xref: /freebsd/sys/sys/file.h (revision 148a8da8)
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	0x04	/* Also update f_nextoff */
85 #define	FOF_NOUPDATE	0x10	/* Do not update f_offset */
86 off_t foffset_lock(struct file *fp, int flags);
87 void foffset_lock_uio(struct file *fp, struct uio *uio, int flags);
88 void foffset_unlock(struct file *fp, off_t val, int flags);
89 void foffset_unlock_uio(struct file *fp, struct uio *uio, int flags);
90 
91 static inline off_t
92 foffset_get(struct file *fp)
93 {
94 
95 	return (foffset_lock(fp, FOF_NOLOCK));
96 }
97 
98 typedef int fo_rdwr_t(struct file *fp, struct uio *uio,
99 		    struct ucred *active_cred, int flags,
100 		    struct thread *td);
101 typedef	int fo_truncate_t(struct file *fp, off_t length,
102 		    struct ucred *active_cred, struct thread *td);
103 typedef	int fo_ioctl_t(struct file *fp, u_long com, void *data,
104 		    struct ucred *active_cred, struct thread *td);
105 typedef	int fo_poll_t(struct file *fp, int events,
106 		    struct ucred *active_cred, struct thread *td);
107 typedef	int fo_kqfilter_t(struct file *fp, struct knote *kn);
108 typedef	int fo_stat_t(struct file *fp, struct stat *sb,
109 		    struct ucred *active_cred, struct thread *td);
110 typedef	int fo_close_t(struct file *fp, struct thread *td);
111 typedef	int fo_chmod_t(struct file *fp, mode_t mode,
112 		    struct ucred *active_cred, struct thread *td);
113 typedef	int fo_chown_t(struct file *fp, uid_t uid, gid_t gid,
114 		    struct ucred *active_cred, struct thread *td);
115 typedef 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);
118 typedef int fo_seek_t(struct file *fp, off_t offset, int whence,
119 		    struct thread *td);
120 typedef int fo_fill_kinfo_t(struct file *fp, struct kinfo_file *kif,
121 		    struct filedesc *fdp);
122 typedef 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);
125 typedef int fo_aio_queue_t(struct file *fp, struct kaiocb *job);
126 typedef	int fo_flags_t;
127 
128 struct 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 
164 struct 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 
170 struct 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  */
211 struct xfile {
212 	ksize_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 	int	_xf_int_pad1;
217 	kvaddr_t xf_file;	/* address of struct file */
218 	short	xf_type;	/* descriptor type */
219 	short	_xf_short_pad1;
220 	int	xf_count;	/* reference count */
221 	int	xf_msgcount;	/* references from message queue */
222 	int	_xf_int_pad2;
223 	off_t	xf_offset;	/* file offset */
224 	kvaddr_t xf_data;	/* file descriptor specific data */
225 	kvaddr_t xf_vnode;	/* vnode pointer */
226 	u_int	xf_flag;	/* flags (see fcntl.h) */
227 	int	_xf_int_pad3;
228 	int64_t	_xf_int64_pad[6];
229 };
230 
231 #ifdef _KERNEL
232 
233 extern struct fileops vnops;
234 extern struct fileops badfileops;
235 extern struct fileops socketops;
236 extern int maxfiles;		/* kernel limit on number of open files */
237 extern int maxfilesperproc;	/* per process limit on number of open files */
238 extern volatile int openfiles;	/* actual number of open files */
239 
240 int fget(struct thread *td, int fd, cap_rights_t *rightsp, struct file **fpp);
241 int fget_mmap(struct thread *td, int fd, cap_rights_t *rightsp,
242     u_char *maxprotp, struct file **fpp);
243 int fget_read(struct thread *td, int fd, cap_rights_t *rightsp,
244     struct file **fpp);
245 int fget_write(struct thread *td, int fd, cap_rights_t *rightsp,
246     struct file **fpp);
247 int fget_fcntl(struct thread *td, int fd, cap_rights_t *rightsp,
248     int needfcntl, struct file **fpp);
249 int _fdrop(struct file *fp, struct thread *td);
250 
251 fo_rdwr_t	invfo_rdwr;
252 fo_truncate_t	invfo_truncate;
253 fo_ioctl_t	invfo_ioctl;
254 fo_poll_t	invfo_poll;
255 fo_kqfilter_t	invfo_kqfilter;
256 fo_chmod_t	invfo_chmod;
257 fo_chown_t	invfo_chown;
258 fo_sendfile_t	invfo_sendfile;
259 
260 fo_sendfile_t	vn_sendfile;
261 fo_seek_t	vn_seek;
262 fo_fill_kinfo_t	vn_fill_kinfo;
263 int vn_fill_kinfo_vnode(struct vnode *vp, struct kinfo_file *kif);
264 
265 void finit(struct file *, u_int, short, void *, struct fileops *);
266 int fgetvp(struct thread *td, int fd, cap_rights_t *rightsp,
267     struct vnode **vpp);
268 int fgetvp_exec(struct thread *td, int fd, cap_rights_t *rightsp,
269     struct vnode **vpp);
270 int fgetvp_rights(struct thread *td, int fd, cap_rights_t *needrightsp,
271     struct filecaps *havecaps, struct vnode **vpp);
272 int fgetvp_read(struct thread *td, int fd, cap_rights_t *rightsp,
273     struct vnode **vpp);
274 int fgetvp_write(struct thread *td, int fd, cap_rights_t *rightsp,
275     struct vnode **vpp);
276 
277 static __inline int
278 _fnoop(void)
279 {
280 
281 	return (0);
282 }
283 
284 #define	fhold(fp)							\
285 	(refcount_acquire(&(fp)->f_count))
286 #define	fdrop(fp, td)							\
287 	(refcount_release(&(fp)->f_count) ? _fdrop((fp), (td)) : _fnoop())
288 
289 static __inline fo_rdwr_t	fo_read;
290 static __inline fo_rdwr_t	fo_write;
291 static __inline fo_truncate_t	fo_truncate;
292 static __inline fo_ioctl_t	fo_ioctl;
293 static __inline fo_poll_t	fo_poll;
294 static __inline fo_kqfilter_t	fo_kqfilter;
295 static __inline fo_stat_t	fo_stat;
296 static __inline fo_close_t	fo_close;
297 static __inline fo_chmod_t	fo_chmod;
298 static __inline fo_chown_t	fo_chown;
299 static __inline fo_sendfile_t	fo_sendfile;
300 
301 static __inline int
302 fo_read(struct file *fp, struct uio *uio, struct ucred *active_cred,
303     int flags, struct thread *td)
304 {
305 
306 	return ((*fp->f_ops->fo_read)(fp, uio, active_cred, flags, td));
307 }
308 
309 static __inline int
310 fo_write(struct file *fp, struct uio *uio, struct ucred *active_cred,
311     int flags, struct thread *td)
312 {
313 
314 	return ((*fp->f_ops->fo_write)(fp, uio, active_cred, flags, td));
315 }
316 
317 static __inline int
318 fo_truncate(struct file *fp, off_t length, struct ucred *active_cred,
319     struct thread *td)
320 {
321 
322 	return ((*fp->f_ops->fo_truncate)(fp, length, active_cred, td));
323 }
324 
325 static __inline int
326 fo_ioctl(struct file *fp, u_long com, void *data, struct ucred *active_cred,
327     struct thread *td)
328 {
329 
330 	return ((*fp->f_ops->fo_ioctl)(fp, com, data, active_cred, td));
331 }
332 
333 static __inline int
334 fo_poll(struct file *fp, int events, struct ucred *active_cred,
335     struct thread *td)
336 {
337 
338 	return ((*fp->f_ops->fo_poll)(fp, events, active_cred, td));
339 }
340 
341 static __inline int
342 fo_stat(struct file *fp, struct stat *sb, struct ucred *active_cred,
343     struct thread *td)
344 {
345 
346 	return ((*fp->f_ops->fo_stat)(fp, sb, active_cred, td));
347 }
348 
349 static __inline int
350 fo_close(struct file *fp, struct thread *td)
351 {
352 
353 	return ((*fp->f_ops->fo_close)(fp, td));
354 }
355 
356 static __inline int
357 fo_kqfilter(struct file *fp, struct knote *kn)
358 {
359 
360 	return ((*fp->f_ops->fo_kqfilter)(fp, kn));
361 }
362 
363 static __inline int
364 fo_chmod(struct file *fp, mode_t mode, struct ucred *active_cred,
365     struct thread *td)
366 {
367 
368 	return ((*fp->f_ops->fo_chmod)(fp, mode, active_cred, td));
369 }
370 
371 static __inline int
372 fo_chown(struct file *fp, uid_t uid, gid_t gid, struct ucred *active_cred,
373     struct thread *td)
374 {
375 
376 	return ((*fp->f_ops->fo_chown)(fp, uid, gid, active_cred, td));
377 }
378 
379 static __inline int
380 fo_sendfile(struct file *fp, int sockfd, struct uio *hdr_uio,
381     struct uio *trl_uio, off_t offset, size_t nbytes, off_t *sent, int flags,
382     struct thread *td)
383 {
384 
385 	return ((*fp->f_ops->fo_sendfile)(fp, sockfd, hdr_uio, trl_uio, offset,
386 	    nbytes, sent, flags, td));
387 }
388 
389 static __inline int
390 fo_seek(struct file *fp, off_t offset, int whence, struct thread *td)
391 {
392 
393 	return ((*fp->f_ops->fo_seek)(fp, offset, whence, td));
394 }
395 
396 static __inline int
397 fo_fill_kinfo(struct file *fp, struct kinfo_file *kif, struct filedesc *fdp)
398 {
399 
400 	return ((*fp->f_ops->fo_fill_kinfo)(fp, kif, fdp));
401 }
402 
403 static __inline int
404 fo_mmap(struct file *fp, vm_map_t map, vm_offset_t *addr, vm_size_t size,
405     vm_prot_t prot, vm_prot_t cap_maxprot, int flags, vm_ooffset_t foff,
406     struct thread *td)
407 {
408 
409 	if (fp->f_ops->fo_mmap == NULL)
410 		return (ENODEV);
411 	return ((*fp->f_ops->fo_mmap)(fp, map, addr, size, prot, cap_maxprot,
412 	    flags, foff, td));
413 }
414 
415 static __inline int
416 fo_aio_queue(struct file *fp, struct kaiocb *job)
417 {
418 
419 	return ((*fp->f_ops->fo_aio_queue)(fp, job));
420 }
421 
422 #endif /* _KERNEL */
423 
424 #endif /* !SYS_FILE_H */
425