1/*	$OpenBSD: shm.h,v 1.30 2021/03/10 10:21:47 jsg Exp $	*/
2/*	$NetBSD: shm.h,v 1.20 1996/04/09 20:55:35 cgd Exp $	*/
3
4/*
5 * Copyright (c) 1994 Adam Glass
6 * All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 *    notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 *    notice, this list of conditions and the following disclaimer in the
15 *    documentation and/or other materials provided with the distribution.
16 * 3. All advertising materials mentioning features or use of this software
17 *    must display the following acknowledgement:
18 *      This product includes software developed by Adam Glass.
19 * 4. The name of the author may not be used to endorse or promote products
20 *    derived from this software without specific prior written permission
21 *
22 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
23 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
24 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
25 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
26 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
27 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
28 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
29 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
30 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
31 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
32 */
33
34/*
35 * As defined+described in "X/Open System Interfaces and Headers"
36 *                         Issue 4, p. XXX
37 */
38
39#ifndef _SYS_SHM_H_
40#define _SYS_SHM_H_
41
42#ifndef _SYS_IPC_H_
43#include <sys/ipc.h>
44#endif
45
46#if __BSD_VISIBLE
47
48/* shm-specific sysctl variables corresponding to members of struct shminfo */
49#define KERN_SHMINFO_SHMMAX	1	/* int: max shm segment size (bytes) */
50#define KERN_SHMINFO_SHMMIN	2	/* int: min shm segment size (bytes) */
51#define KERN_SHMINFO_SHMMNI	3	/* int: max number of shm identifiers */
52#define KERN_SHMINFO_SHMSEG	4	/* int: max shm segments per process */
53#define KERN_SHMINFO_SHMALL	5	/* int: max amount of shm (pages) */
54#define KERN_SHMINFO_MAXID	6	/* number of valid shared memory ids */
55
56#define CTL_KERN_SHMINFO_NAMES { \
57	{ 0, 0 }, \
58	{ "shmmax", CTLTYPE_INT }, \
59	{ "shmmin", CTLTYPE_INT }, \
60	{ "shmmni", CTLTYPE_INT }, \
61	{ "shmseg", CTLTYPE_INT }, \
62	{ "shmall", CTLTYPE_INT }, \
63}
64
65/*
66 * Old (deprecated) access mode definitions--do not use.
67 * Provided for compatibility with old code only.
68 */
69#define SHM_R		IPC_R
70#define SHM_W		IPC_W
71
72#endif /* __BSD_VISIBLE */
73
74/*
75 * Shared memory operation flags for shmat(2).
76 */
77#define	SHM_RDONLY	010000	/* Attach read-only (else read-write) */
78#define	SHM_RND		020000	/* Round attach address to SHMLBA */
79
80/*
81 * Shared memory specific control commands for shmctl().
82 * We accept but ignore these (XXX).
83 */
84#define	SHM_LOCK	3	/* Lock segment in memory. */
85#define	SHM_UNLOCK	4	/* Unlock a segment locked by SHM_LOCK. */
86
87/*
88 * Segment low boundary address multiple
89 */
90#define	SHMLBA		(1U << _MAX_PAGE_SHIFT)
91
92typedef short		shmatt_t;
93
94struct shmid_ds {
95	struct ipc_perm	shm_perm;	/* operation permission structure */
96	int		shm_segsz;	/* size of segment in bytes */
97	pid_t		shm_lpid;	/* process ID of last shm op */
98	pid_t		shm_cpid;	/* process ID of creator */
99	shmatt_t	shm_nattch;	/* number of current attaches */
100	time_t		shm_atime;	/* time of last shmat() */
101	long		__shm_atimensec;
102	time_t		shm_dtime;	/* time of last shmdt() */
103	long		__shm_dtimensec;
104	time_t		shm_ctime;	/* time of last change by shmctl() */
105	long		__shm_ctimensec;
106	void		*shm_internal;	/* implementation specific data */
107};
108
109#if __BSD_VISIBLE
110/*
111 * System V style catch-all structure for shared memory constants that
112 * might be of interest to user programs.  Do we really want/need this?
113 */
114struct shminfo {
115	int	shmmax;		/* max shared memory segment size (bytes) */
116	int	shmmin;		/* min shared memory segment size (bytes) */
117	int	shmmni;		/* max number of shared memory identifiers */
118	int	shmseg;		/* max shared memory segments per process */
119	int	shmall;		/* max amount of shared memory (pages) */
120};
121
122struct shm_sysctl_info {
123	struct	shminfo shminfo;
124	struct	shmid_ds shmids[1];
125};
126#endif /* __BSD_VISIBLE */
127
128#ifdef _KERNEL
129extern struct shminfo shminfo;
130extern struct shmid_ds **shmsegs;
131
132struct proc;
133struct vmspace;
134
135void	shminit(void);
136void	shmfork(struct vmspace *, struct vmspace *);
137void	shmexit(struct vmspace *);
138int	sysctl_sysvshm(int *, u_int, void *, size_t *, void *, size_t);
139
140#else /* !_KERNEL */
141
142__BEGIN_DECLS
143void *shmat(int, const void *, int);
144int shmctl(int, int, struct shmid_ds *);
145int shmdt(const void *);
146int shmget(key_t, size_t, int);
147__END_DECLS
148
149#endif /* !_KERNEL */
150
151#endif /* !_SYS_SHM_H_ */
152