file.h revision 330897
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 * 4. 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: stable/11/sys/sys/file.h 330897 2018-03-14 03:19:51Z eadler $
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
49struct filedesc;
50struct stat;
51struct thread;
52struct uio;
53struct knote;
54struct 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
76struct file;
77struct filecaps;
78struct kaiocb;
79struct kinfo_file;
80struct 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	0x04	/* Also update f_nextoff */
85#define	FOF_NOUPDATE	0x10	/* Do not update f_offset */
86off_t foffset_lock(struct file *fp, int flags);
87void foffset_lock_uio(struct file *fp, struct uio *uio, int flags);
88void foffset_unlock(struct file *fp, off_t val, int flags);
89void foffset_unlock_uio(struct file *fp, struct uio *uio, int flags);
90
91static inline off_t
92foffset_get(struct file *fp)
93{
94
95	return (foffset_lock(fp, FOF_NOLOCK));
96}
97
98typedef int fo_rdwr_t(struct file *fp, struct uio *uio,
99		    struct ucred *active_cred, int flags,
100		    struct thread *td);
101typedef	int fo_truncate_t(struct file *fp, off_t length,
102		    struct ucred *active_cred, struct thread *td);
103typedef	int fo_ioctl_t(struct file *fp, u_long com, void *data,
104		    struct ucred *active_cred, struct thread *td);
105typedef	int fo_poll_t(struct file *fp, int events,
106		    struct ucred *active_cred, struct thread *td);
107typedef	int fo_kqfilter_t(struct file *fp, struct knote *kn);
108typedef	int fo_stat_t(struct file *fp, struct stat *sb,
109		    struct ucred *active_cred, struct thread *td);
110typedef	int fo_close_t(struct file *fp, struct thread *td);
111typedef	int fo_chmod_t(struct file *fp, mode_t mode,
112		    struct ucred *active_cred, struct thread *td);
113typedef	int fo_chown_t(struct file *fp, uid_t uid, gid_t gid,
114		    struct ucred *active_cred, struct thread *td);
115typedef int fo_sendfile_t(struct file *fp, int sockfd, struct uio *hdr_uio,
116		    struct uio *trl_uio, off_t offset, size_t nbytes,
117		    off_t *sent, int flags, struct thread *td);
118typedef int fo_seek_t(struct file *fp, off_t offset, int whence,
119		    struct thread *td);
120typedef int fo_fill_kinfo_t(struct file *fp, struct kinfo_file *kif,
121		    struct filedesc *fdp);
122typedef int fo_mmap_t(struct file *fp, vm_map_t map, vm_offset_t *addr,
123		    vm_size_t size, vm_prot_t prot, vm_prot_t cap_maxprot,
124		    int flags, vm_ooffset_t foff, struct thread *td);
125typedef int fo_aio_queue_t(struct file *fp, struct kaiocb *job);
126typedef	int fo_flags_t;
127
128struct fileops {
129	fo_rdwr_t	*fo_read;
130	fo_rdwr_t	*fo_write;
131	fo_truncate_t	*fo_truncate;
132	fo_ioctl_t	*fo_ioctl;
133	fo_poll_t	*fo_poll;
134	fo_kqfilter_t	*fo_kqfilter;
135	fo_stat_t	*fo_stat;
136	fo_close_t	*fo_close;
137	fo_chmod_t	*fo_chmod;
138	fo_chown_t	*fo_chown;
139	fo_sendfile_t	*fo_sendfile;
140	fo_seek_t	*fo_seek;
141	fo_fill_kinfo_t	*fo_fill_kinfo;
142	fo_mmap_t	*fo_mmap;
143	fo_aio_queue_t	*fo_aio_queue;
144	fo_flags_t	fo_flags;	/* DFLAG_* below */
145};
146
147#define DFLAG_PASSABLE	0x01	/* may be passed via unix sockets. */
148#define DFLAG_SEEKABLE	0x02	/* seekable / nonsequential */
149#endif /* _KERNEL */
150
151#if defined(_KERNEL) || defined(_WANT_FILE)
152/*
153 * Kernel descriptor table.
154 * One entry for each open kernel vnode and socket.
155 *
156 * Below is the list of locks that protects members in struct file.
157 *
158 * (a) f_vnode lock required (shared allows both reads and writes)
159 * (f) protected with mtx_lock(mtx_pool_find(fp))
160 * (d) cdevpriv_mtx
161 * none	not locked
162 */
163
164struct fadvise_info {
165	int		fa_advice;	/* (f) FADV_* type. */
166	off_t		fa_start;	/* (f) Region start. */
167	off_t		fa_end;		/* (f) Region end. */
168};
169
170struct file {
171	void		*f_data;	/* file descriptor specific data */
172	struct fileops	*f_ops;		/* File operations */
173	struct ucred	*f_cred;	/* associated credentials. */
174	struct vnode 	*f_vnode;	/* NULL or applicable vnode */
175	short		f_type;		/* descriptor type */
176	short		f_vnread_flags; /* (f) Sleep lock for f_offset */
177	volatile u_int	f_flag;		/* see fcntl.h */
178	volatile u_int 	f_count;	/* reference count */
179	/*
180	 *  DTYPE_VNODE specific fields.
181	 */
182	int		f_seqcount;	/* (a) Count of sequential accesses. */
183	off_t		f_nextoff;	/* next expected read/write offset. */
184	union {
185		struct cdev_privdata *fvn_cdevpriv;
186					/* (d) Private data for the cdev. */
187		struct fadvise_info *fvn_advice;
188	} f_vnun;
189	/*
190	 *  DFLAG_SEEKABLE specific fields
191	 */
192	off_t		f_offset;
193	/*
194	 * Mandatory Access control information.
195	 */
196	void		*f_label;	/* Place-holder for MAC label. */
197};
198
199#define	f_cdevpriv	f_vnun.fvn_cdevpriv
200#define	f_advice	f_vnun.fvn_advice
201
202#define	FOFFSET_LOCKED       0x1
203#define	FOFFSET_LOCK_WAITING 0x2
204#define	FDEVFS_VNODE	     0x4
205
206#endif /* _KERNEL || _WANT_FILE */
207
208/*
209 * Userland version of struct file, for sysctl
210 */
211struct xfile {
212	size_t	xf_size;	/* size of struct xfile */
213	pid_t	xf_pid;		/* owning process */
214	uid_t	xf_uid;		/* effective uid of owning process */
215	int	xf_fd;		/* descriptor number */
216	void	*xf_file;	/* address of struct file */
217	short	xf_type;	/* descriptor type */
218	int	xf_count;	/* reference count */
219	int	xf_msgcount;	/* references from message queue */
220	off_t	xf_offset;	/* file offset */
221	void	*xf_data;	/* file descriptor specific data */
222	void	*xf_vnode;	/* vnode pointer */
223	u_int	xf_flag;	/* flags (see fcntl.h) */
224};
225
226#ifdef _KERNEL
227
228extern struct fileops vnops;
229extern struct fileops badfileops;
230extern struct fileops socketops;
231extern int maxfiles;		/* kernel limit on number of open files */
232extern int maxfilesperproc;	/* per process limit on number of open files */
233extern volatile int openfiles;	/* actual number of open files */
234
235int fget(struct thread *td, int fd, cap_rights_t *rightsp, struct file **fpp);
236int fget_mmap(struct thread *td, int fd, cap_rights_t *rightsp,
237    u_char *maxprotp, struct file **fpp);
238int fget_read(struct thread *td, int fd, cap_rights_t *rightsp,
239    struct file **fpp);
240int fget_write(struct thread *td, int fd, cap_rights_t *rightsp,
241    struct file **fpp);
242int fget_fcntl(struct thread *td, int fd, cap_rights_t *rightsp,
243    int needfcntl, struct file **fpp);
244int _fdrop(struct file *fp, struct thread *td);
245
246fo_rdwr_t	invfo_rdwr;
247fo_truncate_t	invfo_truncate;
248fo_ioctl_t	invfo_ioctl;
249fo_poll_t	invfo_poll;
250fo_kqfilter_t	invfo_kqfilter;
251fo_chmod_t	invfo_chmod;
252fo_chown_t	invfo_chown;
253fo_sendfile_t	invfo_sendfile;
254
255fo_sendfile_t	vn_sendfile;
256fo_seek_t	vn_seek;
257fo_fill_kinfo_t	vn_fill_kinfo;
258int vn_fill_kinfo_vnode(struct vnode *vp, struct kinfo_file *kif);
259
260void finit(struct file *, u_int, short, void *, struct fileops *);
261int fgetvp(struct thread *td, int fd, cap_rights_t *rightsp,
262    struct vnode **vpp);
263int fgetvp_exec(struct thread *td, int fd, cap_rights_t *rightsp,
264    struct vnode **vpp);
265int fgetvp_rights(struct thread *td, int fd, cap_rights_t *needrightsp,
266    struct filecaps *havecaps, struct vnode **vpp);
267int fgetvp_read(struct thread *td, int fd, cap_rights_t *rightsp,
268    struct vnode **vpp);
269int fgetvp_write(struct thread *td, int fd, cap_rights_t *rightsp,
270    struct vnode **vpp);
271
272static __inline int
273_fnoop(void)
274{
275
276	return (0);
277}
278
279#define	fhold(fp)							\
280	(refcount_acquire(&(fp)->f_count))
281#define	fdrop(fp, td)							\
282	(refcount_release(&(fp)->f_count) ? _fdrop((fp), (td)) : _fnoop())
283
284static __inline fo_rdwr_t	fo_read;
285static __inline fo_rdwr_t	fo_write;
286static __inline fo_truncate_t	fo_truncate;
287static __inline fo_ioctl_t	fo_ioctl;
288static __inline fo_poll_t	fo_poll;
289static __inline fo_kqfilter_t	fo_kqfilter;
290static __inline fo_stat_t	fo_stat;
291static __inline fo_close_t	fo_close;
292static __inline fo_chmod_t	fo_chmod;
293static __inline fo_chown_t	fo_chown;
294static __inline fo_sendfile_t	fo_sendfile;
295
296static __inline int
297fo_read(struct file *fp, struct uio *uio, struct ucred *active_cred,
298    int flags, struct thread *td)
299{
300
301	return ((*fp->f_ops->fo_read)(fp, uio, active_cred, flags, td));
302}
303
304static __inline int
305fo_write(struct file *fp, struct uio *uio, struct ucred *active_cred,
306    int flags, struct thread *td)
307{
308
309	return ((*fp->f_ops->fo_write)(fp, uio, active_cred, flags, td));
310}
311
312static __inline int
313fo_truncate(struct file *fp, off_t length, struct ucred *active_cred,
314    struct thread *td)
315{
316
317	return ((*fp->f_ops->fo_truncate)(fp, length, active_cred, td));
318}
319
320static __inline int
321fo_ioctl(struct file *fp, u_long com, void *data, struct ucred *active_cred,
322    struct thread *td)
323{
324
325	return ((*fp->f_ops->fo_ioctl)(fp, com, data, active_cred, td));
326}
327
328static __inline int
329fo_poll(struct file *fp, int events, struct ucred *active_cred,
330    struct thread *td)
331{
332
333	return ((*fp->f_ops->fo_poll)(fp, events, active_cred, td));
334}
335
336static __inline int
337fo_stat(struct file *fp, struct stat *sb, struct ucred *active_cred,
338    struct thread *td)
339{
340
341	return ((*fp->f_ops->fo_stat)(fp, sb, active_cred, td));
342}
343
344static __inline int
345fo_close(struct file *fp, struct thread *td)
346{
347
348	return ((*fp->f_ops->fo_close)(fp, td));
349}
350
351static __inline int
352fo_kqfilter(struct file *fp, struct knote *kn)
353{
354
355	return ((*fp->f_ops->fo_kqfilter)(fp, kn));
356}
357
358static __inline int
359fo_chmod(struct file *fp, mode_t mode, struct ucred *active_cred,
360    struct thread *td)
361{
362
363	return ((*fp->f_ops->fo_chmod)(fp, mode, active_cred, td));
364}
365
366static __inline int
367fo_chown(struct file *fp, uid_t uid, gid_t gid, struct ucred *active_cred,
368    struct thread *td)
369{
370
371	return ((*fp->f_ops->fo_chown)(fp, uid, gid, active_cred, td));
372}
373
374static __inline int
375fo_sendfile(struct file *fp, int sockfd, struct uio *hdr_uio,
376    struct uio *trl_uio, off_t offset, size_t nbytes, off_t *sent, int flags,
377    struct thread *td)
378{
379
380	return ((*fp->f_ops->fo_sendfile)(fp, sockfd, hdr_uio, trl_uio, offset,
381	    nbytes, sent, flags, td));
382}
383
384static __inline int
385fo_seek(struct file *fp, off_t offset, int whence, struct thread *td)
386{
387
388	return ((*fp->f_ops->fo_seek)(fp, offset, whence, td));
389}
390
391static __inline int
392fo_fill_kinfo(struct file *fp, struct kinfo_file *kif, struct filedesc *fdp)
393{
394
395	return ((*fp->f_ops->fo_fill_kinfo)(fp, kif, fdp));
396}
397
398static __inline int
399fo_mmap(struct file *fp, vm_map_t map, vm_offset_t *addr, vm_size_t size,
400    vm_prot_t prot, vm_prot_t cap_maxprot, int flags, vm_ooffset_t foff,
401    struct thread *td)
402{
403
404	if (fp->f_ops->fo_mmap == NULL)
405		return (ENODEV);
406	return ((*fp->f_ops->fo_mmap)(fp, map, addr, size, prot, cap_maxprot,
407	    flags, foff, td));
408}
409
410static __inline int
411fo_aio_queue(struct file *fp, struct kaiocb *job)
412{
413
414	return ((*fp->f_ops->fo_aio_queue)(fp, job));
415}
416
417#endif /* _KERNEL */
418
419#endif /* !SYS_FILE_H */
420