xref: /386bsd/usr/src/kernel/include/sys/file.h (revision a2142627)
1 /*
2  * Copyright (c) 1982, 1986, 1989 Regents of the University of California.
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 3. All advertising materials mentioning features or use of this software
14  *    must display the following acknowledgement:
15  *	This product includes software developed by the University of
16  *	California, Berkeley and its contributors.
17  * 4. Neither the name of the University nor the names of its contributors
18  *    may be used to endorse or promote products derived from this software
19  *    without specific prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  *
33  *	@(#)file.h	7.10 (Berkeley) 6/4/91
34  */
35 
36 #include <sys/fcntl.h>
37 #include <sys/unistd.h>
38 
39 #ifdef KERNEL
40 /*
41  * Kernel descriptor table.
42  * One entry for each open kernel vnode and socket.
43  */
44 struct file {
45 	struct	file *f_filef;	/* list of active files */
46 	struct	file **f_fileb;	/* list of active files */
47 	short	f_flag;		/* see fcntl.h */
48 #define	DTYPE_VNODE	1	/* file */
49 #define	DTYPE_SOCKET	2	/* communications endpoint */
50 	short	f_type;		/* descriptor type */
51 	short	f_count;	/* reference count */
52 	short	f_msgcount;	/* references from message queue */
53 	struct	ucred *f_cred;	/* credentials associated with descriptor */
54 	struct	fileops {
55 		int	(*fo_read)	__P((struct file *fp, struct uio *uio,
56 					    struct ucred *cred));
57 		int	(*fo_write)	__P((struct file *fp, struct uio *uio,
58 					    struct ucred *cred));
59 		int	(*fo_ioctl)	__P((struct file *fp, int com,
60 					    caddr_t data, struct proc *p));
61 		int	(*fo_select)	__P((struct file *fp, int which,
62 					    struct proc *p));
63 		int	(*fo_close)	__P((struct file *fp, struct proc *p));
64 	} *f_ops;
65 	off_t	f_offset;
66 	caddr_t	f_data;		/* vnode or socket */
67 };
68 
69 extern struct file *filehead;	/* head of list of open files */
70 extern int maxfiles;		/* kernel limit on number of open files */
71 extern int nfiles;		/* actual number of open files */
72 
73 #endif /* KERNEL */
74