1 /*- 2 * SPDX-License-Identifier: BSD-3-Clause 3 * 4 * Copyright (c) 1982, 1986, 1989, 1991, 1993 5 * The Regents of the University of California. All rights reserved. 6 * (c) UNIX System Laboratories, Inc. 7 * All or some portions of this file are derived from material licensed 8 * to the University of California by American Telephone and Telegraph 9 * Co. or Unix System Laboratories, Inc. and are reproduced herein with 10 * the permission of UNIX System Laboratories, Inc. 11 * 12 * Redistribution and use in source and binary forms, with or without 13 * modification, are permitted provided that the following conditions 14 * are met: 15 * 1. Redistributions of source code must retain the above copyright 16 * notice, this list of conditions and the following disclaimer. 17 * 2. Redistributions in binary form must reproduce the above copyright 18 * notice, this list of conditions and the following disclaimer in the 19 * documentation and/or other materials provided with the distribution. 20 * 3. Neither the name of the University nor the names of its contributors 21 * may be used to endorse or promote products derived from this software 22 * without specific prior written permission. 23 * 24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34 * SUCH DAMAGE. 35 * 36 * @(#)kern_descrip.c 8.6 (Berkeley) 4/19/94 37 */ 38 39 #include <sys/cdefs.h> 40 __FBSDID("$FreeBSD$"); 41 42 #include "opt_capsicum.h" 43 #include "opt_ddb.h" 44 #include "opt_ktrace.h" 45 46 #include <sys/param.h> 47 #include <sys/systm.h> 48 49 #include <sys/capsicum.h> 50 #include <sys/conf.h> 51 #include <sys/fcntl.h> 52 #include <sys/file.h> 53 #include <sys/filedesc.h> 54 #include <sys/filio.h> 55 #include <sys/jail.h> 56 #include <sys/kernel.h> 57 #include <sys/limits.h> 58 #include <sys/lock.h> 59 #include <sys/malloc.h> 60 #include <sys/mount.h> 61 #include <sys/mutex.h> 62 #include <sys/namei.h> 63 #include <sys/selinfo.h> 64 #include <sys/priv.h> 65 #include <sys/proc.h> 66 #include <sys/protosw.h> 67 #include <sys/racct.h> 68 #include <sys/resourcevar.h> 69 #include <sys/sbuf.h> 70 #include <sys/signalvar.h> 71 #include <sys/kdb.h> 72 #include <sys/smr.h> 73 #include <sys/stat.h> 74 #include <sys/sx.h> 75 #include <sys/syscallsubr.h> 76 #include <sys/sysctl.h> 77 #include <sys/sysproto.h> 78 #include <sys/unistd.h> 79 #include <sys/user.h> 80 #include <sys/vnode.h> 81 #ifdef KTRACE 82 #include <sys/ktrace.h> 83 #endif 84 85 #include <net/vnet.h> 86 87 #include <security/audit/audit.h> 88 89 #include <vm/uma.h> 90 #include <vm/vm.h> 91 92 #include <ddb/ddb.h> 93 94 static MALLOC_DEFINE(M_FILEDESC, "filedesc", "Open file descriptor table"); 95 static MALLOC_DEFINE(M_PWD, "pwd", "Descriptor table vnodes"); 96 static MALLOC_DEFINE(M_FILEDESC_TO_LEADER, "filedesc_to_leader", 97 "file desc to leader structures"); 98 static MALLOC_DEFINE(M_SIGIO, "sigio", "sigio structures"); 99 MALLOC_DEFINE(M_FILECAPS, "filecaps", "descriptor capabilities"); 100 101 MALLOC_DECLARE(M_FADVISE); 102 103 static __read_mostly uma_zone_t file_zone; 104 static __read_mostly uma_zone_t filedesc0_zone; 105 static __read_mostly uma_zone_t pwd_zone; 106 static __read_mostly smr_t pwd_smr; 107 108 static int closefp(struct filedesc *fdp, int fd, struct file *fp, 109 struct thread *td, int holdleaders); 110 static int fd_first_free(struct filedesc *fdp, int low, int size); 111 static int fd_last_used(struct filedesc *fdp, int size); 112 static void fdgrowtable(struct filedesc *fdp, int nfd); 113 static void fdgrowtable_exp(struct filedesc *fdp, int nfd); 114 static void fdunused(struct filedesc *fdp, int fd); 115 static void fdused(struct filedesc *fdp, int fd); 116 static int getmaxfd(struct thread *td); 117 static u_long *filecaps_copy_prep(const struct filecaps *src); 118 static void filecaps_copy_finish(const struct filecaps *src, 119 struct filecaps *dst, u_long *ioctls); 120 static u_long *filecaps_free_prep(struct filecaps *fcaps); 121 static void filecaps_free_finish(u_long *ioctls); 122 123 static struct pwd *pwd_alloc(void); 124 125 /* 126 * Each process has: 127 * 128 * - An array of open file descriptors (fd_ofiles) 129 * - An array of file flags (fd_ofileflags) 130 * - A bitmap recording which descriptors are in use (fd_map) 131 * 132 * A process starts out with NDFILE descriptors. The value of NDFILE has 133 * been selected based the historical limit of 20 open files, and an 134 * assumption that the majority of processes, especially short-lived 135 * processes like shells, will never need more. 136 * 137 * If this initial allocation is exhausted, a larger descriptor table and 138 * map are allocated dynamically, and the pointers in the process's struct 139 * filedesc are updated to point to those. This is repeated every time 140 * the process runs out of file descriptors (provided it hasn't hit its 141 * resource limit). 142 * 143 * Since threads may hold references to individual descriptor table 144 * entries, the tables are never freed. Instead, they are placed on a 145 * linked list and freed only when the struct filedesc is released. 146 */ 147 #define NDFILE 20 148 #define NDSLOTSIZE sizeof(NDSLOTTYPE) 149 #define NDENTRIES (NDSLOTSIZE * __CHAR_BIT) 150 #define NDSLOT(x) ((x) / NDENTRIES) 151 #define NDBIT(x) ((NDSLOTTYPE)1 << ((x) % NDENTRIES)) 152 #define NDSLOTS(x) (((x) + NDENTRIES - 1) / NDENTRIES) 153 154 /* 155 * SLIST entry used to keep track of ofiles which must be reclaimed when 156 * the process exits. 157 */ 158 struct freetable { 159 struct fdescenttbl *ft_table; 160 SLIST_ENTRY(freetable) ft_next; 161 }; 162 163 /* 164 * Initial allocation: a filedesc structure + the head of SLIST used to 165 * keep track of old ofiles + enough space for NDFILE descriptors. 166 */ 167 168 struct fdescenttbl0 { 169 int fdt_nfiles; 170 struct filedescent fdt_ofiles[NDFILE]; 171 }; 172 173 struct filedesc0 { 174 struct filedesc fd_fd; 175 SLIST_HEAD(, freetable) fd_free; 176 struct fdescenttbl0 fd_dfiles; 177 NDSLOTTYPE fd_dmap[NDSLOTS(NDFILE)]; 178 }; 179 180 /* 181 * Descriptor management. 182 */ 183 static int __exclusive_cache_line openfiles; /* actual number of open files */ 184 struct mtx sigio_lock; /* mtx to protect pointers to sigio */ 185 void __read_mostly (*mq_fdclose)(struct thread *td, int fd, struct file *fp); 186 187 /* 188 * If low >= size, just return low. Otherwise find the first zero bit in the 189 * given bitmap, starting at low and not exceeding size - 1. Return size if 190 * not found. 191 */ 192 static int 193 fd_first_free(struct filedesc *fdp, int low, int size) 194 { 195 NDSLOTTYPE *map = fdp->fd_map; 196 NDSLOTTYPE mask; 197 int off, maxoff; 198 199 if (low >= size) 200 return (low); 201 202 off = NDSLOT(low); 203 if (low % NDENTRIES) { 204 mask = ~(~(NDSLOTTYPE)0 >> (NDENTRIES - (low % NDENTRIES))); 205 if ((mask &= ~map[off]) != 0UL) 206 return (off * NDENTRIES + ffsl(mask) - 1); 207 ++off; 208 } 209 for (maxoff = NDSLOTS(size); off < maxoff; ++off) 210 if (map[off] != ~0UL) 211 return (off * NDENTRIES + ffsl(~map[off]) - 1); 212 return (size); 213 } 214 215 /* 216 * Find the highest non-zero bit in the given bitmap, starting at 0 and 217 * not exceeding size - 1. Return -1 if not found. 218 */ 219 static int 220 fd_last_used(struct filedesc *fdp, int size) 221 { 222 NDSLOTTYPE *map = fdp->fd_map; 223 NDSLOTTYPE mask; 224 int off, minoff; 225 226 off = NDSLOT(size); 227 if (size % NDENTRIES) { 228 mask = ~(~(NDSLOTTYPE)0 << (size % NDENTRIES)); 229 if ((mask &= map[off]) != 0) 230 return (off * NDENTRIES + flsl(mask) - 1); 231 --off; 232 } 233 for (minoff = NDSLOT(0); off >= minoff; --off) 234 if (map[off] != 0) 235 return (off * NDENTRIES + flsl(map[off]) - 1); 236 return (-1); 237 } 238 239 static int 240 fdisused(struct filedesc *fdp, int fd) 241 { 242 243 KASSERT(fd >= 0 && fd < fdp->fd_nfiles, 244 ("file descriptor %d out of range (0, %d)", fd, fdp->fd_nfiles)); 245 246 return ((fdp->fd_map[NDSLOT(fd)] & NDBIT(fd)) != 0); 247 } 248 249 /* 250 * Mark a file descriptor as used. 251 */ 252 static void 253 fdused_init(struct filedesc *fdp, int fd) 254 { 255 256 KASSERT(!fdisused(fdp, fd), ("fd=%d is already used", fd)); 257 258 fdp->fd_map[NDSLOT(fd)] |= NDBIT(fd); 259 } 260 261 static void 262 fdused(struct filedesc *fdp, int fd) 263 { 264 265 FILEDESC_XLOCK_ASSERT(fdp); 266 267 fdused_init(fdp, fd); 268 if (fd > fdp->fd_lastfile) 269 fdp->fd_lastfile = fd; 270 if (fd == fdp->fd_freefile) 271 fdp->fd_freefile++; 272 } 273 274 /* 275 * Mark a file descriptor as unused. 276 */ 277 static void 278 fdunused(struct filedesc *fdp, int fd) 279 { 280 281 FILEDESC_XLOCK_ASSERT(fdp); 282 283 KASSERT(fdisused(fdp, fd), ("fd=%d is already unused", fd)); 284 KASSERT(fdp->fd_ofiles[fd].fde_file == NULL, 285 ("fd=%d is still in use", fd)); 286 287 fdp->fd_map[NDSLOT(fd)] &= ~NDBIT(fd); 288 if (fd < fdp->fd_freefile) 289 fdp->fd_freefile = fd; 290 if (fd == fdp->fd_lastfile) 291 fdp->fd_lastfile = fd_last_used(fdp, fd); 292 } 293 294 /* 295 * Free a file descriptor. 296 * 297 * Avoid some work if fdp is about to be destroyed. 298 */ 299 static inline void 300 fdefree_last(struct filedescent *fde) 301 { 302 303 filecaps_free(&fde->fde_caps); 304 } 305 306 static inline void 307 fdfree(struct filedesc *fdp, int fd) 308 { 309 struct filedescent *fde; 310 311 fde = &fdp->fd_ofiles[fd]; 312 #ifdef CAPABILITIES 313 seqc_write_begin(&fde->fde_seqc); 314 #endif 315 fde->fde_file = NULL; 316 #ifdef CAPABILITIES 317 seqc_write_end(&fde->fde_seqc); 318 #endif 319 fdefree_last(fde); 320 fdunused(fdp, fd); 321 } 322 323 /* 324 * System calls on descriptors. 325 */ 326 #ifndef _SYS_SYSPROTO_H_ 327 struct getdtablesize_args { 328 int dummy; 329 }; 330 #endif 331 /* ARGSUSED */ 332 int 333 sys_getdtablesize(struct thread *td, struct getdtablesize_args *uap) 334 { 335 #ifdef RACCT 336 uint64_t lim; 337 #endif 338 339 td->td_retval[0] = getmaxfd(td); 340 #ifdef RACCT 341 PROC_LOCK(td->td_proc); 342 lim = racct_get_limit(td->td_proc, RACCT_NOFILE); 343 PROC_UNLOCK(td->td_proc); 344 if (lim < td->td_retval[0]) 345 td->td_retval[0] = lim; 346 #endif 347 return (0); 348 } 349 350 /* 351 * Duplicate a file descriptor to a particular value. 352 * 353 * Note: keep in mind that a potential race condition exists when closing 354 * descriptors from a shared descriptor table (via rfork). 355 */ 356 #ifndef _SYS_SYSPROTO_H_ 357 struct dup2_args { 358 u_int from; 359 u_int to; 360 }; 361 #endif 362 /* ARGSUSED */ 363 int 364 sys_dup2(struct thread *td, struct dup2_args *uap) 365 { 366 367 return (kern_dup(td, FDDUP_FIXED, 0, (int)uap->from, (int)uap->to)); 368 } 369 370 /* 371 * Duplicate a file descriptor. 372 */ 373 #ifndef _SYS_SYSPROTO_H_ 374 struct dup_args { 375 u_int fd; 376 }; 377 #endif 378 /* ARGSUSED */ 379 int 380 sys_dup(struct thread *td, struct dup_args *uap) 381 { 382 383 return (kern_dup(td, FDDUP_NORMAL, 0, (int)uap->fd, 0)); 384 } 385 386 /* 387 * The file control system call. 388 */ 389 #ifndef _SYS_SYSPROTO_H_ 390 struct fcntl_args { 391 int fd; 392 int cmd; 393 long arg; 394 }; 395 #endif 396 /* ARGSUSED */ 397 int 398 sys_fcntl(struct thread *td, struct fcntl_args *uap) 399 { 400 401 return (kern_fcntl_freebsd(td, uap->fd, uap->cmd, uap->arg)); 402 } 403 404 int 405 kern_fcntl_freebsd(struct thread *td, int fd, int cmd, long arg) 406 { 407 struct flock fl; 408 struct __oflock ofl; 409 intptr_t arg1; 410 int error, newcmd; 411 412 error = 0; 413 newcmd = cmd; 414 switch (cmd) { 415 case F_OGETLK: 416 case F_OSETLK: 417 case F_OSETLKW: 418 /* 419 * Convert old flock structure to new. 420 */ 421 error = copyin((void *)(intptr_t)arg, &ofl, sizeof(ofl)); 422 fl.l_start = ofl.l_start; 423 fl.l_len = ofl.l_len; 424 fl.l_pid = ofl.l_pid; 425 fl.l_type = ofl.l_type; 426 fl.l_whence = ofl.l_whence; 427 fl.l_sysid = 0; 428 429 switch (cmd) { 430 case F_OGETLK: 431 newcmd = F_GETLK; 432 break; 433 case F_OSETLK: 434 newcmd = F_SETLK; 435 break; 436 case F_OSETLKW: 437 newcmd = F_SETLKW; 438 break; 439 } 440 arg1 = (intptr_t)&fl; 441 break; 442 case F_GETLK: 443 case F_SETLK: 444 case F_SETLKW: 445 case F_SETLK_REMOTE: 446 error = copyin((void *)(intptr_t)arg, &fl, sizeof(fl)); 447 arg1 = (intptr_t)&fl; 448 break; 449 default: 450 arg1 = arg; 451 break; 452 } 453 if (error) 454 return (error); 455 error = kern_fcntl(td, fd, newcmd, arg1); 456 if (error) 457 return (error); 458 if (cmd == F_OGETLK) { 459 ofl.l_start = fl.l_start; 460 ofl.l_len = fl.l_len; 461 ofl.l_pid = fl.l_pid; 462 ofl.l_type = fl.l_type; 463 ofl.l_whence = fl.l_whence; 464 error = copyout(&ofl, (void *)(intptr_t)arg, sizeof(ofl)); 465 } else if (cmd == F_GETLK) { 466 error = copyout(&fl, (void *)(intptr_t)arg, sizeof(fl)); 467 } 468 return (error); 469 } 470 471 int 472 kern_fcntl(struct thread *td, int fd, int cmd, intptr_t arg) 473 { 474 struct filedesc *fdp; 475 struct flock *flp; 476 struct file *fp, *fp2; 477 struct filedescent *fde; 478 struct proc *p; 479 struct vnode *vp; 480 struct mount *mp; 481 int error, flg, seals, tmp; 482 uint64_t bsize; 483 off_t foffset; 484 485 error = 0; 486 flg = F_POSIX; 487 p = td->td_proc; 488 fdp = p->p_fd; 489 490 AUDIT_ARG_FD(cmd); 491 AUDIT_ARG_CMD(cmd); 492 switch (cmd) { 493 case F_DUPFD: 494 tmp = arg; 495 error = kern_dup(td, FDDUP_FCNTL, 0, fd, tmp); 496 break; 497 498 case F_DUPFD_CLOEXEC: 499 tmp = arg; 500 error = kern_dup(td, FDDUP_FCNTL, FDDUP_FLAG_CLOEXEC, fd, tmp); 501 break; 502 503 case F_DUP2FD: 504 tmp = arg; 505 error = kern_dup(td, FDDUP_FIXED, 0, fd, tmp); 506 break; 507 508 case F_DUP2FD_CLOEXEC: 509 tmp = arg; 510 error = kern_dup(td, FDDUP_FIXED, FDDUP_FLAG_CLOEXEC, fd, tmp); 511 break; 512 513 case F_GETFD: 514 error = EBADF; 515 FILEDESC_SLOCK(fdp); 516 fde = fdeget_locked(fdp, fd); 517 if (fde != NULL) { 518 td->td_retval[0] = 519 (fde->fde_flags & UF_EXCLOSE) ? FD_CLOEXEC : 0; 520 error = 0; 521 } 522 FILEDESC_SUNLOCK(fdp); 523 break; 524 525 case F_SETFD: 526 error = EBADF; 527 FILEDESC_XLOCK(fdp); 528 fde = fdeget_locked(fdp, fd); 529 if (fde != NULL) { 530 fde->fde_flags = (fde->fde_flags & ~UF_EXCLOSE) | 531 (arg & FD_CLOEXEC ? UF_EXCLOSE : 0); 532 error = 0; 533 } 534 FILEDESC_XUNLOCK(fdp); 535 break; 536 537 case F_GETFL: 538 error = fget_fcntl(td, fd, &cap_fcntl_rights, F_GETFL, &fp); 539 if (error != 0) 540 break; 541 td->td_retval[0] = OFLAGS(fp->f_flag); 542 fdrop(fp, td); 543 break; 544 545 case F_SETFL: 546 error = fget_fcntl(td, fd, &cap_fcntl_rights, F_SETFL, &fp); 547 if (error != 0) 548 break; 549 do { 550 tmp = flg = fp->f_flag; 551 tmp &= ~FCNTLFLAGS; 552 tmp |= FFLAGS(arg & ~O_ACCMODE) & FCNTLFLAGS; 553 } while(atomic_cmpset_int(&fp->f_flag, flg, tmp) == 0); 554 tmp = fp->f_flag & FNONBLOCK; 555 error = fo_ioctl(fp, FIONBIO, &tmp, td->td_ucred, td); 556 if (error != 0) { 557 fdrop(fp, td); 558 break; 559 } 560 tmp = fp->f_flag & FASYNC; 561 error = fo_ioctl(fp, FIOASYNC, &tmp, td->td_ucred, td); 562 if (error == 0) { 563 fdrop(fp, td); 564 break; 565 } 566 atomic_clear_int(&fp->f_flag, FNONBLOCK); 567 tmp = 0; 568 (void)fo_ioctl(fp, FIONBIO, &tmp, td->td_ucred, td); 569 fdrop(fp, td); 570 break; 571 572 case F_GETOWN: 573 error = fget_fcntl(td, fd, &cap_fcntl_rights, F_GETOWN, &fp); 574 if (error != 0) 575 break; 576 error = fo_ioctl(fp, FIOGETOWN, &tmp, td->td_ucred, td); 577 if (error == 0) 578 td->td_retval[0] = tmp; 579 fdrop(fp, td); 580 break; 581 582 case F_SETOWN: 583 error = fget_fcntl(td, fd, &cap_fcntl_rights, F_SETOWN, &fp); 584 if (error != 0) 585 break; 586 tmp = arg; 587 error = fo_ioctl(fp, FIOSETOWN, &tmp, td->td_ucred, td); 588 fdrop(fp, td); 589 break; 590 591 case F_SETLK_REMOTE: 592 error = priv_check(td, PRIV_NFS_LOCKD); 593 if (error != 0) 594 return (error); 595 flg = F_REMOTE; 596 goto do_setlk; 597 598 case F_SETLKW: 599 flg |= F_WAIT; 600 /* FALLTHROUGH F_SETLK */ 601 602 case F_SETLK: 603 do_setlk: 604 flp = (struct flock *)arg; 605 if ((flg & F_REMOTE) != 0 && flp->l_sysid == 0) { 606 error = EINVAL; 607 break; 608 } 609 610 error = fget_unlocked(fdp, fd, &cap_flock_rights, &fp); 611 if (error != 0) 612 break; 613 if (fp->f_type != DTYPE_VNODE) { 614 error = EBADF; 615 fdrop(fp, td); 616 break; 617 } 618 619 if (flp->l_whence == SEEK_CUR) { 620 foffset = foffset_get(fp); 621 if (foffset < 0 || 622 (flp->l_start > 0 && 623 foffset > OFF_MAX - flp->l_start)) { 624 error = EOVERFLOW; 625 fdrop(fp, td); 626 break; 627 } 628 flp->l_start += foffset; 629 } 630 631 vp = fp->f_vnode; 632 switch (flp->l_type) { 633 case F_RDLCK: 634 if ((fp->f_flag & FREAD) == 0) { 635 error = EBADF; 636 break; 637 } 638 if ((p->p_leader->p_flag & P_ADVLOCK) == 0) { 639 PROC_LOCK(p->p_leader); 640 p->p_leader->p_flag |= P_ADVLOCK; 641 PROC_UNLOCK(p->p_leader); 642 } 643 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_SETLK, 644 flp, flg); 645 break; 646 case F_WRLCK: 647 if ((fp->f_flag & FWRITE) == 0) { 648 error = EBADF; 649 break; 650 } 651 if ((p->p_leader->p_flag & P_ADVLOCK) == 0) { 652 PROC_LOCK(p->p_leader); 653 p->p_leader->p_flag |= P_ADVLOCK; 654 PROC_UNLOCK(p->p_leader); 655 } 656 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_SETLK, 657 flp, flg); 658 break; 659 case F_UNLCK: 660 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_UNLCK, 661 flp, flg); 662 break; 663 case F_UNLCKSYS: 664 if (flg != F_REMOTE) { 665 error = EINVAL; 666 break; 667 } 668 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, 669 F_UNLCKSYS, flp, flg); 670 break; 671 default: 672 error = EINVAL; 673 break; 674 } 675 if (error != 0 || flp->l_type == F_UNLCK || 676 flp->l_type == F_UNLCKSYS) { 677 fdrop(fp, td); 678 break; 679 } 680 681 /* 682 * Check for a race with close. 683 * 684 * The vnode is now advisory locked (or unlocked, but this case 685 * is not really important) as the caller requested. 686 * We had to drop the filedesc lock, so we need to recheck if 687 * the descriptor is still valid, because if it was closed 688 * in the meantime we need to remove advisory lock from the 689 * vnode - close on any descriptor leading to an advisory 690 * locked vnode, removes that lock. 691 * We will return 0 on purpose in that case, as the result of 692 * successful advisory lock might have been externally visible 693 * already. This is fine - effectively we pretend to the caller 694 * that the closing thread was a bit slower and that the 695 * advisory lock succeeded before the close. 696 */ 697 error = fget_unlocked(fdp, fd, &cap_no_rights, &fp2); 698 if (error != 0) { 699 fdrop(fp, td); 700 break; 701 } 702 if (fp != fp2) { 703 flp->l_whence = SEEK_SET; 704 flp->l_start = 0; 705 flp->l_len = 0; 706 flp->l_type = F_UNLCK; 707 (void) VOP_ADVLOCK(vp, (caddr_t)p->p_leader, 708 F_UNLCK, flp, F_POSIX); 709 } 710 fdrop(fp, td); 711 fdrop(fp2, td); 712 break; 713 714 case F_GETLK: 715 error = fget_unlocked(fdp, fd, &cap_flock_rights, &fp); 716 if (error != 0) 717 break; 718 if (fp->f_type != DTYPE_VNODE) { 719 error = EBADF; 720 fdrop(fp, td); 721 break; 722 } 723 flp = (struct flock *)arg; 724 if (flp->l_type != F_RDLCK && flp->l_type != F_WRLCK && 725 flp->l_type != F_UNLCK) { 726 error = EINVAL; 727 fdrop(fp, td); 728 break; 729 } 730 if (flp->l_whence == SEEK_CUR) { 731 foffset = foffset_get(fp); 732 if ((flp->l_start > 0 && 733 foffset > OFF_MAX - flp->l_start) || 734 (flp->l_start < 0 && 735 foffset < OFF_MIN - flp->l_start)) { 736 error = EOVERFLOW; 737 fdrop(fp, td); 738 break; 739 } 740 flp->l_start += foffset; 741 } 742 vp = fp->f_vnode; 743 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_GETLK, flp, 744 F_POSIX); 745 fdrop(fp, td); 746 break; 747 748 case F_ADD_SEALS: 749 error = fget_unlocked(fdp, fd, &cap_no_rights, &fp); 750 if (error != 0) 751 break; 752 error = fo_add_seals(fp, arg); 753 fdrop(fp, td); 754 break; 755 756 case F_GET_SEALS: 757 error = fget_unlocked(fdp, fd, &cap_no_rights, &fp); 758 if (error != 0) 759 break; 760 if (fo_get_seals(fp, &seals) == 0) 761 td->td_retval[0] = seals; 762 else 763 error = EINVAL; 764 fdrop(fp, td); 765 break; 766 767 case F_RDAHEAD: 768 arg = arg ? 128 * 1024: 0; 769 /* FALLTHROUGH */ 770 case F_READAHEAD: 771 error = fget_unlocked(fdp, fd, &cap_no_rights, &fp); 772 if (error != 0) 773 break; 774 if (fp->f_type != DTYPE_VNODE) { 775 fdrop(fp, td); 776 error = EBADF; 777 break; 778 } 779 vp = fp->f_vnode; 780 if (vp->v_type != VREG) { 781 fdrop(fp, td); 782 error = ENOTTY; 783 break; 784 } 785 786 /* 787 * Exclusive lock synchronizes against f_seqcount reads and 788 * writes in sequential_heuristic(). 789 */ 790 error = vn_lock(vp, LK_EXCLUSIVE); 791 if (error != 0) { 792 fdrop(fp, td); 793 break; 794 } 795 if (arg >= 0) { 796 bsize = fp->f_vnode->v_mount->mnt_stat.f_iosize; 797 arg = MIN(arg, INT_MAX - bsize + 1); 798 fp->f_seqcount = MIN(IO_SEQMAX, 799 (arg + bsize - 1) / bsize); 800 atomic_set_int(&fp->f_flag, FRDAHEAD); 801 } else { 802 atomic_clear_int(&fp->f_flag, FRDAHEAD); 803 } 804 VOP_UNLOCK(vp); 805 fdrop(fp, td); 806 break; 807 808 case F_ISUNIONSTACK: 809 /* 810 * Check if the vnode is part of a union stack (either the 811 * "union" flag from mount(2) or unionfs). 812 * 813 * Prior to introduction of this op libc's readdir would call 814 * fstatfs(2), in effect unnecessarily copying kilobytes of 815 * data just to check fs name and a mount flag. 816 * 817 * Fixing the code to handle everything in the kernel instead 818 * is a non-trivial endeavor and has low priority, thus this 819 * horrible kludge facilitates the current behavior in a much 820 * cheaper manner until someone(tm) sorts this out. 821 */ 822 error = fget_unlocked(fdp, fd, &cap_no_rights, &fp); 823 if (error != 0) 824 break; 825 if (fp->f_type != DTYPE_VNODE) { 826 fdrop(fp, td); 827 error = EBADF; 828 break; 829 } 830 vp = fp->f_vnode; 831 /* 832 * Since we don't prevent dooming the vnode even non-null mp 833 * found can become immediately stale. This is tolerable since 834 * mount points are type-stable (providing safe memory access) 835 * and any vfs op on this vnode going forward will return an 836 * error (meaning return value in this case is meaningless). 837 */ 838 mp = atomic_load_ptr(&vp->v_mount); 839 if (__predict_false(mp == NULL)) { 840 fdrop(fp, td); 841 error = EBADF; 842 break; 843 } 844 td->td_retval[0] = 0; 845 if (mp->mnt_kern_flag & MNTK_UNIONFS || 846 mp->mnt_flag & MNT_UNION) 847 td->td_retval[0] = 1; 848 fdrop(fp, td); 849 break; 850 851 default: 852 error = EINVAL; 853 break; 854 } 855 return (error); 856 } 857 858 static int 859 getmaxfd(struct thread *td) 860 { 861 862 return (min((int)lim_cur(td, RLIMIT_NOFILE), maxfilesperproc)); 863 } 864 865 /* 866 * Common code for dup, dup2, fcntl(F_DUPFD) and fcntl(F_DUP2FD). 867 */ 868 int 869 kern_dup(struct thread *td, u_int mode, int flags, int old, int new) 870 { 871 struct filedesc *fdp; 872 struct filedescent *oldfde, *newfde; 873 struct proc *p; 874 struct file *delfp; 875 u_long *oioctls, *nioctls; 876 int error, maxfd; 877 878 p = td->td_proc; 879 fdp = p->p_fd; 880 oioctls = NULL; 881 882 MPASS((flags & ~(FDDUP_FLAG_CLOEXEC)) == 0); 883 MPASS(mode < FDDUP_LASTMODE); 884 885 AUDIT_ARG_FD(old); 886 /* XXXRW: if (flags & FDDUP_FIXED) AUDIT_ARG_FD2(new); */ 887 888 /* 889 * Verify we have a valid descriptor to dup from and possibly to 890 * dup to. Unlike dup() and dup2(), fcntl()'s F_DUPFD should 891 * return EINVAL when the new descriptor is out of bounds. 892 */ 893 if (old < 0) 894 return (EBADF); 895 if (new < 0) 896 return (mode == FDDUP_FCNTL ? EINVAL : EBADF); 897 maxfd = getmaxfd(td); 898 if (new >= maxfd) 899 return (mode == FDDUP_FCNTL ? EINVAL : EBADF); 900 901 error = EBADF; 902 FILEDESC_XLOCK(fdp); 903 if (fget_locked(fdp, old) == NULL) 904 goto unlock; 905 if ((mode == FDDUP_FIXED || mode == FDDUP_MUSTREPLACE) && old == new) { 906 td->td_retval[0] = new; 907 if (flags & FDDUP_FLAG_CLOEXEC) 908 fdp->fd_ofiles[new].fde_flags |= UF_EXCLOSE; 909 error = 0; 910 goto unlock; 911 } 912 913 oldfde = &fdp->fd_ofiles[old]; 914 if (!fhold(oldfde->fde_file)) 915 goto unlock; 916 917 /* 918 * If the caller specified a file descriptor, make sure the file 919 * table is large enough to hold it, and grab it. Otherwise, just 920 * allocate a new descriptor the usual way. 921 */ 922 switch (mode) { 923 case FDDUP_NORMAL: 924 case FDDUP_FCNTL: 925 if ((error = fdalloc(td, new, &new)) != 0) { 926 fdrop(oldfde->fde_file, td); 927 goto unlock; 928 } 929 break; 930 case FDDUP_MUSTREPLACE: 931 /* Target file descriptor must exist. */ 932 if (fget_locked(fdp, new) == NULL) { 933 fdrop(oldfde->fde_file, td); 934 goto unlock; 935 } 936 break; 937 case FDDUP_FIXED: 938 if (new >= fdp->fd_nfiles) { 939 /* 940 * The resource limits are here instead of e.g. 941 * fdalloc(), because the file descriptor table may be 942 * shared between processes, so we can't really use 943 * racct_add()/racct_sub(). Instead of counting the 944 * number of actually allocated descriptors, just put 945 * the limit on the size of the file descriptor table. 946 */ 947 #ifdef RACCT 948 if (RACCT_ENABLED()) { 949 error = racct_set_unlocked(p, RACCT_NOFILE, new + 1); 950 if (error != 0) { 951 error = EMFILE; 952 fdrop(oldfde->fde_file, td); 953 goto unlock; 954 } 955 } 956 #endif 957 fdgrowtable_exp(fdp, new + 1); 958 } 959 if (!fdisused(fdp, new)) 960 fdused(fdp, new); 961 break; 962 default: 963 KASSERT(0, ("%s unsupported mode %d", __func__, mode)); 964 } 965 966 KASSERT(old != new, ("new fd is same as old")); 967 968 newfde = &fdp->fd_ofiles[new]; 969 delfp = newfde->fde_file; 970 971 nioctls = filecaps_copy_prep(&oldfde->fde_caps); 972 973 /* 974 * Duplicate the source descriptor. 975 */ 976 #ifdef CAPABILITIES 977 seqc_write_begin(&newfde->fde_seqc); 978 #endif 979 oioctls = filecaps_free_prep(&newfde->fde_caps); 980 memcpy(newfde, oldfde, fde_change_size); 981 filecaps_copy_finish(&oldfde->fde_caps, &newfde->fde_caps, 982 nioctls); 983 if ((flags & FDDUP_FLAG_CLOEXEC) != 0) 984 newfde->fde_flags = oldfde->fde_flags | UF_EXCLOSE; 985 else 986 newfde->fde_flags = oldfde->fde_flags & ~UF_EXCLOSE; 987 #ifdef CAPABILITIES 988 seqc_write_end(&newfde->fde_seqc); 989 #endif 990 td->td_retval[0] = new; 991 992 error = 0; 993 994 if (delfp != NULL) { 995 (void) closefp(fdp, new, delfp, td, 1); 996 FILEDESC_UNLOCK_ASSERT(fdp); 997 } else { 998 unlock: 999 FILEDESC_XUNLOCK(fdp); 1000 } 1001 1002 filecaps_free_finish(oioctls); 1003 return (error); 1004 } 1005 1006 /* 1007 * If sigio is on the list associated with a process or process group, 1008 * disable signalling from the device, remove sigio from the list and 1009 * free sigio. 1010 */ 1011 void 1012 funsetown(struct sigio **sigiop) 1013 { 1014 struct sigio *sigio; 1015 1016 if (*sigiop == NULL) 1017 return; 1018 SIGIO_LOCK(); 1019 sigio = *sigiop; 1020 if (sigio == NULL) { 1021 SIGIO_UNLOCK(); 1022 return; 1023 } 1024 *(sigio->sio_myref) = NULL; 1025 if ((sigio)->sio_pgid < 0) { 1026 struct pgrp *pg = (sigio)->sio_pgrp; 1027 PGRP_LOCK(pg); 1028 SLIST_REMOVE(&sigio->sio_pgrp->pg_sigiolst, sigio, 1029 sigio, sio_pgsigio); 1030 PGRP_UNLOCK(pg); 1031 } else { 1032 struct proc *p = (sigio)->sio_proc; 1033 PROC_LOCK(p); 1034 SLIST_REMOVE(&sigio->sio_proc->p_sigiolst, sigio, 1035 sigio, sio_pgsigio); 1036 PROC_UNLOCK(p); 1037 } 1038 SIGIO_UNLOCK(); 1039 crfree(sigio->sio_ucred); 1040 free(sigio, M_SIGIO); 1041 } 1042 1043 /* 1044 * Free a list of sigio structures. 1045 * We only need to lock the SIGIO_LOCK because we have made ourselves 1046 * inaccessible to callers of fsetown and therefore do not need to lock 1047 * the proc or pgrp struct for the list manipulation. 1048 */ 1049 void 1050 funsetownlst(struct sigiolst *sigiolst) 1051 { 1052 struct proc *p; 1053 struct pgrp *pg; 1054 struct sigio *sigio; 1055 1056 sigio = SLIST_FIRST(sigiolst); 1057 if (sigio == NULL) 1058 return; 1059 p = NULL; 1060 pg = NULL; 1061 1062 /* 1063 * Every entry of the list should belong 1064 * to a single proc or pgrp. 1065 */ 1066 if (sigio->sio_pgid < 0) { 1067 pg = sigio->sio_pgrp; 1068 PGRP_LOCK_ASSERT(pg, MA_NOTOWNED); 1069 } else /* if (sigio->sio_pgid > 0) */ { 1070 p = sigio->sio_proc; 1071 PROC_LOCK_ASSERT(p, MA_NOTOWNED); 1072 } 1073 1074 SIGIO_LOCK(); 1075 while ((sigio = SLIST_FIRST(sigiolst)) != NULL) { 1076 *(sigio->sio_myref) = NULL; 1077 if (pg != NULL) { 1078 KASSERT(sigio->sio_pgid < 0, 1079 ("Proc sigio in pgrp sigio list")); 1080 KASSERT(sigio->sio_pgrp == pg, 1081 ("Bogus pgrp in sigio list")); 1082 PGRP_LOCK(pg); 1083 SLIST_REMOVE(&pg->pg_sigiolst, sigio, sigio, 1084 sio_pgsigio); 1085 PGRP_UNLOCK(pg); 1086 } else /* if (p != NULL) */ { 1087 KASSERT(sigio->sio_pgid > 0, 1088 ("Pgrp sigio in proc sigio list")); 1089 KASSERT(sigio->sio_proc == p, 1090 ("Bogus proc in sigio list")); 1091 PROC_LOCK(p); 1092 SLIST_REMOVE(&p->p_sigiolst, sigio, sigio, 1093 sio_pgsigio); 1094 PROC_UNLOCK(p); 1095 } 1096 SIGIO_UNLOCK(); 1097 crfree(sigio->sio_ucred); 1098 free(sigio, M_SIGIO); 1099 SIGIO_LOCK(); 1100 } 1101 SIGIO_UNLOCK(); 1102 } 1103 1104 /* 1105 * This is common code for FIOSETOWN ioctl called by fcntl(fd, F_SETOWN, arg). 1106 * 1107 * After permission checking, add a sigio structure to the sigio list for 1108 * the process or process group. 1109 */ 1110 int 1111 fsetown(pid_t pgid, struct sigio **sigiop) 1112 { 1113 struct proc *proc; 1114 struct pgrp *pgrp; 1115 struct sigio *sigio; 1116 int ret; 1117 1118 if (pgid == 0) { 1119 funsetown(sigiop); 1120 return (0); 1121 } 1122 1123 ret = 0; 1124 1125 /* Allocate and fill in the new sigio out of locks. */ 1126 sigio = malloc(sizeof(struct sigio), M_SIGIO, M_WAITOK); 1127 sigio->sio_pgid = pgid; 1128 sigio->sio_ucred = crhold(curthread->td_ucred); 1129 sigio->sio_myref = sigiop; 1130 1131 sx_slock(&proctree_lock); 1132 if (pgid > 0) { 1133 proc = pfind(pgid); 1134 if (proc == NULL) { 1135 ret = ESRCH; 1136 goto fail; 1137 } 1138 1139 /* 1140 * Policy - Don't allow a process to FSETOWN a process 1141 * in another session. 1142 * 1143 * Remove this test to allow maximum flexibility or 1144 * restrict FSETOWN to the current process or process 1145 * group for maximum safety. 1146 */ 1147 PROC_UNLOCK(proc); 1148 if (proc->p_session != curthread->td_proc->p_session) { 1149 ret = EPERM; 1150 goto fail; 1151 } 1152 1153 pgrp = NULL; 1154 } else /* if (pgid < 0) */ { 1155 pgrp = pgfind(-pgid); 1156 if (pgrp == NULL) { 1157 ret = ESRCH; 1158 goto fail; 1159 } 1160 PGRP_UNLOCK(pgrp); 1161 1162 /* 1163 * Policy - Don't allow a process to FSETOWN a process 1164 * in another session. 1165 * 1166 * Remove this test to allow maximum flexibility or 1167 * restrict FSETOWN to the current process or process 1168 * group for maximum safety. 1169 */ 1170 if (pgrp->pg_session != curthread->td_proc->p_session) { 1171 ret = EPERM; 1172 goto fail; 1173 } 1174 1175 proc = NULL; 1176 } 1177 funsetown(sigiop); 1178 if (pgid > 0) { 1179 PROC_LOCK(proc); 1180 /* 1181 * Since funsetownlst() is called without the proctree 1182 * locked, we need to check for P_WEXIT. 1183 * XXX: is ESRCH correct? 1184 */ 1185 if ((proc->p_flag & P_WEXIT) != 0) { 1186 PROC_UNLOCK(proc); 1187 ret = ESRCH; 1188 goto fail; 1189 } 1190 SLIST_INSERT_HEAD(&proc->p_sigiolst, sigio, sio_pgsigio); 1191 sigio->sio_proc = proc; 1192 PROC_UNLOCK(proc); 1193 } else { 1194 PGRP_LOCK(pgrp); 1195 SLIST_INSERT_HEAD(&pgrp->pg_sigiolst, sigio, sio_pgsigio); 1196 sigio->sio_pgrp = pgrp; 1197 PGRP_UNLOCK(pgrp); 1198 } 1199 sx_sunlock(&proctree_lock); 1200 SIGIO_LOCK(); 1201 *sigiop = sigio; 1202 SIGIO_UNLOCK(); 1203 return (0); 1204 1205 fail: 1206 sx_sunlock(&proctree_lock); 1207 crfree(sigio->sio_ucred); 1208 free(sigio, M_SIGIO); 1209 return (ret); 1210 } 1211 1212 /* 1213 * This is common code for FIOGETOWN ioctl called by fcntl(fd, F_GETOWN, arg). 1214 */ 1215 pid_t 1216 fgetown(struct sigio **sigiop) 1217 { 1218 pid_t pgid; 1219 1220 SIGIO_LOCK(); 1221 pgid = (*sigiop != NULL) ? (*sigiop)->sio_pgid : 0; 1222 SIGIO_UNLOCK(); 1223 return (pgid); 1224 } 1225 1226 /* 1227 * Function drops the filedesc lock on return. 1228 */ 1229 static int 1230 closefp(struct filedesc *fdp, int fd, struct file *fp, struct thread *td, 1231 int holdleaders) 1232 { 1233 int error; 1234 1235 FILEDESC_XLOCK_ASSERT(fdp); 1236 1237 if (holdleaders) { 1238 if (td->td_proc->p_fdtol != NULL) { 1239 /* 1240 * Ask fdfree() to sleep to ensure that all relevant 1241 * process leaders can be traversed in closef(). 1242 */ 1243 fdp->fd_holdleaderscount++; 1244 } else { 1245 holdleaders = 0; 1246 } 1247 } 1248 1249 /* 1250 * We now hold the fp reference that used to be owned by the 1251 * descriptor array. We have to unlock the FILEDESC *AFTER* 1252 * knote_fdclose to prevent a race of the fd getting opened, a knote 1253 * added, and deleteing a knote for the new fd. 1254 */ 1255 if (__predict_false(!TAILQ_EMPTY(&fdp->fd_kqlist))) 1256 knote_fdclose(td, fd); 1257 1258 /* 1259 * We need to notify mqueue if the object is of type mqueue. 1260 */ 1261 if (__predict_false(fp->f_type == DTYPE_MQUEUE)) 1262 mq_fdclose(td, fd, fp); 1263 FILEDESC_XUNLOCK(fdp); 1264 1265 error = closef(fp, td); 1266 if (holdleaders) { 1267 FILEDESC_XLOCK(fdp); 1268 fdp->fd_holdleaderscount--; 1269 if (fdp->fd_holdleaderscount == 0 && 1270 fdp->fd_holdleaderswakeup != 0) { 1271 fdp->fd_holdleaderswakeup = 0; 1272 wakeup(&fdp->fd_holdleaderscount); 1273 } 1274 FILEDESC_XUNLOCK(fdp); 1275 } 1276 return (error); 1277 } 1278 1279 /* 1280 * Close a file descriptor. 1281 */ 1282 #ifndef _SYS_SYSPROTO_H_ 1283 struct close_args { 1284 int fd; 1285 }; 1286 #endif 1287 /* ARGSUSED */ 1288 int 1289 sys_close(struct thread *td, struct close_args *uap) 1290 { 1291 1292 return (kern_close(td, uap->fd)); 1293 } 1294 1295 int 1296 kern_close(struct thread *td, int fd) 1297 { 1298 struct filedesc *fdp; 1299 struct file *fp; 1300 1301 fdp = td->td_proc->p_fd; 1302 1303 AUDIT_SYSCLOSE(td, fd); 1304 1305 FILEDESC_XLOCK(fdp); 1306 if ((fp = fget_locked(fdp, fd)) == NULL) { 1307 FILEDESC_XUNLOCK(fdp); 1308 return (EBADF); 1309 } 1310 fdfree(fdp, fd); 1311 1312 /* closefp() drops the FILEDESC lock for us. */ 1313 return (closefp(fdp, fd, fp, td, 1)); 1314 } 1315 1316 int 1317 kern_close_range(struct thread *td, u_int lowfd, u_int highfd) 1318 { 1319 struct filedesc *fdp; 1320 int fd, ret; 1321 1322 ret = 0; 1323 fdp = td->td_proc->p_fd; 1324 FILEDESC_SLOCK(fdp); 1325 1326 /* 1327 * Check this prior to clamping; closefrom(3) with only fd 0, 1, and 2 1328 * open should not be a usage error. From a close_range() perspective, 1329 * close_range(3, ~0U, 0) in the same scenario should also likely not 1330 * be a usage error as all fd above 3 are in-fact already closed. 1331 */ 1332 if (highfd < lowfd) { 1333 ret = EINVAL; 1334 goto out; 1335 } 1336 1337 /* 1338 * If fdp->fd_lastfile == -1, we're dealing with either a fresh file 1339 * table or one in which every fd has been closed. Just return 1340 * successful; there's nothing left to do. 1341 */ 1342 if (fdp->fd_lastfile == -1) 1343 goto out; 1344 /* Clamped to [lowfd, fd_lastfile] */ 1345 highfd = MIN(highfd, fdp->fd_lastfile); 1346 for (fd = lowfd; fd <= highfd; fd++) { 1347 if (fdp->fd_ofiles[fd].fde_file != NULL) { 1348 FILEDESC_SUNLOCK(fdp); 1349 (void)kern_close(td, fd); 1350 FILEDESC_SLOCK(fdp); 1351 } 1352 } 1353 out: 1354 FILEDESC_SUNLOCK(fdp); 1355 return (ret); 1356 } 1357 1358 #ifndef _SYS_SYSPROTO_H_ 1359 struct close_range_args { 1360 u_int lowfd; 1361 u_int highfd; 1362 int flags; 1363 }; 1364 #endif 1365 int 1366 sys_close_range(struct thread *td, struct close_range_args *uap) 1367 { 1368 1369 /* No flags currently defined */ 1370 if (uap->flags != 0) 1371 return (EINVAL); 1372 return (kern_close_range(td, uap->lowfd, uap->highfd)); 1373 } 1374 1375 #ifdef COMPAT_FREEBSD12 1376 /* 1377 * Close open file descriptors. 1378 */ 1379 #ifndef _SYS_SYSPROTO_H_ 1380 struct freebsd12_closefrom_args { 1381 int lowfd; 1382 }; 1383 #endif 1384 /* ARGSUSED */ 1385 int 1386 freebsd12_closefrom(struct thread *td, struct freebsd12_closefrom_args *uap) 1387 { 1388 u_int lowfd; 1389 1390 AUDIT_ARG_FD(uap->lowfd); 1391 1392 /* 1393 * Treat negative starting file descriptor values identical to 1394 * closefrom(0) which closes all files. 1395 */ 1396 lowfd = MAX(0, uap->lowfd); 1397 return (kern_close_range(td, lowfd, ~0U)); 1398 } 1399 #endif /* COMPAT_FREEBSD12 */ 1400 1401 #if defined(COMPAT_43) 1402 /* 1403 * Return status information about a file descriptor. 1404 */ 1405 #ifndef _SYS_SYSPROTO_H_ 1406 struct ofstat_args { 1407 int fd; 1408 struct ostat *sb; 1409 }; 1410 #endif 1411 /* ARGSUSED */ 1412 int 1413 ofstat(struct thread *td, struct ofstat_args *uap) 1414 { 1415 struct ostat oub; 1416 struct stat ub; 1417 int error; 1418 1419 error = kern_fstat(td, uap->fd, &ub); 1420 if (error == 0) { 1421 cvtstat(&ub, &oub); 1422 error = copyout(&oub, uap->sb, sizeof(oub)); 1423 } 1424 return (error); 1425 } 1426 #endif /* COMPAT_43 */ 1427 1428 #if defined(COMPAT_FREEBSD11) 1429 int 1430 freebsd11_fstat(struct thread *td, struct freebsd11_fstat_args *uap) 1431 { 1432 struct stat sb; 1433 struct freebsd11_stat osb; 1434 int error; 1435 1436 error = kern_fstat(td, uap->fd, &sb); 1437 if (error != 0) 1438 return (error); 1439 error = freebsd11_cvtstat(&sb, &osb); 1440 if (error == 0) 1441 error = copyout(&osb, uap->sb, sizeof(osb)); 1442 return (error); 1443 } 1444 #endif /* COMPAT_FREEBSD11 */ 1445 1446 /* 1447 * Return status information about a file descriptor. 1448 */ 1449 #ifndef _SYS_SYSPROTO_H_ 1450 struct fstat_args { 1451 int fd; 1452 struct stat *sb; 1453 }; 1454 #endif 1455 /* ARGSUSED */ 1456 int 1457 sys_fstat(struct thread *td, struct fstat_args *uap) 1458 { 1459 struct stat ub; 1460 int error; 1461 1462 error = kern_fstat(td, uap->fd, &ub); 1463 if (error == 0) 1464 error = copyout(&ub, uap->sb, sizeof(ub)); 1465 return (error); 1466 } 1467 1468 int 1469 kern_fstat(struct thread *td, int fd, struct stat *sbp) 1470 { 1471 struct file *fp; 1472 int error; 1473 1474 AUDIT_ARG_FD(fd); 1475 1476 error = fget(td, fd, &cap_fstat_rights, &fp); 1477 if (__predict_false(error != 0)) 1478 return (error); 1479 1480 AUDIT_ARG_FILE(td->td_proc, fp); 1481 1482 error = fo_stat(fp, sbp, td->td_ucred, td); 1483 fdrop(fp, td); 1484 #ifdef __STAT_TIME_T_EXT 1485 sbp->st_atim_ext = 0; 1486 sbp->st_mtim_ext = 0; 1487 sbp->st_ctim_ext = 0; 1488 sbp->st_btim_ext = 0; 1489 #endif 1490 #ifdef KTRACE 1491 if (KTRPOINT(td, KTR_STRUCT)) 1492 ktrstat_error(sbp, error); 1493 #endif 1494 return (error); 1495 } 1496 1497 #if defined(COMPAT_FREEBSD11) 1498 /* 1499 * Return status information about a file descriptor. 1500 */ 1501 #ifndef _SYS_SYSPROTO_H_ 1502 struct freebsd11_nfstat_args { 1503 int fd; 1504 struct nstat *sb; 1505 }; 1506 #endif 1507 /* ARGSUSED */ 1508 int 1509 freebsd11_nfstat(struct thread *td, struct freebsd11_nfstat_args *uap) 1510 { 1511 struct nstat nub; 1512 struct stat ub; 1513 int error; 1514 1515 error = kern_fstat(td, uap->fd, &ub); 1516 if (error == 0) { 1517 freebsd11_cvtnstat(&ub, &nub); 1518 error = copyout(&nub, uap->sb, sizeof(nub)); 1519 } 1520 return (error); 1521 } 1522 #endif /* COMPAT_FREEBSD11 */ 1523 1524 /* 1525 * Return pathconf information about a file descriptor. 1526 */ 1527 #ifndef _SYS_SYSPROTO_H_ 1528 struct fpathconf_args { 1529 int fd; 1530 int name; 1531 }; 1532 #endif 1533 /* ARGSUSED */ 1534 int 1535 sys_fpathconf(struct thread *td, struct fpathconf_args *uap) 1536 { 1537 long value; 1538 int error; 1539 1540 error = kern_fpathconf(td, uap->fd, uap->name, &value); 1541 if (error == 0) 1542 td->td_retval[0] = value; 1543 return (error); 1544 } 1545 1546 int 1547 kern_fpathconf(struct thread *td, int fd, int name, long *valuep) 1548 { 1549 struct file *fp; 1550 struct vnode *vp; 1551 int error; 1552 1553 error = fget(td, fd, &cap_fpathconf_rights, &fp); 1554 if (error != 0) 1555 return (error); 1556 1557 if (name == _PC_ASYNC_IO) { 1558 *valuep = _POSIX_ASYNCHRONOUS_IO; 1559 goto out; 1560 } 1561 vp = fp->f_vnode; 1562 if (vp != NULL) { 1563 vn_lock(vp, LK_SHARED | LK_RETRY); 1564 error = VOP_PATHCONF(vp, name, valuep); 1565 VOP_UNLOCK(vp); 1566 } else if (fp->f_type == DTYPE_PIPE || fp->f_type == DTYPE_SOCKET) { 1567 if (name != _PC_PIPE_BUF) { 1568 error = EINVAL; 1569 } else { 1570 *valuep = PIPE_BUF; 1571 error = 0; 1572 } 1573 } else { 1574 error = EOPNOTSUPP; 1575 } 1576 out: 1577 fdrop(fp, td); 1578 return (error); 1579 } 1580 1581 /* 1582 * Copy filecaps structure allocating memory for ioctls array if needed. 1583 * 1584 * The last parameter indicates whether the fdtable is locked. If it is not and 1585 * ioctls are encountered, copying fails and the caller must lock the table. 1586 * 1587 * Note that if the table was not locked, the caller has to check the relevant 1588 * sequence counter to determine whether the operation was successful. 1589 */ 1590 bool 1591 filecaps_copy(const struct filecaps *src, struct filecaps *dst, bool locked) 1592 { 1593 size_t size; 1594 1595 if (src->fc_ioctls != NULL && !locked) 1596 return (false); 1597 memcpy(dst, src, sizeof(*src)); 1598 if (src->fc_ioctls == NULL) 1599 return (true); 1600 1601 KASSERT(src->fc_nioctls > 0, 1602 ("fc_ioctls != NULL, but fc_nioctls=%hd", src->fc_nioctls)); 1603 1604 size = sizeof(src->fc_ioctls[0]) * src->fc_nioctls; 1605 dst->fc_ioctls = malloc(size, M_FILECAPS, M_WAITOK); 1606 memcpy(dst->fc_ioctls, src->fc_ioctls, size); 1607 return (true); 1608 } 1609 1610 static u_long * 1611 filecaps_copy_prep(const struct filecaps *src) 1612 { 1613 u_long *ioctls; 1614 size_t size; 1615 1616 if (__predict_true(src->fc_ioctls == NULL)) 1617 return (NULL); 1618 1619 KASSERT(src->fc_nioctls > 0, 1620 ("fc_ioctls != NULL, but fc_nioctls=%hd", src->fc_nioctls)); 1621 1622 size = sizeof(src->fc_ioctls[0]) * src->fc_nioctls; 1623 ioctls = malloc(size, M_FILECAPS, M_WAITOK); 1624 return (ioctls); 1625 } 1626 1627 static void 1628 filecaps_copy_finish(const struct filecaps *src, struct filecaps *dst, 1629 u_long *ioctls) 1630 { 1631 size_t size; 1632 1633 *dst = *src; 1634 if (__predict_true(src->fc_ioctls == NULL)) { 1635 MPASS(ioctls == NULL); 1636 return; 1637 } 1638 1639 size = sizeof(src->fc_ioctls[0]) * src->fc_nioctls; 1640 dst->fc_ioctls = ioctls; 1641 bcopy(src->fc_ioctls, dst->fc_ioctls, size); 1642 } 1643 1644 /* 1645 * Move filecaps structure to the new place and clear the old place. 1646 */ 1647 void 1648 filecaps_move(struct filecaps *src, struct filecaps *dst) 1649 { 1650 1651 *dst = *src; 1652 bzero(src, sizeof(*src)); 1653 } 1654 1655 /* 1656 * Fill the given filecaps structure with full rights. 1657 */ 1658 static void 1659 filecaps_fill(struct filecaps *fcaps) 1660 { 1661 1662 CAP_ALL(&fcaps->fc_rights); 1663 fcaps->fc_ioctls = NULL; 1664 fcaps->fc_nioctls = -1; 1665 fcaps->fc_fcntls = CAP_FCNTL_ALL; 1666 } 1667 1668 /* 1669 * Free memory allocated within filecaps structure. 1670 */ 1671 void 1672 filecaps_free(struct filecaps *fcaps) 1673 { 1674 1675 free(fcaps->fc_ioctls, M_FILECAPS); 1676 bzero(fcaps, sizeof(*fcaps)); 1677 } 1678 1679 static u_long * 1680 filecaps_free_prep(struct filecaps *fcaps) 1681 { 1682 u_long *ioctls; 1683 1684 ioctls = fcaps->fc_ioctls; 1685 bzero(fcaps, sizeof(*fcaps)); 1686 return (ioctls); 1687 } 1688 1689 static void 1690 filecaps_free_finish(u_long *ioctls) 1691 { 1692 1693 free(ioctls, M_FILECAPS); 1694 } 1695 1696 /* 1697 * Validate the given filecaps structure. 1698 */ 1699 static void 1700 filecaps_validate(const struct filecaps *fcaps, const char *func) 1701 { 1702 1703 KASSERT(cap_rights_is_valid(&fcaps->fc_rights), 1704 ("%s: invalid rights", func)); 1705 KASSERT((fcaps->fc_fcntls & ~CAP_FCNTL_ALL) == 0, 1706 ("%s: invalid fcntls", func)); 1707 KASSERT(fcaps->fc_fcntls == 0 || 1708 cap_rights_is_set(&fcaps->fc_rights, CAP_FCNTL), 1709 ("%s: fcntls without CAP_FCNTL", func)); 1710 KASSERT(fcaps->fc_ioctls != NULL ? fcaps->fc_nioctls > 0 : 1711 (fcaps->fc_nioctls == -1 || fcaps->fc_nioctls == 0), 1712 ("%s: invalid ioctls", func)); 1713 KASSERT(fcaps->fc_nioctls == 0 || 1714 cap_rights_is_set(&fcaps->fc_rights, CAP_IOCTL), 1715 ("%s: ioctls without CAP_IOCTL", func)); 1716 } 1717 1718 static void 1719 fdgrowtable_exp(struct filedesc *fdp, int nfd) 1720 { 1721 int nfd1; 1722 1723 FILEDESC_XLOCK_ASSERT(fdp); 1724 1725 nfd1 = fdp->fd_nfiles * 2; 1726 if (nfd1 < nfd) 1727 nfd1 = nfd; 1728 fdgrowtable(fdp, nfd1); 1729 } 1730 1731 /* 1732 * Grow the file table to accommodate (at least) nfd descriptors. 1733 */ 1734 static void 1735 fdgrowtable(struct filedesc *fdp, int nfd) 1736 { 1737 struct filedesc0 *fdp0; 1738 struct freetable *ft; 1739 struct fdescenttbl *ntable; 1740 struct fdescenttbl *otable; 1741 int nnfiles, onfiles; 1742 NDSLOTTYPE *nmap, *omap; 1743 1744 /* 1745 * If lastfile is -1 this struct filedesc was just allocated and we are 1746 * growing it to accommodate for the one we are going to copy from. There 1747 * is no need to have a lock on this one as it's not visible to anyone. 1748 */ 1749 if (fdp->fd_lastfile != -1) 1750 FILEDESC_XLOCK_ASSERT(fdp); 1751 1752 KASSERT(fdp->fd_nfiles > 0, ("zero-length file table")); 1753 1754 /* save old values */ 1755 onfiles = fdp->fd_nfiles; 1756 otable = fdp->fd_files; 1757 omap = fdp->fd_map; 1758 1759 /* compute the size of the new table */ 1760 nnfiles = NDSLOTS(nfd) * NDENTRIES; /* round up */ 1761 if (nnfiles <= onfiles) 1762 /* the table is already large enough */ 1763 return; 1764 1765 /* 1766 * Allocate a new table. We need enough space for the number of 1767 * entries, file entries themselves and the struct freetable we will use 1768 * when we decommission the table and place it on the freelist. 1769 * We place the struct freetable in the middle so we don't have 1770 * to worry about padding. 1771 */ 1772 ntable = malloc(offsetof(struct fdescenttbl, fdt_ofiles) + 1773 nnfiles * sizeof(ntable->fdt_ofiles[0]) + 1774 sizeof(struct freetable), 1775 M_FILEDESC, M_ZERO | M_WAITOK); 1776 /* copy the old data */ 1777 ntable->fdt_nfiles = nnfiles; 1778 memcpy(ntable->fdt_ofiles, otable->fdt_ofiles, 1779 onfiles * sizeof(ntable->fdt_ofiles[0])); 1780 1781 /* 1782 * Allocate a new map only if the old is not large enough. It will 1783 * grow at a slower rate than the table as it can map more 1784 * entries than the table can hold. 1785 */ 1786 if (NDSLOTS(nnfiles) > NDSLOTS(onfiles)) { 1787 nmap = malloc(NDSLOTS(nnfiles) * NDSLOTSIZE, M_FILEDESC, 1788 M_ZERO | M_WAITOK); 1789 /* copy over the old data and update the pointer */ 1790 memcpy(nmap, omap, NDSLOTS(onfiles) * sizeof(*omap)); 1791 fdp->fd_map = nmap; 1792 } 1793 1794 /* 1795 * Make sure that ntable is correctly initialized before we replace 1796 * fd_files poiner. Otherwise fget_unlocked() may see inconsistent 1797 * data. 1798 */ 1799 atomic_store_rel_ptr((volatile void *)&fdp->fd_files, (uintptr_t)ntable); 1800 1801 /* 1802 * Do not free the old file table, as some threads may still 1803 * reference entries within it. Instead, place it on a freelist 1804 * which will be processed when the struct filedesc is released. 1805 * 1806 * Note that if onfiles == NDFILE, we're dealing with the original 1807 * static allocation contained within (struct filedesc0 *)fdp, 1808 * which must not be freed. 1809 */ 1810 if (onfiles > NDFILE) { 1811 ft = (struct freetable *)&otable->fdt_ofiles[onfiles]; 1812 fdp0 = (struct filedesc0 *)fdp; 1813 ft->ft_table = otable; 1814 SLIST_INSERT_HEAD(&fdp0->fd_free, ft, ft_next); 1815 } 1816 /* 1817 * The map does not have the same possibility of threads still 1818 * holding references to it. So always free it as long as it 1819 * does not reference the original static allocation. 1820 */ 1821 if (NDSLOTS(onfiles) > NDSLOTS(NDFILE)) 1822 free(omap, M_FILEDESC); 1823 } 1824 1825 /* 1826 * Allocate a file descriptor for the process. 1827 */ 1828 int 1829 fdalloc(struct thread *td, int minfd, int *result) 1830 { 1831 struct proc *p = td->td_proc; 1832 struct filedesc *fdp = p->p_fd; 1833 int fd, maxfd, allocfd; 1834 #ifdef RACCT 1835 int error; 1836 #endif 1837 1838 FILEDESC_XLOCK_ASSERT(fdp); 1839 1840 if (fdp->fd_freefile > minfd) 1841 minfd = fdp->fd_freefile; 1842 1843 maxfd = getmaxfd(td); 1844 1845 /* 1846 * Search the bitmap for a free descriptor starting at minfd. 1847 * If none is found, grow the file table. 1848 */ 1849 fd = fd_first_free(fdp, minfd, fdp->fd_nfiles); 1850 if (fd >= maxfd) 1851 return (EMFILE); 1852 if (fd >= fdp->fd_nfiles) { 1853 allocfd = min(fd * 2, maxfd); 1854 #ifdef RACCT 1855 if (RACCT_ENABLED()) { 1856 error = racct_set_unlocked(p, RACCT_NOFILE, allocfd); 1857 if (error != 0) 1858 return (EMFILE); 1859 } 1860 #endif 1861 /* 1862 * fd is already equal to first free descriptor >= minfd, so 1863 * we only need to grow the table and we are done. 1864 */ 1865 fdgrowtable_exp(fdp, allocfd); 1866 } 1867 1868 /* 1869 * Perform some sanity checks, then mark the file descriptor as 1870 * used and return it to the caller. 1871 */ 1872 KASSERT(fd >= 0 && fd < min(maxfd, fdp->fd_nfiles), 1873 ("invalid descriptor %d", fd)); 1874 KASSERT(!fdisused(fdp, fd), 1875 ("fd_first_free() returned non-free descriptor")); 1876 KASSERT(fdp->fd_ofiles[fd].fde_file == NULL, 1877 ("file descriptor isn't free")); 1878 fdused(fdp, fd); 1879 *result = fd; 1880 return (0); 1881 } 1882 1883 /* 1884 * Allocate n file descriptors for the process. 1885 */ 1886 int 1887 fdallocn(struct thread *td, int minfd, int *fds, int n) 1888 { 1889 struct proc *p = td->td_proc; 1890 struct filedesc *fdp = p->p_fd; 1891 int i; 1892 1893 FILEDESC_XLOCK_ASSERT(fdp); 1894 1895 for (i = 0; i < n; i++) 1896 if (fdalloc(td, 0, &fds[i]) != 0) 1897 break; 1898 1899 if (i < n) { 1900 for (i--; i >= 0; i--) 1901 fdunused(fdp, fds[i]); 1902 return (EMFILE); 1903 } 1904 1905 return (0); 1906 } 1907 1908 /* 1909 * Create a new open file structure and allocate a file descriptor for the 1910 * process that refers to it. We add one reference to the file for the 1911 * descriptor table and one reference for resultfp. This is to prevent us 1912 * being preempted and the entry in the descriptor table closed after we 1913 * release the FILEDESC lock. 1914 */ 1915 int 1916 falloc_caps(struct thread *td, struct file **resultfp, int *resultfd, int flags, 1917 struct filecaps *fcaps) 1918 { 1919 struct file *fp; 1920 int error, fd; 1921 1922 error = falloc_noinstall(td, &fp); 1923 if (error) 1924 return (error); /* no reference held on error */ 1925 1926 error = finstall(td, fp, &fd, flags, fcaps); 1927 if (error) { 1928 fdrop(fp, td); /* one reference (fp only) */ 1929 return (error); 1930 } 1931 1932 if (resultfp != NULL) 1933 *resultfp = fp; /* copy out result */ 1934 else 1935 fdrop(fp, td); /* release local reference */ 1936 1937 if (resultfd != NULL) 1938 *resultfd = fd; 1939 1940 return (0); 1941 } 1942 1943 /* 1944 * Create a new open file structure without allocating a file descriptor. 1945 */ 1946 int 1947 falloc_noinstall(struct thread *td, struct file **resultfp) 1948 { 1949 struct file *fp; 1950 int maxuserfiles = maxfiles - (maxfiles / 20); 1951 int openfiles_new; 1952 static struct timeval lastfail; 1953 static int curfail; 1954 1955 KASSERT(resultfp != NULL, ("%s: resultfp == NULL", __func__)); 1956 1957 openfiles_new = atomic_fetchadd_int(&openfiles, 1) + 1; 1958 if ((openfiles_new >= maxuserfiles && 1959 priv_check(td, PRIV_MAXFILES) != 0) || 1960 openfiles_new >= maxfiles) { 1961 atomic_subtract_int(&openfiles, 1); 1962 if (ppsratecheck(&lastfail, &curfail, 1)) { 1963 printf("kern.maxfiles limit exceeded by uid %i, (%s) " 1964 "please see tuning(7).\n", td->td_ucred->cr_ruid, td->td_proc->p_comm); 1965 } 1966 return (ENFILE); 1967 } 1968 fp = uma_zalloc(file_zone, M_WAITOK); 1969 bzero(fp, sizeof(*fp)); 1970 refcount_init(&fp->f_count, 1); 1971 fp->f_cred = crhold(td->td_ucred); 1972 fp->f_ops = &badfileops; 1973 *resultfp = fp; 1974 return (0); 1975 } 1976 1977 /* 1978 * Install a file in a file descriptor table. 1979 */ 1980 void 1981 _finstall(struct filedesc *fdp, struct file *fp, int fd, int flags, 1982 struct filecaps *fcaps) 1983 { 1984 struct filedescent *fde; 1985 1986 MPASS(fp != NULL); 1987 if (fcaps != NULL) 1988 filecaps_validate(fcaps, __func__); 1989 FILEDESC_XLOCK_ASSERT(fdp); 1990 1991 fde = &fdp->fd_ofiles[fd]; 1992 #ifdef CAPABILITIES 1993 seqc_write_begin(&fde->fde_seqc); 1994 #endif 1995 fde->fde_file = fp; 1996 fde->fde_flags = (flags & O_CLOEXEC) != 0 ? UF_EXCLOSE : 0; 1997 if (fcaps != NULL) 1998 filecaps_move(fcaps, &fde->fde_caps); 1999 else 2000 filecaps_fill(&fde->fde_caps); 2001 #ifdef CAPABILITIES 2002 seqc_write_end(&fde->fde_seqc); 2003 #endif 2004 } 2005 2006 int 2007 finstall(struct thread *td, struct file *fp, int *fd, int flags, 2008 struct filecaps *fcaps) 2009 { 2010 struct filedesc *fdp = td->td_proc->p_fd; 2011 int error; 2012 2013 MPASS(fd != NULL); 2014 2015 if (!fhold(fp)) 2016 return (EBADF); 2017 FILEDESC_XLOCK(fdp); 2018 error = fdalloc(td, 0, fd); 2019 if (__predict_false(error != 0)) { 2020 FILEDESC_XUNLOCK(fdp); 2021 fdrop(fp, td); 2022 return (error); 2023 } 2024 _finstall(fdp, fp, *fd, flags, fcaps); 2025 FILEDESC_XUNLOCK(fdp); 2026 return (0); 2027 } 2028 2029 /* 2030 * Build a new filedesc structure from another. 2031 * Copy the current, root, and jail root vnode references. 2032 * 2033 * If fdp is not NULL, return with it shared locked. 2034 */ 2035 struct filedesc * 2036 fdinit(struct filedesc *fdp, bool prepfiles) 2037 { 2038 struct filedesc0 *newfdp0; 2039 struct filedesc *newfdp; 2040 struct pwd *newpwd; 2041 2042 newfdp0 = uma_zalloc(filedesc0_zone, M_WAITOK | M_ZERO); 2043 newfdp = &newfdp0->fd_fd; 2044 2045 /* Create the file descriptor table. */ 2046 FILEDESC_LOCK_INIT(newfdp); 2047 refcount_init(&newfdp->fd_refcnt, 1); 2048 refcount_init(&newfdp->fd_holdcnt, 1); 2049 newfdp->fd_cmask = CMASK; 2050 newfdp->fd_map = newfdp0->fd_dmap; 2051 newfdp->fd_lastfile = -1; 2052 newfdp->fd_files = (struct fdescenttbl *)&newfdp0->fd_dfiles; 2053 newfdp->fd_files->fdt_nfiles = NDFILE; 2054 2055 if (fdp == NULL) { 2056 newpwd = pwd_alloc(); 2057 smr_serialized_store(&newfdp->fd_pwd, newpwd, true); 2058 return (newfdp); 2059 } 2060 2061 if (prepfiles && fdp->fd_lastfile >= newfdp->fd_nfiles) 2062 fdgrowtable(newfdp, fdp->fd_lastfile + 1); 2063 2064 FILEDESC_SLOCK(fdp); 2065 newpwd = pwd_hold_filedesc(fdp); 2066 smr_serialized_store(&newfdp->fd_pwd, newpwd, true); 2067 2068 if (!prepfiles) { 2069 FILEDESC_SUNLOCK(fdp); 2070 } else { 2071 while (fdp->fd_lastfile >= newfdp->fd_nfiles) { 2072 FILEDESC_SUNLOCK(fdp); 2073 fdgrowtable(newfdp, fdp->fd_lastfile + 1); 2074 FILEDESC_SLOCK(fdp); 2075 } 2076 } 2077 2078 return (newfdp); 2079 } 2080 2081 static struct filedesc * 2082 fdhold(struct proc *p) 2083 { 2084 struct filedesc *fdp; 2085 2086 PROC_LOCK_ASSERT(p, MA_OWNED); 2087 fdp = p->p_fd; 2088 if (fdp != NULL) 2089 refcount_acquire(&fdp->fd_holdcnt); 2090 return (fdp); 2091 } 2092 2093 static void 2094 fddrop(struct filedesc *fdp) 2095 { 2096 2097 if (fdp->fd_holdcnt > 1) { 2098 if (refcount_release(&fdp->fd_holdcnt) == 0) 2099 return; 2100 } 2101 2102 FILEDESC_LOCK_DESTROY(fdp); 2103 uma_zfree(filedesc0_zone, fdp); 2104 } 2105 2106 /* 2107 * Share a filedesc structure. 2108 */ 2109 struct filedesc * 2110 fdshare(struct filedesc *fdp) 2111 { 2112 2113 refcount_acquire(&fdp->fd_refcnt); 2114 return (fdp); 2115 } 2116 2117 /* 2118 * Unshare a filedesc structure, if necessary by making a copy 2119 */ 2120 void 2121 fdunshare(struct thread *td) 2122 { 2123 struct filedesc *tmp; 2124 struct proc *p = td->td_proc; 2125 2126 if (p->p_fd->fd_refcnt == 1) 2127 return; 2128 2129 tmp = fdcopy(p->p_fd); 2130 fdescfree(td); 2131 p->p_fd = tmp; 2132 } 2133 2134 void 2135 fdinstall_remapped(struct thread *td, struct filedesc *fdp) 2136 { 2137 2138 fdescfree(td); 2139 td->td_proc->p_fd = fdp; 2140 } 2141 2142 /* 2143 * Copy a filedesc structure. A NULL pointer in returns a NULL reference, 2144 * this is to ease callers, not catch errors. 2145 */ 2146 struct filedesc * 2147 fdcopy(struct filedesc *fdp) 2148 { 2149 struct filedesc *newfdp; 2150 struct filedescent *nfde, *ofde; 2151 int i; 2152 2153 MPASS(fdp != NULL); 2154 2155 newfdp = fdinit(fdp, true); 2156 /* copy all passable descriptors (i.e. not kqueue) */ 2157 newfdp->fd_freefile = -1; 2158 for (i = 0; i <= fdp->fd_lastfile; ++i) { 2159 ofde = &fdp->fd_ofiles[i]; 2160 if (ofde->fde_file == NULL || 2161 (ofde->fde_file->f_ops->fo_flags & DFLAG_PASSABLE) == 0 || 2162 !fhold(ofde->fde_file)) { 2163 if (newfdp->fd_freefile == -1) 2164 newfdp->fd_freefile = i; 2165 continue; 2166 } 2167 nfde = &newfdp->fd_ofiles[i]; 2168 *nfde = *ofde; 2169 filecaps_copy(&ofde->fde_caps, &nfde->fde_caps, true); 2170 fdused_init(newfdp, i); 2171 newfdp->fd_lastfile = i; 2172 } 2173 if (newfdp->fd_freefile == -1) 2174 newfdp->fd_freefile = i; 2175 newfdp->fd_cmask = fdp->fd_cmask; 2176 FILEDESC_SUNLOCK(fdp); 2177 return (newfdp); 2178 } 2179 2180 /* 2181 * Copies a filedesc structure, while remapping all file descriptors 2182 * stored inside using a translation table. 2183 * 2184 * File descriptors are copied over to the new file descriptor table, 2185 * regardless of whether the close-on-exec flag is set. 2186 */ 2187 int 2188 fdcopy_remapped(struct filedesc *fdp, const int *fds, size_t nfds, 2189 struct filedesc **ret) 2190 { 2191 struct filedesc *newfdp; 2192 struct filedescent *nfde, *ofde; 2193 int error, i; 2194 2195 MPASS(fdp != NULL); 2196 2197 newfdp = fdinit(fdp, true); 2198 if (nfds > fdp->fd_lastfile + 1) { 2199 /* New table cannot be larger than the old one. */ 2200 error = E2BIG; 2201 goto bad; 2202 } 2203 /* Copy all passable descriptors (i.e. not kqueue). */ 2204 newfdp->fd_freefile = nfds; 2205 for (i = 0; i < nfds; ++i) { 2206 if (fds[i] < 0 || fds[i] > fdp->fd_lastfile) { 2207 /* File descriptor out of bounds. */ 2208 error = EBADF; 2209 goto bad; 2210 } 2211 ofde = &fdp->fd_ofiles[fds[i]]; 2212 if (ofde->fde_file == NULL) { 2213 /* Unused file descriptor. */ 2214 error = EBADF; 2215 goto bad; 2216 } 2217 if ((ofde->fde_file->f_ops->fo_flags & DFLAG_PASSABLE) == 0) { 2218 /* File descriptor cannot be passed. */ 2219 error = EINVAL; 2220 goto bad; 2221 } 2222 if (!fhold(nfde->fde_file)) { 2223 error = EBADF; 2224 goto bad; 2225 } 2226 nfde = &newfdp->fd_ofiles[i]; 2227 *nfde = *ofde; 2228 filecaps_copy(&ofde->fde_caps, &nfde->fde_caps, true); 2229 fdused_init(newfdp, i); 2230 newfdp->fd_lastfile = i; 2231 } 2232 newfdp->fd_cmask = fdp->fd_cmask; 2233 FILEDESC_SUNLOCK(fdp); 2234 *ret = newfdp; 2235 return (0); 2236 bad: 2237 FILEDESC_SUNLOCK(fdp); 2238 fdescfree_remapped(newfdp); 2239 return (error); 2240 } 2241 2242 /* 2243 * Clear POSIX style locks. This is only used when fdp looses a reference (i.e. 2244 * one of processes using it exits) and the table used to be shared. 2245 */ 2246 static void 2247 fdclearlocks(struct thread *td) 2248 { 2249 struct filedesc *fdp; 2250 struct filedesc_to_leader *fdtol; 2251 struct flock lf; 2252 struct file *fp; 2253 struct proc *p; 2254 struct vnode *vp; 2255 int i; 2256 2257 p = td->td_proc; 2258 fdp = p->p_fd; 2259 fdtol = p->p_fdtol; 2260 MPASS(fdtol != NULL); 2261 2262 FILEDESC_XLOCK(fdp); 2263 KASSERT(fdtol->fdl_refcount > 0, 2264 ("filedesc_to_refcount botch: fdl_refcount=%d", 2265 fdtol->fdl_refcount)); 2266 if (fdtol->fdl_refcount == 1 && 2267 (p->p_leader->p_flag & P_ADVLOCK) != 0) { 2268 for (i = 0; i <= fdp->fd_lastfile; i++) { 2269 fp = fdp->fd_ofiles[i].fde_file; 2270 if (fp == NULL || fp->f_type != DTYPE_VNODE || 2271 !fhold(fp)) 2272 continue; 2273 FILEDESC_XUNLOCK(fdp); 2274 lf.l_whence = SEEK_SET; 2275 lf.l_start = 0; 2276 lf.l_len = 0; 2277 lf.l_type = F_UNLCK; 2278 vp = fp->f_vnode; 2279 (void) VOP_ADVLOCK(vp, 2280 (caddr_t)p->p_leader, F_UNLCK, 2281 &lf, F_POSIX); 2282 FILEDESC_XLOCK(fdp); 2283 fdrop(fp, td); 2284 } 2285 } 2286 retry: 2287 if (fdtol->fdl_refcount == 1) { 2288 if (fdp->fd_holdleaderscount > 0 && 2289 (p->p_leader->p_flag & P_ADVLOCK) != 0) { 2290 /* 2291 * close() or kern_dup() has cleared a reference 2292 * in a shared file descriptor table. 2293 */ 2294 fdp->fd_holdleaderswakeup = 1; 2295 sx_sleep(&fdp->fd_holdleaderscount, 2296 FILEDESC_LOCK(fdp), PLOCK, "fdlhold", 0); 2297 goto retry; 2298 } 2299 if (fdtol->fdl_holdcount > 0) { 2300 /* 2301 * Ensure that fdtol->fdl_leader remains 2302 * valid in closef(). 2303 */ 2304 fdtol->fdl_wakeup = 1; 2305 sx_sleep(fdtol, FILEDESC_LOCK(fdp), PLOCK, 2306 "fdlhold", 0); 2307 goto retry; 2308 } 2309 } 2310 fdtol->fdl_refcount--; 2311 if (fdtol->fdl_refcount == 0 && 2312 fdtol->fdl_holdcount == 0) { 2313 fdtol->fdl_next->fdl_prev = fdtol->fdl_prev; 2314 fdtol->fdl_prev->fdl_next = fdtol->fdl_next; 2315 } else 2316 fdtol = NULL; 2317 p->p_fdtol = NULL; 2318 FILEDESC_XUNLOCK(fdp); 2319 if (fdtol != NULL) 2320 free(fdtol, M_FILEDESC_TO_LEADER); 2321 } 2322 2323 /* 2324 * Release a filedesc structure. 2325 */ 2326 static void 2327 fdescfree_fds(struct thread *td, struct filedesc *fdp, bool needclose) 2328 { 2329 struct filedesc0 *fdp0; 2330 struct freetable *ft, *tft; 2331 struct filedescent *fde; 2332 struct file *fp; 2333 int i; 2334 2335 for (i = 0; i <= fdp->fd_lastfile; i++) { 2336 fde = &fdp->fd_ofiles[i]; 2337 fp = fde->fde_file; 2338 if (fp != NULL) { 2339 fdefree_last(fde); 2340 if (needclose) 2341 (void) closef(fp, td); 2342 else 2343 fdrop(fp, td); 2344 } 2345 } 2346 2347 if (NDSLOTS(fdp->fd_nfiles) > NDSLOTS(NDFILE)) 2348 free(fdp->fd_map, M_FILEDESC); 2349 if (fdp->fd_nfiles > NDFILE) 2350 free(fdp->fd_files, M_FILEDESC); 2351 2352 fdp0 = (struct filedesc0 *)fdp; 2353 SLIST_FOREACH_SAFE(ft, &fdp0->fd_free, ft_next, tft) 2354 free(ft->ft_table, M_FILEDESC); 2355 2356 fddrop(fdp); 2357 } 2358 2359 void 2360 fdescfree(struct thread *td) 2361 { 2362 struct proc *p; 2363 struct filedesc *fdp; 2364 struct pwd *pwd; 2365 2366 p = td->td_proc; 2367 fdp = p->p_fd; 2368 MPASS(fdp != NULL); 2369 2370 #ifdef RACCT 2371 if (RACCT_ENABLED()) 2372 racct_set_unlocked(p, RACCT_NOFILE, 0); 2373 #endif 2374 2375 if (p->p_fdtol != NULL) 2376 fdclearlocks(td); 2377 2378 PROC_LOCK(p); 2379 p->p_fd = NULL; 2380 PROC_UNLOCK(p); 2381 2382 if (refcount_release(&fdp->fd_refcnt) == 0) 2383 return; 2384 2385 FILEDESC_XLOCK(fdp); 2386 pwd = FILEDESC_XLOCKED_LOAD_PWD(fdp); 2387 pwd_set(fdp, NULL); 2388 FILEDESC_XUNLOCK(fdp); 2389 2390 pwd_drop(pwd); 2391 2392 fdescfree_fds(td, fdp, 1); 2393 } 2394 2395 void 2396 fdescfree_remapped(struct filedesc *fdp) 2397 { 2398 2399 pwd_drop(smr_serialized_load(&fdp->fd_pwd, true)); 2400 fdescfree_fds(curthread, fdp, 0); 2401 } 2402 2403 /* 2404 * For setugid programs, we don't want to people to use that setugidness 2405 * to generate error messages which write to a file which otherwise would 2406 * otherwise be off-limits to the process. We check for filesystems where 2407 * the vnode can change out from under us after execve (like [lin]procfs). 2408 * 2409 * Since fdsetugidsafety calls this only for fd 0, 1 and 2, this check is 2410 * sufficient. We also don't check for setugidness since we know we are. 2411 */ 2412 static bool 2413 is_unsafe(struct file *fp) 2414 { 2415 struct vnode *vp; 2416 2417 if (fp->f_type != DTYPE_VNODE) 2418 return (false); 2419 2420 vp = fp->f_vnode; 2421 return ((vp->v_vflag & VV_PROCDEP) != 0); 2422 } 2423 2424 /* 2425 * Make this setguid thing safe, if at all possible. 2426 */ 2427 void 2428 fdsetugidsafety(struct thread *td) 2429 { 2430 struct filedesc *fdp; 2431 struct file *fp; 2432 int i; 2433 2434 fdp = td->td_proc->p_fd; 2435 KASSERT(fdp->fd_refcnt == 1, ("the fdtable should not be shared")); 2436 MPASS(fdp->fd_nfiles >= 3); 2437 for (i = 0; i <= 2; i++) { 2438 fp = fdp->fd_ofiles[i].fde_file; 2439 if (fp != NULL && is_unsafe(fp)) { 2440 FILEDESC_XLOCK(fdp); 2441 knote_fdclose(td, i); 2442 /* 2443 * NULL-out descriptor prior to close to avoid 2444 * a race while close blocks. 2445 */ 2446 fdfree(fdp, i); 2447 FILEDESC_XUNLOCK(fdp); 2448 (void) closef(fp, td); 2449 } 2450 } 2451 } 2452 2453 /* 2454 * If a specific file object occupies a specific file descriptor, close the 2455 * file descriptor entry and drop a reference on the file object. This is a 2456 * convenience function to handle a subsequent error in a function that calls 2457 * falloc() that handles the race that another thread might have closed the 2458 * file descriptor out from under the thread creating the file object. 2459 */ 2460 void 2461 fdclose(struct thread *td, struct file *fp, int idx) 2462 { 2463 struct filedesc *fdp = td->td_proc->p_fd; 2464 2465 FILEDESC_XLOCK(fdp); 2466 if (fdp->fd_ofiles[idx].fde_file == fp) { 2467 fdfree(fdp, idx); 2468 FILEDESC_XUNLOCK(fdp); 2469 fdrop(fp, td); 2470 } else 2471 FILEDESC_XUNLOCK(fdp); 2472 } 2473 2474 /* 2475 * Close any files on exec? 2476 */ 2477 void 2478 fdcloseexec(struct thread *td) 2479 { 2480 struct filedesc *fdp; 2481 struct filedescent *fde; 2482 struct file *fp; 2483 int i; 2484 2485 fdp = td->td_proc->p_fd; 2486 KASSERT(fdp->fd_refcnt == 1, ("the fdtable should not be shared")); 2487 for (i = 0; i <= fdp->fd_lastfile; i++) { 2488 fde = &fdp->fd_ofiles[i]; 2489 fp = fde->fde_file; 2490 if (fp != NULL && (fp->f_type == DTYPE_MQUEUE || 2491 (fde->fde_flags & UF_EXCLOSE))) { 2492 FILEDESC_XLOCK(fdp); 2493 fdfree(fdp, i); 2494 (void) closefp(fdp, i, fp, td, 0); 2495 FILEDESC_UNLOCK_ASSERT(fdp); 2496 } 2497 } 2498 } 2499 2500 /* 2501 * It is unsafe for set[ug]id processes to be started with file 2502 * descriptors 0..2 closed, as these descriptors are given implicit 2503 * significance in the Standard C library. fdcheckstd() will create a 2504 * descriptor referencing /dev/null for each of stdin, stdout, and 2505 * stderr that is not already open. 2506 */ 2507 int 2508 fdcheckstd(struct thread *td) 2509 { 2510 struct filedesc *fdp; 2511 register_t save; 2512 int i, error, devnull; 2513 2514 fdp = td->td_proc->p_fd; 2515 KASSERT(fdp->fd_refcnt == 1, ("the fdtable should not be shared")); 2516 MPASS(fdp->fd_nfiles >= 3); 2517 devnull = -1; 2518 for (i = 0; i <= 2; i++) { 2519 if (fdp->fd_ofiles[i].fde_file != NULL) 2520 continue; 2521 2522 save = td->td_retval[0]; 2523 if (devnull != -1) { 2524 error = kern_dup(td, FDDUP_FIXED, 0, devnull, i); 2525 } else { 2526 error = kern_openat(td, AT_FDCWD, "/dev/null", 2527 UIO_SYSSPACE, O_RDWR, 0); 2528 if (error == 0) { 2529 devnull = td->td_retval[0]; 2530 KASSERT(devnull == i, ("we didn't get our fd")); 2531 } 2532 } 2533 td->td_retval[0] = save; 2534 if (error != 0) 2535 return (error); 2536 } 2537 return (0); 2538 } 2539 2540 /* 2541 * Internal form of close. Decrement reference count on file structure. 2542 * Note: td may be NULL when closing a file that was being passed in a 2543 * message. 2544 */ 2545 int 2546 closef(struct file *fp, struct thread *td) 2547 { 2548 struct vnode *vp; 2549 struct flock lf; 2550 struct filedesc_to_leader *fdtol; 2551 struct filedesc *fdp; 2552 2553 /* 2554 * POSIX record locking dictates that any close releases ALL 2555 * locks owned by this process. This is handled by setting 2556 * a flag in the unlock to free ONLY locks obeying POSIX 2557 * semantics, and not to free BSD-style file locks. 2558 * If the descriptor was in a message, POSIX-style locks 2559 * aren't passed with the descriptor, and the thread pointer 2560 * will be NULL. Callers should be careful only to pass a 2561 * NULL thread pointer when there really is no owning 2562 * context that might have locks, or the locks will be 2563 * leaked. 2564 */ 2565 if (fp->f_type == DTYPE_VNODE && td != NULL) { 2566 vp = fp->f_vnode; 2567 if ((td->td_proc->p_leader->p_flag & P_ADVLOCK) != 0) { 2568 lf.l_whence = SEEK_SET; 2569 lf.l_start = 0; 2570 lf.l_len = 0; 2571 lf.l_type = F_UNLCK; 2572 (void) VOP_ADVLOCK(vp, (caddr_t)td->td_proc->p_leader, 2573 F_UNLCK, &lf, F_POSIX); 2574 } 2575 fdtol = td->td_proc->p_fdtol; 2576 if (fdtol != NULL) { 2577 /* 2578 * Handle special case where file descriptor table is 2579 * shared between multiple process leaders. 2580 */ 2581 fdp = td->td_proc->p_fd; 2582 FILEDESC_XLOCK(fdp); 2583 for (fdtol = fdtol->fdl_next; 2584 fdtol != td->td_proc->p_fdtol; 2585 fdtol = fdtol->fdl_next) { 2586 if ((fdtol->fdl_leader->p_flag & 2587 P_ADVLOCK) == 0) 2588 continue; 2589 fdtol->fdl_holdcount++; 2590 FILEDESC_XUNLOCK(fdp); 2591 lf.l_whence = SEEK_SET; 2592 lf.l_start = 0; 2593 lf.l_len = 0; 2594 lf.l_type = F_UNLCK; 2595 vp = fp->f_vnode; 2596 (void) VOP_ADVLOCK(vp, 2597 (caddr_t)fdtol->fdl_leader, F_UNLCK, &lf, 2598 F_POSIX); 2599 FILEDESC_XLOCK(fdp); 2600 fdtol->fdl_holdcount--; 2601 if (fdtol->fdl_holdcount == 0 && 2602 fdtol->fdl_wakeup != 0) { 2603 fdtol->fdl_wakeup = 0; 2604 wakeup(fdtol); 2605 } 2606 } 2607 FILEDESC_XUNLOCK(fdp); 2608 } 2609 } 2610 return (fdrop(fp, td)); 2611 } 2612 2613 /* 2614 * Initialize the file pointer with the specified properties. 2615 * 2616 * The ops are set with release semantics to be certain that the flags, type, 2617 * and data are visible when ops is. This is to prevent ops methods from being 2618 * called with bad data. 2619 */ 2620 void 2621 finit(struct file *fp, u_int flag, short type, void *data, struct fileops *ops) 2622 { 2623 fp->f_data = data; 2624 fp->f_flag = flag; 2625 fp->f_type = type; 2626 atomic_store_rel_ptr((volatile uintptr_t *)&fp->f_ops, (uintptr_t)ops); 2627 } 2628 2629 int 2630 fget_cap_locked(struct filedesc *fdp, int fd, cap_rights_t *needrightsp, 2631 struct file **fpp, struct filecaps *havecapsp) 2632 { 2633 struct filedescent *fde; 2634 int error; 2635 2636 FILEDESC_LOCK_ASSERT(fdp); 2637 2638 fde = fdeget_locked(fdp, fd); 2639 if (fde == NULL) { 2640 error = EBADF; 2641 goto out; 2642 } 2643 2644 #ifdef CAPABILITIES 2645 error = cap_check(cap_rights_fde_inline(fde), needrightsp); 2646 if (error != 0) 2647 goto out; 2648 #endif 2649 2650 if (havecapsp != NULL) 2651 filecaps_copy(&fde->fde_caps, havecapsp, true); 2652 2653 *fpp = fde->fde_file; 2654 2655 error = 0; 2656 out: 2657 return (error); 2658 } 2659 2660 int 2661 fget_cap(struct thread *td, int fd, cap_rights_t *needrightsp, 2662 struct file **fpp, struct filecaps *havecapsp) 2663 { 2664 struct filedesc *fdp = td->td_proc->p_fd; 2665 int error; 2666 #ifndef CAPABILITIES 2667 error = fget_unlocked(fdp, fd, needrightsp, fpp); 2668 if (havecapsp != NULL && error == 0) 2669 filecaps_fill(havecapsp); 2670 #else 2671 struct file *fp; 2672 seqc_t seq; 2673 2674 *fpp = NULL; 2675 for (;;) { 2676 error = fget_unlocked_seq(fdp, fd, needrightsp, &fp, &seq); 2677 if (error != 0) 2678 return (error); 2679 2680 if (havecapsp != NULL) { 2681 if (!filecaps_copy(&fdp->fd_ofiles[fd].fde_caps, 2682 havecapsp, false)) { 2683 fdrop(fp, td); 2684 goto get_locked; 2685 } 2686 } 2687 2688 if (!fd_modified(fdp, fd, seq)) 2689 break; 2690 fdrop(fp, td); 2691 } 2692 2693 *fpp = fp; 2694 return (0); 2695 2696 get_locked: 2697 FILEDESC_SLOCK(fdp); 2698 error = fget_cap_locked(fdp, fd, needrightsp, fpp, havecapsp); 2699 if (error == 0 && !fhold(*fpp)) 2700 error = EBADF; 2701 FILEDESC_SUNLOCK(fdp); 2702 #endif 2703 return (error); 2704 } 2705 2706 int 2707 fget_unlocked_seq(struct filedesc *fdp, int fd, cap_rights_t *needrightsp, 2708 struct file **fpp, seqc_t *seqp) 2709 { 2710 #ifdef CAPABILITIES 2711 const struct filedescent *fde; 2712 #endif 2713 const struct fdescenttbl *fdt; 2714 struct file *fp; 2715 #ifdef CAPABILITIES 2716 seqc_t seq; 2717 cap_rights_t haverights; 2718 int error; 2719 #endif 2720 2721 fdt = fdp->fd_files; 2722 if (__predict_false((u_int)fd >= fdt->fdt_nfiles)) 2723 return (EBADF); 2724 /* 2725 * Fetch the descriptor locklessly. We avoid fdrop() races by 2726 * never raising a refcount above 0. To accomplish this we have 2727 * to use a cmpset loop rather than an atomic_add. The descriptor 2728 * must be re-verified once we acquire a reference to be certain 2729 * that the identity is still correct and we did not lose a race 2730 * due to preemption. 2731 */ 2732 for (;;) { 2733 #ifdef CAPABILITIES 2734 seq = seqc_read(fd_seqc(fdt, fd)); 2735 fde = &fdt->fdt_ofiles[fd]; 2736 haverights = *cap_rights_fde_inline(fde); 2737 fp = fde->fde_file; 2738 if (!seqc_consistent(fd_seqc(fdt, fd), seq)) 2739 continue; 2740 #else 2741 fp = fdt->fdt_ofiles[fd].fde_file; 2742 #endif 2743 if (fp == NULL) 2744 return (EBADF); 2745 #ifdef CAPABILITIES 2746 error = cap_check_inline(&haverights, needrightsp); 2747 if (error != 0) 2748 return (error); 2749 #endif 2750 if (__predict_false(!refcount_acquire_if_not_zero(&fp->f_count))) { 2751 /* 2752 * The count was found either saturated or zero. 2753 * This re-read is not any more racy than using the 2754 * return value from fcmpset. 2755 */ 2756 if (fp->f_count != 0) 2757 return (EBADF); 2758 /* 2759 * Force a reload. Other thread could reallocate the 2760 * table before this fd was closed, so it is possible 2761 * that there is a stale fp pointer in cached version. 2762 */ 2763 fdt = atomic_load_ptr(&fdp->fd_files); 2764 continue; 2765 } 2766 /* 2767 * Use an acquire barrier to force re-reading of fdt so it is 2768 * refreshed for verification. 2769 */ 2770 atomic_thread_fence_acq(); 2771 fdt = fdp->fd_files; 2772 #ifdef CAPABILITIES 2773 if (seqc_consistent_nomb(fd_seqc(fdt, fd), seq)) 2774 #else 2775 if (fp == fdt->fdt_ofiles[fd].fde_file) 2776 #endif 2777 break; 2778 fdrop(fp, curthread); 2779 } 2780 *fpp = fp; 2781 if (seqp != NULL) { 2782 #ifdef CAPABILITIES 2783 *seqp = seq; 2784 #endif 2785 } 2786 return (0); 2787 } 2788 2789 /* 2790 * See the comments in fget_unlocked_seq for an explanation of how this works. 2791 * 2792 * This is a simplified variant which bails out to the aforementioned routine 2793 * if anything goes wrong. In practice this only happens when userspace is 2794 * racing with itself. 2795 */ 2796 int 2797 fget_unlocked(struct filedesc *fdp, int fd, cap_rights_t *needrightsp, 2798 struct file **fpp) 2799 { 2800 #ifdef CAPABILITIES 2801 const struct filedescent *fde; 2802 #endif 2803 const struct fdescenttbl *fdt; 2804 struct file *fp; 2805 #ifdef CAPABILITIES 2806 seqc_t seq; 2807 const cap_rights_t *haverights; 2808 #endif 2809 2810 fdt = fdp->fd_files; 2811 if (__predict_false((u_int)fd >= fdt->fdt_nfiles)) 2812 return (EBADF); 2813 #ifdef CAPABILITIES 2814 seq = seqc_read_any(fd_seqc(fdt, fd)); 2815 if (__predict_false(seqc_in_modify(seq))) 2816 goto out_fallback; 2817 fde = &fdt->fdt_ofiles[fd]; 2818 haverights = cap_rights_fde_inline(fde); 2819 fp = fde->fde_file; 2820 #else 2821 fp = fdt->fdt_ofiles[fd].fde_file; 2822 #endif 2823 if (__predict_false(fp == NULL)) 2824 goto out_fallback; 2825 #ifdef CAPABILITIES 2826 if (__predict_false(cap_check_inline_transient(haverights, needrightsp))) 2827 goto out_fallback; 2828 #endif 2829 if (__predict_false(!refcount_acquire_if_not_zero(&fp->f_count))) 2830 goto out_fallback; 2831 2832 /* 2833 * Use an acquire barrier to force re-reading of fdt so it is 2834 * refreshed for verification. 2835 */ 2836 atomic_thread_fence_acq(); 2837 fdt = fdp->fd_files; 2838 #ifdef CAPABILITIES 2839 if (__predict_false(!seqc_consistent_nomb(fd_seqc(fdt, fd), seq))) 2840 #else 2841 if (__predict_false(fp != fdt->fdt_ofiles[fd].fde_file)) 2842 #endif 2843 goto out_fdrop; 2844 *fpp = fp; 2845 return (0); 2846 out_fdrop: 2847 fdrop(fp, curthread); 2848 out_fallback: 2849 return (fget_unlocked_seq(fdp, fd, needrightsp, fpp, NULL)); 2850 } 2851 2852 /* 2853 * Extract the file pointer associated with the specified descriptor for the 2854 * current user process. 2855 * 2856 * If the descriptor doesn't exist or doesn't match 'flags', EBADF is 2857 * returned. 2858 * 2859 * File's rights will be checked against the capability rights mask. 2860 * 2861 * If an error occurred the non-zero error is returned and *fpp is set to 2862 * NULL. Otherwise *fpp is held and set and zero is returned. Caller is 2863 * responsible for fdrop(). 2864 */ 2865 static __inline int 2866 _fget(struct thread *td, int fd, struct file **fpp, int flags, 2867 cap_rights_t *needrightsp) 2868 { 2869 struct filedesc *fdp; 2870 struct file *fp; 2871 int error; 2872 2873 *fpp = NULL; 2874 fdp = td->td_proc->p_fd; 2875 error = fget_unlocked(fdp, fd, needrightsp, &fp); 2876 if (__predict_false(error != 0)) 2877 return (error); 2878 if (__predict_false(fp->f_ops == &badfileops)) { 2879 fdrop(fp, td); 2880 return (EBADF); 2881 } 2882 2883 /* 2884 * FREAD and FWRITE failure return EBADF as per POSIX. 2885 */ 2886 error = 0; 2887 switch (flags) { 2888 case FREAD: 2889 case FWRITE: 2890 if ((fp->f_flag & flags) == 0) 2891 error = EBADF; 2892 break; 2893 case FEXEC: 2894 if ((fp->f_flag & (FREAD | FEXEC)) == 0 || 2895 ((fp->f_flag & FWRITE) != 0)) 2896 error = EBADF; 2897 break; 2898 case 0: 2899 break; 2900 default: 2901 KASSERT(0, ("wrong flags")); 2902 } 2903 2904 if (error != 0) { 2905 fdrop(fp, td); 2906 return (error); 2907 } 2908 2909 *fpp = fp; 2910 return (0); 2911 } 2912 2913 int 2914 fget(struct thread *td, int fd, cap_rights_t *rightsp, struct file **fpp) 2915 { 2916 2917 return (_fget(td, fd, fpp, 0, rightsp)); 2918 } 2919 2920 int 2921 fget_mmap(struct thread *td, int fd, cap_rights_t *rightsp, vm_prot_t *maxprotp, 2922 struct file **fpp) 2923 { 2924 int error; 2925 #ifndef CAPABILITIES 2926 error = _fget(td, fd, fpp, 0, rightsp); 2927 if (maxprotp != NULL) 2928 *maxprotp = VM_PROT_ALL; 2929 return (error); 2930 #else 2931 cap_rights_t fdrights; 2932 struct filedesc *fdp; 2933 struct file *fp; 2934 seqc_t seq; 2935 2936 *fpp = NULL; 2937 fdp = td->td_proc->p_fd; 2938 MPASS(cap_rights_is_set(rightsp, CAP_MMAP)); 2939 for (;;) { 2940 error = fget_unlocked_seq(fdp, fd, rightsp, &fp, &seq); 2941 if (__predict_false(error != 0)) 2942 return (error); 2943 if (__predict_false(fp->f_ops == &badfileops)) { 2944 fdrop(fp, td); 2945 return (EBADF); 2946 } 2947 if (maxprotp != NULL) 2948 fdrights = *cap_rights(fdp, fd); 2949 if (!fd_modified(fdp, fd, seq)) 2950 break; 2951 fdrop(fp, td); 2952 } 2953 2954 /* 2955 * If requested, convert capability rights to access flags. 2956 */ 2957 if (maxprotp != NULL) 2958 *maxprotp = cap_rights_to_vmprot(&fdrights); 2959 *fpp = fp; 2960 return (0); 2961 #endif 2962 } 2963 2964 int 2965 fget_read(struct thread *td, int fd, cap_rights_t *rightsp, struct file **fpp) 2966 { 2967 2968 return (_fget(td, fd, fpp, FREAD, rightsp)); 2969 } 2970 2971 int 2972 fget_write(struct thread *td, int fd, cap_rights_t *rightsp, struct file **fpp) 2973 { 2974 2975 return (_fget(td, fd, fpp, FWRITE, rightsp)); 2976 } 2977 2978 int 2979 fget_fcntl(struct thread *td, int fd, cap_rights_t *rightsp, int needfcntl, 2980 struct file **fpp) 2981 { 2982 struct filedesc *fdp = td->td_proc->p_fd; 2983 #ifndef CAPABILITIES 2984 return (fget_unlocked(fdp, fd, rightsp, fpp)); 2985 #else 2986 struct file *fp; 2987 int error; 2988 seqc_t seq; 2989 2990 *fpp = NULL; 2991 MPASS(cap_rights_is_set(rightsp, CAP_FCNTL)); 2992 for (;;) { 2993 error = fget_unlocked_seq(fdp, fd, rightsp, &fp, &seq); 2994 if (error != 0) 2995 return (error); 2996 error = cap_fcntl_check(fdp, fd, needfcntl); 2997 if (!fd_modified(fdp, fd, seq)) 2998 break; 2999 fdrop(fp, td); 3000 } 3001 if (error != 0) { 3002 fdrop(fp, td); 3003 return (error); 3004 } 3005 *fpp = fp; 3006 return (0); 3007 #endif 3008 } 3009 3010 /* 3011 * Like fget() but loads the underlying vnode, or returns an error if the 3012 * descriptor does not represent a vnode. Note that pipes use vnodes but 3013 * never have VM objects. The returned vnode will be vref()'d. 3014 * 3015 * XXX: what about the unused flags ? 3016 */ 3017 static __inline int 3018 _fgetvp(struct thread *td, int fd, int flags, cap_rights_t *needrightsp, 3019 struct vnode **vpp) 3020 { 3021 struct file *fp; 3022 int error; 3023 3024 *vpp = NULL; 3025 error = _fget(td, fd, &fp, flags, needrightsp); 3026 if (error != 0) 3027 return (error); 3028 if (fp->f_vnode == NULL) { 3029 error = EINVAL; 3030 } else { 3031 *vpp = fp->f_vnode; 3032 vrefact(*vpp); 3033 } 3034 fdrop(fp, td); 3035 3036 return (error); 3037 } 3038 3039 int 3040 fgetvp(struct thread *td, int fd, cap_rights_t *rightsp, struct vnode **vpp) 3041 { 3042 3043 return (_fgetvp(td, fd, 0, rightsp, vpp)); 3044 } 3045 3046 int 3047 fgetvp_rights(struct thread *td, int fd, cap_rights_t *needrightsp, 3048 struct filecaps *havecaps, struct vnode **vpp) 3049 { 3050 struct filecaps caps; 3051 struct file *fp; 3052 int error; 3053 3054 error = fget_cap(td, fd, needrightsp, &fp, &caps); 3055 if (error != 0) 3056 return (error); 3057 if (fp->f_ops == &badfileops) { 3058 error = EBADF; 3059 goto out; 3060 } 3061 if (fp->f_vnode == NULL) { 3062 error = EINVAL; 3063 goto out; 3064 } 3065 3066 *havecaps = caps; 3067 *vpp = fp->f_vnode; 3068 vrefact(*vpp); 3069 fdrop(fp, td); 3070 3071 return (0); 3072 out: 3073 filecaps_free(&caps); 3074 fdrop(fp, td); 3075 return (error); 3076 } 3077 3078 int 3079 fgetvp_read(struct thread *td, int fd, cap_rights_t *rightsp, struct vnode **vpp) 3080 { 3081 3082 return (_fgetvp(td, fd, FREAD, rightsp, vpp)); 3083 } 3084 3085 int 3086 fgetvp_exec(struct thread *td, int fd, cap_rights_t *rightsp, struct vnode **vpp) 3087 { 3088 3089 return (_fgetvp(td, fd, FEXEC, rightsp, vpp)); 3090 } 3091 3092 #ifdef notyet 3093 int 3094 fgetvp_write(struct thread *td, int fd, cap_rights_t *rightsp, 3095 struct vnode **vpp) 3096 { 3097 3098 return (_fgetvp(td, fd, FWRITE, rightsp, vpp)); 3099 } 3100 #endif 3101 3102 /* 3103 * Handle the last reference to a file being closed. 3104 * 3105 * Without the noinline attribute clang keeps inlining the func thorough this 3106 * file when fdrop is used. 3107 */ 3108 int __noinline 3109 _fdrop(struct file *fp, struct thread *td) 3110 { 3111 int error; 3112 3113 if (fp->f_count != 0) 3114 panic("fdrop: count %d", fp->f_count); 3115 error = fo_close(fp, td); 3116 atomic_subtract_int(&openfiles, 1); 3117 crfree(fp->f_cred); 3118 free(fp->f_advice, M_FADVISE); 3119 uma_zfree(file_zone, fp); 3120 3121 return (error); 3122 } 3123 3124 /* 3125 * Apply an advisory lock on a file descriptor. 3126 * 3127 * Just attempt to get a record lock of the requested type on the entire file 3128 * (l_whence = SEEK_SET, l_start = 0, l_len = 0). 3129 */ 3130 #ifndef _SYS_SYSPROTO_H_ 3131 struct flock_args { 3132 int fd; 3133 int how; 3134 }; 3135 #endif 3136 /* ARGSUSED */ 3137 int 3138 sys_flock(struct thread *td, struct flock_args *uap) 3139 { 3140 struct file *fp; 3141 struct vnode *vp; 3142 struct flock lf; 3143 int error; 3144 3145 error = fget(td, uap->fd, &cap_flock_rights, &fp); 3146 if (error != 0) 3147 return (error); 3148 if (fp->f_type != DTYPE_VNODE) { 3149 fdrop(fp, td); 3150 return (EOPNOTSUPP); 3151 } 3152 3153 vp = fp->f_vnode; 3154 lf.l_whence = SEEK_SET; 3155 lf.l_start = 0; 3156 lf.l_len = 0; 3157 if (uap->how & LOCK_UN) { 3158 lf.l_type = F_UNLCK; 3159 atomic_clear_int(&fp->f_flag, FHASLOCK); 3160 error = VOP_ADVLOCK(vp, (caddr_t)fp, F_UNLCK, &lf, F_FLOCK); 3161 goto done2; 3162 } 3163 if (uap->how & LOCK_EX) 3164 lf.l_type = F_WRLCK; 3165 else if (uap->how & LOCK_SH) 3166 lf.l_type = F_RDLCK; 3167 else { 3168 error = EBADF; 3169 goto done2; 3170 } 3171 atomic_set_int(&fp->f_flag, FHASLOCK); 3172 error = VOP_ADVLOCK(vp, (caddr_t)fp, F_SETLK, &lf, 3173 (uap->how & LOCK_NB) ? F_FLOCK : F_FLOCK | F_WAIT); 3174 done2: 3175 fdrop(fp, td); 3176 return (error); 3177 } 3178 /* 3179 * Duplicate the specified descriptor to a free descriptor. 3180 */ 3181 int 3182 dupfdopen(struct thread *td, struct filedesc *fdp, int dfd, int mode, 3183 int openerror, int *indxp) 3184 { 3185 struct filedescent *newfde, *oldfde; 3186 struct file *fp; 3187 u_long *ioctls; 3188 int error, indx; 3189 3190 KASSERT(openerror == ENODEV || openerror == ENXIO, 3191 ("unexpected error %d in %s", openerror, __func__)); 3192 3193 /* 3194 * If the to-be-dup'd fd number is greater than the allowed number 3195 * of file descriptors, or the fd to be dup'd has already been 3196 * closed, then reject. 3197 */ 3198 FILEDESC_XLOCK(fdp); 3199 if ((fp = fget_locked(fdp, dfd)) == NULL) { 3200 FILEDESC_XUNLOCK(fdp); 3201 return (EBADF); 3202 } 3203 3204 error = fdalloc(td, 0, &indx); 3205 if (error != 0) { 3206 FILEDESC_XUNLOCK(fdp); 3207 return (error); 3208 } 3209 3210 /* 3211 * There are two cases of interest here. 3212 * 3213 * For ENODEV simply dup (dfd) to file descriptor (indx) and return. 3214 * 3215 * For ENXIO steal away the file structure from (dfd) and store it in 3216 * (indx). (dfd) is effectively closed by this operation. 3217 */ 3218 switch (openerror) { 3219 case ENODEV: 3220 /* 3221 * Check that the mode the file is being opened for is a 3222 * subset of the mode of the existing descriptor. 3223 */ 3224 if (((mode & (FREAD|FWRITE)) | fp->f_flag) != fp->f_flag) { 3225 fdunused(fdp, indx); 3226 FILEDESC_XUNLOCK(fdp); 3227 return (EACCES); 3228 } 3229 if (!fhold(fp)) { 3230 fdunused(fdp, indx); 3231 FILEDESC_XUNLOCK(fdp); 3232 return (EBADF); 3233 } 3234 newfde = &fdp->fd_ofiles[indx]; 3235 oldfde = &fdp->fd_ofiles[dfd]; 3236 ioctls = filecaps_copy_prep(&oldfde->fde_caps); 3237 #ifdef CAPABILITIES 3238 seqc_write_begin(&newfde->fde_seqc); 3239 #endif 3240 memcpy(newfde, oldfde, fde_change_size); 3241 filecaps_copy_finish(&oldfde->fde_caps, &newfde->fde_caps, 3242 ioctls); 3243 #ifdef CAPABILITIES 3244 seqc_write_end(&newfde->fde_seqc); 3245 #endif 3246 break; 3247 case ENXIO: 3248 /* 3249 * Steal away the file pointer from dfd and stuff it into indx. 3250 */ 3251 newfde = &fdp->fd_ofiles[indx]; 3252 oldfde = &fdp->fd_ofiles[dfd]; 3253 #ifdef CAPABILITIES 3254 seqc_write_begin(&newfde->fde_seqc); 3255 #endif 3256 memcpy(newfde, oldfde, fde_change_size); 3257 oldfde->fde_file = NULL; 3258 fdunused(fdp, dfd); 3259 #ifdef CAPABILITIES 3260 seqc_write_end(&newfde->fde_seqc); 3261 #endif 3262 break; 3263 } 3264 FILEDESC_XUNLOCK(fdp); 3265 *indxp = indx; 3266 return (0); 3267 } 3268 3269 /* 3270 * This sysctl determines if we will allow a process to chroot(2) if it 3271 * has a directory open: 3272 * 0: disallowed for all processes. 3273 * 1: allowed for processes that were not already chroot(2)'ed. 3274 * 2: allowed for all processes. 3275 */ 3276 3277 static int chroot_allow_open_directories = 1; 3278 3279 SYSCTL_INT(_kern, OID_AUTO, chroot_allow_open_directories, CTLFLAG_RW, 3280 &chroot_allow_open_directories, 0, 3281 "Allow a process to chroot(2) if it has a directory open"); 3282 3283 /* 3284 * Helper function for raised chroot(2) security function: Refuse if 3285 * any filedescriptors are open directories. 3286 */ 3287 static int 3288 chroot_refuse_vdir_fds(struct filedesc *fdp) 3289 { 3290 struct vnode *vp; 3291 struct file *fp; 3292 int fd; 3293 3294 FILEDESC_LOCK_ASSERT(fdp); 3295 3296 for (fd = 0; fd <= fdp->fd_lastfile; fd++) { 3297 fp = fget_locked(fdp, fd); 3298 if (fp == NULL) 3299 continue; 3300 if (fp->f_type == DTYPE_VNODE) { 3301 vp = fp->f_vnode; 3302 if (vp->v_type == VDIR) 3303 return (EPERM); 3304 } 3305 } 3306 return (0); 3307 } 3308 3309 static void 3310 pwd_fill(struct pwd *oldpwd, struct pwd *newpwd) 3311 { 3312 3313 if (newpwd->pwd_cdir == NULL && oldpwd->pwd_cdir != NULL) { 3314 vrefact(oldpwd->pwd_cdir); 3315 newpwd->pwd_cdir = oldpwd->pwd_cdir; 3316 } 3317 3318 if (newpwd->pwd_rdir == NULL && oldpwd->pwd_rdir != NULL) { 3319 vrefact(oldpwd->pwd_rdir); 3320 newpwd->pwd_rdir = oldpwd->pwd_rdir; 3321 } 3322 3323 if (newpwd->pwd_jdir == NULL && oldpwd->pwd_jdir != NULL) { 3324 vrefact(oldpwd->pwd_jdir); 3325 newpwd->pwd_jdir = oldpwd->pwd_jdir; 3326 } 3327 } 3328 3329 struct pwd * 3330 pwd_hold_filedesc(struct filedesc *fdp) 3331 { 3332 struct pwd *pwd; 3333 3334 FILEDESC_LOCK_ASSERT(fdp); 3335 pwd = FILEDESC_LOCKED_LOAD_PWD(fdp); 3336 if (pwd != NULL) 3337 refcount_acquire(&pwd->pwd_refcount); 3338 return (pwd); 3339 } 3340 3341 struct pwd * 3342 pwd_hold(struct thread *td) 3343 { 3344 struct filedesc *fdp; 3345 struct pwd *pwd; 3346 3347 fdp = td->td_proc->p_fd; 3348 3349 smr_enter(pwd_smr); 3350 for (;;) { 3351 pwd = smr_entered_load(&fdp->fd_pwd, pwd_smr); 3352 MPASS(pwd != NULL); 3353 if (refcount_acquire_if_not_zero(&pwd->pwd_refcount)) 3354 break; 3355 } 3356 smr_exit(pwd_smr); 3357 return (pwd); 3358 } 3359 3360 static struct pwd * 3361 pwd_alloc(void) 3362 { 3363 struct pwd *pwd; 3364 3365 pwd = uma_zalloc_smr(pwd_zone, M_WAITOK); 3366 bzero(pwd, sizeof(*pwd)); 3367 refcount_init(&pwd->pwd_refcount, 1); 3368 return (pwd); 3369 } 3370 3371 void 3372 pwd_drop(struct pwd *pwd) 3373 { 3374 3375 if (!refcount_release(&pwd->pwd_refcount)) 3376 return; 3377 3378 if (pwd->pwd_cdir != NULL) 3379 vrele(pwd->pwd_cdir); 3380 if (pwd->pwd_rdir != NULL) 3381 vrele(pwd->pwd_rdir); 3382 if (pwd->pwd_jdir != NULL) 3383 vrele(pwd->pwd_jdir); 3384 uma_zfree_smr(pwd_zone, pwd); 3385 } 3386 3387 /* 3388 * Common routine for kern_chroot() and jail_attach(). The caller is 3389 * responsible for invoking priv_check() and mac_vnode_check_chroot() to 3390 * authorize this operation. 3391 */ 3392 int 3393 pwd_chroot(struct thread *td, struct vnode *vp) 3394 { 3395 struct filedesc *fdp; 3396 struct pwd *newpwd, *oldpwd; 3397 int error; 3398 3399 fdp = td->td_proc->p_fd; 3400 newpwd = pwd_alloc(); 3401 FILEDESC_XLOCK(fdp); 3402 oldpwd = FILEDESC_XLOCKED_LOAD_PWD(fdp); 3403 if (chroot_allow_open_directories == 0 || 3404 (chroot_allow_open_directories == 1 && 3405 oldpwd->pwd_rdir != rootvnode)) { 3406 error = chroot_refuse_vdir_fds(fdp); 3407 if (error != 0) { 3408 FILEDESC_XUNLOCK(fdp); 3409 pwd_drop(newpwd); 3410 return (error); 3411 } 3412 } 3413 3414 vrefact(vp); 3415 newpwd->pwd_rdir = vp; 3416 if (oldpwd->pwd_jdir == NULL) { 3417 vrefact(vp); 3418 newpwd->pwd_jdir = vp; 3419 } 3420 pwd_fill(oldpwd, newpwd); 3421 pwd_set(fdp, newpwd); 3422 FILEDESC_XUNLOCK(fdp); 3423 pwd_drop(oldpwd); 3424 return (0); 3425 } 3426 3427 void 3428 pwd_chdir(struct thread *td, struct vnode *vp) 3429 { 3430 struct filedesc *fdp; 3431 struct pwd *newpwd, *oldpwd; 3432 3433 VNPASS(vp->v_usecount > 0, vp); 3434 3435 newpwd = pwd_alloc(); 3436 fdp = td->td_proc->p_fd; 3437 FILEDESC_XLOCK(fdp); 3438 oldpwd = FILEDESC_XLOCKED_LOAD_PWD(fdp); 3439 newpwd->pwd_cdir = vp; 3440 pwd_fill(oldpwd, newpwd); 3441 pwd_set(fdp, newpwd); 3442 FILEDESC_XUNLOCK(fdp); 3443 pwd_drop(oldpwd); 3444 } 3445 3446 void 3447 pwd_ensure_dirs(void) 3448 { 3449 struct filedesc *fdp; 3450 struct pwd *oldpwd, *newpwd; 3451 3452 fdp = curproc->p_fd; 3453 FILEDESC_XLOCK(fdp); 3454 oldpwd = FILEDESC_XLOCKED_LOAD_PWD(fdp); 3455 if (oldpwd->pwd_cdir != NULL && oldpwd->pwd_rdir != NULL) { 3456 FILEDESC_XUNLOCK(fdp); 3457 return; 3458 } 3459 FILEDESC_XUNLOCK(fdp); 3460 3461 newpwd = pwd_alloc(); 3462 FILEDESC_XLOCK(fdp); 3463 oldpwd = FILEDESC_XLOCKED_LOAD_PWD(fdp); 3464 pwd_fill(oldpwd, newpwd); 3465 if (newpwd->pwd_cdir == NULL) { 3466 vrefact(rootvnode); 3467 newpwd->pwd_cdir = rootvnode; 3468 } 3469 if (newpwd->pwd_rdir == NULL) { 3470 vrefact(rootvnode); 3471 newpwd->pwd_rdir = rootvnode; 3472 } 3473 pwd_set(fdp, newpwd); 3474 FILEDESC_XUNLOCK(fdp); 3475 pwd_drop(oldpwd); 3476 } 3477 3478 void 3479 pwd_set_rootvnode(void) 3480 { 3481 struct filedesc *fdp; 3482 struct pwd *oldpwd, *newpwd; 3483 3484 fdp = curproc->p_fd; 3485 3486 newpwd = pwd_alloc(); 3487 FILEDESC_XLOCK(fdp); 3488 oldpwd = FILEDESC_XLOCKED_LOAD_PWD(fdp); 3489 vrefact(rootvnode); 3490 newpwd->pwd_cdir = rootvnode; 3491 vrefact(rootvnode); 3492 newpwd->pwd_rdir = rootvnode; 3493 pwd_fill(oldpwd, newpwd); 3494 pwd_set(fdp, newpwd); 3495 FILEDESC_XUNLOCK(fdp); 3496 pwd_drop(oldpwd); 3497 } 3498 3499 /* 3500 * Scan all active processes and prisons to see if any of them have a current 3501 * or root directory of `olddp'. If so, replace them with the new mount point. 3502 */ 3503 void 3504 mountcheckdirs(struct vnode *olddp, struct vnode *newdp) 3505 { 3506 struct filedesc *fdp; 3507 struct pwd *newpwd, *oldpwd; 3508 struct prison *pr; 3509 struct proc *p; 3510 int nrele; 3511 3512 if (vrefcnt(olddp) == 1) 3513 return; 3514 nrele = 0; 3515 newpwd = pwd_alloc(); 3516 sx_slock(&allproc_lock); 3517 FOREACH_PROC_IN_SYSTEM(p) { 3518 PROC_LOCK(p); 3519 fdp = fdhold(p); 3520 PROC_UNLOCK(p); 3521 if (fdp == NULL) 3522 continue; 3523 FILEDESC_XLOCK(fdp); 3524 oldpwd = FILEDESC_XLOCKED_LOAD_PWD(fdp); 3525 if (oldpwd == NULL || 3526 (oldpwd->pwd_cdir != olddp && 3527 oldpwd->pwd_rdir != olddp && 3528 oldpwd->pwd_jdir != olddp)) { 3529 FILEDESC_XUNLOCK(fdp); 3530 fddrop(fdp); 3531 continue; 3532 } 3533 if (oldpwd->pwd_cdir == olddp) { 3534 vrefact(newdp); 3535 newpwd->pwd_cdir = newdp; 3536 } 3537 if (oldpwd->pwd_rdir == olddp) { 3538 vrefact(newdp); 3539 newpwd->pwd_rdir = newdp; 3540 } 3541 if (oldpwd->pwd_jdir == olddp) { 3542 vrefact(newdp); 3543 newpwd->pwd_jdir = newdp; 3544 } 3545 pwd_fill(oldpwd, newpwd); 3546 pwd_set(fdp, newpwd); 3547 FILEDESC_XUNLOCK(fdp); 3548 pwd_drop(oldpwd); 3549 fddrop(fdp); 3550 newpwd = pwd_alloc(); 3551 } 3552 sx_sunlock(&allproc_lock); 3553 pwd_drop(newpwd); 3554 if (rootvnode == olddp) { 3555 vrefact(newdp); 3556 rootvnode = newdp; 3557 nrele++; 3558 } 3559 mtx_lock(&prison0.pr_mtx); 3560 if (prison0.pr_root == olddp) { 3561 vrefact(newdp); 3562 prison0.pr_root = newdp; 3563 nrele++; 3564 } 3565 mtx_unlock(&prison0.pr_mtx); 3566 sx_slock(&allprison_lock); 3567 TAILQ_FOREACH(pr, &allprison, pr_list) { 3568 mtx_lock(&pr->pr_mtx); 3569 if (pr->pr_root == olddp) { 3570 vrefact(newdp); 3571 pr->pr_root = newdp; 3572 nrele++; 3573 } 3574 mtx_unlock(&pr->pr_mtx); 3575 } 3576 sx_sunlock(&allprison_lock); 3577 while (nrele--) 3578 vrele(olddp); 3579 } 3580 3581 struct filedesc_to_leader * 3582 filedesc_to_leader_alloc(struct filedesc_to_leader *old, struct filedesc *fdp, struct proc *leader) 3583 { 3584 struct filedesc_to_leader *fdtol; 3585 3586 fdtol = malloc(sizeof(struct filedesc_to_leader), 3587 M_FILEDESC_TO_LEADER, M_WAITOK); 3588 fdtol->fdl_refcount = 1; 3589 fdtol->fdl_holdcount = 0; 3590 fdtol->fdl_wakeup = 0; 3591 fdtol->fdl_leader = leader; 3592 if (old != NULL) { 3593 FILEDESC_XLOCK(fdp); 3594 fdtol->fdl_next = old->fdl_next; 3595 fdtol->fdl_prev = old; 3596 old->fdl_next = fdtol; 3597 fdtol->fdl_next->fdl_prev = fdtol; 3598 FILEDESC_XUNLOCK(fdp); 3599 } else { 3600 fdtol->fdl_next = fdtol; 3601 fdtol->fdl_prev = fdtol; 3602 } 3603 return (fdtol); 3604 } 3605 3606 static int 3607 sysctl_kern_proc_nfds(SYSCTL_HANDLER_ARGS) 3608 { 3609 struct filedesc *fdp; 3610 int i, count, slots; 3611 3612 if (*(int *)arg1 != 0) 3613 return (EINVAL); 3614 3615 fdp = curproc->p_fd; 3616 count = 0; 3617 FILEDESC_SLOCK(fdp); 3618 slots = NDSLOTS(fdp->fd_lastfile + 1); 3619 for (i = 0; i < slots; i++) 3620 count += bitcountl(fdp->fd_map[i]); 3621 FILEDESC_SUNLOCK(fdp); 3622 3623 return (SYSCTL_OUT(req, &count, sizeof(count))); 3624 } 3625 3626 static SYSCTL_NODE(_kern_proc, KERN_PROC_NFDS, nfds, 3627 CTLFLAG_RD|CTLFLAG_CAPRD|CTLFLAG_MPSAFE, sysctl_kern_proc_nfds, 3628 "Number of open file descriptors"); 3629 3630 /* 3631 * Get file structures globally. 3632 */ 3633 static int 3634 sysctl_kern_file(SYSCTL_HANDLER_ARGS) 3635 { 3636 struct xfile xf; 3637 struct filedesc *fdp; 3638 struct file *fp; 3639 struct proc *p; 3640 int error, n; 3641 3642 error = sysctl_wire_old_buffer(req, 0); 3643 if (error != 0) 3644 return (error); 3645 if (req->oldptr == NULL) { 3646 n = 0; 3647 sx_slock(&allproc_lock); 3648 FOREACH_PROC_IN_SYSTEM(p) { 3649 PROC_LOCK(p); 3650 if (p->p_state == PRS_NEW) { 3651 PROC_UNLOCK(p); 3652 continue; 3653 } 3654 fdp = fdhold(p); 3655 PROC_UNLOCK(p); 3656 if (fdp == NULL) 3657 continue; 3658 /* overestimates sparse tables. */ 3659 if (fdp->fd_lastfile > 0) 3660 n += fdp->fd_lastfile; 3661 fddrop(fdp); 3662 } 3663 sx_sunlock(&allproc_lock); 3664 return (SYSCTL_OUT(req, 0, n * sizeof(xf))); 3665 } 3666 error = 0; 3667 bzero(&xf, sizeof(xf)); 3668 xf.xf_size = sizeof(xf); 3669 sx_slock(&allproc_lock); 3670 FOREACH_PROC_IN_SYSTEM(p) { 3671 PROC_LOCK(p); 3672 if (p->p_state == PRS_NEW) { 3673 PROC_UNLOCK(p); 3674 continue; 3675 } 3676 if (p_cansee(req->td, p) != 0) { 3677 PROC_UNLOCK(p); 3678 continue; 3679 } 3680 xf.xf_pid = p->p_pid; 3681 xf.xf_uid = p->p_ucred->cr_uid; 3682 fdp = fdhold(p); 3683 PROC_UNLOCK(p); 3684 if (fdp == NULL) 3685 continue; 3686 FILEDESC_SLOCK(fdp); 3687 for (n = 0; fdp->fd_refcnt > 0 && n <= fdp->fd_lastfile; ++n) { 3688 if ((fp = fdp->fd_ofiles[n].fde_file) == NULL) 3689 continue; 3690 xf.xf_fd = n; 3691 xf.xf_file = (uintptr_t)fp; 3692 xf.xf_data = (uintptr_t)fp->f_data; 3693 xf.xf_vnode = (uintptr_t)fp->f_vnode; 3694 xf.xf_type = (uintptr_t)fp->f_type; 3695 xf.xf_count = fp->f_count; 3696 xf.xf_msgcount = 0; 3697 xf.xf_offset = foffset_get(fp); 3698 xf.xf_flag = fp->f_flag; 3699 error = SYSCTL_OUT(req, &xf, sizeof(xf)); 3700 if (error) 3701 break; 3702 } 3703 FILEDESC_SUNLOCK(fdp); 3704 fddrop(fdp); 3705 if (error) 3706 break; 3707 } 3708 sx_sunlock(&allproc_lock); 3709 return (error); 3710 } 3711 3712 SYSCTL_PROC(_kern, KERN_FILE, file, CTLTYPE_OPAQUE|CTLFLAG_RD|CTLFLAG_MPSAFE, 3713 0, 0, sysctl_kern_file, "S,xfile", "Entire file table"); 3714 3715 #ifdef KINFO_FILE_SIZE 3716 CTASSERT(sizeof(struct kinfo_file) == KINFO_FILE_SIZE); 3717 #endif 3718 3719 static int 3720 xlate_fflags(int fflags) 3721 { 3722 static const struct { 3723 int fflag; 3724 int kf_fflag; 3725 } fflags_table[] = { 3726 { FAPPEND, KF_FLAG_APPEND }, 3727 { FASYNC, KF_FLAG_ASYNC }, 3728 { FFSYNC, KF_FLAG_FSYNC }, 3729 { FHASLOCK, KF_FLAG_HASLOCK }, 3730 { FNONBLOCK, KF_FLAG_NONBLOCK }, 3731 { FREAD, KF_FLAG_READ }, 3732 { FWRITE, KF_FLAG_WRITE }, 3733 { O_CREAT, KF_FLAG_CREAT }, 3734 { O_DIRECT, KF_FLAG_DIRECT }, 3735 { O_EXCL, KF_FLAG_EXCL }, 3736 { O_EXEC, KF_FLAG_EXEC }, 3737 { O_EXLOCK, KF_FLAG_EXLOCK }, 3738 { O_NOFOLLOW, KF_FLAG_NOFOLLOW }, 3739 { O_SHLOCK, KF_FLAG_SHLOCK }, 3740 { O_TRUNC, KF_FLAG_TRUNC } 3741 }; 3742 unsigned int i; 3743 int kflags; 3744 3745 kflags = 0; 3746 for (i = 0; i < nitems(fflags_table); i++) 3747 if (fflags & fflags_table[i].fflag) 3748 kflags |= fflags_table[i].kf_fflag; 3749 return (kflags); 3750 } 3751 3752 /* Trim unused data from kf_path by truncating the structure size. */ 3753 void 3754 pack_kinfo(struct kinfo_file *kif) 3755 { 3756 3757 kif->kf_structsize = offsetof(struct kinfo_file, kf_path) + 3758 strlen(kif->kf_path) + 1; 3759 kif->kf_structsize = roundup(kif->kf_structsize, sizeof(uint64_t)); 3760 } 3761 3762 static void 3763 export_file_to_kinfo(struct file *fp, int fd, cap_rights_t *rightsp, 3764 struct kinfo_file *kif, struct filedesc *fdp, int flags) 3765 { 3766 int error; 3767 3768 bzero(kif, sizeof(*kif)); 3769 3770 /* Set a default type to allow for empty fill_kinfo() methods. */ 3771 kif->kf_type = KF_TYPE_UNKNOWN; 3772 kif->kf_flags = xlate_fflags(fp->f_flag); 3773 if (rightsp != NULL) 3774 kif->kf_cap_rights = *rightsp; 3775 else 3776 cap_rights_init_zero(&kif->kf_cap_rights); 3777 kif->kf_fd = fd; 3778 kif->kf_ref_count = fp->f_count; 3779 kif->kf_offset = foffset_get(fp); 3780 3781 /* 3782 * This may drop the filedesc lock, so the 'fp' cannot be 3783 * accessed after this call. 3784 */ 3785 error = fo_fill_kinfo(fp, kif, fdp); 3786 if (error == 0) 3787 kif->kf_status |= KF_ATTR_VALID; 3788 if ((flags & KERN_FILEDESC_PACK_KINFO) != 0) 3789 pack_kinfo(kif); 3790 else 3791 kif->kf_structsize = roundup2(sizeof(*kif), sizeof(uint64_t)); 3792 } 3793 3794 static void 3795 export_vnode_to_kinfo(struct vnode *vp, int fd, int fflags, 3796 struct kinfo_file *kif, int flags) 3797 { 3798 int error; 3799 3800 bzero(kif, sizeof(*kif)); 3801 3802 kif->kf_type = KF_TYPE_VNODE; 3803 error = vn_fill_kinfo_vnode(vp, kif); 3804 if (error == 0) 3805 kif->kf_status |= KF_ATTR_VALID; 3806 kif->kf_flags = xlate_fflags(fflags); 3807 cap_rights_init_zero(&kif->kf_cap_rights); 3808 kif->kf_fd = fd; 3809 kif->kf_ref_count = -1; 3810 kif->kf_offset = -1; 3811 if ((flags & KERN_FILEDESC_PACK_KINFO) != 0) 3812 pack_kinfo(kif); 3813 else 3814 kif->kf_structsize = roundup2(sizeof(*kif), sizeof(uint64_t)); 3815 vrele(vp); 3816 } 3817 3818 struct export_fd_buf { 3819 struct filedesc *fdp; 3820 struct sbuf *sb; 3821 ssize_t remainder; 3822 struct kinfo_file kif; 3823 int flags; 3824 }; 3825 3826 static int 3827 export_kinfo_to_sb(struct export_fd_buf *efbuf) 3828 { 3829 struct kinfo_file *kif; 3830 3831 kif = &efbuf->kif; 3832 if (efbuf->remainder != -1) { 3833 if (efbuf->remainder < kif->kf_structsize) { 3834 /* Terminate export. */ 3835 efbuf->remainder = 0; 3836 return (0); 3837 } 3838 efbuf->remainder -= kif->kf_structsize; 3839 } 3840 return (sbuf_bcat(efbuf->sb, kif, kif->kf_structsize) == 0 ? 0 : ENOMEM); 3841 } 3842 3843 static int 3844 export_file_to_sb(struct file *fp, int fd, cap_rights_t *rightsp, 3845 struct export_fd_buf *efbuf) 3846 { 3847 int error; 3848 3849 if (efbuf->remainder == 0) 3850 return (0); 3851 export_file_to_kinfo(fp, fd, rightsp, &efbuf->kif, efbuf->fdp, 3852 efbuf->flags); 3853 FILEDESC_SUNLOCK(efbuf->fdp); 3854 error = export_kinfo_to_sb(efbuf); 3855 FILEDESC_SLOCK(efbuf->fdp); 3856 return (error); 3857 } 3858 3859 static int 3860 export_vnode_to_sb(struct vnode *vp, int fd, int fflags, 3861 struct export_fd_buf *efbuf) 3862 { 3863 int error; 3864 3865 if (efbuf->remainder == 0) 3866 return (0); 3867 if (efbuf->fdp != NULL) 3868 FILEDESC_SUNLOCK(efbuf->fdp); 3869 export_vnode_to_kinfo(vp, fd, fflags, &efbuf->kif, efbuf->flags); 3870 error = export_kinfo_to_sb(efbuf); 3871 if (efbuf->fdp != NULL) 3872 FILEDESC_SLOCK(efbuf->fdp); 3873 return (error); 3874 } 3875 3876 /* 3877 * Store a process file descriptor information to sbuf. 3878 * 3879 * Takes a locked proc as argument, and returns with the proc unlocked. 3880 */ 3881 int 3882 kern_proc_filedesc_out(struct proc *p, struct sbuf *sb, ssize_t maxlen, 3883 int flags) 3884 { 3885 struct file *fp; 3886 struct filedesc *fdp; 3887 struct export_fd_buf *efbuf; 3888 struct vnode *cttyvp, *textvp, *tracevp; 3889 struct pwd *pwd; 3890 int error, i; 3891 cap_rights_t rights; 3892 3893 PROC_LOCK_ASSERT(p, MA_OWNED); 3894 3895 /* ktrace vnode */ 3896 tracevp = p->p_tracevp; 3897 if (tracevp != NULL) 3898 vrefact(tracevp); 3899 /* text vnode */ 3900 textvp = p->p_textvp; 3901 if (textvp != NULL) 3902 vrefact(textvp); 3903 /* Controlling tty. */ 3904 cttyvp = NULL; 3905 if (p->p_pgrp != NULL && p->p_pgrp->pg_session != NULL) { 3906 cttyvp = p->p_pgrp->pg_session->s_ttyvp; 3907 if (cttyvp != NULL) 3908 vrefact(cttyvp); 3909 } 3910 fdp = fdhold(p); 3911 PROC_UNLOCK(p); 3912 efbuf = malloc(sizeof(*efbuf), M_TEMP, M_WAITOK); 3913 efbuf->fdp = NULL; 3914 efbuf->sb = sb; 3915 efbuf->remainder = maxlen; 3916 efbuf->flags = flags; 3917 if (tracevp != NULL) 3918 export_vnode_to_sb(tracevp, KF_FD_TYPE_TRACE, FREAD | FWRITE, 3919 efbuf); 3920 if (textvp != NULL) 3921 export_vnode_to_sb(textvp, KF_FD_TYPE_TEXT, FREAD, efbuf); 3922 if (cttyvp != NULL) 3923 export_vnode_to_sb(cttyvp, KF_FD_TYPE_CTTY, FREAD | FWRITE, 3924 efbuf); 3925 error = 0; 3926 if (fdp == NULL) 3927 goto fail; 3928 efbuf->fdp = fdp; 3929 FILEDESC_SLOCK(fdp); 3930 pwd = pwd_hold_filedesc(fdp); 3931 if (pwd != NULL) { 3932 /* working directory */ 3933 if (pwd->pwd_cdir != NULL) { 3934 vrefact(pwd->pwd_cdir); 3935 export_vnode_to_sb(pwd->pwd_cdir, KF_FD_TYPE_CWD, FREAD, efbuf); 3936 } 3937 /* root directory */ 3938 if (pwd->pwd_rdir != NULL) { 3939 vrefact(pwd->pwd_rdir); 3940 export_vnode_to_sb(pwd->pwd_rdir, KF_FD_TYPE_ROOT, FREAD, efbuf); 3941 } 3942 /* jail directory */ 3943 if (pwd->pwd_jdir != NULL) { 3944 vrefact(pwd->pwd_jdir); 3945 export_vnode_to_sb(pwd->pwd_jdir, KF_FD_TYPE_JAIL, FREAD, efbuf); 3946 } 3947 pwd_drop(pwd); 3948 } 3949 for (i = 0; fdp->fd_refcnt > 0 && i <= fdp->fd_lastfile; i++) { 3950 if ((fp = fdp->fd_ofiles[i].fde_file) == NULL) 3951 continue; 3952 #ifdef CAPABILITIES 3953 rights = *cap_rights(fdp, i); 3954 #else /* !CAPABILITIES */ 3955 rights = cap_no_rights; 3956 #endif 3957 /* 3958 * Create sysctl entry. It is OK to drop the filedesc 3959 * lock inside of export_file_to_sb() as we will 3960 * re-validate and re-evaluate its properties when the 3961 * loop continues. 3962 */ 3963 error = export_file_to_sb(fp, i, &rights, efbuf); 3964 if (error != 0 || efbuf->remainder == 0) 3965 break; 3966 } 3967 FILEDESC_SUNLOCK(fdp); 3968 fddrop(fdp); 3969 fail: 3970 free(efbuf, M_TEMP); 3971 return (error); 3972 } 3973 3974 #define FILEDESC_SBUF_SIZE (sizeof(struct kinfo_file) * 5) 3975 3976 /* 3977 * Get per-process file descriptors for use by procstat(1), et al. 3978 */ 3979 static int 3980 sysctl_kern_proc_filedesc(SYSCTL_HANDLER_ARGS) 3981 { 3982 struct sbuf sb; 3983 struct proc *p; 3984 ssize_t maxlen; 3985 int error, error2, *name; 3986 3987 name = (int *)arg1; 3988 3989 sbuf_new_for_sysctl(&sb, NULL, FILEDESC_SBUF_SIZE, req); 3990 sbuf_clear_flags(&sb, SBUF_INCLUDENUL); 3991 error = pget((pid_t)name[0], PGET_CANDEBUG | PGET_NOTWEXIT, &p); 3992 if (error != 0) { 3993 sbuf_delete(&sb); 3994 return (error); 3995 } 3996 maxlen = req->oldptr != NULL ? req->oldlen : -1; 3997 error = kern_proc_filedesc_out(p, &sb, maxlen, 3998 KERN_FILEDESC_PACK_KINFO); 3999 error2 = sbuf_finish(&sb); 4000 sbuf_delete(&sb); 4001 return (error != 0 ? error : error2); 4002 } 4003 4004 #ifdef COMPAT_FREEBSD7 4005 #ifdef KINFO_OFILE_SIZE 4006 CTASSERT(sizeof(struct kinfo_ofile) == KINFO_OFILE_SIZE); 4007 #endif 4008 4009 static void 4010 kinfo_to_okinfo(struct kinfo_file *kif, struct kinfo_ofile *okif) 4011 { 4012 4013 okif->kf_structsize = sizeof(*okif); 4014 okif->kf_type = kif->kf_type; 4015 okif->kf_fd = kif->kf_fd; 4016 okif->kf_ref_count = kif->kf_ref_count; 4017 okif->kf_flags = kif->kf_flags & (KF_FLAG_READ | KF_FLAG_WRITE | 4018 KF_FLAG_APPEND | KF_FLAG_ASYNC | KF_FLAG_FSYNC | KF_FLAG_NONBLOCK | 4019 KF_FLAG_DIRECT | KF_FLAG_HASLOCK); 4020 okif->kf_offset = kif->kf_offset; 4021 if (kif->kf_type == KF_TYPE_VNODE) 4022 okif->kf_vnode_type = kif->kf_un.kf_file.kf_file_type; 4023 else 4024 okif->kf_vnode_type = KF_VTYPE_VNON; 4025 strlcpy(okif->kf_path, kif->kf_path, sizeof(okif->kf_path)); 4026 if (kif->kf_type == KF_TYPE_SOCKET) { 4027 okif->kf_sock_domain = kif->kf_un.kf_sock.kf_sock_domain0; 4028 okif->kf_sock_type = kif->kf_un.kf_sock.kf_sock_type0; 4029 okif->kf_sock_protocol = kif->kf_un.kf_sock.kf_sock_protocol0; 4030 okif->kf_sa_local = kif->kf_un.kf_sock.kf_sa_local; 4031 okif->kf_sa_peer = kif->kf_un.kf_sock.kf_sa_peer; 4032 } else { 4033 okif->kf_sa_local.ss_family = AF_UNSPEC; 4034 okif->kf_sa_peer.ss_family = AF_UNSPEC; 4035 } 4036 } 4037 4038 static int 4039 export_vnode_for_osysctl(struct vnode *vp, int type, struct kinfo_file *kif, 4040 struct kinfo_ofile *okif, struct filedesc *fdp, struct sysctl_req *req) 4041 { 4042 int error; 4043 4044 vrefact(vp); 4045 FILEDESC_SUNLOCK(fdp); 4046 export_vnode_to_kinfo(vp, type, 0, kif, KERN_FILEDESC_PACK_KINFO); 4047 kinfo_to_okinfo(kif, okif); 4048 error = SYSCTL_OUT(req, okif, sizeof(*okif)); 4049 FILEDESC_SLOCK(fdp); 4050 return (error); 4051 } 4052 4053 /* 4054 * Get per-process file descriptors for use by procstat(1), et al. 4055 */ 4056 static int 4057 sysctl_kern_proc_ofiledesc(SYSCTL_HANDLER_ARGS) 4058 { 4059 struct kinfo_ofile *okif; 4060 struct kinfo_file *kif; 4061 struct filedesc *fdp; 4062 struct pwd *pwd; 4063 int error, i, *name; 4064 struct file *fp; 4065 struct proc *p; 4066 4067 name = (int *)arg1; 4068 error = pget((pid_t)name[0], PGET_CANDEBUG | PGET_NOTWEXIT, &p); 4069 if (error != 0) 4070 return (error); 4071 fdp = fdhold(p); 4072 PROC_UNLOCK(p); 4073 if (fdp == NULL) 4074 return (ENOENT); 4075 kif = malloc(sizeof(*kif), M_TEMP, M_WAITOK); 4076 okif = malloc(sizeof(*okif), M_TEMP, M_WAITOK); 4077 FILEDESC_SLOCK(fdp); 4078 pwd = pwd_hold_filedesc(fdp); 4079 if (pwd != NULL) { 4080 if (pwd->pwd_cdir != NULL) 4081 export_vnode_for_osysctl(pwd->pwd_cdir, KF_FD_TYPE_CWD, kif, 4082 okif, fdp, req); 4083 if (pwd->pwd_rdir != NULL) 4084 export_vnode_for_osysctl(pwd->pwd_rdir, KF_FD_TYPE_ROOT, kif, 4085 okif, fdp, req); 4086 if (pwd->pwd_jdir != NULL) 4087 export_vnode_for_osysctl(pwd->pwd_jdir, KF_FD_TYPE_JAIL, kif, 4088 okif, fdp, req); 4089 pwd_drop(pwd); 4090 } 4091 for (i = 0; fdp->fd_refcnt > 0 && i <= fdp->fd_lastfile; i++) { 4092 if ((fp = fdp->fd_ofiles[i].fde_file) == NULL) 4093 continue; 4094 export_file_to_kinfo(fp, i, NULL, kif, fdp, 4095 KERN_FILEDESC_PACK_KINFO); 4096 FILEDESC_SUNLOCK(fdp); 4097 kinfo_to_okinfo(kif, okif); 4098 error = SYSCTL_OUT(req, okif, sizeof(*okif)); 4099 FILEDESC_SLOCK(fdp); 4100 if (error) 4101 break; 4102 } 4103 FILEDESC_SUNLOCK(fdp); 4104 fddrop(fdp); 4105 free(kif, M_TEMP); 4106 free(okif, M_TEMP); 4107 return (0); 4108 } 4109 4110 static SYSCTL_NODE(_kern_proc, KERN_PROC_OFILEDESC, ofiledesc, 4111 CTLFLAG_RD|CTLFLAG_MPSAFE, sysctl_kern_proc_ofiledesc, 4112 "Process ofiledesc entries"); 4113 #endif /* COMPAT_FREEBSD7 */ 4114 4115 int 4116 vntype_to_kinfo(int vtype) 4117 { 4118 struct { 4119 int vtype; 4120 int kf_vtype; 4121 } vtypes_table[] = { 4122 { VBAD, KF_VTYPE_VBAD }, 4123 { VBLK, KF_VTYPE_VBLK }, 4124 { VCHR, KF_VTYPE_VCHR }, 4125 { VDIR, KF_VTYPE_VDIR }, 4126 { VFIFO, KF_VTYPE_VFIFO }, 4127 { VLNK, KF_VTYPE_VLNK }, 4128 { VNON, KF_VTYPE_VNON }, 4129 { VREG, KF_VTYPE_VREG }, 4130 { VSOCK, KF_VTYPE_VSOCK } 4131 }; 4132 unsigned int i; 4133 4134 /* 4135 * Perform vtype translation. 4136 */ 4137 for (i = 0; i < nitems(vtypes_table); i++) 4138 if (vtypes_table[i].vtype == vtype) 4139 return (vtypes_table[i].kf_vtype); 4140 4141 return (KF_VTYPE_UNKNOWN); 4142 } 4143 4144 static SYSCTL_NODE(_kern_proc, KERN_PROC_FILEDESC, filedesc, 4145 CTLFLAG_RD|CTLFLAG_MPSAFE, sysctl_kern_proc_filedesc, 4146 "Process filedesc entries"); 4147 4148 /* 4149 * Store a process current working directory information to sbuf. 4150 * 4151 * Takes a locked proc as argument, and returns with the proc unlocked. 4152 */ 4153 int 4154 kern_proc_cwd_out(struct proc *p, struct sbuf *sb, ssize_t maxlen) 4155 { 4156 struct filedesc *fdp; 4157 struct pwd *pwd; 4158 struct export_fd_buf *efbuf; 4159 struct vnode *cdir; 4160 int error; 4161 4162 PROC_LOCK_ASSERT(p, MA_OWNED); 4163 4164 fdp = fdhold(p); 4165 PROC_UNLOCK(p); 4166 if (fdp == NULL) 4167 return (EINVAL); 4168 4169 efbuf = malloc(sizeof(*efbuf), M_TEMP, M_WAITOK); 4170 efbuf->fdp = fdp; 4171 efbuf->sb = sb; 4172 efbuf->remainder = maxlen; 4173 4174 FILEDESC_SLOCK(fdp); 4175 pwd = FILEDESC_LOCKED_LOAD_PWD(fdp); 4176 cdir = pwd->pwd_cdir; 4177 if (cdir == NULL) { 4178 error = EINVAL; 4179 } else { 4180 vrefact(cdir); 4181 error = export_vnode_to_sb(cdir, KF_FD_TYPE_CWD, FREAD, efbuf); 4182 } 4183 FILEDESC_SUNLOCK(fdp); 4184 fddrop(fdp); 4185 free(efbuf, M_TEMP); 4186 return (error); 4187 } 4188 4189 /* 4190 * Get per-process current working directory. 4191 */ 4192 static int 4193 sysctl_kern_proc_cwd(SYSCTL_HANDLER_ARGS) 4194 { 4195 struct sbuf sb; 4196 struct proc *p; 4197 ssize_t maxlen; 4198 int error, error2, *name; 4199 4200 name = (int *)arg1; 4201 4202 sbuf_new_for_sysctl(&sb, NULL, sizeof(struct kinfo_file), req); 4203 sbuf_clear_flags(&sb, SBUF_INCLUDENUL); 4204 error = pget((pid_t)name[0], PGET_CANDEBUG | PGET_NOTWEXIT, &p); 4205 if (error != 0) { 4206 sbuf_delete(&sb); 4207 return (error); 4208 } 4209 maxlen = req->oldptr != NULL ? req->oldlen : -1; 4210 error = kern_proc_cwd_out(p, &sb, maxlen); 4211 error2 = sbuf_finish(&sb); 4212 sbuf_delete(&sb); 4213 return (error != 0 ? error : error2); 4214 } 4215 4216 static SYSCTL_NODE(_kern_proc, KERN_PROC_CWD, cwd, CTLFLAG_RD|CTLFLAG_MPSAFE, 4217 sysctl_kern_proc_cwd, "Process current working directory"); 4218 4219 #ifdef DDB 4220 /* 4221 * For the purposes of debugging, generate a human-readable string for the 4222 * file type. 4223 */ 4224 static const char * 4225 file_type_to_name(short type) 4226 { 4227 4228 switch (type) { 4229 case 0: 4230 return ("zero"); 4231 case DTYPE_VNODE: 4232 return ("vnode"); 4233 case DTYPE_SOCKET: 4234 return ("socket"); 4235 case DTYPE_PIPE: 4236 return ("pipe"); 4237 case DTYPE_FIFO: 4238 return ("fifo"); 4239 case DTYPE_KQUEUE: 4240 return ("kqueue"); 4241 case DTYPE_CRYPTO: 4242 return ("crypto"); 4243 case DTYPE_MQUEUE: 4244 return ("mqueue"); 4245 case DTYPE_SHM: 4246 return ("shm"); 4247 case DTYPE_SEM: 4248 return ("ksem"); 4249 case DTYPE_PTS: 4250 return ("pts"); 4251 case DTYPE_DEV: 4252 return ("dev"); 4253 case DTYPE_PROCDESC: 4254 return ("proc"); 4255 case DTYPE_LINUXEFD: 4256 return ("levent"); 4257 case DTYPE_LINUXTFD: 4258 return ("ltimer"); 4259 default: 4260 return ("unkn"); 4261 } 4262 } 4263 4264 /* 4265 * For the purposes of debugging, identify a process (if any, perhaps one of 4266 * many) that references the passed file in its file descriptor array. Return 4267 * NULL if none. 4268 */ 4269 static struct proc * 4270 file_to_first_proc(struct file *fp) 4271 { 4272 struct filedesc *fdp; 4273 struct proc *p; 4274 int n; 4275 4276 FOREACH_PROC_IN_SYSTEM(p) { 4277 if (p->p_state == PRS_NEW) 4278 continue; 4279 fdp = p->p_fd; 4280 if (fdp == NULL) 4281 continue; 4282 for (n = 0; n <= fdp->fd_lastfile; n++) { 4283 if (fp == fdp->fd_ofiles[n].fde_file) 4284 return (p); 4285 } 4286 } 4287 return (NULL); 4288 } 4289 4290 static void 4291 db_print_file(struct file *fp, int header) 4292 { 4293 #define XPTRWIDTH ((int)howmany(sizeof(void *) * NBBY, 4)) 4294 struct proc *p; 4295 4296 if (header) 4297 db_printf("%*s %6s %*s %8s %4s %5s %6s %*s %5s %s\n", 4298 XPTRWIDTH, "File", "Type", XPTRWIDTH, "Data", "Flag", 4299 "GCFl", "Count", "MCount", XPTRWIDTH, "Vnode", "FPID", 4300 "FCmd"); 4301 p = file_to_first_proc(fp); 4302 db_printf("%*p %6s %*p %08x %04x %5d %6d %*p %5d %s\n", XPTRWIDTH, 4303 fp, file_type_to_name(fp->f_type), XPTRWIDTH, fp->f_data, 4304 fp->f_flag, 0, fp->f_count, 0, XPTRWIDTH, fp->f_vnode, 4305 p != NULL ? p->p_pid : -1, p != NULL ? p->p_comm : "-"); 4306 4307 #undef XPTRWIDTH 4308 } 4309 4310 DB_SHOW_COMMAND(file, db_show_file) 4311 { 4312 struct file *fp; 4313 4314 if (!have_addr) { 4315 db_printf("usage: show file <addr>\n"); 4316 return; 4317 } 4318 fp = (struct file *)addr; 4319 db_print_file(fp, 1); 4320 } 4321 4322 DB_SHOW_COMMAND(files, db_show_files) 4323 { 4324 struct filedesc *fdp; 4325 struct file *fp; 4326 struct proc *p; 4327 int header; 4328 int n; 4329 4330 header = 1; 4331 FOREACH_PROC_IN_SYSTEM(p) { 4332 if (p->p_state == PRS_NEW) 4333 continue; 4334 if ((fdp = p->p_fd) == NULL) 4335 continue; 4336 for (n = 0; n <= fdp->fd_lastfile; ++n) { 4337 if ((fp = fdp->fd_ofiles[n].fde_file) == NULL) 4338 continue; 4339 db_print_file(fp, header); 4340 header = 0; 4341 } 4342 } 4343 } 4344 #endif 4345 4346 SYSCTL_INT(_kern, KERN_MAXFILESPERPROC, maxfilesperproc, CTLFLAG_RW, 4347 &maxfilesperproc, 0, "Maximum files allowed open per process"); 4348 4349 SYSCTL_INT(_kern, KERN_MAXFILES, maxfiles, CTLFLAG_RW, 4350 &maxfiles, 0, "Maximum number of files"); 4351 4352 SYSCTL_INT(_kern, OID_AUTO, openfiles, CTLFLAG_RD, 4353 &openfiles, 0, "System-wide number of open files"); 4354 4355 /* ARGSUSED*/ 4356 static void 4357 filelistinit(void *dummy) 4358 { 4359 4360 file_zone = uma_zcreate("Files", sizeof(struct file), NULL, NULL, 4361 NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE); 4362 filedesc0_zone = uma_zcreate("filedesc0", sizeof(struct filedesc0), 4363 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0); 4364 pwd_zone = uma_zcreate("PWD", sizeof(struct pwd), NULL, NULL, 4365 NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_SMR); 4366 pwd_smr = uma_zone_get_smr(pwd_zone); 4367 mtx_init(&sigio_lock, "sigio lock", NULL, MTX_DEF); 4368 } 4369 SYSINIT(select, SI_SUB_LOCK, SI_ORDER_FIRST, filelistinit, NULL); 4370 4371 /*-------------------------------------------------------------------*/ 4372 4373 static int 4374 badfo_readwrite(struct file *fp, struct uio *uio, struct ucred *active_cred, 4375 int flags, struct thread *td) 4376 { 4377 4378 return (EBADF); 4379 } 4380 4381 static int 4382 badfo_truncate(struct file *fp, off_t length, struct ucred *active_cred, 4383 struct thread *td) 4384 { 4385 4386 return (EINVAL); 4387 } 4388 4389 static int 4390 badfo_ioctl(struct file *fp, u_long com, void *data, struct ucred *active_cred, 4391 struct thread *td) 4392 { 4393 4394 return (EBADF); 4395 } 4396 4397 static int 4398 badfo_poll(struct file *fp, int events, struct ucred *active_cred, 4399 struct thread *td) 4400 { 4401 4402 return (0); 4403 } 4404 4405 static int 4406 badfo_kqfilter(struct file *fp, struct knote *kn) 4407 { 4408 4409 return (EBADF); 4410 } 4411 4412 static int 4413 badfo_stat(struct file *fp, struct stat *sb, struct ucred *active_cred, 4414 struct thread *td) 4415 { 4416 4417 return (EBADF); 4418 } 4419 4420 static int 4421 badfo_close(struct file *fp, struct thread *td) 4422 { 4423 4424 return (0); 4425 } 4426 4427 static int 4428 badfo_chmod(struct file *fp, mode_t mode, struct ucred *active_cred, 4429 struct thread *td) 4430 { 4431 4432 return (EBADF); 4433 } 4434 4435 static int 4436 badfo_chown(struct file *fp, uid_t uid, gid_t gid, struct ucred *active_cred, 4437 struct thread *td) 4438 { 4439 4440 return (EBADF); 4441 } 4442 4443 static int 4444 badfo_sendfile(struct file *fp, int sockfd, struct uio *hdr_uio, 4445 struct uio *trl_uio, off_t offset, size_t nbytes, off_t *sent, int flags, 4446 struct thread *td) 4447 { 4448 4449 return (EBADF); 4450 } 4451 4452 static int 4453 badfo_fill_kinfo(struct file *fp, struct kinfo_file *kif, struct filedesc *fdp) 4454 { 4455 4456 return (0); 4457 } 4458 4459 struct fileops badfileops = { 4460 .fo_read = badfo_readwrite, 4461 .fo_write = badfo_readwrite, 4462 .fo_truncate = badfo_truncate, 4463 .fo_ioctl = badfo_ioctl, 4464 .fo_poll = badfo_poll, 4465 .fo_kqfilter = badfo_kqfilter, 4466 .fo_stat = badfo_stat, 4467 .fo_close = badfo_close, 4468 .fo_chmod = badfo_chmod, 4469 .fo_chown = badfo_chown, 4470 .fo_sendfile = badfo_sendfile, 4471 .fo_fill_kinfo = badfo_fill_kinfo, 4472 }; 4473 4474 int 4475 invfo_rdwr(struct file *fp, struct uio *uio, struct ucred *active_cred, 4476 int flags, struct thread *td) 4477 { 4478 4479 return (EOPNOTSUPP); 4480 } 4481 4482 int 4483 invfo_truncate(struct file *fp, off_t length, struct ucred *active_cred, 4484 struct thread *td) 4485 { 4486 4487 return (EINVAL); 4488 } 4489 4490 int 4491 invfo_ioctl(struct file *fp, u_long com, void *data, 4492 struct ucred *active_cred, struct thread *td) 4493 { 4494 4495 return (ENOTTY); 4496 } 4497 4498 int 4499 invfo_poll(struct file *fp, int events, struct ucred *active_cred, 4500 struct thread *td) 4501 { 4502 4503 return (poll_no_poll(events)); 4504 } 4505 4506 int 4507 invfo_kqfilter(struct file *fp, struct knote *kn) 4508 { 4509 4510 return (EINVAL); 4511 } 4512 4513 int 4514 invfo_chmod(struct file *fp, mode_t mode, struct ucred *active_cred, 4515 struct thread *td) 4516 { 4517 4518 return (EINVAL); 4519 } 4520 4521 int 4522 invfo_chown(struct file *fp, uid_t uid, gid_t gid, struct ucred *active_cred, 4523 struct thread *td) 4524 { 4525 4526 return (EINVAL); 4527 } 4528 4529 int 4530 invfo_sendfile(struct file *fp, int sockfd, struct uio *hdr_uio, 4531 struct uio *trl_uio, off_t offset, size_t nbytes, off_t *sent, int flags, 4532 struct thread *td) 4533 { 4534 4535 return (EINVAL); 4536 } 4537 4538 /*-------------------------------------------------------------------*/ 4539 4540 /* 4541 * File Descriptor pseudo-device driver (/dev/fd/). 4542 * 4543 * Opening minor device N dup()s the file (if any) connected to file 4544 * descriptor N belonging to the calling process. Note that this driver 4545 * consists of only the ``open()'' routine, because all subsequent 4546 * references to this file will be direct to the other driver. 4547 * 4548 * XXX: we could give this one a cloning event handler if necessary. 4549 */ 4550 4551 /* ARGSUSED */ 4552 static int 4553 fdopen(struct cdev *dev, int mode, int type, struct thread *td) 4554 { 4555 4556 /* 4557 * XXX Kludge: set curthread->td_dupfd to contain the value of the 4558 * the file descriptor being sought for duplication. The error 4559 * return ensures that the vnode for this device will be released 4560 * by vn_open. Open will detect this special error and take the 4561 * actions in dupfdopen below. Other callers of vn_open or VOP_OPEN 4562 * will simply report the error. 4563 */ 4564 td->td_dupfd = dev2unit(dev); 4565 return (ENODEV); 4566 } 4567 4568 static struct cdevsw fildesc_cdevsw = { 4569 .d_version = D_VERSION, 4570 .d_open = fdopen, 4571 .d_name = "FD", 4572 }; 4573 4574 static void 4575 fildesc_drvinit(void *unused) 4576 { 4577 struct cdev *dev; 4578 4579 dev = make_dev_credf(MAKEDEV_ETERNAL, &fildesc_cdevsw, 0, NULL, 4580 UID_ROOT, GID_WHEEL, 0666, "fd/0"); 4581 make_dev_alias(dev, "stdin"); 4582 dev = make_dev_credf(MAKEDEV_ETERNAL, &fildesc_cdevsw, 1, NULL, 4583 UID_ROOT, GID_WHEEL, 0666, "fd/1"); 4584 make_dev_alias(dev, "stdout"); 4585 dev = make_dev_credf(MAKEDEV_ETERNAL, &fildesc_cdevsw, 2, NULL, 4586 UID_ROOT, GID_WHEEL, 0666, "fd/2"); 4587 make_dev_alias(dev, "stderr"); 4588 } 4589 4590 SYSINIT(fildescdev, SI_SUB_DRIVERS, SI_ORDER_MIDDLE, fildesc_drvinit, NULL); 4591