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