xref: /freebsd/sys/sys/file.h (revision 03ca6dbdb80da79408f135d823fbd9a00fd4f25b)
1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
3  *
4  * Copyright (c) 1982, 1986, 1989, 1993
5  *	The Regents of the University of California.  All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. Neither the name of the University nor the names of its contributors
16  *    may be used to endorse or promote products derived from this software
17  *    without specific prior written permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  */
31 
32 #ifndef _SYS_FILE_H_
33 #define	_SYS_FILE_H_
34 
35 #ifndef _KERNEL
36 #include <sys/types.h> /* XXX */
37 #include <sys/fcntl.h>
38 #include <sys/unistd.h>
39 #else
40 #include <sys/errno.h>
41 #include <sys/_lock.h>
42 #include <sys/_mutex.h>
43 #include <sys/_null.h>
44 #include <sys/queue.h>
45 #include <sys/refcount.h>
46 #include <vm/vm.h>
47 
48 struct filedesc;
49 struct proc;
50 struct stat;
51 struct thread;
52 struct uio;
53 struct knote;
54 struct vnode;
55 struct nameidata;
56 
57 #endif /* _KERNEL */
58 
59 #define	DTYPE_NONE	0	/* not yet initialized */
60 #define	DTYPE_VNODE	1	/* file */
61 #define	DTYPE_SOCKET	2	/* communications endpoint */
62 #define	DTYPE_PIPE	3	/* pipe */
63 #define	DTYPE_FIFO	4	/* fifo (named pipe) */
64 #define	DTYPE_KQUEUE	5	/* event queue */
65 #define	DTYPE_CRYPTO	6	/* crypto */
66 #define	DTYPE_MQUEUE	7	/* posix message queue */
67 #define	DTYPE_SHM	8	/* swap-backed shared memory */
68 #define	DTYPE_SEM	9	/* posix semaphore */
69 #define	DTYPE_PTS	10	/* pseudo teletype master device */
70 #define	DTYPE_DEV	11	/* Device specific fd type */
71 #define	DTYPE_PROCDESC	12	/* process descriptor */
72 #define	DTYPE_EVENTFD	13	/* eventfd */
73 #define	DTYPE_TIMERFD	14	/* timerfd */
74 #define	DTYPE_INOTIFY	15	/* inotify descriptor */
75 #define	DTYPE_JAILDESC	16	/* jail descriptor */
76 #define	DTYPE_NTSYNC	17	/* /dev/ntsync */
77 
78 #ifdef _KERNEL
79 
80 struct file;
81 struct filecaps;
82 struct kaiocb;
83 struct kinfo_file;
84 struct ucred;
85 
86 #define	FOF_OFFSET	0x01	/* Use the offset in uio argument */
87 #define	FOF_NOLOCK	0x02	/* Do not take FOFFSET_LOCK */
88 #define	FOF_NEXTOFF_R	0x04	/* Also update f_nextoff[UIO_READ] */
89 #define	FOF_NEXTOFF_W	0x08	/* Also update f_nextoff[UIO_WRITE] */
90 #define	FOF_NOUPDATE	0x10	/* Do not update f_offset */
91 off_t foffset_lock(struct file *fp, int flags);
92 void foffset_lock_pair(struct file *fp1, off_t *off1p, struct file *fp2,
93     off_t *off2p, int flags);
94 void foffset_lock_uio(struct file *fp, struct uio *uio, int flags);
95 void foffset_unlock(struct file *fp, off_t val, int flags);
96 void foffset_unlock_uio(struct file *fp, struct uio *uio, int flags);
97 void fsetfl_lock(struct file *fp);
98 void fsetfl_unlock(struct file *fp);
99 
100 static inline off_t
101 foffset_get(struct file *fp)
102 {
103 
104 	return (foffset_lock(fp, FOF_NOLOCK));
105 }
106 
107 typedef int fo_rdwr_t(struct file *fp, struct uio *uio,
108 		    struct ucred *active_cred, int flags,
109 		    struct thread *td);
110 typedef	int fo_truncate_t(struct file *fp, off_t length,
111 		    struct ucred *active_cred, struct thread *td);
112 typedef	int fo_ioctl_t(struct file *fp, u_long com, void *data,
113 		    struct ucred *active_cred, struct thread *td);
114 typedef	int fo_poll_t(struct file *fp, int events,
115 		    struct ucred *active_cred, struct thread *td);
116 typedef	int fo_kqfilter_t(struct file *fp, struct knote *kn);
117 typedef	int fo_stat_t(struct file *fp, struct stat *sb,
118 		    struct ucred *active_cred);
119 typedef	int fo_close_t(struct file *fp, struct thread *td);
120 typedef	void fo_fdclose_t(struct file *fp, int fd, struct thread *td);
121 typedef	int fo_chmod_t(struct file *fp, mode_t mode,
122 		    struct ucred *active_cred, struct thread *td);
123 typedef	int fo_chown_t(struct file *fp, uid_t uid, gid_t gid,
124 		    struct ucred *active_cred, struct thread *td);
125 typedef int fo_sendfile_t(struct file *fp, int sockfd, struct uio *hdr_uio,
126 		    struct uio *trl_uio, off_t offset, size_t nbytes,
127 		    off_t *sent, int flags, struct thread *td);
128 typedef int fo_seek_t(struct file *fp, off_t offset, int whence,
129 		    struct thread *td);
130 typedef int fo_fill_kinfo_t(struct file *fp, struct kinfo_file *kif,
131 		    struct filedesc *fdp);
132 typedef int fo_mmap_t(struct file *fp, vm_map_t map, vm_offset_t *addr,
133 		    vm_size_t size, vm_prot_t prot, vm_prot_t cap_maxprot,
134 		    int flags, vm_ooffset_t foff, struct thread *td);
135 typedef int fo_aio_queue_t(struct file *fp, struct kaiocb *job);
136 typedef int fo_add_seals_t(struct file *fp, int flags);
137 typedef int fo_get_seals_t(struct file *fp, int *flags);
138 typedef int fo_fallocate_t(struct file *fp, off_t offset, off_t len,
139 		    struct thread *td);
140 typedef int fo_fspacectl_t(struct file *fp, int cmd,
141 		    off_t *offset, off_t *length, int flags,
142 		    struct ucred *active_cred, struct thread *td);
143 typedef int fo_cmp_t(struct file *fp, struct file *fp1, struct thread *td);
144 typedef	int fo_fork_t(struct filedesc *fdp, struct file *fp, struct file **fp1,
145 		    struct proc *p1, struct thread *td);
146 typedef int fo_spare_t(struct file *fp);
147 typedef	int fo_flags_t;
148 
149 struct fileops {
150 	fo_rdwr_t	*fo_read;
151 	fo_rdwr_t	*fo_write;
152 	fo_truncate_t	*fo_truncate;
153 	fo_ioctl_t	*fo_ioctl;
154 	fo_poll_t	*fo_poll;
155 	fo_kqfilter_t	*fo_kqfilter;
156 	fo_stat_t	*fo_stat;
157 	fo_close_t	*fo_close;
158 	fo_fdclose_t	*fo_fdclose;
159 	fo_chmod_t	*fo_chmod;
160 	fo_chown_t	*fo_chown;
161 	fo_sendfile_t	*fo_sendfile;
162 	fo_seek_t	*fo_seek;
163 	fo_fill_kinfo_t	*fo_fill_kinfo;
164 	fo_mmap_t	*fo_mmap;
165 	fo_aio_queue_t	*fo_aio_queue;
166 	fo_add_seals_t	*fo_add_seals;
167 	fo_get_seals_t	*fo_get_seals;
168 	fo_fallocate_t	*fo_fallocate;
169 	fo_fspacectl_t	*fo_fspacectl;
170 	fo_cmp_t	*fo_cmp;
171 	fo_fork_t	*fo_fork;
172 	fo_spare_t	*fo_spares[8];	/* Spare slots */
173 	fo_flags_t	fo_flags;	/* DFLAG_* below */
174 };
175 
176 #define DFLAG_PASSABLE	0x01	/* may be passed via unix sockets. */
177 #define DFLAG_SEEKABLE	0x02	/* seekable / nonsequential */
178 #define	DFLAG_FORK	0x04	/* copy on fork */
179 #endif /* _KERNEL */
180 
181 #if defined(_KERNEL) || defined(_WANT_FILE)
182 /*
183  * Kernel descriptor table.
184  * One entry for each open kernel vnode and socket.
185  *
186  * Below is the list of locks that protects members in struct file.
187  *
188  * (a) f_vnode lock required (shared allows both reads and writes)
189  * (f) updated with atomics and blocking on sleepq
190  * (d) cdevpriv_mtx
191  * none	not locked
192  */
193 
194 #if __BSD_VISIBLE
195 struct fadvise_info {
196 	int		fa_advice;	/* (f) FADV_* type. */
197 	off_t		fa_start;	/* (f) Region start. */
198 	off_t		fa_end;		/* (f) Region end. */
199 };
200 
201 struct file {
202 	volatile u_int	f_flag;		/* see fcntl.h */
203 	volatile u_int 	f_count;	/* reference count */
204 	void		*f_data;	/* file descriptor specific data */
205 	const struct fileops *f_ops;	/* File operations */
206 	struct vnode 	*f_vnode;	/* NULL or applicable vnode */
207 	struct ucred	*f_cred;	/* associated credentials. */
208 	short		f_type;		/* descriptor type */
209 	short		f_vflags;	/* (f) Sleep lock flags for members */
210 	/*
211 	 *  DTYPE_VNODE specific fields.
212 	 */
213 	union {
214 		int16_t	f_seqcount[2];	/* (a) Count of seq. reads and writes. */
215 		int	f_pipegen;
216 	};
217 	off_t		f_nextoff[2];	/* next expected read/write offset. */
218 	union {
219 		struct cdev_privdata *fvn_cdevpriv;
220 					/* (d) Private data for the cdev. */
221 		struct fadvise_info *fvn_advice;
222 	} f_vnun;
223 	/*
224 	 *  DFLAG_SEEKABLE specific fields
225 	 */
226 	off_t		f_offset;
227 };
228 
229 #define	f_cdevpriv	f_vnun.fvn_cdevpriv
230 #define	f_advice	f_vnun.fvn_advice
231 
232 #define	FILE_V_FOFFSET_LOCKED		0x0001
233 #define	FILE_V_FOFFSET_LOCK_WAITING	0x0002
234 #define	FILE_V_SETFL_LOCKED		0x0004
235 #define	FILE_V_SETFL_LOCK_WAITING	0x0008
236 #endif /* __BSD_VISIBLE */
237 
238 #endif /* _KERNEL || _WANT_FILE */
239 
240 /*
241  * Userland version of struct file, for sysctl
242  */
243 #if __BSD_VISIBLE
244 struct xfile {
245 	ksize_t	xf_size;	/* size of struct xfile */
246 	pid_t	xf_pid;		/* owning process */
247 	uid_t	xf_uid;		/* effective uid of owning process */
248 	int	xf_fd;		/* descriptor number */
249 	int	_xf_int_pad1;
250 	kvaddr_t xf_file;	/* address of struct file */
251 	short	xf_type;	/* descriptor type */
252 	short	_xf_short_pad1;
253 	int	xf_count;	/* reference count */
254 	int	xf_msgcount;	/* references from message queue */
255 	int	_xf_int_pad2;
256 	off_t	xf_offset;	/* file offset */
257 	kvaddr_t xf_data;	/* file descriptor specific data */
258 	kvaddr_t xf_vnode;	/* vnode pointer */
259 	u_int	xf_flag;	/* flags (see fcntl.h) */
260 	int	_xf_int_pad3;
261 	int64_t	_xf_int64_pad[6];
262 };
263 #endif /* __BSD_VISIBLE */
264 
265 #ifdef _KERNEL
266 
267 extern const struct fileops vnops;
268 extern const struct fileops badfileops;
269 extern const struct fileops path_fileops;
270 extern const struct fileops socketops;
271 extern int maxfiles;		/* kernel limit on number of open files */
272 extern int maxfilesperproc;	/* per process limit on number of open files */
273 
274 int fget(struct thread *td, int fd, const cap_rights_t *rightsp,
275     struct file **fpp);
276 int fget_mmap(struct thread *td, int fd, const cap_rights_t *rightsp,
277     vm_prot_t *maxprotp, struct file **fpp);
278 int fget_read(struct thread *td, int fd, const cap_rights_t *rightsp,
279     struct file **fpp);
280 int fget_write(struct thread *td, int fd, const cap_rights_t *rightsp,
281     struct file **fpp);
282 int fget_fcntl(struct thread *td, int fd, const cap_rights_t *rightsp,
283     int needfcntl, struct file **fpp);
284 int _fdrop(struct file *fp, struct thread *td);
285 int fget_remote(struct thread *td, struct proc *p, int fd, struct file **fpp);
286 int fget_remote_foreach(struct thread *td, struct proc *p,
287     int (*fn)(struct proc *, int, struct file *, void *), void *arg);
288 
289 fo_rdwr_t	invfo_rdwr;
290 fo_truncate_t	invfo_truncate;
291 fo_ioctl_t	invfo_ioctl;
292 fo_poll_t	invfo_poll;
293 fo_kqfilter_t	invfo_kqfilter;
294 fo_chmod_t	invfo_chmod;
295 fo_chown_t	invfo_chown;
296 fo_sendfile_t	invfo_sendfile;
297 fo_stat_t	vn_statfile;
298 fo_sendfile_t	vn_sendfile;
299 fo_seek_t	vn_seek;
300 fo_fill_kinfo_t	vn_fill_kinfo;
301 fo_kqfilter_t	vn_kqfilter_opath;
302 int vn_fill_kinfo_vnode(struct vnode *vp, struct kinfo_file *kif);
303 int file_kcmp_generic(struct file *fp1, struct file *fp2, struct thread *td);
304 
305 void finit(struct file *, u_int, short, void *, const struct fileops *);
306 void finit_vnode(struct file *, u_int, void *, const struct fileops *);
307 int fgetvp(struct thread *td, int fd, const cap_rights_t *rightsp,
308     struct vnode **vpp);
309 int fgetvp_exec(struct thread *td, int fd, const cap_rights_t *rightsp,
310     struct vnode **vpp);
311 int fgetvp_rights(struct thread *td, int fd, const cap_rights_t *needrightsp,
312     struct filecaps *havecaps, struct vnode **vpp);
313 int fgetvp_read(struct thread *td, int fd, const cap_rights_t *rightsp,
314     struct vnode **vpp);
315 int fgetvp_write(struct thread *td, int fd, const cap_rights_t *rightsp,
316     struct vnode **vpp);
317 int fgetvp_lookup_smr(struct nameidata *ndp, struct vnode **vpp, int *flagsp);
318 int fgetvp_lookup(struct nameidata *ndp, struct vnode **vpp);
319 
320 static __inline __result_use_check bool
321 fhold(struct file *fp)
322 {
323 	return (refcount_acquire_checked(&fp->f_count));
324 }
325 
326 #define	fdrop(fp, td)		({				\
327 	struct file *_fp;					\
328 	int _error;						\
329 								\
330 	_error = 0;						\
331 	_fp = (fp);						\
332 	if (__predict_false(refcount_release(&_fp->f_count)))	\
333 		_error = _fdrop(_fp, td);			\
334 	_error;							\
335 })
336 
337 #define	fdrop_close(fp, td)		({			\
338 	struct file *_fp;					\
339 	int _error;						\
340 								\
341 	_error = 0;						\
342 	_fp = (fp);						\
343 	if (__predict_true(refcount_release(&_fp->f_count)))	\
344 		_error = _fdrop(_fp, td);			\
345 	_error;							\
346 })
347 
348 static __inline fo_rdwr_t	fo_read;
349 static __inline fo_rdwr_t	fo_write;
350 static __inline fo_truncate_t	fo_truncate;
351 static __inline fo_ioctl_t	fo_ioctl;
352 static __inline fo_poll_t	fo_poll;
353 static __inline fo_kqfilter_t	fo_kqfilter;
354 static __inline fo_stat_t	fo_stat;
355 static __inline fo_close_t	fo_close;
356 static __inline fo_chmod_t	fo_chmod;
357 static __inline fo_chown_t	fo_chown;
358 static __inline fo_sendfile_t	fo_sendfile;
359 
360 static __inline int
361 fo_read(struct file *fp, struct uio *uio, struct ucred *active_cred,
362     int flags, struct thread *td)
363 {
364 
365 	return ((*fp->f_ops->fo_read)(fp, uio, active_cred, flags, td));
366 }
367 
368 static __inline int
369 fo_write(struct file *fp, struct uio *uio, struct ucred *active_cred,
370     int flags, struct thread *td)
371 {
372 
373 	return ((*fp->f_ops->fo_write)(fp, uio, active_cred, flags, td));
374 }
375 
376 static __inline int
377 fo_truncate(struct file *fp, off_t length, struct ucred *active_cred,
378     struct thread *td)
379 {
380 
381 	return ((*fp->f_ops->fo_truncate)(fp, length, active_cred, td));
382 }
383 
384 static __inline int
385 fo_ioctl(struct file *fp, u_long com, void *data, struct ucred *active_cred,
386     struct thread *td)
387 {
388 
389 	return ((*fp->f_ops->fo_ioctl)(fp, com, data, active_cred, td));
390 }
391 
392 static __inline int
393 fo_poll(struct file *fp, int events, struct ucred *active_cred,
394     struct thread *td)
395 {
396 
397 	return ((*fp->f_ops->fo_poll)(fp, events, active_cred, td));
398 }
399 
400 static __inline int
401 fo_stat(struct file *fp, struct stat *sb, struct ucred *active_cred)
402 {
403 
404 	return ((*fp->f_ops->fo_stat)(fp, sb, active_cred));
405 }
406 
407 static __inline int
408 fo_close(struct file *fp, struct thread *td)
409 {
410 
411 	return ((*fp->f_ops->fo_close)(fp, td));
412 }
413 
414 static __inline int
415 fo_kqfilter(struct file *fp, struct knote *kn)
416 {
417 
418 	return ((*fp->f_ops->fo_kqfilter)(fp, kn));
419 }
420 
421 static __inline int
422 fo_chmod(struct file *fp, mode_t mode, struct ucred *active_cred,
423     struct thread *td)
424 {
425 
426 	return ((*fp->f_ops->fo_chmod)(fp, mode, active_cred, td));
427 }
428 
429 static __inline int
430 fo_chown(struct file *fp, uid_t uid, gid_t gid, struct ucred *active_cred,
431     struct thread *td)
432 {
433 
434 	return ((*fp->f_ops->fo_chown)(fp, uid, gid, active_cred, td));
435 }
436 
437 static __inline int
438 fo_sendfile(struct file *fp, int sockfd, struct uio *hdr_uio,
439     struct uio *trl_uio, off_t offset, size_t nbytes, off_t *sent, int flags,
440     struct thread *td)
441 {
442 
443 	return ((*fp->f_ops->fo_sendfile)(fp, sockfd, hdr_uio, trl_uio, offset,
444 	    nbytes, sent, flags, td));
445 }
446 
447 static __inline int
448 fo_seek(struct file *fp, off_t offset, int whence, struct thread *td)
449 {
450 
451 	return ((*fp->f_ops->fo_seek)(fp, offset, whence, td));
452 }
453 
454 static __inline int
455 fo_fill_kinfo(struct file *fp, struct kinfo_file *kif, struct filedesc *fdp)
456 {
457 
458 	return ((*fp->f_ops->fo_fill_kinfo)(fp, kif, fdp));
459 }
460 
461 static __inline int
462 fo_mmap(struct file *fp, vm_map_t map, vm_offset_t *addr, vm_size_t size,
463     vm_prot_t prot, vm_prot_t cap_maxprot, int flags, vm_ooffset_t foff,
464     struct thread *td)
465 {
466 
467 	if (fp->f_ops->fo_mmap == NULL)
468 		return (ENODEV);
469 	return ((*fp->f_ops->fo_mmap)(fp, map, addr, size, prot, cap_maxprot,
470 	    flags, foff, td));
471 }
472 
473 static __inline int
474 fo_aio_queue(struct file *fp, struct kaiocb *job)
475 {
476 
477 	return ((*fp->f_ops->fo_aio_queue)(fp, job));
478 }
479 
480 static __inline int
481 fo_add_seals(struct file *fp, int seals)
482 {
483 
484 	if (fp->f_ops->fo_add_seals == NULL)
485 		return (EINVAL);
486 	return ((*fp->f_ops->fo_add_seals)(fp, seals));
487 }
488 
489 static __inline int
490 fo_get_seals(struct file *fp, int *seals)
491 {
492 
493 	if (fp->f_ops->fo_get_seals == NULL)
494 		return (EINVAL);
495 	return ((*fp->f_ops->fo_get_seals)(fp, seals));
496 }
497 
498 static __inline int
499 fo_fallocate(struct file *fp, off_t offset, off_t len, struct thread *td)
500 {
501 
502 	if (fp->f_ops->fo_fallocate == NULL)
503 		return (ENODEV);
504 	return ((*fp->f_ops->fo_fallocate)(fp, offset, len, td));
505 }
506 
507 static __inline int
508 fo_fspacectl(struct file *fp, int cmd, off_t *offset, off_t *length,
509     int flags, struct ucred *active_cred, struct thread *td)
510 {
511 
512 	if (fp->f_ops->fo_fspacectl == NULL)
513 		return (ENODEV);
514 	return ((*fp->f_ops->fo_fspacectl)(fp, cmd, offset, length, flags,
515 	    active_cred, td));
516 }
517 
518 static __inline int
519 fo_cmp(struct file *fp1, struct file *fp2, struct thread *td)
520 {
521 
522 	if (fp1->f_ops->fo_cmp == NULL)
523 		return (ENODEV);
524 	return ((*fp1->f_ops->fo_cmp)(fp1, fp2, td));
525 }
526 
527 #endif /* _KERNEL */
528 
529 #endif /* !SYS_FILE_H */
530