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