xref: /freebsd/sys/sys/file.h (revision 7a202823)
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, struct thread *td);
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_flags_t;
133 
134 struct fileops {
135 	fo_rdwr_t	*fo_read;
136 	fo_rdwr_t	*fo_write;
137 	fo_truncate_t	*fo_truncate;
138 	fo_ioctl_t	*fo_ioctl;
139 	fo_poll_t	*fo_poll;
140 	fo_kqfilter_t	*fo_kqfilter;
141 	fo_stat_t	*fo_stat;
142 	fo_close_t	*fo_close;
143 	fo_chmod_t	*fo_chmod;
144 	fo_chown_t	*fo_chown;
145 	fo_sendfile_t	*fo_sendfile;
146 	fo_seek_t	*fo_seek;
147 	fo_fill_kinfo_t	*fo_fill_kinfo;
148 	fo_mmap_t	*fo_mmap;
149 	fo_aio_queue_t	*fo_aio_queue;
150 	fo_add_seals_t	*fo_add_seals;
151 	fo_get_seals_t	*fo_get_seals;
152 	fo_fallocate_t	*fo_fallocate;
153 	fo_flags_t	fo_flags;	/* DFLAG_* below */
154 };
155 
156 #define DFLAG_PASSABLE	0x01	/* may be passed via unix sockets. */
157 #define DFLAG_SEEKABLE	0x02	/* seekable / nonsequential */
158 #endif /* _KERNEL */
159 
160 #if defined(_KERNEL) || defined(_WANT_FILE)
161 /*
162  * Kernel descriptor table.
163  * One entry for each open kernel vnode and socket.
164  *
165  * Below is the list of locks that protects members in struct file.
166  *
167  * (a) f_vnode lock required (shared allows both reads and writes)
168  * (f) updated with atomics and blocking on sleepq
169  * (d) cdevpriv_mtx
170  * none	not locked
171  */
172 
173 struct fadvise_info {
174 	int		fa_advice;	/* (f) FADV_* type. */
175 	off_t		fa_start;	/* (f) Region start. */
176 	off_t		fa_end;		/* (f) Region end. */
177 };
178 
179 struct file {
180 	volatile u_int	f_flag;		/* see fcntl.h */
181 	volatile u_int 	f_count;	/* reference count */
182 	void		*f_data;	/* file descriptor specific data */
183 	struct fileops	*f_ops;		/* File operations */
184 	struct vnode 	*f_vnode;	/* NULL or applicable vnode */
185 	struct ucred	*f_cred;	/* associated credentials. */
186 	short		f_type;		/* descriptor type */
187 	short		f_vnread_flags; /* (f) Sleep lock for f_offset */
188 	/*
189 	 *  DTYPE_VNODE specific fields.
190 	 */
191 	union {
192 		int16_t	f_seqcount[2];	/* (a) Count of seq. reads and writes. */
193 		int	f_pipegen;
194 	};
195 	off_t		f_nextoff[2];	/* next expected read/write offset. */
196 	union {
197 		struct cdev_privdata *fvn_cdevpriv;
198 					/* (d) Private data for the cdev. */
199 		struct fadvise_info *fvn_advice;
200 	} f_vnun;
201 	/*
202 	 *  DFLAG_SEEKABLE specific fields
203 	 */
204 	off_t		f_offset;
205 };
206 
207 #define	f_cdevpriv	f_vnun.fvn_cdevpriv
208 #define	f_advice	f_vnun.fvn_advice
209 
210 #define	FOFFSET_LOCKED       0x1
211 #define	FOFFSET_LOCK_WAITING 0x2
212 
213 #endif /* _KERNEL || _WANT_FILE */
214 
215 /*
216  * Userland version of struct file, for sysctl
217  */
218 struct xfile {
219 	ksize_t	xf_size;	/* size of struct xfile */
220 	pid_t	xf_pid;		/* owning process */
221 	uid_t	xf_uid;		/* effective uid of owning process */
222 	int	xf_fd;		/* descriptor number */
223 	int	_xf_int_pad1;
224 	kvaddr_t xf_file;	/* address of struct file */
225 	short	xf_type;	/* descriptor type */
226 	short	_xf_short_pad1;
227 	int	xf_count;	/* reference count */
228 	int	xf_msgcount;	/* references from message queue */
229 	int	_xf_int_pad2;
230 	off_t	xf_offset;	/* file offset */
231 	kvaddr_t xf_data;	/* file descriptor specific data */
232 	kvaddr_t xf_vnode;	/* vnode pointer */
233 	u_int	xf_flag;	/* flags (see fcntl.h) */
234 	int	_xf_int_pad3;
235 	int64_t	_xf_int64_pad[6];
236 };
237 
238 #ifdef _KERNEL
239 
240 extern struct fileops vnops;
241 extern struct fileops badfileops;
242 extern struct fileops socketops;
243 extern int maxfiles;		/* kernel limit on number of open files */
244 extern int maxfilesperproc;	/* per process limit on number of open files */
245 
246 int fget(struct thread *td, int fd, cap_rights_t *rightsp, struct file **fpp);
247 int fget_mmap(struct thread *td, int fd, cap_rights_t *rightsp,
248     vm_prot_t *maxprotp, struct file **fpp);
249 int fget_read(struct thread *td, int fd, cap_rights_t *rightsp,
250     struct file **fpp);
251 int fget_write(struct thread *td, int fd, cap_rights_t *rightsp,
252     struct file **fpp);
253 int fget_fcntl(struct thread *td, int fd, cap_rights_t *rightsp,
254     int needfcntl, struct file **fpp);
255 int _fdrop(struct file *fp, struct thread *td);
256 
257 fo_rdwr_t	invfo_rdwr;
258 fo_truncate_t	invfo_truncate;
259 fo_ioctl_t	invfo_ioctl;
260 fo_poll_t	invfo_poll;
261 fo_kqfilter_t	invfo_kqfilter;
262 fo_chmod_t	invfo_chmod;
263 fo_chown_t	invfo_chown;
264 fo_sendfile_t	invfo_sendfile;
265 
266 fo_sendfile_t	vn_sendfile;
267 fo_seek_t	vn_seek;
268 fo_fill_kinfo_t	vn_fill_kinfo;
269 int vn_fill_kinfo_vnode(struct vnode *vp, struct kinfo_file *kif);
270 
271 void finit(struct file *, u_int, short, void *, struct fileops *);
272 void finit_vnode(struct file *, u_int, void *, struct fileops *);
273 int fgetvp(struct thread *td, int fd, cap_rights_t *rightsp,
274     struct vnode **vpp);
275 int fgetvp_exec(struct thread *td, int fd, cap_rights_t *rightsp,
276     struct vnode **vpp);
277 int fgetvp_rights(struct thread *td, int fd, cap_rights_t *needrightsp,
278     struct filecaps *havecaps, struct vnode **vpp);
279 int fgetvp_read(struct thread *td, int fd, cap_rights_t *rightsp,
280     struct vnode **vpp);
281 int fgetvp_write(struct thread *td, int fd, cap_rights_t *rightsp,
282     struct vnode **vpp);
283 int fgetvp_lookup_smr(int fd, struct nameidata *ndp, struct vnode **vpp, bool *fsearch);
284 
285 static __inline __result_use_check bool
286 fhold(struct file *fp)
287 {
288 	return (refcount_acquire_checked(&fp->f_count));
289 }
290 
291 #define	fdrop(fp, td)		({				\
292 	struct file *_fp;					\
293 	int _error;						\
294 								\
295 	_error = 0;						\
296 	_fp = (fp);						\
297 	if (__predict_false(refcount_release(&_fp->f_count)))	\
298 		_error = _fdrop(_fp, td);			\
299 	_error;							\
300 })
301 
302 #define	fdrop_close(fp, td)		({			\
303 	struct file *_fp;					\
304 	int _error;						\
305 								\
306 	_error = 0;						\
307 	_fp = (fp);						\
308 	if (__predict_true(refcount_release(&_fp->f_count)))	\
309 		_error = _fdrop(_fp, td);			\
310 	_error;							\
311 })
312 
313 static __inline fo_rdwr_t	fo_read;
314 static __inline fo_rdwr_t	fo_write;
315 static __inline fo_truncate_t	fo_truncate;
316 static __inline fo_ioctl_t	fo_ioctl;
317 static __inline fo_poll_t	fo_poll;
318 static __inline fo_kqfilter_t	fo_kqfilter;
319 static __inline fo_stat_t	fo_stat;
320 static __inline fo_close_t	fo_close;
321 static __inline fo_chmod_t	fo_chmod;
322 static __inline fo_chown_t	fo_chown;
323 static __inline fo_sendfile_t	fo_sendfile;
324 
325 static __inline int
326 fo_read(struct file *fp, struct uio *uio, struct ucred *active_cred,
327     int flags, struct thread *td)
328 {
329 
330 	return ((*fp->f_ops->fo_read)(fp, uio, active_cred, flags, td));
331 }
332 
333 static __inline int
334 fo_write(struct file *fp, struct uio *uio, struct ucred *active_cred,
335     int flags, struct thread *td)
336 {
337 
338 	return ((*fp->f_ops->fo_write)(fp, uio, active_cred, flags, td));
339 }
340 
341 static __inline int
342 fo_truncate(struct file *fp, off_t length, struct ucred *active_cred,
343     struct thread *td)
344 {
345 
346 	return ((*fp->f_ops->fo_truncate)(fp, length, active_cred, td));
347 }
348 
349 static __inline int
350 fo_ioctl(struct file *fp, u_long com, void *data, struct ucred *active_cred,
351     struct thread *td)
352 {
353 
354 	return ((*fp->f_ops->fo_ioctl)(fp, com, data, active_cred, td));
355 }
356 
357 static __inline int
358 fo_poll(struct file *fp, int events, struct ucred *active_cred,
359     struct thread *td)
360 {
361 
362 	return ((*fp->f_ops->fo_poll)(fp, events, active_cred, td));
363 }
364 
365 static __inline int
366 fo_stat(struct file *fp, struct stat *sb, struct ucred *active_cred,
367     struct thread *td)
368 {
369 
370 	return ((*fp->f_ops->fo_stat)(fp, sb, active_cred, td));
371 }
372 
373 static __inline int
374 fo_close(struct file *fp, struct thread *td)
375 {
376 
377 	return ((*fp->f_ops->fo_close)(fp, td));
378 }
379 
380 static __inline int
381 fo_kqfilter(struct file *fp, struct knote *kn)
382 {
383 
384 	return ((*fp->f_ops->fo_kqfilter)(fp, kn));
385 }
386 
387 static __inline int
388 fo_chmod(struct file *fp, mode_t mode, struct ucred *active_cred,
389     struct thread *td)
390 {
391 
392 	return ((*fp->f_ops->fo_chmod)(fp, mode, active_cred, td));
393 }
394 
395 static __inline int
396 fo_chown(struct file *fp, uid_t uid, gid_t gid, struct ucred *active_cred,
397     struct thread *td)
398 {
399 
400 	return ((*fp->f_ops->fo_chown)(fp, uid, gid, active_cred, td));
401 }
402 
403 static __inline int
404 fo_sendfile(struct file *fp, int sockfd, struct uio *hdr_uio,
405     struct uio *trl_uio, off_t offset, size_t nbytes, off_t *sent, int flags,
406     struct thread *td)
407 {
408 
409 	return ((*fp->f_ops->fo_sendfile)(fp, sockfd, hdr_uio, trl_uio, offset,
410 	    nbytes, sent, flags, td));
411 }
412 
413 static __inline int
414 fo_seek(struct file *fp, off_t offset, int whence, struct thread *td)
415 {
416 
417 	return ((*fp->f_ops->fo_seek)(fp, offset, whence, td));
418 }
419 
420 static __inline int
421 fo_fill_kinfo(struct file *fp, struct kinfo_file *kif, struct filedesc *fdp)
422 {
423 
424 	return ((*fp->f_ops->fo_fill_kinfo)(fp, kif, fdp));
425 }
426 
427 static __inline int
428 fo_mmap(struct file *fp, vm_map_t map, vm_offset_t *addr, vm_size_t size,
429     vm_prot_t prot, vm_prot_t cap_maxprot, int flags, vm_ooffset_t foff,
430     struct thread *td)
431 {
432 
433 	if (fp->f_ops->fo_mmap == NULL)
434 		return (ENODEV);
435 	return ((*fp->f_ops->fo_mmap)(fp, map, addr, size, prot, cap_maxprot,
436 	    flags, foff, td));
437 }
438 
439 static __inline int
440 fo_aio_queue(struct file *fp, struct kaiocb *job)
441 {
442 
443 	return ((*fp->f_ops->fo_aio_queue)(fp, job));
444 }
445 
446 static __inline int
447 fo_add_seals(struct file *fp, int seals)
448 {
449 
450 	if (fp->f_ops->fo_add_seals == NULL)
451 		return (EINVAL);
452 	return ((*fp->f_ops->fo_add_seals)(fp, seals));
453 }
454 
455 static __inline int
456 fo_get_seals(struct file *fp, int *seals)
457 {
458 
459 	if (fp->f_ops->fo_get_seals == NULL)
460 		return (EINVAL);
461 	return ((*fp->f_ops->fo_get_seals)(fp, seals));
462 }
463 
464 static __inline int
465 fo_fallocate(struct file *fp, off_t offset, off_t len, struct thread *td)
466 {
467 
468 	if (fp->f_ops->fo_fallocate == NULL)
469 		return (ENODEV);
470 	return ((*fp->f_ops->fo_fallocate)(fp, offset, len, td));
471 }
472 
473 #endif /* _KERNEL */
474 
475 #endif /* !SYS_FILE_H */
476