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
37 #include "opt_capsicum.h"
38 #include "opt_ddb.h"
39 #include "opt_ktrace.h"
40
41 #define EXTERR_CATEGORY EXTERR_CAT_FILEDESC
42 #include <sys/systm.h>
43 #include <sys/capsicum.h>
44 #include <sys/conf.h>
45 #include <sys/exterrvar.h>
46 #include <sys/fcntl.h>
47 #include <sys/file.h>
48 #include <sys/filedesc.h>
49 #include <sys/filio.h>
50 #include <sys/jail.h>
51 #include <sys/kernel.h>
52 #include <sys/limits.h>
53 #include <sys/lock.h>
54 #include <sys/malloc.h>
55 #include <sys/mount.h>
56 #include <sys/mutex.h>
57 #include <sys/namei.h>
58 #include <sys/selinfo.h>
59 #include <sys/poll.h>
60 #include <sys/priv.h>
61 #include <sys/proc.h>
62 #include <sys/protosw.h>
63 #include <sys/racct.h>
64 #include <sys/resourcevar.h>
65 #include <sys/sbuf.h>
66 #include <sys/signalvar.h>
67 #include <sys/kdb.h>
68 #include <sys/smr.h>
69 #include <sys/stat.h>
70 #include <sys/sx.h>
71 #include <sys/syscallsubr.h>
72 #include <sys/sysctl.h>
73 #include <sys/sysproto.h>
74 #include <sys/unistd.h>
75 #include <sys/user.h>
76 #include <sys/vnode.h>
77 #include <sys/ktrace.h>
78
79 #include <net/vnet.h>
80
81 #include <security/audit/audit.h>
82
83 #include <vm/uma.h>
84 #include <vm/vm.h>
85
86 #include <ddb/ddb.h>
87
88 static MALLOC_DEFINE(M_FILEDESC, "filedesc", "Open file descriptor table");
89 static MALLOC_DEFINE(M_PWD, "pwd", "Descriptor table vnodes");
90 static MALLOC_DEFINE(M_PWDDESC, "pwddesc", "Pwd descriptors");
91 static MALLOC_DEFINE(M_FILEDESC_TO_LEADER, "filedesc_to_leader",
92 "file desc to leader structures");
93 static MALLOC_DEFINE(M_SIGIO, "sigio", "sigio structures");
94 MALLOC_DEFINE(M_FILECAPS, "filecaps", "descriptor capabilities");
95
96 MALLOC_DECLARE(M_FADVISE);
97
98 static __read_mostly uma_zone_t file_zone;
99 static __read_mostly uma_zone_t filedesc0_zone;
100 __read_mostly uma_zone_t pwd_zone;
101 VFS_SMR_DECLARE;
102
103 static int closefp(struct filedesc *fdp, int fd, struct file *fp,
104 struct thread *td, bool holdleaders, bool audit);
105 static void export_file_to_kinfo(struct file *fp, int fd,
106 cap_rights_t *rightsp, struct kinfo_file *kif,
107 struct filedesc *fdp, int flags);
108 static int fd_first_free(struct filedesc *fdp, int low, int size);
109 static void fdgrowtable(struct filedesc *fdp, int nfd);
110 static void fdgrowtable_exp(struct filedesc *fdp, int nfd);
111 static void fdunused(struct filedesc *fdp, int fd);
112 static void fdused(struct filedesc *fdp, int fd);
113 static int fget_unlocked_seq(struct thread *td, int fd,
114 const cap_rights_t *needrightsp, uint8_t *flagsp,
115 struct file **fpp, seqc_t *seqp);
116 static int getmaxfd(struct thread *td);
117 static u_long *filecaps_copy_prep(const struct filecaps *src);
118 static void filecaps_copy_finish(const struct filecaps *src,
119 struct filecaps *dst, u_long *ioctls);
120 static u_long *filecaps_free_prep(struct filecaps *fcaps);
121 static void filecaps_free_finish(u_long *ioctls);
122
123 static struct pwd *pwd_alloc(void);
124
125 /*
126 * Each process has:
127 *
128 * - An array of open file descriptors (fd_ofiles)
129 * - An array of file flags (fd_ofileflags)
130 * - A bitmap recording which descriptors are in use (fd_map)
131 *
132 * A process starts out with NDFILE descriptors. The value of NDFILE has
133 * been selected based the historical limit of 20 open files, and an
134 * assumption that the majority of processes, especially short-lived
135 * processes like shells, will never need more.
136 *
137 * If this initial allocation is exhausted, a larger descriptor table and
138 * map are allocated dynamically, and the pointers in the process's struct
139 * filedesc are updated to point to those. This is repeated every time
140 * the process runs out of file descriptors (provided it hasn't hit its
141 * resource limit).
142 *
143 * Since threads may hold references to individual descriptor table
144 * entries, the tables are never freed. Instead, they are placed on a
145 * linked list and freed only when the struct filedesc is released.
146 */
147 #define NDFILE 20
148 #define NDSLOTSIZE sizeof(NDSLOTTYPE)
149 #define NDENTRIES (NDSLOTSIZE * __CHAR_BIT)
150 #define NDSLOT(x) ((x) / NDENTRIES)
151 #define NDBIT(x) ((NDSLOTTYPE)1 << ((x) % NDENTRIES))
152 #define NDSLOTS(x) (((x) + NDENTRIES - 1) / NDENTRIES)
153
154 #define FILEDESC_FOREACH_FDE(fdp, _iterator, _fde) \
155 struct filedesc *_fdp = (fdp); \
156 int _lastfile = fdlastfile_single(_fdp); \
157 for (_iterator = 0; _iterator <= _lastfile; _iterator++) \
158 if ((_fde = &_fdp->fd_ofiles[_iterator])->fde_file != NULL)
159
160 #define FILEDESC_FOREACH_FP(fdp, _iterator, _fp) \
161 struct filedesc *_fdp = (fdp); \
162 int _lastfile = fdlastfile_single(_fdp); \
163 for (_iterator = 0; _iterator <= _lastfile; _iterator++) \
164 if ((_fp = _fdp->fd_ofiles[_iterator].fde_file) != NULL)
165
166 /*
167 * SLIST entry used to keep track of ofiles which must be reclaimed when
168 * the process exits.
169 */
170 struct freetable {
171 struct fdescenttbl *ft_table;
172 SLIST_ENTRY(freetable) ft_next;
173 };
174
175 /*
176 * Initial allocation: a filedesc structure + the head of SLIST used to
177 * keep track of old ofiles + enough space for NDFILE descriptors.
178 */
179
180 struct fdescenttbl0 {
181 int fdt_nfiles;
182 struct filedescent fdt_ofiles[NDFILE];
183 };
184
185 struct filedesc0 {
186 struct filedesc fd_fd;
187 SLIST_HEAD(, freetable) fd_free;
188 struct fdescenttbl0 fd_dfiles;
189 NDSLOTTYPE fd_dmap[NDSLOTS(NDFILE)];
190 };
191
192 /*
193 * Descriptor management.
194 */
195 static int __exclusive_cache_line openfiles; /* actual number of open files */
196 struct mtx sigio_lock; /* mtx to protect pointers to sigio */
197
198 /*
199 * If low >= size, just return low. Otherwise find the first zero bit in the
200 * given bitmap, starting at low and not exceeding size - 1. Return size if
201 * not found.
202 */
203 static int
fd_first_free(struct filedesc * fdp,int low,int size)204 fd_first_free(struct filedesc *fdp, int low, int size)
205 {
206 NDSLOTTYPE *map = fdp->fd_map;
207 NDSLOTTYPE mask;
208 int off, maxoff;
209
210 if (low >= size)
211 return (low);
212
213 off = NDSLOT(low);
214 if (low % NDENTRIES) {
215 mask = ~(~(NDSLOTTYPE)0 >> (NDENTRIES - (low % NDENTRIES)));
216 if ((mask &= ~map[off]) != 0UL)
217 return (off * NDENTRIES + ffsl(mask) - 1);
218 ++off;
219 }
220 for (maxoff = NDSLOTS(size); off < maxoff; ++off)
221 if (map[off] != ~0UL)
222 return (off * NDENTRIES + ffsl(~map[off]) - 1);
223 return (size);
224 }
225
226 /*
227 * Find the last used fd.
228 *
229 * Call this variant if fdp can't be modified by anyone else (e.g, during exec).
230 * Otherwise use fdlastfile.
231 */
232 int
fdlastfile_single(struct filedesc * fdp)233 fdlastfile_single(struct filedesc *fdp)
234 {
235 NDSLOTTYPE *map = fdp->fd_map;
236 int off, minoff;
237
238 off = NDSLOT(fdp->fd_nfiles - 1);
239 for (minoff = NDSLOT(0); off >= minoff; --off)
240 if (map[off] != 0)
241 return (off * NDENTRIES + flsl(map[off]) - 1);
242 return (-1);
243 }
244
245 int
fdlastfile(struct filedesc * fdp)246 fdlastfile(struct filedesc *fdp)
247 {
248
249 FILEDESC_LOCK_ASSERT(fdp);
250 return (fdlastfile_single(fdp));
251 }
252
253 static int
fdisused(struct filedesc * fdp,int fd)254 fdisused(struct filedesc *fdp, int fd)
255 {
256
257 KASSERT(fd >= 0 && fd < fdp->fd_nfiles,
258 ("file descriptor %d out of range (0, %d)", fd, fdp->fd_nfiles));
259
260 return ((fdp->fd_map[NDSLOT(fd)] & NDBIT(fd)) != 0);
261 }
262
263 /*
264 * Mark a file descriptor as used.
265 */
266 static void
fdused_init(struct filedesc * fdp,int fd)267 fdused_init(struct filedesc *fdp, int fd)
268 {
269
270 KASSERT(!fdisused(fdp, fd), ("fd=%d is already used", fd));
271
272 fdp->fd_map[NDSLOT(fd)] |= NDBIT(fd);
273 }
274
275 static void
fdused(struct filedesc * fdp,int fd)276 fdused(struct filedesc *fdp, int fd)
277 {
278
279 FILEDESC_XLOCK_ASSERT(fdp);
280
281 fdused_init(fdp, fd);
282 if (fd == fdp->fd_freefile)
283 fdp->fd_freefile++;
284 }
285
286 /*
287 * Mark a file descriptor as unused.
288 */
289 static void
fdunused(struct filedesc * fdp,int fd)290 fdunused(struct filedesc *fdp, int fd)
291 {
292
293 FILEDESC_XLOCK_ASSERT(fdp);
294
295 KASSERT(fdisused(fdp, fd), ("fd=%d is already unused", fd));
296 KASSERT(fdp->fd_ofiles[fd].fde_file == NULL,
297 ("fd=%d is still in use", fd));
298
299 fdp->fd_map[NDSLOT(fd)] &= ~NDBIT(fd);
300 if (fd < fdp->fd_freefile)
301 fdp->fd_freefile = fd;
302 }
303
304 /*
305 * Free a file descriptor.
306 *
307 * Avoid some work if fdp is about to be destroyed.
308 */
309 static inline void
fdefree_last(struct filedescent * fde)310 fdefree_last(struct filedescent *fde)
311 {
312
313 filecaps_free(&fde->fde_caps);
314 }
315
316 static inline void
fdfree(struct filedesc * fdp,int fd)317 fdfree(struct filedesc *fdp, int fd)
318 {
319 struct filedescent *fde;
320
321 FILEDESC_XLOCK_ASSERT(fdp);
322 fde = &fdp->fd_ofiles[fd];
323 #ifdef CAPABILITIES
324 seqc_write_begin(&fde->fde_seqc);
325 #endif
326 fde->fde_file = NULL;
327 #ifdef CAPABILITIES
328 seqc_write_end(&fde->fde_seqc);
329 #endif
330 fdefree_last(fde);
331 fdunused(fdp, fd);
332 }
333
334 /*
335 * System calls on descriptors.
336 */
337 #ifndef _SYS_SYSPROTO_H_
338 struct getdtablesize_args {
339 int dummy;
340 };
341 #endif
342 /* ARGSUSED */
343 int
sys_getdtablesize(struct thread * td,struct getdtablesize_args * uap)344 sys_getdtablesize(struct thread *td, struct getdtablesize_args *uap)
345 {
346 #ifdef RACCT
347 uint64_t lim;
348 #endif
349
350 td->td_retval[0] = getmaxfd(td);
351 #ifdef RACCT
352 PROC_LOCK(td->td_proc);
353 lim = racct_get_limit(td->td_proc, RACCT_NOFILE);
354 PROC_UNLOCK(td->td_proc);
355 if (lim < td->td_retval[0])
356 td->td_retval[0] = lim;
357 #endif
358 return (0);
359 }
360
361 /*
362 * Duplicate a file descriptor to a particular value.
363 *
364 * Note: keep in mind that a potential race condition exists when closing
365 * descriptors from a shared descriptor table (via rfork).
366 */
367 #ifndef _SYS_SYSPROTO_H_
368 struct dup2_args {
369 u_int from;
370 u_int to;
371 };
372 #endif
373 /* ARGSUSED */
374 int
sys_dup2(struct thread * td,struct dup2_args * uap)375 sys_dup2(struct thread *td, struct dup2_args *uap)
376 {
377
378 return (kern_dup(td, FDDUP_FIXED, 0, (int)uap->from, (int)uap->to));
379 }
380
381 /*
382 * Duplicate a file descriptor.
383 */
384 #ifndef _SYS_SYSPROTO_H_
385 struct dup_args {
386 u_int fd;
387 };
388 #endif
389 /* ARGSUSED */
390 int
sys_dup(struct thread * td,struct dup_args * uap)391 sys_dup(struct thread *td, struct dup_args *uap)
392 {
393
394 return (kern_dup(td, FDDUP_NORMAL, 0, (int)uap->fd, 0));
395 }
396
397 /*
398 * The file control system call.
399 */
400 #ifndef _SYS_SYSPROTO_H_
401 struct fcntl_args {
402 int fd;
403 int cmd;
404 long arg;
405 };
406 #endif
407 /* ARGSUSED */
408 int
sys_fcntl(struct thread * td,struct fcntl_args * uap)409 sys_fcntl(struct thread *td, struct fcntl_args *uap)
410 {
411
412 return (kern_fcntl_freebsd(td, uap->fd, uap->cmd, uap->arg));
413 }
414
415 int
kern_fcntl_freebsd(struct thread * td,int fd,int cmd,intptr_t arg)416 kern_fcntl_freebsd(struct thread *td, int fd, int cmd, intptr_t arg)
417 {
418 struct flock fl;
419 struct __oflock ofl;
420 intptr_t arg1;
421 int error, newcmd;
422
423 error = 0;
424 newcmd = cmd;
425 switch (cmd) {
426 case F_OGETLK:
427 case F_OSETLK:
428 case F_OSETLKW:
429 /*
430 * Convert old flock structure to new.
431 */
432 error = copyin((void *)arg, &ofl, sizeof(ofl));
433 fl.l_start = ofl.l_start;
434 fl.l_len = ofl.l_len;
435 fl.l_pid = ofl.l_pid;
436 fl.l_type = ofl.l_type;
437 fl.l_whence = ofl.l_whence;
438 fl.l_sysid = 0;
439
440 switch (cmd) {
441 case F_OGETLK:
442 newcmd = F_GETLK;
443 break;
444 case F_OSETLK:
445 newcmd = F_SETLK;
446 break;
447 case F_OSETLKW:
448 newcmd = F_SETLKW;
449 break;
450 }
451 arg1 = (intptr_t)&fl;
452 break;
453 case F_GETLK:
454 case F_SETLK:
455 case F_SETLKW:
456 case F_SETLK_REMOTE:
457 error = copyin((void *)arg, &fl, sizeof(fl));
458 arg1 = (intptr_t)&fl;
459 break;
460 default:
461 arg1 = arg;
462 break;
463 }
464 if (error)
465 return (error);
466 error = kern_fcntl(td, fd, newcmd, arg1);
467 if (error)
468 return (error);
469 if (cmd == F_OGETLK) {
470 ofl.l_start = fl.l_start;
471 ofl.l_len = fl.l_len;
472 ofl.l_pid = fl.l_pid;
473 ofl.l_type = fl.l_type;
474 ofl.l_whence = fl.l_whence;
475 error = copyout(&ofl, (void *)arg, sizeof(ofl));
476 } else if (cmd == F_GETLK) {
477 error = copyout(&fl, (void *)arg, sizeof(fl));
478 }
479 return (error);
480 }
481
482 struct flags_trans_elem {
483 u_int f;
484 u_int t;
485 };
486
487 static u_int
flags_trans(const struct flags_trans_elem * ftes,int nitems,u_int from_flags)488 flags_trans(const struct flags_trans_elem *ftes, int nitems, u_int from_flags)
489 {
490 u_int res;
491 int i;
492
493 res = 0;
494 for (i = 0; i < nitems; i++) {
495 if ((from_flags & ftes[i].f) != 0)
496 res |= ftes[i].t;
497 }
498 return (res);
499 }
500
501 static uint8_t
fd_to_fde_flags(int fd_flags)502 fd_to_fde_flags(int fd_flags)
503 {
504 static const struct flags_trans_elem fd_to_fde_flags_s[] = {
505 { .f = FD_CLOEXEC, .t = UF_EXCLOSE },
506 { .f = FD_CLOFORK, .t = UF_FOCLOSE },
507 { .f = FD_RESOLVE_BENEATH, .t = UF_RESOLVE_BENEATH },
508 };
509
510 return (flags_trans(fd_to_fde_flags_s, nitems(fd_to_fde_flags_s),
511 fd_flags));
512 }
513
514 static int
fde_to_fd_flags(uint8_t fde_flags)515 fde_to_fd_flags(uint8_t fde_flags)
516 {
517 static const struct flags_trans_elem fde_to_fd_flags_s[] = {
518 { .f = UF_EXCLOSE, .t = FD_CLOEXEC },
519 { .f = UF_FOCLOSE, .t = FD_CLOFORK },
520 { .f = UF_RESOLVE_BENEATH, .t = FD_RESOLVE_BENEATH },
521 };
522
523 return (flags_trans(fde_to_fd_flags_s, nitems(fde_to_fd_flags_s),
524 fde_flags));
525 }
526
527 static uint8_t
fddup_to_fde_flags(int fddup_flags)528 fddup_to_fde_flags(int fddup_flags)
529 {
530 static const struct flags_trans_elem fddup_to_fde_flags_s[] = {
531 { .f = FDDUP_FLAG_CLOEXEC, .t = UF_EXCLOSE },
532 { .f = FDDUP_FLAG_CLOFORK, .t = UF_FOCLOSE },
533 };
534
535 return (flags_trans(fddup_to_fde_flags_s, nitems(fddup_to_fde_flags_s),
536 fddup_flags));
537 }
538
539 static uint8_t
close_range_to_fde_flags(int close_range_flags)540 close_range_to_fde_flags(int close_range_flags)
541 {
542 static const struct flags_trans_elem close_range_to_fde_flags_s[] = {
543 { .f = CLOSE_RANGE_CLOEXEC, .t = UF_EXCLOSE },
544 { .f = CLOSE_RANGE_CLOFORK, .t = UF_FOCLOSE },
545 };
546
547 return (flags_trans(close_range_to_fde_flags_s,
548 nitems(close_range_to_fde_flags_s), close_range_flags));
549 }
550
551 static uint8_t
open_to_fde_flags(int open_flags,bool sticky_orb)552 open_to_fde_flags(int open_flags, bool sticky_orb)
553 {
554 static const struct flags_trans_elem open_to_fde_flags_s[] = {
555 { .f = O_CLOEXEC, .t = UF_EXCLOSE },
556 { .f = O_CLOFORK, .t = UF_FOCLOSE },
557 { .f = O_RESOLVE_BENEATH, .t = UF_RESOLVE_BENEATH },
558 };
559 #if defined(__clang__) && __clang_major__ >= 19
560 _Static_assert(open_to_fde_flags_s[nitems(open_to_fde_flags_s) - 1].f ==
561 O_RESOLVE_BENEATH, "O_RESOLVE_BENEATH must be last, for sticky_orb");
562 #endif
563
564 return (flags_trans(open_to_fde_flags_s, nitems(open_to_fde_flags_s) -
565 (sticky_orb ? 0 : 1), open_flags));
566 }
567
568 int
kern_fcntl(struct thread * td,int fd,int cmd,intptr_t arg)569 kern_fcntl(struct thread *td, int fd, int cmd, intptr_t arg)
570 {
571 struct filedesc *fdp;
572 struct flock *flp;
573 struct file *fp, *fp2;
574 struct filedescent *fde;
575 struct proc *p;
576 struct vnode *vp;
577 struct mount *mp;
578 struct kinfo_file *kif;
579 int error, flg, kif_sz, seals, tmp, got_set, got_cleared;
580 uint64_t bsize;
581 off_t foffset;
582 int flags;
583
584 error = 0;
585 flg = F_POSIX;
586 p = td->td_proc;
587 fdp = p->p_fd;
588
589 AUDIT_ARG_FD(cmd);
590 AUDIT_ARG_CMD(cmd);
591 switch (cmd) {
592 case F_DUPFD:
593 tmp = arg;
594 error = kern_dup(td, FDDUP_FCNTL, 0, fd, tmp);
595 break;
596
597 case F_DUPFD_CLOEXEC:
598 tmp = arg;
599 error = kern_dup(td, FDDUP_FCNTL, FDDUP_FLAG_CLOEXEC, fd, tmp);
600 break;
601
602 case F_DUPFD_CLOFORK:
603 tmp = arg;
604 error = kern_dup(td, FDDUP_FCNTL, FDDUP_FLAG_CLOFORK, fd, tmp);
605 break;
606
607 case F_DUP2FD:
608 tmp = arg;
609 error = kern_dup(td, FDDUP_FIXED, 0, fd, tmp);
610 break;
611
612 case F_DUP2FD_CLOEXEC:
613 tmp = arg;
614 error = kern_dup(td, FDDUP_FIXED, FDDUP_FLAG_CLOEXEC, fd, tmp);
615 break;
616
617 case F_GETFD:
618 error = EBADF;
619 FILEDESC_SLOCK(fdp);
620 fde = fdeget_noref(fdp, fd);
621 if (fde != NULL) {
622 td->td_retval[0] = fde_to_fd_flags(fde->fde_flags);
623 error = 0;
624 }
625 FILEDESC_SUNLOCK(fdp);
626 break;
627
628 case F_SETFD:
629 error = EBADF;
630 FILEDESC_XLOCK(fdp);
631 fde = fdeget_noref(fdp, fd);
632 if (fde != NULL) {
633 /*
634 * UF_RESOLVE_BENEATH is sticky and cannot be cleared.
635 */
636 fde->fde_flags = (fde->fde_flags &
637 ~(UF_EXCLOSE | UF_FOCLOSE)) | fd_to_fde_flags(arg);
638 error = 0;
639 }
640 FILEDESC_XUNLOCK(fdp);
641 break;
642
643 case F_GETFL:
644 error = fget_fcntl(td, fd, &cap_fcntl_rights, F_GETFL, &fp);
645 if (error != 0)
646 break;
647 td->td_retval[0] = OFLAGS(fp->f_flag);
648 fdrop(fp, td);
649 break;
650
651 case F_SETFL:
652 error = fget_fcntl(td, fd, &cap_fcntl_rights, F_SETFL, &fp);
653 if (error != 0)
654 break;
655 if (fp->f_ops == &path_fileops) {
656 fdrop(fp, td);
657 error = EBADF;
658 break;
659 }
660 fsetfl_lock(fp);
661 do {
662 tmp = flg = fp->f_flag;
663 tmp &= ~FCNTLFLAGS;
664 tmp |= FFLAGS(arg & ~O_ACCMODE) & FCNTLFLAGS;
665 } while (atomic_cmpset_int(&fp->f_flag, flg, tmp) == 0);
666 got_set = tmp & ~flg;
667 got_cleared = flg & ~tmp;
668 if (((got_set | got_cleared) & FNONBLOCK) != 0) {
669 tmp = fp->f_flag & FNONBLOCK;
670 error = fo_ioctl(fp, FIONBIO, &tmp, td->td_ucred, td);
671 if (error != 0)
672 goto revert_flags;
673 }
674 if (((got_set | got_cleared) & FASYNC) != 0) {
675 tmp = fp->f_flag & FASYNC;
676 error = fo_ioctl(fp, FIOASYNC, &tmp, td->td_ucred, td);
677 if (error != 0)
678 goto revert_nonblock;
679 }
680 fsetfl_unlock(fp);
681 fdrop(fp, td);
682 break;
683 revert_nonblock:
684 if (((got_set | got_cleared) & FNONBLOCK) != 0) {
685 tmp = ~fp->f_flag & FNONBLOCK;
686 (void)fo_ioctl(fp, FIONBIO, &tmp, td->td_ucred, td);
687 }
688 revert_flags:
689 do {
690 tmp = flg = fp->f_flag;
691 tmp &= ~FCNTLFLAGS;
692 tmp |= got_cleared;
693 tmp &= ~got_set;
694 } while (atomic_cmpset_int(&fp->f_flag, flg, tmp) == 0);
695 fsetfl_unlock(fp);
696 fdrop(fp, td);
697 break;
698
699 case F_GETOWN:
700 error = fget_fcntl(td, fd, &cap_fcntl_rights, F_GETOWN, &fp);
701 if (error != 0)
702 break;
703 error = fo_ioctl(fp, FIOGETOWN, &tmp, td->td_ucred, td);
704 if (error == 0)
705 td->td_retval[0] = tmp;
706 fdrop(fp, td);
707 break;
708
709 case F_SETOWN:
710 error = fget_fcntl(td, fd, &cap_fcntl_rights, F_SETOWN, &fp);
711 if (error != 0)
712 break;
713 tmp = arg;
714 error = fo_ioctl(fp, FIOSETOWN, &tmp, td->td_ucred, td);
715 fdrop(fp, td);
716 break;
717
718 case F_SETLK_REMOTE:
719 error = priv_check(td, PRIV_NFS_LOCKD);
720 if (error != 0)
721 return (error);
722 flg = F_REMOTE;
723 goto do_setlk;
724
725 case F_SETLKW:
726 flg |= F_WAIT;
727 /* FALLTHROUGH F_SETLK */
728
729 case F_SETLK:
730 do_setlk:
731 flp = (struct flock *)arg;
732 if ((flg & F_REMOTE) != 0 && flp->l_sysid == 0) {
733 error = EINVAL;
734 break;
735 }
736
737 error = fget_unlocked(td, fd, &cap_flock_rights, &fp);
738 if (error != 0)
739 break;
740 if (fp->f_type != DTYPE_VNODE || fp->f_ops == &path_fileops) {
741 error = EBADF;
742 fdrop(fp, td);
743 break;
744 }
745
746 if (flp->l_whence == SEEK_CUR) {
747 foffset = foffset_get(fp);
748 if (foffset < 0 ||
749 (flp->l_start > 0 &&
750 foffset > OFF_MAX - flp->l_start)) {
751 error = EOVERFLOW;
752 fdrop(fp, td);
753 break;
754 }
755 flp->l_start += foffset;
756 }
757
758 vp = fp->f_vnode;
759 switch (flp->l_type) {
760 case F_RDLCK:
761 if ((fp->f_flag & FREAD) == 0) {
762 error = EBADF;
763 break;
764 }
765 if ((p->p_leader->p_flag & P_ADVLOCK) == 0) {
766 PROC_LOCK(p->p_leader);
767 p->p_leader->p_flag |= P_ADVLOCK;
768 PROC_UNLOCK(p->p_leader);
769 }
770 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_SETLK,
771 flp, flg);
772 break;
773 case F_WRLCK:
774 if ((fp->f_flag & FWRITE) == 0) {
775 error = EBADF;
776 break;
777 }
778 if ((p->p_leader->p_flag & P_ADVLOCK) == 0) {
779 PROC_LOCK(p->p_leader);
780 p->p_leader->p_flag |= P_ADVLOCK;
781 PROC_UNLOCK(p->p_leader);
782 }
783 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_SETLK,
784 flp, flg);
785 break;
786 case F_UNLCK:
787 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_UNLCK,
788 flp, flg);
789 break;
790 case F_UNLCKSYS:
791 if (flg != F_REMOTE) {
792 error = EINVAL;
793 break;
794 }
795 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader,
796 F_UNLCKSYS, flp, flg);
797 break;
798 default:
799 error = EINVAL;
800 break;
801 }
802 if (error != 0 || flp->l_type == F_UNLCK ||
803 flp->l_type == F_UNLCKSYS) {
804 fdrop(fp, td);
805 break;
806 }
807
808 /*
809 * Check for a race with close.
810 *
811 * The vnode is now advisory locked (or unlocked, but this case
812 * is not really important) as the caller requested.
813 * We had to drop the filedesc lock, so we need to recheck if
814 * the descriptor is still valid, because if it was closed
815 * in the meantime we need to remove advisory lock from the
816 * vnode - close on any descriptor leading to an advisory
817 * locked vnode, removes that lock.
818 * We will return 0 on purpose in that case, as the result of
819 * successful advisory lock might have been externally visible
820 * already. This is fine - effectively we pretend to the caller
821 * that the closing thread was a bit slower and that the
822 * advisory lock succeeded before the close.
823 */
824 error = fget_unlocked(td, fd, &cap_no_rights, &fp2);
825 if (error != 0) {
826 fdrop(fp, td);
827 break;
828 }
829 if (fp != fp2) {
830 flp->l_whence = SEEK_SET;
831 flp->l_start = 0;
832 flp->l_len = 0;
833 flp->l_type = F_UNLCK;
834 (void) VOP_ADVLOCK(vp, (caddr_t)p->p_leader,
835 F_UNLCK, flp, F_POSIX);
836 }
837 fdrop(fp, td);
838 fdrop(fp2, td);
839 break;
840
841 case F_GETLK:
842 error = fget_unlocked(td, fd, &cap_flock_rights, &fp);
843 if (error != 0)
844 break;
845 if (fp->f_type != DTYPE_VNODE || fp->f_ops == &path_fileops) {
846 error = EBADF;
847 fdrop(fp, td);
848 break;
849 }
850 flp = (struct flock *)arg;
851 if (flp->l_type != F_RDLCK && flp->l_type != F_WRLCK &&
852 flp->l_type != F_UNLCK) {
853 error = EINVAL;
854 fdrop(fp, td);
855 break;
856 }
857 if (flp->l_whence == SEEK_CUR) {
858 foffset = foffset_get(fp);
859 if ((flp->l_start > 0 &&
860 foffset > OFF_MAX - flp->l_start) ||
861 (flp->l_start < 0 &&
862 foffset < OFF_MIN - flp->l_start)) {
863 error = EOVERFLOW;
864 fdrop(fp, td);
865 break;
866 }
867 flp->l_start += foffset;
868 }
869 vp = fp->f_vnode;
870 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_GETLK, flp,
871 F_POSIX);
872 fdrop(fp, td);
873 break;
874
875 case F_ADD_SEALS:
876 error = fget_unlocked(td, fd, &cap_no_rights, &fp);
877 if (error != 0)
878 break;
879 error = fo_add_seals(fp, arg);
880 fdrop(fp, td);
881 break;
882
883 case F_GET_SEALS:
884 error = fget_unlocked(td, fd, &cap_no_rights, &fp);
885 if (error != 0)
886 break;
887 if (fo_get_seals(fp, &seals) == 0)
888 td->td_retval[0] = seals;
889 else
890 error = EINVAL;
891 fdrop(fp, td);
892 break;
893
894 case F_RDAHEAD:
895 arg = arg ? 128 * 1024: 0;
896 /* FALLTHROUGH */
897 case F_READAHEAD:
898 error = fget_unlocked(td, fd, &cap_no_rights, &fp);
899 if (error != 0)
900 break;
901 if (fp->f_type != DTYPE_VNODE || fp->f_ops == &path_fileops) {
902 fdrop(fp, td);
903 error = EBADF;
904 break;
905 }
906 vp = fp->f_vnode;
907 if (vp->v_type != VREG) {
908 fdrop(fp, td);
909 error = ENOTTY;
910 break;
911 }
912
913 /*
914 * Exclusive lock synchronizes against f_seqcount reads and
915 * writes in sequential_heuristic().
916 */
917 error = vn_lock(vp, LK_EXCLUSIVE);
918 if (error != 0) {
919 fdrop(fp, td);
920 break;
921 }
922 if (arg >= 0) {
923 bsize = fp->f_vnode->v_mount->mnt_stat.f_iosize;
924 arg = MIN(arg, INT_MAX - bsize + 1);
925 fp->f_seqcount[UIO_READ] = MIN(IO_SEQMAX,
926 (arg + bsize - 1) / bsize);
927 atomic_set_int(&fp->f_flag, FRDAHEAD);
928 } else {
929 atomic_clear_int(&fp->f_flag, FRDAHEAD);
930 }
931 VOP_UNLOCK(vp);
932 fdrop(fp, td);
933 break;
934
935 case F_ISUNIONSTACK:
936 /*
937 * Check if the vnode is part of a union stack (either the
938 * "union" flag from mount(2) or unionfs).
939 *
940 * Prior to introduction of this op libc's readdir would call
941 * fstatfs(2), in effect unnecessarily copying kilobytes of
942 * data just to check fs name and a mount flag.
943 *
944 * Fixing the code to handle everything in the kernel instead
945 * is a non-trivial endeavor and has low priority, thus this
946 * horrible kludge facilitates the current behavior in a much
947 * cheaper manner until someone(tm) sorts this out.
948 */
949 error = fget_unlocked(td, fd, &cap_no_rights, &fp);
950 if (error != 0)
951 break;
952 if (fp->f_type != DTYPE_VNODE) {
953 fdrop(fp, td);
954 error = EBADF;
955 break;
956 }
957 vp = fp->f_vnode;
958 /*
959 * Since we don't prevent dooming the vnode even non-null mp
960 * found can become immediately stale. This is tolerable since
961 * mount points are type-stable (providing safe memory access)
962 * and any vfs op on this vnode going forward will return an
963 * error (meaning return value in this case is meaningless).
964 */
965 mp = atomic_load_ptr(&vp->v_mount);
966 if (__predict_false(mp == NULL)) {
967 fdrop(fp, td);
968 error = EBADF;
969 break;
970 }
971 td->td_retval[0] = 0;
972 if (mp->mnt_kern_flag & MNTK_UNIONFS ||
973 mp->mnt_flag & MNT_UNION)
974 td->td_retval[0] = 1;
975 fdrop(fp, td);
976 break;
977
978 case F_KINFO:
979 #ifdef CAPABILITY_MODE
980 if (CAP_TRACING(td))
981 ktrcapfail(CAPFAIL_SYSCALL, &cmd);
982 if (IN_CAPABILITY_MODE(td)) {
983 error = ECAPMODE;
984 break;
985 }
986 #endif
987 error = copyin((void *)arg, &kif_sz, sizeof(kif_sz));
988 if (error != 0)
989 break;
990 if (kif_sz != sizeof(*kif)) {
991 error = EINVAL;
992 break;
993 }
994 kif = malloc(sizeof(*kif), M_TEMP, M_WAITOK | M_ZERO);
995 FILEDESC_SLOCK(fdp);
996 error = fget_cap_noref(fdp, fd, &cap_fcntl_rights, &fp, NULL);
997 if (error == 0 && fhold(fp)) {
998 export_file_to_kinfo(fp, fd, NULL, kif, fdp, 0);
999 FILEDESC_SUNLOCK(fdp);
1000 fdrop(fp, td);
1001 if ((kif->kf_status & KF_ATTR_VALID) != 0) {
1002 kif->kf_structsize = sizeof(*kif);
1003 error = copyout(kif, (void *)arg, sizeof(*kif));
1004 } else {
1005 error = EBADF;
1006 }
1007 } else {
1008 FILEDESC_SUNLOCK(fdp);
1009 if (error == 0)
1010 error = EBADF;
1011 }
1012 free(kif, M_TEMP);
1013 break;
1014
1015 default:
1016 if ((cmd & ((1u << F_DUP3FD_SHIFT) - 1)) != F_DUP3FD)
1017 return (EXTERROR(EINVAL, "invalid fcntl cmd"));
1018 /* Handle F_DUP3FD */
1019 flags = (cmd >> F_DUP3FD_SHIFT);
1020 if ((flags & ~(FD_CLOEXEC | FD_CLOFORK)) != 0)
1021 return (EXTERROR(EINVAL, "invalid flags for F_DUP3FD"));
1022 tmp = arg;
1023 error = kern_dup(td, FDDUP_FIXED,
1024 ((flags & FD_CLOEXEC) != 0 ? FDDUP_FLAG_CLOEXEC : 0) |
1025 ((flags & FD_CLOFORK) != 0 ? FDDUP_FLAG_CLOFORK : 0),
1026 fd, tmp);
1027 break;
1028 }
1029 return (error);
1030 }
1031
1032 static int
getmaxfd(struct thread * td)1033 getmaxfd(struct thread *td)
1034 {
1035
1036 return (min((int)lim_cur(td, RLIMIT_NOFILE), maxfilesperproc));
1037 }
1038
1039 /*
1040 * Common code for dup, dup2, fcntl(F_DUPFD) and fcntl(F_DUP2FD).
1041 */
1042 int
kern_dup(struct thread * td,u_int mode,int flags,int oldd,int newd)1043 kern_dup(struct thread *td, u_int mode, int flags, int oldd, int newd)
1044 {
1045 struct filedesc *fdp;
1046 struct filedescent *oldfde, *newfde;
1047 struct proc *p;
1048 struct file *delfp, *oldfp;
1049 u_long *oioctls, *nioctls;
1050 int error, maxfd;
1051
1052 p = td->td_proc;
1053 fdp = p->p_fd;
1054 oioctls = NULL;
1055
1056 MPASS((flags & ~(FDDUP_FLAG_CLOEXEC | FDDUP_FLAG_CLOFORK)) == 0);
1057 MPASS(mode < FDDUP_LASTMODE);
1058
1059 AUDIT_ARG_FD(oldd);
1060 /* XXXRW: if (flags & FDDUP_FIXED) AUDIT_ARG_FD2(newd); */
1061
1062 /*
1063 * Verify we have a valid descriptor to dup from and possibly to
1064 * dup to. Unlike dup() and dup2(), fcntl()'s F_DUPFD should
1065 * return EINVAL when the new descriptor is out of bounds.
1066 */
1067 if (oldd < 0)
1068 return (EBADF);
1069 if (newd < 0)
1070 return (mode == FDDUP_FCNTL ? EINVAL : EBADF);
1071 maxfd = getmaxfd(td);
1072 if (newd >= maxfd)
1073 return (mode == FDDUP_FCNTL ? EINVAL : EBADF);
1074
1075 error = EBADF;
1076 FILEDESC_XLOCK(fdp);
1077 if (fget_noref(fdp, oldd) == NULL)
1078 goto unlock;
1079 if (mode == FDDUP_FIXED && oldd == newd) {
1080 td->td_retval[0] = newd;
1081 fdp->fd_ofiles[newd].fde_flags |= fddup_to_fde_flags(flags);
1082 error = 0;
1083 goto unlock;
1084 }
1085
1086 oldfde = &fdp->fd_ofiles[oldd];
1087 oldfp = oldfde->fde_file;
1088 if (!fhold(oldfp))
1089 goto unlock;
1090
1091 /*
1092 * If the caller specified a file descriptor, make sure the file
1093 * table is large enough to hold it, and grab it. Otherwise, just
1094 * allocate a new descriptor the usual way.
1095 */
1096 switch (mode) {
1097 case FDDUP_NORMAL:
1098 case FDDUP_FCNTL:
1099 if ((error = fdalloc(td, newd, &newd)) != 0) {
1100 fdrop(oldfp, td);
1101 goto unlock;
1102 }
1103 break;
1104 case FDDUP_FIXED:
1105 if (newd >= fdp->fd_nfiles) {
1106 /*
1107 * The resource limits are here instead of e.g.
1108 * fdalloc(), because the file descriptor table may be
1109 * shared between processes, so we can't really use
1110 * racct_add()/racct_sub(). Instead of counting the
1111 * number of actually allocated descriptors, just put
1112 * the limit on the size of the file descriptor table.
1113 */
1114 #ifdef RACCT
1115 if (RACCT_ENABLED()) {
1116 error = racct_set_unlocked(p, RACCT_NOFILE, newd + 1);
1117 if (error != 0) {
1118 error = EMFILE;
1119 fdrop(oldfp, td);
1120 goto unlock;
1121 }
1122 }
1123 #endif
1124 fdgrowtable_exp(fdp, newd + 1);
1125 }
1126 if (!fdisused(fdp, newd))
1127 fdused(fdp, newd);
1128 break;
1129 default:
1130 KASSERT(0, ("%s unsupported mode %d", __func__, mode));
1131 }
1132
1133 KASSERT(oldd != newd, ("new fd is same as old"));
1134
1135 /* Refetch oldfde because the table may have grown and old one freed. */
1136 oldfde = &fdp->fd_ofiles[oldd];
1137 KASSERT(oldfp == oldfde->fde_file,
1138 ("fdt_ofiles shift from growth observed at fd %d",
1139 oldd));
1140
1141 newfde = &fdp->fd_ofiles[newd];
1142 delfp = newfde->fde_file;
1143
1144 nioctls = filecaps_copy_prep(&oldfde->fde_caps);
1145
1146 /*
1147 * Duplicate the source descriptor.
1148 */
1149 #ifdef CAPABILITIES
1150 seqc_write_begin(&newfde->fde_seqc);
1151 #endif
1152 oioctls = filecaps_free_prep(&newfde->fde_caps);
1153 fde_copy(oldfde, newfde);
1154 filecaps_copy_finish(&oldfde->fde_caps, &newfde->fde_caps,
1155 nioctls);
1156 newfde->fde_flags = (oldfde->fde_flags & ~(UF_EXCLOSE | UF_FOCLOSE)) |
1157 fddup_to_fde_flags(flags);
1158 #ifdef CAPABILITIES
1159 seqc_write_end(&newfde->fde_seqc);
1160 #endif
1161 td->td_retval[0] = newd;
1162
1163 error = 0;
1164
1165 if (delfp != NULL) {
1166 (void) closefp(fdp, newd, delfp, td, true, false);
1167 FILEDESC_UNLOCK_ASSERT(fdp);
1168 } else {
1169 unlock:
1170 FILEDESC_XUNLOCK(fdp);
1171 }
1172
1173 filecaps_free_finish(oioctls);
1174 return (error);
1175 }
1176
1177 static void
sigiofree(struct sigio * sigio)1178 sigiofree(struct sigio *sigio)
1179 {
1180 crfree(sigio->sio_ucred);
1181 free(sigio, M_SIGIO);
1182 }
1183
1184 static struct sigio *
funsetown_locked(struct sigio * sigio)1185 funsetown_locked(struct sigio *sigio)
1186 {
1187 struct proc *p;
1188 struct pgrp *pg;
1189
1190 SIGIO_ASSERT_LOCKED();
1191
1192 if (sigio == NULL)
1193 return (NULL);
1194 *sigio->sio_myref = NULL;
1195 if (sigio->sio_pgid < 0) {
1196 pg = sigio->sio_pgrp;
1197 PGRP_LOCK(pg);
1198 SLIST_REMOVE(&pg->pg_sigiolst, sigio, sigio, sio_pgsigio);
1199 PGRP_UNLOCK(pg);
1200 } else {
1201 p = sigio->sio_proc;
1202 PROC_LOCK(p);
1203 SLIST_REMOVE(&p->p_sigiolst, sigio, sigio, sio_pgsigio);
1204 PROC_UNLOCK(p);
1205 }
1206 return (sigio);
1207 }
1208
1209 /*
1210 * If sigio is on the list associated with a process or process group,
1211 * disable signalling from the device, remove sigio from the list and
1212 * free sigio.
1213 */
1214 void
funsetown(struct sigio ** sigiop)1215 funsetown(struct sigio **sigiop)
1216 {
1217 struct sigio *sigio;
1218
1219 /* Racy check, consumers must provide synchronization. */
1220 if (*sigiop == NULL)
1221 return;
1222
1223 SIGIO_LOCK();
1224 sigio = funsetown_locked(*sigiop);
1225 SIGIO_UNLOCK();
1226 if (sigio != NULL)
1227 sigiofree(sigio);
1228 }
1229
1230 /*
1231 * Free a list of sigio structures. The caller must ensure that new sigio
1232 * structures cannot be added after this point. For process groups this is
1233 * guaranteed using the proctree lock; for processes, the P_WEXIT flag serves
1234 * as an interlock.
1235 */
1236 void
funsetownlst(struct sigiolst * sigiolst)1237 funsetownlst(struct sigiolst *sigiolst)
1238 {
1239 struct proc *p;
1240 struct pgrp *pg;
1241 struct sigio *sigio, *tmp;
1242
1243 /* Racy check. */
1244 sigio = SLIST_FIRST(sigiolst);
1245 if (sigio == NULL)
1246 return;
1247
1248 p = NULL;
1249 pg = NULL;
1250
1251 SIGIO_LOCK();
1252 sigio = SLIST_FIRST(sigiolst);
1253 if (sigio == NULL) {
1254 SIGIO_UNLOCK();
1255 return;
1256 }
1257
1258 /*
1259 * Every entry of the list should belong to a single proc or pgrp.
1260 */
1261 if (sigio->sio_pgid < 0) {
1262 pg = sigio->sio_pgrp;
1263 sx_assert(&proctree_lock, SX_XLOCKED);
1264 PGRP_LOCK(pg);
1265 } else /* if (sigio->sio_pgid > 0) */ {
1266 p = sigio->sio_proc;
1267 PROC_LOCK(p);
1268 KASSERT((p->p_flag & P_WEXIT) != 0,
1269 ("%s: process %p is not exiting", __func__, p));
1270 }
1271
1272 SLIST_FOREACH(sigio, sigiolst, sio_pgsigio) {
1273 *sigio->sio_myref = NULL;
1274 if (pg != NULL) {
1275 KASSERT(sigio->sio_pgid < 0,
1276 ("Proc sigio in pgrp sigio list"));
1277 KASSERT(sigio->sio_pgrp == pg,
1278 ("Bogus pgrp in sigio list"));
1279 } else /* if (p != NULL) */ {
1280 KASSERT(sigio->sio_pgid > 0,
1281 ("Pgrp sigio in proc sigio list"));
1282 KASSERT(sigio->sio_proc == p,
1283 ("Bogus proc in sigio list"));
1284 }
1285 }
1286
1287 if (pg != NULL)
1288 PGRP_UNLOCK(pg);
1289 else
1290 PROC_UNLOCK(p);
1291 SIGIO_UNLOCK();
1292
1293 SLIST_FOREACH_SAFE(sigio, sigiolst, sio_pgsigio, tmp)
1294 sigiofree(sigio);
1295 }
1296
1297 /*
1298 * This is common code for FIOSETOWN ioctl called by fcntl(fd, F_SETOWN, arg).
1299 *
1300 * After permission checking, add a sigio structure to the sigio list for
1301 * the process or process group.
1302 */
1303 int
fsetown(pid_t pgid,struct sigio ** sigiop)1304 fsetown(pid_t pgid, struct sigio **sigiop)
1305 {
1306 struct proc *proc;
1307 struct pgrp *pgrp;
1308 struct sigio *osigio, *sigio;
1309 int ret;
1310
1311 if (pgid == 0) {
1312 funsetown(sigiop);
1313 return (0);
1314 }
1315
1316 sigio = malloc(sizeof(struct sigio), M_SIGIO, M_WAITOK);
1317 sigio->sio_pgid = pgid;
1318 sigio->sio_ucred = crhold(curthread->td_ucred);
1319 sigio->sio_myref = sigiop;
1320
1321 ret = 0;
1322 if (pgid > 0) {
1323 ret = pget(pgid, PGET_NOTWEXIT | PGET_NOTID | PGET_HOLD, &proc);
1324 SIGIO_LOCK();
1325 osigio = funsetown_locked(*sigiop);
1326 if (ret == 0) {
1327 PROC_LOCK(proc);
1328 _PRELE(proc);
1329 if ((proc->p_flag & P_WEXIT) != 0) {
1330 ret = ESRCH;
1331 } else if (proc->p_session !=
1332 curthread->td_proc->p_session) {
1333 /*
1334 * Policy - Don't allow a process to FSETOWN a
1335 * process in another session.
1336 *
1337 * Remove this test to allow maximum flexibility
1338 * or restrict FSETOWN to the current process or
1339 * process group for maximum safety.
1340 */
1341 ret = EPERM;
1342 } else {
1343 sigio->sio_proc = proc;
1344 SLIST_INSERT_HEAD(&proc->p_sigiolst, sigio,
1345 sio_pgsigio);
1346 }
1347 PROC_UNLOCK(proc);
1348 }
1349 } else /* if (pgid < 0) */ {
1350 sx_slock(&proctree_lock);
1351 SIGIO_LOCK();
1352 osigio = funsetown_locked(*sigiop);
1353 pgrp = pgfind(-pgid);
1354 if (pgrp == NULL) {
1355 ret = ESRCH;
1356 } else {
1357 if (pgrp->pg_session != curthread->td_proc->p_session) {
1358 /*
1359 * Policy - Don't allow a process to FSETOWN a
1360 * process in another session.
1361 *
1362 * Remove this test to allow maximum flexibility
1363 * or restrict FSETOWN to the current process or
1364 * process group for maximum safety.
1365 */
1366 ret = EPERM;
1367 } else {
1368 sigio->sio_pgrp = pgrp;
1369 SLIST_INSERT_HEAD(&pgrp->pg_sigiolst, sigio,
1370 sio_pgsigio);
1371 }
1372 PGRP_UNLOCK(pgrp);
1373 }
1374 sx_sunlock(&proctree_lock);
1375 }
1376 if (ret == 0)
1377 *sigiop = sigio;
1378 SIGIO_UNLOCK();
1379 if (osigio != NULL)
1380 sigiofree(osigio);
1381 return (ret);
1382 }
1383
1384 /*
1385 * This is common code for FIOGETOWN ioctl called by fcntl(fd, F_GETOWN, arg).
1386 */
1387 pid_t
fgetown(struct sigio ** sigiop)1388 fgetown(struct sigio **sigiop)
1389 {
1390 pid_t pgid;
1391
1392 SIGIO_LOCK();
1393 pgid = (*sigiop != NULL) ? (*sigiop)->sio_pgid : 0;
1394 SIGIO_UNLOCK();
1395 return (pgid);
1396 }
1397
1398 static int
closefp_impl(struct filedesc * fdp,int fd,struct file * fp,struct thread * td,bool audit)1399 closefp_impl(struct filedesc *fdp, int fd, struct file *fp, struct thread *td,
1400 bool audit)
1401 {
1402 int error;
1403
1404 FILEDESC_XLOCK_ASSERT(fdp);
1405
1406 /*
1407 * We now hold the fp reference that used to be owned by the
1408 * descriptor array. We have to unlock the FILEDESC *AFTER*
1409 * knote_fdclose to prevent a race of the fd getting opened, a knote
1410 * added, and deleteing a knote for the new fd.
1411 */
1412 if (__predict_false(!TAILQ_EMPTY(&fdp->fd_kqlist)))
1413 knote_fdclose(td, fd);
1414
1415 if (fp->f_ops->fo_fdclose != NULL)
1416 fp->f_ops->fo_fdclose(fp, fd, td);
1417 FILEDESC_XUNLOCK(fdp);
1418
1419 #ifdef AUDIT
1420 if (AUDITING_TD(td) && audit)
1421 audit_sysclose(td, fd, fp);
1422 #endif
1423 error = closef(fp, td);
1424
1425 /*
1426 * All paths leading up to closefp() will have already removed or
1427 * replaced the fd in the filedesc table, so a restart would not
1428 * operate on the same file.
1429 */
1430 if (error == ERESTART)
1431 error = EINTR;
1432
1433 return (error);
1434 }
1435
1436 static int
closefp_hl(struct filedesc * fdp,int fd,struct file * fp,struct thread * td,bool holdleaders,bool audit)1437 closefp_hl(struct filedesc *fdp, int fd, struct file *fp, struct thread *td,
1438 bool holdleaders, bool audit)
1439 {
1440 int error;
1441
1442 FILEDESC_XLOCK_ASSERT(fdp);
1443
1444 if (holdleaders) {
1445 if (td->td_proc->p_fdtol != NULL) {
1446 /*
1447 * Ask fdfree() to sleep to ensure that all relevant
1448 * process leaders can be traversed in closef().
1449 */
1450 fdp->fd_holdleaderscount++;
1451 } else {
1452 holdleaders = false;
1453 }
1454 }
1455
1456 error = closefp_impl(fdp, fd, fp, td, audit);
1457 if (holdleaders) {
1458 FILEDESC_XLOCK(fdp);
1459 fdp->fd_holdleaderscount--;
1460 if (fdp->fd_holdleaderscount == 0 &&
1461 fdp->fd_holdleaderswakeup != 0) {
1462 fdp->fd_holdleaderswakeup = 0;
1463 wakeup(&fdp->fd_holdleaderscount);
1464 }
1465 FILEDESC_XUNLOCK(fdp);
1466 }
1467 return (error);
1468 }
1469
1470 static int
closefp(struct filedesc * fdp,int fd,struct file * fp,struct thread * td,bool holdleaders,bool audit)1471 closefp(struct filedesc *fdp, int fd, struct file *fp, struct thread *td,
1472 bool holdleaders, bool audit)
1473 {
1474
1475 FILEDESC_XLOCK_ASSERT(fdp);
1476
1477 if (__predict_false(td->td_proc->p_fdtol != NULL)) {
1478 return (closefp_hl(fdp, fd, fp, td, holdleaders, audit));
1479 } else {
1480 return (closefp_impl(fdp, fd, fp, td, audit));
1481 }
1482 }
1483
1484 /*
1485 * Close a file descriptor.
1486 */
1487 #ifndef _SYS_SYSPROTO_H_
1488 struct close_args {
1489 int fd;
1490 };
1491 #endif
1492 /* ARGSUSED */
1493 int
sys_close(struct thread * td,struct close_args * uap)1494 sys_close(struct thread *td, struct close_args *uap)
1495 {
1496
1497 return (kern_close(td, uap->fd));
1498 }
1499
1500 int
kern_close(struct thread * td,int fd)1501 kern_close(struct thread *td, int fd)
1502 {
1503 struct filedesc *fdp;
1504 struct file *fp;
1505
1506 fdp = td->td_proc->p_fd;
1507
1508 FILEDESC_XLOCK(fdp);
1509 if ((fp = fget_noref(fdp, fd)) == NULL) {
1510 FILEDESC_XUNLOCK(fdp);
1511 return (EBADF);
1512 }
1513 fdfree(fdp, fd);
1514
1515 /* closefp() drops the FILEDESC lock for us. */
1516 return (closefp(fdp, fd, fp, td, true, true));
1517 }
1518
1519 static int
close_range_flags(struct thread * td,u_int lowfd,u_int highfd,int flags)1520 close_range_flags(struct thread *td, u_int lowfd, u_int highfd, int flags)
1521 {
1522 struct filedesc *fdp;
1523 struct fdescenttbl *fdt;
1524 struct filedescent *fde;
1525 int fd, fde_flags;
1526
1527 fde_flags = close_range_to_fde_flags(flags);
1528 fdp = td->td_proc->p_fd;
1529 FILEDESC_XLOCK(fdp);
1530 fdt = atomic_load_ptr(&fdp->fd_files);
1531 highfd = MIN(highfd, fdt->fdt_nfiles - 1);
1532 fd = lowfd;
1533 if (__predict_false(fd > highfd)) {
1534 goto out_locked;
1535 }
1536 for (; fd <= highfd; fd++) {
1537 fde = &fdt->fdt_ofiles[fd];
1538 if (fde->fde_file != NULL)
1539 fde->fde_flags |= fde_flags;
1540 }
1541 out_locked:
1542 FILEDESC_XUNLOCK(fdp);
1543 return (0);
1544 }
1545
1546 static int
close_range_impl(struct thread * td,u_int lowfd,u_int highfd)1547 close_range_impl(struct thread *td, u_int lowfd, u_int highfd)
1548 {
1549 struct filedesc *fdp;
1550 const struct fdescenttbl *fdt;
1551 struct file *fp;
1552 int fd;
1553
1554 fdp = td->td_proc->p_fd;
1555 FILEDESC_XLOCK(fdp);
1556 fdt = atomic_load_ptr(&fdp->fd_files);
1557 highfd = MIN(highfd, fdt->fdt_nfiles - 1);
1558 fd = lowfd;
1559 if (__predict_false(fd > highfd)) {
1560 goto out_locked;
1561 }
1562 for (;;) {
1563 fp = fdt->fdt_ofiles[fd].fde_file;
1564 if (fp == NULL) {
1565 if (fd == highfd)
1566 goto out_locked;
1567 } else {
1568 fdfree(fdp, fd);
1569 (void) closefp(fdp, fd, fp, td, true, true);
1570 if (fd == highfd)
1571 goto out_unlocked;
1572 FILEDESC_XLOCK(fdp);
1573 fdt = atomic_load_ptr(&fdp->fd_files);
1574 }
1575 fd++;
1576 }
1577 out_locked:
1578 FILEDESC_XUNLOCK(fdp);
1579 out_unlocked:
1580 return (0);
1581 }
1582
1583 int
kern_close_range(struct thread * td,int flags,u_int lowfd,u_int highfd)1584 kern_close_range(struct thread *td, int flags, u_int lowfd, u_int highfd)
1585 {
1586
1587 /*
1588 * Check this prior to clamping; closefrom(3) with only fd 0, 1, and 2
1589 * open should not be a usage error. From a close_range() perspective,
1590 * close_range(3, ~0U, 0) in the same scenario should also likely not
1591 * be a usage error as all fd above 3 are in-fact already closed.
1592 */
1593 if (highfd < lowfd) {
1594 return (EINVAL);
1595 }
1596
1597 if ((flags & (CLOSE_RANGE_CLOEXEC | CLOSE_RANGE_CLOFORK)) != 0)
1598 return (close_range_flags(td, lowfd, highfd, flags));
1599
1600 return (close_range_impl(td, lowfd, highfd));
1601 }
1602
1603 #ifndef _SYS_SYSPROTO_H_
1604 struct close_range_args {
1605 u_int lowfd;
1606 u_int highfd;
1607 int flags;
1608 };
1609 #endif
1610 int
sys_close_range(struct thread * td,struct close_range_args * uap)1611 sys_close_range(struct thread *td, struct close_range_args *uap)
1612 {
1613
1614 AUDIT_ARG_FD(uap->lowfd);
1615 AUDIT_ARG_CMD(uap->highfd);
1616 AUDIT_ARG_FFLAGS(uap->flags);
1617
1618 if ((uap->flags & ~(CLOSE_RANGE_CLOEXEC | CLOSE_RANGE_CLOFORK)) != 0)
1619 return (EINVAL);
1620 return (kern_close_range(td, uap->flags, uap->lowfd, uap->highfd));
1621 }
1622
1623 #ifdef COMPAT_FREEBSD12
1624 /*
1625 * Close open file descriptors.
1626 */
1627 #ifndef _SYS_SYSPROTO_H_
1628 struct freebsd12_closefrom_args {
1629 int lowfd;
1630 };
1631 #endif
1632 /* ARGSUSED */
1633 int
freebsd12_closefrom(struct thread * td,struct freebsd12_closefrom_args * uap)1634 freebsd12_closefrom(struct thread *td, struct freebsd12_closefrom_args *uap)
1635 {
1636 u_int lowfd;
1637
1638 AUDIT_ARG_FD(uap->lowfd);
1639
1640 /*
1641 * Treat negative starting file descriptor values identical to
1642 * closefrom(0) which closes all files.
1643 */
1644 lowfd = MAX(0, uap->lowfd);
1645 return (kern_close_range(td, 0, lowfd, ~0U));
1646 }
1647 #endif /* COMPAT_FREEBSD12 */
1648
1649 #if defined(COMPAT_43)
1650 /*
1651 * Return status information about a file descriptor.
1652 */
1653 #ifndef _SYS_SYSPROTO_H_
1654 struct ofstat_args {
1655 int fd;
1656 struct ostat *sb;
1657 };
1658 #endif
1659 /* ARGSUSED */
1660 int
ofstat(struct thread * td,struct ofstat_args * uap)1661 ofstat(struct thread *td, struct ofstat_args *uap)
1662 {
1663 struct ostat oub;
1664 struct stat ub;
1665 int error;
1666
1667 error = kern_fstat(td, uap->fd, &ub);
1668 if (error == 0) {
1669 cvtstat(&ub, &oub);
1670 error = copyout(&oub, uap->sb, sizeof(oub));
1671 }
1672 return (error);
1673 }
1674 #endif /* COMPAT_43 */
1675
1676 #if defined(COMPAT_FREEBSD11)
1677 int
freebsd11_fstat(struct thread * td,struct freebsd11_fstat_args * uap)1678 freebsd11_fstat(struct thread *td, struct freebsd11_fstat_args *uap)
1679 {
1680 struct stat sb;
1681 struct freebsd11_stat osb;
1682 int error;
1683
1684 error = kern_fstat(td, uap->fd, &sb);
1685 if (error != 0)
1686 return (error);
1687 error = freebsd11_cvtstat(&sb, &osb);
1688 if (error == 0)
1689 error = copyout(&osb, uap->sb, sizeof(osb));
1690 return (error);
1691 }
1692 #endif /* COMPAT_FREEBSD11 */
1693
1694 /*
1695 * Return status information about a file descriptor.
1696 */
1697 #ifndef _SYS_SYSPROTO_H_
1698 struct fstat_args {
1699 int fd;
1700 struct stat *sb;
1701 };
1702 #endif
1703 /* ARGSUSED */
1704 int
sys_fstat(struct thread * td,struct fstat_args * uap)1705 sys_fstat(struct thread *td, struct fstat_args *uap)
1706 {
1707 struct stat ub;
1708 int error;
1709
1710 error = kern_fstat(td, uap->fd, &ub);
1711 if (error == 0)
1712 error = copyout(&ub, uap->sb, sizeof(ub));
1713 return (error);
1714 }
1715
1716 int
kern_fstat(struct thread * td,int fd,struct stat * sbp)1717 kern_fstat(struct thread *td, int fd, struct stat *sbp)
1718 {
1719 struct file *fp;
1720 int error;
1721
1722 AUDIT_ARG_FD(fd);
1723
1724 error = fget(td, fd, &cap_fstat_rights, &fp);
1725 if (__predict_false(error != 0))
1726 return (error);
1727
1728 AUDIT_ARG_FILE(td->td_proc, fp);
1729
1730 sbp->st_filerev = 0;
1731 sbp->st_bsdflags = 0;
1732 error = fo_stat(fp, sbp, td->td_ucred);
1733 fdrop(fp, td);
1734 #ifdef __STAT_TIME_T_EXT
1735 sbp->st_atim_ext = 0;
1736 sbp->st_mtim_ext = 0;
1737 sbp->st_ctim_ext = 0;
1738 sbp->st_btim_ext = 0;
1739 #endif
1740 #ifdef KTRACE
1741 if (KTRPOINT(td, KTR_STRUCT))
1742 ktrstat_error(sbp, error);
1743 #endif
1744 return (error);
1745 }
1746
1747 #if defined(COMPAT_FREEBSD11)
1748 /*
1749 * Return status information about a file descriptor.
1750 */
1751 #ifndef _SYS_SYSPROTO_H_
1752 struct freebsd11_nfstat_args {
1753 int fd;
1754 struct nstat *sb;
1755 };
1756 #endif
1757 /* ARGSUSED */
1758 int
freebsd11_nfstat(struct thread * td,struct freebsd11_nfstat_args * uap)1759 freebsd11_nfstat(struct thread *td, struct freebsd11_nfstat_args *uap)
1760 {
1761 struct nstat nub;
1762 struct stat ub;
1763 int error;
1764
1765 error = kern_fstat(td, uap->fd, &ub);
1766 if (error != 0)
1767 return (error);
1768 error = freebsd11_cvtnstat(&ub, &nub);
1769 if (error != 0)
1770 error = copyout(&nub, uap->sb, sizeof(nub));
1771 return (error);
1772 }
1773 #endif /* COMPAT_FREEBSD11 */
1774
1775 /*
1776 * Return pathconf information about a file descriptor.
1777 */
1778 #ifndef _SYS_SYSPROTO_H_
1779 struct fpathconf_args {
1780 int fd;
1781 int name;
1782 };
1783 #endif
1784 /* ARGSUSED */
1785 int
sys_fpathconf(struct thread * td,struct fpathconf_args * uap)1786 sys_fpathconf(struct thread *td, struct fpathconf_args *uap)
1787 {
1788 long value;
1789 int error;
1790
1791 error = kern_fpathconf(td, uap->fd, uap->name, &value);
1792 if (error == 0)
1793 td->td_retval[0] = value;
1794 return (error);
1795 }
1796
1797 int
kern_fpathconf(struct thread * td,int fd,int name,long * valuep)1798 kern_fpathconf(struct thread *td, int fd, int name, long *valuep)
1799 {
1800 struct file *fp;
1801 struct vnode *vp;
1802 int error;
1803
1804 error = fget(td, fd, &cap_fpathconf_rights, &fp);
1805 if (error != 0)
1806 return (error);
1807
1808 if (name == _PC_ASYNC_IO) {
1809 *valuep = _POSIX_ASYNCHRONOUS_IO;
1810 goto out;
1811 }
1812 vp = fp->f_vnode;
1813 if (vp != NULL) {
1814 vn_lock(vp, LK_SHARED | LK_RETRY);
1815 error = VOP_PATHCONF(vp, name, valuep);
1816 VOP_UNLOCK(vp);
1817 } else if (fp->f_type == DTYPE_PIPE || fp->f_type == DTYPE_SOCKET) {
1818 if (name != _PC_PIPE_BUF) {
1819 error = EINVAL;
1820 } else {
1821 *valuep = PIPE_BUF;
1822 error = 0;
1823 }
1824 } else {
1825 error = EOPNOTSUPP;
1826 }
1827 out:
1828 fdrop(fp, td);
1829 return (error);
1830 }
1831
1832 /*
1833 * Copy filecaps structure allocating memory for ioctls array if needed.
1834 *
1835 * The last parameter indicates whether the fdtable is locked. If it is not and
1836 * ioctls are encountered, copying fails and the caller must lock the table.
1837 *
1838 * Note that if the table was not locked, the caller has to check the relevant
1839 * sequence counter to determine whether the operation was successful.
1840 */
1841 bool
filecaps_copy(const struct filecaps * src,struct filecaps * dst,bool locked)1842 filecaps_copy(const struct filecaps *src, struct filecaps *dst, bool locked)
1843 {
1844 size_t size;
1845
1846 if (src->fc_ioctls != NULL && !locked)
1847 return (false);
1848 memcpy(dst, src, sizeof(*src));
1849 if (src->fc_ioctls == NULL)
1850 return (true);
1851
1852 KASSERT(src->fc_nioctls > 0,
1853 ("fc_ioctls != NULL, but fc_nioctls=%hd", src->fc_nioctls));
1854
1855 size = sizeof(src->fc_ioctls[0]) * src->fc_nioctls;
1856 dst->fc_ioctls = malloc(size, M_FILECAPS, M_WAITOK);
1857 memcpy(dst->fc_ioctls, src->fc_ioctls, size);
1858 return (true);
1859 }
1860
1861 static u_long *
filecaps_copy_prep(const struct filecaps * src)1862 filecaps_copy_prep(const struct filecaps *src)
1863 {
1864 u_long *ioctls;
1865 size_t size;
1866
1867 if (__predict_true(src->fc_ioctls == NULL))
1868 return (NULL);
1869
1870 KASSERT(src->fc_nioctls > 0,
1871 ("fc_ioctls != NULL, but fc_nioctls=%hd", src->fc_nioctls));
1872
1873 size = sizeof(src->fc_ioctls[0]) * src->fc_nioctls;
1874 ioctls = malloc(size, M_FILECAPS, M_WAITOK);
1875 return (ioctls);
1876 }
1877
1878 static void
filecaps_copy_finish(const struct filecaps * src,struct filecaps * dst,u_long * ioctls)1879 filecaps_copy_finish(const struct filecaps *src, struct filecaps *dst,
1880 u_long *ioctls)
1881 {
1882 size_t size;
1883
1884 *dst = *src;
1885 if (__predict_true(src->fc_ioctls == NULL)) {
1886 MPASS(ioctls == NULL);
1887 return;
1888 }
1889
1890 size = sizeof(src->fc_ioctls[0]) * src->fc_nioctls;
1891 dst->fc_ioctls = ioctls;
1892 bcopy(src->fc_ioctls, dst->fc_ioctls, size);
1893 }
1894
1895 /*
1896 * Move filecaps structure to the new place and clear the old place.
1897 */
1898 void
filecaps_move(struct filecaps * src,struct filecaps * dst)1899 filecaps_move(struct filecaps *src, struct filecaps *dst)
1900 {
1901
1902 *dst = *src;
1903 bzero(src, sizeof(*src));
1904 }
1905
1906 /*
1907 * Fill the given filecaps structure with full rights.
1908 */
1909 void
filecaps_fill(struct filecaps * fcaps)1910 filecaps_fill(struct filecaps *fcaps)
1911 {
1912
1913 CAP_ALL(&fcaps->fc_rights);
1914 fcaps->fc_ioctls = NULL;
1915 fcaps->fc_nioctls = -1;
1916 fcaps->fc_fcntls = CAP_FCNTL_ALL;
1917 }
1918
1919 /*
1920 * Free memory allocated within filecaps structure.
1921 */
1922 static void
filecaps_free_ioctl(struct filecaps * fcaps)1923 filecaps_free_ioctl(struct filecaps *fcaps)
1924 {
1925
1926 free(fcaps->fc_ioctls, M_FILECAPS);
1927 fcaps->fc_ioctls = NULL;
1928 }
1929
1930 void
filecaps_free(struct filecaps * fcaps)1931 filecaps_free(struct filecaps *fcaps)
1932 {
1933
1934 filecaps_free_ioctl(fcaps);
1935 bzero(fcaps, sizeof(*fcaps));
1936 }
1937
1938 bool
filecaps_full(const struct filecaps * fcaps)1939 filecaps_full(const struct filecaps *fcaps)
1940 {
1941 cap_rights_t allrights;
1942
1943 CAP_ALL(&allrights);
1944 return (cap_rights_contains(&fcaps->fc_rights, &allrights) &&
1945 fcaps->fc_fcntls == CAP_FCNTL_ALL && fcaps->fc_nioctls == -1);
1946 }
1947
1948 /*
1949 * Find the intersection of two filecaps structures and store the result in the
1950 * first structure. This is a destructive operation on the src structure.
1951 */
1952 void
filecaps_intersect(struct filecaps * src,struct filecaps * dst)1953 filecaps_intersect(struct filecaps *src, struct filecaps *dst)
1954 {
1955
1956 cap_rights_intersect(&dst->fc_rights, &src->fc_rights);
1957 dst->fc_fcntls &= src->fc_fcntls;
1958 if (dst->fc_nioctls == -1) {
1959 dst->fc_ioctls = src->fc_ioctls;
1960 dst->fc_nioctls = src->fc_nioctls;
1961 src->fc_ioctls = NULL;
1962 } else if (src->fc_nioctls != -1) {
1963 int count;
1964
1965 /*
1966 * ioctl lists are usually short, so this dumb merge is fine.
1967 * We could alternately sort both lists and walk them in
1968 * parallel.
1969 */
1970 count = 0;
1971 for (int i = 0; i < dst->fc_nioctls; i++) {
1972 bool found;
1973
1974 found = false;
1975 for (int j = 0; j < src->fc_nioctls; j++) {
1976 if (dst->fc_ioctls[i] == src->fc_ioctls[j]) {
1977 count++;
1978 found = true;
1979 break;
1980 }
1981 }
1982 if (!found) {
1983 if (i != dst->fc_nioctls - 1)
1984 dst->fc_ioctls[i] =
1985 dst->fc_ioctls[dst->fc_nioctls - 1];
1986 dst->fc_nioctls--;
1987 i--;
1988 }
1989 }
1990 dst->fc_nioctls = count;
1991 }
1992 if (dst->fc_nioctls == 0)
1993 filecaps_free_ioctl(dst);
1994 filecaps_free(src);
1995 }
1996
1997 static u_long *
filecaps_free_prep(struct filecaps * fcaps)1998 filecaps_free_prep(struct filecaps *fcaps)
1999 {
2000 u_long *ioctls;
2001
2002 ioctls = fcaps->fc_ioctls;
2003 bzero(fcaps, sizeof(*fcaps));
2004 return (ioctls);
2005 }
2006
2007 static void
filecaps_free_finish(u_long * ioctls)2008 filecaps_free_finish(u_long *ioctls)
2009 {
2010
2011 free(ioctls, M_FILECAPS);
2012 }
2013
2014 /*
2015 * Validate the given filecaps structure.
2016 */
2017 static void
filecaps_validate(const struct filecaps * fcaps,const char * func)2018 filecaps_validate(const struct filecaps *fcaps, const char *func)
2019 {
2020
2021 KASSERT(cap_rights_is_valid(&fcaps->fc_rights),
2022 ("%s: invalid rights", func));
2023 KASSERT((fcaps->fc_fcntls & ~CAP_FCNTL_ALL) == 0,
2024 ("%s: invalid fcntls", func));
2025 KASSERT(fcaps->fc_fcntls == 0 ||
2026 cap_rights_is_set(&fcaps->fc_rights, CAP_FCNTL),
2027 ("%s: fcntls without CAP_FCNTL", func));
2028 /*
2029 * open calls without WANTIOCTLCAPS free caps but leave the counter
2030 */
2031 #if 0
2032 KASSERT(fcaps->fc_ioctls != NULL ? fcaps->fc_nioctls > 0 :
2033 (fcaps->fc_nioctls == -1 || fcaps->fc_nioctls == 0),
2034 ("%s: invalid ioctls", func));
2035 #endif
2036 KASSERT(fcaps->fc_nioctls == 0 ||
2037 cap_rights_is_set(&fcaps->fc_rights, CAP_IOCTL),
2038 ("%s: ioctls without CAP_IOCTL", func));
2039 }
2040
2041 static void
fdgrowtable_exp(struct filedesc * fdp,int nfd)2042 fdgrowtable_exp(struct filedesc *fdp, int nfd)
2043 {
2044 int nfd1;
2045
2046 FILEDESC_XLOCK_ASSERT(fdp);
2047
2048 nfd1 = fdp->fd_nfiles * 2;
2049 if (nfd1 < nfd)
2050 nfd1 = nfd;
2051 fdgrowtable(fdp, nfd1);
2052 }
2053
2054 /*
2055 * Grow the file table to accommodate (at least) nfd descriptors.
2056 */
2057 static void
fdgrowtable(struct filedesc * fdp,int nfd)2058 fdgrowtable(struct filedesc *fdp, int nfd)
2059 {
2060 struct filedesc0 *fdp0;
2061 struct freetable *ft;
2062 struct fdescenttbl *ntable;
2063 struct fdescenttbl *otable;
2064 int nnfiles, onfiles;
2065 NDSLOTTYPE *nmap, *omap;
2066
2067 KASSERT(fdp->fd_nfiles > 0, ("zero-length file table"));
2068 KASSERT(fdp->fd_nfiles >= NDFILE, ("file table of length %d shorter "
2069 "than NDFILE (%d)", fdp->fd_nfiles, NDFILE));
2070 KASSERT(fdp->fd_nfiles == NDFILE || fdp->fd_nfiles % NDENTRIES == 0,
2071 ("file table of length %d should be multiple of NDENTRIES (%zu)",
2072 fdp->fd_nfiles, NDENTRIES));
2073 KASSERT((fdp->fd_nfiles == NDFILE) == ((intptr_t)fdp->fd_files -
2074 offsetof(struct filedesc0, fd_dfiles) == (intptr_t)fdp -
2075 offsetof(struct filedesc0, fd_fd)), ("file table of length %d "
2076 "should have %s table", fdp->fd_nfiles, fdp->fd_nfiles == NDFILE ?
2077 "initial" : "dynamic"));
2078 KASSERT((NDSLOTS(fdp->fd_nfiles) <= NDSLOTS(NDFILE)) == ((intptr_t)
2079 fdp->fd_map - offsetof(struct filedesc0, fd_dmap) == (intptr_t)fdp -
2080 offsetof(struct filedesc0, fd_fd)), ("file table of length %d "
2081 "should have %s map", fdp->fd_nfiles, NDSLOTS(fdp->fd_nfiles) <=
2082 NDSLOTS(NDFILE) ? "initial" : "dynamic"));
2083
2084 /* save old values */
2085 onfiles = fdp->fd_nfiles;
2086 otable = fdp->fd_files;
2087 omap = fdp->fd_map;
2088
2089 /* compute the size of the new table */
2090 nnfiles = NDSLOTS(nfd) * NDENTRIES; /* round up */
2091 if (nnfiles <= onfiles)
2092 /* the table is already large enough */
2093 return;
2094
2095 /*
2096 * Allocate a new table. We need enough space for the number of
2097 * entries, file entries themselves and the struct freetable we will use
2098 * when we decommission the table and place it on the freelist.
2099 * We place the struct freetable in the middle so we don't have
2100 * to worry about padding.
2101 */
2102 ntable = malloc(offsetof(struct fdescenttbl, fdt_ofiles) +
2103 nnfiles * sizeof(ntable->fdt_ofiles[0]) +
2104 sizeof(struct freetable),
2105 M_FILEDESC, M_ZERO | M_WAITOK);
2106 /* copy the old data */
2107 ntable->fdt_nfiles = nnfiles;
2108 memcpy(ntable->fdt_ofiles, otable->fdt_ofiles,
2109 onfiles * sizeof(ntable->fdt_ofiles[0]));
2110
2111 /*
2112 * Allocate a new map only if the old one is not large enough.
2113 *
2114 * The initial struct filedesc0 object contains a table and map sized
2115 * for NDFILE (20) entries which means the initial map can accomodate
2116 * up to NDENTRIES (32 or 64) before requiring reallocation.
2117 *
2118 * As the new table size (nnfiles) is always rounded up to a multiple
2119 * of NDENTRIES, the map will be fully utilised following the first
2120 * enlargement, whether it is still the initial map (which will be the
2121 * case if nnfiles == NDENTRIES) or if a new one that has has been
2122 * allocated (which will be the case if nnfiles == X*NDENTRIES for some
2123 * X > 1). In either case, subsequent enlargements will always allocate
2124 * a new map to go along with the new table.
2125 */
2126 if (NDSLOTS(nnfiles) > NDSLOTS(onfiles)) {
2127 nmap = malloc(NDSLOTS(nnfiles) * NDSLOTSIZE, M_FILEDESC,
2128 M_ZERO | M_WAITOK);
2129 /* copy over the old data and update the pointer */
2130 memcpy(nmap, omap, NDSLOTS(onfiles) * sizeof(*omap));
2131 fdp->fd_map = nmap;
2132 } else {
2133 nmap = NULL;
2134 }
2135
2136 /*
2137 * Make sure that ntable is correctly initialized before we replace
2138 * fd_files poiner. Otherwise fget_unlocked() may see inconsistent
2139 * data.
2140 */
2141 atomic_store_rel_ptr((volatile void *)&fdp->fd_files, (uintptr_t)ntable);
2142
2143 /*
2144 * Free the old file table when not shared by other threads or processes.
2145 * The old file table is considered to be shared when either are true:
2146 * - The process has more than one thread.
2147 * - The file descriptor table has been shared via fdshare().
2148 *
2149 * When shared, the old file table will be placed on a freelist
2150 * which will be processed when the struct filedesc is released.
2151 *
2152 * Note that if onfiles == NDFILE, we're dealing with the original
2153 * static allocation contained within (struct filedesc0 *)fdp,
2154 * which must not be freed.
2155 */
2156 if (onfiles > NDFILE) {
2157 /*
2158 * Note we may be called here from fdinit while allocating a
2159 * table for a new process in which case ->p_fd points
2160 * elsewhere.
2161 */
2162 if (curproc->p_fd != fdp || FILEDESC_IS_ONLY_USER(fdp)) {
2163 free(otable, M_FILEDESC);
2164 } else {
2165 ft = (struct freetable *)&otable->fdt_ofiles[onfiles];
2166 fdp0 = (struct filedesc0 *)fdp;
2167 ft->ft_table = otable;
2168 SLIST_INSERT_HEAD(&fdp0->fd_free, ft, ft_next);
2169 }
2170 }
2171 /*
2172 * The map does not have the same possibility of threads still
2173 * holding references to it. So always free it as long as it
2174 * does not reference the original static allocation and a new
2175 * map was allocated.
2176 */
2177 if (nmap != NULL && NDSLOTS(onfiles) > NDSLOTS(NDFILE))
2178 free(omap, M_FILEDESC);
2179 }
2180
2181 /*
2182 * Allocate a file descriptor for the process.
2183 */
2184 int
fdalloc(struct thread * td,int minfd,int * result)2185 fdalloc(struct thread *td, int minfd, int *result)
2186 {
2187 struct proc *p = td->td_proc;
2188 struct filedesc *fdp = p->p_fd;
2189 int fd, maxfd, allocfd;
2190 #ifdef RACCT
2191 int error;
2192 #endif
2193
2194 FILEDESC_XLOCK_ASSERT(fdp);
2195
2196 if (fdp->fd_freefile > minfd)
2197 minfd = fdp->fd_freefile;
2198
2199 maxfd = getmaxfd(td);
2200
2201 /*
2202 * Search the bitmap for a free descriptor starting at minfd.
2203 * If none is found, grow the file table.
2204 */
2205 fd = fd_first_free(fdp, minfd, fdp->fd_nfiles);
2206 if (__predict_false(fd >= maxfd))
2207 return (EMFILE);
2208 if (__predict_false(fd >= fdp->fd_nfiles)) {
2209 allocfd = min(fd * 2, maxfd);
2210 #ifdef RACCT
2211 if (RACCT_ENABLED()) {
2212 error = racct_set_unlocked(p, RACCT_NOFILE, allocfd);
2213 if (error != 0)
2214 return (EMFILE);
2215 }
2216 #endif
2217 /*
2218 * fd is already equal to first free descriptor >= minfd, so
2219 * we only need to grow the table and we are done.
2220 */
2221 fdgrowtable_exp(fdp, allocfd);
2222 }
2223
2224 /*
2225 * Perform some sanity checks, then mark the file descriptor as
2226 * used and return it to the caller.
2227 */
2228 KASSERT(fd >= 0 && fd < min(maxfd, fdp->fd_nfiles),
2229 ("invalid descriptor %d", fd));
2230 KASSERT(!fdisused(fdp, fd),
2231 ("fd_first_free() returned non-free descriptor"));
2232 KASSERT(fdp->fd_ofiles[fd].fde_file == NULL,
2233 ("file descriptor isn't free"));
2234 fdused(fdp, fd);
2235 *result = fd;
2236 return (0);
2237 }
2238
2239 /*
2240 * Allocate n file descriptors for the process.
2241 */
2242 int
fdallocn(struct thread * td,int minfd,int * fds,int n)2243 fdallocn(struct thread *td, int minfd, int *fds, int n)
2244 {
2245 struct proc *p = td->td_proc;
2246 struct filedesc *fdp = p->p_fd;
2247 int i;
2248
2249 FILEDESC_XLOCK_ASSERT(fdp);
2250
2251 for (i = 0; i < n; i++)
2252 if (fdalloc(td, 0, &fds[i]) != 0)
2253 break;
2254
2255 if (i < n) {
2256 for (i--; i >= 0; i--)
2257 fdunused(fdp, fds[i]);
2258 return (EMFILE);
2259 }
2260
2261 return (0);
2262 }
2263
2264 /*
2265 * Create a new open file structure and allocate a file descriptor for the
2266 * process that refers to it. We add one reference to the file for the
2267 * descriptor table and one reference for resultfp. This is to prevent us
2268 * being preempted and the entry in the descriptor table closed after we
2269 * release the FILEDESC lock.
2270 */
2271 int
falloc_caps(struct thread * td,struct file ** resultfp,int * resultfd,int flags,struct filecaps * fcaps)2272 falloc_caps(struct thread *td, struct file **resultfp, int *resultfd, int flags,
2273 struct filecaps *fcaps)
2274 {
2275 struct file *fp;
2276 int error, fd;
2277
2278 MPASS(resultfp != NULL);
2279 MPASS(resultfd != NULL);
2280
2281 error = _falloc_noinstall(td, &fp, 2);
2282 if (__predict_false(error != 0)) {
2283 return (error);
2284 }
2285
2286 error = finstall_refed(td, fp, &fd, flags, fcaps);
2287 if (__predict_false(error != 0)) {
2288 falloc_abort(td, fp);
2289 return (error);
2290 }
2291
2292 *resultfp = fp;
2293 *resultfd = fd;
2294
2295 return (0);
2296 }
2297
2298 /*
2299 * Create a new open file structure without allocating a file descriptor.
2300 */
2301 int
_falloc_noinstall(struct thread * td,struct file ** resultfp,u_int n)2302 _falloc_noinstall(struct thread *td, struct file **resultfp, u_int n)
2303 {
2304 struct file *fp;
2305 int maxuserfiles = maxfiles - (maxfiles / 20);
2306 int openfiles_new;
2307 static struct timeval lastfail;
2308 static int curfail;
2309
2310 KASSERT(resultfp != NULL, ("%s: resultfp == NULL", __func__));
2311 MPASS(n > 0);
2312
2313 openfiles_new = atomic_fetchadd_int(&openfiles, 1) + 1;
2314 if ((openfiles_new >= maxuserfiles &&
2315 priv_check(td, PRIV_MAXFILES) != 0) ||
2316 openfiles_new >= maxfiles) {
2317 atomic_subtract_int(&openfiles, 1);
2318 if (ppsratecheck(&lastfail, &curfail, 1)) {
2319 printf("kern.maxfiles limit exceeded by uid %i, (%s) "
2320 "please see tuning(7).\n", td->td_ucred->cr_ruid, td->td_proc->p_comm);
2321 }
2322 return (ENFILE);
2323 }
2324 fp = uma_zalloc(file_zone, M_WAITOK);
2325 bzero(fp, sizeof(*fp));
2326 refcount_init(&fp->f_count, n);
2327 fp->f_cred = crhold(td->td_ucred);
2328 fp->f_ops = &badfileops;
2329 *resultfp = fp;
2330 return (0);
2331 }
2332
2333 void
falloc_abort(struct thread * td,struct file * fp)2334 falloc_abort(struct thread *td, struct file *fp)
2335 {
2336
2337 /*
2338 * For assertion purposes.
2339 */
2340 refcount_init(&fp->f_count, 0);
2341 _fdrop(fp, td);
2342 }
2343
2344 /*
2345 * Install a file in a file descriptor table.
2346 */
2347 void
_finstall(struct filedesc * fdp,struct file * fp,int fd,int flags,struct filecaps * fcaps)2348 _finstall(struct filedesc *fdp, struct file *fp, int fd, int flags,
2349 struct filecaps *fcaps)
2350 {
2351 struct filedescent *fde;
2352
2353 MPASS(fp != NULL);
2354 if (fcaps != NULL)
2355 filecaps_validate(fcaps, __func__);
2356 FILEDESC_XLOCK_ASSERT(fdp);
2357
2358 fde = &fdp->fd_ofiles[fd];
2359 #ifdef CAPABILITIES
2360 seqc_write_begin(&fde->fde_seqc);
2361 #endif
2362 fde->fde_file = fp;
2363 fde->fde_flags = open_to_fde_flags(flags, true);
2364 if (fcaps != NULL)
2365 filecaps_move(fcaps, &fde->fde_caps);
2366 else
2367 filecaps_fill(&fde->fde_caps);
2368 #ifdef CAPABILITIES
2369 seqc_write_end(&fde->fde_seqc);
2370 #endif
2371 }
2372
2373 int
finstall_refed(struct thread * td,struct file * fp,int * fd,int flags,struct filecaps * fcaps)2374 finstall_refed(struct thread *td, struct file *fp, int *fd, int flags,
2375 struct filecaps *fcaps)
2376 {
2377 struct filedesc *fdp = td->td_proc->p_fd;
2378 int error;
2379
2380 MPASS(fd != NULL);
2381
2382 FILEDESC_XLOCK(fdp);
2383 error = fdalloc(td, 0, fd);
2384 if (__predict_true(error == 0)) {
2385 _finstall(fdp, fp, *fd, flags, fcaps);
2386 }
2387 FILEDESC_XUNLOCK(fdp);
2388 return (error);
2389 }
2390
2391 int
finstall(struct thread * td,struct file * fp,int * fd,int flags,struct filecaps * fcaps)2392 finstall(struct thread *td, struct file *fp, int *fd, int flags,
2393 struct filecaps *fcaps)
2394 {
2395 int error;
2396
2397 MPASS(fd != NULL);
2398
2399 if (!fhold(fp))
2400 return (EBADF);
2401 error = finstall_refed(td, fp, fd, flags, fcaps);
2402 if (__predict_false(error != 0)) {
2403 fdrop(fp, td);
2404 }
2405 return (error);
2406 }
2407
2408 /*
2409 * Build a new filedesc structure from another.
2410 *
2411 * If fdp is not NULL, return with it shared locked.
2412 */
2413 struct filedesc *
fdinit(void)2414 fdinit(void)
2415 {
2416 struct filedesc0 *newfdp0;
2417 struct filedesc *newfdp;
2418
2419 newfdp0 = uma_zalloc(filedesc0_zone, M_WAITOK | M_ZERO);
2420 newfdp = &newfdp0->fd_fd;
2421
2422 /* Create the file descriptor table. */
2423 FILEDESC_LOCK_INIT(newfdp);
2424 refcount_init(&newfdp->fd_refcnt, 1);
2425 refcount_init(&newfdp->fd_holdcnt, 1);
2426 newfdp->fd_map = newfdp0->fd_dmap;
2427 newfdp->fd_files = (struct fdescenttbl *)&newfdp0->fd_dfiles;
2428 newfdp->fd_files->fdt_nfiles = NDFILE;
2429
2430 return (newfdp);
2431 }
2432
2433 /*
2434 * Build a pwddesc structure from another.
2435 * Copy the current, root, and jail root vnode references.
2436 *
2437 * If pdp is not NULL and keeplock is true, return with it (exclusively) locked.
2438 */
2439 struct pwddesc *
pdinit(struct pwddesc * pdp,bool keeplock)2440 pdinit(struct pwddesc *pdp, bool keeplock)
2441 {
2442 struct pwddesc *newpdp;
2443 struct pwd *newpwd;
2444
2445 newpdp = malloc(sizeof(*newpdp), M_PWDDESC, M_WAITOK | M_ZERO);
2446
2447 PWDDESC_LOCK_INIT(newpdp);
2448 refcount_init(&newpdp->pd_refcount, 1);
2449 newpdp->pd_cmask = CMASK;
2450
2451 if (pdp == NULL) {
2452 newpwd = pwd_alloc();
2453 smr_serialized_store(&newpdp->pd_pwd, newpwd, true);
2454 return (newpdp);
2455 }
2456
2457 PWDDESC_XLOCK(pdp);
2458 newpwd = pwd_hold_pwddesc(pdp);
2459 smr_serialized_store(&newpdp->pd_pwd, newpwd, true);
2460 if (!keeplock)
2461 PWDDESC_XUNLOCK(pdp);
2462 return (newpdp);
2463 }
2464
2465 /*
2466 * Hold either filedesc or pwddesc of the passed process.
2467 *
2468 * The process lock is used to synchronize against the target exiting and
2469 * freeing the data.
2470 *
2471 * Clearing can be ilustrated in 3 steps:
2472 * 1. set the pointer to NULL. Either routine can race against it, hence
2473 * atomic_load_ptr.
2474 * 2. observe the process lock as not taken. Until then fdhold/pdhold can
2475 * race to either still see the pointer or find NULL. It is still safe to
2476 * grab a reference as clearing is stalled.
2477 * 3. after the lock is observed as not taken, any fdhold/pdhold calls are
2478 * guaranteed to see NULL, making it safe to finish clearing
2479 */
2480 static struct filedesc *
fdhold(struct proc * p)2481 fdhold(struct proc *p)
2482 {
2483 struct filedesc *fdp;
2484
2485 PROC_LOCK_ASSERT(p, MA_OWNED);
2486 fdp = atomic_load_ptr(&p->p_fd);
2487 if (fdp != NULL)
2488 refcount_acquire(&fdp->fd_holdcnt);
2489 return (fdp);
2490 }
2491
2492 static struct pwddesc *
pdhold(struct proc * p)2493 pdhold(struct proc *p)
2494 {
2495 struct pwddesc *pdp;
2496
2497 PROC_LOCK_ASSERT(p, MA_OWNED);
2498 pdp = atomic_load_ptr(&p->p_pd);
2499 if (pdp != NULL)
2500 refcount_acquire(&pdp->pd_refcount);
2501 return (pdp);
2502 }
2503
2504 static void
fddrop(struct filedesc * fdp)2505 fddrop(struct filedesc *fdp)
2506 {
2507
2508 if (refcount_load(&fdp->fd_holdcnt) > 1) {
2509 if (refcount_release(&fdp->fd_holdcnt) == 0)
2510 return;
2511 }
2512
2513 FILEDESC_LOCK_DESTROY(fdp);
2514 uma_zfree(filedesc0_zone, fdp);
2515 }
2516
2517 static void
pddrop(struct pwddesc * pdp)2518 pddrop(struct pwddesc *pdp)
2519 {
2520 struct pwd *pwd;
2521
2522 if (refcount_release_if_not_last(&pdp->pd_refcount))
2523 return;
2524
2525 PWDDESC_XLOCK(pdp);
2526 if (refcount_release(&pdp->pd_refcount) == 0) {
2527 PWDDESC_XUNLOCK(pdp);
2528 return;
2529 }
2530 pwd = PWDDESC_XLOCKED_LOAD_PWD(pdp);
2531 pwd_set(pdp, NULL);
2532 PWDDESC_XUNLOCK(pdp);
2533 pwd_drop(pwd);
2534
2535 PWDDESC_LOCK_DESTROY(pdp);
2536 free(pdp, M_PWDDESC);
2537 }
2538
2539 /*
2540 * Share a filedesc structure.
2541 */
2542 struct filedesc *
fdshare(struct filedesc * fdp)2543 fdshare(struct filedesc *fdp)
2544 {
2545
2546 refcount_acquire(&fdp->fd_refcnt);
2547 return (fdp);
2548 }
2549
2550 /*
2551 * Share a pwddesc structure.
2552 */
2553 struct pwddesc *
pdshare(struct pwddesc * pdp)2554 pdshare(struct pwddesc *pdp)
2555 {
2556 refcount_acquire(&pdp->pd_refcount);
2557 return (pdp);
2558 }
2559
2560 /*
2561 * Unshare a filedesc structure, if necessary by making a copy
2562 */
2563 void
fdunshare(struct thread * td)2564 fdunshare(struct thread *td)
2565 {
2566 struct filedesc *tmp;
2567 struct proc *p = td->td_proc;
2568
2569 if (refcount_load(&p->p_fd->fd_refcnt) == 1)
2570 return;
2571
2572 tmp = fdcopy(p->p_fd, p);
2573 fdescfree(td);
2574 p->p_fd = tmp;
2575 }
2576
2577 /*
2578 * Unshare a pwddesc structure.
2579 */
2580 void
pdunshare(struct thread * td)2581 pdunshare(struct thread *td)
2582 {
2583 struct pwddesc *pdp;
2584 struct proc *p;
2585
2586 p = td->td_proc;
2587 /* Not shared. */
2588 if (refcount_load(&p->p_pd->pd_refcount) == 1)
2589 return;
2590
2591 pdp = pdcopy(p->p_pd);
2592 pdescfree(td);
2593 p->p_pd = pdp;
2594 }
2595
2596 /*
2597 * Copy a filedesc structure. A NULL pointer in returns a NULL reference,
2598 * this is to ease callers, not catch errors.
2599 */
2600 struct filedesc *
fdcopy(struct filedesc * fdp,struct proc * p1)2601 fdcopy(struct filedesc *fdp, struct proc *p1)
2602 {
2603 struct filedesc *newfdp;
2604 struct filedescent *nfde, *ofde;
2605 struct file *fp;
2606 int i, lastfile;
2607 bool fork_pass;
2608
2609 MPASS(fdp != NULL);
2610
2611 fork_pass = false;
2612 newfdp = fdinit();
2613 FILEDESC_SLOCK(fdp);
2614 for (;;) {
2615 lastfile = fdlastfile(fdp);
2616 if (lastfile < newfdp->fd_nfiles)
2617 break;
2618 FILEDESC_SUNLOCK(fdp);
2619 fdgrowtable(newfdp, lastfile + 1);
2620 FILEDESC_SLOCK(fdp);
2621 }
2622
2623 /*
2624 * Copy all passable descriptors (i.e. not kqueue), and
2625 * prepare to handle copyable but not passable descriptors
2626 * (kqueues).
2627 *
2628 * The pass to handle copying is performed after all passable
2629 * files are installed into the new file descriptor's table,
2630 * since kqueues need all referenced file descriptors already
2631 * valid, including other kqueues. For the same reason the
2632 * copying is done in two passes by itself, first installing
2633 * not fully initialized ('empty') copyable files into the new
2634 * fd table, and then giving the subsystems a second chance to
2635 * really fill the copied file backing structure with the
2636 * content.
2637 */
2638 newfdp->fd_freefile = fdp->fd_freefile;
2639 FILEDESC_FOREACH_FDE(fdp, i, ofde) {
2640 const struct fileops *ops;
2641
2642 ops = ofde->fde_file->f_ops;
2643 fp = NULL;
2644 if ((ops->fo_flags & DFLAG_FORK) != 0 &&
2645 (ofde->fde_flags & UF_FOCLOSE) == 0) {
2646 if (ops->fo_fork(newfdp, ofde->fde_file, &fp, p1,
2647 curthread) != 0)
2648 continue;
2649 fork_pass = true;
2650 } else if ((ops->fo_flags & DFLAG_PASSABLE) == 0 ||
2651 (ofde->fde_flags & UF_FOCLOSE) != 0 ||
2652 !fhold(ofde->fde_file)) {
2653 if (newfdp->fd_freefile == fdp->fd_freefile)
2654 newfdp->fd_freefile = i;
2655 continue;
2656 }
2657 nfde = &newfdp->fd_ofiles[i];
2658 *nfde = *ofde;
2659 if (fp != NULL)
2660 nfde->fde_file = fp;
2661 filecaps_copy(&ofde->fde_caps, &nfde->fde_caps, true);
2662 fdused_init(newfdp, i);
2663 }
2664 MPASS(newfdp->fd_freefile != -1);
2665 FILEDESC_SUNLOCK(fdp);
2666
2667 /*
2668 * Now handle copying kqueues, since all fds, including
2669 * kqueues, are in place.
2670 */
2671 if (__predict_false(fork_pass)) {
2672 FILEDESC_FOREACH_FDE(newfdp, i, nfde) {
2673 const struct fileops *ops;
2674
2675 ops = nfde->fde_file->f_ops;
2676 if ((ops->fo_flags & DFLAG_FORK) == 0 ||
2677 nfde->fde_file == NULL)
2678 continue;
2679 ops->fo_fork(newfdp, NULL, &nfde->fde_file, p1,
2680 curthread);
2681 }
2682 }
2683 return (newfdp);
2684 }
2685
2686 /*
2687 * Copy a pwddesc structure.
2688 */
2689 struct pwddesc *
pdcopy(struct pwddesc * pdp)2690 pdcopy(struct pwddesc *pdp)
2691 {
2692 struct pwddesc *newpdp;
2693
2694 MPASS(pdp != NULL);
2695
2696 newpdp = pdinit(pdp, true);
2697 newpdp->pd_cmask = pdp->pd_cmask;
2698 PWDDESC_XUNLOCK(pdp);
2699 return (newpdp);
2700 }
2701
2702 /*
2703 * Clear POSIX style locks. This is only used when fdp looses a reference (i.e.
2704 * one of processes using it exits) and the table used to be shared.
2705 */
2706 static void
fdclearlocks(struct thread * td)2707 fdclearlocks(struct thread *td)
2708 {
2709 struct filedesc *fdp;
2710 struct filedesc_to_leader *fdtol;
2711 struct flock lf;
2712 struct file *fp;
2713 struct proc *p;
2714 struct vnode *vp;
2715 int i;
2716
2717 p = td->td_proc;
2718 fdp = p->p_fd;
2719 fdtol = p->p_fdtol;
2720 MPASS(fdtol != NULL);
2721
2722 FILEDESC_XLOCK(fdp);
2723 KASSERT(fdtol->fdl_refcount > 0,
2724 ("filedesc_to_refcount botch: fdl_refcount=%d",
2725 fdtol->fdl_refcount));
2726 if (fdtol->fdl_refcount == 1 &&
2727 (p->p_leader->p_flag & P_ADVLOCK) != 0) {
2728 FILEDESC_FOREACH_FP(fdp, i, fp) {
2729 if (fp->f_type != DTYPE_VNODE ||
2730 !fhold(fp))
2731 continue;
2732 FILEDESC_XUNLOCK(fdp);
2733 lf.l_whence = SEEK_SET;
2734 lf.l_start = 0;
2735 lf.l_len = 0;
2736 lf.l_type = F_UNLCK;
2737 vp = fp->f_vnode;
2738 (void) VOP_ADVLOCK(vp,
2739 (caddr_t)p->p_leader, F_UNLCK,
2740 &lf, F_POSIX);
2741 FILEDESC_XLOCK(fdp);
2742 fdrop(fp, td);
2743 }
2744 }
2745 retry:
2746 if (fdtol->fdl_refcount == 1) {
2747 if (fdp->fd_holdleaderscount > 0 &&
2748 (p->p_leader->p_flag & P_ADVLOCK) != 0) {
2749 /*
2750 * close() or kern_dup() has cleared a reference
2751 * in a shared file descriptor table.
2752 */
2753 fdp->fd_holdleaderswakeup = 1;
2754 sx_sleep(&fdp->fd_holdleaderscount,
2755 FILEDESC_LOCK(fdp), PLOCK, "fdlhold", 0);
2756 goto retry;
2757 }
2758 if (fdtol->fdl_holdcount > 0) {
2759 /*
2760 * Ensure that fdtol->fdl_leader remains
2761 * valid in closef().
2762 */
2763 fdtol->fdl_wakeup = 1;
2764 sx_sleep(fdtol, FILEDESC_LOCK(fdp), PLOCK,
2765 "fdlhold", 0);
2766 goto retry;
2767 }
2768 }
2769 fdtol->fdl_refcount--;
2770 if (fdtol->fdl_refcount == 0 &&
2771 fdtol->fdl_holdcount == 0) {
2772 fdtol->fdl_next->fdl_prev = fdtol->fdl_prev;
2773 fdtol->fdl_prev->fdl_next = fdtol->fdl_next;
2774 } else
2775 fdtol = NULL;
2776 p->p_fdtol = NULL;
2777 FILEDESC_XUNLOCK(fdp);
2778 if (fdtol != NULL)
2779 free(fdtol, M_FILEDESC_TO_LEADER);
2780 }
2781
2782 /*
2783 * Release a filedesc structure.
2784 */
2785 static void
fdescfree_fds(struct thread * td,struct filedesc * fdp)2786 fdescfree_fds(struct thread *td, struct filedesc *fdp)
2787 {
2788 struct filedesc0 *fdp0;
2789 struct freetable *ft, *tft;
2790 struct filedescent *fde;
2791 struct file *fp;
2792 int i;
2793
2794 KASSERT(refcount_load(&fdp->fd_refcnt) == 0,
2795 ("%s: fd table %p carries references", __func__, fdp));
2796
2797 /*
2798 * Serialize with threads iterating over the table, if any.
2799 */
2800 if (refcount_load(&fdp->fd_holdcnt) > 1) {
2801 FILEDESC_XLOCK(fdp);
2802 FILEDESC_XUNLOCK(fdp);
2803 }
2804
2805 FILEDESC_FOREACH_FDE(fdp, i, fde) {
2806 fp = fde->fde_file;
2807 fdefree_last(fde);
2808 (void) closef(fp, td);
2809 }
2810
2811 if (NDSLOTS(fdp->fd_nfiles) > NDSLOTS(NDFILE))
2812 free(fdp->fd_map, M_FILEDESC);
2813 if (fdp->fd_nfiles > NDFILE)
2814 free(fdp->fd_files, M_FILEDESC);
2815
2816 fdp0 = (struct filedesc0 *)fdp;
2817 SLIST_FOREACH_SAFE(ft, &fdp0->fd_free, ft_next, tft)
2818 free(ft->ft_table, M_FILEDESC);
2819
2820 fddrop(fdp);
2821 }
2822
2823 void
fdescfree(struct thread * td)2824 fdescfree(struct thread *td)
2825 {
2826 struct proc *p;
2827 struct filedesc *fdp;
2828
2829 p = td->td_proc;
2830 fdp = p->p_fd;
2831 MPASS(fdp != NULL);
2832
2833 #ifdef RACCT
2834 if (RACCT_ENABLED())
2835 racct_set_unlocked(p, RACCT_NOFILE, 0);
2836 #endif
2837
2838 if (p->p_fdtol != NULL)
2839 fdclearlocks(td);
2840
2841 /*
2842 * Check fdhold for an explanation.
2843 */
2844 atomic_store_ptr(&p->p_fd, NULL);
2845 atomic_thread_fence_seq_cst();
2846 PROC_WAIT_UNLOCKED(p);
2847
2848 if (refcount_release(&fdp->fd_refcnt) == 0)
2849 return;
2850
2851 fdescfree_fds(td, fdp);
2852 }
2853
2854 void
pdescfree(struct thread * td)2855 pdescfree(struct thread *td)
2856 {
2857 struct proc *p;
2858 struct pwddesc *pdp;
2859
2860 p = td->td_proc;
2861 pdp = p->p_pd;
2862 MPASS(pdp != NULL);
2863
2864 /*
2865 * Check pdhold for an explanation.
2866 */
2867 atomic_store_ptr(&p->p_pd, NULL);
2868 atomic_thread_fence_seq_cst();
2869 PROC_WAIT_UNLOCKED(p);
2870
2871 pddrop(pdp);
2872 }
2873
2874 /*
2875 * For setugid programs, we don't want to people to use that setugidness
2876 * to generate error messages which write to a file which otherwise would
2877 * otherwise be off-limits to the process. We check for filesystems where
2878 * the vnode can change out from under us after execve (like [lin]procfs).
2879 *
2880 * Since fdsetugidsafety calls this only for fd 0, 1 and 2, this check is
2881 * sufficient. We also don't check for setugidness since we know we are.
2882 */
2883 static bool
is_unsafe(struct file * fp)2884 is_unsafe(struct file *fp)
2885 {
2886 struct vnode *vp;
2887
2888 if (fp->f_type != DTYPE_VNODE)
2889 return (false);
2890
2891 vp = fp->f_vnode;
2892 return ((vp->v_vflag & VV_PROCDEP) != 0);
2893 }
2894
2895 /*
2896 * Make this setguid thing safe, if at all possible.
2897 */
2898 void
fdsetugidsafety(struct thread * td)2899 fdsetugidsafety(struct thread *td)
2900 {
2901 struct filedesc *fdp;
2902 struct file *fp;
2903 int i;
2904
2905 fdp = td->td_proc->p_fd;
2906 KASSERT(refcount_load(&fdp->fd_refcnt) == 1,
2907 ("the fdtable should not be shared"));
2908 MPASS(fdp->fd_nfiles >= 3);
2909 for (i = 0; i <= 2; i++) {
2910 fp = fdp->fd_ofiles[i].fde_file;
2911 if (fp != NULL && is_unsafe(fp)) {
2912 FILEDESC_XLOCK(fdp);
2913 knote_fdclose(td, i);
2914 /*
2915 * NULL-out descriptor prior to close to avoid
2916 * a race while close blocks.
2917 */
2918 fdfree(fdp, i);
2919 FILEDESC_XUNLOCK(fdp);
2920 (void) closef(fp, td);
2921 }
2922 }
2923 }
2924
2925 /*
2926 * If a specific file object occupies a specific file descriptor, close the
2927 * file descriptor entry and drop a reference on the file object. This is a
2928 * convenience function to handle a subsequent error in a function that calls
2929 * falloc() that handles the race that another thread might have closed the
2930 * file descriptor out from under the thread creating the file object.
2931 */
2932 void
fdclose(struct thread * td,struct file * fp,int idx)2933 fdclose(struct thread *td, struct file *fp, int idx)
2934 {
2935 struct filedesc *fdp = td->td_proc->p_fd;
2936
2937 FILEDESC_XLOCK(fdp);
2938 if (fdp->fd_ofiles[idx].fde_file == fp) {
2939 fdfree(fdp, idx);
2940 FILEDESC_XUNLOCK(fdp);
2941 fdrop(fp, td);
2942 } else
2943 FILEDESC_XUNLOCK(fdp);
2944 }
2945
2946 /*
2947 * Close any files on exec?
2948 */
2949 void
fdcloseexec(struct thread * td)2950 fdcloseexec(struct thread *td)
2951 {
2952 struct filedesc *fdp;
2953 struct filedescent *fde;
2954 struct file *fp;
2955 int i;
2956
2957 fdp = td->td_proc->p_fd;
2958 KASSERT(refcount_load(&fdp->fd_refcnt) == 1,
2959 ("the fdtable should not be shared"));
2960 FILEDESC_FOREACH_FDE(fdp, i, fde) {
2961 fp = fde->fde_file;
2962 if (fp->f_type == DTYPE_MQUEUE ||
2963 (fde->fde_flags & UF_EXCLOSE)) {
2964 FILEDESC_XLOCK(fdp);
2965 fdfree(fdp, i);
2966 (void) closefp(fdp, i, fp, td, false, false);
2967 FILEDESC_UNLOCK_ASSERT(fdp);
2968 } else if (fde->fde_flags & UF_FOCLOSE) {
2969 /*
2970 * https://austingroupbugs.net/view.php?id=1851
2971 * FD_CLOFORK should not be preserved across exec
2972 */
2973 fde->fde_flags &= ~UF_FOCLOSE;
2974 }
2975 }
2976 }
2977
2978 /*
2979 * It is unsafe for set[ug]id processes to be started with file
2980 * descriptors 0..2 closed, as these descriptors are given implicit
2981 * significance in the Standard C library. fdcheckstd() will create a
2982 * descriptor referencing /dev/null for each of stdin, stdout, and
2983 * stderr that is not already open.
2984 */
2985 int
fdcheckstd(struct thread * td)2986 fdcheckstd(struct thread *td)
2987 {
2988 struct filedesc *fdp;
2989 register_t save;
2990 int i, error, devnull;
2991
2992 fdp = td->td_proc->p_fd;
2993 KASSERT(refcount_load(&fdp->fd_refcnt) == 1,
2994 ("the fdtable should not be shared"));
2995 MPASS(fdp->fd_nfiles >= 3);
2996 devnull = -1;
2997 for (i = 0; i <= 2; i++) {
2998 if (fdp->fd_ofiles[i].fde_file != NULL)
2999 continue;
3000
3001 save = td->td_retval[0];
3002 if (devnull != -1) {
3003 error = kern_dup(td, FDDUP_FIXED, 0, devnull, i);
3004 } else {
3005 error = kern_openat(td, AT_FDCWD, "/dev/null",
3006 UIO_SYSSPACE, O_RDWR, 0);
3007 if (error == 0) {
3008 devnull = td->td_retval[0];
3009 KASSERT(devnull == i, ("we didn't get our fd"));
3010 }
3011 }
3012 td->td_retval[0] = save;
3013 if (error != 0)
3014 return (error);
3015 }
3016 return (0);
3017 }
3018
3019 /*
3020 * Internal form of close. Decrement reference count on file structure.
3021 * Note: td may be NULL when closing a file that was being passed in a
3022 * message.
3023 */
3024 int
closef(struct file * fp,struct thread * td)3025 closef(struct file *fp, struct thread *td)
3026 {
3027 struct vnode *vp;
3028 struct flock lf;
3029 struct filedesc_to_leader *fdtol;
3030 struct filedesc *fdp;
3031
3032 MPASS(td != NULL);
3033
3034 /*
3035 * POSIX record locking dictates that any close releases ALL
3036 * locks owned by this process. This is handled by setting
3037 * a flag in the unlock to free ONLY locks obeying POSIX
3038 * semantics, and not to free BSD-style file locks.
3039 * If the descriptor was in a message, POSIX-style locks
3040 * aren't passed with the descriptor, and the thread pointer
3041 * will be NULL. Callers should be careful only to pass a
3042 * NULL thread pointer when there really is no owning
3043 * context that might have locks, or the locks will be
3044 * leaked.
3045 */
3046 if (fp->f_type == DTYPE_VNODE) {
3047 vp = fp->f_vnode;
3048 if ((td->td_proc->p_leader->p_flag & P_ADVLOCK) != 0) {
3049 lf.l_whence = SEEK_SET;
3050 lf.l_start = 0;
3051 lf.l_len = 0;
3052 lf.l_type = F_UNLCK;
3053 (void) VOP_ADVLOCK(vp, (caddr_t)td->td_proc->p_leader,
3054 F_UNLCK, &lf, F_POSIX);
3055 }
3056 fdtol = td->td_proc->p_fdtol;
3057 if (fdtol != NULL) {
3058 /*
3059 * Handle special case where file descriptor table is
3060 * shared between multiple process leaders.
3061 */
3062 fdp = td->td_proc->p_fd;
3063 FILEDESC_XLOCK(fdp);
3064 for (fdtol = fdtol->fdl_next;
3065 fdtol != td->td_proc->p_fdtol;
3066 fdtol = fdtol->fdl_next) {
3067 if ((fdtol->fdl_leader->p_flag &
3068 P_ADVLOCK) == 0)
3069 continue;
3070 fdtol->fdl_holdcount++;
3071 FILEDESC_XUNLOCK(fdp);
3072 lf.l_whence = SEEK_SET;
3073 lf.l_start = 0;
3074 lf.l_len = 0;
3075 lf.l_type = F_UNLCK;
3076 vp = fp->f_vnode;
3077 (void) VOP_ADVLOCK(vp,
3078 (caddr_t)fdtol->fdl_leader, F_UNLCK, &lf,
3079 F_POSIX);
3080 FILEDESC_XLOCK(fdp);
3081 fdtol->fdl_holdcount--;
3082 if (fdtol->fdl_holdcount == 0 &&
3083 fdtol->fdl_wakeup != 0) {
3084 fdtol->fdl_wakeup = 0;
3085 wakeup(fdtol);
3086 }
3087 }
3088 FILEDESC_XUNLOCK(fdp);
3089 }
3090 }
3091 return (fdrop_close(fp, td));
3092 }
3093
3094 /*
3095 * Hack for file descriptor passing code.
3096 */
3097 void
closef_nothread(struct file * fp)3098 closef_nothread(struct file *fp)
3099 {
3100
3101 fdrop(fp, NULL);
3102 }
3103
3104 /*
3105 * Initialize the file pointer with the specified properties.
3106 *
3107 * The ops are set with release semantics to be certain that the flags, type,
3108 * and data are visible when ops is. This is to prevent ops methods from being
3109 * called with bad data.
3110 */
3111 void
finit(struct file * fp,u_int flag,short type,void * data,const struct fileops * ops)3112 finit(struct file *fp, u_int flag, short type, void *data,
3113 const struct fileops *ops)
3114 {
3115 fp->f_data = data;
3116 fp->f_flag = flag;
3117 fp->f_type = type;
3118 atomic_store_rel_ptr((volatile uintptr_t *)&fp->f_ops, (uintptr_t)ops);
3119 }
3120
3121 void
finit_vnode(struct file * fp,u_int flag,void * data,const struct fileops * ops)3122 finit_vnode(struct file *fp, u_int flag, void *data, const struct fileops *ops)
3123 {
3124 fp->f_seqcount[UIO_READ] = 1;
3125 fp->f_seqcount[UIO_WRITE] = 1;
3126 finit(fp, (flag & FMASK) | (fp->f_flag & FHASLOCK), DTYPE_VNODE,
3127 data, ops);
3128 }
3129
3130 int
fget_cap_noref(struct filedesc * fdp,int fd,const cap_rights_t * needrightsp,struct file ** fpp,struct filecaps * havecapsp)3131 fget_cap_noref(struct filedesc *fdp, int fd, const cap_rights_t *needrightsp,
3132 struct file **fpp, struct filecaps *havecapsp)
3133 {
3134 struct filedescent *fde;
3135 int error;
3136
3137 FILEDESC_LOCK_ASSERT(fdp);
3138
3139 *fpp = NULL;
3140 fde = fdeget_noref(fdp, fd);
3141 if (fde == NULL) {
3142 error = EBADF;
3143 goto out;
3144 }
3145
3146 #ifdef CAPABILITIES
3147 error = cap_check(cap_rights_fde_inline(fde), needrightsp);
3148 if (error != 0)
3149 goto out;
3150 #endif
3151
3152 if (havecapsp != NULL)
3153 filecaps_copy(&fde->fde_caps, havecapsp, true);
3154
3155 *fpp = fde->fde_file;
3156
3157 error = 0;
3158 out:
3159 return (error);
3160 }
3161
3162 #ifdef CAPABILITIES
3163 int
fget_cap(struct thread * td,int fd,const cap_rights_t * needrightsp,uint8_t * flagsp,struct file ** fpp,struct filecaps * havecapsp)3164 fget_cap(struct thread *td, int fd, const cap_rights_t *needrightsp,
3165 uint8_t *flagsp, struct file **fpp, struct filecaps *havecapsp)
3166 {
3167 struct filedesc *fdp = td->td_proc->p_fd;
3168 int error;
3169 struct file *fp;
3170 seqc_t seq;
3171
3172 *fpp = NULL;
3173 for (;;) {
3174 error = fget_unlocked_seq(td, fd, needrightsp, flagsp, &fp,
3175 &seq);
3176 if (error != 0)
3177 return (error);
3178
3179 if (havecapsp != NULL) {
3180 if (!filecaps_copy(&fdp->fd_ofiles[fd].fde_caps,
3181 havecapsp, false)) {
3182 fdrop(fp, td);
3183 goto get_locked;
3184 }
3185 }
3186
3187 if (!fd_modified(fdp, fd, seq))
3188 break;
3189 fdrop(fp, td);
3190 }
3191
3192 *fpp = fp;
3193 return (0);
3194
3195 get_locked:
3196 FILEDESC_SLOCK(fdp);
3197 error = fget_cap_noref(fdp, fd, needrightsp, fpp, havecapsp);
3198 if (error == 0 && !fhold(*fpp))
3199 error = EBADF;
3200 FILEDESC_SUNLOCK(fdp);
3201 return (error);
3202 }
3203 #else
3204 int
fget_cap(struct thread * td,int fd,const cap_rights_t * needrightsp,uint8_t * flagsp,struct file ** fpp,struct filecaps * havecapsp)3205 fget_cap(struct thread *td, int fd, const cap_rights_t *needrightsp,
3206 uint8_t *flagsp, struct file **fpp, struct filecaps *havecapsp)
3207 {
3208 int error;
3209 error = fget_unlocked_flags(td, fd, needrightsp, flagsp, fpp);
3210 if (havecapsp != NULL && error == 0)
3211 filecaps_fill(havecapsp);
3212
3213 return (error);
3214 }
3215 #endif
3216
3217 int
fget_remote(struct thread * td,struct proc * p,int fd,struct filecaps * fcaps,uint8_t * fd_flags,struct file ** fpp)3218 fget_remote(struct thread *td, struct proc *p, int fd, struct filecaps *fcaps,
3219 uint8_t *fd_flags, struct file **fpp)
3220 {
3221 struct filedesc *fdp;
3222 struct file *fp;
3223 int error;
3224 bool copied __diagused;
3225
3226 /*
3227 * Both fcaps and fd_flags must be either requested together,
3228 * or not at all.
3229 */
3230 MPASS((!(fcaps == NULL) ^ (fd_flags == NULL)));
3231
3232 if (p == td->td_proc && fcaps == NULL) /* curproc */
3233 return (fget_unlocked(td, fd, &cap_no_rights, fpp));
3234
3235 PROC_LOCK(p);
3236 fdp = fdhold(p);
3237 PROC_UNLOCK(p);
3238 if (fdp == NULL)
3239 return (ENOENT);
3240 FILEDESC_SLOCK(fdp);
3241 if (refcount_load(&fdp->fd_refcnt) != 0) {
3242 fp = fget_noref(fdp, fd);
3243 if (fp != NULL && fhold(fp)) {
3244 *fpp = fp;
3245 if (fd_flags != NULL) {
3246 *fd_flags = fde_to_fd_flags(fdp->fd_ofiles[fd].
3247 fde_flags);
3248 }
3249 if (fcaps != NULL) {
3250 copied = filecaps_copy(
3251 &fdp->fd_ofiles[fd].fde_caps, fcaps, true);
3252 MPASS(copied);
3253 }
3254 error = 0;
3255 } else {
3256 error = EBADF;
3257 }
3258 } else {
3259 error = ENOENT;
3260 }
3261 FILEDESC_SUNLOCK(fdp);
3262 fddrop(fdp);
3263 return (error);
3264 }
3265
3266 int
fget_remote_foreach(struct thread * td,struct proc * p,int (* fn)(struct proc *,int,struct file *,void *),void * arg)3267 fget_remote_foreach(struct thread *td, struct proc *p,
3268 int (*fn)(struct proc *, int, struct file *, void *), void *arg)
3269 {
3270 struct filedesc *fdp;
3271 struct fdescenttbl *fdt;
3272 struct file *fp;
3273 int error, error1, fd, highfd;
3274
3275 error = 0;
3276 PROC_LOCK(p);
3277 fdp = fdhold(p);
3278 PROC_UNLOCK(p);
3279 if (fdp == NULL)
3280 return (ENOENT);
3281
3282 FILEDESC_SLOCK(fdp);
3283 if (refcount_load(&fdp->fd_refcnt) != 0) {
3284 fdt = atomic_load_ptr(&fdp->fd_files);
3285 highfd = fdt->fdt_nfiles - 1;
3286 FILEDESC_SUNLOCK(fdp);
3287 } else {
3288 error = ENOENT;
3289 FILEDESC_SUNLOCK(fdp);
3290 goto out;
3291 }
3292
3293 for (fd = 0; fd <= highfd; fd++) {
3294 error1 = fget_remote(td, p, fd, NULL, NULL, &fp);
3295 if (error1 != 0)
3296 continue;
3297 error = fn(p, fd, fp, arg);
3298 fdrop(fp, td);
3299 if (error != 0)
3300 break;
3301 }
3302 out:
3303 fddrop(fdp);
3304 return (error);
3305 }
3306
3307 #ifdef CAPABILITIES
3308 int
fgetvp_lookup_smr(struct nameidata * ndp,struct vnode ** vpp,int * flagsp)3309 fgetvp_lookup_smr(struct nameidata *ndp, struct vnode **vpp, int *flagsp)
3310 {
3311 const struct filedescent *fde;
3312 const struct fdescenttbl *fdt;
3313 struct filedesc *fdp;
3314 struct file *fp;
3315 struct vnode *vp;
3316 const cap_rights_t *haverights;
3317 cap_rights_t rights;
3318 seqc_t seq;
3319 int fd, flags;
3320
3321 VFS_SMR_ASSERT_ENTERED();
3322
3323 fd = ndp->ni_dirfd;
3324 rights = *ndp->ni_rightsneeded;
3325 cap_rights_set_one(&rights, CAP_LOOKUP);
3326
3327 fdp = curproc->p_fd;
3328 fdt = fdp->fd_files;
3329 if (__predict_false((u_int)fd >= fdt->fdt_nfiles))
3330 return (EBADF);
3331 seq = seqc_read_notmodify(fd_seqc(fdt, fd));
3332 fde = &fdt->fdt_ofiles[fd];
3333 haverights = cap_rights_fde_inline(fde);
3334 fp = fde->fde_file;
3335 if (__predict_false(fp == NULL))
3336 return (EAGAIN);
3337 if (__predict_false(cap_check_inline_transient(haverights, &rights)))
3338 return (EAGAIN);
3339 flags = fp->f_flag & FSEARCH;
3340 flags |= (fde->fde_flags & UF_RESOLVE_BENEATH) != 0 ?
3341 O_RESOLVE_BENEATH : 0;
3342 vp = fp->f_vnode;
3343 if (__predict_false(vp == NULL)) {
3344 return (EAGAIN);
3345 }
3346 if (!filecaps_copy(&fde->fde_caps, &ndp->ni_filecaps, false)) {
3347 return (EAGAIN);
3348 }
3349 /*
3350 * Use an acquire barrier to force re-reading of fdt so it is
3351 * refreshed for verification.
3352 */
3353 atomic_thread_fence_acq();
3354 fdt = fdp->fd_files;
3355 if (__predict_false(!seqc_consistent_no_fence(fd_seqc(fdt, fd), seq)))
3356 return (EAGAIN);
3357 /*
3358 * If file descriptor doesn't have all rights,
3359 * all lookups relative to it must also be
3360 * strictly relative.
3361 *
3362 * Not yet supported by fast path.
3363 */
3364 if (!filecaps_full(&ndp->ni_filecaps)) {
3365 #ifdef notyet
3366 ndp->ni_lcf |= NI_LCF_STRICTREL;
3367 #else
3368 return (EAGAIN);
3369 #endif
3370 }
3371 *vpp = vp;
3372 *flagsp = flags;
3373 return (0);
3374 }
3375 #else
3376 int
fgetvp_lookup_smr(struct nameidata * ndp,struct vnode ** vpp,int * flagsp)3377 fgetvp_lookup_smr(struct nameidata *ndp, struct vnode **vpp, int *flagsp)
3378 {
3379 const struct filedescent *fde;
3380 const struct fdescenttbl *fdt;
3381 struct filedesc *fdp;
3382 struct file *fp;
3383 struct vnode *vp;
3384 int fd, flags;
3385
3386 VFS_SMR_ASSERT_ENTERED();
3387
3388 fd = ndp->ni_dirfd;
3389 fdp = curproc->p_fd;
3390 fdt = fdp->fd_files;
3391 if (__predict_false((u_int)fd >= fdt->fdt_nfiles))
3392 return (EBADF);
3393 fde = &fdt->fdt_ofiles[fd];
3394 fp = fde->fde_file;
3395 if (__predict_false(fp == NULL))
3396 return (EAGAIN);
3397 flags = fp->f_flag & FSEARCH;
3398 flags |= (fde->fde_flags & UF_RESOLVE_BENEATH) != 0 ?
3399 O_RESOLVE_BENEATH : 0;
3400 vp = fp->f_vnode;
3401 if (__predict_false(vp == NULL || vp->v_type != VDIR)) {
3402 return (EAGAIN);
3403 }
3404 /*
3405 * Use an acquire barrier to force re-reading of fdt so it is
3406 * refreshed for verification.
3407 */
3408 atomic_thread_fence_acq();
3409 fdt = fdp->fd_files;
3410 if (__predict_false(fp != fdt->fdt_ofiles[fd].fde_file))
3411 return (EAGAIN);
3412 filecaps_fill(&ndp->ni_filecaps);
3413 *vpp = vp;
3414 *flagsp = flags;
3415 return (0);
3416 }
3417 #endif
3418
3419 int
fgetvp_lookup(struct nameidata * ndp,struct vnode ** vpp)3420 fgetvp_lookup(struct nameidata *ndp, struct vnode **vpp)
3421 {
3422 struct thread *td;
3423 struct file *fp;
3424 struct vnode *vp;
3425 struct componentname *cnp;
3426 cap_rights_t rights;
3427 int error;
3428 uint8_t flags;
3429
3430 td = curthread;
3431 rights = *ndp->ni_rightsneeded;
3432 cap_rights_set_one(&rights, CAP_LOOKUP);
3433 cnp = &ndp->ni_cnd;
3434
3435 error = fget_cap(td, ndp->ni_dirfd, &rights, &flags, &fp,
3436 &ndp->ni_filecaps);
3437 if (__predict_false(error != 0))
3438 return (error);
3439 if (__predict_false(fp->f_ops == &badfileops)) {
3440 error = EBADF;
3441 goto out_free;
3442 }
3443 vp = fp->f_vnode;
3444 if (__predict_false(vp == NULL)) {
3445 error = ENOTDIR;
3446 goto out_free;
3447 }
3448 vrefact(vp);
3449 /*
3450 * XXX does not check for VDIR, handled by namei_setup
3451 */
3452 if ((fp->f_flag & FSEARCH) != 0)
3453 cnp->cn_flags |= NOEXECCHECK;
3454 if ((flags & UF_RESOLVE_BENEATH) != 0) {
3455 cnp->cn_flags |= RBENEATH;
3456 ndp->ni_resflags |= NIRES_BENEATH;
3457 }
3458 fdrop(fp, td);
3459
3460 #ifdef CAPABILITIES
3461 /*
3462 * If file descriptor doesn't have all rights,
3463 * all lookups relative to it must also be
3464 * strictly relative.
3465 */
3466 if (!filecaps_full(&ndp->ni_filecaps)) {
3467 ndp->ni_lcf |= NI_LCF_STRICTREL;
3468 ndp->ni_resflags |= NIRES_STRICTREL;
3469 }
3470 #endif
3471
3472 /*
3473 * TODO: avoid copying ioctl caps if it can be helped to begin with
3474 */
3475 if ((cnp->cn_flags & WANTIOCTLCAPS) == 0)
3476 filecaps_free_ioctl(&ndp->ni_filecaps);
3477
3478 *vpp = vp;
3479 return (0);
3480
3481 out_free:
3482 filecaps_free(&ndp->ni_filecaps);
3483 fdrop(fp, td);
3484 return (error);
3485 }
3486
3487 /*
3488 * Fetch the descriptor locklessly.
3489 *
3490 * We avoid fdrop() races by never raising a refcount above 0. To accomplish
3491 * this we have to use a cmpset loop rather than an atomic_add. The descriptor
3492 * must be re-verified once we acquire a reference to be certain that the
3493 * identity is still correct and we did not lose a race due to preemption.
3494 *
3495 * Force a reload of fdt when looping. Another thread could reallocate
3496 * the table before this fd was closed, so it is possible that there is
3497 * a stale fp pointer in cached version.
3498 */
3499 #ifdef CAPABILITIES
3500 static int
fget_unlocked_seq(struct thread * td,int fd,const cap_rights_t * needrightsp,uint8_t * flagsp,struct file ** fpp,seqc_t * seqp)3501 fget_unlocked_seq(struct thread *td, int fd, const cap_rights_t *needrightsp,
3502 uint8_t *flagsp, struct file **fpp, seqc_t *seqp)
3503 {
3504 struct filedesc *fdp;
3505 const struct filedescent *fde;
3506 const struct fdescenttbl *fdt;
3507 struct file *fp;
3508 seqc_t seq;
3509 cap_rights_t haverights;
3510 int error;
3511 uint8_t flags;
3512
3513 fdp = td->td_proc->p_fd;
3514 fdt = fdp->fd_files;
3515 if (__predict_false((u_int)fd >= fdt->fdt_nfiles))
3516 return (EBADF);
3517
3518 for (;;) {
3519 seq = seqc_read_notmodify(fd_seqc(fdt, fd));
3520 fde = &fdt->fdt_ofiles[fd];
3521 haverights = *cap_rights_fde_inline(fde);
3522 fp = fde->fde_file;
3523 flags = fde->fde_flags;
3524 if (__predict_false(fp == NULL)) {
3525 if (seqc_consistent(fd_seqc(fdt, fd), seq))
3526 return (EBADF);
3527 fdt = atomic_load_ptr(&fdp->fd_files);
3528 continue;
3529 }
3530 error = cap_check_inline(&haverights, needrightsp);
3531 if (__predict_false(error != 0)) {
3532 if (seqc_consistent(fd_seqc(fdt, fd), seq))
3533 return (error);
3534 fdt = atomic_load_ptr(&fdp->fd_files);
3535 continue;
3536 }
3537 if (__predict_false(!refcount_acquire_if_not_zero(&fp->f_count))) {
3538 fdt = atomic_load_ptr(&fdp->fd_files);
3539 continue;
3540 }
3541 /*
3542 * Use an acquire barrier to force re-reading of fdt so it is
3543 * refreshed for verification.
3544 */
3545 atomic_thread_fence_acq();
3546 fdt = fdp->fd_files;
3547 if (seqc_consistent_no_fence(fd_seqc(fdt, fd), seq))
3548 break;
3549 fdrop(fp, td);
3550 }
3551 *fpp = fp;
3552 if (flagsp != NULL)
3553 *flagsp = flags;
3554 if (seqp != NULL)
3555 *seqp = seq;
3556 return (0);
3557 }
3558 #else
3559 static int
fget_unlocked_seq(struct thread * td,int fd,const cap_rights_t * needrightsp,uint8_t * flagsp,struct file ** fpp,seqc_t * seqp __unused)3560 fget_unlocked_seq(struct thread *td, int fd, const cap_rights_t *needrightsp,
3561 uint8_t *flagsp, struct file **fpp, seqc_t *seqp __unused)
3562 {
3563 struct filedesc *fdp;
3564 const struct fdescenttbl *fdt;
3565 struct file *fp;
3566 uint8_t flags;
3567
3568 fdp = td->td_proc->p_fd;
3569 fdt = fdp->fd_files;
3570 if (__predict_false((u_int)fd >= fdt->fdt_nfiles))
3571 return (EBADF);
3572
3573 for (;;) {
3574 fp = fdt->fdt_ofiles[fd].fde_file;
3575 flags = fdt->fdt_ofiles[fd].fde_flags;
3576 if (__predict_false(fp == NULL))
3577 return (EBADF);
3578 if (__predict_false(!refcount_acquire_if_not_zero(&fp->f_count))) {
3579 fdt = atomic_load_ptr(&fdp->fd_files);
3580 continue;
3581 }
3582 /*
3583 * Use an acquire barrier to force re-reading of fdt so it is
3584 * refreshed for verification.
3585 */
3586 atomic_thread_fence_acq();
3587 fdt = fdp->fd_files;
3588 if (__predict_true(fp == fdt->fdt_ofiles[fd].fde_file))
3589 break;
3590 fdrop(fp, td);
3591 }
3592 if (flagsp != NULL)
3593 *flagsp = flags;
3594 *fpp = fp;
3595 return (0);
3596 }
3597 #endif
3598
3599 /*
3600 * See the comments in fget_unlocked_seq for an explanation of how this works.
3601 *
3602 * This is a simplified variant which bails out to the aforementioned routine
3603 * if anything goes wrong. In practice this only happens when userspace is
3604 * racing with itself.
3605 */
3606 int
fget_unlocked_flags(struct thread * td,int fd,const cap_rights_t * needrightsp,uint8_t * flagsp,struct file ** fpp)3607 fget_unlocked_flags(struct thread *td, int fd, const cap_rights_t *needrightsp,
3608 uint8_t *flagsp, struct file **fpp)
3609 {
3610 struct filedesc *fdp;
3611 #ifdef CAPABILITIES
3612 const struct filedescent *fde;
3613 #endif
3614 const struct fdescenttbl *fdt;
3615 struct file *fp;
3616 #ifdef CAPABILITIES
3617 seqc_t seq;
3618 const cap_rights_t *haverights;
3619 #endif
3620 uint8_t flags;
3621
3622 fdp = td->td_proc->p_fd;
3623 fdt = fdp->fd_files;
3624 if (__predict_false((u_int)fd >= fdt->fdt_nfiles)) {
3625 *fpp = NULL;
3626 return (EBADF);
3627 }
3628 #ifdef CAPABILITIES
3629 seq = seqc_read_notmodify(fd_seqc(fdt, fd));
3630 fde = &fdt->fdt_ofiles[fd];
3631 haverights = cap_rights_fde_inline(fde);
3632 fp = fde->fde_file;
3633 flags = fde->fde_flags;
3634 #else
3635 fp = fdt->fdt_ofiles[fd].fde_file;
3636 flags = fdt->fdt_ofiles[fd].fde_flags;
3637 #endif
3638 if (__predict_false(fp == NULL))
3639 goto out_fallback;
3640 #ifdef CAPABILITIES
3641 if (__predict_false(cap_check_inline_transient(haverights, needrightsp)))
3642 goto out_fallback;
3643 #endif
3644 if (__predict_false(!refcount_acquire_if_not_zero(&fp->f_count)))
3645 goto out_fallback;
3646
3647 /*
3648 * Use an acquire barrier to force re-reading of fdt so it is
3649 * refreshed for verification.
3650 */
3651 atomic_thread_fence_acq();
3652 fdt = fdp->fd_files;
3653 #ifdef CAPABILITIES
3654 if (__predict_false(!seqc_consistent_no_fence(fd_seqc(fdt, fd), seq)))
3655 #else
3656 if (__predict_false(fp != fdt->fdt_ofiles[fd].fde_file))
3657 #endif
3658 goto out_fdrop;
3659 *fpp = fp;
3660 if (flagsp != NULL)
3661 *flagsp = flags;
3662 return (0);
3663 out_fdrop:
3664 fdrop(fp, td);
3665 out_fallback:
3666 *fpp = NULL;
3667 return (fget_unlocked_seq(td, fd, needrightsp, flagsp, fpp, NULL));
3668 }
3669
3670 int
fget_unlocked(struct thread * td,int fd,const cap_rights_t * needrightsp,struct file ** fpp)3671 fget_unlocked(struct thread *td, int fd, const cap_rights_t *needrightsp,
3672 struct file **fpp)
3673 {
3674 return (fget_unlocked_flags(td, fd, needrightsp, NULL, fpp));
3675 }
3676
3677 /*
3678 * Translate fd -> file when the caller guarantees the file descriptor table
3679 * can't be changed by others.
3680 *
3681 * Note this does not mean the file object itself is only visible to the caller,
3682 * merely that it wont disappear without having to be referenced.
3683 *
3684 * Must be paired with fput_only_user.
3685 */
3686 #ifdef CAPABILITIES
3687 int
fget_only_user(struct filedesc * fdp,int fd,const cap_rights_t * needrightsp,struct file ** fpp)3688 fget_only_user(struct filedesc *fdp, int fd, const cap_rights_t *needrightsp,
3689 struct file **fpp)
3690 {
3691 const struct filedescent *fde;
3692 const struct fdescenttbl *fdt;
3693 const cap_rights_t *haverights;
3694 struct file *fp;
3695 int error;
3696
3697 MPASS(FILEDESC_IS_ONLY_USER(fdp));
3698
3699 *fpp = NULL;
3700 if (__predict_false(fd >= fdp->fd_nfiles))
3701 return (EBADF);
3702
3703 fdt = fdp->fd_files;
3704 fde = &fdt->fdt_ofiles[fd];
3705 fp = fde->fde_file;
3706 if (__predict_false(fp == NULL))
3707 return (EBADF);
3708 MPASS(refcount_load(&fp->f_count) > 0);
3709 haverights = cap_rights_fde_inline(fde);
3710 error = cap_check_inline(haverights, needrightsp);
3711 if (__predict_false(error != 0))
3712 return (error);
3713 *fpp = fp;
3714 return (0);
3715 }
3716 #else
3717 int
fget_only_user(struct filedesc * fdp,int fd,const cap_rights_t * needrightsp,struct file ** fpp)3718 fget_only_user(struct filedesc *fdp, int fd, const cap_rights_t *needrightsp,
3719 struct file **fpp)
3720 {
3721 struct file *fp;
3722
3723 MPASS(FILEDESC_IS_ONLY_USER(fdp));
3724
3725 *fpp = NULL;
3726 if (__predict_false(fd >= fdp->fd_nfiles))
3727 return (EBADF);
3728
3729 fp = fdp->fd_ofiles[fd].fde_file;
3730 if (__predict_false(fp == NULL))
3731 return (EBADF);
3732
3733 MPASS(refcount_load(&fp->f_count) > 0);
3734 *fpp = fp;
3735 return (0);
3736 }
3737 #endif
3738
3739 /*
3740 * Extract the file pointer associated with the specified descriptor for the
3741 * current user process.
3742 *
3743 * If the descriptor doesn't exist or doesn't match 'flags', EBADF is
3744 * returned.
3745 *
3746 * File's rights will be checked against the capability rights mask.
3747 *
3748 * If an error occurred the non-zero error is returned and *fpp is set to
3749 * NULL. Otherwise *fpp is held and set and zero is returned. Caller is
3750 * responsible for fdrop().
3751 */
3752 static __inline int
_fget(struct thread * td,int fd,struct file ** fpp,int flags,const cap_rights_t * needrightsp)3753 _fget(struct thread *td, int fd, struct file **fpp, int flags,
3754 const cap_rights_t *needrightsp)
3755 {
3756 struct file *fp;
3757 int error;
3758
3759 *fpp = NULL;
3760 error = fget_unlocked(td, fd, needrightsp, &fp);
3761 if (__predict_false(error != 0))
3762 return (error);
3763 if (__predict_false(fp->f_ops == &badfileops)) {
3764 fdrop(fp, td);
3765 return (EBADF);
3766 }
3767
3768 /*
3769 * FREAD and FWRITE failure return EBADF as per POSIX.
3770 */
3771 error = 0;
3772 switch (flags) {
3773 case FREAD:
3774 case FWRITE:
3775 if ((fp->f_flag & flags) == 0)
3776 error = EBADF;
3777 break;
3778 case FEXEC:
3779 if (fp->f_ops != &path_fileops &&
3780 ((fp->f_flag & (FREAD | FEXEC)) == 0 ||
3781 (fp->f_flag & FWRITE) != 0))
3782 error = EBADF;
3783 break;
3784 case 0:
3785 break;
3786 default:
3787 KASSERT(0, ("wrong flags"));
3788 }
3789
3790 if (error != 0) {
3791 fdrop(fp, td);
3792 return (error);
3793 }
3794
3795 *fpp = fp;
3796 return (0);
3797 }
3798
3799 int
fget(struct thread * td,int fd,const cap_rights_t * rightsp,struct file ** fpp)3800 fget(struct thread *td, int fd, const cap_rights_t *rightsp, struct file **fpp)
3801 {
3802
3803 return (_fget(td, fd, fpp, 0, rightsp));
3804 }
3805
3806 int
fget_mmap(struct thread * td,int fd,const cap_rights_t * rightsp,vm_prot_t * maxprotp,struct file ** fpp)3807 fget_mmap(struct thread *td, int fd, const cap_rights_t *rightsp,
3808 vm_prot_t *maxprotp, struct file **fpp)
3809 {
3810 int error;
3811 #ifndef CAPABILITIES
3812 error = _fget(td, fd, fpp, 0, rightsp);
3813 if (maxprotp != NULL)
3814 *maxprotp = VM_PROT_ALL;
3815 return (error);
3816 #else
3817 cap_rights_t fdrights;
3818 struct filedesc *fdp;
3819 struct file *fp;
3820 seqc_t seq;
3821
3822 *fpp = NULL;
3823 fdp = td->td_proc->p_fd;
3824 MPASS(cap_rights_is_set(rightsp, CAP_MMAP));
3825 for (;;) {
3826 error = fget_unlocked_seq(td, fd, rightsp, NULL, &fp, &seq);
3827 if (__predict_false(error != 0))
3828 return (error);
3829 if (__predict_false(fp->f_ops == &badfileops)) {
3830 fdrop(fp, td);
3831 return (EBADF);
3832 }
3833 if (maxprotp != NULL)
3834 fdrights = *cap_rights(fdp, fd);
3835 if (!fd_modified(fdp, fd, seq))
3836 break;
3837 fdrop(fp, td);
3838 }
3839
3840 /*
3841 * If requested, convert capability rights to access flags.
3842 */
3843 if (maxprotp != NULL)
3844 *maxprotp = cap_rights_to_vmprot(&fdrights);
3845 *fpp = fp;
3846 return (0);
3847 #endif
3848 }
3849
3850 int
fget_read(struct thread * td,int fd,const cap_rights_t * rightsp,struct file ** fpp)3851 fget_read(struct thread *td, int fd, const cap_rights_t *rightsp,
3852 struct file **fpp)
3853 {
3854
3855 return (_fget(td, fd, fpp, FREAD, rightsp));
3856 }
3857
3858 int
fget_write(struct thread * td,int fd,const cap_rights_t * rightsp,struct file ** fpp)3859 fget_write(struct thread *td, int fd, const cap_rights_t *rightsp,
3860 struct file **fpp)
3861 {
3862
3863 return (_fget(td, fd, fpp, FWRITE, rightsp));
3864 }
3865
3866 int
fget_fcntl(struct thread * td,int fd,const cap_rights_t * rightsp,int needfcntl,struct file ** fpp)3867 fget_fcntl(struct thread *td, int fd, const cap_rights_t *rightsp,
3868 int needfcntl, struct file **fpp)
3869 {
3870 #ifndef CAPABILITIES
3871 return (fget_unlocked(td, fd, rightsp, fpp));
3872 #else
3873 struct filedesc *fdp = td->td_proc->p_fd;
3874 struct file *fp;
3875 int error;
3876 seqc_t seq;
3877
3878 *fpp = NULL;
3879 MPASS(cap_rights_is_set(rightsp, CAP_FCNTL));
3880 for (;;) {
3881 error = fget_unlocked_seq(td, fd, rightsp, NULL, &fp, &seq);
3882 if (error != 0)
3883 return (error);
3884 error = cap_fcntl_check(fdp, fd, needfcntl);
3885 if (!fd_modified(fdp, fd, seq))
3886 break;
3887 fdrop(fp, td);
3888 }
3889 if (error != 0) {
3890 fdrop(fp, td);
3891 return (error);
3892 }
3893 *fpp = fp;
3894 return (0);
3895 #endif
3896 }
3897
3898 /*
3899 * Like fget() but loads the underlying vnode, or returns an error if the
3900 * descriptor does not represent a vnode. Note that pipes use vnodes but
3901 * never have VM objects. The returned vnode will be vref()'d.
3902 *
3903 * XXX: what about the unused flags ?
3904 */
3905 static __inline int
_fgetvp(struct thread * td,int fd,int flags,const cap_rights_t * needrightsp,struct vnode ** vpp)3906 _fgetvp(struct thread *td, int fd, int flags, const cap_rights_t *needrightsp,
3907 struct vnode **vpp)
3908 {
3909 struct file *fp;
3910 int error;
3911
3912 *vpp = NULL;
3913 error = _fget(td, fd, &fp, flags, needrightsp);
3914 if (error != 0)
3915 return (error);
3916 if (fp->f_vnode == NULL) {
3917 error = EINVAL;
3918 } else {
3919 *vpp = fp->f_vnode;
3920 vrefact(*vpp);
3921 }
3922 fdrop(fp, td);
3923
3924 return (error);
3925 }
3926
3927 int
fgetvp(struct thread * td,int fd,const cap_rights_t * rightsp,struct vnode ** vpp)3928 fgetvp(struct thread *td, int fd, const cap_rights_t *rightsp,
3929 struct vnode **vpp)
3930 {
3931
3932 return (_fgetvp(td, fd, 0, rightsp, vpp));
3933 }
3934
3935 int
fgetvp_rights(struct thread * td,int fd,const cap_rights_t * needrightsp,struct filecaps * havecaps,struct vnode ** vpp)3936 fgetvp_rights(struct thread *td, int fd, const cap_rights_t *needrightsp,
3937 struct filecaps *havecaps, struct vnode **vpp)
3938 {
3939 struct filecaps caps;
3940 struct file *fp;
3941 int error;
3942
3943 error = fget_cap(td, fd, needrightsp, NULL, &fp, &caps);
3944 if (error != 0)
3945 return (error);
3946 if (fp->f_ops == &badfileops) {
3947 error = EBADF;
3948 goto out;
3949 }
3950 if (fp->f_vnode == NULL) {
3951 error = EINVAL;
3952 goto out;
3953 }
3954
3955 *havecaps = caps;
3956 *vpp = fp->f_vnode;
3957 vrefact(*vpp);
3958 fdrop(fp, td);
3959
3960 return (0);
3961 out:
3962 filecaps_free(&caps);
3963 fdrop(fp, td);
3964 return (error);
3965 }
3966
3967 int
fgetvp_read(struct thread * td,int fd,const cap_rights_t * rightsp,struct vnode ** vpp)3968 fgetvp_read(struct thread *td, int fd, const cap_rights_t *rightsp,
3969 struct vnode **vpp)
3970 {
3971
3972 return (_fgetvp(td, fd, FREAD, rightsp, vpp));
3973 }
3974
3975 int
fgetvp_exec(struct thread * td,int fd,const cap_rights_t * rightsp,struct vnode ** vpp)3976 fgetvp_exec(struct thread *td, int fd, const cap_rights_t *rightsp,
3977 struct vnode **vpp)
3978 {
3979
3980 return (_fgetvp(td, fd, FEXEC, rightsp, vpp));
3981 }
3982
3983 #ifdef notyet
3984 int
fgetvp_write(struct thread * td,int fd,const cap_rights_t * rightsp,struct vnode ** vpp)3985 fgetvp_write(struct thread *td, int fd, const cap_rights_t *rightsp,
3986 struct vnode **vpp)
3987 {
3988
3989 return (_fgetvp(td, fd, FWRITE, rightsp, vpp));
3990 }
3991 #endif
3992
3993 /*
3994 * Handle the last reference to a file being closed.
3995 *
3996 * Without the noinline attribute clang keeps inlining the func thorough this
3997 * file when fdrop is used.
3998 */
3999 int __noinline
_fdrop(struct file * fp,struct thread * td)4000 _fdrop(struct file *fp, struct thread *td)
4001 {
4002 int error;
4003
4004 KASSERT(refcount_load(&fp->f_count) == 0,
4005 ("fdrop: fp %p count %d", fp, refcount_load(&fp->f_count)));
4006
4007 error = fo_close(fp, td);
4008 atomic_subtract_int(&openfiles, 1);
4009 crfree(fp->f_cred);
4010 free(fp->f_advice, M_FADVISE);
4011 uma_zfree(file_zone, fp);
4012
4013 return (error);
4014 }
4015
4016 /*
4017 * Apply an advisory lock on a file descriptor.
4018 *
4019 * Just attempt to get a record lock of the requested type on the entire file
4020 * (l_whence = SEEK_SET, l_start = 0, l_len = 0).
4021 */
4022 #ifndef _SYS_SYSPROTO_H_
4023 struct flock_args {
4024 int fd;
4025 int how;
4026 };
4027 #endif
4028 /* ARGSUSED */
4029 int
sys_flock(struct thread * td,struct flock_args * uap)4030 sys_flock(struct thread *td, struct flock_args *uap)
4031 {
4032 struct file *fp;
4033 struct vnode *vp;
4034 struct flock lf;
4035 int error;
4036
4037 error = fget(td, uap->fd, &cap_flock_rights, &fp);
4038 if (error != 0)
4039 return (error);
4040 error = EOPNOTSUPP;
4041 if (fp->f_type != DTYPE_VNODE && fp->f_type != DTYPE_FIFO) {
4042 goto done;
4043 }
4044 if (fp->f_ops == &path_fileops) {
4045 goto done;
4046 }
4047
4048 error = 0;
4049 vp = fp->f_vnode;
4050 lf.l_whence = SEEK_SET;
4051 lf.l_start = 0;
4052 lf.l_len = 0;
4053 if (uap->how & LOCK_UN) {
4054 lf.l_type = F_UNLCK;
4055 atomic_clear_int(&fp->f_flag, FHASLOCK);
4056 error = VOP_ADVLOCK(vp, (caddr_t)fp, F_UNLCK, &lf, F_FLOCK);
4057 goto done;
4058 }
4059 if (uap->how & LOCK_EX)
4060 lf.l_type = F_WRLCK;
4061 else if (uap->how & LOCK_SH)
4062 lf.l_type = F_RDLCK;
4063 else {
4064 error = EBADF;
4065 goto done;
4066 }
4067 atomic_set_int(&fp->f_flag, FHASLOCK);
4068 error = VOP_ADVLOCK(vp, (caddr_t)fp, F_SETLK, &lf,
4069 (uap->how & LOCK_NB) ? F_FLOCK : F_FLOCK | F_WAIT);
4070 done:
4071 fdrop(fp, td);
4072 return (error);
4073 }
4074 /*
4075 * Duplicate the specified descriptor to a free descriptor.
4076 */
4077 int
dupfdopen(struct thread * td,struct filedesc * fdp,int dfd,int mode,int openerror,int * indxp)4078 dupfdopen(struct thread *td, struct filedesc *fdp, int dfd, int mode,
4079 int openerror, int *indxp)
4080 {
4081 struct filedescent *newfde, *oldfde;
4082 struct file *fp;
4083 u_long *ioctls;
4084 int error, indx;
4085
4086 KASSERT(openerror == ENODEV || openerror == ENXIO,
4087 ("unexpected error %d in %s", openerror, __func__));
4088
4089 /*
4090 * If the to-be-dup'd fd number is greater than the allowed number
4091 * of file descriptors, or the fd to be dup'd has already been
4092 * closed, then reject.
4093 */
4094 FILEDESC_XLOCK(fdp);
4095 if ((fp = fget_noref(fdp, dfd)) == NULL) {
4096 FILEDESC_XUNLOCK(fdp);
4097 return (EBADF);
4098 }
4099
4100 error = fdalloc(td, 0, &indx);
4101 if (error != 0) {
4102 FILEDESC_XUNLOCK(fdp);
4103 return (error);
4104 }
4105
4106 /*
4107 * There are two cases of interest here.
4108 *
4109 * For ENODEV simply dup (dfd) to file descriptor (indx) and return.
4110 *
4111 * For ENXIO steal away the file structure from (dfd) and store it in
4112 * (indx). (dfd) is effectively closed by this operation.
4113 */
4114 switch (openerror) {
4115 case ENODEV:
4116 /*
4117 * Check that the mode the file is being opened for is a
4118 * subset of the mode of the existing descriptor.
4119 */
4120 if (((mode & (FREAD|FWRITE)) | fp->f_flag) != fp->f_flag) {
4121 fdunused(fdp, indx);
4122 FILEDESC_XUNLOCK(fdp);
4123 return (EACCES);
4124 }
4125 if (!fhold(fp)) {
4126 fdunused(fdp, indx);
4127 FILEDESC_XUNLOCK(fdp);
4128 return (EBADF);
4129 }
4130 newfde = &fdp->fd_ofiles[indx];
4131 oldfde = &fdp->fd_ofiles[dfd];
4132 ioctls = filecaps_copy_prep(&oldfde->fde_caps);
4133 #ifdef CAPABILITIES
4134 seqc_write_begin(&newfde->fde_seqc);
4135 #endif
4136 fde_copy(oldfde, newfde);
4137 filecaps_copy_finish(&oldfde->fde_caps, &newfde->fde_caps,
4138 ioctls);
4139 #ifdef CAPABILITIES
4140 seqc_write_end(&newfde->fde_seqc);
4141 #endif
4142 break;
4143 case ENXIO:
4144 /*
4145 * Steal away the file pointer from dfd and stuff it into indx.
4146 */
4147 newfde = &fdp->fd_ofiles[indx];
4148 oldfde = &fdp->fd_ofiles[dfd];
4149 #ifdef CAPABILITIES
4150 seqc_write_begin(&oldfde->fde_seqc);
4151 seqc_write_begin(&newfde->fde_seqc);
4152 #endif
4153 fde_copy(oldfde, newfde);
4154 oldfde->fde_file = NULL;
4155 fdunused(fdp, dfd);
4156 #ifdef CAPABILITIES
4157 seqc_write_end(&newfde->fde_seqc);
4158 seqc_write_end(&oldfde->fde_seqc);
4159 #endif
4160 break;
4161 }
4162 FILEDESC_XUNLOCK(fdp);
4163 *indxp = indx;
4164 return (0);
4165 }
4166
4167 /*
4168 * This sysctl determines if we will allow a process to chroot(2) if it
4169 * has a directory open:
4170 * 0: disallowed for all processes.
4171 * 1: allowed for processes that were not already chroot(2)'ed.
4172 * 2: allowed for all processes.
4173 */
4174
4175 static int chroot_allow_open_directories = 1;
4176
4177 SYSCTL_INT(_kern, OID_AUTO, chroot_allow_open_directories, CTLFLAG_RW,
4178 &chroot_allow_open_directories, 0,
4179 "Allow a process to chroot(2) if it has a directory open");
4180
4181 /*
4182 * Helper function for raised chroot(2) security function: Refuse if
4183 * any filedescriptors are open directories.
4184 */
4185 static int
chroot_refuse_vdir_fds(struct filedesc * fdp)4186 chroot_refuse_vdir_fds(struct filedesc *fdp)
4187 {
4188 struct vnode *vp;
4189 struct file *fp;
4190 int i;
4191
4192 FILEDESC_LOCK_ASSERT(fdp);
4193
4194 FILEDESC_FOREACH_FP(fdp, i, fp) {
4195 if (fp->f_type == DTYPE_VNODE) {
4196 vp = fp->f_vnode;
4197 if (vp->v_type == VDIR)
4198 return (EPERM);
4199 }
4200 }
4201 return (0);
4202 }
4203
4204 static void
pwd_fill(struct pwd * oldpwd,struct pwd * newpwd)4205 pwd_fill(struct pwd *oldpwd, struct pwd *newpwd)
4206 {
4207
4208 if (newpwd->pwd_cdir == NULL && oldpwd->pwd_cdir != NULL) {
4209 vrefact(oldpwd->pwd_cdir);
4210 newpwd->pwd_cdir = oldpwd->pwd_cdir;
4211 }
4212
4213 if (newpwd->pwd_rdir == NULL && oldpwd->pwd_rdir != NULL) {
4214 vrefact(oldpwd->pwd_rdir);
4215 newpwd->pwd_rdir = oldpwd->pwd_rdir;
4216 }
4217
4218 if (newpwd->pwd_jdir == NULL && oldpwd->pwd_jdir != NULL) {
4219 vrefact(oldpwd->pwd_jdir);
4220 newpwd->pwd_jdir = oldpwd->pwd_jdir;
4221 }
4222
4223 if (newpwd->pwd_adir == NULL && oldpwd->pwd_adir != NULL) {
4224 vrefact(oldpwd->pwd_adir);
4225 newpwd->pwd_adir = oldpwd->pwd_adir;
4226 }
4227 }
4228
4229 struct pwd *
pwd_hold_pwddesc(struct pwddesc * pdp)4230 pwd_hold_pwddesc(struct pwddesc *pdp)
4231 {
4232 struct pwd *pwd;
4233
4234 PWDDESC_ASSERT_XLOCKED(pdp);
4235 pwd = PWDDESC_XLOCKED_LOAD_PWD(pdp);
4236 if (pwd != NULL)
4237 refcount_acquire(&pwd->pwd_refcount);
4238 return (pwd);
4239 }
4240
4241 bool
pwd_hold_smr(struct pwd * pwd)4242 pwd_hold_smr(struct pwd *pwd)
4243 {
4244
4245 MPASS(pwd != NULL);
4246 if (__predict_true(refcount_acquire_if_not_zero(&pwd->pwd_refcount))) {
4247 return (true);
4248 }
4249 return (false);
4250 }
4251
4252 struct pwd *
pwd_hold(struct thread * td)4253 pwd_hold(struct thread *td)
4254 {
4255 struct pwddesc *pdp;
4256 struct pwd *pwd;
4257
4258 pdp = td->td_proc->p_pd;
4259
4260 vfs_smr_enter();
4261 pwd = vfs_smr_entered_load(&pdp->pd_pwd);
4262 if (pwd_hold_smr(pwd)) {
4263 vfs_smr_exit();
4264 return (pwd);
4265 }
4266 vfs_smr_exit();
4267 PWDDESC_XLOCK(pdp);
4268 pwd = pwd_hold_pwddesc(pdp);
4269 MPASS(pwd != NULL);
4270 PWDDESC_XUNLOCK(pdp);
4271 return (pwd);
4272 }
4273
4274 struct pwd *
pwd_hold_proc(struct proc * p)4275 pwd_hold_proc(struct proc *p)
4276 {
4277 struct pwddesc *pdp;
4278 struct pwd *pwd;
4279
4280 PROC_ASSERT_HELD(p);
4281 PROC_LOCK(p);
4282 pdp = pdhold(p);
4283 MPASS(pdp != NULL);
4284 PROC_UNLOCK(p);
4285
4286 PWDDESC_XLOCK(pdp);
4287 pwd = pwd_hold_pwddesc(pdp);
4288 MPASS(pwd != NULL);
4289 PWDDESC_XUNLOCK(pdp);
4290 pddrop(pdp);
4291 return (pwd);
4292 }
4293
4294 static struct pwd *
pwd_alloc(void)4295 pwd_alloc(void)
4296 {
4297 struct pwd *pwd;
4298
4299 pwd = uma_zalloc_smr(pwd_zone, M_WAITOK);
4300 bzero(pwd, sizeof(*pwd));
4301 refcount_init(&pwd->pwd_refcount, 1);
4302 return (pwd);
4303 }
4304
4305 void
pwd_drop(struct pwd * pwd)4306 pwd_drop(struct pwd *pwd)
4307 {
4308
4309 if (!refcount_release(&pwd->pwd_refcount))
4310 return;
4311
4312 if (pwd->pwd_cdir != NULL)
4313 vrele(pwd->pwd_cdir);
4314 if (pwd->pwd_rdir != NULL)
4315 vrele(pwd->pwd_rdir);
4316 if (pwd->pwd_jdir != NULL)
4317 vrele(pwd->pwd_jdir);
4318 if (pwd->pwd_adir != NULL)
4319 vrele(pwd->pwd_adir);
4320 uma_zfree_smr(pwd_zone, pwd);
4321 }
4322
4323 /*
4324 * The caller is responsible for invoking priv_check() and
4325 * mac_vnode_check_chroot() to authorize this operation.
4326 */
4327 int
pwd_chroot(struct thread * td,struct vnode * vp)4328 pwd_chroot(struct thread *td, struct vnode *vp)
4329 {
4330 struct pwddesc *pdp;
4331 struct filedesc *fdp;
4332 struct pwd *newpwd, *oldpwd;
4333 int error;
4334
4335 fdp = td->td_proc->p_fd;
4336 pdp = td->td_proc->p_pd;
4337 newpwd = pwd_alloc();
4338 FILEDESC_SLOCK(fdp);
4339 PWDDESC_XLOCK(pdp);
4340 oldpwd = PWDDESC_XLOCKED_LOAD_PWD(pdp);
4341 if (chroot_allow_open_directories == 0 ||
4342 (chroot_allow_open_directories == 1 &&
4343 oldpwd->pwd_rdir != rootvnode)) {
4344 error = chroot_refuse_vdir_fds(fdp);
4345 FILEDESC_SUNLOCK(fdp);
4346 if (error != 0) {
4347 PWDDESC_XUNLOCK(pdp);
4348 pwd_drop(newpwd);
4349 return (error);
4350 }
4351 } else {
4352 FILEDESC_SUNLOCK(fdp);
4353 }
4354
4355 vrefact(vp);
4356 newpwd->pwd_rdir = vp;
4357 vrefact(vp);
4358 newpwd->pwd_adir = vp;
4359 if (oldpwd->pwd_jdir == NULL) {
4360 vrefact(vp);
4361 newpwd->pwd_jdir = vp;
4362 }
4363 pwd_fill(oldpwd, newpwd);
4364 pwd_set(pdp, newpwd);
4365 PWDDESC_XUNLOCK(pdp);
4366 pwd_drop(oldpwd);
4367 return (0);
4368 }
4369
4370 void
pwd_chdir(struct thread * td,struct vnode * vp)4371 pwd_chdir(struct thread *td, struct vnode *vp)
4372 {
4373 struct pwddesc *pdp;
4374 struct pwd *newpwd, *oldpwd;
4375
4376 VNPASS(vp->v_usecount > 0, vp);
4377
4378 newpwd = pwd_alloc();
4379 pdp = td->td_proc->p_pd;
4380 PWDDESC_XLOCK(pdp);
4381 oldpwd = PWDDESC_XLOCKED_LOAD_PWD(pdp);
4382 newpwd->pwd_cdir = vp;
4383 pwd_fill(oldpwd, newpwd);
4384 pwd_set(pdp, newpwd);
4385 PWDDESC_XUNLOCK(pdp);
4386 pwd_drop(oldpwd);
4387 }
4388
4389 /*
4390 * Process is transitioning to/from a non-native ABI.
4391 */
4392 void
pwd_altroot(struct thread * td,struct vnode * altroot_vp)4393 pwd_altroot(struct thread *td, struct vnode *altroot_vp)
4394 {
4395 struct pwddesc *pdp;
4396 struct pwd *newpwd, *oldpwd;
4397
4398 newpwd = pwd_alloc();
4399 pdp = td->td_proc->p_pd;
4400 PWDDESC_XLOCK(pdp);
4401 oldpwd = PWDDESC_XLOCKED_LOAD_PWD(pdp);
4402 if (altroot_vp != NULL) {
4403 /*
4404 * Native process to a non-native ABI.
4405 */
4406
4407 vrefact(altroot_vp);
4408 newpwd->pwd_adir = altroot_vp;
4409 } else {
4410 /*
4411 * Non-native process to the native ABI.
4412 */
4413
4414 vrefact(oldpwd->pwd_rdir);
4415 newpwd->pwd_adir = oldpwd->pwd_rdir;
4416 }
4417 pwd_fill(oldpwd, newpwd);
4418 pwd_set(pdp, newpwd);
4419 PWDDESC_XUNLOCK(pdp);
4420 pwd_drop(oldpwd);
4421 }
4422
4423 /*
4424 * jail_attach(2) changes both root and working directories.
4425 */
4426 int
pwd_chroot_chdir(struct thread * td,struct vnode * vp)4427 pwd_chroot_chdir(struct thread *td, struct vnode *vp)
4428 {
4429 struct pwddesc *pdp;
4430 struct filedesc *fdp;
4431 struct pwd *newpwd, *oldpwd;
4432 int error;
4433
4434 fdp = td->td_proc->p_fd;
4435 pdp = td->td_proc->p_pd;
4436 newpwd = pwd_alloc();
4437 FILEDESC_SLOCK(fdp);
4438 PWDDESC_XLOCK(pdp);
4439 oldpwd = PWDDESC_XLOCKED_LOAD_PWD(pdp);
4440 error = chroot_refuse_vdir_fds(fdp);
4441 FILEDESC_SUNLOCK(fdp);
4442 if (error != 0) {
4443 PWDDESC_XUNLOCK(pdp);
4444 pwd_drop(newpwd);
4445 return (error);
4446 }
4447
4448 vrefact(vp);
4449 newpwd->pwd_rdir = vp;
4450 vrefact(vp);
4451 newpwd->pwd_cdir = vp;
4452 if (oldpwd->pwd_jdir == NULL) {
4453 vrefact(vp);
4454 newpwd->pwd_jdir = vp;
4455 }
4456 vrefact(vp);
4457 newpwd->pwd_adir = vp;
4458 pwd_fill(oldpwd, newpwd);
4459 pwd_set(pdp, newpwd);
4460 PWDDESC_XUNLOCK(pdp);
4461 pwd_drop(oldpwd);
4462 return (0);
4463 }
4464
4465 void
pwd_ensure_dirs(void)4466 pwd_ensure_dirs(void)
4467 {
4468 struct pwddesc *pdp;
4469 struct pwd *oldpwd, *newpwd;
4470
4471 pdp = curproc->p_pd;
4472 PWDDESC_XLOCK(pdp);
4473 oldpwd = PWDDESC_XLOCKED_LOAD_PWD(pdp);
4474 if (oldpwd->pwd_cdir != NULL && oldpwd->pwd_rdir != NULL &&
4475 oldpwd->pwd_adir != NULL) {
4476 PWDDESC_XUNLOCK(pdp);
4477 return;
4478 }
4479 PWDDESC_XUNLOCK(pdp);
4480
4481 newpwd = pwd_alloc();
4482 PWDDESC_XLOCK(pdp);
4483 oldpwd = PWDDESC_XLOCKED_LOAD_PWD(pdp);
4484 pwd_fill(oldpwd, newpwd);
4485 if (newpwd->pwd_cdir == NULL) {
4486 vrefact(rootvnode);
4487 newpwd->pwd_cdir = rootvnode;
4488 }
4489 if (newpwd->pwd_rdir == NULL) {
4490 vrefact(rootvnode);
4491 newpwd->pwd_rdir = rootvnode;
4492 }
4493 if (newpwd->pwd_adir == NULL) {
4494 vrefact(rootvnode);
4495 newpwd->pwd_adir = rootvnode;
4496 }
4497 pwd_set(pdp, newpwd);
4498 PWDDESC_XUNLOCK(pdp);
4499 pwd_drop(oldpwd);
4500 }
4501
4502 void
pwd_set_rootvnode(void)4503 pwd_set_rootvnode(void)
4504 {
4505 struct pwddesc *pdp;
4506 struct pwd *oldpwd, *newpwd;
4507
4508 pdp = curproc->p_pd;
4509
4510 newpwd = pwd_alloc();
4511 PWDDESC_XLOCK(pdp);
4512 oldpwd = PWDDESC_XLOCKED_LOAD_PWD(pdp);
4513 vrefact(rootvnode);
4514 newpwd->pwd_cdir = rootvnode;
4515 vrefact(rootvnode);
4516 newpwd->pwd_rdir = rootvnode;
4517 vrefact(rootvnode);
4518 newpwd->pwd_adir = rootvnode;
4519 pwd_fill(oldpwd, newpwd);
4520 pwd_set(pdp, newpwd);
4521 PWDDESC_XUNLOCK(pdp);
4522 pwd_drop(oldpwd);
4523 }
4524
4525 /*
4526 * Scan all active processes and prisons to see if any of them have a current
4527 * or root directory of `olddp'. If so, replace them with the new mount point.
4528 */
4529 void
mountcheckdirs(struct vnode * olddp,struct vnode * newdp)4530 mountcheckdirs(struct vnode *olddp, struct vnode *newdp)
4531 {
4532 struct pwddesc *pdp;
4533 struct pwd *newpwd, *oldpwd;
4534 struct prison *pr;
4535 struct proc *p;
4536 int nrele;
4537
4538 if (vrefcnt(olddp) == 1)
4539 return;
4540 nrele = 0;
4541 newpwd = pwd_alloc();
4542 sx_slock(&allproc_lock);
4543 FOREACH_PROC_IN_SYSTEM(p) {
4544 PROC_LOCK(p);
4545 pdp = pdhold(p);
4546 PROC_UNLOCK(p);
4547 if (pdp == NULL)
4548 continue;
4549 PWDDESC_XLOCK(pdp);
4550 oldpwd = PWDDESC_XLOCKED_LOAD_PWD(pdp);
4551 if (oldpwd == NULL ||
4552 (oldpwd->pwd_cdir != olddp &&
4553 oldpwd->pwd_rdir != olddp &&
4554 oldpwd->pwd_jdir != olddp &&
4555 oldpwd->pwd_adir != olddp)) {
4556 PWDDESC_XUNLOCK(pdp);
4557 pddrop(pdp);
4558 continue;
4559 }
4560 if (oldpwd->pwd_cdir == olddp) {
4561 vrefact(newdp);
4562 newpwd->pwd_cdir = newdp;
4563 }
4564 if (oldpwd->pwd_rdir == olddp) {
4565 vrefact(newdp);
4566 newpwd->pwd_rdir = newdp;
4567 }
4568 if (oldpwd->pwd_jdir == olddp) {
4569 vrefact(newdp);
4570 newpwd->pwd_jdir = newdp;
4571 }
4572 if (oldpwd->pwd_adir == olddp) {
4573 vrefact(newdp);
4574 newpwd->pwd_adir = newdp;
4575 }
4576 pwd_fill(oldpwd, newpwd);
4577 pwd_set(pdp, newpwd);
4578 PWDDESC_XUNLOCK(pdp);
4579 pwd_drop(oldpwd);
4580 pddrop(pdp);
4581 newpwd = pwd_alloc();
4582 }
4583 sx_sunlock(&allproc_lock);
4584 pwd_drop(newpwd);
4585 if (rootvnode == olddp) {
4586 vrefact(newdp);
4587 rootvnode = newdp;
4588 nrele++;
4589 }
4590 mtx_lock(&prison0.pr_mtx);
4591 if (prison0.pr_root == olddp) {
4592 vrefact(newdp);
4593 prison0.pr_root = newdp;
4594 nrele++;
4595 }
4596 mtx_unlock(&prison0.pr_mtx);
4597 sx_slock(&allprison_lock);
4598 TAILQ_FOREACH(pr, &allprison, pr_list) {
4599 mtx_lock(&pr->pr_mtx);
4600 if (pr->pr_root == olddp) {
4601 vrefact(newdp);
4602 pr->pr_root = newdp;
4603 nrele++;
4604 }
4605 mtx_unlock(&pr->pr_mtx);
4606 }
4607 sx_sunlock(&allprison_lock);
4608 while (nrele--)
4609 vrele(olddp);
4610 }
4611
4612 int
descrip_check_write_mp(struct filedesc * fdp,struct mount * mp)4613 descrip_check_write_mp(struct filedesc *fdp, struct mount *mp)
4614 {
4615 struct file *fp;
4616 struct vnode *vp;
4617 int error, i;
4618
4619 error = 0;
4620 FILEDESC_SLOCK(fdp);
4621 FILEDESC_FOREACH_FP(fdp, i, fp) {
4622 if (fp->f_type != DTYPE_VNODE ||
4623 (atomic_load_int(&fp->f_flag) & FWRITE) == 0)
4624 continue;
4625 vp = fp->f_vnode;
4626 if (vp->v_mount == mp) {
4627 error = EDEADLK;
4628 break;
4629 }
4630 }
4631 FILEDESC_SUNLOCK(fdp);
4632 return (error);
4633 }
4634
4635 struct filedesc_to_leader *
filedesc_to_leader_alloc(struct filedesc_to_leader * old,struct filedesc * fdp,struct proc * leader)4636 filedesc_to_leader_alloc(struct filedesc_to_leader *old, struct filedesc *fdp,
4637 struct proc *leader)
4638 {
4639 struct filedesc_to_leader *fdtol;
4640
4641 fdtol = malloc(sizeof(struct filedesc_to_leader),
4642 M_FILEDESC_TO_LEADER, M_WAITOK);
4643 fdtol->fdl_refcount = 1;
4644 fdtol->fdl_holdcount = 0;
4645 fdtol->fdl_wakeup = 0;
4646 fdtol->fdl_leader = leader;
4647 if (old != NULL) {
4648 FILEDESC_XLOCK(fdp);
4649 fdtol->fdl_next = old->fdl_next;
4650 fdtol->fdl_prev = old;
4651 old->fdl_next = fdtol;
4652 fdtol->fdl_next->fdl_prev = fdtol;
4653 FILEDESC_XUNLOCK(fdp);
4654 } else {
4655 fdtol->fdl_next = fdtol;
4656 fdtol->fdl_prev = fdtol;
4657 }
4658 return (fdtol);
4659 }
4660
4661 struct filedesc_to_leader *
filedesc_to_leader_share(struct filedesc_to_leader * fdtol,struct filedesc * fdp)4662 filedesc_to_leader_share(struct filedesc_to_leader *fdtol, struct filedesc *fdp)
4663 {
4664 FILEDESC_XLOCK(fdp);
4665 fdtol->fdl_refcount++;
4666 FILEDESC_XUNLOCK(fdp);
4667 return (fdtol);
4668 }
4669
4670 static int
filedesc_nfiles(struct filedesc * fdp)4671 filedesc_nfiles(struct filedesc *fdp)
4672 {
4673 NDSLOTTYPE *map;
4674 int count, off, minoff;
4675
4676 if (fdp == NULL)
4677 return (0);
4678 count = 0;
4679 FILEDESC_SLOCK(fdp);
4680 map = fdp->fd_map;
4681 off = NDSLOT(fdp->fd_nfiles - 1);
4682 for (minoff = NDSLOT(0); off >= minoff; --off)
4683 count += bitcountl(map[off]);
4684 FILEDESC_SUNLOCK(fdp);
4685 return (count);
4686 }
4687
4688 int
proc_nfiles(struct proc * p)4689 proc_nfiles(struct proc *p)
4690 {
4691 struct filedesc *fdp;
4692 int res;
4693
4694 PROC_LOCK(p);
4695 fdp = fdhold(p);
4696 PROC_UNLOCK(p);
4697 res = filedesc_nfiles(fdp);
4698 fddrop(fdp);
4699 return (res);
4700 }
4701
4702 static int
sysctl_kern_proc_nfds(SYSCTL_HANDLER_ARGS)4703 sysctl_kern_proc_nfds(SYSCTL_HANDLER_ARGS)
4704 {
4705 u_int namelen;
4706 int count;
4707
4708 namelen = arg2;
4709 if (namelen != 1)
4710 return (EINVAL);
4711
4712 if (*(int *)arg1 != 0)
4713 return (EINVAL);
4714
4715 count = filedesc_nfiles(curproc->p_fd);
4716 return (SYSCTL_OUT(req, &count, sizeof(count)));
4717 }
4718
4719 static SYSCTL_NODE(_kern_proc, KERN_PROC_NFDS, nfds,
4720 CTLFLAG_RD|CTLFLAG_CAPRD|CTLFLAG_MPSAFE, sysctl_kern_proc_nfds,
4721 "Number of open file descriptors");
4722
4723 /*
4724 * Get file structures globally.
4725 */
4726 static int
sysctl_kern_file(SYSCTL_HANDLER_ARGS)4727 sysctl_kern_file(SYSCTL_HANDLER_ARGS)
4728 {
4729 struct xfile xf;
4730 struct filedesc *fdp;
4731 struct file *fp;
4732 struct proc *p;
4733 int error, n;
4734
4735 error = sysctl_wire_old_buffer(req, 0);
4736 if (error != 0)
4737 return (error);
4738 if (req->oldptr == NULL) {
4739 n = 0;
4740 sx_slock(&allproc_lock);
4741 FOREACH_PROC_IN_SYSTEM(p) {
4742 PROC_LOCK(p);
4743 if (p->p_state == PRS_NEW) {
4744 PROC_UNLOCK(p);
4745 continue;
4746 }
4747 fdp = fdhold(p);
4748 PROC_UNLOCK(p);
4749 if (fdp == NULL)
4750 continue;
4751 /* overestimates sparse tables. */
4752 n += fdp->fd_nfiles;
4753 fddrop(fdp);
4754 }
4755 sx_sunlock(&allproc_lock);
4756 return (SYSCTL_OUT(req, 0, n * sizeof(xf)));
4757 }
4758 error = 0;
4759 bzero(&xf, sizeof(xf));
4760 xf.xf_size = sizeof(xf);
4761 sx_slock(&allproc_lock);
4762 FOREACH_PROC_IN_SYSTEM(p) {
4763 PROC_LOCK(p);
4764 if (p->p_state == PRS_NEW) {
4765 PROC_UNLOCK(p);
4766 continue;
4767 }
4768 if (p_cansee(req->td, p) != 0) {
4769 PROC_UNLOCK(p);
4770 continue;
4771 }
4772 xf.xf_pid = p->p_pid;
4773 xf.xf_uid = p->p_ucred->cr_uid;
4774 fdp = fdhold(p);
4775 PROC_UNLOCK(p);
4776 if (fdp == NULL)
4777 continue;
4778 FILEDESC_SLOCK(fdp);
4779 if (refcount_load(&fdp->fd_refcnt) == 0)
4780 goto nextproc;
4781 FILEDESC_FOREACH_FP(fdp, n, fp) {
4782 xf.xf_fd = n;
4783 xf.xf_file = (uintptr_t)fp;
4784 xf.xf_data = (uintptr_t)fp->f_data;
4785 xf.xf_vnode = (uintptr_t)fp->f_vnode;
4786 xf.xf_type = (uintptr_t)fp->f_type;
4787 xf.xf_count = refcount_load(&fp->f_count);
4788 xf.xf_msgcount = 0;
4789 xf.xf_offset = foffset_get(fp);
4790 xf.xf_flag = fp->f_flag;
4791 error = SYSCTL_OUT(req, &xf, sizeof(xf));
4792
4793 /*
4794 * There is no need to re-check the fdtable refcount
4795 * here since the filedesc lock is not dropped in the
4796 * loop body.
4797 */
4798 if (error != 0)
4799 break;
4800 }
4801 nextproc:
4802 FILEDESC_SUNLOCK(fdp);
4803 fddrop(fdp);
4804 if (error)
4805 break;
4806 }
4807 sx_sunlock(&allproc_lock);
4808 return (error);
4809 }
4810
4811 SYSCTL_PROC(_kern, KERN_FILE, file, CTLTYPE_OPAQUE|CTLFLAG_RD|CTLFLAG_MPSAFE,
4812 0, 0, sysctl_kern_file, "S,xfile", "Entire file table");
4813
4814 #ifdef KINFO_FILE_SIZE
4815 CTASSERT(sizeof(struct kinfo_file) == KINFO_FILE_SIZE);
4816 #endif
4817
4818 static int
xlate_fflags(int fflags)4819 xlate_fflags(int fflags)
4820 {
4821 static const struct {
4822 int fflag;
4823 int kf_fflag;
4824 } fflags_table[] = {
4825 { FAPPEND, KF_FLAG_APPEND },
4826 { FASYNC, KF_FLAG_ASYNC },
4827 { FFSYNC, KF_FLAG_FSYNC },
4828 { FHASLOCK, KF_FLAG_HASLOCK },
4829 { FNONBLOCK, KF_FLAG_NONBLOCK },
4830 { FREAD, KF_FLAG_READ },
4831 { FWRITE, KF_FLAG_WRITE },
4832 { O_CREAT, KF_FLAG_CREAT },
4833 { O_DIRECT, KF_FLAG_DIRECT },
4834 { O_EXCL, KF_FLAG_EXCL },
4835 { O_EXEC, KF_FLAG_EXEC },
4836 { O_EXLOCK, KF_FLAG_EXLOCK },
4837 { O_NOFOLLOW, KF_FLAG_NOFOLLOW },
4838 { O_SHLOCK, KF_FLAG_SHLOCK },
4839 { O_TRUNC, KF_FLAG_TRUNC }
4840 };
4841 unsigned int i;
4842 int kflags;
4843
4844 kflags = 0;
4845 for (i = 0; i < nitems(fflags_table); i++)
4846 if (fflags & fflags_table[i].fflag)
4847 kflags |= fflags_table[i].kf_fflag;
4848 return (kflags);
4849 }
4850
4851 /* Trim unused data from kf_path by truncating the structure size. */
4852 void
pack_kinfo(struct kinfo_file * kif)4853 pack_kinfo(struct kinfo_file *kif)
4854 {
4855
4856 kif->kf_structsize = offsetof(struct kinfo_file, kf_path) +
4857 strlen(kif->kf_path) + 1;
4858 kif->kf_structsize = roundup(kif->kf_structsize, sizeof(uint64_t));
4859 }
4860
4861 static void
export_file_to_kinfo(struct file * fp,int fd,cap_rights_t * rightsp,struct kinfo_file * kif,struct filedesc * fdp,int flags)4862 export_file_to_kinfo(struct file *fp, int fd, cap_rights_t *rightsp,
4863 struct kinfo_file *kif, struct filedesc *fdp, int flags)
4864 {
4865 int error;
4866
4867 bzero(kif, sizeof(*kif));
4868
4869 /* Set a default type to allow for empty fill_kinfo() methods. */
4870 kif->kf_type = KF_TYPE_UNKNOWN;
4871 kif->kf_flags = xlate_fflags(fp->f_flag);
4872 if (rightsp != NULL)
4873 kif->kf_cap_rights = *rightsp;
4874 else
4875 cap_rights_init_zero(&kif->kf_cap_rights);
4876 kif->kf_fd = fd;
4877 kif->kf_ref_count = refcount_load(&fp->f_count);
4878 kif->kf_offset = foffset_get(fp);
4879
4880 /*
4881 * This may drop the filedesc lock, so the 'fp' cannot be
4882 * accessed after this call.
4883 */
4884 error = fo_fill_kinfo(fp, kif, fdp);
4885 if (error == 0)
4886 kif->kf_status |= KF_ATTR_VALID;
4887 if ((flags & KERN_FILEDESC_PACK_KINFO) != 0)
4888 pack_kinfo(kif);
4889 else
4890 kif->kf_structsize = roundup2(sizeof(*kif), sizeof(uint64_t));
4891 }
4892
4893 static void
export_vnode_to_kinfo(struct vnode * vp,int fd,int fflags,struct kinfo_file * kif,int flags)4894 export_vnode_to_kinfo(struct vnode *vp, int fd, int fflags,
4895 struct kinfo_file *kif, int flags)
4896 {
4897 int error;
4898
4899 bzero(kif, sizeof(*kif));
4900
4901 kif->kf_type = KF_TYPE_VNODE;
4902 error = vn_fill_kinfo_vnode(vp, kif);
4903 if (error == 0)
4904 kif->kf_status |= KF_ATTR_VALID;
4905 kif->kf_flags = xlate_fflags(fflags);
4906 cap_rights_init_zero(&kif->kf_cap_rights);
4907 kif->kf_fd = fd;
4908 kif->kf_ref_count = -1;
4909 kif->kf_offset = -1;
4910 if ((flags & KERN_FILEDESC_PACK_KINFO) != 0)
4911 pack_kinfo(kif);
4912 else
4913 kif->kf_structsize = roundup2(sizeof(*kif), sizeof(uint64_t));
4914 vrele(vp);
4915 }
4916
4917 struct export_fd_buf {
4918 struct filedesc *fdp;
4919 struct pwddesc *pdp;
4920 struct sbuf *sb;
4921 ssize_t remainder;
4922 struct kinfo_file kif;
4923 int flags;
4924 };
4925
4926 static int
export_kinfo_to_sb(struct export_fd_buf * efbuf)4927 export_kinfo_to_sb(struct export_fd_buf *efbuf)
4928 {
4929 struct kinfo_file *kif;
4930
4931 kif = &efbuf->kif;
4932 if (efbuf->remainder != -1) {
4933 if (efbuf->remainder < kif->kf_structsize)
4934 return (ENOMEM);
4935 efbuf->remainder -= kif->kf_structsize;
4936 }
4937 if (sbuf_bcat(efbuf->sb, kif, kif->kf_structsize) != 0)
4938 return (sbuf_error(efbuf->sb));
4939 return (0);
4940 }
4941
4942 static int
export_file_to_sb(struct file * fp,int fd,cap_rights_t * rightsp,struct export_fd_buf * efbuf)4943 export_file_to_sb(struct file *fp, int fd, cap_rights_t *rightsp,
4944 struct export_fd_buf *efbuf)
4945 {
4946 int error;
4947
4948 if (efbuf->remainder == 0)
4949 return (ENOMEM);
4950 export_file_to_kinfo(fp, fd, rightsp, &efbuf->kif, efbuf->fdp,
4951 efbuf->flags);
4952 FILEDESC_SUNLOCK(efbuf->fdp);
4953 error = export_kinfo_to_sb(efbuf);
4954 FILEDESC_SLOCK(efbuf->fdp);
4955 return (error);
4956 }
4957
4958 static int
export_vnode_to_sb(struct vnode * vp,int fd,int fflags,struct export_fd_buf * efbuf)4959 export_vnode_to_sb(struct vnode *vp, int fd, int fflags,
4960 struct export_fd_buf *efbuf)
4961 {
4962 int error;
4963
4964 if (efbuf->remainder == 0)
4965 return (ENOMEM);
4966 if (efbuf->pdp != NULL)
4967 PWDDESC_XUNLOCK(efbuf->pdp);
4968 export_vnode_to_kinfo(vp, fd, fflags, &efbuf->kif, efbuf->flags);
4969 error = export_kinfo_to_sb(efbuf);
4970 if (efbuf->pdp != NULL)
4971 PWDDESC_XLOCK(efbuf->pdp);
4972 return (error);
4973 }
4974
4975 /*
4976 * Store a process file descriptor information to sbuf.
4977 *
4978 * Takes a locked proc as argument, and returns with the proc unlocked.
4979 */
4980 int
kern_proc_filedesc_out(struct proc * p,struct sbuf * sb,ssize_t maxlen,int flags)4981 kern_proc_filedesc_out(struct proc *p, struct sbuf *sb, ssize_t maxlen,
4982 int flags)
4983 {
4984 struct file *fp;
4985 struct filedesc *fdp;
4986 struct pwddesc *pdp;
4987 struct export_fd_buf *efbuf;
4988 struct vnode *cttyvp, *textvp, *tracevp;
4989 struct pwd *pwd;
4990 int error, i;
4991 cap_rights_t rights;
4992
4993 PROC_LOCK_ASSERT(p, MA_OWNED);
4994
4995 /* ktrace vnode */
4996 tracevp = ktr_get_tracevp(p, true);
4997 /* text vnode */
4998 textvp = p->p_textvp;
4999 if (textvp != NULL)
5000 vrefact(textvp);
5001 /* Controlling tty. */
5002 cttyvp = NULL;
5003 if (p->p_pgrp != NULL && p->p_pgrp->pg_session != NULL) {
5004 cttyvp = p->p_pgrp->pg_session->s_ttyvp;
5005 if (cttyvp != NULL)
5006 vrefact(cttyvp);
5007 }
5008 fdp = fdhold(p);
5009 pdp = pdhold(p);
5010 PROC_UNLOCK(p);
5011
5012 efbuf = malloc(sizeof(*efbuf), M_TEMP, M_WAITOK);
5013 efbuf->fdp = NULL;
5014 efbuf->pdp = NULL;
5015 efbuf->sb = sb;
5016 efbuf->remainder = maxlen;
5017 efbuf->flags = flags;
5018
5019 error = 0;
5020 if (tracevp != NULL)
5021 error = export_vnode_to_sb(tracevp, KF_FD_TYPE_TRACE,
5022 FREAD | FWRITE, efbuf);
5023 if (error == 0 && textvp != NULL)
5024 error = export_vnode_to_sb(textvp, KF_FD_TYPE_TEXT, FREAD,
5025 efbuf);
5026 if (error == 0 && cttyvp != NULL)
5027 error = export_vnode_to_sb(cttyvp, KF_FD_TYPE_CTTY,
5028 FREAD | FWRITE, efbuf);
5029 if (error != 0 || pdp == NULL || fdp == NULL)
5030 goto fail;
5031 efbuf->fdp = fdp;
5032 efbuf->pdp = pdp;
5033 PWDDESC_XLOCK(pdp);
5034 pwd = pwd_hold_pwddesc(pdp);
5035 if (pwd != NULL) {
5036 /* working directory */
5037 if (pwd->pwd_cdir != NULL) {
5038 vrefact(pwd->pwd_cdir);
5039 error = export_vnode_to_sb(pwd->pwd_cdir,
5040 KF_FD_TYPE_CWD, FREAD, efbuf);
5041 }
5042 /* root directory */
5043 if (error == 0 && pwd->pwd_rdir != NULL) {
5044 vrefact(pwd->pwd_rdir);
5045 error = export_vnode_to_sb(pwd->pwd_rdir,
5046 KF_FD_TYPE_ROOT, FREAD, efbuf);
5047 }
5048 /* jail directory */
5049 if (error == 0 && pwd->pwd_jdir != NULL) {
5050 vrefact(pwd->pwd_jdir);
5051 error = export_vnode_to_sb(pwd->pwd_jdir,
5052 KF_FD_TYPE_JAIL, FREAD, efbuf);
5053 }
5054 }
5055 PWDDESC_XUNLOCK(pdp);
5056 if (error != 0)
5057 goto fail;
5058 if (pwd != NULL)
5059 pwd_drop(pwd);
5060 FILEDESC_SLOCK(fdp);
5061 if (refcount_load(&fdp->fd_refcnt) == 0)
5062 goto skip;
5063 FILEDESC_FOREACH_FP(fdp, i, fp) {
5064 #ifdef CAPABILITIES
5065 rights = *cap_rights(fdp, i);
5066 #else /* !CAPABILITIES */
5067 rights = cap_no_rights;
5068 #endif
5069 /*
5070 * Create sysctl entry. It is OK to drop the filedesc
5071 * lock inside of export_file_to_sb() as we will
5072 * re-validate and re-evaluate its properties when the
5073 * loop continues.
5074 */
5075 error = export_file_to_sb(fp, i, &rights, efbuf);
5076 if (error != 0 || refcount_load(&fdp->fd_refcnt) == 0)
5077 break;
5078 }
5079 skip:
5080 FILEDESC_SUNLOCK(fdp);
5081 fail:
5082 if (fdp != NULL)
5083 fddrop(fdp);
5084 if (pdp != NULL)
5085 pddrop(pdp);
5086 free(efbuf, M_TEMP);
5087 return (error);
5088 }
5089
5090 #define FILEDESC_SBUF_SIZE (sizeof(struct kinfo_file) * 5)
5091
5092 /*
5093 * Get per-process file descriptors for use by procstat(1), et al.
5094 */
5095 static int
sysctl_kern_proc_filedesc(SYSCTL_HANDLER_ARGS)5096 sysctl_kern_proc_filedesc(SYSCTL_HANDLER_ARGS)
5097 {
5098 struct sbuf sb;
5099 struct proc *p;
5100 ssize_t maxlen;
5101 u_int namelen;
5102 int error, error2, *name;
5103
5104 namelen = arg2;
5105 if (namelen != 1)
5106 return (EINVAL);
5107
5108 name = (int *)arg1;
5109
5110 sbuf_new_for_sysctl(&sb, NULL, FILEDESC_SBUF_SIZE, req);
5111 sbuf_clear_flags(&sb, SBUF_INCLUDENUL);
5112 error = pget((pid_t)name[0], PGET_CANDEBUG | PGET_NOTWEXIT, &p);
5113 if (error != 0) {
5114 sbuf_delete(&sb);
5115 return (error);
5116 }
5117 maxlen = req->oldptr != NULL ? req->oldlen : -1;
5118 error = kern_proc_filedesc_out(p, &sb, maxlen,
5119 KERN_FILEDESC_PACK_KINFO);
5120 error2 = sbuf_finish(&sb);
5121 sbuf_delete(&sb);
5122 return (error != 0 ? error : error2);
5123 }
5124
5125 #ifdef COMPAT_FREEBSD7
5126 #ifdef KINFO_OFILE_SIZE
5127 CTASSERT(sizeof(struct kinfo_ofile) == KINFO_OFILE_SIZE);
5128 #endif
5129
5130 static void
kinfo_to_okinfo(struct kinfo_file * kif,struct kinfo_ofile * okif)5131 kinfo_to_okinfo(struct kinfo_file *kif, struct kinfo_ofile *okif)
5132 {
5133
5134 okif->kf_structsize = sizeof(*okif);
5135 okif->kf_type = kif->kf_type;
5136 okif->kf_fd = kif->kf_fd;
5137 okif->kf_ref_count = kif->kf_ref_count;
5138 okif->kf_flags = kif->kf_flags & (KF_FLAG_READ | KF_FLAG_WRITE |
5139 KF_FLAG_APPEND | KF_FLAG_ASYNC | KF_FLAG_FSYNC | KF_FLAG_NONBLOCK |
5140 KF_FLAG_DIRECT | KF_FLAG_HASLOCK);
5141 okif->kf_offset = kif->kf_offset;
5142 if (kif->kf_type == KF_TYPE_VNODE)
5143 okif->kf_vnode_type = kif->kf_un.kf_file.kf_file_type;
5144 else
5145 okif->kf_vnode_type = KF_VTYPE_VNON;
5146 strlcpy(okif->kf_path, kif->kf_path, sizeof(okif->kf_path));
5147 if (kif->kf_type == KF_TYPE_SOCKET) {
5148 okif->kf_sock_domain = kif->kf_un.kf_sock.kf_sock_domain0;
5149 okif->kf_sock_type = kif->kf_un.kf_sock.kf_sock_type0;
5150 okif->kf_sock_protocol = kif->kf_un.kf_sock.kf_sock_protocol0;
5151 okif->kf_sa_local = kif->kf_un.kf_sock.kf_sa_local;
5152 okif->kf_sa_peer = kif->kf_un.kf_sock.kf_sa_peer;
5153 } else {
5154 okif->kf_sa_local.ss_family = AF_UNSPEC;
5155 okif->kf_sa_peer.ss_family = AF_UNSPEC;
5156 }
5157 }
5158
5159 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)5160 export_vnode_for_osysctl(struct vnode *vp, int type, struct kinfo_file *kif,
5161 struct kinfo_ofile *okif, struct pwddesc *pdp, struct sysctl_req *req)
5162 {
5163 int error;
5164
5165 vrefact(vp);
5166 PWDDESC_XUNLOCK(pdp);
5167 export_vnode_to_kinfo(vp, type, 0, kif, KERN_FILEDESC_PACK_KINFO);
5168 kinfo_to_okinfo(kif, okif);
5169 error = SYSCTL_OUT(req, okif, sizeof(*okif));
5170 PWDDESC_XLOCK(pdp);
5171 return (error);
5172 }
5173
5174 /*
5175 * Get per-process file descriptors for use by procstat(1), et al.
5176 */
5177 static int
sysctl_kern_proc_ofiledesc(SYSCTL_HANDLER_ARGS)5178 sysctl_kern_proc_ofiledesc(SYSCTL_HANDLER_ARGS)
5179 {
5180 struct kinfo_ofile *okif;
5181 struct kinfo_file *kif;
5182 struct filedesc *fdp;
5183 struct pwddesc *pdp;
5184 struct pwd *pwd;
5185 u_int namelen;
5186 int error, i, *name;
5187 struct file *fp;
5188 struct proc *p;
5189
5190 namelen = arg2;
5191 if (namelen != 1)
5192 return (EINVAL);
5193
5194 name = (int *)arg1;
5195 error = pget((pid_t)name[0], PGET_CANDEBUG | PGET_NOTWEXIT, &p);
5196 if (error != 0)
5197 return (error);
5198 fdp = fdhold(p);
5199 if (fdp != NULL)
5200 pdp = pdhold(p);
5201 PROC_UNLOCK(p);
5202 if (fdp == NULL || pdp == NULL) {
5203 if (fdp != NULL)
5204 fddrop(fdp);
5205 return (ENOENT);
5206 }
5207 kif = malloc(sizeof(*kif), M_TEMP, M_WAITOK);
5208 okif = malloc(sizeof(*okif), M_TEMP, M_WAITOK | M_ZERO);
5209 PWDDESC_XLOCK(pdp);
5210 pwd = pwd_hold_pwddesc(pdp);
5211 if (pwd != NULL) {
5212 if (pwd->pwd_cdir != NULL)
5213 export_vnode_for_osysctl(pwd->pwd_cdir, KF_FD_TYPE_CWD, kif,
5214 okif, pdp, req);
5215 if (pwd->pwd_rdir != NULL)
5216 export_vnode_for_osysctl(pwd->pwd_rdir, KF_FD_TYPE_ROOT, kif,
5217 okif, pdp, req);
5218 if (pwd->pwd_jdir != NULL)
5219 export_vnode_for_osysctl(pwd->pwd_jdir, KF_FD_TYPE_JAIL, kif,
5220 okif, pdp, req);
5221 }
5222 PWDDESC_XUNLOCK(pdp);
5223 if (pwd != NULL)
5224 pwd_drop(pwd);
5225 FILEDESC_SLOCK(fdp);
5226 if (refcount_load(&fdp->fd_refcnt) == 0)
5227 goto skip;
5228 FILEDESC_FOREACH_FP(fdp, i, fp) {
5229 export_file_to_kinfo(fp, i, NULL, kif, fdp,
5230 KERN_FILEDESC_PACK_KINFO);
5231 FILEDESC_SUNLOCK(fdp);
5232 kinfo_to_okinfo(kif, okif);
5233 error = SYSCTL_OUT(req, okif, sizeof(*okif));
5234 FILEDESC_SLOCK(fdp);
5235 if (error != 0 || refcount_load(&fdp->fd_refcnt) == 0)
5236 break;
5237 }
5238 skip:
5239 FILEDESC_SUNLOCK(fdp);
5240 fddrop(fdp);
5241 pddrop(pdp);
5242 free(kif, M_TEMP);
5243 free(okif, M_TEMP);
5244 return (0);
5245 }
5246
5247 static SYSCTL_NODE(_kern_proc, KERN_PROC_OFILEDESC, ofiledesc,
5248 CTLFLAG_RD|CTLFLAG_MPSAFE, sysctl_kern_proc_ofiledesc,
5249 "Process ofiledesc entries");
5250 #endif /* COMPAT_FREEBSD7 */
5251
5252 int
vntype_to_kinfo(int vtype)5253 vntype_to_kinfo(int vtype)
5254 {
5255 struct {
5256 int vtype;
5257 int kf_vtype;
5258 } vtypes_table[] = {
5259 { VBAD, KF_VTYPE_VBAD },
5260 { VBLK, KF_VTYPE_VBLK },
5261 { VCHR, KF_VTYPE_VCHR },
5262 { VDIR, KF_VTYPE_VDIR },
5263 { VFIFO, KF_VTYPE_VFIFO },
5264 { VLNK, KF_VTYPE_VLNK },
5265 { VNON, KF_VTYPE_VNON },
5266 { VREG, KF_VTYPE_VREG },
5267 { VSOCK, KF_VTYPE_VSOCK }
5268 };
5269 unsigned int i;
5270
5271 /*
5272 * Perform vtype translation.
5273 */
5274 for (i = 0; i < nitems(vtypes_table); i++)
5275 if (vtypes_table[i].vtype == vtype)
5276 return (vtypes_table[i].kf_vtype);
5277
5278 return (KF_VTYPE_UNKNOWN);
5279 }
5280
5281 static SYSCTL_NODE(_kern_proc, KERN_PROC_FILEDESC, filedesc,
5282 CTLFLAG_RD|CTLFLAG_MPSAFE, sysctl_kern_proc_filedesc,
5283 "Process filedesc entries");
5284
5285 /*
5286 * Store a process current working directory information to sbuf.
5287 *
5288 * Takes a locked proc as argument, and returns with the proc unlocked.
5289 */
5290 int
kern_proc_cwd_out(struct proc * p,struct sbuf * sb,ssize_t maxlen)5291 kern_proc_cwd_out(struct proc *p, struct sbuf *sb, ssize_t maxlen)
5292 {
5293 struct pwddesc *pdp;
5294 struct pwd *pwd;
5295 struct export_fd_buf *efbuf;
5296 struct vnode *cdir;
5297 int error;
5298
5299 PROC_LOCK_ASSERT(p, MA_OWNED);
5300
5301 pdp = pdhold(p);
5302 PROC_UNLOCK(p);
5303 if (pdp == NULL)
5304 return (EINVAL);
5305
5306 efbuf = malloc(sizeof(*efbuf), M_TEMP, M_WAITOK);
5307 efbuf->fdp = NULL;
5308 efbuf->pdp = pdp;
5309 efbuf->sb = sb;
5310 efbuf->remainder = maxlen;
5311 efbuf->flags = 0;
5312
5313 PWDDESC_XLOCK(pdp);
5314 pwd = PWDDESC_XLOCKED_LOAD_PWD(pdp);
5315 cdir = pwd->pwd_cdir;
5316 if (cdir == NULL) {
5317 error = EINVAL;
5318 } else {
5319 vrefact(cdir);
5320 error = export_vnode_to_sb(cdir, KF_FD_TYPE_CWD, FREAD, efbuf);
5321 }
5322 PWDDESC_XUNLOCK(pdp);
5323 pddrop(pdp);
5324 free(efbuf, M_TEMP);
5325 return (error);
5326 }
5327
5328 /*
5329 * Get per-process current working directory.
5330 */
5331 static int
sysctl_kern_proc_cwd(SYSCTL_HANDLER_ARGS)5332 sysctl_kern_proc_cwd(SYSCTL_HANDLER_ARGS)
5333 {
5334 struct sbuf sb;
5335 struct proc *p;
5336 ssize_t maxlen;
5337 u_int namelen;
5338 int error, error2, *name;
5339
5340 namelen = arg2;
5341 if (namelen != 1)
5342 return (EINVAL);
5343
5344 name = (int *)arg1;
5345
5346 sbuf_new_for_sysctl(&sb, NULL, sizeof(struct kinfo_file), req);
5347 sbuf_clear_flags(&sb, SBUF_INCLUDENUL);
5348 error = pget((pid_t)name[0], PGET_CANDEBUG | PGET_NOTWEXIT, &p);
5349 if (error != 0) {
5350 sbuf_delete(&sb);
5351 return (error);
5352 }
5353 maxlen = req->oldptr != NULL ? req->oldlen : -1;
5354 error = kern_proc_cwd_out(p, &sb, maxlen);
5355 error2 = sbuf_finish(&sb);
5356 sbuf_delete(&sb);
5357 return (error != 0 ? error : error2);
5358 }
5359
5360 static SYSCTL_NODE(_kern_proc, KERN_PROC_CWD, cwd, CTLFLAG_RD|CTLFLAG_MPSAFE,
5361 sysctl_kern_proc_cwd, "Process current working directory");
5362
5363 #ifdef DDB
5364 /*
5365 * For the purposes of debugging, generate a human-readable string for the
5366 * file type.
5367 */
5368 static const char *
file_type_to_name(short type)5369 file_type_to_name(short type)
5370 {
5371
5372 switch (type) {
5373 case 0:
5374 return ("zero");
5375 case DTYPE_VNODE:
5376 return ("vnode");
5377 case DTYPE_SOCKET:
5378 return ("socket");
5379 case DTYPE_PIPE:
5380 return ("pipe");
5381 case DTYPE_FIFO:
5382 return ("fifo");
5383 case DTYPE_KQUEUE:
5384 return ("kqueue");
5385 case DTYPE_CRYPTO:
5386 return ("crypto");
5387 case DTYPE_MQUEUE:
5388 return ("mqueue");
5389 case DTYPE_SHM:
5390 return ("shm");
5391 case DTYPE_SEM:
5392 return ("ksem");
5393 case DTYPE_PTS:
5394 return ("pts");
5395 case DTYPE_DEV:
5396 return ("dev");
5397 case DTYPE_PROCDESC:
5398 return ("proc");
5399 case DTYPE_EVENTFD:
5400 return ("eventfd");
5401 case DTYPE_TIMERFD:
5402 return ("timerfd");
5403 case DTYPE_JAILDESC:
5404 return ("jail");
5405 default:
5406 return ("unkn");
5407 }
5408 }
5409
5410 /*
5411 * For the purposes of debugging, identify a process (if any, perhaps one of
5412 * many) that references the passed file in its file descriptor array. Return
5413 * NULL if none.
5414 */
5415 static struct proc *
file_to_first_proc(struct file * fp)5416 file_to_first_proc(struct file *fp)
5417 {
5418 struct filedesc *fdp;
5419 struct proc *p;
5420 int n;
5421
5422 FOREACH_PROC_IN_SYSTEM(p) {
5423 if (p->p_state == PRS_NEW)
5424 continue;
5425 fdp = p->p_fd;
5426 if (fdp == NULL)
5427 continue;
5428 for (n = 0; n < fdp->fd_nfiles; n++) {
5429 if (fp == fdp->fd_ofiles[n].fde_file)
5430 return (p);
5431 }
5432 }
5433 return (NULL);
5434 }
5435
5436 static void
db_print_file(struct file * fp,int header)5437 db_print_file(struct file *fp, int header)
5438 {
5439 #define XPTRWIDTH ((int)howmany(sizeof(void *) * NBBY, 4))
5440 struct proc *p;
5441
5442 if (header)
5443 db_printf("%*s %6s %*s %8s %4s %5s %6s %*s %5s %s\n",
5444 XPTRWIDTH, "File", "Type", XPTRWIDTH, "Data", "Flag",
5445 "GCFl", "Count", "MCount", XPTRWIDTH, "Vnode", "FPID",
5446 "FCmd");
5447 p = file_to_first_proc(fp);
5448 db_printf("%*p %6s %*p %08x %04x %5d %6d %*p %5d %s\n", XPTRWIDTH,
5449 fp, file_type_to_name(fp->f_type), XPTRWIDTH, fp->f_data,
5450 fp->f_flag, 0, refcount_load(&fp->f_count), 0, XPTRWIDTH, fp->f_vnode,
5451 p != NULL ? p->p_pid : -1, p != NULL ? p->p_comm : "-");
5452
5453 #undef XPTRWIDTH
5454 }
5455
DB_SHOW_COMMAND(file,db_show_file)5456 DB_SHOW_COMMAND(file, db_show_file)
5457 {
5458 struct file *fp;
5459
5460 if (!have_addr) {
5461 db_printf("usage: show file <addr>\n");
5462 return;
5463 }
5464 fp = (struct file *)addr;
5465 db_print_file(fp, 1);
5466 }
5467
DB_SHOW_COMMAND_FLAGS(files,db_show_files,DB_CMD_MEMSAFE)5468 DB_SHOW_COMMAND_FLAGS(files, db_show_files, DB_CMD_MEMSAFE)
5469 {
5470 struct filedesc *fdp;
5471 struct file *fp;
5472 struct proc *p;
5473 int header;
5474 int n;
5475
5476 header = 1;
5477 FOREACH_PROC_IN_SYSTEM(p) {
5478 if (p->p_state == PRS_NEW)
5479 continue;
5480 if ((fdp = p->p_fd) == NULL)
5481 continue;
5482 for (n = 0; n < fdp->fd_nfiles; ++n) {
5483 if ((fp = fdp->fd_ofiles[n].fde_file) == NULL)
5484 continue;
5485 db_print_file(fp, header);
5486 header = 0;
5487 }
5488 }
5489 }
5490 #endif
5491
5492 SYSCTL_INT(_kern, KERN_MAXFILESPERPROC, maxfilesperproc,
5493 CTLFLAG_RWTUN | CTLFLAG_NOFETCH,
5494 &maxfilesperproc, 0, "Maximum files allowed open per process");
5495
5496 SYSCTL_INT(_kern, KERN_MAXFILES, maxfiles, CTLFLAG_RWTUN | CTLFLAG_NOFETCH,
5497 &maxfiles, 0, "Maximum number of files");
5498
5499 SYSCTL_INT(_kern, OID_AUTO, openfiles, CTLFLAG_RD,
5500 &openfiles, 0, "System-wide number of open files");
5501
5502 /* ARGSUSED*/
5503 static void
filelistinit(void * dummy)5504 filelistinit(void *dummy)
5505 {
5506
5507 file_zone = uma_zcreate("Files", sizeof(struct file), NULL, NULL,
5508 NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE);
5509 filedesc0_zone = uma_zcreate("filedesc0", sizeof(struct filedesc0),
5510 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0);
5511 pwd_zone = uma_zcreate("PWD", sizeof(struct pwd), NULL, NULL,
5512 NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_SMR);
5513 /*
5514 * XXXMJG this is a temporary hack due to boot ordering issues against
5515 * the vnode zone.
5516 */
5517 vfs_smr = uma_zone_get_smr(pwd_zone);
5518 mtx_init(&sigio_lock, "sigio lock", NULL, MTX_DEF);
5519 }
5520 SYSINIT(select, SI_SUB_LOCK, SI_ORDER_FIRST, filelistinit, NULL);
5521
5522 /*-------------------------------------------------------------------*/
5523
5524 static int
badfo_readwrite(struct file * fp,struct uio * uio,struct ucred * active_cred,int flags,struct thread * td)5525 badfo_readwrite(struct file *fp, struct uio *uio, struct ucred *active_cred,
5526 int flags, struct thread *td)
5527 {
5528
5529 return (EBADF);
5530 }
5531
5532 static int
badfo_truncate(struct file * fp,off_t length,struct ucred * active_cred,struct thread * td)5533 badfo_truncate(struct file *fp, off_t length, struct ucred *active_cred,
5534 struct thread *td)
5535 {
5536
5537 return (EINVAL);
5538 }
5539
5540 static int
badfo_ioctl(struct file * fp,u_long com,void * data,struct ucred * active_cred,struct thread * td)5541 badfo_ioctl(struct file *fp, u_long com, void *data, struct ucred *active_cred,
5542 struct thread *td)
5543 {
5544
5545 return (EBADF);
5546 }
5547
5548 static int
badfo_poll(struct file * fp,int events,struct ucred * active_cred,struct thread * td)5549 badfo_poll(struct file *fp, int events, struct ucred *active_cred,
5550 struct thread *td)
5551 {
5552
5553 return (0);
5554 }
5555
5556 static int
badfo_kqfilter(struct file * fp,struct knote * kn)5557 badfo_kqfilter(struct file *fp, struct knote *kn)
5558 {
5559
5560 return (EBADF);
5561 }
5562
5563 static int
badfo_stat(struct file * fp,struct stat * sb,struct ucred * active_cred)5564 badfo_stat(struct file *fp, struct stat *sb, struct ucred *active_cred)
5565 {
5566
5567 return (EBADF);
5568 }
5569
5570 static int
badfo_close(struct file * fp,struct thread * td)5571 badfo_close(struct file *fp, struct thread *td)
5572 {
5573
5574 return (0);
5575 }
5576
5577 static int
badfo_chmod(struct file * fp,mode_t mode,struct ucred * active_cred,struct thread * td)5578 badfo_chmod(struct file *fp, mode_t mode, struct ucred *active_cred,
5579 struct thread *td)
5580 {
5581
5582 return (EBADF);
5583 }
5584
5585 static int
badfo_chown(struct file * fp,uid_t uid,gid_t gid,struct ucred * active_cred,struct thread * td)5586 badfo_chown(struct file *fp, uid_t uid, gid_t gid, struct ucred *active_cred,
5587 struct thread *td)
5588 {
5589
5590 return (EBADF);
5591 }
5592
5593 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)5594 badfo_sendfile(struct file *fp, int sockfd, struct uio *hdr_uio,
5595 struct uio *trl_uio, off_t offset, size_t nbytes, off_t *sent, int flags,
5596 struct thread *td)
5597 {
5598
5599 return (EBADF);
5600 }
5601
5602 static int
badfo_fill_kinfo(struct file * fp,struct kinfo_file * kif,struct filedesc * fdp)5603 badfo_fill_kinfo(struct file *fp, struct kinfo_file *kif, struct filedesc *fdp)
5604 {
5605
5606 return (0);
5607 }
5608
5609 const struct fileops badfileops = {
5610 .fo_read = badfo_readwrite,
5611 .fo_write = badfo_readwrite,
5612 .fo_truncate = badfo_truncate,
5613 .fo_ioctl = badfo_ioctl,
5614 .fo_poll = badfo_poll,
5615 .fo_kqfilter = badfo_kqfilter,
5616 .fo_stat = badfo_stat,
5617 .fo_close = badfo_close,
5618 .fo_chmod = badfo_chmod,
5619 .fo_chown = badfo_chown,
5620 .fo_sendfile = badfo_sendfile,
5621 .fo_fill_kinfo = badfo_fill_kinfo,
5622 };
5623
5624 static int
path_poll(struct file * fp,int events,struct ucred * active_cred,struct thread * td)5625 path_poll(struct file *fp, int events, struct ucred *active_cred,
5626 struct thread *td)
5627 {
5628 return (POLLNVAL);
5629 }
5630
5631 static int
path_close(struct file * fp,struct thread * td)5632 path_close(struct file *fp, struct thread *td)
5633 {
5634 MPASS(fp->f_type == DTYPE_VNODE);
5635 fp->f_ops = &badfileops;
5636 vrele(fp->f_vnode);
5637 return (0);
5638 }
5639
5640 const struct fileops path_fileops = {
5641 .fo_read = badfo_readwrite,
5642 .fo_write = badfo_readwrite,
5643 .fo_truncate = badfo_truncate,
5644 .fo_ioctl = badfo_ioctl,
5645 .fo_poll = path_poll,
5646 .fo_kqfilter = vn_kqfilter_opath,
5647 .fo_stat = vn_statfile,
5648 .fo_close = path_close,
5649 .fo_chmod = badfo_chmod,
5650 .fo_chown = badfo_chown,
5651 .fo_sendfile = badfo_sendfile,
5652 .fo_fill_kinfo = vn_fill_kinfo,
5653 .fo_cmp = vn_cmp,
5654 .fo_flags = DFLAG_PASSABLE,
5655 };
5656
5657 int
invfo_rdwr(struct file * fp,struct uio * uio,struct ucred * active_cred,int flags,struct thread * td)5658 invfo_rdwr(struct file *fp, struct uio *uio, struct ucred *active_cred,
5659 int flags, struct thread *td)
5660 {
5661
5662 return (EOPNOTSUPP);
5663 }
5664
5665 int
invfo_truncate(struct file * fp,off_t length,struct ucred * active_cred,struct thread * td)5666 invfo_truncate(struct file *fp, off_t length, struct ucred *active_cred,
5667 struct thread *td)
5668 {
5669
5670 return (EINVAL);
5671 }
5672
5673 int
invfo_ioctl(struct file * fp,u_long com,void * data,struct ucred * active_cred,struct thread * td)5674 invfo_ioctl(struct file *fp, u_long com, void *data,
5675 struct ucred *active_cred, struct thread *td)
5676 {
5677
5678 return (ENOTTY);
5679 }
5680
5681 int
invfo_poll(struct file * fp,int events,struct ucred * active_cred,struct thread * td)5682 invfo_poll(struct file *fp, int events, struct ucred *active_cred,
5683 struct thread *td)
5684 {
5685
5686 return (poll_no_poll(events));
5687 }
5688
5689 int
invfo_kqfilter(struct file * fp,struct knote * kn)5690 invfo_kqfilter(struct file *fp, struct knote *kn)
5691 {
5692
5693 return (EINVAL);
5694 }
5695
5696 int
invfo_chmod(struct file * fp,mode_t mode,struct ucred * active_cred,struct thread * td)5697 invfo_chmod(struct file *fp, mode_t mode, struct ucred *active_cred,
5698 struct thread *td)
5699 {
5700
5701 return (EINVAL);
5702 }
5703
5704 int
invfo_chown(struct file * fp,uid_t uid,gid_t gid,struct ucred * active_cred,struct thread * td)5705 invfo_chown(struct file *fp, uid_t uid, gid_t gid, struct ucred *active_cred,
5706 struct thread *td)
5707 {
5708
5709 return (EINVAL);
5710 }
5711
5712 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)5713 invfo_sendfile(struct file *fp, int sockfd, struct uio *hdr_uio,
5714 struct uio *trl_uio, off_t offset, size_t nbytes, off_t *sent, int flags,
5715 struct thread *td)
5716 {
5717
5718 return (EINVAL);
5719 }
5720
5721 /*-------------------------------------------------------------------*/
5722
5723 /*
5724 * File Descriptor pseudo-device driver (/dev/fd/).
5725 *
5726 * Opening minor device N dup()s the file (if any) connected to file
5727 * descriptor N belonging to the calling process. Note that this driver
5728 * consists of only the ``open()'' routine, because all subsequent
5729 * references to this file will be direct to the other driver.
5730 *
5731 * XXX: we could give this one a cloning event handler if necessary.
5732 */
5733
5734 /* ARGSUSED */
5735 static int
fdopen(struct cdev * dev,int mode,int type,struct thread * td)5736 fdopen(struct cdev *dev, int mode, int type, struct thread *td)
5737 {
5738
5739 /*
5740 * XXX Kludge: set curthread->td_dupfd to contain the value of the
5741 * the file descriptor being sought for duplication. The error
5742 * return ensures that the vnode for this device will be released
5743 * by vn_open. Open will detect this special error and take the
5744 * actions in dupfdopen below. Other callers of vn_open or VOP_OPEN
5745 * will simply report the error.
5746 */
5747 td->td_dupfd = dev2unit(dev);
5748 return (ENODEV);
5749 }
5750
5751 static struct cdevsw fildesc_cdevsw = {
5752 .d_version = D_VERSION,
5753 .d_open = fdopen,
5754 .d_name = "FD",
5755 };
5756
5757 static void
fildesc_drvinit(void * unused)5758 fildesc_drvinit(void *unused)
5759 {
5760 struct cdev *dev;
5761
5762 dev = make_dev_credf(MAKEDEV_ETERNAL, &fildesc_cdevsw, 0, NULL,
5763 UID_ROOT, GID_WHEEL, 0666, "fd/0");
5764 make_dev_alias(dev, "stdin");
5765 dev = make_dev_credf(MAKEDEV_ETERNAL, &fildesc_cdevsw, 1, NULL,
5766 UID_ROOT, GID_WHEEL, 0666, "fd/1");
5767 make_dev_alias(dev, "stdout");
5768 dev = make_dev_credf(MAKEDEV_ETERNAL, &fildesc_cdevsw, 2, NULL,
5769 UID_ROOT, GID_WHEEL, 0666, "fd/2");
5770 make_dev_alias(dev, "stderr");
5771 }
5772
5773 SYSINIT(fildescdev, SI_SUB_DRIVERS, SI_ORDER_MIDDLE, fildesc_drvinit, NULL);
5774