1 /*- 2 * SPDX-License-Identifier: BSD-3-Clause 3 * 4 * Copyright (c) 1982, 1986, 1989, 1991, 1993 5 * The Regents of the University of California. All rights reserved. 6 * (c) UNIX System Laboratories, Inc. 7 * All or some portions of this file are derived from material licensed 8 * to the University of California by American Telephone and Telegraph 9 * Co. or Unix System Laboratories, Inc. and are reproduced herein with 10 * the permission of UNIX System Laboratories, Inc. 11 * 12 * Redistribution and use in source and binary forms, with or without 13 * modification, are permitted provided that the following conditions 14 * are met: 15 * 1. Redistributions of source code must retain the above copyright 16 * notice, this list of conditions and the following disclaimer. 17 * 2. Redistributions in binary form must reproduce the above copyright 18 * notice, this list of conditions and the following disclaimer in the 19 * documentation and/or other materials provided with the distribution. 20 * 3. Neither the name of the University nor the names of its contributors 21 * may be used to endorse or promote products derived from this software 22 * without specific prior written permission. 23 * 24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34 * SUCH DAMAGE. 35 * 36 * @(#)kern_descrip.c 8.6 (Berkeley) 4/19/94 37 */ 38 39 #include <sys/cdefs.h> 40 __FBSDID("$FreeBSD$"); 41 42 #include "opt_capsicum.h" 43 #include "opt_ddb.h" 44 #include "opt_ktrace.h" 45 46 #include <sys/param.h> 47 #include <sys/systm.h> 48 49 #include <sys/capsicum.h> 50 #include <sys/conf.h> 51 #include <sys/fcntl.h> 52 #include <sys/file.h> 53 #include <sys/filedesc.h> 54 #include <sys/filio.h> 55 #include <sys/jail.h> 56 #include <sys/kernel.h> 57 #include <sys/limits.h> 58 #include <sys/lock.h> 59 #include <sys/malloc.h> 60 #include <sys/mount.h> 61 #include <sys/mutex.h> 62 #include <sys/namei.h> 63 #include <sys/selinfo.h> 64 #include <sys/poll.h> 65 #include <sys/priv.h> 66 #include <sys/proc.h> 67 #include <sys/protosw.h> 68 #include <sys/racct.h> 69 #include <sys/resourcevar.h> 70 #include <sys/sbuf.h> 71 #include <sys/signalvar.h> 72 #include <sys/kdb.h> 73 #include <sys/smr.h> 74 #include <sys/stat.h> 75 #include <sys/sx.h> 76 #include <sys/syscallsubr.h> 77 #include <sys/sysctl.h> 78 #include <sys/sysproto.h> 79 #include <sys/unistd.h> 80 #include <sys/user.h> 81 #include <sys/vnode.h> 82 #include <sys/ktrace.h> 83 84 #include <net/vnet.h> 85 86 #include <security/audit/audit.h> 87 88 #include <vm/uma.h> 89 #include <vm/vm.h> 90 91 #include <ddb/ddb.h> 92 93 static MALLOC_DEFINE(M_FILEDESC, "filedesc", "Open file descriptor table"); 94 static MALLOC_DEFINE(M_PWD, "pwd", "Descriptor table vnodes"); 95 static MALLOC_DEFINE(M_PWDDESC, "pwddesc", "Pwd descriptors"); 96 static MALLOC_DEFINE(M_FILEDESC_TO_LEADER, "filedesc_to_leader", 97 "file desc to leader structures"); 98 static MALLOC_DEFINE(M_SIGIO, "sigio", "sigio structures"); 99 MALLOC_DEFINE(M_FILECAPS, "filecaps", "descriptor capabilities"); 100 101 MALLOC_DECLARE(M_FADVISE); 102 103 static __read_mostly uma_zone_t file_zone; 104 static __read_mostly uma_zone_t filedesc0_zone; 105 __read_mostly uma_zone_t pwd_zone; 106 VFS_SMR_DECLARE; 107 108 static int closefp(struct filedesc *fdp, int fd, struct file *fp, 109 struct thread *td, bool holdleaders, bool audit); 110 static void export_file_to_kinfo(struct file *fp, int fd, 111 cap_rights_t *rightsp, struct kinfo_file *kif, 112 struct filedesc *fdp, int flags); 113 static int fd_first_free(struct filedesc *fdp, int low, int size); 114 static void fdgrowtable(struct filedesc *fdp, int nfd); 115 static void fdgrowtable_exp(struct filedesc *fdp, int nfd); 116 static void fdunused(struct filedesc *fdp, int fd); 117 static void fdused(struct filedesc *fdp, int fd); 118 static int fget_unlocked_seq(struct thread *td, int fd, 119 cap_rights_t *needrightsp, struct file **fpp, seqc_t *seqp); 120 static int getmaxfd(struct thread *td); 121 static u_long *filecaps_copy_prep(const struct filecaps *src); 122 static void filecaps_copy_finish(const struct filecaps *src, 123 struct filecaps *dst, u_long *ioctls); 124 static u_long *filecaps_free_prep(struct filecaps *fcaps); 125 static void filecaps_free_finish(u_long *ioctls); 126 127 static struct pwd *pwd_alloc(void); 128 129 /* 130 * Each process has: 131 * 132 * - An array of open file descriptors (fd_ofiles) 133 * - An array of file flags (fd_ofileflags) 134 * - A bitmap recording which descriptors are in use (fd_map) 135 * 136 * A process starts out with NDFILE descriptors. The value of NDFILE has 137 * been selected based the historical limit of 20 open files, and an 138 * assumption that the majority of processes, especially short-lived 139 * processes like shells, will never need more. 140 * 141 * If this initial allocation is exhausted, a larger descriptor table and 142 * map are allocated dynamically, and the pointers in the process's struct 143 * filedesc are updated to point to those. This is repeated every time 144 * the process runs out of file descriptors (provided it hasn't hit its 145 * resource limit). 146 * 147 * Since threads may hold references to individual descriptor table 148 * entries, the tables are never freed. Instead, they are placed on a 149 * linked list and freed only when the struct filedesc is released. 150 */ 151 #define NDFILE 20 152 #define NDSLOTSIZE sizeof(NDSLOTTYPE) 153 #define NDENTRIES (NDSLOTSIZE * __CHAR_BIT) 154 #define NDSLOT(x) ((x) / NDENTRIES) 155 #define NDBIT(x) ((NDSLOTTYPE)1 << ((x) % NDENTRIES)) 156 #define NDSLOTS(x) (((x) + NDENTRIES - 1) / NDENTRIES) 157 158 #define FILEDESC_FOREACH_FDE(fdp, _iterator, _fde) \ 159 struct filedesc *_fdp = (fdp); \ 160 int _lastfile = fdlastfile_single(_fdp); \ 161 for (_iterator = 0; _iterator <= _lastfile; _iterator++) \ 162 if ((_fde = &_fdp->fd_ofiles[_iterator])->fde_file != NULL) 163 164 #define FILEDESC_FOREACH_FP(fdp, _iterator, _fp) \ 165 struct filedesc *_fdp = (fdp); \ 166 int _lastfile = fdlastfile_single(_fdp); \ 167 for (_iterator = 0; _iterator <= _lastfile; _iterator++) \ 168 if ((_fp = _fdp->fd_ofiles[_iterator].fde_file) != NULL) 169 170 /* 171 * SLIST entry used to keep track of ofiles which must be reclaimed when 172 * the process exits. 173 */ 174 struct freetable { 175 struct fdescenttbl *ft_table; 176 SLIST_ENTRY(freetable) ft_next; 177 }; 178 179 /* 180 * Initial allocation: a filedesc structure + the head of SLIST used to 181 * keep track of old ofiles + enough space for NDFILE descriptors. 182 */ 183 184 struct fdescenttbl0 { 185 int fdt_nfiles; 186 struct filedescent fdt_ofiles[NDFILE]; 187 }; 188 189 struct filedesc0 { 190 struct filedesc fd_fd; 191 SLIST_HEAD(, freetable) fd_free; 192 struct fdescenttbl0 fd_dfiles; 193 NDSLOTTYPE fd_dmap[NDSLOTS(NDFILE)]; 194 }; 195 196 /* 197 * Descriptor management. 198 */ 199 static int __exclusive_cache_line openfiles; /* actual number of open files */ 200 struct mtx sigio_lock; /* mtx to protect pointers to sigio */ 201 void __read_mostly (*mq_fdclose)(struct thread *td, int fd, struct file *fp); 202 203 /* 204 * If low >= size, just return low. Otherwise find the first zero bit in the 205 * given bitmap, starting at low and not exceeding size - 1. Return size if 206 * not found. 207 */ 208 static int 209 fd_first_free(struct filedesc *fdp, int low, int size) 210 { 211 NDSLOTTYPE *map = fdp->fd_map; 212 NDSLOTTYPE mask; 213 int off, maxoff; 214 215 if (low >= size) 216 return (low); 217 218 off = NDSLOT(low); 219 if (low % NDENTRIES) { 220 mask = ~(~(NDSLOTTYPE)0 >> (NDENTRIES - (low % NDENTRIES))); 221 if ((mask &= ~map[off]) != 0UL) 222 return (off * NDENTRIES + ffsl(mask) - 1); 223 ++off; 224 } 225 for (maxoff = NDSLOTS(size); off < maxoff; ++off) 226 if (map[off] != ~0UL) 227 return (off * NDENTRIES + ffsl(~map[off]) - 1); 228 return (size); 229 } 230 231 /* 232 * Find the last used fd. 233 * 234 * Call this variant if fdp can't be modified by anyone else (e.g, during exec). 235 * Otherwise use fdlastfile. 236 */ 237 int 238 fdlastfile_single(struct filedesc *fdp) 239 { 240 NDSLOTTYPE *map = fdp->fd_map; 241 int off, minoff; 242 243 off = NDSLOT(fdp->fd_nfiles - 1); 244 for (minoff = NDSLOT(0); off >= minoff; --off) 245 if (map[off] != 0) 246 return (off * NDENTRIES + flsl(map[off]) - 1); 247 return (-1); 248 } 249 250 int 251 fdlastfile(struct filedesc *fdp) 252 { 253 254 FILEDESC_LOCK_ASSERT(fdp); 255 return (fdlastfile_single(fdp)); 256 } 257 258 static int 259 fdisused(struct filedesc *fdp, int fd) 260 { 261 262 KASSERT(fd >= 0 && fd < fdp->fd_nfiles, 263 ("file descriptor %d out of range (0, %d)", fd, fdp->fd_nfiles)); 264 265 return ((fdp->fd_map[NDSLOT(fd)] & NDBIT(fd)) != 0); 266 } 267 268 /* 269 * Mark a file descriptor as used. 270 */ 271 static void 272 fdused_init(struct filedesc *fdp, int fd) 273 { 274 275 KASSERT(!fdisused(fdp, fd), ("fd=%d is already used", fd)); 276 277 fdp->fd_map[NDSLOT(fd)] |= NDBIT(fd); 278 } 279 280 static void 281 fdused(struct filedesc *fdp, int fd) 282 { 283 284 FILEDESC_XLOCK_ASSERT(fdp); 285 286 fdused_init(fdp, fd); 287 if (fd == fdp->fd_freefile) 288 fdp->fd_freefile++; 289 } 290 291 /* 292 * Mark a file descriptor as unused. 293 */ 294 static void 295 fdunused(struct filedesc *fdp, int fd) 296 { 297 298 FILEDESC_XLOCK_ASSERT(fdp); 299 300 KASSERT(fdisused(fdp, fd), ("fd=%d is already unused", fd)); 301 KASSERT(fdp->fd_ofiles[fd].fde_file == NULL, 302 ("fd=%d is still in use", fd)); 303 304 fdp->fd_map[NDSLOT(fd)] &= ~NDBIT(fd); 305 if (fd < fdp->fd_freefile) 306 fdp->fd_freefile = fd; 307 } 308 309 /* 310 * Free a file descriptor. 311 * 312 * Avoid some work if fdp is about to be destroyed. 313 */ 314 static inline void 315 fdefree_last(struct filedescent *fde) 316 { 317 318 filecaps_free(&fde->fde_caps); 319 } 320 321 static inline void 322 fdfree(struct filedesc *fdp, int fd) 323 { 324 struct filedescent *fde; 325 326 FILEDESC_XLOCK_ASSERT(fdp); 327 fde = &fdp->fd_ofiles[fd]; 328 #ifdef CAPABILITIES 329 seqc_write_begin(&fde->fde_seqc); 330 #endif 331 fde->fde_file = NULL; 332 #ifdef CAPABILITIES 333 seqc_write_end(&fde->fde_seqc); 334 #endif 335 fdefree_last(fde); 336 fdunused(fdp, fd); 337 } 338 339 /* 340 * System calls on descriptors. 341 */ 342 #ifndef _SYS_SYSPROTO_H_ 343 struct getdtablesize_args { 344 int dummy; 345 }; 346 #endif 347 /* ARGSUSED */ 348 int 349 sys_getdtablesize(struct thread *td, struct getdtablesize_args *uap) 350 { 351 #ifdef RACCT 352 uint64_t lim; 353 #endif 354 355 td->td_retval[0] = getmaxfd(td); 356 #ifdef RACCT 357 PROC_LOCK(td->td_proc); 358 lim = racct_get_limit(td->td_proc, RACCT_NOFILE); 359 PROC_UNLOCK(td->td_proc); 360 if (lim < td->td_retval[0]) 361 td->td_retval[0] = lim; 362 #endif 363 return (0); 364 } 365 366 /* 367 * Duplicate a file descriptor to a particular value. 368 * 369 * Note: keep in mind that a potential race condition exists when closing 370 * descriptors from a shared descriptor table (via rfork). 371 */ 372 #ifndef _SYS_SYSPROTO_H_ 373 struct dup2_args { 374 u_int from; 375 u_int to; 376 }; 377 #endif 378 /* ARGSUSED */ 379 int 380 sys_dup2(struct thread *td, struct dup2_args *uap) 381 { 382 383 return (kern_dup(td, FDDUP_FIXED, 0, (int)uap->from, (int)uap->to)); 384 } 385 386 /* 387 * Duplicate a file descriptor. 388 */ 389 #ifndef _SYS_SYSPROTO_H_ 390 struct dup_args { 391 u_int fd; 392 }; 393 #endif 394 /* ARGSUSED */ 395 int 396 sys_dup(struct thread *td, struct dup_args *uap) 397 { 398 399 return (kern_dup(td, FDDUP_NORMAL, 0, (int)uap->fd, 0)); 400 } 401 402 /* 403 * The file control system call. 404 */ 405 #ifndef _SYS_SYSPROTO_H_ 406 struct fcntl_args { 407 int fd; 408 int cmd; 409 long arg; 410 }; 411 #endif 412 /* ARGSUSED */ 413 int 414 sys_fcntl(struct thread *td, struct fcntl_args *uap) 415 { 416 417 return (kern_fcntl_freebsd(td, uap->fd, uap->cmd, uap->arg)); 418 } 419 420 int 421 kern_fcntl_freebsd(struct thread *td, int fd, int cmd, long arg) 422 { 423 struct flock fl; 424 struct __oflock ofl; 425 intptr_t arg1; 426 int error, newcmd; 427 428 error = 0; 429 newcmd = cmd; 430 switch (cmd) { 431 case F_OGETLK: 432 case F_OSETLK: 433 case F_OSETLKW: 434 /* 435 * Convert old flock structure to new. 436 */ 437 error = copyin((void *)(intptr_t)arg, &ofl, sizeof(ofl)); 438 fl.l_start = ofl.l_start; 439 fl.l_len = ofl.l_len; 440 fl.l_pid = ofl.l_pid; 441 fl.l_type = ofl.l_type; 442 fl.l_whence = ofl.l_whence; 443 fl.l_sysid = 0; 444 445 switch (cmd) { 446 case F_OGETLK: 447 newcmd = F_GETLK; 448 break; 449 case F_OSETLK: 450 newcmd = F_SETLK; 451 break; 452 case F_OSETLKW: 453 newcmd = F_SETLKW; 454 break; 455 } 456 arg1 = (intptr_t)&fl; 457 break; 458 case F_GETLK: 459 case F_SETLK: 460 case F_SETLKW: 461 case F_SETLK_REMOTE: 462 error = copyin((void *)(intptr_t)arg, &fl, sizeof(fl)); 463 arg1 = (intptr_t)&fl; 464 break; 465 default: 466 arg1 = arg; 467 break; 468 } 469 if (error) 470 return (error); 471 error = kern_fcntl(td, fd, newcmd, arg1); 472 if (error) 473 return (error); 474 if (cmd == F_OGETLK) { 475 ofl.l_start = fl.l_start; 476 ofl.l_len = fl.l_len; 477 ofl.l_pid = fl.l_pid; 478 ofl.l_type = fl.l_type; 479 ofl.l_whence = fl.l_whence; 480 error = copyout(&ofl, (void *)(intptr_t)arg, sizeof(ofl)); 481 } else if (cmd == F_GETLK) { 482 error = copyout(&fl, (void *)(intptr_t)arg, sizeof(fl)); 483 } 484 return (error); 485 } 486 487 int 488 kern_fcntl(struct thread *td, int fd, int cmd, intptr_t arg) 489 { 490 struct filedesc *fdp; 491 struct flock *flp; 492 struct file *fp, *fp2; 493 struct filedescent *fde; 494 struct proc *p; 495 struct vnode *vp; 496 struct mount *mp; 497 struct kinfo_file *kif; 498 int error, flg, kif_sz, seals, tmp; 499 uint64_t bsize; 500 off_t foffset; 501 502 error = 0; 503 flg = F_POSIX; 504 p = td->td_proc; 505 fdp = p->p_fd; 506 507 AUDIT_ARG_FD(cmd); 508 AUDIT_ARG_CMD(cmd); 509 switch (cmd) { 510 case F_DUPFD: 511 tmp = arg; 512 error = kern_dup(td, FDDUP_FCNTL, 0, fd, tmp); 513 break; 514 515 case F_DUPFD_CLOEXEC: 516 tmp = arg; 517 error = kern_dup(td, FDDUP_FCNTL, FDDUP_FLAG_CLOEXEC, fd, tmp); 518 break; 519 520 case F_DUP2FD: 521 tmp = arg; 522 error = kern_dup(td, FDDUP_FIXED, 0, fd, tmp); 523 break; 524 525 case F_DUP2FD_CLOEXEC: 526 tmp = arg; 527 error = kern_dup(td, FDDUP_FIXED, FDDUP_FLAG_CLOEXEC, fd, tmp); 528 break; 529 530 case F_GETFD: 531 error = EBADF; 532 FILEDESC_SLOCK(fdp); 533 fde = fdeget_noref(fdp, fd); 534 if (fde != NULL) { 535 td->td_retval[0] = 536 (fde->fde_flags & UF_EXCLOSE) ? FD_CLOEXEC : 0; 537 error = 0; 538 } 539 FILEDESC_SUNLOCK(fdp); 540 break; 541 542 case F_SETFD: 543 error = EBADF; 544 FILEDESC_XLOCK(fdp); 545 fde = fdeget_noref(fdp, fd); 546 if (fde != NULL) { 547 fde->fde_flags = (fde->fde_flags & ~UF_EXCLOSE) | 548 (arg & FD_CLOEXEC ? UF_EXCLOSE : 0); 549 error = 0; 550 } 551 FILEDESC_XUNLOCK(fdp); 552 break; 553 554 case F_GETFL: 555 error = fget_fcntl(td, fd, &cap_fcntl_rights, F_GETFL, &fp); 556 if (error != 0) 557 break; 558 td->td_retval[0] = OFLAGS(fp->f_flag); 559 fdrop(fp, td); 560 break; 561 562 case F_SETFL: 563 error = fget_fcntl(td, fd, &cap_fcntl_rights, F_SETFL, &fp); 564 if (error != 0) 565 break; 566 if (fp->f_ops == &path_fileops) { 567 fdrop(fp, td); 568 error = EBADF; 569 break; 570 } 571 do { 572 tmp = flg = fp->f_flag; 573 tmp &= ~FCNTLFLAGS; 574 tmp |= FFLAGS(arg & ~O_ACCMODE) & FCNTLFLAGS; 575 } while (atomic_cmpset_int(&fp->f_flag, flg, tmp) == 0); 576 tmp = fp->f_flag & FNONBLOCK; 577 error = fo_ioctl(fp, FIONBIO, &tmp, td->td_ucred, td); 578 if (error != 0) { 579 fdrop(fp, td); 580 break; 581 } 582 tmp = fp->f_flag & FASYNC; 583 error = fo_ioctl(fp, FIOASYNC, &tmp, td->td_ucred, td); 584 if (error == 0) { 585 fdrop(fp, td); 586 break; 587 } 588 atomic_clear_int(&fp->f_flag, FNONBLOCK); 589 tmp = 0; 590 (void)fo_ioctl(fp, FIONBIO, &tmp, td->td_ucred, td); 591 fdrop(fp, td); 592 break; 593 594 case F_GETOWN: 595 error = fget_fcntl(td, fd, &cap_fcntl_rights, F_GETOWN, &fp); 596 if (error != 0) 597 break; 598 error = fo_ioctl(fp, FIOGETOWN, &tmp, td->td_ucred, td); 599 if (error == 0) 600 td->td_retval[0] = tmp; 601 fdrop(fp, td); 602 break; 603 604 case F_SETOWN: 605 error = fget_fcntl(td, fd, &cap_fcntl_rights, F_SETOWN, &fp); 606 if (error != 0) 607 break; 608 tmp = arg; 609 error = fo_ioctl(fp, FIOSETOWN, &tmp, td->td_ucred, td); 610 fdrop(fp, td); 611 break; 612 613 case F_SETLK_REMOTE: 614 error = priv_check(td, PRIV_NFS_LOCKD); 615 if (error != 0) 616 return (error); 617 flg = F_REMOTE; 618 goto do_setlk; 619 620 case F_SETLKW: 621 flg |= F_WAIT; 622 /* FALLTHROUGH F_SETLK */ 623 624 case F_SETLK: 625 do_setlk: 626 flp = (struct flock *)arg; 627 if ((flg & F_REMOTE) != 0 && flp->l_sysid == 0) { 628 error = EINVAL; 629 break; 630 } 631 632 error = fget_unlocked(td, fd, &cap_flock_rights, &fp); 633 if (error != 0) 634 break; 635 if (fp->f_type != DTYPE_VNODE || fp->f_ops == &path_fileops) { 636 error = EBADF; 637 fdrop(fp, td); 638 break; 639 } 640 641 if (flp->l_whence == SEEK_CUR) { 642 foffset = foffset_get(fp); 643 if (foffset < 0 || 644 (flp->l_start > 0 && 645 foffset > OFF_MAX - flp->l_start)) { 646 error = EOVERFLOW; 647 fdrop(fp, td); 648 break; 649 } 650 flp->l_start += foffset; 651 } 652 653 vp = fp->f_vnode; 654 switch (flp->l_type) { 655 case F_RDLCK: 656 if ((fp->f_flag & FREAD) == 0) { 657 error = EBADF; 658 break; 659 } 660 if ((p->p_leader->p_flag & P_ADVLOCK) == 0) { 661 PROC_LOCK(p->p_leader); 662 p->p_leader->p_flag |= P_ADVLOCK; 663 PROC_UNLOCK(p->p_leader); 664 } 665 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_SETLK, 666 flp, flg); 667 break; 668 case F_WRLCK: 669 if ((fp->f_flag & FWRITE) == 0) { 670 error = EBADF; 671 break; 672 } 673 if ((p->p_leader->p_flag & P_ADVLOCK) == 0) { 674 PROC_LOCK(p->p_leader); 675 p->p_leader->p_flag |= P_ADVLOCK; 676 PROC_UNLOCK(p->p_leader); 677 } 678 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_SETLK, 679 flp, flg); 680 break; 681 case F_UNLCK: 682 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_UNLCK, 683 flp, flg); 684 break; 685 case F_UNLCKSYS: 686 if (flg != F_REMOTE) { 687 error = EINVAL; 688 break; 689 } 690 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, 691 F_UNLCKSYS, flp, flg); 692 break; 693 default: 694 error = EINVAL; 695 break; 696 } 697 if (error != 0 || flp->l_type == F_UNLCK || 698 flp->l_type == F_UNLCKSYS) { 699 fdrop(fp, td); 700 break; 701 } 702 703 /* 704 * Check for a race with close. 705 * 706 * The vnode is now advisory locked (or unlocked, but this case 707 * is not really important) as the caller requested. 708 * We had to drop the filedesc lock, so we need to recheck if 709 * the descriptor is still valid, because if it was closed 710 * in the meantime we need to remove advisory lock from the 711 * vnode - close on any descriptor leading to an advisory 712 * locked vnode, removes that lock. 713 * We will return 0 on purpose in that case, as the result of 714 * successful advisory lock might have been externally visible 715 * already. This is fine - effectively we pretend to the caller 716 * that the closing thread was a bit slower and that the 717 * advisory lock succeeded before the close. 718 */ 719 error = fget_unlocked(td, fd, &cap_no_rights, &fp2); 720 if (error != 0) { 721 fdrop(fp, td); 722 break; 723 } 724 if (fp != fp2) { 725 flp->l_whence = SEEK_SET; 726 flp->l_start = 0; 727 flp->l_len = 0; 728 flp->l_type = F_UNLCK; 729 (void) VOP_ADVLOCK(vp, (caddr_t)p->p_leader, 730 F_UNLCK, flp, F_POSIX); 731 } 732 fdrop(fp, td); 733 fdrop(fp2, td); 734 break; 735 736 case F_GETLK: 737 error = fget_unlocked(td, fd, &cap_flock_rights, &fp); 738 if (error != 0) 739 break; 740 if (fp->f_type != DTYPE_VNODE || fp->f_ops == &path_fileops) { 741 error = EBADF; 742 fdrop(fp, td); 743 break; 744 } 745 flp = (struct flock *)arg; 746 if (flp->l_type != F_RDLCK && flp->l_type != F_WRLCK && 747 flp->l_type != F_UNLCK) { 748 error = EINVAL; 749 fdrop(fp, td); 750 break; 751 } 752 if (flp->l_whence == SEEK_CUR) { 753 foffset = foffset_get(fp); 754 if ((flp->l_start > 0 && 755 foffset > OFF_MAX - flp->l_start) || 756 (flp->l_start < 0 && 757 foffset < OFF_MIN - flp->l_start)) { 758 error = EOVERFLOW; 759 fdrop(fp, td); 760 break; 761 } 762 flp->l_start += foffset; 763 } 764 vp = fp->f_vnode; 765 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_GETLK, flp, 766 F_POSIX); 767 fdrop(fp, td); 768 break; 769 770 case F_ADD_SEALS: 771 error = fget_unlocked(td, fd, &cap_no_rights, &fp); 772 if (error != 0) 773 break; 774 error = fo_add_seals(fp, arg); 775 fdrop(fp, td); 776 break; 777 778 case F_GET_SEALS: 779 error = fget_unlocked(td, fd, &cap_no_rights, &fp); 780 if (error != 0) 781 break; 782 if (fo_get_seals(fp, &seals) == 0) 783 td->td_retval[0] = seals; 784 else 785 error = EINVAL; 786 fdrop(fp, td); 787 break; 788 789 case F_RDAHEAD: 790 arg = arg ? 128 * 1024: 0; 791 /* FALLTHROUGH */ 792 case F_READAHEAD: 793 error = fget_unlocked(td, fd, &cap_no_rights, &fp); 794 if (error != 0) 795 break; 796 if (fp->f_type != DTYPE_VNODE || fp->f_ops == &path_fileops) { 797 fdrop(fp, td); 798 error = EBADF; 799 break; 800 } 801 vp = fp->f_vnode; 802 if (vp->v_type != VREG) { 803 fdrop(fp, td); 804 error = ENOTTY; 805 break; 806 } 807 808 /* 809 * Exclusive lock synchronizes against f_seqcount reads and 810 * writes in sequential_heuristic(). 811 */ 812 error = vn_lock(vp, LK_EXCLUSIVE); 813 if (error != 0) { 814 fdrop(fp, td); 815 break; 816 } 817 if (arg >= 0) { 818 bsize = fp->f_vnode->v_mount->mnt_stat.f_iosize; 819 arg = MIN(arg, INT_MAX - bsize + 1); 820 fp->f_seqcount[UIO_READ] = MIN(IO_SEQMAX, 821 (arg + bsize - 1) / bsize); 822 atomic_set_int(&fp->f_flag, FRDAHEAD); 823 } else { 824 atomic_clear_int(&fp->f_flag, FRDAHEAD); 825 } 826 VOP_UNLOCK(vp); 827 fdrop(fp, td); 828 break; 829 830 case F_ISUNIONSTACK: 831 /* 832 * Check if the vnode is part of a union stack (either the 833 * "union" flag from mount(2) or unionfs). 834 * 835 * Prior to introduction of this op libc's readdir would call 836 * fstatfs(2), in effect unnecessarily copying kilobytes of 837 * data just to check fs name and a mount flag. 838 * 839 * Fixing the code to handle everything in the kernel instead 840 * is a non-trivial endeavor and has low priority, thus this 841 * horrible kludge facilitates the current behavior in a much 842 * cheaper manner until someone(tm) sorts this out. 843 */ 844 error = fget_unlocked(td, fd, &cap_no_rights, &fp); 845 if (error != 0) 846 break; 847 if (fp->f_type != DTYPE_VNODE) { 848 fdrop(fp, td); 849 error = EBADF; 850 break; 851 } 852 vp = fp->f_vnode; 853 /* 854 * Since we don't prevent dooming the vnode even non-null mp 855 * found can become immediately stale. This is tolerable since 856 * mount points are type-stable (providing safe memory access) 857 * and any vfs op on this vnode going forward will return an 858 * error (meaning return value in this case is meaningless). 859 */ 860 mp = atomic_load_ptr(&vp->v_mount); 861 if (__predict_false(mp == NULL)) { 862 fdrop(fp, td); 863 error = EBADF; 864 break; 865 } 866 td->td_retval[0] = 0; 867 if (mp->mnt_kern_flag & MNTK_UNIONFS || 868 mp->mnt_flag & MNT_UNION) 869 td->td_retval[0] = 1; 870 fdrop(fp, td); 871 break; 872 873 case F_KINFO: 874 #ifdef CAPABILITY_MODE 875 if (IN_CAPABILITY_MODE(td)) { 876 error = ECAPMODE; 877 break; 878 } 879 #endif 880 error = copyin((void *)arg, &kif_sz, sizeof(kif_sz)); 881 if (error != 0) 882 break; 883 if (kif_sz != sizeof(*kif)) { 884 error = EINVAL; 885 break; 886 } 887 kif = malloc(sizeof(*kif), M_TEMP, M_WAITOK | M_ZERO); 888 FILEDESC_SLOCK(fdp); 889 error = fget_cap_noref(fdp, fd, &cap_fcntl_rights, &fp, NULL); 890 if (error == 0 && fhold(fp)) { 891 export_file_to_kinfo(fp, fd, NULL, kif, fdp, 0); 892 FILEDESC_SUNLOCK(fdp); 893 fdrop(fp, td); 894 if ((kif->kf_status & KF_ATTR_VALID) != 0) { 895 kif->kf_structsize = sizeof(*kif); 896 error = copyout(kif, (void *)arg, sizeof(*kif)); 897 } else { 898 error = EBADF; 899 } 900 } else { 901 FILEDESC_SUNLOCK(fdp); 902 if (error == 0) 903 error = EBADF; 904 } 905 free(kif, M_TEMP); 906 break; 907 908 default: 909 error = EINVAL; 910 break; 911 } 912 return (error); 913 } 914 915 static int 916 getmaxfd(struct thread *td) 917 { 918 919 return (min((int)lim_cur(td, RLIMIT_NOFILE), maxfilesperproc)); 920 } 921 922 /* 923 * Common code for dup, dup2, fcntl(F_DUPFD) and fcntl(F_DUP2FD). 924 */ 925 int 926 kern_dup(struct thread *td, u_int mode, int flags, int old, int new) 927 { 928 struct filedesc *fdp; 929 struct filedescent *oldfde, *newfde; 930 struct proc *p; 931 struct file *delfp, *oldfp; 932 u_long *oioctls, *nioctls; 933 int error, maxfd; 934 935 p = td->td_proc; 936 fdp = p->p_fd; 937 oioctls = NULL; 938 939 MPASS((flags & ~(FDDUP_FLAG_CLOEXEC)) == 0); 940 MPASS(mode < FDDUP_LASTMODE); 941 942 AUDIT_ARG_FD(old); 943 /* XXXRW: if (flags & FDDUP_FIXED) AUDIT_ARG_FD2(new); */ 944 945 /* 946 * Verify we have a valid descriptor to dup from and possibly to 947 * dup to. Unlike dup() and dup2(), fcntl()'s F_DUPFD should 948 * return EINVAL when the new descriptor is out of bounds. 949 */ 950 if (old < 0) 951 return (EBADF); 952 if (new < 0) 953 return (mode == FDDUP_FCNTL ? EINVAL : EBADF); 954 maxfd = getmaxfd(td); 955 if (new >= maxfd) 956 return (mode == FDDUP_FCNTL ? EINVAL : EBADF); 957 958 error = EBADF; 959 FILEDESC_XLOCK(fdp); 960 if (fget_noref(fdp, old) == NULL) 961 goto unlock; 962 if (mode == FDDUP_FIXED && old == new) { 963 td->td_retval[0] = new; 964 if (flags & FDDUP_FLAG_CLOEXEC) 965 fdp->fd_ofiles[new].fde_flags |= UF_EXCLOSE; 966 error = 0; 967 goto unlock; 968 } 969 970 oldfde = &fdp->fd_ofiles[old]; 971 oldfp = oldfde->fde_file; 972 if (!fhold(oldfp)) 973 goto unlock; 974 975 /* 976 * If the caller specified a file descriptor, make sure the file 977 * table is large enough to hold it, and grab it. Otherwise, just 978 * allocate a new descriptor the usual way. 979 */ 980 switch (mode) { 981 case FDDUP_NORMAL: 982 case FDDUP_FCNTL: 983 if ((error = fdalloc(td, new, &new)) != 0) { 984 fdrop(oldfp, td); 985 goto unlock; 986 } 987 break; 988 case FDDUP_FIXED: 989 if (new >= fdp->fd_nfiles) { 990 /* 991 * The resource limits are here instead of e.g. 992 * fdalloc(), because the file descriptor table may be 993 * shared between processes, so we can't really use 994 * racct_add()/racct_sub(). Instead of counting the 995 * number of actually allocated descriptors, just put 996 * the limit on the size of the file descriptor table. 997 */ 998 #ifdef RACCT 999 if (RACCT_ENABLED()) { 1000 error = racct_set_unlocked(p, RACCT_NOFILE, new + 1); 1001 if (error != 0) { 1002 error = EMFILE; 1003 fdrop(oldfp, td); 1004 goto unlock; 1005 } 1006 } 1007 #endif 1008 fdgrowtable_exp(fdp, new + 1); 1009 } 1010 if (!fdisused(fdp, new)) 1011 fdused(fdp, new); 1012 break; 1013 default: 1014 KASSERT(0, ("%s unsupported mode %d", __func__, mode)); 1015 } 1016 1017 KASSERT(old != new, ("new fd is same as old")); 1018 1019 /* Refetch oldfde because the table may have grown and old one freed. */ 1020 oldfde = &fdp->fd_ofiles[old]; 1021 KASSERT(oldfp == oldfde->fde_file, 1022 ("fdt_ofiles shift from growth observed at fd %d", 1023 old)); 1024 1025 newfde = &fdp->fd_ofiles[new]; 1026 delfp = newfde->fde_file; 1027 1028 nioctls = filecaps_copy_prep(&oldfde->fde_caps); 1029 1030 /* 1031 * Duplicate the source descriptor. 1032 */ 1033 #ifdef CAPABILITIES 1034 seqc_write_begin(&newfde->fde_seqc); 1035 #endif 1036 oioctls = filecaps_free_prep(&newfde->fde_caps); 1037 fde_copy(oldfde, newfde); 1038 filecaps_copy_finish(&oldfde->fde_caps, &newfde->fde_caps, 1039 nioctls); 1040 if ((flags & FDDUP_FLAG_CLOEXEC) != 0) 1041 newfde->fde_flags = oldfde->fde_flags | UF_EXCLOSE; 1042 else 1043 newfde->fde_flags = oldfde->fde_flags & ~UF_EXCLOSE; 1044 #ifdef CAPABILITIES 1045 seqc_write_end(&newfde->fde_seqc); 1046 #endif 1047 td->td_retval[0] = new; 1048 1049 error = 0; 1050 1051 if (delfp != NULL) { 1052 (void) closefp(fdp, new, delfp, td, true, false); 1053 FILEDESC_UNLOCK_ASSERT(fdp); 1054 } else { 1055 unlock: 1056 FILEDESC_XUNLOCK(fdp); 1057 } 1058 1059 filecaps_free_finish(oioctls); 1060 return (error); 1061 } 1062 1063 static void 1064 sigiofree(struct sigio *sigio) 1065 { 1066 crfree(sigio->sio_ucred); 1067 free(sigio, M_SIGIO); 1068 } 1069 1070 static struct sigio * 1071 funsetown_locked(struct sigio *sigio) 1072 { 1073 struct proc *p; 1074 struct pgrp *pg; 1075 1076 SIGIO_ASSERT_LOCKED(); 1077 1078 if (sigio == NULL) 1079 return (NULL); 1080 *sigio->sio_myref = NULL; 1081 if (sigio->sio_pgid < 0) { 1082 pg = sigio->sio_pgrp; 1083 PGRP_LOCK(pg); 1084 SLIST_REMOVE(&pg->pg_sigiolst, sigio, sigio, sio_pgsigio); 1085 PGRP_UNLOCK(pg); 1086 } else { 1087 p = sigio->sio_proc; 1088 PROC_LOCK(p); 1089 SLIST_REMOVE(&p->p_sigiolst, sigio, sigio, sio_pgsigio); 1090 PROC_UNLOCK(p); 1091 } 1092 return (sigio); 1093 } 1094 1095 /* 1096 * If sigio is on the list associated with a process or process group, 1097 * disable signalling from the device, remove sigio from the list and 1098 * free sigio. 1099 */ 1100 void 1101 funsetown(struct sigio **sigiop) 1102 { 1103 struct sigio *sigio; 1104 1105 /* Racy check, consumers must provide synchronization. */ 1106 if (*sigiop == NULL) 1107 return; 1108 1109 SIGIO_LOCK(); 1110 sigio = funsetown_locked(*sigiop); 1111 SIGIO_UNLOCK(); 1112 if (sigio != NULL) 1113 sigiofree(sigio); 1114 } 1115 1116 /* 1117 * Free a list of sigio structures. The caller must ensure that new sigio 1118 * structures cannot be added after this point. For process groups this is 1119 * guaranteed using the proctree lock; for processes, the P_WEXIT flag serves 1120 * as an interlock. 1121 */ 1122 void 1123 funsetownlst(struct sigiolst *sigiolst) 1124 { 1125 struct proc *p; 1126 struct pgrp *pg; 1127 struct sigio *sigio, *tmp; 1128 1129 /* Racy check. */ 1130 sigio = SLIST_FIRST(sigiolst); 1131 if (sigio == NULL) 1132 return; 1133 1134 p = NULL; 1135 pg = NULL; 1136 1137 SIGIO_LOCK(); 1138 sigio = SLIST_FIRST(sigiolst); 1139 if (sigio == NULL) { 1140 SIGIO_UNLOCK(); 1141 return; 1142 } 1143 1144 /* 1145 * Every entry of the list should belong to a single proc or pgrp. 1146 */ 1147 if (sigio->sio_pgid < 0) { 1148 pg = sigio->sio_pgrp; 1149 sx_assert(&proctree_lock, SX_XLOCKED); 1150 PGRP_LOCK(pg); 1151 } else /* if (sigio->sio_pgid > 0) */ { 1152 p = sigio->sio_proc; 1153 PROC_LOCK(p); 1154 KASSERT((p->p_flag & P_WEXIT) != 0, 1155 ("%s: process %p is not exiting", __func__, p)); 1156 } 1157 1158 SLIST_FOREACH(sigio, sigiolst, sio_pgsigio) { 1159 *sigio->sio_myref = NULL; 1160 if (pg != NULL) { 1161 KASSERT(sigio->sio_pgid < 0, 1162 ("Proc sigio in pgrp sigio list")); 1163 KASSERT(sigio->sio_pgrp == pg, 1164 ("Bogus pgrp in sigio list")); 1165 } else /* if (p != NULL) */ { 1166 KASSERT(sigio->sio_pgid > 0, 1167 ("Pgrp sigio in proc sigio list")); 1168 KASSERT(sigio->sio_proc == p, 1169 ("Bogus proc in sigio list")); 1170 } 1171 } 1172 1173 if (pg != NULL) 1174 PGRP_UNLOCK(pg); 1175 else 1176 PROC_UNLOCK(p); 1177 SIGIO_UNLOCK(); 1178 1179 SLIST_FOREACH_SAFE(sigio, sigiolst, sio_pgsigio, tmp) 1180 sigiofree(sigio); 1181 } 1182 1183 /* 1184 * This is common code for FIOSETOWN ioctl called by fcntl(fd, F_SETOWN, arg). 1185 * 1186 * After permission checking, add a sigio structure to the sigio list for 1187 * the process or process group. 1188 */ 1189 int 1190 fsetown(pid_t pgid, struct sigio **sigiop) 1191 { 1192 struct proc *proc; 1193 struct pgrp *pgrp; 1194 struct sigio *osigio, *sigio; 1195 int ret; 1196 1197 if (pgid == 0) { 1198 funsetown(sigiop); 1199 return (0); 1200 } 1201 1202 sigio = malloc(sizeof(struct sigio), M_SIGIO, M_WAITOK); 1203 sigio->sio_pgid = pgid; 1204 sigio->sio_ucred = crhold(curthread->td_ucred); 1205 sigio->sio_myref = sigiop; 1206 1207 ret = 0; 1208 if (pgid > 0) { 1209 ret = pget(pgid, PGET_NOTWEXIT | PGET_NOTID | PGET_HOLD, &proc); 1210 SIGIO_LOCK(); 1211 osigio = funsetown_locked(*sigiop); 1212 if (ret == 0) { 1213 PROC_LOCK(proc); 1214 _PRELE(proc); 1215 if ((proc->p_flag & P_WEXIT) != 0) { 1216 ret = ESRCH; 1217 } else if (proc->p_session != 1218 curthread->td_proc->p_session) { 1219 /* 1220 * Policy - Don't allow a process to FSETOWN a 1221 * process in another session. 1222 * 1223 * Remove this test to allow maximum flexibility 1224 * or restrict FSETOWN to the current process or 1225 * process group for maximum safety. 1226 */ 1227 ret = EPERM; 1228 } else { 1229 sigio->sio_proc = proc; 1230 SLIST_INSERT_HEAD(&proc->p_sigiolst, sigio, 1231 sio_pgsigio); 1232 } 1233 PROC_UNLOCK(proc); 1234 } 1235 } else /* if (pgid < 0) */ { 1236 sx_slock(&proctree_lock); 1237 SIGIO_LOCK(); 1238 osigio = funsetown_locked(*sigiop); 1239 pgrp = pgfind(-pgid); 1240 if (pgrp == NULL) { 1241 ret = ESRCH; 1242 } else { 1243 if (pgrp->pg_session != curthread->td_proc->p_session) { 1244 /* 1245 * Policy - Don't allow a process to FSETOWN a 1246 * process in another session. 1247 * 1248 * Remove this test to allow maximum flexibility 1249 * or restrict FSETOWN to the current process or 1250 * process group for maximum safety. 1251 */ 1252 ret = EPERM; 1253 } else { 1254 sigio->sio_pgrp = pgrp; 1255 SLIST_INSERT_HEAD(&pgrp->pg_sigiolst, sigio, 1256 sio_pgsigio); 1257 } 1258 PGRP_UNLOCK(pgrp); 1259 } 1260 sx_sunlock(&proctree_lock); 1261 } 1262 if (ret == 0) 1263 *sigiop = sigio; 1264 SIGIO_UNLOCK(); 1265 if (osigio != NULL) 1266 sigiofree(osigio); 1267 return (ret); 1268 } 1269 1270 /* 1271 * This is common code for FIOGETOWN ioctl called by fcntl(fd, F_GETOWN, arg). 1272 */ 1273 pid_t 1274 fgetown(struct sigio **sigiop) 1275 { 1276 pid_t pgid; 1277 1278 SIGIO_LOCK(); 1279 pgid = (*sigiop != NULL) ? (*sigiop)->sio_pgid : 0; 1280 SIGIO_UNLOCK(); 1281 return (pgid); 1282 } 1283 1284 static int 1285 closefp_impl(struct filedesc *fdp, int fd, struct file *fp, struct thread *td, 1286 bool audit) 1287 { 1288 int error; 1289 1290 FILEDESC_XLOCK_ASSERT(fdp); 1291 1292 /* 1293 * We now hold the fp reference that used to be owned by the 1294 * descriptor array. We have to unlock the FILEDESC *AFTER* 1295 * knote_fdclose to prevent a race of the fd getting opened, a knote 1296 * added, and deleteing a knote for the new fd. 1297 */ 1298 if (__predict_false(!TAILQ_EMPTY(&fdp->fd_kqlist))) 1299 knote_fdclose(td, fd); 1300 1301 /* 1302 * We need to notify mqueue if the object is of type mqueue. 1303 */ 1304 if (__predict_false(fp->f_type == DTYPE_MQUEUE)) 1305 mq_fdclose(td, fd, fp); 1306 FILEDESC_XUNLOCK(fdp); 1307 1308 #ifdef AUDIT 1309 if (AUDITING_TD(td) && audit) 1310 audit_sysclose(td, fd, fp); 1311 #endif 1312 error = closef(fp, td); 1313 1314 /* 1315 * All paths leading up to closefp() will have already removed or 1316 * replaced the fd in the filedesc table, so a restart would not 1317 * operate on the same file. 1318 */ 1319 if (error == ERESTART) 1320 error = EINTR; 1321 1322 return (error); 1323 } 1324 1325 static int 1326 closefp_hl(struct filedesc *fdp, int fd, struct file *fp, struct thread *td, 1327 bool holdleaders, bool audit) 1328 { 1329 int error; 1330 1331 FILEDESC_XLOCK_ASSERT(fdp); 1332 1333 if (holdleaders) { 1334 if (td->td_proc->p_fdtol != NULL) { 1335 /* 1336 * Ask fdfree() to sleep to ensure that all relevant 1337 * process leaders can be traversed in closef(). 1338 */ 1339 fdp->fd_holdleaderscount++; 1340 } else { 1341 holdleaders = false; 1342 } 1343 } 1344 1345 error = closefp_impl(fdp, fd, fp, td, audit); 1346 if (holdleaders) { 1347 FILEDESC_XLOCK(fdp); 1348 fdp->fd_holdleaderscount--; 1349 if (fdp->fd_holdleaderscount == 0 && 1350 fdp->fd_holdleaderswakeup != 0) { 1351 fdp->fd_holdleaderswakeup = 0; 1352 wakeup(&fdp->fd_holdleaderscount); 1353 } 1354 FILEDESC_XUNLOCK(fdp); 1355 } 1356 return (error); 1357 } 1358 1359 static int 1360 closefp(struct filedesc *fdp, int fd, struct file *fp, struct thread *td, 1361 bool holdleaders, bool audit) 1362 { 1363 1364 FILEDESC_XLOCK_ASSERT(fdp); 1365 1366 if (__predict_false(td->td_proc->p_fdtol != NULL)) { 1367 return (closefp_hl(fdp, fd, fp, td, holdleaders, audit)); 1368 } else { 1369 return (closefp_impl(fdp, fd, fp, td, audit)); 1370 } 1371 } 1372 1373 /* 1374 * Close a file descriptor. 1375 */ 1376 #ifndef _SYS_SYSPROTO_H_ 1377 struct close_args { 1378 int fd; 1379 }; 1380 #endif 1381 /* ARGSUSED */ 1382 int 1383 sys_close(struct thread *td, struct close_args *uap) 1384 { 1385 1386 return (kern_close(td, uap->fd)); 1387 } 1388 1389 int 1390 kern_close(struct thread *td, int fd) 1391 { 1392 struct filedesc *fdp; 1393 struct file *fp; 1394 1395 fdp = td->td_proc->p_fd; 1396 1397 FILEDESC_XLOCK(fdp); 1398 if ((fp = fget_noref(fdp, fd)) == NULL) { 1399 FILEDESC_XUNLOCK(fdp); 1400 return (EBADF); 1401 } 1402 fdfree(fdp, fd); 1403 1404 /* closefp() drops the FILEDESC lock for us. */ 1405 return (closefp(fdp, fd, fp, td, true, true)); 1406 } 1407 1408 static int 1409 close_range_cloexec(struct thread *td, u_int lowfd, u_int highfd) 1410 { 1411 struct filedesc *fdp; 1412 struct fdescenttbl *fdt; 1413 struct filedescent *fde; 1414 int fd; 1415 1416 fdp = td->td_proc->p_fd; 1417 FILEDESC_XLOCK(fdp); 1418 fdt = atomic_load_ptr(&fdp->fd_files); 1419 highfd = MIN(highfd, fdt->fdt_nfiles - 1); 1420 fd = lowfd; 1421 if (__predict_false(fd > highfd)) { 1422 goto out_locked; 1423 } 1424 for (; fd <= highfd; fd++) { 1425 fde = &fdt->fdt_ofiles[fd]; 1426 if (fde->fde_file != NULL) 1427 fde->fde_flags |= UF_EXCLOSE; 1428 } 1429 out_locked: 1430 FILEDESC_XUNLOCK(fdp); 1431 return (0); 1432 } 1433 1434 static int 1435 close_range_impl(struct thread *td, u_int lowfd, u_int highfd) 1436 { 1437 struct filedesc *fdp; 1438 const struct fdescenttbl *fdt; 1439 struct file *fp; 1440 int fd; 1441 1442 fdp = td->td_proc->p_fd; 1443 FILEDESC_XLOCK(fdp); 1444 fdt = atomic_load_ptr(&fdp->fd_files); 1445 highfd = MIN(highfd, fdt->fdt_nfiles - 1); 1446 fd = lowfd; 1447 if (__predict_false(fd > highfd)) { 1448 goto out_locked; 1449 } 1450 for (;;) { 1451 fp = fdt->fdt_ofiles[fd].fde_file; 1452 if (fp == NULL) { 1453 if (fd == highfd) 1454 goto out_locked; 1455 } else { 1456 fdfree(fdp, fd); 1457 (void) closefp(fdp, fd, fp, td, true, true); 1458 if (fd == highfd) 1459 goto out_unlocked; 1460 FILEDESC_XLOCK(fdp); 1461 fdt = atomic_load_ptr(&fdp->fd_files); 1462 } 1463 fd++; 1464 } 1465 out_locked: 1466 FILEDESC_XUNLOCK(fdp); 1467 out_unlocked: 1468 return (0); 1469 } 1470 1471 int 1472 kern_close_range(struct thread *td, int flags, u_int lowfd, u_int highfd) 1473 { 1474 1475 /* 1476 * Check this prior to clamping; closefrom(3) with only fd 0, 1, and 2 1477 * open should not be a usage error. From a close_range() perspective, 1478 * close_range(3, ~0U, 0) in the same scenario should also likely not 1479 * be a usage error as all fd above 3 are in-fact already closed. 1480 */ 1481 if (highfd < lowfd) { 1482 return (EINVAL); 1483 } 1484 1485 if ((flags & CLOSE_RANGE_CLOEXEC) != 0) 1486 return (close_range_cloexec(td, lowfd, highfd)); 1487 1488 return (close_range_impl(td, lowfd, highfd)); 1489 } 1490 1491 #ifndef _SYS_SYSPROTO_H_ 1492 struct close_range_args { 1493 u_int lowfd; 1494 u_int highfd; 1495 int flags; 1496 }; 1497 #endif 1498 int 1499 sys_close_range(struct thread *td, struct close_range_args *uap) 1500 { 1501 1502 AUDIT_ARG_FD(uap->lowfd); 1503 AUDIT_ARG_CMD(uap->highfd); 1504 AUDIT_ARG_FFLAGS(uap->flags); 1505 1506 if ((uap->flags & ~(CLOSE_RANGE_CLOEXEC)) != 0) 1507 return (EINVAL); 1508 return (kern_close_range(td, uap->flags, uap->lowfd, uap->highfd)); 1509 } 1510 1511 #ifdef COMPAT_FREEBSD12 1512 /* 1513 * Close open file descriptors. 1514 */ 1515 #ifndef _SYS_SYSPROTO_H_ 1516 struct freebsd12_closefrom_args { 1517 int lowfd; 1518 }; 1519 #endif 1520 /* ARGSUSED */ 1521 int 1522 freebsd12_closefrom(struct thread *td, struct freebsd12_closefrom_args *uap) 1523 { 1524 u_int lowfd; 1525 1526 AUDIT_ARG_FD(uap->lowfd); 1527 1528 /* 1529 * Treat negative starting file descriptor values identical to 1530 * closefrom(0) which closes all files. 1531 */ 1532 lowfd = MAX(0, uap->lowfd); 1533 return (kern_close_range(td, 0, lowfd, ~0U)); 1534 } 1535 #endif /* COMPAT_FREEBSD12 */ 1536 1537 #if defined(COMPAT_43) 1538 /* 1539 * Return status information about a file descriptor. 1540 */ 1541 #ifndef _SYS_SYSPROTO_H_ 1542 struct ofstat_args { 1543 int fd; 1544 struct ostat *sb; 1545 }; 1546 #endif 1547 /* ARGSUSED */ 1548 int 1549 ofstat(struct thread *td, struct ofstat_args *uap) 1550 { 1551 struct ostat oub; 1552 struct stat ub; 1553 int error; 1554 1555 error = kern_fstat(td, uap->fd, &ub); 1556 if (error == 0) { 1557 cvtstat(&ub, &oub); 1558 error = copyout(&oub, uap->sb, sizeof(oub)); 1559 } 1560 return (error); 1561 } 1562 #endif /* COMPAT_43 */ 1563 1564 #if defined(COMPAT_FREEBSD11) 1565 int 1566 freebsd11_fstat(struct thread *td, struct freebsd11_fstat_args *uap) 1567 { 1568 struct stat sb; 1569 struct freebsd11_stat osb; 1570 int error; 1571 1572 error = kern_fstat(td, uap->fd, &sb); 1573 if (error != 0) 1574 return (error); 1575 error = freebsd11_cvtstat(&sb, &osb); 1576 if (error == 0) 1577 error = copyout(&osb, uap->sb, sizeof(osb)); 1578 return (error); 1579 } 1580 #endif /* COMPAT_FREEBSD11 */ 1581 1582 /* 1583 * Return status information about a file descriptor. 1584 */ 1585 #ifndef _SYS_SYSPROTO_H_ 1586 struct fstat_args { 1587 int fd; 1588 struct stat *sb; 1589 }; 1590 #endif 1591 /* ARGSUSED */ 1592 int 1593 sys_fstat(struct thread *td, struct fstat_args *uap) 1594 { 1595 struct stat ub; 1596 int error; 1597 1598 error = kern_fstat(td, uap->fd, &ub); 1599 if (error == 0) 1600 error = copyout(&ub, uap->sb, sizeof(ub)); 1601 return (error); 1602 } 1603 1604 int 1605 kern_fstat(struct thread *td, int fd, struct stat *sbp) 1606 { 1607 struct file *fp; 1608 int error; 1609 1610 AUDIT_ARG_FD(fd); 1611 1612 error = fget(td, fd, &cap_fstat_rights, &fp); 1613 if (__predict_false(error != 0)) 1614 return (error); 1615 1616 AUDIT_ARG_FILE(td->td_proc, fp); 1617 1618 error = fo_stat(fp, sbp, td->td_ucred); 1619 fdrop(fp, td); 1620 #ifdef __STAT_TIME_T_EXT 1621 sbp->st_atim_ext = 0; 1622 sbp->st_mtim_ext = 0; 1623 sbp->st_ctim_ext = 0; 1624 sbp->st_btim_ext = 0; 1625 #endif 1626 #ifdef KTRACE 1627 if (KTRPOINT(td, KTR_STRUCT)) 1628 ktrstat_error(sbp, error); 1629 #endif 1630 return (error); 1631 } 1632 1633 #if defined(COMPAT_FREEBSD11) 1634 /* 1635 * Return status information about a file descriptor. 1636 */ 1637 #ifndef _SYS_SYSPROTO_H_ 1638 struct freebsd11_nfstat_args { 1639 int fd; 1640 struct nstat *sb; 1641 }; 1642 #endif 1643 /* ARGSUSED */ 1644 int 1645 freebsd11_nfstat(struct thread *td, struct freebsd11_nfstat_args *uap) 1646 { 1647 struct nstat nub; 1648 struct stat ub; 1649 int error; 1650 1651 error = kern_fstat(td, uap->fd, &ub); 1652 if (error != 0) 1653 return (error); 1654 error = freebsd11_cvtnstat(&ub, &nub); 1655 if (error != 0) 1656 error = copyout(&nub, uap->sb, sizeof(nub)); 1657 return (error); 1658 } 1659 #endif /* COMPAT_FREEBSD11 */ 1660 1661 /* 1662 * Return pathconf information about a file descriptor. 1663 */ 1664 #ifndef _SYS_SYSPROTO_H_ 1665 struct fpathconf_args { 1666 int fd; 1667 int name; 1668 }; 1669 #endif 1670 /* ARGSUSED */ 1671 int 1672 sys_fpathconf(struct thread *td, struct fpathconf_args *uap) 1673 { 1674 long value; 1675 int error; 1676 1677 error = kern_fpathconf(td, uap->fd, uap->name, &value); 1678 if (error == 0) 1679 td->td_retval[0] = value; 1680 return (error); 1681 } 1682 1683 int 1684 kern_fpathconf(struct thread *td, int fd, int name, long *valuep) 1685 { 1686 struct file *fp; 1687 struct vnode *vp; 1688 int error; 1689 1690 error = fget(td, fd, &cap_fpathconf_rights, &fp); 1691 if (error != 0) 1692 return (error); 1693 1694 if (name == _PC_ASYNC_IO) { 1695 *valuep = _POSIX_ASYNCHRONOUS_IO; 1696 goto out; 1697 } 1698 vp = fp->f_vnode; 1699 if (vp != NULL) { 1700 vn_lock(vp, LK_SHARED | LK_RETRY); 1701 error = VOP_PATHCONF(vp, name, valuep); 1702 VOP_UNLOCK(vp); 1703 } else if (fp->f_type == DTYPE_PIPE || fp->f_type == DTYPE_SOCKET) { 1704 if (name != _PC_PIPE_BUF) { 1705 error = EINVAL; 1706 } else { 1707 *valuep = PIPE_BUF; 1708 error = 0; 1709 } 1710 } else { 1711 error = EOPNOTSUPP; 1712 } 1713 out: 1714 fdrop(fp, td); 1715 return (error); 1716 } 1717 1718 /* 1719 * Copy filecaps structure allocating memory for ioctls array if needed. 1720 * 1721 * The last parameter indicates whether the fdtable is locked. If it is not and 1722 * ioctls are encountered, copying fails and the caller must lock the table. 1723 * 1724 * Note that if the table was not locked, the caller has to check the relevant 1725 * sequence counter to determine whether the operation was successful. 1726 */ 1727 bool 1728 filecaps_copy(const struct filecaps *src, struct filecaps *dst, bool locked) 1729 { 1730 size_t size; 1731 1732 if (src->fc_ioctls != NULL && !locked) 1733 return (false); 1734 memcpy(dst, src, sizeof(*src)); 1735 if (src->fc_ioctls == NULL) 1736 return (true); 1737 1738 KASSERT(src->fc_nioctls > 0, 1739 ("fc_ioctls != NULL, but fc_nioctls=%hd", src->fc_nioctls)); 1740 1741 size = sizeof(src->fc_ioctls[0]) * src->fc_nioctls; 1742 dst->fc_ioctls = malloc(size, M_FILECAPS, M_WAITOK); 1743 memcpy(dst->fc_ioctls, src->fc_ioctls, size); 1744 return (true); 1745 } 1746 1747 static u_long * 1748 filecaps_copy_prep(const struct filecaps *src) 1749 { 1750 u_long *ioctls; 1751 size_t size; 1752 1753 if (__predict_true(src->fc_ioctls == NULL)) 1754 return (NULL); 1755 1756 KASSERT(src->fc_nioctls > 0, 1757 ("fc_ioctls != NULL, but fc_nioctls=%hd", src->fc_nioctls)); 1758 1759 size = sizeof(src->fc_ioctls[0]) * src->fc_nioctls; 1760 ioctls = malloc(size, M_FILECAPS, M_WAITOK); 1761 return (ioctls); 1762 } 1763 1764 static void 1765 filecaps_copy_finish(const struct filecaps *src, struct filecaps *dst, 1766 u_long *ioctls) 1767 { 1768 size_t size; 1769 1770 *dst = *src; 1771 if (__predict_true(src->fc_ioctls == NULL)) { 1772 MPASS(ioctls == NULL); 1773 return; 1774 } 1775 1776 size = sizeof(src->fc_ioctls[0]) * src->fc_nioctls; 1777 dst->fc_ioctls = ioctls; 1778 bcopy(src->fc_ioctls, dst->fc_ioctls, size); 1779 } 1780 1781 /* 1782 * Move filecaps structure to the new place and clear the old place. 1783 */ 1784 void 1785 filecaps_move(struct filecaps *src, struct filecaps *dst) 1786 { 1787 1788 *dst = *src; 1789 bzero(src, sizeof(*src)); 1790 } 1791 1792 /* 1793 * Fill the given filecaps structure with full rights. 1794 */ 1795 static void 1796 filecaps_fill(struct filecaps *fcaps) 1797 { 1798 1799 CAP_ALL(&fcaps->fc_rights); 1800 fcaps->fc_ioctls = NULL; 1801 fcaps->fc_nioctls = -1; 1802 fcaps->fc_fcntls = CAP_FCNTL_ALL; 1803 } 1804 1805 /* 1806 * Free memory allocated within filecaps structure. 1807 */ 1808 static void 1809 filecaps_free_ioctl(struct filecaps *fcaps) 1810 { 1811 1812 free(fcaps->fc_ioctls, M_FILECAPS); 1813 fcaps->fc_ioctls = NULL; 1814 } 1815 1816 void 1817 filecaps_free(struct filecaps *fcaps) 1818 { 1819 1820 filecaps_free_ioctl(fcaps); 1821 bzero(fcaps, sizeof(*fcaps)); 1822 } 1823 1824 static u_long * 1825 filecaps_free_prep(struct filecaps *fcaps) 1826 { 1827 u_long *ioctls; 1828 1829 ioctls = fcaps->fc_ioctls; 1830 bzero(fcaps, sizeof(*fcaps)); 1831 return (ioctls); 1832 } 1833 1834 static void 1835 filecaps_free_finish(u_long *ioctls) 1836 { 1837 1838 free(ioctls, M_FILECAPS); 1839 } 1840 1841 /* 1842 * Validate the given filecaps structure. 1843 */ 1844 static void 1845 filecaps_validate(const struct filecaps *fcaps, const char *func) 1846 { 1847 1848 KASSERT(cap_rights_is_valid(&fcaps->fc_rights), 1849 ("%s: invalid rights", func)); 1850 KASSERT((fcaps->fc_fcntls & ~CAP_FCNTL_ALL) == 0, 1851 ("%s: invalid fcntls", func)); 1852 KASSERT(fcaps->fc_fcntls == 0 || 1853 cap_rights_is_set(&fcaps->fc_rights, CAP_FCNTL), 1854 ("%s: fcntls without CAP_FCNTL", func)); 1855 /* 1856 * open calls without WANTIOCTLCAPS free caps but leave the counter 1857 */ 1858 #if 0 1859 KASSERT(fcaps->fc_ioctls != NULL ? fcaps->fc_nioctls > 0 : 1860 (fcaps->fc_nioctls == -1 || fcaps->fc_nioctls == 0), 1861 ("%s: invalid ioctls", func)); 1862 #endif 1863 KASSERT(fcaps->fc_nioctls == 0 || 1864 cap_rights_is_set(&fcaps->fc_rights, CAP_IOCTL), 1865 ("%s: ioctls without CAP_IOCTL", func)); 1866 } 1867 1868 static void 1869 fdgrowtable_exp(struct filedesc *fdp, int nfd) 1870 { 1871 int nfd1; 1872 1873 FILEDESC_XLOCK_ASSERT(fdp); 1874 1875 nfd1 = fdp->fd_nfiles * 2; 1876 if (nfd1 < nfd) 1877 nfd1 = nfd; 1878 fdgrowtable(fdp, nfd1); 1879 } 1880 1881 /* 1882 * Grow the file table to accommodate (at least) nfd descriptors. 1883 */ 1884 static void 1885 fdgrowtable(struct filedesc *fdp, int nfd) 1886 { 1887 struct filedesc0 *fdp0; 1888 struct freetable *ft; 1889 struct fdescenttbl *ntable; 1890 struct fdescenttbl *otable; 1891 int nnfiles, onfiles; 1892 NDSLOTTYPE *nmap, *omap; 1893 1894 KASSERT(fdp->fd_nfiles > 0, ("zero-length file table")); 1895 1896 /* save old values */ 1897 onfiles = fdp->fd_nfiles; 1898 otable = fdp->fd_files; 1899 omap = fdp->fd_map; 1900 1901 /* compute the size of the new table */ 1902 nnfiles = NDSLOTS(nfd) * NDENTRIES; /* round up */ 1903 if (nnfiles <= onfiles) 1904 /* the table is already large enough */ 1905 return; 1906 1907 /* 1908 * Allocate a new table. We need enough space for the number of 1909 * entries, file entries themselves and the struct freetable we will use 1910 * when we decommission the table and place it on the freelist. 1911 * We place the struct freetable in the middle so we don't have 1912 * to worry about padding. 1913 */ 1914 ntable = malloc(offsetof(struct fdescenttbl, fdt_ofiles) + 1915 nnfiles * sizeof(ntable->fdt_ofiles[0]) + 1916 sizeof(struct freetable), 1917 M_FILEDESC, M_ZERO | M_WAITOK); 1918 /* copy the old data */ 1919 ntable->fdt_nfiles = nnfiles; 1920 memcpy(ntable->fdt_ofiles, otable->fdt_ofiles, 1921 onfiles * sizeof(ntable->fdt_ofiles[0])); 1922 1923 /* 1924 * Allocate a new map only if the old is not large enough. It will 1925 * grow at a slower rate than the table as it can map more 1926 * entries than the table can hold. 1927 */ 1928 if (NDSLOTS(nnfiles) > NDSLOTS(onfiles)) { 1929 nmap = malloc(NDSLOTS(nnfiles) * NDSLOTSIZE, M_FILEDESC, 1930 M_ZERO | M_WAITOK); 1931 /* copy over the old data and update the pointer */ 1932 memcpy(nmap, omap, NDSLOTS(onfiles) * sizeof(*omap)); 1933 fdp->fd_map = nmap; 1934 } 1935 1936 /* 1937 * Make sure that ntable is correctly initialized before we replace 1938 * fd_files poiner. Otherwise fget_unlocked() may see inconsistent 1939 * data. 1940 */ 1941 atomic_store_rel_ptr((volatile void *)&fdp->fd_files, (uintptr_t)ntable); 1942 1943 /* 1944 * Free the old file table when not shared by other threads or processes. 1945 * The old file table is considered to be shared when either are true: 1946 * - The process has more than one thread. 1947 * - The file descriptor table has been shared via fdshare(). 1948 * 1949 * When shared, the old file table will be placed on a freelist 1950 * which will be processed when the struct filedesc is released. 1951 * 1952 * Note that if onfiles == NDFILE, we're dealing with the original 1953 * static allocation contained within (struct filedesc0 *)fdp, 1954 * which must not be freed. 1955 */ 1956 if (onfiles > NDFILE) { 1957 /* 1958 * Note we may be called here from fdinit while allocating a 1959 * table for a new process in which case ->p_fd points 1960 * elsewhere. 1961 */ 1962 if (curproc->p_fd != fdp || FILEDESC_IS_ONLY_USER(fdp)) { 1963 free(otable, M_FILEDESC); 1964 } else { 1965 ft = (struct freetable *)&otable->fdt_ofiles[onfiles]; 1966 fdp0 = (struct filedesc0 *)fdp; 1967 ft->ft_table = otable; 1968 SLIST_INSERT_HEAD(&fdp0->fd_free, ft, ft_next); 1969 } 1970 } 1971 /* 1972 * The map does not have the same possibility of threads still 1973 * holding references to it. So always free it as long as it 1974 * does not reference the original static allocation. 1975 */ 1976 if (NDSLOTS(onfiles) > NDSLOTS(NDFILE)) 1977 free(omap, M_FILEDESC); 1978 } 1979 1980 /* 1981 * Allocate a file descriptor for the process. 1982 */ 1983 int 1984 fdalloc(struct thread *td, int minfd, int *result) 1985 { 1986 struct proc *p = td->td_proc; 1987 struct filedesc *fdp = p->p_fd; 1988 int fd, maxfd, allocfd; 1989 #ifdef RACCT 1990 int error; 1991 #endif 1992 1993 FILEDESC_XLOCK_ASSERT(fdp); 1994 1995 if (fdp->fd_freefile > minfd) 1996 minfd = fdp->fd_freefile; 1997 1998 maxfd = getmaxfd(td); 1999 2000 /* 2001 * Search the bitmap for a free descriptor starting at minfd. 2002 * If none is found, grow the file table. 2003 */ 2004 fd = fd_first_free(fdp, minfd, fdp->fd_nfiles); 2005 if (__predict_false(fd >= maxfd)) 2006 return (EMFILE); 2007 if (__predict_false(fd >= fdp->fd_nfiles)) { 2008 allocfd = min(fd * 2, maxfd); 2009 #ifdef RACCT 2010 if (RACCT_ENABLED()) { 2011 error = racct_set_unlocked(p, RACCT_NOFILE, allocfd); 2012 if (error != 0) 2013 return (EMFILE); 2014 } 2015 #endif 2016 /* 2017 * fd is already equal to first free descriptor >= minfd, so 2018 * we only need to grow the table and we are done. 2019 */ 2020 fdgrowtable_exp(fdp, allocfd); 2021 } 2022 2023 /* 2024 * Perform some sanity checks, then mark the file descriptor as 2025 * used and return it to the caller. 2026 */ 2027 KASSERT(fd >= 0 && fd < min(maxfd, fdp->fd_nfiles), 2028 ("invalid descriptor %d", fd)); 2029 KASSERT(!fdisused(fdp, fd), 2030 ("fd_first_free() returned non-free descriptor")); 2031 KASSERT(fdp->fd_ofiles[fd].fde_file == NULL, 2032 ("file descriptor isn't free")); 2033 fdused(fdp, fd); 2034 *result = fd; 2035 return (0); 2036 } 2037 2038 /* 2039 * Allocate n file descriptors for the process. 2040 */ 2041 int 2042 fdallocn(struct thread *td, int minfd, int *fds, int n) 2043 { 2044 struct proc *p = td->td_proc; 2045 struct filedesc *fdp = p->p_fd; 2046 int i; 2047 2048 FILEDESC_XLOCK_ASSERT(fdp); 2049 2050 for (i = 0; i < n; i++) 2051 if (fdalloc(td, 0, &fds[i]) != 0) 2052 break; 2053 2054 if (i < n) { 2055 for (i--; i >= 0; i--) 2056 fdunused(fdp, fds[i]); 2057 return (EMFILE); 2058 } 2059 2060 return (0); 2061 } 2062 2063 /* 2064 * Create a new open file structure and allocate a file descriptor for the 2065 * process that refers to it. We add one reference to the file for the 2066 * descriptor table and one reference for resultfp. This is to prevent us 2067 * being preempted and the entry in the descriptor table closed after we 2068 * release the FILEDESC lock. 2069 */ 2070 int 2071 falloc_caps(struct thread *td, struct file **resultfp, int *resultfd, int flags, 2072 struct filecaps *fcaps) 2073 { 2074 struct file *fp; 2075 int error, fd; 2076 2077 MPASS(resultfp != NULL); 2078 MPASS(resultfd != NULL); 2079 2080 error = _falloc_noinstall(td, &fp, 2); 2081 if (__predict_false(error != 0)) { 2082 return (error); 2083 } 2084 2085 error = finstall_refed(td, fp, &fd, flags, fcaps); 2086 if (__predict_false(error != 0)) { 2087 falloc_abort(td, fp); 2088 return (error); 2089 } 2090 2091 *resultfp = fp; 2092 *resultfd = fd; 2093 2094 return (0); 2095 } 2096 2097 /* 2098 * Create a new open file structure without allocating a file descriptor. 2099 */ 2100 int 2101 _falloc_noinstall(struct thread *td, struct file **resultfp, u_int n) 2102 { 2103 struct file *fp; 2104 int maxuserfiles = maxfiles - (maxfiles / 20); 2105 int openfiles_new; 2106 static struct timeval lastfail; 2107 static int curfail; 2108 2109 KASSERT(resultfp != NULL, ("%s: resultfp == NULL", __func__)); 2110 MPASS(n > 0); 2111 2112 openfiles_new = atomic_fetchadd_int(&openfiles, 1) + 1; 2113 if ((openfiles_new >= maxuserfiles && 2114 priv_check(td, PRIV_MAXFILES) != 0) || 2115 openfiles_new >= maxfiles) { 2116 atomic_subtract_int(&openfiles, 1); 2117 if (ppsratecheck(&lastfail, &curfail, 1)) { 2118 printf("kern.maxfiles limit exceeded by uid %i, (%s) " 2119 "please see tuning(7).\n", td->td_ucred->cr_ruid, td->td_proc->p_comm); 2120 } 2121 return (ENFILE); 2122 } 2123 fp = uma_zalloc(file_zone, M_WAITOK); 2124 bzero(fp, sizeof(*fp)); 2125 refcount_init(&fp->f_count, n); 2126 fp->f_cred = crhold(td->td_ucred); 2127 fp->f_ops = &badfileops; 2128 *resultfp = fp; 2129 return (0); 2130 } 2131 2132 void 2133 falloc_abort(struct thread *td, struct file *fp) 2134 { 2135 2136 /* 2137 * For assertion purposes. 2138 */ 2139 refcount_init(&fp->f_count, 0); 2140 _fdrop(fp, td); 2141 } 2142 2143 /* 2144 * Install a file in a file descriptor table. 2145 */ 2146 void 2147 _finstall(struct filedesc *fdp, struct file *fp, int fd, int flags, 2148 struct filecaps *fcaps) 2149 { 2150 struct filedescent *fde; 2151 2152 MPASS(fp != NULL); 2153 if (fcaps != NULL) 2154 filecaps_validate(fcaps, __func__); 2155 FILEDESC_XLOCK_ASSERT(fdp); 2156 2157 fde = &fdp->fd_ofiles[fd]; 2158 #ifdef CAPABILITIES 2159 seqc_write_begin(&fde->fde_seqc); 2160 #endif 2161 fde->fde_file = fp; 2162 fde->fde_flags = (flags & O_CLOEXEC) != 0 ? UF_EXCLOSE : 0; 2163 if (fcaps != NULL) 2164 filecaps_move(fcaps, &fde->fde_caps); 2165 else 2166 filecaps_fill(&fde->fde_caps); 2167 #ifdef CAPABILITIES 2168 seqc_write_end(&fde->fde_seqc); 2169 #endif 2170 } 2171 2172 int 2173 finstall_refed(struct thread *td, struct file *fp, int *fd, int flags, 2174 struct filecaps *fcaps) 2175 { 2176 struct filedesc *fdp = td->td_proc->p_fd; 2177 int error; 2178 2179 MPASS(fd != NULL); 2180 2181 FILEDESC_XLOCK(fdp); 2182 error = fdalloc(td, 0, fd); 2183 if (__predict_true(error == 0)) { 2184 _finstall(fdp, fp, *fd, flags, fcaps); 2185 } 2186 FILEDESC_XUNLOCK(fdp); 2187 return (error); 2188 } 2189 2190 int 2191 finstall(struct thread *td, struct file *fp, int *fd, int flags, 2192 struct filecaps *fcaps) 2193 { 2194 int error; 2195 2196 MPASS(fd != NULL); 2197 2198 if (!fhold(fp)) 2199 return (EBADF); 2200 error = finstall_refed(td, fp, fd, flags, fcaps); 2201 if (__predict_false(error != 0)) { 2202 fdrop(fp, td); 2203 } 2204 return (error); 2205 } 2206 2207 /* 2208 * Build a new filedesc structure from another. 2209 * 2210 * If fdp is not NULL, return with it shared locked. 2211 */ 2212 struct filedesc * 2213 fdinit(void) 2214 { 2215 struct filedesc0 *newfdp0; 2216 struct filedesc *newfdp; 2217 2218 newfdp0 = uma_zalloc(filedesc0_zone, M_WAITOK | M_ZERO); 2219 newfdp = &newfdp0->fd_fd; 2220 2221 /* Create the file descriptor table. */ 2222 FILEDESC_LOCK_INIT(newfdp); 2223 refcount_init(&newfdp->fd_refcnt, 1); 2224 refcount_init(&newfdp->fd_holdcnt, 1); 2225 newfdp->fd_map = newfdp0->fd_dmap; 2226 newfdp->fd_files = (struct fdescenttbl *)&newfdp0->fd_dfiles; 2227 newfdp->fd_files->fdt_nfiles = NDFILE; 2228 2229 return (newfdp); 2230 } 2231 2232 /* 2233 * Build a pwddesc structure from another. 2234 * Copy the current, root, and jail root vnode references. 2235 * 2236 * If pdp is not NULL, return with it shared locked. 2237 */ 2238 struct pwddesc * 2239 pdinit(struct pwddesc *pdp, bool keeplock) 2240 { 2241 struct pwddesc *newpdp; 2242 struct pwd *newpwd; 2243 2244 newpdp = malloc(sizeof(*newpdp), M_PWDDESC, M_WAITOK | M_ZERO); 2245 2246 PWDDESC_LOCK_INIT(newpdp); 2247 refcount_init(&newpdp->pd_refcount, 1); 2248 newpdp->pd_cmask = CMASK; 2249 2250 if (pdp == NULL) { 2251 newpwd = pwd_alloc(); 2252 smr_serialized_store(&newpdp->pd_pwd, newpwd, true); 2253 return (newpdp); 2254 } 2255 2256 PWDDESC_XLOCK(pdp); 2257 newpwd = pwd_hold_pwddesc(pdp); 2258 smr_serialized_store(&newpdp->pd_pwd, newpwd, true); 2259 if (!keeplock) 2260 PWDDESC_XUNLOCK(pdp); 2261 return (newpdp); 2262 } 2263 2264 /* 2265 * Hold either filedesc or pwddesc of the passed process. 2266 * 2267 * The process lock is used to synchronize against the target exiting and 2268 * freeing the data. 2269 * 2270 * Clearing can be ilustrated in 3 steps: 2271 * 1. set the pointer to NULL. Either routine can race against it, hence 2272 * atomic_load_ptr. 2273 * 2. observe the process lock as not taken. Until then fdhold/pdhold can 2274 * race to either still see the pointer or find NULL. It is still safe to 2275 * grab a reference as clearing is stalled. 2276 * 3. after the lock is observed as not taken, any fdhold/pdhold calls are 2277 * guaranteed to see NULL, making it safe to finish clearing 2278 */ 2279 static struct filedesc * 2280 fdhold(struct proc *p) 2281 { 2282 struct filedesc *fdp; 2283 2284 PROC_LOCK_ASSERT(p, MA_OWNED); 2285 fdp = atomic_load_ptr(&p->p_fd); 2286 if (fdp != NULL) 2287 refcount_acquire(&fdp->fd_holdcnt); 2288 return (fdp); 2289 } 2290 2291 static struct pwddesc * 2292 pdhold(struct proc *p) 2293 { 2294 struct pwddesc *pdp; 2295 2296 PROC_LOCK_ASSERT(p, MA_OWNED); 2297 pdp = atomic_load_ptr(&p->p_pd); 2298 if (pdp != NULL) 2299 refcount_acquire(&pdp->pd_refcount); 2300 return (pdp); 2301 } 2302 2303 static void 2304 fddrop(struct filedesc *fdp) 2305 { 2306 2307 if (refcount_load(&fdp->fd_holdcnt) > 1) { 2308 if (refcount_release(&fdp->fd_holdcnt) == 0) 2309 return; 2310 } 2311 2312 FILEDESC_LOCK_DESTROY(fdp); 2313 uma_zfree(filedesc0_zone, fdp); 2314 } 2315 2316 static void 2317 pddrop(struct pwddesc *pdp) 2318 { 2319 struct pwd *pwd; 2320 2321 if (refcount_release_if_not_last(&pdp->pd_refcount)) 2322 return; 2323 2324 PWDDESC_XLOCK(pdp); 2325 if (refcount_release(&pdp->pd_refcount) == 0) { 2326 PWDDESC_XUNLOCK(pdp); 2327 return; 2328 } 2329 pwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); 2330 pwd_set(pdp, NULL); 2331 PWDDESC_XUNLOCK(pdp); 2332 pwd_drop(pwd); 2333 2334 PWDDESC_LOCK_DESTROY(pdp); 2335 free(pdp, M_PWDDESC); 2336 } 2337 2338 /* 2339 * Share a filedesc structure. 2340 */ 2341 struct filedesc * 2342 fdshare(struct filedesc *fdp) 2343 { 2344 2345 refcount_acquire(&fdp->fd_refcnt); 2346 return (fdp); 2347 } 2348 2349 /* 2350 * Share a pwddesc structure. 2351 */ 2352 struct pwddesc * 2353 pdshare(struct pwddesc *pdp) 2354 { 2355 refcount_acquire(&pdp->pd_refcount); 2356 return (pdp); 2357 } 2358 2359 /* 2360 * Unshare a filedesc structure, if necessary by making a copy 2361 */ 2362 void 2363 fdunshare(struct thread *td) 2364 { 2365 struct filedesc *tmp; 2366 struct proc *p = td->td_proc; 2367 2368 if (refcount_load(&p->p_fd->fd_refcnt) == 1) 2369 return; 2370 2371 tmp = fdcopy(p->p_fd); 2372 fdescfree(td); 2373 p->p_fd = tmp; 2374 } 2375 2376 /* 2377 * Unshare a pwddesc structure. 2378 */ 2379 void 2380 pdunshare(struct thread *td) 2381 { 2382 struct pwddesc *pdp; 2383 struct proc *p; 2384 2385 p = td->td_proc; 2386 /* Not shared. */ 2387 if (refcount_load(&p->p_pd->pd_refcount) == 1) 2388 return; 2389 2390 pdp = pdcopy(p->p_pd); 2391 pdescfree(td); 2392 p->p_pd = pdp; 2393 } 2394 2395 /* 2396 * Copy a filedesc structure. A NULL pointer in returns a NULL reference, 2397 * this is to ease callers, not catch errors. 2398 */ 2399 struct filedesc * 2400 fdcopy(struct filedesc *fdp) 2401 { 2402 struct filedesc *newfdp; 2403 struct filedescent *nfde, *ofde; 2404 int i, lastfile; 2405 2406 MPASS(fdp != NULL); 2407 2408 newfdp = fdinit(); 2409 FILEDESC_SLOCK(fdp); 2410 for (;;) { 2411 lastfile = fdlastfile(fdp); 2412 if (lastfile < newfdp->fd_nfiles) 2413 break; 2414 FILEDESC_SUNLOCK(fdp); 2415 fdgrowtable(newfdp, lastfile + 1); 2416 FILEDESC_SLOCK(fdp); 2417 } 2418 /* copy all passable descriptors (i.e. not kqueue) */ 2419 newfdp->fd_freefile = fdp->fd_freefile; 2420 FILEDESC_FOREACH_FDE(fdp, i, ofde) { 2421 if ((ofde->fde_file->f_ops->fo_flags & DFLAG_PASSABLE) == 0 || 2422 !fhold(ofde->fde_file)) { 2423 if (newfdp->fd_freefile == fdp->fd_freefile) 2424 newfdp->fd_freefile = i; 2425 continue; 2426 } 2427 nfde = &newfdp->fd_ofiles[i]; 2428 *nfde = *ofde; 2429 filecaps_copy(&ofde->fde_caps, &nfde->fde_caps, true); 2430 fdused_init(newfdp, i); 2431 } 2432 MPASS(newfdp->fd_freefile != -1); 2433 FILEDESC_SUNLOCK(fdp); 2434 return (newfdp); 2435 } 2436 2437 /* 2438 * Copy a pwddesc structure. 2439 */ 2440 struct pwddesc * 2441 pdcopy(struct pwddesc *pdp) 2442 { 2443 struct pwddesc *newpdp; 2444 2445 MPASS(pdp != NULL); 2446 2447 newpdp = pdinit(pdp, true); 2448 newpdp->pd_cmask = pdp->pd_cmask; 2449 PWDDESC_XUNLOCK(pdp); 2450 return (newpdp); 2451 } 2452 2453 /* 2454 * Clear POSIX style locks. This is only used when fdp looses a reference (i.e. 2455 * one of processes using it exits) and the table used to be shared. 2456 */ 2457 static void 2458 fdclearlocks(struct thread *td) 2459 { 2460 struct filedesc *fdp; 2461 struct filedesc_to_leader *fdtol; 2462 struct flock lf; 2463 struct file *fp; 2464 struct proc *p; 2465 struct vnode *vp; 2466 int i; 2467 2468 p = td->td_proc; 2469 fdp = p->p_fd; 2470 fdtol = p->p_fdtol; 2471 MPASS(fdtol != NULL); 2472 2473 FILEDESC_XLOCK(fdp); 2474 KASSERT(fdtol->fdl_refcount > 0, 2475 ("filedesc_to_refcount botch: fdl_refcount=%d", 2476 fdtol->fdl_refcount)); 2477 if (fdtol->fdl_refcount == 1 && 2478 (p->p_leader->p_flag & P_ADVLOCK) != 0) { 2479 FILEDESC_FOREACH_FP(fdp, i, fp) { 2480 if (fp->f_type != DTYPE_VNODE || 2481 !fhold(fp)) 2482 continue; 2483 FILEDESC_XUNLOCK(fdp); 2484 lf.l_whence = SEEK_SET; 2485 lf.l_start = 0; 2486 lf.l_len = 0; 2487 lf.l_type = F_UNLCK; 2488 vp = fp->f_vnode; 2489 (void) VOP_ADVLOCK(vp, 2490 (caddr_t)p->p_leader, F_UNLCK, 2491 &lf, F_POSIX); 2492 FILEDESC_XLOCK(fdp); 2493 fdrop(fp, td); 2494 } 2495 } 2496 retry: 2497 if (fdtol->fdl_refcount == 1) { 2498 if (fdp->fd_holdleaderscount > 0 && 2499 (p->p_leader->p_flag & P_ADVLOCK) != 0) { 2500 /* 2501 * close() or kern_dup() has cleared a reference 2502 * in a shared file descriptor table. 2503 */ 2504 fdp->fd_holdleaderswakeup = 1; 2505 sx_sleep(&fdp->fd_holdleaderscount, 2506 FILEDESC_LOCK(fdp), PLOCK, "fdlhold", 0); 2507 goto retry; 2508 } 2509 if (fdtol->fdl_holdcount > 0) { 2510 /* 2511 * Ensure that fdtol->fdl_leader remains 2512 * valid in closef(). 2513 */ 2514 fdtol->fdl_wakeup = 1; 2515 sx_sleep(fdtol, FILEDESC_LOCK(fdp), PLOCK, 2516 "fdlhold", 0); 2517 goto retry; 2518 } 2519 } 2520 fdtol->fdl_refcount--; 2521 if (fdtol->fdl_refcount == 0 && 2522 fdtol->fdl_holdcount == 0) { 2523 fdtol->fdl_next->fdl_prev = fdtol->fdl_prev; 2524 fdtol->fdl_prev->fdl_next = fdtol->fdl_next; 2525 } else 2526 fdtol = NULL; 2527 p->p_fdtol = NULL; 2528 FILEDESC_XUNLOCK(fdp); 2529 if (fdtol != NULL) 2530 free(fdtol, M_FILEDESC_TO_LEADER); 2531 } 2532 2533 /* 2534 * Release a filedesc structure. 2535 */ 2536 static void 2537 fdescfree_fds(struct thread *td, struct filedesc *fdp) 2538 { 2539 struct filedesc0 *fdp0; 2540 struct freetable *ft, *tft; 2541 struct filedescent *fde; 2542 struct file *fp; 2543 int i; 2544 2545 KASSERT(refcount_load(&fdp->fd_refcnt) == 0, 2546 ("%s: fd table %p carries references", __func__, fdp)); 2547 2548 /* 2549 * Serialize with threads iterating over the table, if any. 2550 */ 2551 if (refcount_load(&fdp->fd_holdcnt) > 1) { 2552 FILEDESC_XLOCK(fdp); 2553 FILEDESC_XUNLOCK(fdp); 2554 } 2555 2556 FILEDESC_FOREACH_FDE(fdp, i, fde) { 2557 fp = fde->fde_file; 2558 fdefree_last(fde); 2559 (void) closef(fp, td); 2560 } 2561 2562 if (NDSLOTS(fdp->fd_nfiles) > NDSLOTS(NDFILE)) 2563 free(fdp->fd_map, M_FILEDESC); 2564 if (fdp->fd_nfiles > NDFILE) 2565 free(fdp->fd_files, M_FILEDESC); 2566 2567 fdp0 = (struct filedesc0 *)fdp; 2568 SLIST_FOREACH_SAFE(ft, &fdp0->fd_free, ft_next, tft) 2569 free(ft->ft_table, M_FILEDESC); 2570 2571 fddrop(fdp); 2572 } 2573 2574 void 2575 fdescfree(struct thread *td) 2576 { 2577 struct proc *p; 2578 struct filedesc *fdp; 2579 2580 p = td->td_proc; 2581 fdp = p->p_fd; 2582 MPASS(fdp != NULL); 2583 2584 #ifdef RACCT 2585 if (RACCT_ENABLED()) 2586 racct_set_unlocked(p, RACCT_NOFILE, 0); 2587 #endif 2588 2589 if (p->p_fdtol != NULL) 2590 fdclearlocks(td); 2591 2592 /* 2593 * Check fdhold for an explanation. 2594 */ 2595 atomic_store_ptr(&p->p_fd, NULL); 2596 atomic_thread_fence_seq_cst(); 2597 PROC_WAIT_UNLOCKED(p); 2598 2599 if (refcount_release(&fdp->fd_refcnt) == 0) 2600 return; 2601 2602 fdescfree_fds(td, fdp); 2603 } 2604 2605 void 2606 pdescfree(struct thread *td) 2607 { 2608 struct proc *p; 2609 struct pwddesc *pdp; 2610 2611 p = td->td_proc; 2612 pdp = p->p_pd; 2613 MPASS(pdp != NULL); 2614 2615 /* 2616 * Check pdhold for an explanation. 2617 */ 2618 atomic_store_ptr(&p->p_pd, NULL); 2619 atomic_thread_fence_seq_cst(); 2620 PROC_WAIT_UNLOCKED(p); 2621 2622 pddrop(pdp); 2623 } 2624 2625 /* 2626 * For setugid programs, we don't want to people to use that setugidness 2627 * to generate error messages which write to a file which otherwise would 2628 * otherwise be off-limits to the process. We check for filesystems where 2629 * the vnode can change out from under us after execve (like [lin]procfs). 2630 * 2631 * Since fdsetugidsafety calls this only for fd 0, 1 and 2, this check is 2632 * sufficient. We also don't check for setugidness since we know we are. 2633 */ 2634 static bool 2635 is_unsafe(struct file *fp) 2636 { 2637 struct vnode *vp; 2638 2639 if (fp->f_type != DTYPE_VNODE) 2640 return (false); 2641 2642 vp = fp->f_vnode; 2643 return ((vp->v_vflag & VV_PROCDEP) != 0); 2644 } 2645 2646 /* 2647 * Make this setguid thing safe, if at all possible. 2648 */ 2649 void 2650 fdsetugidsafety(struct thread *td) 2651 { 2652 struct filedesc *fdp; 2653 struct file *fp; 2654 int i; 2655 2656 fdp = td->td_proc->p_fd; 2657 KASSERT(refcount_load(&fdp->fd_refcnt) == 1, 2658 ("the fdtable should not be shared")); 2659 MPASS(fdp->fd_nfiles >= 3); 2660 for (i = 0; i <= 2; i++) { 2661 fp = fdp->fd_ofiles[i].fde_file; 2662 if (fp != NULL && is_unsafe(fp)) { 2663 FILEDESC_XLOCK(fdp); 2664 knote_fdclose(td, i); 2665 /* 2666 * NULL-out descriptor prior to close to avoid 2667 * a race while close blocks. 2668 */ 2669 fdfree(fdp, i); 2670 FILEDESC_XUNLOCK(fdp); 2671 (void) closef(fp, td); 2672 } 2673 } 2674 } 2675 2676 /* 2677 * If a specific file object occupies a specific file descriptor, close the 2678 * file descriptor entry and drop a reference on the file object. This is a 2679 * convenience function to handle a subsequent error in a function that calls 2680 * falloc() that handles the race that another thread might have closed the 2681 * file descriptor out from under the thread creating the file object. 2682 */ 2683 void 2684 fdclose(struct thread *td, struct file *fp, int idx) 2685 { 2686 struct filedesc *fdp = td->td_proc->p_fd; 2687 2688 FILEDESC_XLOCK(fdp); 2689 if (fdp->fd_ofiles[idx].fde_file == fp) { 2690 fdfree(fdp, idx); 2691 FILEDESC_XUNLOCK(fdp); 2692 fdrop(fp, td); 2693 } else 2694 FILEDESC_XUNLOCK(fdp); 2695 } 2696 2697 /* 2698 * Close any files on exec? 2699 */ 2700 void 2701 fdcloseexec(struct thread *td) 2702 { 2703 struct filedesc *fdp; 2704 struct filedescent *fde; 2705 struct file *fp; 2706 int i; 2707 2708 fdp = td->td_proc->p_fd; 2709 KASSERT(refcount_load(&fdp->fd_refcnt) == 1, 2710 ("the fdtable should not be shared")); 2711 FILEDESC_FOREACH_FDE(fdp, i, fde) { 2712 fp = fde->fde_file; 2713 if (fp->f_type == DTYPE_MQUEUE || 2714 (fde->fde_flags & UF_EXCLOSE)) { 2715 FILEDESC_XLOCK(fdp); 2716 fdfree(fdp, i); 2717 (void) closefp(fdp, i, fp, td, false, false); 2718 FILEDESC_UNLOCK_ASSERT(fdp); 2719 } 2720 } 2721 } 2722 2723 /* 2724 * It is unsafe for set[ug]id processes to be started with file 2725 * descriptors 0..2 closed, as these descriptors are given implicit 2726 * significance in the Standard C library. fdcheckstd() will create a 2727 * descriptor referencing /dev/null for each of stdin, stdout, and 2728 * stderr that is not already open. 2729 */ 2730 int 2731 fdcheckstd(struct thread *td) 2732 { 2733 struct filedesc *fdp; 2734 register_t save; 2735 int i, error, devnull; 2736 2737 fdp = td->td_proc->p_fd; 2738 KASSERT(refcount_load(&fdp->fd_refcnt) == 1, 2739 ("the fdtable should not be shared")); 2740 MPASS(fdp->fd_nfiles >= 3); 2741 devnull = -1; 2742 for (i = 0; i <= 2; i++) { 2743 if (fdp->fd_ofiles[i].fde_file != NULL) 2744 continue; 2745 2746 save = td->td_retval[0]; 2747 if (devnull != -1) { 2748 error = kern_dup(td, FDDUP_FIXED, 0, devnull, i); 2749 } else { 2750 error = kern_openat(td, AT_FDCWD, "/dev/null", 2751 UIO_SYSSPACE, O_RDWR, 0); 2752 if (error == 0) { 2753 devnull = td->td_retval[0]; 2754 KASSERT(devnull == i, ("we didn't get our fd")); 2755 } 2756 } 2757 td->td_retval[0] = save; 2758 if (error != 0) 2759 return (error); 2760 } 2761 return (0); 2762 } 2763 2764 /* 2765 * Internal form of close. Decrement reference count on file structure. 2766 * Note: td may be NULL when closing a file that was being passed in a 2767 * message. 2768 */ 2769 int 2770 closef(struct file *fp, struct thread *td) 2771 { 2772 struct vnode *vp; 2773 struct flock lf; 2774 struct filedesc_to_leader *fdtol; 2775 struct filedesc *fdp; 2776 2777 MPASS(td != NULL); 2778 2779 /* 2780 * POSIX record locking dictates that any close releases ALL 2781 * locks owned by this process. This is handled by setting 2782 * a flag in the unlock to free ONLY locks obeying POSIX 2783 * semantics, and not to free BSD-style file locks. 2784 * If the descriptor was in a message, POSIX-style locks 2785 * aren't passed with the descriptor, and the thread pointer 2786 * will be NULL. Callers should be careful only to pass a 2787 * NULL thread pointer when there really is no owning 2788 * context that might have locks, or the locks will be 2789 * leaked. 2790 */ 2791 if (fp->f_type == DTYPE_VNODE) { 2792 vp = fp->f_vnode; 2793 if ((td->td_proc->p_leader->p_flag & P_ADVLOCK) != 0) { 2794 lf.l_whence = SEEK_SET; 2795 lf.l_start = 0; 2796 lf.l_len = 0; 2797 lf.l_type = F_UNLCK; 2798 (void) VOP_ADVLOCK(vp, (caddr_t)td->td_proc->p_leader, 2799 F_UNLCK, &lf, F_POSIX); 2800 } 2801 fdtol = td->td_proc->p_fdtol; 2802 if (fdtol != NULL) { 2803 /* 2804 * Handle special case where file descriptor table is 2805 * shared between multiple process leaders. 2806 */ 2807 fdp = td->td_proc->p_fd; 2808 FILEDESC_XLOCK(fdp); 2809 for (fdtol = fdtol->fdl_next; 2810 fdtol != td->td_proc->p_fdtol; 2811 fdtol = fdtol->fdl_next) { 2812 if ((fdtol->fdl_leader->p_flag & 2813 P_ADVLOCK) == 0) 2814 continue; 2815 fdtol->fdl_holdcount++; 2816 FILEDESC_XUNLOCK(fdp); 2817 lf.l_whence = SEEK_SET; 2818 lf.l_start = 0; 2819 lf.l_len = 0; 2820 lf.l_type = F_UNLCK; 2821 vp = fp->f_vnode; 2822 (void) VOP_ADVLOCK(vp, 2823 (caddr_t)fdtol->fdl_leader, F_UNLCK, &lf, 2824 F_POSIX); 2825 FILEDESC_XLOCK(fdp); 2826 fdtol->fdl_holdcount--; 2827 if (fdtol->fdl_holdcount == 0 && 2828 fdtol->fdl_wakeup != 0) { 2829 fdtol->fdl_wakeup = 0; 2830 wakeup(fdtol); 2831 } 2832 } 2833 FILEDESC_XUNLOCK(fdp); 2834 } 2835 } 2836 return (fdrop_close(fp, td)); 2837 } 2838 2839 /* 2840 * Hack for file descriptor passing code. 2841 */ 2842 void 2843 closef_nothread(struct file *fp) 2844 { 2845 2846 fdrop(fp, NULL); 2847 } 2848 2849 /* 2850 * Initialize the file pointer with the specified properties. 2851 * 2852 * The ops are set with release semantics to be certain that the flags, type, 2853 * and data are visible when ops is. This is to prevent ops methods from being 2854 * called with bad data. 2855 */ 2856 void 2857 finit(struct file *fp, u_int flag, short type, void *data, struct fileops *ops) 2858 { 2859 fp->f_data = data; 2860 fp->f_flag = flag; 2861 fp->f_type = type; 2862 atomic_store_rel_ptr((volatile uintptr_t *)&fp->f_ops, (uintptr_t)ops); 2863 } 2864 2865 void 2866 finit_vnode(struct file *fp, u_int flag, void *data, struct fileops *ops) 2867 { 2868 fp->f_seqcount[UIO_READ] = 1; 2869 fp->f_seqcount[UIO_WRITE] = 1; 2870 finit(fp, (flag & FMASK) | (fp->f_flag & FHASLOCK), DTYPE_VNODE, 2871 data, ops); 2872 } 2873 2874 int 2875 fget_cap_noref(struct filedesc *fdp, int fd, cap_rights_t *needrightsp, 2876 struct file **fpp, struct filecaps *havecapsp) 2877 { 2878 struct filedescent *fde; 2879 int error; 2880 2881 FILEDESC_LOCK_ASSERT(fdp); 2882 2883 *fpp = NULL; 2884 fde = fdeget_noref(fdp, fd); 2885 if (fde == NULL) { 2886 error = EBADF; 2887 goto out; 2888 } 2889 2890 #ifdef CAPABILITIES 2891 error = cap_check(cap_rights_fde_inline(fde), needrightsp); 2892 if (error != 0) 2893 goto out; 2894 #endif 2895 2896 if (havecapsp != NULL) 2897 filecaps_copy(&fde->fde_caps, havecapsp, true); 2898 2899 *fpp = fde->fde_file; 2900 2901 error = 0; 2902 out: 2903 return (error); 2904 } 2905 2906 #ifdef CAPABILITIES 2907 int 2908 fget_cap(struct thread *td, int fd, cap_rights_t *needrightsp, 2909 struct file **fpp, struct filecaps *havecapsp) 2910 { 2911 struct filedesc *fdp = td->td_proc->p_fd; 2912 int error; 2913 struct file *fp; 2914 seqc_t seq; 2915 2916 *fpp = NULL; 2917 for (;;) { 2918 error = fget_unlocked_seq(td, fd, needrightsp, &fp, &seq); 2919 if (error != 0) 2920 return (error); 2921 2922 if (havecapsp != NULL) { 2923 if (!filecaps_copy(&fdp->fd_ofiles[fd].fde_caps, 2924 havecapsp, false)) { 2925 fdrop(fp, td); 2926 goto get_locked; 2927 } 2928 } 2929 2930 if (!fd_modified(fdp, fd, seq)) 2931 break; 2932 fdrop(fp, td); 2933 } 2934 2935 *fpp = fp; 2936 return (0); 2937 2938 get_locked: 2939 FILEDESC_SLOCK(fdp); 2940 error = fget_cap_noref(fdp, fd, needrightsp, fpp, havecapsp); 2941 if (error == 0 && !fhold(*fpp)) 2942 error = EBADF; 2943 FILEDESC_SUNLOCK(fdp); 2944 return (error); 2945 } 2946 #else 2947 int 2948 fget_cap(struct thread *td, int fd, cap_rights_t *needrightsp, 2949 struct file **fpp, struct filecaps *havecapsp) 2950 { 2951 int error; 2952 error = fget_unlocked(td, fd, needrightsp, fpp); 2953 if (havecapsp != NULL && error == 0) 2954 filecaps_fill(havecapsp); 2955 2956 return (error); 2957 } 2958 #endif 2959 2960 #ifdef CAPABILITIES 2961 int 2962 fgetvp_lookup_smr(int fd, struct nameidata *ndp, struct vnode **vpp, bool *fsearch) 2963 { 2964 const struct filedescent *fde; 2965 const struct fdescenttbl *fdt; 2966 struct filedesc *fdp; 2967 struct file *fp; 2968 struct vnode *vp; 2969 const cap_rights_t *haverights; 2970 cap_rights_t rights; 2971 seqc_t seq; 2972 2973 VFS_SMR_ASSERT_ENTERED(); 2974 2975 rights = *ndp->ni_rightsneeded; 2976 cap_rights_set_one(&rights, CAP_LOOKUP); 2977 2978 fdp = curproc->p_fd; 2979 fdt = fdp->fd_files; 2980 if (__predict_false((u_int)fd >= fdt->fdt_nfiles)) 2981 return (EBADF); 2982 seq = seqc_read_notmodify(fd_seqc(fdt, fd)); 2983 fde = &fdt->fdt_ofiles[fd]; 2984 haverights = cap_rights_fde_inline(fde); 2985 fp = fde->fde_file; 2986 if (__predict_false(fp == NULL)) 2987 return (EAGAIN); 2988 if (__predict_false(cap_check_inline_transient(haverights, &rights))) 2989 return (EAGAIN); 2990 *fsearch = ((fp->f_flag & FSEARCH) != 0); 2991 vp = fp->f_vnode; 2992 if (__predict_false(vp == NULL)) { 2993 return (EAGAIN); 2994 } 2995 if (!filecaps_copy(&fde->fde_caps, &ndp->ni_filecaps, false)) { 2996 return (EAGAIN); 2997 } 2998 /* 2999 * Use an acquire barrier to force re-reading of fdt so it is 3000 * refreshed for verification. 3001 */ 3002 atomic_thread_fence_acq(); 3003 fdt = fdp->fd_files; 3004 if (__predict_false(!seqc_consistent_no_fence(fd_seqc(fdt, fd), seq))) 3005 return (EAGAIN); 3006 /* 3007 * If file descriptor doesn't have all rights, 3008 * all lookups relative to it must also be 3009 * strictly relative. 3010 * 3011 * Not yet supported by fast path. 3012 */ 3013 CAP_ALL(&rights); 3014 if (!cap_rights_contains(&ndp->ni_filecaps.fc_rights, &rights) || 3015 ndp->ni_filecaps.fc_fcntls != CAP_FCNTL_ALL || 3016 ndp->ni_filecaps.fc_nioctls != -1) { 3017 #ifdef notyet 3018 ndp->ni_lcf |= NI_LCF_STRICTRELATIVE; 3019 #else 3020 return (EAGAIN); 3021 #endif 3022 } 3023 *vpp = vp; 3024 return (0); 3025 } 3026 #else 3027 int 3028 fgetvp_lookup_smr(int fd, struct nameidata *ndp, struct vnode **vpp, bool *fsearch) 3029 { 3030 const struct fdescenttbl *fdt; 3031 struct filedesc *fdp; 3032 struct file *fp; 3033 struct vnode *vp; 3034 3035 VFS_SMR_ASSERT_ENTERED(); 3036 3037 fdp = curproc->p_fd; 3038 fdt = fdp->fd_files; 3039 if (__predict_false((u_int)fd >= fdt->fdt_nfiles)) 3040 return (EBADF); 3041 fp = fdt->fdt_ofiles[fd].fde_file; 3042 if (__predict_false(fp == NULL)) 3043 return (EAGAIN); 3044 *fsearch = ((fp->f_flag & FSEARCH) != 0); 3045 vp = fp->f_vnode; 3046 if (__predict_false(vp == NULL || vp->v_type != VDIR)) { 3047 return (EAGAIN); 3048 } 3049 /* 3050 * Use an acquire barrier to force re-reading of fdt so it is 3051 * refreshed for verification. 3052 */ 3053 atomic_thread_fence_acq(); 3054 fdt = fdp->fd_files; 3055 if (__predict_false(fp != fdt->fdt_ofiles[fd].fde_file)) 3056 return (EAGAIN); 3057 filecaps_fill(&ndp->ni_filecaps); 3058 *vpp = vp; 3059 return (0); 3060 } 3061 #endif 3062 3063 int 3064 fgetvp_lookup(int fd, struct nameidata *ndp, struct vnode **vpp) 3065 { 3066 struct thread *td; 3067 struct file *fp; 3068 struct vnode *vp; 3069 struct componentname *cnp; 3070 cap_rights_t rights; 3071 int error; 3072 3073 td = curthread; 3074 rights = *ndp->ni_rightsneeded; 3075 cap_rights_set_one(&rights, CAP_LOOKUP); 3076 cnp = &ndp->ni_cnd; 3077 3078 error = fget_cap(td, ndp->ni_dirfd, &rights, &fp, &ndp->ni_filecaps); 3079 if (__predict_false(error != 0)) 3080 return (error); 3081 if (__predict_false(fp->f_ops == &badfileops)) { 3082 error = EBADF; 3083 goto out_free; 3084 } 3085 vp = fp->f_vnode; 3086 if (__predict_false(vp == NULL)) { 3087 error = ENOTDIR; 3088 goto out_free; 3089 } 3090 vrefact(vp); 3091 /* 3092 * XXX does not check for VDIR, handled by namei_setup 3093 */ 3094 if ((fp->f_flag & FSEARCH) != 0) 3095 cnp->cn_flags |= NOEXECCHECK; 3096 fdrop(fp, td); 3097 3098 #ifdef CAPABILITIES 3099 /* 3100 * If file descriptor doesn't have all rights, 3101 * all lookups relative to it must also be 3102 * strictly relative. 3103 */ 3104 CAP_ALL(&rights); 3105 if (!cap_rights_contains(&ndp->ni_filecaps.fc_rights, &rights) || 3106 ndp->ni_filecaps.fc_fcntls != CAP_FCNTL_ALL || 3107 ndp->ni_filecaps.fc_nioctls != -1) { 3108 ndp->ni_lcf |= NI_LCF_STRICTRELATIVE; 3109 ndp->ni_resflags |= NIRES_STRICTREL; 3110 } 3111 #endif 3112 3113 /* 3114 * TODO: avoid copying ioctl caps if it can be helped to begin with 3115 */ 3116 if ((cnp->cn_flags & WANTIOCTLCAPS) == 0) 3117 filecaps_free_ioctl(&ndp->ni_filecaps); 3118 3119 *vpp = vp; 3120 return (0); 3121 3122 out_free: 3123 filecaps_free(&ndp->ni_filecaps); 3124 fdrop(fp, td); 3125 return (error); 3126 } 3127 3128 /* 3129 * Fetch the descriptor locklessly. 3130 * 3131 * We avoid fdrop() races by never raising a refcount above 0. To accomplish 3132 * this we have to use a cmpset loop rather than an atomic_add. The descriptor 3133 * must be re-verified once we acquire a reference to be certain that the 3134 * identity is still correct and we did not lose a race due to preemption. 3135 * 3136 * Force a reload of fdt when looping. Another thread could reallocate 3137 * the table before this fd was closed, so it is possible that there is 3138 * a stale fp pointer in cached version. 3139 */ 3140 #ifdef CAPABILITIES 3141 static int 3142 fget_unlocked_seq(struct thread *td, int fd, cap_rights_t *needrightsp, 3143 struct file **fpp, seqc_t *seqp) 3144 { 3145 struct filedesc *fdp; 3146 const struct filedescent *fde; 3147 const struct fdescenttbl *fdt; 3148 struct file *fp; 3149 seqc_t seq; 3150 cap_rights_t haverights; 3151 int error; 3152 3153 fdp = td->td_proc->p_fd; 3154 fdt = fdp->fd_files; 3155 if (__predict_false((u_int)fd >= fdt->fdt_nfiles)) 3156 return (EBADF); 3157 3158 for (;;) { 3159 seq = seqc_read_notmodify(fd_seqc(fdt, fd)); 3160 fde = &fdt->fdt_ofiles[fd]; 3161 haverights = *cap_rights_fde_inline(fde); 3162 fp = fde->fde_file; 3163 if (__predict_false(fp == NULL)) { 3164 if (seqc_consistent(fd_seqc(fdt, fd), seq)) 3165 return (EBADF); 3166 fdt = atomic_load_ptr(&fdp->fd_files); 3167 continue; 3168 } 3169 error = cap_check_inline(&haverights, needrightsp); 3170 if (__predict_false(error != 0)) { 3171 if (seqc_consistent(fd_seqc(fdt, fd), seq)) 3172 return (error); 3173 fdt = atomic_load_ptr(&fdp->fd_files); 3174 continue; 3175 } 3176 if (__predict_false(!refcount_acquire_if_not_zero(&fp->f_count))) { 3177 fdt = atomic_load_ptr(&fdp->fd_files); 3178 continue; 3179 } 3180 /* 3181 * Use an acquire barrier to force re-reading of fdt so it is 3182 * refreshed for verification. 3183 */ 3184 atomic_thread_fence_acq(); 3185 fdt = fdp->fd_files; 3186 if (seqc_consistent_no_fence(fd_seqc(fdt, fd), seq)) 3187 break; 3188 fdrop(fp, td); 3189 } 3190 *fpp = fp; 3191 if (seqp != NULL) { 3192 *seqp = seq; 3193 } 3194 return (0); 3195 } 3196 #else 3197 static int 3198 fget_unlocked_seq(struct thread *td, int fd, cap_rights_t *needrightsp, 3199 struct file **fpp, seqc_t *seqp __unused) 3200 { 3201 struct filedesc *fdp; 3202 const struct fdescenttbl *fdt; 3203 struct file *fp; 3204 3205 fdp = td->td_proc->p_fd; 3206 fdt = fdp->fd_files; 3207 if (__predict_false((u_int)fd >= fdt->fdt_nfiles)) 3208 return (EBADF); 3209 3210 for (;;) { 3211 fp = fdt->fdt_ofiles[fd].fde_file; 3212 if (__predict_false(fp == NULL)) 3213 return (EBADF); 3214 if (__predict_false(!refcount_acquire_if_not_zero(&fp->f_count))) { 3215 fdt = atomic_load_ptr(&fdp->fd_files); 3216 continue; 3217 } 3218 /* 3219 * Use an acquire barrier to force re-reading of fdt so it is 3220 * refreshed for verification. 3221 */ 3222 atomic_thread_fence_acq(); 3223 fdt = fdp->fd_files; 3224 if (__predict_true(fp == fdt->fdt_ofiles[fd].fde_file)) 3225 break; 3226 fdrop(fp, td); 3227 } 3228 *fpp = fp; 3229 return (0); 3230 } 3231 #endif 3232 3233 /* 3234 * See the comments in fget_unlocked_seq for an explanation of how this works. 3235 * 3236 * This is a simplified variant which bails out to the aforementioned routine 3237 * if anything goes wrong. In practice this only happens when userspace is 3238 * racing with itself. 3239 */ 3240 int 3241 fget_unlocked(struct thread *td, int fd, cap_rights_t *needrightsp, 3242 struct file **fpp) 3243 { 3244 struct filedesc *fdp; 3245 #ifdef CAPABILITIES 3246 const struct filedescent *fde; 3247 #endif 3248 const struct fdescenttbl *fdt; 3249 struct file *fp; 3250 #ifdef CAPABILITIES 3251 seqc_t seq; 3252 const cap_rights_t *haverights; 3253 #endif 3254 3255 fdp = td->td_proc->p_fd; 3256 fdt = fdp->fd_files; 3257 if (__predict_false((u_int)fd >= fdt->fdt_nfiles)) { 3258 *fpp = NULL; 3259 return (EBADF); 3260 } 3261 #ifdef CAPABILITIES 3262 seq = seqc_read_notmodify(fd_seqc(fdt, fd)); 3263 fde = &fdt->fdt_ofiles[fd]; 3264 haverights = cap_rights_fde_inline(fde); 3265 fp = fde->fde_file; 3266 #else 3267 fp = fdt->fdt_ofiles[fd].fde_file; 3268 #endif 3269 if (__predict_false(fp == NULL)) 3270 goto out_fallback; 3271 #ifdef CAPABILITIES 3272 if (__predict_false(cap_check_inline_transient(haverights, needrightsp))) 3273 goto out_fallback; 3274 #endif 3275 if (__predict_false(!refcount_acquire_if_not_zero(&fp->f_count))) 3276 goto out_fallback; 3277 3278 /* 3279 * Use an acquire barrier to force re-reading of fdt so it is 3280 * refreshed for verification. 3281 */ 3282 atomic_thread_fence_acq(); 3283 fdt = fdp->fd_files; 3284 #ifdef CAPABILITIES 3285 if (__predict_false(!seqc_consistent_no_fence(fd_seqc(fdt, fd), seq))) 3286 #else 3287 if (__predict_false(fp != fdt->fdt_ofiles[fd].fde_file)) 3288 #endif 3289 goto out_fdrop; 3290 *fpp = fp; 3291 return (0); 3292 out_fdrop: 3293 fdrop(fp, td); 3294 out_fallback: 3295 *fpp = NULL; 3296 return (fget_unlocked_seq(td, fd, needrightsp, fpp, NULL)); 3297 } 3298 3299 /* 3300 * Translate fd -> file when the caller guarantees the file descriptor table 3301 * can't be changed by others. 3302 * 3303 * Note this does not mean the file object itself is only visible to the caller, 3304 * merely that it wont disappear without having to be referenced. 3305 * 3306 * Must be paired with fput_only_user. 3307 */ 3308 #ifdef CAPABILITIES 3309 int 3310 fget_only_user(struct filedesc *fdp, int fd, cap_rights_t *needrightsp, 3311 struct file **fpp) 3312 { 3313 const struct filedescent *fde; 3314 const struct fdescenttbl *fdt; 3315 const cap_rights_t *haverights; 3316 struct file *fp; 3317 int error; 3318 3319 MPASS(FILEDESC_IS_ONLY_USER(fdp)); 3320 3321 *fpp = NULL; 3322 if (__predict_false(fd >= fdp->fd_nfiles)) 3323 return (EBADF); 3324 3325 fdt = fdp->fd_files; 3326 fde = &fdt->fdt_ofiles[fd]; 3327 fp = fde->fde_file; 3328 if (__predict_false(fp == NULL)) 3329 return (EBADF); 3330 MPASS(refcount_load(&fp->f_count) > 0); 3331 haverights = cap_rights_fde_inline(fde); 3332 error = cap_check_inline(haverights, needrightsp); 3333 if (__predict_false(error != 0)) 3334 return (error); 3335 *fpp = fp; 3336 return (0); 3337 } 3338 #else 3339 int 3340 fget_only_user(struct filedesc *fdp, int fd, cap_rights_t *needrightsp, 3341 struct file **fpp) 3342 { 3343 struct file *fp; 3344 3345 MPASS(FILEDESC_IS_ONLY_USER(fdp)); 3346 3347 *fpp = NULL; 3348 if (__predict_false(fd >= fdp->fd_nfiles)) 3349 return (EBADF); 3350 3351 fp = fdp->fd_ofiles[fd].fde_file; 3352 if (__predict_false(fp == NULL)) 3353 return (EBADF); 3354 3355 MPASS(refcount_load(&fp->f_count) > 0); 3356 *fpp = fp; 3357 return (0); 3358 } 3359 #endif 3360 3361 /* 3362 * Extract the file pointer associated with the specified descriptor for the 3363 * current user process. 3364 * 3365 * If the descriptor doesn't exist or doesn't match 'flags', EBADF is 3366 * returned. 3367 * 3368 * File's rights will be checked against the capability rights mask. 3369 * 3370 * If an error occurred the non-zero error is returned and *fpp is set to 3371 * NULL. Otherwise *fpp is held and set and zero is returned. Caller is 3372 * responsible for fdrop(). 3373 */ 3374 static __inline int 3375 _fget(struct thread *td, int fd, struct file **fpp, int flags, 3376 cap_rights_t *needrightsp) 3377 { 3378 struct file *fp; 3379 int error; 3380 3381 *fpp = NULL; 3382 error = fget_unlocked(td, fd, needrightsp, &fp); 3383 if (__predict_false(error != 0)) 3384 return (error); 3385 if (__predict_false(fp->f_ops == &badfileops)) { 3386 fdrop(fp, td); 3387 return (EBADF); 3388 } 3389 3390 /* 3391 * FREAD and FWRITE failure return EBADF as per POSIX. 3392 */ 3393 error = 0; 3394 switch (flags) { 3395 case FREAD: 3396 case FWRITE: 3397 if ((fp->f_flag & flags) == 0) 3398 error = EBADF; 3399 break; 3400 case FEXEC: 3401 if (fp->f_ops != &path_fileops && 3402 ((fp->f_flag & (FREAD | FEXEC)) == 0 || 3403 (fp->f_flag & FWRITE) != 0)) 3404 error = EBADF; 3405 break; 3406 case 0: 3407 break; 3408 default: 3409 KASSERT(0, ("wrong flags")); 3410 } 3411 3412 if (error != 0) { 3413 fdrop(fp, td); 3414 return (error); 3415 } 3416 3417 *fpp = fp; 3418 return (0); 3419 } 3420 3421 int 3422 fget(struct thread *td, int fd, cap_rights_t *rightsp, struct file **fpp) 3423 { 3424 3425 return (_fget(td, fd, fpp, 0, rightsp)); 3426 } 3427 3428 int 3429 fget_mmap(struct thread *td, int fd, cap_rights_t *rightsp, vm_prot_t *maxprotp, 3430 struct file **fpp) 3431 { 3432 int error; 3433 #ifndef CAPABILITIES 3434 error = _fget(td, fd, fpp, 0, rightsp); 3435 if (maxprotp != NULL) 3436 *maxprotp = VM_PROT_ALL; 3437 return (error); 3438 #else 3439 cap_rights_t fdrights; 3440 struct filedesc *fdp; 3441 struct file *fp; 3442 seqc_t seq; 3443 3444 *fpp = NULL; 3445 fdp = td->td_proc->p_fd; 3446 MPASS(cap_rights_is_set(rightsp, CAP_MMAP)); 3447 for (;;) { 3448 error = fget_unlocked_seq(td, fd, rightsp, &fp, &seq); 3449 if (__predict_false(error != 0)) 3450 return (error); 3451 if (__predict_false(fp->f_ops == &badfileops)) { 3452 fdrop(fp, td); 3453 return (EBADF); 3454 } 3455 if (maxprotp != NULL) 3456 fdrights = *cap_rights(fdp, fd); 3457 if (!fd_modified(fdp, fd, seq)) 3458 break; 3459 fdrop(fp, td); 3460 } 3461 3462 /* 3463 * If requested, convert capability rights to access flags. 3464 */ 3465 if (maxprotp != NULL) 3466 *maxprotp = cap_rights_to_vmprot(&fdrights); 3467 *fpp = fp; 3468 return (0); 3469 #endif 3470 } 3471 3472 int 3473 fget_read(struct thread *td, int fd, cap_rights_t *rightsp, struct file **fpp) 3474 { 3475 3476 return (_fget(td, fd, fpp, FREAD, rightsp)); 3477 } 3478 3479 int 3480 fget_write(struct thread *td, int fd, cap_rights_t *rightsp, struct file **fpp) 3481 { 3482 3483 return (_fget(td, fd, fpp, FWRITE, rightsp)); 3484 } 3485 3486 int 3487 fget_fcntl(struct thread *td, int fd, cap_rights_t *rightsp, int needfcntl, 3488 struct file **fpp) 3489 { 3490 #ifndef CAPABILITIES 3491 return (fget_unlocked(td, fd, rightsp, fpp)); 3492 #else 3493 struct filedesc *fdp = td->td_proc->p_fd; 3494 struct file *fp; 3495 int error; 3496 seqc_t seq; 3497 3498 *fpp = NULL; 3499 MPASS(cap_rights_is_set(rightsp, CAP_FCNTL)); 3500 for (;;) { 3501 error = fget_unlocked_seq(td, fd, rightsp, &fp, &seq); 3502 if (error != 0) 3503 return (error); 3504 error = cap_fcntl_check(fdp, fd, needfcntl); 3505 if (!fd_modified(fdp, fd, seq)) 3506 break; 3507 fdrop(fp, td); 3508 } 3509 if (error != 0) { 3510 fdrop(fp, td); 3511 return (error); 3512 } 3513 *fpp = fp; 3514 return (0); 3515 #endif 3516 } 3517 3518 /* 3519 * Like fget() but loads the underlying vnode, or returns an error if the 3520 * descriptor does not represent a vnode. Note that pipes use vnodes but 3521 * never have VM objects. The returned vnode will be vref()'d. 3522 * 3523 * XXX: what about the unused flags ? 3524 */ 3525 static __inline int 3526 _fgetvp(struct thread *td, int fd, int flags, cap_rights_t *needrightsp, 3527 struct vnode **vpp) 3528 { 3529 struct file *fp; 3530 int error; 3531 3532 *vpp = NULL; 3533 error = _fget(td, fd, &fp, flags, needrightsp); 3534 if (error != 0) 3535 return (error); 3536 if (fp->f_vnode == NULL) { 3537 error = EINVAL; 3538 } else { 3539 *vpp = fp->f_vnode; 3540 vrefact(*vpp); 3541 } 3542 fdrop(fp, td); 3543 3544 return (error); 3545 } 3546 3547 int 3548 fgetvp(struct thread *td, int fd, cap_rights_t *rightsp, struct vnode **vpp) 3549 { 3550 3551 return (_fgetvp(td, fd, 0, rightsp, vpp)); 3552 } 3553 3554 int 3555 fgetvp_rights(struct thread *td, int fd, cap_rights_t *needrightsp, 3556 struct filecaps *havecaps, struct vnode **vpp) 3557 { 3558 struct filecaps caps; 3559 struct file *fp; 3560 int error; 3561 3562 error = fget_cap(td, fd, needrightsp, &fp, &caps); 3563 if (error != 0) 3564 return (error); 3565 if (fp->f_ops == &badfileops) { 3566 error = EBADF; 3567 goto out; 3568 } 3569 if (fp->f_vnode == NULL) { 3570 error = EINVAL; 3571 goto out; 3572 } 3573 3574 *havecaps = caps; 3575 *vpp = fp->f_vnode; 3576 vrefact(*vpp); 3577 fdrop(fp, td); 3578 3579 return (0); 3580 out: 3581 filecaps_free(&caps); 3582 fdrop(fp, td); 3583 return (error); 3584 } 3585 3586 int 3587 fgetvp_read(struct thread *td, int fd, cap_rights_t *rightsp, struct vnode **vpp) 3588 { 3589 3590 return (_fgetvp(td, fd, FREAD, rightsp, vpp)); 3591 } 3592 3593 int 3594 fgetvp_exec(struct thread *td, int fd, cap_rights_t *rightsp, struct vnode **vpp) 3595 { 3596 3597 return (_fgetvp(td, fd, FEXEC, rightsp, vpp)); 3598 } 3599 3600 #ifdef notyet 3601 int 3602 fgetvp_write(struct thread *td, int fd, cap_rights_t *rightsp, 3603 struct vnode **vpp) 3604 { 3605 3606 return (_fgetvp(td, fd, FWRITE, rightsp, vpp)); 3607 } 3608 #endif 3609 3610 /* 3611 * Handle the last reference to a file being closed. 3612 * 3613 * Without the noinline attribute clang keeps inlining the func thorough this 3614 * file when fdrop is used. 3615 */ 3616 int __noinline 3617 _fdrop(struct file *fp, struct thread *td) 3618 { 3619 int error; 3620 #ifdef INVARIANTS 3621 int count; 3622 3623 count = refcount_load(&fp->f_count); 3624 if (count != 0) 3625 panic("fdrop: fp %p count %d", fp, count); 3626 #endif 3627 error = fo_close(fp, td); 3628 atomic_subtract_int(&openfiles, 1); 3629 crfree(fp->f_cred); 3630 free(fp->f_advice, M_FADVISE); 3631 uma_zfree(file_zone, fp); 3632 3633 return (error); 3634 } 3635 3636 /* 3637 * Apply an advisory lock on a file descriptor. 3638 * 3639 * Just attempt to get a record lock of the requested type on the entire file 3640 * (l_whence = SEEK_SET, l_start = 0, l_len = 0). 3641 */ 3642 #ifndef _SYS_SYSPROTO_H_ 3643 struct flock_args { 3644 int fd; 3645 int how; 3646 }; 3647 #endif 3648 /* ARGSUSED */ 3649 int 3650 sys_flock(struct thread *td, struct flock_args *uap) 3651 { 3652 struct file *fp; 3653 struct vnode *vp; 3654 struct flock lf; 3655 int error; 3656 3657 error = fget(td, uap->fd, &cap_flock_rights, &fp); 3658 if (error != 0) 3659 return (error); 3660 error = EOPNOTSUPP; 3661 if (fp->f_type != DTYPE_VNODE && fp->f_type != DTYPE_FIFO) { 3662 goto done; 3663 } 3664 if (fp->f_ops == &path_fileops) { 3665 goto done; 3666 } 3667 3668 error = 0; 3669 vp = fp->f_vnode; 3670 lf.l_whence = SEEK_SET; 3671 lf.l_start = 0; 3672 lf.l_len = 0; 3673 if (uap->how & LOCK_UN) { 3674 lf.l_type = F_UNLCK; 3675 atomic_clear_int(&fp->f_flag, FHASLOCK); 3676 error = VOP_ADVLOCK(vp, (caddr_t)fp, F_UNLCK, &lf, F_FLOCK); 3677 goto done; 3678 } 3679 if (uap->how & LOCK_EX) 3680 lf.l_type = F_WRLCK; 3681 else if (uap->how & LOCK_SH) 3682 lf.l_type = F_RDLCK; 3683 else { 3684 error = EBADF; 3685 goto done; 3686 } 3687 atomic_set_int(&fp->f_flag, FHASLOCK); 3688 error = VOP_ADVLOCK(vp, (caddr_t)fp, F_SETLK, &lf, 3689 (uap->how & LOCK_NB) ? F_FLOCK : F_FLOCK | F_WAIT); 3690 done: 3691 fdrop(fp, td); 3692 return (error); 3693 } 3694 /* 3695 * Duplicate the specified descriptor to a free descriptor. 3696 */ 3697 int 3698 dupfdopen(struct thread *td, struct filedesc *fdp, int dfd, int mode, 3699 int openerror, int *indxp) 3700 { 3701 struct filedescent *newfde, *oldfde; 3702 struct file *fp; 3703 u_long *ioctls; 3704 int error, indx; 3705 3706 KASSERT(openerror == ENODEV || openerror == ENXIO, 3707 ("unexpected error %d in %s", openerror, __func__)); 3708 3709 /* 3710 * If the to-be-dup'd fd number is greater than the allowed number 3711 * of file descriptors, or the fd to be dup'd has already been 3712 * closed, then reject. 3713 */ 3714 FILEDESC_XLOCK(fdp); 3715 if ((fp = fget_noref(fdp, dfd)) == NULL) { 3716 FILEDESC_XUNLOCK(fdp); 3717 return (EBADF); 3718 } 3719 3720 error = fdalloc(td, 0, &indx); 3721 if (error != 0) { 3722 FILEDESC_XUNLOCK(fdp); 3723 return (error); 3724 } 3725 3726 /* 3727 * There are two cases of interest here. 3728 * 3729 * For ENODEV simply dup (dfd) to file descriptor (indx) and return. 3730 * 3731 * For ENXIO steal away the file structure from (dfd) and store it in 3732 * (indx). (dfd) is effectively closed by this operation. 3733 */ 3734 switch (openerror) { 3735 case ENODEV: 3736 /* 3737 * Check that the mode the file is being opened for is a 3738 * subset of the mode of the existing descriptor. 3739 */ 3740 if (((mode & (FREAD|FWRITE)) | fp->f_flag) != fp->f_flag) { 3741 fdunused(fdp, indx); 3742 FILEDESC_XUNLOCK(fdp); 3743 return (EACCES); 3744 } 3745 if (!fhold(fp)) { 3746 fdunused(fdp, indx); 3747 FILEDESC_XUNLOCK(fdp); 3748 return (EBADF); 3749 } 3750 newfde = &fdp->fd_ofiles[indx]; 3751 oldfde = &fdp->fd_ofiles[dfd]; 3752 ioctls = filecaps_copy_prep(&oldfde->fde_caps); 3753 #ifdef CAPABILITIES 3754 seqc_write_begin(&newfde->fde_seqc); 3755 #endif 3756 fde_copy(oldfde, newfde); 3757 filecaps_copy_finish(&oldfde->fde_caps, &newfde->fde_caps, 3758 ioctls); 3759 #ifdef CAPABILITIES 3760 seqc_write_end(&newfde->fde_seqc); 3761 #endif 3762 break; 3763 case ENXIO: 3764 /* 3765 * Steal away the file pointer from dfd and stuff it into indx. 3766 */ 3767 newfde = &fdp->fd_ofiles[indx]; 3768 oldfde = &fdp->fd_ofiles[dfd]; 3769 #ifdef CAPABILITIES 3770 seqc_write_begin(&oldfde->fde_seqc); 3771 seqc_write_begin(&newfde->fde_seqc); 3772 #endif 3773 fde_copy(oldfde, newfde); 3774 oldfde->fde_file = NULL; 3775 fdunused(fdp, dfd); 3776 #ifdef CAPABILITIES 3777 seqc_write_end(&newfde->fde_seqc); 3778 seqc_write_end(&oldfde->fde_seqc); 3779 #endif 3780 break; 3781 } 3782 FILEDESC_XUNLOCK(fdp); 3783 *indxp = indx; 3784 return (0); 3785 } 3786 3787 /* 3788 * This sysctl determines if we will allow a process to chroot(2) if it 3789 * has a directory open: 3790 * 0: disallowed for all processes. 3791 * 1: allowed for processes that were not already chroot(2)'ed. 3792 * 2: allowed for all processes. 3793 */ 3794 3795 static int chroot_allow_open_directories = 1; 3796 3797 SYSCTL_INT(_kern, OID_AUTO, chroot_allow_open_directories, CTLFLAG_RW, 3798 &chroot_allow_open_directories, 0, 3799 "Allow a process to chroot(2) if it has a directory open"); 3800 3801 /* 3802 * Helper function for raised chroot(2) security function: Refuse if 3803 * any filedescriptors are open directories. 3804 */ 3805 static int 3806 chroot_refuse_vdir_fds(struct filedesc *fdp) 3807 { 3808 struct vnode *vp; 3809 struct file *fp; 3810 int i; 3811 3812 FILEDESC_LOCK_ASSERT(fdp); 3813 3814 FILEDESC_FOREACH_FP(fdp, i, fp) { 3815 if (fp->f_type == DTYPE_VNODE) { 3816 vp = fp->f_vnode; 3817 if (vp->v_type == VDIR) 3818 return (EPERM); 3819 } 3820 } 3821 return (0); 3822 } 3823 3824 static void 3825 pwd_fill(struct pwd *oldpwd, struct pwd *newpwd) 3826 { 3827 3828 if (newpwd->pwd_cdir == NULL && oldpwd->pwd_cdir != NULL) { 3829 vrefact(oldpwd->pwd_cdir); 3830 newpwd->pwd_cdir = oldpwd->pwd_cdir; 3831 } 3832 3833 if (newpwd->pwd_rdir == NULL && oldpwd->pwd_rdir != NULL) { 3834 vrefact(oldpwd->pwd_rdir); 3835 newpwd->pwd_rdir = oldpwd->pwd_rdir; 3836 } 3837 3838 if (newpwd->pwd_jdir == NULL && oldpwd->pwd_jdir != NULL) { 3839 vrefact(oldpwd->pwd_jdir); 3840 newpwd->pwd_jdir = oldpwd->pwd_jdir; 3841 } 3842 } 3843 3844 struct pwd * 3845 pwd_hold_pwddesc(struct pwddesc *pdp) 3846 { 3847 struct pwd *pwd; 3848 3849 PWDDESC_ASSERT_XLOCKED(pdp); 3850 pwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); 3851 if (pwd != NULL) 3852 refcount_acquire(&pwd->pwd_refcount); 3853 return (pwd); 3854 } 3855 3856 bool 3857 pwd_hold_smr(struct pwd *pwd) 3858 { 3859 3860 MPASS(pwd != NULL); 3861 if (__predict_true(refcount_acquire_if_not_zero(&pwd->pwd_refcount))) { 3862 return (true); 3863 } 3864 return (false); 3865 } 3866 3867 struct pwd * 3868 pwd_hold(struct thread *td) 3869 { 3870 struct pwddesc *pdp; 3871 struct pwd *pwd; 3872 3873 pdp = td->td_proc->p_pd; 3874 3875 vfs_smr_enter(); 3876 pwd = vfs_smr_entered_load(&pdp->pd_pwd); 3877 if (pwd_hold_smr(pwd)) { 3878 vfs_smr_exit(); 3879 return (pwd); 3880 } 3881 vfs_smr_exit(); 3882 PWDDESC_XLOCK(pdp); 3883 pwd = pwd_hold_pwddesc(pdp); 3884 MPASS(pwd != NULL); 3885 PWDDESC_XUNLOCK(pdp); 3886 return (pwd); 3887 } 3888 3889 struct pwd * 3890 pwd_hold_proc(struct proc *p) 3891 { 3892 struct pwddesc *pdp; 3893 struct pwd *pwd; 3894 3895 PROC_ASSERT_HELD(p); 3896 PROC_LOCK(p); 3897 pdp = pdhold(p); 3898 MPASS(pdp != NULL); 3899 PROC_UNLOCK(p); 3900 3901 PWDDESC_XLOCK(pdp); 3902 pwd = pwd_hold_pwddesc(pdp); 3903 MPASS(pwd != NULL); 3904 PWDDESC_XUNLOCK(pdp); 3905 pddrop(pdp); 3906 return (pwd); 3907 } 3908 3909 static struct pwd * 3910 pwd_alloc(void) 3911 { 3912 struct pwd *pwd; 3913 3914 pwd = uma_zalloc_smr(pwd_zone, M_WAITOK); 3915 bzero(pwd, sizeof(*pwd)); 3916 refcount_init(&pwd->pwd_refcount, 1); 3917 return (pwd); 3918 } 3919 3920 void 3921 pwd_drop(struct pwd *pwd) 3922 { 3923 3924 if (!refcount_release(&pwd->pwd_refcount)) 3925 return; 3926 3927 if (pwd->pwd_cdir != NULL) 3928 vrele(pwd->pwd_cdir); 3929 if (pwd->pwd_rdir != NULL) 3930 vrele(pwd->pwd_rdir); 3931 if (pwd->pwd_jdir != NULL) 3932 vrele(pwd->pwd_jdir); 3933 uma_zfree_smr(pwd_zone, pwd); 3934 } 3935 3936 /* 3937 * The caller is responsible for invoking priv_check() and 3938 * mac_vnode_check_chroot() to authorize this operation. 3939 */ 3940 int 3941 pwd_chroot(struct thread *td, struct vnode *vp) 3942 { 3943 struct pwddesc *pdp; 3944 struct filedesc *fdp; 3945 struct pwd *newpwd, *oldpwd; 3946 int error; 3947 3948 fdp = td->td_proc->p_fd; 3949 pdp = td->td_proc->p_pd; 3950 newpwd = pwd_alloc(); 3951 FILEDESC_SLOCK(fdp); 3952 PWDDESC_XLOCK(pdp); 3953 oldpwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); 3954 if (chroot_allow_open_directories == 0 || 3955 (chroot_allow_open_directories == 1 && 3956 oldpwd->pwd_rdir != rootvnode)) { 3957 error = chroot_refuse_vdir_fds(fdp); 3958 FILEDESC_SUNLOCK(fdp); 3959 if (error != 0) { 3960 PWDDESC_XUNLOCK(pdp); 3961 pwd_drop(newpwd); 3962 return (error); 3963 } 3964 } else { 3965 FILEDESC_SUNLOCK(fdp); 3966 } 3967 3968 vrefact(vp); 3969 newpwd->pwd_rdir = vp; 3970 if (oldpwd->pwd_jdir == NULL) { 3971 vrefact(vp); 3972 newpwd->pwd_jdir = vp; 3973 } 3974 pwd_fill(oldpwd, newpwd); 3975 pwd_set(pdp, newpwd); 3976 PWDDESC_XUNLOCK(pdp); 3977 pwd_drop(oldpwd); 3978 return (0); 3979 } 3980 3981 void 3982 pwd_chdir(struct thread *td, struct vnode *vp) 3983 { 3984 struct pwddesc *pdp; 3985 struct pwd *newpwd, *oldpwd; 3986 3987 VNPASS(vp->v_usecount > 0, vp); 3988 3989 newpwd = pwd_alloc(); 3990 pdp = td->td_proc->p_pd; 3991 PWDDESC_XLOCK(pdp); 3992 oldpwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); 3993 newpwd->pwd_cdir = vp; 3994 pwd_fill(oldpwd, newpwd); 3995 pwd_set(pdp, newpwd); 3996 PWDDESC_XUNLOCK(pdp); 3997 pwd_drop(oldpwd); 3998 } 3999 4000 /* 4001 * jail_attach(2) changes both root and working directories. 4002 */ 4003 int 4004 pwd_chroot_chdir(struct thread *td, struct vnode *vp) 4005 { 4006 struct pwddesc *pdp; 4007 struct filedesc *fdp; 4008 struct pwd *newpwd, *oldpwd; 4009 int error; 4010 4011 fdp = td->td_proc->p_fd; 4012 pdp = td->td_proc->p_pd; 4013 newpwd = pwd_alloc(); 4014 FILEDESC_SLOCK(fdp); 4015 PWDDESC_XLOCK(pdp); 4016 oldpwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); 4017 error = chroot_refuse_vdir_fds(fdp); 4018 FILEDESC_SUNLOCK(fdp); 4019 if (error != 0) { 4020 PWDDESC_XUNLOCK(pdp); 4021 pwd_drop(newpwd); 4022 return (error); 4023 } 4024 4025 vrefact(vp); 4026 newpwd->pwd_rdir = vp; 4027 vrefact(vp); 4028 newpwd->pwd_cdir = vp; 4029 if (oldpwd->pwd_jdir == NULL) { 4030 vrefact(vp); 4031 newpwd->pwd_jdir = vp; 4032 } 4033 pwd_fill(oldpwd, newpwd); 4034 pwd_set(pdp, newpwd); 4035 PWDDESC_XUNLOCK(pdp); 4036 pwd_drop(oldpwd); 4037 return (0); 4038 } 4039 4040 void 4041 pwd_ensure_dirs(void) 4042 { 4043 struct pwddesc *pdp; 4044 struct pwd *oldpwd, *newpwd; 4045 4046 pdp = curproc->p_pd; 4047 PWDDESC_XLOCK(pdp); 4048 oldpwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); 4049 if (oldpwd->pwd_cdir != NULL && oldpwd->pwd_rdir != NULL) { 4050 PWDDESC_XUNLOCK(pdp); 4051 return; 4052 } 4053 PWDDESC_XUNLOCK(pdp); 4054 4055 newpwd = pwd_alloc(); 4056 PWDDESC_XLOCK(pdp); 4057 oldpwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); 4058 pwd_fill(oldpwd, newpwd); 4059 if (newpwd->pwd_cdir == NULL) { 4060 vrefact(rootvnode); 4061 newpwd->pwd_cdir = rootvnode; 4062 } 4063 if (newpwd->pwd_rdir == NULL) { 4064 vrefact(rootvnode); 4065 newpwd->pwd_rdir = rootvnode; 4066 } 4067 pwd_set(pdp, newpwd); 4068 PWDDESC_XUNLOCK(pdp); 4069 pwd_drop(oldpwd); 4070 } 4071 4072 void 4073 pwd_set_rootvnode(void) 4074 { 4075 struct pwddesc *pdp; 4076 struct pwd *oldpwd, *newpwd; 4077 4078 pdp = curproc->p_pd; 4079 4080 newpwd = pwd_alloc(); 4081 PWDDESC_XLOCK(pdp); 4082 oldpwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); 4083 vrefact(rootvnode); 4084 newpwd->pwd_cdir = rootvnode; 4085 vrefact(rootvnode); 4086 newpwd->pwd_rdir = rootvnode; 4087 pwd_fill(oldpwd, newpwd); 4088 pwd_set(pdp, newpwd); 4089 PWDDESC_XUNLOCK(pdp); 4090 pwd_drop(oldpwd); 4091 } 4092 4093 /* 4094 * Scan all active processes and prisons to see if any of them have a current 4095 * or root directory of `olddp'. If so, replace them with the new mount point. 4096 */ 4097 void 4098 mountcheckdirs(struct vnode *olddp, struct vnode *newdp) 4099 { 4100 struct pwddesc *pdp; 4101 struct pwd *newpwd, *oldpwd; 4102 struct prison *pr; 4103 struct proc *p; 4104 int nrele; 4105 4106 if (vrefcnt(olddp) == 1) 4107 return; 4108 nrele = 0; 4109 newpwd = pwd_alloc(); 4110 sx_slock(&allproc_lock); 4111 FOREACH_PROC_IN_SYSTEM(p) { 4112 PROC_LOCK(p); 4113 pdp = pdhold(p); 4114 PROC_UNLOCK(p); 4115 if (pdp == NULL) 4116 continue; 4117 PWDDESC_XLOCK(pdp); 4118 oldpwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); 4119 if (oldpwd == NULL || 4120 (oldpwd->pwd_cdir != olddp && 4121 oldpwd->pwd_rdir != olddp && 4122 oldpwd->pwd_jdir != olddp)) { 4123 PWDDESC_XUNLOCK(pdp); 4124 pddrop(pdp); 4125 continue; 4126 } 4127 if (oldpwd->pwd_cdir == olddp) { 4128 vrefact(newdp); 4129 newpwd->pwd_cdir = newdp; 4130 } 4131 if (oldpwd->pwd_rdir == olddp) { 4132 vrefact(newdp); 4133 newpwd->pwd_rdir = newdp; 4134 } 4135 if (oldpwd->pwd_jdir == olddp) { 4136 vrefact(newdp); 4137 newpwd->pwd_jdir = newdp; 4138 } 4139 pwd_fill(oldpwd, newpwd); 4140 pwd_set(pdp, newpwd); 4141 PWDDESC_XUNLOCK(pdp); 4142 pwd_drop(oldpwd); 4143 pddrop(pdp); 4144 newpwd = pwd_alloc(); 4145 } 4146 sx_sunlock(&allproc_lock); 4147 pwd_drop(newpwd); 4148 if (rootvnode == olddp) { 4149 vrefact(newdp); 4150 rootvnode = newdp; 4151 nrele++; 4152 } 4153 mtx_lock(&prison0.pr_mtx); 4154 if (prison0.pr_root == olddp) { 4155 vrefact(newdp); 4156 prison0.pr_root = newdp; 4157 nrele++; 4158 } 4159 mtx_unlock(&prison0.pr_mtx); 4160 sx_slock(&allprison_lock); 4161 TAILQ_FOREACH(pr, &allprison, pr_list) { 4162 mtx_lock(&pr->pr_mtx); 4163 if (pr->pr_root == olddp) { 4164 vrefact(newdp); 4165 pr->pr_root = newdp; 4166 nrele++; 4167 } 4168 mtx_unlock(&pr->pr_mtx); 4169 } 4170 sx_sunlock(&allprison_lock); 4171 while (nrele--) 4172 vrele(olddp); 4173 } 4174 4175 struct filedesc_to_leader * 4176 filedesc_to_leader_alloc(struct filedesc_to_leader *old, struct filedesc *fdp, struct proc *leader) 4177 { 4178 struct filedesc_to_leader *fdtol; 4179 4180 fdtol = malloc(sizeof(struct filedesc_to_leader), 4181 M_FILEDESC_TO_LEADER, M_WAITOK); 4182 fdtol->fdl_refcount = 1; 4183 fdtol->fdl_holdcount = 0; 4184 fdtol->fdl_wakeup = 0; 4185 fdtol->fdl_leader = leader; 4186 if (old != NULL) { 4187 FILEDESC_XLOCK(fdp); 4188 fdtol->fdl_next = old->fdl_next; 4189 fdtol->fdl_prev = old; 4190 old->fdl_next = fdtol; 4191 fdtol->fdl_next->fdl_prev = fdtol; 4192 FILEDESC_XUNLOCK(fdp); 4193 } else { 4194 fdtol->fdl_next = fdtol; 4195 fdtol->fdl_prev = fdtol; 4196 } 4197 return (fdtol); 4198 } 4199 4200 static int 4201 sysctl_kern_proc_nfds(SYSCTL_HANDLER_ARGS) 4202 { 4203 NDSLOTTYPE *map; 4204 struct filedesc *fdp; 4205 u_int namelen; 4206 int count, off, minoff; 4207 4208 namelen = arg2; 4209 if (namelen != 1) 4210 return (EINVAL); 4211 4212 if (*(int *)arg1 != 0) 4213 return (EINVAL); 4214 4215 fdp = curproc->p_fd; 4216 count = 0; 4217 FILEDESC_SLOCK(fdp); 4218 map = fdp->fd_map; 4219 off = NDSLOT(fdp->fd_nfiles - 1); 4220 for (minoff = NDSLOT(0); off >= minoff; --off) 4221 count += bitcountl(map[off]); 4222 FILEDESC_SUNLOCK(fdp); 4223 4224 return (SYSCTL_OUT(req, &count, sizeof(count))); 4225 } 4226 4227 static SYSCTL_NODE(_kern_proc, KERN_PROC_NFDS, nfds, 4228 CTLFLAG_RD|CTLFLAG_CAPRD|CTLFLAG_MPSAFE, sysctl_kern_proc_nfds, 4229 "Number of open file descriptors"); 4230 4231 /* 4232 * Get file structures globally. 4233 */ 4234 static int 4235 sysctl_kern_file(SYSCTL_HANDLER_ARGS) 4236 { 4237 struct xfile xf; 4238 struct filedesc *fdp; 4239 struct file *fp; 4240 struct proc *p; 4241 int error, n; 4242 4243 error = sysctl_wire_old_buffer(req, 0); 4244 if (error != 0) 4245 return (error); 4246 if (req->oldptr == NULL) { 4247 n = 0; 4248 sx_slock(&allproc_lock); 4249 FOREACH_PROC_IN_SYSTEM(p) { 4250 PROC_LOCK(p); 4251 if (p->p_state == PRS_NEW) { 4252 PROC_UNLOCK(p); 4253 continue; 4254 } 4255 fdp = fdhold(p); 4256 PROC_UNLOCK(p); 4257 if (fdp == NULL) 4258 continue; 4259 /* overestimates sparse tables. */ 4260 n += fdp->fd_nfiles; 4261 fddrop(fdp); 4262 } 4263 sx_sunlock(&allproc_lock); 4264 return (SYSCTL_OUT(req, 0, n * sizeof(xf))); 4265 } 4266 error = 0; 4267 bzero(&xf, sizeof(xf)); 4268 xf.xf_size = sizeof(xf); 4269 sx_slock(&allproc_lock); 4270 FOREACH_PROC_IN_SYSTEM(p) { 4271 PROC_LOCK(p); 4272 if (p->p_state == PRS_NEW) { 4273 PROC_UNLOCK(p); 4274 continue; 4275 } 4276 if (p_cansee(req->td, p) != 0) { 4277 PROC_UNLOCK(p); 4278 continue; 4279 } 4280 xf.xf_pid = p->p_pid; 4281 xf.xf_uid = p->p_ucred->cr_uid; 4282 fdp = fdhold(p); 4283 PROC_UNLOCK(p); 4284 if (fdp == NULL) 4285 continue; 4286 FILEDESC_SLOCK(fdp); 4287 if (refcount_load(&fdp->fd_refcnt) == 0) 4288 goto nextproc; 4289 FILEDESC_FOREACH_FP(fdp, n, fp) { 4290 xf.xf_fd = n; 4291 xf.xf_file = (uintptr_t)fp; 4292 xf.xf_data = (uintptr_t)fp->f_data; 4293 xf.xf_vnode = (uintptr_t)fp->f_vnode; 4294 xf.xf_type = (uintptr_t)fp->f_type; 4295 xf.xf_count = refcount_load(&fp->f_count); 4296 xf.xf_msgcount = 0; 4297 xf.xf_offset = foffset_get(fp); 4298 xf.xf_flag = fp->f_flag; 4299 error = SYSCTL_OUT(req, &xf, sizeof(xf)); 4300 4301 /* 4302 * There is no need to re-check the fdtable refcount 4303 * here since the filedesc lock is not dropped in the 4304 * loop body. 4305 */ 4306 if (error != 0) 4307 break; 4308 } 4309 nextproc: 4310 FILEDESC_SUNLOCK(fdp); 4311 fddrop(fdp); 4312 if (error) 4313 break; 4314 } 4315 sx_sunlock(&allproc_lock); 4316 return (error); 4317 } 4318 4319 SYSCTL_PROC(_kern, KERN_FILE, file, CTLTYPE_OPAQUE|CTLFLAG_RD|CTLFLAG_MPSAFE, 4320 0, 0, sysctl_kern_file, "S,xfile", "Entire file table"); 4321 4322 #ifdef KINFO_FILE_SIZE 4323 CTASSERT(sizeof(struct kinfo_file) == KINFO_FILE_SIZE); 4324 #endif 4325 4326 static int 4327 xlate_fflags(int fflags) 4328 { 4329 static const struct { 4330 int fflag; 4331 int kf_fflag; 4332 } fflags_table[] = { 4333 { FAPPEND, KF_FLAG_APPEND }, 4334 { FASYNC, KF_FLAG_ASYNC }, 4335 { FFSYNC, KF_FLAG_FSYNC }, 4336 { FHASLOCK, KF_FLAG_HASLOCK }, 4337 { FNONBLOCK, KF_FLAG_NONBLOCK }, 4338 { FREAD, KF_FLAG_READ }, 4339 { FWRITE, KF_FLAG_WRITE }, 4340 { O_CREAT, KF_FLAG_CREAT }, 4341 { O_DIRECT, KF_FLAG_DIRECT }, 4342 { O_EXCL, KF_FLAG_EXCL }, 4343 { O_EXEC, KF_FLAG_EXEC }, 4344 { O_EXLOCK, KF_FLAG_EXLOCK }, 4345 { O_NOFOLLOW, KF_FLAG_NOFOLLOW }, 4346 { O_SHLOCK, KF_FLAG_SHLOCK }, 4347 { O_TRUNC, KF_FLAG_TRUNC } 4348 }; 4349 unsigned int i; 4350 int kflags; 4351 4352 kflags = 0; 4353 for (i = 0; i < nitems(fflags_table); i++) 4354 if (fflags & fflags_table[i].fflag) 4355 kflags |= fflags_table[i].kf_fflag; 4356 return (kflags); 4357 } 4358 4359 /* Trim unused data from kf_path by truncating the structure size. */ 4360 void 4361 pack_kinfo(struct kinfo_file *kif) 4362 { 4363 4364 kif->kf_structsize = offsetof(struct kinfo_file, kf_path) + 4365 strlen(kif->kf_path) + 1; 4366 kif->kf_structsize = roundup(kif->kf_structsize, sizeof(uint64_t)); 4367 } 4368 4369 static void 4370 export_file_to_kinfo(struct file *fp, int fd, cap_rights_t *rightsp, 4371 struct kinfo_file *kif, struct filedesc *fdp, int flags) 4372 { 4373 int error; 4374 4375 bzero(kif, sizeof(*kif)); 4376 4377 /* Set a default type to allow for empty fill_kinfo() methods. */ 4378 kif->kf_type = KF_TYPE_UNKNOWN; 4379 kif->kf_flags = xlate_fflags(fp->f_flag); 4380 if (rightsp != NULL) 4381 kif->kf_cap_rights = *rightsp; 4382 else 4383 cap_rights_init_zero(&kif->kf_cap_rights); 4384 kif->kf_fd = fd; 4385 kif->kf_ref_count = refcount_load(&fp->f_count); 4386 kif->kf_offset = foffset_get(fp); 4387 4388 /* 4389 * This may drop the filedesc lock, so the 'fp' cannot be 4390 * accessed after this call. 4391 */ 4392 error = fo_fill_kinfo(fp, kif, fdp); 4393 if (error == 0) 4394 kif->kf_status |= KF_ATTR_VALID; 4395 if ((flags & KERN_FILEDESC_PACK_KINFO) != 0) 4396 pack_kinfo(kif); 4397 else 4398 kif->kf_structsize = roundup2(sizeof(*kif), sizeof(uint64_t)); 4399 } 4400 4401 static void 4402 export_vnode_to_kinfo(struct vnode *vp, int fd, int fflags, 4403 struct kinfo_file *kif, int flags) 4404 { 4405 int error; 4406 4407 bzero(kif, sizeof(*kif)); 4408 4409 kif->kf_type = KF_TYPE_VNODE; 4410 error = vn_fill_kinfo_vnode(vp, kif); 4411 if (error == 0) 4412 kif->kf_status |= KF_ATTR_VALID; 4413 kif->kf_flags = xlate_fflags(fflags); 4414 cap_rights_init_zero(&kif->kf_cap_rights); 4415 kif->kf_fd = fd; 4416 kif->kf_ref_count = -1; 4417 kif->kf_offset = -1; 4418 if ((flags & KERN_FILEDESC_PACK_KINFO) != 0) 4419 pack_kinfo(kif); 4420 else 4421 kif->kf_structsize = roundup2(sizeof(*kif), sizeof(uint64_t)); 4422 vrele(vp); 4423 } 4424 4425 struct export_fd_buf { 4426 struct filedesc *fdp; 4427 struct pwddesc *pdp; 4428 struct sbuf *sb; 4429 ssize_t remainder; 4430 struct kinfo_file kif; 4431 int flags; 4432 }; 4433 4434 static int 4435 export_kinfo_to_sb(struct export_fd_buf *efbuf) 4436 { 4437 struct kinfo_file *kif; 4438 4439 kif = &efbuf->kif; 4440 if (efbuf->remainder != -1) { 4441 if (efbuf->remainder < kif->kf_structsize) 4442 return (ENOMEM); 4443 efbuf->remainder -= kif->kf_structsize; 4444 } 4445 if (sbuf_bcat(efbuf->sb, kif, kif->kf_structsize) != 0) 4446 return (sbuf_error(efbuf->sb)); 4447 return (0); 4448 } 4449 4450 static int 4451 export_file_to_sb(struct file *fp, int fd, cap_rights_t *rightsp, 4452 struct export_fd_buf *efbuf) 4453 { 4454 int error; 4455 4456 if (efbuf->remainder == 0) 4457 return (ENOMEM); 4458 export_file_to_kinfo(fp, fd, rightsp, &efbuf->kif, efbuf->fdp, 4459 efbuf->flags); 4460 FILEDESC_SUNLOCK(efbuf->fdp); 4461 error = export_kinfo_to_sb(efbuf); 4462 FILEDESC_SLOCK(efbuf->fdp); 4463 return (error); 4464 } 4465 4466 static int 4467 export_vnode_to_sb(struct vnode *vp, int fd, int fflags, 4468 struct export_fd_buf *efbuf) 4469 { 4470 int error; 4471 4472 if (efbuf->remainder == 0) 4473 return (ENOMEM); 4474 if (efbuf->pdp != NULL) 4475 PWDDESC_XUNLOCK(efbuf->pdp); 4476 export_vnode_to_kinfo(vp, fd, fflags, &efbuf->kif, efbuf->flags); 4477 error = export_kinfo_to_sb(efbuf); 4478 if (efbuf->pdp != NULL) 4479 PWDDESC_XLOCK(efbuf->pdp); 4480 return (error); 4481 } 4482 4483 /* 4484 * Store a process file descriptor information to sbuf. 4485 * 4486 * Takes a locked proc as argument, and returns with the proc unlocked. 4487 */ 4488 int 4489 kern_proc_filedesc_out(struct proc *p, struct sbuf *sb, ssize_t maxlen, 4490 int flags) 4491 { 4492 struct file *fp; 4493 struct filedesc *fdp; 4494 struct pwddesc *pdp; 4495 struct export_fd_buf *efbuf; 4496 struct vnode *cttyvp, *textvp, *tracevp; 4497 struct pwd *pwd; 4498 int error, i; 4499 cap_rights_t rights; 4500 4501 PROC_LOCK_ASSERT(p, MA_OWNED); 4502 4503 /* ktrace vnode */ 4504 tracevp = ktr_get_tracevp(p, true); 4505 /* text vnode */ 4506 textvp = p->p_textvp; 4507 if (textvp != NULL) 4508 vrefact(textvp); 4509 /* Controlling tty. */ 4510 cttyvp = NULL; 4511 if (p->p_pgrp != NULL && p->p_pgrp->pg_session != NULL) { 4512 cttyvp = p->p_pgrp->pg_session->s_ttyvp; 4513 if (cttyvp != NULL) 4514 vrefact(cttyvp); 4515 } 4516 fdp = fdhold(p); 4517 pdp = pdhold(p); 4518 PROC_UNLOCK(p); 4519 4520 efbuf = malloc(sizeof(*efbuf), M_TEMP, M_WAITOK); 4521 efbuf->fdp = NULL; 4522 efbuf->pdp = NULL; 4523 efbuf->sb = sb; 4524 efbuf->remainder = maxlen; 4525 efbuf->flags = flags; 4526 4527 error = 0; 4528 if (tracevp != NULL) 4529 error = export_vnode_to_sb(tracevp, KF_FD_TYPE_TRACE, 4530 FREAD | FWRITE, efbuf); 4531 if (error == 0 && textvp != NULL) 4532 error = export_vnode_to_sb(textvp, KF_FD_TYPE_TEXT, FREAD, 4533 efbuf); 4534 if (error == 0 && cttyvp != NULL) 4535 error = export_vnode_to_sb(cttyvp, KF_FD_TYPE_CTTY, 4536 FREAD | FWRITE, efbuf); 4537 if (error != 0 || pdp == NULL || fdp == NULL) 4538 goto fail; 4539 efbuf->fdp = fdp; 4540 efbuf->pdp = pdp; 4541 PWDDESC_XLOCK(pdp); 4542 pwd = pwd_hold_pwddesc(pdp); 4543 if (pwd != NULL) { 4544 /* working directory */ 4545 if (pwd->pwd_cdir != NULL) { 4546 vrefact(pwd->pwd_cdir); 4547 error = export_vnode_to_sb(pwd->pwd_cdir, 4548 KF_FD_TYPE_CWD, FREAD, efbuf); 4549 } 4550 /* root directory */ 4551 if (error == 0 && pwd->pwd_rdir != NULL) { 4552 vrefact(pwd->pwd_rdir); 4553 error = export_vnode_to_sb(pwd->pwd_rdir, 4554 KF_FD_TYPE_ROOT, FREAD, efbuf); 4555 } 4556 /* jail directory */ 4557 if (error == 0 && pwd->pwd_jdir != NULL) { 4558 vrefact(pwd->pwd_jdir); 4559 error = export_vnode_to_sb(pwd->pwd_jdir, 4560 KF_FD_TYPE_JAIL, FREAD, efbuf); 4561 } 4562 } 4563 PWDDESC_XUNLOCK(pdp); 4564 if (error != 0) 4565 goto fail; 4566 if (pwd != NULL) 4567 pwd_drop(pwd); 4568 FILEDESC_SLOCK(fdp); 4569 if (refcount_load(&fdp->fd_refcnt) == 0) 4570 goto skip; 4571 FILEDESC_FOREACH_FP(fdp, i, fp) { 4572 #ifdef CAPABILITIES 4573 rights = *cap_rights(fdp, i); 4574 #else /* !CAPABILITIES */ 4575 rights = cap_no_rights; 4576 #endif 4577 /* 4578 * Create sysctl entry. It is OK to drop the filedesc 4579 * lock inside of export_file_to_sb() as we will 4580 * re-validate and re-evaluate its properties when the 4581 * loop continues. 4582 */ 4583 error = export_file_to_sb(fp, i, &rights, efbuf); 4584 if (error != 0 || refcount_load(&fdp->fd_refcnt) == 0) 4585 break; 4586 } 4587 skip: 4588 FILEDESC_SUNLOCK(fdp); 4589 fail: 4590 if (fdp != NULL) 4591 fddrop(fdp); 4592 if (pdp != NULL) 4593 pddrop(pdp); 4594 free(efbuf, M_TEMP); 4595 return (error); 4596 } 4597 4598 #define FILEDESC_SBUF_SIZE (sizeof(struct kinfo_file) * 5) 4599 4600 /* 4601 * Get per-process file descriptors for use by procstat(1), et al. 4602 */ 4603 static int 4604 sysctl_kern_proc_filedesc(SYSCTL_HANDLER_ARGS) 4605 { 4606 struct sbuf sb; 4607 struct proc *p; 4608 ssize_t maxlen; 4609 u_int namelen; 4610 int error, error2, *name; 4611 4612 namelen = arg2; 4613 if (namelen != 1) 4614 return (EINVAL); 4615 4616 name = (int *)arg1; 4617 4618 sbuf_new_for_sysctl(&sb, NULL, FILEDESC_SBUF_SIZE, req); 4619 sbuf_clear_flags(&sb, SBUF_INCLUDENUL); 4620 error = pget((pid_t)name[0], PGET_CANDEBUG | PGET_NOTWEXIT, &p); 4621 if (error != 0) { 4622 sbuf_delete(&sb); 4623 return (error); 4624 } 4625 maxlen = req->oldptr != NULL ? req->oldlen : -1; 4626 error = kern_proc_filedesc_out(p, &sb, maxlen, 4627 KERN_FILEDESC_PACK_KINFO); 4628 error2 = sbuf_finish(&sb); 4629 sbuf_delete(&sb); 4630 return (error != 0 ? error : error2); 4631 } 4632 4633 #ifdef COMPAT_FREEBSD7 4634 #ifdef KINFO_OFILE_SIZE 4635 CTASSERT(sizeof(struct kinfo_ofile) == KINFO_OFILE_SIZE); 4636 #endif 4637 4638 static void 4639 kinfo_to_okinfo(struct kinfo_file *kif, struct kinfo_ofile *okif) 4640 { 4641 4642 okif->kf_structsize = sizeof(*okif); 4643 okif->kf_type = kif->kf_type; 4644 okif->kf_fd = kif->kf_fd; 4645 okif->kf_ref_count = kif->kf_ref_count; 4646 okif->kf_flags = kif->kf_flags & (KF_FLAG_READ | KF_FLAG_WRITE | 4647 KF_FLAG_APPEND | KF_FLAG_ASYNC | KF_FLAG_FSYNC | KF_FLAG_NONBLOCK | 4648 KF_FLAG_DIRECT | KF_FLAG_HASLOCK); 4649 okif->kf_offset = kif->kf_offset; 4650 if (kif->kf_type == KF_TYPE_VNODE) 4651 okif->kf_vnode_type = kif->kf_un.kf_file.kf_file_type; 4652 else 4653 okif->kf_vnode_type = KF_VTYPE_VNON; 4654 strlcpy(okif->kf_path, kif->kf_path, sizeof(okif->kf_path)); 4655 if (kif->kf_type == KF_TYPE_SOCKET) { 4656 okif->kf_sock_domain = kif->kf_un.kf_sock.kf_sock_domain0; 4657 okif->kf_sock_type = kif->kf_un.kf_sock.kf_sock_type0; 4658 okif->kf_sock_protocol = kif->kf_un.kf_sock.kf_sock_protocol0; 4659 okif->kf_sa_local = kif->kf_un.kf_sock.kf_sa_local; 4660 okif->kf_sa_peer = kif->kf_un.kf_sock.kf_sa_peer; 4661 } else { 4662 okif->kf_sa_local.ss_family = AF_UNSPEC; 4663 okif->kf_sa_peer.ss_family = AF_UNSPEC; 4664 } 4665 } 4666 4667 static int 4668 export_vnode_for_osysctl(struct vnode *vp, int type, struct kinfo_file *kif, 4669 struct kinfo_ofile *okif, struct pwddesc *pdp, struct sysctl_req *req) 4670 { 4671 int error; 4672 4673 vrefact(vp); 4674 PWDDESC_XUNLOCK(pdp); 4675 export_vnode_to_kinfo(vp, type, 0, kif, KERN_FILEDESC_PACK_KINFO); 4676 kinfo_to_okinfo(kif, okif); 4677 error = SYSCTL_OUT(req, okif, sizeof(*okif)); 4678 PWDDESC_XLOCK(pdp); 4679 return (error); 4680 } 4681 4682 /* 4683 * Get per-process file descriptors for use by procstat(1), et al. 4684 */ 4685 static int 4686 sysctl_kern_proc_ofiledesc(SYSCTL_HANDLER_ARGS) 4687 { 4688 struct kinfo_ofile *okif; 4689 struct kinfo_file *kif; 4690 struct filedesc *fdp; 4691 struct pwddesc *pdp; 4692 struct pwd *pwd; 4693 u_int namelen; 4694 int error, i, *name; 4695 struct file *fp; 4696 struct proc *p; 4697 4698 namelen = arg2; 4699 if (namelen != 1) 4700 return (EINVAL); 4701 4702 name = (int *)arg1; 4703 error = pget((pid_t)name[0], PGET_CANDEBUG | PGET_NOTWEXIT, &p); 4704 if (error != 0) 4705 return (error); 4706 fdp = fdhold(p); 4707 if (fdp != NULL) 4708 pdp = pdhold(p); 4709 PROC_UNLOCK(p); 4710 if (fdp == NULL || pdp == NULL) { 4711 if (fdp != NULL) 4712 fddrop(fdp); 4713 return (ENOENT); 4714 } 4715 kif = malloc(sizeof(*kif), M_TEMP, M_WAITOK); 4716 okif = malloc(sizeof(*okif), M_TEMP, M_WAITOK); 4717 PWDDESC_XLOCK(pdp); 4718 pwd = pwd_hold_pwddesc(pdp); 4719 if (pwd != NULL) { 4720 if (pwd->pwd_cdir != NULL) 4721 export_vnode_for_osysctl(pwd->pwd_cdir, KF_FD_TYPE_CWD, kif, 4722 okif, pdp, req); 4723 if (pwd->pwd_rdir != NULL) 4724 export_vnode_for_osysctl(pwd->pwd_rdir, KF_FD_TYPE_ROOT, kif, 4725 okif, pdp, req); 4726 if (pwd->pwd_jdir != NULL) 4727 export_vnode_for_osysctl(pwd->pwd_jdir, KF_FD_TYPE_JAIL, kif, 4728 okif, pdp, req); 4729 } 4730 PWDDESC_XUNLOCK(pdp); 4731 if (pwd != NULL) 4732 pwd_drop(pwd); 4733 FILEDESC_SLOCK(fdp); 4734 if (refcount_load(&fdp->fd_refcnt) == 0) 4735 goto skip; 4736 FILEDESC_FOREACH_FP(fdp, i, fp) { 4737 export_file_to_kinfo(fp, i, NULL, kif, fdp, 4738 KERN_FILEDESC_PACK_KINFO); 4739 FILEDESC_SUNLOCK(fdp); 4740 kinfo_to_okinfo(kif, okif); 4741 error = SYSCTL_OUT(req, okif, sizeof(*okif)); 4742 FILEDESC_SLOCK(fdp); 4743 if (error != 0 || refcount_load(&fdp->fd_refcnt) == 0) 4744 break; 4745 } 4746 skip: 4747 FILEDESC_SUNLOCK(fdp); 4748 fddrop(fdp); 4749 pddrop(pdp); 4750 free(kif, M_TEMP); 4751 free(okif, M_TEMP); 4752 return (0); 4753 } 4754 4755 static SYSCTL_NODE(_kern_proc, KERN_PROC_OFILEDESC, ofiledesc, 4756 CTLFLAG_RD|CTLFLAG_MPSAFE, sysctl_kern_proc_ofiledesc, 4757 "Process ofiledesc entries"); 4758 #endif /* COMPAT_FREEBSD7 */ 4759 4760 int 4761 vntype_to_kinfo(int vtype) 4762 { 4763 struct { 4764 int vtype; 4765 int kf_vtype; 4766 } vtypes_table[] = { 4767 { VBAD, KF_VTYPE_VBAD }, 4768 { VBLK, KF_VTYPE_VBLK }, 4769 { VCHR, KF_VTYPE_VCHR }, 4770 { VDIR, KF_VTYPE_VDIR }, 4771 { VFIFO, KF_VTYPE_VFIFO }, 4772 { VLNK, KF_VTYPE_VLNK }, 4773 { VNON, KF_VTYPE_VNON }, 4774 { VREG, KF_VTYPE_VREG }, 4775 { VSOCK, KF_VTYPE_VSOCK } 4776 }; 4777 unsigned int i; 4778 4779 /* 4780 * Perform vtype translation. 4781 */ 4782 for (i = 0; i < nitems(vtypes_table); i++) 4783 if (vtypes_table[i].vtype == vtype) 4784 return (vtypes_table[i].kf_vtype); 4785 4786 return (KF_VTYPE_UNKNOWN); 4787 } 4788 4789 static SYSCTL_NODE(_kern_proc, KERN_PROC_FILEDESC, filedesc, 4790 CTLFLAG_RD|CTLFLAG_MPSAFE, sysctl_kern_proc_filedesc, 4791 "Process filedesc entries"); 4792 4793 /* 4794 * Store a process current working directory information to sbuf. 4795 * 4796 * Takes a locked proc as argument, and returns with the proc unlocked. 4797 */ 4798 int 4799 kern_proc_cwd_out(struct proc *p, struct sbuf *sb, ssize_t maxlen) 4800 { 4801 struct pwddesc *pdp; 4802 struct pwd *pwd; 4803 struct export_fd_buf *efbuf; 4804 struct vnode *cdir; 4805 int error; 4806 4807 PROC_LOCK_ASSERT(p, MA_OWNED); 4808 4809 pdp = pdhold(p); 4810 PROC_UNLOCK(p); 4811 if (pdp == NULL) 4812 return (EINVAL); 4813 4814 efbuf = malloc(sizeof(*efbuf), M_TEMP, M_WAITOK); 4815 efbuf->fdp = NULL; 4816 efbuf->pdp = pdp; 4817 efbuf->sb = sb; 4818 efbuf->remainder = maxlen; 4819 efbuf->flags = 0; 4820 4821 PWDDESC_XLOCK(pdp); 4822 pwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); 4823 cdir = pwd->pwd_cdir; 4824 if (cdir == NULL) { 4825 error = EINVAL; 4826 } else { 4827 vrefact(cdir); 4828 error = export_vnode_to_sb(cdir, KF_FD_TYPE_CWD, FREAD, efbuf); 4829 } 4830 PWDDESC_XUNLOCK(pdp); 4831 pddrop(pdp); 4832 free(efbuf, M_TEMP); 4833 return (error); 4834 } 4835 4836 /* 4837 * Get per-process current working directory. 4838 */ 4839 static int 4840 sysctl_kern_proc_cwd(SYSCTL_HANDLER_ARGS) 4841 { 4842 struct sbuf sb; 4843 struct proc *p; 4844 ssize_t maxlen; 4845 u_int namelen; 4846 int error, error2, *name; 4847 4848 namelen = arg2; 4849 if (namelen != 1) 4850 return (EINVAL); 4851 4852 name = (int *)arg1; 4853 4854 sbuf_new_for_sysctl(&sb, NULL, sizeof(struct kinfo_file), req); 4855 sbuf_clear_flags(&sb, SBUF_INCLUDENUL); 4856 error = pget((pid_t)name[0], PGET_CANDEBUG | PGET_NOTWEXIT, &p); 4857 if (error != 0) { 4858 sbuf_delete(&sb); 4859 return (error); 4860 } 4861 maxlen = req->oldptr != NULL ? req->oldlen : -1; 4862 error = kern_proc_cwd_out(p, &sb, maxlen); 4863 error2 = sbuf_finish(&sb); 4864 sbuf_delete(&sb); 4865 return (error != 0 ? error : error2); 4866 } 4867 4868 static SYSCTL_NODE(_kern_proc, KERN_PROC_CWD, cwd, CTLFLAG_RD|CTLFLAG_MPSAFE, 4869 sysctl_kern_proc_cwd, "Process current working directory"); 4870 4871 #ifdef DDB 4872 /* 4873 * For the purposes of debugging, generate a human-readable string for the 4874 * file type. 4875 */ 4876 static const char * 4877 file_type_to_name(short type) 4878 { 4879 4880 switch (type) { 4881 case 0: 4882 return ("zero"); 4883 case DTYPE_VNODE: 4884 return ("vnode"); 4885 case DTYPE_SOCKET: 4886 return ("socket"); 4887 case DTYPE_PIPE: 4888 return ("pipe"); 4889 case DTYPE_FIFO: 4890 return ("fifo"); 4891 case DTYPE_KQUEUE: 4892 return ("kqueue"); 4893 case DTYPE_CRYPTO: 4894 return ("crypto"); 4895 case DTYPE_MQUEUE: 4896 return ("mqueue"); 4897 case DTYPE_SHM: 4898 return ("shm"); 4899 case DTYPE_SEM: 4900 return ("ksem"); 4901 case DTYPE_PTS: 4902 return ("pts"); 4903 case DTYPE_DEV: 4904 return ("dev"); 4905 case DTYPE_PROCDESC: 4906 return ("proc"); 4907 case DTYPE_EVENTFD: 4908 return ("eventfd"); 4909 case DTYPE_LINUXTFD: 4910 return ("ltimer"); 4911 default: 4912 return ("unkn"); 4913 } 4914 } 4915 4916 /* 4917 * For the purposes of debugging, identify a process (if any, perhaps one of 4918 * many) that references the passed file in its file descriptor array. Return 4919 * NULL if none. 4920 */ 4921 static struct proc * 4922 file_to_first_proc(struct file *fp) 4923 { 4924 struct filedesc *fdp; 4925 struct proc *p; 4926 int n; 4927 4928 FOREACH_PROC_IN_SYSTEM(p) { 4929 if (p->p_state == PRS_NEW) 4930 continue; 4931 fdp = p->p_fd; 4932 if (fdp == NULL) 4933 continue; 4934 for (n = 0; n < fdp->fd_nfiles; n++) { 4935 if (fp == fdp->fd_ofiles[n].fde_file) 4936 return (p); 4937 } 4938 } 4939 return (NULL); 4940 } 4941 4942 static void 4943 db_print_file(struct file *fp, int header) 4944 { 4945 #define XPTRWIDTH ((int)howmany(sizeof(void *) * NBBY, 4)) 4946 struct proc *p; 4947 4948 if (header) 4949 db_printf("%*s %6s %*s %8s %4s %5s %6s %*s %5s %s\n", 4950 XPTRWIDTH, "File", "Type", XPTRWIDTH, "Data", "Flag", 4951 "GCFl", "Count", "MCount", XPTRWIDTH, "Vnode", "FPID", 4952 "FCmd"); 4953 p = file_to_first_proc(fp); 4954 db_printf("%*p %6s %*p %08x %04x %5d %6d %*p %5d %s\n", XPTRWIDTH, 4955 fp, file_type_to_name(fp->f_type), XPTRWIDTH, fp->f_data, 4956 fp->f_flag, 0, refcount_load(&fp->f_count), 0, XPTRWIDTH, fp->f_vnode, 4957 p != NULL ? p->p_pid : -1, p != NULL ? p->p_comm : "-"); 4958 4959 #undef XPTRWIDTH 4960 } 4961 4962 DB_SHOW_COMMAND(file, db_show_file) 4963 { 4964 struct file *fp; 4965 4966 if (!have_addr) { 4967 db_printf("usage: show file <addr>\n"); 4968 return; 4969 } 4970 fp = (struct file *)addr; 4971 db_print_file(fp, 1); 4972 } 4973 4974 DB_SHOW_COMMAND(files, db_show_files) 4975 { 4976 struct filedesc *fdp; 4977 struct file *fp; 4978 struct proc *p; 4979 int header; 4980 int n; 4981 4982 header = 1; 4983 FOREACH_PROC_IN_SYSTEM(p) { 4984 if (p->p_state == PRS_NEW) 4985 continue; 4986 if ((fdp = p->p_fd) == NULL) 4987 continue; 4988 for (n = 0; n < fdp->fd_nfiles; ++n) { 4989 if ((fp = fdp->fd_ofiles[n].fde_file) == NULL) 4990 continue; 4991 db_print_file(fp, header); 4992 header = 0; 4993 } 4994 } 4995 } 4996 #endif 4997 4998 SYSCTL_INT(_kern, KERN_MAXFILESPERPROC, maxfilesperproc, CTLFLAG_RW, 4999 &maxfilesperproc, 0, "Maximum files allowed open per process"); 5000 5001 SYSCTL_INT(_kern, KERN_MAXFILES, maxfiles, CTLFLAG_RW, 5002 &maxfiles, 0, "Maximum number of files"); 5003 5004 SYSCTL_INT(_kern, OID_AUTO, openfiles, CTLFLAG_RD, 5005 &openfiles, 0, "System-wide number of open files"); 5006 5007 /* ARGSUSED*/ 5008 static void 5009 filelistinit(void *dummy) 5010 { 5011 5012 file_zone = uma_zcreate("Files", sizeof(struct file), NULL, NULL, 5013 NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE); 5014 filedesc0_zone = uma_zcreate("filedesc0", sizeof(struct filedesc0), 5015 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0); 5016 pwd_zone = uma_zcreate("PWD", sizeof(struct pwd), NULL, NULL, 5017 NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_SMR); 5018 /* 5019 * XXXMJG this is a temporary hack due to boot ordering issues against 5020 * the vnode zone. 5021 */ 5022 vfs_smr = uma_zone_get_smr(pwd_zone); 5023 mtx_init(&sigio_lock, "sigio lock", NULL, MTX_DEF); 5024 } 5025 SYSINIT(select, SI_SUB_LOCK, SI_ORDER_FIRST, filelistinit, NULL); 5026 5027 /*-------------------------------------------------------------------*/ 5028 5029 static int 5030 badfo_readwrite(struct file *fp, struct uio *uio, struct ucred *active_cred, 5031 int flags, struct thread *td) 5032 { 5033 5034 return (EBADF); 5035 } 5036 5037 static int 5038 badfo_truncate(struct file *fp, off_t length, struct ucred *active_cred, 5039 struct thread *td) 5040 { 5041 5042 return (EINVAL); 5043 } 5044 5045 static int 5046 badfo_ioctl(struct file *fp, u_long com, void *data, struct ucred *active_cred, 5047 struct thread *td) 5048 { 5049 5050 return (EBADF); 5051 } 5052 5053 static int 5054 badfo_poll(struct file *fp, int events, struct ucred *active_cred, 5055 struct thread *td) 5056 { 5057 5058 return (0); 5059 } 5060 5061 static int 5062 badfo_kqfilter(struct file *fp, struct knote *kn) 5063 { 5064 5065 return (EBADF); 5066 } 5067 5068 static int 5069 badfo_stat(struct file *fp, struct stat *sb, struct ucred *active_cred) 5070 { 5071 5072 return (EBADF); 5073 } 5074 5075 static int 5076 badfo_close(struct file *fp, struct thread *td) 5077 { 5078 5079 return (0); 5080 } 5081 5082 static int 5083 badfo_chmod(struct file *fp, mode_t mode, struct ucred *active_cred, 5084 struct thread *td) 5085 { 5086 5087 return (EBADF); 5088 } 5089 5090 static int 5091 badfo_chown(struct file *fp, uid_t uid, gid_t gid, struct ucred *active_cred, 5092 struct thread *td) 5093 { 5094 5095 return (EBADF); 5096 } 5097 5098 static int 5099 badfo_sendfile(struct file *fp, int sockfd, struct uio *hdr_uio, 5100 struct uio *trl_uio, off_t offset, size_t nbytes, off_t *sent, int flags, 5101 struct thread *td) 5102 { 5103 5104 return (EBADF); 5105 } 5106 5107 static int 5108 badfo_fill_kinfo(struct file *fp, struct kinfo_file *kif, struct filedesc *fdp) 5109 { 5110 5111 return (0); 5112 } 5113 5114 struct fileops badfileops = { 5115 .fo_read = badfo_readwrite, 5116 .fo_write = badfo_readwrite, 5117 .fo_truncate = badfo_truncate, 5118 .fo_ioctl = badfo_ioctl, 5119 .fo_poll = badfo_poll, 5120 .fo_kqfilter = badfo_kqfilter, 5121 .fo_stat = badfo_stat, 5122 .fo_close = badfo_close, 5123 .fo_chmod = badfo_chmod, 5124 .fo_chown = badfo_chown, 5125 .fo_sendfile = badfo_sendfile, 5126 .fo_fill_kinfo = badfo_fill_kinfo, 5127 }; 5128 5129 static int 5130 path_poll(struct file *fp, int events, struct ucred *active_cred, 5131 struct thread *td) 5132 { 5133 return (POLLNVAL); 5134 } 5135 5136 static int 5137 path_close(struct file *fp, struct thread *td) 5138 { 5139 MPASS(fp->f_type == DTYPE_VNODE); 5140 fp->f_ops = &badfileops; 5141 vrele(fp->f_vnode); 5142 return (0); 5143 } 5144 5145 struct fileops path_fileops = { 5146 .fo_read = badfo_readwrite, 5147 .fo_write = badfo_readwrite, 5148 .fo_truncate = badfo_truncate, 5149 .fo_ioctl = badfo_ioctl, 5150 .fo_poll = path_poll, 5151 .fo_kqfilter = vn_kqfilter_opath, 5152 .fo_stat = vn_statfile, 5153 .fo_close = path_close, 5154 .fo_chmod = badfo_chmod, 5155 .fo_chown = badfo_chown, 5156 .fo_sendfile = badfo_sendfile, 5157 .fo_fill_kinfo = vn_fill_kinfo, 5158 .fo_flags = DFLAG_PASSABLE, 5159 }; 5160 5161 int 5162 invfo_rdwr(struct file *fp, struct uio *uio, struct ucred *active_cred, 5163 int flags, struct thread *td) 5164 { 5165 5166 return (EOPNOTSUPP); 5167 } 5168 5169 int 5170 invfo_truncate(struct file *fp, off_t length, struct ucred *active_cred, 5171 struct thread *td) 5172 { 5173 5174 return (EINVAL); 5175 } 5176 5177 int 5178 invfo_ioctl(struct file *fp, u_long com, void *data, 5179 struct ucred *active_cred, struct thread *td) 5180 { 5181 5182 return (ENOTTY); 5183 } 5184 5185 int 5186 invfo_poll(struct file *fp, int events, struct ucred *active_cred, 5187 struct thread *td) 5188 { 5189 5190 return (poll_no_poll(events)); 5191 } 5192 5193 int 5194 invfo_kqfilter(struct file *fp, struct knote *kn) 5195 { 5196 5197 return (EINVAL); 5198 } 5199 5200 int 5201 invfo_chmod(struct file *fp, mode_t mode, struct ucred *active_cred, 5202 struct thread *td) 5203 { 5204 5205 return (EINVAL); 5206 } 5207 5208 int 5209 invfo_chown(struct file *fp, uid_t uid, gid_t gid, struct ucred *active_cred, 5210 struct thread *td) 5211 { 5212 5213 return (EINVAL); 5214 } 5215 5216 int 5217 invfo_sendfile(struct file *fp, int sockfd, struct uio *hdr_uio, 5218 struct uio *trl_uio, off_t offset, size_t nbytes, off_t *sent, int flags, 5219 struct thread *td) 5220 { 5221 5222 return (EINVAL); 5223 } 5224 5225 /*-------------------------------------------------------------------*/ 5226 5227 /* 5228 * File Descriptor pseudo-device driver (/dev/fd/). 5229 * 5230 * Opening minor device N dup()s the file (if any) connected to file 5231 * descriptor N belonging to the calling process. Note that this driver 5232 * consists of only the ``open()'' routine, because all subsequent 5233 * references to this file will be direct to the other driver. 5234 * 5235 * XXX: we could give this one a cloning event handler if necessary. 5236 */ 5237 5238 /* ARGSUSED */ 5239 static int 5240 fdopen(struct cdev *dev, int mode, int type, struct thread *td) 5241 { 5242 5243 /* 5244 * XXX Kludge: set curthread->td_dupfd to contain the value of the 5245 * the file descriptor being sought for duplication. The error 5246 * return ensures that the vnode for this device will be released 5247 * by vn_open. Open will detect this special error and take the 5248 * actions in dupfdopen below. Other callers of vn_open or VOP_OPEN 5249 * will simply report the error. 5250 */ 5251 td->td_dupfd = dev2unit(dev); 5252 return (ENODEV); 5253 } 5254 5255 static struct cdevsw fildesc_cdevsw = { 5256 .d_version = D_VERSION, 5257 .d_open = fdopen, 5258 .d_name = "FD", 5259 }; 5260 5261 static void 5262 fildesc_drvinit(void *unused) 5263 { 5264 struct cdev *dev; 5265 5266 dev = make_dev_credf(MAKEDEV_ETERNAL, &fildesc_cdevsw, 0, NULL, 5267 UID_ROOT, GID_WHEEL, 0666, "fd/0"); 5268 make_dev_alias(dev, "stdin"); 5269 dev = make_dev_credf(MAKEDEV_ETERNAL, &fildesc_cdevsw, 1, NULL, 5270 UID_ROOT, GID_WHEEL, 0666, "fd/1"); 5271 make_dev_alias(dev, "stdout"); 5272 dev = make_dev_credf(MAKEDEV_ETERNAL, &fildesc_cdevsw, 2, NULL, 5273 UID_ROOT, GID_WHEEL, 0666, "fd/2"); 5274 make_dev_alias(dev, "stderr"); 5275 } 5276 5277 SYSINIT(fildescdev, SI_SUB_DRIVERS, SI_ORDER_MIDDLE, fildesc_drvinit, NULL); 5278