KF_VTYPE_VBLK }, 4279 { VCHR, KF_VTYPE_VCHR }, 4280 { VDIR, KF_VTYPE_VDIR }, 4281 { VFIFO, KF_VTYPE_VFIFO }, 4282 { VLNK, KF_VTYPE_VLNK }, 4283 { VNON, KF_VTYPE_VNON }, 4284 { VREG, KF_VTYPE_VREG }, 4285 { VSOCK, KF_VTYPE_VSOCK } 4286 }; 4287 unsigned int i; 4288 4289 /* 4290 * Perform vtype translation. 4291 */ 4292 for (i = 0; i < nitems(vtypes_table); i++) 4293 if (vtypes_table[i].vtype == vtype) 4294 return (vtypes_table[i].kf_vtype); 4295 4296 return (KF_VTYPE_UNKNOWN); 4297 } 4298 4299 static SYSCTL_NODE(_kern_proc, KERN_PROC_FILEDESC, filedesc, 4300 CTLFLAG_RD|CTLFLAG_MPSAFE, sysctl_kern_proc_filedesc, 4301 "Process filedesc entries"); 4302 4303 /* 4304 * Store a process current working directory information to sbuf. 4305 * 4306 * Takes a locked proc as argument, and returns with the proc unlocked. 4307 */ 4308 int 4309 kern_proc_cwd_out(struct proc *p, struct sbuf *sb, ssize_t maxlen) 4310 { 4311 struct filedesc *fdp; 4312 struct pwd *pwd; 4313 struct export_fd_buf *efbuf; 4314 struct vnode *cdir; 4315 int error; 4316 4317 PROC_LOCK_ASSERT(p, MA_OWNED); 4318 4319 fdp = fdhold(p); 4320 PROC_UNLOCK(p); 4321 if (fdp == NULL) 4322 return (EINVAL); 4323 4324 efbuf = malloc(sizeof(*efbuf), M_TEMP, M_WAITOK); 4325 efbuf->fdp = fdp; 4326 efbuf->sb = sb; 4327 efbuf->remainder = maxlen; 4328 4329 FILEDESC_SLOCK(fdp); 4330 pwd = FILEDESC_LOCKED_LOAD_PWD(fdp); 4331 cdir = pwd->pwd_cdir; 4332 if (cdir == NULL) { 4333 error = EINVAL; 4334 } else { 4335 vrefact(cdir); 4336 error = export_vnode_to_sb(cdir, KF_FD_TYPE_CWD, FREAD, efbuf); 4337 } 4338 FILEDESC_SUNLOCK(fdp); 4339 fddrop(fdp); 4340 free(efbuf, M_TEMP); 4341 return (error); 4342 } 4343 4344 /* 4345 * Get per-process current working directory. 4346 */ 4347 static int 4348 sysctl_kern_proc_cwd(SYSCTL_HANDLER_ARGS) 4349 { 4350 struct sbuf sb; 4351 struct proc *p; 4352 ssize_t maxlen; 4353 int error, error2, *name; 4354 4355 name = (int *)arg1; 4356 4357 sbuf_new_for_sysctl(&sb, NULL, sizeof(struct kinfo_file), req); 4358 sbuf_clear_flags(&sb, SBUF_INCLUDENUL); 4359 error = pget((pid_t)name[0], PGET_CANDEBUG | PGET_NOTWEXIT, &p); 4360 if (error != 0) { 4361 sbuf_delete(&sb); 4362 return (error); 4363 } 4364 maxlen = req->oldptr != NULL ? req->oldlen : -1; 4365 error = kern_proc_cwd_out(p, &sb, maxlen); 4366 error2 = sbuf_finish(&sb); 4367 sbuf_delete(&sb); 4368 return (error != 0 ? error : error2); 4369 } 4370 4371 static SYSCTL_NODE(_kern_proc, KERN_PROC_CWD, cwd, CTLFLAG_RD|CTLFLAG_MPSAFE, 4372 sysctl_kern_proc_cwd, "Process current working directory"); 4373 4374 #ifdef DDB 4375 /* 4376 * For the purposes of debugging, generate a human-readable string for the 4377 * file type. 4378 */ 4379 static const char * 4380 file_type_to_name(short type) 4381 { 4382 4383 switch (type) { 4384 case 0: 4385 return ("zero"); 4386 case DTYPE_VNODE: 4387 return ("vnode"); 4388 case DTYPE_SOCKET: 4389 return ("socket"); 4390 case DTYPE_PIPE: 4391 return ("pipe"); 4392 case DTYPE_FIFO: 4393 return ("fifo"); 4394 case DTYPE_KQUEUE: 4395 return ("kqueue"); 4396 case DTYPE_CRYPTO: 4397 return ("crypto"); 4398 case DTYPE_MQUEUE: 4399 return ("mqueue"); 4400 case DTYPE_SHM: 4401 return ("shm"); 4402 case DTYPE_SEM: 4403 return ("ksem"); 4404 case DTYPE_PTS: 4405 return ("pts"); 4406 case DTYPE_DEV: 4407 return ("dev"); 4408 case DTYPE_PROCDESC: 4409 return ("proc"); 4410 case DTYPE_LINUXEFD: 4411 return ("levent"); 4412 case DTYPE_LINUXTFD: 4413 return ("ltimer"); 4414 default: 4415 return ("unkn"); 4416 } 4417 } 4418 4419 /* 4420 * For the purposes of debugging, identify a process (if any, perhaps one of 4421 * many) that references the passed file in its file descriptor array. Return 4422 * NULL if none. 4423 */ 4424 static struct proc * 4425 file_to_first_proc(struct file *fp) 4426 { 4427 struct filedesc *fdp; 4428 struct proc *p; 4429 int n; 4430 4431 FOREACH_PROC_IN_SYSTEM(p) { 4432 if (p->p_state == PRS_NEW) 4433 continue; 4434 fdp = p->p_fd; 4435 if (fdp == NULL) 4436 continue; 4437 for (n = 0; n < fdp->fd_nfiles; n++) { 4438 if (fp == fdp->fd_ofiles[n].fde_file) 4439 return (p); 4440 } 4441 } 4442 return (NULL); 4443 } 4444 4445 static void 4446 db_print_file(struct file *fp, int header) 4447 { 4448 #define XPTRWIDTH ((int)howmany(sizeof(void *) * NBBY, 4)) 4449 struct proc *p; 4450 4451 if (header) 4452 db_printf("%*s %6s %*s %8s %4s %5s %6s %*s %5s %s\n", 4453 XPTRWIDTH, "File", "Type", XPTRWIDTH, "Data", "Flag", 4454 "GCFl", "Count", "MCount", XPTRWIDTH, "Vnode", "FPID", 4455 "FCmd"); 4456 p = file_to_first_proc(fp); 4457 db_printf("%*p %6s %*p %08x %04x %5d %6d %*p %5d %s\n", XPTRWIDTH, 4458 fp, file_type_to_name(fp->f_type), XPTRWIDTH, fp->f_data, 4459 fp->f_flag, 0, refcount_load(&fp->f_count), 0, XPTRWIDTH, fp->f_vnode, 4460 p != NULL ? p->p_pid : -1, p != NULL ? p->p_comm : "-"); 4461 4462 #undef XPTRWIDTH 4463 } 4464 4465 DB_SHOW_COMMAND(file, db_show_file) 4466 { 4467 struct file *fp; 4468 4469 if (!have_addr) { 4470 db_printf("usage: show file <addr>\n"); 4471 return; 4472 } 4473 fp = (struct file *)addr; 4474 db_print_file(fp, 1); 4475 } 4476 4477 DB_SHOW_COMMAND(files, db_show_files) 4478 { 4479 struct filedesc *fdp; 4480 struct file *fp; 4481 struct proc *p; 4482 int header; 4483 int n; 4484 4485 header = 1; 4486 FOREACH_PROC_IN_SYSTEM(p) { 4487 if (p->p_state == PRS_NEW) 4488 continue; 4489 if ((fdp = p->p_fd) == NULL) 4490 continue; 4491 for (n = 0; n < fdp->fd_nfiles; ++n) { 4492 if ((fp = fdp->fd_ofiles[n].fde_file) == NULL) 4493 continue; 4494 db_print_file(fp, header); 4495 header = 0; 4496 } 4497 } 4498 } 4499 #endif 4500 4501 SYSCTL_INT(_kern, KERN_MAXFILESPERPROC, maxfilesperproc, CTLFLAG_RW, 4502 &maxfilesperproc, 0, "Maximum files allowed open per process"); 4503 4504 SYSCTL_INT(_kern, KERN_MAXFILES, maxfiles, CTLFLAG_RW, 4505 &maxfiles, 0, "Maximum number of files"); 4506 4507 SYSCTL_INT(_kern, OID_AUTO, openfiles, CTLFLAG_RD, 4508 &openfiles, 0, "System-wide number of open files"); 4509 4510 /* ARGSUSED*/ 4511 static void 4512 filelistinit(void *dummy) 4513 { 4514 4515 file_zone = uma_zcreate("Files", sizeof(struct file), NULL, NULL, 4516 NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE); 4517 filedesc0_zone = uma_zcreate("filedesc0", sizeof(struct filedesc0), 4518 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0); 4519 pwd_zone = uma_zcreate("PWD", sizeof(struct pwd), NULL, NULL, 4520 NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_SMR); 4521 /* 4522 * XXXMJG this is a temporary hack due to boot ordering issues against 4523 * the vnode zone. 4524 */ 4525 vfs_smr = uma_zone_get_smr(pwd_zone); 4526 mtx_init(&sigio_lock, "sigio lock", NULL, MTX_DEF); 4527 } 4528 SYSINIT(select, SI_SUB_LOCK, SI_ORDER_FIRST, filelistinit, NULL); 4529 4530 /*-------------------------------------------------------------------*/ 4531 4532 static int 4533 badfo_readwrite(struct file *fp, struct uio *uio, struct ucred *active_cred, 4534 int flags, struct thread *td) 4535 { 4536 4537 return (EBADF); 4538 } 4539 4540 static int 4541 badfo_truncate(struct file *fp, off_t length, struct ucred *active_cred, 4542 struct thread *td) 4543 { 4544 4545 return (EINVAL); 4546 } 4547 4548 static int 4549 badfo_ioctl(struct file *fp, u_long com, void *data, struct ucred *active_cred, 4550 struct thread *td) 4551 { 4552 4553 return (EBADF); 4554 } 4555 4556 static int 4557 badfo_poll(struct file *fp, int events, struct ucred *active_cred, 4558 struct thread *td) 4559 { 4560 4561 return (0); 4562 } 4563 4564 static int 4565 badfo_kqfilter(struct file *fp, struct knote *kn) 4566 { 4567 4568 return (EBADF); 4569 } 4570 4571 static int 4572 badfo_stat(struct file *fp, struct stat *sb, struct ucred *active_cred, 4573 struct thread *td) 4574 { 4575 4576 return (EBADF); 4577 } 4578 4579 static int 4580 badfo_close(struct file *fp, struct thread *td) 4581 { 4582 4583 return (0); 4584 } 4585 4586 static int 4587 badfo_chmod(struct file *fp, mode_t mode, struct ucred *active_cred, 4588 struct thread *td) 4589 { 4590 4591 return (EBADF); 4592 } 4593 4594 static int 4595 badfo_chown(struct file *fp, uid_t uid, gid_t gid, struct ucred *active_cred, 4596 struct thread *td) 4597 { 4598 4599 return (EBADF); 4600 } 4601 4602 static int 4603 badfo_sendfile(struct file *fp, int sockfd, struct uio *hdr_uio, 4604 struct uio *trl_uio, off_t offset, size_t nbytes, off_t *sent, int flags, 4605 struct thread *td) 4606 { 4607 4608 return (EBADF); 4609 } 4610 4611 static int 4612 badfo_fill_kinfo(struct file *fp, struct kinfo_file *kif, struct filedesc *fdp) 4613 { 4614 4615 return (0); 4616 } 4617 4618 struct fileops badfileops = { 4619 .fo_read = badfo_readwrite, 4620 .fo_write = badfo_readwrite, 4621 .fo_truncate = badfo_truncate, 4622 .fo_ioctl = badfo_ioctl, 4623 .fo_poll = badfo_poll, 4624 .fo_kqfilter = badfo_kqfilter, 4625 .fo_stat = badfo_stat, 4626 .fo_close = badfo_close, 4627 .fo_chmod = badfo_chmod, 4628 .fo_chown = badfo_chown, 4629 .fo_sendfile = badfo_sendfile, 4630 .fo_fill_kinfo = badfo_fill_kinfo, 4631 }; 4632 4633 int 4634 invfo_rdwr(struct file *fp, struct uio *uio, struct ucred *active_cred, 4635 int flags, struct thread *td) 4636 { 4637 4638 return (EOPNOTSUPP); 4639 } 4640 4641 int 4642 invfo_truncate(struct file *fp, off_t length, struct ucred *active_cred, 4643 struct thread *td) 4644 { 4645 4646 return (EINVAL); 4647 } 4648 4649 int 4650 invfo_ioctl(struct file *fp, u_long com, void *data, 4651 struct ucred *active_cred, struct thread *td) 4652 { 4653 4654 return (ENOTTY); 4655 } 4656 4657 int 4658 invfo_poll(struct file *fp, int events, struct ucred *active_cred, 4659 struct thread *td) 4660 { 4661 4662 return (poll_no_poll(events)); 4663 } 4664 4665 int 4666 invfo_kqfilter(struct file *fp, struct knote *kn) 4667 { 4668 4669 return (EINVAL); 4670 } 4671 4672 int 4673 invfo_chmod(struct file *fp, mode_t mode, struct ucred *active_cred, 4674 struct thread *td) 4675 { 4676 4677 return (EINVAL); 4678 } 4679 4680 int 4681 invfo_chown(struct file *fp, uid_t uid, gid_t gid, struct ucred *active_cred, 4682 struct thread *td) 4683 { 4684 4685 return (EINVAL); 4686 } 4687 4688 int 4689 invfo_sendfile(struct file *fp, int sockfd, struct uio *hdr_uio, 4690 struct uio *trl_uio, off_t offset, size_t nbytes, off_t *sent, int flags, 4691 struct thread *td) 4692 { 4693 4694 return (EINVAL); 4695 } 4696 4697 /*-------------------------------------------------------------------*/ 4698 4699 /* 4700 * File Descriptor pseudo-device driver (/dev/fd/). 4701 * 4702 * Opening minor device N dup()s the file (if any) connected to file 4703 * descriptor N belonging to the calling process. Note that this driver 4704 * consists of only the ``open()'' routine, because all subsequent 4705 * references to this file will be direct to the other driver. 4706 * 4707 * XXX: we could give this one a cloning event handler if necessary. 4708 */ 4709 4710 /* ARGSUSED */ 4711 static int 4712 fdopen(struct cdev *dev, int mode, int type, struct thread *td) 4713 { 4714 4715 /* 4716 * XXX Kludge: set curthread->td_dupfd to contain the value of the 4717 * the file descriptor being sought for duplication. The error 4718 * return ensures that the vnode for this device will be released 4719 * by vn_open. Open will detect this special error and take the 4720 * actions in dupfdopen below. Other callers of vn_open or VOP_OPEN 4721 * will simply report the error. 4722 */ 4723 td->td_dupfd = dev2unit(dev); 4724 return (ENODEV); 4725 } 4726 4727 static struct cdevsw fildesc_cdevsw = { 4728 .d_version = D_VERSION, 4729 .d_open = fdopen, 4730 .d_name = "FD", 4731 }; 4732 4733 static void 4734 fildesc_drvinit(void *unused) 4735 { 4736 struct cdev *dev; 4737 4738 dev = make_dev_credf(MAKEDEV_ETERNAL, &fildesc_cdevsw, 0, NULL, 4739 UID_ROOT, GID_WHEEL, 0666, "fd/0"); 4740 make_dev_alias(dev, "stdin"); 4741 dev = make_dev_credf(MAKEDEV_ETERNAL, &fildesc_cdevsw, 1, NULL, 4742 UID_ROOT, GID_WHEEL, 0666, "fd/1"); 4743 make_dev_alias(dev, "stdout"); 4744 dev = make_dev_credf(MAKEDEV_ETERNAL, &fildesc_cdevsw, 2, NULL, 4745 UID_ROOT, GID_WHEEL, 0666, "fd/2"); 4746 make_dev_alias(dev, "stderr"); 4747 } 4748 4749 SYSINIT(fildescdev, SI_SUB_DRIVERS, SI_ORDER_MIDDLE, fildesc_drvinit, NULL); 4750