xref: /freebsd/sys/sys/file.h (revision 716fd348)
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  *	@(#)file.h	8.3 (Berkeley) 1/9/95
32  * $FreeBSD$
33  */
34 
35 #ifndef _SYS_FILE_H_
36 #define	_SYS_FILE_H_
37 
38 #ifndef _KERNEL
39 #include <sys/types.h> /* XXX */
40 #include <sys/fcntl.h>
41 #include <sys/unistd.h>
42 #else
43 #include <sys/queue.h>
44 #include <sys/refcount.h>
45 #include <sys/_lock.h>
46 #include <sys/_mutex.h>
47 #include <vm/vm.h>
48 
49 struct filedesc;
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_LINUXTFD	14	/* emulation timerfd type */
74 
75 #ifdef _KERNEL
76 
77 struct file;
78 struct filecaps;
79 struct kaiocb;
80 struct kinfo_file;
81 struct ucred;
82 
83 #define	FOF_OFFSET	0x01	/* Use the offset in uio argument */
84 #define	FOF_NOLOCK	0x02	/* Do not take FOFFSET_LOCK */
85 #define	FOF_NEXTOFF_R	0x04	/* Also update f_nextoff[UIO_READ] */
86 #define	FOF_NEXTOFF_W	0x08	/* Also update f_nextoff[UIO_WRITE] */
87 #define	FOF_NOUPDATE	0x10	/* Do not update f_offset */
88 off_t foffset_lock(struct file *fp, int flags);
89 void foffset_lock_uio(struct file *fp, struct uio *uio, int flags);
90 void foffset_unlock(struct file *fp, off_t val, int flags);
91 void foffset_unlock_uio(struct file *fp, struct uio *uio, int flags);
92 
93 static inline off_t
94 foffset_get(struct file *fp)
95 {
96 
97 	return (foffset_lock(fp, FOF_NOLOCK));
98 }
99 
100 typedef int fo_rdwr_t(struct file *fp, struct uio *uio,
101 		    struct ucred *active_cred, int flags,
102 		    struct thread *td);
103 typedef	int fo_truncate_t(struct file *fp, off_t length,
104 		    struct ucred *active_cred, struct thread *td);
105 typedef	int fo_ioctl_t(struct file *fp, u_long com, void *data,
106 		    struct ucred *active_cred, struct thread *td);
107 typedef	int fo_poll_t(struct file *fp, int events,
108 		    struct ucred *active_cred, struct thread *td);
109 typedef	int fo_kqfilter_t(struct file *fp, struct knote *kn);
110 typedef	int fo_stat_t(struct file *fp, struct stat *sb,
111 		    struct ucred *active_cred);
112 typedef	int fo_close_t(struct file *fp, struct thread *td);
113 typedef	int fo_chmod_t(struct file *fp, mode_t mode,
114 		    struct ucred *active_cred, struct thread *td);
115 typedef	int fo_chown_t(struct file *fp, uid_t uid, gid_t gid,
116 		    struct ucred *active_cred, struct thread *td);
117 typedef int fo_sendfile_t(struct file *fp, int sockfd, struct uio *hdr_uio,
118 		    struct uio *trl_uio, off_t offset, size_t nbytes,
119 		    off_t *sent, int flags, struct thread *td);
120 typedef int fo_seek_t(struct file *fp, off_t offset, int whence,
121 		    struct thread *td);
122 typedef int fo_fill_kinfo_t(struct file *fp, struct kinfo_file *kif,
123 		    struct filedesc *fdp);
124 typedef int fo_mmap_t(struct file *fp, vm_map_t map, vm_offset_t *addr,
125 		    vm_size_t size, vm_prot_t prot, vm_prot_t cap_maxprot,
126 		    int flags, vm_ooffset_t foff, struct thread *td);
127 typedef int fo_aio_queue_t(struct file *fp, struct kaiocb *job);
128 typedef int fo_add_seals_t(struct file *fp, int flags);
129 typedef int fo_get_seals_t(struct file *fp, int *flags);
130 typedef int fo_fallocate_t(struct file *fp, off_t offset, off_t len,
131 		    struct thread *td);
132 typedef int fo_fspacectl_t(struct file *fp, int cmd,
133 		    off_t *offset, off_t *length, int flags,
134 		    struct ucred *active_cred, struct thread *td);
135 typedef	int fo_flags_t;
136 
137 struct fileops {
138 	fo_rdwr_t	*fo_read;
139 	fo_rdwr_t	*fo_write;
140 	fo_truncate_t	*fo_truncate;
141 	fo_ioctl_t	*fo_ioctl;
142 	fo_poll_t	*fo_poll;
143 	fo_kqfilter_t	*fo_kqfilter;
144 	fo_stat_t	*fo_stat;
145 	fo_close_t	*fo_close;
146 	fo_chmod_t	*fo_chmod;
147 	fo_chown_t	*fo_chown;
148 	fo_sendfile_t	*fo_sendfile;
149 	fo_seek_t	*fo_seek;
150 	fo_fill_kinfo_t	*fo_fill_kinfo;
151 	fo_mmap_t	*fo_mmap;
152 	fo_aio_queue_t	*fo_aio_queue;
153 	fo_add_seals_t	*fo_add_seals;
154 	fo_get_seals_t	*fo_get_seals;
155 	fo_fallocate_t	*fo_fallocate;
156 	fo_fspacectl_t	*fo_fspacectl;
157 	fo_flags_t	fo_flags;	/* DFLAG_* below */
158 };
159 
160 #define DFLAG_PASSABLE	0x01	/* may be passed via unix sockets. */
161 #define DFLAG_SEEKABLE	0x02	/* seekable / nonsequential */
162 #endif /* _KERNEL */
163 
164 #if defined(_KERNEL) || defined(_WANT_FILE)
165 /*
166  * Kernel descriptor table.
167  * One entry for each open kernel vnode and socket.
168  *
169  * Below is the list of locks that protects members in struct file.
170  *
171  * (a) f_vnode lock required (shared allows both reads and writes)
172  * (f) updated with atomics and blocking on sleepq
173  * (d) cdevpriv_mtx
174  * none	not locked
175  */
176 
177 #if __BSD_VISIBLE
178 struct fadvise_info {
179 	int		fa_advice;	/* (f) FADV_* type. */
180 	off_t		fa_start;	/* (f) Region start. */
181 	off_t		fa_end;		/* (f) Region end. */
182 };
183 
184 struct file {
185 	volatile u_int	f_flag;		/* see fcntl.h */
186 	volatile u_int 	f_count;	/* reference count */
187 	void		*f_data;	/* file descriptor specific data */
188 	struct fileops	*f_ops;		/* File operations */
189 	struct vnode 	*f_vnode;	/* NULL or applicable vnode */
190 	struct ucred	*f_cred;	/* associated credentials. */
191 	short		f_type;		/* descriptor type */
192 	short		f_vnread_flags; /* (f) Sleep lock for f_offset */
193 	/*
194 	 *  DTYPE_VNODE specific fields.
195 	 */
196 	union {
197 		int16_t	f_seqcount[2];	/* (a) Count of seq. reads and writes. */
198 		int	f_pipegen;
199 	};
200 	off_t		f_nextoff[2];	/* next expected read/write offset. */
201 	union {
202 		struct cdev_privdata *fvn_cdevpriv;
203 					/* (d) Private data for the cdev. */
204 		struct fadvise_info *fvn_advice;
205 	} f_vnun;
206 	/*
207 	 *  DFLAG_SEEKABLE specific fields
208 	 */
209 	off_t		f_offset;
210 };
211 
212 #define	f_cdevpriv	f_vnun.fvn_cdevpriv
213 #define	f_advice	f_vnun.fvn_advice
214 
215 #define	FOFFSET_LOCKED       0x1
216 #define	FOFFSET_LOCK_WAITING 0x2
217 #endif /* __BSD_VISIBLE */
218 
219 #endif /* _KERNEL || _WANT_FILE */
220 
221 /*
222  * Userland version of struct file, for sysctl
223  */
224 #if __BSD_VISIBLE
225 struct xfile {
226 	ksize_t	xf_size;	/* size of struct xfile */
227 	pid_t	xf_pid;		/* owning process */
228 	uid_t	xf_uid;		/* effective uid of owning process */
229 	int	xf_fd;		/* descriptor number */
230 	int	_xf_int_pad1;
231 	kvaddr_t xf_file;	/* address of struct file */
232 	short	xf_type;	/* descriptor type */
233 	short	_xf_short_pad1;
234 	int	xf_count;	/* reference count */
235 	int	xf_msgcount;	/* references from message queue */
236 	int	_xf_int_pad2;
237 	off_t	xf_offset;	/* file offset */
238 	kvaddr_t xf_data;	/* file descriptor specific data */
239 	kvaddr_t xf_vnode;	/* vnode pointer */
240 	u_int	xf_flag;	/* flags (see fcntl.h) */
241 	int	_xf_int_pad3;
242 	int64_t	_xf_int64_pad[6];
243 };
244 #endif /* __BSD_VISIBLE */
245 
246 #ifdef _KERNEL
247 
248 extern struct fileops vnops;
249 extern struct fileops badfileops;
250 extern struct fileops path_fileops;
251 extern struct fileops socketops;
252 extern int maxfiles;		/* kernel limit on number of open files */
253 extern int maxfilesperproc;	/* per process limit on number of open files */
254 
255 int fget(struct thread *td, int fd, cap_rights_t *rightsp, struct file **fpp);
256 int fget_mmap(struct thread *td, int fd, cap_rights_t *rightsp,
257     vm_prot_t *maxprotp, struct file **fpp);
258 int fget_read(struct thread *td, int fd, cap_rights_t *rightsp,
259     struct file **fpp);
260 int fget_write(struct thread *td, int fd, cap_rights_t *rightsp,
261     struct file **fpp);
262 int fget_fcntl(struct thread *td, int fd, cap_rights_t *rightsp,
263     int needfcntl, struct file **fpp);
264 int _fdrop(struct file *fp, struct thread *td);
265 
266 fo_rdwr_t	invfo_rdwr;
267 fo_truncate_t	invfo_truncate;
268 fo_ioctl_t	invfo_ioctl;
269 fo_poll_t	invfo_poll;
270 fo_kqfilter_t	invfo_kqfilter;
271 fo_chmod_t	invfo_chmod;
272 fo_chown_t	invfo_chown;
273 fo_sendfile_t	invfo_sendfile;
274 fo_stat_t	vn_statfile;
275 fo_sendfile_t	vn_sendfile;
276 fo_seek_t	vn_seek;
277 fo_fill_kinfo_t	vn_fill_kinfo;
278 fo_kqfilter_t	vn_kqfilter_opath;
279 int vn_fill_kinfo_vnode(struct vnode *vp, struct kinfo_file *kif);
280 
281 void finit(struct file *, u_int, short, void *, struct fileops *);
282 void finit_vnode(struct file *, u_int, void *, struct fileops *);
283 int fgetvp(struct thread *td, int fd, cap_rights_t *rightsp,
284     struct vnode **vpp);
285 int fgetvp_exec(struct thread *td, int fd, cap_rights_t *rightsp,
286     struct vnode **vpp);
287 int fgetvp_rights(struct thread *td, int fd, cap_rights_t *needrightsp,
288     struct filecaps *havecaps, struct vnode **vpp);
289 int fgetvp_read(struct thread *td, int fd, cap_rights_t *rightsp,
290     struct vnode **vpp);
291 int fgetvp_write(struct thread *td, int fd, cap_rights_t *rightsp,
292     struct vnode **vpp);
293 int fgetvp_lookup_smr(int fd, struct nameidata *ndp, struct vnode **vpp, bool *fsearch);
294 int fgetvp_lookup(int fd, struct nameidata *ndp, struct vnode **vpp);
295 
296 static __inline __result_use_check bool
297 fhold(struct file *fp)
298 {
299 	return (refcount_acquire_checked(&fp->f_count));
300 }
301 
302 #define	fdrop(fp, td)		({				\
303 	struct file *_fp;					\
304 	int _error;						\
305 								\
306 	_error = 0;						\
307 	_fp = (fp);						\
308 	if (__predict_false(refcount_release(&_fp->f_count)))	\
309 		_error = _fdrop(_fp, td);			\
310 	_error;							\
311 })
312 
313 #define	fdrop_close(fp, td)		({			\
314 	struct file *_fp;					\
315 	int _error;						\
316 								\
317 	_error = 0;						\
318 	_fp = (fp);						\
319 	if (__predict_true(refcount_release(&_fp->f_count)))	\
320 		_error = _fdrop(_fp, td);			\
321 	_error;							\
322 })
323 
324 static __inline fo_rdwr_t	fo_read;
325 static __inline fo_rdwr_t	fo_write;
326 static __inline fo_truncate_t	fo_truncate;
327 static __inline fo_ioctl_t	fo_ioctl;
328 static __inline fo_poll_t	fo_poll;
329 static __inline fo_kqfilter_t	fo_kqfilter;
330 static __inline fo_stat_t	fo_stat;
331 static __inline fo_close_t	fo_close;
332 static __inline fo_chmod_t	fo_chmod;
333 static __inline fo_chown_t	fo_chown;
334 static __inline fo_sendfile_t	fo_sendfile;
335 
336 static __inline int
337 fo_read(struct file *fp, struct uio *uio, struct ucred *active_cred,
338     int flags, struct thread *td)
339 {
340 
341 	return ((*fp->f_ops->fo_read)(fp, uio, active_cred, flags, td));
342 }
343 
344 static __inline int
345 fo_write(struct file *fp, struct uio *uio, struct ucred *active_cred,
346     int flags, struct thread *td)
347 {
348 
349 	return ((*fp->f_ops->fo_write)(fp, uio, active_cred, flags, td));
350 }
351 
352 static __inline int
353 fo_truncate(struct file *fp, off_t length, struct ucred *active_cred,
354     struct thread *td)
355 {
356 
357 	return ((*fp->f_ops->fo_truncate)(fp, length, active_cred, td));
358 }
359 
360 static __inline int
361 fo_ioctl(struct file *fp, u_long com, void *data, struct ucred *active_cred,
362     struct thread *td)
363 {
364 
365 	return ((*fp->f_ops->fo_ioctl)(fp, com, data, active_cred, td));
366 }
367 
368 static __inline int
369 fo_poll(struct file *fp, int events, struct ucred *active_cred,
370     struct thread *td)
371 {
372 
373 	return ((*fp->f_ops->fo_poll)(fp, events, active_cred, td));
374 }
375 
376 static __inline int
377 fo_stat(struct file *fp, struct stat *sb, struct ucred *active_cred)
378 {
379 
380 	return ((*fp->f_ops->fo_stat)(fp, sb, active_cred));
381 }
382 
383 static __inline int
384 fo_close(struct file *fp, struct thread *td)
385 {
386 
387 	return ((*fp->f_ops->fo_close)(fp, td));
388 }
389 
390 static __inline int
391 fo_kqfilter(struct file *fp, struct knote *kn)
392 {
393 
394 	return ((*fp->f_ops->fo_kqfilter)(fp, kn));
395 }
396 
397 static __inline int
398 fo_chmod(struct file *fp, mode_t mode, struct ucred *active_cred,
399     struct thread *td)
400 {
401 
402 	return ((*fp->f_ops->fo_chmod)(fp, mode, active_cred, td));
403 }
404 
405 static __inline int
406 fo_chown(struct file *fp, uid_t uid, gid_t gid, struct ucred *active_cred,
407     struct thread *td)
408 {
409 
410 	return ((*fp->f_ops->fo_chown)(fp, uid, gid, active_cred, td));
411 }
412 
413 static __inline int
414 fo_sendfile(struct file *fp, int sockfd, struct uio *hdr_uio,
415     struct uio *trl_uio, off_t offset, size_t nbytes, off_t *sent, int flags,
416     struct thread *td)
417 {
418 
419 	return ((*fp->f_ops->fo_sendfile)(fp, sockfd, hdr_uio, trl_uio, offset,
420 	    nbytes, sent, flags, td));
421 }
422 
423 static __inline int
424 fo_seek(struct file *fp, off_t offset, int whence, struct thread *td)
425 {
426 
427 	return ((*fp->f_ops->fo_seek)(fp, offset, whence, td));
428 }
429 
430 static __inline int
431 fo_fill_kinfo(struct file *fp, struct kinfo_file *kif, struct filedesc *fdp)
432 {
433 
434 	return ((*fp->f_ops->fo_fill_kinfo)(fp, kif, fdp));
435 }
436 
437 static __inline int
438 fo_mmap(struct file *fp, vm_map_t map, vm_offset_t *addr, vm_size_t size,
439     vm_prot_t prot, vm_prot_t cap_maxprot, int flags, vm_ooffset_t foff,
440     struct thread *td)
441 {
442 
443 	if (fp->f_ops->fo_mmap == NULL)
444 		return (ENODEV);
445 	return ((*fp->f_ops->fo_mmap)(fp, map, addr, size, prot, cap_maxprot,
446 	    flags, foff, td));
447 }
448 
449 static __inline int
450 fo_aio_queue(struct file *fp, struct kaiocb *job)
451 {
452 
453 	return ((*fp->f_ops->fo_aio_queue)(fp, job));
454 }
455 
456 static __inline int
457 fo_add_seals(struct file *fp, int seals)
458 {
459 
460 	if (fp->f_ops->fo_add_seals == NULL)
461 		return (EINVAL);
462 	return ((*fp->f_ops->fo_add_seals)(fp, seals));
463 }
464 
465 static __inline int
466 fo_get_seals(struct file *fp, int *seals)
467 {
468 
469 	if (fp->f_ops->fo_get_seals == NULL)
470 		return (EINVAL);
471 	return ((*fp->f_ops->fo_get_seals)(fp, seals));
472 }
473 
474 static __inline int
475 fo_fallocate(struct file *fp, off_t offset, off_t len, struct thread *td)
476 {
477 
478 	if (fp->f_ops->fo_fallocate == NULL)
479 		return (ENODEV);
480 	return ((*fp->f_ops->fo_fallocate)(fp, offset, len, td));
481 }
482 
483 static __inline int fo_fspacectl(struct file *fp, int cmd, off_t *offset,
484     off_t *length, int flags, struct ucred *active_cred, struct thread *td)
485 {
486 
487 	if (fp->f_ops->fo_fspacectl == NULL)
488 		return (ENODEV);
489 	return ((*fp->f_ops->fo_fspacectl)(fp, cmd, offset, length, flags,
490 	    active_cred, td));
491 }
492 
493 
494 #endif /* _KERNEL */
495 
496 #endif /* !SYS_FILE_H */
497