1 /*-
2 * SPDX-License-Identifier: BSD-3-Clause
3 *
4 * Copyright (c) 1982, 1986, 1989, 1991, 1993
5 * The Regents of the University of California. All rights reserved.
6 * (c) UNIX System Laboratories, Inc.
7 * All or some portions of this file are derived from material licensed
8 * to the University of California by American Telephone and Telegraph
9 * Co. or Unix System Laboratories, Inc. and are reproduced herein with
10 * the permission of UNIX System Laboratories, Inc.
11 *
12 * Redistribution and use in source and binary forms, with or without
13 * modification, are permitted provided that the following conditions
14 * are met:
15 * 1. Redistributions of source code must retain the above copyright
16 * notice, this list of conditions and the following disclaimer.
17 * 2. Redistributions in binary form must reproduce the above copyright
18 * notice, this list of conditions and the following disclaimer in the
19 * documentation and/or other materials provided with the distribution.
20 * 3. Neither the name of the University nor the names of its contributors
21 * may be used to endorse or promote products derived from this software
22 * without specific prior written permission.
23 *
24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34 * SUCH DAMAGE.
35 *
36 * @(#)kern_descrip.c 8.6 (Berkeley) 4/19/94
37 */
38
39 #include <sys/cdefs.h>
40 __FBSDID("$FreeBSD$");
41
42 #include "opt_capsicum.h"
43 #include "opt_ddb.h"
44 #include "opt_ktrace.h"
45
46 #include <sys/param.h>
47 #include <sys/systm.h>
48
49 #include <sys/capsicum.h>
50 #include <sys/conf.h>
51 #include <sys/fcntl.h>
52 #include <sys/file.h>
53 #include <sys/filedesc.h>
54 #include <sys/filio.h>
55 #include <sys/jail.h>
56 #include <sys/kernel.h>
57 #include <sys/limits.h>
58 #include <sys/lock.h>
59 #include <sys/malloc.h>
60 #include <sys/mount.h>
61 #include <sys/mutex.h>
62 #include <sys/namei.h>
63 #include <sys/selinfo.h>
64 #include <sys/poll.h>
65 #include <sys/priv.h>
66 #include <sys/proc.h>
67 #include <sys/protosw.h>
68 #include <sys/racct.h>
69 #include <sys/resourcevar.h>
70 #include <sys/sbuf.h>
71 #include <sys/signalvar.h>
72 #include <sys/kdb.h>
73 #include <sys/smr.h>
74 #include <sys/stat.h>
75 #include <sys/sx.h>
76 #include <sys/syscallsubr.h>
77 #include <sys/sysctl.h>
78 #include <sys/sysproto.h>
79 #include <sys/unistd.h>
80 #include <sys/user.h>
81 #include <sys/vnode.h>
82 #include <sys/ktrace.h>
83
84 #include <net/vnet.h>
85
86 #include <security/audit/audit.h>
87
88 #include <vm/uma.h>
89 #include <vm/vm.h>
90
91 #include <ddb/ddb.h>
92
93 static MALLOC_DEFINE(M_FILEDESC, "filedesc", "Open file descriptor table");
94 static MALLOC_DEFINE(M_PWD, "pwd", "Descriptor table vnodes");
95 static MALLOC_DEFINE(M_PWDDESC, "pwddesc", "Pwd descriptors");
96 static MALLOC_DEFINE(M_FILEDESC_TO_LEADER, "filedesc_to_leader",
97 "file desc to leader structures");
98 static MALLOC_DEFINE(M_SIGIO, "sigio", "sigio structures");
99 MALLOC_DEFINE(M_FILECAPS, "filecaps", "descriptor capabilities");
100
101 MALLOC_DECLARE(M_FADVISE);
102
103 static __read_mostly uma_zone_t file_zone;
104 static __read_mostly uma_zone_t filedesc0_zone;
105 __read_mostly uma_zone_t pwd_zone;
106 VFS_SMR_DECLARE;
107
108 static int closefp(struct filedesc *fdp, int fd, struct file *fp,
109 struct thread *td, bool holdleaders, bool audit);
110 static void export_file_to_kinfo(struct file *fp, int fd,
111 cap_rights_t *rightsp, struct kinfo_file *kif,
112 struct filedesc *fdp, int flags);
113 static int fd_first_free(struct filedesc *fdp, int low, int size);
114 static void fdgrowtable(struct filedesc *fdp, int nfd);
115 static void fdgrowtable_exp(struct filedesc *fdp, int nfd);
116 static void fdunused(struct filedesc *fdp, int fd);
117 static void fdused(struct filedesc *fdp, int fd);
118 static int fget_unlocked_seq(struct thread *td, int fd,
119 cap_rights_t *needrightsp, struct file **fpp, seqc_t *seqp);
120 static int getmaxfd(struct thread *td);
121 static u_long *filecaps_copy_prep(const struct filecaps *src);
122 static void filecaps_copy_finish(const struct filecaps *src,
123 struct filecaps *dst, u_long *ioctls);
124 static u_long *filecaps_free_prep(struct filecaps *fcaps);
125 static void filecaps_free_finish(u_long *ioctls);
126
127 static struct pwd *pwd_alloc(void);
128
129 /*
130 * Each process has:
131 *
132 * - An array of open file descriptors (fd_ofiles)
133 * - An array of file flags (fd_ofileflags)
134 * - A bitmap recording which descriptors are in use (fd_map)
135 *
136 * A process starts out with NDFILE descriptors. The value of NDFILE has
137 * been selected based the historical limit of 20 open files, and an
138 * assumption that the majority of processes, especially short-lived
139 * processes like shells, will never need more.
140 *
141 * If this initial allocation is exhausted, a larger descriptor table and
142 * map are allocated dynamically, and the pointers in the process's struct
143 * filedesc are updated to point to those. This is repeated every time
144 * the process runs out of file descriptors (provided it hasn't hit its
145 * resource limit).
146 *
147 * Since threads may hold references to individual descriptor table
148 * entries, the tables are never freed. Instead, they are placed on a
149 * linked list and freed only when the struct filedesc is released.
150 */
151 #define NDFILE 20
152 #define NDSLOTSIZE sizeof(NDSLOTTYPE)
153 #define NDENTRIES (NDSLOTSIZE * __CHAR_BIT)
154 #define NDSLOT(x) ((x) / NDENTRIES)
155 #define NDBIT(x) ((NDSLOTTYPE)1 << ((x) % NDENTRIES))
156 #define NDSLOTS(x) (((x) + NDENTRIES - 1) / NDENTRIES)
157
158 #define FILEDESC_FOREACH_FDE(fdp, _iterator, _fde) \
159 struct filedesc *_fdp = (fdp); \
160 int _lastfile = fdlastfile_single(_fdp); \
161 for (_iterator = 0; _iterator <= _lastfile; _iterator++) \
162 if ((_fde = &_fdp->fd_ofiles[_iterator])->fde_file != NULL)
163
164 #define FILEDESC_FOREACH_FP(fdp, _iterator, _fp) \
165 struct filedesc *_fdp = (fdp); \
166 int _lastfile = fdlastfile_single(_fdp); \
167 for (_iterator = 0; _iterator <= _lastfile; _iterator++) \
168 if ((_fp = _fdp->fd_ofiles[_iterator].fde_file) != NULL)
169
170 /*
171 * SLIST entry used to keep track of ofiles which must be reclaimed when
172 * the process exits.
173 */
174 struct freetable {
175 struct fdescenttbl *ft_table;
176 SLIST_ENTRY(freetable) ft_next;
177 };
178
179 /*
180 * Initial allocation: a filedesc structure + the head of SLIST used to
181 * keep track of old ofiles + enough space for NDFILE descriptors.
182 */
183
184 struct fdescenttbl0 {
185 int fdt_nfiles;
186 struct filedescent fdt_ofiles[NDFILE];
187 };
188
189 struct filedesc0 {
190 struct filedesc fd_fd;
191 SLIST_HEAD(, freetable) fd_free;
192 struct fdescenttbl0 fd_dfiles;
193 NDSLOTTYPE fd_dmap[NDSLOTS(NDFILE)];
194 };
195
196 /*
197 * Descriptor management.
198 */
199 static int __exclusive_cache_line openfiles; /* actual number of open files */
200 struct mtx sigio_lock; /* mtx to protect pointers to sigio */
201 void __read_mostly (*mq_fdclose)(struct thread *td, int fd, struct file *fp);
202
203 /*
204 * If low >= size, just return low. Otherwise find the first zero bit in the
205 * given bitmap, starting at low and not exceeding size - 1. Return size if
206 * not found.
207 */
208 static int
209 fd_first_free(struct filedesc *fdp, int low, int size)
210 {
211 NDSLOTTYPE *map = fdp->fd_map;
212 NDSLOTTYPE mask;
213 int off, maxoff;
214
215 if (low >= size)
216 return (low);
217
218 off = NDSLOT(low);
219 if (low % NDENTRIES) {
220 mask = ~(~(NDSLOTTYPE)0 >> (NDENTRIES - (low % NDENTRIES)));
221 if ((mask &= ~map[off]) != 0UL)
222 return (off * NDENTRIES + ffsl(mask) - 1);
223 ++off;
224 }
225 for (maxoff = NDSLOTS(size); off < maxoff; ++off)
226 if (map[off] != ~0UL)
227 return (off * NDENTRIES + ffsl(~map[off]) - 1);
228 return (size);
229 }
230
231 /*
232 * Find the last used fd.
233 *
234 * Call this variant if fdp can't be modified by anyone else (e.g, during exec).
235 * Otherwise use fdlastfile.
236 */
237 int
238 fdlastfile_single(struct filedesc *fdp)
239 {
240 NDSLOTTYPE *map = fdp->fd_map;
241 int off, minoff;
242
243 off = NDSLOT(fdp->fd_nfiles - 1);
244 for (minoff = NDSLOT(0); off >= minoff; --off)
245 if (map[off] != 0)
246 return (off * NDENTRIES + flsl(map[off]) - 1);
247 return (-1);
248 }
249
250 int
251 fdlastfile(struct filedesc *fdp)
252 {
253
254 FILEDESC_LOCK_ASSERT(fdp);
255 return (fdlastfile_single(fdp));
256 }
257
258 static int
259 fdisused(struct filedesc *fdp, int fd)
260 {
261
262 KASSERT(fd >= 0 && fd < fdp->fd_nfiles,
263 ("file descriptor %d out of range (0, %d)", fd, fdp->fd_nfiles));
264
265 return ((fdp->fd_map[NDSLOT(fd)] & NDBIT(fd)) != 0);
266 }
267
268 /*
269 * Mark a file descriptor as used.
270 */
271 static void
272 fdused_init(struct filedesc *fdp, int fd)
273 {
274
275 KASSERT(!fdisused(fdp, fd), ("fd=%d is already used", fd));
276
277 fdp->fd_map[NDSLOT(fd)] |= NDBIT(fd);
278 }
279
280 static void
281 fdused(struct filedesc *fdp, int fd)
282 {
283
284 FILEDESC_XLOCK_ASSERT(fdp);
285
286 fdused_init(fdp, fd);
287 if (fd == fdp->fd_freefile)
288 fdp->fd_freefile++;
289 }
290
291 /*
292 * Mark a file descriptor as unused.
293 */
294 static void
295 fdunused(struct filedesc *fdp, int fd)
296 {
297
298 FILEDESC_XLOCK_ASSERT(fdp);
299
300 KASSERT(fdisused(fdp, fd), ("fd=%d is already unused", fd));
301 KASSERT(fdp->fd_ofiles[fd].fde_file == NULL,
302 ("fd=%d is still in use", fd));
303
304 fdp->fd_map[NDSLOT(fd)] &= ~NDBIT(fd);
305 if (fd < fdp->fd_freefile)
306 fdp->fd_freefile = fd;
307 }
308
309 /*
310 * Free a file descriptor.
311 *
312 * Avoid some work if fdp is about to be destroyed.
313 */
314 static inline void
315 fdefree_last(struct filedescent *fde)
316 {
317
318 filecaps_free(&fde->fde_caps);
319 }
320
321 static inline void
322 fdfree(struct filedesc *fdp, int fd)
323 {
324 struct filedescent *fde;
325
326 FILEDESC_XLOCK_ASSERT(fdp);
327 fde = &fdp->fd_ofiles[fd];
328 #ifdef CAPABILITIES
329 seqc_write_begin(&fde->fde_seqc);
330 #endif
331 fde->fde_file = NULL;
332 #ifdef CAPABILITIES
333 seqc_write_end(&fde->fde_seqc);
334 #endif
335 fdefree_last(fde);
336 fdunused(fdp, fd);
337 }
338
339 /*
340 * System calls on descriptors.
341 */
342 #ifndef _SYS_SYSPROTO_H_
343 struct getdtablesize_args {
344 int dummy;
345 };
346 #endif
347 /* ARGSUSED */
348 int
349 sys_getdtablesize(struct thread *td, struct getdtablesize_args *uap)
350 {
351 #ifdef RACCT
352 uint64_t lim;
353 #endif
354
355 td->td_retval[0] = getmaxfd(td);
356 #ifdef RACCT
357 PROC_LOCK(td->td_proc);
358 lim = racct_get_limit(td->td_proc, RACCT_NOFILE);
359 PROC_UNLOCK(td->td_proc);
360 if (lim < td->td_retval[0])
361 td->td_retval[0] = lim;
362 #endif
363 return (0);
364 }
365
366 /*
367 * Duplicate a file descriptor to a particular value.
368 *
369 * Note: keep in mind that a potential race condition exists when closing
370 * descriptors from a shared descriptor table (via rfork).
371 */
372 #ifndef _SYS_SYSPROTO_H_
373 struct dup2_args {
374 u_int from;
375 u_int to;
376 };
377 #endif
378 /* ARGSUSED */
379 int
380 sys_dup2(struct thread *td, struct dup2_args *uap)
381 {
382
383 return (kern_dup(td, FDDUP_FIXED, 0, (int)uap->from, (int)uap->to));
384 }
385
386 /*
387 * Duplicate a file descriptor.
388 */
389 #ifndef _SYS_SYSPROTO_H_
390 struct dup_args {
391 u_int fd;
392 };
393 #endif
394 /* ARGSUSED */
395 int
396 sys_dup(struct thread *td, struct dup_args *uap)
397 {
398
399 return (kern_dup(td, FDDUP_NORMAL, 0, (int)uap->fd, 0));
400 }
401
402 /*
403 * The file control system call.
404 */
405 #ifndef _SYS_SYSPROTO_H_
406 struct fcntl_args {
407 int fd;
408 int cmd;
409 long arg;
410 };
411 #endif
412 /* ARGSUSED */
413 int
414 sys_fcntl(struct thread *td, struct fcntl_args *uap)
415 {
416
417 return (kern_fcntl_freebsd(td, uap->fd, uap->cmd, uap->arg));
418 }
419
420 int
421 kern_fcntl_freebsd(struct thread *td, int fd, int cmd, long arg)
422 {
423 struct flock fl;
424 struct __oflock ofl;
425 intptr_t arg1;
426 int error, newcmd;
427
428 error = 0;
429 newcmd = cmd;
430 switch (cmd) {
431 case F_OGETLK:
432 case F_OSETLK:
433 case F_OSETLKW:
434 /*
435 * Convert old flock structure to new.
436 */
437 error = copyin((void *)(intptr_t)arg, &ofl, sizeof(ofl));
438 fl.l_start = ofl.l_start;
439 fl.l_len = ofl.l_len;
440 fl.l_pid = ofl.l_pid;
441 fl.l_type = ofl.l_type;
442 fl.l_whence = ofl.l_whence;
443 fl.l_sysid = 0;
444
445 switch (cmd) {
446 case F_OGETLK:
447 newcmd = F_GETLK;
448 break;
449 case F_OSETLK:
450 newcmd = F_SETLK;
451 break;
452 case F_OSETLKW:
453 newcmd = F_SETLKW;
454 break;
455 }
456 arg1 = (intptr_t)&fl;
457 break;
458 case F_GETLK:
459 case F_SETLK:
460 case F_SETLKW:
461 case F_SETLK_REMOTE:
462 error = copyin((void *)(intptr_t)arg, &fl, sizeof(fl));
463 arg1 = (intptr_t)&fl;
464 break;
465 default:
466 arg1 = arg;
467 break;
468 }
469 if (error)
470 return (error);
471 error = kern_fcntl(td, fd, newcmd, arg1);
472 if (error)
473 return (error);
474 if (cmd == F_OGETLK) {
475 ofl.l_start = fl.l_start;
476 ofl.l_len = fl.l_len;
477 ofl.l_pid = fl.l_pid;
478 ofl.l_type = fl.l_type;
479 ofl.l_whence = fl.l_whence;
480 error = copyout(&ofl, (void *)(intptr_t)arg, sizeof(ofl));
481 } else if (cmd == F_GETLK) {
482 error = copyout(&fl, (void *)(intptr_t)arg, sizeof(fl));
483 }
484 return (error);
485 }
486
487 int
488 kern_fcntl(struct thread *td, int fd, int cmd, intptr_t arg)
489 {
490 struct filedesc *fdp;
491 struct flock *flp;
492 struct file *fp, *fp2;
493 struct filedescent *fde;
494 struct proc *p;
495 struct vnode *vp;
496 struct mount *mp;
497 struct kinfo_file *kif;
498 int error, flg, kif_sz, seals, tmp;
499 uint64_t bsize;
500 off_t foffset;
501
502 error = 0;
503 flg = F_POSIX;
504 p = td->td_proc;
505 fdp = p->p_fd;
506
507 AUDIT_ARG_FD(cmd);
508 AUDIT_ARG_CMD(cmd);
509 switch (cmd) {
510 case F_DUPFD:
511 tmp = arg;
512 error = kern_dup(td, FDDUP_FCNTL, 0, fd, tmp);
513 break;
514
515 case F_DUPFD_CLOEXEC:
516 tmp = arg;
517 error = kern_dup(td, FDDUP_FCNTL, FDDUP_FLAG_CLOEXEC, fd, tmp);
518 break;
519
520 case F_DUP2FD:
521 tmp = arg;
522 error = kern_dup(td, FDDUP_FIXED, 0, fd, tmp);
523 break;
524
525 case F_DUP2FD_CLOEXEC:
526 tmp = arg;
527 error = kern_dup(td, FDDUP_FIXED, FDDUP_FLAG_CLOEXEC, fd, tmp);
528 break;
529
530 case F_GETFD:
531 error = EBADF;
532 FILEDESC_SLOCK(fdp);
533 fde = fdeget_noref(fdp, fd);
534 if (fde != NULL) {
535 td->td_retval[0] =
536 (fde->fde_flags & UF_EXCLOSE) ? FD_CLOEXEC : 0;
537 error = 0;
538 }
539 FILEDESC_SUNLOCK(fdp);
540 break;
541
542 case F_SETFD:
543 error = EBADF;
544 FILEDESC_XLOCK(fdp);
545 fde = fdeget_noref(fdp, fd);
546 if (fde != NULL) {
547 fde->fde_flags = (fde->fde_flags & ~UF_EXCLOSE) |
548 (arg & FD_CLOEXEC ? UF_EXCLOSE : 0);
549 error = 0;
550 }
551 FILEDESC_XUNLOCK(fdp);
552 break;
553
554 case F_GETFL:
555 error = fget_fcntl(td, fd, &cap_fcntl_rights, F_GETFL, &fp);
556 if (error != 0)
557 break;
558 td->td_retval[0] = OFLAGS(fp->f_flag);
559 fdrop(fp, td);
560 break;
561
562 case F_SETFL:
563 error = fget_fcntl(td, fd, &cap_fcntl_rights, F_SETFL, &fp);
564 if (error != 0)
565 break;
566 if (fp->f_ops == &path_fileops) {
567 fdrop(fp, td);
568 error = EBADF;
569 break;
570 }
571 do {
572 tmp = flg = fp->f_flag;
573 tmp &= ~FCNTLFLAGS;
574 tmp |= FFLAGS(arg & ~O_ACCMODE) & FCNTLFLAGS;
575 } while (atomic_cmpset_int(&fp->f_flag, flg, tmp) == 0);
576 tmp = fp->f_flag & FNONBLOCK;
577 error = fo_ioctl(fp, FIONBIO, &tmp, td->td_ucred, td);
578 if (error != 0) {
579 fdrop(fp, td);
580 break;
581 }
582 tmp = fp->f_flag & FASYNC;
583 error = fo_ioctl(fp, FIOASYNC, &tmp, td->td_ucred, td);
584 if (error == 0) {
585 fdrop(fp, td);
586 break;
587 }
588 atomic_clear_int(&fp->f_flag, FNONBLOCK);
589 tmp = 0;
590 (void)fo_ioctl(fp, FIONBIO, &tmp, td->td_ucred, td);
591 fdrop(fp, td);
592 break;
593
594 case F_GETOWN:
595 error = fget_fcntl(td, fd, &cap_fcntl_rights, F_GETOWN, &fp);
596 if (error != 0)
597 break;
598 error = fo_ioctl(fp, FIOGETOWN, &tmp, td->td_ucred, td);
599 if (error == 0)
600 td->td_retval[0] = tmp;
601 fdrop(fp, td);
602 break;
603
604 case F_SETOWN:
605 error = fget_fcntl(td, fd, &cap_fcntl_rights, F_SETOWN, &fp);
606 if (error != 0)
607 break;
608 tmp = arg;
609 error = fo_ioctl(fp, FIOSETOWN, &tmp, td->td_ucred, td);
610 fdrop(fp, td);
611 break;
612
613 case F_SETLK_REMOTE:
614 error = priv_check(td, PRIV_NFS_LOCKD);
615 if (error != 0)
616 return (error);
617 flg = F_REMOTE;
618 goto do_setlk;
619
620 case F_SETLKW:
621 flg |= F_WAIT;
622 /* FALLTHROUGH F_SETLK */
623
624 case F_SETLK:
625 do_setlk:
626 flp = (struct flock *)arg;
627 if ((flg & F_REMOTE) != 0 && flp->l_sysid == 0) {
628 error = EINVAL;
629 break;
630 }
631
632 error = fget_unlocked(td, fd, &cap_flock_rights, &fp);
633 if (error != 0)
634 break;
635 if (fp->f_type != DTYPE_VNODE || fp->f_ops == &path_fileops) {
636 error = EBADF;
637 fdrop(fp, td);
638 break;
639 }
640
641 if (flp->l_whence == SEEK_CUR) {
642 foffset = foffset_get(fp);
643 if (foffset < 0 ||
644 (flp->l_start > 0 &&
645 foffset > OFF_MAX - flp->l_start)) {
646 error = EOVERFLOW;
647 fdrop(fp, td);
648 break;
649 }
650 flp->l_start += foffset;
651 }
652
653 vp = fp->f_vnode;
654 switch (flp->l_type) {
655 case F_RDLCK:
656 if ((fp->f_flag & FREAD) == 0) {
657 error = EBADF;
658 break;
659 }
660 if ((p->p_leader->p_flag & P_ADVLOCK) == 0) {
661 PROC_LOCK(p->p_leader);
662 p->p_leader->p_flag |= P_ADVLOCK;
663 PROC_UNLOCK(p->p_leader);
664 }
665 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_SETLK,
666 flp, flg);
667 break;
668 case F_WRLCK:
669 if ((fp->f_flag & FWRITE) == 0) {
670 error = EBADF;
671 break;
672 }
673 if ((p->p_leader->p_flag & P_ADVLOCK) == 0) {
674 PROC_LOCK(p->p_leader);
675 p->p_leader->p_flag |= P_ADVLOCK;
676 PROC_UNLOCK(p->p_leader);
677 }
678 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_SETLK,
679 flp, flg);
680 break;
681 case F_UNLCK:
682 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_UNLCK,
683 flp, flg);
684 break;
685 case F_UNLCKSYS:
686 if (flg != F_REMOTE) {
687 error = EINVAL;
688 break;
689 }
690 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader,
691 F_UNLCKSYS, flp, flg);
692 break;
693 default:
694 error = EINVAL;
695 break;
696 }
697 if (error != 0 || flp->l_type == F_UNLCK ||
698 flp->l_type == F_UNLCKSYS) {
699 fdrop(fp, td);
700 break;
701 }
702
703 /*
704 * Check for a race with close.
705 *
706 * The vnode is now advisory locked (or unlocked, but this case
707 * is not really important) as the caller requested.
708 * We had to drop the filedesc lock, so we need to recheck if
709 * the descriptor is still valid, because if it was closed
710 * in the meantime we need to remove advisory lock from the
711 * vnode - close on any descriptor leading to an advisory
712 * locked vnode, removes that lock.
713 * We will return 0 on purpose in that case, as the result of
714 * successful advisory lock might have been externally visible
715 * already. This is fine - effectively we pretend to the caller
716 * that the closing thread was a bit slower and that the
717 * advisory lock succeeded before the close.
718 */
719 error = fget_unlocked(td, fd, &cap_no_rights, &fp2);
720 if (error != 0) {
721 fdrop(fp, td);
722 break;
723 }
724 if (fp != fp2) {
725 flp->l_whence = SEEK_SET;
726 flp->l_start = 0;
727 flp->l_len = 0;
728 flp->l_type = F_UNLCK;
729 (void) VOP_ADVLOCK(vp, (caddr_t)p->p_leader,
730 F_UNLCK, flp, F_POSIX);
731 }
732 fdrop(fp, td);
733 fdrop(fp2, td);
734 break;
735
736 case F_GETLK:
737 error = fget_unlocked(td, fd, &cap_flock_rights, &fp);
738 if (error != 0)
739 break;
740 if (fp->f_type != DTYPE_VNODE || fp->f_ops == &path_fileops) {
741 error = EBADF;
742 fdrop(fp, td);
743 break;
744 }
745 flp = (struct flock *)arg;
746 if (flp->l_type != F_RDLCK && flp->l_type != F_WRLCK &&
747 flp->l_type != F_UNLCK) {
748 error = EINVAL;
749 fdrop(fp, td);
750 break;
751 }
752 if (flp->l_whence == SEEK_CUR) {
753 foffset = foffset_get(fp);
754 if ((flp->l_start > 0 &&
755 foffset > OFF_MAX - flp->l_start) ||
756 (flp->l_start < 0 &&
757 foffset < OFF_MIN - flp->l_start)) {
758 error = EOVERFLOW;
759 fdrop(fp, td);
760 break;
761 }
762 flp->l_start += foffset;
763 }
764 vp = fp->f_vnode;
765 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_GETLK, flp,
766 F_POSIX);
767 fdrop(fp, td);
768 break;
769
770 case F_ADD_SEALS:
771 error = fget_unlocked(td, fd, &cap_no_rights, &fp);
772 if (error != 0)
773 break;
774 error = fo_add_seals(fp, arg);
775 fdrop(fp, td);
776 break;
777
778 case F_GET_SEALS:
779 error = fget_unlocked(td, fd, &cap_no_rights, &fp);
780 if (error != 0)
781 break;
782 if (fo_get_seals(fp, &seals) == 0)
783 td->td_retval[0] = seals;
784 else
785 error = EINVAL;
786 fdrop(fp, td);
787 break;
788
789 case F_RDAHEAD:
790 arg = arg ? 128 * 1024: 0;
791 /* FALLTHROUGH */
792 case F_READAHEAD:
793 error = fget_unlocked(td, fd, &cap_no_rights, &fp);
794 if (error != 0)
795 break;
796 if (fp->f_type != DTYPE_VNODE || fp->f_ops == &path_fileops) {
797 fdrop(fp, td);
798 error = EBADF;
799 break;
800 }
801 vp = fp->f_vnode;
802 if (vp->v_type != VREG) {
803 fdrop(fp, td);
804 error = ENOTTY;
805 break;
806 }
807
808 /*
809 * Exclusive lock synchronizes against f_seqcount reads and
810 * writes in sequential_heuristic().
811 */
812 error = vn_lock(vp, LK_EXCLUSIVE);
813 if (error != 0) {
814 fdrop(fp, td);
815 break;
816 }
817 if (arg >= 0) {
818 bsize = fp->f_vnode->v_mount->mnt_stat.f_iosize;
819 arg = MIN(arg, INT_MAX - bsize + 1);
820 fp->f_seqcount[UIO_READ] = MIN(IO_SEQMAX,
821 (arg + bsize - 1) / bsize);
822 atomic_set_int(&fp->f_flag, FRDAHEAD);
823 } else {
824 atomic_clear_int(&fp->f_flag, FRDAHEAD);
825 }
826 VOP_UNLOCK(vp);
827 fdrop(fp, td);
828 break;
829
830 case F_ISUNIONSTACK:
831 /*
832 * Check if the vnode is part of a union stack (either the
833 * "union" flag from mount(2) or unionfs).
834 *
835 * Prior to introduction of this op libc's readdir would call
836 * fstatfs(2), in effect unnecessarily copying kilobytes of
837 * data just to check fs name and a mount flag.
838 *
839 * Fixing the code to handle everything in the kernel instead
840 * is a non-trivial endeavor and has low priority, thus this
841 * horrible kludge facilitates the current behavior in a much
842 * cheaper manner until someone(tm) sorts this out.
843 */
844 error = fget_unlocked(td, fd, &cap_no_rights, &fp);
845 if (error != 0)
846 break;
847 if (fp->f_type != DTYPE_VNODE) {
848 fdrop(fp, td);
849 error = EBADF;
850 break;
851 }
852 vp = fp->f_vnode;
853 /*
854 * Since we don't prevent dooming the vnode even non-null mp
855 * found can become immediately stale. This is tolerable since
856 * mount points are type-stable (providing safe memory access)
857 * and any vfs op on this vnode going forward will return an
858 * error (meaning return value in this case is meaningless).
859 */
860 mp = atomic_load_ptr(&vp->v_mount);
861 if (__predict_false(mp == NULL)) {
862 fdrop(fp, td);
863 error = EBADF;
864 break;
865 }
866 td->td_retval[0] = 0;
867 if (mp->mnt_kern_flag & MNTK_UNIONFS ||
868 mp->mnt_flag & MNT_UNION)
869 td->td_retval[0] = 1;
870 fdrop(fp, td);
871 break;
872
873 case F_KINFO:
874 #ifdef CAPABILITY_MODE
875 if (IN_CAPABILITY_MODE(td)) {
876 error = ECAPMODE;
877 break;
878 }
879 #endif
880 error = copyin((void *)arg, &kif_sz, sizeof(kif_sz));
881 if (error != 0)
882 break;
883 if (kif_sz != sizeof(*kif)) {
884 error = EINVAL;
885 break;
886 }
887 kif = malloc(sizeof(*kif), M_TEMP, M_WAITOK | M_ZERO);
888 FILEDESC_SLOCK(fdp);
889 error = fget_cap_noref(fdp, fd, &cap_fcntl_rights, &fp, NULL);
890 if (error == 0 && fhold(fp)) {
891 export_file_to_kinfo(fp, fd, NULL, kif, fdp, 0);
892 FILEDESC_SUNLOCK(fdp);
893 fdrop(fp, td);
894 if ((kif->kf_status & KF_ATTR_VALID) != 0) {
895 kif->kf_structsize = sizeof(*kif);
896 error = copyout(kif, (void *)arg, sizeof(*kif));
897 } else {
898 error = EBADF;
899 }
900 } else {
901 FILEDESC_SUNLOCK(fdp);
902 if (error == 0)
903 error = EBADF;
904 }
905 free(kif, M_TEMP);
906 break;
907
908 default:
909 error = EINVAL;
910 break;
911 }
912 return (error);
913 }
914
915 static int
916 getmaxfd(struct thread *td)
917 {
918
919 return (min((int)lim_cur(td, RLIMIT_NOFILE), maxfilesperproc));
920 }
921
922 /*
923 * Common code for dup, dup2, fcntl(F_DUPFD) and fcntl(F_DUP2FD).
924 */
925 int
926 kern_dup(struct thread *td, u_int mode, int flags, int old, int new)
927 {
928 struct filedesc *fdp;
929 struct filedescent *oldfde, *newfde;
930 struct proc *p;
931 struct file *delfp, *oldfp;
932 u_long *oioctls, *nioctls;
933 int error, maxfd;
934
935 p = td->td_proc;
936 fdp = p->p_fd;
937 oioctls = NULL;
938
939 MPASS((flags & ~(FDDUP_FLAG_CLOEXEC)) == 0);
940 MPASS(mode < FDDUP_LASTMODE);
941
942 AUDIT_ARG_FD(old);
943 /* XXXRW: if (flags & FDDUP_FIXED) AUDIT_ARG_FD2(new); */
944
945 /*
946 * Verify we have a valid descriptor to dup from and possibly to
947 * dup to. Unlike dup() and dup2(), fcntl()'s F_DUPFD should
948 * return EINVAL when the new descriptor is out of bounds.
949 */
950 if (old < 0)
951 return (EBADF);
952 if (new < 0)
953 return (mode == FDDUP_FCNTL ? EINVAL : EBADF);
954 maxfd = getmaxfd(td);
955 if (new >= maxfd)
956 return (mode == FDDUP_FCNTL ? EINVAL : EBADF);
957
958 error = EBADF;
959 FILEDESC_XLOCK(fdp);
960 if (fget_noref(fdp, old) == NULL)
961 goto unlock;
962 if (mode == FDDUP_FIXED && old == new) {
963 td->td_retval[0] = new;
964 if (flags & FDDUP_FLAG_CLOEXEC)
965 fdp->fd_ofiles[new].fde_flags |= UF_EXCLOSE;
966 error = 0;
967 goto unlock;
968 }
969
970 oldfde = &fdp->fd_ofiles[old];
971 oldfp = oldfde->fde_file;
972 if (!fhold(oldfp))
973 goto unlock;
974
975 /*
976 * If the caller specified a file descriptor, make sure the file
977 * table is large enough to hold it, and grab it. Otherwise, just
978 * allocate a new descriptor the usual way.
979 */
980 switch (mode) {
981 case FDDUP_NORMAL:
982 case FDDUP_FCNTL:
983 if ((error = fdalloc(td, new, &new)) != 0) {
984 fdrop(oldfp, td);
985 goto unlock;
986 }
987 break;
988 case FDDUP_FIXED:
989 if (new >= fdp->fd_nfiles) {
990 /*
991 * The resource limits are here instead of e.g.
992 * fdalloc(), because the file descriptor table may be
993 * shared between processes, so we can't really use
994 * racct_add()/racct_sub(). Instead of counting the
995 * number of actually allocated descriptors, just put
996 * the limit on the size of the file descriptor table.
997 */
998 #ifdef RACCT
999 if (RACCT_ENABLED()) {
1000 error = racct_set_unlocked(p, RACCT_NOFILE, new + 1);
1001 if (error != 0) {
1002 error = EMFILE;
1003 fdrop(oldfp, td);
1004 goto unlock;
1005 }
1006 }
1007 #endif
1008 fdgrowtable_exp(fdp, new + 1);
1009 }
1010 if (!fdisused(fdp, new))
1011 fdused(fdp, new);
1012 break;
1013 default:
1014 KASSERT(0, ("%s unsupported mode %d", __func__, mode));
1015 }
1016
1017 KASSERT(old != new, ("new fd is same as old"));
1018
1019 /* Refetch oldfde because the table may have grown and old one freed. */
1020 oldfde = &fdp->fd_ofiles[old];
1021 KASSERT(oldfp == oldfde->fde_file,
1022 ("fdt_ofiles shift from growth observed at fd %d",
1023 old));
1024
1025 newfde = &fdp->fd_ofiles[new];
1026 delfp = newfde->fde_file;
1027
1028 nioctls = filecaps_copy_prep(&oldfde->fde_caps);
1029
1030 /*
1031 * Duplicate the source descriptor.
1032 */
1033 #ifdef CAPABILITIES
1034 seqc_write_begin(&newfde->fde_seqc);
1035 #endif
1036 oioctls = filecaps_free_prep(&newfde->fde_caps);
1037 fde_copy(oldfde, newfde);
1038 filecaps_copy_finish(&oldfde->fde_caps, &newfde->fde_caps,
1039 nioctls);
1040 if ((flags & FDDUP_FLAG_CLOEXEC) != 0)
1041 newfde->fde_flags = oldfde->fde_flags | UF_EXCLOSE;
1042 else
1043 newfde->fde_flags = oldfde->fde_flags & ~UF_EXCLOSE;
1044 #ifdef CAPABILITIES
1045 seqc_write_end(&newfde->fde_seqc);
1046 #endif
1047 td->td_retval[0] = new;
1048
1049 error = 0;
1050
1051 if (delfp != NULL) {
1052 (void) closefp(fdp, new, delfp, td, true, false);
1053 FILEDESC_UNLOCK_ASSERT(fdp);
1054 } else {
1055 unlock:
1056 FILEDESC_XUNLOCK(fdp);
1057 }
1058
1059 filecaps_free_finish(oioctls);
1060 return (error);
1061 }
1062
1063 static void
1064 sigiofree(struct sigio *sigio)
1065 {
1066 crfree(sigio->sio_ucred);
1067 free(sigio, M_SIGIO);
1068 }
1069
1070 static struct sigio *
1071 funsetown_locked(struct sigio *sigio)
1072 {
1073 struct proc *p;
1074 struct pgrp *pg;
1075
1076 SIGIO_ASSERT_LOCKED();
1077
1078 if (sigio == NULL)
1079 return (NULL);
1080 *sigio->sio_myref = NULL;
1081 if (sigio->sio_pgid < 0) {
1082 pg = sigio->sio_pgrp;
1083 PGRP_LOCK(pg);
1084 SLIST_REMOVE(&pg->pg_sigiolst, sigio, sigio, sio_pgsigio);
1085 PGRP_UNLOCK(pg);
1086 } else {
1087 p = sigio->sio_proc;
1088 PROC_LOCK(p);
1089 SLIST_REMOVE(&p->p_sigiolst, sigio, sigio, sio_pgsigio);
1090 PROC_UNLOCK(p);
1091 }
1092 return (sigio);
1093 }
1094
1095 /*
1096 * If sigio is on the list associated with a process or process group,
1097 * disable signalling from the device, remove sigio from the list and
1098 * free sigio.
1099 */
1100 void
1101 funsetown(struct sigio **sigiop)
1102 {
1103 struct sigio *sigio;
1104
1105 /* Racy check, consumers must provide synchronization. */
1106 if (*sigiop == NULL)
1107 return;
1108
1109 SIGIO_LOCK();
1110 sigio = funsetown_locked(*sigiop);
1111 SIGIO_UNLOCK();
1112 if (sigio != NULL)
1113 sigiofree(sigio);
1114 }
1115
1116 /*
1117 * Free a list of sigio structures. The caller must ensure that new sigio
1118 * structures cannot be added after this point. For process groups this is
1119 * guaranteed using the proctree lock; for processes, the P_WEXIT flag serves
1120 * as an interlock.
1121 */
1122 void
1123 funsetownlst(struct sigiolst *sigiolst)
1124 {
1125 struct proc *p;
1126 struct pgrp *pg;
1127 struct sigio *sigio, *tmp;
1128
1129 /* Racy check. */
1130 sigio = SLIST_FIRST(sigiolst);
1131 if (sigio == NULL)
1132 return;
1133
1134 p = NULL;
1135 pg = NULL;
1136
1137 SIGIO_LOCK();
1138 sigio = SLIST_FIRST(sigiolst);
1139 if (sigio == NULL) {
1140 SIGIO_UNLOCK();
1141 return;
1142 }
1143
1144 /*
1145 * Every entry of the list should belong to a single proc or pgrp.
1146 */
1147 if (sigio->sio_pgid < 0) {
1148 pg = sigio->sio_pgrp;
1149 sx_assert(&proctree_lock, SX_XLOCKED);
1150 PGRP_LOCK(pg);
1151 } else /* if (sigio->sio_pgid > 0) */ {
1152 p = sigio->sio_proc;
1153 PROC_LOCK(p);
1154 KASSERT((p->p_flag & P_WEXIT) != 0,
1155 ("%s: process %p is not exiting", __func__, p));
1156 }
1157
1158 SLIST_FOREACH(sigio, sigiolst, sio_pgsigio) {
1159 *sigio->sio_myref = NULL;
1160 if (pg != NULL) {
1161 KASSERT(sigio->sio_pgid < 0,
1162 ("Proc sigio in pgrp sigio list"));
1163 KASSERT(sigio->sio_pgrp == pg,
1164 ("Bogus pgrp in sigio list"));
1165 } else /* if (p != NULL) */ {
1166 KASSERT(sigio->sio_pgid > 0,
1167 ("Pgrp sigio in proc sigio list"));
1168 KASSERT(sigio->sio_proc == p,
1169 ("Bogus proc in sigio list"));
1170 }
1171 }
1172
1173 if (pg != NULL)
1174 PGRP_UNLOCK(pg);
1175 else
1176 PROC_UNLOCK(p);
1177 SIGIO_UNLOCK();
1178
1179 SLIST_FOREACH_SAFE(sigio, sigiolst, sio_pgsigio, tmp)
1180 sigiofree(sigio);
1181 }
1182
1183 /*
1184 * This is common code for FIOSETOWN ioctl called by fcntl(fd, F_SETOWN, arg).
1185 *
1186 * After permission checking, add a sigio structure to the sigio list for
1187 * the process or process group.
1188 */
1189 int
1190 fsetown(pid_t pgid, struct sigio **sigiop)
1191 {
1192 struct proc *proc;
1193 struct pgrp *pgrp;
1194 struct sigio *osigio, *sigio;
1195 int ret;
1196
1197 if (pgid == 0) {
1198 funsetown(sigiop);
1199 return (0);
1200 }
1201
1202 sigio = malloc(sizeof(struct sigio), M_SIGIO, M_WAITOK);
1203 sigio->sio_pgid = pgid;
1204 sigio->sio_ucred = crhold(curthread->td_ucred);
1205 sigio->sio_myref = sigiop;
1206
1207 ret = 0;
1208 if (pgid > 0) {
1209 ret = pget(pgid, PGET_NOTWEXIT | PGET_NOTID | PGET_HOLD, &proc);
1210 SIGIO_LOCK();
1211 osigio = funsetown_locked(*sigiop);
1212 if (ret == 0) {
1213 PROC_LOCK(proc);
1214 _PRELE(proc);
1215 if ((proc->p_flag & P_WEXIT) != 0) {
1216 ret = ESRCH;
1217 } else if (proc->p_session !=
1218 curthread->td_proc->p_session) {
1219 /*
1220 * Policy - Don't allow a process to FSETOWN a
1221 * process in another session.
1222 *
1223 * Remove this test to allow maximum flexibility
1224 * or restrict FSETOWN to the current process or
1225 * process group for maximum safety.
1226 */
1227 ret = EPERM;
1228 } else {
1229 sigio->sio_proc = proc;
1230 SLIST_INSERT_HEAD(&proc->p_sigiolst, sigio,
1231 sio_pgsigio);
1232 }
1233 PROC_UNLOCK(proc);
1234 }
1235 } else /* if (pgid < 0) */ {
1236 sx_slock(&proctree_lock);
1237 SIGIO_LOCK();
1238 osigio = funsetown_locked(*sigiop);
1239 pgrp = pgfind(-pgid);
1240 if (pgrp == NULL) {
1241 ret = ESRCH;
1242 } else {
1243 if (pgrp->pg_session != curthread->td_proc->p_session) {
1244 /*
1245 * Policy - Don't allow a process to FSETOWN a
1246 * process in another session.
1247 *
1248 * Remove this test to allow maximum flexibility
1249 * or restrict FSETOWN to the current process or
1250 * process group for maximum safety.
1251 */
1252 ret = EPERM;
1253 } else {
1254 sigio->sio_pgrp = pgrp;
1255 SLIST_INSERT_HEAD(&pgrp->pg_sigiolst, sigio,
1256 sio_pgsigio);
1257 }
1258 PGRP_UNLOCK(pgrp);
1259 }
1260 sx_sunlock(&proctree_lock);
1261 }
1262 if (ret == 0)
1263 *sigiop = sigio;
1264 SIGIO_UNLOCK();
1265 if (osigio != NULL)
1266 sigiofree(osigio);
1267 return (ret);
1268 }
1269
1270 /*
1271 * This is common code for FIOGETOWN ioctl called by fcntl(fd, F_GETOWN, arg).
1272 */
1273 pid_t
1274 fgetown(struct sigio **sigiop)
1275 {
1276 pid_t pgid;
1277
1278 SIGIO_LOCK();
1279 pgid = (*sigiop != NULL) ? (*sigiop)->sio_pgid : 0;
1280 SIGIO_UNLOCK();
1281 return (pgid);
1282 }
1283
1284 static int
1285 closefp_impl(struct filedesc *fdp, int fd, struct file *fp, struct thread *td,
1286 bool audit)
1287 {
1288 int error;
1289
1290 FILEDESC_XLOCK_ASSERT(fdp);
1291
1292 /*
1293 * We now hold the fp reference that used to be owned by the
1294 * descriptor array. We have to unlock the FILEDESC *AFTER*
1295 * knote_fdclose to prevent a race of the fd getting opened, a knote
1296 * added, and deleteing a knote for the new fd.
1297 */
1298 if (__predict_false(!TAILQ_EMPTY(&fdp->fd_kqlist)))
1299 knote_fdclose(td, fd);
1300
1301 /*
1302 * We need to notify mqueue if the object is of type mqueue.
1303 */
1304 if (__predict_false(fp->f_type == DTYPE_MQUEUE))
1305 mq_fdclose(td, fd, fp);
1306 FILEDESC_XUNLOCK(fdp);
1307
1308 #ifdef AUDIT
1309 if (AUDITING_TD(td) && audit)
1310 audit_sysclose(td, fd, fp);
1311 #endif
1312 error = closef(fp, td);
1313
1314 /*
1315 * All paths leading up to closefp() will have already removed or
1316 * replaced the fd in the filedesc table, so a restart would not
1317 * operate on the same file.
1318 */
1319 if (error == ERESTART)
1320 error = EINTR;
1321
1322 return (error);
1323 }
1324
1325 static int
1326 closefp_hl(struct filedesc *fdp, int fd, struct file *fp, struct thread *td,
1327 bool holdleaders, bool audit)
1328 {
1329 int error;
1330
1331 FILEDESC_XLOCK_ASSERT(fdp);
1332
1333 if (holdleaders) {
1334 if (td->td_proc->p_fdtol != NULL) {
1335 /*
1336 * Ask fdfree() to sleep to ensure that all relevant
1337 * process leaders can be traversed in closef().
1338 */
1339 fdp->fd_holdleaderscount++;
1340 } else {
1341 holdleaders = false;
1342 }
1343 }
1344
1345 error = closefp_impl(fdp, fd, fp, td, audit);
1346 if (holdleaders) {
1347 FILEDESC_XLOCK(fdp);
1348 fdp->fd_holdleaderscount--;
1349 if (fdp->fd_holdleaderscount == 0 &&
1350 fdp->fd_holdleaderswakeup != 0) {
1351 fdp->fd_holdleaderswakeup = 0;
1352 wakeup(&fdp->fd_holdleaderscount);
1353 }
1354 FILEDESC_XUNLOCK(fdp);
1355 }
1356 return (error);
1357 }
1358
1359 static int
1360 closefp(struct filedesc *fdp, int fd, struct file *fp, struct thread *td,
1361 bool holdleaders, bool audit)
1362 {
1363
1364 FILEDESC_XLOCK_ASSERT(fdp);
1365
1366 if (__predict_false(td->td_proc->p_fdtol != NULL)) {
1367 return (closefp_hl(fdp, fd, fp, td, holdleaders, audit));
1368 } else {
1369 return (closefp_impl(fdp, fd, fp, td, audit));
1370 }
1371 }
1372
1373 /*
1374 * Close a file descriptor.
1375 */
1376 #ifndef _SYS_SYSPROTO_H_
1377 struct close_args {
1378 int fd;
1379 };
1380 #endif
1381 /* ARGSUSED */
1382 int
1383 sys_close(struct thread *td, struct close_args *uap)
1384 {
1385
1386 return (kern_close(td, uap->fd));
1387 }
1388
1389 int
1390 kern_close(struct thread *td, int fd)
1391 {
1392 struct filedesc *fdp;
1393 struct file *fp;
1394
1395 fdp = td->td_proc->p_fd;
1396
1397 FILEDESC_XLOCK(fdp);
1398 if ((fp = fget_noref(fdp, fd)) == NULL) {
1399 FILEDESC_XUNLOCK(fdp);
1400 return (EBADF);
1401 }
1402 fdfree(fdp, fd);
1403
1404 /* closefp() drops the FILEDESC lock for us. */
1405 return (closefp(fdp, fd, fp, td, true, true));
1406 }
1407
1408 static int
1409 close_range_cloexec(struct thread *td, u_int lowfd, u_int highfd)
1410 {
1411 struct filedesc *fdp;
1412 struct fdescenttbl *fdt;
1413 struct filedescent *fde;
1414 int fd;
1415
1416 fdp = td->td_proc->p_fd;
1417 FILEDESC_XLOCK(fdp);
1418 fdt = atomic_load_ptr(&fdp->fd_files);
1419 highfd = MIN(highfd, fdt->fdt_nfiles - 1);
1420 fd = lowfd;
1421 if (__predict_false(fd > highfd)) {
1422 goto out_locked;
1423 }
1424 for (; fd <= highfd; fd++) {
1425 fde = &fdt->fdt_ofiles[fd];
1426 if (fde->fde_file != NULL)
1427 fde->fde_flags |= UF_EXCLOSE;
1428 }
1429 out_locked:
1430 FILEDESC_XUNLOCK(fdp);
1431 return (0);
1432 }
1433
1434 static int
1435 close_range_impl(struct thread *td, u_int lowfd, u_int highfd)
1436 {
1437 struct filedesc *fdp;
1438 const struct fdescenttbl *fdt;
1439 struct file *fp;
1440 int fd;
1441
1442 fdp = td->td_proc->p_fd;
1443 FILEDESC_XLOCK(fdp);
1444 fdt = atomic_load_ptr(&fdp->fd_files);
1445 highfd = MIN(highfd, fdt->fdt_nfiles - 1);
1446 fd = lowfd;
1447 if (__predict_false(fd > highfd)) {
1448 goto out_locked;
1449 }
1450 for (;;) {
1451 fp = fdt->fdt_ofiles[fd].fde_file;
1452 if (fp == NULL) {
1453 if (fd == highfd)
1454 goto out_locked;
1455 } else {
1456 fdfree(fdp, fd);
1457 (void) closefp(fdp, fd, fp, td, true, true);
1458 if (fd == highfd)
1459 goto out_unlocked;
1460 FILEDESC_XLOCK(fdp);
1461 fdt = atomic_load_ptr(&fdp->fd_files);
1462 }
1463 fd++;
1464 }
1465 out_locked:
1466 FILEDESC_XUNLOCK(fdp);
1467 out_unlocked:
1468 return (0);
1469 }
1470
1471 int
1472 kern_close_range(struct thread *td, int flags, u_int lowfd, u_int highfd)
1473 {
1474
1475 /*
1476 * Check this prior to clamping; closefrom(3) with only fd 0, 1, and 2
1477 * open should not be a usage error. From a close_range() perspective,
1478 * close_range(3, ~0U, 0) in the same scenario should also likely not
1479 * be a usage error as all fd above 3 are in-fact already closed.
1480 */
1481 if (highfd < lowfd) {
1482 return (EINVAL);
1483 }
1484
1485 if ((flags & CLOSE_RANGE_CLOEXEC) != 0)
1486 return (close_range_cloexec(td, lowfd, highfd));
1487
1488 return (close_range_impl(td, lowfd, highfd));
1489 }
1490
1491 #ifndef _SYS_SYSPROTO_H_
1492 struct close_range_args {
1493 u_int lowfd;
1494 u_int highfd;
1495 int flags;
1496 };
1497 #endif
1498 int
1499 sys_close_range(struct thread *td, struct close_range_args *uap)
1500 {
1501
1502 AUDIT_ARG_FD(uap->lowfd);
1503 AUDIT_ARG_CMD(uap->highfd);
1504 AUDIT_ARG_FFLAGS(uap->flags);
1505
1506 if ((uap->flags & ~(CLOSE_RANGE_CLOEXEC)) != 0)
1507 return (EINVAL);
1508 return (kern_close_range(td, uap->flags, uap->lowfd, uap->highfd));
1509 }
1510
1511 #ifdef COMPAT_FREEBSD12
1512 /*
1513 * Close open file descriptors.
1514 */
1515 #ifndef _SYS_SYSPROTO_H_
1516 struct freebsd12_closefrom_args {
1517 int lowfd;
1518 };
1519 #endif
1520 /* ARGSUSED */
1521 int
1522 freebsd12_closefrom(struct thread *td, struct freebsd12_closefrom_args *uap)
1523 {
1524 u_int lowfd;
1525
1526 AUDIT_ARG_FD(uap->lowfd);
1527
1528 /*
1529 * Treat negative starting file descriptor values identical to
1530 * closefrom(0) which closes all files.
1531 */
1532 lowfd = MAX(0, uap->lowfd);
1533 return (kern_close_range(td, 0, lowfd, ~0U));
1534 }
1535 #endif /* COMPAT_FREEBSD12 */
1536
1537 #if defined(COMPAT_43)
1538 /*
1539 * Return status information about a file descriptor.
1540 */
1541 #ifndef _SYS_SYSPROTO_H_
1542 struct ofstat_args {
1543 int fd;
1544 struct ostat *sb;
1545 };
1546 #endif
1547 /* ARGSUSED */
1548 int
1549 ofstat(struct thread *td, struct ofstat_args *uap)
1550 {
1551 struct ostat oub;
1552 struct stat ub;
1553 int error;
1554
1555 error = kern_fstat(td, uap->fd, &ub);
1556 if (error == 0) {
1557 cvtstat(&ub, &oub);
1558 error = copyout(&oub, uap->sb, sizeof(oub));
1559 }
1560 return (error);
1561 }
1562 #endif /* COMPAT_43 */
1563
1564 #if defined(COMPAT_FREEBSD11)
1565 int
1566 freebsd11_fstat(struct thread *td, struct freebsd11_fstat_args *uap)
1567 {
1568 struct stat sb;
1569 struct freebsd11_stat osb;
1570 int error;
1571
1572 error = kern_fstat(td, uap->fd, &sb);
1573 if (error != 0)
1574 return (error);
1575 error = freebsd11_cvtstat(&sb, &osb);
1576 if (error == 0)
1577 error = copyout(&osb, uap->sb, sizeof(osb));
1578 return (error);
1579 }
1580 #endif /* COMPAT_FREEBSD11 */
1581
1582 /*
1583 * Return status information about a file descriptor.
1584 */
1585 #ifndef _SYS_SYSPROTO_H_
1586 struct fstat_args {
1587 int fd;
1588 struct stat *sb;
1589 };
1590 #endif
1591 /* ARGSUSED */
1592 int
1593 sys_fstat(struct thread *td, struct fstat_args *uap)
1594 {
1595 struct stat ub;
1596 int error;
1597
1598 error = kern_fstat(td, uap->fd, &ub);
1599 if (error == 0)
1600 error = copyout(&ub, uap->sb, sizeof(ub));
1601 return (error);
1602 }
1603
1604 int
1605 kern_fstat(struct thread *td, int fd, struct stat *sbp)
1606 {
1607 struct file *fp;
1608 int error;
1609
1610 AUDIT_ARG_FD(fd);
1611
1612 error = fget(td, fd, &cap_fstat_rights, &fp);
1613 if (__predict_false(error != 0))
1614 return (error);
1615
1616 AUDIT_ARG_FILE(td->td_proc, fp);
1617
1618 error = fo_stat(fp, sbp, td->td_ucred);
1619 fdrop(fp, td);
1620 #ifdef __STAT_TIME_T_EXT
1621 sbp->st_atim_ext = 0;
1622 sbp->st_mtim_ext = 0;
1623 sbp->st_ctim_ext = 0;
1624 sbp->st_btim_ext = 0;
1625 #endif
1626 #ifdef KTRACE
1627 if (KTRPOINT(td, KTR_STRUCT))
1628 ktrstat_error(sbp, error);
1629 #endif
1630 return (error);
1631 }
1632
1633 #if defined(COMPAT_FREEBSD11)
1634 /*
1635 * Return status information about a file descriptor.
1636 */
1637 #ifndef _SYS_SYSPROTO_H_
1638 struct freebsd11_nfstat_args {
1639 int fd;
1640 struct nstat *sb;
1641 };
1642 #endif
1643 /* ARGSUSED */
1644 int
1645 freebsd11_nfstat(struct thread *td, struct freebsd11_nfstat_args *uap)
1646 {
1647 struct nstat nub;
1648 struct stat ub;
1649 int error;
1650
1651 error = kern_fstat(td, uap->fd, &ub);
1652 if (error != 0)
1653 return (error);
1654 error = freebsd11_cvtnstat(&ub, &nub);
1655 if (error != 0)
1656 error = copyout(&nub, uap->sb, sizeof(nub));
1657 return (error);
1658 }
1659 #endif /* COMPAT_FREEBSD11 */
1660
1661 /*
1662 * Return pathconf information about a file descriptor.
1663 */
1664 #ifndef _SYS_SYSPROTO_H_
1665 struct fpathconf_args {
1666 int fd;
1667 int name;
1668 };
1669 #endif
1670 /* ARGSUSED */
1671 int
1672 sys_fpathconf(struct thread *td, struct fpathconf_args *uap)
1673 {
1674 long value;
1675 int error;
1676
1677 error = kern_fpathconf(td, uap->fd, uap->name, &value);
1678 if (error == 0)
1679 td->td_retval[0] = value;
1680 return (error);
1681 }
1682
1683 int
1684 kern_fpathconf(struct thread *td, int fd, int name, long *valuep)
1685 {
1686 struct file *fp;
1687 struct vnode *vp;
1688 int error;
1689
1690 error = fget(td, fd, &cap_fpathconf_rights, &fp);
1691 if (error != 0)
1692 return (error);
1693
1694 if (name == _PC_ASYNC_IO) {
1695 *valuep = _POSIX_ASYNCHRONOUS_IO;
1696 goto out;
1697 }
1698 vp = fp->f_vnode;
1699 if (vp != NULL) {
1700 vn_lock(vp, LK_SHARED | LK_RETRY);
1701 error = VOP_PATHCONF(vp, name, valuep);
1702 VOP_UNLOCK(vp);
1703 } else if (fp->f_type == DTYPE_PIPE || fp->f_type == DTYPE_SOCKET) {
1704 if (name != _PC_PIPE_BUF) {
1705 error = EINVAL;
1706 } else {
1707 *valuep = PIPE_BUF;
1708 error = 0;
1709 }
1710 } else {
1711 error = EOPNOTSUPP;
1712 }
1713 out:
1714 fdrop(fp, td);
1715 return (error);
1716 }
1717
1718 /*
1719 * Copy filecaps structure allocating memory for ioctls array if needed.
1720 *
1721 * The last parameter indicates whether the fdtable is locked. If it is not and
1722 * ioctls are encountered, copying fails and the caller must lock the table.
1723 *
1724 * Note that if the table was not locked, the caller has to check the relevant
1725 * sequence counter to determine whether the operation was successful.
1726 */
1727 bool
1728 filecaps_copy(const struct filecaps *src, struct filecaps *dst, bool locked)
1729 {
1730 size_t size;
1731
1732 if (src->fc_ioctls != NULL && !locked)
1733 return (false);
1734 memcpy(dst, src, sizeof(*src));
1735 if (src->fc_ioctls == NULL)
1736 return (true);
1737
1738 KASSERT(src->fc_nioctls > 0,
1739 ("fc_ioctls != NULL, but fc_nioctls=%hd", src->fc_nioctls));
1740
1741 size = sizeof(src->fc_ioctls[0]) * src->fc_nioctls;
1742 dst->fc_ioctls = malloc(size, M_FILECAPS, M_WAITOK);
1743 memcpy(dst->fc_ioctls, src->fc_ioctls, size);
1744 return (true);
1745 }
1746
1747 static u_long *
1748 filecaps_copy_prep(const struct filecaps *src)
1749 {
1750 u_long *ioctls;
1751 size_t size;
1752
1753 if (__predict_true(src->fc_ioctls == NULL))
1754 return (NULL);
1755
1756 KASSERT(src->fc_nioctls > 0,
1757 ("fc_ioctls != NULL, but fc_nioctls=%hd", src->fc_nioctls));
1758
1759 size = sizeof(src->fc_ioctls[0]) * src->fc_nioctls;
1760 ioctls = malloc(size, M_FILECAPS, M_WAITOK);
1761 return (ioctls);
1762 }
1763
1764 static void
1765 filecaps_copy_finish(const struct filecaps *src, struct filecaps *dst,
1766 u_long *ioctls)
1767 {
1768 size_t size;
1769
1770 *dst = *src;
1771 if (__predict_true(src->fc_ioctls == NULL)) {
1772 MPASS(ioctls == NULL);
1773 return;
1774 }
1775
1776 size = sizeof(src->fc_ioctls[0]) * src->fc_nioctls;
1777 dst->fc_ioctls = ioctls;
1778 bcopy(src->fc_ioctls, dst->fc_ioctls, size);
1779 }
1780
1781 /*
1782 * Move filecaps structure to the new place and clear the old place.
1783 */
1784 void
1785 filecaps_move(struct filecaps *src, struct filecaps *dst)
1786 {
1787
1788 *dst = *src;
1789 bzero(src, sizeof(*src));
1790 }
1791
1792 /*
1793 * Fill the given filecaps structure with full rights.
1794 */
1795 static void
1796 filecaps_fill(struct filecaps *fcaps)
1797 {
1798
1799 CAP_ALL(&fcaps->fc_rights);
1800 fcaps->fc_ioctls = NULL;
1801 fcaps->fc_nioctls = -1;
1802 fcaps->fc_fcntls = CAP_FCNTL_ALL;
1803 }
1804
1805 /*
1806 * Free memory allocated within filecaps structure.
1807 */
1808 static void
1809 filecaps_free_ioctl(struct filecaps *fcaps)
1810 {
1811
1812 free(fcaps->fc_ioctls, M_FILECAPS);
1813 fcaps->fc_ioctls = NULL;
1814 }
1815
1816 void
1817 filecaps_free(struct filecaps *fcaps)
1818 {
1819
1820 filecaps_free_ioctl(fcaps);
1821 bzero(fcaps, sizeof(*fcaps));
1822 }
1823
1824 static u_long *
1825 filecaps_free_prep(struct filecaps *fcaps)
1826 {
1827 u_long *ioctls;
1828
1829 ioctls = fcaps->fc_ioctls;
1830 bzero(fcaps, sizeof(*fcaps));
1831 return (ioctls);
1832 }
1833
1834 static void
1835 filecaps_free_finish(u_long *ioctls)
1836 {
1837
1838 free(ioctls, M_FILECAPS);
1839 }
1840
1841 /*
1842 * Validate the given filecaps structure.
1843 */
1844 static void
1845 filecaps_validate(const struct filecaps *fcaps, const char *func)
1846 {
1847
1848 KASSERT(cap_rights_is_valid(&fcaps->fc_rights),
1849 ("%s: invalid rights", func));
1850 KASSERT((fcaps->fc_fcntls & ~CAP_FCNTL_ALL) == 0,
1851 ("%s: invalid fcntls", func));
1852 KASSERT(fcaps->fc_fcntls == 0 ||
1853 cap_rights_is_set(&fcaps->fc_rights, CAP_FCNTL),
1854 ("%s: fcntls without CAP_FCNTL", func));
1855 /*
1856 * open calls without WANTIOCTLCAPS free caps but leave the counter
1857 */
1858 #if 0
1859 KASSERT(fcaps->fc_ioctls != NULL ? fcaps->fc_nioctls > 0 :
1860 (fcaps->fc_nioctls == -1 || fcaps->fc_nioctls == 0),
1861 ("%s: invalid ioctls", func));
1862 #endif
1863 KASSERT(fcaps->fc_nioctls == 0 ||
1864 cap_rights_is_set(&fcaps->fc_rights, CAP_IOCTL),
1865 ("%s: ioctls without CAP_IOCTL", func));
1866 }
1867
1868 static void
1869 fdgrowtable_exp(struct filedesc *fdp, int nfd)
1870 {
1871 int nfd1;
1872
1873 FILEDESC_XLOCK_ASSERT(fdp);
1874
1875 nfd1 = fdp->fd_nfiles * 2;
1876 if (nfd1 < nfd)
1877 nfd1 = nfd;
1878 fdgrowtable(fdp, nfd1);
1879 }
1880
1881 /*
1882 * Grow the file table to accommodate (at least) nfd descriptors.
1883 */
1884 static void
1885 fdgrowtable(struct filedesc *fdp, int nfd)
1886 {
1887 struct filedesc0 *fdp0;
1888 struct freetable *ft;
1889 struct fdescenttbl *ntable;
1890 struct fdescenttbl *otable;
1891 int nnfiles, onfiles;
1892 NDSLOTTYPE *nmap, *omap;
1893
1894 KASSERT(fdp->fd_nfiles > 0, ("zero-length file table"));
1895
1896 /* save old values */
1897 onfiles = fdp->fd_nfiles;
1898 otable = fdp->fd_files;
1899 omap = fdp->fd_map;
1900
1901 /* compute the size of the new table */
1902 nnfiles = NDSLOTS(nfd) * NDENTRIES; /* round up */
1903 if (nnfiles <= onfiles)
1904 /* the table is already large enough */
1905 return;
1906
1907 /*
1908 * Allocate a new table. We need enough space for the number of
1909 * entries, file entries themselves and the struct freetable we will use
1910 * when we decommission the table and place it on the freelist.
1911 * We place the struct freetable in the middle so we don't have
1912 * to worry about padding.
1913 */
1914 ntable = malloc(offsetof(struct fdescenttbl, fdt_ofiles) +
1915 nnfiles * sizeof(ntable->fdt_ofiles[0]) +
1916 sizeof(struct freetable),
1917 M_FILEDESC, M_ZERO | M_WAITOK);
1918 /* copy the old data */
1919 ntable->fdt_nfiles = nnfiles;
1920 memcpy(ntable->fdt_ofiles, otable->fdt_ofiles,
1921 onfiles * sizeof(ntable->fdt_ofiles[0]));
1922
1923 /*
1924 * Allocate a new map only if the old is not large enough. It will
1925 * grow at a slower rate than the table as it can map more
1926 * entries than the table can hold.
1927 */
1928 if (NDSLOTS(nnfiles) > NDSLOTS(onfiles)) {
1929 nmap = malloc(NDSLOTS(nnfiles) * NDSLOTSIZE, M_FILEDESC,
1930 M_ZERO | M_WAITOK);
1931 /* copy over the old data and update the pointer */
1932 memcpy(nmap, omap, NDSLOTS(onfiles) * sizeof(*omap));
1933 fdp->fd_map = nmap;
1934 }
1935
1936 /*
1937 * Make sure that ntable is correctly initialized before we replace
1938 * fd_files poiner. Otherwise fget_unlocked() may see inconsistent
1939 * data.
1940 */
1941 atomic_store_rel_ptr((volatile void *)&fdp->fd_files, (uintptr_t)ntable);
1942
1943 /*
1944 * Free the old file table when not shared by other threads or processes.
1945 * The old file table is considered to be shared when either are true:
1946 * - The process has more than one thread.
1947 * - The file descriptor table has been shared via fdshare().
1948 *
1949 * When shared, the old file table will be placed on a freelist
1950 * which will be processed when the struct filedesc is released.
1951 *
1952 * Note that if onfiles == NDFILE, we're dealing with the original
1953 * static allocation contained within (struct filedesc0 *)fdp,
1954 * which must not be freed.
1955 */
1956 if (onfiles > NDFILE) {
1957 /*
1958 * Note we may be called here from fdinit while allocating a
1959 * table for a new process in which case ->p_fd points
1960 * elsewhere.
1961 */
1962 if (curproc->p_fd != fdp || FILEDESC_IS_ONLY_USER(fdp)) {
1963 free(otable, M_FILEDESC);
1964 } else {
1965 ft = (struct freetable *)&otable->fdt_ofiles[onfiles];
1966 fdp0 = (struct filedesc0 *)fdp;
1967 ft->ft_table = otable;
1968 SLIST_INSERT_HEAD(&fdp0->fd_free, ft, ft_next);
1969 }
1970 }
1971 /*
1972 * The map does not have the same possibility of threads still
1973 * holding references to it. So always free it as long as it
1974 * does not reference the original static allocation.
1975 */
1976 if (NDSLOTS(onfiles) > NDSLOTS(NDFILE))
1977 free(omap, M_FILEDESC);
1978 }
1979
1980 /*
1981 * Allocate a file descriptor for the process.
1982 */
1983 int
1984 fdalloc(struct thread *td, int minfd, int *result)
1985 {
1986 struct proc *p = td->td_proc;
1987 struct filedesc *fdp = p->p_fd;
1988 int fd, maxfd, allocfd;
1989 #ifdef RACCT
1990 int error;
1991 #endif
1992
1993 FILEDESC_XLOCK_ASSERT(fdp);
1994
1995 if (fdp->fd_freefile > minfd)
1996 minfd = fdp->fd_freefile;
1997
1998 maxfd = getmaxfd(td);
1999
2000 /*
2001 * Search the bitmap for a free descriptor starting at minfd.
2002 * If none is found, grow the file table.
2003 */
2004 fd = fd_first_free(fdp, minfd, fdp->fd_nfiles);
2005 if (__predict_false(fd >= maxfd))
2006 return (EMFILE);
2007 if (__predict_false(fd >= fdp->fd_nfiles)) {
2008 allocfd = min(fd * 2, maxfd);
2009 #ifdef RACCT
2010 if (RACCT_ENABLED()) {
2011 error = racct_set_unlocked(p, RACCT_NOFILE, allocfd);
2012 if (error != 0)
2013 return (EMFILE);
2014 }
2015 #endif
2016 /*
2017 * fd is already equal to first free descriptor >= minfd, so
2018 * we only need to grow the table and we are done.
2019 */
2020 fdgrowtable_exp(fdp, allocfd);
2021 }
2022
2023 /*
2024 * Perform some sanity checks, then mark the file descriptor as
2025 * used and return it to the caller.
2026 */
2027 KASSERT(fd >= 0 && fd < min(maxfd, fdp->fd_nfiles),
2028 ("invalid descriptor %d", fd));
2029 KASSERT(!fdisused(fdp, fd),
2030 ("fd_first_free() returned non-free descriptor"));
2031 KASSERT(fdp->fd_ofiles[fd].fde_file == NULL,
2032 ("file descriptor isn't free"));
2033 fdused(fdp, fd);
2034 *result = fd;
2035 return (0);
2036 }
2037
2038 /*
2039 * Allocate n file descriptors for the process.
2040 */
2041 int
2042 fdallocn(struct thread *td, int minfd, int *fds, int n)
2043 {
2044 struct proc *p = td->td_proc;
2045 struct filedesc *fdp = p->p_fd;
2046 int i;
2047
2048 FILEDESC_XLOCK_ASSERT(fdp);
2049
2050 for (i = 0; i < n; i++)
2051 if (fdalloc(td, 0, &fds[i]) != 0)
2052 break;
2053
2054 if (i < n) {
2055 for (i--; i >= 0; i--)
2056 fdunused(fdp, fds[i]);
2057 return (EMFILE);
2058 }
2059
2060 return (0);
2061 }
2062
2063 /*
2064 * Create a new open file structure and allocate a file descriptor for the
2065 * process that refers to it. We add one reference to the file for the
2066 * descriptor table and one reference for resultfp. This is to prevent us
2067 * being preempted and the entry in the descriptor table closed after we
2068 * release the FILEDESC lock.
2069 */
2070 int
2071 falloc_caps(struct thread *td, struct file **resultfp, int *resultfd, int flags,
2072 struct filecaps *fcaps)
2073 {
2074 struct file *fp;
2075 int error, fd;
2076
2077 MPASS(resultfp != NULL);
2078 MPASS(resultfd != NULL);
2079
2080 error = _falloc_noinstall(td, &fp, 2);
2081 if (__predict_false(error != 0)) {
2082 return (error);
2083 }
2084
2085 error = finstall_refed(td, fp, &fd, flags, fcaps);
2086 if (__predict_false(error != 0)) {
2087 falloc_abort(td, fp);
2088 return (error);
2089 }
2090
2091 *resultfp = fp;
2092 *resultfd = fd;
2093
2094 return (0);
2095 }
2096
2097 /*
2098 * Create a new open file structure without allocating a file descriptor.
2099 */
2100 int
2101 _falloc_noinstall(struct thread *td, struct file **resultfp, u_int n)
2102 {
2103 struct file *fp;
2104 int maxuserfiles = maxfiles - (maxfiles / 20);
2105 int openfiles_new;
2106 static struct timeval lastfail;
2107 static int curfail;
2108
2109 KASSERT(resultfp != NULL, ("%s: resultfp == NULL", __func__));
2110 MPASS(n > 0);
2111
2112 openfiles_new = atomic_fetchadd_int(&openfiles, 1) + 1;
2113 if ((openfiles_new >= maxuserfiles &&
2114 priv_check(td, PRIV_MAXFILES) != 0) ||
2115 openfiles_new >= maxfiles) {
2116 atomic_subtract_int(&openfiles, 1);
2117 if (ppsratecheck(&lastfail, &curfail, 1)) {
2118 printf("kern.maxfiles limit exceeded by uid %i, (%s) "
2119 "please see tuning(7).\n", td->td_ucred->cr_ruid, td->td_proc->p_comm);
2120 }
2121 return (ENFILE);
2122 }
2123 fp = uma_zalloc(file_zone, M_WAITOK);
2124 bzero(fp, sizeof(*fp));
2125 refcount_init(&fp->f_count, n);
2126 fp->f_cred = crhold(td->td_ucred);
2127 fp->f_ops = &badfileops;
2128 *resultfp = fp;
2129 return (0);
2130 }
2131
2132 void
2133 falloc_abort(struct thread *td, struct file *fp)
2134 {
2135
2136 /*
2137 * For assertion purposes.
2138 */
2139 refcount_init(&fp->f_count, 0);
2140 _fdrop(fp, td);
2141 }
2142
2143 /*
2144 * Install a file in a file descriptor table.
2145 */
2146 void
2147 _finstall(struct filedesc *fdp, struct file *fp, int fd, int flags,
2148 struct filecaps *fcaps)
2149 {
2150 struct filedescent *fde;
2151
2152 MPASS(fp != NULL);
2153 if (fcaps != NULL)
2154 filecaps_validate(fcaps, __func__);
2155 FILEDESC_XLOCK_ASSERT(fdp);
2156
2157 fde = &fdp->fd_ofiles[fd];
2158 #ifdef CAPABILITIES
2159 seqc_write_begin(&fde->fde_seqc);
2160 #endif
2161 fde->fde_file = fp;
2162 fde->fde_flags = (flags & O_CLOEXEC) != 0 ? UF_EXCLOSE : 0;
2163 if (fcaps != NULL)
2164 filecaps_move(fcaps, &fde->fde_caps);
2165 else
2166 filecaps_fill(&fde->fde_caps);
2167 #ifdef CAPABILITIES
2168 seqc_write_end(&fde->fde_seqc);
2169 #endif
2170 }
2171
2172 int
2173 finstall_refed(struct thread *td, struct file *fp, int *fd, int flags,
2174 struct filecaps *fcaps)
2175 {
2176 struct filedesc *fdp = td->td_proc->p_fd;
2177 int error;
2178
2179 MPASS(fd != NULL);
2180
2181 FILEDESC_XLOCK(fdp);
2182 error = fdalloc(td, 0, fd);
2183 if (__predict_true(error == 0)) {
2184 _finstall(fdp, fp, *fd, flags, fcaps);
2185 }
2186 FILEDESC_XUNLOCK(fdp);
2187 return (error);
2188 }
2189
2190 int
2191 finstall(struct thread *td, struct file *fp, int *fd, int flags,
2192 struct filecaps *fcaps)
2193 {
2194 int error;
2195
2196 MPASS(fd != NULL);
2197
2198 if (!fhold(fp))
2199 return (EBADF);
2200 error = finstall_refed(td, fp, fd, flags, fcaps);
2201 if (__predict_false(error != 0)) {
2202 fdrop(fp, td);
2203 }
2204 return (error);
2205 }
2206
2207 /*
2208 * Build a new filedesc structure from another.
2209 *
2210 * If fdp is not NULL, return with it shared locked.
2211 */
2212 struct filedesc *
2213 fdinit(void)
2214 {
2215 struct filedesc0 *newfdp0;
2216 struct filedesc *newfdp;
2217
2218 newfdp0 = uma_zalloc(filedesc0_zone, M_WAITOK | M_ZERO);
2219 newfdp = &newfdp0->fd_fd;
2220
2221 /* Create the file descriptor table. */
2222 FILEDESC_LOCK_INIT(newfdp);
2223 refcount_init(&newfdp->fd_refcnt, 1);
2224 refcount_init(&newfdp->fd_holdcnt, 1);
2225 newfdp->fd_map = newfdp0->fd_dmap;
2226 newfdp->fd_files = (struct fdescenttbl *)&newfdp0->fd_dfiles;
2227 newfdp->fd_files->fdt_nfiles = NDFILE;
2228
2229 return (newfdp);
2230 }
2231
2232 /*
2233 * Build a pwddesc structure from another.
2234 * Copy the current, root, and jail root vnode references.
2235 *
2236 * If pdp is not NULL, return with it shared locked.
2237 */
2238 struct pwddesc *
2239 pdinit(struct pwddesc *pdp, bool keeplock)
2240 {
2241 struct pwddesc *newpdp;
2242 struct pwd *newpwd;
2243
2244 newpdp = malloc(sizeof(*newpdp), M_PWDDESC, M_WAITOK | M_ZERO);
2245
2246 PWDDESC_LOCK_INIT(newpdp);
2247 refcount_init(&newpdp->pd_refcount, 1);
2248 newpdp->pd_cmask = CMASK;
2249
2250 if (pdp == NULL) {
2251 newpwd = pwd_alloc();
2252 smr_serialized_store(&newpdp->pd_pwd, newpwd, true);
2253 return (newpdp);
2254 }
2255
2256 PWDDESC_XLOCK(pdp);
2257 newpwd = pwd_hold_pwddesc(pdp);
2258 smr_serialized_store(&newpdp->pd_pwd, newpwd, true);
2259 if (!keeplock)
2260 PWDDESC_XUNLOCK(pdp);
2261 return (newpdp);
2262 }
2263
2264 /*
2265 * Hold either filedesc or pwddesc of the passed process.
2266 *
2267 * The process lock is used to synchronize against the target exiting and
2268 * freeing the data.
2269 *
2270 * Clearing can be ilustrated in 3 steps:
2271 * 1. set the pointer to NULL. Either routine can race against it, hence
2272 * atomic_load_ptr.
2273 * 2. observe the process lock as not taken. Until then fdhold/pdhold can
2274 * race to either still see the pointer or find NULL. It is still safe to
2275 * grab a reference as clearing is stalled.
2276 * 3. after the lock is observed as not taken, any fdhold/pdhold calls are
2277 * guaranteed to see NULL, making it safe to finish clearing
2278 */
2279 static struct filedesc *
2280 fdhold(struct proc *p)
2281 {
2282 struct filedesc *fdp;
2283
2284 PROC_LOCK_ASSERT(p, MA_OWNED);
2285 fdp = atomic_load_ptr(&p->p_fd);
2286 if (fdp != NULL)
2287 refcount_acquire(&fdp->fd_holdcnt);
2288 return (fdp);
2289 }
2290
2291 static struct pwddesc *
2292 pdhold(struct proc *p)
2293 {
2294 struct pwddesc *pdp;
2295
2296 PROC_LOCK_ASSERT(p, MA_OWNED);
2297 pdp = atomic_load_ptr(&p->p_pd);
2298 if (pdp != NULL)
2299 refcount_acquire(&pdp->pd_refcount);
2300 return (pdp);
2301 }
2302
2303 static void
2304 fddrop(struct filedesc *fdp)
2305 {
2306
2307 if (refcount_load(&fdp->fd_holdcnt) > 1) {
2308 if (refcount_release(&fdp->fd_holdcnt) == 0)
2309 return;
2310 }
2311
2312 FILEDESC_LOCK_DESTROY(fdp);
2313 uma_zfree(filedesc0_zone, fdp);
2314 }
2315
2316 static void
2317 pddrop(struct pwddesc *pdp)
2318 {
2319 struct pwd *pwd;
2320
2321 if (refcount_release_if_not_last(&pdp->pd_refcount))
2322 return;
2323
2324 PWDDESC_XLOCK(pdp);
2325 if (refcount_release(&pdp->pd_refcount) == 0) {
2326 PWDDESC_XUNLOCK(pdp);
2327 return;
2328 }
2329 pwd = PWDDESC_XLOCKED_LOAD_PWD(pdp);
2330 pwd_set(pdp, NULL);
2331 PWDDESC_XUNLOCK(pdp);
2332 pwd_drop(pwd);
2333
2334 PWDDESC_LOCK_DESTROY(pdp);
2335 free(pdp, M_PWDDESC);
2336 }
2337
2338 /*
2339 * Share a filedesc structure.
2340 */
2341 struct filedesc *
2342 fdshare(struct filedesc *fdp)
2343 {
2344
2345 refcount_acquire(&fdp->fd_refcnt);
2346 return (fdp);
2347 }
2348
2349 /*
2350 * Share a pwddesc structure.
2351 */
2352 struct pwddesc *
2353 pdshare(struct pwddesc *pdp)
2354 {
2355 refcount_acquire(&pdp->pd_refcount);
2356 return (pdp);
2357 }
2358
2359 /*
2360 * Unshare a filedesc structure, if necessary by making a copy
2361 */
2362 void
2363 fdunshare(struct thread *td)
2364 {
2365 struct filedesc *tmp;
2366 struct proc *p = td->td_proc;
2367
2368 if (refcount_load(&p->p_fd->fd_refcnt) == 1)
2369 return;
2370
2371 tmp = fdcopy(p->p_fd);
2372 fdescfree(td);
2373 p->p_fd = tmp;
2374 }
2375
2376 /*
2377 * Unshare a pwddesc structure.
2378 */
2379 void
2380 pdunshare(struct thread *td)
2381 {
2382 struct pwddesc *pdp;
2383 struct proc *p;
2384
2385 p = td->td_proc;
2386 /* Not shared. */
2387 if (refcount_load(&p->p_pd->pd_refcount) == 1)
2388 return;
2389
2390 pdp = pdcopy(p->p_pd);
2391 pdescfree(td);
2392 p->p_pd = pdp;
2393 }
2394
2395 /*
2396 * Copy a filedesc structure. A NULL pointer in returns a NULL reference,
2397 * this is to ease callers, not catch errors.
2398 */
2399 struct filedesc *
2400 fdcopy(struct filedesc *fdp)
2401 {
2402 struct filedesc *newfdp;
2403 struct filedescent *nfde, *ofde;
2404 int i, lastfile;
2405
2406 MPASS(fdp != NULL);
2407
2408 newfdp = fdinit();
2409 FILEDESC_SLOCK(fdp);
2410 for (;;) {
2411 lastfile = fdlastfile(fdp);
2412 if (lastfile < newfdp->fd_nfiles)
2413 break;
2414 FILEDESC_SUNLOCK(fdp);
2415 fdgrowtable(newfdp, lastfile + 1);
2416 FILEDESC_SLOCK(fdp);
2417 }
2418 /* copy all passable descriptors (i.e. not kqueue) */
2419 newfdp->fd_freefile = fdp->fd_freefile;
2420 FILEDESC_FOREACH_FDE(fdp, i, ofde) {
2421 if ((ofde->fde_file->f_ops->fo_flags & DFLAG_PASSABLE) == 0 ||
2422 !fhold(ofde->fde_file)) {
2423 if (newfdp->fd_freefile == fdp->fd_freefile)
2424 newfdp->fd_freefile = i;
2425 continue;
2426 }
2427 nfde = &newfdp->fd_ofiles[i];
2428 *nfde = *ofde;
2429 filecaps_copy(&ofde->fde_caps, &nfde->fde_caps, true);
2430 fdused_init(newfdp, i);
2431 }
2432 MPASS(newfdp->fd_freefile != -1);
2433 FILEDESC_SUNLOCK(fdp);
2434 return (newfdp);
2435 }
2436
2437 /*
2438 * Copy a pwddesc structure.
2439 */
2440 struct pwddesc *
2441 pdcopy(struct pwddesc *pdp)
2442 {
2443 struct pwddesc *newpdp;
2444
2445 MPASS(pdp != NULL);
2446
2447 newpdp = pdinit(pdp, true);
2448 newpdp->pd_cmask = pdp->pd_cmask;
2449 PWDDESC_XUNLOCK(pdp);
2450 return (newpdp);
2451 }
2452
2453 /*
2454 * Clear POSIX style locks. This is only used when fdp looses a reference (i.e.
2455 * one of processes using it exits) and the table used to be shared.
2456 */
2457 static void
2458 fdclearlocks(struct thread *td)
2459 {
2460 struct filedesc *fdp;
2461 struct filedesc_to_leader *fdtol;
2462 struct flock lf;
2463 struct file *fp;
2464 struct proc *p;
2465 struct vnode *vp;
2466 int i;
2467
2468 p = td->td_proc;
2469 fdp = p->p_fd;
2470 fdtol = p->p_fdtol;
2471 MPASS(fdtol != NULL);
2472
2473 FILEDESC_XLOCK(fdp);
2474 KASSERT(fdtol->fdl_refcount > 0,
2475 ("filedesc_to_refcount botch: fdl_refcount=%d",
2476 fdtol->fdl_refcount));
2477 if (fdtol->fdl_refcount == 1 &&
2478 (p->p_leader->p_flag & P_ADVLOCK) != 0) {
2479 FILEDESC_FOREACH_FP(fdp, i, fp) {
2480 if (fp->f_type != DTYPE_VNODE ||
2481 !fhold(fp))
2482 continue;
2483 FILEDESC_XUNLOCK(fdp);
2484 lf.l_whence = SEEK_SET;
2485 lf.l_start = 0;
2486 lf.l_len = 0;
2487 lf.l_type = F_UNLCK;
2488 vp = fp->f_vnode;
2489 (void) VOP_ADVLOCK(vp,
2490 (caddr_t)p->p_leader, F_UNLCK,
2491 &lf, F_POSIX);
2492 FILEDESC_XLOCK(fdp);
2493 fdrop(fp, td);
2494 }
2495 }
2496 retry:
2497 if (fdtol->fdl_refcount == 1) {
2498 if (fdp->fd_holdleaderscount > 0 &&
2499 (p->p_leader->p_flag & P_ADVLOCK) != 0) {
2500 /*
2501 * close() or kern_dup() has cleared a reference
2502 * in a shared file descriptor table.
2503 */
2504 fdp->fd_holdleaderswakeup = 1;
2505 sx_sleep(&fdp->fd_holdleaderscount,
2506 FILEDESC_LOCK(fdp), PLOCK, "fdlhold", 0);
2507 goto retry;
2508 }
2509 if (fdtol->fdl_holdcount > 0) {
2510 /*
2511 * Ensure that fdtol->fdl_leader remains
2512 * valid in closef().
2513 */
2514 fdtol->fdl_wakeup = 1;
2515 sx_sleep(fdtol, FILEDESC_LOCK(fdp), PLOCK,
2516 "fdlhold", 0);
2517 goto retry;
2518 }
2519 }
2520 fdtol->fdl_refcount--;
2521 if (fdtol->fdl_refcount == 0 &&
2522 fdtol->fdl_holdcount == 0) {
2523 fdtol->fdl_next->fdl_prev = fdtol->fdl_prev;
2524 fdtol->fdl_prev->fdl_next = fdtol->fdl_next;
2525 } else
2526 fdtol = NULL;
2527 p->p_fdtol = NULL;
2528 FILEDESC_XUNLOCK(fdp);
2529 if (fdtol != NULL)
2530 free(fdtol, M_FILEDESC_TO_LEADER);
2531 }
2532
2533 /*
2534 * Release a filedesc structure.
2535 */
2536 static void
2537 fdescfree_fds(struct thread *td, struct filedesc *fdp)
2538 {
2539 struct filedesc0 *fdp0;
2540 struct freetable *ft, *tft;
2541 struct filedescent *fde;
2542 struct file *fp;
2543 int i;
2544
2545 KASSERT(refcount_load(&fdp->fd_refcnt) == 0,
2546 ("%s: fd table %p carries references", __func__, fdp));
2547
2548 /*
2549 * Serialize with threads iterating over the table, if any.
2550 */
2551 if (refcount_load(&fdp->fd_holdcnt) > 1) {
2552 FILEDESC_XLOCK(fdp);
2553 FILEDESC_XUNLOCK(fdp);
2554 }
2555
2556 FILEDESC_FOREACH_FDE(fdp, i, fde) {
2557 fp = fde->fde_file;
2558 fdefree_last(fde);
2559 (void) closef(fp, td);
2560 }
2561
2562 if (NDSLOTS(fdp->fd_nfiles) > NDSLOTS(NDFILE))
2563 free(fdp->fd_map, M_FILEDESC);
2564 if (fdp->fd_nfiles > NDFILE)
2565 free(fdp->fd_files, M_FILEDESC);
2566
2567 fdp0 = (struct filedesc0 *)fdp;
2568 SLIST_FOREACH_SAFE(ft, &fdp0->fd_free, ft_next, tft)
2569 free(ft->ft_table, M_FILEDESC);
2570
2571 fddrop(fdp);
2572 }
2573
2574 void
2575 fdescfree(struct thread *td)
2576 {
2577 struct proc *p;
2578 struct filedesc *fdp;
2579
2580 p = td->td_proc;
2581 fdp = p->p_fd;
2582 MPASS(fdp != NULL);
2583
2584 #ifdef RACCT
2585 if (RACCT_ENABLED())
2586 racct_set_unlocked(p, RACCT_NOFILE, 0);
2587 #endif
2588
2589 if (p->p_fdtol != NULL)
2590 fdclearlocks(td);
2591
2592 /*
2593 * Check fdhold for an explanation.
2594 */
2595 atomic_store_ptr(&p->p_fd, NULL);
2596 atomic_thread_fence_seq_cst();
2597 PROC_WAIT_UNLOCKED(p);
2598
2599 if (refcount_release(&fdp->fd_refcnt) == 0)
2600 return;
2601
2602 fdescfree_fds(td, fdp);
2603 }
2604
2605 void
2606 pdescfree(struct thread *td)
2607 {
2608 struct proc *p;
2609 struct pwddesc *pdp;
2610
2611 p = td->td_proc;
2612 pdp = p->p_pd;
2613 MPASS(pdp != NULL);
2614
2615 /*
2616 * Check pdhold for an explanation.
2617 */
2618 atomic_store_ptr(&p->p_pd, NULL);
2619 atomic_thread_fence_seq_cst();
2620 PROC_WAIT_UNLOCKED(p);
2621
2622 pddrop(pdp);
2623 }
2624
2625 /*
2626 * For setugid programs, we don't want to people to use that setugidness
2627 * to generate error messages which write to a file which otherwise would
2628 * otherwise be off-limits to the process. We check for filesystems where
2629 * the vnode can change out from under us after execve (like [lin]procfs).
2630 *
2631 * Since fdsetugidsafety calls this only for fd 0, 1 and 2, this check is
2632 * sufficient. We also don't check for setugidness since we know we are.
2633 */
2634 static bool
2635 is_unsafe(struct file *fp)
2636 {
2637 struct vnode *vp;
2638
2639 if (fp->f_type != DTYPE_VNODE)
2640 return (false);
2641
2642 vp = fp->f_vnode;
2643 return ((vp->v_vflag & VV_PROCDEP) != 0);
2644 }
2645
2646 /*
2647 * Make this setguid thing safe, if at all possible.
2648 */
2649 void
2650 fdsetugidsafety(struct thread *td)
2651 {
2652 struct filedesc *fdp;
2653 struct file *fp;
2654 int i;
2655
2656 fdp = td->td_proc->p_fd;
2657 KASSERT(refcount_load(&fdp->fd_refcnt) == 1,
2658 ("the fdtable should not be shared"));
2659 MPASS(fdp->fd_nfiles >= 3);
2660 for (i = 0; i <= 2; i++) {
2661 fp = fdp->fd_ofiles[i].fde_file;
2662 if (fp != NULL && is_unsafe(fp)) {
2663 FILEDESC_XLOCK(fdp);
2664 knote_fdclose(td, i);
2665 /*
2666 * NULL-out descriptor prior to close to avoid
2667 * a race while close blocks.
2668 */
2669 fdfree(fdp, i);
2670 FILEDESC_XUNLOCK(fdp);
2671 (void) closef(fp, td);
2672 }
2673 }
2674 }
2675
2676 /*
2677 * If a specific file object occupies a specific file descriptor, close the
2678 * file descriptor entry and drop a reference on the file object. This is a
2679 * convenience function to handle a subsequent error in a function that calls
2680 * falloc() that handles the race that another thread might have closed the
2681 * file descriptor out from under the thread creating the file object.
2682 */
2683 void
2684 fdclose(struct thread *td, struct file *fp, int idx)
2685 {
2686 struct filedesc *fdp = td->td_proc->p_fd;
2687
2688 FILEDESC_XLOCK(fdp);
2689 if (fdp->fd_ofiles[idx].fde_file == fp) {
2690 fdfree(fdp, idx);
2691 FILEDESC_XUNLOCK(fdp);
2692 fdrop(fp, td);
2693 } else
2694 FILEDESC_XUNLOCK(fdp);
2695 }
2696
2697 /*
2698 * Close any files on exec?
2699 */
2700 void
2701 fdcloseexec(struct thread *td)
2702 {
2703 struct filedesc *fdp;
2704 struct filedescent *fde;
2705 struct file *fp;
2706 int i;
2707
2708 fdp = td->td_proc->p_fd;
2709 KASSERT(refcount_load(&fdp->fd_refcnt) == 1,
2710 ("the fdtable should not be shared"));
2711 FILEDESC_FOREACH_FDE(fdp, i, fde) {
2712 fp = fde->fde_file;
2713 if (fp->f_type == DTYPE_MQUEUE ||
2714 (fde->fde_flags & UF_EXCLOSE)) {
2715 FILEDESC_XLOCK(fdp);
2716 fdfree(fdp, i);
2717 (void) closefp(fdp, i, fp, td, false, false);
2718 FILEDESC_UNLOCK_ASSERT(fdp);
2719 }
2720 }
2721 }
2722
2723 /*
2724 * It is unsafe for set[ug]id processes to be started with file
2725 * descriptors 0..2 closed, as these descriptors are given implicit
2726 * significance in the Standard C library. fdcheckstd() will create a
2727 * descriptor referencing /dev/null for each of stdin, stdout, and
2728 * stderr that is not already open.
2729 */
2730 int
2731 fdcheckstd(struct thread *td)
2732 {
2733 struct filedesc *fdp;
2734 register_t save;
2735 int i, error, devnull;
2736
2737 fdp = td->td_proc->p_fd;
2738 KASSERT(refcount_load(&fdp->fd_refcnt) == 1,
2739 ("the fdtable should not be shared"));
2740 MPASS(fdp->fd_nfiles >= 3);
2741 devnull = -1;
2742 for (i = 0; i <= 2; i++) {
2743 if (fdp->fd_ofiles[i].fde_file != NULL)
2744 continue;
2745
2746 save = td->td_retval[0];
2747 if (devnull != -1) {
2748 error = kern_dup(td, FDDUP_FIXED, 0, devnull, i);
2749 } else {
2750 error = kern_openat(td, AT_FDCWD, "/dev/null",
2751 UIO_SYSSPACE, O_RDWR, 0);
2752 if (error == 0) {
2753 devnull = td->td_retval[0];
2754 KASSERT(devnull == i, ("we didn't get our fd"));
2755 }
2756 }
2757 td->td_retval[0] = save;
2758 if (error != 0)
2759 return (error);
2760 }
2761 return (0);
2762 }
2763
2764 /*
2765 * Internal form of close. Decrement reference count on file structure.
2766 * Note: td may be NULL when closing a file that was being passed in a
2767 * message.
2768 */
2769 int
2770 closef(struct file *fp, struct thread *td)
2771 {
2772 struct vnode *vp;
2773 struct flock lf;
2774 struct filedesc_to_leader *fdtol;
2775 struct filedesc *fdp;
2776
2777 MPASS(td != NULL);
2778
2779 /*
2780 * POSIX record locking dictates that any close releases ALL
2781 * locks owned by this process. This is handled by setting
2782 * a flag in the unlock to free ONLY locks obeying POSIX
2783 * semantics, and not to free BSD-style file locks.
2784 * If the descriptor was in a message, POSIX-style locks
2785 * aren't passed with the descriptor, and the thread pointer
2786 * will be NULL. Callers should be careful only to pass a
2787 * NULL thread pointer when there really is no owning
2788 * context that might have locks, or the locks will be
2789 * leaked.
2790 */
2791 if (fp->f_type == DTYPE_VNODE) {
2792 vp = fp->f_vnode;
2793 if ((td->td_proc->p_leader->p_flag & P_ADVLOCK) != 0) {
2794 lf.l_whence = SEEK_SET;
2795 lf.l_start = 0;
2796 lf.l_len = 0;
2797 lf.l_type = F_UNLCK;
2798 (void) VOP_ADVLOCK(vp, (caddr_t)td->td_proc->p_leader,
2799 F_UNLCK, &lf, F_POSIX);
2800 }
2801 fdtol = td->td_proc->p_fdtol;
2802 if (fdtol != NULL) {
2803 /*
2804 * Handle special case where file descriptor table is
2805 * shared between multiple process leaders.
2806 */
2807 fdp = td->td_proc->p_fd;
2808 FILEDESC_XLOCK(fdp);
2809 for (fdtol = fdtol->fdl_next;
2810 fdtol != td->td_proc->p_fdtol;
2811 fdtol = fdtol->fdl_next) {
2812 if ((fdtol->fdl_leader->p_flag &
2813 P_ADVLOCK) == 0)
2814 continue;
2815 fdtol->fdl_holdcount++;
2816 FILEDESC_XUNLOCK(fdp);
2817 lf.l_whence = SEEK_SET;
2818 lf.l_start = 0;
2819 lf.l_len = 0;
2820 lf.l_type = F_UNLCK;
2821 vp = fp->f_vnode;
2822 (void) VOP_ADVLOCK(vp,
2823 (caddr_t)fdtol->fdl_leader, F_UNLCK, &lf,
2824 F_POSIX);
2825 FILEDESC_XLOCK(fdp);
2826 fdtol->fdl_holdcount--;
2827 if (fdtol->fdl_holdcount == 0 &&
2828 fdtol->fdl_wakeup != 0) {
2829 fdtol->fdl_wakeup = 0;
2830 wakeup(fdtol);
2831 }
2832 }
2833 FILEDESC_XUNLOCK(fdp);
2834 }
2835 }
2836 return (fdrop_close(fp, td));
2837 }
2838
2839 /*
2840 * Hack for file descriptor passing code.
2841 */
2842 void
2843 closef_nothread(struct file *fp)
2844 {
2845
2846 fdrop(fp, NULL);
2847 }
2848
2849 /*
2850 * Initialize the file pointer with the specified properties.
2851 *
2852 * The ops are set with release semantics to be certain that the flags, type,
2853 * and data are visible when ops is. This is to prevent ops methods from being
2854 * called with bad data.
2855 */
2856 void
2857 finit(struct file *fp, u_int flag, short type, void *data, struct fileops *ops)
2858 {
2859 fp->f_data = data;
2860 fp->f_flag = flag;
2861 fp->f_type = type;
2862 atomic_store_rel_ptr((volatile uintptr_t *)&fp->f_ops, (uintptr_t)ops);
2863 }
2864
2865 void
2866 finit_vnode(struct file *fp, u_int flag, void *data, struct fileops *ops)
2867 {
2868 fp->f_seqcount[UIO_READ] = 1;
2869 fp->f_seqcount[UIO_WRITE] = 1;
2870 finit(fp, (flag & FMASK) | (fp->f_flag & FHASLOCK), DTYPE_VNODE,
2871 data, ops);
2872 }
2873
2874 int
2875 fget_cap_noref(struct filedesc *fdp, int fd, cap_rights_t *needrightsp,
2876 struct file **fpp, struct filecaps *havecapsp)
2877 {
2878 struct filedescent *fde;
2879 int error;
2880
2881 FILEDESC_LOCK_ASSERT(fdp);
2882
2883 *fpp = NULL;
2884 fde = fdeget_noref(fdp, fd);
2885 if (fde == NULL) {
2886 error = EBADF;
2887 goto out;
2888 }
2889
2890 #ifdef CAPABILITIES
2891 error = cap_check(cap_rights_fde_inline(fde), needrightsp);
2892 if (error != 0)
2893 goto out;
2894 #endif
2895
2896 if (havecapsp != NULL)
2897 filecaps_copy(&fde->fde_caps, havecapsp, true);
2898
2899 *fpp = fde->fde_file;
2900
2901 error = 0;
2902 out:
2903 return (error);
2904 }
2905
2906 #ifdef CAPABILITIES
2907 int
2908 fget_cap(struct thread *td, int fd, cap_rights_t *needrightsp,
2909 struct file **fpp, struct filecaps *havecapsp)
2910 {
2911 struct filedesc *fdp = td->td_proc->p_fd;
2912 int error;
2913 struct file *fp;
2914 seqc_t seq;
2915
2916 *fpp = NULL;
2917 for (;;) {
2918 error = fget_unlocked_seq(td, fd, needrightsp, &fp, &seq);
2919 if (error != 0)
2920 return (error);
2921
2922 if (havecapsp != NULL) {
2923 if (!filecaps_copy(&fdp->fd_ofiles[fd].fde_caps,
2924 havecapsp, false)) {
2925 fdrop(fp, td);
2926 goto get_locked;
2927 }
2928 }
2929
2930 if (!fd_modified(fdp, fd, seq))
2931 break;
2932 fdrop(fp, td);
2933 }
2934
2935 *fpp = fp;
2936 return (0);
2937
2938 get_locked:
2939 FILEDESC_SLOCK(fdp);
2940 error = fget_cap_noref(fdp, fd, needrightsp, fpp, havecapsp);
2941 if (error == 0 && !fhold(*fpp))
2942 error = EBADF;
2943 FILEDESC_SUNLOCK(fdp);
2944 return (error);
2945 }
2946 #else
2947 int
2948 fget_cap(struct thread *td, int fd, cap_rights_t *needrightsp,
2949 struct file **fpp, struct filecaps *havecapsp)
2950 {
2951 int error;
2952 error = fget_unlocked(td, fd, needrightsp, fpp);
2953 if (havecapsp != NULL && error == 0)
2954 filecaps_fill(havecapsp);
2955
2956 return (error);
2957 }
2958 #endif
2959
2960 #ifdef CAPABILITIES
2961 int
2962 fgetvp_lookup_smr(int fd, struct nameidata *ndp, struct vnode **vpp, bool *fsearch)
2963 {
2964 const struct filedescent *fde;
2965 const struct fdescenttbl *fdt;
2966 struct filedesc *fdp;
2967 struct file *fp;
2968 struct vnode *vp;
2969 const cap_rights_t *haverights;
2970 cap_rights_t rights;
2971 seqc_t seq;
2972
2973 VFS_SMR_ASSERT_ENTERED();
2974
2975 rights = *ndp->ni_rightsneeded;
2976 cap_rights_set_one(&rights, CAP_LOOKUP);
2977
2978 fdp = curproc->p_fd;
2979 fdt = fdp->fd_files;
2980 if (__predict_false((u_int)fd >= fdt->fdt_nfiles))
2981 return (EBADF);
2982 seq = seqc_read_notmodify(fd_seqc(fdt, fd));
2983 fde = &fdt->fdt_ofiles[fd];
2984 haverights = cap_rights_fde_inline(fde);
2985 fp = fde->fde_file;
2986 if (__predict_false(fp == NULL))
2987 return (EAGAIN);
2988 if (__predict_false(cap_check_inline_transient(haverights, &rights)))
2989 return (EAGAIN);
2990 *fsearch = ((fp->f_flag & FSEARCH) != 0);
2991 vp = fp->f_vnode;
2992 if (__predict_false(vp == NULL)) {
2993 return (EAGAIN);
2994 }
2995 if (!filecaps_copy(&fde->fde_caps, &ndp->ni_filecaps, false)) {
2996 return (EAGAIN);
2997 }
2998 /*
2999 * Use an acquire barrier to force re-reading of fdt so it is
3000 * refreshed for verification.
3001 */
3002 atomic_thread_fence_acq();
3003 fdt = fdp->fd_files;
3004 if (__predict_false(!seqc_consistent_no_fence(fd_seqc(fdt, fd), seq)))
3005 return (EAGAIN);
3006 /*
3007 * If file descriptor doesn't have all rights,
3008 * all lookups relative to it must also be
3009 * strictly relative.
3010 *
3011 * Not yet supported by fast path.
3012 */
3013 CAP_ALL(&rights);
3014 if (!cap_rights_contains(&ndp->ni_filecaps.fc_rights, &rights) ||
3015 ndp->ni_filecaps.fc_fcntls != CAP_FCNTL_ALL ||
3016 ndp->ni_filecaps.fc_nioctls != -1) {
3017 #ifdef notyet
3018 ndp->ni_lcf |= NI_LCF_STRICTRELATIVE;
3019 #else
3020 return (EAGAIN);
3021 #endif
3022 }
3023 *vpp = vp;
3024 return (0);
3025 }
3026 #else
3027 int
3028 fgetvp_lookup_smr(int fd, struct nameidata *ndp, struct vnode **vpp, bool *fsearch)
3029 {
3030 const struct fdescenttbl *fdt;
3031 struct filedesc *fdp;
3032 struct file *fp;
3033 struct vnode *vp;
3034
3035 VFS_SMR_ASSERT_ENTERED();
3036
3037 fdp = curproc->p_fd;
3038 fdt = fdp->fd_files;
3039 if (__predict_false((u_int)fd >= fdt->fdt_nfiles))
3040 return (EBADF);
3041 fp = fdt->fdt_ofiles[fd].fde_file;
3042 if (__predict_false(fp == NULL))
3043 return (EAGAIN);
3044 *fsearch = ((fp->f_flag & FSEARCH) != 0);
3045 vp = fp->f_vnode;
3046 if (__predict_false(vp == NULL || vp->v_type != VDIR)) {
3047 return (EAGAIN);
3048 }
3049 /*
3050 * Use an acquire barrier to force re-reading of fdt so it is
3051 * refreshed for verification.
3052 */
3053 atomic_thread_fence_acq();
3054 fdt = fdp->fd_files;
3055 if (__predict_false(fp != fdt->fdt_ofiles[fd].fde_file))
3056 return (EAGAIN);
3057 filecaps_fill(&ndp->ni_filecaps);
3058 *vpp = vp;
3059 return (0);
3060 }
3061 #endif
3062
3063 int
3064 fgetvp_lookup(int fd, struct nameidata *ndp, struct vnode **vpp)
3065 {
3066 struct thread *td;
3067 struct file *fp;
3068 struct vnode *vp;
3069 struct componentname *cnp;
3070 cap_rights_t rights;
3071 int error;
3072
3073 td = curthread;
3074 rights = *ndp->ni_rightsneeded;
3075 cap_rights_set_one(&rights, CAP_LOOKUP);
3076 cnp = &ndp->ni_cnd;
3077
3078 error = fget_cap(td, ndp->ni_dirfd, &rights, &fp, &ndp->ni_filecaps);
3079 if (__predict_false(error != 0))
3080 return (error);
3081 if (__predict_false(fp->f_ops == &badfileops)) {
3082 error = EBADF;
3083 goto out_free;
3084 }
3085 vp = fp->f_vnode;
3086 if (__predict_false(vp == NULL)) {
3087 error = ENOTDIR;
3088 goto out_free;
3089 }
3090 vrefact(vp);
3091 /*
3092 * XXX does not check for VDIR, handled by namei_setup
3093 */
3094 if ((fp->f_flag & FSEARCH) != 0)
3095 cnp->cn_flags |= NOEXECCHECK;
3096 fdrop(fp, td);
3097
3098 #ifdef CAPABILITIES
3099 /*
3100 * If file descriptor doesn't have all rights,
3101 * all lookups relative to it must also be
3102 * strictly relative.
3103 */
3104 CAP_ALL(&rights);
3105 if (!cap_rights_contains(&ndp->ni_filecaps.fc_rights, &rights) ||
3106 ndp->ni_filecaps.fc_fcntls != CAP_FCNTL_ALL ||
3107 ndp->ni_filecaps.fc_nioctls != -1) {
3108 ndp->ni_lcf |= NI_LCF_STRICTRELATIVE;
3109 ndp->ni_resflags |= NIRES_STRICTREL;
3110 }
3111 #endif
3112
3113 /*
3114 * TODO: avoid copying ioctl caps if it can be helped to begin with
3115 */
3116 if ((cnp->cn_flags & WANTIOCTLCAPS) == 0)
3117 filecaps_free_ioctl(&ndp->ni_filecaps);
3118
3119 *vpp = vp;
3120 return (0);
3121
3122 out_free:
3123 filecaps_free(&ndp->ni_filecaps);
3124 fdrop(fp, td);
3125 return (error);
3126 }
3127
3128 /*
3129 * Fetch the descriptor locklessly.
3130 *
3131 * We avoid fdrop() races by never raising a refcount above 0. To accomplish
3132 * this we have to use a cmpset loop rather than an atomic_add. The descriptor
3133 * must be re-verified once we acquire a reference to be certain that the
3134 * identity is still correct and we did not lose a race due to preemption.
3135 *
3136 * Force a reload of fdt when looping. Another thread could reallocate
3137 * the table before this fd was closed, so it is possible that there is
3138 * a stale fp pointer in cached version.
3139 */
3140 #ifdef CAPABILITIES
3141 static int
3142 fget_unlocked_seq(struct thread *td, int fd, cap_rights_t *needrightsp,
3143 struct file **fpp, seqc_t *seqp)
3144 {
3145 struct filedesc *fdp;
3146 const struct filedescent *fde;
3147 const struct fdescenttbl *fdt;
3148 struct file *fp;
3149 seqc_t seq;
3150 cap_rights_t haverights;
3151 int error;
3152
3153 fdp = td->td_proc->p_fd;
3154 fdt = fdp->fd_files;
3155 if (__predict_false((u_int)fd >= fdt->fdt_nfiles))
3156 return (EBADF);
3157
3158 for (;;) {
3159 seq = seqc_read_notmodify(fd_seqc(fdt, fd));
3160 fde = &fdt->fdt_ofiles[fd];
3161 haverights = *cap_rights_fde_inline(fde);
3162 fp = fde->fde_file;
3163 if (__predict_false(fp == NULL)) {
3164 if (seqc_consistent(fd_seqc(fdt, fd), seq))
3165 return (EBADF);
3166 fdt = atomic_load_ptr(&fdp->fd_files);
3167 continue;
3168 }
3169 error = cap_check_inline(&haverights, needrightsp);
3170 if (__predict_false(error != 0)) {
3171 if (seqc_consistent(fd_seqc(fdt, fd), seq))
3172 return (error);
3173 fdt = atomic_load_ptr(&fdp->fd_files);
3174 continue;
3175 }
3176 if (__predict_false(!refcount_acquire_if_not_zero(&fp->f_count))) {
3177 fdt = atomic_load_ptr(&fdp->fd_files);
3178 continue;
3179 }
3180 /*
3181 * Use an acquire barrier to force re-reading of fdt so it is
3182 * refreshed for verification.
3183 */
3184 atomic_thread_fence_acq();
3185 fdt = fdp->fd_files;
3186 if (seqc_consistent_no_fence(fd_seqc(fdt, fd), seq))
3187 break;
3188 fdrop(fp, td);
3189 }
3190 *fpp = fp;
3191 if (seqp != NULL) {
3192 *seqp = seq;
3193 }
3194 return (0);
3195 }
3196 #else
3197 static int
3198 fget_unlocked_seq(struct thread *td, int fd, cap_rights_t *needrightsp,
3199 struct file **fpp, seqc_t *seqp __unused)
3200 {
3201 struct filedesc *fdp;
3202 const struct fdescenttbl *fdt;
3203 struct file *fp;
3204
3205 fdp = td->td_proc->p_fd;
3206 fdt = fdp->fd_files;
3207 if (__predict_false((u_int)fd >= fdt->fdt_nfiles))
3208 return (EBADF);
3209
3210 for (;;) {
3211 fp = fdt->fdt_ofiles[fd].fde_file;
3212 if (__predict_false(fp == NULL))
3213 return (EBADF);
3214 if (__predict_false(!refcount_acquire_if_not_zero(&fp->f_count))) {
3215 fdt = atomic_load_ptr(&fdp->fd_files);
3216 continue;
3217 }
3218 /*
3219 * Use an acquire barrier to force re-reading of fdt so it is
3220 * refreshed for verification.
3221 */
3222 atomic_thread_fence_acq();
3223 fdt = fdp->fd_files;
3224 if (__predict_true(fp == fdt->fdt_ofiles[fd].fde_file))
3225 break;
3226 fdrop(fp, td);
3227 }
3228 *fpp = fp;
3229 return (0);
3230 }
3231 #endif
3232
3233 /*
3234 * See the comments in fget_unlocked_seq for an explanation of how this works.
3235 *
3236 * This is a simplified variant which bails out to the aforementioned routine
3237 * if anything goes wrong. In practice this only happens when userspace is
3238 * racing with itself.
3239 */
3240 int
3241 fget_unlocked(struct thread *td, int fd, cap_rights_t *needrightsp,
3242 struct file **fpp)
3243 {
3244 struct filedesc *fdp;
3245 #ifdef CAPABILITIES
3246 const struct filedescent *fde;
3247 #endif
3248 const struct fdescenttbl *fdt;
3249 struct file *fp;
3250 #ifdef CAPABILITIES
3251 seqc_t seq;
3252 const cap_rights_t *haverights;
3253 #endif
3254
3255 fdp = td->td_proc->p_fd;
3256 fdt = fdp->fd_files;
3257 if (__predict_false((u_int)fd >= fdt->fdt_nfiles)) {
3258 *fpp = NULL;
3259 return (EBADF);
3260 }
3261 #ifdef CAPABILITIES
3262 seq = seqc_read_notmodify(fd_seqc(fdt, fd));
3263 fde = &fdt->fdt_ofiles[fd];
3264 haverights = cap_rights_fde_inline(fde);
3265 fp = fde->fde_file;
3266 #else
3267 fp = fdt->fdt_ofiles[fd].fde_file;
3268 #endif
3269 if (__predict_false(fp == NULL))
3270 goto out_fallback;
3271 #ifdef CAPABILITIES
3272 if (__predict_false(cap_check_inline_transient(haverights, needrightsp)))
3273 goto out_fallback;
3274 #endif
3275 if (__predict_false(!refcount_acquire_if_not_zero(&fp->f_count)))
3276 goto out_fallback;
3277
3278 /*
3279 * Use an acquire barrier to force re-reading of fdt so it is
3280 * refreshed for verification.
3281 */
3282 atomic_thread_fence_acq();
3283 fdt = fdp->fd_files;
3284 #ifdef CAPABILITIES
3285 if (__predict_false(!seqc_consistent_no_fence(fd_seqc(fdt, fd), seq)))
3286 #else
3287 if (__predict_false(fp != fdt->fdt_ofiles[fd].fde_file))
3288 #endif
3289 goto out_fdrop;
3290 *fpp = fp;
3291 return (0);
3292 out_fdrop:
3293 fdrop(fp, td);
3294 out_fallback:
3295 *fpp = NULL;
3296 return (fget_unlocked_seq(td, fd, needrightsp, fpp, NULL));
3297 }
3298
3299 /*
3300 * Translate fd -> file when the caller guarantees the file descriptor table
3301 * can't be changed by others.
3302 *
3303 * Note this does not mean the file object itself is only visible to the caller,
3304 * merely that it wont disappear without having to be referenced.
3305 *
3306 * Must be paired with fput_only_user.
3307 */
3308 #ifdef CAPABILITIES
3309 int
3310 fget_only_user(struct filedesc *fdp, int fd, cap_rights_t *needrightsp,
3311 struct file **fpp)
3312 {
3313 const struct filedescent *fde;
3314 const struct fdescenttbl *fdt;
3315 const cap_rights_t *haverights;
3316 struct file *fp;
3317 int error;
3318
3319 MPASS(FILEDESC_IS_ONLY_USER(fdp));
3320
3321 *fpp = NULL;
3322 if (__predict_false(fd >= fdp->fd_nfiles))
3323 return (EBADF);
3324
3325 fdt = fdp->fd_files;
3326 fde = &fdt->fdt_ofiles[fd];
3327 fp = fde->fde_file;
3328 if (__predict_false(fp == NULL))
3329 return (EBADF);
3330 MPASS(refcount_load(&fp->f_count) > 0);
3331 haverights = cap_rights_fde_inline(fde);
3332 error = cap_check_inline(haverights, needrightsp);
3333 if (__predict_false(error != 0))
3334 return (error);
3335 *fpp = fp;
3336 return (0);
3337 }
3338 #else
3339 int
3340 fget_only_user(struct filedesc *fdp, int fd, cap_rights_t *needrightsp,
3341 struct file **fpp)
3342 {
3343 struct file *fp;
3344
3345 MPASS(FILEDESC_IS_ONLY_USER(fdp));
3346
3347 *fpp = NULL;
3348 if (__predict_false(fd >= fdp->fd_nfiles))
3349 return (EBADF);
3350
3351 fp = fdp->fd_ofiles[fd].fde_file;
3352 if (__predict_false(fp == NULL))
3353 return (EBADF);
3354
3355 MPASS(refcount_load(&fp->f_count) > 0);
3356 *fpp = fp;
3357 return (0);
3358 }
3359 #endif
3360
3361 /*
3362 * Extract the file pointer associated with the specified descriptor for the
3363 * current user process.
3364 *
3365 * If the descriptor doesn't exist or doesn't match 'flags', EBADF is
3366 * returned.
3367 *
3368 * File's rights will be checked against the capability rights mask.
3369 *
3370 * If an error occurred the non-zero error is returned and *fpp is set to
3371 * NULL. Otherwise *fpp is held and set and zero is returned. Caller is
3372 * responsible for fdrop().
3373 */
3374 static __inline int
3375 _fget(struct thread *td, int fd, struct file **fpp, int flags,
3376 cap_rights_t *needrightsp)
3377 {
3378 struct file *fp;
3379 int error;
3380
3381 *fpp = NULL;
3382 error = fget_unlocked(td, fd, needrightsp, &fp);
3383 if (__predict_false(error != 0))
3384 return (error);
3385 if (__predict_false(fp->f_ops == &badfileops)) {
3386 fdrop(fp, td);
3387 return (EBADF);
3388 }
3389
3390 /*
3391 * FREAD and FWRITE failure return EBADF as per POSIX.
3392 */
3393 error = 0;
3394 switch (flags) {
3395 case FREAD:
3396 case FWRITE:
3397 if ((fp->f_flag & flags) == 0)
3398 error = EBADF;
3399 break;
3400 case FEXEC:
3401 if (fp->f_ops != &path_fileops &&
3402 ((fp->f_flag & (FREAD | FEXEC)) == 0 ||
3403 (fp->f_flag & FWRITE) != 0))
3404 error = EBADF;
3405 break;
3406 case 0:
3407 break;
3408 default:
3409 KASSERT(0, ("wrong flags"));
3410 }
3411
3412 if (error != 0) {
3413 fdrop(fp, td);
3414 return (error);
3415 }
3416
3417 *fpp = fp;
3418 return (0);
3419 }
3420
3421 int
3422 fget(struct thread *td, int fd, cap_rights_t *rightsp, struct file **fpp)
3423 {
3424
3425 return (_fget(td, fd, fpp, 0, rightsp));
3426 }
3427
3428 int
3429 fget_mmap(struct thread *td, int fd, cap_rights_t *rightsp, vm_prot_t *maxprotp,
3430 struct file **fpp)
3431 {
3432 int error;
3433 #ifndef CAPABILITIES
3434 error = _fget(td, fd, fpp, 0, rightsp);
3435 if (maxprotp != NULL)
3436 *maxprotp = VM_PROT_ALL;
3437 return (error);
3438 #else
3439 cap_rights_t fdrights;
3440 struct filedesc *fdp;
3441 struct file *fp;
3442 seqc_t seq;
3443
3444 *fpp = NULL;
3445 fdp = td->td_proc->p_fd;
3446 MPASS(cap_rights_is_set(rightsp, CAP_MMAP));
3447 for (;;) {
3448 error = fget_unlocked_seq(td, fd, rightsp, &fp, &seq);
3449 if (__predict_false(error != 0))
3450 return (error);
3451 if (__predict_false(fp->f_ops == &badfileops)) {
3452 fdrop(fp, td);
3453 return (EBADF);
3454 }
3455 if (maxprotp != NULL)
3456 fdrights = *cap_rights(fdp, fd);
3457 if (!fd_modified(fdp, fd, seq))
3458 break;
3459 fdrop(fp, td);
3460 }
3461
3462 /*
3463 * If requested, convert capability rights to access flags.
3464 */
3465 if (maxprotp != NULL)
3466 *maxprotp = cap_rights_to_vmprot(&fdrights);
3467 *fpp = fp;
3468 return (0);
3469 #endif
3470 }
3471
3472 int
3473 fget_read(struct thread *td, int fd, cap_rights_t *rightsp, struct file **fpp)
3474 {
3475
3476 return (_fget(td, fd, fpp, FREAD, rightsp));
3477 }
3478
3479 int
3480 fget_write(struct thread *td, int fd, cap_rights_t *rightsp, struct file **fpp)
3481 {
3482
3483 return (_fget(td, fd, fpp, FWRITE, rightsp));
3484 }
3485
3486 int
3487 fget_fcntl(struct thread *td, int fd, cap_rights_t *rightsp, int needfcntl,
3488 struct file **fpp)
3489 {
3490 #ifndef CAPABILITIES
3491 return (fget_unlocked(td, fd, rightsp, fpp));
3492 #else
3493 struct filedesc *fdp = td->td_proc->p_fd;
3494 struct file *fp;
3495 int error;
3496 seqc_t seq;
3497
3498 *fpp = NULL;
3499 MPASS(cap_rights_is_set(rightsp, CAP_FCNTL));
3500 for (;;) {
3501 error = fget_unlocked_seq(td, fd, rightsp, &fp, &seq);
3502 if (error != 0)
3503 return (error);
3504 error = cap_fcntl_check(fdp, fd, needfcntl);
3505 if (!fd_modified(fdp, fd, seq))
3506 break;
3507 fdrop(fp, td);
3508 }
3509 if (error != 0) {
3510 fdrop(fp, td);
3511 return (error);
3512 }
3513 *fpp = fp;
3514 return (0);
3515 #endif
3516 }
3517
3518 /*
3519 * Like fget() but loads the underlying vnode, or returns an error if the
3520 * descriptor does not represent a vnode. Note that pipes use vnodes but
3521 * never have VM objects. The returned vnode will be vref()'d.
3522 *
3523 * XXX: what about the unused flags ?
3524 */
3525 static __inline int
3526 _fgetvp(struct thread *td, int fd, int flags, cap_rights_t *needrightsp,
3527 struct vnode **vpp)
3528 {
3529 struct file *fp;
3530 int error;
3531
3532 *vpp = NULL;
3533 error = _fget(td, fd, &fp, flags, needrightsp);
3534 if (error != 0)
3535 return (error);
3536 if (fp->f_vnode == NULL) {
3537 error = EINVAL;
3538 } else {
3539 *vpp = fp->f_vnode;
3540 vrefact(*vpp);
3541 }
3542 fdrop(fp, td);
3543
3544 return (error);
3545 }
3546
3547 int
3548 fgetvp(struct thread *td, int fd, cap_rights_t *rightsp, struct vnode **vpp)
3549 {
3550
3551 return (_fgetvp(td, fd, 0, rightsp, vpp));
3552 }
3553
3554 int
3555 fgetvp_rights(struct thread *td, int fd, cap_rights_t *needrightsp,
3556 struct filecaps *havecaps, struct vnode **vpp)
3557 {
3558 struct filecaps caps;
3559 struct file *fp;
3560 int error;
3561
3562 error = fget_cap(td, fd, needrightsp, &fp, &caps);
3563 if (error != 0)
3564 return (error);
3565 if (fp->f_ops == &badfileops) {
3566 error = EBADF;
3567 goto out;
3568 }
3569 if (fp->f_vnode == NULL) {
3570 error = EINVAL;
3571 goto out;
3572 }
3573
3574 *havecaps = caps;
3575 *vpp = fp->f_vnode;
3576 vrefact(*vpp);
3577 fdrop(fp, td);
3578
3579 return (0);
3580 out:
3581 filecaps_free(&caps);
3582 fdrop(fp, td);
3583 return (error);
3584 }
3585
3586 int
3587 fgetvp_read(struct thread *td, int fd, cap_rights_t *rightsp, struct vnode **vpp)
3588 {
3589
3590 return (_fgetvp(td, fd, FREAD, rightsp, vpp));
3591 }
3592
3593 int
3594 fgetvp_exec(struct thread *td, int fd, cap_rights_t *rightsp, struct vnode **vpp)
3595 {
3596
3597 return (_fgetvp(td, fd, FEXEC, rightsp, vpp));
3598 }
3599
3600 #ifdef notyet
3601 int
3602 fgetvp_write(struct thread *td, int fd, cap_rights_t *rightsp,
3603 struct vnode **vpp)
3604 {
3605
3606 return (_fgetvp(td, fd, FWRITE, rightsp, vpp));
3607 }
3608 #endif
3609
3610 /*
3611 * Handle the last reference to a file being closed.
3612 *
3613 * Without the noinline attribute clang keeps inlining the func thorough this
3614 * file when fdrop is used.
3615 */
3616 int __noinline
3617 _fdrop(struct file *fp, struct thread *td)
3618 {
3619 int error;
3620 #ifdef INVARIANTS
3621 int count;
3622
3623 count = refcount_load(&fp->f_count);
3624 if (count != 0)
3625 panic("fdrop: fp %p count %d", fp, count);
3626 #endif
3627 error = fo_close(fp, td);
3628 atomic_subtract_int(&openfiles, 1);
3629 crfree(fp->f_cred);
3630 free(fp->f_advice, M_FADVISE);
3631 uma_zfree(file_zone, fp);
3632
3633 return (error);
3634 }
3635
3636 /*
3637 * Apply an advisory lock on a file descriptor.
3638 *
3639 * Just attempt to get a record lock of the requested type on the entire file
3640 * (l_whence = SEEK_SET, l_start = 0, l_len = 0).
3641 */
3642 #ifndef _SYS_SYSPROTO_H_
3643 struct flock_args {
3644 int fd;
3645 int how;
3646 };
3647 #endif
3648 /* ARGSUSED */
3649 int
3650 sys_flock(struct thread *td, struct flock_args *uap)
3651 {
3652 struct file *fp;
3653 struct vnode *vp;
3654 struct flock lf;
3655 int error;
3656
3657 error = fget(td, uap->fd, &cap_flock_rights, &fp);
3658 if (error != 0)
3659 return (error);
3660 error = EOPNOTSUPP;
3661 if (fp->f_type != DTYPE_VNODE && fp->f_type != DTYPE_FIFO) {
3662 goto done;
3663 }
3664 if (fp->f_ops == &path_fileops) {
3665 goto done;
3666 }
3667
3668 error = 0;
3669 vp = fp->f_vnode;
3670 lf.l_whence = SEEK_SET;
3671 lf.l_start = 0;
3672 lf.l_len = 0;
3673 if (uap->how & LOCK_UN) {
3674 lf.l_type = F_UNLCK;
3675 atomic_clear_int(&fp->f_flag, FHASLOCK);
3676 error = VOP_ADVLOCK(vp, (caddr_t)fp, F_UNLCK, &lf, F_FLOCK);
3677 goto done;
3678 }
3679 if (uap->how & LOCK_EX)
3680 lf.l_type = F_WRLCK;
3681 else if (uap->how & LOCK_SH)
3682 lf.l_type = F_RDLCK;
3683 else {
3684 error = EBADF;
3685 goto done;
3686 }
3687 atomic_set_int(&fp->f_flag, FHASLOCK);
3688 error = VOP_ADVLOCK(vp, (caddr_t)fp, F_SETLK, &lf,
3689 (uap->how & LOCK_NB) ? F_FLOCK : F_FLOCK | F_WAIT);
3690 done:
3691 fdrop(fp, td);
3692 return (error);
3693 }
3694 /*
3695 * Duplicate the specified descriptor to a free descriptor.
3696 */
3697 int
3698 dupfdopen(struct thread *td, struct filedesc *fdp, int dfd, int mode,
3699 int openerror, int *indxp)
3700 {
3701 struct filedescent *newfde, *oldfde;
3702 struct file *fp;
3703 u_long *ioctls;
3704 int error, indx;
3705
3706 KASSERT(openerror == ENODEV || openerror == ENXIO,
3707 ("unexpected error %d in %s", openerror, __func__));
3708
3709 /*
3710 * If the to-be-dup'd fd number is greater than the allowed number
3711 * of file descriptors, or the fd to be dup'd has already been
3712 * closed, then reject.
3713 */
3714 FILEDESC_XLOCK(fdp);
3715 if ((fp = fget_noref(fdp, dfd)) == NULL) {
3716 FILEDESC_XUNLOCK(fdp);
3717 return (EBADF);
3718 }
3719
3720 error = fdalloc(td, 0, &indx);
3721 if (error != 0) {
3722 FILEDESC_XUNLOCK(fdp);
3723 return (error);
3724 }
3725
3726 /*
3727 * There are two cases of interest here.
3728 *
3729 * For ENODEV simply dup (dfd) to file descriptor (indx) and return.
3730 *
3731 * For ENXIO steal away the file structure from (dfd) and store it in
3732 * (indx). (dfd) is effectively closed by this operation.
3733 */
3734 switch (openerror) {
3735 case ENODEV:
3736 /*
3737 * Check that the mode the file is being opened for is a
3738 * subset of the mode of the existing descriptor.
3739 */
3740 if (((mode & (FREAD|FWRITE)) | fp->f_flag) != fp->f_flag) {
3741 fdunused(fdp, indx);
3742 FILEDESC_XUNLOCK(fdp);
3743 return (EACCES);
3744 }
3745 if (!fhold(fp)) {
3746 fdunused(fdp, indx);
3747 FILEDESC_XUNLOCK(fdp);
3748 return (EBADF);
3749 }
3750 newfde = &fdp->fd_ofiles[indx];
3751 oldfde = &fdp->fd_ofiles[dfd];
3752 ioctls = filecaps_copy_prep(&oldfde->fde_caps);
3753 #ifdef CAPABILITIES
3754 seqc_write_begin(&newfde->fde_seqc);
3755 #endif
3756 fde_copy(oldfde, newfde);
3757 filecaps_copy_finish(&oldfde->fde_caps, &newfde->fde_caps,
3758 ioctls);
3759 #ifdef CAPABILITIES
3760 seqc_write_end(&newfde->fde_seqc);
3761 #endif
3762 break;
3763 case ENXIO:
3764 /*
3765 * Steal away the file pointer from dfd and stuff it into indx.
3766 */
3767 newfde = &fdp->fd_ofiles[indx];
3768 oldfde = &fdp->fd_ofiles[dfd];
3769 #ifdef CAPABILITIES
3770 seqc_write_begin(&oldfde->fde_seqc);
3771 seqc_write_begin(&newfde->fde_seqc);
3772 #endif
3773 fde_copy(oldfde, newfde);
3774 oldfde->fde_file = NULL;
3775 fdunused(fdp, dfd);
3776 #ifdef CAPABILITIES
3777 seqc_write_end(&newfde->fde_seqc);
3778 seqc_write_end(&oldfde->fde_seqc);
3779 #endif
3780 break;
3781 }
3782 FILEDESC_XUNLOCK(fdp);
3783 *indxp = indx;
3784 return (0);
3785 }
3786
3787 /*
3788 * This sysctl determines if we will allow a process to chroot(2) if it
3789 * has a directory open:
3790 * 0: disallowed for all processes.
3791 * 1: allowed for processes that were not already chroot(2)'ed.
3792 * 2: allowed for all processes.
3793 */
3794
3795 static int chroot_allow_open_directories = 1;
3796
3797 SYSCTL_INT(_kern, OID_AUTO, chroot_allow_open_directories, CTLFLAG_RW,
3798 &chroot_allow_open_directories, 0,
3799 "Allow a process to chroot(2) if it has a directory open");
3800
3801 /*
3802 * Helper function for raised chroot(2) security function: Refuse if
3803 * any filedescriptors are open directories.
3804 */
3805 static int
3806 chroot_refuse_vdir_fds(struct filedesc *fdp)
3807 {
3808 struct vnode *vp;
3809 struct file *fp;
3810 int i;
3811
3812 FILEDESC_LOCK_ASSERT(fdp);
3813
3814 FILEDESC_FOREACH_FP(fdp, i, fp) {
3815 if (fp->f_type == DTYPE_VNODE) {
3816 vp = fp->f_vnode;
3817 if (vp->v_type == VDIR)
3818 return (EPERM);
3819 }
3820 }
3821 return (0);
3822 }
3823
3824 static void
3825 pwd_fill(struct pwd *oldpwd, struct pwd *newpwd)
3826 {
3827
3828 if (newpwd->pwd_cdir == NULL && oldpwd->pwd_cdir != NULL) {
3829 vrefact(oldpwd->pwd_cdir);
3830 newpwd->pwd_cdir = oldpwd->pwd_cdir;
3831 }
3832
3833 if (newpwd->pwd_rdir == NULL && oldpwd->pwd_rdir != NULL) {
3834 vrefact(oldpwd->pwd_rdir);
3835 newpwd->pwd_rdir = oldpwd->pwd_rdir;
3836 }
3837
3838 if (newpwd->pwd_jdir == NULL && oldpwd->pwd_jdir != NULL) {
3839 vrefact(oldpwd->pwd_jdir);
3840 newpwd->pwd_jdir = oldpwd->pwd_jdir;
3841 }
3842 }
3843
3844 struct pwd *
3845 pwd_hold_pwddesc(struct pwddesc *pdp)
3846 {
3847 struct pwd *pwd;
3848
3849 PWDDESC_ASSERT_XLOCKED(pdp);
3850 pwd = PWDDESC_XLOCKED_LOAD_PWD(pdp);
3851 if (pwd != NULL)
3852 refcount_acquire(&pwd->pwd_refcount);
3853 return (pwd);
3854 }
3855
3856 bool
3857 pwd_hold_smr(struct pwd *pwd)
3858 {
3859
3860 MPASS(pwd != NULL);
3861 if (__predict_true(refcount_acquire_if_not_zero(&pwd->pwd_refcount))) {
3862 return (true);
3863 }
3864 return (false);
3865 }
3866
3867 struct pwd *
3868 pwd_hold(struct thread *td)
3869 {
3870 struct pwddesc *pdp;
3871 struct pwd *pwd;
3872
3873 pdp = td->td_proc->p_pd;
3874
3875 vfs_smr_enter();
3876 pwd = vfs_smr_entered_load(&pdp->pd_pwd);
3877 if (pwd_hold_smr(pwd)) {
3878 vfs_smr_exit();
3879 return (pwd);
3880 }
3881 vfs_smr_exit();
3882 PWDDESC_XLOCK(pdp);
3883 pwd = pwd_hold_pwddesc(pdp);
3884 MPASS(pwd != NULL);
3885 PWDDESC_XUNLOCK(pdp);
3886 return (pwd);
3887 }
3888
3889 struct pwd *
3890 pwd_hold_proc(struct proc *p)
3891 {
3892 struct pwddesc *pdp;
3893 struct pwd *pwd;
3894
3895 PROC_ASSERT_HELD(p);
3896 PROC_LOCK(p);
3897 pdp = pdhold(p);
3898 MPASS(pdp != NULL);
3899 PROC_UNLOCK(p);
3900
3901 PWDDESC_XLOCK(pdp);
3902 pwd = pwd_hold_pwddesc(pdp);
3903 MPASS(pwd != NULL);
3904 PWDDESC_XUNLOCK(pdp);
3905 pddrop(pdp);
3906 return (pwd);
3907 }
3908
3909 static struct pwd *
3910 pwd_alloc(void)
3911 {
3912 struct pwd *pwd;
3913
3914 pwd = uma_zalloc_smr(pwd_zone, M_WAITOK);
3915 bzero(pwd, sizeof(*pwd));
3916 refcount_init(&pwd->pwd_refcount, 1);
3917 return (pwd);
3918 }
3919
3920 void
3921 pwd_drop(struct pwd *pwd)
3922 {
3923
3924 if (!refcount_release(&pwd->pwd_refcount))
3925 return;
3926
3927 if (pwd->pwd_cdir != NULL)
3928 vrele(pwd->pwd_cdir);
3929 if (pwd->pwd_rdir != NULL)
3930 vrele(pwd->pwd_rdir);
3931 if (pwd->pwd_jdir != NULL)
3932 vrele(pwd->pwd_jdir);
3933 uma_zfree_smr(pwd_zone, pwd);
3934 }
3935
3936 /*
3937 * The caller is responsible for invoking priv_check() and
3938 * mac_vnode_check_chroot() to authorize this operation.
3939 */
3940 int
3941 pwd_chroot(struct thread *td, struct vnode *vp)
3942 {
3943 struct pwddesc *pdp;
3944 struct filedesc *fdp;
3945 struct pwd *newpwd, *oldpwd;
3946 int error;
3947
3948 fdp = td->td_proc->p_fd;
3949 pdp = td->td_proc->p_pd;
3950 newpwd = pwd_alloc();
3951 FILEDESC_SLOCK(fdp);
3952 PWDDESC_XLOCK(pdp);
3953 oldpwd = PWDDESC_XLOCKED_LOAD_PWD(pdp);
3954 if (chroot_allow_open_directories == 0 ||
3955 (chroot_allow_open_directories == 1 &&
3956 oldpwd->pwd_rdir != rootvnode)) {
3957 error = chroot_refuse_vdir_fds(fdp);
3958 FILEDESC_SUNLOCK(fdp);
3959 if (error != 0) {
3960 PWDDESC_XUNLOCK(pdp);
3961 pwd_drop(newpwd);
3962 return (error);
3963 }
3964 } else {
3965 FILEDESC_SUNLOCK(fdp);
3966 }
3967
3968 vrefact(vp);
3969 newpwd->pwd_rdir = vp;
3970 if (oldpwd->pwd_jdir == NULL) {
3971 vrefact(vp);
3972 newpwd->pwd_jdir = vp;
3973 }
3974 pwd_fill(oldpwd, newpwd);
3975 pwd_set(pdp, newpwd);
3976 PWDDESC_XUNLOCK(pdp);
3977 pwd_drop(oldpwd);
3978 return (0);
3979 }
3980
3981 void
3982 pwd_chdir(struct thread *td, struct vnode *vp)
3983 {
3984 struct pwddesc *pdp;
3985 struct pwd *newpwd, *oldpwd;
3986
3987 VNPASS(vp->v_usecount > 0, vp);
3988
3989 newpwd = pwd_alloc();
3990 pdp = td->td_proc->p_pd;
3991 PWDDESC_XLOCK(pdp);
3992 oldpwd = PWDDESC_XLOCKED_LOAD_PWD(pdp);
3993 newpwd->pwd_cdir = vp;
3994 pwd_fill(oldpwd, newpwd);
3995 pwd_set(pdp, newpwd);
3996 PWDDESC_XUNLOCK(pdp);
3997 pwd_drop(oldpwd);
3998 }
3999
4000 /*
4001 * jail_attach(2) changes both root and working directories.
4002 */
4003 int
4004 pwd_chroot_chdir(struct thread *td, struct vnode *vp)
4005 {
4006 struct pwddesc *pdp;
4007 struct filedesc *fdp;
4008 struct pwd *newpwd, *oldpwd;
4009 int error;
4010
4011 fdp = td->td_proc->p_fd;
4012 pdp = td->td_proc->p_pd;
4013 newpwd = pwd_alloc();
4014 FILEDESC_SLOCK(fdp);
4015 PWDDESC_XLOCK(pdp);
4016 oldpwd = PWDDESC_XLOCKED_LOAD_PWD(pdp);
4017 error = chroot_refuse_vdir_fds(fdp);
4018 FILEDESC_SUNLOCK(fdp);
4019 if (error != 0) {
4020 PWDDESC_XUNLOCK(pdp);
4021 pwd_drop(newpwd);
4022 return (error);
4023 }
4024
4025 vrefact(vp);
4026 newpwd->pwd_rdir = vp;
4027 vrefact(vp);
4028 newpwd->pwd_cdir = vp;
4029 if (oldpwd->pwd_jdir == NULL) {
4030 vrefact(vp);
4031 newpwd->pwd_jdir = vp;
4032 }
4033 pwd_fill(oldpwd, newpwd);
4034 pwd_set(pdp, newpwd);
4035 PWDDESC_XUNLOCK(pdp);
4036 pwd_drop(oldpwd);
4037 return (0);
4038 }
4039
4040 void
4041 pwd_ensure_dirs(void)
4042 {
4043 struct pwddesc *pdp;
4044 struct pwd *oldpwd, *newpwd;
4045
4046 pdp = curproc->p_pd;
4047 PWDDESC_XLOCK(pdp);
4048 oldpwd = PWDDESC_XLOCKED_LOAD_PWD(pdp);
4049 if (oldpwd->pwd_cdir != NULL && oldpwd->pwd_rdir != NULL) {
4050 PWDDESC_XUNLOCK(pdp);
4051 return;
4052 }
4053 PWDDESC_XUNLOCK(pdp);
4054
4055 newpwd = pwd_alloc();
4056 PWDDESC_XLOCK(pdp);
4057 oldpwd = PWDDESC_XLOCKED_LOAD_PWD(pdp);
4058 pwd_fill(oldpwd, newpwd);
4059 if (newpwd->pwd_cdir == NULL) {
4060 vrefact(rootvnode);
4061 newpwd->pwd_cdir = rootvnode;
4062 }
4063 if (newpwd->pwd_rdir == NULL) {
4064 vrefact(rootvnode);
4065 newpwd->pwd_rdir = rootvnode;
4066 }
4067 pwd_set(pdp, newpwd);
4068 PWDDESC_XUNLOCK(pdp);
4069 pwd_drop(oldpwd);
4070 }
4071
4072 void
4073 pwd_set_rootvnode(void)
4074 {
4075 struct pwddesc *pdp;
4076 struct pwd *oldpwd, *newpwd;
4077
4078 pdp = curproc->p_pd;
4079
4080 newpwd = pwd_alloc();
4081 PWDDESC_XLOCK(pdp);
4082 oldpwd = PWDDESC_XLOCKED_LOAD_PWD(pdp);
4083 vrefact(rootvnode);
4084 newpwd->pwd_cdir = rootvnode;
4085 vrefact(rootvnode);
4086 newpwd->pwd_rdir = rootvnode;
4087 pwd_fill(oldpwd, newpwd);
4088 pwd_set(pdp, newpwd);
4089 PWDDESC_XUNLOCK(pdp);
4090 pwd_drop(oldpwd);
4091 }
4092
4093 /*
4094 * Scan all active processes and prisons to see if any of them have a current
4095 * or root directory of `olddp'. If so, replace them with the new mount point.
4096 */
4097 void
4098 mountcheckdirs(struct vnode *olddp, struct vnode *newdp)
4099 {
4100 struct pwddesc *pdp;
4101 struct pwd *newpwd, *oldpwd;
4102 struct prison *pr;
4103 struct proc *p;
4104 int nrele;
4105
4106 if (vrefcnt(olddp) == 1)
4107 return;
4108 nrele = 0;
4109 newpwd = pwd_alloc();
4110 sx_slock(&allproc_lock);
4111 FOREACH_PROC_IN_SYSTEM(p) {
4112 PROC_LOCK(p);
4113 pdp = pdhold(p);
4114 PROC_UNLOCK(p);
4115 if (pdp == NULL)
4116 continue;
4117 PWDDESC_XLOCK(pdp);
4118 oldpwd = PWDDESC_XLOCKED_LOAD_PWD(pdp);
4119 if (oldpwd == NULL ||
4120 (oldpwd->pwd_cdir != olddp &&
4121 oldpwd->pwd_rdir != olddp &&
4122 oldpwd->pwd_jdir != olddp)) {
4123 PWDDESC_XUNLOCK(pdp);
4124 pddrop(pdp);
4125 continue;
4126 }
4127 if (oldpwd->pwd_cdir == olddp) {
4128 vrefact(newdp);
4129 newpwd->pwd_cdir = newdp;
4130 }
4131 if (oldpwd->pwd_rdir == olddp) {
4132 vrefact(newdp);
4133 newpwd->pwd_rdir = newdp;
4134 }
4135 if (oldpwd->pwd_jdir == olddp) {
4136 vrefact(newdp);
4137 newpwd->pwd_jdir = newdp;
4138 }
4139 pwd_fill(oldpwd, newpwd);
4140 pwd_set(pdp, newpwd);
4141 PWDDESC_XUNLOCK(pdp);
4142 pwd_drop(oldpwd);
4143 pddrop(pdp);
4144 newpwd = pwd_alloc();
4145 }
4146 sx_sunlock(&allproc_lock);
4147 pwd_drop(newpwd);
4148 if (rootvnode == olddp) {
4149 vrefact(newdp);
4150 rootvnode = newdp;
4151 nrele++;
4152 }
4153 mtx_lock(&prison0.pr_mtx);
4154 if (prison0.pr_root == olddp) {
4155 vrefact(newdp);
4156 prison0.pr_root = newdp;
4157 nrele++;
4158 }
4159 mtx_unlock(&prison0.pr_mtx);
4160 sx_slock(&allprison_lock);
4161 TAILQ_FOREACH(pr, &allprison, pr_list) {
4162 mtx_lock(&pr->pr_mtx);
4163 if (pr->pr_root == olddp) {
4164 vrefact(newdp);
4165 pr->pr_root = newdp;
4166 nrele++;
4167 }
4168 mtx_unlock(&pr->pr_mtx);
4169 }
4170 sx_sunlock(&allprison_lock);
4171 while (nrele--)
4172 vrele(olddp);
4173 }
4174
4175 int
4176 descrip_check_write_mp(struct filedesc *fdp, struct mount *mp)
4177 {
4178 struct file *fp;
4179 struct vnode *vp;
4180 int error, i;
4181
4182 error = 0;
4183 FILEDESC_SLOCK(fdp);
4184 FILEDESC_FOREACH_FP(fdp, i, fp) {
4185 if (fp->f_type != DTYPE_VNODE ||
4186 (atomic_load_int(&fp->f_flag) & FWRITE) == 0)
4187 continue;
4188 vp = fp->f_vnode;
4189 if (vp->v_mount == mp) {
4190 error = EDEADLK;
4191 break;
4192 }
4193 }
4194 FILEDESC_SUNLOCK(fdp);
4195 return (error);
4196 }
4197
4198 struct filedesc_to_leader *
4199 filedesc_to_leader_alloc(struct filedesc_to_leader *old, struct filedesc *fdp,
4200 struct proc *leader)
4201 {
4202 struct filedesc_to_leader *fdtol;
4203
4204 fdtol = malloc(sizeof(struct filedesc_to_leader),
4205 M_FILEDESC_TO_LEADER, M_WAITOK);
4206 fdtol->fdl_refcount = 1;
4207 fdtol->fdl_holdcount = 0;
4208 fdtol->fdl_wakeup = 0;
4209 fdtol->fdl_leader = leader;
4210 if (old != NULL) {
4211 FILEDESC_XLOCK(fdp);
4212 fdtol->fdl_next = old->fdl_next;
4213 fdtol->fdl_prev = old;
4214 old->fdl_next = fdtol;
4215 fdtol->fdl_next->fdl_prev = fdtol;
4216 FILEDESC_XUNLOCK(fdp);
4217 } else {
4218 fdtol->fdl_next = fdtol;
4219 fdtol->fdl_prev = fdtol;
4220 }
4221 return (fdtol);
4222 }
4223
4224 struct filedesc_to_leader *
4225 filedesc_to_leader_share(struct filedesc_to_leader *fdtol, struct filedesc *fdp)
4226 {
4227 FILEDESC_XLOCK(fdp);
4228 fdtol->fdl_refcount++;
4229 FILEDESC_XUNLOCK(fdp);
4230 return (fdtol);
4231 }
4232
4233 static int
4234 sysctl_kern_proc_nfds(SYSCTL_HANDLER_ARGS)
4235 {
4236 NDSLOTTYPE *map;
4237 struct filedesc *fdp;
4238 u_int namelen;
4239 int count, off, minoff;
4240
4241 namelen = arg2;
4242 if (namelen != 1)
4243 return (EINVAL);
4244
4245 if (*(int *)arg1 != 0)
4246 return (EINVAL);
4247
4248 fdp = curproc->p_fd;
4249 count = 0;
4250 FILEDESC_SLOCK(fdp);
4251 map = fdp->fd_map;
4252 off = NDSLOT(fdp->fd_nfiles - 1);
4253 for (minoff = NDSLOT(0); off >= minoff; --off)
4254 count += bitcountl(map[off]);
4255 FILEDESC_SUNLOCK(fdp);
4256
4257 return (SYSCTL_OUT(req, &count, sizeof(count)));
4258 }
4259
4260 static SYSCTL_NODE(_kern_proc, KERN_PROC_NFDS, nfds,
4261 CTLFLAG_RD|CTLFLAG_CAPRD|CTLFLAG_MPSAFE, sysctl_kern_proc_nfds,
4262 "Number of open file descriptors");
4263
4264 /*
4265 * Get file structures globally.
4266 */
4267 static int
4268 sysctl_kern_file(SYSCTL_HANDLER_ARGS)
4269 {
4270 struct xfile xf;
4271 struct filedesc *fdp;
4272 struct file *fp;
4273 struct proc *p;
4274 int error, n;
4275
4276 error = sysctl_wire_old_buffer(req, 0);
4277 if (error != 0)
4278 return (error);
4279 if (req->oldptr == NULL) {
4280 n = 0;
4281 sx_slock(&allproc_lock);
4282 FOREACH_PROC_IN_SYSTEM(p) {
4283 PROC_LOCK(p);
4284 if (p->p_state == PRS_NEW) {
4285 PROC_UNLOCK(p);
4286 continue;
4287 }
4288 fdp = fdhold(p);
4289 PROC_UNLOCK(p);
4290 if (fdp == NULL)
4291 continue;
4292 /* overestimates sparse tables. */
4293 n += fdp->fd_nfiles;
4294 fddrop(fdp);
4295 }
4296 sx_sunlock(&allproc_lock);
4297 return (SYSCTL_OUT(req, 0, n * sizeof(xf)));
4298 }
4299 error = 0;
4300 bzero(&xf, sizeof(xf));
4301 xf.xf_size = sizeof(xf);
4302 sx_slock(&allproc_lock);
4303 FOREACH_PROC_IN_SYSTEM(p) {
4304 PROC_LOCK(p);
4305 if (p->p_state == PRS_NEW) {
4306 PROC_UNLOCK(p);
4307 continue;
4308 }
4309 if (p_cansee(req->td, p) != 0) {
4310 PROC_UNLOCK(p);
4311 continue;
4312 }
4313 xf.xf_pid = p->p_pid;
4314 xf.xf_uid = p->p_ucred->cr_uid;
4315 fdp = fdhold(p);
4316 PROC_UNLOCK(p);
4317 if (fdp == NULL)
4318 continue;
4319 FILEDESC_SLOCK(fdp);
4320 if (refcount_load(&fdp->fd_refcnt) == 0)
4321 goto nextproc;
4322 FILEDESC_FOREACH_FP(fdp, n, fp) {
4323 xf.xf_fd = n;
4324 xf.xf_file = (uintptr_t)fp;
4325 xf.xf_data = (uintptr_t)fp->f_data;
4326 xf.xf_vnode = (uintptr_t)fp->f_vnode;
4327 xf.xf_type = (uintptr_t)fp->f_type;
4328 xf.xf_count = refcount_load(&fp->f_count);
4329 xf.xf_msgcount = 0;
4330 xf.xf_offset = foffset_get(fp);
4331 xf.xf_flag = fp->f_flag;
4332 error = SYSCTL_OUT(req, &xf, sizeof(xf));
4333
4334 /*
4335 * There is no need to re-check the fdtable refcount
4336 * here since the filedesc lock is not dropped in the
4337 * loop body.
4338 */
4339 if (error != 0)
4340 break;
4341 }
4342 nextproc:
4343 FILEDESC_SUNLOCK(fdp);
4344 fddrop(fdp);
4345 if (error)
4346 break;
4347 }
4348 sx_sunlock(&allproc_lock);
4349 return (error);
4350 }
4351
4352 SYSCTL_PROC(_kern, KERN_FILE, file, CTLTYPE_OPAQUE|CTLFLAG_RD|CTLFLAG_MPSAFE,
4353 0, 0, sysctl_kern_file, "S,xfile", "Entire file table");
4354
4355 #ifdef KINFO_FILE_SIZE
4356 CTASSERT(sizeof(struct kinfo_file) == KINFO_FILE_SIZE);
4357 #endif
4358
4359 static int
4360 xlate_fflags(int fflags)
4361 {
4362 static const struct {
4363 int fflag;
4364 int kf_fflag;
4365 } fflags_table[] = {
4366 { FAPPEND, KF_FLAG_APPEND },
4367 { FASYNC, KF_FLAG_ASYNC },
4368 { FFSYNC, KF_FLAG_FSYNC },
4369 { FHASLOCK, KF_FLAG_HASLOCK },
4370 { FNONBLOCK, KF_FLAG_NONBLOCK },
4371 { FREAD, KF_FLAG_READ },
4372 { FWRITE, KF_FLAG_WRITE },
4373 { O_CREAT, KF_FLAG_CREAT },
4374 { O_DIRECT, KF_FLAG_DIRECT },
4375 { O_EXCL, KF_FLAG_EXCL },
4376 { O_EXEC, KF_FLAG_EXEC },
4377 { O_EXLOCK, KF_FLAG_EXLOCK },
4378 { O_NOFOLLOW, KF_FLAG_NOFOLLOW },
4379 { O_SHLOCK, KF_FLAG_SHLOCK },
4380 { O_TRUNC, KF_FLAG_TRUNC }
4381 };
4382 unsigned int i;
4383 int kflags;
4384
4385 kflags = 0;
4386 for (i = 0; i < nitems(fflags_table); i++)
4387 if (fflags & fflags_table[i].fflag)
4388 kflags |= fflags_table[i].kf_fflag;
4389 return (kflags);
4390 }
4391
4392 /* Trim unused data from kf_path by truncating the structure size. */
4393 void
4394 pack_kinfo(struct kinfo_file *kif)
4395 {
4396
4397 kif->kf_structsize = offsetof(struct kinfo_file, kf_path) +
4398 strlen(kif->kf_path) + 1;
4399 kif->kf_structsize = roundup(kif->kf_structsize, sizeof(uint64_t));
4400 }
4401
4402 static void
4403 export_file_to_kinfo(struct file *fp, int fd, cap_rights_t *rightsp,
4404 struct kinfo_file *kif, struct filedesc *fdp, int flags)
4405 {
4406 int error;
4407
4408 bzero(kif, sizeof(*kif));
4409
4410 /* Set a default type to allow for empty fill_kinfo() methods. */
4411 kif->kf_type = KF_TYPE_UNKNOWN;
4412 kif->kf_flags = xlate_fflags(fp->f_flag);
4413 if (rightsp != NULL)
4414 kif->kf_cap_rights = *rightsp;
4415 else
4416 cap_rights_init_zero(&kif->kf_cap_rights);
4417 kif->kf_fd = fd;
4418 kif->kf_ref_count = refcount_load(&fp->f_count);
4419 kif->kf_offset = foffset_get(fp);
4420
4421 /*
4422 * This may drop the filedesc lock, so the 'fp' cannot be
4423 * accessed after this call.
4424 */
4425 error = fo_fill_kinfo(fp, kif, fdp);
4426 if (error == 0)
4427 kif->kf_status |= KF_ATTR_VALID;
4428 if ((flags & KERN_FILEDESC_PACK_KINFO) != 0)
4429 pack_kinfo(kif);
4430 else
4431 kif->kf_structsize = roundup2(sizeof(*kif), sizeof(uint64_t));
4432 }
4433
4434 static void
4435 export_vnode_to_kinfo(struct vnode *vp, int fd, int fflags,
4436 struct kinfo_file *kif, int flags)
4437 {
4438 int error;
4439
4440 bzero(kif, sizeof(*kif));
4441
4442 kif->kf_type = KF_TYPE_VNODE;
4443 error = vn_fill_kinfo_vnode(vp, kif);
4444 if (error == 0)
4445 kif->kf_status |= KF_ATTR_VALID;
4446 kif->kf_flags = xlate_fflags(fflags);
4447 cap_rights_init_zero(&kif->kf_cap_rights);
4448 kif->kf_fd = fd;
4449 kif->kf_ref_count = -1;
4450 kif->kf_offset = -1;
4451 if ((flags & KERN_FILEDESC_PACK_KINFO) != 0)
4452 pack_kinfo(kif);
4453 else
4454 kif->kf_structsize = roundup2(sizeof(*kif), sizeof(uint64_t));
4455 vrele(vp);
4456 }
4457
4458 struct export_fd_buf {
4459 struct filedesc *fdp;
4460 struct pwddesc *pdp;
4461 struct sbuf *sb;
4462 ssize_t remainder;
4463 struct kinfo_file kif;
4464 int flags;
4465 };
4466
4467 static int
4468 export_kinfo_to_sb(struct export_fd_buf *efbuf)
4469 {
4470 struct kinfo_file *kif;
4471
4472 kif = &efbuf->kif;
4473 if (efbuf->remainder != -1) {
4474 if (efbuf->remainder < kif->kf_structsize)
4475 return (ENOMEM);
4476 efbuf->remainder -= kif->kf_structsize;
4477 }
4478 if (sbuf_bcat(efbuf->sb, kif, kif->kf_structsize) != 0)
4479 return (sbuf_error(efbuf->sb));
4480 return (0);
4481 }
4482
4483 static int
4484 export_file_to_sb(struct file *fp, int fd, cap_rights_t *rightsp,
4485 struct export_fd_buf *efbuf)
4486 {
4487 int error;
4488
4489 if (efbuf->remainder == 0)
4490 return (ENOMEM);
4491 export_file_to_kinfo(fp, fd, rightsp, &efbuf->kif, efbuf->fdp,
4492 efbuf->flags);
4493 FILEDESC_SUNLOCK(efbuf->fdp);
4494 error = export_kinfo_to_sb(efbuf);
4495 FILEDESC_SLOCK(efbuf->fdp);
4496 return (error);
4497 }
4498
4499 static int
4500 export_vnode_to_sb(struct vnode *vp, int fd, int fflags,
4501 struct export_fd_buf *efbuf)
4502 {
4503 int error;
4504
4505 if (efbuf->remainder == 0)
4506 return (ENOMEM);
4507 if (efbuf->pdp != NULL)
4508 PWDDESC_XUNLOCK(efbuf->pdp);
4509 export_vnode_to_kinfo(vp, fd, fflags, &efbuf->kif, efbuf->flags);
4510 error = export_kinfo_to_sb(efbuf);
4511 if (efbuf->pdp != NULL)
4512 PWDDESC_XLOCK(efbuf->pdp);
4513 return (error);
4514 }
4515
4516 /*
4517 * Store a process file descriptor information to sbuf.
4518 *
4519 * Takes a locked proc as argument, and returns with the proc unlocked.
4520 */
4521 int
4522 kern_proc_filedesc_out(struct proc *p, struct sbuf *sb, ssize_t maxlen,
4523 int flags)
4524 {
4525 struct file *fp;
4526 struct filedesc *fdp;
4527 struct pwddesc *pdp;
4528 struct export_fd_buf *efbuf;
4529 struct vnode *cttyvp, *textvp, *tracevp;
4530 struct pwd *pwd;
4531 int error, i;
4532 cap_rights_t rights;
4533
4534 PROC_LOCK_ASSERT(p, MA_OWNED);
4535
4536 /* ktrace vnode */
4537 tracevp = ktr_get_tracevp(p, true);
4538 /* text vnode */
4539 textvp = p->p_textvp;
4540 if (textvp != NULL)
4541 vrefact(textvp);
4542 /* Controlling tty. */
4543 cttyvp = NULL;
4544 if (p->p_pgrp != NULL && p->p_pgrp->pg_session != NULL) {
4545 cttyvp = p->p_pgrp->pg_session->s_ttyvp;
4546 if (cttyvp != NULL)
4547 vrefact(cttyvp);
4548 }
4549 fdp = fdhold(p);
4550 pdp = pdhold(p);
4551 PROC_UNLOCK(p);
4552
4553 efbuf = malloc(sizeof(*efbuf), M_TEMP, M_WAITOK);
4554 efbuf->fdp = NULL;
4555 efbuf->pdp = NULL;
4556 efbuf->sb = sb;
4557 efbuf->remainder = maxlen;
4558 efbuf->flags = flags;
4559
4560 error = 0;
4561 if (tracevp != NULL)
4562 error = export_vnode_to_sb(tracevp, KF_FD_TYPE_TRACE,
4563 FREAD | FWRITE, efbuf);
4564 if (error == 0 && textvp != NULL)
4565 error = export_vnode_to_sb(textvp, KF_FD_TYPE_TEXT, FREAD,
4566 efbuf);
4567 if (error == 0 && cttyvp != NULL)
4568 error = export_vnode_to_sb(cttyvp, KF_FD_TYPE_CTTY,
4569 FREAD | FWRITE, efbuf);
4570 if (error != 0 || pdp == NULL || fdp == NULL)
4571 goto fail;
4572 efbuf->fdp = fdp;
4573 efbuf->pdp = pdp;
4574 PWDDESC_XLOCK(pdp);
4575 pwd = pwd_hold_pwddesc(pdp);
4576 if (pwd != NULL) {
4577 /* working directory */
4578 if (pwd->pwd_cdir != NULL) {
4579 vrefact(pwd->pwd_cdir);
4580 error = export_vnode_to_sb(pwd->pwd_cdir,
4581 KF_FD_TYPE_CWD, FREAD, efbuf);
4582 }
4583 /* root directory */
4584 if (error == 0 && pwd->pwd_rdir != NULL) {
4585 vrefact(pwd->pwd_rdir);
4586 error = export_vnode_to_sb(pwd->pwd_rdir,
4587 KF_FD_TYPE_ROOT, FREAD, efbuf);
4588 }
4589 /* jail directory */
4590 if (error == 0 && pwd->pwd_jdir != NULL) {
4591 vrefact(pwd->pwd_jdir);
4592 error = export_vnode_to_sb(pwd->pwd_jdir,
4593 KF_FD_TYPE_JAIL, FREAD, efbuf);
4594 }
4595 }
4596 PWDDESC_XUNLOCK(pdp);
4597 if (error != 0)
4598 goto fail;
4599 if (pwd != NULL)
4600 pwd_drop(pwd);
4601 FILEDESC_SLOCK(fdp);
4602 if (refcount_load(&fdp->fd_refcnt) == 0)
4603 goto skip;
4604 FILEDESC_FOREACH_FP(fdp, i, fp) {
4605 #ifdef CAPABILITIES
4606 rights = *cap_rights(fdp, i);
4607 #else /* !CAPABILITIES */
4608 rights = cap_no_rights;
4609 #endif
4610 /*
4611 * Create sysctl entry. It is OK to drop the filedesc
4612 * lock inside of export_file_to_sb() as we will
4613 * re-validate and re-evaluate its properties when the
4614 * loop continues.
4615 */
4616 error = export_file_to_sb(fp, i, &rights, efbuf);
4617 if (error != 0 || refcount_load(&fdp->fd_refcnt) == 0)
4618 break;
4619 }
4620 skip:
4621 FILEDESC_SUNLOCK(fdp);
4622 fail:
4623 if (fdp != NULL)
4624 fddrop(fdp);
4625 if (pdp != NULL)
4626 pddrop(pdp);
4627 free(efbuf, M_TEMP);
4628 return (error);
4629 }
4630
4631 #define FILEDESC_SBUF_SIZE (sizeof(struct kinfo_file) * 5)
4632
4633 /*
4634 * Get per-process file descriptors for use by procstat(1), et al.
4635 */
4636 static int
4637 sysctl_kern_proc_filedesc(SYSCTL_HANDLER_ARGS)
4638 {
4639 struct sbuf sb;
4640 struct proc *p;
4641 ssize_t maxlen;
4642 u_int namelen;
4643 int error, error2, *name;
4644
4645 namelen = arg2;
4646 if (namelen != 1)
4647 return (EINVAL);
4648
4649 name = (int *)arg1;
4650
4651 sbuf_new_for_sysctl(&sb, NULL, FILEDESC_SBUF_SIZE, req);
4652 sbuf_clear_flags(&sb, SBUF_INCLUDENUL);
4653 error = pget((pid_t)name[0], PGET_CANDEBUG | PGET_NOTWEXIT, &p);
4654 if (error != 0) {
4655 sbuf_delete(&sb);
4656 return (error);
4657 }
4658 maxlen = req->oldptr != NULL ? req->oldlen : -1;
4659 error = kern_proc_filedesc_out(p, &sb, maxlen,
4660 KERN_FILEDESC_PACK_KINFO);
4661 error2 = sbuf_finish(&sb);
4662 sbuf_delete(&sb);
4663 return (error != 0 ? error : error2);
4664 }
4665
4666 #ifdef COMPAT_FREEBSD7
4667 #ifdef KINFO_OFILE_SIZE
4668 CTASSERT(sizeof(struct kinfo_ofile) == KINFO_OFILE_SIZE);
4669 #endif
4670
4671 static void
4672 kinfo_to_okinfo(struct kinfo_file *kif, struct kinfo_ofile *okif)
4673 {
4674
4675 okif->kf_structsize = sizeof(*okif);
4676 okif->kf_type = kif->kf_type;
4677 okif->kf_fd = kif->kf_fd;
4678 okif->kf_ref_count = kif->kf_ref_count;
4679 okif->kf_flags = kif->kf_flags & (KF_FLAG_READ | KF_FLAG_WRITE |
4680 KF_FLAG_APPEND | KF_FLAG_ASYNC | KF_FLAG_FSYNC | KF_FLAG_NONBLOCK |
4681 KF_FLAG_DIRECT | KF_FLAG_HASLOCK);
4682 okif->kf_offset = kif->kf_offset;
4683 if (kif->kf_type == KF_TYPE_VNODE)
4684 okif->kf_vnode_type = kif->kf_un.kf_file.kf_file_type;
4685 else
4686 okif->kf_vnode_type = KF_VTYPE_VNON;
4687 strlcpy(okif->kf_path, kif->kf_path, sizeof(okif->kf_path));
4688 if (kif->kf_type == KF_TYPE_SOCKET) {
4689 okif->kf_sock_domain = kif->kf_un.kf_sock.kf_sock_domain0;
4690 okif->kf_sock_type = kif->kf_un.kf_sock.kf_sock_type0;
4691 okif->kf_sock_protocol = kif->kf_un.kf_sock.kf_sock_protocol0;
4692 okif->kf_sa_local = kif->kf_un.kf_sock.kf_sa_local;
4693 okif->kf_sa_peer = kif->kf_un.kf_sock.kf_sa_peer;
4694 } else {
4695 okif->kf_sa_local.ss_family = AF_UNSPEC;
4696 okif->kf_sa_peer.ss_family = AF_UNSPEC;
4697 }
4698 }
4699
4700 static int
4701 export_vnode_for_osysctl(struct vnode *vp, int type, struct kinfo_file *kif,
4702 struct kinfo_ofile *okif, struct pwddesc *pdp, struct sysctl_req *req)
4703 {
4704 int error;
4705
4706 vrefact(vp);
4707 PWDDESC_XUNLOCK(pdp);
4708 export_vnode_to_kinfo(vp, type, 0, kif, KERN_FILEDESC_PACK_KINFO);
4709 kinfo_to_okinfo(kif, okif);
4710 error = SYSCTL_OUT(req, okif, sizeof(*okif));
4711 PWDDESC_XLOCK(pdp);
4712 return (error);
4713 }
4714
4715 /*
4716 * Get per-process file descriptors for use by procstat(1), et al.
4717 */
4718 static int
4719 sysctl_kern_proc_ofiledesc(SYSCTL_HANDLER_ARGS)
4720 {
4721 struct kinfo_ofile *okif;
4722 struct kinfo_file *kif;
4723 struct filedesc *fdp;
4724 struct pwddesc *pdp;
4725 struct pwd *pwd;
4726 u_int namelen;
4727 int error, i, *name;
4728 struct file *fp;
4729 struct proc *p;
4730
4731 namelen = arg2;
4732 if (namelen != 1)
4733 return (EINVAL);
4734
4735 name = (int *)arg1;
4736 error = pget((pid_t)name[0], PGET_CANDEBUG | PGET_NOTWEXIT, &p);
4737 if (error != 0)
4738 return (error);
4739 fdp = fdhold(p);
4740 if (fdp != NULL)
4741 pdp = pdhold(p);
4742 PROC_UNLOCK(p);
4743 if (fdp == NULL || pdp == NULL) {
4744 if (fdp != NULL)
4745 fddrop(fdp);
4746 return (ENOENT);
4747 }
4748 kif = malloc(sizeof(*kif), M_TEMP, M_WAITOK);
4749 okif = malloc(sizeof(*okif), M_TEMP, M_WAITOK);
4750 PWDDESC_XLOCK(pdp);
4751 pwd = pwd_hold_pwddesc(pdp);
4752 if (pwd != NULL) {
4753 if (pwd->pwd_cdir != NULL)
4754 export_vnode_for_osysctl(pwd->pwd_cdir, KF_FD_TYPE_CWD, kif,
4755 okif, pdp, req);
4756 if (pwd->pwd_rdir != NULL)
4757 export_vnode_for_osysctl(pwd->pwd_rdir, KF_FD_TYPE_ROOT, kif,
4758 okif, pdp, req);
4759 if (pwd->pwd_jdir != NULL)
4760 export_vnode_for_osysctl(pwd->pwd_jdir, KF_FD_TYPE_JAIL, kif,
4761 okif, pdp, req);
4762 }
4763 PWDDESC_XUNLOCK(pdp);
4764 if (pwd != NULL)
4765 pwd_drop(pwd);
4766 FILEDESC_SLOCK(fdp);
4767 if (refcount_load(&fdp->fd_refcnt) == 0)
4768 goto skip;
4769 FILEDESC_FOREACH_FP(fdp, i, fp) {
4770 export_file_to_kinfo(fp, i, NULL, kif, fdp,
4771 KERN_FILEDESC_PACK_KINFO);
4772 FILEDESC_SUNLOCK(fdp);
4773 kinfo_to_okinfo(kif, okif);
4774 error = SYSCTL_OUT(req, okif, sizeof(*okif));
4775 FILEDESC_SLOCK(fdp);
4776 if (error != 0 || refcount_load(&fdp->fd_refcnt) == 0)
4777 break;
4778 }
4779 skip:
4780 FILEDESC_SUNLOCK(fdp);
4781 fddrop(fdp);
4782 pddrop(pdp);
4783 free(kif, M_TEMP);
4784 free(okif, M_TEMP);
4785 return (0);
4786 }
4787
4788 static SYSCTL_NODE(_kern_proc, KERN_PROC_OFILEDESC, ofiledesc,
4789 CTLFLAG_RD|CTLFLAG_MPSAFE, sysctl_kern_proc_ofiledesc,
4790 "Process ofiledesc entries");
4791 #endif /* COMPAT_FREEBSD7 */
4792
4793 int
4794 vntype_to_kinfo(int vtype)
4795 {
4796 struct {
4797 int vtype;
4798 int kf_vtype;
4799 } vtypes_table[] = {
4800 { VBAD, KF_VTYPE_VBAD },
4801 { VBLK, KF_VTYPE_VBLK },
4802 { VCHR, KF_VTYPE_VCHR },
4803 { VDIR, KF_VTYPE_VDIR },
4804 { VFIFO, KF_VTYPE_VFIFO },
4805 { VLNK, KF_VTYPE_VLNK },
4806 { VNON, KF_VTYPE_VNON },
4807 { VREG, KF_VTYPE_VREG },
4808 { VSOCK, KF_VTYPE_VSOCK }
4809 };
4810 unsigned int i;
4811
4812 /*
4813 * Perform vtype translation.
4814 */
4815 for (i = 0; i < nitems(vtypes_table); i++)
4816 if (vtypes_table[i].vtype == vtype)
4817 return (vtypes_table[i].kf_vtype);
4818
4819 return (KF_VTYPE_UNKNOWN);
4820 }
4821
4822 static SYSCTL_NODE(_kern_proc, KERN_PROC_FILEDESC, filedesc,
4823 CTLFLAG_RD|CTLFLAG_MPSAFE, sysctl_kern_proc_filedesc,
4824 "Process filedesc entries");
4825
4826 /*
4827 * Store a process current working directory information to sbuf.
4828 *
4829 * Takes a locked proc as argument, and returns with the proc unlocked.
4830 */
4831 int
4832 kern_proc_cwd_out(struct proc *p, struct sbuf *sb, ssize_t maxlen)
4833 {
4834 struct pwddesc *pdp;
4835 struct pwd *pwd;
4836 struct export_fd_buf *efbuf;
4837 struct vnode *cdir;
4838 int error;
4839
4840 PROC_LOCK_ASSERT(p, MA_OWNED);
4841
4842 pdp = pdhold(p);
4843 PROC_UNLOCK(p);
4844 if (pdp == NULL)
4845 return (EINVAL);
4846
4847 efbuf = malloc(sizeof(*efbuf), M_TEMP, M_WAITOK);
4848 efbuf->fdp = NULL;
4849 efbuf->pdp = pdp;
4850 efbuf->sb = sb;
4851 efbuf->remainder = maxlen;
4852 efbuf->flags = 0;
4853
4854 PWDDESC_XLOCK(pdp);
4855 pwd = PWDDESC_XLOCKED_LOAD_PWD(pdp);
4856 cdir = pwd->pwd_cdir;
4857 if (cdir == NULL) {
4858 error = EINVAL;
4859 } else {
4860 vrefact(cdir);
4861 error = export_vnode_to_sb(cdir, KF_FD_TYPE_CWD, FREAD, efbuf);
4862 }
4863 PWDDESC_XUNLOCK(pdp);
4864 pddrop(pdp);
4865 free(efbuf, M_TEMP);
4866 return (error);
4867 }
4868
4869 /*
4870 * Get per-process current working directory.
4871 */
4872 static int
4873 sysctl_kern_proc_cwd(SYSCTL_HANDLER_ARGS)
4874 {
4875 struct sbuf sb;
4876 struct proc *p;
4877 ssize_t maxlen;
4878 u_int namelen;
4879 int error, error2, *name;
4880
4881 namelen = arg2;
4882 if (namelen != 1)
4883 return (EINVAL);
4884
4885 name = (int *)arg1;
4886
4887 sbuf_new_for_sysctl(&sb, NULL, sizeof(struct kinfo_file), req);
4888 sbuf_clear_flags(&sb, SBUF_INCLUDENUL);
4889 error = pget((pid_t)name[0], PGET_CANDEBUG | PGET_NOTWEXIT, &p);
4890 if (error != 0) {
4891 sbuf_delete(&sb);
4892 return (error);
4893 }
4894 maxlen = req->oldptr != NULL ? req->oldlen : -1;
4895 error = kern_proc_cwd_out(p, &sb, maxlen);
4896 error2 = sbuf_finish(&sb);
4897 sbuf_delete(&sb);
4898 return (error != 0 ? error : error2);
4899 }
4900
4901 static SYSCTL_NODE(_kern_proc, KERN_PROC_CWD, cwd, CTLFLAG_RD|CTLFLAG_MPSAFE,
4902 sysctl_kern_proc_cwd, "Process current working directory");
4903
4904 #ifdef DDB
4905 /*
4906 * For the purposes of debugging, generate a human-readable string for the
4907 * file type.
4908 */
4909 static const char *
4910 file_type_to_name(short type)
4911 {
4912
4913 switch (type) {
4914 case 0:
4915 return ("zero");
4916 case DTYPE_VNODE:
4917 return ("vnode");
4918 case DTYPE_SOCKET:
4919 return ("socket");
4920 case DTYPE_PIPE:
4921 return ("pipe");
4922 case DTYPE_FIFO:
4923 return ("fifo");
4924 case DTYPE_KQUEUE:
4925 return ("kqueue");
4926 case DTYPE_CRYPTO:
4927 return ("crypto");
4928 case DTYPE_MQUEUE:
4929 return ("mqueue");
4930 case DTYPE_SHM:
4931 return ("shm");
4932 case DTYPE_SEM:
4933 return ("ksem");
4934 case DTYPE_PTS:
4935 return ("pts");
4936 case DTYPE_DEV:
4937 return ("dev");
4938 case DTYPE_PROCDESC:
4939 return ("proc");
4940 case DTYPE_EVENTFD:
4941 return ("eventfd");
4942 case DTYPE_LINUXTFD:
4943 return ("ltimer");
4944 default:
4945 return ("unkn");
4946 }
4947 }
4948
4949 /*
4950 * For the purposes of debugging, identify a process (if any, perhaps one of
4951 * many) that references the passed file in its file descriptor array. Return
4952 * NULL if none.
4953 */
4954 static struct proc *
4955 file_to_first_proc(struct file *fp)
4956 {
4957 struct filedesc *fdp;
4958 struct proc *p;
4959 int n;
4960
4961 FOREACH_PROC_IN_SYSTEM(p) {
4962 if (p->p_state == PRS_NEW)
4963 continue;
4964 fdp = p->p_fd;
4965 if (fdp == NULL)
4966 continue;
4967 for (n = 0; n < fdp->fd_nfiles; n++) {
4968 if (fp == fdp->fd_ofiles[n].fde_file)
4969 return (p);
4970 }
4971 }
4972 return (NULL);
4973 }
4974
4975 static void
4976 db_print_file(struct file *fp, int header)
4977 {
4978 #define XPTRWIDTH ((int)howmany(sizeof(void *) * NBBY, 4))
4979 struct proc *p;
4980
4981 if (header)
4982 db_printf("%*s %6s %*s %8s %4s %5s %6s %*s %5s %s\n",
4983 XPTRWIDTH, "File", "Type", XPTRWIDTH, "Data", "Flag",
4984 "GCFl", "Count", "MCount", XPTRWIDTH, "Vnode", "FPID",
4985 "FCmd");
4986 p = file_to_first_proc(fp);
4987 db_printf("%*p %6s %*p %08x %04x %5d %6d %*p %5d %s\n", XPTRWIDTH,
4988 fp, file_type_to_name(fp->f_type), XPTRWIDTH, fp->f_data,
4989 fp->f_flag, 0, refcount_load(&fp->f_count), 0, XPTRWIDTH, fp->f_vnode,
4990 p != NULL ? p->p_pid : -1, p != NULL ? p->p_comm : "-");
4991
4992 #undef XPTRWIDTH
4993 }
4994
4995 DB_SHOW_COMMAND(file, db_show_file)
4996 {
4997 struct file *fp;
4998
4999 if (!have_addr) {
5000 db_printf("usage: show file <addr>\n");
5001 return;
5002 }
5003 fp = (struct file *)addr;
5004 db_print_file(fp, 1);
5005 }
5006
5007 DB_SHOW_COMMAND_FLAGS(files, db_show_files, DB_CMD_MEMSAFE)
5008 {
5009 struct filedesc *fdp;
5010 struct file *fp;
5011 struct proc *p;
5012 int header;
5013 int n;
5014
5015 header = 1;
5016 FOREACH_PROC_IN_SYSTEM(p) {
5017 if (p->p_state == PRS_NEW)
5018 continue;
5019 if ((fdp = p->p_fd) == NULL)
5020 continue;
5021 for (n = 0; n < fdp->fd_nfiles; ++n) {
5022 if ((fp = fdp->fd_ofiles[n].fde_file) == NULL)
5023 continue;
5024 db_print_file(fp, header);
5025 header = 0;
5026 }
5027 }
5028 }
5029 #endif
5030
5031 SYSCTL_INT(_kern, KERN_MAXFILESPERPROC, maxfilesperproc, CTLFLAG_RW,
5032 &maxfilesperproc, 0, "Maximum files allowed open per process");
5033
5034 SYSCTL_INT(_kern, KERN_MAXFILES, maxfiles, CTLFLAG_RW,
5035 &maxfiles, 0, "Maximum number of files");
5036
5037 SYSCTL_INT(_kern, OID_AUTO, openfiles, CTLFLAG_RD,
5038 &openfiles, 0, "System-wide number of open files");
5039
5040 /* ARGSUSED*/
5041 static void
5042 filelistinit(void *dummy)
5043 {
5044
5045 file_zone = uma_zcreate("Files", sizeof(struct file), NULL, NULL,
5046 NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE);
5047 filedesc0_zone = uma_zcreate("filedesc0", sizeof(struct filedesc0),
5048 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0);
5049 pwd_zone = uma_zcreate("PWD", sizeof(struct pwd), NULL, NULL,
5050 NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_SMR);
5051 /*
5052 * XXXMJG this is a temporary hack due to boot ordering issues against
5053 * the vnode zone.
5054 */
5055 vfs_smr = uma_zone_get_smr(pwd_zone);
5056 mtx_init(&sigio_lock, "sigio lock", NULL, MTX_DEF);
5057 }
5058 SYSINIT(select, SI_SUB_LOCK, SI_ORDER_FIRST, filelistinit, NULL);
5059
5060 /*-------------------------------------------------------------------*/
5061
5062 static int
5063 badfo_readwrite(struct file *fp, struct uio *uio, struct ucred *active_cred,
5064 int flags, struct thread *td)
5065 {
5066
5067 return (EBADF);
5068 }
5069
5070 static int
5071 badfo_truncate(struct file *fp, off_t length, struct ucred *active_cred,
5072 struct thread *td)
5073 {
5074
5075 return (EINVAL);
5076 }
5077
5078 static int
5079 badfo_ioctl(struct file *fp, u_long com, void *data, struct ucred *active_cred,
5080 struct thread *td)
5081 {
5082
5083 return (EBADF);
5084 }
5085
5086 static int
5087 badfo_poll(struct file *fp, int events, struct ucred *active_cred,
5088 struct thread *td)
5089 {
5090
5091 return (0);
5092 }
5093
5094 static int
5095 badfo_kqfilter(struct file *fp, struct knote *kn)
5096 {
5097
5098 return (EBADF);
5099 }
5100
5101 static int
5102 badfo_stat(struct file *fp, struct stat *sb, struct ucred *active_cred)
5103 {
5104
5105 return (EBADF);
5106 }
5107
5108 static int
5109 badfo_close(struct file *fp, struct thread *td)
5110 {
5111
5112 return (0);
5113 }
5114
5115 static int
5116 badfo_chmod(struct file *fp, mode_t mode, struct ucred *active_cred,
5117 struct thread *td)
5118 {
5119
5120 return (EBADF);
5121 }
5122
5123 static int
5124 badfo_chown(struct file *fp, uid_t uid, gid_t gid, struct ucred *active_cred,
5125 struct thread *td)
5126 {
5127
5128 return (EBADF);
5129 }
5130
5131 static int
5132 badfo_sendfile(struct file *fp, int sockfd, struct uio *hdr_uio,
5133 struct uio *trl_uio, off_t offset, size_t nbytes, off_t *sent, int flags,
5134 struct thread *td)
5135 {
5136
5137 return (EBADF);
5138 }
5139
5140 static int
5141 badfo_fill_kinfo(struct file *fp, struct kinfo_file *kif, struct filedesc *fdp)
5142 {
5143
5144 return (0);
5145 }
5146
5147 struct fileops badfileops = {
5148 .fo_read = badfo_readwrite,
5149 .fo_write = badfo_readwrite,
5150 .fo_truncate = badfo_truncate,
5151 .fo_ioctl = badfo_ioctl,
5152 .fo_poll = badfo_poll,
5153 .fo_kqfilter = badfo_kqfilter,
5154 .fo_stat = badfo_stat,
5155 .fo_close = badfo_close,
5156 .fo_chmod = badfo_chmod,
5157 .fo_chown = badfo_chown,
5158 .fo_sendfile = badfo_sendfile,
5159 .fo_fill_kinfo = badfo_fill_kinfo,
5160 };
5161
5162 static int
5163 path_poll(struct file *fp, int events, struct ucred *active_cred,
5164 struct thread *td)
5165 {
5166 return (POLLNVAL);
5167 }
5168
5169 static int
5170 path_close(struct file *fp, struct thread *td)
5171 {
5172 MPASS(fp->f_type == DTYPE_VNODE);
5173 fp->f_ops = &badfileops;
5174 vrele(fp->f_vnode);
5175 return (0);
5176 }
5177
5178 struct fileops path_fileops = {
5179 .fo_read = badfo_readwrite,
5180 .fo_write = badfo_readwrite,
5181 .fo_truncate = badfo_truncate,
5182 .fo_ioctl = badfo_ioctl,
5183 .fo_poll = path_poll,
5184 .fo_kqfilter = vn_kqfilter_opath,
5185 .fo_stat = vn_statfile,
5186 .fo_close = path_close,
5187 .fo_chmod = badfo_chmod,
5188 .fo_chown = badfo_chown,
5189 .fo_sendfile = badfo_sendfile,
5190 .fo_fill_kinfo = vn_fill_kinfo,
5191 .fo_flags = DFLAG_PASSABLE,
5192 };
5193
5194 int
5195 invfo_rdwr(struct file *fp, struct uio *uio, struct ucred *active_cred,
5196 int flags, struct thread *td)
5197 {
5198
5199 return (EOPNOTSUPP);
5200 }
5201
5202 int
5203 invfo_truncate(struct file *fp, off_t length, struct ucred *active_cred,
5204 struct thread *td)
5205 {
5206
5207 return (EINVAL);
5208 }
5209
5210 int
5211 invfo_ioctl(struct file *fp, u_long com, void *data,
5212 struct ucred *active_cred, struct thread *td)
5213 {
5214
5215 return (ENOTTY);
5216 }
5217
5218 int
5219 invfo_poll(struct file *fp, int events, struct ucred *active_cred,
5220 struct thread *td)
5221 {
5222
5223 return (poll_no_poll(events));
5224 }
5225
5226 int
5227 invfo_kqfilter(struct file *fp, struct knote *kn)
5228 {
5229
5230 return (EINVAL);
5231 }
5232
5233 int
5234 invfo_chmod(struct file *fp, mode_t mode, struct ucred *active_cred,
5235 struct thread *td)
5236 {
5237
5238 return (EINVAL);
5239 }
5240
5241 int
5242 invfo_chown(struct file *fp, uid_t uid, gid_t gid, struct ucred *active_cred,
5243 struct thread *td)
5244 {
5245
5246 return (EINVAL);
5247 }
5248
5249 int
5250 invfo_sendfile(struct file *fp, int sockfd, struct uio *hdr_uio,
5251 struct uio *trl_uio, off_t offset, size_t nbytes, off_t *sent, int flags,
5252 struct thread *td)
5253 {
5254
5255 return (EINVAL);
5256 }
5257
5258 /*-------------------------------------------------------------------*/
5259
5260 /*
5261 * File Descriptor pseudo-device driver (/dev/fd/).
5262 *
5263 * Opening minor device N dup()s the file (if any) connected to file
5264 * descriptor N belonging to the calling process. Note that this driver
5265 * consists of only the ``open()'' routine, because all subsequent
5266 * references to this file will be direct to the other driver.
5267 *
5268 * XXX: we could give this one a cloning event handler if necessary.
5269 */
5270
5271 /* ARGSUSED */
5272 static int
5273 fdopen(struct cdev *dev, int mode, int type, struct thread *td)
5274 {
5275
5276 /*
5277 * XXX Kludge: set curthread->td_dupfd to contain the value of the
5278 * the file descriptor being sought for duplication. The error
5279 * return ensures that the vnode for this device will be released
5280 * by vn_open. Open will detect this special error and take the
5281 * actions in dupfdopen below. Other callers of vn_open or VOP_OPEN
5282 * will simply report the error.
5283 */
5284 td->td_dupfd = dev2unit(dev);
5285 return (ENODEV);
5286 }
5287
5288 static struct cdevsw fildesc_cdevsw = {
5289 .d_version = D_VERSION,
5290 .d_open = fdopen,
5291 .d_name = "FD",
5292 };
5293
5294 static void
5295 fildesc_drvinit(void *unused)
5296 {
5297 struct cdev *dev;
5298
5299 dev = make_dev_credf(MAKEDEV_ETERNAL, &fildesc_cdevsw, 0, NULL,
5300 UID_ROOT, GID_WHEEL, 0666, "fd/0");
5301 make_dev_alias(dev, "stdin");
5302 dev = make_dev_credf(MAKEDEV_ETERNAL, &fildesc_cdevsw, 1, NULL,
5303 UID_ROOT, GID_WHEEL, 0666, "fd/1");
5304 make_dev_alias(dev, "stdout");
5305 dev = make_dev_credf(MAKEDEV_ETERNAL, &fildesc_cdevsw, 2, NULL,
5306 UID_ROOT, GID_WHEEL, 0666, "fd/2");
5307 make_dev_alias(dev, "stderr");
5308 }
5309
5310 SYSINIT(fildescdev, SI_SUB_DRIVERS, SI_ORDER_MIDDLE, fildesc_drvinit, NULL);
Cache object: 3204883388440205161738b3143c403f
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