1 /*-
2 * SPDX-License-Identifier: BSD-3-Clause
3 *
4 * Copyright (c) 1982, 1986, 1989, 1991, 1993
5 * The Regents of the University of California. All rights reserved.
6 * (c) UNIX System Laboratories, Inc.
7 * All or some portions of this file are derived from material licensed
8 * to the University of California by American Telephone and Telegraph
9 * Co. or Unix System Laboratories, Inc. and are reproduced herein with
10 * the permission of UNIX System Laboratories, Inc.
11 *
12 * Redistribution and use in source and binary forms, with or without
13 * modification, are permitted provided that the following conditions
14 * are met:
15 * 1. Redistributions of source code must retain the above copyright
16 * notice, this list of conditions and the following disclaimer.
17 * 2. Redistributions in binary form must reproduce the above copyright
18 * notice, this list of conditions and the following disclaimer in the
19 * documentation and/or other materials provided with the distribution.
20 * 3. Neither the name of the University nor the names of its contributors
21 * may be used to endorse or promote products derived from this software
22 * without specific prior written permission.
23 *
24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34 * SUCH DAMAGE.
35 *
36 * @(#)kern_descrip.c 8.6 (Berkeley) 4/19/94
37 */
38
39 #include <sys/cdefs.h>
40 __FBSDID("$FreeBSD$");
41
42 #include "opt_capsicum.h"
43 #include "opt_ddb.h"
44 #include "opt_ktrace.h"
45
46 #include <sys/param.h>
47 #include <sys/systm.h>
48
49 #include <sys/capsicum.h>
50 #include <sys/conf.h>
51 #include <sys/fcntl.h>
52 #include <sys/file.h>
53 #include <sys/filedesc.h>
54 #include <sys/filio.h>
55 #include <sys/jail.h>
56 #include <sys/kernel.h>
57 #include <sys/limits.h>
58 #include <sys/lock.h>
59 #include <sys/malloc.h>
60 #include <sys/mount.h>
61 #include <sys/mutex.h>
62 #include <sys/namei.h>
63 #include <sys/selinfo.h>
64 #include <sys/priv.h>
65 #include <sys/proc.h>
66 #include <sys/protosw.h>
67 #include <sys/racct.h>
68 #include <sys/resourcevar.h>
69 #include <sys/sbuf.h>
70 #include <sys/signalvar.h>
71 #include <sys/kdb.h>
72 #include <sys/smr.h>
73 #include <sys/stat.h>
74 #include <sys/sx.h>
75 #include <sys/syscallsubr.h>
76 #include <sys/sysctl.h>
77 #include <sys/sysproto.h>
78 #include <sys/unistd.h>
79 #include <sys/user.h>
80 #include <sys/vnode.h>
81 #ifdef KTRACE
82 #include <sys/ktrace.h>
83 #endif
84
85 #include <net/vnet.h>
86
87 #include <security/audit/audit.h>
88
89 #include <vm/uma.h>
90 #include <vm/vm.h>
91
92 #include <ddb/ddb.h>
93
94 static MALLOC_DEFINE(M_FILEDESC, "filedesc", "Open file descriptor table");
95 static MALLOC_DEFINE(M_PWD, "pwd", "Descriptor table vnodes");
96 static MALLOC_DEFINE(M_PWDDESC, "pwddesc", "Pwd descriptors");
97 static MALLOC_DEFINE(M_FILEDESC_TO_LEADER, "filedesc_to_leader",
98 "file desc to leader structures");
99 static MALLOC_DEFINE(M_SIGIO, "sigio", "sigio structures");
100 MALLOC_DEFINE(M_FILECAPS, "filecaps", "descriptor capabilities");
101
102 MALLOC_DECLARE(M_FADVISE);
103
104 static __read_mostly uma_zone_t file_zone;
105 static __read_mostly uma_zone_t filedesc0_zone;
106 __read_mostly uma_zone_t pwd_zone;
107 VFS_SMR_DECLARE;
108
109 static int closefp(struct filedesc *fdp, int fd, struct file *fp,
110 struct thread *td, bool holdleaders, bool audit);
111 static int fd_first_free(struct filedesc *fdp, int low, int size);
112 static void fdgrowtable(struct filedesc *fdp, int nfd);
113 static void fdgrowtable_exp(struct filedesc *fdp, int nfd);
114 static void fdunused(struct filedesc *fdp, int fd);
115 static void fdused(struct filedesc *fdp, int fd);
116 static int getmaxfd(struct thread *td);
117 static u_long *filecaps_copy_prep(const struct filecaps *src);
118 static void filecaps_copy_finish(const struct filecaps *src,
119 struct filecaps *dst, u_long *ioctls);
120 static u_long *filecaps_free_prep(struct filecaps *fcaps);
121 static void filecaps_free_finish(u_long *ioctls);
122
123 static struct pwd *pwd_alloc(void);
124
125 /*
126 * Each process has:
127 *
128 * - An array of open file descriptors (fd_ofiles)
129 * - An array of file flags (fd_ofileflags)
130 * - A bitmap recording which descriptors are in use (fd_map)
131 *
132 * A process starts out with NDFILE descriptors. The value of NDFILE has
133 * been selected based the historical limit of 20 open files, and an
134 * assumption that the majority of processes, especially short-lived
135 * processes like shells, will never need more.
136 *
137 * If this initial allocation is exhausted, a larger descriptor table and
138 * map are allocated dynamically, and the pointers in the process's struct
139 * filedesc are updated to point to those. This is repeated every time
140 * the process runs out of file descriptors (provided it hasn't hit its
141 * resource limit).
142 *
143 * Since threads may hold references to individual descriptor table
144 * entries, the tables are never freed. Instead, they are placed on a
145 * linked list and freed only when the struct filedesc is released.
146 */
147 #define NDFILE 20
148 #define NDSLOTSIZE sizeof(NDSLOTTYPE)
149 #define NDENTRIES (NDSLOTSIZE * __CHAR_BIT)
150 #define NDSLOT(x) ((x) / NDENTRIES)
151 #define NDBIT(x) ((NDSLOTTYPE)1 << ((x) % NDENTRIES))
152 #define NDSLOTS(x) (((x) + NDENTRIES - 1) / NDENTRIES)
153
154 /*
155 * SLIST entry used to keep track of ofiles which must be reclaimed when
156 * the process exits.
157 */
158 struct freetable {
159 struct fdescenttbl *ft_table;
160 SLIST_ENTRY(freetable) ft_next;
161 };
162
163 /*
164 * Initial allocation: a filedesc structure + the head of SLIST used to
165 * keep track of old ofiles + enough space for NDFILE descriptors.
166 */
167
168 struct fdescenttbl0 {
169 int fdt_nfiles;
170 struct filedescent fdt_ofiles[NDFILE];
171 };
172
173 struct filedesc0 {
174 struct filedesc fd_fd;
175 SLIST_HEAD(, freetable) fd_free;
176 struct fdescenttbl0 fd_dfiles;
177 NDSLOTTYPE fd_dmap[NDSLOTS(NDFILE)];
178 };
179
180 /*
181 * Descriptor management.
182 */
183 static int __exclusive_cache_line openfiles; /* actual number of open files */
184 struct mtx sigio_lock; /* mtx to protect pointers to sigio */
185 void __read_mostly (*mq_fdclose)(struct thread *td, int fd, struct file *fp);
186
187 /*
188 * If low >= size, just return low. Otherwise find the first zero bit in the
189 * given bitmap, starting at low and not exceeding size - 1. Return size if
190 * not found.
191 */
192 static int
193 fd_first_free(struct filedesc *fdp, int low, int size)
194 {
195 NDSLOTTYPE *map = fdp->fd_map;
196 NDSLOTTYPE mask;
197 int off, maxoff;
198
199 if (low >= size)
200 return (low);
201
202 off = NDSLOT(low);
203 if (low % NDENTRIES) {
204 mask = ~(~(NDSLOTTYPE)0 >> (NDENTRIES - (low % NDENTRIES)));
205 if ((mask &= ~map[off]) != 0UL)
206 return (off * NDENTRIES + ffsl(mask) - 1);
207 ++off;
208 }
209 for (maxoff = NDSLOTS(size); off < maxoff; ++off)
210 if (map[off] != ~0UL)
211 return (off * NDENTRIES + ffsl(~map[off]) - 1);
212 return (size);
213 }
214
215 /*
216 * Find the last used fd.
217 *
218 * Call this variant if fdp can't be modified by anyone else (e.g, during exec).
219 * Otherwise use fdlastfile.
220 */
221 int
222 fdlastfile_single(struct filedesc *fdp)
223 {
224 NDSLOTTYPE *map = fdp->fd_map;
225 int off, minoff;
226
227 off = NDSLOT(fdp->fd_nfiles - 1);
228 for (minoff = NDSLOT(0); off >= minoff; --off)
229 if (map[off] != 0)
230 return (off * NDENTRIES + flsl(map[off]) - 1);
231 return (-1);
232 }
233
234 int
235 fdlastfile(struct filedesc *fdp)
236 {
237
238 FILEDESC_LOCK_ASSERT(fdp);
239 return (fdlastfile_single(fdp));
240 }
241
242 static int
243 fdisused(struct filedesc *fdp, int fd)
244 {
245
246 KASSERT(fd >= 0 && fd < fdp->fd_nfiles,
247 ("file descriptor %d out of range (0, %d)", fd, fdp->fd_nfiles));
248
249 return ((fdp->fd_map[NDSLOT(fd)] & NDBIT(fd)) != 0);
250 }
251
252 /*
253 * Mark a file descriptor as used.
254 */
255 static void
256 fdused_init(struct filedesc *fdp, int fd)
257 {
258
259 KASSERT(!fdisused(fdp, fd), ("fd=%d is already used", fd));
260
261 fdp->fd_map[NDSLOT(fd)] |= NDBIT(fd);
262 }
263
264 static void
265 fdused(struct filedesc *fdp, int fd)
266 {
267
268 FILEDESC_XLOCK_ASSERT(fdp);
269
270 fdused_init(fdp, fd);
271 if (fd == fdp->fd_freefile)
272 fdp->fd_freefile++;
273 }
274
275 /*
276 * Mark a file descriptor as unused.
277 */
278 static void
279 fdunused(struct filedesc *fdp, int fd)
280 {
281
282 FILEDESC_XLOCK_ASSERT(fdp);
283
284 KASSERT(fdisused(fdp, fd), ("fd=%d is already unused", fd));
285 KASSERT(fdp->fd_ofiles[fd].fde_file == NULL,
286 ("fd=%d is still in use", fd));
287
288 fdp->fd_map[NDSLOT(fd)] &= ~NDBIT(fd);
289 if (fd < fdp->fd_freefile)
290 fdp->fd_freefile = fd;
291 }
292
293 /*
294 * Free a file descriptor.
295 *
296 * Avoid some work if fdp is about to be destroyed.
297 */
298 static inline void
299 fdefree_last(struct filedescent *fde)
300 {
301
302 filecaps_free(&fde->fde_caps);
303 }
304
305 static inline void
306 fdfree(struct filedesc *fdp, int fd)
307 {
308 struct filedescent *fde;
309
310 FILEDESC_XLOCK_ASSERT(fdp);
311 fde = &fdp->fd_ofiles[fd];
312 #ifdef CAPABILITIES
313 seqc_write_begin(&fde->fde_seqc);
314 #endif
315 fde->fde_file = NULL;
316 #ifdef CAPABILITIES
317 seqc_write_end(&fde->fde_seqc);
318 #endif
319 fdefree_last(fde);
320 fdunused(fdp, fd);
321 }
322
323 /*
324 * System calls on descriptors.
325 */
326 #ifndef _SYS_SYSPROTO_H_
327 struct getdtablesize_args {
328 int dummy;
329 };
330 #endif
331 /* ARGSUSED */
332 int
333 sys_getdtablesize(struct thread *td, struct getdtablesize_args *uap)
334 {
335 #ifdef RACCT
336 uint64_t lim;
337 #endif
338
339 td->td_retval[0] = getmaxfd(td);
340 #ifdef RACCT
341 PROC_LOCK(td->td_proc);
342 lim = racct_get_limit(td->td_proc, RACCT_NOFILE);
343 PROC_UNLOCK(td->td_proc);
344 if (lim < td->td_retval[0])
345 td->td_retval[0] = lim;
346 #endif
347 return (0);
348 }
349
350 /*
351 * Duplicate a file descriptor to a particular value.
352 *
353 * Note: keep in mind that a potential race condition exists when closing
354 * descriptors from a shared descriptor table (via rfork).
355 */
356 #ifndef _SYS_SYSPROTO_H_
357 struct dup2_args {
358 u_int from;
359 u_int to;
360 };
361 #endif
362 /* ARGSUSED */
363 int
364 sys_dup2(struct thread *td, struct dup2_args *uap)
365 {
366
367 return (kern_dup(td, FDDUP_FIXED, 0, (int)uap->from, (int)uap->to));
368 }
369
370 /*
371 * Duplicate a file descriptor.
372 */
373 #ifndef _SYS_SYSPROTO_H_
374 struct dup_args {
375 u_int fd;
376 };
377 #endif
378 /* ARGSUSED */
379 int
380 sys_dup(struct thread *td, struct dup_args *uap)
381 {
382
383 return (kern_dup(td, FDDUP_NORMAL, 0, (int)uap->fd, 0));
384 }
385
386 /*
387 * The file control system call.
388 */
389 #ifndef _SYS_SYSPROTO_H_
390 struct fcntl_args {
391 int fd;
392 int cmd;
393 long arg;
394 };
395 #endif
396 /* ARGSUSED */
397 int
398 sys_fcntl(struct thread *td, struct fcntl_args *uap)
399 {
400
401 return (kern_fcntl_freebsd(td, uap->fd, uap->cmd, uap->arg));
402 }
403
404 int
405 kern_fcntl_freebsd(struct thread *td, int fd, int cmd, long arg)
406 {
407 struct flock fl;
408 struct __oflock ofl;
409 intptr_t arg1;
410 int error, newcmd;
411
412 error = 0;
413 newcmd = cmd;
414 switch (cmd) {
415 case F_OGETLK:
416 case F_OSETLK:
417 case F_OSETLKW:
418 /*
419 * Convert old flock structure to new.
420 */
421 error = copyin((void *)(intptr_t)arg, &ofl, sizeof(ofl));
422 fl.l_start = ofl.l_start;
423 fl.l_len = ofl.l_len;
424 fl.l_pid = ofl.l_pid;
425 fl.l_type = ofl.l_type;
426 fl.l_whence = ofl.l_whence;
427 fl.l_sysid = 0;
428
429 switch (cmd) {
430 case F_OGETLK:
431 newcmd = F_GETLK;
432 break;
433 case F_OSETLK:
434 newcmd = F_SETLK;
435 break;
436 case F_OSETLKW:
437 newcmd = F_SETLKW;
438 break;
439 }
440 arg1 = (intptr_t)&fl;
441 break;
442 case F_GETLK:
443 case F_SETLK:
444 case F_SETLKW:
445 case F_SETLK_REMOTE:
446 error = copyin((void *)(intptr_t)arg, &fl, sizeof(fl));
447 arg1 = (intptr_t)&fl;
448 break;
449 default:
450 arg1 = arg;
451 break;
452 }
453 if (error)
454 return (error);
455 error = kern_fcntl(td, fd, newcmd, arg1);
456 if (error)
457 return (error);
458 if (cmd == F_OGETLK) {
459 ofl.l_start = fl.l_start;
460 ofl.l_len = fl.l_len;
461 ofl.l_pid = fl.l_pid;
462 ofl.l_type = fl.l_type;
463 ofl.l_whence = fl.l_whence;
464 error = copyout(&ofl, (void *)(intptr_t)arg, sizeof(ofl));
465 } else if (cmd == F_GETLK) {
466 error = copyout(&fl, (void *)(intptr_t)arg, sizeof(fl));
467 }
468 return (error);
469 }
470
471 int
472 kern_fcntl(struct thread *td, int fd, int cmd, intptr_t arg)
473 {
474 struct filedesc *fdp;
475 struct flock *flp;
476 struct file *fp, *fp2;
477 struct filedescent *fde;
478 struct proc *p;
479 struct vnode *vp;
480 struct mount *mp;
481 int error, flg, seals, tmp;
482 uint64_t bsize;
483 off_t foffset;
484
485 error = 0;
486 flg = F_POSIX;
487 p = td->td_proc;
488 fdp = p->p_fd;
489
490 AUDIT_ARG_FD(cmd);
491 AUDIT_ARG_CMD(cmd);
492 switch (cmd) {
493 case F_DUPFD:
494 tmp = arg;
495 error = kern_dup(td, FDDUP_FCNTL, 0, fd, tmp);
496 break;
497
498 case F_DUPFD_CLOEXEC:
499 tmp = arg;
500 error = kern_dup(td, FDDUP_FCNTL, FDDUP_FLAG_CLOEXEC, fd, tmp);
501 break;
502
503 case F_DUP2FD:
504 tmp = arg;
505 error = kern_dup(td, FDDUP_FIXED, 0, fd, tmp);
506 break;
507
508 case F_DUP2FD_CLOEXEC:
509 tmp = arg;
510 error = kern_dup(td, FDDUP_FIXED, FDDUP_FLAG_CLOEXEC, fd, tmp);
511 break;
512
513 case F_GETFD:
514 error = EBADF;
515 FILEDESC_SLOCK(fdp);
516 fde = fdeget_locked(fdp, fd);
517 if (fde != NULL) {
518 td->td_retval[0] =
519 (fde->fde_flags & UF_EXCLOSE) ? FD_CLOEXEC : 0;
520 error = 0;
521 }
522 FILEDESC_SUNLOCK(fdp);
523 break;
524
525 case F_SETFD:
526 error = EBADF;
527 FILEDESC_XLOCK(fdp);
528 fde = fdeget_locked(fdp, fd);
529 if (fde != NULL) {
530 fde->fde_flags = (fde->fde_flags & ~UF_EXCLOSE) |
531 (arg & FD_CLOEXEC ? UF_EXCLOSE : 0);
532 error = 0;
533 }
534 FILEDESC_XUNLOCK(fdp);
535 break;
536
537 case F_GETFL:
538 error = fget_fcntl(td, fd, &cap_fcntl_rights, F_GETFL, &fp);
539 if (error != 0)
540 break;
541 td->td_retval[0] = OFLAGS(fp->f_flag);
542 fdrop(fp, td);
543 break;
544
545 case F_SETFL:
546 error = fget_fcntl(td, fd, &cap_fcntl_rights, F_SETFL, &fp);
547 if (error != 0)
548 break;
549 do {
550 tmp = flg = fp->f_flag;
551 tmp &= ~FCNTLFLAGS;
552 tmp |= FFLAGS(arg & ~O_ACCMODE) & FCNTLFLAGS;
553 } while(atomic_cmpset_int(&fp->f_flag, flg, tmp) == 0);
554 tmp = fp->f_flag & FNONBLOCK;
555 error = fo_ioctl(fp, FIONBIO, &tmp, td->td_ucred, td);
556 if (error != 0) {
557 fdrop(fp, td);
558 break;
559 }
560 tmp = fp->f_flag & FASYNC;
561 error = fo_ioctl(fp, FIOASYNC, &tmp, td->td_ucred, td);
562 if (error == 0) {
563 fdrop(fp, td);
564 break;
565 }
566 atomic_clear_int(&fp->f_flag, FNONBLOCK);
567 tmp = 0;
568 (void)fo_ioctl(fp, FIONBIO, &tmp, td->td_ucred, td);
569 fdrop(fp, td);
570 break;
571
572 case F_GETOWN:
573 error = fget_fcntl(td, fd, &cap_fcntl_rights, F_GETOWN, &fp);
574 if (error != 0)
575 break;
576 error = fo_ioctl(fp, FIOGETOWN, &tmp, td->td_ucred, td);
577 if (error == 0)
578 td->td_retval[0] = tmp;
579 fdrop(fp, td);
580 break;
581
582 case F_SETOWN:
583 error = fget_fcntl(td, fd, &cap_fcntl_rights, F_SETOWN, &fp);
584 if (error != 0)
585 break;
586 tmp = arg;
587 error = fo_ioctl(fp, FIOSETOWN, &tmp, td->td_ucred, td);
588 fdrop(fp, td);
589 break;
590
591 case F_SETLK_REMOTE:
592 error = priv_check(td, PRIV_NFS_LOCKD);
593 if (error != 0)
594 return (error);
595 flg = F_REMOTE;
596 goto do_setlk;
597
598 case F_SETLKW:
599 flg |= F_WAIT;
600 /* FALLTHROUGH F_SETLK */
601
602 case F_SETLK:
603 do_setlk:
604 flp = (struct flock *)arg;
605 if ((flg & F_REMOTE) != 0 && flp->l_sysid == 0) {
606 error = EINVAL;
607 break;
608 }
609
610 error = fget_unlocked(fdp, fd, &cap_flock_rights, &fp);
611 if (error != 0)
612 break;
613 if (fp->f_type != DTYPE_VNODE) {
614 error = EBADF;
615 fdrop(fp, td);
616 break;
617 }
618
619 if (flp->l_whence == SEEK_CUR) {
620 foffset = foffset_get(fp);
621 if (foffset < 0 ||
622 (flp->l_start > 0 &&
623 foffset > OFF_MAX - flp->l_start)) {
624 error = EOVERFLOW;
625 fdrop(fp, td);
626 break;
627 }
628 flp->l_start += foffset;
629 }
630
631 vp = fp->f_vnode;
632 switch (flp->l_type) {
633 case F_RDLCK:
634 if ((fp->f_flag & FREAD) == 0) {
635 error = EBADF;
636 break;
637 }
638 if ((p->p_leader->p_flag & P_ADVLOCK) == 0) {
639 PROC_LOCK(p->p_leader);
640 p->p_leader->p_flag |= P_ADVLOCK;
641 PROC_UNLOCK(p->p_leader);
642 }
643 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_SETLK,
644 flp, flg);
645 break;
646 case F_WRLCK:
647 if ((fp->f_flag & FWRITE) == 0) {
648 error = EBADF;
649 break;
650 }
651 if ((p->p_leader->p_flag & P_ADVLOCK) == 0) {
652 PROC_LOCK(p->p_leader);
653 p->p_leader->p_flag |= P_ADVLOCK;
654 PROC_UNLOCK(p->p_leader);
655 }
656 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_SETLK,
657 flp, flg);
658 break;
659 case F_UNLCK:
660 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_UNLCK,
661 flp, flg);
662 break;
663 case F_UNLCKSYS:
664 if (flg != F_REMOTE) {
665 error = EINVAL;
666 break;
667 }
668 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader,
669 F_UNLCKSYS, flp, flg);
670 break;
671 default:
672 error = EINVAL;
673 break;
674 }
675 if (error != 0 || flp->l_type == F_UNLCK ||
676 flp->l_type == F_UNLCKSYS) {
677 fdrop(fp, td);
678 break;
679 }
680
681 /*
682 * Check for a race with close.
683 *
684 * The vnode is now advisory locked (or unlocked, but this case
685 * is not really important) as the caller requested.
686 * We had to drop the filedesc lock, so we need to recheck if
687 * the descriptor is still valid, because if it was closed
688 * in the meantime we need to remove advisory lock from the
689 * vnode - close on any descriptor leading to an advisory
690 * locked vnode, removes that lock.
691 * We will return 0 on purpose in that case, as the result of
692 * successful advisory lock might have been externally visible
693 * already. This is fine - effectively we pretend to the caller
694 * that the closing thread was a bit slower and that the
695 * advisory lock succeeded before the close.
696 */
697 error = fget_unlocked(fdp, fd, &cap_no_rights, &fp2);
698 if (error != 0) {
699 fdrop(fp, td);
700 break;
701 }
702 if (fp != fp2) {
703 flp->l_whence = SEEK_SET;
704 flp->l_start = 0;
705 flp->l_len = 0;
706 flp->l_type = F_UNLCK;
707 (void) VOP_ADVLOCK(vp, (caddr_t)p->p_leader,
708 F_UNLCK, flp, F_POSIX);
709 }
710 fdrop(fp, td);
711 fdrop(fp2, td);
712 break;
713
714 case F_GETLK:
715 error = fget_unlocked(fdp, fd, &cap_flock_rights, &fp);
716 if (error != 0)
717 break;
718 if (fp->f_type != DTYPE_VNODE) {
719 error = EBADF;
720 fdrop(fp, td);
721 break;
722 }
723 flp = (struct flock *)arg;
724 if (flp->l_type != F_RDLCK && flp->l_type != F_WRLCK &&
725 flp->l_type != F_UNLCK) {
726 error = EINVAL;
727 fdrop(fp, td);
728 break;
729 }
730 if (flp->l_whence == SEEK_CUR) {
731 foffset = foffset_get(fp);
732 if ((flp->l_start > 0 &&
733 foffset > OFF_MAX - flp->l_start) ||
734 (flp->l_start < 0 &&
735 foffset < OFF_MIN - flp->l_start)) {
736 error = EOVERFLOW;
737 fdrop(fp, td);
738 break;
739 }
740 flp->l_start += foffset;
741 }
742 vp = fp->f_vnode;
743 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_GETLK, flp,
744 F_POSIX);
745 fdrop(fp, td);
746 break;
747
748 case F_ADD_SEALS:
749 error = fget_unlocked(fdp, fd, &cap_no_rights, &fp);
750 if (error != 0)
751 break;
752 error = fo_add_seals(fp, arg);
753 fdrop(fp, td);
754 break;
755
756 case F_GET_SEALS:
757 error = fget_unlocked(fdp, fd, &cap_no_rights, &fp);
758 if (error != 0)
759 break;
760 if (fo_get_seals(fp, &seals) == 0)
761 td->td_retval[0] = seals;
762 else
763 error = EINVAL;
764 fdrop(fp, td);
765 break;
766
767 case F_RDAHEAD:
768 arg = arg ? 128 * 1024: 0;
769 /* FALLTHROUGH */
770 case F_READAHEAD:
771 error = fget_unlocked(fdp, fd, &cap_no_rights, &fp);
772 if (error != 0)
773 break;
774 if (fp->f_type != DTYPE_VNODE) {
775 fdrop(fp, td);
776 error = EBADF;
777 break;
778 }
779 vp = fp->f_vnode;
780 if (vp->v_type != VREG) {
781 fdrop(fp, td);
782 error = ENOTTY;
783 break;
784 }
785
786 /*
787 * Exclusive lock synchronizes against f_seqcount reads and
788 * writes in sequential_heuristic().
789 */
790 error = vn_lock(vp, LK_EXCLUSIVE);
791 if (error != 0) {
792 fdrop(fp, td);
793 break;
794 }
795 if (arg >= 0) {
796 bsize = fp->f_vnode->v_mount->mnt_stat.f_iosize;
797 arg = MIN(arg, INT_MAX - bsize + 1);
798 fp->f_seqcount[UIO_READ] = MIN(IO_SEQMAX,
799 (arg + bsize - 1) / bsize);
800 atomic_set_int(&fp->f_flag, FRDAHEAD);
801 } else {
802 atomic_clear_int(&fp->f_flag, FRDAHEAD);
803 }
804 VOP_UNLOCK(vp);
805 fdrop(fp, td);
806 break;
807
808 case F_ISUNIONSTACK:
809 /*
810 * Check if the vnode is part of a union stack (either the
811 * "union" flag from mount(2) or unionfs).
812 *
813 * Prior to introduction of this op libc's readdir would call
814 * fstatfs(2), in effect unnecessarily copying kilobytes of
815 * data just to check fs name and a mount flag.
816 *
817 * Fixing the code to handle everything in the kernel instead
818 * is a non-trivial endeavor and has low priority, thus this
819 * horrible kludge facilitates the current behavior in a much
820 * cheaper manner until someone(tm) sorts this out.
821 */
822 error = fget_unlocked(fdp, fd, &cap_no_rights, &fp);
823 if (error != 0)
824 break;
825 if (fp->f_type != DTYPE_VNODE) {
826 fdrop(fp, td);
827 error = EBADF;
828 break;
829 }
830 vp = fp->f_vnode;
831 /*
832 * Since we don't prevent dooming the vnode even non-null mp
833 * found can become immediately stale. This is tolerable since
834 * mount points are type-stable (providing safe memory access)
835 * and any vfs op on this vnode going forward will return an
836 * error (meaning return value in this case is meaningless).
837 */
838 mp = atomic_load_ptr(&vp->v_mount);
839 if (__predict_false(mp == NULL)) {
840 fdrop(fp, td);
841 error = EBADF;
842 break;
843 }
844 td->td_retval[0] = 0;
845 if (mp->mnt_kern_flag & MNTK_UNIONFS ||
846 mp->mnt_flag & MNT_UNION)
847 td->td_retval[0] = 1;
848 fdrop(fp, td);
849 break;
850
851 default:
852 error = EINVAL;
853 break;
854 }
855 return (error);
856 }
857
858 static int
859 getmaxfd(struct thread *td)
860 {
861
862 return (min((int)lim_cur(td, RLIMIT_NOFILE), maxfilesperproc));
863 }
864
865 /*
866 * Common code for dup, dup2, fcntl(F_DUPFD) and fcntl(F_DUP2FD).
867 */
868 int
869 kern_dup(struct thread *td, u_int mode, int flags, int old, int new)
870 {
871 struct filedesc *fdp;
872 struct filedescent *oldfde, *newfde;
873 struct proc *p;
874 struct file *delfp, *oldfp;
875 u_long *oioctls, *nioctls;
876 int error, maxfd;
877
878 p = td->td_proc;
879 fdp = p->p_fd;
880 oioctls = NULL;
881
882 MPASS((flags & ~(FDDUP_FLAG_CLOEXEC)) == 0);
883 MPASS(mode < FDDUP_LASTMODE);
884
885 AUDIT_ARG_FD(old);
886 /* XXXRW: if (flags & FDDUP_FIXED) AUDIT_ARG_FD2(new); */
887
888 /*
889 * Verify we have a valid descriptor to dup from and possibly to
890 * dup to. Unlike dup() and dup2(), fcntl()'s F_DUPFD should
891 * return EINVAL when the new descriptor is out of bounds.
892 */
893 if (old < 0)
894 return (EBADF);
895 if (new < 0)
896 return (mode == FDDUP_FCNTL ? EINVAL : EBADF);
897 maxfd = getmaxfd(td);
898 if (new >= maxfd)
899 return (mode == FDDUP_FCNTL ? EINVAL : EBADF);
900
901 error = EBADF;
902 FILEDESC_XLOCK(fdp);
903 if (fget_locked(fdp, old) == NULL)
904 goto unlock;
905 if ((mode == FDDUP_FIXED || mode == FDDUP_MUSTREPLACE) && old == new) {
906 td->td_retval[0] = new;
907 if (flags & FDDUP_FLAG_CLOEXEC)
908 fdp->fd_ofiles[new].fde_flags |= UF_EXCLOSE;
909 error = 0;
910 goto unlock;
911 }
912
913 oldfde = &fdp->fd_ofiles[old];
914 oldfp = oldfde->fde_file;
915 if (!fhold(oldfp))
916 goto unlock;
917
918 /*
919 * If the caller specified a file descriptor, make sure the file
920 * table is large enough to hold it, and grab it. Otherwise, just
921 * allocate a new descriptor the usual way.
922 */
923 switch (mode) {
924 case FDDUP_NORMAL:
925 case FDDUP_FCNTL:
926 if ((error = fdalloc(td, new, &new)) != 0) {
927 fdrop(oldfp, td);
928 goto unlock;
929 }
930 break;
931 case FDDUP_MUSTREPLACE:
932 /* Target file descriptor must exist. */
933 if (fget_locked(fdp, new) == NULL) {
934 fdrop(oldfp, td);
935 goto unlock;
936 }
937 break;
938 case FDDUP_FIXED:
939 if (new >= fdp->fd_nfiles) {
940 /*
941 * The resource limits are here instead of e.g.
942 * fdalloc(), because the file descriptor table may be
943 * shared between processes, so we can't really use
944 * racct_add()/racct_sub(). Instead of counting the
945 * number of actually allocated descriptors, just put
946 * the limit on the size of the file descriptor table.
947 */
948 #ifdef RACCT
949 if (RACCT_ENABLED()) {
950 error = racct_set_unlocked(p, RACCT_NOFILE, new + 1);
951 if (error != 0) {
952 error = EMFILE;
953 fdrop(oldfp, td);
954 goto unlock;
955 }
956 }
957 #endif
958 fdgrowtable_exp(fdp, new + 1);
959 }
960 if (!fdisused(fdp, new))
961 fdused(fdp, new);
962 break;
963 default:
964 KASSERT(0, ("%s unsupported mode %d", __func__, mode));
965 }
966
967 KASSERT(old != new, ("new fd is same as old"));
968
969 /* Refetch oldfde because the table may have grown and old one freed. */
970 oldfde = &fdp->fd_ofiles[old];
971 KASSERT(oldfp == oldfde->fde_file,
972 ("fdt_ofiles shift from growth observed at fd %d",
973 old));
974
975 newfde = &fdp->fd_ofiles[new];
976 delfp = newfde->fde_file;
977
978 nioctls = filecaps_copy_prep(&oldfde->fde_caps);
979
980 /*
981 * Duplicate the source descriptor.
982 */
983 #ifdef CAPABILITIES
984 seqc_write_begin(&newfde->fde_seqc);
985 #endif
986 oioctls = filecaps_free_prep(&newfde->fde_caps);
987 memcpy(newfde, oldfde, fde_change_size);
988 filecaps_copy_finish(&oldfde->fde_caps, &newfde->fde_caps,
989 nioctls);
990 if ((flags & FDDUP_FLAG_CLOEXEC) != 0)
991 newfde->fde_flags = oldfde->fde_flags | UF_EXCLOSE;
992 else
993 newfde->fde_flags = oldfde->fde_flags & ~UF_EXCLOSE;
994 #ifdef CAPABILITIES
995 seqc_write_end(&newfde->fde_seqc);
996 #endif
997 td->td_retval[0] = new;
998
999 error = 0;
1000
1001 if (delfp != NULL) {
1002 (void) closefp(fdp, new, delfp, td, true, false);
1003 FILEDESC_UNLOCK_ASSERT(fdp);
1004 } else {
1005 unlock:
1006 FILEDESC_XUNLOCK(fdp);
1007 }
1008
1009 filecaps_free_finish(oioctls);
1010 return (error);
1011 }
1012
1013 static void
1014 sigiofree(struct sigio *sigio)
1015 {
1016 crfree(sigio->sio_ucred);
1017 free(sigio, M_SIGIO);
1018 }
1019
1020 static struct sigio *
1021 funsetown_locked(struct sigio *sigio)
1022 {
1023 struct proc *p;
1024 struct pgrp *pg;
1025
1026 SIGIO_ASSERT_LOCKED();
1027
1028 if (sigio == NULL)
1029 return (NULL);
1030 *(sigio->sio_myref) = NULL;
1031 if (sigio->sio_pgid < 0) {
1032 pg = sigio->sio_pgrp;
1033 PGRP_LOCK(pg);
1034 SLIST_REMOVE(&sigio->sio_pgrp->pg_sigiolst, sigio,
1035 sigio, sio_pgsigio);
1036 PGRP_UNLOCK(pg);
1037 } else {
1038 p = sigio->sio_proc;
1039 PROC_LOCK(p);
1040 SLIST_REMOVE(&sigio->sio_proc->p_sigiolst, sigio,
1041 sigio, sio_pgsigio);
1042 PROC_UNLOCK(p);
1043 }
1044 return (sigio);
1045 }
1046
1047 /*
1048 * If sigio is on the list associated with a process or process group,
1049 * disable signalling from the device, remove sigio from the list and
1050 * free sigio.
1051 */
1052 void
1053 funsetown(struct sigio **sigiop)
1054 {
1055 struct sigio *sigio;
1056
1057 /* Racy check, consumers must provide synchronization. */
1058 if (*sigiop == NULL)
1059 return;
1060
1061 SIGIO_LOCK();
1062 sigio = funsetown_locked(*sigiop);
1063 SIGIO_UNLOCK();
1064 if (sigio != NULL)
1065 sigiofree(sigio);
1066 }
1067
1068 /*
1069 * Free a list of sigio structures. The caller must ensure that new sigio
1070 * structures cannot be added after this point. For process groups this is
1071 * guaranteed using the proctree lock; for processes, the P_WEXIT flag serves
1072 * as an interlock.
1073 */
1074 void
1075 funsetownlst(struct sigiolst *sigiolst)
1076 {
1077 struct proc *p;
1078 struct pgrp *pg;
1079 struct sigio *sigio, *tmp;
1080
1081 /* Racy check. */
1082 sigio = SLIST_FIRST(sigiolst);
1083 if (sigio == NULL)
1084 return;
1085
1086 p = NULL;
1087 pg = NULL;
1088
1089 SIGIO_LOCK();
1090 sigio = SLIST_FIRST(sigiolst);
1091 if (sigio == NULL) {
1092 SIGIO_UNLOCK();
1093 return;
1094 }
1095
1096 /*
1097 * Every entry of the list should belong to a single proc or pgrp.
1098 */
1099 if (sigio->sio_pgid < 0) {
1100 pg = sigio->sio_pgrp;
1101 sx_assert(&proctree_lock, SX_XLOCKED);
1102 PGRP_LOCK(pg);
1103 } else /* if (sigio->sio_pgid > 0) */ {
1104 p = sigio->sio_proc;
1105 PROC_LOCK(p);
1106 KASSERT((p->p_flag & P_WEXIT) != 0,
1107 ("%s: process %p is not exiting", __func__, p));
1108 }
1109
1110 SLIST_FOREACH(sigio, sigiolst, sio_pgsigio) {
1111 *sigio->sio_myref = NULL;
1112 if (pg != NULL) {
1113 KASSERT(sigio->sio_pgid < 0,
1114 ("Proc sigio in pgrp sigio list"));
1115 KASSERT(sigio->sio_pgrp == pg,
1116 ("Bogus pgrp in sigio list"));
1117 } else /* if (p != NULL) */ {
1118 KASSERT(sigio->sio_pgid > 0,
1119 ("Pgrp sigio in proc sigio list"));
1120 KASSERT(sigio->sio_proc == p,
1121 ("Bogus proc in sigio list"));
1122 }
1123 }
1124
1125 if (pg != NULL)
1126 PGRP_UNLOCK(pg);
1127 else
1128 PROC_UNLOCK(p);
1129 SIGIO_UNLOCK();
1130
1131 SLIST_FOREACH_SAFE(sigio, sigiolst, sio_pgsigio, tmp)
1132 sigiofree(sigio);
1133 }
1134
1135 /*
1136 * This is common code for FIOSETOWN ioctl called by fcntl(fd, F_SETOWN, arg).
1137 *
1138 * After permission checking, add a sigio structure to the sigio list for
1139 * the process or process group.
1140 */
1141 int
1142 fsetown(pid_t pgid, struct sigio **sigiop)
1143 {
1144 struct proc *proc;
1145 struct pgrp *pgrp;
1146 struct sigio *osigio, *sigio;
1147 int ret;
1148
1149 if (pgid == 0) {
1150 funsetown(sigiop);
1151 return (0);
1152 }
1153
1154 ret = 0;
1155
1156 sigio = malloc(sizeof(struct sigio), M_SIGIO, M_WAITOK);
1157 sigio->sio_pgid = pgid;
1158 sigio->sio_ucred = crhold(curthread->td_ucred);
1159 sigio->sio_myref = sigiop;
1160
1161 sx_slock(&proctree_lock);
1162 SIGIO_LOCK();
1163 osigio = funsetown_locked(*sigiop);
1164 if (pgid > 0) {
1165 proc = pfind(pgid);
1166 if (proc == NULL) {
1167 ret = ESRCH;
1168 goto fail;
1169 }
1170
1171 /*
1172 * Policy - Don't allow a process to FSETOWN a process
1173 * in another session.
1174 *
1175 * Remove this test to allow maximum flexibility or
1176 * restrict FSETOWN to the current process or process
1177 * group for maximum safety.
1178 */
1179 if (proc->p_session != curthread->td_proc->p_session) {
1180 PROC_UNLOCK(proc);
1181 ret = EPERM;
1182 goto fail;
1183 }
1184
1185 sigio->sio_proc = proc;
1186 SLIST_INSERT_HEAD(&proc->p_sigiolst, sigio, sio_pgsigio);
1187 PROC_UNLOCK(proc);
1188 } else /* if (pgid < 0) */ {
1189 pgrp = pgfind(-pgid);
1190 if (pgrp == NULL) {
1191 ret = ESRCH;
1192 goto fail;
1193 }
1194
1195 /*
1196 * Policy - Don't allow a process to FSETOWN a process
1197 * in another session.
1198 *
1199 * Remove this test to allow maximum flexibility or
1200 * restrict FSETOWN to the current process or process
1201 * group for maximum safety.
1202 */
1203 if (pgrp->pg_session != curthread->td_proc->p_session) {
1204 PGRP_UNLOCK(pgrp);
1205 ret = EPERM;
1206 goto fail;
1207 }
1208
1209 SLIST_INSERT_HEAD(&pgrp->pg_sigiolst, sigio, sio_pgsigio);
1210 sigio->sio_pgrp = pgrp;
1211 PGRP_UNLOCK(pgrp);
1212 }
1213 sx_sunlock(&proctree_lock);
1214 *sigiop = sigio;
1215 SIGIO_UNLOCK();
1216 if (osigio != NULL)
1217 sigiofree(osigio);
1218 return (0);
1219
1220 fail:
1221 SIGIO_UNLOCK();
1222 sx_sunlock(&proctree_lock);
1223 sigiofree(sigio);
1224 if (osigio != NULL)
1225 sigiofree(osigio);
1226 return (ret);
1227 }
1228
1229 /*
1230 * This is common code for FIOGETOWN ioctl called by fcntl(fd, F_GETOWN, arg).
1231 */
1232 pid_t
1233 fgetown(struct sigio **sigiop)
1234 {
1235 pid_t pgid;
1236
1237 SIGIO_LOCK();
1238 pgid = (*sigiop != NULL) ? (*sigiop)->sio_pgid : 0;
1239 SIGIO_UNLOCK();
1240 return (pgid);
1241 }
1242
1243 static int
1244 closefp_impl(struct filedesc *fdp, int fd, struct file *fp, struct thread *td,
1245 bool audit)
1246 {
1247 int error;
1248
1249 FILEDESC_XLOCK_ASSERT(fdp);
1250
1251 /*
1252 * We now hold the fp reference that used to be owned by the
1253 * descriptor array. We have to unlock the FILEDESC *AFTER*
1254 * knote_fdclose to prevent a race of the fd getting opened, a knote
1255 * added, and deleteing a knote for the new fd.
1256 */
1257 if (__predict_false(!TAILQ_EMPTY(&fdp->fd_kqlist)))
1258 knote_fdclose(td, fd);
1259
1260 /*
1261 * We need to notify mqueue if the object is of type mqueue.
1262 */
1263 if (__predict_false(fp->f_type == DTYPE_MQUEUE))
1264 mq_fdclose(td, fd, fp);
1265 FILEDESC_XUNLOCK(fdp);
1266
1267 #ifdef AUDIT
1268 if (AUDITING_TD(td) && audit)
1269 audit_sysclose(td, fd, fp);
1270 #endif
1271 error = closef(fp, td);
1272
1273 /*
1274 * All paths leading up to closefp() will have already removed or
1275 * replaced the fd in the filedesc table, so a restart would not
1276 * operate on the same file.
1277 */
1278 if (error == ERESTART)
1279 error = EINTR;
1280
1281 return (error);
1282 }
1283
1284 static int
1285 closefp_hl(struct filedesc *fdp, int fd, struct file *fp, struct thread *td,
1286 bool holdleaders, bool audit)
1287 {
1288 int error;
1289
1290 FILEDESC_XLOCK_ASSERT(fdp);
1291
1292 if (holdleaders) {
1293 if (td->td_proc->p_fdtol != NULL) {
1294 /*
1295 * Ask fdfree() to sleep to ensure that all relevant
1296 * process leaders can be traversed in closef().
1297 */
1298 fdp->fd_holdleaderscount++;
1299 } else {
1300 holdleaders = false;
1301 }
1302 }
1303
1304 error = closefp_impl(fdp, fd, fp, td, audit);
1305 if (holdleaders) {
1306 FILEDESC_XLOCK(fdp);
1307 fdp->fd_holdleaderscount--;
1308 if (fdp->fd_holdleaderscount == 0 &&
1309 fdp->fd_holdleaderswakeup != 0) {
1310 fdp->fd_holdleaderswakeup = 0;
1311 wakeup(&fdp->fd_holdleaderscount);
1312 }
1313 FILEDESC_XUNLOCK(fdp);
1314 }
1315 return (error);
1316 }
1317
1318 static int
1319 closefp(struct filedesc *fdp, int fd, struct file *fp, struct thread *td,
1320 bool holdleaders, bool audit)
1321 {
1322
1323 FILEDESC_XLOCK_ASSERT(fdp);
1324
1325 if (__predict_false(td->td_proc->p_fdtol != NULL)) {
1326 return (closefp_hl(fdp, fd, fp, td, holdleaders, audit));
1327 } else {
1328 return (closefp_impl(fdp, fd, fp, td, audit));
1329 }
1330 }
1331
1332 /*
1333 * Close a file descriptor.
1334 */
1335 #ifndef _SYS_SYSPROTO_H_
1336 struct close_args {
1337 int fd;
1338 };
1339 #endif
1340 /* ARGSUSED */
1341 int
1342 sys_close(struct thread *td, struct close_args *uap)
1343 {
1344
1345 return (kern_close(td, uap->fd));
1346 }
1347
1348 int
1349 kern_close(struct thread *td, int fd)
1350 {
1351 struct filedesc *fdp;
1352 struct file *fp;
1353
1354 fdp = td->td_proc->p_fd;
1355
1356 FILEDESC_XLOCK(fdp);
1357 if ((fp = fget_locked(fdp, fd)) == NULL) {
1358 FILEDESC_XUNLOCK(fdp);
1359 return (EBADF);
1360 }
1361 fdfree(fdp, fd);
1362
1363 /* closefp() drops the FILEDESC lock for us. */
1364 return (closefp(fdp, fd, fp, td, true, true));
1365 }
1366
1367 int
1368 kern_close_range(struct thread *td, u_int lowfd, u_int highfd)
1369 {
1370 struct filedesc *fdp;
1371 const struct fdescenttbl *fdt;
1372 struct file *fp;
1373 int fd;
1374
1375 /*
1376 * Check this prior to clamping; closefrom(3) with only fd 0, 1, and 2
1377 * open should not be a usage error. From a close_range() perspective,
1378 * close_range(3, ~0U, 0) in the same scenario should also likely not
1379 * be a usage error as all fd above 3 are in-fact already closed.
1380 */
1381 if (highfd < lowfd) {
1382 return (EINVAL);
1383 }
1384
1385 fdp = td->td_proc->p_fd;
1386 FILEDESC_XLOCK(fdp);
1387 fdt = atomic_load_ptr(&fdp->fd_files);
1388 highfd = MIN(highfd, fdt->fdt_nfiles - 1);
1389 fd = lowfd;
1390 if (__predict_false(fd > highfd)) {
1391 goto out_locked;
1392 }
1393 for (;;) {
1394 fp = fdt->fdt_ofiles[fd].fde_file;
1395 if (fp == NULL) {
1396 if (fd == highfd)
1397 goto out_locked;
1398 } else {
1399 fdfree(fdp, fd);
1400 (void) closefp(fdp, fd, fp, td, true, true);
1401 if (fd == highfd)
1402 goto out_unlocked;
1403 FILEDESC_XLOCK(fdp);
1404 fdt = atomic_load_ptr(&fdp->fd_files);
1405 }
1406 fd++;
1407 }
1408 out_locked:
1409 FILEDESC_XUNLOCK(fdp);
1410 out_unlocked:
1411 return (0);
1412 }
1413
1414 #ifndef _SYS_SYSPROTO_H_
1415 struct close_range_args {
1416 u_int lowfd;
1417 u_int highfd;
1418 int flags;
1419 };
1420 #endif
1421 int
1422 sys_close_range(struct thread *td, struct close_range_args *uap)
1423 {
1424
1425 /* No flags currently defined */
1426 if (uap->flags != 0)
1427 return (EINVAL);
1428 return (kern_close_range(td, uap->lowfd, uap->highfd));
1429 }
1430
1431 #ifdef COMPAT_FREEBSD12
1432 /*
1433 * Close open file descriptors.
1434 */
1435 #ifndef _SYS_SYSPROTO_H_
1436 struct freebsd12_closefrom_args {
1437 int lowfd;
1438 };
1439 #endif
1440 /* ARGSUSED */
1441 int
1442 freebsd12_closefrom(struct thread *td, struct freebsd12_closefrom_args *uap)
1443 {
1444 u_int lowfd;
1445
1446 AUDIT_ARG_FD(uap->lowfd);
1447
1448 /*
1449 * Treat negative starting file descriptor values identical to
1450 * closefrom(0) which closes all files.
1451 */
1452 lowfd = MAX(0, uap->lowfd);
1453 return (kern_close_range(td, lowfd, ~0U));
1454 }
1455 #endif /* COMPAT_FREEBSD12 */
1456
1457 #if defined(COMPAT_43)
1458 /*
1459 * Return status information about a file descriptor.
1460 */
1461 #ifndef _SYS_SYSPROTO_H_
1462 struct ofstat_args {
1463 int fd;
1464 struct ostat *sb;
1465 };
1466 #endif
1467 /* ARGSUSED */
1468 int
1469 ofstat(struct thread *td, struct ofstat_args *uap)
1470 {
1471 struct ostat oub;
1472 struct stat ub;
1473 int error;
1474
1475 error = kern_fstat(td, uap->fd, &ub);
1476 if (error == 0) {
1477 cvtstat(&ub, &oub);
1478 error = copyout(&oub, uap->sb, sizeof(oub));
1479 }
1480 return (error);
1481 }
1482 #endif /* COMPAT_43 */
1483
1484 #if defined(COMPAT_FREEBSD11)
1485 int
1486 freebsd11_fstat(struct thread *td, struct freebsd11_fstat_args *uap)
1487 {
1488 struct stat sb;
1489 struct freebsd11_stat osb;
1490 int error;
1491
1492 error = kern_fstat(td, uap->fd, &sb);
1493 if (error != 0)
1494 return (error);
1495 error = freebsd11_cvtstat(&sb, &osb);
1496 if (error == 0)
1497 error = copyout(&osb, uap->sb, sizeof(osb));
1498 return (error);
1499 }
1500 #endif /* COMPAT_FREEBSD11 */
1501
1502 /*
1503 * Return status information about a file descriptor.
1504 */
1505 #ifndef _SYS_SYSPROTO_H_
1506 struct fstat_args {
1507 int fd;
1508 struct stat *sb;
1509 };
1510 #endif
1511 /* ARGSUSED */
1512 int
1513 sys_fstat(struct thread *td, struct fstat_args *uap)
1514 {
1515 struct stat ub;
1516 int error;
1517
1518 error = kern_fstat(td, uap->fd, &ub);
1519 if (error == 0)
1520 error = copyout(&ub, uap->sb, sizeof(ub));
1521 return (error);
1522 }
1523
1524 int
1525 kern_fstat(struct thread *td, int fd, struct stat *sbp)
1526 {
1527 struct file *fp;
1528 int error;
1529
1530 AUDIT_ARG_FD(fd);
1531
1532 error = fget(td, fd, &cap_fstat_rights, &fp);
1533 if (__predict_false(error != 0))
1534 return (error);
1535
1536 AUDIT_ARG_FILE(td->td_proc, fp);
1537
1538 error = fo_stat(fp, sbp, td->td_ucred, td);
1539 fdrop(fp, td);
1540 #ifdef __STAT_TIME_T_EXT
1541 sbp->st_atim_ext = 0;
1542 sbp->st_mtim_ext = 0;
1543 sbp->st_ctim_ext = 0;
1544 sbp->st_btim_ext = 0;
1545 #endif
1546 #ifdef KTRACE
1547 if (KTRPOINT(td, KTR_STRUCT))
1548 ktrstat_error(sbp, error);
1549 #endif
1550 return (error);
1551 }
1552
1553 #if defined(COMPAT_FREEBSD11)
1554 /*
1555 * Return status information about a file descriptor.
1556 */
1557 #ifndef _SYS_SYSPROTO_H_
1558 struct freebsd11_nfstat_args {
1559 int fd;
1560 struct nstat *sb;
1561 };
1562 #endif
1563 /* ARGSUSED */
1564 int
1565 freebsd11_nfstat(struct thread *td, struct freebsd11_nfstat_args *uap)
1566 {
1567 struct nstat nub;
1568 struct stat ub;
1569 int error;
1570
1571 error = kern_fstat(td, uap->fd, &ub);
1572 if (error == 0) {
1573 freebsd11_cvtnstat(&ub, &nub);
1574 error = copyout(&nub, uap->sb, sizeof(nub));
1575 }
1576 return (error);
1577 }
1578 #endif /* COMPAT_FREEBSD11 */
1579
1580 /*
1581 * Return pathconf information about a file descriptor.
1582 */
1583 #ifndef _SYS_SYSPROTO_H_
1584 struct fpathconf_args {
1585 int fd;
1586 int name;
1587 };
1588 #endif
1589 /* ARGSUSED */
1590 int
1591 sys_fpathconf(struct thread *td, struct fpathconf_args *uap)
1592 {
1593 long value;
1594 int error;
1595
1596 error = kern_fpathconf(td, uap->fd, uap->name, &value);
1597 if (error == 0)
1598 td->td_retval[0] = value;
1599 return (error);
1600 }
1601
1602 int
1603 kern_fpathconf(struct thread *td, int fd, int name, long *valuep)
1604 {
1605 struct file *fp;
1606 struct vnode *vp;
1607 int error;
1608
1609 error = fget(td, fd, &cap_fpathconf_rights, &fp);
1610 if (error != 0)
1611 return (error);
1612
1613 if (name == _PC_ASYNC_IO) {
1614 *valuep = _POSIX_ASYNCHRONOUS_IO;
1615 goto out;
1616 }
1617 vp = fp->f_vnode;
1618 if (vp != NULL) {
1619 vn_lock(vp, LK_SHARED | LK_RETRY);
1620 error = VOP_PATHCONF(vp, name, valuep);
1621 VOP_UNLOCK(vp);
1622 } else if (fp->f_type == DTYPE_PIPE || fp->f_type == DTYPE_SOCKET) {
1623 if (name != _PC_PIPE_BUF) {
1624 error = EINVAL;
1625 } else {
1626 *valuep = PIPE_BUF;
1627 error = 0;
1628 }
1629 } else {
1630 error = EOPNOTSUPP;
1631 }
1632 out:
1633 fdrop(fp, td);
1634 return (error);
1635 }
1636
1637 /*
1638 * Copy filecaps structure allocating memory for ioctls array if needed.
1639 *
1640 * The last parameter indicates whether the fdtable is locked. If it is not and
1641 * ioctls are encountered, copying fails and the caller must lock the table.
1642 *
1643 * Note that if the table was not locked, the caller has to check the relevant
1644 * sequence counter to determine whether the operation was successful.
1645 */
1646 bool
1647 filecaps_copy(const struct filecaps *src, struct filecaps *dst, bool locked)
1648 {
1649 size_t size;
1650
1651 if (src->fc_ioctls != NULL && !locked)
1652 return (false);
1653 memcpy(dst, src, sizeof(*src));
1654 if (src->fc_ioctls == NULL)
1655 return (true);
1656
1657 KASSERT(src->fc_nioctls > 0,
1658 ("fc_ioctls != NULL, but fc_nioctls=%hd", src->fc_nioctls));
1659
1660 size = sizeof(src->fc_ioctls[0]) * src->fc_nioctls;
1661 dst->fc_ioctls = malloc(size, M_FILECAPS, M_WAITOK);
1662 memcpy(dst->fc_ioctls, src->fc_ioctls, size);
1663 return (true);
1664 }
1665
1666 static u_long *
1667 filecaps_copy_prep(const struct filecaps *src)
1668 {
1669 u_long *ioctls;
1670 size_t size;
1671
1672 if (__predict_true(src->fc_ioctls == NULL))
1673 return (NULL);
1674
1675 KASSERT(src->fc_nioctls > 0,
1676 ("fc_ioctls != NULL, but fc_nioctls=%hd", src->fc_nioctls));
1677
1678 size = sizeof(src->fc_ioctls[0]) * src->fc_nioctls;
1679 ioctls = malloc(size, M_FILECAPS, M_WAITOK);
1680 return (ioctls);
1681 }
1682
1683 static void
1684 filecaps_copy_finish(const struct filecaps *src, struct filecaps *dst,
1685 u_long *ioctls)
1686 {
1687 size_t size;
1688
1689 *dst = *src;
1690 if (__predict_true(src->fc_ioctls == NULL)) {
1691 MPASS(ioctls == NULL);
1692 return;
1693 }
1694
1695 size = sizeof(src->fc_ioctls[0]) * src->fc_nioctls;
1696 dst->fc_ioctls = ioctls;
1697 bcopy(src->fc_ioctls, dst->fc_ioctls, size);
1698 }
1699
1700 /*
1701 * Move filecaps structure to the new place and clear the old place.
1702 */
1703 void
1704 filecaps_move(struct filecaps *src, struct filecaps *dst)
1705 {
1706
1707 *dst = *src;
1708 bzero(src, sizeof(*src));
1709 }
1710
1711 /*
1712 * Fill the given filecaps structure with full rights.
1713 */
1714 static void
1715 filecaps_fill(struct filecaps *fcaps)
1716 {
1717
1718 CAP_ALL(&fcaps->fc_rights);
1719 fcaps->fc_ioctls = NULL;
1720 fcaps->fc_nioctls = -1;
1721 fcaps->fc_fcntls = CAP_FCNTL_ALL;
1722 }
1723
1724 /*
1725 * Free memory allocated within filecaps structure.
1726 */
1727 void
1728 filecaps_free(struct filecaps *fcaps)
1729 {
1730
1731 free(fcaps->fc_ioctls, M_FILECAPS);
1732 bzero(fcaps, sizeof(*fcaps));
1733 }
1734
1735 static u_long *
1736 filecaps_free_prep(struct filecaps *fcaps)
1737 {
1738 u_long *ioctls;
1739
1740 ioctls = fcaps->fc_ioctls;
1741 bzero(fcaps, sizeof(*fcaps));
1742 return (ioctls);
1743 }
1744
1745 static void
1746 filecaps_free_finish(u_long *ioctls)
1747 {
1748
1749 free(ioctls, M_FILECAPS);
1750 }
1751
1752 /*
1753 * Validate the given filecaps structure.
1754 */
1755 static void
1756 filecaps_validate(const struct filecaps *fcaps, const char *func)
1757 {
1758
1759 KASSERT(cap_rights_is_valid(&fcaps->fc_rights),
1760 ("%s: invalid rights", func));
1761 KASSERT((fcaps->fc_fcntls & ~CAP_FCNTL_ALL) == 0,
1762 ("%s: invalid fcntls", func));
1763 KASSERT(fcaps->fc_fcntls == 0 ||
1764 cap_rights_is_set(&fcaps->fc_rights, CAP_FCNTL),
1765 ("%s: fcntls without CAP_FCNTL", func));
1766 KASSERT(fcaps->fc_ioctls != NULL ? fcaps->fc_nioctls > 0 :
1767 (fcaps->fc_nioctls == -1 || fcaps->fc_nioctls == 0),
1768 ("%s: invalid ioctls", func));
1769 KASSERT(fcaps->fc_nioctls == 0 ||
1770 cap_rights_is_set(&fcaps->fc_rights, CAP_IOCTL),
1771 ("%s: ioctls without CAP_IOCTL", func));
1772 }
1773
1774 static void
1775 fdgrowtable_exp(struct filedesc *fdp, int nfd)
1776 {
1777 int nfd1;
1778
1779 FILEDESC_XLOCK_ASSERT(fdp);
1780
1781 nfd1 = fdp->fd_nfiles * 2;
1782 if (nfd1 < nfd)
1783 nfd1 = nfd;
1784 fdgrowtable(fdp, nfd1);
1785 }
1786
1787 /*
1788 * Grow the file table to accommodate (at least) nfd descriptors.
1789 */
1790 static void
1791 fdgrowtable(struct filedesc *fdp, int nfd)
1792 {
1793 struct filedesc0 *fdp0;
1794 struct freetable *ft;
1795 struct fdescenttbl *ntable;
1796 struct fdescenttbl *otable;
1797 int nnfiles, onfiles;
1798 NDSLOTTYPE *nmap, *omap;
1799
1800 KASSERT(fdp->fd_nfiles > 0, ("zero-length file table"));
1801
1802 /* save old values */
1803 onfiles = fdp->fd_nfiles;
1804 otable = fdp->fd_files;
1805 omap = fdp->fd_map;
1806
1807 /* compute the size of the new table */
1808 nnfiles = NDSLOTS(nfd) * NDENTRIES; /* round up */
1809 if (nnfiles <= onfiles)
1810 /* the table is already large enough */
1811 return;
1812
1813 /*
1814 * Allocate a new table. We need enough space for the number of
1815 * entries, file entries themselves and the struct freetable we will use
1816 * when we decommission the table and place it on the freelist.
1817 * We place the struct freetable in the middle so we don't have
1818 * to worry about padding.
1819 */
1820 ntable = malloc(offsetof(struct fdescenttbl, fdt_ofiles) +
1821 nnfiles * sizeof(ntable->fdt_ofiles[0]) +
1822 sizeof(struct freetable),
1823 M_FILEDESC, M_ZERO | M_WAITOK);
1824 /* copy the old data */
1825 ntable->fdt_nfiles = nnfiles;
1826 memcpy(ntable->fdt_ofiles, otable->fdt_ofiles,
1827 onfiles * sizeof(ntable->fdt_ofiles[0]));
1828
1829 /*
1830 * Allocate a new map only if the old is not large enough. It will
1831 * grow at a slower rate than the table as it can map more
1832 * entries than the table can hold.
1833 */
1834 if (NDSLOTS(nnfiles) > NDSLOTS(onfiles)) {
1835 nmap = malloc(NDSLOTS(nnfiles) * NDSLOTSIZE, M_FILEDESC,
1836 M_ZERO | M_WAITOK);
1837 /* copy over the old data and update the pointer */
1838 memcpy(nmap, omap, NDSLOTS(onfiles) * sizeof(*omap));
1839 fdp->fd_map = nmap;
1840 }
1841
1842 /*
1843 * Make sure that ntable is correctly initialized before we replace
1844 * fd_files poiner. Otherwise fget_unlocked() may see inconsistent
1845 * data.
1846 */
1847 atomic_store_rel_ptr((volatile void *)&fdp->fd_files, (uintptr_t)ntable);
1848
1849 /*
1850 * Free the old file table when not shared by other threads or processes.
1851 * The old file table is considered to be shared when either are true:
1852 * - The process has more than one thread.
1853 * - The file descriptor table has been shared via fdshare().
1854 *
1855 * When shared, the old file table will be placed on a freelist
1856 * which will be processed when the struct filedesc is released.
1857 *
1858 * Note that if onfiles == NDFILE, we're dealing with the original
1859 * static allocation contained within (struct filedesc0 *)fdp,
1860 * which must not be freed.
1861 */
1862 if (onfiles > NDFILE) {
1863 /*
1864 * Note we may be called here from fdinit while allocating a
1865 * table for a new process in which case ->p_fd points
1866 * elsewhere.
1867 */
1868 if (curproc->p_fd != fdp || FILEDESC_IS_ONLY_USER(fdp)) {
1869 free(otable, M_FILEDESC);
1870 } else {
1871 ft = (struct freetable *)&otable->fdt_ofiles[onfiles];
1872 fdp0 = (struct filedesc0 *)fdp;
1873 ft->ft_table = otable;
1874 SLIST_INSERT_HEAD(&fdp0->fd_free, ft, ft_next);
1875 }
1876 }
1877 /*
1878 * The map does not have the same possibility of threads still
1879 * holding references to it. So always free it as long as it
1880 * does not reference the original static allocation.
1881 */
1882 if (NDSLOTS(onfiles) > NDSLOTS(NDFILE))
1883 free(omap, M_FILEDESC);
1884 }
1885
1886 /*
1887 * Allocate a file descriptor for the process.
1888 */
1889 int
1890 fdalloc(struct thread *td, int minfd, int *result)
1891 {
1892 struct proc *p = td->td_proc;
1893 struct filedesc *fdp = p->p_fd;
1894 int fd, maxfd, allocfd;
1895 #ifdef RACCT
1896 int error;
1897 #endif
1898
1899 FILEDESC_XLOCK_ASSERT(fdp);
1900
1901 if (fdp->fd_freefile > minfd)
1902 minfd = fdp->fd_freefile;
1903
1904 maxfd = getmaxfd(td);
1905
1906 /*
1907 * Search the bitmap for a free descriptor starting at minfd.
1908 * If none is found, grow the file table.
1909 */
1910 fd = fd_first_free(fdp, minfd, fdp->fd_nfiles);
1911 if (__predict_false(fd >= maxfd))
1912 return (EMFILE);
1913 if (__predict_false(fd >= fdp->fd_nfiles)) {
1914 allocfd = min(fd * 2, maxfd);
1915 #ifdef RACCT
1916 if (RACCT_ENABLED()) {
1917 error = racct_set_unlocked(p, RACCT_NOFILE, allocfd);
1918 if (error != 0)
1919 return (EMFILE);
1920 }
1921 #endif
1922 /*
1923 * fd is already equal to first free descriptor >= minfd, so
1924 * we only need to grow the table and we are done.
1925 */
1926 fdgrowtable_exp(fdp, allocfd);
1927 }
1928
1929 /*
1930 * Perform some sanity checks, then mark the file descriptor as
1931 * used and return it to the caller.
1932 */
1933 KASSERT(fd >= 0 && fd < min(maxfd, fdp->fd_nfiles),
1934 ("invalid descriptor %d", fd));
1935 KASSERT(!fdisused(fdp, fd),
1936 ("fd_first_free() returned non-free descriptor"));
1937 KASSERT(fdp->fd_ofiles[fd].fde_file == NULL,
1938 ("file descriptor isn't free"));
1939 fdused(fdp, fd);
1940 *result = fd;
1941 return (0);
1942 }
1943
1944 /*
1945 * Allocate n file descriptors for the process.
1946 */
1947 int
1948 fdallocn(struct thread *td, int minfd, int *fds, int n)
1949 {
1950 struct proc *p = td->td_proc;
1951 struct filedesc *fdp = p->p_fd;
1952 int i;
1953
1954 FILEDESC_XLOCK_ASSERT(fdp);
1955
1956 for (i = 0; i < n; i++)
1957 if (fdalloc(td, 0, &fds[i]) != 0)
1958 break;
1959
1960 if (i < n) {
1961 for (i--; i >= 0; i--)
1962 fdunused(fdp, fds[i]);
1963 return (EMFILE);
1964 }
1965
1966 return (0);
1967 }
1968
1969 /*
1970 * Create a new open file structure and allocate a file descriptor for the
1971 * process that refers to it. We add one reference to the file for the
1972 * descriptor table and one reference for resultfp. This is to prevent us
1973 * being preempted and the entry in the descriptor table closed after we
1974 * release the FILEDESC lock.
1975 */
1976 int
1977 falloc_caps(struct thread *td, struct file **resultfp, int *resultfd, int flags,
1978 struct filecaps *fcaps)
1979 {
1980 struct file *fp;
1981 int error, fd;
1982
1983 MPASS(resultfp != NULL);
1984 MPASS(resultfd != NULL);
1985
1986 error = _falloc_noinstall(td, &fp, 2);
1987 if (__predict_false(error != 0)) {
1988 return (error);
1989 }
1990
1991 error = finstall_refed(td, fp, &fd, flags, fcaps);
1992 if (__predict_false(error != 0)) {
1993 falloc_abort(td, fp);
1994 return (error);
1995 }
1996
1997 *resultfp = fp;
1998 *resultfd = fd;
1999
2000 return (0);
2001 }
2002
2003 /*
2004 * Create a new open file structure without allocating a file descriptor.
2005 */
2006 int
2007 _falloc_noinstall(struct thread *td, struct file **resultfp, u_int n)
2008 {
2009 struct file *fp;
2010 int maxuserfiles = maxfiles - (maxfiles / 20);
2011 int openfiles_new;
2012 static struct timeval lastfail;
2013 static int curfail;
2014
2015 KASSERT(resultfp != NULL, ("%s: resultfp == NULL", __func__));
2016 MPASS(n > 0);
2017
2018 openfiles_new = atomic_fetchadd_int(&openfiles, 1) + 1;
2019 if ((openfiles_new >= maxuserfiles &&
2020 priv_check(td, PRIV_MAXFILES) != 0) ||
2021 openfiles_new >= maxfiles) {
2022 atomic_subtract_int(&openfiles, 1);
2023 if (ppsratecheck(&lastfail, &curfail, 1)) {
2024 printf("kern.maxfiles limit exceeded by uid %i, (%s) "
2025 "please see tuning(7).\n", td->td_ucred->cr_ruid, td->td_proc->p_comm);
2026 }
2027 return (ENFILE);
2028 }
2029 fp = uma_zalloc(file_zone, M_WAITOK);
2030 bzero(fp, sizeof(*fp));
2031 refcount_init(&fp->f_count, n);
2032 fp->f_cred = crhold(td->td_ucred);
2033 fp->f_ops = &badfileops;
2034 *resultfp = fp;
2035 return (0);
2036 }
2037
2038 void
2039 falloc_abort(struct thread *td, struct file *fp)
2040 {
2041
2042 /*
2043 * For assertion purposes.
2044 */
2045 refcount_init(&fp->f_count, 0);
2046 _fdrop(fp, td);
2047 }
2048
2049 /*
2050 * Install a file in a file descriptor table.
2051 */
2052 void
2053 _finstall(struct filedesc *fdp, struct file *fp, int fd, int flags,
2054 struct filecaps *fcaps)
2055 {
2056 struct filedescent *fde;
2057
2058 MPASS(fp != NULL);
2059 if (fcaps != NULL)
2060 filecaps_validate(fcaps, __func__);
2061 FILEDESC_XLOCK_ASSERT(fdp);
2062
2063 fde = &fdp->fd_ofiles[fd];
2064 #ifdef CAPABILITIES
2065 seqc_write_begin(&fde->fde_seqc);
2066 #endif
2067 fde->fde_file = fp;
2068 fde->fde_flags = (flags & O_CLOEXEC) != 0 ? UF_EXCLOSE : 0;
2069 if (fcaps != NULL)
2070 filecaps_move(fcaps, &fde->fde_caps);
2071 else
2072 filecaps_fill(&fde->fde_caps);
2073 #ifdef CAPABILITIES
2074 seqc_write_end(&fde->fde_seqc);
2075 #endif
2076 }
2077
2078 int
2079 finstall_refed(struct thread *td, struct file *fp, int *fd, int flags,
2080 struct filecaps *fcaps)
2081 {
2082 struct filedesc *fdp = td->td_proc->p_fd;
2083 int error;
2084
2085 MPASS(fd != NULL);
2086
2087 FILEDESC_XLOCK(fdp);
2088 error = fdalloc(td, 0, fd);
2089 if (__predict_true(error == 0)) {
2090 _finstall(fdp, fp, *fd, flags, fcaps);
2091 }
2092 FILEDESC_XUNLOCK(fdp);
2093 return (error);
2094 }
2095
2096 int
2097 finstall(struct thread *td, struct file *fp, int *fd, int flags,
2098 struct filecaps *fcaps)
2099 {
2100 int error;
2101
2102 MPASS(fd != NULL);
2103
2104 if (!fhold(fp))
2105 return (EBADF);
2106 error = finstall_refed(td, fp, fd, flags, fcaps);
2107 if (__predict_false(error != 0)) {
2108 fdrop(fp, td);
2109 }
2110 return (error);
2111 }
2112
2113 /*
2114 * Build a new filedesc structure from another.
2115 *
2116 * If fdp is not NULL, return with it shared locked.
2117 */
2118 struct filedesc *
2119 fdinit(struct filedesc *fdp, bool prepfiles, int *lastfile)
2120 {
2121 struct filedesc0 *newfdp0;
2122 struct filedesc *newfdp;
2123
2124 if (prepfiles)
2125 MPASS(lastfile != NULL);
2126 else
2127 MPASS(lastfile == NULL);
2128
2129 newfdp0 = uma_zalloc(filedesc0_zone, M_WAITOK | M_ZERO);
2130 newfdp = &newfdp0->fd_fd;
2131
2132 /* Create the file descriptor table. */
2133 FILEDESC_LOCK_INIT(newfdp);
2134 refcount_init(&newfdp->fd_refcnt, 1);
2135 refcount_init(&newfdp->fd_holdcnt, 1);
2136 newfdp->fd_map = newfdp0->fd_dmap;
2137 newfdp->fd_files = (struct fdescenttbl *)&newfdp0->fd_dfiles;
2138 newfdp->fd_files->fdt_nfiles = NDFILE;
2139
2140 if (fdp == NULL)
2141 return (newfdp);
2142
2143 FILEDESC_SLOCK(fdp);
2144 if (!prepfiles) {
2145 FILEDESC_SUNLOCK(fdp);
2146 return (newfdp);
2147 }
2148
2149 for (;;) {
2150 *lastfile = fdlastfile(fdp);
2151 if (*lastfile < newfdp->fd_nfiles)
2152 break;
2153 FILEDESC_SUNLOCK(fdp);
2154 fdgrowtable(newfdp, *lastfile + 1);
2155 FILEDESC_SLOCK(fdp);
2156 }
2157
2158 return (newfdp);
2159 }
2160
2161 /*
2162 * Build a pwddesc structure from another.
2163 * Copy the current, root, and jail root vnode references.
2164 *
2165 * If pdp is not NULL, return with it shared locked.
2166 */
2167 struct pwddesc *
2168 pdinit(struct pwddesc *pdp, bool keeplock)
2169 {
2170 struct pwddesc *newpdp;
2171 struct pwd *newpwd;
2172
2173 newpdp = malloc(sizeof(*newpdp), M_PWDDESC, M_WAITOK | M_ZERO);
2174
2175 PWDDESC_LOCK_INIT(newpdp);
2176 refcount_init(&newpdp->pd_refcount, 1);
2177 newpdp->pd_cmask = CMASK;
2178
2179 if (pdp == NULL) {
2180 newpwd = pwd_alloc();
2181 smr_serialized_store(&newpdp->pd_pwd, newpwd, true);
2182 return (newpdp);
2183 }
2184
2185 PWDDESC_XLOCK(pdp);
2186 newpwd = pwd_hold_pwddesc(pdp);
2187 smr_serialized_store(&newpdp->pd_pwd, newpwd, true);
2188 if (!keeplock)
2189 PWDDESC_XUNLOCK(pdp);
2190 return (newpdp);
2191 }
2192
2193 static struct filedesc *
2194 fdhold(struct proc *p)
2195 {
2196 struct filedesc *fdp;
2197
2198 PROC_LOCK_ASSERT(p, MA_OWNED);
2199 fdp = p->p_fd;
2200 if (fdp != NULL)
2201 refcount_acquire(&fdp->fd_holdcnt);
2202 return (fdp);
2203 }
2204
2205 static struct pwddesc *
2206 pdhold(struct proc *p)
2207 {
2208 struct pwddesc *pdp;
2209
2210 PROC_LOCK_ASSERT(p, MA_OWNED);
2211 pdp = p->p_pd;
2212 if (pdp != NULL)
2213 refcount_acquire(&pdp->pd_refcount);
2214 return (pdp);
2215 }
2216
2217 static void
2218 fddrop(struct filedesc *fdp)
2219 {
2220
2221 if (refcount_load(&fdp->fd_holdcnt) > 1) {
2222 if (refcount_release(&fdp->fd_holdcnt) == 0)
2223 return;
2224 }
2225
2226 FILEDESC_LOCK_DESTROY(fdp);
2227 uma_zfree(filedesc0_zone, fdp);
2228 }
2229
2230 static void
2231 pddrop(struct pwddesc *pdp)
2232 {
2233 struct pwd *pwd;
2234
2235 if (refcount_release_if_not_last(&pdp->pd_refcount))
2236 return;
2237
2238 PWDDESC_XLOCK(pdp);
2239 if (refcount_release(&pdp->pd_refcount) == 0) {
2240 PWDDESC_XUNLOCK(pdp);
2241 return;
2242 }
2243 pwd = PWDDESC_XLOCKED_LOAD_PWD(pdp);
2244 pwd_set(pdp, NULL);
2245 PWDDESC_XUNLOCK(pdp);
2246 pwd_drop(pwd);
2247
2248 PWDDESC_LOCK_DESTROY(pdp);
2249 free(pdp, M_PWDDESC);
2250 }
2251
2252 /*
2253 * Share a filedesc structure.
2254 */
2255 struct filedesc *
2256 fdshare(struct filedesc *fdp)
2257 {
2258
2259 refcount_acquire(&fdp->fd_refcnt);
2260 return (fdp);
2261 }
2262
2263 /*
2264 * Share a pwddesc structure.
2265 */
2266 struct pwddesc *
2267 pdshare(struct pwddesc *pdp)
2268 {
2269 refcount_acquire(&pdp->pd_refcount);
2270 return (pdp);
2271 }
2272
2273 /*
2274 * Unshare a filedesc structure, if necessary by making a copy
2275 */
2276 void
2277 fdunshare(struct thread *td)
2278 {
2279 struct filedesc *tmp;
2280 struct proc *p = td->td_proc;
2281
2282 if (refcount_load(&p->p_fd->fd_refcnt) == 1)
2283 return;
2284
2285 tmp = fdcopy(p->p_fd);
2286 fdescfree(td);
2287 p->p_fd = tmp;
2288 }
2289
2290 /*
2291 * Unshare a pwddesc structure.
2292 */
2293 void
2294 pdunshare(struct thread *td)
2295 {
2296 struct pwddesc *pdp;
2297 struct proc *p;
2298
2299 p = td->td_proc;
2300 /* Not shared. */
2301 if (p->p_pd->pd_refcount == 1)
2302 return;
2303
2304 pdp = pdcopy(p->p_pd);
2305 pdescfree(td);
2306 p->p_pd = pdp;
2307 }
2308
2309 void
2310 fdinstall_remapped(struct thread *td, struct filedesc *fdp)
2311 {
2312
2313 fdescfree(td);
2314 td->td_proc->p_fd = fdp;
2315 }
2316
2317 /*
2318 * Copy a filedesc structure. A NULL pointer in returns a NULL reference,
2319 * this is to ease callers, not catch errors.
2320 */
2321 struct filedesc *
2322 fdcopy(struct filedesc *fdp)
2323 {
2324 struct filedesc *newfdp;
2325 struct filedescent *nfde, *ofde;
2326 int i, lastfile;
2327
2328 MPASS(fdp != NULL);
2329
2330 newfdp = fdinit(fdp, true, &lastfile);
2331 /* copy all passable descriptors (i.e. not kqueue) */
2332 newfdp->fd_freefile = -1;
2333 for (i = 0; i <= lastfile; ++i) {
2334 ofde = &fdp->fd_ofiles[i];
2335 if (ofde->fde_file == NULL ||
2336 (ofde->fde_file->f_ops->fo_flags & DFLAG_PASSABLE) == 0 ||
2337 !fhold(ofde->fde_file)) {
2338 if (newfdp->fd_freefile == -1)
2339 newfdp->fd_freefile = i;
2340 continue;
2341 }
2342 nfde = &newfdp->fd_ofiles[i];
2343 *nfde = *ofde;
2344 filecaps_copy(&ofde->fde_caps, &nfde->fde_caps, true);
2345 fdused_init(newfdp, i);
2346 }
2347 if (newfdp->fd_freefile == -1)
2348 newfdp->fd_freefile = i;
2349 FILEDESC_SUNLOCK(fdp);
2350 return (newfdp);
2351 }
2352
2353 /*
2354 * Copy a pwddesc structure.
2355 */
2356 struct pwddesc *
2357 pdcopy(struct pwddesc *pdp)
2358 {
2359 struct pwddesc *newpdp;
2360
2361 MPASS(pdp != NULL);
2362
2363 newpdp = pdinit(pdp, true);
2364 newpdp->pd_cmask = pdp->pd_cmask;
2365 PWDDESC_XUNLOCK(pdp);
2366 return (newpdp);
2367 }
2368
2369 /*
2370 * Copies a filedesc structure, while remapping all file descriptors
2371 * stored inside using a translation table.
2372 *
2373 * File descriptors are copied over to the new file descriptor table,
2374 * regardless of whether the close-on-exec flag is set.
2375 */
2376 int
2377 fdcopy_remapped(struct filedesc *fdp, const int *fds, size_t nfds,
2378 struct filedesc **ret)
2379 {
2380 struct filedesc *newfdp;
2381 struct filedescent *nfde, *ofde;
2382 int error, i, lastfile;
2383
2384 MPASS(fdp != NULL);
2385
2386 newfdp = fdinit(fdp, true, &lastfile);
2387 if (nfds > lastfile + 1) {
2388 /* New table cannot be larger than the old one. */
2389 error = E2BIG;
2390 goto bad;
2391 }
2392 /* Copy all passable descriptors (i.e. not kqueue). */
2393 newfdp->fd_freefile = nfds;
2394 for (i = 0; i < nfds; ++i) {
2395 if (fds[i] < 0 || fds[i] > lastfile) {
2396 /* File descriptor out of bounds. */
2397 error = EBADF;
2398 goto bad;
2399 }
2400 ofde = &fdp->fd_ofiles[fds[i]];
2401 if (ofde->fde_file == NULL) {
2402 /* Unused file descriptor. */
2403 error = EBADF;
2404 goto bad;
2405 }
2406 if ((ofde->fde_file->f_ops->fo_flags & DFLAG_PASSABLE) == 0) {
2407 /* File descriptor cannot be passed. */
2408 error = EINVAL;
2409 goto bad;
2410 }
2411 if (!fhold(ofde->fde_file)) {
2412 error = EBADF;
2413 goto bad;
2414 }
2415 nfde = &newfdp->fd_ofiles[i];
2416 *nfde = *ofde;
2417 filecaps_copy(&ofde->fde_caps, &nfde->fde_caps, true);
2418 fdused_init(newfdp, i);
2419 }
2420 FILEDESC_SUNLOCK(fdp);
2421 *ret = newfdp;
2422 return (0);
2423 bad:
2424 FILEDESC_SUNLOCK(fdp);
2425 fdescfree_remapped(newfdp);
2426 return (error);
2427 }
2428
2429 /*
2430 * Clear POSIX style locks. This is only used when fdp looses a reference (i.e.
2431 * one of processes using it exits) and the table used to be shared.
2432 */
2433 static void
2434 fdclearlocks(struct thread *td)
2435 {
2436 struct filedesc *fdp;
2437 struct filedesc_to_leader *fdtol;
2438 struct flock lf;
2439 struct file *fp;
2440 struct proc *p;
2441 struct vnode *vp;
2442 int i, lastfile;
2443
2444 p = td->td_proc;
2445 fdp = p->p_fd;
2446 fdtol = p->p_fdtol;
2447 MPASS(fdtol != NULL);
2448
2449 FILEDESC_XLOCK(fdp);
2450 KASSERT(fdtol->fdl_refcount > 0,
2451 ("filedesc_to_refcount botch: fdl_refcount=%d",
2452 fdtol->fdl_refcount));
2453 if (fdtol->fdl_refcount == 1 &&
2454 (p->p_leader->p_flag & P_ADVLOCK) != 0) {
2455 lastfile = fdlastfile(fdp);
2456 for (i = 0; i <= lastfile; i++) {
2457 fp = fdp->fd_ofiles[i].fde_file;
2458 if (fp == NULL || fp->f_type != DTYPE_VNODE ||
2459 !fhold(fp))
2460 continue;
2461 FILEDESC_XUNLOCK(fdp);
2462 lf.l_whence = SEEK_SET;
2463 lf.l_start = 0;
2464 lf.l_len = 0;
2465 lf.l_type = F_UNLCK;
2466 vp = fp->f_vnode;
2467 (void) VOP_ADVLOCK(vp,
2468 (caddr_t)p->p_leader, F_UNLCK,
2469 &lf, F_POSIX);
2470 FILEDESC_XLOCK(fdp);
2471 fdrop(fp, td);
2472 }
2473 }
2474 retry:
2475 if (fdtol->fdl_refcount == 1) {
2476 if (fdp->fd_holdleaderscount > 0 &&
2477 (p->p_leader->p_flag & P_ADVLOCK) != 0) {
2478 /*
2479 * close() or kern_dup() has cleared a reference
2480 * in a shared file descriptor table.
2481 */
2482 fdp->fd_holdleaderswakeup = 1;
2483 sx_sleep(&fdp->fd_holdleaderscount,
2484 FILEDESC_LOCK(fdp), PLOCK, "fdlhold", 0);
2485 goto retry;
2486 }
2487 if (fdtol->fdl_holdcount > 0) {
2488 /*
2489 * Ensure that fdtol->fdl_leader remains
2490 * valid in closef().
2491 */
2492 fdtol->fdl_wakeup = 1;
2493 sx_sleep(fdtol, FILEDESC_LOCK(fdp), PLOCK,
2494 "fdlhold", 0);
2495 goto retry;
2496 }
2497 }
2498 fdtol->fdl_refcount--;
2499 if (fdtol->fdl_refcount == 0 &&
2500 fdtol->fdl_holdcount == 0) {
2501 fdtol->fdl_next->fdl_prev = fdtol->fdl_prev;
2502 fdtol->fdl_prev->fdl_next = fdtol->fdl_next;
2503 } else
2504 fdtol = NULL;
2505 p->p_fdtol = NULL;
2506 FILEDESC_XUNLOCK(fdp);
2507 if (fdtol != NULL)
2508 free(fdtol, M_FILEDESC_TO_LEADER);
2509 }
2510
2511 /*
2512 * Release a filedesc structure.
2513 */
2514 static void
2515 fdescfree_fds(struct thread *td, struct filedesc *fdp, bool needclose)
2516 {
2517 struct filedesc0 *fdp0;
2518 struct freetable *ft, *tft;
2519 struct filedescent *fde;
2520 struct file *fp;
2521 int i, lastfile;
2522
2523 KASSERT(refcount_load(&fdp->fd_refcnt) == 0,
2524 ("%s: fd table %p carries references", __func__, fdp));
2525
2526 /*
2527 * Serialize with threads iterating over the table, if any.
2528 */
2529 if (refcount_load(&fdp->fd_holdcnt) > 1) {
2530 FILEDESC_XLOCK(fdp);
2531 FILEDESC_XUNLOCK(fdp);
2532 }
2533
2534 lastfile = fdlastfile_single(fdp);
2535 for (i = 0; i <= lastfile; i++) {
2536 fde = &fdp->fd_ofiles[i];
2537 fp = fde->fde_file;
2538 if (fp != NULL) {
2539 fdefree_last(fde);
2540 if (needclose)
2541 (void) closef(fp, td);
2542 else
2543 fdrop(fp, td);
2544 }
2545 }
2546
2547 if (NDSLOTS(fdp->fd_nfiles) > NDSLOTS(NDFILE))
2548 free(fdp->fd_map, M_FILEDESC);
2549 if (fdp->fd_nfiles > NDFILE)
2550 free(fdp->fd_files, M_FILEDESC);
2551
2552 fdp0 = (struct filedesc0 *)fdp;
2553 SLIST_FOREACH_SAFE(ft, &fdp0->fd_free, ft_next, tft)
2554 free(ft->ft_table, M_FILEDESC);
2555
2556 fddrop(fdp);
2557 }
2558
2559 void
2560 fdescfree(struct thread *td)
2561 {
2562 struct proc *p;
2563 struct filedesc *fdp;
2564
2565 p = td->td_proc;
2566 fdp = p->p_fd;
2567 MPASS(fdp != NULL);
2568
2569 #ifdef RACCT
2570 if (RACCT_ENABLED())
2571 racct_set_unlocked(p, RACCT_NOFILE, 0);
2572 #endif
2573
2574 if (p->p_fdtol != NULL)
2575 fdclearlocks(td);
2576
2577 PROC_LOCK(p);
2578 p->p_fd = NULL;
2579 PROC_UNLOCK(p);
2580
2581 if (refcount_release(&fdp->fd_refcnt) == 0)
2582 return;
2583
2584 fdescfree_fds(td, fdp, 1);
2585 }
2586
2587 void
2588 pdescfree(struct thread *td)
2589 {
2590 struct proc *p;
2591 struct pwddesc *pdp;
2592
2593 p = td->td_proc;
2594 pdp = p->p_pd;
2595 MPASS(pdp != NULL);
2596
2597 PROC_LOCK(p);
2598 p->p_pd = NULL;
2599 PROC_UNLOCK(p);
2600
2601 pddrop(pdp);
2602 }
2603
2604 void
2605 fdescfree_remapped(struct filedesc *fdp)
2606 {
2607 #ifdef INVARIANTS
2608 /* fdescfree_fds() asserts that fd_refcnt == 0. */
2609 if (!refcount_release(&fdp->fd_refcnt))
2610 panic("%s: fd table %p has extra references", __func__, fdp);
2611 #endif
2612 fdescfree_fds(curthread, fdp, 0);
2613 }
2614
2615 /*
2616 * For setugid programs, we don't want to people to use that setugidness
2617 * to generate error messages which write to a file which otherwise would
2618 * otherwise be off-limits to the process. We check for filesystems where
2619 * the vnode can change out from under us after execve (like [lin]procfs).
2620 *
2621 * Since fdsetugidsafety calls this only for fd 0, 1 and 2, this check is
2622 * sufficient. We also don't check for setugidness since we know we are.
2623 */
2624 static bool
2625 is_unsafe(struct file *fp)
2626 {
2627 struct vnode *vp;
2628
2629 if (fp->f_type != DTYPE_VNODE)
2630 return (false);
2631
2632 vp = fp->f_vnode;
2633 return ((vp->v_vflag & VV_PROCDEP) != 0);
2634 }
2635
2636 /*
2637 * Make this setguid thing safe, if at all possible.
2638 */
2639 void
2640 fdsetugidsafety(struct thread *td)
2641 {
2642 struct filedesc *fdp;
2643 struct file *fp;
2644 int i;
2645
2646 fdp = td->td_proc->p_fd;
2647 KASSERT(refcount_load(&fdp->fd_refcnt) == 1,
2648 ("the fdtable should not be shared"));
2649 MPASS(fdp->fd_nfiles >= 3);
2650 for (i = 0; i <= 2; i++) {
2651 fp = fdp->fd_ofiles[i].fde_file;
2652 if (fp != NULL && is_unsafe(fp)) {
2653 FILEDESC_XLOCK(fdp);
2654 knote_fdclose(td, i);
2655 /*
2656 * NULL-out descriptor prior to close to avoid
2657 * a race while close blocks.
2658 */
2659 fdfree(fdp, i);
2660 FILEDESC_XUNLOCK(fdp);
2661 (void) closef(fp, td);
2662 }
2663 }
2664 }
2665
2666 /*
2667 * If a specific file object occupies a specific file descriptor, close the
2668 * file descriptor entry and drop a reference on the file object. This is a
2669 * convenience function to handle a subsequent error in a function that calls
2670 * falloc() that handles the race that another thread might have closed the
2671 * file descriptor out from under the thread creating the file object.
2672 */
2673 void
2674 fdclose(struct thread *td, struct file *fp, int idx)
2675 {
2676 struct filedesc *fdp = td->td_proc->p_fd;
2677
2678 FILEDESC_XLOCK(fdp);
2679 if (fdp->fd_ofiles[idx].fde_file == fp) {
2680 fdfree(fdp, idx);
2681 FILEDESC_XUNLOCK(fdp);
2682 fdrop(fp, td);
2683 } else
2684 FILEDESC_XUNLOCK(fdp);
2685 }
2686
2687 /*
2688 * Close any files on exec?
2689 */
2690 void
2691 fdcloseexec(struct thread *td)
2692 {
2693 struct filedesc *fdp;
2694 struct filedescent *fde;
2695 struct file *fp;
2696 int i, lastfile;
2697
2698 fdp = td->td_proc->p_fd;
2699 KASSERT(refcount_load(&fdp->fd_refcnt) == 1,
2700 ("the fdtable should not be shared"));
2701 lastfile = fdlastfile_single(fdp);
2702 for (i = 0; i <= lastfile; i++) {
2703 fde = &fdp->fd_ofiles[i];
2704 fp = fde->fde_file;
2705 if (fp != NULL && (fp->f_type == DTYPE_MQUEUE ||
2706 (fde->fde_flags & UF_EXCLOSE))) {
2707 FILEDESC_XLOCK(fdp);
2708 fdfree(fdp, i);
2709 (void) closefp(fdp, i, fp, td, false, false);
2710 FILEDESC_UNLOCK_ASSERT(fdp);
2711 }
2712 }
2713 }
2714
2715 /*
2716 * It is unsafe for set[ug]id processes to be started with file
2717 * descriptors 0..2 closed, as these descriptors are given implicit
2718 * significance in the Standard C library. fdcheckstd() will create a
2719 * descriptor referencing /dev/null for each of stdin, stdout, and
2720 * stderr that is not already open.
2721 */
2722 int
2723 fdcheckstd(struct thread *td)
2724 {
2725 struct filedesc *fdp;
2726 register_t save;
2727 int i, error, devnull;
2728
2729 fdp = td->td_proc->p_fd;
2730 KASSERT(refcount_load(&fdp->fd_refcnt) == 1,
2731 ("the fdtable should not be shared"));
2732 MPASS(fdp->fd_nfiles >= 3);
2733 devnull = -1;
2734 for (i = 0; i <= 2; i++) {
2735 if (fdp->fd_ofiles[i].fde_file != NULL)
2736 continue;
2737
2738 save = td->td_retval[0];
2739 if (devnull != -1) {
2740 error = kern_dup(td, FDDUP_FIXED, 0, devnull, i);
2741 } else {
2742 error = kern_openat(td, AT_FDCWD, "/dev/null",
2743 UIO_SYSSPACE, O_RDWR, 0);
2744 if (error == 0) {
2745 devnull = td->td_retval[0];
2746 KASSERT(devnull == i, ("we didn't get our fd"));
2747 }
2748 }
2749 td->td_retval[0] = save;
2750 if (error != 0)
2751 return (error);
2752 }
2753 return (0);
2754 }
2755
2756 /*
2757 * Internal form of close. Decrement reference count on file structure.
2758 * Note: td may be NULL when closing a file that was being passed in a
2759 * message.
2760 */
2761 int
2762 closef(struct file *fp, struct thread *td)
2763 {
2764 struct vnode *vp;
2765 struct flock lf;
2766 struct filedesc_to_leader *fdtol;
2767 struct filedesc *fdp;
2768
2769 MPASS(td != NULL);
2770
2771 /*
2772 * POSIX record locking dictates that any close releases ALL
2773 * locks owned by this process. This is handled by setting
2774 * a flag in the unlock to free ONLY locks obeying POSIX
2775 * semantics, and not to free BSD-style file locks.
2776 * If the descriptor was in a message, POSIX-style locks
2777 * aren't passed with the descriptor, and the thread pointer
2778 * will be NULL. Callers should be careful only to pass a
2779 * NULL thread pointer when there really is no owning
2780 * context that might have locks, or the locks will be
2781 * leaked.
2782 */
2783 if (fp->f_type == DTYPE_VNODE) {
2784 vp = fp->f_vnode;
2785 if ((td->td_proc->p_leader->p_flag & P_ADVLOCK) != 0) {
2786 lf.l_whence = SEEK_SET;
2787 lf.l_start = 0;
2788 lf.l_len = 0;
2789 lf.l_type = F_UNLCK;
2790 (void) VOP_ADVLOCK(vp, (caddr_t)td->td_proc->p_leader,
2791 F_UNLCK, &lf, F_POSIX);
2792 }
2793 fdtol = td->td_proc->p_fdtol;
2794 if (fdtol != NULL) {
2795 /*
2796 * Handle special case where file descriptor table is
2797 * shared between multiple process leaders.
2798 */
2799 fdp = td->td_proc->p_fd;
2800 FILEDESC_XLOCK(fdp);
2801 for (fdtol = fdtol->fdl_next;
2802 fdtol != td->td_proc->p_fdtol;
2803 fdtol = fdtol->fdl_next) {
2804 if ((fdtol->fdl_leader->p_flag &
2805 P_ADVLOCK) == 0)
2806 continue;
2807 fdtol->fdl_holdcount++;
2808 FILEDESC_XUNLOCK(fdp);
2809 lf.l_whence = SEEK_SET;
2810 lf.l_start = 0;
2811 lf.l_len = 0;
2812 lf.l_type = F_UNLCK;
2813 vp = fp->f_vnode;
2814 (void) VOP_ADVLOCK(vp,
2815 (caddr_t)fdtol->fdl_leader, F_UNLCK, &lf,
2816 F_POSIX);
2817 FILEDESC_XLOCK(fdp);
2818 fdtol->fdl_holdcount--;
2819 if (fdtol->fdl_holdcount == 0 &&
2820 fdtol->fdl_wakeup != 0) {
2821 fdtol->fdl_wakeup = 0;
2822 wakeup(fdtol);
2823 }
2824 }
2825 FILEDESC_XUNLOCK(fdp);
2826 }
2827 }
2828 return (fdrop_close(fp, td));
2829 }
2830
2831 /*
2832 * Hack for file descriptor passing code.
2833 */
2834 void
2835 closef_nothread(struct file *fp)
2836 {
2837
2838 fdrop(fp, NULL);
2839 }
2840
2841 /*
2842 * Initialize the file pointer with the specified properties.
2843 *
2844 * The ops are set with release semantics to be certain that the flags, type,
2845 * and data are visible when ops is. This is to prevent ops methods from being
2846 * called with bad data.
2847 */
2848 void
2849 finit(struct file *fp, u_int flag, short type, void *data, struct fileops *ops)
2850 {
2851 fp->f_data = data;
2852 fp->f_flag = flag;
2853 fp->f_type = type;
2854 atomic_store_rel_ptr((volatile uintptr_t *)&fp->f_ops, (uintptr_t)ops);
2855 }
2856
2857 void
2858 finit_vnode(struct file *fp, u_int flag, void *data, struct fileops *ops)
2859 {
2860 fp->f_seqcount[UIO_READ] = 1;
2861 fp->f_seqcount[UIO_WRITE] = 1;
2862 finit(fp, (flag & FMASK) | (fp->f_flag & FHASLOCK), DTYPE_VNODE,
2863 data, ops);
2864 }
2865
2866 int
2867 fget_cap_locked(struct filedesc *fdp, int fd, cap_rights_t *needrightsp,
2868 struct file **fpp, struct filecaps *havecapsp)
2869 {
2870 struct filedescent *fde;
2871 int error;
2872
2873 FILEDESC_LOCK_ASSERT(fdp);
2874
2875 fde = fdeget_locked(fdp, fd);
2876 if (fde == NULL) {
2877 error = EBADF;
2878 goto out;
2879 }
2880
2881 #ifdef CAPABILITIES
2882 error = cap_check(cap_rights_fde_inline(fde), needrightsp);
2883 if (error != 0)
2884 goto out;
2885 #endif
2886
2887 if (havecapsp != NULL)
2888 filecaps_copy(&fde->fde_caps, havecapsp, true);
2889
2890 *fpp = fde->fde_file;
2891
2892 error = 0;
2893 out:
2894 return (error);
2895 }
2896
2897 int
2898 fget_cap(struct thread *td, int fd, cap_rights_t *needrightsp,
2899 struct file **fpp, struct filecaps *havecapsp)
2900 {
2901 struct filedesc *fdp = td->td_proc->p_fd;
2902 int error;
2903 #ifndef CAPABILITIES
2904 error = fget_unlocked(fdp, fd, needrightsp, fpp);
2905 if (havecapsp != NULL && error == 0)
2906 filecaps_fill(havecapsp);
2907 #else
2908 struct file *fp;
2909 seqc_t seq;
2910
2911 *fpp = NULL;
2912 for (;;) {
2913 error = fget_unlocked_seq(fdp, fd, needrightsp, &fp, &seq);
2914 if (error != 0)
2915 return (error);
2916
2917 if (havecapsp != NULL) {
2918 if (!filecaps_copy(&fdp->fd_ofiles[fd].fde_caps,
2919 havecapsp, false)) {
2920 fdrop(fp, td);
2921 goto get_locked;
2922 }
2923 }
2924
2925 if (!fd_modified(fdp, fd, seq))
2926 break;
2927 fdrop(fp, td);
2928 }
2929
2930 *fpp = fp;
2931 return (0);
2932
2933 get_locked:
2934 FILEDESC_SLOCK(fdp);
2935 error = fget_cap_locked(fdp, fd, needrightsp, fpp, havecapsp);
2936 if (error == 0 && !fhold(*fpp))
2937 error = EBADF;
2938 FILEDESC_SUNLOCK(fdp);
2939 #endif
2940 return (error);
2941 }
2942
2943 #ifdef CAPABILITIES
2944 int
2945 fgetvp_lookup_smr(int fd, struct nameidata *ndp, struct vnode **vpp, bool *fsearch)
2946 {
2947 const struct filedescent *fde;
2948 const struct fdescenttbl *fdt;
2949 struct filedesc *fdp;
2950 struct file *fp;
2951 struct vnode *vp;
2952 const cap_rights_t *haverights;
2953 cap_rights_t rights;
2954 seqc_t seq;
2955
2956 VFS_SMR_ASSERT_ENTERED();
2957
2958 rights = *ndp->ni_rightsneeded;
2959 cap_rights_set_one(&rights, CAP_LOOKUP);
2960
2961 fdp = curproc->p_fd;
2962 fdt = fdp->fd_files;
2963 if (__predict_false((u_int)fd >= fdt->fdt_nfiles))
2964 return (EBADF);
2965 seq = seqc_read_notmodify(fd_seqc(fdt, fd));
2966 fde = &fdt->fdt_ofiles[fd];
2967 haverights = cap_rights_fde_inline(fde);
2968 fp = fde->fde_file;
2969 if (__predict_false(fp == NULL))
2970 return (EAGAIN);
2971 if (__predict_false(cap_check_inline_transient(haverights, &rights)))
2972 return (EAGAIN);
2973 *fsearch = ((fp->f_flag & FSEARCH) != 0);
2974 vp = fp->f_vnode;
2975 if (__predict_false(vp == NULL || vp->v_type != VDIR)) {
2976 return (EAGAIN);
2977 }
2978 if (!filecaps_copy(&fde->fde_caps, &ndp->ni_filecaps, false)) {
2979 return (EAGAIN);
2980 }
2981 /*
2982 * Use an acquire barrier to force re-reading of fdt so it is
2983 * refreshed for verification.
2984 */
2985 atomic_thread_fence_acq();
2986 fdt = fdp->fd_files;
2987 if (__predict_false(!seqc_consistent_nomb(fd_seqc(fdt, fd), seq)))
2988 return (EAGAIN);
2989 /*
2990 * If file descriptor doesn't have all rights,
2991 * all lookups relative to it must also be
2992 * strictly relative.
2993 *
2994 * Not yet supported by fast path.
2995 */
2996 CAP_ALL(&rights);
2997 if (!cap_rights_contains(&ndp->ni_filecaps.fc_rights, &rights) ||
2998 ndp->ni_filecaps.fc_fcntls != CAP_FCNTL_ALL ||
2999 ndp->ni_filecaps.fc_nioctls != -1) {
3000 #ifdef notyet
3001 ndp->ni_lcf |= NI_LCF_STRICTRELATIVE;
3002 #else
3003 return (EAGAIN);
3004 #endif
3005 }
3006 *vpp = vp;
3007 return (0);
3008 }
3009 #else
3010 int
3011 fgetvp_lookup_smr(int fd, struct nameidata *ndp, struct vnode **vpp, bool *fsearch)
3012 {
3013 const struct fdescenttbl *fdt;
3014 struct filedesc *fdp;
3015 struct file *fp;
3016 struct vnode *vp;
3017
3018 VFS_SMR_ASSERT_ENTERED();
3019
3020 fdp = curproc->p_fd;
3021 fdt = fdp->fd_files;
3022 if (__predict_false((u_int)fd >= fdt->fdt_nfiles))
3023 return (EBADF);
3024 fp = fdt->fdt_ofiles[fd].fde_file;
3025 if (__predict_false(fp == NULL))
3026 return (EAGAIN);
3027 *fsearch = ((fp->f_flag & FSEARCH) != 0);
3028 vp = fp->f_vnode;
3029 if (__predict_false(vp == NULL || vp->v_type != VDIR)) {
3030 return (EAGAIN);
3031 }
3032 /*
3033 * Use an acquire barrier to force re-reading of fdt so it is
3034 * refreshed for verification.
3035 */
3036 atomic_thread_fence_acq();
3037 fdt = fdp->fd_files;
3038 if (__predict_false(fp != fdt->fdt_ofiles[fd].fde_file))
3039 return (EAGAIN);
3040 filecaps_fill(&ndp->ni_filecaps);
3041 *vpp = vp;
3042 return (0);
3043 }
3044 #endif
3045
3046 int
3047 fget_unlocked_seq(struct filedesc *fdp, int fd, cap_rights_t *needrightsp,
3048 struct file **fpp, seqc_t *seqp)
3049 {
3050 #ifdef CAPABILITIES
3051 const struct filedescent *fde;
3052 #endif
3053 const struct fdescenttbl *fdt;
3054 struct file *fp;
3055 #ifdef CAPABILITIES
3056 seqc_t seq;
3057 cap_rights_t haverights;
3058 int error;
3059 #endif
3060
3061 fdt = fdp->fd_files;
3062 if (__predict_false((u_int)fd >= fdt->fdt_nfiles))
3063 return (EBADF);
3064 /*
3065 * Fetch the descriptor locklessly. We avoid fdrop() races by
3066 * never raising a refcount above 0. To accomplish this we have
3067 * to use a cmpset loop rather than an atomic_add. The descriptor
3068 * must be re-verified once we acquire a reference to be certain
3069 * that the identity is still correct and we did not lose a race
3070 * due to preemption.
3071 */
3072 for (;;) {
3073 #ifdef CAPABILITIES
3074 seq = seqc_read_notmodify(fd_seqc(fdt, fd));
3075 fde = &fdt->fdt_ofiles[fd];
3076 haverights = *cap_rights_fde_inline(fde);
3077 fp = fde->fde_file;
3078 if (!seqc_consistent(fd_seqc(fdt, fd), seq))
3079 continue;
3080 #else
3081 fp = fdt->fdt_ofiles[fd].fde_file;
3082 #endif
3083 if (fp == NULL)
3084 return (EBADF);
3085 #ifdef CAPABILITIES
3086 error = cap_check_inline(&haverights, needrightsp);
3087 if (error != 0)
3088 return (error);
3089 #endif
3090 if (__predict_false(!refcount_acquire_if_not_zero(&fp->f_count))) {
3091 /*
3092 * Force a reload. Other thread could reallocate the
3093 * table before this fd was closed, so it is possible
3094 * that there is a stale fp pointer in cached version.
3095 */
3096 fdt = atomic_load_ptr(&fdp->fd_files);
3097 continue;
3098 }
3099 /*
3100 * Use an acquire barrier to force re-reading of fdt so it is
3101 * refreshed for verification.
3102 */
3103 atomic_thread_fence_acq();
3104 fdt = fdp->fd_files;
3105 #ifdef CAPABILITIES
3106 if (seqc_consistent_nomb(fd_seqc(fdt, fd), seq))
3107 #else
3108 if (fp == fdt->fdt_ofiles[fd].fde_file)
3109 #endif
3110 break;
3111 fdrop(fp, curthread);
3112 }
3113 *fpp = fp;
3114 if (seqp != NULL) {
3115 #ifdef CAPABILITIES
3116 *seqp = seq;
3117 #endif
3118 }
3119 return (0);
3120 }
3121
3122 /*
3123 * See the comments in fget_unlocked_seq for an explanation of how this works.
3124 *
3125 * This is a simplified variant which bails out to the aforementioned routine
3126 * if anything goes wrong. In practice this only happens when userspace is
3127 * racing with itself.
3128 */
3129 int
3130 fget_unlocked(struct filedesc *fdp, int fd, cap_rights_t *needrightsp,
3131 struct file **fpp)
3132 {
3133 #ifdef CAPABILITIES
3134 const struct filedescent *fde;
3135 #endif
3136 const struct fdescenttbl *fdt;
3137 struct file *fp;
3138 #ifdef CAPABILITIES
3139 seqc_t seq;
3140 const cap_rights_t *haverights;
3141 #endif
3142
3143 fdt = fdp->fd_files;
3144 if (__predict_false((u_int)fd >= fdt->fdt_nfiles))
3145 return (EBADF);
3146 #ifdef CAPABILITIES
3147 seq = seqc_read_notmodify(fd_seqc(fdt, fd));
3148 fde = &fdt->fdt_ofiles[fd];
3149 haverights = cap_rights_fde_inline(fde);
3150 fp = fde->fde_file;
3151 #else
3152 fp = fdt->fdt_ofiles[fd].fde_file;
3153 #endif
3154 if (__predict_false(fp == NULL))
3155 goto out_fallback;
3156 #ifdef CAPABILITIES
3157 if (__predict_false(cap_check_inline_transient(haverights, needrightsp)))
3158 goto out_fallback;
3159 #endif
3160 if (__predict_false(!refcount_acquire_if_not_zero(&fp->f_count)))
3161 goto out_fallback;
3162
3163 /*
3164 * Use an acquire barrier to force re-reading of fdt so it is
3165 * refreshed for verification.
3166 */
3167 atomic_thread_fence_acq();
3168 fdt = fdp->fd_files;
3169 #ifdef CAPABILITIES
3170 if (__predict_false(!seqc_consistent_nomb(fd_seqc(fdt, fd), seq)))
3171 #else
3172 if (__predict_false(fp != fdt->fdt_ofiles[fd].fde_file))
3173 #endif
3174 goto out_fdrop;
3175 *fpp = fp;
3176 return (0);
3177 out_fdrop:
3178 fdrop(fp, curthread);
3179 out_fallback:
3180 return (fget_unlocked_seq(fdp, fd, needrightsp, fpp, NULL));
3181 }
3182
3183 /*
3184 * Translate fd -> file when the caller guarantees the file descriptor table
3185 * can't be changed by others.
3186 *
3187 * Note this does not mean the file object itself is only visible to the caller,
3188 * merely that it wont disappear without having to be referenced.
3189 *
3190 * Must be paired with fput_only_user.
3191 */
3192 #ifdef CAPABILITIES
3193 int
3194 fget_only_user(struct filedesc *fdp, int fd, cap_rights_t *needrightsp,
3195 struct file **fpp)
3196 {
3197 const struct filedescent *fde;
3198 const struct fdescenttbl *fdt;
3199 const cap_rights_t *haverights;
3200 struct file *fp;
3201 int error;
3202
3203 MPASS(FILEDESC_IS_ONLY_USER(fdp));
3204
3205 if (__predict_false(fd >= fdp->fd_nfiles))
3206 return (EBADF);
3207
3208 fdt = fdp->fd_files;
3209 fde = &fdt->fdt_ofiles[fd];
3210 fp = fde->fde_file;
3211 if (__predict_false(fp == NULL))
3212 return (EBADF);
3213 MPASS(refcount_load(&fp->f_count) > 0);
3214 haverights = cap_rights_fde_inline(fde);
3215 error = cap_check_inline(haverights, needrightsp);
3216 if (__predict_false(error != 0))
3217 return (EBADF);
3218 *fpp = fp;
3219 return (0);
3220 }
3221 #else
3222 int
3223 fget_only_user(struct filedesc *fdp, int fd, cap_rights_t *needrightsp,
3224 struct file **fpp)
3225 {
3226 struct file *fp;
3227
3228 MPASS(FILEDESC_IS_ONLY_USER(fdp));
3229
3230 if (__predict_false(fd >= fdp->fd_nfiles))
3231 return (EBADF);
3232
3233 fp = fdp->fd_ofiles[fd].fde_file;
3234 if (__predict_false(fp == NULL))
3235 return (EBADF);
3236
3237 MPASS(refcount_load(&fp->f_count) > 0);
3238 *fpp = fp;
3239 return (0);
3240 }
3241 #endif
3242
3243 /*
3244 * Extract the file pointer associated with the specified descriptor for the
3245 * current user process.
3246 *
3247 * If the descriptor doesn't exist or doesn't match 'flags', EBADF is
3248 * returned.
3249 *
3250 * File's rights will be checked against the capability rights mask.
3251 *
3252 * If an error occurred the non-zero error is returned and *fpp is set to
3253 * NULL. Otherwise *fpp is held and set and zero is returned. Caller is
3254 * responsible for fdrop().
3255 */
3256 static __inline int
3257 _fget(struct thread *td, int fd, struct file **fpp, int flags,
3258 cap_rights_t *needrightsp)
3259 {
3260 struct filedesc *fdp;
3261 struct file *fp;
3262 int error;
3263
3264 *fpp = NULL;
3265 fdp = td->td_proc->p_fd;
3266 error = fget_unlocked(fdp, fd, needrightsp, &fp);
3267 if (__predict_false(error != 0))
3268 return (error);
3269 if (__predict_false(fp->f_ops == &badfileops)) {
3270 fdrop(fp, td);
3271 return (EBADF);
3272 }
3273
3274 /*
3275 * FREAD and FWRITE failure return EBADF as per POSIX.
3276 */
3277 error = 0;
3278 switch (flags) {
3279 case FREAD:
3280 case FWRITE:
3281 if ((fp->f_flag & flags) == 0)
3282 error = EBADF;
3283 break;
3284 case FEXEC:
3285 if ((fp->f_flag & (FREAD | FEXEC)) == 0 ||
3286 ((fp->f_flag & FWRITE) != 0))
3287 error = EBADF;
3288 break;
3289 case 0:
3290 break;
3291 default:
3292 KASSERT(0, ("wrong flags"));
3293 }
3294
3295 if (error != 0) {
3296 fdrop(fp, td);
3297 return (error);
3298 }
3299
3300 *fpp = fp;
3301 return (0);
3302 }
3303
3304 int
3305 fget(struct thread *td, int fd, cap_rights_t *rightsp, struct file **fpp)
3306 {
3307
3308 return (_fget(td, fd, fpp, 0, rightsp));
3309 }
3310
3311 int
3312 fget_mmap(struct thread *td, int fd, cap_rights_t *rightsp, vm_prot_t *maxprotp,
3313 struct file **fpp)
3314 {
3315 int error;
3316 #ifndef CAPABILITIES
3317 error = _fget(td, fd, fpp, 0, rightsp);
3318 if (maxprotp != NULL)
3319 *maxprotp = VM_PROT_ALL;
3320 return (error);
3321 #else
3322 cap_rights_t fdrights;
3323 struct filedesc *fdp;
3324 struct file *fp;
3325 seqc_t seq;
3326
3327 *fpp = NULL;
3328 fdp = td->td_proc->p_fd;
3329 MPASS(cap_rights_is_set(rightsp, CAP_MMAP));
3330 for (;;) {
3331 error = fget_unlocked_seq(fdp, fd, rightsp, &fp, &seq);
3332 if (__predict_false(error != 0))
3333 return (error);
3334 if (__predict_false(fp->f_ops == &badfileops)) {
3335 fdrop(fp, td);
3336 return (EBADF);
3337 }
3338 if (maxprotp != NULL)
3339 fdrights = *cap_rights(fdp, fd);
3340 if (!fd_modified(fdp, fd, seq))
3341 break;
3342 fdrop(fp, td);
3343 }
3344
3345 /*
3346 * If requested, convert capability rights to access flags.
3347 */
3348 if (maxprotp != NULL)
3349 *maxprotp = cap_rights_to_vmprot(&fdrights);
3350 *fpp = fp;
3351 return (0);
3352 #endif
3353 }
3354
3355 int
3356 fget_read(struct thread *td, int fd, cap_rights_t *rightsp, struct file **fpp)
3357 {
3358
3359 return (_fget(td, fd, fpp, FREAD, rightsp));
3360 }
3361
3362 int
3363 fget_write(struct thread *td, int fd, cap_rights_t *rightsp, struct file **fpp)
3364 {
3365
3366 return (_fget(td, fd, fpp, FWRITE, rightsp));
3367 }
3368
3369 int
3370 fget_fcntl(struct thread *td, int fd, cap_rights_t *rightsp, int needfcntl,
3371 struct file **fpp)
3372 {
3373 struct filedesc *fdp = td->td_proc->p_fd;
3374 #ifndef CAPABILITIES
3375 return (fget_unlocked(fdp, fd, rightsp, fpp));
3376 #else
3377 struct file *fp;
3378 int error;
3379 seqc_t seq;
3380
3381 *fpp = NULL;
3382 MPASS(cap_rights_is_set(rightsp, CAP_FCNTL));
3383 for (;;) {
3384 error = fget_unlocked_seq(fdp, fd, rightsp, &fp, &seq);
3385 if (error != 0)
3386 return (error);
3387 error = cap_fcntl_check(fdp, fd, needfcntl);
3388 if (!fd_modified(fdp, fd, seq))
3389 break;
3390 fdrop(fp, td);
3391 }
3392 if (error != 0) {
3393 fdrop(fp, td);
3394 return (error);
3395 }
3396 *fpp = fp;
3397 return (0);
3398 #endif
3399 }
3400
3401 /*
3402 * Like fget() but loads the underlying vnode, or returns an error if the
3403 * descriptor does not represent a vnode. Note that pipes use vnodes but
3404 * never have VM objects. The returned vnode will be vref()'d.
3405 *
3406 * XXX: what about the unused flags ?
3407 */
3408 static __inline int
3409 _fgetvp(struct thread *td, int fd, int flags, cap_rights_t *needrightsp,
3410 struct vnode **vpp)
3411 {
3412 struct file *fp;
3413 int error;
3414
3415 *vpp = NULL;
3416 error = _fget(td, fd, &fp, flags, needrightsp);
3417 if (error != 0)
3418 return (error);
3419 if (fp->f_vnode == NULL) {
3420 error = EINVAL;
3421 } else {
3422 *vpp = fp->f_vnode;
3423 vrefact(*vpp);
3424 }
3425 fdrop(fp, td);
3426
3427 return (error);
3428 }
3429
3430 int
3431 fgetvp(struct thread *td, int fd, cap_rights_t *rightsp, struct vnode **vpp)
3432 {
3433
3434 return (_fgetvp(td, fd, 0, rightsp, vpp));
3435 }
3436
3437 int
3438 fgetvp_rights(struct thread *td, int fd, cap_rights_t *needrightsp,
3439 struct filecaps *havecaps, struct vnode **vpp)
3440 {
3441 struct filecaps caps;
3442 struct file *fp;
3443 int error;
3444
3445 error = fget_cap(td, fd, needrightsp, &fp, &caps);
3446 if (error != 0)
3447 return (error);
3448 if (fp->f_ops == &badfileops) {
3449 error = EBADF;
3450 goto out;
3451 }
3452 if (fp->f_vnode == NULL) {
3453 error = EINVAL;
3454 goto out;
3455 }
3456
3457 *havecaps = caps;
3458 *vpp = fp->f_vnode;
3459 vrefact(*vpp);
3460 fdrop(fp, td);
3461
3462 return (0);
3463 out:
3464 filecaps_free(&caps);
3465 fdrop(fp, td);
3466 return (error);
3467 }
3468
3469 int
3470 fgetvp_read(struct thread *td, int fd, cap_rights_t *rightsp, struct vnode **vpp)
3471 {
3472
3473 return (_fgetvp(td, fd, FREAD, rightsp, vpp));
3474 }
3475
3476 int
3477 fgetvp_exec(struct thread *td, int fd, cap_rights_t *rightsp, struct vnode **vpp)
3478 {
3479
3480 return (_fgetvp(td, fd, FEXEC, rightsp, vpp));
3481 }
3482
3483 #ifdef notyet
3484 int
3485 fgetvp_write(struct thread *td, int fd, cap_rights_t *rightsp,
3486 struct vnode **vpp)
3487 {
3488
3489 return (_fgetvp(td, fd, FWRITE, rightsp, vpp));
3490 }
3491 #endif
3492
3493 /*
3494 * Handle the last reference to a file being closed.
3495 *
3496 * Without the noinline attribute clang keeps inlining the func thorough this
3497 * file when fdrop is used.
3498 */
3499 int __noinline
3500 _fdrop(struct file *fp, struct thread *td)
3501 {
3502 int error;
3503 #ifdef INVARIANTS
3504 int count;
3505
3506 count = refcount_load(&fp->f_count);
3507 if (count != 0)
3508 panic("fdrop: fp %p count %d", fp, count);
3509 #endif
3510 error = fo_close(fp, td);
3511 atomic_subtract_int(&openfiles, 1);
3512 crfree(fp->f_cred);
3513 free(fp->f_advice, M_FADVISE);
3514 uma_zfree(file_zone, fp);
3515
3516 return (error);
3517 }
3518
3519 /*
3520 * Apply an advisory lock on a file descriptor.
3521 *
3522 * Just attempt to get a record lock of the requested type on the entire file
3523 * (l_whence = SEEK_SET, l_start = 0, l_len = 0).
3524 */
3525 #ifndef _SYS_SYSPROTO_H_
3526 struct flock_args {
3527 int fd;
3528 int how;
3529 };
3530 #endif
3531 /* ARGSUSED */
3532 int
3533 sys_flock(struct thread *td, struct flock_args *uap)
3534 {
3535 struct file *fp;
3536 struct vnode *vp;
3537 struct flock lf;
3538 int error;
3539
3540 error = fget(td, uap->fd, &cap_flock_rights, &fp);
3541 if (error != 0)
3542 return (error);
3543 if (fp->f_type != DTYPE_VNODE) {
3544 fdrop(fp, td);
3545 return (EOPNOTSUPP);
3546 }
3547
3548 vp = fp->f_vnode;
3549 lf.l_whence = SEEK_SET;
3550 lf.l_start = 0;
3551 lf.l_len = 0;
3552 if (uap->how & LOCK_UN) {
3553 lf.l_type = F_UNLCK;
3554 atomic_clear_int(&fp->f_flag, FHASLOCK);
3555 error = VOP_ADVLOCK(vp, (caddr_t)fp, F_UNLCK, &lf, F_FLOCK);
3556 goto done2;
3557 }
3558 if (uap->how & LOCK_EX)
3559 lf.l_type = F_WRLCK;
3560 else if (uap->how & LOCK_SH)
3561 lf.l_type = F_RDLCK;
3562 else {
3563 error = EBADF;
3564 goto done2;
3565 }
3566 atomic_set_int(&fp->f_flag, FHASLOCK);
3567 error = VOP_ADVLOCK(vp, (caddr_t)fp, F_SETLK, &lf,
3568 (uap->how & LOCK_NB) ? F_FLOCK : F_FLOCK | F_WAIT);
3569 done2:
3570 fdrop(fp, td);
3571 return (error);
3572 }
3573 /*
3574 * Duplicate the specified descriptor to a free descriptor.
3575 */
3576 int
3577 dupfdopen(struct thread *td, struct filedesc *fdp, int dfd, int mode,
3578 int openerror, int *indxp)
3579 {
3580 struct filedescent *newfde, *oldfde;
3581 struct file *fp;
3582 u_long *ioctls;
3583 int error, indx;
3584
3585 KASSERT(openerror == ENODEV || openerror == ENXIO,
3586 ("unexpected error %d in %s", openerror, __func__));
3587
3588 /*
3589 * If the to-be-dup'd fd number is greater than the allowed number
3590 * of file descriptors, or the fd to be dup'd has already been
3591 * closed, then reject.
3592 */
3593 FILEDESC_XLOCK(fdp);
3594 if ((fp = fget_locked(fdp, dfd)) == NULL) {
3595 FILEDESC_XUNLOCK(fdp);
3596 return (EBADF);
3597 }
3598
3599 error = fdalloc(td, 0, &indx);
3600 if (error != 0) {
3601 FILEDESC_XUNLOCK(fdp);
3602 return (error);
3603 }
3604
3605 /*
3606 * There are two cases of interest here.
3607 *
3608 * For ENODEV simply dup (dfd) to file descriptor (indx) and return.
3609 *
3610 * For ENXIO steal away the file structure from (dfd) and store it in
3611 * (indx). (dfd) is effectively closed by this operation.
3612 */
3613 switch (openerror) {
3614 case ENODEV:
3615 /*
3616 * Check that the mode the file is being opened for is a
3617 * subset of the mode of the existing descriptor.
3618 */
3619 if (((mode & (FREAD|FWRITE)) | fp->f_flag) != fp->f_flag) {
3620 fdunused(fdp, indx);
3621 FILEDESC_XUNLOCK(fdp);
3622 return (EACCES);
3623 }
3624 if (!fhold(fp)) {
3625 fdunused(fdp, indx);
3626 FILEDESC_XUNLOCK(fdp);
3627 return (EBADF);
3628 }
3629 newfde = &fdp->fd_ofiles[indx];
3630 oldfde = &fdp->fd_ofiles[dfd];
3631 ioctls = filecaps_copy_prep(&oldfde->fde_caps);
3632 #ifdef CAPABILITIES
3633 seqc_write_begin(&newfde->fde_seqc);
3634 #endif
3635 memcpy(newfde, oldfde, fde_change_size);
3636 filecaps_copy_finish(&oldfde->fde_caps, &newfde->fde_caps,
3637 ioctls);
3638 #ifdef CAPABILITIES
3639 seqc_write_end(&newfde->fde_seqc);
3640 #endif
3641 break;
3642 case ENXIO:
3643 /*
3644 * Steal away the file pointer from dfd and stuff it into indx.
3645 */
3646 newfde = &fdp->fd_ofiles[indx];
3647 oldfde = &fdp->fd_ofiles[dfd];
3648 #ifdef CAPABILITIES
3649 seqc_write_begin(&newfde->fde_seqc);
3650 #endif
3651 memcpy(newfde, oldfde, fde_change_size);
3652 oldfde->fde_file = NULL;
3653 fdunused(fdp, dfd);
3654 #ifdef CAPABILITIES
3655 seqc_write_end(&newfde->fde_seqc);
3656 #endif
3657 break;
3658 }
3659 FILEDESC_XUNLOCK(fdp);
3660 *indxp = indx;
3661 return (0);
3662 }
3663
3664 /*
3665 * This sysctl determines if we will allow a process to chroot(2) if it
3666 * has a directory open:
3667 * 0: disallowed for all processes.
3668 * 1: allowed for processes that were not already chroot(2)'ed.
3669 * 2: allowed for all processes.
3670 */
3671
3672 static int chroot_allow_open_directories = 1;
3673
3674 SYSCTL_INT(_kern, OID_AUTO, chroot_allow_open_directories, CTLFLAG_RW,
3675 &chroot_allow_open_directories, 0,
3676 "Allow a process to chroot(2) if it has a directory open");
3677
3678 /*
3679 * Helper function for raised chroot(2) security function: Refuse if
3680 * any filedescriptors are open directories.
3681 */
3682 static int
3683 chroot_refuse_vdir_fds(struct filedesc *fdp)
3684 {
3685 struct vnode *vp;
3686 struct file *fp;
3687 int fd, lastfile;
3688
3689 FILEDESC_LOCK_ASSERT(fdp);
3690
3691 lastfile = fdlastfile(fdp);
3692 for (fd = 0; fd <= lastfile; fd++) {
3693 fp = fget_locked(fdp, fd);
3694 if (fp == NULL)
3695 continue;
3696 if (fp->f_type == DTYPE_VNODE) {
3697 vp = fp->f_vnode;
3698 if (vp->v_type == VDIR)
3699 return (EPERM);
3700 }
3701 }
3702 return (0);
3703 }
3704
3705 static void
3706 pwd_fill(struct pwd *oldpwd, struct pwd *newpwd)
3707 {
3708
3709 if (newpwd->pwd_cdir == NULL && oldpwd->pwd_cdir != NULL) {
3710 vrefact(oldpwd->pwd_cdir);
3711 newpwd->pwd_cdir = oldpwd->pwd_cdir;
3712 }
3713
3714 if (newpwd->pwd_rdir == NULL && oldpwd->pwd_rdir != NULL) {
3715 vrefact(oldpwd->pwd_rdir);
3716 newpwd->pwd_rdir = oldpwd->pwd_rdir;
3717 }
3718
3719 if (newpwd->pwd_jdir == NULL && oldpwd->pwd_jdir != NULL) {
3720 vrefact(oldpwd->pwd_jdir);
3721 newpwd->pwd_jdir = oldpwd->pwd_jdir;
3722 }
3723 }
3724
3725 struct pwd *
3726 pwd_hold_pwddesc(struct pwddesc *pdp)
3727 {
3728 struct pwd *pwd;
3729
3730 PWDDESC_ASSERT_XLOCKED(pdp);
3731 pwd = PWDDESC_XLOCKED_LOAD_PWD(pdp);
3732 if (pwd != NULL)
3733 refcount_acquire(&pwd->pwd_refcount);
3734 return (pwd);
3735 }
3736
3737 bool
3738 pwd_hold_smr(struct pwd *pwd)
3739 {
3740
3741 MPASS(pwd != NULL);
3742 if (__predict_true(refcount_acquire_if_not_zero(&pwd->pwd_refcount))) {
3743 return (true);
3744 }
3745 return (false);
3746 }
3747
3748 struct pwd *
3749 pwd_hold(struct thread *td)
3750 {
3751 struct pwddesc *pdp;
3752 struct pwd *pwd;
3753
3754 pdp = td->td_proc->p_pd;
3755
3756 vfs_smr_enter();
3757 pwd = vfs_smr_entered_load(&pdp->pd_pwd);
3758 if (pwd_hold_smr(pwd)) {
3759 vfs_smr_exit();
3760 return (pwd);
3761 }
3762 vfs_smr_exit();
3763 PWDDESC_XLOCK(pdp);
3764 pwd = pwd_hold_pwddesc(pdp);
3765 MPASS(pwd != NULL);
3766 PWDDESC_XUNLOCK(pdp);
3767 return (pwd);
3768 }
3769
3770 static struct pwd *
3771 pwd_alloc(void)
3772 {
3773 struct pwd *pwd;
3774
3775 pwd = uma_zalloc_smr(pwd_zone, M_WAITOK);
3776 bzero(pwd, sizeof(*pwd));
3777 refcount_init(&pwd->pwd_refcount, 1);
3778 return (pwd);
3779 }
3780
3781 void
3782 pwd_drop(struct pwd *pwd)
3783 {
3784
3785 if (!refcount_release(&pwd->pwd_refcount))
3786 return;
3787
3788 if (pwd->pwd_cdir != NULL)
3789 vrele(pwd->pwd_cdir);
3790 if (pwd->pwd_rdir != NULL)
3791 vrele(pwd->pwd_rdir);
3792 if (pwd->pwd_jdir != NULL)
3793 vrele(pwd->pwd_jdir);
3794 uma_zfree_smr(pwd_zone, pwd);
3795 }
3796
3797 /*
3798 * The caller is responsible for invoking priv_check() and
3799 * mac_vnode_check_chroot() to authorize this operation.
3800 */
3801 int
3802 pwd_chroot(struct thread *td, struct vnode *vp)
3803 {
3804 struct pwddesc *pdp;
3805 struct filedesc *fdp;
3806 struct pwd *newpwd, *oldpwd;
3807 int error;
3808
3809 fdp = td->td_proc->p_fd;
3810 pdp = td->td_proc->p_pd;
3811 newpwd = pwd_alloc();
3812 FILEDESC_SLOCK(fdp);
3813 PWDDESC_XLOCK(pdp);
3814 oldpwd = PWDDESC_XLOCKED_LOAD_PWD(pdp);
3815 if (chroot_allow_open_directories == 0 ||
3816 (chroot_allow_open_directories == 1 &&
3817 oldpwd->pwd_rdir != rootvnode)) {
3818 error = chroot_refuse_vdir_fds(fdp);
3819 FILEDESC_SUNLOCK(fdp);
3820 if (error != 0) {
3821 PWDDESC_XUNLOCK(pdp);
3822 pwd_drop(newpwd);
3823 return (error);
3824 }
3825 } else {
3826 FILEDESC_SUNLOCK(fdp);
3827 }
3828
3829 vrefact(vp);
3830 newpwd->pwd_rdir = vp;
3831 if (oldpwd->pwd_jdir == NULL) {
3832 vrefact(vp);
3833 newpwd->pwd_jdir = vp;
3834 }
3835 pwd_fill(oldpwd, newpwd);
3836 pwd_set(pdp, newpwd);
3837 PWDDESC_XUNLOCK(pdp);
3838 pwd_drop(oldpwd);
3839 return (0);
3840 }
3841
3842 void
3843 pwd_chdir(struct thread *td, struct vnode *vp)
3844 {
3845 struct pwddesc *pdp;
3846 struct pwd *newpwd, *oldpwd;
3847
3848 VNPASS(vp->v_usecount > 0, vp);
3849
3850 newpwd = pwd_alloc();
3851 pdp = td->td_proc->p_pd;
3852 PWDDESC_XLOCK(pdp);
3853 oldpwd = PWDDESC_XLOCKED_LOAD_PWD(pdp);
3854 newpwd->pwd_cdir = vp;
3855 pwd_fill(oldpwd, newpwd);
3856 pwd_set(pdp, newpwd);
3857 PWDDESC_XUNLOCK(pdp);
3858 pwd_drop(oldpwd);
3859 }
3860
3861 /*
3862 * jail_attach(2) changes both root and working directories.
3863 */
3864 int
3865 pwd_chroot_chdir(struct thread *td, struct vnode *vp)
3866 {
3867 struct pwddesc *pdp;
3868 struct filedesc *fdp;
3869 struct pwd *newpwd, *oldpwd;
3870 int error;
3871
3872 fdp = td->td_proc->p_fd;
3873 pdp = td->td_proc->p_pd;
3874 newpwd = pwd_alloc();
3875 FILEDESC_SLOCK(fdp);
3876 PWDDESC_XLOCK(pdp);
3877 oldpwd = PWDDESC_XLOCKED_LOAD_PWD(pdp);
3878 error = chroot_refuse_vdir_fds(fdp);
3879 FILEDESC_SUNLOCK(fdp);
3880 if (error != 0) {
3881 PWDDESC_XUNLOCK(pdp);
3882 pwd_drop(newpwd);
3883 return (error);
3884 }
3885
3886 vrefact(vp);
3887 newpwd->pwd_rdir = vp;
3888 vrefact(vp);
3889 newpwd->pwd_cdir = vp;
3890 if (oldpwd->pwd_jdir == NULL) {
3891 vrefact(vp);
3892 newpwd->pwd_jdir = vp;
3893 }
3894 pwd_fill(oldpwd, newpwd);
3895 pwd_set(pdp, newpwd);
3896 PWDDESC_XUNLOCK(pdp);
3897 pwd_drop(oldpwd);
3898 return (0);
3899 }
3900
3901 void
3902 pwd_ensure_dirs(void)
3903 {
3904 struct pwddesc *pdp;
3905 struct pwd *oldpwd, *newpwd;
3906
3907 pdp = curproc->p_pd;
3908 PWDDESC_XLOCK(pdp);
3909 oldpwd = PWDDESC_XLOCKED_LOAD_PWD(pdp);
3910 if (oldpwd->pwd_cdir != NULL && oldpwd->pwd_rdir != NULL) {
3911 PWDDESC_XUNLOCK(pdp);
3912 return;
3913 }
3914 PWDDESC_XUNLOCK(pdp);
3915
3916 newpwd = pwd_alloc();
3917 PWDDESC_XLOCK(pdp);
3918 oldpwd = PWDDESC_XLOCKED_LOAD_PWD(pdp);
3919 pwd_fill(oldpwd, newpwd);
3920 if (newpwd->pwd_cdir == NULL) {
3921 vrefact(rootvnode);
3922 newpwd->pwd_cdir = rootvnode;
3923 }
3924 if (newpwd->pwd_rdir == NULL) {
3925 vrefact(rootvnode);
3926 newpwd->pwd_rdir = rootvnode;
3927 }
3928 pwd_set(pdp, newpwd);
3929 PWDDESC_XUNLOCK(pdp);
3930 pwd_drop(oldpwd);
3931 }
3932
3933 void
3934 pwd_set_rootvnode(void)
3935 {
3936 struct pwddesc *pdp;
3937 struct pwd *oldpwd, *newpwd;
3938
3939 pdp = curproc->p_pd;
3940
3941 newpwd = pwd_alloc();
3942 PWDDESC_XLOCK(pdp);
3943 oldpwd = PWDDESC_XLOCKED_LOAD_PWD(pdp);
3944 vrefact(rootvnode);
3945 newpwd->pwd_cdir = rootvnode;
3946 vrefact(rootvnode);
3947 newpwd->pwd_rdir = rootvnode;
3948 pwd_fill(oldpwd, newpwd);
3949 pwd_set(pdp, newpwd);
3950 PWDDESC_XUNLOCK(pdp);
3951 pwd_drop(oldpwd);
3952 }
3953
3954 /*
3955 * Scan all active processes and prisons to see if any of them have a current
3956 * or root directory of `olddp'. If so, replace them with the new mount point.
3957 */
3958 void
3959 mountcheckdirs(struct vnode *olddp, struct vnode *newdp)
3960 {
3961 struct pwddesc *pdp;
3962 struct pwd *newpwd, *oldpwd;
3963 struct prison *pr;
3964 struct proc *p;
3965 int nrele;
3966
3967 if (vrefcnt(olddp) == 1)
3968 return;
3969 nrele = 0;
3970 newpwd = pwd_alloc();
3971 sx_slock(&allproc_lock);
3972 FOREACH_PROC_IN_SYSTEM(p) {
3973 PROC_LOCK(p);
3974 pdp = pdhold(p);
3975 PROC_UNLOCK(p);
3976 if (pdp == NULL)
3977 continue;
3978 PWDDESC_XLOCK(pdp);
3979 oldpwd = PWDDESC_XLOCKED_LOAD_PWD(pdp);
3980 if (oldpwd == NULL ||
3981 (oldpwd->pwd_cdir != olddp &&
3982 oldpwd->pwd_rdir != olddp &&
3983 oldpwd->pwd_jdir != olddp)) {
3984 PWDDESC_XUNLOCK(pdp);
3985 pddrop(pdp);
3986 continue;
3987 }
3988 if (oldpwd->pwd_cdir == olddp) {
3989 vrefact(newdp);
3990 newpwd->pwd_cdir = newdp;
3991 }
3992 if (oldpwd->pwd_rdir == olddp) {
3993 vrefact(newdp);
3994 newpwd->pwd_rdir = newdp;
3995 }
3996 if (oldpwd->pwd_jdir == olddp) {
3997 vrefact(newdp);
3998 newpwd->pwd_jdir = newdp;
3999 }
4000 pwd_fill(oldpwd, newpwd);
4001 pwd_set(pdp, newpwd);
4002 PWDDESC_XUNLOCK(pdp);
4003 pwd_drop(oldpwd);
4004 pddrop(pdp);
4005 newpwd = pwd_alloc();
4006 }
4007 sx_sunlock(&allproc_lock);
4008 pwd_drop(newpwd);
4009 if (rootvnode == olddp) {
4010 vrefact(newdp);
4011 rootvnode = newdp;
4012 nrele++;
4013 }
4014 mtx_lock(&prison0.pr_mtx);
4015 if (prison0.pr_root == olddp) {
4016 vrefact(newdp);
4017 prison0.pr_root = newdp;
4018 nrele++;
4019 }
4020 mtx_unlock(&prison0.pr_mtx);
4021 sx_slock(&allprison_lock);
4022 TAILQ_FOREACH(pr, &allprison, pr_list) {
4023 mtx_lock(&pr->pr_mtx);
4024 if (pr->pr_root == olddp) {
4025 vrefact(newdp);
4026 pr->pr_root = newdp;
4027 nrele++;
4028 }
4029 mtx_unlock(&pr->pr_mtx);
4030 }
4031 sx_sunlock(&allprison_lock);
4032 while (nrele--)
4033 vrele(olddp);
4034 }
4035
4036 struct filedesc_to_leader *
4037 filedesc_to_leader_alloc(struct filedesc_to_leader *old, struct filedesc *fdp, struct proc *leader)
4038 {
4039 struct filedesc_to_leader *fdtol;
4040
4041 fdtol = malloc(sizeof(struct filedesc_to_leader),
4042 M_FILEDESC_TO_LEADER, M_WAITOK);
4043 fdtol->fdl_refcount = 1;
4044 fdtol->fdl_holdcount = 0;
4045 fdtol->fdl_wakeup = 0;
4046 fdtol->fdl_leader = leader;
4047 if (old != NULL) {
4048 FILEDESC_XLOCK(fdp);
4049 fdtol->fdl_next = old->fdl_next;
4050 fdtol->fdl_prev = old;
4051 old->fdl_next = fdtol;
4052 fdtol->fdl_next->fdl_prev = fdtol;
4053 FILEDESC_XUNLOCK(fdp);
4054 } else {
4055 fdtol->fdl_next = fdtol;
4056 fdtol->fdl_prev = fdtol;
4057 }
4058 return (fdtol);
4059 }
4060
4061 static int
4062 sysctl_kern_proc_nfds(SYSCTL_HANDLER_ARGS)
4063 {
4064 NDSLOTTYPE *map;
4065 struct filedesc *fdp;
4066 int count, off, minoff;
4067
4068 if (*(int *)arg1 != 0)
4069 return (EINVAL);
4070
4071 fdp = curproc->p_fd;
4072 count = 0;
4073 FILEDESC_SLOCK(fdp);
4074 map = fdp->fd_map;
4075 off = NDSLOT(fdp->fd_nfiles - 1);
4076 for (minoff = NDSLOT(0); off >= minoff; --off)
4077 count += bitcountl(map[off]);
4078 FILEDESC_SUNLOCK(fdp);
4079
4080 return (SYSCTL_OUT(req, &count, sizeof(count)));
4081 }
4082
4083 static SYSCTL_NODE(_kern_proc, KERN_PROC_NFDS, nfds,
4084 CTLFLAG_RD|CTLFLAG_CAPRD|CTLFLAG_MPSAFE, sysctl_kern_proc_nfds,
4085 "Number of open file descriptors");
4086
4087 /*
4088 * Get file structures globally.
4089 */
4090 static int
4091 sysctl_kern_file(SYSCTL_HANDLER_ARGS)
4092 {
4093 struct xfile xf;
4094 struct filedesc *fdp;
4095 struct file *fp;
4096 struct proc *p;
4097 int error, n, lastfile;
4098
4099 error = sysctl_wire_old_buffer(req, 0);
4100 if (error != 0)
4101 return (error);
4102 if (req->oldptr == NULL) {
4103 n = 0;
4104 sx_slock(&allproc_lock);
4105 FOREACH_PROC_IN_SYSTEM(p) {
4106 PROC_LOCK(p);
4107 if (p->p_state == PRS_NEW) {
4108 PROC_UNLOCK(p);
4109 continue;
4110 }
4111 fdp = fdhold(p);
4112 PROC_UNLOCK(p);
4113 if (fdp == NULL)
4114 continue;
4115 /* overestimates sparse tables. */
4116 n += fdp->fd_nfiles;
4117 fddrop(fdp);
4118 }
4119 sx_sunlock(&allproc_lock);
4120 return (SYSCTL_OUT(req, 0, n * sizeof(xf)));
4121 }
4122 error = 0;
4123 bzero(&xf, sizeof(xf));
4124 xf.xf_size = sizeof(xf);
4125 sx_slock(&allproc_lock);
4126 FOREACH_PROC_IN_SYSTEM(p) {
4127 PROC_LOCK(p);
4128 if (p->p_state == PRS_NEW) {
4129 PROC_UNLOCK(p);
4130 continue;
4131 }
4132 if (p_cansee(req->td, p) != 0) {
4133 PROC_UNLOCK(p);
4134 continue;
4135 }
4136 xf.xf_pid = p->p_pid;
4137 xf.xf_uid = p->p_ucred->cr_uid;
4138 fdp = fdhold(p);
4139 PROC_UNLOCK(p);
4140 if (fdp == NULL)
4141 continue;
4142 FILEDESC_SLOCK(fdp);
4143 lastfile = fdlastfile(fdp);
4144 for (n = 0; refcount_load(&fdp->fd_refcnt) > 0 && n <= lastfile;
4145 n++) {
4146 if ((fp = fdp->fd_ofiles[n].fde_file) == NULL)
4147 continue;
4148 xf.xf_fd = n;
4149 xf.xf_file = (uintptr_t)fp;
4150 xf.xf_data = (uintptr_t)fp->f_data;
4151 xf.xf_vnode = (uintptr_t)fp->f_vnode;
4152 xf.xf_type = (uintptr_t)fp->f_type;
4153 xf.xf_count = refcount_load(&fp->f_count);
4154 xf.xf_msgcount = 0;
4155 xf.xf_offset = foffset_get(fp);
4156 xf.xf_flag = fp->f_flag;
4157 error = SYSCTL_OUT(req, &xf, sizeof(xf));
4158 if (error)
4159 break;
4160 }
4161 FILEDESC_SUNLOCK(fdp);
4162 fddrop(fdp);
4163 if (error)
4164 break;
4165 }
4166 sx_sunlock(&allproc_lock);
4167 return (error);
4168 }
4169
4170 SYSCTL_PROC(_kern, KERN_FILE, file, CTLTYPE_OPAQUE|CTLFLAG_RD|CTLFLAG_MPSAFE,
4171 0, 0, sysctl_kern_file, "S,xfile", "Entire file table");
4172
4173 #ifdef KINFO_FILE_SIZE
4174 CTASSERT(sizeof(struct kinfo_file) == KINFO_FILE_SIZE);
4175 #endif
4176
4177 static int
4178 xlate_fflags(int fflags)
4179 {
4180 static const struct {
4181 int fflag;
4182 int kf_fflag;
4183 } fflags_table[] = {
4184 { FAPPEND, KF_FLAG_APPEND },
4185 { FASYNC, KF_FLAG_ASYNC },
4186 { FFSYNC, KF_FLAG_FSYNC },
4187 { FHASLOCK, KF_FLAG_HASLOCK },
4188 { FNONBLOCK, KF_FLAG_NONBLOCK },
4189 { FREAD, KF_FLAG_READ },
4190 { FWRITE, KF_FLAG_WRITE },
4191 { O_CREAT, KF_FLAG_CREAT },
4192 { O_DIRECT, KF_FLAG_DIRECT },
4193 { O_EXCL, KF_FLAG_EXCL },
4194 { O_EXEC, KF_FLAG_EXEC },
4195 { O_EXLOCK, KF_FLAG_EXLOCK },
4196 { O_NOFOLLOW, KF_FLAG_NOFOLLOW },
4197 { O_SHLOCK, KF_FLAG_SHLOCK },
4198 { O_TRUNC, KF_FLAG_TRUNC }
4199 };
4200 unsigned int i;
4201 int kflags;
4202
4203 kflags = 0;
4204 for (i = 0; i < nitems(fflags_table); i++)
4205 if (fflags & fflags_table[i].fflag)
4206 kflags |= fflags_table[i].kf_fflag;
4207 return (kflags);
4208 }
4209
4210 /* Trim unused data from kf_path by truncating the structure size. */
4211 void
4212 pack_kinfo(struct kinfo_file *kif)
4213 {
4214
4215 kif->kf_structsize = offsetof(struct kinfo_file, kf_path) +
4216 strlen(kif->kf_path) + 1;
4217 kif->kf_structsize = roundup(kif->kf_structsize, sizeof(uint64_t));
4218 }
4219
4220 static void
4221 export_file_to_kinfo(struct file *fp, int fd, cap_rights_t *rightsp,
4222 struct kinfo_file *kif, struct filedesc *fdp, int flags)
4223 {
4224 int error;
4225
4226 bzero(kif, sizeof(*kif));
4227
4228 /* Set a default type to allow for empty fill_kinfo() methods. */
4229 kif->kf_type = KF_TYPE_UNKNOWN;
4230 kif->kf_flags = xlate_fflags(fp->f_flag);
4231 if (rightsp != NULL)
4232 kif->kf_cap_rights = *rightsp;
4233 else
4234 cap_rights_init_zero(&kif->kf_cap_rights);
4235 kif->kf_fd = fd;
4236 kif->kf_ref_count = refcount_load(&fp->f_count);
4237 kif->kf_offset = foffset_get(fp);
4238
4239 /*
4240 * This may drop the filedesc lock, so the 'fp' cannot be
4241 * accessed after this call.
4242 */
4243 error = fo_fill_kinfo(fp, kif, fdp);
4244 if (error == 0)
4245 kif->kf_status |= KF_ATTR_VALID;
4246 if ((flags & KERN_FILEDESC_PACK_KINFO) != 0)
4247 pack_kinfo(kif);
4248 else
4249 kif->kf_structsize = roundup2(sizeof(*kif), sizeof(uint64_t));
4250 }
4251
4252 static void
4253 export_vnode_to_kinfo(struct vnode *vp, int fd, int fflags,
4254 struct kinfo_file *kif, int flags)
4255 {
4256 int error;
4257
4258 bzero(kif, sizeof(*kif));
4259
4260 kif->kf_type = KF_TYPE_VNODE;
4261 error = vn_fill_kinfo_vnode(vp, kif);
4262 if (error == 0)
4263 kif->kf_status |= KF_ATTR_VALID;
4264 kif->kf_flags = xlate_fflags(fflags);
4265 cap_rights_init_zero(&kif->kf_cap_rights);
4266 kif->kf_fd = fd;
4267 kif->kf_ref_count = -1;
4268 kif->kf_offset = -1;
4269 if ((flags & KERN_FILEDESC_PACK_KINFO) != 0)
4270 pack_kinfo(kif);
4271 else
4272 kif->kf_structsize = roundup2(sizeof(*kif), sizeof(uint64_t));
4273 vrele(vp);
4274 }
4275
4276 struct export_fd_buf {
4277 struct filedesc *fdp;
4278 struct pwddesc *pdp;
4279 struct sbuf *sb;
4280 ssize_t remainder;
4281 struct kinfo_file kif;
4282 int flags;
4283 };
4284
4285 static int
4286 export_kinfo_to_sb(struct export_fd_buf *efbuf)
4287 {
4288 struct kinfo_file *kif;
4289
4290 kif = &efbuf->kif;
4291 if (efbuf->remainder != -1) {
4292 if (efbuf->remainder < kif->kf_structsize) {
4293 /* Terminate export. */
4294 efbuf->remainder = 0;
4295 return (0);
4296 }
4297 efbuf->remainder -= kif->kf_structsize;
4298 }
4299 return (sbuf_bcat(efbuf->sb, kif, kif->kf_structsize) == 0 ? 0 : ENOMEM);
4300 }
4301
4302 static int
4303 export_file_to_sb(struct file *fp, int fd, cap_rights_t *rightsp,
4304 struct export_fd_buf *efbuf)
4305 {
4306 int error;
4307
4308 if (efbuf->remainder == 0)
4309 return (0);
4310 export_file_to_kinfo(fp, fd, rightsp, &efbuf->kif, efbuf->fdp,
4311 efbuf->flags);
4312 FILEDESC_SUNLOCK(efbuf->fdp);
4313 error = export_kinfo_to_sb(efbuf);
4314 FILEDESC_SLOCK(efbuf->fdp);
4315 return (error);
4316 }
4317
4318 static int
4319 export_vnode_to_sb(struct vnode *vp, int fd, int fflags,
4320 struct export_fd_buf *efbuf)
4321 {
4322 int error;
4323
4324 if (efbuf->remainder == 0)
4325 return (0);
4326 if (efbuf->pdp != NULL)
4327 PWDDESC_XUNLOCK(efbuf->pdp);
4328 export_vnode_to_kinfo(vp, fd, fflags, &efbuf->kif, efbuf->flags);
4329 error = export_kinfo_to_sb(efbuf);
4330 if (efbuf->pdp != NULL)
4331 PWDDESC_XLOCK(efbuf->pdp);
4332 return (error);
4333 }
4334
4335 /*
4336 * Store a process file descriptor information to sbuf.
4337 *
4338 * Takes a locked proc as argument, and returns with the proc unlocked.
4339 */
4340 int
4341 kern_proc_filedesc_out(struct proc *p, struct sbuf *sb, ssize_t maxlen,
4342 int flags)
4343 {
4344 struct file *fp;
4345 struct filedesc *fdp;
4346 struct pwddesc *pdp;
4347 struct export_fd_buf *efbuf;
4348 struct vnode *cttyvp, *textvp, *tracevp;
4349 struct pwd *pwd;
4350 int error, i, lastfile;
4351 cap_rights_t rights;
4352
4353 PROC_LOCK_ASSERT(p, MA_OWNED);
4354
4355 /* ktrace vnode */
4356 tracevp = p->p_tracevp;
4357 if (tracevp != NULL)
4358 vrefact(tracevp);
4359 /* text vnode */
4360 textvp = p->p_textvp;
4361 if (textvp != NULL)
4362 vrefact(textvp);
4363 /* Controlling tty. */
4364 cttyvp = NULL;
4365 if (p->p_pgrp != NULL && p->p_pgrp->pg_session != NULL) {
4366 cttyvp = p->p_pgrp->pg_session->s_ttyvp;
4367 if (cttyvp != NULL)
4368 vrefact(cttyvp);
4369 }
4370 fdp = fdhold(p);
4371 pdp = pdhold(p);
4372 PROC_UNLOCK(p);
4373 efbuf = malloc(sizeof(*efbuf), M_TEMP, M_WAITOK);
4374 efbuf->fdp = NULL;
4375 efbuf->pdp = NULL;
4376 efbuf->sb = sb;
4377 efbuf->remainder = maxlen;
4378 efbuf->flags = flags;
4379 if (tracevp != NULL)
4380 export_vnode_to_sb(tracevp, KF_FD_TYPE_TRACE, FREAD | FWRITE,
4381 efbuf);
4382 if (textvp != NULL)
4383 export_vnode_to_sb(textvp, KF_FD_TYPE_TEXT, FREAD, efbuf);
4384 if (cttyvp != NULL)
4385 export_vnode_to_sb(cttyvp, KF_FD_TYPE_CTTY, FREAD | FWRITE,
4386 efbuf);
4387 error = 0;
4388 if (pdp == NULL || fdp == NULL)
4389 goto fail;
4390 efbuf->fdp = fdp;
4391 efbuf->pdp = pdp;
4392 PWDDESC_XLOCK(pdp);
4393 pwd = pwd_hold_pwddesc(pdp);
4394 if (pwd != NULL) {
4395 /* working directory */
4396 if (pwd->pwd_cdir != NULL) {
4397 vrefact(pwd->pwd_cdir);
4398 export_vnode_to_sb(pwd->pwd_cdir, KF_FD_TYPE_CWD, FREAD, efbuf);
4399 }
4400 /* root directory */
4401 if (pwd->pwd_rdir != NULL) {
4402 vrefact(pwd->pwd_rdir);
4403 export_vnode_to_sb(pwd->pwd_rdir, KF_FD_TYPE_ROOT, FREAD, efbuf);
4404 }
4405 /* jail directory */
4406 if (pwd->pwd_jdir != NULL) {
4407 vrefact(pwd->pwd_jdir);
4408 export_vnode_to_sb(pwd->pwd_jdir, KF_FD_TYPE_JAIL, FREAD, efbuf);
4409 }
4410 }
4411 PWDDESC_XUNLOCK(pdp);
4412 if (pwd != NULL)
4413 pwd_drop(pwd);
4414 FILEDESC_SLOCK(fdp);
4415 lastfile = fdlastfile(fdp);
4416 for (i = 0; refcount_load(&fdp->fd_refcnt) > 0 && i <= lastfile; i++) {
4417 if ((fp = fdp->fd_ofiles[i].fde_file) == NULL)
4418 continue;
4419 #ifdef CAPABILITIES
4420 rights = *cap_rights(fdp, i);
4421 #else /* !CAPABILITIES */
4422 rights = cap_no_rights;
4423 #endif
4424 /*
4425 * Create sysctl entry. It is OK to drop the filedesc
4426 * lock inside of export_file_to_sb() as we will
4427 * re-validate and re-evaluate its properties when the
4428 * loop continues.
4429 */
4430 error = export_file_to_sb(fp, i, &rights, efbuf);
4431 if (error != 0 || efbuf->remainder == 0)
4432 break;
4433 }
4434 FILEDESC_SUNLOCK(fdp);
4435 fail:
4436 if (fdp != NULL)
4437 fddrop(fdp);
4438 if (pdp != NULL)
4439 pddrop(pdp);
4440 free(efbuf, M_TEMP);
4441 return (error);
4442 }
4443
4444 #define FILEDESC_SBUF_SIZE (sizeof(struct kinfo_file) * 5)
4445
4446 /*
4447 * Get per-process file descriptors for use by procstat(1), et al.
4448 */
4449 static int
4450 sysctl_kern_proc_filedesc(SYSCTL_HANDLER_ARGS)
4451 {
4452 struct sbuf sb;
4453 struct proc *p;
4454 ssize_t maxlen;
4455 int error, error2, *name;
4456
4457 name = (int *)arg1;
4458
4459 sbuf_new_for_sysctl(&sb, NULL, FILEDESC_SBUF_SIZE, req);
4460 sbuf_clear_flags(&sb, SBUF_INCLUDENUL);
4461 error = pget((pid_t)name[0], PGET_CANDEBUG | PGET_NOTWEXIT, &p);
4462 if (error != 0) {
4463 sbuf_delete(&sb);
4464 return (error);
4465 }
4466 maxlen = req->oldptr != NULL ? req->oldlen : -1;
4467 error = kern_proc_filedesc_out(p, &sb, maxlen,
4468 KERN_FILEDESC_PACK_KINFO);
4469 error2 = sbuf_finish(&sb);
4470 sbuf_delete(&sb);
4471 return (error != 0 ? error : error2);
4472 }
4473
4474 #ifdef COMPAT_FREEBSD7
4475 #ifdef KINFO_OFILE_SIZE
4476 CTASSERT(sizeof(struct kinfo_ofile) == KINFO_OFILE_SIZE);
4477 #endif
4478
4479 static void
4480 kinfo_to_okinfo(struct kinfo_file *kif, struct kinfo_ofile *okif)
4481 {
4482
4483 okif->kf_structsize = sizeof(*okif);
4484 okif->kf_type = kif->kf_type;
4485 okif->kf_fd = kif->kf_fd;
4486 okif->kf_ref_count = kif->kf_ref_count;
4487 okif->kf_flags = kif->kf_flags & (KF_FLAG_READ | KF_FLAG_WRITE |
4488 KF_FLAG_APPEND | KF_FLAG_ASYNC | KF_FLAG_FSYNC | KF_FLAG_NONBLOCK |
4489 KF_FLAG_DIRECT | KF_FLAG_HASLOCK);
4490 okif->kf_offset = kif->kf_offset;
4491 if (kif->kf_type == KF_TYPE_VNODE)
4492 okif->kf_vnode_type = kif->kf_un.kf_file.kf_file_type;
4493 else
4494 okif->kf_vnode_type = KF_VTYPE_VNON;
4495 strlcpy(okif->kf_path, kif->kf_path, sizeof(okif->kf_path));
4496 if (kif->kf_type == KF_TYPE_SOCKET) {
4497 okif->kf_sock_domain = kif->kf_un.kf_sock.kf_sock_domain0;
4498 okif->kf_sock_type = kif->kf_un.kf_sock.kf_sock_type0;
4499 okif->kf_sock_protocol = kif->kf_un.kf_sock.kf_sock_protocol0;
4500 okif->kf_sa_local = kif->kf_un.kf_sock.kf_sa_local;
4501 okif->kf_sa_peer = kif->kf_un.kf_sock.kf_sa_peer;
4502 } else {
4503 okif->kf_sa_local.ss_family = AF_UNSPEC;
4504 okif->kf_sa_peer.ss_family = AF_UNSPEC;
4505 }
4506 }
4507
4508 static int
4509 export_vnode_for_osysctl(struct vnode *vp, int type, struct kinfo_file *kif,
4510 struct kinfo_ofile *okif, struct pwddesc *pdp, struct sysctl_req *req)
4511 {
4512 int error;
4513
4514 vrefact(vp);
4515 PWDDESC_XUNLOCK(pdp);
4516 export_vnode_to_kinfo(vp, type, 0, kif, KERN_FILEDESC_PACK_KINFO);
4517 kinfo_to_okinfo(kif, okif);
4518 error = SYSCTL_OUT(req, okif, sizeof(*okif));
4519 PWDDESC_XLOCK(pdp);
4520 return (error);
4521 }
4522
4523 /*
4524 * Get per-process file descriptors for use by procstat(1), et al.
4525 */
4526 static int
4527 sysctl_kern_proc_ofiledesc(SYSCTL_HANDLER_ARGS)
4528 {
4529 struct kinfo_ofile *okif;
4530 struct kinfo_file *kif;
4531 struct filedesc *fdp;
4532 struct pwddesc *pdp;
4533 struct pwd *pwd;
4534 int error, i, lastfile, *name;
4535 struct file *fp;
4536 struct proc *p;
4537
4538 name = (int *)arg1;
4539 error = pget((pid_t)name[0], PGET_CANDEBUG | PGET_NOTWEXIT, &p);
4540 if (error != 0)
4541 return (error);
4542 fdp = fdhold(p);
4543 if (fdp != NULL)
4544 pdp = pdhold(p);
4545 PROC_UNLOCK(p);
4546 if (fdp == NULL || pdp == NULL) {
4547 if (fdp != NULL)
4548 fddrop(fdp);
4549 return (ENOENT);
4550 }
4551 kif = malloc(sizeof(*kif), M_TEMP, M_WAITOK);
4552 okif = malloc(sizeof(*okif), M_TEMP, M_WAITOK);
4553 PWDDESC_XLOCK(pdp);
4554 pwd = pwd_hold_pwddesc(pdp);
4555 if (pwd != NULL) {
4556 if (pwd->pwd_cdir != NULL)
4557 export_vnode_for_osysctl(pwd->pwd_cdir, KF_FD_TYPE_CWD, kif,
4558 okif, pdp, req);
4559 if (pwd->pwd_rdir != NULL)
4560 export_vnode_for_osysctl(pwd->pwd_rdir, KF_FD_TYPE_ROOT, kif,
4561 okif, pdp, req);
4562 if (pwd->pwd_jdir != NULL)
4563 export_vnode_for_osysctl(pwd->pwd_jdir, KF_FD_TYPE_JAIL, kif,
4564 okif, pdp, req);
4565 }
4566 PWDDESC_XUNLOCK(pdp);
4567 if (pwd != NULL)
4568 pwd_drop(pwd);
4569 FILEDESC_SLOCK(fdp);
4570 lastfile = fdlastfile(fdp);
4571 for (i = 0; refcount_load(&fdp->fd_refcnt) > 0 && i <= lastfile; i++) {
4572 if ((fp = fdp->fd_ofiles[i].fde_file) == NULL)
4573 continue;
4574 export_file_to_kinfo(fp, i, NULL, kif, fdp,
4575 KERN_FILEDESC_PACK_KINFO);
4576 FILEDESC_SUNLOCK(fdp);
4577 kinfo_to_okinfo(kif, okif);
4578 error = SYSCTL_OUT(req, okif, sizeof(*okif));
4579 FILEDESC_SLOCK(fdp);
4580 if (error)
4581 break;
4582 }
4583 FILEDESC_SUNLOCK(fdp);
4584 fddrop(fdp);
4585 pddrop(pdp);
4586 free(kif, M_TEMP);
4587 free(okif, M_TEMP);
4588 return (0);
4589 }
4590
4591 static SYSCTL_NODE(_kern_proc, KERN_PROC_OFILEDESC, ofiledesc,
4592 CTLFLAG_RD|CTLFLAG_MPSAFE, sysctl_kern_proc_ofiledesc,
4593 "Process ofiledesc entries");
4594 #endif /* COMPAT_FREEBSD7 */
4595
4596 int
4597 vntype_to_kinfo(int vtype)
4598 {
4599 struct {
4600 int vtype;
4601 int kf_vtype;
4602 } vtypes_table[] = {
4603 { VBAD, KF_VTYPE_VBAD },
4604 { VBLK, KF_VTYPE_VBLK },
4605 { VCHR, KF_VTYPE_VCHR },
4606 { VDIR, KF_VTYPE_VDIR },
4607 { VFIFO, KF_VTYPE_VFIFO },
4608 { VLNK, KF_VTYPE_VLNK },
4609 { VNON, KF_VTYPE_VNON },
4610 { VREG, KF_VTYPE_VREG },
4611 { VSOCK, KF_VTYPE_VSOCK }
4612 };
4613 unsigned int i;
4614
4615 /*
4616 * Perform vtype translation.
4617 */
4618 for (i = 0; i < nitems(vtypes_table); i++)
4619 if (vtypes_table[i].vtype == vtype)
4620 return (vtypes_table[i].kf_vtype);
4621
4622 return (KF_VTYPE_UNKNOWN);
4623 }
4624
4625 static SYSCTL_NODE(_kern_proc, KERN_PROC_FILEDESC, filedesc,
4626 CTLFLAG_RD|CTLFLAG_MPSAFE, sysctl_kern_proc_filedesc,
4627 "Process filedesc entries");
4628
4629 /*
4630 * Store a process current working directory information to sbuf.
4631 *
4632 * Takes a locked proc as argument, and returns with the proc unlocked.
4633 */
4634 int
4635 kern_proc_cwd_out(struct proc *p, struct sbuf *sb, ssize_t maxlen)
4636 {
4637 struct pwddesc *pdp;
4638 struct pwd *pwd;
4639 struct export_fd_buf *efbuf;
4640 struct vnode *cdir;
4641 int error;
4642
4643 PROC_LOCK_ASSERT(p, MA_OWNED);
4644
4645 pdp = pdhold(p);
4646 PROC_UNLOCK(p);
4647 if (pdp == NULL)
4648 return (EINVAL);
4649
4650 efbuf = malloc(sizeof(*efbuf), M_TEMP, M_WAITOK);
4651 efbuf->pdp = pdp;
4652 efbuf->sb = sb;
4653 efbuf->remainder = maxlen;
4654
4655 PWDDESC_XLOCK(pdp);
4656 pwd = PWDDESC_XLOCKED_LOAD_PWD(pdp);
4657 cdir = pwd->pwd_cdir;
4658 if (cdir == NULL) {
4659 error = EINVAL;
4660 } else {
4661 vrefact(cdir);
4662 error = export_vnode_to_sb(cdir, KF_FD_TYPE_CWD, FREAD, efbuf);
4663 }
4664 PWDDESC_XUNLOCK(pdp);
4665 pddrop(pdp);
4666 free(efbuf, M_TEMP);
4667 return (error);
4668 }
4669
4670 /*
4671 * Get per-process current working directory.
4672 */
4673 static int
4674 sysctl_kern_proc_cwd(SYSCTL_HANDLER_ARGS)
4675 {
4676 struct sbuf sb;
4677 struct proc *p;
4678 ssize_t maxlen;
4679 int error, error2, *name;
4680
4681 name = (int *)arg1;
4682
4683 sbuf_new_for_sysctl(&sb, NULL, sizeof(struct kinfo_file), req);
4684 sbuf_clear_flags(&sb, SBUF_INCLUDENUL);
4685 error = pget((pid_t)name[0], PGET_CANDEBUG | PGET_NOTWEXIT, &p);
4686 if (error != 0) {
4687 sbuf_delete(&sb);
4688 return (error);
4689 }
4690 maxlen = req->oldptr != NULL ? req->oldlen : -1;
4691 error = kern_proc_cwd_out(p, &sb, maxlen);
4692 error2 = sbuf_finish(&sb);
4693 sbuf_delete(&sb);
4694 return (error != 0 ? error : error2);
4695 }
4696
4697 static SYSCTL_NODE(_kern_proc, KERN_PROC_CWD, cwd, CTLFLAG_RD|CTLFLAG_MPSAFE,
4698 sysctl_kern_proc_cwd, "Process current working directory");
4699
4700 #ifdef DDB
4701 /*
4702 * For the purposes of debugging, generate a human-readable string for the
4703 * file type.
4704 */
4705 static const char *
4706 file_type_to_name(short type)
4707 {
4708
4709 switch (type) {
4710 case 0:
4711 return ("zero");
4712 case DTYPE_VNODE:
4713 return ("vnode");
4714 case DTYPE_SOCKET:
4715 return ("socket");
4716 case DTYPE_PIPE:
4717 return ("pipe");
4718 case DTYPE_FIFO:
4719 return ("fifo");
4720 case DTYPE_KQUEUE:
4721 return ("kqueue");
4722 case DTYPE_CRYPTO:
4723 return ("crypto");
4724 case DTYPE_MQUEUE:
4725 return ("mqueue");
4726 case DTYPE_SHM:
4727 return ("shm");
4728 case DTYPE_SEM:
4729 return ("ksem");
4730 case DTYPE_PTS:
4731 return ("pts");
4732 case DTYPE_DEV:
4733 return ("dev");
4734 case DTYPE_PROCDESC:
4735 return ("proc");
4736 case DTYPE_EVENTFD:
4737 return ("eventfd");
4738 case DTYPE_LINUXTFD:
4739 return ("ltimer");
4740 default:
4741 return ("unkn");
4742 }
4743 }
4744
4745 /*
4746 * For the purposes of debugging, identify a process (if any, perhaps one of
4747 * many) that references the passed file in its file descriptor array. Return
4748 * NULL if none.
4749 */
4750 static struct proc *
4751 file_to_first_proc(struct file *fp)
4752 {
4753 struct filedesc *fdp;
4754 struct proc *p;
4755 int n;
4756
4757 FOREACH_PROC_IN_SYSTEM(p) {
4758 if (p->p_state == PRS_NEW)
4759 continue;
4760 fdp = p->p_fd;
4761 if (fdp == NULL)
4762 continue;
4763 for (n = 0; n < fdp->fd_nfiles; n++) {
4764 if (fp == fdp->fd_ofiles[n].fde_file)
4765 return (p);
4766 }
4767 }
4768 return (NULL);
4769 }
4770
4771 static void
4772 db_print_file(struct file *fp, int header)
4773 {
4774 #define XPTRWIDTH ((int)howmany(sizeof(void *) * NBBY, 4))
4775 struct proc *p;
4776
4777 if (header)
4778 db_printf("%*s %6s %*s %8s %4s %5s %6s %*s %5s %s\n",
4779 XPTRWIDTH, "File", "Type", XPTRWIDTH, "Data", "Flag",
4780 "GCFl", "Count", "MCount", XPTRWIDTH, "Vnode", "FPID",
4781 "FCmd");
4782 p = file_to_first_proc(fp);
4783 db_printf("%*p %6s %*p %08x %04x %5d %6d %*p %5d %s\n", XPTRWIDTH,
4784 fp, file_type_to_name(fp->f_type), XPTRWIDTH, fp->f_data,
4785 fp->f_flag, 0, refcount_load(&fp->f_count), 0, XPTRWIDTH, fp->f_vnode,
4786 p != NULL ? p->p_pid : -1, p != NULL ? p->p_comm : "-");
4787
4788 #undef XPTRWIDTH
4789 }
4790
4791 DB_SHOW_COMMAND(file, db_show_file)
4792 {
4793 struct file *fp;
4794
4795 if (!have_addr) {
4796 db_printf("usage: show file <addr>\n");
4797 return;
4798 }
4799 fp = (struct file *)addr;
4800 db_print_file(fp, 1);
4801 }
4802
4803 DB_SHOW_COMMAND(files, db_show_files)
4804 {
4805 struct filedesc *fdp;
4806 struct file *fp;
4807 struct proc *p;
4808 int header;
4809 int n;
4810
4811 header = 1;
4812 FOREACH_PROC_IN_SYSTEM(p) {
4813 if (p->p_state == PRS_NEW)
4814 continue;
4815 if ((fdp = p->p_fd) == NULL)
4816 continue;
4817 for (n = 0; n < fdp->fd_nfiles; ++n) {
4818 if ((fp = fdp->fd_ofiles[n].fde_file) == NULL)
4819 continue;
4820 db_print_file(fp, header);
4821 header = 0;
4822 }
4823 }
4824 }
4825 #endif
4826
4827 SYSCTL_INT(_kern, KERN_MAXFILESPERPROC, maxfilesperproc, CTLFLAG_RW,
4828 &maxfilesperproc, 0, "Maximum files allowed open per process");
4829
4830 SYSCTL_INT(_kern, KERN_MAXFILES, maxfiles, CTLFLAG_RW,
4831 &maxfiles, 0, "Maximum number of files");
4832
4833 SYSCTL_INT(_kern, OID_AUTO, openfiles, CTLFLAG_RD,
4834 &openfiles, 0, "System-wide number of open files");
4835
4836 /* ARGSUSED*/
4837 static void
4838 filelistinit(void *dummy)
4839 {
4840
4841 file_zone = uma_zcreate("Files", sizeof(struct file), NULL, NULL,
4842 NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE);
4843 filedesc0_zone = uma_zcreate("filedesc0", sizeof(struct filedesc0),
4844 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0);
4845 pwd_zone = uma_zcreate("PWD", sizeof(struct pwd), NULL, NULL,
4846 NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_SMR);
4847 /*
4848 * XXXMJG this is a temporary hack due to boot ordering issues against
4849 * the vnode zone.
4850 */
4851 vfs_smr = uma_zone_get_smr(pwd_zone);
4852 mtx_init(&sigio_lock, "sigio lock", NULL, MTX_DEF);
4853 }
4854 SYSINIT(select, SI_SUB_LOCK, SI_ORDER_FIRST, filelistinit, NULL);
4855
4856 /*-------------------------------------------------------------------*/
4857
4858 static int
4859 badfo_readwrite(struct file *fp, struct uio *uio, struct ucred *active_cred,
4860 int flags, struct thread *td)
4861 {
4862
4863 return (EBADF);
4864 }
4865
4866 static int
4867 badfo_truncate(struct file *fp, off_t length, struct ucred *active_cred,
4868 struct thread *td)
4869 {
4870
4871 return (EINVAL);
4872 }
4873
4874 static int
4875 badfo_ioctl(struct file *fp, u_long com, void *data, struct ucred *active_cred,
4876 struct thread *td)
4877 {
4878
4879 return (EBADF);
4880 }
4881
4882 static int
4883 badfo_poll(struct file *fp, int events, struct ucred *active_cred,
4884 struct thread *td)
4885 {
4886
4887 return (0);
4888 }
4889
4890 static int
4891 badfo_kqfilter(struct file *fp, struct knote *kn)
4892 {
4893
4894 return (EBADF);
4895 }
4896
4897 static int
4898 badfo_stat(struct file *fp, struct stat *sb, struct ucred *active_cred,
4899 struct thread *td)
4900 {
4901
4902 return (EBADF);
4903 }
4904
4905 static int
4906 badfo_close(struct file *fp, struct thread *td)
4907 {
4908
4909 return (0);
4910 }
4911
4912 static int
4913 badfo_chmod(struct file *fp, mode_t mode, struct ucred *active_cred,
4914 struct thread *td)
4915 {
4916
4917 return (EBADF);
4918 }
4919
4920 static int
4921 badfo_chown(struct file *fp, uid_t uid, gid_t gid, struct ucred *active_cred,
4922 struct thread *td)
4923 {
4924
4925 return (EBADF);
4926 }
4927
4928 static int
4929 badfo_sendfile(struct file *fp, int sockfd, struct uio *hdr_uio,
4930 struct uio *trl_uio, off_t offset, size_t nbytes, off_t *sent, int flags,
4931 struct thread *td)
4932 {
4933
4934 return (EBADF);
4935 }
4936
4937 static int
4938 badfo_fill_kinfo(struct file *fp, struct kinfo_file *kif, struct filedesc *fdp)
4939 {
4940
4941 return (0);
4942 }
4943
4944 struct fileops badfileops = {
4945 .fo_read = badfo_readwrite,
4946 .fo_write = badfo_readwrite,
4947 .fo_truncate = badfo_truncate,
4948 .fo_ioctl = badfo_ioctl,
4949 .fo_poll = badfo_poll,
4950 .fo_kqfilter = badfo_kqfilter,
4951 .fo_stat = badfo_stat,
4952 .fo_close = badfo_close,
4953 .fo_chmod = badfo_chmod,
4954 .fo_chown = badfo_chown,
4955 .fo_sendfile = badfo_sendfile,
4956 .fo_fill_kinfo = badfo_fill_kinfo,
4957 };
4958
4959 int
4960 invfo_rdwr(struct file *fp, struct uio *uio, struct ucred *active_cred,
4961 int flags, struct thread *td)
4962 {
4963
4964 return (EOPNOTSUPP);
4965 }
4966
4967 int
4968 invfo_truncate(struct file *fp, off_t length, struct ucred *active_cred,
4969 struct thread *td)
4970 {
4971
4972 return (EINVAL);
4973 }
4974
4975 int
4976 invfo_ioctl(struct file *fp, u_long com, void *data,
4977 struct ucred *active_cred, struct thread *td)
4978 {
4979
4980 return (ENOTTY);
4981 }
4982
4983 int
4984 invfo_poll(struct file *fp, int events, struct ucred *active_cred,
4985 struct thread *td)
4986 {
4987
4988 return (poll_no_poll(events));
4989 }
4990
4991 int
4992 invfo_kqfilter(struct file *fp, struct knote *kn)
4993 {
4994
4995 return (EINVAL);
4996 }
4997
4998 int
4999 invfo_chmod(struct file *fp, mode_t mode, struct ucred *active_cred,
5000 struct thread *td)
5001 {
5002
5003 return (EINVAL);
5004 }
5005
5006 int
5007 invfo_chown(struct file *fp, uid_t uid, gid_t gid, struct ucred *active_cred,
5008 struct thread *td)
5009 {
5010
5011 return (EINVAL);
5012 }
5013
5014 int
5015 invfo_sendfile(struct file *fp, int sockfd, struct uio *hdr_uio,
5016 struct uio *trl_uio, off_t offset, size_t nbytes, off_t *sent, int flags,
5017 struct thread *td)
5018 {
5019
5020 return (EINVAL);
5021 }
5022
5023 /*-------------------------------------------------------------------*/
5024
5025 /*
5026 * File Descriptor pseudo-device driver (/dev/fd/).
5027 *
5028 * Opening minor device N dup()s the file (if any) connected to file
5029 * descriptor N belonging to the calling process. Note that this driver
5030 * consists of only the ``open()'' routine, because all subsequent
5031 * references to this file will be direct to the other driver.
5032 *
5033 * XXX: we could give this one a cloning event handler if necessary.
5034 */
5035
5036 /* ARGSUSED */
5037 static int
5038 fdopen(struct cdev *dev, int mode, int type, struct thread *td)
5039 {
5040
5041 /*
5042 * XXX Kludge: set curthread->td_dupfd to contain the value of the
5043 * the file descriptor being sought for duplication. The error
5044 * return ensures that the vnode for this device will be released
5045 * by vn_open. Open will detect this special error and take the
5046 * actions in dupfdopen below. Other callers of vn_open or VOP_OPEN
5047 * will simply report the error.
5048 */
5049 td->td_dupfd = dev2unit(dev);
5050 return (ENODEV);
5051 }
5052
5053 static struct cdevsw fildesc_cdevsw = {
5054 .d_version = D_VERSION,
5055 .d_open = fdopen,
5056 .d_name = "FD",
5057 };
5058
5059 static void
5060 fildesc_drvinit(void *unused)
5061 {
5062 struct cdev *dev;
5063
5064 dev = make_dev_credf(MAKEDEV_ETERNAL, &fildesc_cdevsw, 0, NULL,
5065 UID_ROOT, GID_WHEEL, 0666, "fd/0");
5066 make_dev_alias(dev, "stdin");
5067 dev = make_dev_credf(MAKEDEV_ETERNAL, &fildesc_cdevsw, 1, NULL,
5068 UID_ROOT, GID_WHEEL, 0666, "fd/1");
5069 make_dev_alias(dev, "stdout");
5070 dev = make_dev_credf(MAKEDEV_ETERNAL, &fildesc_cdevsw, 2, NULL,
5071 UID_ROOT, GID_WHEEL, 0666, "fd/2");
5072 make_dev_alias(dev, "stderr");
5073 }
5074
5075 SYSINIT(fildescdev, SI_SUB_DRIVERS, SI_ORDER_MIDDLE, fildesc_drvinit, NULL);
Cache object: 5160e1ce0cd96c3aa9cdf4e784eb8324
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