xref: /freebsd/sys/sys/file.h (revision e17f5b1d)
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 
56 #endif /* _KERNEL */
57 
58 #define	DTYPE_NONE	0	/* not yet initialized */
59 #define	DTYPE_VNODE	1	/* file */
60 #define	DTYPE_SOCKET	2	/* communications endpoint */
61 #define	DTYPE_PIPE	3	/* pipe */
62 #define	DTYPE_FIFO	4	/* fifo (named pipe) */
63 #define	DTYPE_KQUEUE	5	/* event queue */
64 #define	DTYPE_CRYPTO	6	/* crypto */
65 #define	DTYPE_MQUEUE	7	/* posix message queue */
66 #define	DTYPE_SHM	8	/* swap-backed shared memory */
67 #define	DTYPE_SEM	9	/* posix semaphore */
68 #define	DTYPE_PTS	10	/* pseudo teletype master device */
69 #define	DTYPE_DEV	11	/* Device specific fd type */
70 #define	DTYPE_PROCDESC	12	/* process descriptor */
71 #define	DTYPE_LINUXEFD	13	/* emulation eventfd type */
72 #define	DTYPE_LINUXTFD	14	/* emulation timerfd type */
73 
74 #ifdef _KERNEL
75 
76 struct file;
77 struct filecaps;
78 struct kaiocb;
79 struct kinfo_file;
80 struct ucred;
81 
82 #define	FOF_OFFSET	0x01	/* Use the offset in uio argument */
83 #define	FOF_NOLOCK	0x02	/* Do not take FOFFSET_LOCK */
84 #define	FOF_NEXTOFF_R	0x04	/* Also update f_nextoff[UIO_READ] */
85 #define	FOF_NEXTOFF_W	0x08	/* Also update f_nextoff[UIO_WRITE] */
86 #define	FOF_NOUPDATE	0x10	/* Do not update f_offset */
87 off_t foffset_lock(struct file *fp, int flags);
88 void foffset_lock_uio(struct file *fp, struct uio *uio, int flags);
89 void foffset_unlock(struct file *fp, off_t val, int flags);
90 void foffset_unlock_uio(struct file *fp, struct uio *uio, int flags);
91 
92 static inline off_t
93 foffset_get(struct file *fp)
94 {
95 
96 	return (foffset_lock(fp, FOF_NOLOCK));
97 }
98 
99 typedef int fo_rdwr_t(struct file *fp, struct uio *uio,
100 		    struct ucred *active_cred, int flags,
101 		    struct thread *td);
102 typedef	int fo_truncate_t(struct file *fp, off_t length,
103 		    struct ucred *active_cred, struct thread *td);
104 typedef	int fo_ioctl_t(struct file *fp, u_long com, void *data,
105 		    struct ucred *active_cred, struct thread *td);
106 typedef	int fo_poll_t(struct file *fp, int events,
107 		    struct ucred *active_cred, struct thread *td);
108 typedef	int fo_kqfilter_t(struct file *fp, struct knote *kn);
109 typedef	int fo_stat_t(struct file *fp, struct stat *sb,
110 		    struct ucred *active_cred, struct thread *td);
111 typedef	int fo_close_t(struct file *fp, struct thread *td);
112 typedef	int fo_chmod_t(struct file *fp, mode_t mode,
113 		    struct ucred *active_cred, struct thread *td);
114 typedef	int fo_chown_t(struct file *fp, uid_t uid, gid_t gid,
115 		    struct ucred *active_cred, struct thread *td);
116 typedef int fo_sendfile_t(struct file *fp, int sockfd, struct uio *hdr_uio,
117 		    struct uio *trl_uio, off_t offset, size_t nbytes,
118 		    off_t *sent, int flags, struct thread *td);
119 typedef int fo_seek_t(struct file *fp, off_t offset, int whence,
120 		    struct thread *td);
121 typedef int fo_fill_kinfo_t(struct file *fp, struct kinfo_file *kif,
122 		    struct filedesc *fdp);
123 typedef int fo_mmap_t(struct file *fp, vm_map_t map, vm_offset_t *addr,
124 		    vm_size_t size, vm_prot_t prot, vm_prot_t cap_maxprot,
125 		    int flags, vm_ooffset_t foff, struct thread *td);
126 typedef int fo_aio_queue_t(struct file *fp, struct kaiocb *job);
127 typedef int fo_add_seals_t(struct file *fp, int flags);
128 typedef int fo_get_seals_t(struct file *fp, int *flags);
129 typedef int fo_fallocate_t(struct file *fp, off_t offset, off_t len,
130 		    struct thread *td);
131 typedef	int fo_flags_t;
132 
133 struct fileops {
134 	fo_rdwr_t	*fo_read;
135 	fo_rdwr_t	*fo_write;
136 	fo_truncate_t	*fo_truncate;
137 	fo_ioctl_t	*fo_ioctl;
138 	fo_poll_t	*fo_poll;
139 	fo_kqfilter_t	*fo_kqfilter;
140 	fo_stat_t	*fo_stat;
141 	fo_close_t	*fo_close;
142 	fo_chmod_t	*fo_chmod;
143 	fo_chown_t	*fo_chown;
144 	fo_sendfile_t	*fo_sendfile;
145 	fo_seek_t	*fo_seek;
146 	fo_fill_kinfo_t	*fo_fill_kinfo;
147 	fo_mmap_t	*fo_mmap;
148 	fo_aio_queue_t	*fo_aio_queue;
149 	fo_add_seals_t	*fo_add_seals;
150 	fo_get_seals_t	*fo_get_seals;
151 	fo_fallocate_t	*fo_fallocate;
152 	fo_flags_t	fo_flags;	/* DFLAG_* below */
153 };
154 
155 #define DFLAG_PASSABLE	0x01	/* may be passed via unix sockets. */
156 #define DFLAG_SEEKABLE	0x02	/* seekable / nonsequential */
157 #endif /* _KERNEL */
158 
159 #if defined(_KERNEL) || defined(_WANT_FILE)
160 /*
161  * Kernel descriptor table.
162  * One entry for each open kernel vnode and socket.
163  *
164  * Below is the list of locks that protects members in struct file.
165  *
166  * (a) f_vnode lock required (shared allows both reads and writes)
167  * (f) updated with atomics and blocking on sleepq
168  * (d) cdevpriv_mtx
169  * none	not locked
170  */
171 
172 struct fadvise_info {
173 	int		fa_advice;	/* (f) FADV_* type. */
174 	off_t		fa_start;	/* (f) Region start. */
175 	off_t		fa_end;		/* (f) Region end. */
176 };
177 
178 struct file {
179 	void		*f_data;	/* file descriptor specific data */
180 	struct fileops	*f_ops;		/* File operations */
181 	struct ucred	*f_cred;	/* associated credentials. */
182 	struct vnode 	*f_vnode;	/* NULL or applicable vnode */
183 	short		f_type;		/* descriptor type */
184 	short		f_vnread_flags; /* (f) Sleep lock for f_offset */
185 	volatile u_int	f_flag;		/* see fcntl.h */
186 	volatile u_int 	f_count;	/* reference count */
187 	/*
188 	 *  DTYPE_VNODE specific fields.
189 	 */
190 	union {
191 		int16_t	f_seqcount[2];	/* (a) Count of seq. reads and writes. */
192 		int	f_pipegen;
193 	};
194 	off_t		f_nextoff[2];	/* next expected read/write offset. */
195 	union {
196 		struct cdev_privdata *fvn_cdevpriv;
197 					/* (d) Private data for the cdev. */
198 		struct fadvise_info *fvn_advice;
199 	} f_vnun;
200 	/*
201 	 *  DFLAG_SEEKABLE specific fields
202 	 */
203 	off_t		f_offset;
204 };
205 
206 #define	f_cdevpriv	f_vnun.fvn_cdevpriv
207 #define	f_advice	f_vnun.fvn_advice
208 
209 #define	FOFFSET_LOCKED       0x1
210 #define	FOFFSET_LOCK_WAITING 0x2
211 
212 #endif /* _KERNEL || _WANT_FILE */
213 
214 /*
215  * Userland version of struct file, for sysctl
216  */
217 struct xfile {
218 	ksize_t	xf_size;	/* size of struct xfile */
219 	pid_t	xf_pid;		/* owning process */
220 	uid_t	xf_uid;		/* effective uid of owning process */
221 	int	xf_fd;		/* descriptor number */
222 	int	_xf_int_pad1;
223 	kvaddr_t xf_file;	/* address of struct file */
224 	short	xf_type;	/* descriptor type */
225 	short	_xf_short_pad1;
226 	int	xf_count;	/* reference count */
227 	int	xf_msgcount;	/* references from message queue */
228 	int	_xf_int_pad2;
229 	off_t	xf_offset;	/* file offset */
230 	kvaddr_t xf_data;	/* file descriptor specific data */
231 	kvaddr_t xf_vnode;	/* vnode pointer */
232 	u_int	xf_flag;	/* flags (see fcntl.h) */
233 	int	_xf_int_pad3;
234 	int64_t	_xf_int64_pad[6];
235 };
236 
237 #ifdef _KERNEL
238 
239 extern struct fileops vnops;
240 extern struct fileops badfileops;
241 extern struct fileops socketops;
242 extern int maxfiles;		/* kernel limit on number of open files */
243 extern int maxfilesperproc;	/* per process limit on number of open files */
244 
245 int fget(struct thread *td, int fd, cap_rights_t *rightsp, struct file **fpp);
246 int fget_mmap(struct thread *td, int fd, cap_rights_t *rightsp,
247     vm_prot_t *maxprotp, struct file **fpp);
248 int fget_read(struct thread *td, int fd, cap_rights_t *rightsp,
249     struct file **fpp);
250 int fget_write(struct thread *td, int fd, cap_rights_t *rightsp,
251     struct file **fpp);
252 int fget_fcntl(struct thread *td, int fd, cap_rights_t *rightsp,
253     int needfcntl, struct file **fpp);
254 int _fdrop(struct file *fp, struct thread *td);
255 
256 fo_rdwr_t	invfo_rdwr;
257 fo_truncate_t	invfo_truncate;
258 fo_ioctl_t	invfo_ioctl;
259 fo_poll_t	invfo_poll;
260 fo_kqfilter_t	invfo_kqfilter;
261 fo_chmod_t	invfo_chmod;
262 fo_chown_t	invfo_chown;
263 fo_sendfile_t	invfo_sendfile;
264 
265 fo_sendfile_t	vn_sendfile;
266 fo_seek_t	vn_seek;
267 fo_fill_kinfo_t	vn_fill_kinfo;
268 int vn_fill_kinfo_vnode(struct vnode *vp, struct kinfo_file *kif);
269 
270 void finit(struct file *, u_int, short, void *, struct fileops *);
271 int fgetvp(struct thread *td, int fd, cap_rights_t *rightsp,
272     struct vnode **vpp);
273 int fgetvp_exec(struct thread *td, int fd, cap_rights_t *rightsp,
274     struct vnode **vpp);
275 int fgetvp_rights(struct thread *td, int fd, cap_rights_t *needrightsp,
276     struct filecaps *havecaps, struct vnode **vpp);
277 int fgetvp_read(struct thread *td, int fd, cap_rights_t *rightsp,
278     struct vnode **vpp);
279 int fgetvp_write(struct thread *td, int fd, cap_rights_t *rightsp,
280     struct vnode **vpp);
281 
282 static __inline int
283 _fnoop(void)
284 {
285 
286 	return (0);
287 }
288 
289 static __inline __result_use_check bool
290 fhold(struct file *fp)
291 {
292 	return (refcount_acquire_checked(&fp->f_count));
293 }
294 
295 #define	fdrop(fp, td)							\
296 	(refcount_release(&(fp)->f_count) ? _fdrop((fp), (td)) : _fnoop())
297 
298 static __inline fo_rdwr_t	fo_read;
299 static __inline fo_rdwr_t	fo_write;
300 static __inline fo_truncate_t	fo_truncate;
301 static __inline fo_ioctl_t	fo_ioctl;
302 static __inline fo_poll_t	fo_poll;
303 static __inline fo_kqfilter_t	fo_kqfilter;
304 static __inline fo_stat_t	fo_stat;
305 static __inline fo_close_t	fo_close;
306 static __inline fo_chmod_t	fo_chmod;
307 static __inline fo_chown_t	fo_chown;
308 static __inline fo_sendfile_t	fo_sendfile;
309 
310 static __inline int
311 fo_read(struct file *fp, struct uio *uio, struct ucred *active_cred,
312     int flags, struct thread *td)
313 {
314 
315 	return ((*fp->f_ops->fo_read)(fp, uio, active_cred, flags, td));
316 }
317 
318 static __inline int
319 fo_write(struct file *fp, struct uio *uio, struct ucred *active_cred,
320     int flags, struct thread *td)
321 {
322 
323 	return ((*fp->f_ops->fo_write)(fp, uio, active_cred, flags, td));
324 }
325 
326 static __inline int
327 fo_truncate(struct file *fp, off_t length, struct ucred *active_cred,
328     struct thread *td)
329 {
330 
331 	return ((*fp->f_ops->fo_truncate)(fp, length, active_cred, td));
332 }
333 
334 static __inline int
335 fo_ioctl(struct file *fp, u_long com, void *data, struct ucred *active_cred,
336     struct thread *td)
337 {
338 
339 	return ((*fp->f_ops->fo_ioctl)(fp, com, data, active_cred, td));
340 }
341 
342 static __inline int
343 fo_poll(struct file *fp, int events, struct ucred *active_cred,
344     struct thread *td)
345 {
346 
347 	return ((*fp->f_ops->fo_poll)(fp, events, active_cred, td));
348 }
349 
350 static __inline int
351 fo_stat(struct file *fp, struct stat *sb, struct ucred *active_cred,
352     struct thread *td)
353 {
354 
355 	return ((*fp->f_ops->fo_stat)(fp, sb, active_cred, td));
356 }
357 
358 static __inline int
359 fo_close(struct file *fp, struct thread *td)
360 {
361 
362 	return ((*fp->f_ops->fo_close)(fp, td));
363 }
364 
365 static __inline int
366 fo_kqfilter(struct file *fp, struct knote *kn)
367 {
368 
369 	return ((*fp->f_ops->fo_kqfilter)(fp, kn));
370 }
371 
372 static __inline int
373 fo_chmod(struct file *fp, mode_t mode, struct ucred *active_cred,
374     struct thread *td)
375 {
376 
377 	return ((*fp->f_ops->fo_chmod)(fp, mode, active_cred, td));
378 }
379 
380 static __inline int
381 fo_chown(struct file *fp, uid_t uid, gid_t gid, struct ucred *active_cred,
382     struct thread *td)
383 {
384 
385 	return ((*fp->f_ops->fo_chown)(fp, uid, gid, active_cred, td));
386 }
387 
388 static __inline int
389 fo_sendfile(struct file *fp, int sockfd, struct uio *hdr_uio,
390     struct uio *trl_uio, off_t offset, size_t nbytes, off_t *sent, int flags,
391     struct thread *td)
392 {
393 
394 	return ((*fp->f_ops->fo_sendfile)(fp, sockfd, hdr_uio, trl_uio, offset,
395 	    nbytes, sent, flags, td));
396 }
397 
398 static __inline int
399 fo_seek(struct file *fp, off_t offset, int whence, struct thread *td)
400 {
401 
402 	return ((*fp->f_ops->fo_seek)(fp, offset, whence, td));
403 }
404 
405 static __inline int
406 fo_fill_kinfo(struct file *fp, struct kinfo_file *kif, struct filedesc *fdp)
407 {
408 
409 	return ((*fp->f_ops->fo_fill_kinfo)(fp, kif, fdp));
410 }
411 
412 static __inline int
413 fo_mmap(struct file *fp, vm_map_t map, vm_offset_t *addr, vm_size_t size,
414     vm_prot_t prot, vm_prot_t cap_maxprot, int flags, vm_ooffset_t foff,
415     struct thread *td)
416 {
417 
418 	if (fp->f_ops->fo_mmap == NULL)
419 		return (ENODEV);
420 	return ((*fp->f_ops->fo_mmap)(fp, map, addr, size, prot, cap_maxprot,
421 	    flags, foff, td));
422 }
423 
424 static __inline int
425 fo_aio_queue(struct file *fp, struct kaiocb *job)
426 {
427 
428 	return ((*fp->f_ops->fo_aio_queue)(fp, job));
429 }
430 
431 static __inline int
432 fo_add_seals(struct file *fp, int seals)
433 {
434 
435 	if (fp->f_ops->fo_add_seals == NULL)
436 		return (EINVAL);
437 	return ((*fp->f_ops->fo_add_seals)(fp, seals));
438 }
439 
440 static __inline int
441 fo_get_seals(struct file *fp, int *seals)
442 {
443 
444 	if (fp->f_ops->fo_get_seals == NULL)
445 		return (EINVAL);
446 	return ((*fp->f_ops->fo_get_seals)(fp, seals));
447 }
448 
449 static __inline int
450 fo_fallocate(struct file *fp, off_t offset, off_t len, struct thread *td)
451 {
452 
453 	if (fp->f_ops->fo_fallocate == NULL)
454 		return (ENODEV);
455 	return ((*fp->f_ops->fo_fallocate)(fp, offset, len, td));
456 }
457 
458 #endif /* _KERNEL */
459 
460 #endif /* !SYS_FILE_H */
461