1 /*- 2 * SPDX-License-Identifier: BSD-3-Clause 3 * 4 * Copyright (c) 1982, 1986, 1989, 1991, 1993 5 * The Regents of the University of California. All rights reserved. 6 * (c) UNIX System Laboratories, Inc. 7 * All or some portions of this file are derived from material licensed 8 * to the University of California by American Telephone and Telegraph 9 * Co. or Unix System Laboratories, Inc. and are reproduced herein with 10 * the permission of UNIX System Laboratories, Inc. 11 * 12 * Redistribution and use in source and binary forms, with or without 13 * modification, are permitted provided that the following conditions 14 * are met: 15 * 1. Redistributions of source code must retain the above copyright 16 * notice, this list of conditions and the following disclaimer. 17 * 2. Redistributions in binary form must reproduce the above copyright 18 * notice, this list of conditions and the following disclaimer in the 19 * documentation and/or other materials provided with the distribution. 20 * 3. Neither the name of the University nor the names of its contributors 21 * may be used to endorse or promote products derived from this software 22 * without specific prior written permission. 23 * 24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34 * SUCH DAMAGE. 35 * 36 * @(#)kern_descrip.c 8.6 (Berkeley) 4/19/94 37 */ 38 39 #include <sys/cdefs.h> 40 __FBSDID("$FreeBSD$"); 41 42 #include "opt_capsicum.h" 43 #include "opt_ddb.h" 44 #include "opt_ktrace.h" 45 46 #include <sys/param.h> 47 #include <sys/systm.h> 48 49 #include <sys/capsicum.h> 50 #include <sys/conf.h> 51 #include <sys/fcntl.h> 52 #include <sys/file.h> 53 #include <sys/filedesc.h> 54 #include <sys/filio.h> 55 #include <sys/jail.h> 56 #include <sys/kernel.h> 57 #include <sys/limits.h> 58 #include <sys/lock.h> 59 #include <sys/malloc.h> 60 #include <sys/mount.h> 61 #include <sys/mutex.h> 62 #include <sys/namei.h> 63 #include <sys/selinfo.h> 64 #include <sys/priv.h> 65 #include <sys/proc.h> 66 #include <sys/protosw.h> 67 #include <sys/racct.h> 68 #include <sys/resourcevar.h> 69 #include <sys/sbuf.h> 70 #include <sys/signalvar.h> 71 #include <sys/kdb.h> 72 #include <sys/smr.h> 73 #include <sys/stat.h> 74 #include <sys/sx.h> 75 #include <sys/syscallsubr.h> 76 #include <sys/sysctl.h> 77 #include <sys/sysproto.h> 78 #include <sys/unistd.h> 79 #include <sys/user.h> 80 #include <sys/vnode.h> 81 #ifdef KTRACE 82 #include <sys/ktrace.h> 83 #endif 84 85 #include <net/vnet.h> 86 87 #include <security/audit/audit.h> 88 89 #include <vm/uma.h> 90 #include <vm/vm.h> 91 92 #include <ddb/ddb.h> 93 94 static MALLOC_DEFINE(M_FILEDESC, "filedesc", "Open file descriptor table"); 95 static MALLOC_DEFINE(M_PWD, "pwd", "Descriptor table vnodes"); 96 static MALLOC_DEFINE(M_FILEDESC_TO_LEADER, "filedesc_to_leader", 97 "file desc to leader structures"); 98 static MALLOC_DEFINE(M_SIGIO, "sigio", "sigio structures"); 99 MALLOC_DEFINE(M_FILECAPS, "filecaps", "descriptor capabilities"); 100 101 MALLOC_DECLARE(M_FADVISE); 102 103 static __read_mostly uma_zone_t file_zone; 104 static __read_mostly uma_zone_t filedesc0_zone; 105 __read_mostly uma_zone_t pwd_zone; 106 VFS_SMR_DECLARE; 107 108 static int closefp(struct filedesc *fdp, int fd, struct file *fp, 109 struct thread *td, int holdleaders); 110 static int fd_first_free(struct filedesc *fdp, int low, int size); 111 static void fdgrowtable(struct filedesc *fdp, int nfd); 112 static void fdgrowtable_exp(struct filedesc *fdp, int nfd); 113 static void fdunused(struct filedesc *fdp, int fd); 114 static void fdused(struct filedesc *fdp, int fd); 115 static int getmaxfd(struct thread *td); 116 static u_long *filecaps_copy_prep(const struct filecaps *src); 117 static void filecaps_copy_finish(const struct filecaps *src, 118 struct filecaps *dst, u_long *ioctls); 119 static u_long *filecaps_free_prep(struct filecaps *fcaps); 120 static void filecaps_free_finish(u_long *ioctls); 121 122 static struct pwd *pwd_alloc(void); 123 124 /* 125 * Each process has: 126 * 127 * - An array of open file descriptors (fd_ofiles) 128 * - An array of file flags (fd_ofileflags) 129 * - A bitmap recording which descriptors are in use (fd_map) 130 * 131 * A process starts out with NDFILE descriptors. The value of NDFILE has 132 * been selected based the historical limit of 20 open files, and an 133 * assumption that the majority of processes, especially short-lived 134 * processes like shells, will never need more. 135 * 136 * If this initial allocation is exhausted, a larger descriptor table and 137 * map are allocated dynamically, and the pointers in the process's struct 138 * filedesc are updated to point to those. This is repeated every time 139 * the process runs out of file descriptors (provided it hasn't hit its 140 * resource limit). 141 * 142 * Since threads may hold references to individual descriptor table 143 * entries, the tables are never freed. Instead, they are placed on a 144 * linked list and freed only when the struct filedesc is released. 145 */ 146 #define NDFILE 20 147 #define NDSLOTSIZE sizeof(NDSLOTTYPE) 148 #define NDENTRIES (NDSLOTSIZE * __CHAR_BIT) 149 #define NDSLOT(x) ((x) / NDENTRIES) 150 #define NDBIT(x) ((NDSLOTTYPE)1 << ((x) % NDENTRIES)) 151 #define NDSLOTS(x) (((x) + NDENTRIES - 1) / NDENTRIES) 152 153 /* 154 * SLIST entry used to keep track of ofiles which must be reclaimed when 155 * the process exits. 156 */ 157 struct freetable { 158 struct fdescenttbl *ft_table; 159 SLIST_ENTRY(freetable) ft_next; 160 }; 161 162 /* 163 * Initial allocation: a filedesc structure + the head of SLIST used to 164 * keep track of old ofiles + enough space for NDFILE descriptors. 165 */ 166 167 struct fdescenttbl0 { 168 int fdt_nfiles; 169 struct filedescent fdt_ofiles[NDFILE]; 170 }; 171 172 struct filedesc0 { 173 struct filedesc fd_fd; 174 SLIST_HEAD(, freetable) fd_free; 175 struct fdescenttbl0 fd_dfiles; 176 NDSLOTTYPE fd_dmap[NDSLOTS(NDFILE)]; 177 }; 178 179 /* 180 * Descriptor management. 181 */ 182 static int __exclusive_cache_line openfiles; /* actual number of open files */ 183 struct mtx sigio_lock; /* mtx to protect pointers to sigio */ 184 void __read_mostly (*mq_fdclose)(struct thread *td, int fd, struct file *fp); 185 186 /* 187 * If low >= size, just return low. Otherwise find the first zero bit in the 188 * given bitmap, starting at low and not exceeding size - 1. Return size if 189 * not found. 190 */ 191 static int 192 fd_first_free(struct filedesc *fdp, int low, int size) 193 { 194 NDSLOTTYPE *map = fdp->fd_map; 195 NDSLOTTYPE mask; 196 int off, maxoff; 197 198 if (low >= size) 199 return (low); 200 201 off = NDSLOT(low); 202 if (low % NDENTRIES) { 203 mask = ~(~(NDSLOTTYPE)0 >> (NDENTRIES - (low % NDENTRIES))); 204 if ((mask &= ~map[off]) != 0UL) 205 return (off * NDENTRIES + ffsl(mask) - 1); 206 ++off; 207 } 208 for (maxoff = NDSLOTS(size); off < maxoff; ++off) 209 if (map[off] != ~0UL) 210 return (off * NDENTRIES + ffsl(~map[off]) - 1); 211 return (size); 212 } 213 214 /* 215 * Find the last used fd. 216 * 217 * Call this variant if fdp can't be modified by anyone else (e.g, during exec). 218 * Otherwise use fdlastfile. 219 */ 220 int 221 fdlastfile_single(struct filedesc *fdp) 222 { 223 NDSLOTTYPE *map = fdp->fd_map; 224 int off, minoff; 225 226 off = NDSLOT(fdp->fd_nfiles - 1); 227 for (minoff = NDSLOT(0); off >= minoff; --off) 228 if (map[off] != 0) 229 return (off * NDENTRIES + flsl(map[off]) - 1); 230 return (-1); 231 } 232 233 int 234 fdlastfile(struct filedesc *fdp) 235 { 236 237 FILEDESC_LOCK_ASSERT(fdp); 238 return (fdlastfile_single(fdp)); 239 } 240 241 static int 242 fdisused(struct filedesc *fdp, int fd) 243 { 244 245 KASSERT(fd >= 0 && fd < fdp->fd_nfiles, 246 ("file descriptor %d out of range (0, %d)", fd, fdp->fd_nfiles)); 247 248 return ((fdp->fd_map[NDSLOT(fd)] & NDBIT(fd)) != 0); 249 } 250 251 /* 252 * Mark a file descriptor as used. 253 */ 254 static void 255 fdused_init(struct filedesc *fdp, int fd) 256 { 257 258 KASSERT(!fdisused(fdp, fd), ("fd=%d is already used", fd)); 259 260 fdp->fd_map[NDSLOT(fd)] |= NDBIT(fd); 261 } 262 263 static void 264 fdused(struct filedesc *fdp, int fd) 265 { 266 267 FILEDESC_XLOCK_ASSERT(fdp); 268 269 fdused_init(fdp, fd); 270 if (fd == fdp->fd_freefile) 271 fdp->fd_freefile++; 272 } 273 274 /* 275 * Mark a file descriptor as unused. 276 */ 277 static void 278 fdunused(struct filedesc *fdp, int fd) 279 { 280 281 FILEDESC_XLOCK_ASSERT(fdp); 282 283 KASSERT(fdisused(fdp, fd), ("fd=%d is already unused", fd)); 284 KASSERT(fdp->fd_ofiles[fd].fde_file == NULL, 285 ("fd=%d is still in use", fd)); 286 287 fdp->fd_map[NDSLOT(fd)] &= ~NDBIT(fd); 288 if (fd < fdp->fd_freefile) 289 fdp->fd_freefile = fd; 290 } 291 292 /* 293 * Free a file descriptor. 294 * 295 * Avoid some work if fdp is about to be destroyed. 296 */ 297 static inline void 298 fdefree_last(struct filedescent *fde) 299 { 300 301 filecaps_free(&fde->fde_caps); 302 } 303 304 static inline void 305 fdfree(struct filedesc *fdp, int fd) 306 { 307 struct filedescent *fde; 308 309 fde = &fdp->fd_ofiles[fd]; 310 #ifdef CAPABILITIES 311 seqc_write_begin(&fde->fde_seqc); 312 #endif 313 fde->fde_file = NULL; 314 #ifdef CAPABILITIES 315 seqc_write_end(&fde->fde_seqc); 316 #endif 317 fdefree_last(fde); 318 fdunused(fdp, fd); 319 } 320 321 /* 322 * System calls on descriptors. 323 */ 324 #ifndef _SYS_SYSPROTO_H_ 325 struct getdtablesize_args { 326 int dummy; 327 }; 328 #endif 329 /* ARGSUSED */ 330 int 331 sys_getdtablesize(struct thread *td, struct getdtablesize_args *uap) 332 { 333 #ifdef RACCT 334 uint64_t lim; 335 #endif 336 337 td->td_retval[0] = getmaxfd(td); 338 #ifdef RACCT 339 PROC_LOCK(td->td_proc); 340 lim = racct_get_limit(td->td_proc, RACCT_NOFILE); 341 PROC_UNLOCK(td->td_proc); 342 if (lim < td->td_retval[0]) 343 td->td_retval[0] = lim; 344 #endif 345 return (0); 346 } 347 348 /* 349 * Duplicate a file descriptor to a particular value. 350 * 351 * Note: keep in mind that a potential race condition exists when closing 352 * descriptors from a shared descriptor table (via rfork). 353 */ 354 #ifndef _SYS_SYSPROTO_H_ 355 struct dup2_args { 356 u_int from; 357 u_int to; 358 }; 359 #endif 360 /* ARGSUSED */ 361 int 362 sys_dup2(struct thread *td, struct dup2_args *uap) 363 { 364 365 return (kern_dup(td, FDDUP_FIXED, 0, (int)uap->from, (int)uap->to)); 366 } 367 368 /* 369 * Duplicate a file descriptor. 370 */ 371 #ifndef _SYS_SYSPROTO_H_ 372 struct dup_args { 373 u_int fd; 374 }; 375 #endif 376 /* ARGSUSED */ 377 int 378 sys_dup(struct thread *td, struct dup_args *uap) 379 { 380 381 return (kern_dup(td, FDDUP_NORMAL, 0, (int)uap->fd, 0)); 382 } 383 384 /* 385 * The file control system call. 386 */ 387 #ifndef _SYS_SYSPROTO_H_ 388 struct fcntl_args { 389 int fd; 390 int cmd; 391 long arg; 392 }; 393 #endif 394 /* ARGSUSED */ 395 int 396 sys_fcntl(struct thread *td, struct fcntl_args *uap) 397 { 398 399 return (kern_fcntl_freebsd(td, uap->fd, uap->cmd, uap->arg)); 400 } 401 402 int 403 kern_fcntl_freebsd(struct thread *td, int fd, int cmd, long arg) 404 { 405 struct flock fl; 406 struct __oflock ofl; 407 intptr_t arg1; 408 int error, newcmd; 409 410 error = 0; 411 newcmd = cmd; 412 switch (cmd) { 413 case F_OGETLK: 414 case F_OSETLK: 415 case F_OSETLKW: 416 /* 417 * Convert old flock structure to new. 418 */ 419 error = copyin((void *)(intptr_t)arg, &ofl, sizeof(ofl)); 420 fl.l_start = ofl.l_start; 421 fl.l_len = ofl.l_len; 422 fl.l_pid = ofl.l_pid; 423 fl.l_type = ofl.l_type; 424 fl.l_whence = ofl.l_whence; 425 fl.l_sysid = 0; 426 427 switch (cmd) { 428 case F_OGETLK: 429 newcmd = F_GETLK; 430 break; 431 case F_OSETLK: 432 newcmd = F_SETLK; 433 break; 434 case F_OSETLKW: 435 newcmd = F_SETLKW; 436 break; 437 } 438 arg1 = (intptr_t)&fl; 439 break; 440 case F_GETLK: 441 case F_SETLK: 442 case F_SETLKW: 443 case F_SETLK_REMOTE: 444 error = copyin((void *)(intptr_t)arg, &fl, sizeof(fl)); 445 arg1 = (intptr_t)&fl; 446 break; 447 default: 448 arg1 = arg; 449 break; 450 } 451 if (error) 452 return (error); 453 error = kern_fcntl(td, fd, newcmd, arg1); 454 if (error) 455 return (error); 456 if (cmd == F_OGETLK) { 457 ofl.l_start = fl.l_start; 458 ofl.l_len = fl.l_len; 459 ofl.l_pid = fl.l_pid; 460 ofl.l_type = fl.l_type; 461 ofl.l_whence = fl.l_whence; 462 error = copyout(&ofl, (void *)(intptr_t)arg, sizeof(ofl)); 463 } else if (cmd == F_GETLK) { 464 error = copyout(&fl, (void *)(intptr_t)arg, sizeof(fl)); 465 } 466 return (error); 467 } 468 469 int 470 kern_fcntl(struct thread *td, int fd, int cmd, intptr_t arg) 471 { 472 struct filedesc *fdp; 473 struct flock *flp; 474 struct file *fp, *fp2; 475 struct filedescent *fde; 476 struct proc *p; 477 struct vnode *vp; 478 struct mount *mp; 479 int error, flg, seals, tmp; 480 uint64_t bsize; 481 off_t foffset; 482 483 error = 0; 484 flg = F_POSIX; 485 p = td->td_proc; 486 fdp = p->p_fd; 487 488 AUDIT_ARG_FD(cmd); 489 AUDIT_ARG_CMD(cmd); 490 switch (cmd) { 491 case F_DUPFD: 492 tmp = arg; 493 error = kern_dup(td, FDDUP_FCNTL, 0, fd, tmp); 494 break; 495 496 case F_DUPFD_CLOEXEC: 497 tmp = arg; 498 error = kern_dup(td, FDDUP_FCNTL, FDDUP_FLAG_CLOEXEC, fd, tmp); 499 break; 500 501 case F_DUP2FD: 502 tmp = arg; 503 error = kern_dup(td, FDDUP_FIXED, 0, fd, tmp); 504 break; 505 506 case F_DUP2FD_CLOEXEC: 507 tmp = arg; 508 error = kern_dup(td, FDDUP_FIXED, FDDUP_FLAG_CLOEXEC, fd, tmp); 509 break; 510 511 case F_GETFD: 512 error = EBADF; 513 FILEDESC_SLOCK(fdp); 514 fde = fdeget_locked(fdp, fd); 515 if (fde != NULL) { 516 td->td_retval[0] = 517 (fde->fde_flags & UF_EXCLOSE) ? FD_CLOEXEC : 0; 518 error = 0; 519 } 520 FILEDESC_SUNLOCK(fdp); 521 break; 522 523 case F_SETFD: 524 error = EBADF; 525 FILEDESC_XLOCK(fdp); 526 fde = fdeget_locked(fdp, fd); 527 if (fde != NULL) { 528 fde->fde_flags = (fde->fde_flags & ~UF_EXCLOSE) | 529 (arg & FD_CLOEXEC ? UF_EXCLOSE : 0); 530 error = 0; 531 } 532 FILEDESC_XUNLOCK(fdp); 533 break; 534 535 case F_GETFL: 536 error = fget_fcntl(td, fd, &cap_fcntl_rights, F_GETFL, &fp); 537 if (error != 0) 538 break; 539 td->td_retval[0] = OFLAGS(fp->f_flag); 540 fdrop(fp, td); 541 break; 542 543 case F_SETFL: 544 error = fget_fcntl(td, fd, &cap_fcntl_rights, F_SETFL, &fp); 545 if (error != 0) 546 break; 547 do { 548 tmp = flg = fp->f_flag; 549 tmp &= ~FCNTLFLAGS; 550 tmp |= FFLAGS(arg & ~O_ACCMODE) & FCNTLFLAGS; 551 } while(atomic_cmpset_int(&fp->f_flag, flg, tmp) == 0); 552 tmp = fp->f_flag & FNONBLOCK; 553 error = fo_ioctl(fp, FIONBIO, &tmp, td->td_ucred, td); 554 if (error != 0) { 555 fdrop(fp, td); 556 break; 557 } 558 tmp = fp->f_flag & FASYNC; 559 error = fo_ioctl(fp, FIOASYNC, &tmp, td->td_ucred, td); 560 if (error == 0) { 561 fdrop(fp, td); 562 break; 563 } 564 atomic_clear_int(&fp->f_flag, FNONBLOCK); 565 tmp = 0; 566 (void)fo_ioctl(fp, FIONBIO, &tmp, td->td_ucred, td); 567 fdrop(fp, td); 568 break; 569 570 case F_GETOWN: 571 error = fget_fcntl(td, fd, &cap_fcntl_rights, F_GETOWN, &fp); 572 if (error != 0) 573 break; 574 error = fo_ioctl(fp, FIOGETOWN, &tmp, td->td_ucred, td); 575 if (error == 0) 576 td->td_retval[0] = tmp; 577 fdrop(fp, td); 578 break; 579 580 case F_SETOWN: 581 error = fget_fcntl(td, fd, &cap_fcntl_rights, F_SETOWN, &fp); 582 if (error != 0) 583 break; 584 tmp = arg; 585 error = fo_ioctl(fp, FIOSETOWN, &tmp, td->td_ucred, td); 586 fdrop(fp, td); 587 break; 588 589 case F_SETLK_REMOTE: 590 error = priv_check(td, PRIV_NFS_LOCKD); 591 if (error != 0) 592 return (error); 593 flg = F_REMOTE; 594 goto do_setlk; 595 596 case F_SETLKW: 597 flg |= F_WAIT; 598 /* FALLTHROUGH F_SETLK */ 599 600 case F_SETLK: 601 do_setlk: 602 flp = (struct flock *)arg; 603 if ((flg & F_REMOTE) != 0 && flp->l_sysid == 0) { 604 error = EINVAL; 605 break; 606 } 607 608 error = fget_unlocked(fdp, fd, &cap_flock_rights, &fp); 609 if (error != 0) 610 break; 611 if (fp->f_type != DTYPE_VNODE) { 612 error = EBADF; 613 fdrop(fp, td); 614 break; 615 } 616 617 if (flp->l_whence == SEEK_CUR) { 618 foffset = foffset_get(fp); 619 if (foffset < 0 || 620 (flp->l_start > 0 && 621 foffset > OFF_MAX - flp->l_start)) { 622 error = EOVERFLOW; 623 fdrop(fp, td); 624 break; 625 } 626 flp->l_start += foffset; 627 } 628 629 vp = fp->f_vnode; 630 switch (flp->l_type) { 631 case F_RDLCK: 632 if ((fp->f_flag & FREAD) == 0) { 633 error = EBADF; 634 break; 635 } 636 if ((p->p_leader->p_flag & P_ADVLOCK) == 0) { 637 PROC_LOCK(p->p_leader); 638 p->p_leader->p_flag |= P_ADVLOCK; 639 PROC_UNLOCK(p->p_leader); 640 } 641 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_SETLK, 642 flp, flg); 643 break; 644 case F_WRLCK: 645 if ((fp->f_flag & FWRITE) == 0) { 646 error = EBADF; 647 break; 648 } 649 if ((p->p_leader->p_flag & P_ADVLOCK) == 0) { 650 PROC_LOCK(p->p_leader); 651 p->p_leader->p_flag |= P_ADVLOCK; 652 PROC_UNLOCK(p->p_leader); 653 } 654 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_SETLK, 655 flp, flg); 656 break; 657 case F_UNLCK: 658 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_UNLCK, 659 flp, flg); 660 break; 661 case F_UNLCKSYS: 662 if (flg != F_REMOTE) { 663 error = EINVAL; 664 break; 665 } 666 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, 667 F_UNLCKSYS, flp, flg); 668 break; 669 default: 670 error = EINVAL; 671 break; 672 } 673 if (error != 0 || flp->l_type == F_UNLCK || 674 flp->l_type == F_UNLCKSYS) { 675 fdrop(fp, td); 676 break; 677 } 678 679 /* 680 * Check for a race with close. 681 * 682 * The vnode is now advisory locked (or unlocked, but this case 683 * is not really important) as the caller requested. 684 * We had to drop the filedesc lock, so we need to recheck if 685 * the descriptor is still valid, because if it was closed 686 * in the meantime we need to remove advisory lock from the 687 * vnode - close on any descriptor leading to an advisory 688 * locked vnode, removes that lock. 689 * We will return 0 on purpose in that case, as the result of 690 * successful advisory lock might have been externally visible 691 * already. This is fine - effectively we pretend to the caller 692 * that the closing thread was a bit slower and that the 693 * advisory lock succeeded before the close. 694 */ 695 error = fget_unlocked(fdp, fd, &cap_no_rights, &fp2); 696 if (error != 0) { 697 fdrop(fp, td); 698 break; 699 } 700 if (fp != fp2) { 701 flp->l_whence = SEEK_SET; 702 flp->l_start = 0; 703 flp->l_len = 0; 704 flp->l_type = F_UNLCK; 705 (void) VOP_ADVLOCK(vp, (caddr_t)p->p_leader, 706 F_UNLCK, flp, F_POSIX); 707 } 708 fdrop(fp, td); 709 fdrop(fp2, td); 710 break; 711 712 case F_GETLK: 713 error = fget_unlocked(fdp, fd, &cap_flock_rights, &fp); 714 if (error != 0) 715 break; 716 if (fp->f_type != DTYPE_VNODE) { 717 error = EBADF; 718 fdrop(fp, td); 719 break; 720 } 721 flp = (struct flock *)arg; 722 if (flp->l_type != F_RDLCK && flp->l_type != F_WRLCK && 723 flp->l_type != F_UNLCK) { 724 error = EINVAL; 725 fdrop(fp, td); 726 break; 727 } 728 if (flp->l_whence == SEEK_CUR) { 729 foffset = foffset_get(fp); 730 if ((flp->l_start > 0 && 731 foffset > OFF_MAX - flp->l_start) || 732 (flp->l_start < 0 && 733 foffset < OFF_MIN - flp->l_start)) { 734 error = EOVERFLOW; 735 fdrop(fp, td); 736 break; 737 } 738 flp->l_start += foffset; 739 } 740 vp = fp->f_vnode; 741 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_GETLK, flp, 742 F_POSIX); 743 fdrop(fp, td); 744 break; 745 746 case F_ADD_SEALS: 747 error = fget_unlocked(fdp, fd, &cap_no_rights, &fp); 748 if (error != 0) 749 break; 750 error = fo_add_seals(fp, arg); 751 fdrop(fp, td); 752 break; 753 754 case F_GET_SEALS: 755 error = fget_unlocked(fdp, fd, &cap_no_rights, &fp); 756 if (error != 0) 757 break; 758 if (fo_get_seals(fp, &seals) == 0) 759 td->td_retval[0] = seals; 760 else 761 error = EINVAL; 762 fdrop(fp, td); 763 break; 764 765 case F_RDAHEAD: 766 arg = arg ? 128 * 1024: 0; 767 /* FALLTHROUGH */ 768 case F_READAHEAD: 769 error = fget_unlocked(fdp, fd, &cap_no_rights, &fp); 770 if (error != 0) 771 break; 772 if (fp->f_type != DTYPE_VNODE) { 773 fdrop(fp, td); 774 error = EBADF; 775 break; 776 } 777 vp = fp->f_vnode; 778 if (vp->v_type != VREG) { 779 fdrop(fp, td); 780 error = ENOTTY; 781 break; 782 } 783 784 /* 785 * Exclusive lock synchronizes against f_seqcount reads and 786 * writes in sequential_heuristic(). 787 */ 788 error = vn_lock(vp, LK_EXCLUSIVE); 789 if (error != 0) { 790 fdrop(fp, td); 791 break; 792 } 793 if (arg >= 0) { 794 bsize = fp->f_vnode->v_mount->mnt_stat.f_iosize; 795 arg = MIN(arg, INT_MAX - bsize + 1); 796 fp->f_seqcount[UIO_READ] = MIN(IO_SEQMAX, 797 (arg + bsize - 1) / bsize); 798 atomic_set_int(&fp->f_flag, FRDAHEAD); 799 } else { 800 atomic_clear_int(&fp->f_flag, FRDAHEAD); 801 } 802 VOP_UNLOCK(vp); 803 fdrop(fp, td); 804 break; 805 806 case F_ISUNIONSTACK: 807 /* 808 * Check if the vnode is part of a union stack (either the 809 * "union" flag from mount(2) or unionfs). 810 * 811 * Prior to introduction of this op libc's readdir would call 812 * fstatfs(2), in effect unnecessarily copying kilobytes of 813 * data just to check fs name and a mount flag. 814 * 815 * Fixing the code to handle everything in the kernel instead 816 * is a non-trivial endeavor and has low priority, thus this 817 * horrible kludge facilitates the current behavior in a much 818 * cheaper manner until someone(tm) sorts this out. 819 */ 820 error = fget_unlocked(fdp, fd, &cap_no_rights, &fp); 821 if (error != 0) 822 break; 823 if (fp->f_type != DTYPE_VNODE) { 824 fdrop(fp, td); 825 error = EBADF; 826 break; 827 } 828 vp = fp->f_vnode; 829 /* 830 * Since we don't prevent dooming the vnode even non-null mp 831 * found can become immediately stale. This is tolerable since 832 * mount points are type-stable (providing safe memory access) 833 * and any vfs op on this vnode going forward will return an 834 * error (meaning return value in this case is meaningless). 835 */ 836 mp = atomic_load_ptr(&vp->v_mount); 837 if (__predict_false(mp == NULL)) { 838 fdrop(fp, td); 839 error = EBADF; 840 break; 841 } 842 td->td_retval[0] = 0; 843 if (mp->mnt_kern_flag & MNTK_UNIONFS || 844 mp->mnt_flag & MNT_UNION) 845 td->td_retval[0] = 1; 846 fdrop(fp, td); 847 break; 848 849 default: 850 error = EINVAL; 851 break; 852 } 853 return (error); 854 } 855 856 static int 857 getmaxfd(struct thread *td) 858 { 859 860 return (min((int)lim_cur(td, RLIMIT_NOFILE), maxfilesperproc)); 861 } 862 863 /* 864 * Common code for dup, dup2, fcntl(F_DUPFD) and fcntl(F_DUP2FD). 865 */ 866 int 867 kern_dup(struct thread *td, u_int mode, int flags, int old, int new) 868 { 869 struct filedesc *fdp; 870 struct filedescent *oldfde, *newfde; 871 struct proc *p; 872 struct file *delfp; 873 u_long *oioctls, *nioctls; 874 int error, maxfd; 875 876 p = td->td_proc; 877 fdp = p->p_fd; 878 oioctls = NULL; 879 880 MPASS((flags & ~(FDDUP_FLAG_CLOEXEC)) == 0); 881 MPASS(mode < FDDUP_LASTMODE); 882 883 AUDIT_ARG_FD(old); 884 /* XXXRW: if (flags & FDDUP_FIXED) AUDIT_ARG_FD2(new); */ 885 886 /* 887 * Verify we have a valid descriptor to dup from and possibly to 888 * dup to. Unlike dup() and dup2(), fcntl()'s F_DUPFD should 889 * return EINVAL when the new descriptor is out of bounds. 890 */ 891 if (old < 0) 892 return (EBADF); 893 if (new < 0) 894 return (mode == FDDUP_FCNTL ? EINVAL : EBADF); 895 maxfd = getmaxfd(td); 896 if (new >= maxfd) 897 return (mode == FDDUP_FCNTL ? EINVAL : EBADF); 898 899 error = EBADF; 900 FILEDESC_XLOCK(fdp); 901 if (fget_locked(fdp, old) == NULL) 902 goto unlock; 903 if ((mode == FDDUP_FIXED || mode == FDDUP_MUSTREPLACE) && old == new) { 904 td->td_retval[0] = new; 905 if (flags & FDDUP_FLAG_CLOEXEC) 906 fdp->fd_ofiles[new].fde_flags |= UF_EXCLOSE; 907 error = 0; 908 goto unlock; 909 } 910 911 oldfde = &fdp->fd_ofiles[old]; 912 if (!fhold(oldfde->fde_file)) 913 goto unlock; 914 915 /* 916 * If the caller specified a file descriptor, make sure the file 917 * table is large enough to hold it, and grab it. Otherwise, just 918 * allocate a new descriptor the usual way. 919 */ 920 switch (mode) { 921 case FDDUP_NORMAL: 922 case FDDUP_FCNTL: 923 if ((error = fdalloc(td, new, &new)) != 0) { 924 fdrop(oldfde->fde_file, td); 925 goto unlock; 926 } 927 break; 928 case FDDUP_MUSTREPLACE: 929 /* Target file descriptor must exist. */ 930 if (fget_locked(fdp, new) == NULL) { 931 fdrop(oldfde->fde_file, td); 932 goto unlock; 933 } 934 break; 935 case FDDUP_FIXED: 936 if (new >= fdp->fd_nfiles) { 937 /* 938 * The resource limits are here instead of e.g. 939 * fdalloc(), because the file descriptor table may be 940 * shared between processes, so we can't really use 941 * racct_add()/racct_sub(). Instead of counting the 942 * number of actually allocated descriptors, just put 943 * the limit on the size of the file descriptor table. 944 */ 945 #ifdef RACCT 946 if (RACCT_ENABLED()) { 947 error = racct_set_unlocked(p, RACCT_NOFILE, new + 1); 948 if (error != 0) { 949 error = EMFILE; 950 fdrop(oldfde->fde_file, td); 951 goto unlock; 952 } 953 } 954 #endif 955 fdgrowtable_exp(fdp, new + 1); 956 } 957 if (!fdisused(fdp, new)) 958 fdused(fdp, new); 959 break; 960 default: 961 KASSERT(0, ("%s unsupported mode %d", __func__, mode)); 962 } 963 964 KASSERT(old != new, ("new fd is same as old")); 965 966 newfde = &fdp->fd_ofiles[new]; 967 delfp = newfde->fde_file; 968 969 nioctls = filecaps_copy_prep(&oldfde->fde_caps); 970 971 /* 972 * Duplicate the source descriptor. 973 */ 974 #ifdef CAPABILITIES 975 seqc_write_begin(&newfde->fde_seqc); 976 #endif 977 oioctls = filecaps_free_prep(&newfde->fde_caps); 978 memcpy(newfde, oldfde, fde_change_size); 979 filecaps_copy_finish(&oldfde->fde_caps, &newfde->fde_caps, 980 nioctls); 981 if ((flags & FDDUP_FLAG_CLOEXEC) != 0) 982 newfde->fde_flags = oldfde->fde_flags | UF_EXCLOSE; 983 else 984 newfde->fde_flags = oldfde->fde_flags & ~UF_EXCLOSE; 985 #ifdef CAPABILITIES 986 seqc_write_end(&newfde->fde_seqc); 987 #endif 988 td->td_retval[0] = new; 989 990 error = 0; 991 992 if (delfp != NULL) { 993 (void) closefp(fdp, new, delfp, td, 1); 994 FILEDESC_UNLOCK_ASSERT(fdp); 995 } else { 996 unlock: 997 FILEDESC_XUNLOCK(fdp); 998 } 999 1000 filecaps_free_finish(oioctls); 1001 return (error); 1002 } 1003 1004 /* 1005 * If sigio is on the list associated with a process or process group, 1006 * disable signalling from the device, remove sigio from the list and 1007 * free sigio. 1008 */ 1009 void 1010 funsetown(struct sigio **sigiop) 1011 { 1012 struct sigio *sigio; 1013 1014 if (*sigiop == NULL) 1015 return; 1016 SIGIO_LOCK(); 1017 sigio = *sigiop; 1018 if (sigio == NULL) { 1019 SIGIO_UNLOCK(); 1020 return; 1021 } 1022 *(sigio->sio_myref) = NULL; 1023 if ((sigio)->sio_pgid < 0) { 1024 struct pgrp *pg = (sigio)->sio_pgrp; 1025 PGRP_LOCK(pg); 1026 SLIST_REMOVE(&sigio->sio_pgrp->pg_sigiolst, sigio, 1027 sigio, sio_pgsigio); 1028 PGRP_UNLOCK(pg); 1029 } else { 1030 struct proc *p = (sigio)->sio_proc; 1031 PROC_LOCK(p); 1032 SLIST_REMOVE(&sigio->sio_proc->p_sigiolst, sigio, 1033 sigio, sio_pgsigio); 1034 PROC_UNLOCK(p); 1035 } 1036 SIGIO_UNLOCK(); 1037 crfree(sigio->sio_ucred); 1038 free(sigio, M_SIGIO); 1039 } 1040 1041 /* 1042 * Free a list of sigio structures. 1043 * We only need to lock the SIGIO_LOCK because we have made ourselves 1044 * inaccessible to callers of fsetown and therefore do not need to lock 1045 * the proc or pgrp struct for the list manipulation. 1046 */ 1047 void 1048 funsetownlst(struct sigiolst *sigiolst) 1049 { 1050 struct proc *p; 1051 struct pgrp *pg; 1052 struct sigio *sigio; 1053 1054 sigio = SLIST_FIRST(sigiolst); 1055 if (sigio == NULL) 1056 return; 1057 p = NULL; 1058 pg = NULL; 1059 1060 /* 1061 * Every entry of the list should belong 1062 * to a single proc or pgrp. 1063 */ 1064 if (sigio->sio_pgid < 0) { 1065 pg = sigio->sio_pgrp; 1066 PGRP_LOCK_ASSERT(pg, MA_NOTOWNED); 1067 } else /* if (sigio->sio_pgid > 0) */ { 1068 p = sigio->sio_proc; 1069 PROC_LOCK_ASSERT(p, MA_NOTOWNED); 1070 } 1071 1072 SIGIO_LOCK(); 1073 while ((sigio = SLIST_FIRST(sigiolst)) != NULL) { 1074 *(sigio->sio_myref) = NULL; 1075 if (pg != NULL) { 1076 KASSERT(sigio->sio_pgid < 0, 1077 ("Proc sigio in pgrp sigio list")); 1078 KASSERT(sigio->sio_pgrp == pg, 1079 ("Bogus pgrp in sigio list")); 1080 PGRP_LOCK(pg); 1081 SLIST_REMOVE(&pg->pg_sigiolst, sigio, sigio, 1082 sio_pgsigio); 1083 PGRP_UNLOCK(pg); 1084 } else /* if (p != NULL) */ { 1085 KASSERT(sigio->sio_pgid > 0, 1086 ("Pgrp sigio in proc sigio list")); 1087 KASSERT(sigio->sio_proc == p, 1088 ("Bogus proc in sigio list")); 1089 PROC_LOCK(p); 1090 SLIST_REMOVE(&p->p_sigiolst, sigio, sigio, 1091 sio_pgsigio); 1092 PROC_UNLOCK(p); 1093 } 1094 SIGIO_UNLOCK(); 1095 crfree(sigio->sio_ucred); 1096 free(sigio, M_SIGIO); 1097 SIGIO_LOCK(); 1098 } 1099 SIGIO_UNLOCK(); 1100 } 1101 1102 /* 1103 * This is common code for FIOSETOWN ioctl called by fcntl(fd, F_SETOWN, arg). 1104 * 1105 * After permission checking, add a sigio structure to the sigio list for 1106 * the process or process group. 1107 */ 1108 int 1109 fsetown(pid_t pgid, struct sigio **sigiop) 1110 { 1111 struct proc *proc; 1112 struct pgrp *pgrp; 1113 struct sigio *sigio; 1114 int ret; 1115 1116 if (pgid == 0) { 1117 funsetown(sigiop); 1118 return (0); 1119 } 1120 1121 ret = 0; 1122 1123 /* Allocate and fill in the new sigio out of locks. */ 1124 sigio = malloc(sizeof(struct sigio), M_SIGIO, M_WAITOK); 1125 sigio->sio_pgid = pgid; 1126 sigio->sio_ucred = crhold(curthread->td_ucred); 1127 sigio->sio_myref = sigiop; 1128 1129 sx_slock(&proctree_lock); 1130 if (pgid > 0) { 1131 proc = pfind(pgid); 1132 if (proc == NULL) { 1133 ret = ESRCH; 1134 goto fail; 1135 } 1136 1137 /* 1138 * Policy - Don't allow a process to FSETOWN a process 1139 * in another session. 1140 * 1141 * Remove this test to allow maximum flexibility or 1142 * restrict FSETOWN to the current process or process 1143 * group for maximum safety. 1144 */ 1145 PROC_UNLOCK(proc); 1146 if (proc->p_session != curthread->td_proc->p_session) { 1147 ret = EPERM; 1148 goto fail; 1149 } 1150 1151 pgrp = NULL; 1152 } else /* if (pgid < 0) */ { 1153 pgrp = pgfind(-pgid); 1154 if (pgrp == NULL) { 1155 ret = ESRCH; 1156 goto fail; 1157 } 1158 PGRP_UNLOCK(pgrp); 1159 1160 /* 1161 * Policy - Don't allow a process to FSETOWN a process 1162 * in another session. 1163 * 1164 * Remove this test to allow maximum flexibility or 1165 * restrict FSETOWN to the current process or process 1166 * group for maximum safety. 1167 */ 1168 if (pgrp->pg_session != curthread->td_proc->p_session) { 1169 ret = EPERM; 1170 goto fail; 1171 } 1172 1173 proc = NULL; 1174 } 1175 funsetown(sigiop); 1176 if (pgid > 0) { 1177 PROC_LOCK(proc); 1178 /* 1179 * Since funsetownlst() is called without the proctree 1180 * locked, we need to check for P_WEXIT. 1181 * XXX: is ESRCH correct? 1182 */ 1183 if ((proc->p_flag & P_WEXIT) != 0) { 1184 PROC_UNLOCK(proc); 1185 ret = ESRCH; 1186 goto fail; 1187 } 1188 SLIST_INSERT_HEAD(&proc->p_sigiolst, sigio, sio_pgsigio); 1189 sigio->sio_proc = proc; 1190 PROC_UNLOCK(proc); 1191 } else { 1192 PGRP_LOCK(pgrp); 1193 SLIST_INSERT_HEAD(&pgrp->pg_sigiolst, sigio, sio_pgsigio); 1194 sigio->sio_pgrp = pgrp; 1195 PGRP_UNLOCK(pgrp); 1196 } 1197 sx_sunlock(&proctree_lock); 1198 SIGIO_LOCK(); 1199 *sigiop = sigio; 1200 SIGIO_UNLOCK(); 1201 return (0); 1202 1203 fail: 1204 sx_sunlock(&proctree_lock); 1205 crfree(sigio->sio_ucred); 1206 free(sigio, M_SIGIO); 1207 return (ret); 1208 } 1209 1210 /* 1211 * This is common code for FIOGETOWN ioctl called by fcntl(fd, F_GETOWN, arg). 1212 */ 1213 pid_t 1214 fgetown(struct sigio **sigiop) 1215 { 1216 pid_t pgid; 1217 1218 SIGIO_LOCK(); 1219 pgid = (*sigiop != NULL) ? (*sigiop)->sio_pgid : 0; 1220 SIGIO_UNLOCK(); 1221 return (pgid); 1222 } 1223 1224 /* 1225 * Function drops the filedesc lock on return. 1226 */ 1227 static int 1228 closefp(struct filedesc *fdp, int fd, struct file *fp, struct thread *td, 1229 int holdleaders) 1230 { 1231 int error; 1232 1233 FILEDESC_XLOCK_ASSERT(fdp); 1234 1235 if (holdleaders) { 1236 if (td->td_proc->p_fdtol != NULL) { 1237 /* 1238 * Ask fdfree() to sleep to ensure that all relevant 1239 * process leaders can be traversed in closef(). 1240 */ 1241 fdp->fd_holdleaderscount++; 1242 } else { 1243 holdleaders = 0; 1244 } 1245 } 1246 1247 /* 1248 * We now hold the fp reference that used to be owned by the 1249 * descriptor array. We have to unlock the FILEDESC *AFTER* 1250 * knote_fdclose to prevent a race of the fd getting opened, a knote 1251 * added, and deleteing a knote for the new fd. 1252 */ 1253 if (__predict_false(!TAILQ_EMPTY(&fdp->fd_kqlist))) 1254 knote_fdclose(td, fd); 1255 1256 /* 1257 * We need to notify mqueue if the object is of type mqueue. 1258 */ 1259 if (__predict_false(fp->f_type == DTYPE_MQUEUE)) 1260 mq_fdclose(td, fd, fp); 1261 FILEDESC_XUNLOCK(fdp); 1262 1263 error = closef(fp, td); 1264 if (holdleaders) { 1265 FILEDESC_XLOCK(fdp); 1266 fdp->fd_holdleaderscount--; 1267 if (fdp->fd_holdleaderscount == 0 && 1268 fdp->fd_holdleaderswakeup != 0) { 1269 fdp->fd_holdleaderswakeup = 0; 1270 wakeup(&fdp->fd_holdleaderscount); 1271 } 1272 FILEDESC_XUNLOCK(fdp); 1273 } 1274 return (error); 1275 } 1276 1277 /* 1278 * Close a file descriptor. 1279 */ 1280 #ifndef _SYS_SYSPROTO_H_ 1281 struct close_args { 1282 int fd; 1283 }; 1284 #endif 1285 /* ARGSUSED */ 1286 int 1287 sys_close(struct thread *td, struct close_args *uap) 1288 { 1289 1290 return (kern_close(td, uap->fd)); 1291 } 1292 1293 int 1294 kern_close(struct thread *td, int fd) 1295 { 1296 struct filedesc *fdp; 1297 struct file *fp; 1298 1299 fdp = td->td_proc->p_fd; 1300 1301 AUDIT_SYSCLOSE(td, fd); 1302 1303 FILEDESC_XLOCK(fdp); 1304 if ((fp = fget_locked(fdp, fd)) == NULL) { 1305 FILEDESC_XUNLOCK(fdp); 1306 return (EBADF); 1307 } 1308 fdfree(fdp, fd); 1309 1310 /* closefp() drops the FILEDESC lock for us. */ 1311 return (closefp(fdp, fd, fp, td, 1)); 1312 } 1313 1314 int 1315 kern_close_range(struct thread *td, u_int lowfd, u_int highfd) 1316 { 1317 struct filedesc *fdp; 1318 int fd, ret, lastfile; 1319 1320 ret = 0; 1321 fdp = td->td_proc->p_fd; 1322 FILEDESC_SLOCK(fdp); 1323 1324 /* 1325 * Check this prior to clamping; closefrom(3) with only fd 0, 1, and 2 1326 * open should not be a usage error. From a close_range() perspective, 1327 * close_range(3, ~0U, 0) in the same scenario should also likely not 1328 * be a usage error as all fd above 3 are in-fact already closed. 1329 */ 1330 if (highfd < lowfd) { 1331 ret = EINVAL; 1332 goto out; 1333 } 1334 1335 /* 1336 * If lastfile == -1, we're dealing with either a fresh file 1337 * table or one in which every fd has been closed. Just return 1338 * successful; there's nothing left to do. 1339 */ 1340 lastfile = fdlastfile(fdp); 1341 if (lastfile == -1) 1342 goto out; 1343 /* Clamped to [lowfd, lastfile] */ 1344 highfd = MIN(highfd, lastfile); 1345 for (fd = lowfd; fd <= highfd; fd++) { 1346 if (fdp->fd_ofiles[fd].fde_file != NULL) { 1347 FILEDESC_SUNLOCK(fdp); 1348 (void)kern_close(td, fd); 1349 FILEDESC_SLOCK(fdp); 1350 } 1351 } 1352 out: 1353 FILEDESC_SUNLOCK(fdp); 1354 return (ret); 1355 } 1356 1357 #ifndef _SYS_SYSPROTO_H_ 1358 struct close_range_args { 1359 u_int lowfd; 1360 u_int highfd; 1361 int flags; 1362 }; 1363 #endif 1364 int 1365 sys_close_range(struct thread *td, struct close_range_args *uap) 1366 { 1367 1368 /* No flags currently defined */ 1369 if (uap->flags != 0) 1370 return (EINVAL); 1371 return (kern_close_range(td, uap->lowfd, uap->highfd)); 1372 } 1373 1374 #ifdef COMPAT_FREEBSD12 1375 /* 1376 * Close open file descriptors. 1377 */ 1378 #ifndef _SYS_SYSPROTO_H_ 1379 struct freebsd12_closefrom_args { 1380 int lowfd; 1381 }; 1382 #endif 1383 /* ARGSUSED */ 1384 int 1385 freebsd12_closefrom(struct thread *td, struct freebsd12_closefrom_args *uap) 1386 { 1387 u_int lowfd; 1388 1389 AUDIT_ARG_FD(uap->lowfd); 1390 1391 /* 1392 * Treat negative starting file descriptor values identical to 1393 * closefrom(0) which closes all files. 1394 */ 1395 lowfd = MAX(0, uap->lowfd); 1396 return (kern_close_range(td, lowfd, ~0U)); 1397 } 1398 #endif /* COMPAT_FREEBSD12 */ 1399 1400 #if defined(COMPAT_43) 1401 /* 1402 * Return status information about a file descriptor. 1403 */ 1404 #ifndef _SYS_SYSPROTO_H_ 1405 struct ofstat_args { 1406 int fd; 1407 struct ostat *sb; 1408 }; 1409 #endif 1410 /* ARGSUSED */ 1411 int 1412 ofstat(struct thread *td, struct ofstat_args *uap) 1413 { 1414 struct ostat oub; 1415 struct stat ub; 1416 int error; 1417 1418 error = kern_fstat(td, uap->fd, &ub); 1419 if (error == 0) { 1420 cvtstat(&ub, &oub); 1421 error = copyout(&oub, uap->sb, sizeof(oub)); 1422 } 1423 return (error); 1424 } 1425 #endif /* COMPAT_43 */ 1426 1427 #if defined(COMPAT_FREEBSD11) 1428 int 1429 freebsd11_fstat(struct thread *td, struct freebsd11_fstat_args *uap) 1430 { 1431 struct stat sb; 1432 struct freebsd11_stat osb; 1433 int error; 1434 1435 error = kern_fstat(td, uap->fd, &sb); 1436 if (error != 0) 1437 return (error); 1438 error = freebsd11_cvtstat(&sb, &osb); 1439 if (error == 0) 1440 error = copyout(&osb, uap->sb, sizeof(osb)); 1441 return (error); 1442 } 1443 #endif /* COMPAT_FREEBSD11 */ 1444 1445 /* 1446 * Return status information about a file descriptor. 1447 */ 1448 #ifndef _SYS_SYSPROTO_H_ 1449 struct fstat_args { 1450 int fd; 1451 struct stat *sb; 1452 }; 1453 #endif 1454 /* ARGSUSED */ 1455 int 1456 sys_fstat(struct thread *td, struct fstat_args *uap) 1457 { 1458 struct stat ub; 1459 int error; 1460 1461 error = kern_fstat(td, uap->fd, &ub); 1462 if (error == 0) 1463 error = copyout(&ub, uap->sb, sizeof(ub)); 1464 return (error); 1465 } 1466 1467 int 1468 kern_fstat(struct thread *td, int fd, struct stat *sbp) 1469 { 1470 struct file *fp; 1471 int error; 1472 1473 AUDIT_ARG_FD(fd); 1474 1475 error = fget(td, fd, &cap_fstat_rights, &fp); 1476 if (__predict_false(error != 0)) 1477 return (error); 1478 1479 AUDIT_ARG_FILE(td->td_proc, fp); 1480 1481 error = fo_stat(fp, sbp, td->td_ucred, td); 1482 fdrop(fp, td); 1483 #ifdef __STAT_TIME_T_EXT 1484 sbp->st_atim_ext = 0; 1485 sbp->st_mtim_ext = 0; 1486 sbp->st_ctim_ext = 0; 1487 sbp->st_btim_ext = 0; 1488 #endif 1489 #ifdef KTRACE 1490 if (KTRPOINT(td, KTR_STRUCT)) 1491 ktrstat_error(sbp, error); 1492 #endif 1493 return (error); 1494 } 1495 1496 #if defined(COMPAT_FREEBSD11) 1497 /* 1498 * Return status information about a file descriptor. 1499 */ 1500 #ifndef _SYS_SYSPROTO_H_ 1501 struct freebsd11_nfstat_args { 1502 int fd; 1503 struct nstat *sb; 1504 }; 1505 #endif 1506 /* ARGSUSED */ 1507 int 1508 freebsd11_nfstat(struct thread *td, struct freebsd11_nfstat_args *uap) 1509 { 1510 struct nstat nub; 1511 struct stat ub; 1512 int error; 1513 1514 error = kern_fstat(td, uap->fd, &ub); 1515 if (error == 0) { 1516 freebsd11_cvtnstat(&ub, &nub); 1517 error = copyout(&nub, uap->sb, sizeof(nub)); 1518 } 1519 return (error); 1520 } 1521 #endif /* COMPAT_FREEBSD11 */ 1522 1523 /* 1524 * Return pathconf information about a file descriptor. 1525 */ 1526 #ifndef _SYS_SYSPROTO_H_ 1527 struct fpathconf_args { 1528 int fd; 1529 int name; 1530 }; 1531 #endif 1532 /* ARGSUSED */ 1533 int 1534 sys_fpathconf(struct thread *td, struct fpathconf_args *uap) 1535 { 1536 long value; 1537 int error; 1538 1539 error = kern_fpathconf(td, uap->fd, uap->name, &value); 1540 if (error == 0) 1541 td->td_retval[0] = value; 1542 return (error); 1543 } 1544 1545 int 1546 kern_fpathconf(struct thread *td, int fd, int name, long *valuep) 1547 { 1548 struct file *fp; 1549 struct vnode *vp; 1550 int error; 1551 1552 error = fget(td, fd, &cap_fpathconf_rights, &fp); 1553 if (error != 0) 1554 return (error); 1555 1556 if (name == _PC_ASYNC_IO) { 1557 *valuep = _POSIX_ASYNCHRONOUS_IO; 1558 goto out; 1559 } 1560 vp = fp->f_vnode; 1561 if (vp != NULL) { 1562 vn_lock(vp, LK_SHARED | LK_RETRY); 1563 error = VOP_PATHCONF(vp, name, valuep); 1564 VOP_UNLOCK(vp); 1565 } else if (fp->f_type == DTYPE_PIPE || fp->f_type == DTYPE_SOCKET) { 1566 if (name != _PC_PIPE_BUF) { 1567 error = EINVAL; 1568 } else { 1569 *valuep = PIPE_BUF; 1570 error = 0; 1571 } 1572 } else { 1573 error = EOPNOTSUPP; 1574 } 1575 out: 1576 fdrop(fp, td); 1577 return (error); 1578 } 1579 1580 /* 1581 * Copy filecaps structure allocating memory for ioctls array if needed. 1582 * 1583 * The last parameter indicates whether the fdtable is locked. If it is not and 1584 * ioctls are encountered, copying fails and the caller must lock the table. 1585 * 1586 * Note that if the table was not locked, the caller has to check the relevant 1587 * sequence counter to determine whether the operation was successful. 1588 */ 1589 bool 1590 filecaps_copy(const struct filecaps *src, struct filecaps *dst, bool locked) 1591 { 1592 size_t size; 1593 1594 if (src->fc_ioctls != NULL && !locked) 1595 return (false); 1596 memcpy(dst, src, sizeof(*src)); 1597 if (src->fc_ioctls == NULL) 1598 return (true); 1599 1600 KASSERT(src->fc_nioctls > 0, 1601 ("fc_ioctls != NULL, but fc_nioctls=%hd", src->fc_nioctls)); 1602 1603 size = sizeof(src->fc_ioctls[0]) * src->fc_nioctls; 1604 dst->fc_ioctls = malloc(size, M_FILECAPS, M_WAITOK); 1605 memcpy(dst->fc_ioctls, src->fc_ioctls, size); 1606 return (true); 1607 } 1608 1609 static u_long * 1610 filecaps_copy_prep(const struct filecaps *src) 1611 { 1612 u_long *ioctls; 1613 size_t size; 1614 1615 if (__predict_true(src->fc_ioctls == NULL)) 1616 return (NULL); 1617 1618 KASSERT(src->fc_nioctls > 0, 1619 ("fc_ioctls != NULL, but fc_nioctls=%hd", src->fc_nioctls)); 1620 1621 size = sizeof(src->fc_ioctls[0]) * src->fc_nioctls; 1622 ioctls = malloc(size, M_FILECAPS, M_WAITOK); 1623 return (ioctls); 1624 } 1625 1626 static void 1627 filecaps_copy_finish(const struct filecaps *src, struct filecaps *dst, 1628 u_long *ioctls) 1629 { 1630 size_t size; 1631 1632 *dst = *src; 1633 if (__predict_true(src->fc_ioctls == NULL)) { 1634 MPASS(ioctls == NULL); 1635 return; 1636 } 1637 1638 size = sizeof(src->fc_ioctls[0]) * src->fc_nioctls; 1639 dst->fc_ioctls = ioctls; 1640 bcopy(src->fc_ioctls, dst->fc_ioctls, size); 1641 } 1642 1643 /* 1644 * Move filecaps structure to the new place and clear the old place. 1645 */ 1646 void 1647 filecaps_move(struct filecaps *src, struct filecaps *dst) 1648 { 1649 1650 *dst = *src; 1651 bzero(src, sizeof(*src)); 1652 } 1653 1654 /* 1655 * Fill the given filecaps structure with full rights. 1656 */ 1657 static void 1658 filecaps_fill(struct filecaps *fcaps) 1659 { 1660 1661 CAP_ALL(&fcaps->fc_rights); 1662 fcaps->fc_ioctls = NULL; 1663 fcaps->fc_nioctls = -1; 1664 fcaps->fc_fcntls = CAP_FCNTL_ALL; 1665 } 1666 1667 /* 1668 * Free memory allocated within filecaps structure. 1669 */ 1670 void 1671 filecaps_free(struct filecaps *fcaps) 1672 { 1673 1674 free(fcaps->fc_ioctls, M_FILECAPS); 1675 bzero(fcaps, sizeof(*fcaps)); 1676 } 1677 1678 static u_long * 1679 filecaps_free_prep(struct filecaps *fcaps) 1680 { 1681 u_long *ioctls; 1682 1683 ioctls = fcaps->fc_ioctls; 1684 bzero(fcaps, sizeof(*fcaps)); 1685 return (ioctls); 1686 } 1687 1688 static void 1689 filecaps_free_finish(u_long *ioctls) 1690 { 1691 1692 free(ioctls, M_FILECAPS); 1693 } 1694 1695 /* 1696 * Validate the given filecaps structure. 1697 */ 1698 static void 1699 filecaps_validate(const struct filecaps *fcaps, const char *func) 1700 { 1701 1702 KASSERT(cap_rights_is_valid(&fcaps->fc_rights), 1703 ("%s: invalid rights", func)); 1704 KASSERT((fcaps->fc_fcntls & ~CAP_FCNTL_ALL) == 0, 1705 ("%s: invalid fcntls", func)); 1706 KASSERT(fcaps->fc_fcntls == 0 || 1707 cap_rights_is_set(&fcaps->fc_rights, CAP_FCNTL), 1708 ("%s: fcntls without CAP_FCNTL", func)); 1709 KASSERT(fcaps->fc_ioctls != NULL ? fcaps->fc_nioctls > 0 : 1710 (fcaps->fc_nioctls == -1 || fcaps->fc_nioctls == 0), 1711 ("%s: invalid ioctls", func)); 1712 KASSERT(fcaps->fc_nioctls == 0 || 1713 cap_rights_is_set(&fcaps->fc_rights, CAP_IOCTL), 1714 ("%s: ioctls without CAP_IOCTL", func)); 1715 } 1716 1717 static void 1718 fdgrowtable_exp(struct filedesc *fdp, int nfd) 1719 { 1720 int nfd1; 1721 1722 FILEDESC_XLOCK_ASSERT(fdp); 1723 1724 nfd1 = fdp->fd_nfiles * 2; 1725 if (nfd1 < nfd) 1726 nfd1 = nfd; 1727 fdgrowtable(fdp, nfd1); 1728 } 1729 1730 /* 1731 * Grow the file table to accommodate (at least) nfd descriptors. 1732 */ 1733 static void 1734 fdgrowtable(struct filedesc *fdp, int nfd) 1735 { 1736 struct filedesc0 *fdp0; 1737 struct freetable *ft; 1738 struct fdescenttbl *ntable; 1739 struct fdescenttbl *otable; 1740 int nnfiles, onfiles; 1741 NDSLOTTYPE *nmap, *omap; 1742 1743 KASSERT(fdp->fd_nfiles > 0, ("zero-length file table")); 1744 1745 /* save old values */ 1746 onfiles = fdp->fd_nfiles; 1747 otable = fdp->fd_files; 1748 omap = fdp->fd_map; 1749 1750 /* compute the size of the new table */ 1751 nnfiles = NDSLOTS(nfd) * NDENTRIES; /* round up */ 1752 if (nnfiles <= onfiles) 1753 /* the table is already large enough */ 1754 return; 1755 1756 /* 1757 * Allocate a new table. We need enough space for the number of 1758 * entries, file entries themselves and the struct freetable we will use 1759 * when we decommission the table and place it on the freelist. 1760 * We place the struct freetable in the middle so we don't have 1761 * to worry about padding. 1762 */ 1763 ntable = malloc(offsetof(struct fdescenttbl, fdt_ofiles) + 1764 nnfiles * sizeof(ntable->fdt_ofiles[0]) + 1765 sizeof(struct freetable), 1766 M_FILEDESC, M_ZERO | M_WAITOK); 1767 /* copy the old data */ 1768 ntable->fdt_nfiles = nnfiles; 1769 memcpy(ntable->fdt_ofiles, otable->fdt_ofiles, 1770 onfiles * sizeof(ntable->fdt_ofiles[0])); 1771 1772 /* 1773 * Allocate a new map only if the old is not large enough. It will 1774 * grow at a slower rate than the table as it can map more 1775 * entries than the table can hold. 1776 */ 1777 if (NDSLOTS(nnfiles) > NDSLOTS(onfiles)) { 1778 nmap = malloc(NDSLOTS(nnfiles) * NDSLOTSIZE, M_FILEDESC, 1779 M_ZERO | M_WAITOK); 1780 /* copy over the old data and update the pointer */ 1781 memcpy(nmap, omap, NDSLOTS(onfiles) * sizeof(*omap)); 1782 fdp->fd_map = nmap; 1783 } 1784 1785 /* 1786 * Make sure that ntable is correctly initialized before we replace 1787 * fd_files poiner. Otherwise fget_unlocked() may see inconsistent 1788 * data. 1789 */ 1790 atomic_store_rel_ptr((volatile void *)&fdp->fd_files, (uintptr_t)ntable); 1791 1792 /* 1793 * Do not free the old file table, as some threads may still 1794 * reference entries within it. Instead, place it on a freelist 1795 * which will be processed when the struct filedesc is released. 1796 * 1797 * Note that if onfiles == NDFILE, we're dealing with the original 1798 * static allocation contained within (struct filedesc0 *)fdp, 1799 * which must not be freed. 1800 */ 1801 if (onfiles > NDFILE) { 1802 ft = (struct freetable *)&otable->fdt_ofiles[onfiles]; 1803 fdp0 = (struct filedesc0 *)fdp; 1804 ft->ft_table = otable; 1805 SLIST_INSERT_HEAD(&fdp0->fd_free, ft, ft_next); 1806 } 1807 /* 1808 * The map does not have the same possibility of threads still 1809 * holding references to it. So always free it as long as it 1810 * does not reference the original static allocation. 1811 */ 1812 if (NDSLOTS(onfiles) > NDSLOTS(NDFILE)) 1813 free(omap, M_FILEDESC); 1814 } 1815 1816 /* 1817 * Allocate a file descriptor for the process. 1818 */ 1819 int 1820 fdalloc(struct thread *td, int minfd, int *result) 1821 { 1822 struct proc *p = td->td_proc; 1823 struct filedesc *fdp = p->p_fd; 1824 int fd, maxfd, allocfd; 1825 #ifdef RACCT 1826 int error; 1827 #endif 1828 1829 FILEDESC_XLOCK_ASSERT(fdp); 1830 1831 if (fdp->fd_freefile > minfd) 1832 minfd = fdp->fd_freefile; 1833 1834 maxfd = getmaxfd(td); 1835 1836 /* 1837 * Search the bitmap for a free descriptor starting at minfd. 1838 * If none is found, grow the file table. 1839 */ 1840 fd = fd_first_free(fdp, minfd, fdp->fd_nfiles); 1841 if (__predict_false(fd >= maxfd)) 1842 return (EMFILE); 1843 if (__predict_false(fd >= fdp->fd_nfiles)) { 1844 allocfd = min(fd * 2, maxfd); 1845 #ifdef RACCT 1846 if (RACCT_ENABLED()) { 1847 error = racct_set_unlocked(p, RACCT_NOFILE, allocfd); 1848 if (error != 0) 1849 return (EMFILE); 1850 } 1851 #endif 1852 /* 1853 * fd is already equal to first free descriptor >= minfd, so 1854 * we only need to grow the table and we are done. 1855 */ 1856 fdgrowtable_exp(fdp, allocfd); 1857 } 1858 1859 /* 1860 * Perform some sanity checks, then mark the file descriptor as 1861 * used and return it to the caller. 1862 */ 1863 KASSERT(fd >= 0 && fd < min(maxfd, fdp->fd_nfiles), 1864 ("invalid descriptor %d", fd)); 1865 KASSERT(!fdisused(fdp, fd), 1866 ("fd_first_free() returned non-free descriptor")); 1867 KASSERT(fdp->fd_ofiles[fd].fde_file == NULL, 1868 ("file descriptor isn't free")); 1869 fdused(fdp, fd); 1870 *result = fd; 1871 return (0); 1872 } 1873 1874 /* 1875 * Allocate n file descriptors for the process. 1876 */ 1877 int 1878 fdallocn(struct thread *td, int minfd, int *fds, int n) 1879 { 1880 struct proc *p = td->td_proc; 1881 struct filedesc *fdp = p->p_fd; 1882 int i; 1883 1884 FILEDESC_XLOCK_ASSERT(fdp); 1885 1886 for (i = 0; i < n; i++) 1887 if (fdalloc(td, 0, &fds[i]) != 0) 1888 break; 1889 1890 if (i < n) { 1891 for (i--; i >= 0; i--) 1892 fdunused(fdp, fds[i]); 1893 return (EMFILE); 1894 } 1895 1896 return (0); 1897 } 1898 1899 /* 1900 * Create a new open file structure and allocate a file descriptor for the 1901 * process that refers to it. We add one reference to the file for the 1902 * descriptor table and one reference for resultfp. This is to prevent us 1903 * being preempted and the entry in the descriptor table closed after we 1904 * release the FILEDESC lock. 1905 */ 1906 int 1907 falloc_caps(struct thread *td, struct file **resultfp, int *resultfd, int flags, 1908 struct filecaps *fcaps) 1909 { 1910 struct file *fp; 1911 int error, fd; 1912 1913 error = falloc_noinstall(td, &fp); 1914 if (error) 1915 return (error); /* no reference held on error */ 1916 1917 error = finstall(td, fp, &fd, flags, fcaps); 1918 if (error) { 1919 fdrop(fp, td); /* one reference (fp only) */ 1920 return (error); 1921 } 1922 1923 if (resultfp != NULL) 1924 *resultfp = fp; /* copy out result */ 1925 else 1926 fdrop(fp, td); /* release local reference */ 1927 1928 if (resultfd != NULL) 1929 *resultfd = fd; 1930 1931 return (0); 1932 } 1933 1934 /* 1935 * Create a new open file structure without allocating a file descriptor. 1936 */ 1937 int 1938 falloc_noinstall(struct thread *td, struct file **resultfp) 1939 { 1940 struct file *fp; 1941 int maxuserfiles = maxfiles - (maxfiles / 20); 1942 int openfiles_new; 1943 static struct timeval lastfail; 1944 static int curfail; 1945 1946 KASSERT(resultfp != NULL, ("%s: resultfp == NULL", __func__)); 1947 1948 openfiles_new = atomic_fetchadd_int(&openfiles, 1) + 1; 1949 if ((openfiles_new >= maxuserfiles && 1950 priv_check(td, PRIV_MAXFILES) != 0) || 1951 openfiles_new >= maxfiles) { 1952 atomic_subtract_int(&openfiles, 1); 1953 if (ppsratecheck(&lastfail, &curfail, 1)) { 1954 printf("kern.maxfiles limit exceeded by uid %i, (%s) " 1955 "please see tuning(7).\n", td->td_ucred->cr_ruid, td->td_proc->p_comm); 1956 } 1957 return (ENFILE); 1958 } 1959 fp = uma_zalloc(file_zone, M_WAITOK); 1960 bzero(fp, sizeof(*fp)); 1961 refcount_init(&fp->f_count, 1); 1962 fp->f_cred = crhold(td->td_ucred); 1963 fp->f_ops = &badfileops; 1964 *resultfp = fp; 1965 return (0); 1966 } 1967 1968 /* 1969 * Install a file in a file descriptor table. 1970 */ 1971 void 1972 _finstall(struct filedesc *fdp, struct file *fp, int fd, int flags, 1973 struct filecaps *fcaps) 1974 { 1975 struct filedescent *fde; 1976 1977 MPASS(fp != NULL); 1978 if (fcaps != NULL) 1979 filecaps_validate(fcaps, __func__); 1980 FILEDESC_XLOCK_ASSERT(fdp); 1981 1982 fde = &fdp->fd_ofiles[fd]; 1983 #ifdef CAPABILITIES 1984 seqc_write_begin(&fde->fde_seqc); 1985 #endif 1986 fde->fde_file = fp; 1987 fde->fde_flags = (flags & O_CLOEXEC) != 0 ? UF_EXCLOSE : 0; 1988 if (fcaps != NULL) 1989 filecaps_move(fcaps, &fde->fde_caps); 1990 else 1991 filecaps_fill(&fde->fde_caps); 1992 #ifdef CAPABILITIES 1993 seqc_write_end(&fde->fde_seqc); 1994 #endif 1995 } 1996 1997 int 1998 finstall(struct thread *td, struct file *fp, int *fd, int flags, 1999 struct filecaps *fcaps) 2000 { 2001 struct filedesc *fdp = td->td_proc->p_fd; 2002 int error; 2003 2004 MPASS(fd != NULL); 2005 2006 if (!fhold(fp)) 2007 return (EBADF); 2008 FILEDESC_XLOCK(fdp); 2009 error = fdalloc(td, 0, fd); 2010 if (__predict_false(error != 0)) { 2011 FILEDESC_XUNLOCK(fdp); 2012 fdrop(fp, td); 2013 return (error); 2014 } 2015 _finstall(fdp, fp, *fd, flags, fcaps); 2016 FILEDESC_XUNLOCK(fdp); 2017 return (0); 2018 } 2019 2020 /* 2021 * Build a new filedesc structure from another. 2022 * Copy the current, root, and jail root vnode references. 2023 * 2024 * If fdp is not NULL, return with it shared locked. 2025 */ 2026 struct filedesc * 2027 fdinit(struct filedesc *fdp, bool prepfiles, int *lastfile) 2028 { 2029 struct filedesc0 *newfdp0; 2030 struct filedesc *newfdp; 2031 struct pwd *newpwd; 2032 2033 if (prepfiles) 2034 MPASS(lastfile != NULL); 2035 else 2036 MPASS(lastfile == NULL); 2037 2038 newfdp0 = uma_zalloc(filedesc0_zone, M_WAITOK | M_ZERO); 2039 newfdp = &newfdp0->fd_fd; 2040 2041 /* Create the file descriptor table. */ 2042 FILEDESC_LOCK_INIT(newfdp); 2043 refcount_init(&newfdp->fd_refcnt, 1); 2044 refcount_init(&newfdp->fd_holdcnt, 1); 2045 newfdp->fd_cmask = CMASK; 2046 newfdp->fd_map = newfdp0->fd_dmap; 2047 newfdp->fd_files = (struct fdescenttbl *)&newfdp0->fd_dfiles; 2048 newfdp->fd_files->fdt_nfiles = NDFILE; 2049 2050 if (fdp == NULL) { 2051 newpwd = pwd_alloc(); 2052 smr_serialized_store(&newfdp->fd_pwd, newpwd, true); 2053 return (newfdp); 2054 } 2055 2056 FILEDESC_SLOCK(fdp); 2057 newpwd = pwd_hold_filedesc(fdp); 2058 smr_serialized_store(&newfdp->fd_pwd, newpwd, true); 2059 if (!prepfiles) { 2060 FILEDESC_SUNLOCK(fdp); 2061 return (newfdp); 2062 } 2063 2064 for (;;) { 2065 *lastfile = fdlastfile(fdp); 2066 if (*lastfile < newfdp->fd_nfiles) 2067 break; 2068 FILEDESC_SUNLOCK(fdp); 2069 fdgrowtable(newfdp, *lastfile + 1); 2070 FILEDESC_SLOCK(fdp); 2071 } 2072 2073 return (newfdp); 2074 } 2075 2076 static struct filedesc * 2077 fdhold(struct proc *p) 2078 { 2079 struct filedesc *fdp; 2080 2081 PROC_LOCK_ASSERT(p, MA_OWNED); 2082 fdp = p->p_fd; 2083 if (fdp != NULL) 2084 refcount_acquire(&fdp->fd_holdcnt); 2085 return (fdp); 2086 } 2087 2088 static void 2089 fddrop(struct filedesc *fdp) 2090 { 2091 2092 if (fdp->fd_holdcnt > 1) { 2093 if (refcount_release(&fdp->fd_holdcnt) == 0) 2094 return; 2095 } 2096 2097 FILEDESC_LOCK_DESTROY(fdp); 2098 uma_zfree(filedesc0_zone, fdp); 2099 } 2100 2101 /* 2102 * Share a filedesc structure. 2103 */ 2104 struct filedesc * 2105 fdshare(struct filedesc *fdp) 2106 { 2107 2108 refcount_acquire(&fdp->fd_refcnt); 2109 return (fdp); 2110 } 2111 2112 /* 2113 * Unshare a filedesc structure, if necessary by making a copy 2114 */ 2115 void 2116 fdunshare(struct thread *td) 2117 { 2118 struct filedesc *tmp; 2119 struct proc *p = td->td_proc; 2120 2121 if (p->p_fd->fd_refcnt == 1) 2122 return; 2123 2124 tmp = fdcopy(p->p_fd); 2125 fdescfree(td); 2126 p->p_fd = tmp; 2127 } 2128 2129 void 2130 fdinstall_remapped(struct thread *td, struct filedesc *fdp) 2131 { 2132 2133 fdescfree(td); 2134 td->td_proc->p_fd = fdp; 2135 } 2136 2137 /* 2138 * Copy a filedesc structure. A NULL pointer in returns a NULL reference, 2139 * this is to ease callers, not catch errors. 2140 */ 2141 struct filedesc * 2142 fdcopy(struct filedesc *fdp) 2143 { 2144 struct filedesc *newfdp; 2145 struct filedescent *nfde, *ofde; 2146 int i, lastfile; 2147 2148 MPASS(fdp != NULL); 2149 2150 newfdp = fdinit(fdp, true, &lastfile); 2151 /* copy all passable descriptors (i.e. not kqueue) */ 2152 newfdp->fd_freefile = -1; 2153 for (i = 0; i <= lastfile; ++i) { 2154 ofde = &fdp->fd_ofiles[i]; 2155 if (ofde->fde_file == NULL || 2156 (ofde->fde_file->f_ops->fo_flags & DFLAG_PASSABLE) == 0 || 2157 !fhold(ofde->fde_file)) { 2158 if (newfdp->fd_freefile == -1) 2159 newfdp->fd_freefile = i; 2160 continue; 2161 } 2162 nfde = &newfdp->fd_ofiles[i]; 2163 *nfde = *ofde; 2164 filecaps_copy(&ofde->fde_caps, &nfde->fde_caps, true); 2165 fdused_init(newfdp, i); 2166 } 2167 if (newfdp->fd_freefile == -1) 2168 newfdp->fd_freefile = i; 2169 newfdp->fd_cmask = fdp->fd_cmask; 2170 FILEDESC_SUNLOCK(fdp); 2171 return (newfdp); 2172 } 2173 2174 /* 2175 * Copies a filedesc structure, while remapping all file descriptors 2176 * stored inside using a translation table. 2177 * 2178 * File descriptors are copied over to the new file descriptor table, 2179 * regardless of whether the close-on-exec flag is set. 2180 */ 2181 int 2182 fdcopy_remapped(struct filedesc *fdp, const int *fds, size_t nfds, 2183 struct filedesc **ret) 2184 { 2185 struct filedesc *newfdp; 2186 struct filedescent *nfde, *ofde; 2187 int error, i, lastfile; 2188 2189 MPASS(fdp != NULL); 2190 2191 newfdp = fdinit(fdp, true, &lastfile); 2192 if (nfds > lastfile + 1) { 2193 /* New table cannot be larger than the old one. */ 2194 error = E2BIG; 2195 goto bad; 2196 } 2197 /* Copy all passable descriptors (i.e. not kqueue). */ 2198 newfdp->fd_freefile = nfds; 2199 for (i = 0; i < nfds; ++i) { 2200 if (fds[i] < 0 || fds[i] > lastfile) { 2201 /* File descriptor out of bounds. */ 2202 error = EBADF; 2203 goto bad; 2204 } 2205 ofde = &fdp->fd_ofiles[fds[i]]; 2206 if (ofde->fde_file == NULL) { 2207 /* Unused file descriptor. */ 2208 error = EBADF; 2209 goto bad; 2210 } 2211 if ((ofde->fde_file->f_ops->fo_flags & DFLAG_PASSABLE) == 0) { 2212 /* File descriptor cannot be passed. */ 2213 error = EINVAL; 2214 goto bad; 2215 } 2216 if (!fhold(nfde->fde_file)) { 2217 error = EBADF; 2218 goto bad; 2219 } 2220 nfde = &newfdp->fd_ofiles[i]; 2221 *nfde = *ofde; 2222 filecaps_copy(&ofde->fde_caps, &nfde->fde_caps, true); 2223 fdused_init(newfdp, i); 2224 } 2225 newfdp->fd_cmask = fdp->fd_cmask; 2226 FILEDESC_SUNLOCK(fdp); 2227 *ret = newfdp; 2228 return (0); 2229 bad: 2230 FILEDESC_SUNLOCK(fdp); 2231 fdescfree_remapped(newfdp); 2232 return (error); 2233 } 2234 2235 /* 2236 * Clear POSIX style locks. This is only used when fdp looses a reference (i.e. 2237 * one of processes using it exits) and the table used to be shared. 2238 */ 2239 static void 2240 fdclearlocks(struct thread *td) 2241 { 2242 struct filedesc *fdp; 2243 struct filedesc_to_leader *fdtol; 2244 struct flock lf; 2245 struct file *fp; 2246 struct proc *p; 2247 struct vnode *vp; 2248 int i, lastfile; 2249 2250 p = td->td_proc; 2251 fdp = p->p_fd; 2252 fdtol = p->p_fdtol; 2253 MPASS(fdtol != NULL); 2254 2255 FILEDESC_XLOCK(fdp); 2256 KASSERT(fdtol->fdl_refcount > 0, 2257 ("filedesc_to_refcount botch: fdl_refcount=%d", 2258 fdtol->fdl_refcount)); 2259 if (fdtol->fdl_refcount == 1 && 2260 (p->p_leader->p_flag & P_ADVLOCK) != 0) { 2261 lastfile = fdlastfile(fdp); 2262 for (i = 0; i <= lastfile; i++) { 2263 fp = fdp->fd_ofiles[i].fde_file; 2264 if (fp == NULL || fp->f_type != DTYPE_VNODE || 2265 !fhold(fp)) 2266 continue; 2267 FILEDESC_XUNLOCK(fdp); 2268 lf.l_whence = SEEK_SET; 2269 lf.l_start = 0; 2270 lf.l_len = 0; 2271 lf.l_type = F_UNLCK; 2272 vp = fp->f_vnode; 2273 (void) VOP_ADVLOCK(vp, 2274 (caddr_t)p->p_leader, F_UNLCK, 2275 &lf, F_POSIX); 2276 FILEDESC_XLOCK(fdp); 2277 fdrop(fp, td); 2278 } 2279 } 2280 retry: 2281 if (fdtol->fdl_refcount == 1) { 2282 if (fdp->fd_holdleaderscount > 0 && 2283 (p->p_leader->p_flag & P_ADVLOCK) != 0) { 2284 /* 2285 * close() or kern_dup() has cleared a reference 2286 * in a shared file descriptor table. 2287 */ 2288 fdp->fd_holdleaderswakeup = 1; 2289 sx_sleep(&fdp->fd_holdleaderscount, 2290 FILEDESC_LOCK(fdp), PLOCK, "fdlhold", 0); 2291 goto retry; 2292 } 2293 if (fdtol->fdl_holdcount > 0) { 2294 /* 2295 * Ensure that fdtol->fdl_leader remains 2296 * valid in closef(). 2297 */ 2298 fdtol->fdl_wakeup = 1; 2299 sx_sleep(fdtol, FILEDESC_LOCK(fdp), PLOCK, 2300 "fdlhold", 0); 2301 goto retry; 2302 } 2303 } 2304 fdtol->fdl_refcount--; 2305 if (fdtol->fdl_refcount == 0 && 2306 fdtol->fdl_holdcount == 0) { 2307 fdtol->fdl_next->fdl_prev = fdtol->fdl_prev; 2308 fdtol->fdl_prev->fdl_next = fdtol->fdl_next; 2309 } else 2310 fdtol = NULL; 2311 p->p_fdtol = NULL; 2312 FILEDESC_XUNLOCK(fdp); 2313 if (fdtol != NULL) 2314 free(fdtol, M_FILEDESC_TO_LEADER); 2315 } 2316 2317 /* 2318 * Release a filedesc structure. 2319 */ 2320 static void 2321 fdescfree_fds(struct thread *td, struct filedesc *fdp, bool needclose) 2322 { 2323 struct filedesc0 *fdp0; 2324 struct freetable *ft, *tft; 2325 struct filedescent *fde; 2326 struct file *fp; 2327 int i, lastfile; 2328 2329 lastfile = fdlastfile_single(fdp); 2330 for (i = 0; i <= lastfile; i++) { 2331 fde = &fdp->fd_ofiles[i]; 2332 fp = fde->fde_file; 2333 if (fp != NULL) { 2334 fdefree_last(fde); 2335 if (needclose) 2336 (void) closef(fp, td); 2337 else 2338 fdrop(fp, td); 2339 } 2340 } 2341 2342 if (NDSLOTS(fdp->fd_nfiles) > NDSLOTS(NDFILE)) 2343 free(fdp->fd_map, M_FILEDESC); 2344 if (fdp->fd_nfiles > NDFILE) 2345 free(fdp->fd_files, M_FILEDESC); 2346 2347 fdp0 = (struct filedesc0 *)fdp; 2348 SLIST_FOREACH_SAFE(ft, &fdp0->fd_free, ft_next, tft) 2349 free(ft->ft_table, M_FILEDESC); 2350 2351 fddrop(fdp); 2352 } 2353 2354 void 2355 fdescfree(struct thread *td) 2356 { 2357 struct proc *p; 2358 struct filedesc *fdp; 2359 struct pwd *pwd; 2360 2361 p = td->td_proc; 2362 fdp = p->p_fd; 2363 MPASS(fdp != NULL); 2364 2365 #ifdef RACCT 2366 if (RACCT_ENABLED()) 2367 racct_set_unlocked(p, RACCT_NOFILE, 0); 2368 #endif 2369 2370 if (p->p_fdtol != NULL) 2371 fdclearlocks(td); 2372 2373 PROC_LOCK(p); 2374 p->p_fd = NULL; 2375 PROC_UNLOCK(p); 2376 2377 if (refcount_release(&fdp->fd_refcnt) == 0) 2378 return; 2379 2380 FILEDESC_XLOCK(fdp); 2381 pwd = FILEDESC_XLOCKED_LOAD_PWD(fdp); 2382 pwd_set(fdp, NULL); 2383 FILEDESC_XUNLOCK(fdp); 2384 2385 pwd_drop(pwd); 2386 2387 fdescfree_fds(td, fdp, 1); 2388 } 2389 2390 void 2391 fdescfree_remapped(struct filedesc *fdp) 2392 { 2393 2394 pwd_drop(smr_serialized_load(&fdp->fd_pwd, true)); 2395 fdescfree_fds(curthread, fdp, 0); 2396 } 2397 2398 /* 2399 * For setugid programs, we don't want to people to use that setugidness 2400 * to generate error messages which write to a file which otherwise would 2401 * otherwise be off-limits to the process. We check for filesystems where 2402 * the vnode can change out from under us after execve (like [lin]procfs). 2403 * 2404 * Since fdsetugidsafety calls this only for fd 0, 1 and 2, this check is 2405 * sufficient. We also don't check for setugidness since we know we are. 2406 */ 2407 static bool 2408 is_unsafe(struct file *fp) 2409 { 2410 struct vnode *vp; 2411 2412 if (fp->f_type != DTYPE_VNODE) 2413 return (false); 2414 2415 vp = fp->f_vnode; 2416 return ((vp->v_vflag & VV_PROCDEP) != 0); 2417 } 2418 2419 /* 2420 * Make this setguid thing safe, if at all possible. 2421 */ 2422 void 2423 fdsetugidsafety(struct thread *td) 2424 { 2425 struct filedesc *fdp; 2426 struct file *fp; 2427 int i; 2428 2429 fdp = td->td_proc->p_fd; 2430 KASSERT(fdp->fd_refcnt == 1, ("the fdtable should not be shared")); 2431 MPASS(fdp->fd_nfiles >= 3); 2432 for (i = 0; i <= 2; i++) { 2433 fp = fdp->fd_ofiles[i].fde_file; 2434 if (fp != NULL && is_unsafe(fp)) { 2435 FILEDESC_XLOCK(fdp); 2436 knote_fdclose(td, i); 2437 /* 2438 * NULL-out descriptor prior to close to avoid 2439 * a race while close blocks. 2440 */ 2441 fdfree(fdp, i); 2442 FILEDESC_XUNLOCK(fdp); 2443 (void) closef(fp, td); 2444 } 2445 } 2446 } 2447 2448 /* 2449 * If a specific file object occupies a specific file descriptor, close the 2450 * file descriptor entry and drop a reference on the file object. This is a 2451 * convenience function to handle a subsequent error in a function that calls 2452 * falloc() that handles the race that another thread might have closed the 2453 * file descriptor out from under the thread creating the file object. 2454 */ 2455 void 2456 fdclose(struct thread *td, struct file *fp, int idx) 2457 { 2458 struct filedesc *fdp = td->td_proc->p_fd; 2459 2460 FILEDESC_XLOCK(fdp); 2461 if (fdp->fd_ofiles[idx].fde_file == fp) { 2462 fdfree(fdp, idx); 2463 FILEDESC_XUNLOCK(fdp); 2464 fdrop(fp, td); 2465 } else 2466 FILEDESC_XUNLOCK(fdp); 2467 } 2468 2469 /* 2470 * Close any files on exec? 2471 */ 2472 void 2473 fdcloseexec(struct thread *td) 2474 { 2475 struct filedesc *fdp; 2476 struct filedescent *fde; 2477 struct file *fp; 2478 int i, lastfile; 2479 2480 fdp = td->td_proc->p_fd; 2481 KASSERT(fdp->fd_refcnt == 1, ("the fdtable should not be shared")); 2482 lastfile = fdlastfile_single(fdp); 2483 for (i = 0; i <= lastfile; i++) { 2484 fde = &fdp->fd_ofiles[i]; 2485 fp = fde->fde_file; 2486 if (fp != NULL && (fp->f_type == DTYPE_MQUEUE || 2487 (fde->fde_flags & UF_EXCLOSE))) { 2488 FILEDESC_XLOCK(fdp); 2489 fdfree(fdp, i); 2490 (void) closefp(fdp, i, fp, td, 0); 2491 FILEDESC_UNLOCK_ASSERT(fdp); 2492 } 2493 } 2494 } 2495 2496 /* 2497 * It is unsafe for set[ug]id processes to be started with file 2498 * descriptors 0..2 closed, as these descriptors are given implicit 2499 * significance in the Standard C library. fdcheckstd() will create a 2500 * descriptor referencing /dev/null for each of stdin, stdout, and 2501 * stderr that is not already open. 2502 */ 2503 int 2504 fdcheckstd(struct thread *td) 2505 { 2506 struct filedesc *fdp; 2507 register_t save; 2508 int i, error, devnull; 2509 2510 fdp = td->td_proc->p_fd; 2511 KASSERT(fdp->fd_refcnt == 1, ("the fdtable should not be shared")); 2512 MPASS(fdp->fd_nfiles >= 3); 2513 devnull = -1; 2514 for (i = 0; i <= 2; i++) { 2515 if (fdp->fd_ofiles[i].fde_file != NULL) 2516 continue; 2517 2518 save = td->td_retval[0]; 2519 if (devnull != -1) { 2520 error = kern_dup(td, FDDUP_FIXED, 0, devnull, i); 2521 } else { 2522 error = kern_openat(td, AT_FDCWD, "/dev/null", 2523 UIO_SYSSPACE, O_RDWR, 0); 2524 if (error == 0) { 2525 devnull = td->td_retval[0]; 2526 KASSERT(devnull == i, ("we didn't get our fd")); 2527 } 2528 } 2529 td->td_retval[0] = save; 2530 if (error != 0) 2531 return (error); 2532 } 2533 return (0); 2534 } 2535 2536 /* 2537 * Internal form of close. Decrement reference count on file structure. 2538 * Note: td may be NULL when closing a file that was being passed in a 2539 * message. 2540 */ 2541 int 2542 closef(struct file *fp, struct thread *td) 2543 { 2544 struct vnode *vp; 2545 struct flock lf; 2546 struct filedesc_to_leader *fdtol; 2547 struct filedesc *fdp; 2548 2549 /* 2550 * POSIX record locking dictates that any close releases ALL 2551 * locks owned by this process. This is handled by setting 2552 * a flag in the unlock to free ONLY locks obeying POSIX 2553 * semantics, and not to free BSD-style file locks. 2554 * If the descriptor was in a message, POSIX-style locks 2555 * aren't passed with the descriptor, and the thread pointer 2556 * will be NULL. Callers should be careful only to pass a 2557 * NULL thread pointer when there really is no owning 2558 * context that might have locks, or the locks will be 2559 * leaked. 2560 */ 2561 if (fp->f_type == DTYPE_VNODE && td != NULL) { 2562 vp = fp->f_vnode; 2563 if ((td->td_proc->p_leader->p_flag & P_ADVLOCK) != 0) { 2564 lf.l_whence = SEEK_SET; 2565 lf.l_start = 0; 2566 lf.l_len = 0; 2567 lf.l_type = F_UNLCK; 2568 (void) VOP_ADVLOCK(vp, (caddr_t)td->td_proc->p_leader, 2569 F_UNLCK, &lf, F_POSIX); 2570 } 2571 fdtol = td->td_proc->p_fdtol; 2572 if (fdtol != NULL) { 2573 /* 2574 * Handle special case where file descriptor table is 2575 * shared between multiple process leaders. 2576 */ 2577 fdp = td->td_proc->p_fd; 2578 FILEDESC_XLOCK(fdp); 2579 for (fdtol = fdtol->fdl_next; 2580 fdtol != td->td_proc->p_fdtol; 2581 fdtol = fdtol->fdl_next) { 2582 if ((fdtol->fdl_leader->p_flag & 2583 P_ADVLOCK) == 0) 2584 continue; 2585 fdtol->fdl_holdcount++; 2586 FILEDESC_XUNLOCK(fdp); 2587 lf.l_whence = SEEK_SET; 2588 lf.l_start = 0; 2589 lf.l_len = 0; 2590 lf.l_type = F_UNLCK; 2591 vp = fp->f_vnode; 2592 (void) VOP_ADVLOCK(vp, 2593 (caddr_t)fdtol->fdl_leader, F_UNLCK, &lf, 2594 F_POSIX); 2595 FILEDESC_XLOCK(fdp); 2596 fdtol->fdl_holdcount--; 2597 if (fdtol->fdl_holdcount == 0 && 2598 fdtol->fdl_wakeup != 0) { 2599 fdtol->fdl_wakeup = 0; 2600 wakeup(fdtol); 2601 } 2602 } 2603 FILEDESC_XUNLOCK(fdp); 2604 } 2605 } 2606 return (fdrop(fp, td)); 2607 } 2608 2609 /* 2610 * Initialize the file pointer with the specified properties. 2611 * 2612 * The ops are set with release semantics to be certain that the flags, type, 2613 * and data are visible when ops is. This is to prevent ops methods from being 2614 * called with bad data. 2615 */ 2616 void 2617 finit(struct file *fp, u_int flag, short type, void *data, struct fileops *ops) 2618 { 2619 fp->f_data = data; 2620 fp->f_flag = flag; 2621 fp->f_type = type; 2622 atomic_store_rel_ptr((volatile uintptr_t *)&fp->f_ops, (uintptr_t)ops); 2623 } 2624 2625 int 2626 fget_cap_locked(struct filedesc *fdp, int fd, cap_rights_t *needrightsp, 2627 struct file **fpp, struct filecaps *havecapsp) 2628 { 2629 struct filedescent *fde; 2630 int error; 2631 2632 FILEDESC_LOCK_ASSERT(fdp); 2633 2634 fde = fdeget_locked(fdp, fd); 2635 if (fde == NULL) { 2636 error = EBADF; 2637 goto out; 2638 } 2639 2640 #ifdef CAPABILITIES 2641 error = cap_check(cap_rights_fde_inline(fde), needrightsp); 2642 if (error != 0) 2643 goto out; 2644 #endif 2645 2646 if (havecapsp != NULL) 2647 filecaps_copy(&fde->fde_caps, havecapsp, true); 2648 2649 *fpp = fde->fde_file; 2650 2651 error = 0; 2652 out: 2653 return (error); 2654 } 2655 2656 int 2657 fget_cap(struct thread *td, int fd, cap_rights_t *needrightsp, 2658 struct file **fpp, struct filecaps *havecapsp) 2659 { 2660 struct filedesc *fdp = td->td_proc->p_fd; 2661 int error; 2662 #ifndef CAPABILITIES 2663 error = fget_unlocked(fdp, fd, needrightsp, fpp); 2664 if (havecapsp != NULL && error == 0) 2665 filecaps_fill(havecapsp); 2666 #else 2667 struct file *fp; 2668 seqc_t seq; 2669 2670 *fpp = NULL; 2671 for (;;) { 2672 error = fget_unlocked_seq(fdp, fd, needrightsp, &fp, &seq); 2673 if (error != 0) 2674 return (error); 2675 2676 if (havecapsp != NULL) { 2677 if (!filecaps_copy(&fdp->fd_ofiles[fd].fde_caps, 2678 havecapsp, false)) { 2679 fdrop(fp, td); 2680 goto get_locked; 2681 } 2682 } 2683 2684 if (!fd_modified(fdp, fd, seq)) 2685 break; 2686 fdrop(fp, td); 2687 } 2688 2689 *fpp = fp; 2690 return (0); 2691 2692 get_locked: 2693 FILEDESC_SLOCK(fdp); 2694 error = fget_cap_locked(fdp, fd, needrightsp, fpp, havecapsp); 2695 if (error == 0 && !fhold(*fpp)) 2696 error = EBADF; 2697 FILEDESC_SUNLOCK(fdp); 2698 #endif 2699 return (error); 2700 } 2701 2702 int 2703 fget_unlocked_seq(struct filedesc *fdp, int fd, cap_rights_t *needrightsp, 2704 struct file **fpp, seqc_t *seqp) 2705 { 2706 #ifdef CAPABILITIES 2707 const struct filedescent *fde; 2708 #endif 2709 const struct fdescenttbl *fdt; 2710 struct file *fp; 2711 #ifdef CAPABILITIES 2712 seqc_t seq; 2713 cap_rights_t haverights; 2714 int error; 2715 #endif 2716 2717 fdt = fdp->fd_files; 2718 if (__predict_false((u_int)fd >= fdt->fdt_nfiles)) 2719 return (EBADF); 2720 /* 2721 * Fetch the descriptor locklessly. We avoid fdrop() races by 2722 * never raising a refcount above 0. To accomplish this we have 2723 * to use a cmpset loop rather than an atomic_add. The descriptor 2724 * must be re-verified once we acquire a reference to be certain 2725 * that the identity is still correct and we did not lose a race 2726 * due to preemption. 2727 */ 2728 for (;;) { 2729 #ifdef CAPABILITIES 2730 seq = seqc_read(fd_seqc(fdt, fd)); 2731 fde = &fdt->fdt_ofiles[fd]; 2732 haverights = *cap_rights_fde_inline(fde); 2733 fp = fde->fde_file; 2734 if (!seqc_consistent(fd_seqc(fdt, fd), seq)) 2735 continue; 2736 #else 2737 fp = fdt->fdt_ofiles[fd].fde_file; 2738 #endif 2739 if (fp == NULL) 2740 return (EBADF); 2741 #ifdef CAPABILITIES 2742 error = cap_check_inline(&haverights, needrightsp); 2743 if (error != 0) 2744 return (error); 2745 #endif 2746 if (__predict_false(!refcount_acquire_if_not_zero(&fp->f_count))) { 2747 /* 2748 * The count was found either saturated or zero. 2749 * This re-read is not any more racy than using the 2750 * return value from fcmpset. 2751 */ 2752 if (fp->f_count != 0) 2753 return (EBADF); 2754 /* 2755 * Force a reload. Other thread could reallocate the 2756 * table before this fd was closed, so it is possible 2757 * that there is a stale fp pointer in cached version. 2758 */ 2759 fdt = atomic_load_ptr(&fdp->fd_files); 2760 continue; 2761 } 2762 /* 2763 * Use an acquire barrier to force re-reading of fdt so it is 2764 * refreshed for verification. 2765 */ 2766 atomic_thread_fence_acq(); 2767 fdt = fdp->fd_files; 2768 #ifdef CAPABILITIES 2769 if (seqc_consistent_nomb(fd_seqc(fdt, fd), seq)) 2770 #else 2771 if (fp == fdt->fdt_ofiles[fd].fde_file) 2772 #endif 2773 break; 2774 fdrop(fp, curthread); 2775 } 2776 *fpp = fp; 2777 if (seqp != NULL) { 2778 #ifdef CAPABILITIES 2779 *seqp = seq; 2780 #endif 2781 } 2782 return (0); 2783 } 2784 2785 /* 2786 * See the comments in fget_unlocked_seq for an explanation of how this works. 2787 * 2788 * This is a simplified variant which bails out to the aforementioned routine 2789 * if anything goes wrong. In practice this only happens when userspace is 2790 * racing with itself. 2791 */ 2792 int 2793 fget_unlocked(struct filedesc *fdp, int fd, cap_rights_t *needrightsp, 2794 struct file **fpp) 2795 { 2796 #ifdef CAPABILITIES 2797 const struct filedescent *fde; 2798 #endif 2799 const struct fdescenttbl *fdt; 2800 struct file *fp; 2801 #ifdef CAPABILITIES 2802 seqc_t seq; 2803 const cap_rights_t *haverights; 2804 #endif 2805 2806 fdt = fdp->fd_files; 2807 if (__predict_false((u_int)fd >= fdt->fdt_nfiles)) 2808 return (EBADF); 2809 #ifdef CAPABILITIES 2810 seq = seqc_read_any(fd_seqc(fdt, fd)); 2811 if (__predict_false(seqc_in_modify(seq))) 2812 goto out_fallback; 2813 fde = &fdt->fdt_ofiles[fd]; 2814 haverights = cap_rights_fde_inline(fde); 2815 fp = fde->fde_file; 2816 #else 2817 fp = fdt->fdt_ofiles[fd].fde_file; 2818 #endif 2819 if (__predict_false(fp == NULL)) 2820 goto out_fallback; 2821 #ifdef CAPABILITIES 2822 if (__predict_false(cap_check_inline_transient(haverights, needrightsp))) 2823 goto out_fallback; 2824 #endif 2825 if (__predict_false(!refcount_acquire_if_not_zero(&fp->f_count))) 2826 goto out_fallback; 2827 2828 /* 2829 * Use an acquire barrier to force re-reading of fdt so it is 2830 * refreshed for verification. 2831 */ 2832 atomic_thread_fence_acq(); 2833 fdt = fdp->fd_files; 2834 #ifdef CAPABILITIES 2835 if (__predict_false(!seqc_consistent_nomb(fd_seqc(fdt, fd), seq))) 2836 #else 2837 if (__predict_false(fp != fdt->fdt_ofiles[fd].fde_file)) 2838 #endif 2839 goto out_fdrop; 2840 *fpp = fp; 2841 return (0); 2842 out_fdrop: 2843 fdrop(fp, curthread); 2844 out_fallback: 2845 return (fget_unlocked_seq(fdp, fd, needrightsp, fpp, NULL)); 2846 } 2847 2848 /* 2849 * Extract the file pointer associated with the specified descriptor for the 2850 * current user process. 2851 * 2852 * If the descriptor doesn't exist or doesn't match 'flags', EBADF is 2853 * returned. 2854 * 2855 * File's rights will be checked against the capability rights mask. 2856 * 2857 * If an error occurred the non-zero error is returned and *fpp is set to 2858 * NULL. Otherwise *fpp is held and set and zero is returned. Caller is 2859 * responsible for fdrop(). 2860 */ 2861 static __inline int 2862 _fget(struct thread *td, int fd, struct file **fpp, int flags, 2863 cap_rights_t *needrightsp) 2864 { 2865 struct filedesc *fdp; 2866 struct file *fp; 2867 int error; 2868 2869 *fpp = NULL; 2870 fdp = td->td_proc->p_fd; 2871 error = fget_unlocked(fdp, fd, needrightsp, &fp); 2872 if (__predict_false(error != 0)) 2873 return (error); 2874 if (__predict_false(fp->f_ops == &badfileops)) { 2875 fdrop(fp, td); 2876 return (EBADF); 2877 } 2878 2879 /* 2880 * FREAD and FWRITE failure return EBADF as per POSIX. 2881 */ 2882 error = 0; 2883 switch (flags) { 2884 case FREAD: 2885 case FWRITE: 2886 if ((fp->f_flag & flags) == 0) 2887 error = EBADF; 2888 break; 2889 case FEXEC: 2890 if ((fp->f_flag & (FREAD | FEXEC)) == 0 || 2891 ((fp->f_flag & FWRITE) != 0)) 2892 error = EBADF; 2893 break; 2894 case 0: 2895 break; 2896 default: 2897 KASSERT(0, ("wrong flags")); 2898 } 2899 2900 if (error != 0) { 2901 fdrop(fp, td); 2902 return (error); 2903 } 2904 2905 *fpp = fp; 2906 return (0); 2907 } 2908 2909 int 2910 fget(struct thread *td, int fd, cap_rights_t *rightsp, struct file **fpp) 2911 { 2912 2913 return (_fget(td, fd, fpp, 0, rightsp)); 2914 } 2915 2916 int 2917 fget_mmap(struct thread *td, int fd, cap_rights_t *rightsp, vm_prot_t *maxprotp, 2918 struct file **fpp) 2919 { 2920 int error; 2921 #ifndef CAPABILITIES 2922 error = _fget(td, fd, fpp, 0, rightsp); 2923 if (maxprotp != NULL) 2924 *maxprotp = VM_PROT_ALL; 2925 return (error); 2926 #else 2927 cap_rights_t fdrights; 2928 struct filedesc *fdp; 2929 struct file *fp; 2930 seqc_t seq; 2931 2932 *fpp = NULL; 2933 fdp = td->td_proc->p_fd; 2934 MPASS(cap_rights_is_set(rightsp, CAP_MMAP)); 2935 for (;;) { 2936 error = fget_unlocked_seq(fdp, fd, rightsp, &fp, &seq); 2937 if (__predict_false(error != 0)) 2938 return (error); 2939 if (__predict_false(fp->f_ops == &badfileops)) { 2940 fdrop(fp, td); 2941 return (EBADF); 2942 } 2943 if (maxprotp != NULL) 2944 fdrights = *cap_rights(fdp, fd); 2945 if (!fd_modified(fdp, fd, seq)) 2946 break; 2947 fdrop(fp, td); 2948 } 2949 2950 /* 2951 * If requested, convert capability rights to access flags. 2952 */ 2953 if (maxprotp != NULL) 2954 *maxprotp = cap_rights_to_vmprot(&fdrights); 2955 *fpp = fp; 2956 return (0); 2957 #endif 2958 } 2959 2960 int 2961 fget_read(struct thread *td, int fd, cap_rights_t *rightsp, struct file **fpp) 2962 { 2963 2964 return (_fget(td, fd, fpp, FREAD, rightsp)); 2965 } 2966 2967 int 2968 fget_write(struct thread *td, int fd, cap_rights_t *rightsp, struct file **fpp) 2969 { 2970 2971 return (_fget(td, fd, fpp, FWRITE, rightsp)); 2972 } 2973 2974 int 2975 fget_fcntl(struct thread *td, int fd, cap_rights_t *rightsp, int needfcntl, 2976 struct file **fpp) 2977 { 2978 struct filedesc *fdp = td->td_proc->p_fd; 2979 #ifndef CAPABILITIES 2980 return (fget_unlocked(fdp, fd, rightsp, fpp)); 2981 #else 2982 struct file *fp; 2983 int error; 2984 seqc_t seq; 2985 2986 *fpp = NULL; 2987 MPASS(cap_rights_is_set(rightsp, CAP_FCNTL)); 2988 for (;;) { 2989 error = fget_unlocked_seq(fdp, fd, rightsp, &fp, &seq); 2990 if (error != 0) 2991 return (error); 2992 error = cap_fcntl_check(fdp, fd, needfcntl); 2993 if (!fd_modified(fdp, fd, seq)) 2994 break; 2995 fdrop(fp, td); 2996 } 2997 if (error != 0) { 2998 fdrop(fp, td); 2999 return (error); 3000 } 3001 *fpp = fp; 3002 return (0); 3003 #endif 3004 } 3005 3006 /* 3007 * Like fget() but loads the underlying vnode, or returns an error if the 3008 * descriptor does not represent a vnode. Note that pipes use vnodes but 3009 * never have VM objects. The returned vnode will be vref()'d. 3010 * 3011 * XXX: what about the unused flags ? 3012 */ 3013 static __inline int 3014 _fgetvp(struct thread *td, int fd, int flags, cap_rights_t *needrightsp, 3015 struct vnode **vpp) 3016 { 3017 struct file *fp; 3018 int error; 3019 3020 *vpp = NULL; 3021 error = _fget(td, fd, &fp, flags, needrightsp); 3022 if (error != 0) 3023 return (error); 3024 if (fp->f_vnode == NULL) { 3025 error = EINVAL; 3026 } else { 3027 *vpp = fp->f_vnode; 3028 vrefact(*vpp); 3029 } 3030 fdrop(fp, td); 3031 3032 return (error); 3033 } 3034 3035 int 3036 fgetvp(struct thread *td, int fd, cap_rights_t *rightsp, struct vnode **vpp) 3037 { 3038 3039 return (_fgetvp(td, fd, 0, rightsp, vpp)); 3040 } 3041 3042 int 3043 fgetvp_rights(struct thread *td, int fd, cap_rights_t *needrightsp, 3044 struct filecaps *havecaps, struct vnode **vpp) 3045 { 3046 struct filecaps caps; 3047 struct file *fp; 3048 int error; 3049 3050 error = fget_cap(td, fd, needrightsp, &fp, &caps); 3051 if (error != 0) 3052 return (error); 3053 if (fp->f_ops == &badfileops) { 3054 error = EBADF; 3055 goto out; 3056 } 3057 if (fp->f_vnode == NULL) { 3058 error = EINVAL; 3059 goto out; 3060 } 3061 3062 *havecaps = caps; 3063 *vpp = fp->f_vnode; 3064 vrefact(*vpp); 3065 fdrop(fp, td); 3066 3067 return (0); 3068 out: 3069 filecaps_free(&caps); 3070 fdrop(fp, td); 3071 return (error); 3072 } 3073 3074 int 3075 fgetvp_read(struct thread *td, int fd, cap_rights_t *rightsp, struct vnode **vpp) 3076 { 3077 3078 return (_fgetvp(td, fd, FREAD, rightsp, vpp)); 3079 } 3080 3081 int 3082 fgetvp_exec(struct thread *td, int fd, cap_rights_t *rightsp, struct vnode **vpp) 3083 { 3084 3085 return (_fgetvp(td, fd, FEXEC, rightsp, vpp)); 3086 } 3087 3088 #ifdef notyet 3089 int 3090 fgetvp_write(struct thread *td, int fd, cap_rights_t *rightsp, 3091 struct vnode **vpp) 3092 { 3093 3094 return (_fgetvp(td, fd, FWRITE, rightsp, vpp)); 3095 } 3096 #endif 3097 3098 /* 3099 * Handle the last reference to a file being closed. 3100 * 3101 * Without the noinline attribute clang keeps inlining the func thorough this 3102 * file when fdrop is used. 3103 */ 3104 int __noinline 3105 _fdrop(struct file *fp, struct thread *td) 3106 { 3107 int error; 3108 3109 if (fp->f_count != 0) 3110 panic("fdrop: count %d", fp->f_count); 3111 error = fo_close(fp, td); 3112 atomic_subtract_int(&openfiles, 1); 3113 crfree(fp->f_cred); 3114 free(fp->f_advice, M_FADVISE); 3115 uma_zfree(file_zone, fp); 3116 3117 return (error); 3118 } 3119 3120 /* 3121 * Apply an advisory lock on a file descriptor. 3122 * 3123 * Just attempt to get a record lock of the requested type on the entire file 3124 * (l_whence = SEEK_SET, l_start = 0, l_len = 0). 3125 */ 3126 #ifndef _SYS_SYSPROTO_H_ 3127 struct flock_args { 3128 int fd; 3129 int how; 3130 }; 3131 #endif 3132 /* ARGSUSED */ 3133 int 3134 sys_flock(struct thread *td, struct flock_args *uap) 3135 { 3136 struct file *fp; 3137 struct vnode *vp; 3138 struct flock lf; 3139 int error; 3140 3141 error = fget(td, uap->fd, &cap_flock_rights, &fp); 3142 if (error != 0) 3143 return (error); 3144 if (fp->f_type != DTYPE_VNODE) { 3145 fdrop(fp, td); 3146 return (EOPNOTSUPP); 3147 } 3148 3149 vp = fp->f_vnode; 3150 lf.l_whence = SEEK_SET; 3151 lf.l_start = 0; 3152 lf.l_len = 0; 3153 if (uap->how & LOCK_UN) { 3154 lf.l_type = F_UNLCK; 3155 atomic_clear_int(&fp->f_flag, FHASLOCK); 3156 error = VOP_ADVLOCK(vp, (caddr_t)fp, F_UNLCK, &lf, F_FLOCK); 3157 goto done2; 3158 } 3159 if (uap->how & LOCK_EX) 3160 lf.l_type = F_WRLCK; 3161 else if (uap->how & LOCK_SH) 3162 lf.l_type = F_RDLCK; 3163 else { 3164 error = EBADF; 3165 goto done2; 3166 } 3167 atomic_set_int(&fp->f_flag, FHASLOCK); 3168 error = VOP_ADVLOCK(vp, (caddr_t)fp, F_SETLK, &lf, 3169 (uap->how & LOCK_NB) ? F_FLOCK : F_FLOCK | F_WAIT); 3170 done2: 3171 fdrop(fp, td); 3172 return (error); 3173 } 3174 /* 3175 * Duplicate the specified descriptor to a free descriptor. 3176 */ 3177 int 3178 dupfdopen(struct thread *td, struct filedesc *fdp, int dfd, int mode, 3179 int openerror, int *indxp) 3180 { 3181 struct filedescent *newfde, *oldfde; 3182 struct file *fp; 3183 u_long *ioctls; 3184 int error, indx; 3185 3186 KASSERT(openerror == ENODEV || openerror == ENXIO, 3187 ("unexpected error %d in %s", openerror, __func__)); 3188 3189 /* 3190 * If the to-be-dup'd fd number is greater than the allowed number 3191 * of file descriptors, or the fd to be dup'd has already been 3192 * closed, then reject. 3193 */ 3194 FILEDESC_XLOCK(fdp); 3195 if ((fp = fget_locked(fdp, dfd)) == NULL) { 3196 FILEDESC_XUNLOCK(fdp); 3197 return (EBADF); 3198 } 3199 3200 error = fdalloc(td, 0, &indx); 3201 if (error != 0) { 3202 FILEDESC_XUNLOCK(fdp); 3203 return (error); 3204 } 3205 3206 /* 3207 * There are two cases of interest here. 3208 * 3209 * For ENODEV simply dup (dfd) to file descriptor (indx) and return. 3210 * 3211 * For ENXIO steal away the file structure from (dfd) and store it in 3212 * (indx). (dfd) is effectively closed by this operation. 3213 */ 3214 switch (openerror) { 3215 case ENODEV: 3216 /* 3217 * Check that the mode the file is being opened for is a 3218 * subset of the mode of the existing descriptor. 3219 */ 3220 if (((mode & (FREAD|FWRITE)) | fp->f_flag) != fp->f_flag) { 3221 fdunused(fdp, indx); 3222 FILEDESC_XUNLOCK(fdp); 3223 return (EACCES); 3224 } 3225 if (!fhold(fp)) { 3226 fdunused(fdp, indx); 3227 FILEDESC_XUNLOCK(fdp); 3228 return (EBADF); 3229 } 3230 newfde = &fdp->fd_ofiles[indx]; 3231 oldfde = &fdp->fd_ofiles[dfd]; 3232 ioctls = filecaps_copy_prep(&oldfde->fde_caps); 3233 #ifdef CAPABILITIES 3234 seqc_write_begin(&newfde->fde_seqc); 3235 #endif 3236 memcpy(newfde, oldfde, fde_change_size); 3237 filecaps_copy_finish(&oldfde->fde_caps, &newfde->fde_caps, 3238 ioctls); 3239 #ifdef CAPABILITIES 3240 seqc_write_end(&newfde->fde_seqc); 3241 #endif 3242 break; 3243 case ENXIO: 3244 /* 3245 * Steal away the file pointer from dfd and stuff it into indx. 3246 */ 3247 newfde = &fdp->fd_ofiles[indx]; 3248 oldfde = &fdp->fd_ofiles[dfd]; 3249 #ifdef CAPABILITIES 3250 seqc_write_begin(&newfde->fde_seqc); 3251 #endif 3252 memcpy(newfde, oldfde, fde_change_size); 3253 oldfde->fde_file = NULL; 3254 fdunused(fdp, dfd); 3255 #ifdef CAPABILITIES 3256 seqc_write_end(&newfde->fde_seqc); 3257 #endif 3258 break; 3259 } 3260 FILEDESC_XUNLOCK(fdp); 3261 *indxp = indx; 3262 return (0); 3263 } 3264 3265 /* 3266 * This sysctl determines if we will allow a process to chroot(2) if it 3267 * has a directory open: 3268 * 0: disallowed for all processes. 3269 * 1: allowed for processes that were not already chroot(2)'ed. 3270 * 2: allowed for all processes. 3271 */ 3272 3273 static int chroot_allow_open_directories = 1; 3274 3275 SYSCTL_INT(_kern, OID_AUTO, chroot_allow_open_directories, CTLFLAG_RW, 3276 &chroot_allow_open_directories, 0, 3277 "Allow a process to chroot(2) if it has a directory open"); 3278 3279 /* 3280 * Helper function for raised chroot(2) security function: Refuse if 3281 * any filedescriptors are open directories. 3282 */ 3283 static int 3284 chroot_refuse_vdir_fds(struct filedesc *fdp) 3285 { 3286 struct vnode *vp; 3287 struct file *fp; 3288 int fd, lastfile; 3289 3290 FILEDESC_LOCK_ASSERT(fdp); 3291 3292 lastfile = fdlastfile(fdp); 3293 for (fd = 0; fd <= lastfile; fd++) { 3294 fp = fget_locked(fdp, fd); 3295 if (fp == NULL) 3296 continue; 3297 if (fp->f_type == DTYPE_VNODE) { 3298 vp = fp->f_vnode; 3299 if (vp->v_type == VDIR) 3300 return (EPERM); 3301 } 3302 } 3303 return (0); 3304 } 3305 3306 static void 3307 pwd_fill(struct pwd *oldpwd, struct pwd *newpwd) 3308 { 3309 3310 if (newpwd->pwd_cdir == NULL && oldpwd->pwd_cdir != NULL) { 3311 vrefact(oldpwd->pwd_cdir); 3312 newpwd->pwd_cdir = oldpwd->pwd_cdir; 3313 } 3314 3315 if (newpwd->pwd_rdir == NULL && oldpwd->pwd_rdir != NULL) { 3316 vrefact(oldpwd->pwd_rdir); 3317 newpwd->pwd_rdir = oldpwd->pwd_rdir; 3318 } 3319 3320 if (newpwd->pwd_jdir == NULL && oldpwd->pwd_jdir != NULL) { 3321 vrefact(oldpwd->pwd_jdir); 3322 newpwd->pwd_jdir = oldpwd->pwd_jdir; 3323 } 3324 } 3325 3326 struct pwd * 3327 pwd_hold_filedesc(struct filedesc *fdp) 3328 { 3329 struct pwd *pwd; 3330 3331 FILEDESC_LOCK_ASSERT(fdp); 3332 pwd = FILEDESC_LOCKED_LOAD_PWD(fdp); 3333 if (pwd != NULL) 3334 refcount_acquire(&pwd->pwd_refcount); 3335 return (pwd); 3336 } 3337 3338 struct pwd * 3339 pwd_hold(struct thread *td) 3340 { 3341 struct filedesc *fdp; 3342 struct pwd *pwd; 3343 3344 fdp = td->td_proc->p_fd; 3345 3346 vfs_smr_enter(); 3347 pwd = vfs_smr_entered_load(&fdp->fd_pwd); 3348 MPASS(pwd != NULL); 3349 if (__predict_true(refcount_acquire_if_not_zero(&pwd->pwd_refcount))) { 3350 vfs_smr_exit(); 3351 return (pwd); 3352 } 3353 vfs_smr_exit(); 3354 FILEDESC_SLOCK(fdp); 3355 pwd = pwd_hold_filedesc(fdp); 3356 MPASS(pwd != NULL); 3357 FILEDESC_SUNLOCK(fdp); 3358 return (pwd); 3359 } 3360 3361 struct pwd * 3362 pwd_get_smr(void) 3363 { 3364 struct pwd *pwd; 3365 3366 pwd = vfs_smr_entered_load(&curproc->p_fd->fd_pwd); 3367 MPASS(pwd != NULL); 3368 return (pwd); 3369 } 3370 3371 static struct pwd * 3372 pwd_alloc(void) 3373 { 3374 struct pwd *pwd; 3375 3376 pwd = uma_zalloc_smr(pwd_zone, M_WAITOK); 3377 bzero(pwd, sizeof(*pwd)); 3378 refcount_init(&pwd->pwd_refcount, 1); 3379 return (pwd); 3380 } 3381 3382 void 3383 pwd_drop(struct pwd *pwd) 3384 { 3385 3386 if (!refcount_release(&pwd->pwd_refcount)) 3387 return; 3388 3389 if (pwd->pwd_cdir != NULL) 3390 vrele(pwd->pwd_cdir); 3391 if (pwd->pwd_rdir != NULL) 3392 vrele(pwd->pwd_rdir); 3393 if (pwd->pwd_jdir != NULL) 3394 vrele(pwd->pwd_jdir); 3395 uma_zfree_smr(pwd_zone, pwd); 3396 } 3397 3398 /* 3399 * Common routine for kern_chroot() and jail_attach(). The caller is 3400 * responsible for invoking priv_check() and mac_vnode_check_chroot() to 3401 * authorize this operation. 3402 */ 3403 int 3404 pwd_chroot(struct thread *td, struct vnode *vp) 3405 { 3406 struct filedesc *fdp; 3407 struct pwd *newpwd, *oldpwd; 3408 int error; 3409 3410 fdp = td->td_proc->p_fd; 3411 newpwd = pwd_alloc(); 3412 FILEDESC_XLOCK(fdp); 3413 oldpwd = FILEDESC_XLOCKED_LOAD_PWD(fdp); 3414 if (chroot_allow_open_directories == 0 || 3415 (chroot_allow_open_directories == 1 && 3416 oldpwd->pwd_rdir != rootvnode)) { 3417 error = chroot_refuse_vdir_fds(fdp); 3418 if (error != 0) { 3419 FILEDESC_XUNLOCK(fdp); 3420 pwd_drop(newpwd); 3421 return (error); 3422 } 3423 } 3424 3425 vrefact(vp); 3426 newpwd->pwd_rdir = vp; 3427 if (oldpwd->pwd_jdir == NULL) { 3428 vrefact(vp); 3429 newpwd->pwd_jdir = vp; 3430 } 3431 pwd_fill(oldpwd, newpwd); 3432 pwd_set(fdp, newpwd); 3433 FILEDESC_XUNLOCK(fdp); 3434 pwd_drop(oldpwd); 3435 return (0); 3436 } 3437 3438 void 3439 pwd_chdir(struct thread *td, struct vnode *vp) 3440 { 3441 struct filedesc *fdp; 3442 struct pwd *newpwd, *oldpwd; 3443 3444 VNPASS(vp->v_usecount > 0, vp); 3445 3446 newpwd = pwd_alloc(); 3447 fdp = td->td_proc->p_fd; 3448 FILEDESC_XLOCK(fdp); 3449 oldpwd = FILEDESC_XLOCKED_LOAD_PWD(fdp); 3450 newpwd->pwd_cdir = vp; 3451 pwd_fill(oldpwd, newpwd); 3452 pwd_set(fdp, newpwd); 3453 FILEDESC_XUNLOCK(fdp); 3454 pwd_drop(oldpwd); 3455 } 3456 3457 void 3458 pwd_ensure_dirs(void) 3459 { 3460 struct filedesc *fdp; 3461 struct pwd *oldpwd, *newpwd; 3462 3463 fdp = curproc->p_fd; 3464 FILEDESC_XLOCK(fdp); 3465 oldpwd = FILEDESC_XLOCKED_LOAD_PWD(fdp); 3466 if (oldpwd->pwd_cdir != NULL && oldpwd->pwd_rdir != NULL) { 3467 FILEDESC_XUNLOCK(fdp); 3468 return; 3469 } 3470 FILEDESC_XUNLOCK(fdp); 3471 3472 newpwd = pwd_alloc(); 3473 FILEDESC_XLOCK(fdp); 3474 oldpwd = FILEDESC_XLOCKED_LOAD_PWD(fdp); 3475 pwd_fill(oldpwd, newpwd); 3476 if (newpwd->pwd_cdir == NULL) { 3477 vrefact(rootvnode); 3478 newpwd->pwd_cdir = rootvnode; 3479 } 3480 if (newpwd->pwd_rdir == NULL) { 3481 vrefact(rootvnode); 3482 newpwd->pwd_rdir = rootvnode; 3483 } 3484 pwd_set(fdp, newpwd); 3485 FILEDESC_XUNLOCK(fdp); 3486 pwd_drop(oldpwd); 3487 } 3488 3489 void 3490 pwd_set_rootvnode(void) 3491 { 3492 struct filedesc *fdp; 3493 struct pwd *oldpwd, *newpwd; 3494 3495 fdp = curproc->p_fd; 3496 3497 newpwd = pwd_alloc(); 3498 FILEDESC_XLOCK(fdp); 3499 oldpwd = FILEDESC_XLOCKED_LOAD_PWD(fdp); 3500 vrefact(rootvnode); 3501 newpwd->pwd_cdir = rootvnode; 3502 vrefact(rootvnode); 3503 newpwd->pwd_rdir = rootvnode; 3504 pwd_fill(oldpwd, newpwd); 3505 pwd_set(fdp, newpwd); 3506 FILEDESC_XUNLOCK(fdp); 3507 pwd_drop(oldpwd); 3508 } 3509 3510 /* 3511 * Scan all active processes and prisons to see if any of them have a current 3512 * or root directory of `olddp'. If so, replace them with the new mount point. 3513 */ 3514 void 3515 mountcheckdirs(struct vnode *olddp, struct vnode *newdp) 3516 { 3517 struct filedesc *fdp; 3518 struct pwd *newpwd, *oldpwd; 3519 struct prison *pr; 3520 struct proc *p; 3521 int nrele; 3522 3523 if (vrefcnt(olddp) == 1) 3524 return; 3525 nrele = 0; 3526 newpwd = pwd_alloc(); 3527 sx_slock(&allproc_lock); 3528 FOREACH_PROC_IN_SYSTEM(p) { 3529 PROC_LOCK(p); 3530 fdp = fdhold(p); 3531 PROC_UNLOCK(p); 3532 if (fdp == NULL) 3533 continue; 3534 FILEDESC_XLOCK(fdp); 3535 oldpwd = FILEDESC_XLOCKED_LOAD_PWD(fdp); 3536 if (oldpwd == NULL || 3537 (oldpwd->pwd_cdir != olddp && 3538 oldpwd->pwd_rdir != olddp && 3539 oldpwd->pwd_jdir != olddp)) { 3540 FILEDESC_XUNLOCK(fdp); 3541 fddrop(fdp); 3542 continue; 3543 } 3544 if (oldpwd->pwd_cdir == olddp) { 3545 vrefact(newdp); 3546 newpwd->pwd_cdir = newdp; 3547 } 3548 if (oldpwd->pwd_rdir == olddp) { 3549 vrefact(newdp); 3550 newpwd->pwd_rdir = newdp; 3551 } 3552 if (oldpwd->pwd_jdir == olddp) { 3553 vrefact(newdp); 3554 newpwd->pwd_jdir = newdp; 3555 } 3556 pwd_fill(oldpwd, newpwd); 3557 pwd_set(fdp, newpwd); 3558 FILEDESC_XUNLOCK(fdp); 3559 pwd_drop(oldpwd); 3560 fddrop(fdp); 3561 newpwd = pwd_alloc(); 3562 } 3563 sx_sunlock(&allproc_lock); 3564 pwd_drop(newpwd); 3565 if (rootvnode == olddp) { 3566 vrefact(newdp); 3567 rootvnode = newdp; 3568 nrele++; 3569 } 3570 mtx_lock(&prison0.pr_mtx); 3571 if (prison0.pr_root == olddp) { 3572 vrefact(newdp); 3573 prison0.pr_root = newdp; 3574 nrele++; 3575 } 3576 mtx_unlock(&prison0.pr_mtx); 3577 sx_slock(&allprison_lock); 3578 TAILQ_FOREACH(pr, &allprison, pr_list) { 3579 mtx_lock(&pr->pr_mtx); 3580 if (pr->pr_root == olddp) { 3581 vrefact(newdp); 3582 pr->pr_root = newdp; 3583 nrele++; 3584 } 3585 mtx_unlock(&pr->pr_mtx); 3586 } 3587 sx_sunlock(&allprison_lock); 3588 while (nrele--) 3589 vrele(olddp); 3590 } 3591 3592 struct filedesc_to_leader * 3593 filedesc_to_leader_alloc(struct filedesc_to_leader *old, struct filedesc *fdp, struct proc *leader) 3594 { 3595 struct filedesc_to_leader *fdtol; 3596 3597 fdtol = malloc(sizeof(struct filedesc_to_leader), 3598 M_FILEDESC_TO_LEADER, M_WAITOK); 3599 fdtol->fdl_refcount = 1; 3600 fdtol->fdl_holdcount = 0; 3601 fdtol->fdl_wakeup = 0; 3602 fdtol->fdl_leader = leader; 3603 if (old != NULL) { 3604 FILEDESC_XLOCK(fdp); 3605 fdtol->fdl_next = old->fdl_next; 3606 fdtol->fdl_prev = old; 3607 old->fdl_next = fdtol; 3608 fdtol->fdl_next->fdl_prev = fdtol; 3609 FILEDESC_XUNLOCK(fdp); 3610 } else { 3611 fdtol->fdl_next = fdtol; 3612 fdtol->fdl_prev = fdtol; 3613 } 3614 return (fdtol); 3615 } 3616 3617 static int 3618 sysctl_kern_proc_nfds(SYSCTL_HANDLER_ARGS) 3619 { 3620 NDSLOTTYPE *map; 3621 struct filedesc *fdp; 3622 int count, off, minoff; 3623 3624 if (*(int *)arg1 != 0) 3625 return (EINVAL); 3626 3627 fdp = curproc->p_fd; 3628 count = 0; 3629 FILEDESC_SLOCK(fdp); 3630 map = fdp->fd_map; 3631 off = NDSLOT(fdp->fd_nfiles - 1); 3632 for (minoff = NDSLOT(0); off >= minoff; --off) 3633 count += bitcountl(map[off]); 3634 FILEDESC_SUNLOCK(fdp); 3635 3636 return (SYSCTL_OUT(req, &count, sizeof(count))); 3637 } 3638 3639 static SYSCTL_NODE(_kern_proc, KERN_PROC_NFDS, nfds, 3640 CTLFLAG_RD|CTLFLAG_CAPRD|CTLFLAG_MPSAFE, sysctl_kern_proc_nfds, 3641 "Number of open file descriptors"); 3642 3643 /* 3644 * Get file structures globally. 3645 */ 3646 static int 3647 sysctl_kern_file(SYSCTL_HANDLER_ARGS) 3648 { 3649 struct xfile xf; 3650 struct filedesc *fdp; 3651 struct file *fp; 3652 struct proc *p; 3653 int error, n, lastfile; 3654 3655 error = sysctl_wire_old_buffer(req, 0); 3656 if (error != 0) 3657 return (error); 3658 if (req->oldptr == NULL) { 3659 n = 0; 3660 sx_slock(&allproc_lock); 3661 FOREACH_PROC_IN_SYSTEM(p) { 3662 PROC_LOCK(p); 3663 if (p->p_state == PRS_NEW) { 3664 PROC_UNLOCK(p); 3665 continue; 3666 } 3667 fdp = fdhold(p); 3668 PROC_UNLOCK(p); 3669 if (fdp == NULL) 3670 continue; 3671 /* overestimates sparse tables. */ 3672 n += fdp->fd_nfiles; 3673 fddrop(fdp); 3674 } 3675 sx_sunlock(&allproc_lock); 3676 return (SYSCTL_OUT(req, 0, n * sizeof(xf))); 3677 } 3678 error = 0; 3679 bzero(&xf, sizeof(xf)); 3680 xf.xf_size = sizeof(xf); 3681 sx_slock(&allproc_lock); 3682 FOREACH_PROC_IN_SYSTEM(p) { 3683 PROC_LOCK(p); 3684 if (p->p_state == PRS_NEW) { 3685 PROC_UNLOCK(p); 3686 continue; 3687 } 3688 if (p_cansee(req->td, p) != 0) { 3689 PROC_UNLOCK(p); 3690 continue; 3691 } 3692 xf.xf_pid = p->p_pid; 3693 xf.xf_uid = p->p_ucred->cr_uid; 3694 fdp = fdhold(p); 3695 PROC_UNLOCK(p); 3696 if (fdp == NULL) 3697 continue; 3698 FILEDESC_SLOCK(fdp); 3699 lastfile = fdlastfile(fdp); 3700 for (n = 0; fdp->fd_refcnt > 0 && n <= lastfile; ++n) { 3701 if ((fp = fdp->fd_ofiles[n].fde_file) == NULL) 3702 continue; 3703 xf.xf_fd = n; 3704 xf.xf_file = (uintptr_t)fp; 3705 xf.xf_data = (uintptr_t)fp->f_data; 3706 xf.xf_vnode = (uintptr_t)fp->f_vnode; 3707 xf.xf_type = (uintptr_t)fp->f_type; 3708 xf.xf_count = fp->f_count; 3709 xf.xf_msgcount = 0; 3710 xf.xf_offset = foffset_get(fp); 3711 xf.xf_flag = fp->f_flag; 3712 error = SYSCTL_OUT(req, &xf, sizeof(xf)); 3713 if (error) 3714 break; 3715 } 3716 FILEDESC_SUNLOCK(fdp); 3717 fddrop(fdp); 3718 if (error) 3719 break; 3720 } 3721 sx_sunlock(&allproc_lock); 3722 return (error); 3723 } 3724 3725 SYSCTL_PROC(_kern, KERN_FILE, file, CTLTYPE_OPAQUE|CTLFLAG_RD|CTLFLAG_MPSAFE, 3726 0, 0, sysctl_kern_file, "S,xfile", "Entire file table"); 3727 3728 #ifdef KINFO_FILE_SIZE 3729 CTASSERT(sizeof(struct kinfo_file) == KINFO_FILE_SIZE); 3730 #endif 3731 3732 static int 3733 xlate_fflags(int fflags) 3734 { 3735 static const struct { 3736 int fflag; 3737 int kf_fflag; 3738 } fflags_table[] = { 3739 { FAPPEND, KF_FLAG_APPEND }, 3740 { FASYNC, KF_FLAG_ASYNC }, 3741 { FFSYNC, KF_FLAG_FSYNC }, 3742 { FHASLOCK, KF_FLAG_HASLOCK }, 3743 { FNONBLOCK, KF_FLAG_NONBLOCK }, 3744 { FREAD, KF_FLAG_READ }, 3745 { FWRITE, KF_FLAG_WRITE }, 3746 { O_CREAT, KF_FLAG_CREAT }, 3747 { O_DIRECT, KF_FLAG_DIRECT }, 3748 { O_EXCL, KF_FLAG_EXCL }, 3749 { O_EXEC, KF_FLAG_EXEC }, 3750 { O_EXLOCK, KF_FLAG_EXLOCK }, 3751 { O_NOFOLLOW, KF_FLAG_NOFOLLOW }, 3752 { O_SHLOCK, KF_FLAG_SHLOCK }, 3753 { O_TRUNC, KF_FLAG_TRUNC } 3754 }; 3755 unsigned int i; 3756 int kflags; 3757 3758 kflags = 0; 3759 for (i = 0; i < nitems(fflags_table); i++) 3760 if (fflags & fflags_table[i].fflag) 3761 kflags |= fflags_table[i].kf_fflag; 3762 return (kflags); 3763 } 3764 3765 /* Trim unused data from kf_path by truncating the structure size. */ 3766 void 3767 pack_kinfo(struct kinfo_file *kif) 3768 { 3769 3770 kif->kf_structsize = offsetof(struct kinfo_file, kf_path) + 3771 strlen(kif->kf_path) + 1; 3772 kif->kf_structsize = roundup(kif->kf_structsize, sizeof(uint64_t)); 3773 } 3774 3775 static void 3776 export_file_to_kinfo(struct file *fp, int fd, cap_rights_t *rightsp, 3777 struct kinfo_file *kif, struct filedesc *fdp, int flags) 3778 { 3779 int error; 3780 3781 bzero(kif, sizeof(*kif)); 3782 3783 /* Set a default type to allow for empty fill_kinfo() methods. */ 3784 kif->kf_type = KF_TYPE_UNKNOWN; 3785 kif->kf_flags = xlate_fflags(fp->f_flag); 3786 if (rightsp != NULL) 3787 kif->kf_cap_rights = *rightsp; 3788 else 3789 cap_rights_init_zero(&kif->kf_cap_rights); 3790 kif->kf_fd = fd; 3791 kif->kf_ref_count = fp->f_count; 3792 kif->kf_offset = foffset_get(fp); 3793 3794 /* 3795 * This may drop the filedesc lock, so the 'fp' cannot be 3796 * accessed after this call. 3797 */ 3798 error = fo_fill_kinfo(fp, kif, fdp); 3799 if (error == 0) 3800 kif->kf_status |= KF_ATTR_VALID; 3801 if ((flags & KERN_FILEDESC_PACK_KINFO) != 0) 3802 pack_kinfo(kif); 3803 else 3804 kif->kf_structsize = roundup2(sizeof(*kif), sizeof(uint64_t)); 3805 } 3806 3807 static void 3808 export_vnode_to_kinfo(struct vnode *vp, int fd, int fflags, 3809 struct kinfo_file *kif, int flags) 3810 { 3811 int error; 3812 3813 bzero(kif, sizeof(*kif)); 3814 3815 kif->kf_type = KF_TYPE_VNODE; 3816 error = vn_fill_kinfo_vnode(vp, kif); 3817 if (error == 0) 3818 kif->kf_status |= KF_ATTR_VALID; 3819 kif->kf_flags = xlate_fflags(fflags); 3820 cap_rights_init_zero(&kif->kf_cap_rights); 3821 kif->kf_fd = fd; 3822 kif->kf_ref_count = -1; 3823 kif->kf_offset = -1; 3824 if ((flags & KERN_FILEDESC_PACK_KINFO) != 0) 3825 pack_kinfo(kif); 3826 else 3827 kif->kf_structsize = roundup2(sizeof(*kif), sizeof(uint64_t)); 3828 vrele(vp); 3829 } 3830 3831 struct export_fd_buf { 3832 struct filedesc *fdp; 3833 struct sbuf *sb; 3834 ssize_t remainder; 3835 struct kinfo_file kif; 3836 int flags; 3837 }; 3838 3839 static int 3840 export_kinfo_to_sb(struct export_fd_buf *efbuf) 3841 { 3842 struct kinfo_file *kif; 3843 3844 kif = &efbuf->kif; 3845 if (efbuf->remainder != -1) { 3846 if (efbuf->remainder < kif->kf_structsize) { 3847 /* Terminate export. */ 3848 efbuf->remainder = 0; 3849 return (0); 3850 } 3851 efbuf->remainder -= kif->kf_structsize; 3852 } 3853 return (sbuf_bcat(efbuf->sb, kif, kif->kf_structsize) == 0 ? 0 : ENOMEM); 3854 } 3855 3856 static int 3857 export_file_to_sb(struct file *fp, int fd, cap_rights_t *rightsp, 3858 struct export_fd_buf *efbuf) 3859 { 3860 int error; 3861 3862 if (efbuf->remainder == 0) 3863 return (0); 3864 export_file_to_kinfo(fp, fd, rightsp, &efbuf->kif, efbuf->fdp, 3865 efbuf->flags); 3866 FILEDESC_SUNLOCK(efbuf->fdp); 3867 error = export_kinfo_to_sb(efbuf); 3868 FILEDESC_SLOCK(efbuf->fdp); 3869 return (error); 3870 } 3871 3872 static int 3873 export_vnode_to_sb(struct vnode *vp, int fd, int fflags, 3874 struct export_fd_buf *efbuf) 3875 { 3876 int error; 3877 3878 if (efbuf->remainder == 0) 3879 return (0); 3880 if (efbuf->fdp != NULL) 3881 FILEDESC_SUNLOCK(efbuf->fdp); 3882 export_vnode_to_kinfo(vp, fd, fflags, &efbuf->kif, efbuf->flags); 3883 error = export_kinfo_to_sb(efbuf); 3884 if (efbuf->fdp != NULL) 3885 FILEDESC_SLOCK(efbuf->fdp); 3886 return (error); 3887 } 3888 3889 /* 3890 * Store a process file descriptor information to sbuf. 3891 * 3892 * Takes a locked proc as argument, and returns with the proc unlocked. 3893 */ 3894 int 3895 kern_proc_filedesc_out(struct proc *p, struct sbuf *sb, ssize_t maxlen, 3896 int flags) 3897 { 3898 struct file *fp; 3899 struct filedesc *fdp; 3900 struct export_fd_buf *efbuf; 3901 struct vnode *cttyvp, *textvp, *tracevp; 3902 struct pwd *pwd; 3903 int error, i, lastfile; 3904 cap_rights_t rights; 3905 3906 PROC_LOCK_ASSERT(p, MA_OWNED); 3907 3908 /* ktrace vnode */ 3909 tracevp = p->p_tracevp; 3910 if (tracevp != NULL) 3911 vrefact(tracevp); 3912 /* text vnode */ 3913 textvp = p->p_textvp; 3914 if (textvp != NULL) 3915 vrefact(textvp); 3916 /* Controlling tty. */ 3917 cttyvp = NULL; 3918 if (p->p_pgrp != NULL && p->p_pgrp->pg_session != NULL) { 3919 cttyvp = p->p_pgrp->pg_session->s_ttyvp; 3920 if (cttyvp != NULL) 3921 vrefact(cttyvp); 3922 } 3923 fdp = fdhold(p); 3924 PROC_UNLOCK(p); 3925 efbuf = malloc(sizeof(*efbuf), M_TEMP, M_WAITOK); 3926 efbuf->fdp = NULL; 3927 efbuf->sb = sb; 3928 efbuf->remainder = maxlen; 3929 efbuf->flags = flags; 3930 if (tracevp != NULL) 3931 export_vnode_to_sb(tracevp, KF_FD_TYPE_TRACE, FREAD | FWRITE, 3932 efbuf); 3933 if (textvp != NULL) 3934 export_vnode_to_sb(textvp, KF_FD_TYPE_TEXT, FREAD, efbuf); 3935 if (cttyvp != NULL) 3936 export_vnode_to_sb(cttyvp, KF_FD_TYPE_CTTY, FREAD | FWRITE, 3937 efbuf); 3938 error = 0; 3939 if (fdp == NULL) 3940 goto fail; 3941 efbuf->fdp = fdp; 3942 FILEDESC_SLOCK(fdp); 3943 pwd = pwd_hold_filedesc(fdp); 3944 if (pwd != NULL) { 3945 /* working directory */ 3946 if (pwd->pwd_cdir != NULL) { 3947 vrefact(pwd->pwd_cdir); 3948 export_vnode_to_sb(pwd->pwd_cdir, KF_FD_TYPE_CWD, FREAD, efbuf); 3949 } 3950 /* root directory */ 3951 if (pwd->pwd_rdir != NULL) { 3952 vrefact(pwd->pwd_rdir); 3953 export_vnode_to_sb(pwd->pwd_rdir, KF_FD_TYPE_ROOT, FREAD, efbuf); 3954 } 3955 /* jail directory */ 3956 if (pwd->pwd_jdir != NULL) { 3957 vrefact(pwd->pwd_jdir); 3958 export_vnode_to_sb(pwd->pwd_jdir, KF_FD_TYPE_JAIL, FREAD, efbuf); 3959 } 3960 pwd_drop(pwd); 3961 } 3962 lastfile = fdlastfile(fdp); 3963 for (i = 0; fdp->fd_refcnt > 0 && i <= lastfile; i++) { 3964 if ((fp = fdp->fd_ofiles[i].fde_file) == NULL) 3965 continue; 3966 #ifdef CAPABILITIES 3967 rights = *cap_rights(fdp, i); 3968 #else /* !CAPABILITIES */ 3969 rights = cap_no_rights; 3970 #endif 3971 /* 3972 * Create sysctl entry. It is OK to drop the filedesc 3973 * lock inside of export_file_to_sb() as we will 3974 * re-validate and re-evaluate its properties when the 3975 * loop continues. 3976 */ 3977 error = export_file_to_sb(fp, i, &rights, efbuf); 3978 if (error != 0 || efbuf->remainder == 0) 3979 break; 3980 } 3981 FILEDESC_SUNLOCK(fdp); 3982 fddrop(fdp); 3983 fail: 3984 free(efbuf, M_TEMP); 3985 return (error); 3986 } 3987 3988 #define FILEDESC_SBUF_SIZE (sizeof(struct kinfo_file) * 5) 3989 3990 /* 3991 * Get per-process file descriptors for use by procstat(1), et al. 3992 */ 3993 static int 3994 sysctl_kern_proc_filedesc(SYSCTL_HANDLER_ARGS) 3995 { 3996 struct sbuf sb; 3997 struct proc *p; 3998 ssize_t maxlen; 3999 int error, error2, *name; 4000 4001 name = (int *)arg1; 4002 4003 sbuf_new_for_sysctl(&sb, NULL, FILEDESC_SBUF_SIZE, req); 4004 sbuf_clear_flags(&sb, SBUF_INCLUDENUL); 4005 error = pget((pid_t)name[0], PGET_CANDEBUG | PGET_NOTWEXIT, &p); 4006 if (error != 0) { 4007 sbuf_delete(&sb); 4008 return (error); 4009 } 4010 maxlen = req->oldptr != NULL ? req->oldlen : -1; 4011 error = kern_proc_filedesc_out(p, &sb, maxlen, 4012 KERN_FILEDESC_PACK_KINFO); 4013 error2 = sbuf_finish(&sb); 4014 sbuf_delete(&sb); 4015 return (error != 0 ? error : error2); 4016 } 4017 4018 #ifdef COMPAT_FREEBSD7 4019 #ifdef KINFO_OFILE_SIZE 4020 CTASSERT(sizeof(struct kinfo_ofile) == KINFO_OFILE_SIZE); 4021 #endif 4022 4023 static void 4024 kinfo_to_okinfo(struct kinfo_file *kif, struct kinfo_ofile *okif) 4025 { 4026 4027 okif->kf_structsize = sizeof(*okif); 4028 okif->kf_type = kif->kf_type; 4029 okif->kf_fd = kif->kf_fd; 4030 okif->kf_ref_count = kif->kf_ref_count; 4031 okif->kf_flags = kif->kf_flags & (KF_FLAG_READ | KF_FLAG_WRITE | 4032 KF_FLAG_APPEND | KF_FLAG_ASYNC | KF_FLAG_FSYNC | KF_FLAG_NONBLOCK | 4033 KF_FLAG_DIRECT | KF_FLAG_HASLOCK); 4034 okif->kf_offset = kif->kf_offset; 4035 if (kif->kf_type == KF_TYPE_VNODE) 4036 okif->kf_vnode_type = kif->kf_un.kf_file.kf_file_type; 4037 else 4038 okif->kf_vnode_type = KF_VTYPE_VNON; 4039 strlcpy(okif->kf_path, kif->kf_path, sizeof(okif->kf_path)); 4040 if (kif->kf_type == KF_TYPE_SOCKET) { 4041 okif->kf_sock_domain = kif->kf_un.kf_sock.kf_sock_domain0; 4042 okif->kf_sock_type = kif->kf_un.kf_sock.kf_sock_type0; 4043 okif->kf_sock_protocol = kif->kf_un.kf_sock.kf_sock_protocol0; 4044 okif->kf_sa_local = kif->kf_un.kf_sock.kf_sa_local; 4045 okif->kf_sa_peer = kif->kf_un.kf_sock.kf_sa_peer; 4046 } else { 4047 okif->kf_sa_local.ss_family = AF_UNSPEC; 4048 okif->kf_sa_peer.ss_family = AF_UNSPEC; 4049 } 4050 } 4051 4052 static int 4053 export_vnode_for_osysctl(struct vnode *vp, int type, struct kinfo_file *kif, 4054 struct kinfo_ofile *okif, struct filedesc *fdp, struct sysctl_req *req) 4055 { 4056 int error; 4057 4058 vrefact(vp); 4059 FILEDESC_SUNLOCK(fdp); 4060 export_vnode_to_kinfo(vp, type, 0, kif, KERN_FILEDESC_PACK_KINFO); 4061 kinfo_to_okinfo(kif, okif); 4062 error = SYSCTL_OUT(req, okif, sizeof(*okif)); 4063 FILEDESC_SLOCK(fdp); 4064 return (error); 4065 } 4066 4067 /* 4068 * Get per-process file descriptors for use by procstat(1), et al. 4069 */ 4070 static int 4071 sysctl_kern_proc_ofiledesc(SYSCTL_HANDLER_ARGS) 4072 { 4073 struct kinfo_ofile *okif; 4074 struct kinfo_file *kif; 4075 struct filedesc *fdp; 4076 struct pwd *pwd; 4077 int error, i, lastfile, *name; 4078 struct file *fp; 4079 struct proc *p; 4080 4081 name = (int *)arg1; 4082 error = pget((pid_t)name[0], PGET_CANDEBUG | PGET_NOTWEXIT, &p); 4083 if (error != 0) 4084 return (error); 4085 fdp = fdhold(p); 4086 PROC_UNLOCK(p); 4087 if (fdp == NULL) 4088 return (ENOENT); 4089 kif = malloc(sizeof(*kif), M_TEMP, M_WAITOK); 4090 okif = malloc(sizeof(*okif), M_TEMP, M_WAITOK); 4091 FILEDESC_SLOCK(fdp); 4092 pwd = pwd_hold_filedesc(fdp); 4093 if (pwd != NULL) { 4094 if (pwd->pwd_cdir != NULL) 4095 export_vnode_for_osysctl(pwd->pwd_cdir, KF_FD_TYPE_CWD, kif, 4096 okif, fdp, req); 4097 if (pwd->pwd_rdir != NULL) 4098 export_vnode_for_osysctl(pwd->pwd_rdir, KF_FD_TYPE_ROOT, kif, 4099 okif, fdp, req); 4100 if (pwd->pwd_jdir != NULL) 4101 export_vnode_for_osysctl(pwd->pwd_jdir, KF_FD_TYPE_JAIL, kif, 4102 okif, fdp, req); 4103 pwd_drop(pwd); 4104 } 4105 lastfile = fdlastfile(fdp); 4106 for (i = 0; fdp->fd_refcnt > 0 && i <= lastfile; i++) { 4107 if ((fp = fdp->fd_ofiles[i].fde_file) == NULL) 4108 continue; 4109 export_file_to_kinfo(fp, i, NULL, kif, fdp, 4110 KERN_FILEDESC_PACK_KINFO); 4111 FILEDESC_SUNLOCK(fdp); 4112 kinfo_to_okinfo(kif, okif); 4113 error = SYSCTL_OUT(req, okif, sizeof(*okif)); 4114 FILEDESC_SLOCK(fdp); 4115 if (error) 4116 break; 4117 } 4118 FILEDESC_SUNLOCK(fdp); 4119 fddrop(fdp); 4120 free(kif, M_TEMP); 4121 free(okif, M_TEMP); 4122 return (0); 4123 } 4124 4125 static SYSCTL_NODE(_kern_proc, KERN_PROC_OFILEDESC, ofiledesc, 4126 CTLFLAG_RD|CTLFLAG_MPSAFE, sysctl_kern_proc_ofiledesc, 4127 "Process ofiledesc entries"); 4128 #endif /* COMPAT_FREEBSD7 */ 4129 4130 int 4131 vntype_to_kinfo(int vtype) 4132 { 4133 struct { 4134 int vtype; 4135 int kf_vtype; 4136 } vtypes_table[] = { 4137 { VBAD, KF_VTYPE_VBAD }, 4138 { VBLK, KF_VTYPE_VBLK }, 4139 { VCHR, KF_VTYPE_VCHR }, 4140 { VDIR, KF_VTYPE_VDIR }, 4141 { VFIFO, KF_VTYPE_VFIFO }, 4142 { VLNK, KF_VTYPE_VLNK }, 4143 { VNON, KF_VTYPE_VNON }, 4144 { VREG, KF_VTYPE_VREG }, 4145 { VSOCK, KF_VTYPE_VSOCK } 4146 }; 4147 unsigned int i; 4148 4149 /* 4150 * Perform vtype translation. 4151 */ 4152 for (i = 0; i < nitems(vtypes_table); i++) 4153 if (vtypes_table[i].vtype == vtype) 4154 return (vtypes_table[i].kf_vtype); 4155 4156 return (KF_VTYPE_UNKNOWN); 4157 } 4158 4159 static SYSCTL_NODE(_kern_proc, KERN_PROC_FILEDESC, filedesc, 4160 CTLFLAG_RD|CTLFLAG_MPSAFE, sysctl_kern_proc_filedesc, 4161 "Process filedesc entries"); 4162 4163 /* 4164 * Store a process current working directory information to sbuf. 4165 * 4166 * Takes a locked proc as argument, and returns with the proc unlocked. 4167 */ 4168 int 4169 kern_proc_cwd_out(struct proc *p, struct sbuf *sb, ssize_t maxlen) 4170 { 4171 struct filedesc *fdp; 4172 struct pwd *pwd; 4173 struct export_fd_buf *efbuf; 4174 struct vnode *cdir; 4175 int error; 4176 4177 PROC_LOCK_ASSERT(p, MA_OWNED); 4178 4179 fdp = fdhold(p); 4180 PROC_UNLOCK(p); 4181 if (fdp == NULL) 4182 return (EINVAL); 4183 4184 efbuf = malloc(sizeof(*efbuf), M_TEMP, M_WAITOK); 4185 efbuf->fdp = fdp; 4186 efbuf->sb = sb; 4187 efbuf->remainder = maxlen; 4188 4189 FILEDESC_SLOCK(fdp); 4190 pwd = FILEDESC_LOCKED_LOAD_PWD(fdp); 4191 cdir = pwd->pwd_cdir; 4192 if (cdir == NULL) { 4193 error = EINVAL; 4194 } else { 4195 vrefact(cdir); 4196 error = export_vnode_to_sb(cdir, KF_FD_TYPE_CWD, FREAD, efbuf); 4197 } 4198 FILEDESC_SUNLOCK(fdp); 4199 fddrop(fdp); 4200 free(efbuf, M_TEMP); 4201 return (error); 4202 } 4203 4204 /* 4205 * Get per-process current working directory. 4206 */ 4207 static int 4208 sysctl_kern_proc_cwd(SYSCTL_HANDLER_ARGS) 4209 { 4210 struct sbuf sb; 4211 struct proc *p; 4212 ssize_t maxlen; 4213 int error, error2, *name; 4214 4215 name = (int *)arg1; 4216 4217 sbuf_new_for_sysctl(&sb, NULL, sizeof(struct kinfo_file), req); 4218 sbuf_clear_flags(&sb, SBUF_INCLUDENUL); 4219 error = pget((pid_t)name[0], PGET_CANDEBUG | PGET_NOTWEXIT, &p); 4220 if (error != 0) { 4221 sbuf_delete(&sb); 4222 return (error); 4223 } 4224 maxlen = req->oldptr != NULL ? req->oldlen : -1; 4225 error = kern_proc_cwd_out(p, &sb, maxlen); 4226 error2 = sbuf_finish(&sb); 4227 sbuf_delete(&sb); 4228 return (error != 0 ? error : error2); 4229 } 4230 4231 static SYSCTL_NODE(_kern_proc, KERN_PROC_CWD, cwd, CTLFLAG_RD|CTLFLAG_MPSAFE, 4232 sysctl_kern_proc_cwd, "Process current working directory"); 4233 4234 #ifdef DDB 4235 /* 4236 * For the purposes of debugging, generate a human-readable string for the 4237 * file type. 4238 */ 4239 static const char * 4240 file_type_to_name(short type) 4241 { 4242 4243 switch (type) { 4244 case 0: 4245 return ("zero"); 4246 case DTYPE_VNODE: 4247 return ("vnode"); 4248 case DTYPE_SOCKET: 4249 return ("socket"); 4250 case DTYPE_PIPE: 4251 return ("pipe"); 4252 case DTYPE_FIFO: 4253 return ("fifo"); 4254 case DTYPE_KQUEUE: 4255 return ("kqueue"); 4256 case DTYPE_CRYPTO: 4257 return ("crypto"); 4258 case DTYPE_MQUEUE: 4259 return ("mqueue"); 4260 case DTYPE_SHM: 4261 return ("shm"); 4262 case DTYPE_SEM: 4263 return ("ksem"); 4264 case DTYPE_PTS: 4265 return ("pts"); 4266 case DTYPE_DEV: 4267 return ("dev"); 4268 case DTYPE_PROCDESC: 4269 return ("proc"); 4270 case DTYPE_LINUXEFD: 4271 return ("levent"); 4272 case DTYPE_LINUXTFD: 4273 return ("ltimer"); 4274 default: 4275 return ("unkn"); 4276 } 4277 } 4278 4279 /* 4280 * For the purposes of debugging, identify a process (if any, perhaps one of 4281 * many) that references the passed file in its file descriptor array. Return 4282 * NULL if none. 4283 */ 4284 static struct proc * 4285 file_to_first_proc(struct file *fp) 4286 { 4287 struct filedesc *fdp; 4288 struct proc *p; 4289 int n; 4290 4291 FOREACH_PROC_IN_SYSTEM(p) { 4292 if (p->p_state == PRS_NEW) 4293 continue; 4294 fdp = p->p_fd; 4295 if (fdp == NULL) 4296 continue; 4297 for (n = 0; n < fdp->fd_nfiles; n++) { 4298 if (fp == fdp->fd_ofiles[n].fde_file) 4299 return (p); 4300 } 4301 } 4302 return (NULL); 4303 } 4304 4305 static void 4306 db_print_file(struct file *fp, int header) 4307 { 4308 #define XPTRWIDTH ((int)howmany(sizeof(void *) * NBBY, 4)) 4309 struct proc *p; 4310 4311 if (header) 4312 db_printf("%*s %6s %*s %8s %4s %5s %6s %*s %5s %s\n", 4313 XPTRWIDTH, "File", "Type", XPTRWIDTH, "Data", "Flag", 4314 "GCFl", "Count", "MCount", XPTRWIDTH, "Vnode", "FPID", 4315 "FCmd"); 4316 p = file_to_first_proc(fp); 4317 db_printf("%*p %6s %*p %08x %04x %5d %6d %*p %5d %s\n", XPTRWIDTH, 4318 fp, file_type_to_name(fp->f_type), XPTRWIDTH, fp->f_data, 4319 fp->f_flag, 0, fp->f_count, 0, XPTRWIDTH, fp->f_vnode, 4320 p != NULL ? p->p_pid : -1, p != NULL ? p->p_comm : "-"); 4321 4322 #undef XPTRWIDTH 4323 } 4324 4325 DB_SHOW_COMMAND(file, db_show_file) 4326 { 4327 struct file *fp; 4328 4329 if (!have_addr) { 4330 db_printf("usage: show file <addr>\n"); 4331 return; 4332 } 4333 fp = (struct file *)addr; 4334 db_print_file(fp, 1); 4335 } 4336 4337 DB_SHOW_COMMAND(files, db_show_files) 4338 { 4339 struct filedesc *fdp; 4340 struct file *fp; 4341 struct proc *p; 4342 int header; 4343 int n; 4344 4345 header = 1; 4346 FOREACH_PROC_IN_SYSTEM(p) { 4347 if (p->p_state == PRS_NEW) 4348 continue; 4349 if ((fdp = p->p_fd) == NULL) 4350 continue; 4351 for (n = 0; n < fdp->fd_nfiles; ++n) { 4352 if ((fp = fdp->fd_ofiles[n].fde_file) == NULL) 4353 continue; 4354 db_print_file(fp, header); 4355 header = 0; 4356 } 4357 } 4358 } 4359 #endif 4360 4361 SYSCTL_INT(_kern, KERN_MAXFILESPERPROC, maxfilesperproc, CTLFLAG_RW, 4362 &maxfilesperproc, 0, "Maximum files allowed open per process"); 4363 4364 SYSCTL_INT(_kern, KERN_MAXFILES, maxfiles, CTLFLAG_RW, 4365 &maxfiles, 0, "Maximum number of files"); 4366 4367 SYSCTL_INT(_kern, OID_AUTO, openfiles, CTLFLAG_RD, 4368 &openfiles, 0, "System-wide number of open files"); 4369 4370 /* ARGSUSED*/ 4371 static void 4372 filelistinit(void *dummy) 4373 { 4374 4375 file_zone = uma_zcreate("Files", sizeof(struct file), NULL, NULL, 4376 NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE); 4377 filedesc0_zone = uma_zcreate("filedesc0", sizeof(struct filedesc0), 4378 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0); 4379 pwd_zone = uma_zcreate("PWD", sizeof(struct pwd), NULL, NULL, 4380 NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_SMR); 4381 /* 4382 * XXXMJG this is a temporary hack due to boot ordering issues against 4383 * the vnode zone. 4384 */ 4385 vfs_smr = uma_zone_get_smr(pwd_zone); 4386 mtx_init(&sigio_lock, "sigio lock", NULL, MTX_DEF); 4387 } 4388 SYSINIT(select, SI_SUB_LOCK, SI_ORDER_FIRST, filelistinit, NULL); 4389 4390 /*-------------------------------------------------------------------*/ 4391 4392 static int 4393 badfo_readwrite(struct file *fp, struct uio *uio, struct ucred *active_cred, 4394 int flags, struct thread *td) 4395 { 4396 4397 return (EBADF); 4398 } 4399 4400 static int 4401 badfo_truncate(struct file *fp, off_t length, struct ucred *active_cred, 4402 struct thread *td) 4403 { 4404 4405 return (EINVAL); 4406 } 4407 4408 static int 4409 badfo_ioctl(struct file *fp, u_long com, void *data, struct ucred *active_cred, 4410 struct thread *td) 4411 { 4412 4413 return (EBADF); 4414 } 4415 4416 static int 4417 badfo_poll(struct file *fp, int events, struct ucred *active_cred, 4418 struct thread *td) 4419 { 4420 4421 return (0); 4422 } 4423 4424 static int 4425 badfo_kqfilter(struct file *fp, struct knote *kn) 4426 { 4427 4428 return (EBADF); 4429 } 4430 4431 static int 4432 badfo_stat(struct file *fp, struct stat *sb, struct ucred *active_cred, 4433 struct thread *td) 4434 { 4435 4436 return (EBADF); 4437 } 4438 4439 static int 4440 badfo_close(struct file *fp, struct thread *td) 4441 { 4442 4443 return (0); 4444 } 4445 4446 static int 4447 badfo_chmod(struct file *fp, mode_t mode, struct ucred *active_cred, 4448 struct thread *td) 4449 { 4450 4451 return (EBADF); 4452 } 4453 4454 static int 4455 badfo_chown(struct file *fp, uid_t uid, gid_t gid, struct ucred *active_cred, 4456 struct thread *td) 4457 { 4458 4459 return (EBADF); 4460 } 4461 4462 static int 4463 badfo_sendfile(struct file *fp, int sockfd, struct uio *hdr_uio, 4464 struct uio *trl_uio, off_t offset, size_t nbytes, off_t *sent, int flags, 4465 struct thread *td) 4466 { 4467 4468 return (EBADF); 4469 } 4470 4471 static int 4472 badfo_fill_kinfo(struct file *fp, struct kinfo_file *kif, struct filedesc *fdp) 4473 { 4474 4475 return (0); 4476 } 4477 4478 struct fileops badfileops = { 4479 .fo_read = badfo_readwrite, 4480 .fo_write = badfo_readwrite, 4481 .fo_truncate = badfo_truncate, 4482 .fo_ioctl = badfo_ioctl, 4483 .fo_poll = badfo_poll, 4484 .fo_kqfilter = badfo_kqfilter, 4485 .fo_stat = badfo_stat, 4486 .fo_close = badfo_close, 4487 .fo_chmod = badfo_chmod, 4488 .fo_chown = badfo_chown, 4489 .fo_sendfile = badfo_sendfile, 4490 .fo_fill_kinfo = badfo_fill_kinfo, 4491 }; 4492 4493 int 4494 invfo_rdwr(struct file *fp, struct uio *uio, struct ucred *active_cred, 4495 int flags, struct thread *td) 4496 { 4497 4498 return (EOPNOTSUPP); 4499 } 4500 4501 int 4502 invfo_truncate(struct file *fp, off_t length, struct ucred *active_cred, 4503 struct thread *td) 4504 { 4505 4506 return (EINVAL); 4507 } 4508 4509 int 4510 invfo_ioctl(struct file *fp, u_long com, void *data, 4511 struct ucred *active_cred, struct thread *td) 4512 { 4513 4514 return (ENOTTY); 4515 } 4516 4517 int 4518 invfo_poll(struct file *fp, int events, struct ucred *active_cred, 4519 struct thread *td) 4520 { 4521 4522 return (poll_no_poll(events)); 4523 } 4524 4525 int 4526 invfo_kqfilter(struct file *fp, struct knote *kn) 4527 { 4528 4529 return (EINVAL); 4530 } 4531 4532 int 4533 invfo_chmod(struct file *fp, mode_t mode, struct ucred *active_cred, 4534 struct thread *td) 4535 { 4536 4537 return (EINVAL); 4538 } 4539 4540 int 4541 invfo_chown(struct file *fp, uid_t uid, gid_t gid, struct ucred *active_cred, 4542 struct thread *td) 4543 { 4544 4545 return (EINVAL); 4546 } 4547 4548 int 4549 invfo_sendfile(struct file *fp, int sockfd, struct uio *hdr_uio, 4550 struct uio *trl_uio, off_t offset, size_t nbytes, off_t *sent, int flags, 4551 struct thread *td) 4552 { 4553 4554 return (EINVAL); 4555 } 4556 4557 /*-------------------------------------------------------------------*/ 4558 4559 /* 4560 * File Descriptor pseudo-device driver (/dev/fd/). 4561 * 4562 * Opening minor device N dup()s the file (if any) connected to file 4563 * descriptor N belonging to the calling process. Note that this driver 4564 * consists of only the ``open()'' routine, because all subsequent 4565 * references to this file will be direct to the other driver. 4566 * 4567 * XXX: we could give this one a cloning event handler if necessary. 4568 */ 4569 4570 /* ARGSUSED */ 4571 static int 4572 fdopen(struct cdev *dev, int mode, int type, struct thread *td) 4573 { 4574 4575 /* 4576 * XXX Kludge: set curthread->td_dupfd to contain the value of the 4577 * the file descriptor being sought for duplication. The error 4578 * return ensures that the vnode for this device will be released 4579 * by vn_open. Open will detect this special error and take the 4580 * actions in dupfdopen below. Other callers of vn_open or VOP_OPEN 4581 * will simply report the error. 4582 */ 4583 td->td_dupfd = dev2unit(dev); 4584 return (ENODEV); 4585 } 4586 4587 static struct cdevsw fildesc_cdevsw = { 4588 .d_version = D_VERSION, 4589 .d_open = fdopen, 4590 .d_name = "FD", 4591 }; 4592 4593 static void 4594 fildesc_drvinit(void *unused) 4595 { 4596 struct cdev *dev; 4597 4598 dev = make_dev_credf(MAKEDEV_ETERNAL, &fildesc_cdevsw, 0, NULL, 4599 UID_ROOT, GID_WHEEL, 0666, "fd/0"); 4600 make_dev_alias(dev, "stdin"); 4601 dev = make_dev_credf(MAKEDEV_ETERNAL, &fildesc_cdevsw, 1, NULL, 4602 UID_ROOT, GID_WHEEL, 0666, "fd/1"); 4603 make_dev_alias(dev, "stdout"); 4604 dev = make_dev_credf(MAKEDEV_ETERNAL, &fildesc_cdevsw, 2, NULL, 4605 UID_ROOT, GID_WHEEL, 0666, "fd/2"); 4606 make_dev_alias(dev, "stderr"); 4607 } 4608 4609 SYSINIT(fildescdev, SI_SUB_DRIVERS, SI_ORDER_MIDDLE, fildesc_drvinit, NULL); 4610