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 #include "opt_capsicum.h"
41 #include "opt_ddb.h"
42 #include "opt_ktrace.h"
43
44 #include <sys/param.h>
45 #include <sys/systm.h>
46
47 #include <sys/capsicum.h>
48 #include <sys/conf.h>
49 #include <sys/fcntl.h>
50 #include <sys/file.h>
51 #include <sys/filedesc.h>
52 #include <sys/filio.h>
53 #include <sys/jail.h>
54 #include <sys/kernel.h>
55 #include <sys/limits.h>
56 #include <sys/lock.h>
57 #include <sys/malloc.h>
58 #include <sys/mount.h>
59 #include <sys/mutex.h>
60 #include <sys/namei.h>
61 #include <sys/selinfo.h>
62 #include <sys/poll.h>
63 #include <sys/priv.h>
64 #include <sys/proc.h>
65 #include <sys/protosw.h>
66 #include <sys/racct.h>
67 #include <sys/resourcevar.h>
68 #include <sys/sbuf.h>
69 #include <sys/signalvar.h>
70 #include <sys/kdb.h>
71 #include <sys/smr.h>
72 #include <sys/stat.h>
73 #include <sys/sx.h>
74 #include <sys/syscallsubr.h>
75 #include <sys/sysctl.h>
76 #include <sys/sysproto.h>
77 #include <sys/unistd.h>
78 #include <sys/user.h>
79 #include <sys/vnode.h>
80 #include <sys/ktrace.h>
81
82 #include <net/vnet.h>
83
84 #include <security/audit/audit.h>
85
86 #include <vm/uma.h>
87 #include <vm/vm.h>
88
89 #include <ddb/ddb.h>
90
91 static MALLOC_DEFINE(M_FILEDESC, "filedesc", "Open file descriptor table");
92 static MALLOC_DEFINE(M_PWD, "pwd", "Descriptor table vnodes");
93 static MALLOC_DEFINE(M_PWDDESC, "pwddesc", "Pwd descriptors");
94 static MALLOC_DEFINE(M_FILEDESC_TO_LEADER, "filedesc_to_leader",
95 "file desc to leader structures");
96 static MALLOC_DEFINE(M_SIGIO, "sigio", "sigio structures");
97 MALLOC_DEFINE(M_FILECAPS, "filecaps", "descriptor capabilities");
98
99 MALLOC_DECLARE(M_FADVISE);
100
101 static __read_mostly uma_zone_t file_zone;
102 static __read_mostly uma_zone_t filedesc0_zone;
103 __read_mostly uma_zone_t pwd_zone;
104 VFS_SMR_DECLARE;
105
106 static int closefp(struct filedesc *fdp, int fd, struct file *fp,
107 struct thread *td, bool holdleaders, bool audit);
108 static void export_file_to_kinfo(struct file *fp, int fd,
109 cap_rights_t *rightsp, struct kinfo_file *kif,
110 struct filedesc *fdp, int flags);
111 static int fd_first_free(struct filedesc *fdp, int low, int size);
112 static void fdgrowtable(struct filedesc *fdp, int nfd);
113 static void fdgrowtable_exp(struct filedesc *fdp, int nfd);
114 static void fdunused(struct filedesc *fdp, int fd);
115 static void fdused(struct filedesc *fdp, int fd);
116 static int fget_unlocked_seq(struct filedesc *fdp, int fd,
117 cap_rights_t *needrightsp, struct file **fpp, seqc_t *seqp);
118 static int getmaxfd(struct thread *td);
119 static u_long *filecaps_copy_prep(const struct filecaps *src);
120 static void filecaps_copy_finish(const struct filecaps *src,
121 struct filecaps *dst, u_long *ioctls);
122 static u_long *filecaps_free_prep(struct filecaps *fcaps);
123 static void filecaps_free_finish(u_long *ioctls);
124
125 static struct pwd *pwd_alloc(void);
126
127 /*
128 * Each process has:
129 *
130 * - An array of open file descriptors (fd_ofiles)
131 * - An array of file flags (fd_ofileflags)
132 * - A bitmap recording which descriptors are in use (fd_map)
133 *
134 * A process starts out with NDFILE descriptors. The value of NDFILE has
135 * been selected based the historical limit of 20 open files, and an
136 * assumption that the majority of processes, especially short-lived
137 * processes like shells, will never need more.
138 *
139 * If this initial allocation is exhausted, a larger descriptor table and
140 * map are allocated dynamically, and the pointers in the process's struct
141 * filedesc are updated to point to those. This is repeated every time
142 * the process runs out of file descriptors (provided it hasn't hit its
143 * resource limit).
144 *
145 * Since threads may hold references to individual descriptor table
146 * entries, the tables are never freed. Instead, they are placed on a
147 * linked list and freed only when the struct filedesc is released.
148 */
149 #define NDFILE 20
150 #define NDSLOTSIZE sizeof(NDSLOTTYPE)
151 #define NDENTRIES (NDSLOTSIZE * __CHAR_BIT)
152 #define NDSLOT(x) ((x) / NDENTRIES)
153 #define NDBIT(x) ((NDSLOTTYPE)1 << ((x) % NDENTRIES))
154 #define NDSLOTS(x) (((x) + NDENTRIES - 1) / NDENTRIES)
155
156 /*
157 * SLIST entry used to keep track of ofiles which must be reclaimed when
158 * the process exits.
159 */
160 struct freetable {
161 struct fdescenttbl *ft_table;
162 SLIST_ENTRY(freetable) ft_next;
163 };
164
165 /*
166 * Initial allocation: a filedesc structure + the head of SLIST used to
167 * keep track of old ofiles + enough space for NDFILE descriptors.
168 */
169
170 struct fdescenttbl0 {
171 int fdt_nfiles;
172 struct filedescent fdt_ofiles[NDFILE];
173 };
174
175 struct filedesc0 {
176 struct filedesc fd_fd;
177 SLIST_HEAD(, freetable) fd_free;
178 struct fdescenttbl0 fd_dfiles;
179 NDSLOTTYPE fd_dmap[NDSLOTS(NDFILE)];
180 };
181
182 /*
183 * Descriptor management.
184 */
185 static int __exclusive_cache_line openfiles; /* actual number of open files */
186 struct mtx sigio_lock; /* mtx to protect pointers to sigio */
187 void __read_mostly (*mq_fdclose)(struct thread *td, int fd, struct file *fp);
188
189 /*
190 * If low >= size, just return low. Otherwise find the first zero bit in the
191 * given bitmap, starting at low and not exceeding size - 1. Return size if
192 * not found.
193 */
194 static int
fd_first_free(struct filedesc * fdp,int low,int size)195 fd_first_free(struct filedesc *fdp, int low, int size)
196 {
197 NDSLOTTYPE *map = fdp->fd_map;
198 NDSLOTTYPE mask;
199 int off, maxoff;
200
201 if (low >= size)
202 return (low);
203
204 off = NDSLOT(low);
205 if (low % NDENTRIES) {
206 mask = ~(~(NDSLOTTYPE)0 >> (NDENTRIES - (low % NDENTRIES)));
207 if ((mask &= ~map[off]) != 0UL)
208 return (off * NDENTRIES + ffsl(mask) - 1);
209 ++off;
210 }
211 for (maxoff = NDSLOTS(size); off < maxoff; ++off)
212 if (map[off] != ~0UL)
213 return (off * NDENTRIES + ffsl(~map[off]) - 1);
214 return (size);
215 }
216
217 /*
218 * Find the last used fd.
219 *
220 * Call this variant if fdp can't be modified by anyone else (e.g, during exec).
221 * Otherwise use fdlastfile.
222 */
223 int
fdlastfile_single(struct filedesc * fdp)224 fdlastfile_single(struct filedesc *fdp)
225 {
226 NDSLOTTYPE *map = fdp->fd_map;
227 int off, minoff;
228
229 off = NDSLOT(fdp->fd_nfiles - 1);
230 for (minoff = NDSLOT(0); off >= minoff; --off)
231 if (map[off] != 0)
232 return (off * NDENTRIES + flsl(map[off]) - 1);
233 return (-1);
234 }
235
236 int
fdlastfile(struct filedesc * fdp)237 fdlastfile(struct filedesc *fdp)
238 {
239
240 FILEDESC_LOCK_ASSERT(fdp);
241 return (fdlastfile_single(fdp));
242 }
243
244 static int
fdisused(struct filedesc * fdp,int fd)245 fdisused(struct filedesc *fdp, int fd)
246 {
247
248 KASSERT(fd >= 0 && fd < fdp->fd_nfiles,
249 ("file descriptor %d out of range (0, %d)", fd, fdp->fd_nfiles));
250
251 return ((fdp->fd_map[NDSLOT(fd)] & NDBIT(fd)) != 0);
252 }
253
254 /*
255 * Mark a file descriptor as used.
256 */
257 static void
fdused_init(struct filedesc * fdp,int fd)258 fdused_init(struct filedesc *fdp, int fd)
259 {
260
261 KASSERT(!fdisused(fdp, fd), ("fd=%d is already used", fd));
262
263 fdp->fd_map[NDSLOT(fd)] |= NDBIT(fd);
264 }
265
266 static void
fdused(struct filedesc * fdp,int fd)267 fdused(struct filedesc *fdp, int fd)
268 {
269
270 FILEDESC_XLOCK_ASSERT(fdp);
271
272 fdused_init(fdp, fd);
273 if (fd == fdp->fd_freefile)
274 fdp->fd_freefile++;
275 }
276
277 /*
278 * Mark a file descriptor as unused.
279 */
280 static void
fdunused(struct filedesc * fdp,int fd)281 fdunused(struct filedesc *fdp, int fd)
282 {
283
284 FILEDESC_XLOCK_ASSERT(fdp);
285
286 KASSERT(fdisused(fdp, fd), ("fd=%d is already unused", fd));
287 KASSERT(fdp->fd_ofiles[fd].fde_file == NULL,
288 ("fd=%d is still in use", fd));
289
290 fdp->fd_map[NDSLOT(fd)] &= ~NDBIT(fd);
291 if (fd < fdp->fd_freefile)
292 fdp->fd_freefile = fd;
293 }
294
295 /*
296 * Free a file descriptor.
297 *
298 * Avoid some work if fdp is about to be destroyed.
299 */
300 static inline void
fdefree_last(struct filedescent * fde)301 fdefree_last(struct filedescent *fde)
302 {
303
304 filecaps_free(&fde->fde_caps);
305 }
306
307 static inline void
fdfree(struct filedesc * fdp,int fd)308 fdfree(struct filedesc *fdp, int fd)
309 {
310 struct filedescent *fde;
311
312 FILEDESC_XLOCK_ASSERT(fdp);
313 fde = &fdp->fd_ofiles[fd];
314 #ifdef CAPABILITIES
315 seqc_write_begin(&fde->fde_seqc);
316 #endif
317 fde->fde_file = NULL;
318 #ifdef CAPABILITIES
319 seqc_write_end(&fde->fde_seqc);
320 #endif
321 fdefree_last(fde);
322 fdunused(fdp, fd);
323 }
324
325 /*
326 * System calls on descriptors.
327 */
328 #ifndef _SYS_SYSPROTO_H_
329 struct getdtablesize_args {
330 int dummy;
331 };
332 #endif
333 /* ARGSUSED */
334 int
sys_getdtablesize(struct thread * td,struct getdtablesize_args * uap)335 sys_getdtablesize(struct thread *td, struct getdtablesize_args *uap)
336 {
337 #ifdef RACCT
338 uint64_t lim;
339 #endif
340
341 td->td_retval[0] = getmaxfd(td);
342 #ifdef RACCT
343 PROC_LOCK(td->td_proc);
344 lim = racct_get_limit(td->td_proc, RACCT_NOFILE);
345 PROC_UNLOCK(td->td_proc);
346 if (lim < td->td_retval[0])
347 td->td_retval[0] = lim;
348 #endif
349 return (0);
350 }
351
352 /*
353 * Duplicate a file descriptor to a particular value.
354 *
355 * Note: keep in mind that a potential race condition exists when closing
356 * descriptors from a shared descriptor table (via rfork).
357 */
358 #ifndef _SYS_SYSPROTO_H_
359 struct dup2_args {
360 u_int from;
361 u_int to;
362 };
363 #endif
364 /* ARGSUSED */
365 int
sys_dup2(struct thread * td,struct dup2_args * uap)366 sys_dup2(struct thread *td, struct dup2_args *uap)
367 {
368
369 return (kern_dup(td, FDDUP_FIXED, 0, (int)uap->from, (int)uap->to));
370 }
371
372 /*
373 * Duplicate a file descriptor.
374 */
375 #ifndef _SYS_SYSPROTO_H_
376 struct dup_args {
377 u_int fd;
378 };
379 #endif
380 /* ARGSUSED */
381 int
sys_dup(struct thread * td,struct dup_args * uap)382 sys_dup(struct thread *td, struct dup_args *uap)
383 {
384
385 return (kern_dup(td, FDDUP_NORMAL, 0, (int)uap->fd, 0));
386 }
387
388 /*
389 * The file control system call.
390 */
391 #ifndef _SYS_SYSPROTO_H_
392 struct fcntl_args {
393 int fd;
394 int cmd;
395 long arg;
396 };
397 #endif
398 /* ARGSUSED */
399 int
sys_fcntl(struct thread * td,struct fcntl_args * uap)400 sys_fcntl(struct thread *td, struct fcntl_args *uap)
401 {
402
403 return (kern_fcntl_freebsd(td, uap->fd, uap->cmd, uap->arg));
404 }
405
406 int
kern_fcntl_freebsd(struct thread * td,int fd,int cmd,long arg)407 kern_fcntl_freebsd(struct thread *td, int fd, int cmd, long arg)
408 {
409 struct flock fl;
410 struct __oflock ofl;
411 intptr_t arg1;
412 int error, newcmd;
413
414 error = 0;
415 newcmd = cmd;
416 switch (cmd) {
417 case F_OGETLK:
418 case F_OSETLK:
419 case F_OSETLKW:
420 /*
421 * Convert old flock structure to new.
422 */
423 error = copyin((void *)(intptr_t)arg, &ofl, sizeof(ofl));
424 fl.l_start = ofl.l_start;
425 fl.l_len = ofl.l_len;
426 fl.l_pid = ofl.l_pid;
427 fl.l_type = ofl.l_type;
428 fl.l_whence = ofl.l_whence;
429 fl.l_sysid = 0;
430
431 switch (cmd) {
432 case F_OGETLK:
433 newcmd = F_GETLK;
434 break;
435 case F_OSETLK:
436 newcmd = F_SETLK;
437 break;
438 case F_OSETLKW:
439 newcmd = F_SETLKW;
440 break;
441 }
442 arg1 = (intptr_t)&fl;
443 break;
444 case F_GETLK:
445 case F_SETLK:
446 case F_SETLKW:
447 case F_SETLK_REMOTE:
448 error = copyin((void *)(intptr_t)arg, &fl, sizeof(fl));
449 arg1 = (intptr_t)&fl;
450 break;
451 default:
452 arg1 = arg;
453 break;
454 }
455 if (error)
456 return (error);
457 error = kern_fcntl(td, fd, newcmd, arg1);
458 if (error)
459 return (error);
460 if (cmd == F_OGETLK) {
461 ofl.l_start = fl.l_start;
462 ofl.l_len = fl.l_len;
463 ofl.l_pid = fl.l_pid;
464 ofl.l_type = fl.l_type;
465 ofl.l_whence = fl.l_whence;
466 error = copyout(&ofl, (void *)(intptr_t)arg, sizeof(ofl));
467 } else if (cmd == F_GETLK) {
468 error = copyout(&fl, (void *)(intptr_t)arg, sizeof(fl));
469 }
470 return (error);
471 }
472
473 int
kern_fcntl(struct thread * td,int fd,int cmd,intptr_t arg)474 kern_fcntl(struct thread *td, int fd, int cmd, intptr_t arg)
475 {
476 struct filedesc *fdp;
477 struct flock *flp;
478 struct file *fp, *fp2;
479 struct filedescent *fde;
480 struct proc *p;
481 struct vnode *vp;
482 struct mount *mp;
483 struct kinfo_file *kif;
484 int error, flg, kif_sz, seals, tmp, got_set, got_cleared;
485 uint64_t bsize;
486 off_t foffset;
487
488 error = 0;
489 flg = F_POSIX;
490 p = td->td_proc;
491 fdp = p->p_fd;
492
493 AUDIT_ARG_FD(cmd);
494 AUDIT_ARG_CMD(cmd);
495 switch (cmd) {
496 case F_DUPFD:
497 tmp = arg;
498 error = kern_dup(td, FDDUP_FCNTL, 0, fd, tmp);
499 break;
500
501 case F_DUPFD_CLOEXEC:
502 tmp = arg;
503 error = kern_dup(td, FDDUP_FCNTL, FDDUP_FLAG_CLOEXEC, fd, tmp);
504 break;
505
506 case F_DUP2FD:
507 tmp = arg;
508 error = kern_dup(td, FDDUP_FIXED, 0, fd, tmp);
509 break;
510
511 case F_DUP2FD_CLOEXEC:
512 tmp = arg;
513 error = kern_dup(td, FDDUP_FIXED, FDDUP_FLAG_CLOEXEC, fd, tmp);
514 break;
515
516 case F_GETFD:
517 error = EBADF;
518 FILEDESC_SLOCK(fdp);
519 fde = fdeget_locked(fdp, fd);
520 if (fde != NULL) {
521 td->td_retval[0] =
522 (fde->fde_flags & UF_EXCLOSE) ? FD_CLOEXEC : 0;
523 error = 0;
524 }
525 FILEDESC_SUNLOCK(fdp);
526 break;
527
528 case F_SETFD:
529 error = EBADF;
530 FILEDESC_XLOCK(fdp);
531 fde = fdeget_locked(fdp, fd);
532 if (fde != NULL) {
533 fde->fde_flags = (fde->fde_flags & ~UF_EXCLOSE) |
534 (arg & FD_CLOEXEC ? UF_EXCLOSE : 0);
535 error = 0;
536 }
537 FILEDESC_XUNLOCK(fdp);
538 break;
539
540 case F_GETFL:
541 error = fget_fcntl(td, fd, &cap_fcntl_rights, F_GETFL, &fp);
542 if (error != 0)
543 break;
544 td->td_retval[0] = OFLAGS(fp->f_flag);
545 fdrop(fp, td);
546 break;
547
548 case F_SETFL:
549 error = fget_fcntl(td, fd, &cap_fcntl_rights, F_SETFL, &fp);
550 if (error != 0)
551 break;
552 if (fp->f_ops == &path_fileops) {
553 fdrop(fp, td);
554 error = EBADF;
555 break;
556 }
557 do {
558 tmp = flg = fp->f_flag;
559 tmp &= ~FCNTLFLAGS;
560 tmp |= FFLAGS(arg & ~O_ACCMODE) & FCNTLFLAGS;
561 } while (atomic_cmpset_int(&fp->f_flag, flg, tmp) == 0);
562 got_set = tmp & ~flg;
563 got_cleared = flg & ~tmp;
564 tmp = fp->f_flag & FNONBLOCK;
565 error = fo_ioctl(fp, FIONBIO, &tmp, td->td_ucred, td);
566 if (error != 0)
567 goto revert_f_setfl;
568 tmp = fp->f_flag & FASYNC;
569 error = fo_ioctl(fp, FIOASYNC, &tmp, td->td_ucred, td);
570 if (error == 0) {
571 fdrop(fp, td);
572 break;
573 }
574 atomic_clear_int(&fp->f_flag, FNONBLOCK);
575 tmp = 0;
576 (void)fo_ioctl(fp, FIONBIO, &tmp, td->td_ucred, td);
577 revert_f_setfl:
578 do {
579 tmp = flg = fp->f_flag;
580 tmp &= ~FCNTLFLAGS;
581 tmp |= got_cleared;
582 tmp &= ~got_set;
583 } while (atomic_cmpset_int(&fp->f_flag, flg, tmp) == 0);
584 fdrop(fp, td);
585 break;
586
587 case F_GETOWN:
588 error = fget_fcntl(td, fd, &cap_fcntl_rights, F_GETOWN, &fp);
589 if (error != 0)
590 break;
591 error = fo_ioctl(fp, FIOGETOWN, &tmp, td->td_ucred, td);
592 if (error == 0)
593 td->td_retval[0] = tmp;
594 fdrop(fp, td);
595 break;
596
597 case F_SETOWN:
598 error = fget_fcntl(td, fd, &cap_fcntl_rights, F_SETOWN, &fp);
599 if (error != 0)
600 break;
601 tmp = arg;
602 error = fo_ioctl(fp, FIOSETOWN, &tmp, td->td_ucred, td);
603 fdrop(fp, td);
604 break;
605
606 case F_SETLK_REMOTE:
607 error = priv_check(td, PRIV_NFS_LOCKD);
608 if (error != 0)
609 return (error);
610 flg = F_REMOTE;
611 goto do_setlk;
612
613 case F_SETLKW:
614 flg |= F_WAIT;
615 /* FALLTHROUGH F_SETLK */
616
617 case F_SETLK:
618 do_setlk:
619 flp = (struct flock *)arg;
620 if ((flg & F_REMOTE) != 0 && flp->l_sysid == 0) {
621 error = EINVAL;
622 break;
623 }
624
625 error = fget_unlocked(fdp, fd, &cap_flock_rights, &fp);
626 if (error != 0)
627 break;
628 if (fp->f_type != DTYPE_VNODE || fp->f_ops == &path_fileops) {
629 error = EBADF;
630 fdrop(fp, td);
631 break;
632 }
633
634 if (flp->l_whence == SEEK_CUR) {
635 foffset = foffset_get(fp);
636 if (foffset < 0 ||
637 (flp->l_start > 0 &&
638 foffset > OFF_MAX - flp->l_start)) {
639 error = EOVERFLOW;
640 fdrop(fp, td);
641 break;
642 }
643 flp->l_start += foffset;
644 }
645
646 vp = fp->f_vnode;
647 switch (flp->l_type) {
648 case F_RDLCK:
649 if ((fp->f_flag & FREAD) == 0) {
650 error = EBADF;
651 break;
652 }
653 if ((p->p_leader->p_flag & P_ADVLOCK) == 0) {
654 PROC_LOCK(p->p_leader);
655 p->p_leader->p_flag |= P_ADVLOCK;
656 PROC_UNLOCK(p->p_leader);
657 }
658 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_SETLK,
659 flp, flg);
660 break;
661 case F_WRLCK:
662 if ((fp->f_flag & FWRITE) == 0) {
663 error = EBADF;
664 break;
665 }
666 if ((p->p_leader->p_flag & P_ADVLOCK) == 0) {
667 PROC_LOCK(p->p_leader);
668 p->p_leader->p_flag |= P_ADVLOCK;
669 PROC_UNLOCK(p->p_leader);
670 }
671 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_SETLK,
672 flp, flg);
673 break;
674 case F_UNLCK:
675 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_UNLCK,
676 flp, flg);
677 break;
678 case F_UNLCKSYS:
679 if (flg != F_REMOTE) {
680 error = EINVAL;
681 break;
682 }
683 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader,
684 F_UNLCKSYS, flp, flg);
685 break;
686 default:
687 error = EINVAL;
688 break;
689 }
690 if (error != 0 || flp->l_type == F_UNLCK ||
691 flp->l_type == F_UNLCKSYS) {
692 fdrop(fp, td);
693 break;
694 }
695
696 /*
697 * Check for a race with close.
698 *
699 * The vnode is now advisory locked (or unlocked, but this case
700 * is not really important) as the caller requested.
701 * We had to drop the filedesc lock, so we need to recheck if
702 * the descriptor is still valid, because if it was closed
703 * in the meantime we need to remove advisory lock from the
704 * vnode - close on any descriptor leading to an advisory
705 * locked vnode, removes that lock.
706 * We will return 0 on purpose in that case, as the result of
707 * successful advisory lock might have been externally visible
708 * already. This is fine - effectively we pretend to the caller
709 * that the closing thread was a bit slower and that the
710 * advisory lock succeeded before the close.
711 */
712 error = fget_unlocked(fdp, fd, &cap_no_rights, &fp2);
713 if (error != 0) {
714 fdrop(fp, td);
715 break;
716 }
717 if (fp != fp2) {
718 flp->l_whence = SEEK_SET;
719 flp->l_start = 0;
720 flp->l_len = 0;
721 flp->l_type = F_UNLCK;
722 (void) VOP_ADVLOCK(vp, (caddr_t)p->p_leader,
723 F_UNLCK, flp, F_POSIX);
724 }
725 fdrop(fp, td);
726 fdrop(fp2, td);
727 break;
728
729 case F_GETLK:
730 error = fget_unlocked(fdp, fd, &cap_flock_rights, &fp);
731 if (error != 0)
732 break;
733 if (fp->f_type != DTYPE_VNODE || fp->f_ops == &path_fileops) {
734 error = EBADF;
735 fdrop(fp, td);
736 break;
737 }
738 flp = (struct flock *)arg;
739 if (flp->l_type != F_RDLCK && flp->l_type != F_WRLCK &&
740 flp->l_type != F_UNLCK) {
741 error = EINVAL;
742 fdrop(fp, td);
743 break;
744 }
745 if (flp->l_whence == SEEK_CUR) {
746 foffset = foffset_get(fp);
747 if ((flp->l_start > 0 &&
748 foffset > OFF_MAX - flp->l_start) ||
749 (flp->l_start < 0 &&
750 foffset < OFF_MIN - flp->l_start)) {
751 error = EOVERFLOW;
752 fdrop(fp, td);
753 break;
754 }
755 flp->l_start += foffset;
756 }
757 vp = fp->f_vnode;
758 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_GETLK, flp,
759 F_POSIX);
760 fdrop(fp, td);
761 break;
762
763 case F_ADD_SEALS:
764 error = fget_unlocked(fdp, fd, &cap_no_rights, &fp);
765 if (error != 0)
766 break;
767 error = fo_add_seals(fp, arg);
768 fdrop(fp, td);
769 break;
770
771 case F_GET_SEALS:
772 error = fget_unlocked(fdp, fd, &cap_no_rights, &fp);
773 if (error != 0)
774 break;
775 if (fo_get_seals(fp, &seals) == 0)
776 td->td_retval[0] = seals;
777 else
778 error = EINVAL;
779 fdrop(fp, td);
780 break;
781
782 case F_RDAHEAD:
783 arg = arg ? 128 * 1024: 0;
784 /* FALLTHROUGH */
785 case F_READAHEAD:
786 error = fget_unlocked(fdp, fd, &cap_no_rights, &fp);
787 if (error != 0)
788 break;
789 if (fp->f_type != DTYPE_VNODE || fp->f_ops == &path_fileops) {
790 fdrop(fp, td);
791 error = EBADF;
792 break;
793 }
794 vp = fp->f_vnode;
795 if (vp->v_type != VREG) {
796 fdrop(fp, td);
797 error = ENOTTY;
798 break;
799 }
800
801 /*
802 * Exclusive lock synchronizes against f_seqcount reads and
803 * writes in sequential_heuristic().
804 */
805 error = vn_lock(vp, LK_EXCLUSIVE);
806 if (error != 0) {
807 fdrop(fp, td);
808 break;
809 }
810 if (arg >= 0) {
811 bsize = fp->f_vnode->v_mount->mnt_stat.f_iosize;
812 arg = MIN(arg, INT_MAX - bsize + 1);
813 fp->f_seqcount[UIO_READ] = MIN(IO_SEQMAX,
814 (arg + bsize - 1) / bsize);
815 atomic_set_int(&fp->f_flag, FRDAHEAD);
816 } else {
817 atomic_clear_int(&fp->f_flag, FRDAHEAD);
818 }
819 VOP_UNLOCK(vp);
820 fdrop(fp, td);
821 break;
822
823 case F_ISUNIONSTACK:
824 /*
825 * Check if the vnode is part of a union stack (either the
826 * "union" flag from mount(2) or unionfs).
827 *
828 * Prior to introduction of this op libc's readdir would call
829 * fstatfs(2), in effect unnecessarily copying kilobytes of
830 * data just to check fs name and a mount flag.
831 *
832 * Fixing the code to handle everything in the kernel instead
833 * is a non-trivial endeavor and has low priority, thus this
834 * horrible kludge facilitates the current behavior in a much
835 * cheaper manner until someone(tm) sorts this out.
836 */
837 error = fget_unlocked(fdp, fd, &cap_no_rights, &fp);
838 if (error != 0)
839 break;
840 if (fp->f_type != DTYPE_VNODE) {
841 fdrop(fp, td);
842 error = EBADF;
843 break;
844 }
845 vp = fp->f_vnode;
846 /*
847 * Since we don't prevent dooming the vnode even non-null mp
848 * found can become immediately stale. This is tolerable since
849 * mount points are type-stable (providing safe memory access)
850 * and any vfs op on this vnode going forward will return an
851 * error (meaning return value in this case is meaningless).
852 */
853 mp = atomic_load_ptr(&vp->v_mount);
854 if (__predict_false(mp == NULL)) {
855 fdrop(fp, td);
856 error = EBADF;
857 break;
858 }
859 td->td_retval[0] = 0;
860 if (mp->mnt_kern_flag & MNTK_UNIONFS ||
861 mp->mnt_flag & MNT_UNION)
862 td->td_retval[0] = 1;
863 fdrop(fp, td);
864 break;
865
866 case F_KINFO:
867 #ifdef CAPABILITY_MODE
868 if (IN_CAPABILITY_MODE(td)) {
869 error = ECAPMODE;
870 break;
871 }
872 #endif
873 error = copyin((void *)arg, &kif_sz, sizeof(kif_sz));
874 if (error != 0)
875 break;
876 if (kif_sz != sizeof(*kif)) {
877 error = EINVAL;
878 break;
879 }
880 kif = malloc(sizeof(*kif), M_TEMP, M_WAITOK | M_ZERO);
881 FILEDESC_SLOCK(fdp);
882 error = fget_cap_locked(fdp, fd, &cap_fcntl_rights, &fp, NULL);
883 if (error == 0 && fhold(fp)) {
884 export_file_to_kinfo(fp, fd, NULL, kif, fdp, 0);
885 FILEDESC_SUNLOCK(fdp);
886 fdrop(fp, td);
887 if ((kif->kf_status & KF_ATTR_VALID) != 0) {
888 kif->kf_structsize = sizeof(*kif);
889 error = copyout(kif, (void *)arg, sizeof(*kif));
890 } else {
891 error = EBADF;
892 }
893 } else {
894 FILEDESC_SUNLOCK(fdp);
895 if (error == 0)
896 error = EBADF;
897 }
898 free(kif, M_TEMP);
899 break;
900
901 default:
902 error = EINVAL;
903 break;
904 }
905 return (error);
906 }
907
908 static int
getmaxfd(struct thread * td)909 getmaxfd(struct thread *td)
910 {
911
912 return (min((int)lim_cur(td, RLIMIT_NOFILE), maxfilesperproc));
913 }
914
915 /*
916 * Common code for dup, dup2, fcntl(F_DUPFD) and fcntl(F_DUP2FD).
917 */
918 int
kern_dup(struct thread * td,u_int mode,int flags,int old,int new)919 kern_dup(struct thread *td, u_int mode, int flags, int old, int new)
920 {
921 struct filedesc *fdp;
922 struct filedescent *oldfde, *newfde;
923 struct proc *p;
924 struct file *delfp, *oldfp;
925 u_long *oioctls, *nioctls;
926 int error, maxfd;
927
928 p = td->td_proc;
929 fdp = p->p_fd;
930 oioctls = NULL;
931
932 MPASS((flags & ~(FDDUP_FLAG_CLOEXEC)) == 0);
933 MPASS(mode < FDDUP_LASTMODE);
934
935 AUDIT_ARG_FD(old);
936 /* XXXRW: if (flags & FDDUP_FIXED) AUDIT_ARG_FD2(new); */
937
938 /*
939 * Verify we have a valid descriptor to dup from and possibly to
940 * dup to. Unlike dup() and dup2(), fcntl()'s F_DUPFD should
941 * return EINVAL when the new descriptor is out of bounds.
942 */
943 if (old < 0)
944 return (EBADF);
945 if (new < 0)
946 return (mode == FDDUP_FCNTL ? EINVAL : EBADF);
947 maxfd = getmaxfd(td);
948 if (new >= maxfd)
949 return (mode == FDDUP_FCNTL ? EINVAL : EBADF);
950
951 error = EBADF;
952 FILEDESC_XLOCK(fdp);
953 if (fget_locked(fdp, old) == NULL)
954 goto unlock;
955 if ((mode == FDDUP_FIXED || mode == FDDUP_MUSTREPLACE) && old == new) {
956 td->td_retval[0] = new;
957 if (flags & FDDUP_FLAG_CLOEXEC)
958 fdp->fd_ofiles[new].fde_flags |= UF_EXCLOSE;
959 error = 0;
960 goto unlock;
961 }
962
963 oldfde = &fdp->fd_ofiles[old];
964 oldfp = oldfde->fde_file;
965 if (!fhold(oldfp))
966 goto unlock;
967
968 /*
969 * If the caller specified a file descriptor, make sure the file
970 * table is large enough to hold it, and grab it. Otherwise, just
971 * allocate a new descriptor the usual way.
972 */
973 switch (mode) {
974 case FDDUP_NORMAL:
975 case FDDUP_FCNTL:
976 if ((error = fdalloc(td, new, &new)) != 0) {
977 fdrop(oldfp, td);
978 goto unlock;
979 }
980 break;
981 case FDDUP_MUSTREPLACE:
982 /* Target file descriptor must exist. */
983 if (fget_locked(fdp, new) == NULL) {
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 memcpy(newfde, oldfde, fde_change_size);
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
sigiofree(struct sigio * sigio)1064 sigiofree(struct sigio *sigio)
1065 {
1066 crfree(sigio->sio_ucred);
1067 free(sigio, M_SIGIO);
1068 }
1069
1070 static struct sigio *
funsetown_locked(struct sigio * 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
funsetown(struct sigio ** sigiop)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
funsetownlst(struct sigiolst * sigiolst)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
fsetown(pid_t pgid,struct sigio ** sigiop)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
fgetown(struct sigio ** sigiop)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
closefp_impl(struct filedesc * fdp,int fd,struct file * fp,struct thread * td,bool audit)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
closefp_hl(struct filedesc * fdp,int fd,struct file * fp,struct thread * td,bool holdleaders,bool audit)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
closefp(struct filedesc * fdp,int fd,struct file * fp,struct thread * td,bool holdleaders,bool audit)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
sys_close(struct thread * td,struct close_args * uap)1383 sys_close(struct thread *td, struct close_args *uap)
1384 {
1385
1386 return (kern_close(td, uap->fd));
1387 }
1388
1389 int
kern_close(struct thread * td,int fd)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_locked(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
close_range_cloexec(struct thread * td,u_int lowfd,u_int highfd)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
close_range_impl(struct thread * td,u_int lowfd,u_int highfd)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
kern_close_range(struct thread * td,int flags,u_int lowfd,u_int highfd)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
sys_close_range(struct thread * td,struct close_range_args * uap)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
freebsd12_closefrom(struct thread * td,struct freebsd12_closefrom_args * uap)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
ofstat(struct thread * td,struct ofstat_args * uap)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
freebsd11_fstat(struct thread * td,struct freebsd11_fstat_args * uap)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
sys_fstat(struct thread * td,struct fstat_args * uap)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
kern_fstat(struct thread * td,int fd,struct stat * sbp)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, td);
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
freebsd11_nfstat(struct thread * td,struct freebsd11_nfstat_args * uap)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 freebsd11_cvtnstat(&ub, &nub);
1654 error = copyout(&nub, uap->sb, sizeof(nub));
1655 }
1656 return (error);
1657 }
1658 #endif /* COMPAT_FREEBSD11 */
1659
1660 /*
1661 * Return pathconf information about a file descriptor.
1662 */
1663 #ifndef _SYS_SYSPROTO_H_
1664 struct fpathconf_args {
1665 int fd;
1666 int name;
1667 };
1668 #endif
1669 /* ARGSUSED */
1670 int
sys_fpathconf(struct thread * td,struct fpathconf_args * uap)1671 sys_fpathconf(struct thread *td, struct fpathconf_args *uap)
1672 {
1673 long value;
1674 int error;
1675
1676 error = kern_fpathconf(td, uap->fd, uap->name, &value);
1677 if (error == 0)
1678 td->td_retval[0] = value;
1679 return (error);
1680 }
1681
1682 int
kern_fpathconf(struct thread * td,int fd,int name,long * valuep)1683 kern_fpathconf(struct thread *td, int fd, int name, long *valuep)
1684 {
1685 struct file *fp;
1686 struct vnode *vp;
1687 int error;
1688
1689 error = fget(td, fd, &cap_fpathconf_rights, &fp);
1690 if (error != 0)
1691 return (error);
1692
1693 if (name == _PC_ASYNC_IO) {
1694 *valuep = _POSIX_ASYNCHRONOUS_IO;
1695 goto out;
1696 }
1697 vp = fp->f_vnode;
1698 if (vp != NULL) {
1699 vn_lock(vp, LK_SHARED | LK_RETRY);
1700 error = VOP_PATHCONF(vp, name, valuep);
1701 VOP_UNLOCK(vp);
1702 } else if (fp->f_type == DTYPE_PIPE || fp->f_type == DTYPE_SOCKET) {
1703 if (name != _PC_PIPE_BUF) {
1704 error = EINVAL;
1705 } else {
1706 *valuep = PIPE_BUF;
1707 error = 0;
1708 }
1709 } else {
1710 error = EOPNOTSUPP;
1711 }
1712 out:
1713 fdrop(fp, td);
1714 return (error);
1715 }
1716
1717 /*
1718 * Copy filecaps structure allocating memory for ioctls array if needed.
1719 *
1720 * The last parameter indicates whether the fdtable is locked. If it is not and
1721 * ioctls are encountered, copying fails and the caller must lock the table.
1722 *
1723 * Note that if the table was not locked, the caller has to check the relevant
1724 * sequence counter to determine whether the operation was successful.
1725 */
1726 bool
filecaps_copy(const struct filecaps * src,struct filecaps * dst,bool locked)1727 filecaps_copy(const struct filecaps *src, struct filecaps *dst, bool locked)
1728 {
1729 size_t size;
1730
1731 if (src->fc_ioctls != NULL && !locked)
1732 return (false);
1733 memcpy(dst, src, sizeof(*src));
1734 if (src->fc_ioctls == NULL)
1735 return (true);
1736
1737 KASSERT(src->fc_nioctls > 0,
1738 ("fc_ioctls != NULL, but fc_nioctls=%hd", src->fc_nioctls));
1739
1740 size = sizeof(src->fc_ioctls[0]) * src->fc_nioctls;
1741 dst->fc_ioctls = malloc(size, M_FILECAPS, M_WAITOK);
1742 memcpy(dst->fc_ioctls, src->fc_ioctls, size);
1743 return (true);
1744 }
1745
1746 static u_long *
filecaps_copy_prep(const struct filecaps * src)1747 filecaps_copy_prep(const struct filecaps *src)
1748 {
1749 u_long *ioctls;
1750 size_t size;
1751
1752 if (__predict_true(src->fc_ioctls == NULL))
1753 return (NULL);
1754
1755 KASSERT(src->fc_nioctls > 0,
1756 ("fc_ioctls != NULL, but fc_nioctls=%hd", src->fc_nioctls));
1757
1758 size = sizeof(src->fc_ioctls[0]) * src->fc_nioctls;
1759 ioctls = malloc(size, M_FILECAPS, M_WAITOK);
1760 return (ioctls);
1761 }
1762
1763 static void
filecaps_copy_finish(const struct filecaps * src,struct filecaps * dst,u_long * ioctls)1764 filecaps_copy_finish(const struct filecaps *src, struct filecaps *dst,
1765 u_long *ioctls)
1766 {
1767 size_t size;
1768
1769 *dst = *src;
1770 if (__predict_true(src->fc_ioctls == NULL)) {
1771 MPASS(ioctls == NULL);
1772 return;
1773 }
1774
1775 size = sizeof(src->fc_ioctls[0]) * src->fc_nioctls;
1776 dst->fc_ioctls = ioctls;
1777 bcopy(src->fc_ioctls, dst->fc_ioctls, size);
1778 }
1779
1780 /*
1781 * Move filecaps structure to the new place and clear the old place.
1782 */
1783 void
filecaps_move(struct filecaps * src,struct filecaps * dst)1784 filecaps_move(struct filecaps *src, struct filecaps *dst)
1785 {
1786
1787 *dst = *src;
1788 bzero(src, sizeof(*src));
1789 }
1790
1791 /*
1792 * Fill the given filecaps structure with full rights.
1793 */
1794 static void
filecaps_fill(struct filecaps * fcaps)1795 filecaps_fill(struct filecaps *fcaps)
1796 {
1797
1798 CAP_ALL(&fcaps->fc_rights);
1799 fcaps->fc_ioctls = NULL;
1800 fcaps->fc_nioctls = -1;
1801 fcaps->fc_fcntls = CAP_FCNTL_ALL;
1802 }
1803
1804 /*
1805 * Free memory allocated within filecaps structure.
1806 */
1807 static void
filecaps_free_ioctl(struct filecaps * fcaps)1808 filecaps_free_ioctl(struct filecaps *fcaps)
1809 {
1810
1811 free(fcaps->fc_ioctls, M_FILECAPS);
1812 fcaps->fc_ioctls = NULL;
1813 }
1814
1815 void
filecaps_free(struct filecaps * fcaps)1816 filecaps_free(struct filecaps *fcaps)
1817 {
1818
1819 filecaps_free_ioctl(fcaps);
1820 bzero(fcaps, sizeof(*fcaps));
1821 }
1822
1823 static u_long *
filecaps_free_prep(struct filecaps * fcaps)1824 filecaps_free_prep(struct filecaps *fcaps)
1825 {
1826 u_long *ioctls;
1827
1828 ioctls = fcaps->fc_ioctls;
1829 bzero(fcaps, sizeof(*fcaps));
1830 return (ioctls);
1831 }
1832
1833 static void
filecaps_free_finish(u_long * ioctls)1834 filecaps_free_finish(u_long *ioctls)
1835 {
1836
1837 free(ioctls, M_FILECAPS);
1838 }
1839
1840 /*
1841 * Validate the given filecaps structure.
1842 */
1843 static void
filecaps_validate(const struct filecaps * fcaps,const char * func)1844 filecaps_validate(const struct filecaps *fcaps, const char *func)
1845 {
1846
1847 KASSERT(cap_rights_is_valid(&fcaps->fc_rights),
1848 ("%s: invalid rights", func));
1849 KASSERT((fcaps->fc_fcntls & ~CAP_FCNTL_ALL) == 0,
1850 ("%s: invalid fcntls", func));
1851 KASSERT(fcaps->fc_fcntls == 0 ||
1852 cap_rights_is_set(&fcaps->fc_rights, CAP_FCNTL),
1853 ("%s: fcntls without CAP_FCNTL", func));
1854 /*
1855 * open calls without WANTIOCTLCAPS free caps but leave the counter
1856 */
1857 #if 0
1858 KASSERT(fcaps->fc_ioctls != NULL ? fcaps->fc_nioctls > 0 :
1859 (fcaps->fc_nioctls == -1 || fcaps->fc_nioctls == 0),
1860 ("%s: invalid ioctls", func));
1861 #endif
1862 KASSERT(fcaps->fc_nioctls == 0 ||
1863 cap_rights_is_set(&fcaps->fc_rights, CAP_IOCTL),
1864 ("%s: ioctls without CAP_IOCTL", func));
1865 }
1866
1867 static void
fdgrowtable_exp(struct filedesc * fdp,int nfd)1868 fdgrowtable_exp(struct filedesc *fdp, int nfd)
1869 {
1870 int nfd1;
1871
1872 FILEDESC_XLOCK_ASSERT(fdp);
1873
1874 nfd1 = fdp->fd_nfiles * 2;
1875 if (nfd1 < nfd)
1876 nfd1 = nfd;
1877 fdgrowtable(fdp, nfd1);
1878 }
1879
1880 /*
1881 * Grow the file table to accommodate (at least) nfd descriptors.
1882 */
1883 static void
fdgrowtable(struct filedesc * fdp,int nfd)1884 fdgrowtable(struct filedesc *fdp, int nfd)
1885 {
1886 struct filedesc0 *fdp0;
1887 struct freetable *ft;
1888 struct fdescenttbl *ntable;
1889 struct fdescenttbl *otable;
1890 int nnfiles, onfiles;
1891 NDSLOTTYPE *nmap, *omap;
1892
1893 KASSERT(fdp->fd_nfiles > 0, ("zero-length file table"));
1894
1895 /* save old values */
1896 onfiles = fdp->fd_nfiles;
1897 otable = fdp->fd_files;
1898 omap = fdp->fd_map;
1899
1900 /* compute the size of the new table */
1901 nnfiles = NDSLOTS(nfd) * NDENTRIES; /* round up */
1902 if (nnfiles <= onfiles)
1903 /* the table is already large enough */
1904 return;
1905
1906 /*
1907 * Allocate a new table. We need enough space for the number of
1908 * entries, file entries themselves and the struct freetable we will use
1909 * when we decommission the table and place it on the freelist.
1910 * We place the struct freetable in the middle so we don't have
1911 * to worry about padding.
1912 */
1913 ntable = malloc(offsetof(struct fdescenttbl, fdt_ofiles) +
1914 nnfiles * sizeof(ntable->fdt_ofiles[0]) +
1915 sizeof(struct freetable),
1916 M_FILEDESC, M_ZERO | M_WAITOK);
1917 /* copy the old data */
1918 ntable->fdt_nfiles = nnfiles;
1919 memcpy(ntable->fdt_ofiles, otable->fdt_ofiles,
1920 onfiles * sizeof(ntable->fdt_ofiles[0]));
1921
1922 /*
1923 * Allocate a new map only if the old is not large enough. It will
1924 * grow at a slower rate than the table as it can map more
1925 * entries than the table can hold.
1926 */
1927 if (NDSLOTS(nnfiles) > NDSLOTS(onfiles)) {
1928 nmap = malloc(NDSLOTS(nnfiles) * NDSLOTSIZE, M_FILEDESC,
1929 M_ZERO | M_WAITOK);
1930 /* copy over the old data and update the pointer */
1931 memcpy(nmap, omap, NDSLOTS(onfiles) * sizeof(*omap));
1932 fdp->fd_map = nmap;
1933 }
1934
1935 /*
1936 * Make sure that ntable is correctly initialized before we replace
1937 * fd_files poiner. Otherwise fget_unlocked() may see inconsistent
1938 * data.
1939 */
1940 atomic_store_rel_ptr((volatile void *)&fdp->fd_files, (uintptr_t)ntable);
1941
1942 /*
1943 * Free the old file table when not shared by other threads or processes.
1944 * The old file table is considered to be shared when either are true:
1945 * - The process has more than one thread.
1946 * - The file descriptor table has been shared via fdshare().
1947 *
1948 * When shared, the old file table will be placed on a freelist
1949 * which will be processed when the struct filedesc is released.
1950 *
1951 * Note that if onfiles == NDFILE, we're dealing with the original
1952 * static allocation contained within (struct filedesc0 *)fdp,
1953 * which must not be freed.
1954 */
1955 if (onfiles > NDFILE) {
1956 /*
1957 * Note we may be called here from fdinit while allocating a
1958 * table for a new process in which case ->p_fd points
1959 * elsewhere.
1960 */
1961 if (curproc->p_fd != fdp || FILEDESC_IS_ONLY_USER(fdp)) {
1962 free(otable, M_FILEDESC);
1963 } else {
1964 ft = (struct freetable *)&otable->fdt_ofiles[onfiles];
1965 fdp0 = (struct filedesc0 *)fdp;
1966 ft->ft_table = otable;
1967 SLIST_INSERT_HEAD(&fdp0->fd_free, ft, ft_next);
1968 }
1969 }
1970 /*
1971 * The map does not have the same possibility of threads still
1972 * holding references to it. So always free it as long as it
1973 * does not reference the original static allocation.
1974 */
1975 if (NDSLOTS(onfiles) > NDSLOTS(NDFILE))
1976 free(omap, M_FILEDESC);
1977 }
1978
1979 /*
1980 * Allocate a file descriptor for the process.
1981 */
1982 int
fdalloc(struct thread * td,int minfd,int * result)1983 fdalloc(struct thread *td, int minfd, int *result)
1984 {
1985 struct proc *p = td->td_proc;
1986 struct filedesc *fdp = p->p_fd;
1987 int fd, maxfd, allocfd;
1988 #ifdef RACCT
1989 int error;
1990 #endif
1991
1992 FILEDESC_XLOCK_ASSERT(fdp);
1993
1994 if (fdp->fd_freefile > minfd)
1995 minfd = fdp->fd_freefile;
1996
1997 maxfd = getmaxfd(td);
1998
1999 /*
2000 * Search the bitmap for a free descriptor starting at minfd.
2001 * If none is found, grow the file table.
2002 */
2003 fd = fd_first_free(fdp, minfd, fdp->fd_nfiles);
2004 if (__predict_false(fd >= maxfd))
2005 return (EMFILE);
2006 if (__predict_false(fd >= fdp->fd_nfiles)) {
2007 allocfd = min(fd * 2, maxfd);
2008 #ifdef RACCT
2009 if (RACCT_ENABLED()) {
2010 error = racct_set_unlocked(p, RACCT_NOFILE, allocfd);
2011 if (error != 0)
2012 return (EMFILE);
2013 }
2014 #endif
2015 /*
2016 * fd is already equal to first free descriptor >= minfd, so
2017 * we only need to grow the table and we are done.
2018 */
2019 fdgrowtable_exp(fdp, allocfd);
2020 }
2021
2022 /*
2023 * Perform some sanity checks, then mark the file descriptor as
2024 * used and return it to the caller.
2025 */
2026 KASSERT(fd >= 0 && fd < min(maxfd, fdp->fd_nfiles),
2027 ("invalid descriptor %d", fd));
2028 KASSERT(!fdisused(fdp, fd),
2029 ("fd_first_free() returned non-free descriptor"));
2030 KASSERT(fdp->fd_ofiles[fd].fde_file == NULL,
2031 ("file descriptor isn't free"));
2032 fdused(fdp, fd);
2033 *result = fd;
2034 return (0);
2035 }
2036
2037 /*
2038 * Allocate n file descriptors for the process.
2039 */
2040 int
fdallocn(struct thread * td,int minfd,int * fds,int n)2041 fdallocn(struct thread *td, int minfd, int *fds, int n)
2042 {
2043 struct proc *p = td->td_proc;
2044 struct filedesc *fdp = p->p_fd;
2045 int i;
2046
2047 FILEDESC_XLOCK_ASSERT(fdp);
2048
2049 for (i = 0; i < n; i++)
2050 if (fdalloc(td, 0, &fds[i]) != 0)
2051 break;
2052
2053 if (i < n) {
2054 for (i--; i >= 0; i--)
2055 fdunused(fdp, fds[i]);
2056 return (EMFILE);
2057 }
2058
2059 return (0);
2060 }
2061
2062 /*
2063 * Create a new open file structure and allocate a file descriptor for the
2064 * process that refers to it. We add one reference to the file for the
2065 * descriptor table and one reference for resultfp. This is to prevent us
2066 * being preempted and the entry in the descriptor table closed after we
2067 * release the FILEDESC lock.
2068 */
2069 int
falloc_caps(struct thread * td,struct file ** resultfp,int * resultfd,int flags,struct filecaps * fcaps)2070 falloc_caps(struct thread *td, struct file **resultfp, int *resultfd, int flags,
2071 struct filecaps *fcaps)
2072 {
2073 struct file *fp;
2074 int error, fd;
2075
2076 MPASS(resultfp != NULL);
2077 MPASS(resultfd != NULL);
2078
2079 error = _falloc_noinstall(td, &fp, 2);
2080 if (__predict_false(error != 0)) {
2081 return (error);
2082 }
2083
2084 error = finstall_refed(td, fp, &fd, flags, fcaps);
2085 if (__predict_false(error != 0)) {
2086 falloc_abort(td, fp);
2087 return (error);
2088 }
2089
2090 *resultfp = fp;
2091 *resultfd = fd;
2092
2093 return (0);
2094 }
2095
2096 /*
2097 * Create a new open file structure without allocating a file descriptor.
2098 */
2099 int
_falloc_noinstall(struct thread * td,struct file ** resultfp,u_int n)2100 _falloc_noinstall(struct thread *td, struct file **resultfp, u_int n)
2101 {
2102 struct file *fp;
2103 int maxuserfiles = maxfiles - (maxfiles / 20);
2104 int openfiles_new;
2105 static struct timeval lastfail;
2106 static int curfail;
2107
2108 KASSERT(resultfp != NULL, ("%s: resultfp == NULL", __func__));
2109 MPASS(n > 0);
2110
2111 openfiles_new = atomic_fetchadd_int(&openfiles, 1) + 1;
2112 if ((openfiles_new >= maxuserfiles &&
2113 priv_check(td, PRIV_MAXFILES) != 0) ||
2114 openfiles_new >= maxfiles) {
2115 atomic_subtract_int(&openfiles, 1);
2116 if (ppsratecheck(&lastfail, &curfail, 1)) {
2117 printf("kern.maxfiles limit exceeded by uid %i, (%s) "
2118 "please see tuning(7).\n", td->td_ucred->cr_ruid, td->td_proc->p_comm);
2119 }
2120 return (ENFILE);
2121 }
2122 fp = uma_zalloc(file_zone, M_WAITOK);
2123 bzero(fp, sizeof(*fp));
2124 refcount_init(&fp->f_count, n);
2125 fp->f_cred = crhold(td->td_ucred);
2126 fp->f_ops = &badfileops;
2127 *resultfp = fp;
2128 return (0);
2129 }
2130
2131 void
falloc_abort(struct thread * td,struct file * fp)2132 falloc_abort(struct thread *td, struct file *fp)
2133 {
2134
2135 /*
2136 * For assertion purposes.
2137 */
2138 refcount_init(&fp->f_count, 0);
2139 _fdrop(fp, td);
2140 }
2141
2142 /*
2143 * Install a file in a file descriptor table.
2144 */
2145 void
_finstall(struct filedesc * fdp,struct file * fp,int fd,int flags,struct filecaps * fcaps)2146 _finstall(struct filedesc *fdp, struct file *fp, int fd, int flags,
2147 struct filecaps *fcaps)
2148 {
2149 struct filedescent *fde;
2150
2151 MPASS(fp != NULL);
2152 if (fcaps != NULL)
2153 filecaps_validate(fcaps, __func__);
2154 FILEDESC_XLOCK_ASSERT(fdp);
2155
2156 fde = &fdp->fd_ofiles[fd];
2157 #ifdef CAPABILITIES
2158 seqc_write_begin(&fde->fde_seqc);
2159 #endif
2160 fde->fde_file = fp;
2161 fde->fde_flags = (flags & O_CLOEXEC) != 0 ? UF_EXCLOSE : 0;
2162 if (fcaps != NULL)
2163 filecaps_move(fcaps, &fde->fde_caps);
2164 else
2165 filecaps_fill(&fde->fde_caps);
2166 #ifdef CAPABILITIES
2167 seqc_write_end(&fde->fde_seqc);
2168 #endif
2169 }
2170
2171 int
finstall_refed(struct thread * td,struct file * fp,int * fd,int flags,struct filecaps * fcaps)2172 finstall_refed(struct thread *td, struct file *fp, int *fd, int flags,
2173 struct filecaps *fcaps)
2174 {
2175 struct filedesc *fdp = td->td_proc->p_fd;
2176 int error;
2177
2178 MPASS(fd != NULL);
2179
2180 FILEDESC_XLOCK(fdp);
2181 error = fdalloc(td, 0, fd);
2182 if (__predict_true(error == 0)) {
2183 _finstall(fdp, fp, *fd, flags, fcaps);
2184 }
2185 FILEDESC_XUNLOCK(fdp);
2186 return (error);
2187 }
2188
2189 int
finstall(struct thread * td,struct file * fp,int * fd,int flags,struct filecaps * fcaps)2190 finstall(struct thread *td, struct file *fp, int *fd, int flags,
2191 struct filecaps *fcaps)
2192 {
2193 int error;
2194
2195 MPASS(fd != NULL);
2196
2197 if (!fhold(fp))
2198 return (EBADF);
2199 error = finstall_refed(td, fp, fd, flags, fcaps);
2200 if (__predict_false(error != 0)) {
2201 fdrop(fp, td);
2202 }
2203 return (error);
2204 }
2205
2206 /*
2207 * Build a new filedesc structure from another.
2208 *
2209 * If fdp is not NULL, return with it shared locked.
2210 */
2211 struct filedesc *
fdinit(struct filedesc * fdp,bool prepfiles,int * lastfile)2212 fdinit(struct filedesc *fdp, bool prepfiles, int *lastfile)
2213 {
2214 struct filedesc0 *newfdp0;
2215 struct filedesc *newfdp;
2216
2217 if (prepfiles)
2218 MPASS(lastfile != NULL);
2219 else
2220 MPASS(lastfile == NULL);
2221
2222 newfdp0 = uma_zalloc(filedesc0_zone, M_WAITOK | M_ZERO);
2223 newfdp = &newfdp0->fd_fd;
2224
2225 /* Create the file descriptor table. */
2226 FILEDESC_LOCK_INIT(newfdp);
2227 refcount_init(&newfdp->fd_refcnt, 1);
2228 refcount_init(&newfdp->fd_holdcnt, 1);
2229 newfdp->fd_map = newfdp0->fd_dmap;
2230 newfdp->fd_files = (struct fdescenttbl *)&newfdp0->fd_dfiles;
2231 newfdp->fd_files->fdt_nfiles = NDFILE;
2232
2233 if (fdp == NULL)
2234 return (newfdp);
2235
2236 FILEDESC_SLOCK(fdp);
2237 if (!prepfiles) {
2238 FILEDESC_SUNLOCK(fdp);
2239 return (newfdp);
2240 }
2241
2242 for (;;) {
2243 *lastfile = fdlastfile(fdp);
2244 if (*lastfile < newfdp->fd_nfiles)
2245 break;
2246 FILEDESC_SUNLOCK(fdp);
2247 fdgrowtable(newfdp, *lastfile + 1);
2248 FILEDESC_SLOCK(fdp);
2249 }
2250
2251 return (newfdp);
2252 }
2253
2254 /*
2255 * Build a pwddesc structure from another.
2256 * Copy the current, root, and jail root vnode references.
2257 *
2258 * If pdp is not NULL and keeplock is true, return with it (exclusively) locked.
2259 */
2260 struct pwddesc *
pdinit(struct pwddesc * pdp,bool keeplock)2261 pdinit(struct pwddesc *pdp, bool keeplock)
2262 {
2263 struct pwddesc *newpdp;
2264 struct pwd *newpwd;
2265
2266 newpdp = malloc(sizeof(*newpdp), M_PWDDESC, M_WAITOK | M_ZERO);
2267
2268 PWDDESC_LOCK_INIT(newpdp);
2269 refcount_init(&newpdp->pd_refcount, 1);
2270 newpdp->pd_cmask = CMASK;
2271
2272 if (pdp == NULL) {
2273 newpwd = pwd_alloc();
2274 smr_serialized_store(&newpdp->pd_pwd, newpwd, true);
2275 return (newpdp);
2276 }
2277
2278 PWDDESC_XLOCK(pdp);
2279 newpwd = pwd_hold_pwddesc(pdp);
2280 smr_serialized_store(&newpdp->pd_pwd, newpwd, true);
2281 if (!keeplock)
2282 PWDDESC_XUNLOCK(pdp);
2283 return (newpdp);
2284 }
2285
2286 /*
2287 * Hold either filedesc or pwddesc of the passed process.
2288 *
2289 * The process lock is used to synchronize against the target exiting and
2290 * freeing the data.
2291 *
2292 * Clearing can be ilustrated in 3 steps:
2293 * 1. set the pointer to NULL. Either routine can race against it, hence
2294 * atomic_load_ptr.
2295 * 2. observe the process lock as not taken. Until then fdhold/pdhold can
2296 * race to either still see the pointer or find NULL. It is still safe to
2297 * grab a reference as clearing is stalled.
2298 * 3. after the lock is observed as not taken, any fdhold/pdhold calls are
2299 * guaranteed to see NULL, making it safe to finish clearing
2300 */
2301 static struct filedesc *
fdhold(struct proc * p)2302 fdhold(struct proc *p)
2303 {
2304 struct filedesc *fdp;
2305
2306 PROC_LOCK_ASSERT(p, MA_OWNED);
2307 fdp = atomic_load_ptr(&p->p_fd);
2308 if (fdp != NULL)
2309 refcount_acquire(&fdp->fd_holdcnt);
2310 return (fdp);
2311 }
2312
2313 static struct pwddesc *
pdhold(struct proc * p)2314 pdhold(struct proc *p)
2315 {
2316 struct pwddesc *pdp;
2317
2318 PROC_LOCK_ASSERT(p, MA_OWNED);
2319 pdp = atomic_load_ptr(&p->p_pd);
2320 if (pdp != NULL)
2321 refcount_acquire(&pdp->pd_refcount);
2322 return (pdp);
2323 }
2324
2325 static void
fddrop(struct filedesc * fdp)2326 fddrop(struct filedesc *fdp)
2327 {
2328
2329 if (refcount_load(&fdp->fd_holdcnt) > 1) {
2330 if (refcount_release(&fdp->fd_holdcnt) == 0)
2331 return;
2332 }
2333
2334 FILEDESC_LOCK_DESTROY(fdp);
2335 uma_zfree(filedesc0_zone, fdp);
2336 }
2337
2338 static void
pddrop(struct pwddesc * pdp)2339 pddrop(struct pwddesc *pdp)
2340 {
2341 struct pwd *pwd;
2342
2343 if (refcount_release_if_not_last(&pdp->pd_refcount))
2344 return;
2345
2346 PWDDESC_XLOCK(pdp);
2347 if (refcount_release(&pdp->pd_refcount) == 0) {
2348 PWDDESC_XUNLOCK(pdp);
2349 return;
2350 }
2351 pwd = PWDDESC_XLOCKED_LOAD_PWD(pdp);
2352 pwd_set(pdp, NULL);
2353 PWDDESC_XUNLOCK(pdp);
2354 pwd_drop(pwd);
2355
2356 PWDDESC_LOCK_DESTROY(pdp);
2357 free(pdp, M_PWDDESC);
2358 }
2359
2360 /*
2361 * Share a filedesc structure.
2362 */
2363 struct filedesc *
fdshare(struct filedesc * fdp)2364 fdshare(struct filedesc *fdp)
2365 {
2366
2367 refcount_acquire(&fdp->fd_refcnt);
2368 return (fdp);
2369 }
2370
2371 /*
2372 * Share a pwddesc structure.
2373 */
2374 struct pwddesc *
pdshare(struct pwddesc * pdp)2375 pdshare(struct pwddesc *pdp)
2376 {
2377 refcount_acquire(&pdp->pd_refcount);
2378 return (pdp);
2379 }
2380
2381 /*
2382 * Unshare a filedesc structure, if necessary by making a copy
2383 */
2384 void
fdunshare(struct thread * td)2385 fdunshare(struct thread *td)
2386 {
2387 struct filedesc *tmp;
2388 struct proc *p = td->td_proc;
2389
2390 if (refcount_load(&p->p_fd->fd_refcnt) == 1)
2391 return;
2392
2393 tmp = fdcopy(p->p_fd);
2394 fdescfree(td);
2395 p->p_fd = tmp;
2396 }
2397
2398 /*
2399 * Unshare a pwddesc structure.
2400 */
2401 void
pdunshare(struct thread * td)2402 pdunshare(struct thread *td)
2403 {
2404 struct pwddesc *pdp;
2405 struct proc *p;
2406
2407 p = td->td_proc;
2408 /* Not shared. */
2409 if (p->p_pd->pd_refcount == 1)
2410 return;
2411
2412 pdp = pdcopy(p->p_pd);
2413 pdescfree(td);
2414 p->p_pd = pdp;
2415 }
2416
2417 void
fdinstall_remapped(struct thread * td,struct filedesc * fdp)2418 fdinstall_remapped(struct thread *td, struct filedesc *fdp)
2419 {
2420
2421 fdescfree(td);
2422 td->td_proc->p_fd = fdp;
2423 }
2424
2425 /*
2426 * Copy a filedesc structure. A NULL pointer in returns a NULL reference,
2427 * this is to ease callers, not catch errors.
2428 */
2429 struct filedesc *
fdcopy(struct filedesc * fdp)2430 fdcopy(struct filedesc *fdp)
2431 {
2432 struct filedesc *newfdp;
2433 struct filedescent *nfde, *ofde;
2434 int i, lastfile;
2435
2436 MPASS(fdp != NULL);
2437
2438 newfdp = fdinit(fdp, true, &lastfile);
2439 /* copy all passable descriptors (i.e. not kqueue) */
2440 newfdp->fd_freefile = -1;
2441 for (i = 0; i <= lastfile; ++i) {
2442 ofde = &fdp->fd_ofiles[i];
2443 if (ofde->fde_file == NULL ||
2444 (ofde->fde_file->f_ops->fo_flags & DFLAG_PASSABLE) == 0 ||
2445 !fhold(ofde->fde_file)) {
2446 if (newfdp->fd_freefile == -1)
2447 newfdp->fd_freefile = i;
2448 continue;
2449 }
2450 nfde = &newfdp->fd_ofiles[i];
2451 *nfde = *ofde;
2452 filecaps_copy(&ofde->fde_caps, &nfde->fde_caps, true);
2453 fdused_init(newfdp, i);
2454 }
2455 if (newfdp->fd_freefile == -1)
2456 newfdp->fd_freefile = i;
2457 FILEDESC_SUNLOCK(fdp);
2458 return (newfdp);
2459 }
2460
2461 /*
2462 * Copy a pwddesc structure.
2463 */
2464 struct pwddesc *
pdcopy(struct pwddesc * pdp)2465 pdcopy(struct pwddesc *pdp)
2466 {
2467 struct pwddesc *newpdp;
2468
2469 MPASS(pdp != NULL);
2470
2471 newpdp = pdinit(pdp, true);
2472 newpdp->pd_cmask = pdp->pd_cmask;
2473 PWDDESC_XUNLOCK(pdp);
2474 return (newpdp);
2475 }
2476
2477 /*
2478 * Copies a filedesc structure, while remapping all file descriptors
2479 * stored inside using a translation table.
2480 *
2481 * File descriptors are copied over to the new file descriptor table,
2482 * regardless of whether the close-on-exec flag is set.
2483 */
2484 int
fdcopy_remapped(struct filedesc * fdp,const int * fds,size_t nfds,struct filedesc ** ret)2485 fdcopy_remapped(struct filedesc *fdp, const int *fds, size_t nfds,
2486 struct filedesc **ret)
2487 {
2488 struct filedesc *newfdp;
2489 struct filedescent *nfde, *ofde;
2490 int error, i, lastfile;
2491
2492 MPASS(fdp != NULL);
2493
2494 newfdp = fdinit(fdp, true, &lastfile);
2495 if (nfds > lastfile + 1) {
2496 /* New table cannot be larger than the old one. */
2497 error = E2BIG;
2498 goto bad;
2499 }
2500 /* Copy all passable descriptors (i.e. not kqueue). */
2501 newfdp->fd_freefile = nfds;
2502 for (i = 0; i < nfds; ++i) {
2503 if (fds[i] < 0 || fds[i] > lastfile) {
2504 /* File descriptor out of bounds. */
2505 error = EBADF;
2506 goto bad;
2507 }
2508 ofde = &fdp->fd_ofiles[fds[i]];
2509 if (ofde->fde_file == NULL) {
2510 /* Unused file descriptor. */
2511 error = EBADF;
2512 goto bad;
2513 }
2514 if ((ofde->fde_file->f_ops->fo_flags & DFLAG_PASSABLE) == 0) {
2515 /* File descriptor cannot be passed. */
2516 error = EINVAL;
2517 goto bad;
2518 }
2519 if (!fhold(ofde->fde_file)) {
2520 error = EBADF;
2521 goto bad;
2522 }
2523 nfde = &newfdp->fd_ofiles[i];
2524 *nfde = *ofde;
2525 filecaps_copy(&ofde->fde_caps, &nfde->fde_caps, true);
2526 fdused_init(newfdp, i);
2527 }
2528 FILEDESC_SUNLOCK(fdp);
2529 *ret = newfdp;
2530 return (0);
2531 bad:
2532 FILEDESC_SUNLOCK(fdp);
2533 fdescfree_remapped(newfdp);
2534 return (error);
2535 }
2536
2537 /*
2538 * Clear POSIX style locks. This is only used when fdp looses a reference (i.e.
2539 * one of processes using it exits) and the table used to be shared.
2540 */
2541 static void
fdclearlocks(struct thread * td)2542 fdclearlocks(struct thread *td)
2543 {
2544 struct filedesc *fdp;
2545 struct filedesc_to_leader *fdtol;
2546 struct flock lf;
2547 struct file *fp;
2548 struct proc *p;
2549 struct vnode *vp;
2550 int i, lastfile;
2551
2552 p = td->td_proc;
2553 fdp = p->p_fd;
2554 fdtol = p->p_fdtol;
2555 MPASS(fdtol != NULL);
2556
2557 FILEDESC_XLOCK(fdp);
2558 KASSERT(fdtol->fdl_refcount > 0,
2559 ("filedesc_to_refcount botch: fdl_refcount=%d",
2560 fdtol->fdl_refcount));
2561 if (fdtol->fdl_refcount == 1 &&
2562 (p->p_leader->p_flag & P_ADVLOCK) != 0) {
2563 lastfile = fdlastfile(fdp);
2564 for (i = 0; i <= lastfile; i++) {
2565 fp = fdp->fd_ofiles[i].fde_file;
2566 if (fp == NULL || fp->f_type != DTYPE_VNODE ||
2567 !fhold(fp))
2568 continue;
2569 FILEDESC_XUNLOCK(fdp);
2570 lf.l_whence = SEEK_SET;
2571 lf.l_start = 0;
2572 lf.l_len = 0;
2573 lf.l_type = F_UNLCK;
2574 vp = fp->f_vnode;
2575 (void) VOP_ADVLOCK(vp,
2576 (caddr_t)p->p_leader, F_UNLCK,
2577 &lf, F_POSIX);
2578 FILEDESC_XLOCK(fdp);
2579 fdrop(fp, td);
2580 }
2581 }
2582 retry:
2583 if (fdtol->fdl_refcount == 1) {
2584 if (fdp->fd_holdleaderscount > 0 &&
2585 (p->p_leader->p_flag & P_ADVLOCK) != 0) {
2586 /*
2587 * close() or kern_dup() has cleared a reference
2588 * in a shared file descriptor table.
2589 */
2590 fdp->fd_holdleaderswakeup = 1;
2591 sx_sleep(&fdp->fd_holdleaderscount,
2592 FILEDESC_LOCK(fdp), PLOCK, "fdlhold", 0);
2593 goto retry;
2594 }
2595 if (fdtol->fdl_holdcount > 0) {
2596 /*
2597 * Ensure that fdtol->fdl_leader remains
2598 * valid in closef().
2599 */
2600 fdtol->fdl_wakeup = 1;
2601 sx_sleep(fdtol, FILEDESC_LOCK(fdp), PLOCK,
2602 "fdlhold", 0);
2603 goto retry;
2604 }
2605 }
2606 fdtol->fdl_refcount--;
2607 if (fdtol->fdl_refcount == 0 &&
2608 fdtol->fdl_holdcount == 0) {
2609 fdtol->fdl_next->fdl_prev = fdtol->fdl_prev;
2610 fdtol->fdl_prev->fdl_next = fdtol->fdl_next;
2611 } else
2612 fdtol = NULL;
2613 p->p_fdtol = NULL;
2614 FILEDESC_XUNLOCK(fdp);
2615 if (fdtol != NULL)
2616 free(fdtol, M_FILEDESC_TO_LEADER);
2617 }
2618
2619 /*
2620 * Release a filedesc structure.
2621 */
2622 static void
fdescfree_fds(struct thread * td,struct filedesc * fdp,bool needclose)2623 fdescfree_fds(struct thread *td, struct filedesc *fdp, bool needclose)
2624 {
2625 struct filedesc0 *fdp0;
2626 struct freetable *ft, *tft;
2627 struct filedescent *fde;
2628 struct file *fp;
2629 int i, lastfile;
2630
2631 KASSERT(refcount_load(&fdp->fd_refcnt) == 0,
2632 ("%s: fd table %p carries references", __func__, fdp));
2633
2634 /*
2635 * Serialize with threads iterating over the table, if any.
2636 */
2637 if (refcount_load(&fdp->fd_holdcnt) > 1) {
2638 FILEDESC_XLOCK(fdp);
2639 FILEDESC_XUNLOCK(fdp);
2640 }
2641
2642 lastfile = fdlastfile_single(fdp);
2643 for (i = 0; i <= lastfile; i++) {
2644 fde = &fdp->fd_ofiles[i];
2645 fp = fde->fde_file;
2646 if (fp != NULL) {
2647 fdefree_last(fde);
2648 if (needclose)
2649 (void) closef(fp, td);
2650 else
2651 fdrop(fp, td);
2652 }
2653 }
2654
2655 if (NDSLOTS(fdp->fd_nfiles) > NDSLOTS(NDFILE))
2656 free(fdp->fd_map, M_FILEDESC);
2657 if (fdp->fd_nfiles > NDFILE)
2658 free(fdp->fd_files, M_FILEDESC);
2659
2660 fdp0 = (struct filedesc0 *)fdp;
2661 SLIST_FOREACH_SAFE(ft, &fdp0->fd_free, ft_next, tft)
2662 free(ft->ft_table, M_FILEDESC);
2663
2664 fddrop(fdp);
2665 }
2666
2667 void
fdescfree(struct thread * td)2668 fdescfree(struct thread *td)
2669 {
2670 struct proc *p;
2671 struct filedesc *fdp;
2672
2673 p = td->td_proc;
2674 fdp = p->p_fd;
2675 MPASS(fdp != NULL);
2676
2677 #ifdef RACCT
2678 if (RACCT_ENABLED())
2679 racct_set_unlocked(p, RACCT_NOFILE, 0);
2680 #endif
2681
2682 if (p->p_fdtol != NULL)
2683 fdclearlocks(td);
2684
2685 /*
2686 * Check fdhold for an explanation.
2687 */
2688 atomic_store_ptr(&p->p_fd, NULL);
2689 atomic_thread_fence_seq_cst();
2690 PROC_WAIT_UNLOCKED(p);
2691
2692 if (refcount_release(&fdp->fd_refcnt) == 0)
2693 return;
2694
2695 fdescfree_fds(td, fdp, 1);
2696 }
2697
2698 void
pdescfree(struct thread * td)2699 pdescfree(struct thread *td)
2700 {
2701 struct proc *p;
2702 struct pwddesc *pdp;
2703
2704 p = td->td_proc;
2705 pdp = p->p_pd;
2706 MPASS(pdp != NULL);
2707
2708 /*
2709 * Check pdhold for an explanation.
2710 */
2711 atomic_store_ptr(&p->p_pd, NULL);
2712 atomic_thread_fence_seq_cst();
2713 PROC_WAIT_UNLOCKED(p);
2714
2715 pddrop(pdp);
2716 }
2717
2718 void
fdescfree_remapped(struct filedesc * fdp)2719 fdescfree_remapped(struct filedesc *fdp)
2720 {
2721 #ifdef INVARIANTS
2722 /* fdescfree_fds() asserts that fd_refcnt == 0. */
2723 if (!refcount_release(&fdp->fd_refcnt))
2724 panic("%s: fd table %p has extra references", __func__, fdp);
2725 #endif
2726 fdescfree_fds(curthread, fdp, 0);
2727 }
2728
2729 /*
2730 * For setugid programs, we don't want to people to use that setugidness
2731 * to generate error messages which write to a file which otherwise would
2732 * otherwise be off-limits to the process. We check for filesystems where
2733 * the vnode can change out from under us after execve (like [lin]procfs).
2734 *
2735 * Since fdsetugidsafety calls this only for fd 0, 1 and 2, this check is
2736 * sufficient. We also don't check for setugidness since we know we are.
2737 */
2738 static bool
is_unsafe(struct file * fp)2739 is_unsafe(struct file *fp)
2740 {
2741 struct vnode *vp;
2742
2743 if (fp->f_type != DTYPE_VNODE)
2744 return (false);
2745
2746 vp = fp->f_vnode;
2747 return ((vp->v_vflag & VV_PROCDEP) != 0);
2748 }
2749
2750 /*
2751 * Make this setguid thing safe, if at all possible.
2752 */
2753 void
fdsetugidsafety(struct thread * td)2754 fdsetugidsafety(struct thread *td)
2755 {
2756 struct filedesc *fdp;
2757 struct file *fp;
2758 int i;
2759
2760 fdp = td->td_proc->p_fd;
2761 KASSERT(refcount_load(&fdp->fd_refcnt) == 1,
2762 ("the fdtable should not be shared"));
2763 MPASS(fdp->fd_nfiles >= 3);
2764 for (i = 0; i <= 2; i++) {
2765 fp = fdp->fd_ofiles[i].fde_file;
2766 if (fp != NULL && is_unsafe(fp)) {
2767 FILEDESC_XLOCK(fdp);
2768 knote_fdclose(td, i);
2769 /*
2770 * NULL-out descriptor prior to close to avoid
2771 * a race while close blocks.
2772 */
2773 fdfree(fdp, i);
2774 FILEDESC_XUNLOCK(fdp);
2775 (void) closef(fp, td);
2776 }
2777 }
2778 }
2779
2780 /*
2781 * If a specific file object occupies a specific file descriptor, close the
2782 * file descriptor entry and drop a reference on the file object. This is a
2783 * convenience function to handle a subsequent error in a function that calls
2784 * falloc() that handles the race that another thread might have closed the
2785 * file descriptor out from under the thread creating the file object.
2786 */
2787 void
fdclose(struct thread * td,struct file * fp,int idx)2788 fdclose(struct thread *td, struct file *fp, int idx)
2789 {
2790 struct filedesc *fdp = td->td_proc->p_fd;
2791
2792 FILEDESC_XLOCK(fdp);
2793 if (fdp->fd_ofiles[idx].fde_file == fp) {
2794 fdfree(fdp, idx);
2795 FILEDESC_XUNLOCK(fdp);
2796 fdrop(fp, td);
2797 } else
2798 FILEDESC_XUNLOCK(fdp);
2799 }
2800
2801 /*
2802 * Close any files on exec?
2803 */
2804 void
fdcloseexec(struct thread * td)2805 fdcloseexec(struct thread *td)
2806 {
2807 struct filedesc *fdp;
2808 struct filedescent *fde;
2809 struct file *fp;
2810 int i, lastfile;
2811
2812 fdp = td->td_proc->p_fd;
2813 KASSERT(refcount_load(&fdp->fd_refcnt) == 1,
2814 ("the fdtable should not be shared"));
2815 lastfile = fdlastfile_single(fdp);
2816 for (i = 0; i <= lastfile; i++) {
2817 fde = &fdp->fd_ofiles[i];
2818 fp = fde->fde_file;
2819 if (fp != NULL && (fp->f_type == DTYPE_MQUEUE ||
2820 (fde->fde_flags & UF_EXCLOSE))) {
2821 FILEDESC_XLOCK(fdp);
2822 fdfree(fdp, i);
2823 (void) closefp(fdp, i, fp, td, false, false);
2824 FILEDESC_UNLOCK_ASSERT(fdp);
2825 }
2826 }
2827 }
2828
2829 /*
2830 * It is unsafe for set[ug]id processes to be started with file
2831 * descriptors 0..2 closed, as these descriptors are given implicit
2832 * significance in the Standard C library. fdcheckstd() will create a
2833 * descriptor referencing /dev/null for each of stdin, stdout, and
2834 * stderr that is not already open.
2835 */
2836 int
fdcheckstd(struct thread * td)2837 fdcheckstd(struct thread *td)
2838 {
2839 struct filedesc *fdp;
2840 register_t save;
2841 int i, error, devnull;
2842
2843 fdp = td->td_proc->p_fd;
2844 KASSERT(refcount_load(&fdp->fd_refcnt) == 1,
2845 ("the fdtable should not be shared"));
2846 MPASS(fdp->fd_nfiles >= 3);
2847 devnull = -1;
2848 for (i = 0; i <= 2; i++) {
2849 if (fdp->fd_ofiles[i].fde_file != NULL)
2850 continue;
2851
2852 save = td->td_retval[0];
2853 if (devnull != -1) {
2854 error = kern_dup(td, FDDUP_FIXED, 0, devnull, i);
2855 } else {
2856 error = kern_openat(td, AT_FDCWD, "/dev/null",
2857 UIO_SYSSPACE, O_RDWR, 0);
2858 if (error == 0) {
2859 devnull = td->td_retval[0];
2860 KASSERT(devnull == i, ("we didn't get our fd"));
2861 }
2862 }
2863 td->td_retval[0] = save;
2864 if (error != 0)
2865 return (error);
2866 }
2867 return (0);
2868 }
2869
2870 /*
2871 * Internal form of close. Decrement reference count on file structure.
2872 * Note: td may be NULL when closing a file that was being passed in a
2873 * message.
2874 */
2875 int
closef(struct file * fp,struct thread * td)2876 closef(struct file *fp, struct thread *td)
2877 {
2878 struct vnode *vp;
2879 struct flock lf;
2880 struct filedesc_to_leader *fdtol;
2881 struct filedesc *fdp;
2882
2883 MPASS(td != NULL);
2884
2885 /*
2886 * POSIX record locking dictates that any close releases ALL
2887 * locks owned by this process. This is handled by setting
2888 * a flag in the unlock to free ONLY locks obeying POSIX
2889 * semantics, and not to free BSD-style file locks.
2890 * If the descriptor was in a message, POSIX-style locks
2891 * aren't passed with the descriptor, and the thread pointer
2892 * will be NULL. Callers should be careful only to pass a
2893 * NULL thread pointer when there really is no owning
2894 * context that might have locks, or the locks will be
2895 * leaked.
2896 */
2897 if (fp->f_type == DTYPE_VNODE) {
2898 vp = fp->f_vnode;
2899 if ((td->td_proc->p_leader->p_flag & P_ADVLOCK) != 0) {
2900 lf.l_whence = SEEK_SET;
2901 lf.l_start = 0;
2902 lf.l_len = 0;
2903 lf.l_type = F_UNLCK;
2904 (void) VOP_ADVLOCK(vp, (caddr_t)td->td_proc->p_leader,
2905 F_UNLCK, &lf, F_POSIX);
2906 }
2907 fdtol = td->td_proc->p_fdtol;
2908 if (fdtol != NULL) {
2909 /*
2910 * Handle special case where file descriptor table is
2911 * shared between multiple process leaders.
2912 */
2913 fdp = td->td_proc->p_fd;
2914 FILEDESC_XLOCK(fdp);
2915 for (fdtol = fdtol->fdl_next;
2916 fdtol != td->td_proc->p_fdtol;
2917 fdtol = fdtol->fdl_next) {
2918 if ((fdtol->fdl_leader->p_flag &
2919 P_ADVLOCK) == 0)
2920 continue;
2921 fdtol->fdl_holdcount++;
2922 FILEDESC_XUNLOCK(fdp);
2923 lf.l_whence = SEEK_SET;
2924 lf.l_start = 0;
2925 lf.l_len = 0;
2926 lf.l_type = F_UNLCK;
2927 vp = fp->f_vnode;
2928 (void) VOP_ADVLOCK(vp,
2929 (caddr_t)fdtol->fdl_leader, F_UNLCK, &lf,
2930 F_POSIX);
2931 FILEDESC_XLOCK(fdp);
2932 fdtol->fdl_holdcount--;
2933 if (fdtol->fdl_holdcount == 0 &&
2934 fdtol->fdl_wakeup != 0) {
2935 fdtol->fdl_wakeup = 0;
2936 wakeup(fdtol);
2937 }
2938 }
2939 FILEDESC_XUNLOCK(fdp);
2940 }
2941 }
2942 return (fdrop_close(fp, td));
2943 }
2944
2945 /*
2946 * Hack for file descriptor passing code.
2947 */
2948 void
closef_nothread(struct file * fp)2949 closef_nothread(struct file *fp)
2950 {
2951
2952 fdrop(fp, NULL);
2953 }
2954
2955 /*
2956 * Initialize the file pointer with the specified properties.
2957 *
2958 * The ops are set with release semantics to be certain that the flags, type,
2959 * and data are visible when ops is. This is to prevent ops methods from being
2960 * called with bad data.
2961 */
2962 void
finit(struct file * fp,u_int flag,short type,void * data,struct fileops * ops)2963 finit(struct file *fp, u_int flag, short type, void *data, struct fileops *ops)
2964 {
2965 fp->f_data = data;
2966 fp->f_flag = flag;
2967 fp->f_type = type;
2968 atomic_store_rel_ptr((volatile uintptr_t *)&fp->f_ops, (uintptr_t)ops);
2969 }
2970
2971 void
finit_vnode(struct file * fp,u_int flag,void * data,struct fileops * ops)2972 finit_vnode(struct file *fp, u_int flag, void *data, struct fileops *ops)
2973 {
2974 fp->f_seqcount[UIO_READ] = 1;
2975 fp->f_seqcount[UIO_WRITE] = 1;
2976 finit(fp, (flag & FMASK) | (fp->f_flag & FHASLOCK), DTYPE_VNODE,
2977 data, ops);
2978 }
2979
2980 int
fget_cap_locked(struct filedesc * fdp,int fd,cap_rights_t * needrightsp,struct file ** fpp,struct filecaps * havecapsp)2981 fget_cap_locked(struct filedesc *fdp, int fd, cap_rights_t *needrightsp,
2982 struct file **fpp, struct filecaps *havecapsp)
2983 {
2984 struct filedescent *fde;
2985 int error;
2986
2987 FILEDESC_LOCK_ASSERT(fdp);
2988
2989 *fpp = NULL;
2990 fde = fdeget_locked(fdp, fd);
2991 if (fde == NULL) {
2992 error = EBADF;
2993 goto out;
2994 }
2995
2996 #ifdef CAPABILITIES
2997 error = cap_check(cap_rights_fde_inline(fde), needrightsp);
2998 if (error != 0)
2999 goto out;
3000 #endif
3001
3002 if (havecapsp != NULL)
3003 filecaps_copy(&fde->fde_caps, havecapsp, true);
3004
3005 *fpp = fde->fde_file;
3006
3007 error = 0;
3008 out:
3009 return (error);
3010 }
3011
3012 int
fget_cap(struct thread * td,int fd,cap_rights_t * needrightsp,struct file ** fpp,struct filecaps * havecapsp)3013 fget_cap(struct thread *td, int fd, cap_rights_t *needrightsp,
3014 struct file **fpp, struct filecaps *havecapsp)
3015 {
3016 struct filedesc *fdp = td->td_proc->p_fd;
3017 int error;
3018 #ifndef CAPABILITIES
3019 error = fget_unlocked(fdp, fd, needrightsp, fpp);
3020 if (havecapsp != NULL && error == 0)
3021 filecaps_fill(havecapsp);
3022 #else
3023 struct file *fp;
3024 seqc_t seq;
3025
3026 *fpp = NULL;
3027 for (;;) {
3028 error = fget_unlocked_seq(fdp, fd, needrightsp, &fp, &seq);
3029 if (error != 0)
3030 return (error);
3031
3032 if (havecapsp != NULL) {
3033 if (!filecaps_copy(&fdp->fd_ofiles[fd].fde_caps,
3034 havecapsp, false)) {
3035 fdrop(fp, td);
3036 goto get_locked;
3037 }
3038 }
3039
3040 if (!fd_modified(fdp, fd, seq))
3041 break;
3042 fdrop(fp, td);
3043 }
3044
3045 *fpp = fp;
3046 return (0);
3047
3048 get_locked:
3049 FILEDESC_SLOCK(fdp);
3050 error = fget_cap_locked(fdp, fd, needrightsp, fpp, havecapsp);
3051 if (error == 0 && !fhold(*fpp))
3052 error = EBADF;
3053 FILEDESC_SUNLOCK(fdp);
3054 #endif
3055 return (error);
3056 }
3057
3058 int
fget_remote(struct thread * td,struct proc * p,int fd,struct file ** fpp)3059 fget_remote(struct thread *td, struct proc *p, int fd, struct file **fpp)
3060 {
3061 struct filedesc *fdp;
3062 struct file *fp;
3063 int error;
3064
3065 if (p == td->td_proc) /* curproc */
3066 return (fget_unlocked(p->p_fd, fd, &cap_no_rights, fpp));
3067
3068 PROC_LOCK(p);
3069 fdp = fdhold(p);
3070 PROC_UNLOCK(p);
3071 if (fdp == NULL)
3072 return (ENOENT);
3073 FILEDESC_SLOCK(fdp);
3074 if (refcount_load(&fdp->fd_refcnt) != 0) {
3075 fp = fget_locked(fdp, fd);
3076 if (fp != NULL && fhold(fp)) {
3077 *fpp = fp;
3078 error = 0;
3079 } else {
3080 error = EBADF;
3081 }
3082 } else {
3083 error = ENOENT;
3084 }
3085 FILEDESC_SUNLOCK(fdp);
3086 fddrop(fdp);
3087 return (error);
3088 }
3089
3090 #ifdef CAPABILITIES
3091 int
fgetvp_lookup_smr(int fd,struct nameidata * ndp,struct vnode ** vpp,bool * fsearch)3092 fgetvp_lookup_smr(int fd, struct nameidata *ndp, struct vnode **vpp, bool *fsearch)
3093 {
3094 const struct filedescent *fde;
3095 const struct fdescenttbl *fdt;
3096 struct filedesc *fdp;
3097 struct file *fp;
3098 struct vnode *vp;
3099 const cap_rights_t *haverights;
3100 cap_rights_t rights;
3101 seqc_t seq;
3102
3103 VFS_SMR_ASSERT_ENTERED();
3104
3105 rights = *ndp->ni_rightsneeded;
3106 cap_rights_set_one(&rights, CAP_LOOKUP);
3107
3108 fdp = curproc->p_fd;
3109 fdt = fdp->fd_files;
3110 if (__predict_false((u_int)fd >= fdt->fdt_nfiles))
3111 return (EBADF);
3112 seq = seqc_read_notmodify(fd_seqc(fdt, fd));
3113 fde = &fdt->fdt_ofiles[fd];
3114 haverights = cap_rights_fde_inline(fde);
3115 fp = fde->fde_file;
3116 if (__predict_false(fp == NULL))
3117 return (EAGAIN);
3118 if (__predict_false(cap_check_inline_transient(haverights, &rights)))
3119 return (EAGAIN);
3120 *fsearch = ((fp->f_flag & FSEARCH) != 0);
3121 vp = fp->f_vnode;
3122 if (__predict_false(vp == NULL)) {
3123 return (EAGAIN);
3124 }
3125 if (!filecaps_copy(&fde->fde_caps, &ndp->ni_filecaps, false)) {
3126 return (EAGAIN);
3127 }
3128 /*
3129 * Use an acquire barrier to force re-reading of fdt so it is
3130 * refreshed for verification.
3131 */
3132 atomic_thread_fence_acq();
3133 fdt = fdp->fd_files;
3134 if (__predict_false(!seqc_consistent_nomb(fd_seqc(fdt, fd), seq)))
3135 return (EAGAIN);
3136 /*
3137 * If file descriptor doesn't have all rights,
3138 * all lookups relative to it must also be
3139 * strictly relative.
3140 *
3141 * Not yet supported by fast path.
3142 */
3143 CAP_ALL(&rights);
3144 if (!cap_rights_contains(&ndp->ni_filecaps.fc_rights, &rights) ||
3145 ndp->ni_filecaps.fc_fcntls != CAP_FCNTL_ALL ||
3146 ndp->ni_filecaps.fc_nioctls != -1) {
3147 #ifdef notyet
3148 ndp->ni_lcf |= NI_LCF_STRICTRELATIVE;
3149 #else
3150 return (EAGAIN);
3151 #endif
3152 }
3153 *vpp = vp;
3154 return (0);
3155 }
3156 #else
3157 int
fgetvp_lookup_smr(int fd,struct nameidata * ndp,struct vnode ** vpp,bool * fsearch)3158 fgetvp_lookup_smr(int fd, struct nameidata *ndp, struct vnode **vpp, bool *fsearch)
3159 {
3160 const struct fdescenttbl *fdt;
3161 struct filedesc *fdp;
3162 struct file *fp;
3163 struct vnode *vp;
3164
3165 VFS_SMR_ASSERT_ENTERED();
3166
3167 fdp = curproc->p_fd;
3168 fdt = fdp->fd_files;
3169 if (__predict_false((u_int)fd >= fdt->fdt_nfiles))
3170 return (EBADF);
3171 fp = fdt->fdt_ofiles[fd].fde_file;
3172 if (__predict_false(fp == NULL))
3173 return (EAGAIN);
3174 *fsearch = ((fp->f_flag & FSEARCH) != 0);
3175 vp = fp->f_vnode;
3176 if (__predict_false(vp == NULL || vp->v_type != VDIR)) {
3177 return (EAGAIN);
3178 }
3179 /*
3180 * Use an acquire barrier to force re-reading of fdt so it is
3181 * refreshed for verification.
3182 */
3183 atomic_thread_fence_acq();
3184 fdt = fdp->fd_files;
3185 if (__predict_false(fp != fdt->fdt_ofiles[fd].fde_file))
3186 return (EAGAIN);
3187 filecaps_fill(&ndp->ni_filecaps);
3188 *vpp = vp;
3189 return (0);
3190 }
3191 #endif
3192
3193 int
fgetvp_lookup(int fd,struct nameidata * ndp,struct vnode ** vpp)3194 fgetvp_lookup(int fd, struct nameidata *ndp, struct vnode **vpp)
3195 {
3196 struct thread *td;
3197 struct file *fp;
3198 struct vnode *vp;
3199 struct componentname *cnp;
3200 cap_rights_t rights;
3201 int error;
3202
3203 td = curthread;
3204 rights = *ndp->ni_rightsneeded;
3205 cap_rights_set_one(&rights, CAP_LOOKUP);
3206 cnp = &ndp->ni_cnd;
3207
3208 error = fget_cap(td, ndp->ni_dirfd, &rights, &fp, &ndp->ni_filecaps);
3209 if (__predict_false(error != 0))
3210 return (error);
3211 if (__predict_false(fp->f_ops == &badfileops)) {
3212 error = EBADF;
3213 goto out_free;
3214 }
3215 vp = fp->f_vnode;
3216 if (__predict_false(vp == NULL)) {
3217 error = ENOTDIR;
3218 goto out_free;
3219 }
3220 vrefact(vp);
3221 /*
3222 * XXX does not check for VDIR, handled by namei_setup
3223 */
3224 if ((fp->f_flag & FSEARCH) != 0)
3225 cnp->cn_flags |= NOEXECCHECK;
3226 fdrop(fp, td);
3227
3228 #ifdef CAPABILITIES
3229 /*
3230 * If file descriptor doesn't have all rights,
3231 * all lookups relative to it must also be
3232 * strictly relative.
3233 */
3234 CAP_ALL(&rights);
3235 if (!cap_rights_contains(&ndp->ni_filecaps.fc_rights, &rights) ||
3236 ndp->ni_filecaps.fc_fcntls != CAP_FCNTL_ALL ||
3237 ndp->ni_filecaps.fc_nioctls != -1) {
3238 ndp->ni_lcf |= NI_LCF_STRICTRELATIVE;
3239 ndp->ni_resflags |= NIRES_STRICTREL;
3240 }
3241 #endif
3242
3243 /*
3244 * TODO: avoid copying ioctl caps if it can be helped to begin with
3245 */
3246 if ((cnp->cn_flags & WANTIOCTLCAPS) == 0)
3247 filecaps_free_ioctl(&ndp->ni_filecaps);
3248
3249 *vpp = vp;
3250 return (0);
3251
3252 out_free:
3253 filecaps_free(&ndp->ni_filecaps);
3254 fdrop(fp, td);
3255 return (error);
3256 }
3257
3258 static int
fget_unlocked_seq(struct filedesc * fdp,int fd,cap_rights_t * needrightsp,struct file ** fpp,seqc_t * seqp)3259 fget_unlocked_seq(struct filedesc *fdp, int fd, cap_rights_t *needrightsp,
3260 struct file **fpp, seqc_t *seqp)
3261 {
3262 #ifdef CAPABILITIES
3263 const struct filedescent *fde;
3264 #endif
3265 const struct fdescenttbl *fdt;
3266 struct file *fp;
3267 #ifdef CAPABILITIES
3268 seqc_t seq;
3269 cap_rights_t haverights;
3270 int error;
3271 #endif
3272
3273 fdt = fdp->fd_files;
3274 if (__predict_false((u_int)fd >= fdt->fdt_nfiles))
3275 return (EBADF);
3276 /*
3277 * Fetch the descriptor locklessly. We avoid fdrop() races by
3278 * never raising a refcount above 0. To accomplish this we have
3279 * to use a cmpset loop rather than an atomic_add. The descriptor
3280 * must be re-verified once we acquire a reference to be certain
3281 * that the identity is still correct and we did not lose a race
3282 * due to preemption.
3283 */
3284 for (;;) {
3285 #ifdef CAPABILITIES
3286 seq = seqc_read_notmodify(fd_seqc(fdt, fd));
3287 fde = &fdt->fdt_ofiles[fd];
3288 haverights = *cap_rights_fde_inline(fde);
3289 fp = fde->fde_file;
3290 if (!seqc_consistent(fd_seqc(fdt, fd), seq))
3291 continue;
3292 #else
3293 fp = fdt->fdt_ofiles[fd].fde_file;
3294 #endif
3295 if (fp == NULL)
3296 return (EBADF);
3297 #ifdef CAPABILITIES
3298 error = cap_check_inline(&haverights, needrightsp);
3299 if (error != 0)
3300 return (error);
3301 #endif
3302 if (__predict_false(!refcount_acquire_if_not_zero(&fp->f_count))) {
3303 /*
3304 * Force a reload. Other thread could reallocate the
3305 * table before this fd was closed, so it is possible
3306 * that there is a stale fp pointer in cached version.
3307 */
3308 fdt = atomic_load_ptr(&fdp->fd_files);
3309 continue;
3310 }
3311 /*
3312 * Use an acquire barrier to force re-reading of fdt so it is
3313 * refreshed for verification.
3314 */
3315 atomic_thread_fence_acq();
3316 fdt = fdp->fd_files;
3317 #ifdef CAPABILITIES
3318 if (seqc_consistent_nomb(fd_seqc(fdt, fd), seq))
3319 #else
3320 if (fp == fdt->fdt_ofiles[fd].fde_file)
3321 #endif
3322 break;
3323 fdrop(fp, curthread);
3324 }
3325 *fpp = fp;
3326 if (seqp != NULL) {
3327 #ifdef CAPABILITIES
3328 *seqp = seq;
3329 #endif
3330 }
3331 return (0);
3332 }
3333
3334 /*
3335 * See the comments in fget_unlocked_seq for an explanation of how this works.
3336 *
3337 * This is a simplified variant which bails out to the aforementioned routine
3338 * if anything goes wrong. In practice this only happens when userspace is
3339 * racing with itself.
3340 */
3341 int
fget_unlocked(struct filedesc * fdp,int fd,cap_rights_t * needrightsp,struct file ** fpp)3342 fget_unlocked(struct filedesc *fdp, int fd, cap_rights_t *needrightsp,
3343 struct file **fpp)
3344 {
3345 #ifdef CAPABILITIES
3346 const struct filedescent *fde;
3347 #endif
3348 const struct fdescenttbl *fdt;
3349 struct file *fp;
3350 #ifdef CAPABILITIES
3351 seqc_t seq;
3352 const cap_rights_t *haverights;
3353 #endif
3354
3355 fdt = fdp->fd_files;
3356 if (__predict_false((u_int)fd >= fdt->fdt_nfiles)) {
3357 *fpp = NULL;
3358 return (EBADF);
3359 }
3360 #ifdef CAPABILITIES
3361 seq = seqc_read_notmodify(fd_seqc(fdt, fd));
3362 fde = &fdt->fdt_ofiles[fd];
3363 haverights = cap_rights_fde_inline(fde);
3364 fp = fde->fde_file;
3365 #else
3366 fp = fdt->fdt_ofiles[fd].fde_file;
3367 #endif
3368 if (__predict_false(fp == NULL))
3369 goto out_fallback;
3370 #ifdef CAPABILITIES
3371 if (__predict_false(cap_check_inline_transient(haverights, needrightsp)))
3372 goto out_fallback;
3373 #endif
3374 if (__predict_false(!refcount_acquire_if_not_zero(&fp->f_count)))
3375 goto out_fallback;
3376
3377 /*
3378 * Use an acquire barrier to force re-reading of fdt so it is
3379 * refreshed for verification.
3380 */
3381 atomic_thread_fence_acq();
3382 fdt = fdp->fd_files;
3383 #ifdef CAPABILITIES
3384 if (__predict_false(!seqc_consistent_nomb(fd_seqc(fdt, fd), seq)))
3385 #else
3386 if (__predict_false(fp != fdt->fdt_ofiles[fd].fde_file))
3387 #endif
3388 goto out_fdrop;
3389 *fpp = fp;
3390 return (0);
3391 out_fdrop:
3392 fdrop(fp, curthread);
3393 out_fallback:
3394 *fpp = NULL;
3395 return (fget_unlocked_seq(fdp, fd, needrightsp, fpp, NULL));
3396 }
3397
3398 /*
3399 * Translate fd -> file when the caller guarantees the file descriptor table
3400 * can't be changed by others.
3401 *
3402 * Note this does not mean the file object itself is only visible to the caller,
3403 * merely that it wont disappear without having to be referenced.
3404 *
3405 * Must be paired with fput_only_user.
3406 */
3407 #ifdef CAPABILITIES
3408 int
fget_only_user(struct filedesc * fdp,int fd,cap_rights_t * needrightsp,struct file ** fpp)3409 fget_only_user(struct filedesc *fdp, int fd, cap_rights_t *needrightsp,
3410 struct file **fpp)
3411 {
3412 const struct filedescent *fde;
3413 const struct fdescenttbl *fdt;
3414 const cap_rights_t *haverights;
3415 struct file *fp;
3416 int error;
3417
3418 MPASS(FILEDESC_IS_ONLY_USER(fdp));
3419
3420 *fpp = NULL;
3421 if (__predict_false(fd >= fdp->fd_nfiles))
3422 return (EBADF);
3423
3424 fdt = fdp->fd_files;
3425 fde = &fdt->fdt_ofiles[fd];
3426 fp = fde->fde_file;
3427 if (__predict_false(fp == NULL))
3428 return (EBADF);
3429 MPASS(refcount_load(&fp->f_count) > 0);
3430 haverights = cap_rights_fde_inline(fde);
3431 error = cap_check_inline(haverights, needrightsp);
3432 if (__predict_false(error != 0))
3433 return (error);
3434 *fpp = fp;
3435 return (0);
3436 }
3437 #else
3438 int
fget_only_user(struct filedesc * fdp,int fd,cap_rights_t * needrightsp,struct file ** fpp)3439 fget_only_user(struct filedesc *fdp, int fd, cap_rights_t *needrightsp,
3440 struct file **fpp)
3441 {
3442 struct file *fp;
3443
3444 MPASS(FILEDESC_IS_ONLY_USER(fdp));
3445
3446 *fpp = NULL;
3447 if (__predict_false(fd >= fdp->fd_nfiles))
3448 return (EBADF);
3449
3450 fp = fdp->fd_ofiles[fd].fde_file;
3451 if (__predict_false(fp == NULL))
3452 return (EBADF);
3453
3454 MPASS(refcount_load(&fp->f_count) > 0);
3455 *fpp = fp;
3456 return (0);
3457 }
3458 #endif
3459
3460 /*
3461 * Extract the file pointer associated with the specified descriptor for the
3462 * current user process.
3463 *
3464 * If the descriptor doesn't exist or doesn't match 'flags', EBADF is
3465 * returned.
3466 *
3467 * File's rights will be checked against the capability rights mask.
3468 *
3469 * If an error occurred the non-zero error is returned and *fpp is set to
3470 * NULL. Otherwise *fpp is held and set and zero is returned. Caller is
3471 * responsible for fdrop().
3472 */
3473 static __inline int
_fget(struct thread * td,int fd,struct file ** fpp,int flags,cap_rights_t * needrightsp)3474 _fget(struct thread *td, int fd, struct file **fpp, int flags,
3475 cap_rights_t *needrightsp)
3476 {
3477 struct filedesc *fdp;
3478 struct file *fp;
3479 int error;
3480
3481 *fpp = NULL;
3482 fdp = td->td_proc->p_fd;
3483 error = fget_unlocked(fdp, fd, needrightsp, &fp);
3484 if (__predict_false(error != 0))
3485 return (error);
3486 if (__predict_false(fp->f_ops == &badfileops)) {
3487 fdrop(fp, td);
3488 return (EBADF);
3489 }
3490
3491 /*
3492 * FREAD and FWRITE failure return EBADF as per POSIX.
3493 */
3494 error = 0;
3495 switch (flags) {
3496 case FREAD:
3497 case FWRITE:
3498 if ((fp->f_flag & flags) == 0)
3499 error = EBADF;
3500 break;
3501 case FEXEC:
3502 if (fp->f_ops != &path_fileops &&
3503 ((fp->f_flag & (FREAD | FEXEC)) == 0 ||
3504 (fp->f_flag & FWRITE) != 0))
3505 error = EBADF;
3506 break;
3507 case 0:
3508 break;
3509 default:
3510 KASSERT(0, ("wrong flags"));
3511 }
3512
3513 if (error != 0) {
3514 fdrop(fp, td);
3515 return (error);
3516 }
3517
3518 *fpp = fp;
3519 return (0);
3520 }
3521
3522 int
fget(struct thread * td,int fd,cap_rights_t * rightsp,struct file ** fpp)3523 fget(struct thread *td, int fd, cap_rights_t *rightsp, struct file **fpp)
3524 {
3525
3526 return (_fget(td, fd, fpp, 0, rightsp));
3527 }
3528
3529 int
fget_mmap(struct thread * td,int fd,cap_rights_t * rightsp,vm_prot_t * maxprotp,struct file ** fpp)3530 fget_mmap(struct thread *td, int fd, cap_rights_t *rightsp, vm_prot_t *maxprotp,
3531 struct file **fpp)
3532 {
3533 int error;
3534 #ifndef CAPABILITIES
3535 error = _fget(td, fd, fpp, 0, rightsp);
3536 if (maxprotp != NULL)
3537 *maxprotp = VM_PROT_ALL;
3538 return (error);
3539 #else
3540 cap_rights_t fdrights;
3541 struct filedesc *fdp;
3542 struct file *fp;
3543 seqc_t seq;
3544
3545 *fpp = NULL;
3546 fdp = td->td_proc->p_fd;
3547 MPASS(cap_rights_is_set(rightsp, CAP_MMAP));
3548 for (;;) {
3549 error = fget_unlocked_seq(fdp, fd, rightsp, &fp, &seq);
3550 if (__predict_false(error != 0))
3551 return (error);
3552 if (__predict_false(fp->f_ops == &badfileops)) {
3553 fdrop(fp, td);
3554 return (EBADF);
3555 }
3556 if (maxprotp != NULL)
3557 fdrights = *cap_rights(fdp, fd);
3558 if (!fd_modified(fdp, fd, seq))
3559 break;
3560 fdrop(fp, td);
3561 }
3562
3563 /*
3564 * If requested, convert capability rights to access flags.
3565 */
3566 if (maxprotp != NULL)
3567 *maxprotp = cap_rights_to_vmprot(&fdrights);
3568 *fpp = fp;
3569 return (0);
3570 #endif
3571 }
3572
3573 int
fget_read(struct thread * td,int fd,cap_rights_t * rightsp,struct file ** fpp)3574 fget_read(struct thread *td, int fd, cap_rights_t *rightsp, struct file **fpp)
3575 {
3576
3577 return (_fget(td, fd, fpp, FREAD, rightsp));
3578 }
3579
3580 int
fget_write(struct thread * td,int fd,cap_rights_t * rightsp,struct file ** fpp)3581 fget_write(struct thread *td, int fd, cap_rights_t *rightsp, struct file **fpp)
3582 {
3583
3584 return (_fget(td, fd, fpp, FWRITE, rightsp));
3585 }
3586
3587 int
fget_fcntl(struct thread * td,int fd,cap_rights_t * rightsp,int needfcntl,struct file ** fpp)3588 fget_fcntl(struct thread *td, int fd, cap_rights_t *rightsp, int needfcntl,
3589 struct file **fpp)
3590 {
3591 struct filedesc *fdp = td->td_proc->p_fd;
3592 #ifndef CAPABILITIES
3593 return (fget_unlocked(fdp, fd, rightsp, fpp));
3594 #else
3595 struct file *fp;
3596 int error;
3597 seqc_t seq;
3598
3599 *fpp = NULL;
3600 MPASS(cap_rights_is_set(rightsp, CAP_FCNTL));
3601 for (;;) {
3602 error = fget_unlocked_seq(fdp, fd, rightsp, &fp, &seq);
3603 if (error != 0)
3604 return (error);
3605 error = cap_fcntl_check(fdp, fd, needfcntl);
3606 if (!fd_modified(fdp, fd, seq))
3607 break;
3608 fdrop(fp, td);
3609 }
3610 if (error != 0) {
3611 fdrop(fp, td);
3612 return (error);
3613 }
3614 *fpp = fp;
3615 return (0);
3616 #endif
3617 }
3618
3619 /*
3620 * Like fget() but loads the underlying vnode, or returns an error if the
3621 * descriptor does not represent a vnode. Note that pipes use vnodes but
3622 * never have VM objects. The returned vnode will be vref()'d.
3623 *
3624 * XXX: what about the unused flags ?
3625 */
3626 static __inline int
_fgetvp(struct thread * td,int fd,int flags,cap_rights_t * needrightsp,struct vnode ** vpp)3627 _fgetvp(struct thread *td, int fd, int flags, cap_rights_t *needrightsp,
3628 struct vnode **vpp)
3629 {
3630 struct file *fp;
3631 int error;
3632
3633 *vpp = NULL;
3634 error = _fget(td, fd, &fp, flags, needrightsp);
3635 if (error != 0)
3636 return (error);
3637 if (fp->f_vnode == NULL) {
3638 error = EINVAL;
3639 } else {
3640 *vpp = fp->f_vnode;
3641 vrefact(*vpp);
3642 }
3643 fdrop(fp, td);
3644
3645 return (error);
3646 }
3647
3648 int
fgetvp(struct thread * td,int fd,cap_rights_t * rightsp,struct vnode ** vpp)3649 fgetvp(struct thread *td, int fd, cap_rights_t *rightsp, struct vnode **vpp)
3650 {
3651
3652 return (_fgetvp(td, fd, 0, rightsp, vpp));
3653 }
3654
3655 int
fgetvp_rights(struct thread * td,int fd,cap_rights_t * needrightsp,struct filecaps * havecaps,struct vnode ** vpp)3656 fgetvp_rights(struct thread *td, int fd, cap_rights_t *needrightsp,
3657 struct filecaps *havecaps, struct vnode **vpp)
3658 {
3659 struct filecaps caps;
3660 struct file *fp;
3661 int error;
3662
3663 error = fget_cap(td, fd, needrightsp, &fp, &caps);
3664 if (error != 0)
3665 return (error);
3666 if (fp->f_ops == &badfileops) {
3667 error = EBADF;
3668 goto out;
3669 }
3670 if (fp->f_vnode == NULL) {
3671 error = EINVAL;
3672 goto out;
3673 }
3674
3675 *havecaps = caps;
3676 *vpp = fp->f_vnode;
3677 vrefact(*vpp);
3678 fdrop(fp, td);
3679
3680 return (0);
3681 out:
3682 filecaps_free(&caps);
3683 fdrop(fp, td);
3684 return (error);
3685 }
3686
3687 int
fgetvp_read(struct thread * td,int fd,cap_rights_t * rightsp,struct vnode ** vpp)3688 fgetvp_read(struct thread *td, int fd, cap_rights_t *rightsp, struct vnode **vpp)
3689 {
3690
3691 return (_fgetvp(td, fd, FREAD, rightsp, vpp));
3692 }
3693
3694 int
fgetvp_exec(struct thread * td,int fd,cap_rights_t * rightsp,struct vnode ** vpp)3695 fgetvp_exec(struct thread *td, int fd, cap_rights_t *rightsp, struct vnode **vpp)
3696 {
3697
3698 return (_fgetvp(td, fd, FEXEC, rightsp, vpp));
3699 }
3700
3701 #ifdef notyet
3702 int
fgetvp_write(struct thread * td,int fd,cap_rights_t * rightsp,struct vnode ** vpp)3703 fgetvp_write(struct thread *td, int fd, cap_rights_t *rightsp,
3704 struct vnode **vpp)
3705 {
3706
3707 return (_fgetvp(td, fd, FWRITE, rightsp, vpp));
3708 }
3709 #endif
3710
3711 /*
3712 * Handle the last reference to a file being closed.
3713 *
3714 * Without the noinline attribute clang keeps inlining the func thorough this
3715 * file when fdrop is used.
3716 */
3717 int __noinline
_fdrop(struct file * fp,struct thread * td)3718 _fdrop(struct file *fp, struct thread *td)
3719 {
3720 int error;
3721 #ifdef INVARIANTS
3722 int count;
3723
3724 count = refcount_load(&fp->f_count);
3725 if (count != 0)
3726 panic("fdrop: fp %p count %d", fp, count);
3727 #endif
3728 error = fo_close(fp, td);
3729 atomic_subtract_int(&openfiles, 1);
3730 crfree(fp->f_cred);
3731 free(fp->f_advice, M_FADVISE);
3732 uma_zfree(file_zone, fp);
3733
3734 return (error);
3735 }
3736
3737 /*
3738 * Apply an advisory lock on a file descriptor.
3739 *
3740 * Just attempt to get a record lock of the requested type on the entire file
3741 * (l_whence = SEEK_SET, l_start = 0, l_len = 0).
3742 */
3743 #ifndef _SYS_SYSPROTO_H_
3744 struct flock_args {
3745 int fd;
3746 int how;
3747 };
3748 #endif
3749 /* ARGSUSED */
3750 int
sys_flock(struct thread * td,struct flock_args * uap)3751 sys_flock(struct thread *td, struct flock_args *uap)
3752 {
3753 struct file *fp;
3754 struct vnode *vp;
3755 struct flock lf;
3756 int error;
3757
3758 error = fget(td, uap->fd, &cap_flock_rights, &fp);
3759 if (error != 0)
3760 return (error);
3761 error = EOPNOTSUPP;
3762 if (fp->f_type != DTYPE_VNODE && fp->f_type != DTYPE_FIFO) {
3763 goto done;
3764 }
3765 if (fp->f_ops == &path_fileops) {
3766 goto done;
3767 }
3768
3769 error = 0;
3770 vp = fp->f_vnode;
3771 lf.l_whence = SEEK_SET;
3772 lf.l_start = 0;
3773 lf.l_len = 0;
3774 if (uap->how & LOCK_UN) {
3775 lf.l_type = F_UNLCK;
3776 atomic_clear_int(&fp->f_flag, FHASLOCK);
3777 error = VOP_ADVLOCK(vp, (caddr_t)fp, F_UNLCK, &lf, F_FLOCK);
3778 goto done;
3779 }
3780 if (uap->how & LOCK_EX)
3781 lf.l_type = F_WRLCK;
3782 else if (uap->how & LOCK_SH)
3783 lf.l_type = F_RDLCK;
3784 else {
3785 error = EBADF;
3786 goto done;
3787 }
3788 atomic_set_int(&fp->f_flag, FHASLOCK);
3789 error = VOP_ADVLOCK(vp, (caddr_t)fp, F_SETLK, &lf,
3790 (uap->how & LOCK_NB) ? F_FLOCK : F_FLOCK | F_WAIT);
3791 done:
3792 fdrop(fp, td);
3793 return (error);
3794 }
3795 /*
3796 * Duplicate the specified descriptor to a free descriptor.
3797 */
3798 int
dupfdopen(struct thread * td,struct filedesc * fdp,int dfd,int mode,int openerror,int * indxp)3799 dupfdopen(struct thread *td, struct filedesc *fdp, int dfd, int mode,
3800 int openerror, int *indxp)
3801 {
3802 struct filedescent *newfde, *oldfde;
3803 struct file *fp;
3804 u_long *ioctls;
3805 int error, indx;
3806
3807 KASSERT(openerror == ENODEV || openerror == ENXIO,
3808 ("unexpected error %d in %s", openerror, __func__));
3809
3810 /*
3811 * If the to-be-dup'd fd number is greater than the allowed number
3812 * of file descriptors, or the fd to be dup'd has already been
3813 * closed, then reject.
3814 */
3815 FILEDESC_XLOCK(fdp);
3816 if ((fp = fget_locked(fdp, dfd)) == NULL) {
3817 FILEDESC_XUNLOCK(fdp);
3818 return (EBADF);
3819 }
3820
3821 error = fdalloc(td, 0, &indx);
3822 if (error != 0) {
3823 FILEDESC_XUNLOCK(fdp);
3824 return (error);
3825 }
3826
3827 /*
3828 * There are two cases of interest here.
3829 *
3830 * For ENODEV simply dup (dfd) to file descriptor (indx) and return.
3831 *
3832 * For ENXIO steal away the file structure from (dfd) and store it in
3833 * (indx). (dfd) is effectively closed by this operation.
3834 */
3835 switch (openerror) {
3836 case ENODEV:
3837 /*
3838 * Check that the mode the file is being opened for is a
3839 * subset of the mode of the existing descriptor.
3840 */
3841 if (((mode & (FREAD|FWRITE)) | fp->f_flag) != fp->f_flag) {
3842 fdunused(fdp, indx);
3843 FILEDESC_XUNLOCK(fdp);
3844 return (EACCES);
3845 }
3846 if (!fhold(fp)) {
3847 fdunused(fdp, indx);
3848 FILEDESC_XUNLOCK(fdp);
3849 return (EBADF);
3850 }
3851 newfde = &fdp->fd_ofiles[indx];
3852 oldfde = &fdp->fd_ofiles[dfd];
3853 ioctls = filecaps_copy_prep(&oldfde->fde_caps);
3854 #ifdef CAPABILITIES
3855 seqc_write_begin(&newfde->fde_seqc);
3856 #endif
3857 memcpy(newfde, oldfde, fde_change_size);
3858 filecaps_copy_finish(&oldfde->fde_caps, &newfde->fde_caps,
3859 ioctls);
3860 #ifdef CAPABILITIES
3861 seqc_write_end(&newfde->fde_seqc);
3862 #endif
3863 break;
3864 case ENXIO:
3865 /*
3866 * Steal away the file pointer from dfd and stuff it into indx.
3867 */
3868 newfde = &fdp->fd_ofiles[indx];
3869 oldfde = &fdp->fd_ofiles[dfd];
3870 #ifdef CAPABILITIES
3871 seqc_write_begin(&newfde->fde_seqc);
3872 #endif
3873 memcpy(newfde, oldfde, fde_change_size);
3874 oldfde->fde_file = NULL;
3875 fdunused(fdp, dfd);
3876 #ifdef CAPABILITIES
3877 seqc_write_end(&newfde->fde_seqc);
3878 #endif
3879 break;
3880 }
3881 FILEDESC_XUNLOCK(fdp);
3882 *indxp = indx;
3883 return (0);
3884 }
3885
3886 /*
3887 * This sysctl determines if we will allow a process to chroot(2) if it
3888 * has a directory open:
3889 * 0: disallowed for all processes.
3890 * 1: allowed for processes that were not already chroot(2)'ed.
3891 * 2: allowed for all processes.
3892 */
3893
3894 static int chroot_allow_open_directories = 1;
3895
3896 SYSCTL_INT(_kern, OID_AUTO, chroot_allow_open_directories, CTLFLAG_RW,
3897 &chroot_allow_open_directories, 0,
3898 "Allow a process to chroot(2) if it has a directory open");
3899
3900 /*
3901 * Helper function for raised chroot(2) security function: Refuse if
3902 * any filedescriptors are open directories.
3903 */
3904 static int
chroot_refuse_vdir_fds(struct filedesc * fdp)3905 chroot_refuse_vdir_fds(struct filedesc *fdp)
3906 {
3907 struct vnode *vp;
3908 struct file *fp;
3909 int fd, lastfile;
3910
3911 FILEDESC_LOCK_ASSERT(fdp);
3912
3913 lastfile = fdlastfile(fdp);
3914 for (fd = 0; fd <= lastfile; fd++) {
3915 fp = fget_locked(fdp, fd);
3916 if (fp == NULL)
3917 continue;
3918 if (fp->f_type == DTYPE_VNODE) {
3919 vp = fp->f_vnode;
3920 if (vp->v_type == VDIR)
3921 return (EPERM);
3922 }
3923 }
3924 return (0);
3925 }
3926
3927 static void
pwd_fill(struct pwd * oldpwd,struct pwd * newpwd)3928 pwd_fill(struct pwd *oldpwd, struct pwd *newpwd)
3929 {
3930
3931 if (newpwd->pwd_cdir == NULL && oldpwd->pwd_cdir != NULL) {
3932 vrefact(oldpwd->pwd_cdir);
3933 newpwd->pwd_cdir = oldpwd->pwd_cdir;
3934 }
3935
3936 if (newpwd->pwd_rdir == NULL && oldpwd->pwd_rdir != NULL) {
3937 vrefact(oldpwd->pwd_rdir);
3938 newpwd->pwd_rdir = oldpwd->pwd_rdir;
3939 }
3940
3941 if (newpwd->pwd_jdir == NULL && oldpwd->pwd_jdir != NULL) {
3942 vrefact(oldpwd->pwd_jdir);
3943 newpwd->pwd_jdir = oldpwd->pwd_jdir;
3944 }
3945 }
3946
3947 struct pwd *
pwd_hold_pwddesc(struct pwddesc * pdp)3948 pwd_hold_pwddesc(struct pwddesc *pdp)
3949 {
3950 struct pwd *pwd;
3951
3952 PWDDESC_ASSERT_XLOCKED(pdp);
3953 pwd = PWDDESC_XLOCKED_LOAD_PWD(pdp);
3954 if (pwd != NULL)
3955 refcount_acquire(&pwd->pwd_refcount);
3956 return (pwd);
3957 }
3958
3959 bool
pwd_hold_smr(struct pwd * pwd)3960 pwd_hold_smr(struct pwd *pwd)
3961 {
3962
3963 MPASS(pwd != NULL);
3964 if (__predict_true(refcount_acquire_if_not_zero(&pwd->pwd_refcount))) {
3965 return (true);
3966 }
3967 return (false);
3968 }
3969
3970 struct pwd *
pwd_hold(struct thread * td)3971 pwd_hold(struct thread *td)
3972 {
3973 struct pwddesc *pdp;
3974 struct pwd *pwd;
3975
3976 pdp = td->td_proc->p_pd;
3977
3978 vfs_smr_enter();
3979 pwd = vfs_smr_entered_load(&pdp->pd_pwd);
3980 if (pwd_hold_smr(pwd)) {
3981 vfs_smr_exit();
3982 return (pwd);
3983 }
3984 vfs_smr_exit();
3985 PWDDESC_XLOCK(pdp);
3986 pwd = pwd_hold_pwddesc(pdp);
3987 MPASS(pwd != NULL);
3988 PWDDESC_XUNLOCK(pdp);
3989 return (pwd);
3990 }
3991
3992 struct pwd *
pwd_hold_proc(struct proc * p)3993 pwd_hold_proc(struct proc *p)
3994 {
3995 struct pwddesc *pdp;
3996 struct pwd *pwd;
3997
3998 PROC_ASSERT_HELD(p);
3999 PROC_LOCK(p);
4000 pdp = pdhold(p);
4001 MPASS(pdp != NULL);
4002 PROC_UNLOCK(p);
4003
4004 PWDDESC_XLOCK(pdp);
4005 pwd = pwd_hold_pwddesc(pdp);
4006 MPASS(pwd != NULL);
4007 PWDDESC_XUNLOCK(pdp);
4008 pddrop(pdp);
4009 return (pwd);
4010 }
4011
4012 static struct pwd *
pwd_alloc(void)4013 pwd_alloc(void)
4014 {
4015 struct pwd *pwd;
4016
4017 pwd = uma_zalloc_smr(pwd_zone, M_WAITOK);
4018 bzero(pwd, sizeof(*pwd));
4019 refcount_init(&pwd->pwd_refcount, 1);
4020 return (pwd);
4021 }
4022
4023 void
pwd_drop(struct pwd * pwd)4024 pwd_drop(struct pwd *pwd)
4025 {
4026
4027 if (!refcount_release(&pwd->pwd_refcount))
4028 return;
4029
4030 if (pwd->pwd_cdir != NULL)
4031 vrele(pwd->pwd_cdir);
4032 if (pwd->pwd_rdir != NULL)
4033 vrele(pwd->pwd_rdir);
4034 if (pwd->pwd_jdir != NULL)
4035 vrele(pwd->pwd_jdir);
4036 uma_zfree_smr(pwd_zone, pwd);
4037 }
4038
4039 /*
4040 * The caller is responsible for invoking priv_check() and
4041 * mac_vnode_check_chroot() to authorize this operation.
4042 */
4043 int
pwd_chroot(struct thread * td,struct vnode * vp)4044 pwd_chroot(struct thread *td, struct vnode *vp)
4045 {
4046 struct pwddesc *pdp;
4047 struct filedesc *fdp;
4048 struct pwd *newpwd, *oldpwd;
4049 int error;
4050
4051 fdp = td->td_proc->p_fd;
4052 pdp = td->td_proc->p_pd;
4053 newpwd = pwd_alloc();
4054 FILEDESC_SLOCK(fdp);
4055 PWDDESC_XLOCK(pdp);
4056 oldpwd = PWDDESC_XLOCKED_LOAD_PWD(pdp);
4057 if (chroot_allow_open_directories == 0 ||
4058 (chroot_allow_open_directories == 1 &&
4059 oldpwd->pwd_rdir != rootvnode)) {
4060 error = chroot_refuse_vdir_fds(fdp);
4061 FILEDESC_SUNLOCK(fdp);
4062 if (error != 0) {
4063 PWDDESC_XUNLOCK(pdp);
4064 pwd_drop(newpwd);
4065 return (error);
4066 }
4067 } else {
4068 FILEDESC_SUNLOCK(fdp);
4069 }
4070
4071 vrefact(vp);
4072 newpwd->pwd_rdir = vp;
4073 if (oldpwd->pwd_jdir == NULL) {
4074 vrefact(vp);
4075 newpwd->pwd_jdir = vp;
4076 }
4077 pwd_fill(oldpwd, newpwd);
4078 pwd_set(pdp, newpwd);
4079 PWDDESC_XUNLOCK(pdp);
4080 pwd_drop(oldpwd);
4081 return (0);
4082 }
4083
4084 void
pwd_chdir(struct thread * td,struct vnode * vp)4085 pwd_chdir(struct thread *td, struct vnode *vp)
4086 {
4087 struct pwddesc *pdp;
4088 struct pwd *newpwd, *oldpwd;
4089
4090 VNPASS(vp->v_usecount > 0, vp);
4091
4092 newpwd = pwd_alloc();
4093 pdp = td->td_proc->p_pd;
4094 PWDDESC_XLOCK(pdp);
4095 oldpwd = PWDDESC_XLOCKED_LOAD_PWD(pdp);
4096 newpwd->pwd_cdir = vp;
4097 pwd_fill(oldpwd, newpwd);
4098 pwd_set(pdp, newpwd);
4099 PWDDESC_XUNLOCK(pdp);
4100 pwd_drop(oldpwd);
4101 }
4102
4103 /*
4104 * jail_attach(2) changes both root and working directories.
4105 */
4106 int
pwd_chroot_chdir(struct thread * td,struct vnode * vp)4107 pwd_chroot_chdir(struct thread *td, struct vnode *vp)
4108 {
4109 struct pwddesc *pdp;
4110 struct filedesc *fdp;
4111 struct pwd *newpwd, *oldpwd;
4112 int error;
4113
4114 fdp = td->td_proc->p_fd;
4115 pdp = td->td_proc->p_pd;
4116 newpwd = pwd_alloc();
4117 FILEDESC_SLOCK(fdp);
4118 PWDDESC_XLOCK(pdp);
4119 oldpwd = PWDDESC_XLOCKED_LOAD_PWD(pdp);
4120 error = chroot_refuse_vdir_fds(fdp);
4121 FILEDESC_SUNLOCK(fdp);
4122 if (error != 0) {
4123 PWDDESC_XUNLOCK(pdp);
4124 pwd_drop(newpwd);
4125 return (error);
4126 }
4127
4128 vrefact(vp);
4129 newpwd->pwd_rdir = vp;
4130 vrefact(vp);
4131 newpwd->pwd_cdir = vp;
4132 if (oldpwd->pwd_jdir == NULL) {
4133 vrefact(vp);
4134 newpwd->pwd_jdir = vp;
4135 }
4136 pwd_fill(oldpwd, newpwd);
4137 pwd_set(pdp, newpwd);
4138 PWDDESC_XUNLOCK(pdp);
4139 pwd_drop(oldpwd);
4140 return (0);
4141 }
4142
4143 void
pwd_ensure_dirs(void)4144 pwd_ensure_dirs(void)
4145 {
4146 struct pwddesc *pdp;
4147 struct pwd *oldpwd, *newpwd;
4148
4149 pdp = curproc->p_pd;
4150 PWDDESC_XLOCK(pdp);
4151 oldpwd = PWDDESC_XLOCKED_LOAD_PWD(pdp);
4152 if (oldpwd->pwd_cdir != NULL && oldpwd->pwd_rdir != NULL) {
4153 PWDDESC_XUNLOCK(pdp);
4154 return;
4155 }
4156 PWDDESC_XUNLOCK(pdp);
4157
4158 newpwd = pwd_alloc();
4159 PWDDESC_XLOCK(pdp);
4160 oldpwd = PWDDESC_XLOCKED_LOAD_PWD(pdp);
4161 pwd_fill(oldpwd, newpwd);
4162 if (newpwd->pwd_cdir == NULL) {
4163 vrefact(rootvnode);
4164 newpwd->pwd_cdir = rootvnode;
4165 }
4166 if (newpwd->pwd_rdir == NULL) {
4167 vrefact(rootvnode);
4168 newpwd->pwd_rdir = rootvnode;
4169 }
4170 pwd_set(pdp, newpwd);
4171 PWDDESC_XUNLOCK(pdp);
4172 pwd_drop(oldpwd);
4173 }
4174
4175 void
pwd_set_rootvnode(void)4176 pwd_set_rootvnode(void)
4177 {
4178 struct pwddesc *pdp;
4179 struct pwd *oldpwd, *newpwd;
4180
4181 pdp = curproc->p_pd;
4182
4183 newpwd = pwd_alloc();
4184 PWDDESC_XLOCK(pdp);
4185 oldpwd = PWDDESC_XLOCKED_LOAD_PWD(pdp);
4186 vrefact(rootvnode);
4187 newpwd->pwd_cdir = rootvnode;
4188 vrefact(rootvnode);
4189 newpwd->pwd_rdir = rootvnode;
4190 pwd_fill(oldpwd, newpwd);
4191 pwd_set(pdp, newpwd);
4192 PWDDESC_XUNLOCK(pdp);
4193 pwd_drop(oldpwd);
4194 }
4195
4196 /*
4197 * Scan all active processes and prisons to see if any of them have a current
4198 * or root directory of `olddp'. If so, replace them with the new mount point.
4199 */
4200 void
mountcheckdirs(struct vnode * olddp,struct vnode * newdp)4201 mountcheckdirs(struct vnode *olddp, struct vnode *newdp)
4202 {
4203 struct pwddesc *pdp;
4204 struct pwd *newpwd, *oldpwd;
4205 struct prison *pr;
4206 struct proc *p;
4207 int nrele;
4208
4209 if (vrefcnt(olddp) == 1)
4210 return;
4211 nrele = 0;
4212 newpwd = pwd_alloc();
4213 sx_slock(&allproc_lock);
4214 FOREACH_PROC_IN_SYSTEM(p) {
4215 PROC_LOCK(p);
4216 pdp = pdhold(p);
4217 PROC_UNLOCK(p);
4218 if (pdp == NULL)
4219 continue;
4220 PWDDESC_XLOCK(pdp);
4221 oldpwd = PWDDESC_XLOCKED_LOAD_PWD(pdp);
4222 if (oldpwd == NULL ||
4223 (oldpwd->pwd_cdir != olddp &&
4224 oldpwd->pwd_rdir != olddp &&
4225 oldpwd->pwd_jdir != olddp)) {
4226 PWDDESC_XUNLOCK(pdp);
4227 pddrop(pdp);
4228 continue;
4229 }
4230 if (oldpwd->pwd_cdir == olddp) {
4231 vrefact(newdp);
4232 newpwd->pwd_cdir = newdp;
4233 }
4234 if (oldpwd->pwd_rdir == olddp) {
4235 vrefact(newdp);
4236 newpwd->pwd_rdir = newdp;
4237 }
4238 if (oldpwd->pwd_jdir == olddp) {
4239 vrefact(newdp);
4240 newpwd->pwd_jdir = newdp;
4241 }
4242 pwd_fill(oldpwd, newpwd);
4243 pwd_set(pdp, newpwd);
4244 PWDDESC_XUNLOCK(pdp);
4245 pwd_drop(oldpwd);
4246 pddrop(pdp);
4247 newpwd = pwd_alloc();
4248 }
4249 sx_sunlock(&allproc_lock);
4250 pwd_drop(newpwd);
4251 if (rootvnode == olddp) {
4252 vrefact(newdp);
4253 rootvnode = newdp;
4254 nrele++;
4255 }
4256 mtx_lock(&prison0.pr_mtx);
4257 if (prison0.pr_root == olddp) {
4258 vrefact(newdp);
4259 prison0.pr_root = newdp;
4260 nrele++;
4261 }
4262 mtx_unlock(&prison0.pr_mtx);
4263 sx_slock(&allprison_lock);
4264 TAILQ_FOREACH(pr, &allprison, pr_list) {
4265 mtx_lock(&pr->pr_mtx);
4266 if (pr->pr_root == olddp) {
4267 vrefact(newdp);
4268 pr->pr_root = newdp;
4269 nrele++;
4270 }
4271 mtx_unlock(&pr->pr_mtx);
4272 }
4273 sx_sunlock(&allprison_lock);
4274 while (nrele--)
4275 vrele(olddp);
4276 }
4277
4278 int
descrip_check_write_mp(struct filedesc * fdp,struct mount * mp)4279 descrip_check_write_mp(struct filedesc *fdp, struct mount *mp)
4280 {
4281 struct file *fp;
4282 struct vnode *vp;
4283 int error, i, lastfile;
4284
4285 error = 0;
4286 FILEDESC_SLOCK(fdp);
4287 lastfile = fdlastfile(fdp);
4288 for (i = 0; i <= lastfile; i++) {
4289 fp = fdp->fd_ofiles[i].fde_file;
4290 if (fp->f_type != DTYPE_VNODE ||
4291 (atomic_load_int(&fp->f_flag) & FWRITE) == 0)
4292 continue;
4293 vp = fp->f_vnode;
4294 if (vp->v_mount == mp) {
4295 error = EDEADLK;
4296 break;
4297 }
4298 }
4299 FILEDESC_SUNLOCK(fdp);
4300 return (error);
4301 }
4302
4303 struct filedesc_to_leader *
filedesc_to_leader_alloc(struct filedesc_to_leader * old,struct filedesc * fdp,struct proc * leader)4304 filedesc_to_leader_alloc(struct filedesc_to_leader *old, struct filedesc *fdp,
4305 struct proc *leader)
4306 {
4307 struct filedesc_to_leader *fdtol;
4308
4309 fdtol = malloc(sizeof(struct filedesc_to_leader),
4310 M_FILEDESC_TO_LEADER, M_WAITOK);
4311 fdtol->fdl_refcount = 1;
4312 fdtol->fdl_holdcount = 0;
4313 fdtol->fdl_wakeup = 0;
4314 fdtol->fdl_leader = leader;
4315 if (old != NULL) {
4316 FILEDESC_XLOCK(fdp);
4317 fdtol->fdl_next = old->fdl_next;
4318 fdtol->fdl_prev = old;
4319 old->fdl_next = fdtol;
4320 fdtol->fdl_next->fdl_prev = fdtol;
4321 FILEDESC_XUNLOCK(fdp);
4322 } else {
4323 fdtol->fdl_next = fdtol;
4324 fdtol->fdl_prev = fdtol;
4325 }
4326 return (fdtol);
4327 }
4328
4329 struct filedesc_to_leader *
filedesc_to_leader_share(struct filedesc_to_leader * fdtol,struct filedesc * fdp)4330 filedesc_to_leader_share(struct filedesc_to_leader *fdtol, struct filedesc *fdp)
4331 {
4332 FILEDESC_XLOCK(fdp);
4333 fdtol->fdl_refcount++;
4334 FILEDESC_XUNLOCK(fdp);
4335 return (fdtol);
4336 }
4337
4338 static int
sysctl_kern_proc_nfds(SYSCTL_HANDLER_ARGS)4339 sysctl_kern_proc_nfds(SYSCTL_HANDLER_ARGS)
4340 {
4341 NDSLOTTYPE *map;
4342 struct filedesc *fdp;
4343 u_int namelen;
4344 int count, off, minoff;
4345
4346 namelen = arg2;
4347 if (namelen != 1)
4348 return (EINVAL);
4349
4350 if (*(int *)arg1 != 0)
4351 return (EINVAL);
4352
4353 fdp = curproc->p_fd;
4354 count = 0;
4355 FILEDESC_SLOCK(fdp);
4356 map = fdp->fd_map;
4357 off = NDSLOT(fdp->fd_nfiles - 1);
4358 for (minoff = NDSLOT(0); off >= minoff; --off)
4359 count += bitcountl(map[off]);
4360 FILEDESC_SUNLOCK(fdp);
4361
4362 return (SYSCTL_OUT(req, &count, sizeof(count)));
4363 }
4364
4365 static SYSCTL_NODE(_kern_proc, KERN_PROC_NFDS, nfds,
4366 CTLFLAG_RD|CTLFLAG_CAPRD|CTLFLAG_MPSAFE, sysctl_kern_proc_nfds,
4367 "Number of open file descriptors");
4368
4369 /*
4370 * Get file structures globally.
4371 */
4372 static int
sysctl_kern_file(SYSCTL_HANDLER_ARGS)4373 sysctl_kern_file(SYSCTL_HANDLER_ARGS)
4374 {
4375 struct xfile xf;
4376 struct filedesc *fdp;
4377 struct file *fp;
4378 struct proc *p;
4379 int error, n, lastfile;
4380
4381 error = sysctl_wire_old_buffer(req, 0);
4382 if (error != 0)
4383 return (error);
4384 if (req->oldptr == NULL) {
4385 n = 0;
4386 sx_slock(&allproc_lock);
4387 FOREACH_PROC_IN_SYSTEM(p) {
4388 PROC_LOCK(p);
4389 if (p->p_state == PRS_NEW) {
4390 PROC_UNLOCK(p);
4391 continue;
4392 }
4393 fdp = fdhold(p);
4394 PROC_UNLOCK(p);
4395 if (fdp == NULL)
4396 continue;
4397 /* overestimates sparse tables. */
4398 n += fdp->fd_nfiles;
4399 fddrop(fdp);
4400 }
4401 sx_sunlock(&allproc_lock);
4402 return (SYSCTL_OUT(req, 0, n * sizeof(xf)));
4403 }
4404 error = 0;
4405 bzero(&xf, sizeof(xf));
4406 xf.xf_size = sizeof(xf);
4407 sx_slock(&allproc_lock);
4408 FOREACH_PROC_IN_SYSTEM(p) {
4409 PROC_LOCK(p);
4410 if (p->p_state == PRS_NEW) {
4411 PROC_UNLOCK(p);
4412 continue;
4413 }
4414 if (p_cansee(req->td, p) != 0) {
4415 PROC_UNLOCK(p);
4416 continue;
4417 }
4418 xf.xf_pid = p->p_pid;
4419 xf.xf_uid = p->p_ucred->cr_uid;
4420 fdp = fdhold(p);
4421 PROC_UNLOCK(p);
4422 if (fdp == NULL)
4423 continue;
4424 FILEDESC_SLOCK(fdp);
4425 if (refcount_load(&fdp->fd_refcnt) == 0)
4426 goto nextproc;
4427 lastfile = fdlastfile(fdp);
4428 for (n = 0; refcount_load(&fdp->fd_refcnt) > 0 && n <= lastfile;
4429 n++) {
4430 if ((fp = fdp->fd_ofiles[n].fde_file) == NULL)
4431 continue;
4432 xf.xf_fd = n;
4433 xf.xf_file = (uintptr_t)fp;
4434 xf.xf_data = (uintptr_t)fp->f_data;
4435 xf.xf_vnode = (uintptr_t)fp->f_vnode;
4436 xf.xf_type = (uintptr_t)fp->f_type;
4437 xf.xf_count = refcount_load(&fp->f_count);
4438 xf.xf_msgcount = 0;
4439 xf.xf_offset = foffset_get(fp);
4440 xf.xf_flag = fp->f_flag;
4441 error = SYSCTL_OUT(req, &xf, sizeof(xf));
4442
4443 /*
4444 * There is no need to re-check the fdtable refcount
4445 * here since the filedesc lock is not dropped in the
4446 * loop body.
4447 */
4448 if (error != 0)
4449 break;
4450 }
4451 nextproc:
4452 FILEDESC_SUNLOCK(fdp);
4453 fddrop(fdp);
4454 if (error)
4455 break;
4456 }
4457 sx_sunlock(&allproc_lock);
4458 return (error);
4459 }
4460
4461 SYSCTL_PROC(_kern, KERN_FILE, file, CTLTYPE_OPAQUE|CTLFLAG_RD|CTLFLAG_MPSAFE,
4462 0, 0, sysctl_kern_file, "S,xfile", "Entire file table");
4463
4464 #ifdef KINFO_FILE_SIZE
4465 CTASSERT(sizeof(struct kinfo_file) == KINFO_FILE_SIZE);
4466 #endif
4467
4468 static int
xlate_fflags(int fflags)4469 xlate_fflags(int fflags)
4470 {
4471 static const struct {
4472 int fflag;
4473 int kf_fflag;
4474 } fflags_table[] = {
4475 { FAPPEND, KF_FLAG_APPEND },
4476 { FASYNC, KF_FLAG_ASYNC },
4477 { FFSYNC, KF_FLAG_FSYNC },
4478 { FHASLOCK, KF_FLAG_HASLOCK },
4479 { FNONBLOCK, KF_FLAG_NONBLOCK },
4480 { FREAD, KF_FLAG_READ },
4481 { FWRITE, KF_FLAG_WRITE },
4482 { O_CREAT, KF_FLAG_CREAT },
4483 { O_DIRECT, KF_FLAG_DIRECT },
4484 { O_EXCL, KF_FLAG_EXCL },
4485 { O_EXEC, KF_FLAG_EXEC },
4486 { O_EXLOCK, KF_FLAG_EXLOCK },
4487 { O_NOFOLLOW, KF_FLAG_NOFOLLOW },
4488 { O_SHLOCK, KF_FLAG_SHLOCK },
4489 { O_TRUNC, KF_FLAG_TRUNC }
4490 };
4491 unsigned int i;
4492 int kflags;
4493
4494 kflags = 0;
4495 for (i = 0; i < nitems(fflags_table); i++)
4496 if (fflags & fflags_table[i].fflag)
4497 kflags |= fflags_table[i].kf_fflag;
4498 return (kflags);
4499 }
4500
4501 /* Trim unused data from kf_path by truncating the structure size. */
4502 void
pack_kinfo(struct kinfo_file * kif)4503 pack_kinfo(struct kinfo_file *kif)
4504 {
4505
4506 kif->kf_structsize = offsetof(struct kinfo_file, kf_path) +
4507 strlen(kif->kf_path) + 1;
4508 kif->kf_structsize = roundup(kif->kf_structsize, sizeof(uint64_t));
4509 }
4510
4511 static void
export_file_to_kinfo(struct file * fp,int fd,cap_rights_t * rightsp,struct kinfo_file * kif,struct filedesc * fdp,int flags)4512 export_file_to_kinfo(struct file *fp, int fd, cap_rights_t *rightsp,
4513 struct kinfo_file *kif, struct filedesc *fdp, int flags)
4514 {
4515 int error;
4516
4517 bzero(kif, sizeof(*kif));
4518
4519 /* Set a default type to allow for empty fill_kinfo() methods. */
4520 kif->kf_type = KF_TYPE_UNKNOWN;
4521 kif->kf_flags = xlate_fflags(fp->f_flag);
4522 if (rightsp != NULL)
4523 kif->kf_cap_rights = *rightsp;
4524 else
4525 cap_rights_init_zero(&kif->kf_cap_rights);
4526 kif->kf_fd = fd;
4527 kif->kf_ref_count = refcount_load(&fp->f_count);
4528 kif->kf_offset = foffset_get(fp);
4529
4530 /*
4531 * This may drop the filedesc lock, so the 'fp' cannot be
4532 * accessed after this call.
4533 */
4534 error = fo_fill_kinfo(fp, kif, fdp);
4535 if (error == 0)
4536 kif->kf_status |= KF_ATTR_VALID;
4537 if ((flags & KERN_FILEDESC_PACK_KINFO) != 0)
4538 pack_kinfo(kif);
4539 else
4540 kif->kf_structsize = roundup2(sizeof(*kif), sizeof(uint64_t));
4541 }
4542
4543 static void
export_vnode_to_kinfo(struct vnode * vp,int fd,int fflags,struct kinfo_file * kif,int flags)4544 export_vnode_to_kinfo(struct vnode *vp, int fd, int fflags,
4545 struct kinfo_file *kif, int flags)
4546 {
4547 int error;
4548
4549 bzero(kif, sizeof(*kif));
4550
4551 kif->kf_type = KF_TYPE_VNODE;
4552 error = vn_fill_kinfo_vnode(vp, kif);
4553 if (error == 0)
4554 kif->kf_status |= KF_ATTR_VALID;
4555 kif->kf_flags = xlate_fflags(fflags);
4556 cap_rights_init_zero(&kif->kf_cap_rights);
4557 kif->kf_fd = fd;
4558 kif->kf_ref_count = -1;
4559 kif->kf_offset = -1;
4560 if ((flags & KERN_FILEDESC_PACK_KINFO) != 0)
4561 pack_kinfo(kif);
4562 else
4563 kif->kf_structsize = roundup2(sizeof(*kif), sizeof(uint64_t));
4564 vrele(vp);
4565 }
4566
4567 struct export_fd_buf {
4568 struct filedesc *fdp;
4569 struct pwddesc *pdp;
4570 struct sbuf *sb;
4571 ssize_t remainder;
4572 struct kinfo_file kif;
4573 int flags;
4574 };
4575
4576 static int
export_kinfo_to_sb(struct export_fd_buf * efbuf)4577 export_kinfo_to_sb(struct export_fd_buf *efbuf)
4578 {
4579 struct kinfo_file *kif;
4580
4581 kif = &efbuf->kif;
4582 if (efbuf->remainder != -1) {
4583 if (efbuf->remainder < kif->kf_structsize)
4584 return (ENOMEM);
4585 efbuf->remainder -= kif->kf_structsize;
4586 }
4587 if (sbuf_bcat(efbuf->sb, kif, kif->kf_structsize) != 0)
4588 return (sbuf_error(efbuf->sb));
4589 return (0);
4590 }
4591
4592 static int
export_file_to_sb(struct file * fp,int fd,cap_rights_t * rightsp,struct export_fd_buf * efbuf)4593 export_file_to_sb(struct file *fp, int fd, cap_rights_t *rightsp,
4594 struct export_fd_buf *efbuf)
4595 {
4596 int error;
4597
4598 if (efbuf->remainder == 0)
4599 return (ENOMEM);
4600 export_file_to_kinfo(fp, fd, rightsp, &efbuf->kif, efbuf->fdp,
4601 efbuf->flags);
4602 FILEDESC_SUNLOCK(efbuf->fdp);
4603 error = export_kinfo_to_sb(efbuf);
4604 FILEDESC_SLOCK(efbuf->fdp);
4605 return (error);
4606 }
4607
4608 static int
export_vnode_to_sb(struct vnode * vp,int fd,int fflags,struct export_fd_buf * efbuf)4609 export_vnode_to_sb(struct vnode *vp, int fd, int fflags,
4610 struct export_fd_buf *efbuf)
4611 {
4612 int error;
4613
4614 if (efbuf->remainder == 0)
4615 return (ENOMEM);
4616 if (efbuf->pdp != NULL)
4617 PWDDESC_XUNLOCK(efbuf->pdp);
4618 export_vnode_to_kinfo(vp, fd, fflags, &efbuf->kif, efbuf->flags);
4619 error = export_kinfo_to_sb(efbuf);
4620 if (efbuf->pdp != NULL)
4621 PWDDESC_XLOCK(efbuf->pdp);
4622 return (error);
4623 }
4624
4625 /*
4626 * Store a process file descriptor information to sbuf.
4627 *
4628 * Takes a locked proc as argument, and returns with the proc unlocked.
4629 */
4630 int
kern_proc_filedesc_out(struct proc * p,struct sbuf * sb,ssize_t maxlen,int flags)4631 kern_proc_filedesc_out(struct proc *p, struct sbuf *sb, ssize_t maxlen,
4632 int flags)
4633 {
4634 struct file *fp;
4635 struct filedesc *fdp;
4636 struct pwddesc *pdp;
4637 struct export_fd_buf *efbuf;
4638 struct vnode *cttyvp, *textvp, *tracevp;
4639 struct pwd *pwd;
4640 int error, i, lastfile;
4641 cap_rights_t rights;
4642
4643 PROC_LOCK_ASSERT(p, MA_OWNED);
4644
4645 /* ktrace vnode */
4646 tracevp = ktr_get_tracevp(p, true);
4647 /* text vnode */
4648 textvp = p->p_textvp;
4649 if (textvp != NULL)
4650 vrefact(textvp);
4651 /* Controlling tty. */
4652 cttyvp = NULL;
4653 if (p->p_pgrp != NULL && p->p_pgrp->pg_session != NULL) {
4654 cttyvp = p->p_pgrp->pg_session->s_ttyvp;
4655 if (cttyvp != NULL)
4656 vrefact(cttyvp);
4657 }
4658 fdp = fdhold(p);
4659 pdp = pdhold(p);
4660 PROC_UNLOCK(p);
4661
4662 efbuf = malloc(sizeof(*efbuf), M_TEMP, M_WAITOK);
4663 efbuf->fdp = NULL;
4664 efbuf->pdp = NULL;
4665 efbuf->sb = sb;
4666 efbuf->remainder = maxlen;
4667 efbuf->flags = flags;
4668
4669 error = 0;
4670 if (tracevp != NULL)
4671 error = export_vnode_to_sb(tracevp, KF_FD_TYPE_TRACE,
4672 FREAD | FWRITE, efbuf);
4673 if (error == 0 && textvp != NULL)
4674 error = export_vnode_to_sb(textvp, KF_FD_TYPE_TEXT, FREAD,
4675 efbuf);
4676 if (error == 0 && cttyvp != NULL)
4677 error = export_vnode_to_sb(cttyvp, KF_FD_TYPE_CTTY,
4678 FREAD | FWRITE, efbuf);
4679 if (error != 0 || pdp == NULL || fdp == NULL)
4680 goto fail;
4681 efbuf->fdp = fdp;
4682 efbuf->pdp = pdp;
4683 PWDDESC_XLOCK(pdp);
4684 pwd = pwd_hold_pwddesc(pdp);
4685 if (pwd != NULL) {
4686 /* working directory */
4687 if (pwd->pwd_cdir != NULL) {
4688 vrefact(pwd->pwd_cdir);
4689 error = export_vnode_to_sb(pwd->pwd_cdir,
4690 KF_FD_TYPE_CWD, FREAD, efbuf);
4691 }
4692 /* root directory */
4693 if (error == 0 && pwd->pwd_rdir != NULL) {
4694 vrefact(pwd->pwd_rdir);
4695 error = export_vnode_to_sb(pwd->pwd_rdir,
4696 KF_FD_TYPE_ROOT, FREAD, efbuf);
4697 }
4698 /* jail directory */
4699 if (error == 0 && pwd->pwd_jdir != NULL) {
4700 vrefact(pwd->pwd_jdir);
4701 error = export_vnode_to_sb(pwd->pwd_jdir,
4702 KF_FD_TYPE_JAIL, FREAD, efbuf);
4703 }
4704 }
4705 PWDDESC_XUNLOCK(pdp);
4706 if (error != 0)
4707 goto fail;
4708 if (pwd != NULL)
4709 pwd_drop(pwd);
4710 FILEDESC_SLOCK(fdp);
4711 if (refcount_load(&fdp->fd_refcnt) == 0)
4712 goto skip;
4713 lastfile = fdlastfile(fdp);
4714 for (i = 0; i <= lastfile; i++) {
4715 if ((fp = fdp->fd_ofiles[i].fde_file) == NULL)
4716 continue;
4717 #ifdef CAPABILITIES
4718 rights = *cap_rights(fdp, i);
4719 #else /* !CAPABILITIES */
4720 rights = cap_no_rights;
4721 #endif
4722 /*
4723 * Create sysctl entry. It is OK to drop the filedesc
4724 * lock inside of export_file_to_sb() as we will
4725 * re-validate and re-evaluate its properties when the
4726 * loop continues.
4727 */
4728 error = export_file_to_sb(fp, i, &rights, efbuf);
4729 if (error != 0 || refcount_load(&fdp->fd_refcnt) == 0)
4730 break;
4731 }
4732 skip:
4733 FILEDESC_SUNLOCK(fdp);
4734 fail:
4735 if (fdp != NULL)
4736 fddrop(fdp);
4737 if (pdp != NULL)
4738 pddrop(pdp);
4739 free(efbuf, M_TEMP);
4740 return (error);
4741 }
4742
4743 #define FILEDESC_SBUF_SIZE (sizeof(struct kinfo_file) * 5)
4744
4745 /*
4746 * Get per-process file descriptors for use by procstat(1), et al.
4747 */
4748 static int
sysctl_kern_proc_filedesc(SYSCTL_HANDLER_ARGS)4749 sysctl_kern_proc_filedesc(SYSCTL_HANDLER_ARGS)
4750 {
4751 struct sbuf sb;
4752 struct proc *p;
4753 ssize_t maxlen;
4754 u_int namelen;
4755 int error, error2, *name;
4756
4757 namelen = arg2;
4758 if (namelen != 1)
4759 return (EINVAL);
4760
4761 name = (int *)arg1;
4762
4763 sbuf_new_for_sysctl(&sb, NULL, FILEDESC_SBUF_SIZE, req);
4764 sbuf_clear_flags(&sb, SBUF_INCLUDENUL);
4765 error = pget((pid_t)name[0], PGET_CANDEBUG | PGET_NOTWEXIT, &p);
4766 if (error != 0) {
4767 sbuf_delete(&sb);
4768 return (error);
4769 }
4770 maxlen = req->oldptr != NULL ? req->oldlen : -1;
4771 error = kern_proc_filedesc_out(p, &sb, maxlen,
4772 KERN_FILEDESC_PACK_KINFO);
4773 error2 = sbuf_finish(&sb);
4774 sbuf_delete(&sb);
4775 return (error != 0 ? error : error2);
4776 }
4777
4778 #ifdef COMPAT_FREEBSD7
4779 #ifdef KINFO_OFILE_SIZE
4780 CTASSERT(sizeof(struct kinfo_ofile) == KINFO_OFILE_SIZE);
4781 #endif
4782
4783 static void
kinfo_to_okinfo(struct kinfo_file * kif,struct kinfo_ofile * okif)4784 kinfo_to_okinfo(struct kinfo_file *kif, struct kinfo_ofile *okif)
4785 {
4786
4787 okif->kf_structsize = sizeof(*okif);
4788 okif->kf_type = kif->kf_type;
4789 okif->kf_fd = kif->kf_fd;
4790 okif->kf_ref_count = kif->kf_ref_count;
4791 okif->kf_flags = kif->kf_flags & (KF_FLAG_READ | KF_FLAG_WRITE |
4792 KF_FLAG_APPEND | KF_FLAG_ASYNC | KF_FLAG_FSYNC | KF_FLAG_NONBLOCK |
4793 KF_FLAG_DIRECT | KF_FLAG_HASLOCK);
4794 okif->kf_offset = kif->kf_offset;
4795 if (kif->kf_type == KF_TYPE_VNODE)
4796 okif->kf_vnode_type = kif->kf_un.kf_file.kf_file_type;
4797 else
4798 okif->kf_vnode_type = KF_VTYPE_VNON;
4799 strlcpy(okif->kf_path, kif->kf_path, sizeof(okif->kf_path));
4800 if (kif->kf_type == KF_TYPE_SOCKET) {
4801 okif->kf_sock_domain = kif->kf_un.kf_sock.kf_sock_domain0;
4802 okif->kf_sock_type = kif->kf_un.kf_sock.kf_sock_type0;
4803 okif->kf_sock_protocol = kif->kf_un.kf_sock.kf_sock_protocol0;
4804 okif->kf_sa_local = kif->kf_un.kf_sock.kf_sa_local;
4805 okif->kf_sa_peer = kif->kf_un.kf_sock.kf_sa_peer;
4806 } else {
4807 okif->kf_sa_local.ss_family = AF_UNSPEC;
4808 okif->kf_sa_peer.ss_family = AF_UNSPEC;
4809 }
4810 }
4811
4812 static int
export_vnode_for_osysctl(struct vnode * vp,int type,struct kinfo_file * kif,struct kinfo_ofile * okif,struct pwddesc * pdp,struct sysctl_req * req)4813 export_vnode_for_osysctl(struct vnode *vp, int type, struct kinfo_file *kif,
4814 struct kinfo_ofile *okif, struct pwddesc *pdp, struct sysctl_req *req)
4815 {
4816 int error;
4817
4818 vrefact(vp);
4819 PWDDESC_XUNLOCK(pdp);
4820 export_vnode_to_kinfo(vp, type, 0, kif, KERN_FILEDESC_PACK_KINFO);
4821 kinfo_to_okinfo(kif, okif);
4822 error = SYSCTL_OUT(req, okif, sizeof(*okif));
4823 PWDDESC_XLOCK(pdp);
4824 return (error);
4825 }
4826
4827 /*
4828 * Get per-process file descriptors for use by procstat(1), et al.
4829 */
4830 static int
sysctl_kern_proc_ofiledesc(SYSCTL_HANDLER_ARGS)4831 sysctl_kern_proc_ofiledesc(SYSCTL_HANDLER_ARGS)
4832 {
4833 struct kinfo_ofile *okif;
4834 struct kinfo_file *kif;
4835 struct filedesc *fdp;
4836 struct pwddesc *pdp;
4837 struct pwd *pwd;
4838 u_int namelen;
4839 int error, i, lastfile, *name;
4840 struct file *fp;
4841 struct proc *p;
4842
4843 namelen = arg2;
4844 if (namelen != 1)
4845 return (EINVAL);
4846
4847 name = (int *)arg1;
4848 error = pget((pid_t)name[0], PGET_CANDEBUG | PGET_NOTWEXIT, &p);
4849 if (error != 0)
4850 return (error);
4851 fdp = fdhold(p);
4852 if (fdp != NULL)
4853 pdp = pdhold(p);
4854 PROC_UNLOCK(p);
4855 if (fdp == NULL || pdp == NULL) {
4856 if (fdp != NULL)
4857 fddrop(fdp);
4858 return (ENOENT);
4859 }
4860 kif = malloc(sizeof(*kif), M_TEMP, M_WAITOK);
4861 okif = malloc(sizeof(*okif), M_TEMP, M_WAITOK);
4862 PWDDESC_XLOCK(pdp);
4863 pwd = pwd_hold_pwddesc(pdp);
4864 if (pwd != NULL) {
4865 if (pwd->pwd_cdir != NULL)
4866 export_vnode_for_osysctl(pwd->pwd_cdir, KF_FD_TYPE_CWD, kif,
4867 okif, pdp, req);
4868 if (pwd->pwd_rdir != NULL)
4869 export_vnode_for_osysctl(pwd->pwd_rdir, KF_FD_TYPE_ROOT, kif,
4870 okif, pdp, req);
4871 if (pwd->pwd_jdir != NULL)
4872 export_vnode_for_osysctl(pwd->pwd_jdir, KF_FD_TYPE_JAIL, kif,
4873 okif, pdp, req);
4874 }
4875 PWDDESC_XUNLOCK(pdp);
4876 if (pwd != NULL)
4877 pwd_drop(pwd);
4878 FILEDESC_SLOCK(fdp);
4879 if (refcount_load(&fdp->fd_refcnt) == 0)
4880 goto skip;
4881 lastfile = fdlastfile(fdp);
4882 for (i = 0; i <= lastfile; i++) {
4883 if ((fp = fdp->fd_ofiles[i].fde_file) == NULL)
4884 continue;
4885 export_file_to_kinfo(fp, i, NULL, kif, fdp,
4886 KERN_FILEDESC_PACK_KINFO);
4887 FILEDESC_SUNLOCK(fdp);
4888 kinfo_to_okinfo(kif, okif);
4889 error = SYSCTL_OUT(req, okif, sizeof(*okif));
4890 FILEDESC_SLOCK(fdp);
4891 if (error != 0 || refcount_load(&fdp->fd_refcnt) == 0)
4892 break;
4893 }
4894 skip:
4895 FILEDESC_SUNLOCK(fdp);
4896 fddrop(fdp);
4897 pddrop(pdp);
4898 free(kif, M_TEMP);
4899 free(okif, M_TEMP);
4900 return (0);
4901 }
4902
4903 static SYSCTL_NODE(_kern_proc, KERN_PROC_OFILEDESC, ofiledesc,
4904 CTLFLAG_RD|CTLFLAG_MPSAFE, sysctl_kern_proc_ofiledesc,
4905 "Process ofiledesc entries");
4906 #endif /* COMPAT_FREEBSD7 */
4907
4908 int
vntype_to_kinfo(int vtype)4909 vntype_to_kinfo(int vtype)
4910 {
4911 struct {
4912 int vtype;
4913 int kf_vtype;
4914 } vtypes_table[] = {
4915 { VBAD, KF_VTYPE_VBAD },
4916 { VBLK, KF_VTYPE_VBLK },
4917 { VCHR, KF_VTYPE_VCHR },
4918 { VDIR, KF_VTYPE_VDIR },
4919 { VFIFO, KF_VTYPE_VFIFO },
4920 { VLNK, KF_VTYPE_VLNK },
4921 { VNON, KF_VTYPE_VNON },
4922 { VREG, KF_VTYPE_VREG },
4923 { VSOCK, KF_VTYPE_VSOCK }
4924 };
4925 unsigned int i;
4926
4927 /*
4928 * Perform vtype translation.
4929 */
4930 for (i = 0; i < nitems(vtypes_table); i++)
4931 if (vtypes_table[i].vtype == vtype)
4932 return (vtypes_table[i].kf_vtype);
4933
4934 return (KF_VTYPE_UNKNOWN);
4935 }
4936
4937 static SYSCTL_NODE(_kern_proc, KERN_PROC_FILEDESC, filedesc,
4938 CTLFLAG_RD|CTLFLAG_MPSAFE, sysctl_kern_proc_filedesc,
4939 "Process filedesc entries");
4940
4941 /*
4942 * Store a process current working directory information to sbuf.
4943 *
4944 * Takes a locked proc as argument, and returns with the proc unlocked.
4945 */
4946 int
kern_proc_cwd_out(struct proc * p,struct sbuf * sb,ssize_t maxlen)4947 kern_proc_cwd_out(struct proc *p, struct sbuf *sb, ssize_t maxlen)
4948 {
4949 struct pwddesc *pdp;
4950 struct pwd *pwd;
4951 struct export_fd_buf *efbuf;
4952 struct vnode *cdir;
4953 int error;
4954
4955 PROC_LOCK_ASSERT(p, MA_OWNED);
4956
4957 pdp = pdhold(p);
4958 PROC_UNLOCK(p);
4959 if (pdp == NULL)
4960 return (EINVAL);
4961
4962 efbuf = malloc(sizeof(*efbuf), M_TEMP, M_WAITOK);
4963 efbuf->fdp = NULL;
4964 efbuf->pdp = pdp;
4965 efbuf->sb = sb;
4966 efbuf->remainder = maxlen;
4967 efbuf->flags = 0;
4968
4969 PWDDESC_XLOCK(pdp);
4970 pwd = PWDDESC_XLOCKED_LOAD_PWD(pdp);
4971 cdir = pwd->pwd_cdir;
4972 if (cdir == NULL) {
4973 error = EINVAL;
4974 } else {
4975 vrefact(cdir);
4976 error = export_vnode_to_sb(cdir, KF_FD_TYPE_CWD, FREAD, efbuf);
4977 }
4978 PWDDESC_XUNLOCK(pdp);
4979 pddrop(pdp);
4980 free(efbuf, M_TEMP);
4981 return (error);
4982 }
4983
4984 /*
4985 * Get per-process current working directory.
4986 */
4987 static int
sysctl_kern_proc_cwd(SYSCTL_HANDLER_ARGS)4988 sysctl_kern_proc_cwd(SYSCTL_HANDLER_ARGS)
4989 {
4990 struct sbuf sb;
4991 struct proc *p;
4992 ssize_t maxlen;
4993 u_int namelen;
4994 int error, error2, *name;
4995
4996 namelen = arg2;
4997 if (namelen != 1)
4998 return (EINVAL);
4999
5000 name = (int *)arg1;
5001
5002 sbuf_new_for_sysctl(&sb, NULL, sizeof(struct kinfo_file), req);
5003 sbuf_clear_flags(&sb, SBUF_INCLUDENUL);
5004 error = pget((pid_t)name[0], PGET_CANDEBUG | PGET_NOTWEXIT, &p);
5005 if (error != 0) {
5006 sbuf_delete(&sb);
5007 return (error);
5008 }
5009 maxlen = req->oldptr != NULL ? req->oldlen : -1;
5010 error = kern_proc_cwd_out(p, &sb, maxlen);
5011 error2 = sbuf_finish(&sb);
5012 sbuf_delete(&sb);
5013 return (error != 0 ? error : error2);
5014 }
5015
5016 static SYSCTL_NODE(_kern_proc, KERN_PROC_CWD, cwd, CTLFLAG_RD|CTLFLAG_MPSAFE,
5017 sysctl_kern_proc_cwd, "Process current working directory");
5018
5019 #ifdef DDB
5020 /*
5021 * For the purposes of debugging, generate a human-readable string for the
5022 * file type.
5023 */
5024 static const char *
file_type_to_name(short type)5025 file_type_to_name(short type)
5026 {
5027
5028 switch (type) {
5029 case 0:
5030 return ("zero");
5031 case DTYPE_VNODE:
5032 return ("vnode");
5033 case DTYPE_SOCKET:
5034 return ("socket");
5035 case DTYPE_PIPE:
5036 return ("pipe");
5037 case DTYPE_FIFO:
5038 return ("fifo");
5039 case DTYPE_KQUEUE:
5040 return ("kqueue");
5041 case DTYPE_CRYPTO:
5042 return ("crypto");
5043 case DTYPE_MQUEUE:
5044 return ("mqueue");
5045 case DTYPE_SHM:
5046 return ("shm");
5047 case DTYPE_SEM:
5048 return ("ksem");
5049 case DTYPE_PTS:
5050 return ("pts");
5051 case DTYPE_DEV:
5052 return ("dev");
5053 case DTYPE_PROCDESC:
5054 return ("proc");
5055 case DTYPE_EVENTFD:
5056 return ("eventfd");
5057 case DTYPE_LINUXTFD:
5058 return ("ltimer");
5059 default:
5060 return ("unkn");
5061 }
5062 }
5063
5064 /*
5065 * For the purposes of debugging, identify a process (if any, perhaps one of
5066 * many) that references the passed file in its file descriptor array. Return
5067 * NULL if none.
5068 */
5069 static struct proc *
file_to_first_proc(struct file * fp)5070 file_to_first_proc(struct file *fp)
5071 {
5072 struct filedesc *fdp;
5073 struct proc *p;
5074 int n;
5075
5076 FOREACH_PROC_IN_SYSTEM(p) {
5077 if (p->p_state == PRS_NEW)
5078 continue;
5079 fdp = p->p_fd;
5080 if (fdp == NULL)
5081 continue;
5082 for (n = 0; n < fdp->fd_nfiles; n++) {
5083 if (fp == fdp->fd_ofiles[n].fde_file)
5084 return (p);
5085 }
5086 }
5087 return (NULL);
5088 }
5089
5090 static void
db_print_file(struct file * fp,int header)5091 db_print_file(struct file *fp, int header)
5092 {
5093 #define XPTRWIDTH ((int)howmany(sizeof(void *) * NBBY, 4))
5094 struct proc *p;
5095
5096 if (header)
5097 db_printf("%*s %6s %*s %8s %4s %5s %6s %*s %5s %s\n",
5098 XPTRWIDTH, "File", "Type", XPTRWIDTH, "Data", "Flag",
5099 "GCFl", "Count", "MCount", XPTRWIDTH, "Vnode", "FPID",
5100 "FCmd");
5101 p = file_to_first_proc(fp);
5102 db_printf("%*p %6s %*p %08x %04x %5d %6d %*p %5d %s\n", XPTRWIDTH,
5103 fp, file_type_to_name(fp->f_type), XPTRWIDTH, fp->f_data,
5104 fp->f_flag, 0, refcount_load(&fp->f_count), 0, XPTRWIDTH, fp->f_vnode,
5105 p != NULL ? p->p_pid : -1, p != NULL ? p->p_comm : "-");
5106
5107 #undef XPTRWIDTH
5108 }
5109
DB_SHOW_COMMAND(file,db_show_file)5110 DB_SHOW_COMMAND(file, db_show_file)
5111 {
5112 struct file *fp;
5113
5114 if (!have_addr) {
5115 db_printf("usage: show file <addr>\n");
5116 return;
5117 }
5118 fp = (struct file *)addr;
5119 db_print_file(fp, 1);
5120 }
5121
DB_SHOW_COMMAND(files,db_show_files)5122 DB_SHOW_COMMAND(files, db_show_files)
5123 {
5124 struct filedesc *fdp;
5125 struct file *fp;
5126 struct proc *p;
5127 int header;
5128 int n;
5129
5130 header = 1;
5131 FOREACH_PROC_IN_SYSTEM(p) {
5132 if (p->p_state == PRS_NEW)
5133 continue;
5134 if ((fdp = p->p_fd) == NULL)
5135 continue;
5136 for (n = 0; n < fdp->fd_nfiles; ++n) {
5137 if ((fp = fdp->fd_ofiles[n].fde_file) == NULL)
5138 continue;
5139 db_print_file(fp, header);
5140 header = 0;
5141 }
5142 }
5143 }
5144 #endif
5145
5146 SYSCTL_INT(_kern, KERN_MAXFILESPERPROC, maxfilesperproc,
5147 CTLFLAG_RWTUN | CTLFLAG_NOFETCH,
5148 &maxfilesperproc, 0, "Maximum files allowed open per process");
5149
5150 SYSCTL_INT(_kern, KERN_MAXFILES, maxfiles, CTLFLAG_RWTUN | CTLFLAG_NOFETCH,
5151 &maxfiles, 0, "Maximum number of files");
5152
5153 SYSCTL_INT(_kern, OID_AUTO, openfiles, CTLFLAG_RD,
5154 &openfiles, 0, "System-wide number of open files");
5155
5156 /* ARGSUSED*/
5157 static void
filelistinit(void * dummy)5158 filelistinit(void *dummy)
5159 {
5160
5161 file_zone = uma_zcreate("Files", sizeof(struct file), NULL, NULL,
5162 NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE);
5163 filedesc0_zone = uma_zcreate("filedesc0", sizeof(struct filedesc0),
5164 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0);
5165 pwd_zone = uma_zcreate("PWD", sizeof(struct pwd), NULL, NULL,
5166 NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_SMR);
5167 /*
5168 * XXXMJG this is a temporary hack due to boot ordering issues against
5169 * the vnode zone.
5170 */
5171 vfs_smr = uma_zone_get_smr(pwd_zone);
5172 mtx_init(&sigio_lock, "sigio lock", NULL, MTX_DEF);
5173 }
5174 SYSINIT(select, SI_SUB_LOCK, SI_ORDER_FIRST, filelistinit, NULL);
5175
5176 /*-------------------------------------------------------------------*/
5177
5178 static int
badfo_readwrite(struct file * fp,struct uio * uio,struct ucred * active_cred,int flags,struct thread * td)5179 badfo_readwrite(struct file *fp, struct uio *uio, struct ucred *active_cred,
5180 int flags, struct thread *td)
5181 {
5182
5183 return (EBADF);
5184 }
5185
5186 static int
badfo_truncate(struct file * fp,off_t length,struct ucred * active_cred,struct thread * td)5187 badfo_truncate(struct file *fp, off_t length, struct ucred *active_cred,
5188 struct thread *td)
5189 {
5190
5191 return (EINVAL);
5192 }
5193
5194 static int
badfo_ioctl(struct file * fp,u_long com,void * data,struct ucred * active_cred,struct thread * td)5195 badfo_ioctl(struct file *fp, u_long com, void *data, struct ucred *active_cred,
5196 struct thread *td)
5197 {
5198
5199 return (EBADF);
5200 }
5201
5202 static int
badfo_poll(struct file * fp,int events,struct ucred * active_cred,struct thread * td)5203 badfo_poll(struct file *fp, int events, struct ucred *active_cred,
5204 struct thread *td)
5205 {
5206
5207 return (0);
5208 }
5209
5210 static int
badfo_kqfilter(struct file * fp,struct knote * kn)5211 badfo_kqfilter(struct file *fp, struct knote *kn)
5212 {
5213
5214 return (EBADF);
5215 }
5216
5217 static int
badfo_stat(struct file * fp,struct stat * sb,struct ucred * active_cred,struct thread * td)5218 badfo_stat(struct file *fp, struct stat *sb, struct ucred *active_cred,
5219 struct thread *td)
5220 {
5221
5222 return (EBADF);
5223 }
5224
5225 static int
badfo_close(struct file * fp,struct thread * td)5226 badfo_close(struct file *fp, struct thread *td)
5227 {
5228
5229 return (0);
5230 }
5231
5232 static int
badfo_chmod(struct file * fp,mode_t mode,struct ucred * active_cred,struct thread * td)5233 badfo_chmod(struct file *fp, mode_t mode, struct ucred *active_cred,
5234 struct thread *td)
5235 {
5236
5237 return (EBADF);
5238 }
5239
5240 static int
badfo_chown(struct file * fp,uid_t uid,gid_t gid,struct ucred * active_cred,struct thread * td)5241 badfo_chown(struct file *fp, uid_t uid, gid_t gid, struct ucred *active_cred,
5242 struct thread *td)
5243 {
5244
5245 return (EBADF);
5246 }
5247
5248 static int
badfo_sendfile(struct file * fp,int sockfd,struct uio * hdr_uio,struct uio * trl_uio,off_t offset,size_t nbytes,off_t * sent,int flags,struct thread * td)5249 badfo_sendfile(struct file *fp, int sockfd, struct uio *hdr_uio,
5250 struct uio *trl_uio, off_t offset, size_t nbytes, off_t *sent, int flags,
5251 struct thread *td)
5252 {
5253
5254 return (EBADF);
5255 }
5256
5257 static int
badfo_fill_kinfo(struct file * fp,struct kinfo_file * kif,struct filedesc * fdp)5258 badfo_fill_kinfo(struct file *fp, struct kinfo_file *kif, struct filedesc *fdp)
5259 {
5260
5261 return (0);
5262 }
5263
5264 struct fileops badfileops = {
5265 .fo_read = badfo_readwrite,
5266 .fo_write = badfo_readwrite,
5267 .fo_truncate = badfo_truncate,
5268 .fo_ioctl = badfo_ioctl,
5269 .fo_poll = badfo_poll,
5270 .fo_kqfilter = badfo_kqfilter,
5271 .fo_stat = badfo_stat,
5272 .fo_close = badfo_close,
5273 .fo_chmod = badfo_chmod,
5274 .fo_chown = badfo_chown,
5275 .fo_sendfile = badfo_sendfile,
5276 .fo_fill_kinfo = badfo_fill_kinfo,
5277 };
5278
5279 static int
path_poll(struct file * fp,int events,struct ucred * active_cred,struct thread * td)5280 path_poll(struct file *fp, int events, struct ucred *active_cred,
5281 struct thread *td)
5282 {
5283 return (POLLNVAL);
5284 }
5285
5286 static int
path_close(struct file * fp,struct thread * td)5287 path_close(struct file *fp, struct thread *td)
5288 {
5289 MPASS(fp->f_type == DTYPE_VNODE);
5290 fp->f_ops = &badfileops;
5291 vrele(fp->f_vnode);
5292 return (0);
5293 }
5294
5295 struct fileops path_fileops = {
5296 .fo_read = badfo_readwrite,
5297 .fo_write = badfo_readwrite,
5298 .fo_truncate = badfo_truncate,
5299 .fo_ioctl = badfo_ioctl,
5300 .fo_poll = path_poll,
5301 .fo_kqfilter = vn_kqfilter_opath,
5302 .fo_stat = vn_statfile,
5303 .fo_close = path_close,
5304 .fo_chmod = badfo_chmod,
5305 .fo_chown = badfo_chown,
5306 .fo_sendfile = badfo_sendfile,
5307 .fo_fill_kinfo = vn_fill_kinfo,
5308 .fo_cmp = vn_cmp,
5309 .fo_flags = DFLAG_PASSABLE,
5310 };
5311
5312 int
invfo_rdwr(struct file * fp,struct uio * uio,struct ucred * active_cred,int flags,struct thread * td)5313 invfo_rdwr(struct file *fp, struct uio *uio, struct ucred *active_cred,
5314 int flags, struct thread *td)
5315 {
5316
5317 return (EOPNOTSUPP);
5318 }
5319
5320 int
invfo_truncate(struct file * fp,off_t length,struct ucred * active_cred,struct thread * td)5321 invfo_truncate(struct file *fp, off_t length, struct ucred *active_cred,
5322 struct thread *td)
5323 {
5324
5325 return (EINVAL);
5326 }
5327
5328 int
invfo_ioctl(struct file * fp,u_long com,void * data,struct ucred * active_cred,struct thread * td)5329 invfo_ioctl(struct file *fp, u_long com, void *data,
5330 struct ucred *active_cred, struct thread *td)
5331 {
5332
5333 return (ENOTTY);
5334 }
5335
5336 int
invfo_poll(struct file * fp,int events,struct ucred * active_cred,struct thread * td)5337 invfo_poll(struct file *fp, int events, struct ucred *active_cred,
5338 struct thread *td)
5339 {
5340
5341 return (poll_no_poll(events));
5342 }
5343
5344 int
invfo_kqfilter(struct file * fp,struct knote * kn)5345 invfo_kqfilter(struct file *fp, struct knote *kn)
5346 {
5347
5348 return (EINVAL);
5349 }
5350
5351 int
invfo_chmod(struct file * fp,mode_t mode,struct ucred * active_cred,struct thread * td)5352 invfo_chmod(struct file *fp, mode_t mode, struct ucred *active_cred,
5353 struct thread *td)
5354 {
5355
5356 return (EINVAL);
5357 }
5358
5359 int
invfo_chown(struct file * fp,uid_t uid,gid_t gid,struct ucred * active_cred,struct thread * td)5360 invfo_chown(struct file *fp, uid_t uid, gid_t gid, struct ucred *active_cred,
5361 struct thread *td)
5362 {
5363
5364 return (EINVAL);
5365 }
5366
5367 int
invfo_sendfile(struct file * fp,int sockfd,struct uio * hdr_uio,struct uio * trl_uio,off_t offset,size_t nbytes,off_t * sent,int flags,struct thread * td)5368 invfo_sendfile(struct file *fp, int sockfd, struct uio *hdr_uio,
5369 struct uio *trl_uio, off_t offset, size_t nbytes, off_t *sent, int flags,
5370 struct thread *td)
5371 {
5372
5373 return (EINVAL);
5374 }
5375
5376 /*-------------------------------------------------------------------*/
5377
5378 /*
5379 * File Descriptor pseudo-device driver (/dev/fd/).
5380 *
5381 * Opening minor device N dup()s the file (if any) connected to file
5382 * descriptor N belonging to the calling process. Note that this driver
5383 * consists of only the ``open()'' routine, because all subsequent
5384 * references to this file will be direct to the other driver.
5385 *
5386 * XXX: we could give this one a cloning event handler if necessary.
5387 */
5388
5389 /* ARGSUSED */
5390 static int
fdopen(struct cdev * dev,int mode,int type,struct thread * td)5391 fdopen(struct cdev *dev, int mode, int type, struct thread *td)
5392 {
5393
5394 /*
5395 * XXX Kludge: set curthread->td_dupfd to contain the value of the
5396 * the file descriptor being sought for duplication. The error
5397 * return ensures that the vnode for this device will be released
5398 * by vn_open. Open will detect this special error and take the
5399 * actions in dupfdopen below. Other callers of vn_open or VOP_OPEN
5400 * will simply report the error.
5401 */
5402 td->td_dupfd = dev2unit(dev);
5403 return (ENODEV);
5404 }
5405
5406 static struct cdevsw fildesc_cdevsw = {
5407 .d_version = D_VERSION,
5408 .d_open = fdopen,
5409 .d_name = "FD",
5410 };
5411
5412 static void
fildesc_drvinit(void * unused)5413 fildesc_drvinit(void *unused)
5414 {
5415 struct cdev *dev;
5416
5417 dev = make_dev_credf(MAKEDEV_ETERNAL, &fildesc_cdevsw, 0, NULL,
5418 UID_ROOT, GID_WHEEL, 0666, "fd/0");
5419 make_dev_alias(dev, "stdin");
5420 dev = make_dev_credf(MAKEDEV_ETERNAL, &fildesc_cdevsw, 1, NULL,
5421 UID_ROOT, GID_WHEEL, 0666, "fd/1");
5422 make_dev_alias(dev, "stdout");
5423 dev = make_dev_credf(MAKEDEV_ETERNAL, &fildesc_cdevsw, 2, NULL,
5424 UID_ROOT, GID_WHEEL, 0666, "fd/2");
5425 make_dev_alias(dev, "stderr");
5426 }
5427
5428 SYSINIT(fildescdev, SI_SUB_DRIVERS, SI_ORDER_MIDDLE, fildesc_drvinit, NULL);
5429