xref: /freebsd/sys/sys/file.h (revision f1f230439fa48581f40a57f095627f667a9713c3)
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 
76 #ifdef _KERNEL
77 
78 struct file;
79 struct filecaps;
80 struct kaiocb;
81 struct kinfo_file;
82 struct ucred;
83 
84 #define	FOF_OFFSET	0x01	/* Use the offset in uio argument */
85 #define	FOF_NOLOCK	0x02	/* Do not take FOFFSET_LOCK */
86 #define	FOF_NEXTOFF_R	0x04	/* Also update f_nextoff[UIO_READ] */
87 #define	FOF_NEXTOFF_W	0x08	/* Also update f_nextoff[UIO_WRITE] */
88 #define	FOF_NOUPDATE	0x10	/* Do not update f_offset */
89 off_t foffset_lock(struct file *fp, int flags);
90 void foffset_lock_pair(struct file *fp1, off_t *off1p, struct file *fp2,
91     off_t *off2p, int flags);
92 void foffset_lock_uio(struct file *fp, struct uio *uio, int flags);
93 void foffset_unlock(struct file *fp, off_t val, int flags);
94 void foffset_unlock_uio(struct file *fp, struct uio *uio, int flags);
95 
96 static inline off_t
foffset_get(struct file * fp)97 foffset_get(struct file *fp)
98 {
99 
100 	return (foffset_lock(fp, FOF_NOLOCK));
101 }
102 
103 typedef int fo_rdwr_t(struct file *fp, struct uio *uio,
104 		    struct ucred *active_cred, int flags,
105 		    struct thread *td);
106 typedef	int fo_truncate_t(struct file *fp, off_t length,
107 		    struct ucred *active_cred, struct thread *td);
108 typedef	int fo_ioctl_t(struct file *fp, u_long com, void *data,
109 		    struct ucred *active_cred, struct thread *td);
110 typedef	int fo_poll_t(struct file *fp, int events,
111 		    struct ucred *active_cred, struct thread *td);
112 typedef	int fo_kqfilter_t(struct file *fp, struct knote *kn);
113 typedef	int fo_stat_t(struct file *fp, struct stat *sb,
114 		    struct ucred *active_cred);
115 typedef	int fo_close_t(struct file *fp, struct thread *td);
116 typedef	int fo_chmod_t(struct file *fp, mode_t mode,
117 		    struct ucred *active_cred, struct thread *td);
118 typedef	int fo_chown_t(struct file *fp, uid_t uid, gid_t gid,
119 		    struct ucred *active_cred, struct thread *td);
120 typedef int fo_sendfile_t(struct file *fp, int sockfd, struct uio *hdr_uio,
121 		    struct uio *trl_uio, off_t offset, size_t nbytes,
122 		    off_t *sent, int flags, struct thread *td);
123 typedef int fo_seek_t(struct file *fp, off_t offset, int whence,
124 		    struct thread *td);
125 typedef int fo_fill_kinfo_t(struct file *fp, struct kinfo_file *kif,
126 		    struct filedesc *fdp);
127 typedef int fo_mmap_t(struct file *fp, vm_map_t map, vm_offset_t *addr,
128 		    vm_size_t size, vm_prot_t prot, vm_prot_t cap_maxprot,
129 		    int flags, vm_ooffset_t foff, struct thread *td);
130 typedef int fo_aio_queue_t(struct file *fp, struct kaiocb *job);
131 typedef int fo_add_seals_t(struct file *fp, int flags);
132 typedef int fo_get_seals_t(struct file *fp, int *flags);
133 typedef int fo_fallocate_t(struct file *fp, off_t offset, off_t len,
134 		    struct thread *td);
135 typedef int fo_fspacectl_t(struct file *fp, int cmd,
136 		    off_t *offset, off_t *length, int flags,
137 		    struct ucred *active_cred, struct thread *td);
138 typedef int fo_cmp_t(struct file *fp, struct file *fp1, struct thread *td);
139 typedef int fo_spare_t(struct file *fp);
140 typedef	int fo_flags_t;
141 
142 struct fileops {
143 	fo_rdwr_t	*fo_read;
144 	fo_rdwr_t	*fo_write;
145 	fo_truncate_t	*fo_truncate;
146 	fo_ioctl_t	*fo_ioctl;
147 	fo_poll_t	*fo_poll;
148 	fo_kqfilter_t	*fo_kqfilter;
149 	fo_stat_t	*fo_stat;
150 	fo_close_t	*fo_close;
151 	fo_chmod_t	*fo_chmod;
152 	fo_chown_t	*fo_chown;
153 	fo_sendfile_t	*fo_sendfile;
154 	fo_seek_t	*fo_seek;
155 	fo_fill_kinfo_t	*fo_fill_kinfo;
156 	fo_mmap_t	*fo_mmap;
157 	fo_aio_queue_t	*fo_aio_queue;
158 	fo_add_seals_t	*fo_add_seals;
159 	fo_get_seals_t	*fo_get_seals;
160 	fo_fallocate_t	*fo_fallocate;
161 	fo_fspacectl_t	*fo_fspacectl;
162 	fo_cmp_t	*fo_cmp;
163 	fo_spare_t	*fo_spares[8];	/* Spare slots */
164 	fo_flags_t	fo_flags;	/* DFLAG_* below */
165 };
166 
167 #define DFLAG_PASSABLE	0x01	/* may be passed via unix sockets. */
168 #define DFLAG_SEEKABLE	0x02	/* seekable / nonsequential */
169 #endif /* _KERNEL */
170 
171 #if defined(_KERNEL) || defined(_WANT_FILE)
172 /*
173  * Kernel descriptor table.
174  * One entry for each open kernel vnode and socket.
175  *
176  * Below is the list of locks that protects members in struct file.
177  *
178  * (a) f_vnode lock required (shared allows both reads and writes)
179  * (f) updated with atomics and blocking on sleepq
180  * (d) cdevpriv_mtx
181  * none	not locked
182  */
183 
184 #if __BSD_VISIBLE
185 struct fadvise_info {
186 	int		fa_advice;	/* (f) FADV_* type. */
187 	off_t		fa_start;	/* (f) Region start. */
188 	off_t		fa_end;		/* (f) Region end. */
189 };
190 
191 struct file {
192 	volatile u_int	f_flag;		/* see fcntl.h */
193 	volatile u_int 	f_count;	/* reference count */
194 	void		*f_data;	/* file descriptor specific data */
195 	const struct fileops *f_ops;	/* File operations */
196 	struct vnode 	*f_vnode;	/* NULL or applicable vnode */
197 	struct ucred	*f_cred;	/* associated credentials. */
198 	short		f_type;		/* descriptor type */
199 	short		f_vnread_flags; /* (f) Sleep lock for f_offset */
200 	/*
201 	 *  DTYPE_VNODE specific fields.
202 	 */
203 	union {
204 		int16_t	f_seqcount[2];	/* (a) Count of seq. reads and writes. */
205 		int	f_pipegen;
206 	};
207 	off_t		f_nextoff[2];	/* next expected read/write offset. */
208 	union {
209 		struct cdev_privdata *fvn_cdevpriv;
210 					/* (d) Private data for the cdev. */
211 		struct fadvise_info *fvn_advice;
212 	} f_vnun;
213 	/*
214 	 *  DFLAG_SEEKABLE specific fields
215 	 */
216 	off_t		f_offset;
217 };
218 
219 #define	f_cdevpriv	f_vnun.fvn_cdevpriv
220 #define	f_advice	f_vnun.fvn_advice
221 
222 #define	FOFFSET_LOCKED       0x1
223 #define	FOFFSET_LOCK_WAITING 0x2
224 #endif /* __BSD_VISIBLE */
225 
226 #endif /* _KERNEL || _WANT_FILE */
227 
228 /*
229  * Userland version of struct file, for sysctl
230  */
231 #if __BSD_VISIBLE
232 struct xfile {
233 	ksize_t	xf_size;	/* size of struct xfile */
234 	pid_t	xf_pid;		/* owning process */
235 	uid_t	xf_uid;		/* effective uid of owning process */
236 	int	xf_fd;		/* descriptor number */
237 	int	_xf_int_pad1;
238 	kvaddr_t xf_file;	/* address of struct file */
239 	short	xf_type;	/* descriptor type */
240 	short	_xf_short_pad1;
241 	int	xf_count;	/* reference count */
242 	int	xf_msgcount;	/* references from message queue */
243 	int	_xf_int_pad2;
244 	off_t	xf_offset;	/* file offset */
245 	kvaddr_t xf_data;	/* file descriptor specific data */
246 	kvaddr_t xf_vnode;	/* vnode pointer */
247 	u_int	xf_flag;	/* flags (see fcntl.h) */
248 	int	_xf_int_pad3;
249 	int64_t	_xf_int64_pad[6];
250 };
251 #endif /* __BSD_VISIBLE */
252 
253 #ifdef _KERNEL
254 
255 extern const struct fileops vnops;
256 extern const struct fileops badfileops;
257 extern const struct fileops path_fileops;
258 extern const struct fileops socketops;
259 extern int maxfiles;		/* kernel limit on number of open files */
260 extern int maxfilesperproc;	/* per process limit on number of open files */
261 
262 int fget(struct thread *td, int fd, const cap_rights_t *rightsp,
263     struct file **fpp);
264 int fget_mmap(struct thread *td, int fd, const cap_rights_t *rightsp,
265     vm_prot_t *maxprotp, struct file **fpp);
266 int fget_read(struct thread *td, int fd, const cap_rights_t *rightsp,
267     struct file **fpp);
268 int fget_write(struct thread *td, int fd, const cap_rights_t *rightsp,
269     struct file **fpp);
270 int fget_fcntl(struct thread *td, int fd, const cap_rights_t *rightsp,
271     int needfcntl, struct file **fpp);
272 int _fdrop(struct file *fp, struct thread *td);
273 int fget_remote(struct thread *td, struct proc *p, int fd, struct file **fpp);
274 int fget_remote_foreach(struct thread *td, struct proc *p,
275     int (*fn)(struct proc *, int, struct file *, void *), void *arg);
276 
277 fo_rdwr_t	invfo_rdwr;
278 fo_truncate_t	invfo_truncate;
279 fo_ioctl_t	invfo_ioctl;
280 fo_poll_t	invfo_poll;
281 fo_kqfilter_t	invfo_kqfilter;
282 fo_chmod_t	invfo_chmod;
283 fo_chown_t	invfo_chown;
284 fo_sendfile_t	invfo_sendfile;
285 fo_stat_t	vn_statfile;
286 fo_sendfile_t	vn_sendfile;
287 fo_seek_t	vn_seek;
288 fo_fill_kinfo_t	vn_fill_kinfo;
289 fo_kqfilter_t	vn_kqfilter_opath;
290 int vn_fill_kinfo_vnode(struct vnode *vp, struct kinfo_file *kif);
291 int file_kcmp_generic(struct file *fp1, struct file *fp2, struct thread *td);
292 
293 void finit(struct file *, u_int, short, void *, const struct fileops *);
294 void finit_vnode(struct file *, u_int, void *, const struct fileops *);
295 int fgetvp(struct thread *td, int fd, const cap_rights_t *rightsp,
296     struct vnode **vpp);
297 int fgetvp_exec(struct thread *td, int fd, const cap_rights_t *rightsp,
298     struct vnode **vpp);
299 int fgetvp_rights(struct thread *td, int fd, const cap_rights_t *needrightsp,
300     struct filecaps *havecaps, struct vnode **vpp);
301 int fgetvp_read(struct thread *td, int fd, const cap_rights_t *rightsp,
302     struct vnode **vpp);
303 int fgetvp_write(struct thread *td, int fd, const cap_rights_t *rightsp,
304     struct vnode **vpp);
305 int fgetvp_lookup_smr(struct nameidata *ndp, struct vnode **vpp, int *flagsp);
306 int fgetvp_lookup(struct nameidata *ndp, struct vnode **vpp);
307 
308 static __inline __result_use_check bool
fhold(struct file * fp)309 fhold(struct file *fp)
310 {
311 	return (refcount_acquire_checked(&fp->f_count));
312 }
313 
314 #define	fdrop(fp, td)		({				\
315 	struct file *_fp;					\
316 	int _error;						\
317 								\
318 	_error = 0;						\
319 	_fp = (fp);						\
320 	if (__predict_false(refcount_release(&_fp->f_count)))	\
321 		_error = _fdrop(_fp, td);			\
322 	_error;							\
323 })
324 
325 #define	fdrop_close(fp, td)		({			\
326 	struct file *_fp;					\
327 	int _error;						\
328 								\
329 	_error = 0;						\
330 	_fp = (fp);						\
331 	if (__predict_true(refcount_release(&_fp->f_count)))	\
332 		_error = _fdrop(_fp, td);			\
333 	_error;							\
334 })
335 
336 static __inline fo_rdwr_t	fo_read;
337 static __inline fo_rdwr_t	fo_write;
338 static __inline fo_truncate_t	fo_truncate;
339 static __inline fo_ioctl_t	fo_ioctl;
340 static __inline fo_poll_t	fo_poll;
341 static __inline fo_kqfilter_t	fo_kqfilter;
342 static __inline fo_stat_t	fo_stat;
343 static __inline fo_close_t	fo_close;
344 static __inline fo_chmod_t	fo_chmod;
345 static __inline fo_chown_t	fo_chown;
346 static __inline fo_sendfile_t	fo_sendfile;
347 
348 static __inline int
fo_read(struct file * fp,struct uio * uio,struct ucred * active_cred,int flags,struct thread * td)349 fo_read(struct file *fp, struct uio *uio, struct ucred *active_cred,
350     int flags, struct thread *td)
351 {
352 
353 	return ((*fp->f_ops->fo_read)(fp, uio, active_cred, flags, td));
354 }
355 
356 static __inline int
fo_write(struct file * fp,struct uio * uio,struct ucred * active_cred,int flags,struct thread * td)357 fo_write(struct file *fp, struct uio *uio, struct ucred *active_cred,
358     int flags, struct thread *td)
359 {
360 
361 	return ((*fp->f_ops->fo_write)(fp, uio, active_cred, flags, td));
362 }
363 
364 static __inline int
fo_truncate(struct file * fp,off_t length,struct ucred * active_cred,struct thread * td)365 fo_truncate(struct file *fp, off_t length, struct ucred *active_cred,
366     struct thread *td)
367 {
368 
369 	return ((*fp->f_ops->fo_truncate)(fp, length, active_cred, td));
370 }
371 
372 static __inline int
fo_ioctl(struct file * fp,u_long com,void * data,struct ucred * active_cred,struct thread * td)373 fo_ioctl(struct file *fp, u_long com, void *data, struct ucred *active_cred,
374     struct thread *td)
375 {
376 
377 	return ((*fp->f_ops->fo_ioctl)(fp, com, data, active_cred, td));
378 }
379 
380 static __inline int
fo_poll(struct file * fp,int events,struct ucred * active_cred,struct thread * td)381 fo_poll(struct file *fp, int events, struct ucred *active_cred,
382     struct thread *td)
383 {
384 
385 	return ((*fp->f_ops->fo_poll)(fp, events, active_cred, td));
386 }
387 
388 static __inline int
fo_stat(struct file * fp,struct stat * sb,struct ucred * active_cred)389 fo_stat(struct file *fp, struct stat *sb, struct ucred *active_cred)
390 {
391 
392 	return ((*fp->f_ops->fo_stat)(fp, sb, active_cred));
393 }
394 
395 static __inline int
fo_close(struct file * fp,struct thread * td)396 fo_close(struct file *fp, struct thread *td)
397 {
398 
399 	return ((*fp->f_ops->fo_close)(fp, td));
400 }
401 
402 static __inline int
fo_kqfilter(struct file * fp,struct knote * kn)403 fo_kqfilter(struct file *fp, struct knote *kn)
404 {
405 
406 	return ((*fp->f_ops->fo_kqfilter)(fp, kn));
407 }
408 
409 static __inline int
fo_chmod(struct file * fp,mode_t mode,struct ucred * active_cred,struct thread * td)410 fo_chmod(struct file *fp, mode_t mode, struct ucred *active_cred,
411     struct thread *td)
412 {
413 
414 	return ((*fp->f_ops->fo_chmod)(fp, mode, active_cred, td));
415 }
416 
417 static __inline int
fo_chown(struct file * fp,uid_t uid,gid_t gid,struct ucred * active_cred,struct thread * td)418 fo_chown(struct file *fp, uid_t uid, gid_t gid, struct ucred *active_cred,
419     struct thread *td)
420 {
421 
422 	return ((*fp->f_ops->fo_chown)(fp, uid, gid, active_cred, td));
423 }
424 
425 static __inline int
fo_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)426 fo_sendfile(struct file *fp, int sockfd, struct uio *hdr_uio,
427     struct uio *trl_uio, off_t offset, size_t nbytes, off_t *sent, int flags,
428     struct thread *td)
429 {
430 
431 	return ((*fp->f_ops->fo_sendfile)(fp, sockfd, hdr_uio, trl_uio, offset,
432 	    nbytes, sent, flags, td));
433 }
434 
435 static __inline int
fo_seek(struct file * fp,off_t offset,int whence,struct thread * td)436 fo_seek(struct file *fp, off_t offset, int whence, struct thread *td)
437 {
438 
439 	return ((*fp->f_ops->fo_seek)(fp, offset, whence, td));
440 }
441 
442 static __inline int
fo_fill_kinfo(struct file * fp,struct kinfo_file * kif,struct filedesc * fdp)443 fo_fill_kinfo(struct file *fp, struct kinfo_file *kif, struct filedesc *fdp)
444 {
445 
446 	return ((*fp->f_ops->fo_fill_kinfo)(fp, kif, fdp));
447 }
448 
449 static __inline int
fo_mmap(struct file * fp,vm_map_t map,vm_offset_t * addr,vm_size_t size,vm_prot_t prot,vm_prot_t cap_maxprot,int flags,vm_ooffset_t foff,struct thread * td)450 fo_mmap(struct file *fp, vm_map_t map, vm_offset_t *addr, vm_size_t size,
451     vm_prot_t prot, vm_prot_t cap_maxprot, int flags, vm_ooffset_t foff,
452     struct thread *td)
453 {
454 
455 	if (fp->f_ops->fo_mmap == NULL)
456 		return (ENODEV);
457 	return ((*fp->f_ops->fo_mmap)(fp, map, addr, size, prot, cap_maxprot,
458 	    flags, foff, td));
459 }
460 
461 static __inline int
fo_aio_queue(struct file * fp,struct kaiocb * job)462 fo_aio_queue(struct file *fp, struct kaiocb *job)
463 {
464 
465 	return ((*fp->f_ops->fo_aio_queue)(fp, job));
466 }
467 
468 static __inline int
fo_add_seals(struct file * fp,int seals)469 fo_add_seals(struct file *fp, int seals)
470 {
471 
472 	if (fp->f_ops->fo_add_seals == NULL)
473 		return (EINVAL);
474 	return ((*fp->f_ops->fo_add_seals)(fp, seals));
475 }
476 
477 static __inline int
fo_get_seals(struct file * fp,int * seals)478 fo_get_seals(struct file *fp, int *seals)
479 {
480 
481 	if (fp->f_ops->fo_get_seals == NULL)
482 		return (EINVAL);
483 	return ((*fp->f_ops->fo_get_seals)(fp, seals));
484 }
485 
486 static __inline int
fo_fallocate(struct file * fp,off_t offset,off_t len,struct thread * td)487 fo_fallocate(struct file *fp, off_t offset, off_t len, struct thread *td)
488 {
489 
490 	if (fp->f_ops->fo_fallocate == NULL)
491 		return (ENODEV);
492 	return ((*fp->f_ops->fo_fallocate)(fp, offset, len, td));
493 }
494 
495 static __inline int
fo_fspacectl(struct file * fp,int cmd,off_t * offset,off_t * length,int flags,struct ucred * active_cred,struct thread * td)496 fo_fspacectl(struct file *fp, int cmd, off_t *offset, off_t *length,
497     int flags, struct ucred *active_cred, struct thread *td)
498 {
499 
500 	if (fp->f_ops->fo_fspacectl == NULL)
501 		return (ENODEV);
502 	return ((*fp->f_ops->fo_fspacectl)(fp, cmd, offset, length, flags,
503 	    active_cred, td));
504 }
505 
506 static __inline int
fo_cmp(struct file * fp1,struct file * fp2,struct thread * td)507 fo_cmp(struct file *fp1, struct file *fp2, struct thread *td)
508 {
509 
510 	if (fp1->f_ops->fo_cmp == NULL)
511 		return (ENODEV);
512 	return ((*fp1->f_ops->fo_cmp)(fp1, fp2, td));
513 }
514 
515 #endif /* _KERNEL */
516 
517 #endif /* !SYS_FILE_H */
518