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 37 #include <sys/cdefs.h> 38 #include "opt_capsicum.h" 39 #include "opt_ddb.h" 40 #include "opt_ktrace.h" 41 42 #include <sys/param.h> 43 #include <sys/systm.h> 44 45 #include <sys/capsicum.h> 46 #include <sys/conf.h> 47 #include <sys/fcntl.h> 48 #include <sys/file.h> 49 #include <sys/filedesc.h> 50 #include <sys/filio.h> 51 #include <sys/jail.h> 52 #include <sys/kernel.h> 53 #include <sys/limits.h> 54 #include <sys/lock.h> 55 #include <sys/malloc.h> 56 #include <sys/mount.h> 57 #include <sys/mutex.h> 58 #include <sys/namei.h> 59 #include <sys/selinfo.h> 60 #include <sys/poll.h> 61 #include <sys/priv.h> 62 #include <sys/proc.h> 63 #include <sys/protosw.h> 64 #include <sys/racct.h> 65 #include <sys/resourcevar.h> 66 #include <sys/sbuf.h> 67 #include <sys/signalvar.h> 68 #include <sys/kdb.h> 69 #include <sys/smr.h> 70 #include <sys/stat.h> 71 #include <sys/sx.h> 72 #include <sys/syscallsubr.h> 73 #include <sys/sysctl.h> 74 #include <sys/sysproto.h> 75 #include <sys/unistd.h> 76 #include <sys/user.h> 77 #include <sys/vnode.h> 78 #include <sys/ktrace.h> 79 80 #include <net/vnet.h> 81 82 #include <security/audit/audit.h> 83 84 #include <vm/uma.h> 85 #include <vm/vm.h> 86 87 #include <ddb/ddb.h> 88 89 static MALLOC_DEFINE(M_FILEDESC, "filedesc", "Open file descriptor table"); 90 static MALLOC_DEFINE(M_PWD, "pwd", "Descriptor table vnodes"); 91 static MALLOC_DEFINE(M_PWDDESC, "pwddesc", "Pwd descriptors"); 92 static MALLOC_DEFINE(M_FILEDESC_TO_LEADER, "filedesc_to_leader", 93 "file desc to leader structures"); 94 static MALLOC_DEFINE(M_SIGIO, "sigio", "sigio structures"); 95 MALLOC_DEFINE(M_FILECAPS, "filecaps", "descriptor capabilities"); 96 97 MALLOC_DECLARE(M_FADVISE); 98 99 static __read_mostly uma_zone_t file_zone; 100 static __read_mostly uma_zone_t filedesc0_zone; 101 __read_mostly uma_zone_t pwd_zone; 102 VFS_SMR_DECLARE; 103 104 static int closefp(struct filedesc *fdp, int fd, struct file *fp, 105 struct thread *td, bool holdleaders, bool audit); 106 static void export_file_to_kinfo(struct file *fp, int fd, 107 cap_rights_t *rightsp, struct kinfo_file *kif, 108 struct filedesc *fdp, int flags); 109 static int fd_first_free(struct filedesc *fdp, int low, int size); 110 static void fdgrowtable(struct filedesc *fdp, int nfd); 111 static void fdgrowtable_exp(struct filedesc *fdp, int nfd); 112 static void fdunused(struct filedesc *fdp, int fd); 113 static void fdused(struct filedesc *fdp, int fd); 114 static int fget_unlocked_seq(struct thread *td, int fd, 115 cap_rights_t *needrightsp, struct file **fpp, seqc_t *seqp); 116 static int getmaxfd(struct thread *td); 117 static u_long *filecaps_copy_prep(const struct filecaps *src); 118 static void filecaps_copy_finish(const struct filecaps *src, 119 struct filecaps *dst, u_long *ioctls); 120 static u_long *filecaps_free_prep(struct filecaps *fcaps); 121 static void filecaps_free_finish(u_long *ioctls); 122 123 static struct pwd *pwd_alloc(void); 124 125 /* 126 * Each process has: 127 * 128 * - An array of open file descriptors (fd_ofiles) 129 * - An array of file flags (fd_ofileflags) 130 * - A bitmap recording which descriptors are in use (fd_map) 131 * 132 * A process starts out with NDFILE descriptors. The value of NDFILE has 133 * been selected based the historical limit of 20 open files, and an 134 * assumption that the majority of processes, especially short-lived 135 * processes like shells, will never need more. 136 * 137 * If this initial allocation is exhausted, a larger descriptor table and 138 * map are allocated dynamically, and the pointers in the process's struct 139 * filedesc are updated to point to those. This is repeated every time 140 * the process runs out of file descriptors (provided it hasn't hit its 141 * resource limit). 142 * 143 * Since threads may hold references to individual descriptor table 144 * entries, the tables are never freed. Instead, they are placed on a 145 * linked list and freed only when the struct filedesc is released. 146 */ 147 #define NDFILE 20 148 #define NDSLOTSIZE sizeof(NDSLOTTYPE) 149 #define NDENTRIES (NDSLOTSIZE * __CHAR_BIT) 150 #define NDSLOT(x) ((x) / NDENTRIES) 151 #define NDBIT(x) ((NDSLOTTYPE)1 << ((x) % NDENTRIES)) 152 #define NDSLOTS(x) (((x) + NDENTRIES - 1) / NDENTRIES) 153 154 #define FILEDESC_FOREACH_FDE(fdp, _iterator, _fde) \ 155 struct filedesc *_fdp = (fdp); \ 156 int _lastfile = fdlastfile_single(_fdp); \ 157 for (_iterator = 0; _iterator <= _lastfile; _iterator++) \ 158 if ((_fde = &_fdp->fd_ofiles[_iterator])->fde_file != NULL) 159 160 #define FILEDESC_FOREACH_FP(fdp, _iterator, _fp) \ 161 struct filedesc *_fdp = (fdp); \ 162 int _lastfile = fdlastfile_single(_fdp); \ 163 for (_iterator = 0; _iterator <= _lastfile; _iterator++) \ 164 if ((_fp = _fdp->fd_ofiles[_iterator].fde_file) != NULL) 165 166 /* 167 * SLIST entry used to keep track of ofiles which must be reclaimed when 168 * the process exits. 169 */ 170 struct freetable { 171 struct fdescenttbl *ft_table; 172 SLIST_ENTRY(freetable) ft_next; 173 }; 174 175 /* 176 * Initial allocation: a filedesc structure + the head of SLIST used to 177 * keep track of old ofiles + enough space for NDFILE descriptors. 178 */ 179 180 struct fdescenttbl0 { 181 int fdt_nfiles; 182 struct filedescent fdt_ofiles[NDFILE]; 183 }; 184 185 struct filedesc0 { 186 struct filedesc fd_fd; 187 SLIST_HEAD(, freetable) fd_free; 188 struct fdescenttbl0 fd_dfiles; 189 NDSLOTTYPE fd_dmap[NDSLOTS(NDFILE)]; 190 }; 191 192 /* 193 * Descriptor management. 194 */ 195 static int __exclusive_cache_line openfiles; /* actual number of open files */ 196 struct mtx sigio_lock; /* mtx to protect pointers to sigio */ 197 void __read_mostly (*mq_fdclose)(struct thread *td, int fd, struct file *fp); 198 199 /* 200 * If low >= size, just return low. Otherwise find the first zero bit in the 201 * given bitmap, starting at low and not exceeding size - 1. Return size if 202 * not found. 203 */ 204 static int 205 fd_first_free(struct filedesc *fdp, int low, int size) 206 { 207 NDSLOTTYPE *map = fdp->fd_map; 208 NDSLOTTYPE mask; 209 int off, maxoff; 210 211 if (low >= size) 212 return (low); 213 214 off = NDSLOT(low); 215 if (low % NDENTRIES) { 216 mask = ~(~(NDSLOTTYPE)0 >> (NDENTRIES - (low % NDENTRIES))); 217 if ((mask &= ~map[off]) != 0UL) 218 return (off * NDENTRIES + ffsl(mask) - 1); 219 ++off; 220 } 221 for (maxoff = NDSLOTS(size); off < maxoff; ++off) 222 if (map[off] != ~0UL) 223 return (off * NDENTRIES + ffsl(~map[off]) - 1); 224 return (size); 225 } 226 227 /* 228 * Find the last used fd. 229 * 230 * Call this variant if fdp can't be modified by anyone else (e.g, during exec). 231 * Otherwise use fdlastfile. 232 */ 233 int 234 fdlastfile_single(struct filedesc *fdp) 235 { 236 NDSLOTTYPE *map = fdp->fd_map; 237 int off, minoff; 238 239 off = NDSLOT(fdp->fd_nfiles - 1); 240 for (minoff = NDSLOT(0); off >= minoff; --off) 241 if (map[off] != 0) 242 return (off * NDENTRIES + flsl(map[off]) - 1); 243 return (-1); 244 } 245 246 int 247 fdlastfile(struct filedesc *fdp) 248 { 249 250 FILEDESC_LOCK_ASSERT(fdp); 251 return (fdlastfile_single(fdp)); 252 } 253 254 static int 255 fdisused(struct filedesc *fdp, int fd) 256 { 257 258 KASSERT(fd >= 0 && fd < fdp->fd_nfiles, 259 ("file descriptor %d out of range (0, %d)", fd, fdp->fd_nfiles)); 260 261 return ((fdp->fd_map[NDSLOT(fd)] & NDBIT(fd)) != 0); 262 } 263 264 /* 265 * Mark a file descriptor as used. 266 */ 267 static void 268 fdused_init(struct filedesc *fdp, int fd) 269 { 270 271 KASSERT(!fdisused(fdp, fd), ("fd=%d is already used", fd)); 272 273 fdp->fd_map[NDSLOT(fd)] |= NDBIT(fd); 274 } 275 276 static void 277 fdused(struct filedesc *fdp, int fd) 278 { 279 280 FILEDESC_XLOCK_ASSERT(fdp); 281 282 fdused_init(fdp, fd); 283 if (fd == fdp->fd_freefile) 284 fdp->fd_freefile++; 285 } 286 287 /* 288 * Mark a file descriptor as unused. 289 */ 290 static void 291 fdunused(struct filedesc *fdp, int fd) 292 { 293 294 FILEDESC_XLOCK_ASSERT(fdp); 295 296 KASSERT(fdisused(fdp, fd), ("fd=%d is already unused", fd)); 297 KASSERT(fdp->fd_ofiles[fd].fde_file == NULL, 298 ("fd=%d is still in use", fd)); 299 300 fdp->fd_map[NDSLOT(fd)] &= ~NDBIT(fd); 301 if (fd < fdp->fd_freefile) 302 fdp->fd_freefile = fd; 303 } 304 305 /* 306 * Free a file descriptor. 307 * 308 * Avoid some work if fdp is about to be destroyed. 309 */ 310 static inline void 311 fdefree_last(struct filedescent *fde) 312 { 313 314 filecaps_free(&fde->fde_caps); 315 } 316 317 static inline void 318 fdfree(struct filedesc *fdp, int fd) 319 { 320 struct filedescent *fde; 321 322 FILEDESC_XLOCK_ASSERT(fdp); 323 fde = &fdp->fd_ofiles[fd]; 324 #ifdef CAPABILITIES 325 seqc_write_begin(&fde->fde_seqc); 326 #endif 327 fde->fde_file = NULL; 328 #ifdef CAPABILITIES 329 seqc_write_end(&fde->fde_seqc); 330 #endif 331 fdefree_last(fde); 332 fdunused(fdp, fd); 333 } 334 335 /* 336 * System calls on descriptors. 337 */ 338 #ifndef _SYS_SYSPROTO_H_ 339 struct getdtablesize_args { 340 int dummy; 341 }; 342 #endif 343 /* ARGSUSED */ 344 int 345 sys_getdtablesize(struct thread *td, struct getdtablesize_args *uap) 346 { 347 #ifdef RACCT 348 uint64_t lim; 349 #endif 350 351 td->td_retval[0] = getmaxfd(td); 352 #ifdef RACCT 353 PROC_LOCK(td->td_proc); 354 lim = racct_get_limit(td->td_proc, RACCT_NOFILE); 355 PROC_UNLOCK(td->td_proc); 356 if (lim < td->td_retval[0]) 357 td->td_retval[0] = lim; 358 #endif 359 return (0); 360 } 361 362 /* 363 * Duplicate a file descriptor to a particular value. 364 * 365 * Note: keep in mind that a potential race condition exists when closing 366 * descriptors from a shared descriptor table (via rfork). 367 */ 368 #ifndef _SYS_SYSPROTO_H_ 369 struct dup2_args { 370 u_int from; 371 u_int to; 372 }; 373 #endif 374 /* ARGSUSED */ 375 int 376 sys_dup2(struct thread *td, struct dup2_args *uap) 377 { 378 379 return (kern_dup(td, FDDUP_FIXED, 0, (int)uap->from, (int)uap->to)); 380 } 381 382 /* 383 * Duplicate a file descriptor. 384 */ 385 #ifndef _SYS_SYSPROTO_H_ 386 struct dup_args { 387 u_int fd; 388 }; 389 #endif 390 /* ARGSUSED */ 391 int 392 sys_dup(struct thread *td, struct dup_args *uap) 393 { 394 395 return (kern_dup(td, FDDUP_NORMAL, 0, (int)uap->fd, 0)); 396 } 397 398 /* 399 * The file control system call. 400 */ 401 #ifndef _SYS_SYSPROTO_H_ 402 struct fcntl_args { 403 int fd; 404 int cmd; 405 long arg; 406 }; 407 #endif 408 /* ARGSUSED */ 409 int 410 sys_fcntl(struct thread *td, struct fcntl_args *uap) 411 { 412 413 return (kern_fcntl_freebsd(td, uap->fd, uap->cmd, uap->arg)); 414 } 415 416 int 417 kern_fcntl_freebsd(struct thread *td, int fd, int cmd, intptr_t arg) 418 { 419 struct flock fl; 420 struct __oflock ofl; 421 intptr_t arg1; 422 int error, newcmd; 423 424 error = 0; 425 newcmd = cmd; 426 switch (cmd) { 427 case F_OGETLK: 428 case F_OSETLK: 429 case F_OSETLKW: 430 /* 431 * Convert old flock structure to new. 432 */ 433 error = copyin((void *)arg, &ofl, sizeof(ofl)); 434 fl.l_start = ofl.l_start; 435 fl.l_len = ofl.l_len; 436 fl.l_pid = ofl.l_pid; 437 fl.l_type = ofl.l_type; 438 fl.l_whence = ofl.l_whence; 439 fl.l_sysid = 0; 440 441 switch (cmd) { 442 case F_OGETLK: 443 newcmd = F_GETLK; 444 break; 445 case F_OSETLK: 446 newcmd = F_SETLK; 447 break; 448 case F_OSETLKW: 449 newcmd = F_SETLKW; 450 break; 451 } 452 arg1 = (intptr_t)&fl; 453 break; 454 case F_GETLK: 455 case F_SETLK: 456 case F_SETLKW: 457 case F_SETLK_REMOTE: 458 error = copyin((void *)arg, &fl, sizeof(fl)); 459 arg1 = (intptr_t)&fl; 460 break; 461 default: 462 arg1 = arg; 463 break; 464 } 465 if (error) 466 return (error); 467 error = kern_fcntl(td, fd, newcmd, arg1); 468 if (error) 469 return (error); 470 if (cmd == F_OGETLK) { 471 ofl.l_start = fl.l_start; 472 ofl.l_len = fl.l_len; 473 ofl.l_pid = fl.l_pid; 474 ofl.l_type = fl.l_type; 475 ofl.l_whence = fl.l_whence; 476 error = copyout(&ofl, (void *)arg, sizeof(ofl)); 477 } else if (cmd == F_GETLK) { 478 error = copyout(&fl, (void *)arg, sizeof(fl)); 479 } 480 return (error); 481 } 482 483 int 484 kern_fcntl(struct thread *td, int fd, int cmd, intptr_t arg) 485 { 486 struct filedesc *fdp; 487 struct flock *flp; 488 struct file *fp, *fp2; 489 struct filedescent *fde; 490 struct proc *p; 491 struct vnode *vp; 492 struct mount *mp; 493 struct kinfo_file *kif; 494 int error, flg, kif_sz, seals, tmp, got_set, got_cleared; 495 uint64_t bsize; 496 off_t foffset; 497 498 error = 0; 499 flg = F_POSIX; 500 p = td->td_proc; 501 fdp = p->p_fd; 502 503 AUDIT_ARG_FD(cmd); 504 AUDIT_ARG_CMD(cmd); 505 switch (cmd) { 506 case F_DUPFD: 507 tmp = arg; 508 error = kern_dup(td, FDDUP_FCNTL, 0, fd, tmp); 509 break; 510 511 case F_DUPFD_CLOEXEC: 512 tmp = arg; 513 error = kern_dup(td, FDDUP_FCNTL, FDDUP_FLAG_CLOEXEC, fd, tmp); 514 break; 515 516 case F_DUP2FD: 517 tmp = arg; 518 error = kern_dup(td, FDDUP_FIXED, 0, fd, tmp); 519 break; 520 521 case F_DUP2FD_CLOEXEC: 522 tmp = arg; 523 error = kern_dup(td, FDDUP_FIXED, FDDUP_FLAG_CLOEXEC, fd, tmp); 524 break; 525 526 case F_GETFD: 527 error = EBADF; 528 FILEDESC_SLOCK(fdp); 529 fde = fdeget_noref(fdp, fd); 530 if (fde != NULL) { 531 td->td_retval[0] = 532 (fde->fde_flags & UF_EXCLOSE) ? FD_CLOEXEC : 0; 533 error = 0; 534 } 535 FILEDESC_SUNLOCK(fdp); 536 break; 537 538 case F_SETFD: 539 error = EBADF; 540 FILEDESC_XLOCK(fdp); 541 fde = fdeget_noref(fdp, fd); 542 if (fde != NULL) { 543 fde->fde_flags = (fde->fde_flags & ~UF_EXCLOSE) | 544 (arg & FD_CLOEXEC ? UF_EXCLOSE : 0); 545 error = 0; 546 } 547 FILEDESC_XUNLOCK(fdp); 548 break; 549 550 case F_GETFL: 551 error = fget_fcntl(td, fd, &cap_fcntl_rights, F_GETFL, &fp); 552 if (error != 0) 553 break; 554 td->td_retval[0] = OFLAGS(fp->f_flag); 555 fdrop(fp, td); 556 break; 557 558 case F_SETFL: 559 error = fget_fcntl(td, fd, &cap_fcntl_rights, F_SETFL, &fp); 560 if (error != 0) 561 break; 562 if (fp->f_ops == &path_fileops) { 563 fdrop(fp, td); 564 error = EBADF; 565 break; 566 } 567 do { 568 tmp = flg = fp->f_flag; 569 tmp &= ~FCNTLFLAGS; 570 tmp |= FFLAGS(arg & ~O_ACCMODE) & FCNTLFLAGS; 571 } while (atomic_cmpset_int(&fp->f_flag, flg, tmp) == 0); 572 got_set = tmp & ~flg; 573 got_cleared = flg & ~tmp; 574 tmp = fp->f_flag & FNONBLOCK; 575 error = fo_ioctl(fp, FIONBIO, &tmp, td->td_ucred, td); 576 if (error != 0) 577 goto revert_f_setfl; 578 tmp = fp->f_flag & FASYNC; 579 error = fo_ioctl(fp, FIOASYNC, &tmp, td->td_ucred, td); 580 if (error == 0) { 581 fdrop(fp, td); 582 break; 583 } 584 atomic_clear_int(&fp->f_flag, FNONBLOCK); 585 tmp = 0; 586 (void)fo_ioctl(fp, FIONBIO, &tmp, td->td_ucred, td); 587 revert_f_setfl: 588 do { 589 tmp = flg = fp->f_flag; 590 tmp &= ~FCNTLFLAGS; 591 tmp |= got_cleared; 592 tmp &= ~got_set; 593 } while (atomic_cmpset_int(&fp->f_flag, flg, tmp) == 0); 594 fdrop(fp, td); 595 break; 596 597 case F_GETOWN: 598 error = fget_fcntl(td, fd, &cap_fcntl_rights, F_GETOWN, &fp); 599 if (error != 0) 600 break; 601 error = fo_ioctl(fp, FIOGETOWN, &tmp, td->td_ucred, td); 602 if (error == 0) 603 td->td_retval[0] = tmp; 604 fdrop(fp, td); 605 break; 606 607 case F_SETOWN: 608 error = fget_fcntl(td, fd, &cap_fcntl_rights, F_SETOWN, &fp); 609 if (error != 0) 610 break; 611 tmp = arg; 612 error = fo_ioctl(fp, FIOSETOWN, &tmp, td->td_ucred, td); 613 fdrop(fp, td); 614 break; 615 616 case F_SETLK_REMOTE: 617 error = priv_check(td, PRIV_NFS_LOCKD); 618 if (error != 0) 619 return (error); 620 flg = F_REMOTE; 621 goto do_setlk; 622 623 case F_SETLKW: 624 flg |= F_WAIT; 625 /* FALLTHROUGH F_SETLK */ 626 627 case F_SETLK: 628 do_setlk: 629 flp = (struct flock *)arg; 630 if ((flg & F_REMOTE) != 0 && flp->l_sysid == 0) { 631 error = EINVAL; 632 break; 633 } 634 635 error = fget_unlocked(td, fd, &cap_flock_rights, &fp); 636 if (error != 0) 637 break; 638 if (fp->f_type != DTYPE_VNODE || fp->f_ops == &path_fileops) { 639 error = EBADF; 640 fdrop(fp, td); 641 break; 642 } 643 644 if (flp->l_whence == SEEK_CUR) { 645 foffset = foffset_get(fp); 646 if (foffset < 0 || 647 (flp->l_start > 0 && 648 foffset > OFF_MAX - flp->l_start)) { 649 error = EOVERFLOW; 650 fdrop(fp, td); 651 break; 652 } 653 flp->l_start += foffset; 654 } 655 656 vp = fp->f_vnode; 657 switch (flp->l_type) { 658 case F_RDLCK: 659 if ((fp->f_flag & FREAD) == 0) { 660 error = EBADF; 661 break; 662 } 663 if ((p->p_leader->p_flag & P_ADVLOCK) == 0) { 664 PROC_LOCK(p->p_leader); 665 p->p_leader->p_flag |= P_ADVLOCK; 666 PROC_UNLOCK(p->p_leader); 667 } 668 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_SETLK, 669 flp, flg); 670 break; 671 case F_WRLCK: 672 if ((fp->f_flag & FWRITE) == 0) { 673 error = EBADF; 674 break; 675 } 676 if ((p->p_leader->p_flag & P_ADVLOCK) == 0) { 677 PROC_LOCK(p->p_leader); 678 p->p_leader->p_flag |= P_ADVLOCK; 679 PROC_UNLOCK(p->p_leader); 680 } 681 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_SETLK, 682 flp, flg); 683 break; 684 case F_UNLCK: 685 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_UNLCK, 686 flp, flg); 687 break; 688 case F_UNLCKSYS: 689 if (flg != F_REMOTE) { 690 error = EINVAL; 691 break; 692 } 693 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, 694 F_UNLCKSYS, flp, flg); 695 break; 696 default: 697 error = EINVAL; 698 break; 699 } 700 if (error != 0 || flp->l_type == F_UNLCK || 701 flp->l_type == F_UNLCKSYS) { 702 fdrop(fp, td); 703 break; 704 } 705 706 /* 707 * Check for a race with close. 708 * 709 * The vnode is now advisory locked (or unlocked, but this case 710 * is not really important) as the caller requested. 711 * We had to drop the filedesc lock, so we need to recheck if 712 * the descriptor is still valid, because if it was closed 713 * in the meantime we need to remove advisory lock from the 714 * vnode - close on any descriptor leading to an advisory 715 * locked vnode, removes that lock. 716 * We will return 0 on purpose in that case, as the result of 717 * successful advisory lock might have been externally visible 718 * already. This is fine - effectively we pretend to the caller 719 * that the closing thread was a bit slower and that the 720 * advisory lock succeeded before the close. 721 */ 722 error = fget_unlocked(td, fd, &cap_no_rights, &fp2); 723 if (error != 0) { 724 fdrop(fp, td); 725 break; 726 } 727 if (fp != fp2) { 728 flp->l_whence = SEEK_SET; 729 flp->l_start = 0; 730 flp->l_len = 0; 731 flp->l_type = F_UNLCK; 732 (void) VOP_ADVLOCK(vp, (caddr_t)p->p_leader, 733 F_UNLCK, flp, F_POSIX); 734 } 735 fdrop(fp, td); 736 fdrop(fp2, td); 737 break; 738 739 case F_GETLK: 740 error = fget_unlocked(td, fd, &cap_flock_rights, &fp); 741 if (error != 0) 742 break; 743 if (fp->f_type != DTYPE_VNODE || fp->f_ops == &path_fileops) { 744 error = EBADF; 745 fdrop(fp, td); 746 break; 747 } 748 flp = (struct flock *)arg; 749 if (flp->l_type != F_RDLCK && flp->l_type != F_WRLCK && 750 flp->l_type != F_UNLCK) { 751 error = EINVAL; 752 fdrop(fp, td); 753 break; 754 } 755 if (flp->l_whence == SEEK_CUR) { 756 foffset = foffset_get(fp); 757 if ((flp->l_start > 0 && 758 foffset > OFF_MAX - flp->l_start) || 759 (flp->l_start < 0 && 760 foffset < OFF_MIN - flp->l_start)) { 761 error = EOVERFLOW; 762 fdrop(fp, td); 763 break; 764 } 765 flp->l_start += foffset; 766 } 767 vp = fp->f_vnode; 768 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_GETLK, flp, 769 F_POSIX); 770 fdrop(fp, td); 771 break; 772 773 case F_ADD_SEALS: 774 error = fget_unlocked(td, fd, &cap_no_rights, &fp); 775 if (error != 0) 776 break; 777 error = fo_add_seals(fp, arg); 778 fdrop(fp, td); 779 break; 780 781 case F_GET_SEALS: 782 error = fget_unlocked(td, fd, &cap_no_rights, &fp); 783 if (error != 0) 784 break; 785 if (fo_get_seals(fp, &seals) == 0) 786 td->td_retval[0] = seals; 787 else 788 error = EINVAL; 789 fdrop(fp, td); 790 break; 791 792 case F_RDAHEAD: 793 arg = arg ? 128 * 1024: 0; 794 /* FALLTHROUGH */ 795 case F_READAHEAD: 796 error = fget_unlocked(td, fd, &cap_no_rights, &fp); 797 if (error != 0) 798 break; 799 if (fp->f_type != DTYPE_VNODE || fp->f_ops == &path_fileops) { 800 fdrop(fp, td); 801 error = EBADF; 802 break; 803 } 804 vp = fp->f_vnode; 805 if (vp->v_type != VREG) { 806 fdrop(fp, td); 807 error = ENOTTY; 808 break; 809 } 810 811 /* 812 * Exclusive lock synchronizes against f_seqcount reads and 813 * writes in sequential_heuristic(). 814 */ 815 error = vn_lock(vp, LK_EXCLUSIVE); 816 if (error != 0) { 817 fdrop(fp, td); 818 break; 819 } 820 if (arg >= 0) { 821 bsize = fp->f_vnode->v_mount->mnt_stat.f_iosize; 822 arg = MIN(arg, INT_MAX - bsize + 1); 823 fp->f_seqcount[UIO_READ] = MIN(IO_SEQMAX, 824 (arg + bsize - 1) / bsize); 825 atomic_set_int(&fp->f_flag, FRDAHEAD); 826 } else { 827 atomic_clear_int(&fp->f_flag, FRDAHEAD); 828 } 829 VOP_UNLOCK(vp); 830 fdrop(fp, td); 831 break; 832 833 case F_ISUNIONSTACK: 834 /* 835 * Check if the vnode is part of a union stack (either the 836 * "union" flag from mount(2) or unionfs). 837 * 838 * Prior to introduction of this op libc's readdir would call 839 * fstatfs(2), in effect unnecessarily copying kilobytes of 840 * data just to check fs name and a mount flag. 841 * 842 * Fixing the code to handle everything in the kernel instead 843 * is a non-trivial endeavor and has low priority, thus this 844 * horrible kludge facilitates the current behavior in a much 845 * cheaper manner until someone(tm) sorts this out. 846 */ 847 error = fget_unlocked(td, fd, &cap_no_rights, &fp); 848 if (error != 0) 849 break; 850 if (fp->f_type != DTYPE_VNODE) { 851 fdrop(fp, td); 852 error = EBADF; 853 break; 854 } 855 vp = fp->f_vnode; 856 /* 857 * Since we don't prevent dooming the vnode even non-null mp 858 * found can become immediately stale. This is tolerable since 859 * mount points are type-stable (providing safe memory access) 860 * and any vfs op on this vnode going forward will return an 861 * error (meaning return value in this case is meaningless). 862 */ 863 mp = atomic_load_ptr(&vp->v_mount); 864 if (__predict_false(mp == NULL)) { 865 fdrop(fp, td); 866 error = EBADF; 867 break; 868 } 869 td->td_retval[0] = 0; 870 if (mp->mnt_kern_flag & MNTK_UNIONFS || 871 mp->mnt_flag & MNT_UNION) 872 td->td_retval[0] = 1; 873 fdrop(fp, td); 874 break; 875 876 case F_KINFO: 877 #ifdef CAPABILITY_MODE 878 if (CAP_TRACING(td)) 879 ktrcapfail(CAPFAIL_SYSCALL, &cmd); 880 if (IN_CAPABILITY_MODE(td)) { 881 error = ECAPMODE; 882 break; 883 } 884 #endif 885 error = copyin((void *)arg, &kif_sz, sizeof(kif_sz)); 886 if (error != 0) 887 break; 888 if (kif_sz != sizeof(*kif)) { 889 error = EINVAL; 890 break; 891 } 892 kif = malloc(sizeof(*kif), M_TEMP, M_WAITOK | M_ZERO); 893 FILEDESC_SLOCK(fdp); 894 error = fget_cap_noref(fdp, fd, &cap_fcntl_rights, &fp, NULL); 895 if (error == 0 && fhold(fp)) { 896 export_file_to_kinfo(fp, fd, NULL, kif, fdp, 0); 897 FILEDESC_SUNLOCK(fdp); 898 fdrop(fp, td); 899 if ((kif->kf_status & KF_ATTR_VALID) != 0) { 900 kif->kf_structsize = sizeof(*kif); 901 error = copyout(kif, (void *)arg, sizeof(*kif)); 902 } else { 903 error = EBADF; 904 } 905 } else { 906 FILEDESC_SUNLOCK(fdp); 907 if (error == 0) 908 error = EBADF; 909 } 910 free(kif, M_TEMP); 911 break; 912 913 default: 914 error = EINVAL; 915 break; 916 } 917 return (error); 918 } 919 920 static int 921 getmaxfd(struct thread *td) 922 { 923 924 return (min((int)lim_cur(td, RLIMIT_NOFILE), maxfilesperproc)); 925 } 926 927 /* 928 * Common code for dup, dup2, fcntl(F_DUPFD) and fcntl(F_DUP2FD). 929 */ 930 int 931 kern_dup(struct thread *td, u_int mode, int flags, int old, int new) 932 { 933 struct filedesc *fdp; 934 struct filedescent *oldfde, *newfde; 935 struct proc *p; 936 struct file *delfp, *oldfp; 937 u_long *oioctls, *nioctls; 938 int error, maxfd; 939 940 p = td->td_proc; 941 fdp = p->p_fd; 942 oioctls = NULL; 943 944 MPASS((flags & ~(FDDUP_FLAG_CLOEXEC)) == 0); 945 MPASS(mode < FDDUP_LASTMODE); 946 947 AUDIT_ARG_FD(old); 948 /* XXXRW: if (flags & FDDUP_FIXED) AUDIT_ARG_FD2(new); */ 949 950 /* 951 * Verify we have a valid descriptor to dup from and possibly to 952 * dup to. Unlike dup() and dup2(), fcntl()'s F_DUPFD should 953 * return EINVAL when the new descriptor is out of bounds. 954 */ 955 if (old < 0) 956 return (EBADF); 957 if (new < 0) 958 return (mode == FDDUP_FCNTL ? EINVAL : EBADF); 959 maxfd = getmaxfd(td); 960 if (new >= maxfd) 961 return (mode == FDDUP_FCNTL ? EINVAL : EBADF); 962 963 error = EBADF; 964 FILEDESC_XLOCK(fdp); 965 if (fget_noref(fdp, old) == NULL) 966 goto unlock; 967 if (mode == FDDUP_FIXED && old == new) { 968 td->td_retval[0] = new; 969 if (flags & FDDUP_FLAG_CLOEXEC) 970 fdp->fd_ofiles[new].fde_flags |= UF_EXCLOSE; 971 error = 0; 972 goto unlock; 973 } 974 975 oldfde = &fdp->fd_ofiles[old]; 976 oldfp = oldfde->fde_file; 977 if (!fhold(oldfp)) 978 goto unlock; 979 980 /* 981 * If the caller specified a file descriptor, make sure the file 982 * table is large enough to hold it, and grab it. Otherwise, just 983 * allocate a new descriptor the usual way. 984 */ 985 switch (mode) { 986 case FDDUP_NORMAL: 987 case FDDUP_FCNTL: 988 if ((error = fdalloc(td, new, &new)) != 0) { 989 fdrop(oldfp, td); 990 goto unlock; 991 } 992 break; 993 case FDDUP_FIXED: 994 if (new >= fdp->fd_nfiles) { 995 /* 996 * The resource limits are here instead of e.g. 997 * fdalloc(), because the file descriptor table may be 998 * shared between processes, so we can't really use 999 * racct_add()/racct_sub(). Instead of counting the 1000 * number of actually allocated descriptors, just put 1001 * the limit on the size of the file descriptor table. 1002 */ 1003 #ifdef RACCT 1004 if (RACCT_ENABLED()) { 1005 error = racct_set_unlocked(p, RACCT_NOFILE, new + 1); 1006 if (error != 0) { 1007 error = EMFILE; 1008 fdrop(oldfp, td); 1009 goto unlock; 1010 } 1011 } 1012 #endif 1013 fdgrowtable_exp(fdp, new + 1); 1014 } 1015 if (!fdisused(fdp, new)) 1016 fdused(fdp, new); 1017 break; 1018 default: 1019 KASSERT(0, ("%s unsupported mode %d", __func__, mode)); 1020 } 1021 1022 KASSERT(old != new, ("new fd is same as old")); 1023 1024 /* Refetch oldfde because the table may have grown and old one freed. */ 1025 oldfde = &fdp->fd_ofiles[old]; 1026 KASSERT(oldfp == oldfde->fde_file, 1027 ("fdt_ofiles shift from growth observed at fd %d", 1028 old)); 1029 1030 newfde = &fdp->fd_ofiles[new]; 1031 delfp = newfde->fde_file; 1032 1033 nioctls = filecaps_copy_prep(&oldfde->fde_caps); 1034 1035 /* 1036 * Duplicate the source descriptor. 1037 */ 1038 #ifdef CAPABILITIES 1039 seqc_write_begin(&newfde->fde_seqc); 1040 #endif 1041 oioctls = filecaps_free_prep(&newfde->fde_caps); 1042 fde_copy(oldfde, newfde); 1043 filecaps_copy_finish(&oldfde->fde_caps, &newfde->fde_caps, 1044 nioctls); 1045 if ((flags & FDDUP_FLAG_CLOEXEC) != 0) 1046 newfde->fde_flags = oldfde->fde_flags | UF_EXCLOSE; 1047 else 1048 newfde->fde_flags = oldfde->fde_flags & ~UF_EXCLOSE; 1049 #ifdef CAPABILITIES 1050 seqc_write_end(&newfde->fde_seqc); 1051 #endif 1052 td->td_retval[0] = new; 1053 1054 error = 0; 1055 1056 if (delfp != NULL) { 1057 (void) closefp(fdp, new, delfp, td, true, false); 1058 FILEDESC_UNLOCK_ASSERT(fdp); 1059 } else { 1060 unlock: 1061 FILEDESC_XUNLOCK(fdp); 1062 } 1063 1064 filecaps_free_finish(oioctls); 1065 return (error); 1066 } 1067 1068 static void 1069 sigiofree(struct sigio *sigio) 1070 { 1071 crfree(sigio->sio_ucred); 1072 free(sigio, M_SIGIO); 1073 } 1074 1075 static struct sigio * 1076 funsetown_locked(struct sigio *sigio) 1077 { 1078 struct proc *p; 1079 struct pgrp *pg; 1080 1081 SIGIO_ASSERT_LOCKED(); 1082 1083 if (sigio == NULL) 1084 return (NULL); 1085 *sigio->sio_myref = NULL; 1086 if (sigio->sio_pgid < 0) { 1087 pg = sigio->sio_pgrp; 1088 PGRP_LOCK(pg); 1089 SLIST_REMOVE(&pg->pg_sigiolst, sigio, sigio, sio_pgsigio); 1090 PGRP_UNLOCK(pg); 1091 } else { 1092 p = sigio->sio_proc; 1093 PROC_LOCK(p); 1094 SLIST_REMOVE(&p->p_sigiolst, sigio, sigio, sio_pgsigio); 1095 PROC_UNLOCK(p); 1096 } 1097 return (sigio); 1098 } 1099 1100 /* 1101 * If sigio is on the list associated with a process or process group, 1102 * disable signalling from the device, remove sigio from the list and 1103 * free sigio. 1104 */ 1105 void 1106 funsetown(struct sigio **sigiop) 1107 { 1108 struct sigio *sigio; 1109 1110 /* Racy check, consumers must provide synchronization. */ 1111 if (*sigiop == NULL) 1112 return; 1113 1114 SIGIO_LOCK(); 1115 sigio = funsetown_locked(*sigiop); 1116 SIGIO_UNLOCK(); 1117 if (sigio != NULL) 1118 sigiofree(sigio); 1119 } 1120 1121 /* 1122 * Free a list of sigio structures. The caller must ensure that new sigio 1123 * structures cannot be added after this point. For process groups this is 1124 * guaranteed using the proctree lock; for processes, the P_WEXIT flag serves 1125 * as an interlock. 1126 */ 1127 void 1128 funsetownlst(struct sigiolst *sigiolst) 1129 { 1130 struct proc *p; 1131 struct pgrp *pg; 1132 struct sigio *sigio, *tmp; 1133 1134 /* Racy check. */ 1135 sigio = SLIST_FIRST(sigiolst); 1136 if (sigio == NULL) 1137 return; 1138 1139 p = NULL; 1140 pg = NULL; 1141 1142 SIGIO_LOCK(); 1143 sigio = SLIST_FIRST(sigiolst); 1144 if (sigio == NULL) { 1145 SIGIO_UNLOCK(); 1146 return; 1147 } 1148 1149 /* 1150 * Every entry of the list should belong to a single proc or pgrp. 1151 */ 1152 if (sigio->sio_pgid < 0) { 1153 pg = sigio->sio_pgrp; 1154 sx_assert(&proctree_lock, SX_XLOCKED); 1155 PGRP_LOCK(pg); 1156 } else /* if (sigio->sio_pgid > 0) */ { 1157 p = sigio->sio_proc; 1158 PROC_LOCK(p); 1159 KASSERT((p->p_flag & P_WEXIT) != 0, 1160 ("%s: process %p is not exiting", __func__, p)); 1161 } 1162 1163 SLIST_FOREACH(sigio, sigiolst, sio_pgsigio) { 1164 *sigio->sio_myref = NULL; 1165 if (pg != NULL) { 1166 KASSERT(sigio->sio_pgid < 0, 1167 ("Proc sigio in pgrp sigio list")); 1168 KASSERT(sigio->sio_pgrp == pg, 1169 ("Bogus pgrp in sigio list")); 1170 } else /* if (p != NULL) */ { 1171 KASSERT(sigio->sio_pgid > 0, 1172 ("Pgrp sigio in proc sigio list")); 1173 KASSERT(sigio->sio_proc == p, 1174 ("Bogus proc in sigio list")); 1175 } 1176 } 1177 1178 if (pg != NULL) 1179 PGRP_UNLOCK(pg); 1180 else 1181 PROC_UNLOCK(p); 1182 SIGIO_UNLOCK(); 1183 1184 SLIST_FOREACH_SAFE(sigio, sigiolst, sio_pgsigio, tmp) 1185 sigiofree(sigio); 1186 } 1187 1188 /* 1189 * This is common code for FIOSETOWN ioctl called by fcntl(fd, F_SETOWN, arg). 1190 * 1191 * After permission checking, add a sigio structure to the sigio list for 1192 * the process or process group. 1193 */ 1194 int 1195 fsetown(pid_t pgid, struct sigio **sigiop) 1196 { 1197 struct proc *proc; 1198 struct pgrp *pgrp; 1199 struct sigio *osigio, *sigio; 1200 int ret; 1201 1202 if (pgid == 0) { 1203 funsetown(sigiop); 1204 return (0); 1205 } 1206 1207 sigio = malloc(sizeof(struct sigio), M_SIGIO, M_WAITOK); 1208 sigio->sio_pgid = pgid; 1209 sigio->sio_ucred = crhold(curthread->td_ucred); 1210 sigio->sio_myref = sigiop; 1211 1212 ret = 0; 1213 if (pgid > 0) { 1214 ret = pget(pgid, PGET_NOTWEXIT | PGET_NOTID | PGET_HOLD, &proc); 1215 SIGIO_LOCK(); 1216 osigio = funsetown_locked(*sigiop); 1217 if (ret == 0) { 1218 PROC_LOCK(proc); 1219 _PRELE(proc); 1220 if ((proc->p_flag & P_WEXIT) != 0) { 1221 ret = ESRCH; 1222 } else if (proc->p_session != 1223 curthread->td_proc->p_session) { 1224 /* 1225 * Policy - Don't allow a process to FSETOWN a 1226 * process in another session. 1227 * 1228 * Remove this test to allow maximum flexibility 1229 * or restrict FSETOWN to the current process or 1230 * process group for maximum safety. 1231 */ 1232 ret = EPERM; 1233 } else { 1234 sigio->sio_proc = proc; 1235 SLIST_INSERT_HEAD(&proc->p_sigiolst, sigio, 1236 sio_pgsigio); 1237 } 1238 PROC_UNLOCK(proc); 1239 } 1240 } else /* if (pgid < 0) */ { 1241 sx_slock(&proctree_lock); 1242 SIGIO_LOCK(); 1243 osigio = funsetown_locked(*sigiop); 1244 pgrp = pgfind(-pgid); 1245 if (pgrp == NULL) { 1246 ret = ESRCH; 1247 } else { 1248 if (pgrp->pg_session != curthread->td_proc->p_session) { 1249 /* 1250 * Policy - Don't allow a process to FSETOWN a 1251 * process in another session. 1252 * 1253 * Remove this test to allow maximum flexibility 1254 * or restrict FSETOWN to the current process or 1255 * process group for maximum safety. 1256 */ 1257 ret = EPERM; 1258 } else { 1259 sigio->sio_pgrp = pgrp; 1260 SLIST_INSERT_HEAD(&pgrp->pg_sigiolst, sigio, 1261 sio_pgsigio); 1262 } 1263 PGRP_UNLOCK(pgrp); 1264 } 1265 sx_sunlock(&proctree_lock); 1266 } 1267 if (ret == 0) 1268 *sigiop = sigio; 1269 SIGIO_UNLOCK(); 1270 if (osigio != NULL) 1271 sigiofree(osigio); 1272 return (ret); 1273 } 1274 1275 /* 1276 * This is common code for FIOGETOWN ioctl called by fcntl(fd, F_GETOWN, arg). 1277 */ 1278 pid_t 1279 fgetown(struct sigio **sigiop) 1280 { 1281 pid_t pgid; 1282 1283 SIGIO_LOCK(); 1284 pgid = (*sigiop != NULL) ? (*sigiop)->sio_pgid : 0; 1285 SIGIO_UNLOCK(); 1286 return (pgid); 1287 } 1288 1289 static int 1290 closefp_impl(struct filedesc *fdp, int fd, struct file *fp, struct thread *td, 1291 bool audit) 1292 { 1293 int error; 1294 1295 FILEDESC_XLOCK_ASSERT(fdp); 1296 1297 /* 1298 * We now hold the fp reference that used to be owned by the 1299 * descriptor array. We have to unlock the FILEDESC *AFTER* 1300 * knote_fdclose to prevent a race of the fd getting opened, a knote 1301 * added, and deleteing a knote for the new fd. 1302 */ 1303 if (__predict_false(!TAILQ_EMPTY(&fdp->fd_kqlist))) 1304 knote_fdclose(td, fd); 1305 1306 /* 1307 * We need to notify mqueue if the object is of type mqueue. 1308 */ 1309 if (__predict_false(fp->f_type == DTYPE_MQUEUE)) 1310 mq_fdclose(td, fd, fp); 1311 FILEDESC_XUNLOCK(fdp); 1312 1313 #ifdef AUDIT 1314 if (AUDITING_TD(td) && audit) 1315 audit_sysclose(td, fd, fp); 1316 #endif 1317 error = closef(fp, td); 1318 1319 /* 1320 * All paths leading up to closefp() will have already removed or 1321 * replaced the fd in the filedesc table, so a restart would not 1322 * operate on the same file. 1323 */ 1324 if (error == ERESTART) 1325 error = EINTR; 1326 1327 return (error); 1328 } 1329 1330 static int 1331 closefp_hl(struct filedesc *fdp, int fd, struct file *fp, struct thread *td, 1332 bool holdleaders, bool audit) 1333 { 1334 int error; 1335 1336 FILEDESC_XLOCK_ASSERT(fdp); 1337 1338 if (holdleaders) { 1339 if (td->td_proc->p_fdtol != NULL) { 1340 /* 1341 * Ask fdfree() to sleep to ensure that all relevant 1342 * process leaders can be traversed in closef(). 1343 */ 1344 fdp->fd_holdleaderscount++; 1345 } else { 1346 holdleaders = false; 1347 } 1348 } 1349 1350 error = closefp_impl(fdp, fd, fp, td, audit); 1351 if (holdleaders) { 1352 FILEDESC_XLOCK(fdp); 1353 fdp->fd_holdleaderscount--; 1354 if (fdp->fd_holdleaderscount == 0 && 1355 fdp->fd_holdleaderswakeup != 0) { 1356 fdp->fd_holdleaderswakeup = 0; 1357 wakeup(&fdp->fd_holdleaderscount); 1358 } 1359 FILEDESC_XUNLOCK(fdp); 1360 } 1361 return (error); 1362 } 1363 1364 static int 1365 closefp(struct filedesc *fdp, int fd, struct file *fp, struct thread *td, 1366 bool holdleaders, bool audit) 1367 { 1368 1369 FILEDESC_XLOCK_ASSERT(fdp); 1370 1371 if (__predict_false(td->td_proc->p_fdtol != NULL)) { 1372 return (closefp_hl(fdp, fd, fp, td, holdleaders, audit)); 1373 } else { 1374 return (closefp_impl(fdp, fd, fp, td, audit)); 1375 } 1376 } 1377 1378 /* 1379 * Close a file descriptor. 1380 */ 1381 #ifndef _SYS_SYSPROTO_H_ 1382 struct close_args { 1383 int fd; 1384 }; 1385 #endif 1386 /* ARGSUSED */ 1387 int 1388 sys_close(struct thread *td, struct close_args *uap) 1389 { 1390 1391 return (kern_close(td, uap->fd)); 1392 } 1393 1394 int 1395 kern_close(struct thread *td, int fd) 1396 { 1397 struct filedesc *fdp; 1398 struct file *fp; 1399 1400 fdp = td->td_proc->p_fd; 1401 1402 FILEDESC_XLOCK(fdp); 1403 if ((fp = fget_noref(fdp, fd)) == NULL) { 1404 FILEDESC_XUNLOCK(fdp); 1405 return (EBADF); 1406 } 1407 fdfree(fdp, fd); 1408 1409 /* closefp() drops the FILEDESC lock for us. */ 1410 return (closefp(fdp, fd, fp, td, true, true)); 1411 } 1412 1413 static int 1414 close_range_cloexec(struct thread *td, u_int lowfd, u_int highfd) 1415 { 1416 struct filedesc *fdp; 1417 struct fdescenttbl *fdt; 1418 struct filedescent *fde; 1419 int fd; 1420 1421 fdp = td->td_proc->p_fd; 1422 FILEDESC_XLOCK(fdp); 1423 fdt = atomic_load_ptr(&fdp->fd_files); 1424 highfd = MIN(highfd, fdt->fdt_nfiles - 1); 1425 fd = lowfd; 1426 if (__predict_false(fd > highfd)) { 1427 goto out_locked; 1428 } 1429 for (; fd <= highfd; fd++) { 1430 fde = &fdt->fdt_ofiles[fd]; 1431 if (fde->fde_file != NULL) 1432 fde->fde_flags |= UF_EXCLOSE; 1433 } 1434 out_locked: 1435 FILEDESC_XUNLOCK(fdp); 1436 return (0); 1437 } 1438 1439 static int 1440 close_range_impl(struct thread *td, u_int lowfd, u_int highfd) 1441 { 1442 struct filedesc *fdp; 1443 const struct fdescenttbl *fdt; 1444 struct file *fp; 1445 int fd; 1446 1447 fdp = td->td_proc->p_fd; 1448 FILEDESC_XLOCK(fdp); 1449 fdt = atomic_load_ptr(&fdp->fd_files); 1450 highfd = MIN(highfd, fdt->fdt_nfiles - 1); 1451 fd = lowfd; 1452 if (__predict_false(fd > highfd)) { 1453 goto out_locked; 1454 } 1455 for (;;) { 1456 fp = fdt->fdt_ofiles[fd].fde_file; 1457 if (fp == NULL) { 1458 if (fd == highfd) 1459 goto out_locked; 1460 } else { 1461 fdfree(fdp, fd); 1462 (void) closefp(fdp, fd, fp, td, true, true); 1463 if (fd == highfd) 1464 goto out_unlocked; 1465 FILEDESC_XLOCK(fdp); 1466 fdt = atomic_load_ptr(&fdp->fd_files); 1467 } 1468 fd++; 1469 } 1470 out_locked: 1471 FILEDESC_XUNLOCK(fdp); 1472 out_unlocked: 1473 return (0); 1474 } 1475 1476 int 1477 kern_close_range(struct thread *td, int flags, u_int lowfd, u_int highfd) 1478 { 1479 1480 /* 1481 * Check this prior to clamping; closefrom(3) with only fd 0, 1, and 2 1482 * open should not be a usage error. From a close_range() perspective, 1483 * close_range(3, ~0U, 0) in the same scenario should also likely not 1484 * be a usage error as all fd above 3 are in-fact already closed. 1485 */ 1486 if (highfd < lowfd) { 1487 return (EINVAL); 1488 } 1489 1490 if ((flags & CLOSE_RANGE_CLOEXEC) != 0) 1491 return (close_range_cloexec(td, lowfd, highfd)); 1492 1493 return (close_range_impl(td, lowfd, highfd)); 1494 } 1495 1496 #ifndef _SYS_SYSPROTO_H_ 1497 struct close_range_args { 1498 u_int lowfd; 1499 u_int highfd; 1500 int flags; 1501 }; 1502 #endif 1503 int 1504 sys_close_range(struct thread *td, struct close_range_args *uap) 1505 { 1506 1507 AUDIT_ARG_FD(uap->lowfd); 1508 AUDIT_ARG_CMD(uap->highfd); 1509 AUDIT_ARG_FFLAGS(uap->flags); 1510 1511 if ((uap->flags & ~(CLOSE_RANGE_CLOEXEC)) != 0) 1512 return (EINVAL); 1513 return (kern_close_range(td, uap->flags, uap->lowfd, uap->highfd)); 1514 } 1515 1516 #ifdef COMPAT_FREEBSD12 1517 /* 1518 * Close open file descriptors. 1519 */ 1520 #ifndef _SYS_SYSPROTO_H_ 1521 struct freebsd12_closefrom_args { 1522 int lowfd; 1523 }; 1524 #endif 1525 /* ARGSUSED */ 1526 int 1527 freebsd12_closefrom(struct thread *td, struct freebsd12_closefrom_args *uap) 1528 { 1529 u_int lowfd; 1530 1531 AUDIT_ARG_FD(uap->lowfd); 1532 1533 /* 1534 * Treat negative starting file descriptor values identical to 1535 * closefrom(0) which closes all files. 1536 */ 1537 lowfd = MAX(0, uap->lowfd); 1538 return (kern_close_range(td, 0, lowfd, ~0U)); 1539 } 1540 #endif /* COMPAT_FREEBSD12 */ 1541 1542 #if defined(COMPAT_43) 1543 /* 1544 * Return status information about a file descriptor. 1545 */ 1546 #ifndef _SYS_SYSPROTO_H_ 1547 struct ofstat_args { 1548 int fd; 1549 struct ostat *sb; 1550 }; 1551 #endif 1552 /* ARGSUSED */ 1553 int 1554 ofstat(struct thread *td, struct ofstat_args *uap) 1555 { 1556 struct ostat oub; 1557 struct stat ub; 1558 int error; 1559 1560 error = kern_fstat(td, uap->fd, &ub); 1561 if (error == 0) { 1562 cvtstat(&ub, &oub); 1563 error = copyout(&oub, uap->sb, sizeof(oub)); 1564 } 1565 return (error); 1566 } 1567 #endif /* COMPAT_43 */ 1568 1569 #if defined(COMPAT_FREEBSD11) 1570 int 1571 freebsd11_fstat(struct thread *td, struct freebsd11_fstat_args *uap) 1572 { 1573 struct stat sb; 1574 struct freebsd11_stat osb; 1575 int error; 1576 1577 error = kern_fstat(td, uap->fd, &sb); 1578 if (error != 0) 1579 return (error); 1580 error = freebsd11_cvtstat(&sb, &osb); 1581 if (error == 0) 1582 error = copyout(&osb, uap->sb, sizeof(osb)); 1583 return (error); 1584 } 1585 #endif /* COMPAT_FREEBSD11 */ 1586 1587 /* 1588 * Return status information about a file descriptor. 1589 */ 1590 #ifndef _SYS_SYSPROTO_H_ 1591 struct fstat_args { 1592 int fd; 1593 struct stat *sb; 1594 }; 1595 #endif 1596 /* ARGSUSED */ 1597 int 1598 sys_fstat(struct thread *td, struct fstat_args *uap) 1599 { 1600 struct stat ub; 1601 int error; 1602 1603 error = kern_fstat(td, uap->fd, &ub); 1604 if (error == 0) 1605 error = copyout(&ub, uap->sb, sizeof(ub)); 1606 return (error); 1607 } 1608 1609 int 1610 kern_fstat(struct thread *td, int fd, struct stat *sbp) 1611 { 1612 struct file *fp; 1613 int error; 1614 1615 AUDIT_ARG_FD(fd); 1616 1617 error = fget(td, fd, &cap_fstat_rights, &fp); 1618 if (__predict_false(error != 0)) 1619 return (error); 1620 1621 AUDIT_ARG_FILE(td->td_proc, fp); 1622 1623 error = fo_stat(fp, sbp, td->td_ucred); 1624 fdrop(fp, td); 1625 #ifdef __STAT_TIME_T_EXT 1626 sbp->st_atim_ext = 0; 1627 sbp->st_mtim_ext = 0; 1628 sbp->st_ctim_ext = 0; 1629 sbp->st_btim_ext = 0; 1630 #endif 1631 #ifdef KTRACE 1632 if (KTRPOINT(td, KTR_STRUCT)) 1633 ktrstat_error(sbp, error); 1634 #endif 1635 return (error); 1636 } 1637 1638 #if defined(COMPAT_FREEBSD11) 1639 /* 1640 * Return status information about a file descriptor. 1641 */ 1642 #ifndef _SYS_SYSPROTO_H_ 1643 struct freebsd11_nfstat_args { 1644 int fd; 1645 struct nstat *sb; 1646 }; 1647 #endif 1648 /* ARGSUSED */ 1649 int 1650 freebsd11_nfstat(struct thread *td, struct freebsd11_nfstat_args *uap) 1651 { 1652 struct nstat nub; 1653 struct stat ub; 1654 int error; 1655 1656 error = kern_fstat(td, uap->fd, &ub); 1657 if (error != 0) 1658 return (error); 1659 error = freebsd11_cvtnstat(&ub, &nub); 1660 if (error != 0) 1661 error = copyout(&nub, uap->sb, sizeof(nub)); 1662 return (error); 1663 } 1664 #endif /* COMPAT_FREEBSD11 */ 1665 1666 /* 1667 * Return pathconf information about a file descriptor. 1668 */ 1669 #ifndef _SYS_SYSPROTO_H_ 1670 struct fpathconf_args { 1671 int fd; 1672 int name; 1673 }; 1674 #endif 1675 /* ARGSUSED */ 1676 int 1677 sys_fpathconf(struct thread *td, struct fpathconf_args *uap) 1678 { 1679 long value; 1680 int error; 1681 1682 error = kern_fpathconf(td, uap->fd, uap->name, &value); 1683 if (error == 0) 1684 td->td_retval[0] = value; 1685 return (error); 1686 } 1687 1688 int 1689 kern_fpathconf(struct thread *td, int fd, int name, long *valuep) 1690 { 1691 struct file *fp; 1692 struct vnode *vp; 1693 int error; 1694 1695 error = fget(td, fd, &cap_fpathconf_rights, &fp); 1696 if (error != 0) 1697 return (error); 1698 1699 if (name == _PC_ASYNC_IO) { 1700 *valuep = _POSIX_ASYNCHRONOUS_IO; 1701 goto out; 1702 } 1703 vp = fp->f_vnode; 1704 if (vp != NULL) { 1705 vn_lock(vp, LK_SHARED | LK_RETRY); 1706 error = VOP_PATHCONF(vp, name, valuep); 1707 VOP_UNLOCK(vp); 1708 } else if (fp->f_type == DTYPE_PIPE || fp->f_type == DTYPE_SOCKET) { 1709 if (name != _PC_PIPE_BUF) { 1710 error = EINVAL; 1711 } else { 1712 *valuep = PIPE_BUF; 1713 error = 0; 1714 } 1715 } else { 1716 error = EOPNOTSUPP; 1717 } 1718 out: 1719 fdrop(fp, td); 1720 return (error); 1721 } 1722 1723 /* 1724 * Copy filecaps structure allocating memory for ioctls array if needed. 1725 * 1726 * The last parameter indicates whether the fdtable is locked. If it is not and 1727 * ioctls are encountered, copying fails and the caller must lock the table. 1728 * 1729 * Note that if the table was not locked, the caller has to check the relevant 1730 * sequence counter to determine whether the operation was successful. 1731 */ 1732 bool 1733 filecaps_copy(const struct filecaps *src, struct filecaps *dst, bool locked) 1734 { 1735 size_t size; 1736 1737 if (src->fc_ioctls != NULL && !locked) 1738 return (false); 1739 memcpy(dst, src, sizeof(*src)); 1740 if (src->fc_ioctls == NULL) 1741 return (true); 1742 1743 KASSERT(src->fc_nioctls > 0, 1744 ("fc_ioctls != NULL, but fc_nioctls=%hd", src->fc_nioctls)); 1745 1746 size = sizeof(src->fc_ioctls[0]) * src->fc_nioctls; 1747 dst->fc_ioctls = malloc(size, M_FILECAPS, M_WAITOK); 1748 memcpy(dst->fc_ioctls, src->fc_ioctls, size); 1749 return (true); 1750 } 1751 1752 static u_long * 1753 filecaps_copy_prep(const struct filecaps *src) 1754 { 1755 u_long *ioctls; 1756 size_t size; 1757 1758 if (__predict_true(src->fc_ioctls == NULL)) 1759 return (NULL); 1760 1761 KASSERT(src->fc_nioctls > 0, 1762 ("fc_ioctls != NULL, but fc_nioctls=%hd", src->fc_nioctls)); 1763 1764 size = sizeof(src->fc_ioctls[0]) * src->fc_nioctls; 1765 ioctls = malloc(size, M_FILECAPS, M_WAITOK); 1766 return (ioctls); 1767 } 1768 1769 static void 1770 filecaps_copy_finish(const struct filecaps *src, struct filecaps *dst, 1771 u_long *ioctls) 1772 { 1773 size_t size; 1774 1775 *dst = *src; 1776 if (__predict_true(src->fc_ioctls == NULL)) { 1777 MPASS(ioctls == NULL); 1778 return; 1779 } 1780 1781 size = sizeof(src->fc_ioctls[0]) * src->fc_nioctls; 1782 dst->fc_ioctls = ioctls; 1783 bcopy(src->fc_ioctls, dst->fc_ioctls, size); 1784 } 1785 1786 /* 1787 * Move filecaps structure to the new place and clear the old place. 1788 */ 1789 void 1790 filecaps_move(struct filecaps *src, struct filecaps *dst) 1791 { 1792 1793 *dst = *src; 1794 bzero(src, sizeof(*src)); 1795 } 1796 1797 /* 1798 * Fill the given filecaps structure with full rights. 1799 */ 1800 static void 1801 filecaps_fill(struct filecaps *fcaps) 1802 { 1803 1804 CAP_ALL(&fcaps->fc_rights); 1805 fcaps->fc_ioctls = NULL; 1806 fcaps->fc_nioctls = -1; 1807 fcaps->fc_fcntls = CAP_FCNTL_ALL; 1808 } 1809 1810 /* 1811 * Free memory allocated within filecaps structure. 1812 */ 1813 static void 1814 filecaps_free_ioctl(struct filecaps *fcaps) 1815 { 1816 1817 free(fcaps->fc_ioctls, M_FILECAPS); 1818 fcaps->fc_ioctls = NULL; 1819 } 1820 1821 void 1822 filecaps_free(struct filecaps *fcaps) 1823 { 1824 1825 filecaps_free_ioctl(fcaps); 1826 bzero(fcaps, sizeof(*fcaps)); 1827 } 1828 1829 static u_long * 1830 filecaps_free_prep(struct filecaps *fcaps) 1831 { 1832 u_long *ioctls; 1833 1834 ioctls = fcaps->fc_ioctls; 1835 bzero(fcaps, sizeof(*fcaps)); 1836 return (ioctls); 1837 } 1838 1839 static void 1840 filecaps_free_finish(u_long *ioctls) 1841 { 1842 1843 free(ioctls, M_FILECAPS); 1844 } 1845 1846 /* 1847 * Validate the given filecaps structure. 1848 */ 1849 static void 1850 filecaps_validate(const struct filecaps *fcaps, const char *func) 1851 { 1852 1853 KASSERT(cap_rights_is_valid(&fcaps->fc_rights), 1854 ("%s: invalid rights", func)); 1855 KASSERT((fcaps->fc_fcntls & ~CAP_FCNTL_ALL) == 0, 1856 ("%s: invalid fcntls", func)); 1857 KASSERT(fcaps->fc_fcntls == 0 || 1858 cap_rights_is_set(&fcaps->fc_rights, CAP_FCNTL), 1859 ("%s: fcntls without CAP_FCNTL", func)); 1860 /* 1861 * open calls without WANTIOCTLCAPS free caps but leave the counter 1862 */ 1863 #if 0 1864 KASSERT(fcaps->fc_ioctls != NULL ? fcaps->fc_nioctls > 0 : 1865 (fcaps->fc_nioctls == -1 || fcaps->fc_nioctls == 0), 1866 ("%s: invalid ioctls", func)); 1867 #endif 1868 KASSERT(fcaps->fc_nioctls == 0 || 1869 cap_rights_is_set(&fcaps->fc_rights, CAP_IOCTL), 1870 ("%s: ioctls without CAP_IOCTL", func)); 1871 } 1872 1873 static void 1874 fdgrowtable_exp(struct filedesc *fdp, int nfd) 1875 { 1876 int nfd1; 1877 1878 FILEDESC_XLOCK_ASSERT(fdp); 1879 1880 nfd1 = fdp->fd_nfiles * 2; 1881 if (nfd1 < nfd) 1882 nfd1 = nfd; 1883 fdgrowtable(fdp, nfd1); 1884 } 1885 1886 /* 1887 * Grow the file table to accommodate (at least) nfd descriptors. 1888 */ 1889 static void 1890 fdgrowtable(struct filedesc *fdp, int nfd) 1891 { 1892 struct filedesc0 *fdp0; 1893 struct freetable *ft; 1894 struct fdescenttbl *ntable; 1895 struct fdescenttbl *otable; 1896 int nnfiles, onfiles; 1897 NDSLOTTYPE *nmap, *omap; 1898 1899 KASSERT(fdp->fd_nfiles > 0, ("zero-length file table")); 1900 1901 /* save old values */ 1902 onfiles = fdp->fd_nfiles; 1903 otable = fdp->fd_files; 1904 omap = fdp->fd_map; 1905 1906 /* compute the size of the new table */ 1907 nnfiles = NDSLOTS(nfd) * NDENTRIES; /* round up */ 1908 if (nnfiles <= onfiles) 1909 /* the table is already large enough */ 1910 return; 1911 1912 /* 1913 * Allocate a new table. We need enough space for the number of 1914 * entries, file entries themselves and the struct freetable we will use 1915 * when we decommission the table and place it on the freelist. 1916 * We place the struct freetable in the middle so we don't have 1917 * to worry about padding. 1918 */ 1919 ntable = malloc(offsetof(struct fdescenttbl, fdt_ofiles) + 1920 nnfiles * sizeof(ntable->fdt_ofiles[0]) + 1921 sizeof(struct freetable), 1922 M_FILEDESC, M_ZERO | M_WAITOK); 1923 /* copy the old data */ 1924 ntable->fdt_nfiles = nnfiles; 1925 memcpy(ntable->fdt_ofiles, otable->fdt_ofiles, 1926 onfiles * sizeof(ntable->fdt_ofiles[0])); 1927 1928 /* 1929 * Allocate a new map only if the old is not large enough. It will 1930 * grow at a slower rate than the table as it can map more 1931 * entries than the table can hold. 1932 */ 1933 if (NDSLOTS(nnfiles) > NDSLOTS(onfiles)) { 1934 nmap = malloc(NDSLOTS(nnfiles) * NDSLOTSIZE, M_FILEDESC, 1935 M_ZERO | M_WAITOK); 1936 /* copy over the old data and update the pointer */ 1937 memcpy(nmap, omap, NDSLOTS(onfiles) * sizeof(*omap)); 1938 fdp->fd_map = nmap; 1939 } 1940 1941 /* 1942 * Make sure that ntable is correctly initialized before we replace 1943 * fd_files poiner. Otherwise fget_unlocked() may see inconsistent 1944 * data. 1945 */ 1946 atomic_store_rel_ptr((volatile void *)&fdp->fd_files, (uintptr_t)ntable); 1947 1948 /* 1949 * Free the old file table when not shared by other threads or processes. 1950 * The old file table is considered to be shared when either are true: 1951 * - The process has more than one thread. 1952 * - The file descriptor table has been shared via fdshare(). 1953 * 1954 * When shared, the old file table will be placed on a freelist 1955 * which will be processed when the struct filedesc is released. 1956 * 1957 * Note that if onfiles == NDFILE, we're dealing with the original 1958 * static allocation contained within (struct filedesc0 *)fdp, 1959 * which must not be freed. 1960 */ 1961 if (onfiles > NDFILE) { 1962 /* 1963 * Note we may be called here from fdinit while allocating a 1964 * table for a new process in which case ->p_fd points 1965 * elsewhere. 1966 */ 1967 if (curproc->p_fd != fdp || FILEDESC_IS_ONLY_USER(fdp)) { 1968 free(otable, M_FILEDESC); 1969 } else { 1970 ft = (struct freetable *)&otable->fdt_ofiles[onfiles]; 1971 fdp0 = (struct filedesc0 *)fdp; 1972 ft->ft_table = otable; 1973 SLIST_INSERT_HEAD(&fdp0->fd_free, ft, ft_next); 1974 } 1975 } 1976 /* 1977 * The map does not have the same possibility of threads still 1978 * holding references to it. So always free it as long as it 1979 * does not reference the original static allocation. 1980 */ 1981 if (NDSLOTS(onfiles) > NDSLOTS(NDFILE)) 1982 free(omap, M_FILEDESC); 1983 } 1984 1985 /* 1986 * Allocate a file descriptor for the process. 1987 */ 1988 int 1989 fdalloc(struct thread *td, int minfd, int *result) 1990 { 1991 struct proc *p = td->td_proc; 1992 struct filedesc *fdp = p->p_fd; 1993 int fd, maxfd, allocfd; 1994 #ifdef RACCT 1995 int error; 1996 #endif 1997 1998 FILEDESC_XLOCK_ASSERT(fdp); 1999 2000 if (fdp->fd_freefile > minfd) 2001 minfd = fdp->fd_freefile; 2002 2003 maxfd = getmaxfd(td); 2004 2005 /* 2006 * Search the bitmap for a free descriptor starting at minfd. 2007 * If none is found, grow the file table. 2008 */ 2009 fd = fd_first_free(fdp, minfd, fdp->fd_nfiles); 2010 if (__predict_false(fd >= maxfd)) 2011 return (EMFILE); 2012 if (__predict_false(fd >= fdp->fd_nfiles)) { 2013 allocfd = min(fd * 2, maxfd); 2014 #ifdef RACCT 2015 if (RACCT_ENABLED()) { 2016 error = racct_set_unlocked(p, RACCT_NOFILE, allocfd); 2017 if (error != 0) 2018 return (EMFILE); 2019 } 2020 #endif 2021 /* 2022 * fd is already equal to first free descriptor >= minfd, so 2023 * we only need to grow the table and we are done. 2024 */ 2025 fdgrowtable_exp(fdp, allocfd); 2026 } 2027 2028 /* 2029 * Perform some sanity checks, then mark the file descriptor as 2030 * used and return it to the caller. 2031 */ 2032 KASSERT(fd >= 0 && fd < min(maxfd, fdp->fd_nfiles), 2033 ("invalid descriptor %d", fd)); 2034 KASSERT(!fdisused(fdp, fd), 2035 ("fd_first_free() returned non-free descriptor")); 2036 KASSERT(fdp->fd_ofiles[fd].fde_file == NULL, 2037 ("file descriptor isn't free")); 2038 fdused(fdp, fd); 2039 *result = fd; 2040 return (0); 2041 } 2042 2043 /* 2044 * Allocate n file descriptors for the process. 2045 */ 2046 int 2047 fdallocn(struct thread *td, int minfd, int *fds, int n) 2048 { 2049 struct proc *p = td->td_proc; 2050 struct filedesc *fdp = p->p_fd; 2051 int i; 2052 2053 FILEDESC_XLOCK_ASSERT(fdp); 2054 2055 for (i = 0; i < n; i++) 2056 if (fdalloc(td, 0, &fds[i]) != 0) 2057 break; 2058 2059 if (i < n) { 2060 for (i--; i >= 0; i--) 2061 fdunused(fdp, fds[i]); 2062 return (EMFILE); 2063 } 2064 2065 return (0); 2066 } 2067 2068 /* 2069 * Create a new open file structure and allocate a file descriptor for the 2070 * process that refers to it. We add one reference to the file for the 2071 * descriptor table and one reference for resultfp. This is to prevent us 2072 * being preempted and the entry in the descriptor table closed after we 2073 * release the FILEDESC lock. 2074 */ 2075 int 2076 falloc_caps(struct thread *td, struct file **resultfp, int *resultfd, int flags, 2077 struct filecaps *fcaps) 2078 { 2079 struct file *fp; 2080 int error, fd; 2081 2082 MPASS(resultfp != NULL); 2083 MPASS(resultfd != NULL); 2084 2085 error = _falloc_noinstall(td, &fp, 2); 2086 if (__predict_false(error != 0)) { 2087 return (error); 2088 } 2089 2090 error = finstall_refed(td, fp, &fd, flags, fcaps); 2091 if (__predict_false(error != 0)) { 2092 falloc_abort(td, fp); 2093 return (error); 2094 } 2095 2096 *resultfp = fp; 2097 *resultfd = fd; 2098 2099 return (0); 2100 } 2101 2102 /* 2103 * Create a new open file structure without allocating a file descriptor. 2104 */ 2105 int 2106 _falloc_noinstall(struct thread *td, struct file **resultfp, u_int n) 2107 { 2108 struct file *fp; 2109 int maxuserfiles = maxfiles - (maxfiles / 20); 2110 int openfiles_new; 2111 static struct timeval lastfail; 2112 static int curfail; 2113 2114 KASSERT(resultfp != NULL, ("%s: resultfp == NULL", __func__)); 2115 MPASS(n > 0); 2116 2117 openfiles_new = atomic_fetchadd_int(&openfiles, 1) + 1; 2118 if ((openfiles_new >= maxuserfiles && 2119 priv_check(td, PRIV_MAXFILES) != 0) || 2120 openfiles_new >= maxfiles) { 2121 atomic_subtract_int(&openfiles, 1); 2122 if (ppsratecheck(&lastfail, &curfail, 1)) { 2123 printf("kern.maxfiles limit exceeded by uid %i, (%s) " 2124 "please see tuning(7).\n", td->td_ucred->cr_ruid, td->td_proc->p_comm); 2125 } 2126 return (ENFILE); 2127 } 2128 fp = uma_zalloc(file_zone, M_WAITOK); 2129 bzero(fp, sizeof(*fp)); 2130 refcount_init(&fp->f_count, n); 2131 fp->f_cred = crhold(td->td_ucred); 2132 fp->f_ops = &badfileops; 2133 *resultfp = fp; 2134 return (0); 2135 } 2136 2137 void 2138 falloc_abort(struct thread *td, struct file *fp) 2139 { 2140 2141 /* 2142 * For assertion purposes. 2143 */ 2144 refcount_init(&fp->f_count, 0); 2145 _fdrop(fp, td); 2146 } 2147 2148 /* 2149 * Install a file in a file descriptor table. 2150 */ 2151 void 2152 _finstall(struct filedesc *fdp, struct file *fp, int fd, int flags, 2153 struct filecaps *fcaps) 2154 { 2155 struct filedescent *fde; 2156 2157 MPASS(fp != NULL); 2158 if (fcaps != NULL) 2159 filecaps_validate(fcaps, __func__); 2160 FILEDESC_XLOCK_ASSERT(fdp); 2161 2162 fde = &fdp->fd_ofiles[fd]; 2163 #ifdef CAPABILITIES 2164 seqc_write_begin(&fde->fde_seqc); 2165 #endif 2166 fde->fde_file = fp; 2167 fde->fde_flags = (flags & O_CLOEXEC) != 0 ? UF_EXCLOSE : 0; 2168 if (fcaps != NULL) 2169 filecaps_move(fcaps, &fde->fde_caps); 2170 else 2171 filecaps_fill(&fde->fde_caps); 2172 #ifdef CAPABILITIES 2173 seqc_write_end(&fde->fde_seqc); 2174 #endif 2175 } 2176 2177 int 2178 finstall_refed(struct thread *td, struct file *fp, int *fd, int flags, 2179 struct filecaps *fcaps) 2180 { 2181 struct filedesc *fdp = td->td_proc->p_fd; 2182 int error; 2183 2184 MPASS(fd != NULL); 2185 2186 FILEDESC_XLOCK(fdp); 2187 error = fdalloc(td, 0, fd); 2188 if (__predict_true(error == 0)) { 2189 _finstall(fdp, fp, *fd, flags, fcaps); 2190 } 2191 FILEDESC_XUNLOCK(fdp); 2192 return (error); 2193 } 2194 2195 int 2196 finstall(struct thread *td, struct file *fp, int *fd, int flags, 2197 struct filecaps *fcaps) 2198 { 2199 int error; 2200 2201 MPASS(fd != NULL); 2202 2203 if (!fhold(fp)) 2204 return (EBADF); 2205 error = finstall_refed(td, fp, fd, flags, fcaps); 2206 if (__predict_false(error != 0)) { 2207 fdrop(fp, td); 2208 } 2209 return (error); 2210 } 2211 2212 /* 2213 * Build a new filedesc structure from another. 2214 * 2215 * If fdp is not NULL, return with it shared locked. 2216 */ 2217 struct filedesc * 2218 fdinit(void) 2219 { 2220 struct filedesc0 *newfdp0; 2221 struct filedesc *newfdp; 2222 2223 newfdp0 = uma_zalloc(filedesc0_zone, M_WAITOK | M_ZERO); 2224 newfdp = &newfdp0->fd_fd; 2225 2226 /* Create the file descriptor table. */ 2227 FILEDESC_LOCK_INIT(newfdp); 2228 refcount_init(&newfdp->fd_refcnt, 1); 2229 refcount_init(&newfdp->fd_holdcnt, 1); 2230 newfdp->fd_map = newfdp0->fd_dmap; 2231 newfdp->fd_files = (struct fdescenttbl *)&newfdp0->fd_dfiles; 2232 newfdp->fd_files->fdt_nfiles = NDFILE; 2233 2234 return (newfdp); 2235 } 2236 2237 /* 2238 * Build a pwddesc structure from another. 2239 * Copy the current, root, and jail root vnode references. 2240 * 2241 * If pdp is not NULL and keeplock is true, return with it (exclusively) locked. 2242 */ 2243 struct pwddesc * 2244 pdinit(struct pwddesc *pdp, bool keeplock) 2245 { 2246 struct pwddesc *newpdp; 2247 struct pwd *newpwd; 2248 2249 newpdp = malloc(sizeof(*newpdp), M_PWDDESC, M_WAITOK | M_ZERO); 2250 2251 PWDDESC_LOCK_INIT(newpdp); 2252 refcount_init(&newpdp->pd_refcount, 1); 2253 newpdp->pd_cmask = CMASK; 2254 2255 if (pdp == NULL) { 2256 newpwd = pwd_alloc(); 2257 smr_serialized_store(&newpdp->pd_pwd, newpwd, true); 2258 return (newpdp); 2259 } 2260 2261 PWDDESC_XLOCK(pdp); 2262 newpwd = pwd_hold_pwddesc(pdp); 2263 smr_serialized_store(&newpdp->pd_pwd, newpwd, true); 2264 if (!keeplock) 2265 PWDDESC_XUNLOCK(pdp); 2266 return (newpdp); 2267 } 2268 2269 /* 2270 * Hold either filedesc or pwddesc of the passed process. 2271 * 2272 * The process lock is used to synchronize against the target exiting and 2273 * freeing the data. 2274 * 2275 * Clearing can be ilustrated in 3 steps: 2276 * 1. set the pointer to NULL. Either routine can race against it, hence 2277 * atomic_load_ptr. 2278 * 2. observe the process lock as not taken. Until then fdhold/pdhold can 2279 * race to either still see the pointer or find NULL. It is still safe to 2280 * grab a reference as clearing is stalled. 2281 * 3. after the lock is observed as not taken, any fdhold/pdhold calls are 2282 * guaranteed to see NULL, making it safe to finish clearing 2283 */ 2284 static struct filedesc * 2285 fdhold(struct proc *p) 2286 { 2287 struct filedesc *fdp; 2288 2289 PROC_LOCK_ASSERT(p, MA_OWNED); 2290 fdp = atomic_load_ptr(&p->p_fd); 2291 if (fdp != NULL) 2292 refcount_acquire(&fdp->fd_holdcnt); 2293 return (fdp); 2294 } 2295 2296 static struct pwddesc * 2297 pdhold(struct proc *p) 2298 { 2299 struct pwddesc *pdp; 2300 2301 PROC_LOCK_ASSERT(p, MA_OWNED); 2302 pdp = atomic_load_ptr(&p->p_pd); 2303 if (pdp != NULL) 2304 refcount_acquire(&pdp->pd_refcount); 2305 return (pdp); 2306 } 2307 2308 static void 2309 fddrop(struct filedesc *fdp) 2310 { 2311 2312 if (refcount_load(&fdp->fd_holdcnt) > 1) { 2313 if (refcount_release(&fdp->fd_holdcnt) == 0) 2314 return; 2315 } 2316 2317 FILEDESC_LOCK_DESTROY(fdp); 2318 uma_zfree(filedesc0_zone, fdp); 2319 } 2320 2321 static void 2322 pddrop(struct pwddesc *pdp) 2323 { 2324 struct pwd *pwd; 2325 2326 if (refcount_release_if_not_last(&pdp->pd_refcount)) 2327 return; 2328 2329 PWDDESC_XLOCK(pdp); 2330 if (refcount_release(&pdp->pd_refcount) == 0) { 2331 PWDDESC_XUNLOCK(pdp); 2332 return; 2333 } 2334 pwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); 2335 pwd_set(pdp, NULL); 2336 PWDDESC_XUNLOCK(pdp); 2337 pwd_drop(pwd); 2338 2339 PWDDESC_LOCK_DESTROY(pdp); 2340 free(pdp, M_PWDDESC); 2341 } 2342 2343 /* 2344 * Share a filedesc structure. 2345 */ 2346 struct filedesc * 2347 fdshare(struct filedesc *fdp) 2348 { 2349 2350 refcount_acquire(&fdp->fd_refcnt); 2351 return (fdp); 2352 } 2353 2354 /* 2355 * Share a pwddesc structure. 2356 */ 2357 struct pwddesc * 2358 pdshare(struct pwddesc *pdp) 2359 { 2360 refcount_acquire(&pdp->pd_refcount); 2361 return (pdp); 2362 } 2363 2364 /* 2365 * Unshare a filedesc structure, if necessary by making a copy 2366 */ 2367 void 2368 fdunshare(struct thread *td) 2369 { 2370 struct filedesc *tmp; 2371 struct proc *p = td->td_proc; 2372 2373 if (refcount_load(&p->p_fd->fd_refcnt) == 1) 2374 return; 2375 2376 tmp = fdcopy(p->p_fd); 2377 fdescfree(td); 2378 p->p_fd = tmp; 2379 } 2380 2381 /* 2382 * Unshare a pwddesc structure. 2383 */ 2384 void 2385 pdunshare(struct thread *td) 2386 { 2387 struct pwddesc *pdp; 2388 struct proc *p; 2389 2390 p = td->td_proc; 2391 /* Not shared. */ 2392 if (refcount_load(&p->p_pd->pd_refcount) == 1) 2393 return; 2394 2395 pdp = pdcopy(p->p_pd); 2396 pdescfree(td); 2397 p->p_pd = pdp; 2398 } 2399 2400 /* 2401 * Copy a filedesc structure. A NULL pointer in returns a NULL reference, 2402 * this is to ease callers, not catch errors. 2403 */ 2404 struct filedesc * 2405 fdcopy(struct filedesc *fdp) 2406 { 2407 struct filedesc *newfdp; 2408 struct filedescent *nfde, *ofde; 2409 int i, lastfile; 2410 2411 MPASS(fdp != NULL); 2412 2413 newfdp = fdinit(); 2414 FILEDESC_SLOCK(fdp); 2415 for (;;) { 2416 lastfile = fdlastfile(fdp); 2417 if (lastfile < newfdp->fd_nfiles) 2418 break; 2419 FILEDESC_SUNLOCK(fdp); 2420 fdgrowtable(newfdp, lastfile + 1); 2421 FILEDESC_SLOCK(fdp); 2422 } 2423 /* copy all passable descriptors (i.e. not kqueue) */ 2424 newfdp->fd_freefile = fdp->fd_freefile; 2425 FILEDESC_FOREACH_FDE(fdp, i, ofde) { 2426 if ((ofde->fde_file->f_ops->fo_flags & DFLAG_PASSABLE) == 0 || 2427 !fhold(ofde->fde_file)) { 2428 if (newfdp->fd_freefile == fdp->fd_freefile) 2429 newfdp->fd_freefile = i; 2430 continue; 2431 } 2432 nfde = &newfdp->fd_ofiles[i]; 2433 *nfde = *ofde; 2434 filecaps_copy(&ofde->fde_caps, &nfde->fde_caps, true); 2435 fdused_init(newfdp, i); 2436 } 2437 MPASS(newfdp->fd_freefile != -1); 2438 FILEDESC_SUNLOCK(fdp); 2439 return (newfdp); 2440 } 2441 2442 /* 2443 * Copy a pwddesc structure. 2444 */ 2445 struct pwddesc * 2446 pdcopy(struct pwddesc *pdp) 2447 { 2448 struct pwddesc *newpdp; 2449 2450 MPASS(pdp != NULL); 2451 2452 newpdp = pdinit(pdp, true); 2453 newpdp->pd_cmask = pdp->pd_cmask; 2454 PWDDESC_XUNLOCK(pdp); 2455 return (newpdp); 2456 } 2457 2458 /* 2459 * Clear POSIX style locks. This is only used when fdp looses a reference (i.e. 2460 * one of processes using it exits) and the table used to be shared. 2461 */ 2462 static void 2463 fdclearlocks(struct thread *td) 2464 { 2465 struct filedesc *fdp; 2466 struct filedesc_to_leader *fdtol; 2467 struct flock lf; 2468 struct file *fp; 2469 struct proc *p; 2470 struct vnode *vp; 2471 int i; 2472 2473 p = td->td_proc; 2474 fdp = p->p_fd; 2475 fdtol = p->p_fdtol; 2476 MPASS(fdtol != NULL); 2477 2478 FILEDESC_XLOCK(fdp); 2479 KASSERT(fdtol->fdl_refcount > 0, 2480 ("filedesc_to_refcount botch: fdl_refcount=%d", 2481 fdtol->fdl_refcount)); 2482 if (fdtol->fdl_refcount == 1 && 2483 (p->p_leader->p_flag & P_ADVLOCK) != 0) { 2484 FILEDESC_FOREACH_FP(fdp, i, fp) { 2485 if (fp->f_type != DTYPE_VNODE || 2486 !fhold(fp)) 2487 continue; 2488 FILEDESC_XUNLOCK(fdp); 2489 lf.l_whence = SEEK_SET; 2490 lf.l_start = 0; 2491 lf.l_len = 0; 2492 lf.l_type = F_UNLCK; 2493 vp = fp->f_vnode; 2494 (void) VOP_ADVLOCK(vp, 2495 (caddr_t)p->p_leader, F_UNLCK, 2496 &lf, F_POSIX); 2497 FILEDESC_XLOCK(fdp); 2498 fdrop(fp, td); 2499 } 2500 } 2501 retry: 2502 if (fdtol->fdl_refcount == 1) { 2503 if (fdp->fd_holdleaderscount > 0 && 2504 (p->p_leader->p_flag & P_ADVLOCK) != 0) { 2505 /* 2506 * close() or kern_dup() has cleared a reference 2507 * in a shared file descriptor table. 2508 */ 2509 fdp->fd_holdleaderswakeup = 1; 2510 sx_sleep(&fdp->fd_holdleaderscount, 2511 FILEDESC_LOCK(fdp), PLOCK, "fdlhold", 0); 2512 goto retry; 2513 } 2514 if (fdtol->fdl_holdcount > 0) { 2515 /* 2516 * Ensure that fdtol->fdl_leader remains 2517 * valid in closef(). 2518 */ 2519 fdtol->fdl_wakeup = 1; 2520 sx_sleep(fdtol, FILEDESC_LOCK(fdp), PLOCK, 2521 "fdlhold", 0); 2522 goto retry; 2523 } 2524 } 2525 fdtol->fdl_refcount--; 2526 if (fdtol->fdl_refcount == 0 && 2527 fdtol->fdl_holdcount == 0) { 2528 fdtol->fdl_next->fdl_prev = fdtol->fdl_prev; 2529 fdtol->fdl_prev->fdl_next = fdtol->fdl_next; 2530 } else 2531 fdtol = NULL; 2532 p->p_fdtol = NULL; 2533 FILEDESC_XUNLOCK(fdp); 2534 if (fdtol != NULL) 2535 free(fdtol, M_FILEDESC_TO_LEADER); 2536 } 2537 2538 /* 2539 * Release a filedesc structure. 2540 */ 2541 static void 2542 fdescfree_fds(struct thread *td, struct filedesc *fdp) 2543 { 2544 struct filedesc0 *fdp0; 2545 struct freetable *ft, *tft; 2546 struct filedescent *fde; 2547 struct file *fp; 2548 int i; 2549 2550 KASSERT(refcount_load(&fdp->fd_refcnt) == 0, 2551 ("%s: fd table %p carries references", __func__, fdp)); 2552 2553 /* 2554 * Serialize with threads iterating over the table, if any. 2555 */ 2556 if (refcount_load(&fdp->fd_holdcnt) > 1) { 2557 FILEDESC_XLOCK(fdp); 2558 FILEDESC_XUNLOCK(fdp); 2559 } 2560 2561 FILEDESC_FOREACH_FDE(fdp, i, fde) { 2562 fp = fde->fde_file; 2563 fdefree_last(fde); 2564 (void) closef(fp, td); 2565 } 2566 2567 if (NDSLOTS(fdp->fd_nfiles) > NDSLOTS(NDFILE)) 2568 free(fdp->fd_map, M_FILEDESC); 2569 if (fdp->fd_nfiles > NDFILE) 2570 free(fdp->fd_files, M_FILEDESC); 2571 2572 fdp0 = (struct filedesc0 *)fdp; 2573 SLIST_FOREACH_SAFE(ft, &fdp0->fd_free, ft_next, tft) 2574 free(ft->ft_table, M_FILEDESC); 2575 2576 fddrop(fdp); 2577 } 2578 2579 void 2580 fdescfree(struct thread *td) 2581 { 2582 struct proc *p; 2583 struct filedesc *fdp; 2584 2585 p = td->td_proc; 2586 fdp = p->p_fd; 2587 MPASS(fdp != NULL); 2588 2589 #ifdef RACCT 2590 if (RACCT_ENABLED()) 2591 racct_set_unlocked(p, RACCT_NOFILE, 0); 2592 #endif 2593 2594 if (p->p_fdtol != NULL) 2595 fdclearlocks(td); 2596 2597 /* 2598 * Check fdhold for an explanation. 2599 */ 2600 atomic_store_ptr(&p->p_fd, NULL); 2601 atomic_thread_fence_seq_cst(); 2602 PROC_WAIT_UNLOCKED(p); 2603 2604 if (refcount_release(&fdp->fd_refcnt) == 0) 2605 return; 2606 2607 fdescfree_fds(td, fdp); 2608 } 2609 2610 void 2611 pdescfree(struct thread *td) 2612 { 2613 struct proc *p; 2614 struct pwddesc *pdp; 2615 2616 p = td->td_proc; 2617 pdp = p->p_pd; 2618 MPASS(pdp != NULL); 2619 2620 /* 2621 * Check pdhold for an explanation. 2622 */ 2623 atomic_store_ptr(&p->p_pd, NULL); 2624 atomic_thread_fence_seq_cst(); 2625 PROC_WAIT_UNLOCKED(p); 2626 2627 pddrop(pdp); 2628 } 2629 2630 /* 2631 * For setugid programs, we don't want to people to use that setugidness 2632 * to generate error messages which write to a file which otherwise would 2633 * otherwise be off-limits to the process. We check for filesystems where 2634 * the vnode can change out from under us after execve (like [lin]procfs). 2635 * 2636 * Since fdsetugidsafety calls this only for fd 0, 1 and 2, this check is 2637 * sufficient. We also don't check for setugidness since we know we are. 2638 */ 2639 static bool 2640 is_unsafe(struct file *fp) 2641 { 2642 struct vnode *vp; 2643 2644 if (fp->f_type != DTYPE_VNODE) 2645 return (false); 2646 2647 vp = fp->f_vnode; 2648 return ((vp->v_vflag & VV_PROCDEP) != 0); 2649 } 2650 2651 /* 2652 * Make this setguid thing safe, if at all possible. 2653 */ 2654 void 2655 fdsetugidsafety(struct thread *td) 2656 { 2657 struct filedesc *fdp; 2658 struct file *fp; 2659 int i; 2660 2661 fdp = td->td_proc->p_fd; 2662 KASSERT(refcount_load(&fdp->fd_refcnt) == 1, 2663 ("the fdtable should not be shared")); 2664 MPASS(fdp->fd_nfiles >= 3); 2665 for (i = 0; i <= 2; i++) { 2666 fp = fdp->fd_ofiles[i].fde_file; 2667 if (fp != NULL && is_unsafe(fp)) { 2668 FILEDESC_XLOCK(fdp); 2669 knote_fdclose(td, i); 2670 /* 2671 * NULL-out descriptor prior to close to avoid 2672 * a race while close blocks. 2673 */ 2674 fdfree(fdp, i); 2675 FILEDESC_XUNLOCK(fdp); 2676 (void) closef(fp, td); 2677 } 2678 } 2679 } 2680 2681 /* 2682 * If a specific file object occupies a specific file descriptor, close the 2683 * file descriptor entry and drop a reference on the file object. This is a 2684 * convenience function to handle a subsequent error in a function that calls 2685 * falloc() that handles the race that another thread might have closed the 2686 * file descriptor out from under the thread creating the file object. 2687 */ 2688 void 2689 fdclose(struct thread *td, struct file *fp, int idx) 2690 { 2691 struct filedesc *fdp = td->td_proc->p_fd; 2692 2693 FILEDESC_XLOCK(fdp); 2694 if (fdp->fd_ofiles[idx].fde_file == fp) { 2695 fdfree(fdp, idx); 2696 FILEDESC_XUNLOCK(fdp); 2697 fdrop(fp, td); 2698 } else 2699 FILEDESC_XUNLOCK(fdp); 2700 } 2701 2702 /* 2703 * Close any files on exec? 2704 */ 2705 void 2706 fdcloseexec(struct thread *td) 2707 { 2708 struct filedesc *fdp; 2709 struct filedescent *fde; 2710 struct file *fp; 2711 int i; 2712 2713 fdp = td->td_proc->p_fd; 2714 KASSERT(refcount_load(&fdp->fd_refcnt) == 1, 2715 ("the fdtable should not be shared")); 2716 FILEDESC_FOREACH_FDE(fdp, i, fde) { 2717 fp = fde->fde_file; 2718 if (fp->f_type == DTYPE_MQUEUE || 2719 (fde->fde_flags & UF_EXCLOSE)) { 2720 FILEDESC_XLOCK(fdp); 2721 fdfree(fdp, i); 2722 (void) closefp(fdp, i, fp, td, false, false); 2723 FILEDESC_UNLOCK_ASSERT(fdp); 2724 } 2725 } 2726 } 2727 2728 /* 2729 * It is unsafe for set[ug]id processes to be started with file 2730 * descriptors 0..2 closed, as these descriptors are given implicit 2731 * significance in the Standard C library. fdcheckstd() will create a 2732 * descriptor referencing /dev/null for each of stdin, stdout, and 2733 * stderr that is not already open. 2734 */ 2735 int 2736 fdcheckstd(struct thread *td) 2737 { 2738 struct filedesc *fdp; 2739 register_t save; 2740 int i, error, devnull; 2741 2742 fdp = td->td_proc->p_fd; 2743 KASSERT(refcount_load(&fdp->fd_refcnt) == 1, 2744 ("the fdtable should not be shared")); 2745 MPASS(fdp->fd_nfiles >= 3); 2746 devnull = -1; 2747 for (i = 0; i <= 2; i++) { 2748 if (fdp->fd_ofiles[i].fde_file != NULL) 2749 continue; 2750 2751 save = td->td_retval[0]; 2752 if (devnull != -1) { 2753 error = kern_dup(td, FDDUP_FIXED, 0, devnull, i); 2754 } else { 2755 error = kern_openat(td, AT_FDCWD, "/dev/null", 2756 UIO_SYSSPACE, O_RDWR, 0); 2757 if (error == 0) { 2758 devnull = td->td_retval[0]; 2759 KASSERT(devnull == i, ("we didn't get our fd")); 2760 } 2761 } 2762 td->td_retval[0] = save; 2763 if (error != 0) 2764 return (error); 2765 } 2766 return (0); 2767 } 2768 2769 /* 2770 * Internal form of close. Decrement reference count on file structure. 2771 * Note: td may be NULL when closing a file that was being passed in a 2772 * message. 2773 */ 2774 int 2775 closef(struct file *fp, struct thread *td) 2776 { 2777 struct vnode *vp; 2778 struct flock lf; 2779 struct filedesc_to_leader *fdtol; 2780 struct filedesc *fdp; 2781 2782 MPASS(td != NULL); 2783 2784 /* 2785 * POSIX record locking dictates that any close releases ALL 2786 * locks owned by this process. This is handled by setting 2787 * a flag in the unlock to free ONLY locks obeying POSIX 2788 * semantics, and not to free BSD-style file locks. 2789 * If the descriptor was in a message, POSIX-style locks 2790 * aren't passed with the descriptor, and the thread pointer 2791 * will be NULL. Callers should be careful only to pass a 2792 * NULL thread pointer when there really is no owning 2793 * context that might have locks, or the locks will be 2794 * leaked. 2795 */ 2796 if (fp->f_type == DTYPE_VNODE) { 2797 vp = fp->f_vnode; 2798 if ((td->td_proc->p_leader->p_flag & P_ADVLOCK) != 0) { 2799 lf.l_whence = SEEK_SET; 2800 lf.l_start = 0; 2801 lf.l_len = 0; 2802 lf.l_type = F_UNLCK; 2803 (void) VOP_ADVLOCK(vp, (caddr_t)td->td_proc->p_leader, 2804 F_UNLCK, &lf, F_POSIX); 2805 } 2806 fdtol = td->td_proc->p_fdtol; 2807 if (fdtol != NULL) { 2808 /* 2809 * Handle special case where file descriptor table is 2810 * shared between multiple process leaders. 2811 */ 2812 fdp = td->td_proc->p_fd; 2813 FILEDESC_XLOCK(fdp); 2814 for (fdtol = fdtol->fdl_next; 2815 fdtol != td->td_proc->p_fdtol; 2816 fdtol = fdtol->fdl_next) { 2817 if ((fdtol->fdl_leader->p_flag & 2818 P_ADVLOCK) == 0) 2819 continue; 2820 fdtol->fdl_holdcount++; 2821 FILEDESC_XUNLOCK(fdp); 2822 lf.l_whence = SEEK_SET; 2823 lf.l_start = 0; 2824 lf.l_len = 0; 2825 lf.l_type = F_UNLCK; 2826 vp = fp->f_vnode; 2827 (void) VOP_ADVLOCK(vp, 2828 (caddr_t)fdtol->fdl_leader, F_UNLCK, &lf, 2829 F_POSIX); 2830 FILEDESC_XLOCK(fdp); 2831 fdtol->fdl_holdcount--; 2832 if (fdtol->fdl_holdcount == 0 && 2833 fdtol->fdl_wakeup != 0) { 2834 fdtol->fdl_wakeup = 0; 2835 wakeup(fdtol); 2836 } 2837 } 2838 FILEDESC_XUNLOCK(fdp); 2839 } 2840 } 2841 return (fdrop_close(fp, td)); 2842 } 2843 2844 /* 2845 * Hack for file descriptor passing code. 2846 */ 2847 void 2848 closef_nothread(struct file *fp) 2849 { 2850 2851 fdrop(fp, NULL); 2852 } 2853 2854 /* 2855 * Initialize the file pointer with the specified properties. 2856 * 2857 * The ops are set with release semantics to be certain that the flags, type, 2858 * and data are visible when ops is. This is to prevent ops methods from being 2859 * called with bad data. 2860 */ 2861 void 2862 finit(struct file *fp, u_int flag, short type, void *data, struct fileops *ops) 2863 { 2864 fp->f_data = data; 2865 fp->f_flag = flag; 2866 fp->f_type = type; 2867 atomic_store_rel_ptr((volatile uintptr_t *)&fp->f_ops, (uintptr_t)ops); 2868 } 2869 2870 void 2871 finit_vnode(struct file *fp, u_int flag, void *data, struct fileops *ops) 2872 { 2873 fp->f_seqcount[UIO_READ] = 1; 2874 fp->f_seqcount[UIO_WRITE] = 1; 2875 finit(fp, (flag & FMASK) | (fp->f_flag & FHASLOCK), DTYPE_VNODE, 2876 data, ops); 2877 } 2878 2879 int 2880 fget_cap_noref(struct filedesc *fdp, int fd, cap_rights_t *needrightsp, 2881 struct file **fpp, struct filecaps *havecapsp) 2882 { 2883 struct filedescent *fde; 2884 int error; 2885 2886 FILEDESC_LOCK_ASSERT(fdp); 2887 2888 *fpp = NULL; 2889 fde = fdeget_noref(fdp, fd); 2890 if (fde == NULL) { 2891 error = EBADF; 2892 goto out; 2893 } 2894 2895 #ifdef CAPABILITIES 2896 error = cap_check(cap_rights_fde_inline(fde), needrightsp); 2897 if (error != 0) 2898 goto out; 2899 #endif 2900 2901 if (havecapsp != NULL) 2902 filecaps_copy(&fde->fde_caps, havecapsp, true); 2903 2904 *fpp = fde->fde_file; 2905 2906 error = 0; 2907 out: 2908 return (error); 2909 } 2910 2911 #ifdef CAPABILITIES 2912 int 2913 fget_cap(struct thread *td, int fd, cap_rights_t *needrightsp, 2914 struct file **fpp, struct filecaps *havecapsp) 2915 { 2916 struct filedesc *fdp = td->td_proc->p_fd; 2917 int error; 2918 struct file *fp; 2919 seqc_t seq; 2920 2921 *fpp = NULL; 2922 for (;;) { 2923 error = fget_unlocked_seq(td, fd, needrightsp, &fp, &seq); 2924 if (error != 0) 2925 return (error); 2926 2927 if (havecapsp != NULL) { 2928 if (!filecaps_copy(&fdp->fd_ofiles[fd].fde_caps, 2929 havecapsp, false)) { 2930 fdrop(fp, td); 2931 goto get_locked; 2932 } 2933 } 2934 2935 if (!fd_modified(fdp, fd, seq)) 2936 break; 2937 fdrop(fp, td); 2938 } 2939 2940 *fpp = fp; 2941 return (0); 2942 2943 get_locked: 2944 FILEDESC_SLOCK(fdp); 2945 error = fget_cap_noref(fdp, fd, needrightsp, fpp, havecapsp); 2946 if (error == 0 && !fhold(*fpp)) 2947 error = EBADF; 2948 FILEDESC_SUNLOCK(fdp); 2949 return (error); 2950 } 2951 #else 2952 int 2953 fget_cap(struct thread *td, int fd, cap_rights_t *needrightsp, 2954 struct file **fpp, struct filecaps *havecapsp) 2955 { 2956 int error; 2957 error = fget_unlocked(td, fd, needrightsp, fpp); 2958 if (havecapsp != NULL && error == 0) 2959 filecaps_fill(havecapsp); 2960 2961 return (error); 2962 } 2963 #endif 2964 2965 int 2966 fget_remote(struct thread *td, struct proc *p, int fd, struct file **fpp) 2967 { 2968 struct filedesc *fdp; 2969 struct file *fp; 2970 int error; 2971 2972 if (p == td->td_proc) /* curproc */ 2973 return (fget_unlocked(td, fd, &cap_no_rights, fpp)); 2974 2975 PROC_LOCK(p); 2976 fdp = fdhold(p); 2977 PROC_UNLOCK(p); 2978 if (fdp == NULL) 2979 return (ENOENT); 2980 FILEDESC_SLOCK(fdp); 2981 if (refcount_load(&fdp->fd_refcnt) != 0) { 2982 fp = fget_noref(fdp, fd); 2983 if (fp != NULL && fhold(fp)) { 2984 *fpp = fp; 2985 error = 0; 2986 } else { 2987 error = EBADF; 2988 } 2989 } else { 2990 error = ENOENT; 2991 } 2992 FILEDESC_SUNLOCK(fdp); 2993 fddrop(fdp); 2994 return (error); 2995 } 2996 2997 #ifdef CAPABILITIES 2998 int 2999 fgetvp_lookup_smr(struct nameidata *ndp, struct vnode **vpp, bool *fsearch) 3000 { 3001 const struct filedescent *fde; 3002 const struct fdescenttbl *fdt; 3003 struct filedesc *fdp; 3004 struct file *fp; 3005 struct vnode *vp; 3006 const cap_rights_t *haverights; 3007 cap_rights_t rights; 3008 seqc_t seq; 3009 int fd; 3010 3011 VFS_SMR_ASSERT_ENTERED(); 3012 3013 fd = ndp->ni_dirfd; 3014 rights = *ndp->ni_rightsneeded; 3015 cap_rights_set_one(&rights, CAP_LOOKUP); 3016 3017 fdp = curproc->p_fd; 3018 fdt = fdp->fd_files; 3019 if (__predict_false((u_int)fd >= fdt->fdt_nfiles)) 3020 return (EBADF); 3021 seq = seqc_read_notmodify(fd_seqc(fdt, fd)); 3022 fde = &fdt->fdt_ofiles[fd]; 3023 haverights = cap_rights_fde_inline(fde); 3024 fp = fde->fde_file; 3025 if (__predict_false(fp == NULL)) 3026 return (EAGAIN); 3027 if (__predict_false(cap_check_inline_transient(haverights, &rights))) 3028 return (EAGAIN); 3029 *fsearch = ((fp->f_flag & FSEARCH) != 0); 3030 vp = fp->f_vnode; 3031 if (__predict_false(vp == NULL)) { 3032 return (EAGAIN); 3033 } 3034 if (!filecaps_copy(&fde->fde_caps, &ndp->ni_filecaps, false)) { 3035 return (EAGAIN); 3036 } 3037 /* 3038 * Use an acquire barrier to force re-reading of fdt so it is 3039 * refreshed for verification. 3040 */ 3041 atomic_thread_fence_acq(); 3042 fdt = fdp->fd_files; 3043 if (__predict_false(!seqc_consistent_no_fence(fd_seqc(fdt, fd), seq))) 3044 return (EAGAIN); 3045 /* 3046 * If file descriptor doesn't have all rights, 3047 * all lookups relative to it must also be 3048 * strictly relative. 3049 * 3050 * Not yet supported by fast path. 3051 */ 3052 CAP_ALL(&rights); 3053 if (!cap_rights_contains(&ndp->ni_filecaps.fc_rights, &rights) || 3054 ndp->ni_filecaps.fc_fcntls != CAP_FCNTL_ALL || 3055 ndp->ni_filecaps.fc_nioctls != -1) { 3056 #ifdef notyet 3057 ndp->ni_lcf |= NI_LCF_STRICTREL; 3058 #else 3059 return (EAGAIN); 3060 #endif 3061 } 3062 *vpp = vp; 3063 return (0); 3064 } 3065 #else 3066 int 3067 fgetvp_lookup_smr(struct nameidata *ndp, struct vnode **vpp, bool *fsearch) 3068 { 3069 const struct fdescenttbl *fdt; 3070 struct filedesc *fdp; 3071 struct file *fp; 3072 struct vnode *vp; 3073 int fd; 3074 3075 VFS_SMR_ASSERT_ENTERED(); 3076 3077 fd = ndp->ni_dirfd; 3078 fdp = curproc->p_fd; 3079 fdt = fdp->fd_files; 3080 if (__predict_false((u_int)fd >= fdt->fdt_nfiles)) 3081 return (EBADF); 3082 fp = fdt->fdt_ofiles[fd].fde_file; 3083 if (__predict_false(fp == NULL)) 3084 return (EAGAIN); 3085 *fsearch = ((fp->f_flag & FSEARCH) != 0); 3086 vp = fp->f_vnode; 3087 if (__predict_false(vp == NULL || vp->v_type != VDIR)) { 3088 return (EAGAIN); 3089 } 3090 /* 3091 * Use an acquire barrier to force re-reading of fdt so it is 3092 * refreshed for verification. 3093 */ 3094 atomic_thread_fence_acq(); 3095 fdt = fdp->fd_files; 3096 if (__predict_false(fp != fdt->fdt_ofiles[fd].fde_file)) 3097 return (EAGAIN); 3098 filecaps_fill(&ndp->ni_filecaps); 3099 *vpp = vp; 3100 return (0); 3101 } 3102 #endif 3103 3104 int 3105 fgetvp_lookup(struct nameidata *ndp, struct vnode **vpp) 3106 { 3107 struct thread *td; 3108 struct file *fp; 3109 struct vnode *vp; 3110 struct componentname *cnp; 3111 cap_rights_t rights; 3112 int error; 3113 3114 td = curthread; 3115 rights = *ndp->ni_rightsneeded; 3116 cap_rights_set_one(&rights, CAP_LOOKUP); 3117 cnp = &ndp->ni_cnd; 3118 3119 error = fget_cap(td, ndp->ni_dirfd, &rights, &fp, &ndp->ni_filecaps); 3120 if (__predict_false(error != 0)) 3121 return (error); 3122 if (__predict_false(fp->f_ops == &badfileops)) { 3123 error = EBADF; 3124 goto out_free; 3125 } 3126 vp = fp->f_vnode; 3127 if (__predict_false(vp == NULL)) { 3128 error = ENOTDIR; 3129 goto out_free; 3130 } 3131 vrefact(vp); 3132 /* 3133 * XXX does not check for VDIR, handled by namei_setup 3134 */ 3135 if ((fp->f_flag & FSEARCH) != 0) 3136 cnp->cn_flags |= NOEXECCHECK; 3137 fdrop(fp, td); 3138 3139 #ifdef CAPABILITIES 3140 /* 3141 * If file descriptor doesn't have all rights, 3142 * all lookups relative to it must also be 3143 * strictly relative. 3144 */ 3145 CAP_ALL(&rights); 3146 if (!cap_rights_contains(&ndp->ni_filecaps.fc_rights, &rights) || 3147 ndp->ni_filecaps.fc_fcntls != CAP_FCNTL_ALL || 3148 ndp->ni_filecaps.fc_nioctls != -1) { 3149 ndp->ni_lcf |= NI_LCF_STRICTREL; 3150 ndp->ni_resflags |= NIRES_STRICTREL; 3151 } 3152 #endif 3153 3154 /* 3155 * TODO: avoid copying ioctl caps if it can be helped to begin with 3156 */ 3157 if ((cnp->cn_flags & WANTIOCTLCAPS) == 0) 3158 filecaps_free_ioctl(&ndp->ni_filecaps); 3159 3160 *vpp = vp; 3161 return (0); 3162 3163 out_free: 3164 filecaps_free(&ndp->ni_filecaps); 3165 fdrop(fp, td); 3166 return (error); 3167 } 3168 3169 /* 3170 * Fetch the descriptor locklessly. 3171 * 3172 * We avoid fdrop() races by never raising a refcount above 0. To accomplish 3173 * this we have to use a cmpset loop rather than an atomic_add. The descriptor 3174 * must be re-verified once we acquire a reference to be certain that the 3175 * identity is still correct and we did not lose a race due to preemption. 3176 * 3177 * Force a reload of fdt when looping. Another thread could reallocate 3178 * the table before this fd was closed, so it is possible that there is 3179 * a stale fp pointer in cached version. 3180 */ 3181 #ifdef CAPABILITIES 3182 static int 3183 fget_unlocked_seq(struct thread *td, int fd, cap_rights_t *needrightsp, 3184 struct file **fpp, seqc_t *seqp) 3185 { 3186 struct filedesc *fdp; 3187 const struct filedescent *fde; 3188 const struct fdescenttbl *fdt; 3189 struct file *fp; 3190 seqc_t seq; 3191 cap_rights_t haverights; 3192 int error; 3193 3194 fdp = td->td_proc->p_fd; 3195 fdt = fdp->fd_files; 3196 if (__predict_false((u_int)fd >= fdt->fdt_nfiles)) 3197 return (EBADF); 3198 3199 for (;;) { 3200 seq = seqc_read_notmodify(fd_seqc(fdt, fd)); 3201 fde = &fdt->fdt_ofiles[fd]; 3202 haverights = *cap_rights_fde_inline(fde); 3203 fp = fde->fde_file; 3204 if (__predict_false(fp == NULL)) { 3205 if (seqc_consistent(fd_seqc(fdt, fd), seq)) 3206 return (EBADF); 3207 fdt = atomic_load_ptr(&fdp->fd_files); 3208 continue; 3209 } 3210 error = cap_check_inline(&haverights, needrightsp); 3211 if (__predict_false(error != 0)) { 3212 if (seqc_consistent(fd_seqc(fdt, fd), seq)) 3213 return (error); 3214 fdt = atomic_load_ptr(&fdp->fd_files); 3215 continue; 3216 } 3217 if (__predict_false(!refcount_acquire_if_not_zero(&fp->f_count))) { 3218 fdt = atomic_load_ptr(&fdp->fd_files); 3219 continue; 3220 } 3221 /* 3222 * Use an acquire barrier to force re-reading of fdt so it is 3223 * refreshed for verification. 3224 */ 3225 atomic_thread_fence_acq(); 3226 fdt = fdp->fd_files; 3227 if (seqc_consistent_no_fence(fd_seqc(fdt, fd), seq)) 3228 break; 3229 fdrop(fp, td); 3230 } 3231 *fpp = fp; 3232 if (seqp != NULL) { 3233 *seqp = seq; 3234 } 3235 return (0); 3236 } 3237 #else 3238 static int 3239 fget_unlocked_seq(struct thread *td, int fd, cap_rights_t *needrightsp, 3240 struct file **fpp, seqc_t *seqp __unused) 3241 { 3242 struct filedesc *fdp; 3243 const struct fdescenttbl *fdt; 3244 struct file *fp; 3245 3246 fdp = td->td_proc->p_fd; 3247 fdt = fdp->fd_files; 3248 if (__predict_false((u_int)fd >= fdt->fdt_nfiles)) 3249 return (EBADF); 3250 3251 for (;;) { 3252 fp = fdt->fdt_ofiles[fd].fde_file; 3253 if (__predict_false(fp == NULL)) 3254 return (EBADF); 3255 if (__predict_false(!refcount_acquire_if_not_zero(&fp->f_count))) { 3256 fdt = atomic_load_ptr(&fdp->fd_files); 3257 continue; 3258 } 3259 /* 3260 * Use an acquire barrier to force re-reading of fdt so it is 3261 * refreshed for verification. 3262 */ 3263 atomic_thread_fence_acq(); 3264 fdt = fdp->fd_files; 3265 if (__predict_true(fp == fdt->fdt_ofiles[fd].fde_file)) 3266 break; 3267 fdrop(fp, td); 3268 } 3269 *fpp = fp; 3270 return (0); 3271 } 3272 #endif 3273 3274 /* 3275 * See the comments in fget_unlocked_seq for an explanation of how this works. 3276 * 3277 * This is a simplified variant which bails out to the aforementioned routine 3278 * if anything goes wrong. In practice this only happens when userspace is 3279 * racing with itself. 3280 */ 3281 int 3282 fget_unlocked(struct thread *td, int fd, cap_rights_t *needrightsp, 3283 struct file **fpp) 3284 { 3285 struct filedesc *fdp; 3286 #ifdef CAPABILITIES 3287 const struct filedescent *fde; 3288 #endif 3289 const struct fdescenttbl *fdt; 3290 struct file *fp; 3291 #ifdef CAPABILITIES 3292 seqc_t seq; 3293 const cap_rights_t *haverights; 3294 #endif 3295 3296 fdp = td->td_proc->p_fd; 3297 fdt = fdp->fd_files; 3298 if (__predict_false((u_int)fd >= fdt->fdt_nfiles)) { 3299 *fpp = NULL; 3300 return (EBADF); 3301 } 3302 #ifdef CAPABILITIES 3303 seq = seqc_read_notmodify(fd_seqc(fdt, fd)); 3304 fde = &fdt->fdt_ofiles[fd]; 3305 haverights = cap_rights_fde_inline(fde); 3306 fp = fde->fde_file; 3307 #else 3308 fp = fdt->fdt_ofiles[fd].fde_file; 3309 #endif 3310 if (__predict_false(fp == NULL)) 3311 goto out_fallback; 3312 #ifdef CAPABILITIES 3313 if (__predict_false(cap_check_inline_transient(haverights, needrightsp))) 3314 goto out_fallback; 3315 #endif 3316 if (__predict_false(!refcount_acquire_if_not_zero(&fp->f_count))) 3317 goto out_fallback; 3318 3319 /* 3320 * Use an acquire barrier to force re-reading of fdt so it is 3321 * refreshed for verification. 3322 */ 3323 atomic_thread_fence_acq(); 3324 fdt = fdp->fd_files; 3325 #ifdef CAPABILITIES 3326 if (__predict_false(!seqc_consistent_no_fence(fd_seqc(fdt, fd), seq))) 3327 #else 3328 if (__predict_false(fp != fdt->fdt_ofiles[fd].fde_file)) 3329 #endif 3330 goto out_fdrop; 3331 *fpp = fp; 3332 return (0); 3333 out_fdrop: 3334 fdrop(fp, td); 3335 out_fallback: 3336 *fpp = NULL; 3337 return (fget_unlocked_seq(td, fd, needrightsp, fpp, NULL)); 3338 } 3339 3340 /* 3341 * Translate fd -> file when the caller guarantees the file descriptor table 3342 * can't be changed by others. 3343 * 3344 * Note this does not mean the file object itself is only visible to the caller, 3345 * merely that it wont disappear without having to be referenced. 3346 * 3347 * Must be paired with fput_only_user. 3348 */ 3349 #ifdef CAPABILITIES 3350 int 3351 fget_only_user(struct filedesc *fdp, int fd, cap_rights_t *needrightsp, 3352 struct file **fpp) 3353 { 3354 const struct filedescent *fde; 3355 const struct fdescenttbl *fdt; 3356 const cap_rights_t *haverights; 3357 struct file *fp; 3358 int error; 3359 3360 MPASS(FILEDESC_IS_ONLY_USER(fdp)); 3361 3362 *fpp = NULL; 3363 if (__predict_false(fd >= fdp->fd_nfiles)) 3364 return (EBADF); 3365 3366 fdt = fdp->fd_files; 3367 fde = &fdt->fdt_ofiles[fd]; 3368 fp = fde->fde_file; 3369 if (__predict_false(fp == NULL)) 3370 return (EBADF); 3371 MPASS(refcount_load(&fp->f_count) > 0); 3372 haverights = cap_rights_fde_inline(fde); 3373 error = cap_check_inline(haverights, needrightsp); 3374 if (__predict_false(error != 0)) 3375 return (error); 3376 *fpp = fp; 3377 return (0); 3378 } 3379 #else 3380 int 3381 fget_only_user(struct filedesc *fdp, int fd, cap_rights_t *needrightsp, 3382 struct file **fpp) 3383 { 3384 struct file *fp; 3385 3386 MPASS(FILEDESC_IS_ONLY_USER(fdp)); 3387 3388 *fpp = NULL; 3389 if (__predict_false(fd >= fdp->fd_nfiles)) 3390 return (EBADF); 3391 3392 fp = fdp->fd_ofiles[fd].fde_file; 3393 if (__predict_false(fp == NULL)) 3394 return (EBADF); 3395 3396 MPASS(refcount_load(&fp->f_count) > 0); 3397 *fpp = fp; 3398 return (0); 3399 } 3400 #endif 3401 3402 /* 3403 * Extract the file pointer associated with the specified descriptor for the 3404 * current user process. 3405 * 3406 * If the descriptor doesn't exist or doesn't match 'flags', EBADF is 3407 * returned. 3408 * 3409 * File's rights will be checked against the capability rights mask. 3410 * 3411 * If an error occurred the non-zero error is returned and *fpp is set to 3412 * NULL. Otherwise *fpp is held and set and zero is returned. Caller is 3413 * responsible for fdrop(). 3414 */ 3415 static __inline int 3416 _fget(struct thread *td, int fd, struct file **fpp, int flags, 3417 cap_rights_t *needrightsp) 3418 { 3419 struct file *fp; 3420 int error; 3421 3422 *fpp = NULL; 3423 error = fget_unlocked(td, fd, needrightsp, &fp); 3424 if (__predict_false(error != 0)) 3425 return (error); 3426 if (__predict_false(fp->f_ops == &badfileops)) { 3427 fdrop(fp, td); 3428 return (EBADF); 3429 } 3430 3431 /* 3432 * FREAD and FWRITE failure return EBADF as per POSIX. 3433 */ 3434 error = 0; 3435 switch (flags) { 3436 case FREAD: 3437 case FWRITE: 3438 if ((fp->f_flag & flags) == 0) 3439 error = EBADF; 3440 break; 3441 case FEXEC: 3442 if (fp->f_ops != &path_fileops && 3443 ((fp->f_flag & (FREAD | FEXEC)) == 0 || 3444 (fp->f_flag & FWRITE) != 0)) 3445 error = EBADF; 3446 break; 3447 case 0: 3448 break; 3449 default: 3450 KASSERT(0, ("wrong flags")); 3451 } 3452 3453 if (error != 0) { 3454 fdrop(fp, td); 3455 return (error); 3456 } 3457 3458 *fpp = fp; 3459 return (0); 3460 } 3461 3462 int 3463 fget(struct thread *td, int fd, cap_rights_t *rightsp, struct file **fpp) 3464 { 3465 3466 return (_fget(td, fd, fpp, 0, rightsp)); 3467 } 3468 3469 int 3470 fget_mmap(struct thread *td, int fd, cap_rights_t *rightsp, vm_prot_t *maxprotp, 3471 struct file **fpp) 3472 { 3473 int error; 3474 #ifndef CAPABILITIES 3475 error = _fget(td, fd, fpp, 0, rightsp); 3476 if (maxprotp != NULL) 3477 *maxprotp = VM_PROT_ALL; 3478 return (error); 3479 #else 3480 cap_rights_t fdrights; 3481 struct filedesc *fdp; 3482 struct file *fp; 3483 seqc_t seq; 3484 3485 *fpp = NULL; 3486 fdp = td->td_proc->p_fd; 3487 MPASS(cap_rights_is_set(rightsp, CAP_MMAP)); 3488 for (;;) { 3489 error = fget_unlocked_seq(td, fd, rightsp, &fp, &seq); 3490 if (__predict_false(error != 0)) 3491 return (error); 3492 if (__predict_false(fp->f_ops == &badfileops)) { 3493 fdrop(fp, td); 3494 return (EBADF); 3495 } 3496 if (maxprotp != NULL) 3497 fdrights = *cap_rights(fdp, fd); 3498 if (!fd_modified(fdp, fd, seq)) 3499 break; 3500 fdrop(fp, td); 3501 } 3502 3503 /* 3504 * If requested, convert capability rights to access flags. 3505 */ 3506 if (maxprotp != NULL) 3507 *maxprotp = cap_rights_to_vmprot(&fdrights); 3508 *fpp = fp; 3509 return (0); 3510 #endif 3511 } 3512 3513 int 3514 fget_read(struct thread *td, int fd, cap_rights_t *rightsp, struct file **fpp) 3515 { 3516 3517 return (_fget(td, fd, fpp, FREAD, rightsp)); 3518 } 3519 3520 int 3521 fget_write(struct thread *td, int fd, cap_rights_t *rightsp, struct file **fpp) 3522 { 3523 3524 return (_fget(td, fd, fpp, FWRITE, rightsp)); 3525 } 3526 3527 int 3528 fget_fcntl(struct thread *td, int fd, cap_rights_t *rightsp, int needfcntl, 3529 struct file **fpp) 3530 { 3531 #ifndef CAPABILITIES 3532 return (fget_unlocked(td, fd, rightsp, fpp)); 3533 #else 3534 struct filedesc *fdp = td->td_proc->p_fd; 3535 struct file *fp; 3536 int error; 3537 seqc_t seq; 3538 3539 *fpp = NULL; 3540 MPASS(cap_rights_is_set(rightsp, CAP_FCNTL)); 3541 for (;;) { 3542 error = fget_unlocked_seq(td, fd, rightsp, &fp, &seq); 3543 if (error != 0) 3544 return (error); 3545 error = cap_fcntl_check(fdp, fd, needfcntl); 3546 if (!fd_modified(fdp, fd, seq)) 3547 break; 3548 fdrop(fp, td); 3549 } 3550 if (error != 0) { 3551 fdrop(fp, td); 3552 return (error); 3553 } 3554 *fpp = fp; 3555 return (0); 3556 #endif 3557 } 3558 3559 /* 3560 * Like fget() but loads the underlying vnode, or returns an error if the 3561 * descriptor does not represent a vnode. Note that pipes use vnodes but 3562 * never have VM objects. The returned vnode will be vref()'d. 3563 * 3564 * XXX: what about the unused flags ? 3565 */ 3566 static __inline int 3567 _fgetvp(struct thread *td, int fd, int flags, cap_rights_t *needrightsp, 3568 struct vnode **vpp) 3569 { 3570 struct file *fp; 3571 int error; 3572 3573 *vpp = NULL; 3574 error = _fget(td, fd, &fp, flags, needrightsp); 3575 if (error != 0) 3576 return (error); 3577 if (fp->f_vnode == NULL) { 3578 error = EINVAL; 3579 } else { 3580 *vpp = fp->f_vnode; 3581 vrefact(*vpp); 3582 } 3583 fdrop(fp, td); 3584 3585 return (error); 3586 } 3587 3588 int 3589 fgetvp(struct thread *td, int fd, cap_rights_t *rightsp, struct vnode **vpp) 3590 { 3591 3592 return (_fgetvp(td, fd, 0, rightsp, vpp)); 3593 } 3594 3595 int 3596 fgetvp_rights(struct thread *td, int fd, cap_rights_t *needrightsp, 3597 struct filecaps *havecaps, struct vnode **vpp) 3598 { 3599 struct filecaps caps; 3600 struct file *fp; 3601 int error; 3602 3603 error = fget_cap(td, fd, needrightsp, &fp, &caps); 3604 if (error != 0) 3605 return (error); 3606 if (fp->f_ops == &badfileops) { 3607 error = EBADF; 3608 goto out; 3609 } 3610 if (fp->f_vnode == NULL) { 3611 error = EINVAL; 3612 goto out; 3613 } 3614 3615 *havecaps = caps; 3616 *vpp = fp->f_vnode; 3617 vrefact(*vpp); 3618 fdrop(fp, td); 3619 3620 return (0); 3621 out: 3622 filecaps_free(&caps); 3623 fdrop(fp, td); 3624 return (error); 3625 } 3626 3627 int 3628 fgetvp_read(struct thread *td, int fd, cap_rights_t *rightsp, struct vnode **vpp) 3629 { 3630 3631 return (_fgetvp(td, fd, FREAD, rightsp, vpp)); 3632 } 3633 3634 int 3635 fgetvp_exec(struct thread *td, int fd, cap_rights_t *rightsp, struct vnode **vpp) 3636 { 3637 3638 return (_fgetvp(td, fd, FEXEC, rightsp, vpp)); 3639 } 3640 3641 #ifdef notyet 3642 int 3643 fgetvp_write(struct thread *td, int fd, cap_rights_t *rightsp, 3644 struct vnode **vpp) 3645 { 3646 3647 return (_fgetvp(td, fd, FWRITE, rightsp, vpp)); 3648 } 3649 #endif 3650 3651 /* 3652 * Handle the last reference to a file being closed. 3653 * 3654 * Without the noinline attribute clang keeps inlining the func thorough this 3655 * file when fdrop is used. 3656 */ 3657 int __noinline 3658 _fdrop(struct file *fp, struct thread *td) 3659 { 3660 int error; 3661 #ifdef INVARIANTS 3662 int count; 3663 3664 count = refcount_load(&fp->f_count); 3665 if (count != 0) 3666 panic("fdrop: fp %p count %d", fp, count); 3667 #endif 3668 error = fo_close(fp, td); 3669 atomic_subtract_int(&openfiles, 1); 3670 crfree(fp->f_cred); 3671 free(fp->f_advice, M_FADVISE); 3672 uma_zfree(file_zone, fp); 3673 3674 return (error); 3675 } 3676 3677 /* 3678 * Apply an advisory lock on a file descriptor. 3679 * 3680 * Just attempt to get a record lock of the requested type on the entire file 3681 * (l_whence = SEEK_SET, l_start = 0, l_len = 0). 3682 */ 3683 #ifndef _SYS_SYSPROTO_H_ 3684 struct flock_args { 3685 int fd; 3686 int how; 3687 }; 3688 #endif 3689 /* ARGSUSED */ 3690 int 3691 sys_flock(struct thread *td, struct flock_args *uap) 3692 { 3693 struct file *fp; 3694 struct vnode *vp; 3695 struct flock lf; 3696 int error; 3697 3698 error = fget(td, uap->fd, &cap_flock_rights, &fp); 3699 if (error != 0) 3700 return (error); 3701 error = EOPNOTSUPP; 3702 if (fp->f_type != DTYPE_VNODE && fp->f_type != DTYPE_FIFO) { 3703 goto done; 3704 } 3705 if (fp->f_ops == &path_fileops) { 3706 goto done; 3707 } 3708 3709 error = 0; 3710 vp = fp->f_vnode; 3711 lf.l_whence = SEEK_SET; 3712 lf.l_start = 0; 3713 lf.l_len = 0; 3714 if (uap->how & LOCK_UN) { 3715 lf.l_type = F_UNLCK; 3716 atomic_clear_int(&fp->f_flag, FHASLOCK); 3717 error = VOP_ADVLOCK(vp, (caddr_t)fp, F_UNLCK, &lf, F_FLOCK); 3718 goto done; 3719 } 3720 if (uap->how & LOCK_EX) 3721 lf.l_type = F_WRLCK; 3722 else if (uap->how & LOCK_SH) 3723 lf.l_type = F_RDLCK; 3724 else { 3725 error = EBADF; 3726 goto done; 3727 } 3728 atomic_set_int(&fp->f_flag, FHASLOCK); 3729 error = VOP_ADVLOCK(vp, (caddr_t)fp, F_SETLK, &lf, 3730 (uap->how & LOCK_NB) ? F_FLOCK : F_FLOCK | F_WAIT); 3731 done: 3732 fdrop(fp, td); 3733 return (error); 3734 } 3735 /* 3736 * Duplicate the specified descriptor to a free descriptor. 3737 */ 3738 int 3739 dupfdopen(struct thread *td, struct filedesc *fdp, int dfd, int mode, 3740 int openerror, int *indxp) 3741 { 3742 struct filedescent *newfde, *oldfde; 3743 struct file *fp; 3744 u_long *ioctls; 3745 int error, indx; 3746 3747 KASSERT(openerror == ENODEV || openerror == ENXIO, 3748 ("unexpected error %d in %s", openerror, __func__)); 3749 3750 /* 3751 * If the to-be-dup'd fd number is greater than the allowed number 3752 * of file descriptors, or the fd to be dup'd has already been 3753 * closed, then reject. 3754 */ 3755 FILEDESC_XLOCK(fdp); 3756 if ((fp = fget_noref(fdp, dfd)) == NULL) { 3757 FILEDESC_XUNLOCK(fdp); 3758 return (EBADF); 3759 } 3760 3761 error = fdalloc(td, 0, &indx); 3762 if (error != 0) { 3763 FILEDESC_XUNLOCK(fdp); 3764 return (error); 3765 } 3766 3767 /* 3768 * There are two cases of interest here. 3769 * 3770 * For ENODEV simply dup (dfd) to file descriptor (indx) and return. 3771 * 3772 * For ENXIO steal away the file structure from (dfd) and store it in 3773 * (indx). (dfd) is effectively closed by this operation. 3774 */ 3775 switch (openerror) { 3776 case ENODEV: 3777 /* 3778 * Check that the mode the file is being opened for is a 3779 * subset of the mode of the existing descriptor. 3780 */ 3781 if (((mode & (FREAD|FWRITE)) | fp->f_flag) != fp->f_flag) { 3782 fdunused(fdp, indx); 3783 FILEDESC_XUNLOCK(fdp); 3784 return (EACCES); 3785 } 3786 if (!fhold(fp)) { 3787 fdunused(fdp, indx); 3788 FILEDESC_XUNLOCK(fdp); 3789 return (EBADF); 3790 } 3791 newfde = &fdp->fd_ofiles[indx]; 3792 oldfde = &fdp->fd_ofiles[dfd]; 3793 ioctls = filecaps_copy_prep(&oldfde->fde_caps); 3794 #ifdef CAPABILITIES 3795 seqc_write_begin(&newfde->fde_seqc); 3796 #endif 3797 fde_copy(oldfde, newfde); 3798 filecaps_copy_finish(&oldfde->fde_caps, &newfde->fde_caps, 3799 ioctls); 3800 #ifdef CAPABILITIES 3801 seqc_write_end(&newfde->fde_seqc); 3802 #endif 3803 break; 3804 case ENXIO: 3805 /* 3806 * Steal away the file pointer from dfd and stuff it into indx. 3807 */ 3808 newfde = &fdp->fd_ofiles[indx]; 3809 oldfde = &fdp->fd_ofiles[dfd]; 3810 #ifdef CAPABILITIES 3811 seqc_write_begin(&oldfde->fde_seqc); 3812 seqc_write_begin(&newfde->fde_seqc); 3813 #endif 3814 fde_copy(oldfde, newfde); 3815 oldfde->fde_file = NULL; 3816 fdunused(fdp, dfd); 3817 #ifdef CAPABILITIES 3818 seqc_write_end(&newfde->fde_seqc); 3819 seqc_write_end(&oldfde->fde_seqc); 3820 #endif 3821 break; 3822 } 3823 FILEDESC_XUNLOCK(fdp); 3824 *indxp = indx; 3825 return (0); 3826 } 3827 3828 /* 3829 * This sysctl determines if we will allow a process to chroot(2) if it 3830 * has a directory open: 3831 * 0: disallowed for all processes. 3832 * 1: allowed for processes that were not already chroot(2)'ed. 3833 * 2: allowed for all processes. 3834 */ 3835 3836 static int chroot_allow_open_directories = 1; 3837 3838 SYSCTL_INT(_kern, OID_AUTO, chroot_allow_open_directories, CTLFLAG_RW, 3839 &chroot_allow_open_directories, 0, 3840 "Allow a process to chroot(2) if it has a directory open"); 3841 3842 /* 3843 * Helper function for raised chroot(2) security function: Refuse if 3844 * any filedescriptors are open directories. 3845 */ 3846 static int 3847 chroot_refuse_vdir_fds(struct filedesc *fdp) 3848 { 3849 struct vnode *vp; 3850 struct file *fp; 3851 int i; 3852 3853 FILEDESC_LOCK_ASSERT(fdp); 3854 3855 FILEDESC_FOREACH_FP(fdp, i, fp) { 3856 if (fp->f_type == DTYPE_VNODE) { 3857 vp = fp->f_vnode; 3858 if (vp->v_type == VDIR) 3859 return (EPERM); 3860 } 3861 } 3862 return (0); 3863 } 3864 3865 static void 3866 pwd_fill(struct pwd *oldpwd, struct pwd *newpwd) 3867 { 3868 3869 if (newpwd->pwd_cdir == NULL && oldpwd->pwd_cdir != NULL) { 3870 vrefact(oldpwd->pwd_cdir); 3871 newpwd->pwd_cdir = oldpwd->pwd_cdir; 3872 } 3873 3874 if (newpwd->pwd_rdir == NULL && oldpwd->pwd_rdir != NULL) { 3875 vrefact(oldpwd->pwd_rdir); 3876 newpwd->pwd_rdir = oldpwd->pwd_rdir; 3877 } 3878 3879 if (newpwd->pwd_jdir == NULL && oldpwd->pwd_jdir != NULL) { 3880 vrefact(oldpwd->pwd_jdir); 3881 newpwd->pwd_jdir = oldpwd->pwd_jdir; 3882 } 3883 3884 if (newpwd->pwd_adir == NULL && oldpwd->pwd_adir != NULL) { 3885 vrefact(oldpwd->pwd_adir); 3886 newpwd->pwd_adir = oldpwd->pwd_adir; 3887 } 3888 } 3889 3890 struct pwd * 3891 pwd_hold_pwddesc(struct pwddesc *pdp) 3892 { 3893 struct pwd *pwd; 3894 3895 PWDDESC_ASSERT_XLOCKED(pdp); 3896 pwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); 3897 if (pwd != NULL) 3898 refcount_acquire(&pwd->pwd_refcount); 3899 return (pwd); 3900 } 3901 3902 bool 3903 pwd_hold_smr(struct pwd *pwd) 3904 { 3905 3906 MPASS(pwd != NULL); 3907 if (__predict_true(refcount_acquire_if_not_zero(&pwd->pwd_refcount))) { 3908 return (true); 3909 } 3910 return (false); 3911 } 3912 3913 struct pwd * 3914 pwd_hold(struct thread *td) 3915 { 3916 struct pwddesc *pdp; 3917 struct pwd *pwd; 3918 3919 pdp = td->td_proc->p_pd; 3920 3921 vfs_smr_enter(); 3922 pwd = vfs_smr_entered_load(&pdp->pd_pwd); 3923 if (pwd_hold_smr(pwd)) { 3924 vfs_smr_exit(); 3925 return (pwd); 3926 } 3927 vfs_smr_exit(); 3928 PWDDESC_XLOCK(pdp); 3929 pwd = pwd_hold_pwddesc(pdp); 3930 MPASS(pwd != NULL); 3931 PWDDESC_XUNLOCK(pdp); 3932 return (pwd); 3933 } 3934 3935 struct pwd * 3936 pwd_hold_proc(struct proc *p) 3937 { 3938 struct pwddesc *pdp; 3939 struct pwd *pwd; 3940 3941 PROC_ASSERT_HELD(p); 3942 PROC_LOCK(p); 3943 pdp = pdhold(p); 3944 MPASS(pdp != NULL); 3945 PROC_UNLOCK(p); 3946 3947 PWDDESC_XLOCK(pdp); 3948 pwd = pwd_hold_pwddesc(pdp); 3949 MPASS(pwd != NULL); 3950 PWDDESC_XUNLOCK(pdp); 3951 pddrop(pdp); 3952 return (pwd); 3953 } 3954 3955 static struct pwd * 3956 pwd_alloc(void) 3957 { 3958 struct pwd *pwd; 3959 3960 pwd = uma_zalloc_smr(pwd_zone, M_WAITOK); 3961 bzero(pwd, sizeof(*pwd)); 3962 refcount_init(&pwd->pwd_refcount, 1); 3963 return (pwd); 3964 } 3965 3966 void 3967 pwd_drop(struct pwd *pwd) 3968 { 3969 3970 if (!refcount_release(&pwd->pwd_refcount)) 3971 return; 3972 3973 if (pwd->pwd_cdir != NULL) 3974 vrele(pwd->pwd_cdir); 3975 if (pwd->pwd_rdir != NULL) 3976 vrele(pwd->pwd_rdir); 3977 if (pwd->pwd_jdir != NULL) 3978 vrele(pwd->pwd_jdir); 3979 if (pwd->pwd_adir != NULL) 3980 vrele(pwd->pwd_adir); 3981 uma_zfree_smr(pwd_zone, pwd); 3982 } 3983 3984 /* 3985 * The caller is responsible for invoking priv_check() and 3986 * mac_vnode_check_chroot() to authorize this operation. 3987 */ 3988 int 3989 pwd_chroot(struct thread *td, struct vnode *vp) 3990 { 3991 struct pwddesc *pdp; 3992 struct filedesc *fdp; 3993 struct pwd *newpwd, *oldpwd; 3994 int error; 3995 3996 fdp = td->td_proc->p_fd; 3997 pdp = td->td_proc->p_pd; 3998 newpwd = pwd_alloc(); 3999 FILEDESC_SLOCK(fdp); 4000 PWDDESC_XLOCK(pdp); 4001 oldpwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); 4002 if (chroot_allow_open_directories == 0 || 4003 (chroot_allow_open_directories == 1 && 4004 oldpwd->pwd_rdir != rootvnode)) { 4005 error = chroot_refuse_vdir_fds(fdp); 4006 FILEDESC_SUNLOCK(fdp); 4007 if (error != 0) { 4008 PWDDESC_XUNLOCK(pdp); 4009 pwd_drop(newpwd); 4010 return (error); 4011 } 4012 } else { 4013 FILEDESC_SUNLOCK(fdp); 4014 } 4015 4016 vrefact(vp); 4017 newpwd->pwd_rdir = vp; 4018 vrefact(vp); 4019 newpwd->pwd_adir = vp; 4020 if (oldpwd->pwd_jdir == NULL) { 4021 vrefact(vp); 4022 newpwd->pwd_jdir = vp; 4023 } 4024 pwd_fill(oldpwd, newpwd); 4025 pwd_set(pdp, newpwd); 4026 PWDDESC_XUNLOCK(pdp); 4027 pwd_drop(oldpwd); 4028 return (0); 4029 } 4030 4031 void 4032 pwd_chdir(struct thread *td, struct vnode *vp) 4033 { 4034 struct pwddesc *pdp; 4035 struct pwd *newpwd, *oldpwd; 4036 4037 VNPASS(vp->v_usecount > 0, vp); 4038 4039 newpwd = pwd_alloc(); 4040 pdp = td->td_proc->p_pd; 4041 PWDDESC_XLOCK(pdp); 4042 oldpwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); 4043 newpwd->pwd_cdir = vp; 4044 pwd_fill(oldpwd, newpwd); 4045 pwd_set(pdp, newpwd); 4046 PWDDESC_XUNLOCK(pdp); 4047 pwd_drop(oldpwd); 4048 } 4049 4050 /* 4051 * Process is transitioning to/from a non-native ABI. 4052 */ 4053 void 4054 pwd_altroot(struct thread *td, struct vnode *altroot_vp) 4055 { 4056 struct pwddesc *pdp; 4057 struct pwd *newpwd, *oldpwd; 4058 4059 newpwd = pwd_alloc(); 4060 pdp = td->td_proc->p_pd; 4061 PWDDESC_XLOCK(pdp); 4062 oldpwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); 4063 if (altroot_vp != NULL) { 4064 /* 4065 * Native process to a non-native ABI. 4066 */ 4067 4068 vrefact(altroot_vp); 4069 newpwd->pwd_adir = altroot_vp; 4070 } else { 4071 /* 4072 * Non-native process to the native ABI. 4073 */ 4074 4075 vrefact(oldpwd->pwd_rdir); 4076 newpwd->pwd_adir = oldpwd->pwd_rdir; 4077 } 4078 pwd_fill(oldpwd, newpwd); 4079 pwd_set(pdp, newpwd); 4080 PWDDESC_XUNLOCK(pdp); 4081 pwd_drop(oldpwd); 4082 } 4083 4084 /* 4085 * jail_attach(2) changes both root and working directories. 4086 */ 4087 int 4088 pwd_chroot_chdir(struct thread *td, struct vnode *vp) 4089 { 4090 struct pwddesc *pdp; 4091 struct filedesc *fdp; 4092 struct pwd *newpwd, *oldpwd; 4093 int error; 4094 4095 fdp = td->td_proc->p_fd; 4096 pdp = td->td_proc->p_pd; 4097 newpwd = pwd_alloc(); 4098 FILEDESC_SLOCK(fdp); 4099 PWDDESC_XLOCK(pdp); 4100 oldpwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); 4101 error = chroot_refuse_vdir_fds(fdp); 4102 FILEDESC_SUNLOCK(fdp); 4103 if (error != 0) { 4104 PWDDESC_XUNLOCK(pdp); 4105 pwd_drop(newpwd); 4106 return (error); 4107 } 4108 4109 vrefact(vp); 4110 newpwd->pwd_rdir = vp; 4111 vrefact(vp); 4112 newpwd->pwd_cdir = vp; 4113 if (oldpwd->pwd_jdir == NULL) { 4114 vrefact(vp); 4115 newpwd->pwd_jdir = vp; 4116 } 4117 vrefact(vp); 4118 newpwd->pwd_adir = vp; 4119 pwd_fill(oldpwd, newpwd); 4120 pwd_set(pdp, newpwd); 4121 PWDDESC_XUNLOCK(pdp); 4122 pwd_drop(oldpwd); 4123 return (0); 4124 } 4125 4126 void 4127 pwd_ensure_dirs(void) 4128 { 4129 struct pwddesc *pdp; 4130 struct pwd *oldpwd, *newpwd; 4131 4132 pdp = curproc->p_pd; 4133 PWDDESC_XLOCK(pdp); 4134 oldpwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); 4135 if (oldpwd->pwd_cdir != NULL && oldpwd->pwd_rdir != NULL && 4136 oldpwd->pwd_adir != NULL) { 4137 PWDDESC_XUNLOCK(pdp); 4138 return; 4139 } 4140 PWDDESC_XUNLOCK(pdp); 4141 4142 newpwd = pwd_alloc(); 4143 PWDDESC_XLOCK(pdp); 4144 oldpwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); 4145 pwd_fill(oldpwd, newpwd); 4146 if (newpwd->pwd_cdir == NULL) { 4147 vrefact(rootvnode); 4148 newpwd->pwd_cdir = rootvnode; 4149 } 4150 if (newpwd->pwd_rdir == NULL) { 4151 vrefact(rootvnode); 4152 newpwd->pwd_rdir = rootvnode; 4153 } 4154 if (newpwd->pwd_adir == NULL) { 4155 vrefact(rootvnode); 4156 newpwd->pwd_adir = rootvnode; 4157 } 4158 pwd_set(pdp, newpwd); 4159 PWDDESC_XUNLOCK(pdp); 4160 pwd_drop(oldpwd); 4161 } 4162 4163 void 4164 pwd_set_rootvnode(void) 4165 { 4166 struct pwddesc *pdp; 4167 struct pwd *oldpwd, *newpwd; 4168 4169 pdp = curproc->p_pd; 4170 4171 newpwd = pwd_alloc(); 4172 PWDDESC_XLOCK(pdp); 4173 oldpwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); 4174 vrefact(rootvnode); 4175 newpwd->pwd_cdir = rootvnode; 4176 vrefact(rootvnode); 4177 newpwd->pwd_rdir = rootvnode; 4178 vrefact(rootvnode); 4179 newpwd->pwd_adir = rootvnode; 4180 pwd_fill(oldpwd, newpwd); 4181 pwd_set(pdp, newpwd); 4182 PWDDESC_XUNLOCK(pdp); 4183 pwd_drop(oldpwd); 4184 } 4185 4186 /* 4187 * Scan all active processes and prisons to see if any of them have a current 4188 * or root directory of `olddp'. If so, replace them with the new mount point. 4189 */ 4190 void 4191 mountcheckdirs(struct vnode *olddp, struct vnode *newdp) 4192 { 4193 struct pwddesc *pdp; 4194 struct pwd *newpwd, *oldpwd; 4195 struct prison *pr; 4196 struct proc *p; 4197 int nrele; 4198 4199 if (vrefcnt(olddp) == 1) 4200 return; 4201 nrele = 0; 4202 newpwd = pwd_alloc(); 4203 sx_slock(&allproc_lock); 4204 FOREACH_PROC_IN_SYSTEM(p) { 4205 PROC_LOCK(p); 4206 pdp = pdhold(p); 4207 PROC_UNLOCK(p); 4208 if (pdp == NULL) 4209 continue; 4210 PWDDESC_XLOCK(pdp); 4211 oldpwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); 4212 if (oldpwd == NULL || 4213 (oldpwd->pwd_cdir != olddp && 4214 oldpwd->pwd_rdir != olddp && 4215 oldpwd->pwd_jdir != olddp && 4216 oldpwd->pwd_adir != olddp)) { 4217 PWDDESC_XUNLOCK(pdp); 4218 pddrop(pdp); 4219 continue; 4220 } 4221 if (oldpwd->pwd_cdir == olddp) { 4222 vrefact(newdp); 4223 newpwd->pwd_cdir = newdp; 4224 } 4225 if (oldpwd->pwd_rdir == olddp) { 4226 vrefact(newdp); 4227 newpwd->pwd_rdir = newdp; 4228 } 4229 if (oldpwd->pwd_jdir == olddp) { 4230 vrefact(newdp); 4231 newpwd->pwd_jdir = newdp; 4232 } 4233 if (oldpwd->pwd_adir == olddp) { 4234 vrefact(newdp); 4235 newpwd->pwd_adir = newdp; 4236 } 4237 pwd_fill(oldpwd, newpwd); 4238 pwd_set(pdp, newpwd); 4239 PWDDESC_XUNLOCK(pdp); 4240 pwd_drop(oldpwd); 4241 pddrop(pdp); 4242 newpwd = pwd_alloc(); 4243 } 4244 sx_sunlock(&allproc_lock); 4245 pwd_drop(newpwd); 4246 if (rootvnode == olddp) { 4247 vrefact(newdp); 4248 rootvnode = newdp; 4249 nrele++; 4250 } 4251 mtx_lock(&prison0.pr_mtx); 4252 if (prison0.pr_root == olddp) { 4253 vrefact(newdp); 4254 prison0.pr_root = newdp; 4255 nrele++; 4256 } 4257 mtx_unlock(&prison0.pr_mtx); 4258 sx_slock(&allprison_lock); 4259 TAILQ_FOREACH(pr, &allprison, pr_list) { 4260 mtx_lock(&pr->pr_mtx); 4261 if (pr->pr_root == olddp) { 4262 vrefact(newdp); 4263 pr->pr_root = newdp; 4264 nrele++; 4265 } 4266 mtx_unlock(&pr->pr_mtx); 4267 } 4268 sx_sunlock(&allprison_lock); 4269 while (nrele--) 4270 vrele(olddp); 4271 } 4272 4273 int 4274 descrip_check_write_mp(struct filedesc *fdp, struct mount *mp) 4275 { 4276 struct file *fp; 4277 struct vnode *vp; 4278 int error, i; 4279 4280 error = 0; 4281 FILEDESC_SLOCK(fdp); 4282 FILEDESC_FOREACH_FP(fdp, i, fp) { 4283 if (fp->f_type != DTYPE_VNODE || 4284 (atomic_load_int(&fp->f_flag) & FWRITE) == 0) 4285 continue; 4286 vp = fp->f_vnode; 4287 if (vp->v_mount == mp) { 4288 error = EDEADLK; 4289 break; 4290 } 4291 } 4292 FILEDESC_SUNLOCK(fdp); 4293 return (error); 4294 } 4295 4296 struct filedesc_to_leader * 4297 filedesc_to_leader_alloc(struct filedesc_to_leader *old, struct filedesc *fdp, 4298 struct proc *leader) 4299 { 4300 struct filedesc_to_leader *fdtol; 4301 4302 fdtol = malloc(sizeof(struct filedesc_to_leader), 4303 M_FILEDESC_TO_LEADER, M_WAITOK); 4304 fdtol->fdl_refcount = 1; 4305 fdtol->fdl_holdcount = 0; 4306 fdtol->fdl_wakeup = 0; 4307 fdtol->fdl_leader = leader; 4308 if (old != NULL) { 4309 FILEDESC_XLOCK(fdp); 4310 fdtol->fdl_next = old->fdl_next; 4311 fdtol->fdl_prev = old; 4312 old->fdl_next = fdtol; 4313 fdtol->fdl_next->fdl_prev = fdtol; 4314 FILEDESC_XUNLOCK(fdp); 4315 } else { 4316 fdtol->fdl_next = fdtol; 4317 fdtol->fdl_prev = fdtol; 4318 } 4319 return (fdtol); 4320 } 4321 4322 struct filedesc_to_leader * 4323 filedesc_to_leader_share(struct filedesc_to_leader *fdtol, struct filedesc *fdp) 4324 { 4325 FILEDESC_XLOCK(fdp); 4326 fdtol->fdl_refcount++; 4327 FILEDESC_XUNLOCK(fdp); 4328 return (fdtol); 4329 } 4330 4331 static int 4332 sysctl_kern_proc_nfds(SYSCTL_HANDLER_ARGS) 4333 { 4334 NDSLOTTYPE *map; 4335 struct filedesc *fdp; 4336 u_int namelen; 4337 int count, off, minoff; 4338 4339 namelen = arg2; 4340 if (namelen != 1) 4341 return (EINVAL); 4342 4343 if (*(int *)arg1 != 0) 4344 return (EINVAL); 4345 4346 fdp = curproc->p_fd; 4347 count = 0; 4348 FILEDESC_SLOCK(fdp); 4349 map = fdp->fd_map; 4350 off = NDSLOT(fdp->fd_nfiles - 1); 4351 for (minoff = NDSLOT(0); off >= minoff; --off) 4352 count += bitcountl(map[off]); 4353 FILEDESC_SUNLOCK(fdp); 4354 4355 return (SYSCTL_OUT(req, &count, sizeof(count))); 4356 } 4357 4358 static SYSCTL_NODE(_kern_proc, KERN_PROC_NFDS, nfds, 4359 CTLFLAG_RD|CTLFLAG_CAPRD|CTLFLAG_MPSAFE, sysctl_kern_proc_nfds, 4360 "Number of open file descriptors"); 4361 4362 /* 4363 * Get file structures globally. 4364 */ 4365 static int 4366 sysctl_kern_file(SYSCTL_HANDLER_ARGS) 4367 { 4368 struct xfile xf; 4369 struct filedesc *fdp; 4370 struct file *fp; 4371 struct proc *p; 4372 int error, n; 4373 4374 error = sysctl_wire_old_buffer(req, 0); 4375 if (error != 0) 4376 return (error); 4377 if (req->oldptr == NULL) { 4378 n = 0; 4379 sx_slock(&allproc_lock); 4380 FOREACH_PROC_IN_SYSTEM(p) { 4381 PROC_LOCK(p); 4382 if (p->p_state == PRS_NEW) { 4383 PROC_UNLOCK(p); 4384 continue; 4385 } 4386 fdp = fdhold(p); 4387 PROC_UNLOCK(p); 4388 if (fdp == NULL) 4389 continue; 4390 /* overestimates sparse tables. */ 4391 n += fdp->fd_nfiles; 4392 fddrop(fdp); 4393 } 4394 sx_sunlock(&allproc_lock); 4395 return (SYSCTL_OUT(req, 0, n * sizeof(xf))); 4396 } 4397 error = 0; 4398 bzero(&xf, sizeof(xf)); 4399 xf.xf_size = sizeof(xf); 4400 sx_slock(&allproc_lock); 4401 FOREACH_PROC_IN_SYSTEM(p) { 4402 PROC_LOCK(p); 4403 if (p->p_state == PRS_NEW) { 4404 PROC_UNLOCK(p); 4405 continue; 4406 } 4407 if (p_cansee(req->td, p) != 0) { 4408 PROC_UNLOCK(p); 4409 continue; 4410 } 4411 xf.xf_pid = p->p_pid; 4412 xf.xf_uid = p->p_ucred->cr_uid; 4413 fdp = fdhold(p); 4414 PROC_UNLOCK(p); 4415 if (fdp == NULL) 4416 continue; 4417 FILEDESC_SLOCK(fdp); 4418 if (refcount_load(&fdp->fd_refcnt) == 0) 4419 goto nextproc; 4420 FILEDESC_FOREACH_FP(fdp, n, fp) { 4421 xf.xf_fd = n; 4422 xf.xf_file = (uintptr_t)fp; 4423 xf.xf_data = (uintptr_t)fp->f_data; 4424 xf.xf_vnode = (uintptr_t)fp->f_vnode; 4425 xf.xf_type = (uintptr_t)fp->f_type; 4426 xf.xf_count = refcount_load(&fp->f_count); 4427 xf.xf_msgcount = 0; 4428 xf.xf_offset = foffset_get(fp); 4429 xf.xf_flag = fp->f_flag; 4430 error = SYSCTL_OUT(req, &xf, sizeof(xf)); 4431 4432 /* 4433 * There is no need to re-check the fdtable refcount 4434 * here since the filedesc lock is not dropped in the 4435 * loop body. 4436 */ 4437 if (error != 0) 4438 break; 4439 } 4440 nextproc: 4441 FILEDESC_SUNLOCK(fdp); 4442 fddrop(fdp); 4443 if (error) 4444 break; 4445 } 4446 sx_sunlock(&allproc_lock); 4447 return (error); 4448 } 4449 4450 SYSCTL_PROC(_kern, KERN_FILE, file, CTLTYPE_OPAQUE|CTLFLAG_RD|CTLFLAG_MPSAFE, 4451 0, 0, sysctl_kern_file, "S,xfile", "Entire file table"); 4452 4453 #ifdef KINFO_FILE_SIZE 4454 CTASSERT(sizeof(struct kinfo_file) == KINFO_FILE_SIZE); 4455 #endif 4456 4457 static int 4458 xlate_fflags(int fflags) 4459 { 4460 static const struct { 4461 int fflag; 4462 int kf_fflag; 4463 } fflags_table[] = { 4464 { FAPPEND, KF_FLAG_APPEND }, 4465 { FASYNC, KF_FLAG_ASYNC }, 4466 { FFSYNC, KF_FLAG_FSYNC }, 4467 { FHASLOCK, KF_FLAG_HASLOCK }, 4468 { FNONBLOCK, KF_FLAG_NONBLOCK }, 4469 { FREAD, KF_FLAG_READ }, 4470 { FWRITE, KF_FLAG_WRITE }, 4471 { O_CREAT, KF_FLAG_CREAT }, 4472 { O_DIRECT, KF_FLAG_DIRECT }, 4473 { O_EXCL, KF_FLAG_EXCL }, 4474 { O_EXEC, KF_FLAG_EXEC }, 4475 { O_EXLOCK, KF_FLAG_EXLOCK }, 4476 { O_NOFOLLOW, KF_FLAG_NOFOLLOW }, 4477 { O_SHLOCK, KF_FLAG_SHLOCK }, 4478 { O_TRUNC, KF_FLAG_TRUNC } 4479 }; 4480 unsigned int i; 4481 int kflags; 4482 4483 kflags = 0; 4484 for (i = 0; i < nitems(fflags_table); i++) 4485 if (fflags & fflags_table[i].fflag) 4486 kflags |= fflags_table[i].kf_fflag; 4487 return (kflags); 4488 } 4489 4490 /* Trim unused data from kf_path by truncating the structure size. */ 4491 void 4492 pack_kinfo(struct kinfo_file *kif) 4493 { 4494 4495 kif->kf_structsize = offsetof(struct kinfo_file, kf_path) + 4496 strlen(kif->kf_path) + 1; 4497 kif->kf_structsize = roundup(kif->kf_structsize, sizeof(uint64_t)); 4498 } 4499 4500 static void 4501 export_file_to_kinfo(struct file *fp, int fd, cap_rights_t *rightsp, 4502 struct kinfo_file *kif, struct filedesc *fdp, int flags) 4503 { 4504 int error; 4505 4506 bzero(kif, sizeof(*kif)); 4507 4508 /* Set a default type to allow for empty fill_kinfo() methods. */ 4509 kif->kf_type = KF_TYPE_UNKNOWN; 4510 kif->kf_flags = xlate_fflags(fp->f_flag); 4511 if (rightsp != NULL) 4512 kif->kf_cap_rights = *rightsp; 4513 else 4514 cap_rights_init_zero(&kif->kf_cap_rights); 4515 kif->kf_fd = fd; 4516 kif->kf_ref_count = refcount_load(&fp->f_count); 4517 kif->kf_offset = foffset_get(fp); 4518 4519 /* 4520 * This may drop the filedesc lock, so the 'fp' cannot be 4521 * accessed after this call. 4522 */ 4523 error = fo_fill_kinfo(fp, kif, fdp); 4524 if (error == 0) 4525 kif->kf_status |= KF_ATTR_VALID; 4526 if ((flags & KERN_FILEDESC_PACK_KINFO) != 0) 4527 pack_kinfo(kif); 4528 else 4529 kif->kf_structsize = roundup2(sizeof(*kif), sizeof(uint64_t)); 4530 } 4531 4532 static void 4533 export_vnode_to_kinfo(struct vnode *vp, int fd, int fflags, 4534 struct kinfo_file *kif, int flags) 4535 { 4536 int error; 4537 4538 bzero(kif, sizeof(*kif)); 4539 4540 kif->kf_type = KF_TYPE_VNODE; 4541 error = vn_fill_kinfo_vnode(vp, kif); 4542 if (error == 0) 4543 kif->kf_status |= KF_ATTR_VALID; 4544 kif->kf_flags = xlate_fflags(fflags); 4545 cap_rights_init_zero(&kif->kf_cap_rights); 4546 kif->kf_fd = fd; 4547 kif->kf_ref_count = -1; 4548 kif->kf_offset = -1; 4549 if ((flags & KERN_FILEDESC_PACK_KINFO) != 0) 4550 pack_kinfo(kif); 4551 else 4552 kif->kf_structsize = roundup2(sizeof(*kif), sizeof(uint64_t)); 4553 vrele(vp); 4554 } 4555 4556 struct export_fd_buf { 4557 struct filedesc *fdp; 4558 struct pwddesc *pdp; 4559 struct sbuf *sb; 4560 ssize_t remainder; 4561 struct kinfo_file kif; 4562 int flags; 4563 }; 4564 4565 static int 4566 export_kinfo_to_sb(struct export_fd_buf *efbuf) 4567 { 4568 struct kinfo_file *kif; 4569 4570 kif = &efbuf->kif; 4571 if (efbuf->remainder != -1) { 4572 if (efbuf->remainder < kif->kf_structsize) 4573 return (ENOMEM); 4574 efbuf->remainder -= kif->kf_structsize; 4575 } 4576 if (sbuf_bcat(efbuf->sb, kif, kif->kf_structsize) != 0) 4577 return (sbuf_error(efbuf->sb)); 4578 return (0); 4579 } 4580 4581 static int 4582 export_file_to_sb(struct file *fp, int fd, cap_rights_t *rightsp, 4583 struct export_fd_buf *efbuf) 4584 { 4585 int error; 4586 4587 if (efbuf->remainder == 0) 4588 return (ENOMEM); 4589 export_file_to_kinfo(fp, fd, rightsp, &efbuf->kif, efbuf->fdp, 4590 efbuf->flags); 4591 FILEDESC_SUNLOCK(efbuf->fdp); 4592 error = export_kinfo_to_sb(efbuf); 4593 FILEDESC_SLOCK(efbuf->fdp); 4594 return (error); 4595 } 4596 4597 static int 4598 export_vnode_to_sb(struct vnode *vp, int fd, int fflags, 4599 struct export_fd_buf *efbuf) 4600 { 4601 int error; 4602 4603 if (efbuf->remainder == 0) 4604 return (ENOMEM); 4605 if (efbuf->pdp != NULL) 4606 PWDDESC_XUNLOCK(efbuf->pdp); 4607 export_vnode_to_kinfo(vp, fd, fflags, &efbuf->kif, efbuf->flags); 4608 error = export_kinfo_to_sb(efbuf); 4609 if (efbuf->pdp != NULL) 4610 PWDDESC_XLOCK(efbuf->pdp); 4611 return (error); 4612 } 4613 4614 /* 4615 * Store a process file descriptor information to sbuf. 4616 * 4617 * Takes a locked proc as argument, and returns with the proc unlocked. 4618 */ 4619 int 4620 kern_proc_filedesc_out(struct proc *p, struct sbuf *sb, ssize_t maxlen, 4621 int flags) 4622 { 4623 struct file *fp; 4624 struct filedesc *fdp; 4625 struct pwddesc *pdp; 4626 struct export_fd_buf *efbuf; 4627 struct vnode *cttyvp, *textvp, *tracevp; 4628 struct pwd *pwd; 4629 int error, i; 4630 cap_rights_t rights; 4631 4632 PROC_LOCK_ASSERT(p, MA_OWNED); 4633 4634 /* ktrace vnode */ 4635 tracevp = ktr_get_tracevp(p, true); 4636 /* text vnode */ 4637 textvp = p->p_textvp; 4638 if (textvp != NULL) 4639 vrefact(textvp); 4640 /* Controlling tty. */ 4641 cttyvp = NULL; 4642 if (p->p_pgrp != NULL && p->p_pgrp->pg_session != NULL) { 4643 cttyvp = p->p_pgrp->pg_session->s_ttyvp; 4644 if (cttyvp != NULL) 4645 vrefact(cttyvp); 4646 } 4647 fdp = fdhold(p); 4648 pdp = pdhold(p); 4649 PROC_UNLOCK(p); 4650 4651 efbuf = malloc(sizeof(*efbuf), M_TEMP, M_WAITOK); 4652 efbuf->fdp = NULL; 4653 efbuf->pdp = NULL; 4654 efbuf->sb = sb; 4655 efbuf->remainder = maxlen; 4656 efbuf->flags = flags; 4657 4658 error = 0; 4659 if (tracevp != NULL) 4660 error = export_vnode_to_sb(tracevp, KF_FD_TYPE_TRACE, 4661 FREAD | FWRITE, efbuf); 4662 if (error == 0 && textvp != NULL) 4663 error = export_vnode_to_sb(textvp, KF_FD_TYPE_TEXT, FREAD, 4664 efbuf); 4665 if (error == 0 && cttyvp != NULL) 4666 error = export_vnode_to_sb(cttyvp, KF_FD_TYPE_CTTY, 4667 FREAD | FWRITE, efbuf); 4668 if (error != 0 || pdp == NULL || fdp == NULL) 4669 goto fail; 4670 efbuf->fdp = fdp; 4671 efbuf->pdp = pdp; 4672 PWDDESC_XLOCK(pdp); 4673 pwd = pwd_hold_pwddesc(pdp); 4674 if (pwd != NULL) { 4675 /* working directory */ 4676 if (pwd->pwd_cdir != NULL) { 4677 vrefact(pwd->pwd_cdir); 4678 error = export_vnode_to_sb(pwd->pwd_cdir, 4679 KF_FD_TYPE_CWD, FREAD, efbuf); 4680 } 4681 /* root directory */ 4682 if (error == 0 && pwd->pwd_rdir != NULL) { 4683 vrefact(pwd->pwd_rdir); 4684 error = export_vnode_to_sb(pwd->pwd_rdir, 4685 KF_FD_TYPE_ROOT, FREAD, efbuf); 4686 } 4687 /* jail directory */ 4688 if (error == 0 && pwd->pwd_jdir != NULL) { 4689 vrefact(pwd->pwd_jdir); 4690 error = export_vnode_to_sb(pwd->pwd_jdir, 4691 KF_FD_TYPE_JAIL, FREAD, efbuf); 4692 } 4693 } 4694 PWDDESC_XUNLOCK(pdp); 4695 if (error != 0) 4696 goto fail; 4697 if (pwd != NULL) 4698 pwd_drop(pwd); 4699 FILEDESC_SLOCK(fdp); 4700 if (refcount_load(&fdp->fd_refcnt) == 0) 4701 goto skip; 4702 FILEDESC_FOREACH_FP(fdp, i, fp) { 4703 #ifdef CAPABILITIES 4704 rights = *cap_rights(fdp, i); 4705 #else /* !CAPABILITIES */ 4706 rights = cap_no_rights; 4707 #endif 4708 /* 4709 * Create sysctl entry. It is OK to drop the filedesc 4710 * lock inside of export_file_to_sb() as we will 4711 * re-validate and re-evaluate its properties when the 4712 * loop continues. 4713 */ 4714 error = export_file_to_sb(fp, i, &rights, efbuf); 4715 if (error != 0 || refcount_load(&fdp->fd_refcnt) == 0) 4716 break; 4717 } 4718 skip: 4719 FILEDESC_SUNLOCK(fdp); 4720 fail: 4721 if (fdp != NULL) 4722 fddrop(fdp); 4723 if (pdp != NULL) 4724 pddrop(pdp); 4725 free(efbuf, M_TEMP); 4726 return (error); 4727 } 4728 4729 #define FILEDESC_SBUF_SIZE (sizeof(struct kinfo_file) * 5) 4730 4731 /* 4732 * Get per-process file descriptors for use by procstat(1), et al. 4733 */ 4734 static int 4735 sysctl_kern_proc_filedesc(SYSCTL_HANDLER_ARGS) 4736 { 4737 struct sbuf sb; 4738 struct proc *p; 4739 ssize_t maxlen; 4740 u_int namelen; 4741 int error, error2, *name; 4742 4743 namelen = arg2; 4744 if (namelen != 1) 4745 return (EINVAL); 4746 4747 name = (int *)arg1; 4748 4749 sbuf_new_for_sysctl(&sb, NULL, FILEDESC_SBUF_SIZE, req); 4750 sbuf_clear_flags(&sb, SBUF_INCLUDENUL); 4751 error = pget((pid_t)name[0], PGET_CANDEBUG | PGET_NOTWEXIT, &p); 4752 if (error != 0) { 4753 sbuf_delete(&sb); 4754 return (error); 4755 } 4756 maxlen = req->oldptr != NULL ? req->oldlen : -1; 4757 error = kern_proc_filedesc_out(p, &sb, maxlen, 4758 KERN_FILEDESC_PACK_KINFO); 4759 error2 = sbuf_finish(&sb); 4760 sbuf_delete(&sb); 4761 return (error != 0 ? error : error2); 4762 } 4763 4764 #ifdef COMPAT_FREEBSD7 4765 #ifdef KINFO_OFILE_SIZE 4766 CTASSERT(sizeof(struct kinfo_ofile) == KINFO_OFILE_SIZE); 4767 #endif 4768 4769 static void 4770 kinfo_to_okinfo(struct kinfo_file *kif, struct kinfo_ofile *okif) 4771 { 4772 4773 okif->kf_structsize = sizeof(*okif); 4774 okif->kf_type = kif->kf_type; 4775 okif->kf_fd = kif->kf_fd; 4776 okif->kf_ref_count = kif->kf_ref_count; 4777 okif->kf_flags = kif->kf_flags & (KF_FLAG_READ | KF_FLAG_WRITE | 4778 KF_FLAG_APPEND | KF_FLAG_ASYNC | KF_FLAG_FSYNC | KF_FLAG_NONBLOCK | 4779 KF_FLAG_DIRECT | KF_FLAG_HASLOCK); 4780 okif->kf_offset = kif->kf_offset; 4781 if (kif->kf_type == KF_TYPE_VNODE) 4782 okif->kf_vnode_type = kif->kf_un.kf_file.kf_file_type; 4783 else 4784 okif->kf_vnode_type = KF_VTYPE_VNON; 4785 strlcpy(okif->kf_path, kif->kf_path, sizeof(okif->kf_path)); 4786 if (kif->kf_type == KF_TYPE_SOCKET) { 4787 okif->kf_sock_domain = kif->kf_un.kf_sock.kf_sock_domain0; 4788 okif->kf_sock_type = kif->kf_un.kf_sock.kf_sock_type0; 4789 okif->kf_sock_protocol = kif->kf_un.kf_sock.kf_sock_protocol0; 4790 okif->kf_sa_local = kif->kf_un.kf_sock.kf_sa_local; 4791 okif->kf_sa_peer = kif->kf_un.kf_sock.kf_sa_peer; 4792 } else { 4793 okif->kf_sa_local.ss_family = AF_UNSPEC; 4794 okif->kf_sa_peer.ss_family = AF_UNSPEC; 4795 } 4796 } 4797 4798 static int 4799 export_vnode_for_osysctl(struct vnode *vp, int type, struct kinfo_file *kif, 4800 struct kinfo_ofile *okif, struct pwddesc *pdp, struct sysctl_req *req) 4801 { 4802 int error; 4803 4804 vrefact(vp); 4805 PWDDESC_XUNLOCK(pdp); 4806 export_vnode_to_kinfo(vp, type, 0, kif, KERN_FILEDESC_PACK_KINFO); 4807 kinfo_to_okinfo(kif, okif); 4808 error = SYSCTL_OUT(req, okif, sizeof(*okif)); 4809 PWDDESC_XLOCK(pdp); 4810 return (error); 4811 } 4812 4813 /* 4814 * Get per-process file descriptors for use by procstat(1), et al. 4815 */ 4816 static int 4817 sysctl_kern_proc_ofiledesc(SYSCTL_HANDLER_ARGS) 4818 { 4819 struct kinfo_ofile *okif; 4820 struct kinfo_file *kif; 4821 struct filedesc *fdp; 4822 struct pwddesc *pdp; 4823 struct pwd *pwd; 4824 u_int namelen; 4825 int error, i, *name; 4826 struct file *fp; 4827 struct proc *p; 4828 4829 namelen = arg2; 4830 if (namelen != 1) 4831 return (EINVAL); 4832 4833 name = (int *)arg1; 4834 error = pget((pid_t)name[0], PGET_CANDEBUG | PGET_NOTWEXIT, &p); 4835 if (error != 0) 4836 return (error); 4837 fdp = fdhold(p); 4838 if (fdp != NULL) 4839 pdp = pdhold(p); 4840 PROC_UNLOCK(p); 4841 if (fdp == NULL || pdp == NULL) { 4842 if (fdp != NULL) 4843 fddrop(fdp); 4844 return (ENOENT); 4845 } 4846 kif = malloc(sizeof(*kif), M_TEMP, M_WAITOK); 4847 okif = malloc(sizeof(*okif), M_TEMP, M_WAITOK); 4848 PWDDESC_XLOCK(pdp); 4849 pwd = pwd_hold_pwddesc(pdp); 4850 if (pwd != NULL) { 4851 if (pwd->pwd_cdir != NULL) 4852 export_vnode_for_osysctl(pwd->pwd_cdir, KF_FD_TYPE_CWD, kif, 4853 okif, pdp, req); 4854 if (pwd->pwd_rdir != NULL) 4855 export_vnode_for_osysctl(pwd->pwd_rdir, KF_FD_TYPE_ROOT, kif, 4856 okif, pdp, req); 4857 if (pwd->pwd_jdir != NULL) 4858 export_vnode_for_osysctl(pwd->pwd_jdir, KF_FD_TYPE_JAIL, kif, 4859 okif, pdp, req); 4860 } 4861 PWDDESC_XUNLOCK(pdp); 4862 if (pwd != NULL) 4863 pwd_drop(pwd); 4864 FILEDESC_SLOCK(fdp); 4865 if (refcount_load(&fdp->fd_refcnt) == 0) 4866 goto skip; 4867 FILEDESC_FOREACH_FP(fdp, i, fp) { 4868 export_file_to_kinfo(fp, i, NULL, kif, fdp, 4869 KERN_FILEDESC_PACK_KINFO); 4870 FILEDESC_SUNLOCK(fdp); 4871 kinfo_to_okinfo(kif, okif); 4872 error = SYSCTL_OUT(req, okif, sizeof(*okif)); 4873 FILEDESC_SLOCK(fdp); 4874 if (error != 0 || refcount_load(&fdp->fd_refcnt) == 0) 4875 break; 4876 } 4877 skip: 4878 FILEDESC_SUNLOCK(fdp); 4879 fddrop(fdp); 4880 pddrop(pdp); 4881 free(kif, M_TEMP); 4882 free(okif, M_TEMP); 4883 return (0); 4884 } 4885 4886 static SYSCTL_NODE(_kern_proc, KERN_PROC_OFILEDESC, ofiledesc, 4887 CTLFLAG_RD|CTLFLAG_MPSAFE, sysctl_kern_proc_ofiledesc, 4888 "Process ofiledesc entries"); 4889 #endif /* COMPAT_FREEBSD7 */ 4890 4891 int 4892 vntype_to_kinfo(int vtype) 4893 { 4894 struct { 4895 int vtype; 4896 int kf_vtype; 4897 } vtypes_table[] = { 4898 { VBAD, KF_VTYPE_VBAD }, 4899 { VBLK, KF_VTYPE_VBLK }, 4900 { VCHR, KF_VTYPE_VCHR }, 4901 { VDIR, KF_VTYPE_VDIR }, 4902 { VFIFO, KF_VTYPE_VFIFO }, 4903 { VLNK, KF_VTYPE_VLNK }, 4904 { VNON, KF_VTYPE_VNON }, 4905 { VREG, KF_VTYPE_VREG }, 4906 { VSOCK, KF_VTYPE_VSOCK } 4907 }; 4908 unsigned int i; 4909 4910 /* 4911 * Perform vtype translation. 4912 */ 4913 for (i = 0; i < nitems(vtypes_table); i++) 4914 if (vtypes_table[i].vtype == vtype) 4915 return (vtypes_table[i].kf_vtype); 4916 4917 return (KF_VTYPE_UNKNOWN); 4918 } 4919 4920 static SYSCTL_NODE(_kern_proc, KERN_PROC_FILEDESC, filedesc, 4921 CTLFLAG_RD|CTLFLAG_MPSAFE, sysctl_kern_proc_filedesc, 4922 "Process filedesc entries"); 4923 4924 /* 4925 * Store a process current working directory information to sbuf. 4926 * 4927 * Takes a locked proc as argument, and returns with the proc unlocked. 4928 */ 4929 int 4930 kern_proc_cwd_out(struct proc *p, struct sbuf *sb, ssize_t maxlen) 4931 { 4932 struct pwddesc *pdp; 4933 struct pwd *pwd; 4934 struct export_fd_buf *efbuf; 4935 struct vnode *cdir; 4936 int error; 4937 4938 PROC_LOCK_ASSERT(p, MA_OWNED); 4939 4940 pdp = pdhold(p); 4941 PROC_UNLOCK(p); 4942 if (pdp == NULL) 4943 return (EINVAL); 4944 4945 efbuf = malloc(sizeof(*efbuf), M_TEMP, M_WAITOK); 4946 efbuf->fdp = NULL; 4947 efbuf->pdp = pdp; 4948 efbuf->sb = sb; 4949 efbuf->remainder = maxlen; 4950 efbuf->flags = 0; 4951 4952 PWDDESC_XLOCK(pdp); 4953 pwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); 4954 cdir = pwd->pwd_cdir; 4955 if (cdir == NULL) { 4956 error = EINVAL; 4957 } else { 4958 vrefact(cdir); 4959 error = export_vnode_to_sb(cdir, KF_FD_TYPE_CWD, FREAD, efbuf); 4960 } 4961 PWDDESC_XUNLOCK(pdp); 4962 pddrop(pdp); 4963 free(efbuf, M_TEMP); 4964 return (error); 4965 } 4966 4967 /* 4968 * Get per-process current working directory. 4969 */ 4970 static int 4971 sysctl_kern_proc_cwd(SYSCTL_HANDLER_ARGS) 4972 { 4973 struct sbuf sb; 4974 struct proc *p; 4975 ssize_t maxlen; 4976 u_int namelen; 4977 int error, error2, *name; 4978 4979 namelen = arg2; 4980 if (namelen != 1) 4981 return (EINVAL); 4982 4983 name = (int *)arg1; 4984 4985 sbuf_new_for_sysctl(&sb, NULL, sizeof(struct kinfo_file), req); 4986 sbuf_clear_flags(&sb, SBUF_INCLUDENUL); 4987 error = pget((pid_t)name[0], PGET_CANDEBUG | PGET_NOTWEXIT, &p); 4988 if (error != 0) { 4989 sbuf_delete(&sb); 4990 return (error); 4991 } 4992 maxlen = req->oldptr != NULL ? req->oldlen : -1; 4993 error = kern_proc_cwd_out(p, &sb, maxlen); 4994 error2 = sbuf_finish(&sb); 4995 sbuf_delete(&sb); 4996 return (error != 0 ? error : error2); 4997 } 4998 4999 static SYSCTL_NODE(_kern_proc, KERN_PROC_CWD, cwd, CTLFLAG_RD|CTLFLAG_MPSAFE, 5000 sysctl_kern_proc_cwd, "Process current working directory"); 5001 5002 #ifdef DDB 5003 /* 5004 * For the purposes of debugging, generate a human-readable string for the 5005 * file type. 5006 */ 5007 static const char * 5008 file_type_to_name(short type) 5009 { 5010 5011 switch (type) { 5012 case 0: 5013 return ("zero"); 5014 case DTYPE_VNODE: 5015 return ("vnode"); 5016 case DTYPE_SOCKET: 5017 return ("socket"); 5018 case DTYPE_PIPE: 5019 return ("pipe"); 5020 case DTYPE_FIFO: 5021 return ("fifo"); 5022 case DTYPE_KQUEUE: 5023 return ("kqueue"); 5024 case DTYPE_CRYPTO: 5025 return ("crypto"); 5026 case DTYPE_MQUEUE: 5027 return ("mqueue"); 5028 case DTYPE_SHM: 5029 return ("shm"); 5030 case DTYPE_SEM: 5031 return ("ksem"); 5032 case DTYPE_PTS: 5033 return ("pts"); 5034 case DTYPE_DEV: 5035 return ("dev"); 5036 case DTYPE_PROCDESC: 5037 return ("proc"); 5038 case DTYPE_EVENTFD: 5039 return ("eventfd"); 5040 case DTYPE_TIMERFD: 5041 return ("timerfd"); 5042 default: 5043 return ("unkn"); 5044 } 5045 } 5046 5047 /* 5048 * For the purposes of debugging, identify a process (if any, perhaps one of 5049 * many) that references the passed file in its file descriptor array. Return 5050 * NULL if none. 5051 */ 5052 static struct proc * 5053 file_to_first_proc(struct file *fp) 5054 { 5055 struct filedesc *fdp; 5056 struct proc *p; 5057 int n; 5058 5059 FOREACH_PROC_IN_SYSTEM(p) { 5060 if (p->p_state == PRS_NEW) 5061 continue; 5062 fdp = p->p_fd; 5063 if (fdp == NULL) 5064 continue; 5065 for (n = 0; n < fdp->fd_nfiles; n++) { 5066 if (fp == fdp->fd_ofiles[n].fde_file) 5067 return (p); 5068 } 5069 } 5070 return (NULL); 5071 } 5072 5073 static void 5074 db_print_file(struct file *fp, int header) 5075 { 5076 #define XPTRWIDTH ((int)howmany(sizeof(void *) * NBBY, 4)) 5077 struct proc *p; 5078 5079 if (header) 5080 db_printf("%*s %6s %*s %8s %4s %5s %6s %*s %5s %s\n", 5081 XPTRWIDTH, "File", "Type", XPTRWIDTH, "Data", "Flag", 5082 "GCFl", "Count", "MCount", XPTRWIDTH, "Vnode", "FPID", 5083 "FCmd"); 5084 p = file_to_first_proc(fp); 5085 db_printf("%*p %6s %*p %08x %04x %5d %6d %*p %5d %s\n", XPTRWIDTH, 5086 fp, file_type_to_name(fp->f_type), XPTRWIDTH, fp->f_data, 5087 fp->f_flag, 0, refcount_load(&fp->f_count), 0, XPTRWIDTH, fp->f_vnode, 5088 p != NULL ? p->p_pid : -1, p != NULL ? p->p_comm : "-"); 5089 5090 #undef XPTRWIDTH 5091 } 5092 5093 DB_SHOW_COMMAND(file, db_show_file) 5094 { 5095 struct file *fp; 5096 5097 if (!have_addr) { 5098 db_printf("usage: show file <addr>\n"); 5099 return; 5100 } 5101 fp = (struct file *)addr; 5102 db_print_file(fp, 1); 5103 } 5104 5105 DB_SHOW_COMMAND_FLAGS(files, db_show_files, DB_CMD_MEMSAFE) 5106 { 5107 struct filedesc *fdp; 5108 struct file *fp; 5109 struct proc *p; 5110 int header; 5111 int n; 5112 5113 header = 1; 5114 FOREACH_PROC_IN_SYSTEM(p) { 5115 if (p->p_state == PRS_NEW) 5116 continue; 5117 if ((fdp = p->p_fd) == NULL) 5118 continue; 5119 for (n = 0; n < fdp->fd_nfiles; ++n) { 5120 if ((fp = fdp->fd_ofiles[n].fde_file) == NULL) 5121 continue; 5122 db_print_file(fp, header); 5123 header = 0; 5124 } 5125 } 5126 } 5127 #endif 5128 5129 SYSCTL_INT(_kern, KERN_MAXFILESPERPROC, maxfilesperproc, 5130 CTLFLAG_RWTUN | CTLFLAG_NOFETCH, 5131 &maxfilesperproc, 0, "Maximum files allowed open per process"); 5132 5133 SYSCTL_INT(_kern, KERN_MAXFILES, maxfiles, CTLFLAG_RWTUN | CTLFLAG_NOFETCH, 5134 &maxfiles, 0, "Maximum number of files"); 5135 5136 SYSCTL_INT(_kern, OID_AUTO, openfiles, CTLFLAG_RD, 5137 &openfiles, 0, "System-wide number of open files"); 5138 5139 /* ARGSUSED*/ 5140 static void 5141 filelistinit(void *dummy) 5142 { 5143 5144 file_zone = uma_zcreate("Files", sizeof(struct file), NULL, NULL, 5145 NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE); 5146 filedesc0_zone = uma_zcreate("filedesc0", sizeof(struct filedesc0), 5147 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0); 5148 pwd_zone = uma_zcreate("PWD", sizeof(struct pwd), NULL, NULL, 5149 NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_SMR); 5150 /* 5151 * XXXMJG this is a temporary hack due to boot ordering issues against 5152 * the vnode zone. 5153 */ 5154 vfs_smr = uma_zone_get_smr(pwd_zone); 5155 mtx_init(&sigio_lock, "sigio lock", NULL, MTX_DEF); 5156 } 5157 SYSINIT(select, SI_SUB_LOCK, SI_ORDER_FIRST, filelistinit, NULL); 5158 5159 /*-------------------------------------------------------------------*/ 5160 5161 static int 5162 badfo_readwrite(struct file *fp, struct uio *uio, struct ucred *active_cred, 5163 int flags, struct thread *td) 5164 { 5165 5166 return (EBADF); 5167 } 5168 5169 static int 5170 badfo_truncate(struct file *fp, off_t length, struct ucred *active_cred, 5171 struct thread *td) 5172 { 5173 5174 return (EINVAL); 5175 } 5176 5177 static int 5178 badfo_ioctl(struct file *fp, u_long com, void *data, struct ucred *active_cred, 5179 struct thread *td) 5180 { 5181 5182 return (EBADF); 5183 } 5184 5185 static int 5186 badfo_poll(struct file *fp, int events, struct ucred *active_cred, 5187 struct thread *td) 5188 { 5189 5190 return (0); 5191 } 5192 5193 static int 5194 badfo_kqfilter(struct file *fp, struct knote *kn) 5195 { 5196 5197 return (EBADF); 5198 } 5199 5200 static int 5201 badfo_stat(struct file *fp, struct stat *sb, struct ucred *active_cred) 5202 { 5203 5204 return (EBADF); 5205 } 5206 5207 static int 5208 badfo_close(struct file *fp, struct thread *td) 5209 { 5210 5211 return (0); 5212 } 5213 5214 static int 5215 badfo_chmod(struct file *fp, mode_t mode, struct ucred *active_cred, 5216 struct thread *td) 5217 { 5218 5219 return (EBADF); 5220 } 5221 5222 static int 5223 badfo_chown(struct file *fp, uid_t uid, gid_t gid, struct ucred *active_cred, 5224 struct thread *td) 5225 { 5226 5227 return (EBADF); 5228 } 5229 5230 static int 5231 badfo_sendfile(struct file *fp, int sockfd, struct uio *hdr_uio, 5232 struct uio *trl_uio, off_t offset, size_t nbytes, off_t *sent, int flags, 5233 struct thread *td) 5234 { 5235 5236 return (EBADF); 5237 } 5238 5239 static int 5240 badfo_fill_kinfo(struct file *fp, struct kinfo_file *kif, struct filedesc *fdp) 5241 { 5242 5243 return (0); 5244 } 5245 5246 struct fileops badfileops = { 5247 .fo_read = badfo_readwrite, 5248 .fo_write = badfo_readwrite, 5249 .fo_truncate = badfo_truncate, 5250 .fo_ioctl = badfo_ioctl, 5251 .fo_poll = badfo_poll, 5252 .fo_kqfilter = badfo_kqfilter, 5253 .fo_stat = badfo_stat, 5254 .fo_close = badfo_close, 5255 .fo_chmod = badfo_chmod, 5256 .fo_chown = badfo_chown, 5257 .fo_sendfile = badfo_sendfile, 5258 .fo_fill_kinfo = badfo_fill_kinfo, 5259 }; 5260 5261 static int 5262 path_poll(struct file *fp, int events, struct ucred *active_cred, 5263 struct thread *td) 5264 { 5265 return (POLLNVAL); 5266 } 5267 5268 static int 5269 path_close(struct file *fp, struct thread *td) 5270 { 5271 MPASS(fp->f_type == DTYPE_VNODE); 5272 fp->f_ops = &badfileops; 5273 vrele(fp->f_vnode); 5274 return (0); 5275 } 5276 5277 struct fileops path_fileops = { 5278 .fo_read = badfo_readwrite, 5279 .fo_write = badfo_readwrite, 5280 .fo_truncate = badfo_truncate, 5281 .fo_ioctl = badfo_ioctl, 5282 .fo_poll = path_poll, 5283 .fo_kqfilter = vn_kqfilter_opath, 5284 .fo_stat = vn_statfile, 5285 .fo_close = path_close, 5286 .fo_chmod = badfo_chmod, 5287 .fo_chown = badfo_chown, 5288 .fo_sendfile = badfo_sendfile, 5289 .fo_fill_kinfo = vn_fill_kinfo, 5290 .fo_cmp = vn_cmp, 5291 .fo_flags = DFLAG_PASSABLE, 5292 }; 5293 5294 int 5295 invfo_rdwr(struct file *fp, struct uio *uio, struct ucred *active_cred, 5296 int flags, struct thread *td) 5297 { 5298 5299 return (EOPNOTSUPP); 5300 } 5301 5302 int 5303 invfo_truncate(struct file *fp, off_t length, struct ucred *active_cred, 5304 struct thread *td) 5305 { 5306 5307 return (EINVAL); 5308 } 5309 5310 int 5311 invfo_ioctl(struct file *fp, u_long com, void *data, 5312 struct ucred *active_cred, struct thread *td) 5313 { 5314 5315 return (ENOTTY); 5316 } 5317 5318 int 5319 invfo_poll(struct file *fp, int events, struct ucred *active_cred, 5320 struct thread *td) 5321 { 5322 5323 return (poll_no_poll(events)); 5324 } 5325 5326 int 5327 invfo_kqfilter(struct file *fp, struct knote *kn) 5328 { 5329 5330 return (EINVAL); 5331 } 5332 5333 int 5334 invfo_chmod(struct file *fp, mode_t mode, struct ucred *active_cred, 5335 struct thread *td) 5336 { 5337 5338 return (EINVAL); 5339 } 5340 5341 int 5342 invfo_chown(struct file *fp, uid_t uid, gid_t gid, struct ucred *active_cred, 5343 struct thread *td) 5344 { 5345 5346 return (EINVAL); 5347 } 5348 5349 int 5350 invfo_sendfile(struct file *fp, int sockfd, struct uio *hdr_uio, 5351 struct uio *trl_uio, off_t offset, size_t nbytes, off_t *sent, int flags, 5352 struct thread *td) 5353 { 5354 5355 return (EINVAL); 5356 } 5357 5358 /*-------------------------------------------------------------------*/ 5359 5360 /* 5361 * File Descriptor pseudo-device driver (/dev/fd/). 5362 * 5363 * Opening minor device N dup()s the file (if any) connected to file 5364 * descriptor N belonging to the calling process. Note that this driver 5365 * consists of only the ``open()'' routine, because all subsequent 5366 * references to this file will be direct to the other driver. 5367 * 5368 * XXX: we could give this one a cloning event handler if necessary. 5369 */ 5370 5371 /* ARGSUSED */ 5372 static int 5373 fdopen(struct cdev *dev, int mode, int type, struct thread *td) 5374 { 5375 5376 /* 5377 * XXX Kludge: set curthread->td_dupfd to contain the value of the 5378 * the file descriptor being sought for duplication. The error 5379 * return ensures that the vnode for this device will be released 5380 * by vn_open. Open will detect this special error and take the 5381 * actions in dupfdopen below. Other callers of vn_open or VOP_OPEN 5382 * will simply report the error. 5383 */ 5384 td->td_dupfd = dev2unit(dev); 5385 return (ENODEV); 5386 } 5387 5388 static struct cdevsw fildesc_cdevsw = { 5389 .d_version = D_VERSION, 5390 .d_open = fdopen, 5391 .d_name = "FD", 5392 }; 5393 5394 static void 5395 fildesc_drvinit(void *unused) 5396 { 5397 struct cdev *dev; 5398 5399 dev = make_dev_credf(MAKEDEV_ETERNAL, &fildesc_cdevsw, 0, NULL, 5400 UID_ROOT, GID_WHEEL, 0666, "fd/0"); 5401 make_dev_alias(dev, "stdin"); 5402 dev = make_dev_credf(MAKEDEV_ETERNAL, &fildesc_cdevsw, 1, NULL, 5403 UID_ROOT, GID_WHEEL, 0666, "fd/1"); 5404 make_dev_alias(dev, "stdout"); 5405 dev = make_dev_credf(MAKEDEV_ETERNAL, &fildesc_cdevsw, 2, NULL, 5406 UID_ROOT, GID_WHEEL, 0666, "fd/2"); 5407 make_dev_alias(dev, "stderr"); 5408 } 5409 5410 SYSINIT(fildescdev, SI_SUB_DRIVERS, SI_ORDER_MIDDLE, fildesc_drvinit, NULL); 5411